The success of any perimeter intrusion detection system depends on three important performance parameters： the probability of detection （POD）, the nuisance alarm rate （NAR）, and the false alarm rate （FAR）. The ...The success of any perimeter intrusion detection system depends on three important performance parameters： the probability of detection （POD）, the nuisance alarm rate （NAR）, and the false alarm rate （FAR）. The most fundamental parameter, POD, is normally related to a number of factors such as the event of interest, the sensitivity of the sensor, the installation quality of the system, and the reliability of the sensing equipment. The suppression of nuisance alarms without degrading sensitivity in fiber optic intrusion detection systems is key to maintaining acceptable performance. Signal processing algorithms that maintain the POD and eliminate nuisance alarms are crucial for achieving this. In this paper, a robust event classification system using supervised neural networks together with a level crossings （LCs） based feature extraction algorithm is presented for the detection and recognition of intrusion and non-intrusion events in a fence-based fiber-optic intrusion detection system. A level crossings algorithm is also used with a dynamic threshold to suppress torrential rain-induced nuisance alarms in a fence system. Results show that rain-induced nuisance alarms can be suppressed for rainfall rates in excess of 100mm/hr with the simultaneous detection of intrusion events. The use of a level crossing based detection and novel classification algorithm is also presented for a buried pipeline fiber optic intrusion detection system for the suppression of nuisance events and discrimination of intrusion events. The sensor employed for both types of systems is a distributed bidirectional fiber-optic Mach-Zehnder （MZ） interferometer.展开更多
As is well known to mineral processing scientists and engineers, fine and ultrafine particles are difficult to float mainly due to the low bubble-particle collision efficiencies. Though many efforts have been made to ...As is well known to mineral processing scientists and engineers, fine and ultrafine particles are difficult to float mainly due to the low bubble-particle collision efficiencies. Though many efforts have been made to improve flotation performance of fine and ultrafine particles, there is still much more to be done. In this paper, the effects of nano-microbubbles （nanobuhbles and microbubbles） on the flotation of fine （-38 ＋ 14.36 μm） and ultrafine （-14.36 ＋ 5μm） chalcopyrite particles were investigated in a laboratory scale Denver flotation cell. Nano-microbubbles were generated using a specially-designed nano- microbubble generator based on the cavitation phenomenon in Venturi tubes. In order to better under- stand the mechanisms of nano-microbubble enhanced froth flotation of fine and ultrafine chalcopyrite particles, the nano-microbubble size distribution, stability and the effect of frother concentration on nano- bubble size were also studied by a laser diffraction method. Comparative flotation tests were performed in the presence and absence of nano-microbubbles to evaluate their impact on the fine and ultrafine chalcopyrite particle flotation recovery. According to the results, the mean size of nano-microbubbles increased over time, and decreased with increase of frother concentration. The laboratory-scale flotation test results indicated that flotation recovery of chalcopyrite fine and ultrafine particles increased by approximately 16-21% in the presence of nano-microbubbles, depending on operating conditions of the process. The presence of nano-microbubbles increased the recovery of ultrafine particles （-14.36 ＋ 5 μm） more than that of fine particles （-38 ＋ 14.36 μm）. Another major advantage is that the use of nano-microbubbles reduced the collector and frother consumptions by up to 75% and 50%, respectively.展开更多
Spermatogenesis is a complex process regulated by endocrine and testicular paracrine/autocrine factors. Gonadotropins are involved in the regulation of several testicular paracrine factors, mainly of the IL-1 family a...Spermatogenesis is a complex process regulated by endocrine and testicular paracrine/autocrine factors. Gonadotropins are involved in the regulation of several testicular paracrine factors, mainly of the IL-1 family and testicular hormones. Testicular cytokines and growth factors (such as IL-1, IL-6, TNF, IFN-γ, LIF and SCF) were shown to affect both the germ cell proliferation and the Leydig and Sertoli cells functions and secretion. Cytokines and growth factors are produced by immune cells and in the interstitial and seminiferous tubular compartments by various testicular cells, including Sertoli, Leydig, peritubular cells, spermatogonia, differentiated spermatogonia and even spermatozoa. Corresponding cytokine and growth factor receptors were demonstrated on some of the testicular cells. These cytokines also control the secretion of the gonadotropins and testosterone in the testis. Under pathological conditions the levels of pro-inflammatory cytokines are increased and negatively affected spermatogenesis. Thus, the expression levels and the mechanisms involved in the regulation of testicular paracrine/autocrine factors should be considered in future therapeutic strategies for male infertility.展开更多
We develop a new integrated navigation system, which integrates multi-constellations GNSS precise point positioning (PPP), including GPS, GLONASS and Galileo, with low-cost micro-electro-mechanical sensor (MEMS) inert...We develop a new integrated navigation system, which integrates multi-constellations GNSS precise point positioning (PPP), including GPS, GLONASS and Galileo, with low-cost micro-electro-mechanical sensor (MEMS) inertial system, for precise positioning applications. To integrate GNSS and the MEMS-based inertial system, the process and measurement models are developed. Tightly coupled mechanism is adopted, which is carried out in the GNSS raw measurements domain. Both un-differenced and between-satellite single-difference (BSSD) ionosphere-free linear combinations of pseudorange and carrier phase GNSS measurements are processed. Rigorous models are employed to correct GNSS errors and biases. The GNSS inter-system biases are considered as additional unknowns in the integrated error state vector. The developed stochastic model for inertial sensors errors and biases are defined based on first order Gaussian Markov process. Extended Kalman filter is developed to integrate GNSS and inertial measurements and estimate inertial measurements biases and errors. Two field experiments are executed, which represent different real-world scenarios in land-based navigation. The data are processed by using our developed Ryerson PPP GNSS/MEMS software. The results indicate that the proposed integrated system achieves decimeter to centimeter level positioning accuracy when the measurement updates from GNSS are available. During complete GNSS outages the developed integrated system continues to achieve decimeter level accuracy for up to 30 seconds while it achieves meter-level accuracy when a 60-second outage is introduced.展开更多
Due to its strong piezoelectric effect and photo-elastic property, lithium niobate is widely used for acousto-optical applications. However, conventional bulk lithium niobate waveguide devices exhibit a large footprin...Due to its strong piezoelectric effect and photo-elastic property, lithium niobate is widely used for acousto-optical applications. However, conventional bulk lithium niobate waveguide devices exhibit a large footprint and limited light–sound interaction resulting from the weak guiding of light. Here, we report the first acousto-optical modulators with surface acoustic wave generation, phononic cavity, and low-loss photonic waveguide devices monolithically integrated on a 500 nm thick film of lithium niobate on an insulator. Modulation efficiency was optimized by properly arranging the propagation directions of surface acoustic waves and optical guided modes.The effective photo-elastic coefficient extracted by comparing the first and third harmonic modulation signals from an on-chip Mach–Zehnder interferometer indicates the excellent acousto-optical properties of lithium niobate are preserved in the thin film implementation. Such material property finding is of crucial importance in designing various types of acousto-optical devices. Much stronger amplitude modulation was achieved in a high Q(>300,000) optical resonator due to the higher optical sensitivity. Our results pave the path for developing novel acousto-optical devices using thin film lithium niobate.展开更多
The clinical course of infections with the hepatitis B virus (HBV) substantially varies between individuals, as a consequence of a complex interplay between viral, host, environmental and other factors. Due to the hig...The clinical course of infections with the hepatitis B virus (HBV) substantially varies between individuals, as a consequence of a complex interplay between viral, host, environmental and other factors. Due to the high genetic variability of HBV, the virus can be categorized into different HBV genotypes and subgenotypes, which considerably differ with respect to geographical distribution, transmission routes, disease progression, responses to antiviral therapy or vaccination, and clinical outcome measures such as cirrhosis or hepatocellular carcinoma. However, HBV (sub)genotyping has caused some controversies in the past due to misclassifications and incorrect interpretations of different genotyping methods. Thus, an accurate, holistic and dynamic classification system is essential. In this review article, we aimed at highlighting potential pitfalls in genetic and phylogenetic analyses of HBV and suggest novel terms for HBV classification. Analyzing full-length genome sequences when classifying genotypes and subgenotypes is the foremost prerequisite of this classification system. Careful attention must be paid to all aspects of phylogenetic analysis, such as bootstrapping values and meeting the necessary thresholds for (sub)genotyping. Quasi-subgenotype refers to subgenotypes that were incorrectly suggested to be novel. As many of these strains were misclassified due to genetic differences resulting from recombination, we propose the term “recombino-subgenotype”. Moreover, immigration is an important confounding facet of global HBV distribution and substantially changes the geographic pattern of HBV (sub)genotypes. We therefore suggest the term “immigro-subgenotype” to distinguish exotic (sub)genotypes from native ones. We are strongly convinced that applying these two proposed terms in HBV classification will help harmonize this rapidly progressing field and allow for improved prophylaxis, diagnosis and treatment.展开更多
Establishment of an in vitro system that allows the development of testicular germ cells to sperm will be valuable for studies of spermatogenesis and future treatments for male infertility. In the present study, we de...Establishment of an in vitro system that allows the development of testicular germ cells to sperm will be valuable for studies of spermatogenesis and future treatments for male infertility. In the present study, we developed in vitro culture conditions using three-dimensional agar culture system （SACS）, which has the capacity to induce testicular germ cells to reach the final stages of spermatogenesis, including spermatozoa generation. Seminiferous tubules from testes of 7-day-old mice were enzymatically dissociated, and intratubular cells were cultured in the upper layer of the SACS in RPMI medium supplemented with fetal calf serum （FCS）. The lower layer of the SACS contained only RPMI medium supplemented with FCS. Colonies in the upper layer were isolated after 14 and 28 days of culture and were classified according to their size. Immunofluorescence and real-time PCR were used to analyse specific markers expressed in undifferentiated and differentiated spermatogonia （Vasa, Dazl, OCT-4, C-Kit, GFR- a-l, CD9 and a-6-integrin）, meiotic cells （LDH, Crem-1 and Boule） and post-meiotic cells （Protamine-1, Acrosin and SP-IO）. Our results reveal that it is possible to induce mouse testicular pre-meiotic germ cell expansion and induce their differentiation to spermatozoa in SACS. The spermatozoa showed normal morphology and contained acrosomes. Thus, our results demonstrate that SACS could be used as a novel in vitro system for the maturation of pre-meiotic mouse germ cells to post-meiotic stages and morphologically-normal spermatozoa.展开更多
Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 stee...Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 steels are the state of the art process and grades, respectively; however novel processes and steel grades are under considerations. In the current research, behavior of the steel grade MSW1200 blanks under semi and fully hot stamping processes was characterized. During semi-hot stamping process, the blank was firstly heated to a temperature of about 650℃ and then formed and quenched in the die assembly, simultaneously. Microstructure and mechanical properties of semi and fully hot stamped blanks were studied and the results were compared with those of normally water/air quenched blanks. The hot stamped blanks attained the strength values as high as water quenched blanks. The highest ductility and consequently, the best formability were achieved for the blank which had been semi-hot stamped. It was concluded that for the mentioned steel, semi-hot stamping process could be considered as an improved thermo-mechanical process which not only guaranteed a high formability, but also led to ultra high strength values.展开更多
Mycotoxins are secondary metabolites of different species of fungi.Aflatoxin B1(AFB1),deoxynivalenol(DON),zearalenone(ZEN)and fumonisin B1(FB1)are the main mycotoxins contaminating animal feedstuffs.These mycotoxins c...Mycotoxins are secondary metabolites of different species of fungi.Aflatoxin B1(AFB1),deoxynivalenol(DON),zearalenone(ZEN)and fumonisin B1(FB1)are the main mycotoxins contaminating animal feedstuffs.These mycotoxins can primarily induce hepatotoxicity,immunotoxicity,neurotoxicity and nephrotoxicity,consequently cause adverse effects on the health and performance of animals.Therefore,physical,chemical,biological and nutritional regulation approaches have been developed as primary strategies for the decontamination and detoxification of these mycotoxins in the feed industry.Meanwhile,each of these techniques has its drawbacks,including inefficient,costly,or impractically applied on large scale.This review summarized the advantages and disadvantages of the different remediation strategies,as well as updates of the research progress of these strategies for AFB1,DON,ZEN and FB1 control in the feed industry.展开更多
Hepatitis C virus(HCV)infection represents a significant health problem and represents a heavy load on some countries like Egypt in which about 20%of the total population are infected.Initial infection is usually asym...Hepatitis C virus(HCV)infection represents a significant health problem and represents a heavy load on some countries like Egypt in which about 20%of the total population are infected.Initial infection is usually asymptomatic and result in chronic hepatitis that give rise to complications including cirrhosis and hepatocellular carcinoma.The management of HCV infection should not only be focus on therapy,but also to screen carrier individuals in order to prevent transmission.In the present,molecular detection and quantification of HCV genome by real time polymerase chain reaction(PCR)represent the gold standard in HCV diagnosis and plays a crucial role in the management of therapeutic regimens.However,real time PCR is a complicated approach and of limited distribution.On the other hand,isothermal DNA amplification techniques have been developed and offer molecular diagnosis of infectious dieses at point-of-care.In this review we discuss recombinase polymerase amplification technique and illustrate its diagnostic value over both PCR and other isothermal amplification techniques.展开更多
AIM To evaluate the clinicopathological features and the surgical outcomes of patients with fibrolamellar hepato-cellular carcinoma(FL-HCC)over a 15-year period. METHODS This is a retrospective study including 22 pati...AIM To evaluate the clinicopathological features and the surgical outcomes of patients with fibrolamellar hepato-cellular carcinoma(FL-HCC)over a 15-year period. METHODS This is a retrospective study including 22 patients with a pathologic diagnosis of FL-HCC who underwent hepatectomy over a 15-year period. Tumor characteristics,survival and recurrence were evaluated. RESULTS There were 11 male and 11 female with a median age of 29 years(range from 21 to 58 years). Two(9%)patients had hepatitis C viral infection and only 2(9%)patients had alpha-fetoprotein level > 200 ng/m L. The median size of the tumors was 12 cm(range from 5-20 cm). Vascular invasion was detected in 5(23%)patients. Four(18%)patients had lymph node metastases. The median follow up period was 42 mo and the 5-year survival was 65%. Five(23%)patients had a recurrent disease,4 of them had a second surgery with 36 mo median time interval. Vascular invasion is the only significant negative prognostic factor CONCLUSION FL-HCC has a favorable prognosis than common HCC and should be suspected in young patients with non cirrhotic liver. Aggressive surgical resection should be done for all patients. Repeated hepatectomy should be considered for these patients as it has a relatively indolent course.展开更多
AIMTo evaluate the reversibility of minimal hepatic encephalopathy (MHE) following liver transplantation (LT) in Egyptian cirrhotic patients. METHODSThis prospective study included twenty patients with biopsy-proven l...AIMTo evaluate the reversibility of minimal hepatic encephalopathy (MHE) following liver transplantation (LT) in Egyptian cirrhotic patients. METHODSThis prospective study included twenty patients with biopsy-proven liver cirrhosis listed for LT and twenty age- and sex-matched healthy control subjects. All underwent neuro-psychiatric examination, laboratory investigations, radiological studies and psychometric tests including trail making test A (TMT A), TMT B, digit symbol test and serial dotting test. The psychometric hepatic encephalopathy score (PHES) was calculated for patients to diagnose MHE. Psychometric tests were repeated six months following LT in the cirrhotic patient group. RESULTSBefore LT, psychometric tests showed highly significant deficits in cirrhotic patients in comparison to controls (P P P P = 0.005). More patients in whom reversal of MHE was observed had a pre-transplant MELD score CONCLUSIONReversal of MHE in cirrhotic patients could be achieved by LT, especially in those with a MELD score展开更多
Sepsis and septic shock are life threatening condition associated with high mortality rate in critically-ill patients. This high mortality is mainly related to the inadequacy between oxygen delivery and cellular deman...Sepsis and septic shock are life threatening condition associated with high mortality rate in critically-ill patients. This high mortality is mainly related to the inadequacy between oxygen delivery and cellular demand leading to the onset of multiorgan dysfunction. Whether this multiorgan failure affect the pancreas is not fully investigated. In fact, pancreatic injury may occur because of ischemia, overwhelming inflammatory response, oxidative stress, cellular apoptosis and/or metabolic derangement. Increased serum amylase and/or lipase levels are common in patients with septic shock. However, imaging test rarely reveal significant pancreatic damage. Whether pancreatic dysfunction does affect the prognosis of patients with septic shock or not is still a matter of debate. In fact, only few studies with limited sample size assessed the clinical relevance of the pancreatic injury in this group of patients. In this review, we aimed to describe the epidemiology and the physiopathology of pancreatic injury in septic shock patients, to clarify whether it requires specific management and to assess its prognostic value. Our main finding is that pancreatic injury does not significantly affect the outcome in septic shock patients. Hence, increased serum pancreatic enzymes without clinical features of acute pancreatitis do not require further imaging investigations and specific therapeutic intervention.展开更多
AIM:To evaluate effective alternative antibiotics in treatment of cefotaxime-resistant spontaneous bacterial peritonitis.METHODS:One hundred cirrhotic patients with spontaneous bacterial peritonitis [ascitic fluid pol...AIM:To evaluate effective alternative antibiotics in treatment of cefotaxime-resistant spontaneous bacterial peritonitis.METHODS:One hundred cirrhotic patients with spontaneous bacterial peritonitis [ascitic fluid polymorphonuclear cell count(PMNLs) ≥ 250 cells/mm 3 at admission] were empirically treated with cefotaxime sodium 2 g/12 h and volume expansion by intravenous human albumin.All patients were subjected to history taking,complete examination,laboratory tests(including a complete blood cell count,prothrombin time,biochemical tests of liver and kidney function,and fresh urine sediment),chest X-ray,a diagnostic abdominal paracentesis,and the sample subjected to total and differential cell count,chemical examination,aerobic and anaerobic cultures.Patients were divided after 2 d by a second ascitic PMNL count into group Ⅰ;patients sensitive to cefotaxime(n = 81),group Ⅱ(n = 19);cases resistant to cefotaxime(less than 25% decrease in ascitic PMNL count).Patients of group Ⅱ were randomly assigned into meropenem(n = 11) or levofloxacin(n = 8) subgroups.All patients performed an end of treatment ascitic PMNL count.Patients were considered improved when:PMNLs decreased to < 250 cells/mm 3,no growth in previously positive culture cases,and improved clinical manifestations with at least 5 d of antibiotic therapy.RESULTS:Age,sex,and Child classes showed no significant difference between group Ⅰ and group Ⅱ.Fever and abdominal pain were the most frequent manifestations and were reported in 82.7% and 80.2% of patients in group Ⅰ and in 94.7% and 84.2% of patients in group Ⅱ,respectively.Patients in group Ⅱ had a more severe ascitic inflammatory response than group Ⅰ and this was demonstrated by more ascitic lactate dehydrogenase(LDH) [median:540 IU/L(range:150-1200 IU/L) vs median:240 IU/L(range:180-500 IU/L),P = 0.000] and PMNL [median:15 000 cell/mm 3(range:957-23 822 cell/mm 3) vs 3400 cell/mm 3(range:695-26 400 cell/mm 3),P = 0.000] counts.Ascitic fluid culture was positive in 32% of cases.Cefot展开更多
Congenital abnormalities of the kidney and urinary tract(CAKUT) include a wide range of abnormalities ranging from asymptomatic ectopic kidneys to life threatening renal agenesis(bilateral). Many of them are detected ...Congenital abnormalities of the kidney and urinary tract(CAKUT) include a wide range of abnormalities ranging from asymptomatic ectopic kidneys to life threatening renal agenesis(bilateral). Many of them are detected in the antenatal or immediate postnatal with a significant proportion identified in the adult population with varying degree of severity. CAKUT can be classified on embryological basis in to abnormalities in the renal parenchymal development, aberrant embryonic migration and abnormalities of the collecting system. Renal parenchymal abnormalities include multi cystic dysplastic kidneys, renal hypoplasia, number(agenesis or supernumerary), shape and cystic renal diseases. Aberrant embryonic migration encompasses abnormal location and fusion anomalies. Collecting system abnormalities include duplex kidneys and Pelvi ureteric junction obstruction. Ultrasonography(US) is typically the first imaging performed as it is easily available, noninvasive and radiation free used both antenatally and postnatally. Computed tomography(CT) and magnetic resonance imaging(MRI) are useful to confirm the ultrasound detected abnormality, detection of complex malformations, demonstration of collecting system and vascular anatomy and more importantly for early detection of complications like renal calculi, infection and malignancies. As CAKUT are one of the leading causes of end stage renal disease, it is important for the radiologists to be familiar with the varying imaging appearances of CAKUT on US, CT and MRI, thereby helping in prompt diagnosis and optimal management.展开更多
Tumoral calcinosis(TC) has long been a controversial clinico-pathological entity. Its pathogenesis and genetic background have been gradually unravelled since its first description in 1943. According to the presence o...Tumoral calcinosis(TC) has long been a controversial clinico-pathological entity. Its pathogenesis and genetic background have been gradually unravelled since its first description in 1943. According to the presence or absence of an underlying calcifying disease process, TC has been divided into primary and secondary varieties. Two subtypes of the primary variety exist; a hyperphosphatemic type with familial basis represented by mutations in Gal NAc transferase 3 gene(GALNT3), KLOTHO or Fibroblast growth factor 23(FGF23) genes, and a normo-phosphatemic type with growing evidence of underlying familial base represented by mutation in SAMD9 gene. The secondary variety is mainly associated with chronic renal failure and the resulting secondary or tertiary hyperparathyroidism. Diagnosis of TC relies on typical radiographic features(on plain radiographs and computed tomography) and the biochemical profile. Magnetic resonance imaging can be done in difficult cases, and scintigraphy reflects the disease activity. Treatment is mainly surgical for the primary variety; however, a stage-oriented conservative approach using phosphate binders, phosphate restricted dietsand acetazolamide should be considered before the surgical approach is pursued due to the high rate of recurrences and complications after surgical intervention. Medical treatment is the mainstay for treatment of the secondary variety, with failure warranting subtotal or total parathyroidectomy. Surgical intervention in these patients should be kept as a last resort.展开更多
文摘The success of any perimeter intrusion detection system depends on three important performance parameters： the probability of detection （POD）, the nuisance alarm rate （NAR）, and the false alarm rate （FAR）. The most fundamental parameter, POD, is normally related to a number of factors such as the event of interest, the sensitivity of the sensor, the installation quality of the system, and the reliability of the sensing equipment. The suppression of nuisance alarms without degrading sensitivity in fiber optic intrusion detection systems is key to maintaining acceptable performance. Signal processing algorithms that maintain the POD and eliminate nuisance alarms are crucial for achieving this. In this paper, a robust event classification system using supervised neural networks together with a level crossings （LCs） based feature extraction algorithm is presented for the detection and recognition of intrusion and non-intrusion events in a fence-based fiber-optic intrusion detection system. A level crossings algorithm is also used with a dynamic threshold to suppress torrential rain-induced nuisance alarms in a fence system. Results show that rain-induced nuisance alarms can be suppressed for rainfall rates in excess of 100mm/hr with the simultaneous detection of intrusion events. The use of a level crossing based detection and novel classification algorithm is also presented for a buried pipeline fiber optic intrusion detection system for the suppression of nuisance events and discrimination of intrusion events. The sensor employed for both types of systems is a distributed bidirectional fiber-optic Mach-Zehnder （MZ） interferometer.
基金the Tarbiat Modares University (TMU), the Iran Mineral Processing Research Center (IMPRC) and the IMIDRO for the technical assistance and financial support
文摘As is well known to mineral processing scientists and engineers, fine and ultrafine particles are difficult to float mainly due to the low bubble-particle collision efficiencies. Though many efforts have been made to improve flotation performance of fine and ultrafine particles, there is still much more to be done. In this paper, the effects of nano-microbubbles （nanobuhbles and microbubbles） on the flotation of fine （-38 ＋ 14.36 μm） and ultrafine （-14.36 ＋ 5μm） chalcopyrite particles were investigated in a laboratory scale Denver flotation cell. Nano-microbubbles were generated using a specially-designed nano- microbubble generator based on the cavitation phenomenon in Venturi tubes. In order to better under- stand the mechanisms of nano-microbubble enhanced froth flotation of fine and ultrafine chalcopyrite particles, the nano-microbubble size distribution, stability and the effect of frother concentration on nano- bubble size were also studied by a laser diffraction method. Comparative flotation tests were performed in the presence and absence of nano-microbubbles to evaluate their impact on the fine and ultrafine chalcopyrite particle flotation recovery. According to the results, the mean size of nano-microbubbles increased over time, and decreased with increase of frother concentration. The laboratory-scale flotation test results indicated that flotation recovery of chalcopyrite fine and ultrafine particles increased by approximately 16-21% in the presence of nano-microbubbles, depending on operating conditions of the process. The presence of nano-microbubbles increased the recovery of ultrafine particles （-14.36 ＋ 5 μm） more than that of fine particles （-38 ＋ 14.36 μm）. Another major advantage is that the use of nano-microbubbles reduced the collector and frother consumptions by up to 75% and 50%, respectively.
文摘Spermatogenesis is a complex process regulated by endocrine and testicular paracrine/autocrine factors. Gonadotropins are involved in the regulation of several testicular paracrine factors, mainly of the IL-1 family and testicular hormones. Testicular cytokines and growth factors (such as IL-1, IL-6, TNF, IFN-γ, LIF and SCF) were shown to affect both the germ cell proliferation and the Leydig and Sertoli cells functions and secretion. Cytokines and growth factors are produced by immune cells and in the interstitial and seminiferous tubular compartments by various testicular cells, including Sertoli, Leydig, peritubular cells, spermatogonia, differentiated spermatogonia and even spermatozoa. Corresponding cytokine and growth factor receptors were demonstrated on some of the testicular cells. These cytokines also control the secretion of the gonadotropins and testosterone in the testis. Under pathological conditions the levels of pro-inflammatory cytokines are increased and negatively affected spermatogenesis. Thus, the expression levels and the mechanisms involved in the regulation of testicular paracrine/autocrine factors should be considered in future therapeutic strategies for male infertility.
文摘We develop a new integrated navigation system, which integrates multi-constellations GNSS precise point positioning (PPP), including GPS, GLONASS and Galileo, with low-cost micro-electro-mechanical sensor (MEMS) inertial system, for precise positioning applications. To integrate GNSS and the MEMS-based inertial system, the process and measurement models are developed. Tightly coupled mechanism is adopted, which is carried out in the GNSS raw measurements domain. Both un-differenced and between-satellite single-difference (BSSD) ionosphere-free linear combinations of pseudorange and carrier phase GNSS measurements are processed. Rigorous models are employed to correct GNSS errors and biases. The GNSS inter-system biases are considered as additional unknowns in the integrated error state vector. The developed stochastic model for inertial sensors errors and biases are defined based on first order Gaussian Markov process. Extended Kalman filter is developed to integrate GNSS and inertial measurements and estimate inertial measurements biases and errors. Two field experiments are executed, which represent different real-world scenarios in land-based navigation. The data are processed by using our developed Ryerson PPP GNSS/MEMS software. The results indicate that the proposed integrated system achieves decimeter to centimeter level positioning accuracy when the measurement updates from GNSS are available. During complete GNSS outages the developed integrated system continues to achieve decimeter level accuracy for up to 30 seconds while it achieves meter-level accuracy when a 60-second outage is introduced.
基金Defense Advanced Research Projects Agency(DARPA)(N66001-16-1-4025)
文摘Due to its strong piezoelectric effect and photo-elastic property, lithium niobate is widely used for acousto-optical applications. However, conventional bulk lithium niobate waveguide devices exhibit a large footprint and limited light–sound interaction resulting from the weak guiding of light. Here, we report the first acousto-optical modulators with surface acoustic wave generation, phononic cavity, and low-loss photonic waveguide devices monolithically integrated on a 500 nm thick film of lithium niobate on an insulator. Modulation efficiency was optimized by properly arranging the propagation directions of surface acoustic waves and optical guided modes.The effective photo-elastic coefficient extracted by comparing the first and third harmonic modulation signals from an on-chip Mach–Zehnder interferometer indicates the excellent acousto-optical properties of lithium niobate are preserved in the thin film implementation. Such material property finding is of crucial importance in designing various types of acousto-optical devices. Much stronger amplitude modulation was achieved in a high Q(>300,000) optical resonator due to the higher optical sensitivity. Our results pave the path for developing novel acousto-optical devices using thin film lithium niobate.
基金Supported by Mahmoud Reza Pourkarim is supported by a postdoctoral grant from the''Fonds voor Wetenschappelijk Onderzoek Vlaanderen''
文摘The clinical course of infections with the hepatitis B virus (HBV) substantially varies between individuals, as a consequence of a complex interplay between viral, host, environmental and other factors. Due to the high genetic variability of HBV, the virus can be categorized into different HBV genotypes and subgenotypes, which considerably differ with respect to geographical distribution, transmission routes, disease progression, responses to antiviral therapy or vaccination, and clinical outcome measures such as cirrhosis or hepatocellular carcinoma. However, HBV (sub)genotyping has caused some controversies in the past due to misclassifications and incorrect interpretations of different genotyping methods. Thus, an accurate, holistic and dynamic classification system is essential. In this review article, we aimed at highlighting potential pitfalls in genetic and phylogenetic analyses of HBV and suggest novel terms for HBV classification. Analyzing full-length genome sequences when classifying genotypes and subgenotypes is the foremost prerequisite of this classification system. Careful attention must be paid to all aspects of phylogenetic analysis, such as bootstrapping values and meeting the necessary thresholds for (sub)genotyping. Quasi-subgenotype refers to subgenotypes that were incorrectly suggested to be novel. As many of these strains were misclassified due to genetic differences resulting from recombination, we propose the term “recombino-subgenotype”. Moreover, immigration is an important confounding facet of global HBV distribution and substantially changes the geographic pattern of HBV (sub)genotypes. We therefore suggest the term “immigro-subgenotype” to distinguish exotic (sub)genotypes from native ones. We are strongly convinced that applying these two proposed terms in HBV classification will help harmonize this rapidly progressing field and allow for improved prophylaxis, diagnosis and treatment.
文摘Establishment of an in vitro system that allows the development of testicular germ cells to sperm will be valuable for studies of spermatogenesis and future treatments for male infertility. In the present study, we developed in vitro culture conditions using three-dimensional agar culture system （SACS）, which has the capacity to induce testicular germ cells to reach the final stages of spermatogenesis, including spermatozoa generation. Seminiferous tubules from testes of 7-day-old mice were enzymatically dissociated, and intratubular cells were cultured in the upper layer of the SACS in RPMI medium supplemented with fetal calf serum （FCS）. The lower layer of the SACS contained only RPMI medium supplemented with FCS. Colonies in the upper layer were isolated after 14 and 28 days of culture and were classified according to their size. Immunofluorescence and real-time PCR were used to analyse specific markers expressed in undifferentiated and differentiated spermatogonia （Vasa, Dazl, OCT-4, C-Kit, GFR- a-l, CD9 and a-6-integrin）, meiotic cells （LDH, Crem-1 and Boule） and post-meiotic cells （Protamine-1, Acrosin and SP-IO）. Our results reveal that it is possible to induce mouse testicular pre-meiotic germ cell expansion and induce their differentiation to spermatozoa in SACS. The spermatozoa showed normal morphology and contained acrosomes. Thus, our results demonstrate that SACS could be used as a novel in vitro system for the maturation of pre-meiotic mouse germ cells to post-meiotic stages and morphologically-normal spermatozoa.
文摘Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 steels are the state of the art process and grades, respectively; however novel processes and steel grades are under considerations. In the current research, behavior of the steel grade MSW1200 blanks under semi and fully hot stamping processes was characterized. During semi-hot stamping process, the blank was firstly heated to a temperature of about 650℃ and then formed and quenched in the die assembly, simultaneously. Microstructure and mechanical properties of semi and fully hot stamped blanks were studied and the results were compared with those of normally water/air quenched blanks. The hot stamped blanks attained the strength values as high as water quenched blanks. The highest ductility and consequently, the best formability were achieved for the blank which had been semi-hot stamped. It was concluded that for the mentioned steel, semi-hot stamping process could be considered as an improved thermo-mechanical process which not only guaranteed a high formability, but also led to ultra high strength values.
基金supported by the Chinese Natural Sciences (32072775 and 31772636)Nutreco N.V.(Netherlands)
文摘Mycotoxins are secondary metabolites of different species of fungi.Aflatoxin B1(AFB1),deoxynivalenol(DON),zearalenone(ZEN)and fumonisin B1(FB1)are the main mycotoxins contaminating animal feedstuffs.These mycotoxins can primarily induce hepatotoxicity,immunotoxicity,neurotoxicity and nephrotoxicity,consequently cause adverse effects on the health and performance of animals.Therefore,physical,chemical,biological and nutritional regulation approaches have been developed as primary strategies for the decontamination and detoxification of these mycotoxins in the feed industry.Meanwhile,each of these techniques has its drawbacks,including inefficient,costly,or impractically applied on large scale.This review summarized the advantages and disadvantages of the different remediation strategies,as well as updates of the research progress of these strategies for AFB1,DON,ZEN and FB1 control in the feed industry.
文摘Hepatitis C virus(HCV)infection represents a significant health problem and represents a heavy load on some countries like Egypt in which about 20%of the total population are infected.Initial infection is usually asymptomatic and result in chronic hepatitis that give rise to complications including cirrhosis and hepatocellular carcinoma.The management of HCV infection should not only be focus on therapy,but also to screen carrier individuals in order to prevent transmission.In the present,molecular detection and quantification of HCV genome by real time polymerase chain reaction(PCR)represent the gold standard in HCV diagnosis and plays a crucial role in the management of therapeutic regimens.However,real time PCR is a complicated approach and of limited distribution.On the other hand,isothermal DNA amplification techniques have been developed and offer molecular diagnosis of infectious dieses at point-of-care.In this review we discuss recombinase polymerase amplification technique and illustrate its diagnostic value over both PCR and other isothermal amplification techniques.
文摘AIM To evaluate the clinicopathological features and the surgical outcomes of patients with fibrolamellar hepato-cellular carcinoma(FL-HCC)over a 15-year period. METHODS This is a retrospective study including 22 patients with a pathologic diagnosis of FL-HCC who underwent hepatectomy over a 15-year period. Tumor characteristics,survival and recurrence were evaluated. RESULTS There were 11 male and 11 female with a median age of 29 years(range from 21 to 58 years). Two(9%)patients had hepatitis C viral infection and only 2(9%)patients had alpha-fetoprotein level > 200 ng/m L. The median size of the tumors was 12 cm(range from 5-20 cm). Vascular invasion was detected in 5(23%)patients. Four(18%)patients had lymph node metastases. The median follow up period was 42 mo and the 5-year survival was 65%. Five(23%)patients had a recurrent disease,4 of them had a second surgery with 36 mo median time interval. Vascular invasion is the only significant negative prognostic factor CONCLUSION FL-HCC has a favorable prognosis than common HCC and should be suspected in young patients with non cirrhotic liver. Aggressive surgical resection should be done for all patients. Repeated hepatectomy should be considered for these patients as it has a relatively indolent course.
文摘AIMTo evaluate the reversibility of minimal hepatic encephalopathy (MHE) following liver transplantation (LT) in Egyptian cirrhotic patients. METHODSThis prospective study included twenty patients with biopsy-proven liver cirrhosis listed for LT and twenty age- and sex-matched healthy control subjects. All underwent neuro-psychiatric examination, laboratory investigations, radiological studies and psychometric tests including trail making test A (TMT A), TMT B, digit symbol test and serial dotting test. The psychometric hepatic encephalopathy score (PHES) was calculated for patients to diagnose MHE. Psychometric tests were repeated six months following LT in the cirrhotic patient group. RESULTSBefore LT, psychometric tests showed highly significant deficits in cirrhotic patients in comparison to controls (P P P P = 0.005). More patients in whom reversal of MHE was observed had a pre-transplant MELD score CONCLUSIONReversal of MHE in cirrhotic patients could be achieved by LT, especially in those with a MELD score
文摘Sepsis and septic shock are life threatening condition associated with high mortality rate in critically-ill patients. This high mortality is mainly related to the inadequacy between oxygen delivery and cellular demand leading to the onset of multiorgan dysfunction. Whether this multiorgan failure affect the pancreas is not fully investigated. In fact, pancreatic injury may occur because of ischemia, overwhelming inflammatory response, oxidative stress, cellular apoptosis and/or metabolic derangement. Increased serum amylase and/or lipase levels are common in patients with septic shock. However, imaging test rarely reveal significant pancreatic damage. Whether pancreatic dysfunction does affect the prognosis of patients with septic shock or not is still a matter of debate. In fact, only few studies with limited sample size assessed the clinical relevance of the pancreatic injury in this group of patients. In this review, we aimed to describe the epidemiology and the physiopathology of pancreatic injury in septic shock patients, to clarify whether it requires specific management and to assess its prognostic value. Our main finding is that pancreatic injury does not significantly affect the outcome in septic shock patients. Hence, increased serum pancreatic enzymes without clinical features of acute pancreatitis do not require further imaging investigations and specific therapeutic intervention.
文摘AIM:To evaluate effective alternative antibiotics in treatment of cefotaxime-resistant spontaneous bacterial peritonitis.METHODS:One hundred cirrhotic patients with spontaneous bacterial peritonitis [ascitic fluid polymorphonuclear cell count(PMNLs) ≥ 250 cells/mm 3 at admission] were empirically treated with cefotaxime sodium 2 g/12 h and volume expansion by intravenous human albumin.All patients were subjected to history taking,complete examination,laboratory tests(including a complete blood cell count,prothrombin time,biochemical tests of liver and kidney function,and fresh urine sediment),chest X-ray,a diagnostic abdominal paracentesis,and the sample subjected to total and differential cell count,chemical examination,aerobic and anaerobic cultures.Patients were divided after 2 d by a second ascitic PMNL count into group Ⅰ;patients sensitive to cefotaxime(n = 81),group Ⅱ(n = 19);cases resistant to cefotaxime(less than 25% decrease in ascitic PMNL count).Patients of group Ⅱ were randomly assigned into meropenem(n = 11) or levofloxacin(n = 8) subgroups.All patients performed an end of treatment ascitic PMNL count.Patients were considered improved when:PMNLs decreased to < 250 cells/mm 3,no growth in previously positive culture cases,and improved clinical manifestations with at least 5 d of antibiotic therapy.RESULTS:Age,sex,and Child classes showed no significant difference between group Ⅰ and group Ⅱ.Fever and abdominal pain were the most frequent manifestations and were reported in 82.7% and 80.2% of patients in group Ⅰ and in 94.7% and 84.2% of patients in group Ⅱ,respectively.Patients in group Ⅱ had a more severe ascitic inflammatory response than group Ⅰ and this was demonstrated by more ascitic lactate dehydrogenase(LDH) [median:540 IU/L(range:150-1200 IU/L) vs median:240 IU/L(range:180-500 IU/L),P = 0.000] and PMNL [median:15 000 cell/mm 3(range:957-23 822 cell/mm 3) vs 3400 cell/mm 3(range:695-26 400 cell/mm 3),P = 0.000] counts.Ascitic fluid culture was positive in 32% of cases.Cefot
文摘Congenital abnormalities of the kidney and urinary tract(CAKUT) include a wide range of abnormalities ranging from asymptomatic ectopic kidneys to life threatening renal agenesis(bilateral). Many of them are detected in the antenatal or immediate postnatal with a significant proportion identified in the adult population with varying degree of severity. CAKUT can be classified on embryological basis in to abnormalities in the renal parenchymal development, aberrant embryonic migration and abnormalities of the collecting system. Renal parenchymal abnormalities include multi cystic dysplastic kidneys, renal hypoplasia, number(agenesis or supernumerary), shape and cystic renal diseases. Aberrant embryonic migration encompasses abnormal location and fusion anomalies. Collecting system abnormalities include duplex kidneys and Pelvi ureteric junction obstruction. Ultrasonography(US) is typically the first imaging performed as it is easily available, noninvasive and radiation free used both antenatally and postnatally. Computed tomography(CT) and magnetic resonance imaging(MRI) are useful to confirm the ultrasound detected abnormality, detection of complex malformations, demonstration of collecting system and vascular anatomy and more importantly for early detection of complications like renal calculi, infection and malignancies. As CAKUT are one of the leading causes of end stage renal disease, it is important for the radiologists to be familiar with the varying imaging appearances of CAKUT on US, CT and MRI, thereby helping in prompt diagnosis and optimal management.
文摘Tumoral calcinosis(TC) has long been a controversial clinico-pathological entity. Its pathogenesis and genetic background have been gradually unravelled since its first description in 1943. According to the presence or absence of an underlying calcifying disease process, TC has been divided into primary and secondary varieties. Two subtypes of the primary variety exist; a hyperphosphatemic type with familial basis represented by mutations in Gal NAc transferase 3 gene(GALNT3), KLOTHO or Fibroblast growth factor 23(FGF23) genes, and a normo-phosphatemic type with growing evidence of underlying familial base represented by mutation in SAMD9 gene. The secondary variety is mainly associated with chronic renal failure and the resulting secondary or tertiary hyperparathyroidism. Diagnosis of TC relies on typical radiographic features(on plain radiographs and computed tomography) and the biochemical profile. Magnetic resonance imaging can be done in difficult cases, and scintigraphy reflects the disease activity. Treatment is mainly surgical for the primary variety; however, a stage-oriented conservative approach using phosphate binders, phosphate restricted dietsand acetazolamide should be considered before the surgical approach is pursued due to the high rate of recurrences and complications after surgical intervention. Medical treatment is the mainstay for treatment of the secondary variety, with failure warranting subtotal or total parathyroidectomy. Surgical intervention in these patients should be kept as a last resort.
