AIM: To assess whether acoustic radiation force impulse (ARFI) elastography can differentiate normal from pathological thyroid parenchyma. METHODS: We evaluated 136 subjects (mean age 45.8 ± 15.6 years, 106 women...AIM: To assess whether acoustic radiation force impulse (ARFI) elastography can differentiate normal from pathological thyroid parenchyma. METHODS: We evaluated 136 subjects (mean age 45.8 ± 15.6 years, 106 women and 30 men): 44 (32.3%) without thyroid pathology, 48 (35.3%) with Basedow-Graves’ disease (GD), 37 (27.2%) with chronic autoimmune thyroiditis (CAT; diagnosed by specific tests), 4 (2.9%) with diffuse thyroid goiter and 3 (2.2%) cases with thyroid pathology induced by amiodarone. In all patients, 10 elastographic measurements were made in the right thyroid lobe and 10 in the left thyroid lobe, using a 1-4.5 MHZ convex probe and a 4-9 MHz linear probe, respectively. Median values were calculated for thyroid stiffness and expressed in meters/second (m/s). RESULTS: Thyroid stiffness (TS) assessed by means of ARFI in healthy subjects (2 ± 0.40 m/s) was significantly lower than in GD (2.67 ± 0.53 m/s) (P < 0.0001) and CAT patients (2.43 ± 0.58 m/s) (P = 0.0002), but the differences were not significant between GD vs CAT patients (P = 0.053). The optimal cut-off value for the prediction of diffuse thyroid pathology was 2.36 m/s. For this cut-off value, TS had 62.5% sensitivity, 79.5% specificity, 87.6% predictive positive value, 55.5% negative predictive value and 72.7% accuracy for the presence of diffuse thyroid gland pathology (AUROC = 0.804). There were no significant differences between the TS values obtained with linear vs convex probes and when 5 vs 10 measurements were taken in each lobe (median values). CONCLUSION: ARFI seems to be a useful method for the assessment of diffuse thyroid gland pathology.展开更多
AIM:To determine whether acoustic radiation force impulse(ARFI) elastography is a reliable method for predicting fibrosis severity in patients with chronic hepatitis C virus(HCV) hepatitis.METHODS:We performed a multi...AIM:To determine whether acoustic radiation force impulse(ARFI) elastography is a reliable method for predicting fibrosis severity in patients with chronic hepatitis C virus(HCV) hepatitis.METHODS:We performed a multicenter study including 274 subjects with HCV chronic hepatitis in which we compared ARFI with liver biopsy(LB).In each patient we performed LB(evaluated according to the Metavir score) and ARFI measurements(using a Siemens Acuson S2000TM ultrasound system:10 valid measurements were performed and median values were calculated and expressed in meters/second(m/s).RESULTS:A direct,strong,correlation(Spearman r = 0.707) was found between ARFI measurements and fibrosis(P < 0.0001).For predicting the presence of fibrosis(F ≥ 1 Metavir),significant fibrosis(F ≥ 2),severe fibrosis(F ≥ 3) and cirrhosis(F = 4),the cutoff values of 1.19,1.21,1.58 and 1.82 m/s were determined,respectively,liver stiffness measurements had 73%,84%,84% and 91% Se respectively;93%,91%,94%,90% Sp,respectively;with AUROCs of 0.880,0.893,0.908 and 0.937,respectively.CONCLUSION:ARFI measurement is a reliable method for predicting the severity of fibrosis in HCV展开更多
AIM:To assess the values of liver stiffness (LS) in pa-tients with hepatitis B virus (HBV) chronic hepatitis and to compare them with those in patients with hepatitis C virus (HCV) chronic hepatitis. METHODS: The stud...AIM:To assess the values of liver stiffness (LS) in pa-tients with hepatitis B virus (HBV) chronic hepatitis and to compare them with those in patients with hepatitis C virus (HCV) chronic hepatitis. METHODS: The study included 140 patients with HBV chronic hepatitis, and 317 patients with HCV chronic hepatitis, in which LS was measured (FibroScan-Echo-sens) and liver biopsy was performed in the same session (assessed according to the Metavir score). RESULTS:According to the Metavir score of the 140 HBV patients: one had F0,32 had F1, 67 had F2,33 had F3 and 7 had F4. Of the 317 HCV patients:5 had F0, 34 had F1, 146 had F2, 93 had F3 and 39 had F4. For the same severity of fibrosis, the mean values of LS in HBV patients were similar to those in HCV patients:F1,6.5±1.9 kPa vs 5.8±2.1 kPa (P=0.0889); F2,7.1±2 kPa vs 6.9±2.5 kPa (P = 0.3369); F3,9.1±3.6 kPa vs 9.9±5 kPa (P=0.7038); F4,19.8± 8.6 kPa vs 17.3±6.1 kPa (P=0.6574). A signif icant direct correlation between LS measurements and fibrosis was found in HCV patients (Spearman’s r=0.578, P<0.0001), as well as in HBV patients (r=0.408, P<0.0001). The correlation was more signif icant in HCV than in HBV patients (Fisher’s Z-test,Z= 2.210,P=0.0271). CONCLUSION:In our group, the mean values of LS in patients with chronic B hepatitis were similar to those in patients with chronic HCV hepatitis, for the same stage of f ibrosis. Also, LS was correlated with the severity of fibrosis both in HBV and HCV chronic hepatitis patients.展开更多
AIM:To determine if liver stiffness(LS) measurements by means of transient elastography(TE) correlate with the presence of significant esophageal varices(EV) and if they can predict the occurrence of variceal bleeding...AIM:To determine if liver stiffness(LS) measurements by means of transient elastography(TE) correlate with the presence of significant esophageal varices(EV) and if they can predict the occurrence of variceal bleeding.METHODS:We studied 1000 cases of liver cirrhosis divided into 2 groups:patients without EV or with grade 1 varices(647 cases) and patients with significant varices(grade 2 and 3 EV)(353 cases).We divided the group of 540 cases with EV into another 2 subgroups:without variceal hemorrhage(375 patients) and patients with a history of variceal bleeding(165 cases).We compared the LS values between the groups using the unpaired t-test and we established cut-off LS values for the presence of significant EV and for the risk of bleeding by using the ROC curve.RESULTS:The mean LS values in the 647 patients without or with grade 1 EV was statistically significantly lower than in the 353 patients with significant EV(26.29 ± 0.60 kPa vs 45.21 ± 1.07 kPa,P < 0.0001).Using the ROC curve we established a cut-off value of 31 kPa for the presence of EV,with 83% sensitivity(95%CI:79.73%-85.93%) and 62% specificity(95% CI:57.15%-66.81%),with 76.2% positive predictive value(PPV)(95% CI:72.72%-79.43%) and 71.3% negative predictive value(NPV)(95% CI:66.37%-76.05%)(AUROC 0.7807,P < 0.0001).The mean LS values in the group with a history of variceal bleeding(165 patients) was statistically significantly higher than in the group with no bleeding history(375 patients):51.92 ± 1.56 kPa vs 35.20 ± 0.91 kPa,P < 0.0001).For a cut-off value of 50.7 kPa,LS had 53.33% sensitivity(95% CI:45.42%-61.13%) and 82.67% specificity(95% CI:78.45%-86.36%),with 82.71% PPV(95% CI:78.5%-86.4%) and 53.66% NPV(95% CI:45.72%-61.47%)(AUROC 0.7300,P < 0.0001) for the prediction of esophageal bleeding.展开更多
Chronic viral hepatitis is a common disease in the general population.During chronic hepatitis,the prognosis and clinical management are highly dependent on the extent of liver fibrosis.The fibrosis evaluation can be ...Chronic viral hepatitis is a common disease in the general population.During chronic hepatitis,the prognosis and clinical management are highly dependent on the extent of liver fibrosis.The fibrosis evaluation can be performed by FibroTest(using serological markers),by Elastography or FibroScan(a noninvasive percutaneous technique using the elastic properties of the hepatic tissue) and by liver biopsy(LB),considered to be the "gold standard".Currently,there are three techniques for performing LB:percutaneous,transjugular and laparoscopic.The percutaneous LB can be performed blind,ultrasound(US) guided or US assisted.There are two main categories of specialists who perform LB:gastroenterologists(hepatologists) and radiologists,and the specialty of the individual who performs the LB determines if the LB is performed under ultrasound guidance or not.There are two types of biopsy needles used for LB:cutting needles(Tru-Cut,Vim-Silverman) and suction needles(Menghini,Klatzkin,Jamshidi).The rate of major complications after percutaneous LB ranges from 0.09% to 2.3%,but the echo-guided percutaneous liver biopsy is a safe method for the diagnosis of chronic diffuse hepatitis(cost-effective as compared to blind biopsy) and the rate of complications seems to be related to the experience of the physician and the type of the needle used(Menghini type needle seems to be safer).Maybe,in a few years we will use non-invasive markers of fibrosis,but at this time,most authorities in the field consider that the LB is useful and necessary for the evaluation of chronic hepatopathies,despite the fact that it is not a perfect test.展开更多
In patients with respiratory allergy,cross-reactivity between aeroallergens and foods may induce food allergy,symptoms ranging from oral allergy syndrome to severe anaphylaxis.Clinical entities due to Ig E sensitizati...In patients with respiratory allergy,cross-reactivity between aeroallergens and foods may induce food allergy,symptoms ranging from oral allergy syndrome to severe anaphylaxis.Clinical entities due to Ig E sensitization to cross-reactive aeroallergen and food allergen components are described for many sources of plant origin(pollen-food syndromes and associations,such as birch-apple,cypress-peach and celery-mugwortspice syndromes,and mugwort-peach,mugwortchamomile,mugwort-mustard,ragweed-melon-banana,goosefoot-melon associations),fungal origin(Alternariaspinach syndrome),and invertebrate,mammalian or avian origin(mite-shrimp,cat-pork,and bird-egg syndromes).Clinical cases of allergic reactions to ingestion of food products containing pollen grains of specific plants,in patients with respiratory allergy to Asteraceae pollen,especially mugwort and ragweed,are also mentioned,for honey,royal jelly and bee polen dietary supplements,along with allergic reactions to foods contaminated with mites or fungi in patients with respiratory allergy to these aeroallergens.Medical history and diagnosis approach may be guided by the knowledge about the diverse cross-reacting allergens involved,and by the understanding of these clinical entities which may vary significantly or may be overlapping.The association between primary Ig E sensitization with respiratory symptoms to inhaled allergens and food allergy due to cross-reactive allergen components is important to assess in allergy practice.The use of molecular-based diagnosis improves the understanding of clinically relevant Ig E sensitization to cross-reactive allergen components from aeroallergen sources and foods.展开更多
AIM:To find out if by combining 2 ultrasound based elastographic methods:acoustic radiation force impulse(ARFI)elastography and transient elastography(TE),we can improve the prediction of fibrosis in patients with chr...AIM:To find out if by combining 2 ultrasound based elastographic methods:acoustic radiation force impulse(ARFI)elastography and transient elastography(TE),we can improve the prediction of fibrosis in patients with chronic hepatitis C.METHODS:Our study included 197 patients with chronic hepatitis C.In each patient,we performed,in the same session,liver stiffness(LS)measurements by means of TE and ARFI,respectively,and liver biopsy(LB),assessed according to the Metavir score.10 LS measurements were performed both by TE and ARFI;median values were calculated and expressed in kilopascals(kPa)and meters/second(m/s),respectively.Only TE and ARFI measurements with IQR<30%andSR≥60%were considered reliable.RESULTS:On LB 13(6.6%)patients had F0,32(16.2%) had F1,52(26.4%)had F2,47(23.9%)had F3,and 53(26.9%)had F4.A direct,strong correlation was found between TE measurements and fibrosis(r=0.741),between ARFI and fibrosis(r=0.730)and also between TE and ARFI(r=0.675).For predicting significant fibrosis(F≥2),for a cutoff of 6.7 kPa,TE had 77.5% sensitivity(Se)and 86.5%specificity(Sp)[area under the receiver operating characteristic curve(AUROC)0.87] and for a cutoff of 1.2 m/s,ARFI had 76.9%Se and 86.7%Sp(AUROC 0.84).For predicting cirrhosis(F=4),for a cutoff of 12.2 kPa,TE had 96.2%Se and 89.6% Sp(AUROC 0.97)and for a cutoff of 1.8 m/s,ARFI had 90.4%Se and 85.6%Sp(AUROC 0.91).When both elastographic methods were taken into consideration,for predicting significant fibrosis(F≥2),(TE≥6.7 kPa and ARFI≥1.2 m/s)we obtained 60.5%Se,93.3% Sp,96.8%positive predictive value(PPV),41.4%negative predictive value(NPV)and 68%accuracy,while for predicting cirrhosis(TE≥12.2 kPa and ARFI≥1.8 m/s) we obtained 84.9%Se,94.4%Sp,84.9%PPV,94.4% NPV and 91.8%accuracy.CONCLUSION:TE used in combination with ARFI is highly specific for predicting significant fibrosis;therefore when the two methods are concordant,liver biopsy can be avoided.展开更多
AIM: To analyze whether computer-enhanced dynamic analysis of elastography movies is able to better characterize and differentiate between different degrees of liver fibrosis. METHODS: The study design was prospective...AIM: To analyze whether computer-enhanced dynamic analysis of elastography movies is able to better characterize and differentiate between different degrees of liver fibrosis. METHODS: The study design was prospective. A total of 132 consecutive patients with chronic liver diseases and healthy volunteers were examined by transabdominal ultrasound elastography. All examinations were done by two doctors.RESULTS: Due to the limitations of the method, we obtained high-quality elastography information in only 73.48% of the patients. The κ-means clustering method was applied to assess the inter-observer diagnosis varia- bility, which showed good variability values in accordance with the experience of ultrasound examination of every observer. Cohen’sκ test indicated a moderate agreement between the study observers (κ = 0.4728). Furthermore, we compared the way the two observers clustered the patients, using the test for comparing two proportions (t value, two-sided test). There was no statistically significant difference between the two physicians, regardless of the patients’ real status. CONCLUSION: Transabdominal real-time elastography is certainly a very useful method in depicting liver hard- ness, although it is incompletely tested in large multicenter studies.展开更多
BACKGROUND: The global risk of hepatocellular carcinoma(HCC) is largely due to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. In recent years, however, an increased prevalence of non-viral HCC has bee...BACKGROUND: The global risk of hepatocellular carcinoma(HCC) is largely due to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. In recent years, however, an increased prevalence of non-viral HCC has been noted. The clinical impact of the presence/absence of viral infections in HCC remains controversial. The present study aimed to assess the effect of hepatitis viruses on demographics, clinical and pathological features and long-term outcome in a large cohort of Romanian patients who underwent surgery for HCC. METHODS: The study included 404 patients with HCC who had undergone resection, transplantation or radiofrequency ablation at a single institution between 2001 and 2010. The patients were divided into four groups: 85 patients with hepatitis B virus infection (HBV group), 164 patients with hepatitis C virus infection (HCV group), 39 patients with hepatitis B and C virus co-infection (HBCV group), and 116 patients without viral infection (non-BC group). RESULTS: The patients of both HBV (56.0±11.3 years) and HBCV groups (56.0±9.9 years) were significantly younger than those of the HCV (61.0±8.5 years, P=0.001) and non-BC groups(61.0±13.0 years, P=0.002). Interestingly, the prevalence of liver cirrhosis was significantly lower in the non-BC group (47%)than in any other subsets (72%-90%, P【0.002). Furthermore, the non-BC patients were more advanced according to the Barcelona Clinic Liver Cancer stages than the patients of the HCV or HBCV groups (P【0.020); accordingly, they were more frequently assessed beyond the Milan criteria than any other groups (P=0.001). No significant differences in the disease-free or overall survival rates were observed among these groups. CONCLUSIONS: Patients with non-viral HCC are diagnosed at advanced ages and stages, a situation plausibly due to the poor effectiveness of cancer surveillance in community practice. The presence of viral infections does not appear to impair the longterm prognosis after surgical treatment in patients with HCC; however, there is 展开更多
In 1969,Emil Wolf proposed diffraction tomography using coherent holographic imaging to extract 3D information from transparent,inhomogeneous objects.In the same era,the Wolf equations were first used to describe the ...In 1969,Emil Wolf proposed diffraction tomography using coherent holographic imaging to extract 3D information from transparent,inhomogeneous objects.In the same era,the Wolf equations were first used to describe the propagation correlations associated with partially coherent fields.Combining these two concepts,we present Wolf phase tomography(WPT),which is a method for performing diffraction tomography using partially coherent fields.WPT reconstruction works directly in the space-time domain,without the need for Fourier transformation,and decouples the refractive index(RI)distribution from the thickness of the sample.We demonstrate the WPT principle using the data acquired by a quantitative-phase-imaging method that upgrades an existing phase-contrast microscope by introducing controlled phase shifts between the incident and scattered fields.The illumination field in WPT is partially spatially coherent(emerging from a ring-shaped pupil function)and of low temporal coherence(white light),and as such,it is well suited for the Wolf equations.From three intensity measurements corresponding to different phase-contrast frames,the 3D RI distribution is obtained immediately by computing the Laplacian and second time derivative of the measured complex correlation function.We validate WPT with measurements of standard samples(microbeads),spermatozoa,and live neural cultures.The high throughput and simplicity of this method enables the study of 3D,dynamic events in living cells across the entire multiwell plate,with an RI sensitivity on the order of 10^(−5).展开更多
We present epi-diffraction phase microscopy(epi-DPM)as a non-destructive optical method for monitoring semiconductor fabrication processes in real time and with nanometer level sensitivity.The method uses a compact M...We present epi-diffraction phase microscopy(epi-DPM)as a non-destructive optical method for monitoring semiconductor fabrication processes in real time and with nanometer level sensitivity.The method uses a compact Mach–Zehnder interferometer to recover quantitative amplitude and phase maps of the field reflected by the sample.The low temporal noise of 0.6 nm per pixel at 8.93 frames per second enabled us to collect a three-dimensional movie showing the dynamics of wet etching and thereby accurately quantify non-uniformities in the etch rate both across the sample and over time.By displaying a gray-scale digital image on the sample with a computer projector,we performed photochemical etching to define arrays of microlenses while simultaneously monitoring their etch profiles with epi-DPM.展开更多
AIM: To identify severe adverse events (SAEs) leading to treatment discontinuation that occur during antiviral therapy in hepatitis C virus (HCV)-infected cirrhotic patients. METHODS: We identified all the articles pu...AIM: To identify severe adverse events (SAEs) leading to treatment discontinuation that occur during antiviral therapy in hepatitis C virus (HCV)-infected cirrhotic patients. METHODS: We identified all the articles published prior to December 2011 in the PubMed, Medline, Lilacs, Scopus, Ovid, EMBASE, Cochrane and Medscape databases that presented these data in cirrhotic patients. These studies evaluated the rate of SAEs leading to discontinuation of standard care treatment: Pegylated interferon (PegIFN) alpha 2a (135-180 μg/wk) or PegIFN alpha 2b (1 or 1.5 μg/kg per week) and ribavirin (800-1200 mg/d). Patients with genotype 1 + 4 underwent treatment for 48 wk, whereas those with genotypes 2 + 3 were treated for 24 wk.RESULTS: We included 17 papers in this review, comprising of 1133 patients. Treatment was discontinued due to SAEs in 14.5% of the patients. The most common SAEs were: severe thrombocytopenia and/or neutropenia (23.2%), psychiatric disorders (15.5%), decompensation of liver cirrhosis (12.1%) and severe anemia (11.2%). The proportion of patients who needed to discontinue their therapy due to SAEs was significantly higher in patients with Child-Pugh class B and Cvs those with Child-Pugh class A: 22%vs 11.4% (P = 0.003). A similar discontinuation rate was found in cirrhotic patients treated with PegIFN alpha 2a and those treated with PegIFN alpha 2b, in combination with ribavirin: 14.2%vs 13.7% (P = 0.96). The overall sustained virological response rate in cirrhotic patients was 37% (95%CI: 33.5-43.1) but was significantly lower in patients with genotype 1 + 4 than in those with genotype 2 + 3: 20.5% (95%CI: 17.9-24.8) vs 56.5% (95%CI: 51.5-63.2), (P < 0.0001). CONCLUSION: Fourteen point five percent of HCV cirrhotic patients treated with PegIFN and ribavirin needed early discontinuation of therapy due to SAEs, the most common cause being hematological disorders.展开更多
Gastrointestinal cancers represent a major cause of morbidity and mortality,with incomplete response to chemotherapy in the advanced stages and poor prognosis.Angiogenesis plays a crucial part in tumor growth and meta...Gastrointestinal cancers represent a major cause of morbidity and mortality,with incomplete response to chemotherapy in the advanced stages and poor prognosis.Angiogenesis plays a crucial part in tumor growth and metastasis,with most gastrointestinal cancers depending strictly on the development of a new and devoted capillary network.Confocal laser endomicroscopy is a new technology which allows in vivo microscopic analysis of the gastrointestinal mucosa and its microvascularization during ongoing endoscopy by using topically or systemically administered contrast agents.Targeting markers of angiogenesis in association with confocal laser endomicroscopic examination(immunoendoscopy),as a future challenge,will add functional analysis to the morphological aspect of the neoplastic process.This review describes previous experience in endomicroscopic examination of the upper and lower digestive tract with emphasis on vascularization,resulting in a broad spectrum of potential clinical applications,and also preclinical research that could be translated to human studies.展开更多
As silicon photonics transitions from research to commercial deployment,packaging solutions that efficiently couple light into highly compact and functional sub-micrometer silicon waveguides are imperative but remain ...As silicon photonics transitions from research to commercial deployment,packaging solutions that efficiently couple light into highly compact and functional sub-micrometer silicon waveguides are imperative but remain challenging.The 220 nm silicon-on-insulator(SOI)platform,poised to enable large-scale integration,is the most widely adopted by foundries,resulting in established fabrication processes and extensive photonic component libraries.The development of a highly efficient,scalable,and broadband coupling scheme for this platform is therefore of paramount importance.Leveraging two-photon polymerization(TPP)and a deterministic free-form micro-optics design methodology based on the Fermat’s principle,this work demonstrates an ultraefficient and broadband 3-D coupler interface between standard SMF-28 single-mode fibers and silicon waveguides on the 220 nm SOI platform.The coupler achieves a low coupling loss of 0.8 dB for the fundamental TE mode,along with 1 dB bandwidth exceeding 180 nm.The broadband operation enables diverse bandwidthdriven applications ranging from communications to spectroscopy.Furthermore,the 3-D free-form coupler also enables large tolerance to fiber misalignments and manufacturing variability,thereby relaxing packaging requirements toward cost reduction capitalizing on standard electronic packaging process flows.展开更多
Scientific studies have focused on environmentally friendly solutions as effective as the reuse of crop products owing to plastic-waste problems in recent years.This issue is the main driving force for upcoming academ...Scientific studies have focused on environmentally friendly solutions as effective as the reuse of crop products owing to plastic-waste problems in recent years.This issue is the main driving force for upcoming academic research attempts in waste valorization-related studies.Herein,we integrated an aqua-waste,mussel shell(MS),as a bioadditive form into green thermoplastic polyurethane(TPU)green composites.Tuning of the MS surface was performed to achieve strong adhesion between composite phases.The surface functionalities of MS powders were evaluated via infrared spectroscopy and scanning electron microscopy(SEM)images.Composite samples were prepared by melt-compounding followed by injection molding techniques.It was confirmed by morphological analysis that relatively better adhesion between the phases was achieved for composites involving surface-modified MS compared to unmodified MS.Tensile strength and Young’s modulus of surface-modified MS-filled composites were found to be higher than those of unmodified MS,whereas the elongation at break shifted to lower values with MS inclusions.The shore hardness of TPU was remarkably improved after being incorporated with silane-treated MS(AS-MS).Stearic acid-treated MS(ST-MS)additions resulted in an enhancement in the thermal stability of the composites.Thermo-mechanical analysis showed that the storage moduli of composites were higher than those of unfilled TPU.ST-MS additions led to an increase in the characteristic glass transition temperature of TPU.Melt flow index(MFI)of neat TPU was highly improved after MS loading regardless of modification type.According to the wear test,surface modification of MS displayed a positive effect on the wear resistance of TPU.As the water absorption data of the composites were evaluated,the TPU/AS-MS composite yielded the lowest water absorption.The silane layer on MS inclusion promoted water repellency of composites due to the hydrophobicity of silane.The results of the biodegradation investigation demonstrated that adding unmodif展开更多
Progressive fibrosis is encountered in almost all chronicliver diseases. Its clinical signs are diagnostic in advanced cirrhosis, but compensated liver cirrhosis is harder to diagnose. Liver biopsy is still considered...Progressive fibrosis is encountered in almost all chronicliver diseases. Its clinical signs are diagnostic in advanced cirrhosis, but compensated liver cirrhosis is harder to diagnose. Liver biopsy is still considered the reference method for staging the severity of fibrosis, but due to its drawbacks(inter and intra-observer variability, sampling errors, unequal distribution of fibrosis in the liver, and risk of complications and even death), non-invasive methods were developed to assess fibrosis(serologic and elastographic). Elastographic methods can be ultrasound-based or magnetic resonance imaging-based. All ultrasoundbased elastographic methods are valuable for the early diagnosis of cirrhosis, especially transient elastography(TE) and acoustic radiation force impulse(ARFI) elastography, which have similar sensitivities and specificities, although ARFI has better feasibility. TE is a promising method for predicting portal hypertension in cirrhotic patients, but it cannot replace upper digestive endoscopy. The diagnostic accuracy of using ARFI in the liver to predict portal hypertension in cirrhotic patients is debatable, with controversial results in published studies. The accuracy of ARFI elastography may be significantly increased if spleen stiffness is assessed, either alone or in combination with liver stiffness and other parameters. Two-dimensional shearwave elastography, the Elast PQ technique and strain elastography all need to be evaluated as predictors of portal hypertension.展开更多
The authors prepared,characterized and preliminary studied the properties of some neoteric solvents-ionic liquids based on choline chloride,i.e.,three ionic liquids based on the eutectics of choline chloride（2-hydrox...The authors prepared,characterized and preliminary studied the properties of some neoteric solvents-ionic liquids based on choline chloride,i.e.,three ionic liquids based on the eutectics of choline chloride（2-hydroxyN,N,N-trimethylethanaminium chloride） with,respectively,urea,malonic acid and citric acid.The obtained mixtures were clear and colorless ionic liquids at room temperature.The thermophysical properties,namely,density,viscosity,and electrical conductivity of these mixtures were investigated as a function of temperature within a range of 298-353 K.Correlations for the temperature dependence of the measured properties were generated and discussed in terms of Arrhenius theory.Finally the electrochemical windows of the eutectic liquids were determined.展开更多
Carbon(C)is a key constitutive element in living organisms(plants,microbes,animals,and humans).Carbon is also a basic component of agriculture because it plays a dynamic role in crop growth,development,nutrient cyclin...Carbon(C)is a key constitutive element in living organisms(plants,microbes,animals,and humans).Carbon is also a basic component of agriculture because it plays a dynamic role in crop growth,development,nutrient cycling,soil fertility,and other agricultural features.The presence of C enhances soil physical,chemical,and biological properties.The C cycle supports all life on the Earth by transferring C between living organisms and the environment.The global climate is changing,and this change is attributable to the release of carbon dioxide and other greenhouse gases from human activities.Owing to the global climate change,agriculture is expected to be majorly affected.Agricultural production is directly linked to the climate.The five main global C pools are the oceanic,geologic,pedologic,atmospheric,and biotic pools,with specific reservoirs and inter-pool fluxes.The soil organic matter has various organic C pools(active,slow,and passive pools),containing various C-based fractions and specific liability pools.Climate,geology,land use,and management techniques are some of the variables that affect organic C and its reservoirs.The dynamics of each of these variables must be understood for a thorough knowledge of how they impact the soil C pools and storage capacity under the changing climate conditions.This review provides a comprehensive overview of the various factors that affect soil C pools/fractions and their C sequestration capacity.展开更多
Photonic Random-Access Memories(P-RAM)are an essential component for the on-chip non-von Neumann photonic computing by eliminating optoelectronic conversion losses in data links.Emerging Phase-Change Materials(PCMs)ha...Photonic Random-Access Memories(P-RAM)are an essential component for the on-chip non-von Neumann photonic computing by eliminating optoelectronic conversion losses in data links.Emerging Phase-Change Materials(PCMs)have been showed multilevel memory capability,but demonstrations still yield relatively high optical loss and require cumbersome WRITE-ERASE approaches increasing power consumption and system package challenges.Here we demonstrate a multistate electrically programmed low-loss nonvolatile photonic memory based on a broadband transparent phase-change material(Ge2Sb2Se5,GSSe)with ultralow absorption in the amorphous state.A zero-staticpower and electrically programmed multi-bit P-RAM is demonstrated on a silicon-on-insulator platform,featuring efficient amplitude modulation up to 0.2 dB/μm and an ultralow insertion loss of total 0.12 dB for a 4-bit memory showing a 100×improved signal to loss ratio compared to other phase-change-materials based photonic memories.We further optimize the positioning of dual microheaters validating performance tradeoffs.Experimentally we demonstrate a half-a-million cyclability test showcasing the robust approach of this material and device.Low-loss photonic retention-of-state adds a key feature for photonic functional and programmable circuits impacting many applications including neural networks,LiDAR,and sensors for example.展开更多
Flexible dielectric materials with environmental-friendly,low-cost and high-energy density characteristics are in increasing demand as the world steps into the new Industrial 4.0 era.In this work,an elastomeric nanoco...Flexible dielectric materials with environmental-friendly,low-cost and high-energy density characteristics are in increasing demand as the world steps into the new Industrial 4.0 era.In this work,an elastomeric nanocomposite was developed by incorporating two components:cellulose nanofibrils(CNFs)and recycled alum sludge,as the reinforcement phase and to improve the dielectric properties,in a bio-elastomer matrix.CNF and alum sludge were produced by processing waste materials that would otherwise be disposed to landfills.A biodegradable elastomer polydimethylsiloxane was used as the matrix and the nanocomposites were processed by casting the materials in Petri dishes.Nanocellulose extraction and heat treatment of alum sludge were conducted and characterized using various techniques including scanning electron microscopy(SEM),thermogravimetric analysis/derivative thermogravimetric(TGA/DTG)and X-ray diffraction(XRD)analysis.When preparing the nanocomposite samples,various amount of alum sludge was added to examine their impact on the mechanical,thermal and electrical properties.Results have shown that it could be a sustainable practice of reusing such wastes in preparing flexible,lightweight and miniature dielectric materials that can be used for energy storage applications.展开更多
文摘AIM: To assess whether acoustic radiation force impulse (ARFI) elastography can differentiate normal from pathological thyroid parenchyma. METHODS: We evaluated 136 subjects (mean age 45.8 ± 15.6 years, 106 women and 30 men): 44 (32.3%) without thyroid pathology, 48 (35.3%) with Basedow-Graves’ disease (GD), 37 (27.2%) with chronic autoimmune thyroiditis (CAT; diagnosed by specific tests), 4 (2.9%) with diffuse thyroid goiter and 3 (2.2%) cases with thyroid pathology induced by amiodarone. In all patients, 10 elastographic measurements were made in the right thyroid lobe and 10 in the left thyroid lobe, using a 1-4.5 MHZ convex probe and a 4-9 MHz linear probe, respectively. Median values were calculated for thyroid stiffness and expressed in meters/second (m/s). RESULTS: Thyroid stiffness (TS) assessed by means of ARFI in healthy subjects (2 ± 0.40 m/s) was significantly lower than in GD (2.67 ± 0.53 m/s) (P < 0.0001) and CAT patients (2.43 ± 0.58 m/s) (P = 0.0002), but the differences were not significant between GD vs CAT patients (P = 0.053). The optimal cut-off value for the prediction of diffuse thyroid pathology was 2.36 m/s. For this cut-off value, TS had 62.5% sensitivity, 79.5% specificity, 87.6% predictive positive value, 55.5% negative predictive value and 72.7% accuracy for the presence of diffuse thyroid gland pathology (AUROC = 0.804). There were no significant differences between the TS values obtained with linear vs convex probes and when 5 vs 10 measurements were taken in each lobe (median values). CONCLUSION: ARFI seems to be a useful method for the assessment of diffuse thyroid gland pathology.
文摘AIM:To determine whether acoustic radiation force impulse(ARFI) elastography is a reliable method for predicting fibrosis severity in patients with chronic hepatitis C virus(HCV) hepatitis.METHODS:We performed a multicenter study including 274 subjects with HCV chronic hepatitis in which we compared ARFI with liver biopsy(LB).In each patient we performed LB(evaluated according to the Metavir score) and ARFI measurements(using a Siemens Acuson S2000TM ultrasound system:10 valid measurements were performed and median values were calculated and expressed in meters/second(m/s).RESULTS:A direct,strong,correlation(Spearman r = 0.707) was found between ARFI measurements and fibrosis(P < 0.0001).For predicting the presence of fibrosis(F ≥ 1 Metavir),significant fibrosis(F ≥ 2),severe fibrosis(F ≥ 3) and cirrhosis(F = 4),the cutoff values of 1.19,1.21,1.58 and 1.82 m/s were determined,respectively,liver stiffness measurements had 73%,84%,84% and 91% Se respectively;93%,91%,94%,90% Sp,respectively;with AUROCs of 0.880,0.893,0.908 and 0.937,respectively.CONCLUSION:ARFI measurement is a reliable method for predicting the severity of fibrosis in HCV
文摘AIM:To assess the values of liver stiffness (LS) in pa-tients with hepatitis B virus (HBV) chronic hepatitis and to compare them with those in patients with hepatitis C virus (HCV) chronic hepatitis. METHODS: The study included 140 patients with HBV chronic hepatitis, and 317 patients with HCV chronic hepatitis, in which LS was measured (FibroScan-Echo-sens) and liver biopsy was performed in the same session (assessed according to the Metavir score). RESULTS:According to the Metavir score of the 140 HBV patients: one had F0,32 had F1, 67 had F2,33 had F3 and 7 had F4. Of the 317 HCV patients:5 had F0, 34 had F1, 146 had F2, 93 had F3 and 39 had F4. For the same severity of fibrosis, the mean values of LS in HBV patients were similar to those in HCV patients:F1,6.5±1.9 kPa vs 5.8±2.1 kPa (P=0.0889); F2,7.1±2 kPa vs 6.9±2.5 kPa (P = 0.3369); F3,9.1±3.6 kPa vs 9.9±5 kPa (P=0.7038); F4,19.8± 8.6 kPa vs 17.3±6.1 kPa (P=0.6574). A signif icant direct correlation between LS measurements and fibrosis was found in HCV patients (Spearman’s r=0.578, P<0.0001), as well as in HBV patients (r=0.408, P<0.0001). The correlation was more signif icant in HCV than in HBV patients (Fisher’s Z-test,Z= 2.210,P=0.0271). CONCLUSION:In our group, the mean values of LS in patients with chronic B hepatitis were similar to those in patients with chronic HCV hepatitis, for the same stage of f ibrosis. Also, LS was correlated with the severity of fibrosis both in HBV and HCV chronic hepatitis patients.
文摘AIM:To determine if liver stiffness(LS) measurements by means of transient elastography(TE) correlate with the presence of significant esophageal varices(EV) and if they can predict the occurrence of variceal bleeding.METHODS:We studied 1000 cases of liver cirrhosis divided into 2 groups:patients without EV or with grade 1 varices(647 cases) and patients with significant varices(grade 2 and 3 EV)(353 cases).We divided the group of 540 cases with EV into another 2 subgroups:without variceal hemorrhage(375 patients) and patients with a history of variceal bleeding(165 cases).We compared the LS values between the groups using the unpaired t-test and we established cut-off LS values for the presence of significant EV and for the risk of bleeding by using the ROC curve.RESULTS:The mean LS values in the 647 patients without or with grade 1 EV was statistically significantly lower than in the 353 patients with significant EV(26.29 ± 0.60 kPa vs 45.21 ± 1.07 kPa,P < 0.0001).Using the ROC curve we established a cut-off value of 31 kPa for the presence of EV,with 83% sensitivity(95%CI:79.73%-85.93%) and 62% specificity(95% CI:57.15%-66.81%),with 76.2% positive predictive value(PPV)(95% CI:72.72%-79.43%) and 71.3% negative predictive value(NPV)(95% CI:66.37%-76.05%)(AUROC 0.7807,P < 0.0001).The mean LS values in the group with a history of variceal bleeding(165 patients) was statistically significantly higher than in the group with no bleeding history(375 patients):51.92 ± 1.56 kPa vs 35.20 ± 0.91 kPa,P < 0.0001).For a cut-off value of 50.7 kPa,LS had 53.33% sensitivity(95% CI:45.42%-61.13%) and 82.67% specificity(95% CI:78.45%-86.36%),with 82.71% PPV(95% CI:78.5%-86.4%) and 53.66% NPV(95% CI:45.72%-61.47%)(AUROC 0.7300,P < 0.0001) for the prediction of esophageal bleeding.
文摘Chronic viral hepatitis is a common disease in the general population.During chronic hepatitis,the prognosis and clinical management are highly dependent on the extent of liver fibrosis.The fibrosis evaluation can be performed by FibroTest(using serological markers),by Elastography or FibroScan(a noninvasive percutaneous technique using the elastic properties of the hepatic tissue) and by liver biopsy(LB),considered to be the "gold standard".Currently,there are three techniques for performing LB:percutaneous,transjugular and laparoscopic.The percutaneous LB can be performed blind,ultrasound(US) guided or US assisted.There are two main categories of specialists who perform LB:gastroenterologists(hepatologists) and radiologists,and the specialty of the individual who performs the LB determines if the LB is performed under ultrasound guidance or not.There are two types of biopsy needles used for LB:cutting needles(Tru-Cut,Vim-Silverman) and suction needles(Menghini,Klatzkin,Jamshidi).The rate of major complications after percutaneous LB ranges from 0.09% to 2.3%,but the echo-guided percutaneous liver biopsy is a safe method for the diagnosis of chronic diffuse hepatitis(cost-effective as compared to blind biopsy) and the rate of complications seems to be related to the experience of the physician and the type of the needle used(Menghini type needle seems to be safer).Maybe,in a few years we will use non-invasive markers of fibrosis,but at this time,most authorities in the field consider that the LB is useful and necessary for the evaluation of chronic hepatopathies,despite the fact that it is not a perfect test.
文摘In patients with respiratory allergy,cross-reactivity between aeroallergens and foods may induce food allergy,symptoms ranging from oral allergy syndrome to severe anaphylaxis.Clinical entities due to Ig E sensitization to cross-reactive aeroallergen and food allergen components are described for many sources of plant origin(pollen-food syndromes and associations,such as birch-apple,cypress-peach and celery-mugwortspice syndromes,and mugwort-peach,mugwortchamomile,mugwort-mustard,ragweed-melon-banana,goosefoot-melon associations),fungal origin(Alternariaspinach syndrome),and invertebrate,mammalian or avian origin(mite-shrimp,cat-pork,and bird-egg syndromes).Clinical cases of allergic reactions to ingestion of food products containing pollen grains of specific plants,in patients with respiratory allergy to Asteraceae pollen,especially mugwort and ragweed,are also mentioned,for honey,royal jelly and bee polen dietary supplements,along with allergic reactions to foods contaminated with mites or fungi in patients with respiratory allergy to these aeroallergens.Medical history and diagnosis approach may be guided by the knowledge about the diverse cross-reacting allergens involved,and by the understanding of these clinical entities which may vary significantly or may be overlapping.The association between primary Ig E sensitization with respiratory symptoms to inhaled allergens and food allergy due to cross-reactive allergen components is important to assess in allergy practice.The use of molecular-based diagnosis improves the understanding of clinically relevant Ig E sensitization to cross-reactive allergen components from aeroallergen sources and foods.
文摘AIM:To find out if by combining 2 ultrasound based elastographic methods:acoustic radiation force impulse(ARFI)elastography and transient elastography(TE),we can improve the prediction of fibrosis in patients with chronic hepatitis C.METHODS:Our study included 197 patients with chronic hepatitis C.In each patient,we performed,in the same session,liver stiffness(LS)measurements by means of TE and ARFI,respectively,and liver biopsy(LB),assessed according to the Metavir score.10 LS measurements were performed both by TE and ARFI;median values were calculated and expressed in kilopascals(kPa)and meters/second(m/s),respectively.Only TE and ARFI measurements with IQR<30%andSR≥60%were considered reliable.RESULTS:On LB 13(6.6%)patients had F0,32(16.2%) had F1,52(26.4%)had F2,47(23.9%)had F3,and 53(26.9%)had F4.A direct,strong correlation was found between TE measurements and fibrosis(r=0.741),between ARFI and fibrosis(r=0.730)and also between TE and ARFI(r=0.675).For predicting significant fibrosis(F≥2),for a cutoff of 6.7 kPa,TE had 77.5% sensitivity(Se)and 86.5%specificity(Sp)[area under the receiver operating characteristic curve(AUROC)0.87] and for a cutoff of 1.2 m/s,ARFI had 76.9%Se and 86.7%Sp(AUROC 0.84).For predicting cirrhosis(F=4),for a cutoff of 12.2 kPa,TE had 96.2%Se and 89.6% Sp(AUROC 0.97)and for a cutoff of 1.8 m/s,ARFI had 90.4%Se and 85.6%Sp(AUROC 0.91).When both elastographic methods were taken into consideration,for predicting significant fibrosis(F≥2),(TE≥6.7 kPa and ARFI≥1.2 m/s)we obtained 60.5%Se,93.3% Sp,96.8%positive predictive value(PPV),41.4%negative predictive value(NPV)and 68%accuracy,while for predicting cirrhosis(TE≥12.2 kPa and ARFI≥1.8 m/s) we obtained 84.9%Se,94.4%Sp,84.9%PPV,94.4% NPV and 91.8%accuracy.CONCLUSION:TE used in combination with ARFI is highly specific for predicting significant fibrosis;therefore when the two methods are concordant,liver biopsy can be avoided.
基金Supported by Research Grant, No. 2076/2007, Entitled SONO-FIBROCAST, Financed by the Romanian Ministry of Educationand Research
文摘AIM: To analyze whether computer-enhanced dynamic analysis of elastography movies is able to better characterize and differentiate between different degrees of liver fibrosis. METHODS: The study design was prospective. A total of 132 consecutive patients with chronic liver diseases and healthy volunteers were examined by transabdominal ultrasound elastography. All examinations were done by two doctors.RESULTS: Due to the limitations of the method, we obtained high-quality elastography information in only 73.48% of the patients. The κ-means clustering method was applied to assess the inter-observer diagnosis varia- bility, which showed good variability values in accordance with the experience of ultrasound examination of every observer. Cohen’sκ test indicated a moderate agreement between the study observers (κ = 0.4728). Furthermore, we compared the way the two observers clustered the patients, using the test for comparing two proportions (t value, two-sided test). There was no statistically significant difference between the two physicians, regardless of the patients’ real status. CONCLUSION: Transabdominal real-time elastography is certainly a very useful method in depicting liver hard- ness, although it is incompletely tested in large multicenter studies.
文摘BACKGROUND: The global risk of hepatocellular carcinoma(HCC) is largely due to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. In recent years, however, an increased prevalence of non-viral HCC has been noted. The clinical impact of the presence/absence of viral infections in HCC remains controversial. The present study aimed to assess the effect of hepatitis viruses on demographics, clinical and pathological features and long-term outcome in a large cohort of Romanian patients who underwent surgery for HCC. METHODS: The study included 404 patients with HCC who had undergone resection, transplantation or radiofrequency ablation at a single institution between 2001 and 2010. The patients were divided into four groups: 85 patients with hepatitis B virus infection (HBV group), 164 patients with hepatitis C virus infection (HCV group), 39 patients with hepatitis B and C virus co-infection (HBCV group), and 116 patients without viral infection (non-BC group). RESULTS: The patients of both HBV (56.0±11.3 years) and HBCV groups (56.0±9.9 years) were significantly younger than those of the HCV (61.0±8.5 years, P=0.001) and non-BC groups(61.0±13.0 years, P=0.002). Interestingly, the prevalence of liver cirrhosis was significantly lower in the non-BC group (47%)than in any other subsets (72%-90%, P【0.002). Furthermore, the non-BC patients were more advanced according to the Barcelona Clinic Liver Cancer stages than the patients of the HCV or HBCV groups (P【0.020); accordingly, they were more frequently assessed beyond the Milan criteria than any other groups (P=0.001). No significant differences in the disease-free or overall survival rates were observed among these groups. CONCLUSIONS: Patients with non-viral HCC are diagnosed at advanced ages and stages, a situation plausibly due to the poor effectiveness of cancer surveillance in community practice. The presence of viral infections does not appear to impair the longterm prognosis after surgical treatment in patients with HCC; however, there is
基金supported by the National Science Foundation(CBET0939511 STC,NRT-UtB 1735252)the National Institute of General Medical Sciences(GM129709)the National Cancer Institute(CA238191).
文摘In 1969,Emil Wolf proposed diffraction tomography using coherent holographic imaging to extract 3D information from transparent,inhomogeneous objects.In the same era,the Wolf equations were first used to describe the propagation correlations associated with partially coherent fields.Combining these two concepts,we present Wolf phase tomography(WPT),which is a method for performing diffraction tomography using partially coherent fields.WPT reconstruction works directly in the space-time domain,without the need for Fourier transformation,and decouples the refractive index(RI)distribution from the thickness of the sample.We demonstrate the WPT principle using the data acquired by a quantitative-phase-imaging method that upgrades an existing phase-contrast microscope by introducing controlled phase shifts between the incident and scattered fields.The illumination field in WPT is partially spatially coherent(emerging from a ring-shaped pupil function)and of low temporal coherence(white light),and as such,it is well suited for the Wolf equations.From three intensity measurements corresponding to different phase-contrast frames,the 3D RI distribution is obtained immediately by computing the Laplacian and second time derivative of the measured complex correlation function.We validate WPT with measurements of standard samples(microbeads),spermatozoa,and live neural cultures.The high throughput and simplicity of this method enables the study of 3D,dynamic events in living cells across the entire multiwell plate,with an RI sensitivity on the order of 10^(−5).
基金The authors thank Hoa Pham for assistance with the power spectral density calculations and Brian Cunningham,Xiuling Li,Logan Liu and Daniel Wasserman for helpful discussions. This work is supported by NSF CBET-1040462 MRI award.
文摘We present epi-diffraction phase microscopy(epi-DPM)as a non-destructive optical method for monitoring semiconductor fabrication processes in real time and with nanometer level sensitivity.The method uses a compact Mach–Zehnder interferometer to recover quantitative amplitude and phase maps of the field reflected by the sample.The low temporal noise of 0.6 nm per pixel at 8.93 frames per second enabled us to collect a three-dimensional movie showing the dynamics of wet etching and thereby accurately quantify non-uniformities in the etch rate both across the sample and over time.By displaying a gray-scale digital image on the sample with a computer projector,we performed photochemical etching to define arrays of microlenses while simultaneously monitoring their etch profiles with epi-DPM.
文摘AIM: To identify severe adverse events (SAEs) leading to treatment discontinuation that occur during antiviral therapy in hepatitis C virus (HCV)-infected cirrhotic patients. METHODS: We identified all the articles published prior to December 2011 in the PubMed, Medline, Lilacs, Scopus, Ovid, EMBASE, Cochrane and Medscape databases that presented these data in cirrhotic patients. These studies evaluated the rate of SAEs leading to discontinuation of standard care treatment: Pegylated interferon (PegIFN) alpha 2a (135-180 μg/wk) or PegIFN alpha 2b (1 or 1.5 μg/kg per week) and ribavirin (800-1200 mg/d). Patients with genotype 1 + 4 underwent treatment for 48 wk, whereas those with genotypes 2 + 3 were treated for 24 wk.RESULTS: We included 17 papers in this review, comprising of 1133 patients. Treatment was discontinued due to SAEs in 14.5% of the patients. The most common SAEs were: severe thrombocytopenia and/or neutropenia (23.2%), psychiatric disorders (15.5%), decompensation of liver cirrhosis (12.1%) and severe anemia (11.2%). The proportion of patients who needed to discontinue their therapy due to SAEs was significantly higher in patients with Child-Pugh class B and Cvs those with Child-Pugh class A: 22%vs 11.4% (P = 0.003). A similar discontinuation rate was found in cirrhotic patients treated with PegIFN alpha 2a and those treated with PegIFN alpha 2b, in combination with ribavirin: 14.2%vs 13.7% (P = 0.96). The overall sustained virological response rate in cirrhotic patients was 37% (95%CI: 33.5-43.1) but was significantly lower in patients with genotype 1 + 4 than in those with genotype 2 + 3: 20.5% (95%CI: 17.9-24.8) vs 56.5% (95%CI: 51.5-63.2), (P < 0.0001). CONCLUSION: Fourteen point five percent of HCV cirrhotic patients treated with PegIFN and ribavirin needed early discontinuation of therapy due to SAEs, the most common cause being hematological disorders.
基金Supported by Research Grant,No.239/2007,entitled OCTEUS,financed by the CNCSIS Romaniaby the Sectoral Operational Programme Human Resources Development (SOP HRD),financed from the European Social Fundby the RomanianGovernment under the contract number POSDRU/89/1.5/S/64109
文摘Gastrointestinal cancers represent a major cause of morbidity and mortality,with incomplete response to chemotherapy in the advanced stages and poor prognosis.Angiogenesis plays a crucial part in tumor growth and metastasis,with most gastrointestinal cancers depending strictly on the development of a new and devoted capillary network.Confocal laser endomicroscopy is a new technology which allows in vivo microscopic analysis of the gastrointestinal mucosa and its microvascularization during ongoing endoscopy by using topically or systemically administered contrast agents.Targeting markers of angiogenesis in association with confocal laser endomicroscopic examination(immunoendoscopy),as a future challenge,will add functional analysis to the morphological aspect of the neoplastic process.This review describes previous experience in endomicroscopic examination of the upper and lower digestive tract with emphasis on vascularization,resulting in a broad spectrum of potential clinical applications,and also preclinical research that could be translated to human studies.
基金National Science Foundation(ITE-2236093,NSF ITE Convergence Accelerator)Ministry of Education-Singapore(International Postdoctoral Fellowship)。
文摘As silicon photonics transitions from research to commercial deployment,packaging solutions that efficiently couple light into highly compact and functional sub-micrometer silicon waveguides are imperative but remain challenging.The 220 nm silicon-on-insulator(SOI)platform,poised to enable large-scale integration,is the most widely adopted by foundries,resulting in established fabrication processes and extensive photonic component libraries.The development of a highly efficient,scalable,and broadband coupling scheme for this platform is therefore of paramount importance.Leveraging two-photon polymerization(TPP)and a deterministic free-form micro-optics design methodology based on the Fermat’s principle,this work demonstrates an ultraefficient and broadband 3-D coupler interface between standard SMF-28 single-mode fibers and silicon waveguides on the 220 nm SOI platform.The coupler achieves a low coupling loss of 0.8 dB for the fundamental TE mode,along with 1 dB bandwidth exceeding 180 nm.The broadband operation enables diverse bandwidthdriven applications ranging from communications to spectroscopy.Furthermore,the 3-D free-form coupler also enables large tolerance to fiber misalignments and manufacturing variability,thereby relaxing packaging requirements toward cost reduction capitalizing on standard electronic packaging process flows.
文摘Scientific studies have focused on environmentally friendly solutions as effective as the reuse of crop products owing to plastic-waste problems in recent years.This issue is the main driving force for upcoming academic research attempts in waste valorization-related studies.Herein,we integrated an aqua-waste,mussel shell(MS),as a bioadditive form into green thermoplastic polyurethane(TPU)green composites.Tuning of the MS surface was performed to achieve strong adhesion between composite phases.The surface functionalities of MS powders were evaluated via infrared spectroscopy and scanning electron microscopy(SEM)images.Composite samples were prepared by melt-compounding followed by injection molding techniques.It was confirmed by morphological analysis that relatively better adhesion between the phases was achieved for composites involving surface-modified MS compared to unmodified MS.Tensile strength and Young’s modulus of surface-modified MS-filled composites were found to be higher than those of unmodified MS,whereas the elongation at break shifted to lower values with MS inclusions.The shore hardness of TPU was remarkably improved after being incorporated with silane-treated MS(AS-MS).Stearic acid-treated MS(ST-MS)additions resulted in an enhancement in the thermal stability of the composites.Thermo-mechanical analysis showed that the storage moduli of composites were higher than those of unfilled TPU.ST-MS additions led to an increase in the characteristic glass transition temperature of TPU.Melt flow index(MFI)of neat TPU was highly improved after MS loading regardless of modification type.According to the wear test,surface modification of MS displayed a positive effect on the wear resistance of TPU.As the water absorption data of the composites were evaluated,the TPU/AS-MS composite yielded the lowest water absorption.The silane layer on MS inclusion promoted water repellency of composites due to the hydrophobicity of silane.The results of the biodegradation investigation demonstrated that adding unmodif
文摘Progressive fibrosis is encountered in almost all chronicliver diseases. Its clinical signs are diagnostic in advanced cirrhosis, but compensated liver cirrhosis is harder to diagnose. Liver biopsy is still considered the reference method for staging the severity of fibrosis, but due to its drawbacks(inter and intra-observer variability, sampling errors, unequal distribution of fibrosis in the liver, and risk of complications and even death), non-invasive methods were developed to assess fibrosis(serologic and elastographic). Elastographic methods can be ultrasound-based or magnetic resonance imaging-based. All ultrasoundbased elastographic methods are valuable for the early diagnosis of cirrhosis, especially transient elastography(TE) and acoustic radiation force impulse(ARFI) elastography, which have similar sensitivities and specificities, although ARFI has better feasibility. TE is a promising method for predicting portal hypertension in cirrhotic patients, but it cannot replace upper digestive endoscopy. The diagnostic accuracy of using ARFI in the liver to predict portal hypertension in cirrhotic patients is debatable, with controversial results in published studies. The accuracy of ARFI elastography may be significantly increased if spleen stiffness is assessed, either alone or in combination with liver stiffness and other parameters. Two-dimensional shearwave elastography, the Elast PQ technique and strain elastography all need to be evaluated as predictors of portal hypertension.
文摘The authors prepared,characterized and preliminary studied the properties of some neoteric solvents-ionic liquids based on choline chloride,i.e.,three ionic liquids based on the eutectics of choline chloride（2-hydroxyN,N,N-trimethylethanaminium chloride） with,respectively,urea,malonic acid and citric acid.The obtained mixtures were clear and colorless ionic liquids at room temperature.The thermophysical properties,namely,density,viscosity,and electrical conductivity of these mixtures were investigated as a function of temperature within a range of 298-353 K.Correlations for the temperature dependence of the measured properties were generated and discussed in terms of Arrhenius theory.Finally the electrochemical windows of the eutectic liquids were determined.
文摘Carbon(C)is a key constitutive element in living organisms(plants,microbes,animals,and humans).Carbon is also a basic component of agriculture because it plays a dynamic role in crop growth,development,nutrient cycling,soil fertility,and other agricultural features.The presence of C enhances soil physical,chemical,and biological properties.The C cycle supports all life on the Earth by transferring C between living organisms and the environment.The global climate is changing,and this change is attributable to the release of carbon dioxide and other greenhouse gases from human activities.Owing to the global climate change,agriculture is expected to be majorly affected.Agricultural production is directly linked to the climate.The five main global C pools are the oceanic,geologic,pedologic,atmospheric,and biotic pools,with specific reservoirs and inter-pool fluxes.The soil organic matter has various organic C pools(active,slow,and passive pools),containing various C-based fractions and specific liability pools.Climate,geology,land use,and management techniques are some of the variables that affect organic C and its reservoirs.The dynamics of each of these variables must be understood for a thorough knowledge of how they impact the soil C pools and storage capacity under the changing climate conditions.This review provides a comprehensive overview of the various factors that affect soil C pools/fractions and their C sequestration capacity.
基金This work was performed in part at the George Washington University Nanofabrication and Imaging Center(GWNIC).Thin film material analysis is supported by NIST Center for Nanoscale Science and Nanotechnology(CNST),and J.A.Woollam Co.V.J.S.is supported by AFOSR(FA9550-20-1-0193)under the Presidential Early Career Award in Science and Engineering(PECASE).
文摘Photonic Random-Access Memories(P-RAM)are an essential component for the on-chip non-von Neumann photonic computing by eliminating optoelectronic conversion losses in data links.Emerging Phase-Change Materials(PCMs)have been showed multilevel memory capability,but demonstrations still yield relatively high optical loss and require cumbersome WRITE-ERASE approaches increasing power consumption and system package challenges.Here we demonstrate a multistate electrically programmed low-loss nonvolatile photonic memory based on a broadband transparent phase-change material(Ge2Sb2Se5,GSSe)with ultralow absorption in the amorphous state.A zero-staticpower and electrically programmed multi-bit P-RAM is demonstrated on a silicon-on-insulator platform,featuring efficient amplitude modulation up to 0.2 dB/μm and an ultralow insertion loss of total 0.12 dB for a 4-bit memory showing a 100×improved signal to loss ratio compared to other phase-change-materials based photonic memories.We further optimize the positioning of dual microheaters validating performance tradeoffs.Experimentally we demonstrate a half-a-million cyclability test showcasing the robust approach of this material and device.Low-loss photonic retention-of-state adds a key feature for photonic functional and programmable circuits impacting many applications including neural networks,LiDAR,and sensors for example.
基金supported by a Research Environment Links Grant No.MIGHT/CEO/NUOF/1-2022(2)from the British Council and Malaysia Industry-Government Group for High Technologypart of the British Council’s Going Global Partnerships programThe program builds stronger,more inclusive,internationally connected higher education and TVET systems。
文摘Flexible dielectric materials with environmental-friendly,low-cost and high-energy density characteristics are in increasing demand as the world steps into the new Industrial 4.0 era.In this work,an elastomeric nanocomposite was developed by incorporating two components:cellulose nanofibrils(CNFs)and recycled alum sludge,as the reinforcement phase and to improve the dielectric properties,in a bio-elastomer matrix.CNF and alum sludge were produced by processing waste materials that would otherwise be disposed to landfills.A biodegradable elastomer polydimethylsiloxane was used as the matrix and the nanocomposites were processed by casting the materials in Petri dishes.Nanocellulose extraction and heat treatment of alum sludge were conducted and characterized using various techniques including scanning electron microscopy(SEM),thermogravimetric analysis/derivative thermogravimetric(TGA/DTG)and X-ray diffraction(XRD)analysis.When preparing the nanocomposite samples,various amount of alum sludge was added to examine their impact on the mechanical,thermal and electrical properties.Results have shown that it could be a sustainable practice of reusing such wastes in preparing flexible,lightweight and miniature dielectric materials that can be used for energy storage applications.
