Porous and functionally graded materials have seen extensive applications in modern biomedical devices—allowing for improved site-specific performance;their appreciable mechanical,corrosive,and biocompatible properti...Porous and functionally graded materials have seen extensive applications in modern biomedical devices—allowing for improved site-specific performance;their appreciable mechanical,corrosive,and biocompatible properties are highly sought after for lightweight and high-strength load-bearing orthopedic and dental implants.Examples of such porous materials are metals,ceramics,and polymers.Although,easy to manufacture and lightweight,porous polymers do not inherently exhibit the required mechanical strength for hard tissue repair or replacement.Alternatively,porous ceramics are brittle and do not possess the required fatigue resistance.On the other hand,porous biocompatible metals have shown tailorable strength,fatigue resistance,and toughness.Thereby,a significant interest in investigating the manufacturing challenges of porous metals has taken place in recent years.Past research has shown that once the advantages of porous metallic structures in the orthopedic implant industry have been realized,their biological and biomechanical compatibility—with the host bone—has been followed up with extensive methodical research.Various manufacturing methods for porous or functionally graded metals are discussed and compared in this review,specifically,how the manufacturing process influences microstructure,graded composition,porosity,biocompatibility,and mechanical properties.Most of the studies discussed in this review are related to porous structures for bone implant applications;however,the understanding of these investigations may also be extended to other devices beyond the biomedical field.展开更多
Corrosion behavior of 2024 Al-Cu-Mg alloy of different tempers was assessed by potentiodynamic polarization studies in 3.5% NaCl solution, 3.5% NaCI＋I.0% H2O2 solution and 3.5% NaCl solution at pH 12. Polarization cu...Corrosion behavior of 2024 Al-Cu-Mg alloy of different tempers was assessed by potentiodynamic polarization studies in 3.5% NaCl solution, 3.5% NaCI＋I.0% H2O2 solution and 3.5% NaCl solution at pH 12. Polarization curves showed shifting of corrosion potential （φPcor） towards more negative potential with increasing ageing time and shifting of φcorr in the positive direction with the addition of H2O2 in NaCl solution. Polarization curves in 3.5% NaCl solution at pH 12 exhibited distinct passivity phenomenon. Optical micrographs of the corroded surfaces showed general corrosion, extensive pitting and intergranular corrosion as well. Cyclic potentiodynamic polarization curves exhibited wide hysteresis loop and the mode of corrosion attack confirmed that the alloy states are susceptible to pit growth damage. Attempts were made to explain the observed corrosion behavior of the alloy of various tempers in different electrolytes with the help of microstructural features.展开更多
Power systems are moving toward a low-carbon or carbon-neutral future where high penetration of renewables is expected.With conventional fossil-fueled synchronous generators in the transmission network being replaced ...Power systems are moving toward a low-carbon or carbon-neutral future where high penetration of renewables is expected.With conventional fossil-fueled synchronous generators in the transmission network being replaced by renewable energy generation which is highly distributed across the entire grid,new challenges are emerging to the control and stability of large-scale power systems.New analysis and control methods are needed for power systems to cope with the ongoing transformation.In the CSEE JPES forum,six leading experts were invited to deliver keynote speeches,and the participating researchers and professionals had extensive exchanges and discussions on the control and stability of power systems.Specifically,potential changes and challenges of power systems with high penetration of renewable energy generation were introduced and explained,and advanced control methods were proposed and analyzed for the transient stability enhancement of power grids.展开更多
Approximately 170 million people worldwide are chronically infected with hepatitis C virus(HCV).Chronic HCV infection is the leading cause for the development of liver fibrosis,cirrhosis,hepatocellular carcinoma(HCC)a...Approximately 170 million people worldwide are chronically infected with hepatitis C virus(HCV).Chronic HCV infection is the leading cause for the development of liver fibrosis,cirrhosis,hepatocellular carcinoma(HCC)and is the primary cause for liver transplantation in the western world.Insulin resistance is one of the pathological features in patients with HCV infection and often leads to development of typeⅡdiabetes.Insulin resistance plays an important role in the development of various complications associated with HCV infection.Recent evidence indicates that HCV associated insulin resistance may result in hepatic fibrosis,steatosis,HCC and resistance to anti-viral treatment.Thus,HCV associated insulin resistance is a therapeutic target at any stage of HCV infection.HCV modulates normal cellular gene expression and interferes with the insulin signaling pathway.Various mechanisms have been proposed in regard to HCV mediated insulin resistance,involving up regulation of inflammatory cytokines,like tumor necrosis factor-α,phosphorylation of insulin-receptor substrate-1,Akt,up-regulation of gluconeogenic genes like glucose 6 phosphatase,phosphoenolpyruvate carboxykinase 2,and accumulation of lipid droplets.In this review,we summarize the available information on how HCV infection interferes with insulin signaling pathways resulting in insulin resistance.展开更多
Bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the m...Bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum(Ta)–Copper(Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological,mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta(10Ta) and 3 wt.% Cu(3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e.78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse infammatory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.展开更多
The recent development of cloud computing offers various services on demand for organization and individual users,such as storage,shared computing space,networking,etc.Although Cloud Computing provides various advanta...The recent development of cloud computing offers various services on demand for organization and individual users,such as storage,shared computing space,networking,etc.Although Cloud Computing provides various advantages for users,it remains vulnerable to many types of attacks that attract cyber criminals.Distributed Denial of Service(DDoS)is the most common type of attack on cloud computing.Consequently,Cloud computing professionals and security experts have focused on the growth of preventive processes towards DDoS attacks.Since DDoS attacks have become increasingly widespread,it becomes difficult for some DDoS attack methods based on individual network flow features to distinguish various types of DDoS attacks.Further,the monitoring pattern of traffic changes and accurate detection of DDoS attacks are most important and urgent.In this research work,DDoS attack detection methods based on deep belief network feature extraction and Hybrid Long Short-Term Memory(LSTM)model have been proposed with NSL-KDD dataset.In Hybrid LSTM method,the Particle Swarm Optimization(PSO)technique,which is combined to optimize the weights of the LSTM neural network,reduces the prediction error.This deep belief network method is used to extract the features of IP packets,and it identifies DDoS attacks based on PSO-LSTM model.Moreover,it accurately predicts normal network traffic and detects anomalies resulting from DDoS attacks.The proposed PSO-LSTM architecture outperforms the classification techniques including standard Support Vector Machine(SVM)and LSTM in terms of attack detection performance along with the results of the measurement of accuracy,recall,f-measure,precision.展开更多
Additive manufacturing provides achievability for the fabrication of bimetallic and multi-material structures;however,the material compatibility and bondability directly affect the parts’formability and final quality...Additive manufacturing provides achievability for the fabrication of bimetallic and multi-material structures;however,the material compatibility and bondability directly affect the parts’formability and final quality.It is essential to understand the underlying printability of different material combinations based on an adapted process.Here,the printability disparities of two common and attractive material combinations(nickel-and iron-based alloys)are evaluated at the macro and micro levels via laser directed energy deposition(DED).The deposition processes were captured using in situ high-speed imaging,and the dissimilarities in melt pool features and track morphology were quantitatively investigated within specific process windows.Moreover,the microstructure diversity of the tracks and blocks processed with varied material pairs was comparatively elaborated and,complemented with the informative multi-physics modeling,the presented non-uniformity in mechanical properties(microhardness)among the heterogeneous material pairs was rationalized.The differences in melt flow induced by the unlike thermophysical properties of the material pairs and the resulting element intermixing and localized re-alloying during solidification dominate the presented dissimilarity in printability among the material combinations.This work provides an in-depth understanding of the phenomenological differences in the deposition of dissimilar materials and aims to guide more reliable DED forming of bimetallic parts.展开更多
Objective:To explore correlation of neutrophil-to-lymphocyte ratio(NLR)to severity of coronary artery disease(CAD)and in-hospital clinical outcomes in patients with acute coronary syndrome(ACS).Methods:In this prospec...Objective:To explore correlation of neutrophil-to-lymphocyte ratio(NLR)to severity of coronary artery disease(CAD)and in-hospital clinical outcomes in patients with acute coronary syndrome(ACS).Methods:In this prospective and observational study,we recruited 500 patients with ACS.For all the eligible patients,demographic details were collected,and laboratory parameters were evaluated.The CAD severity was evaluated in terms of the number of involved vessels.The NLR was calculated based on neutrophils and lymphocytes and the correlation of various risk factors and severity and outcome of CAD was performed.Results:77.2%of Patients was male,and 52%of the patients aged between 55-70 years.Based on the type of ACS,396 out of 500 patients had ST-elevation myocardial infarction.An ascending trend in the white blood cell levels and NLR value was noted as the severity of the ACS increased and the highest white blood cell levels and NLR was noted among classⅣpatients.The mean NLR value among the non-survivors were higher compared to the survivors(9.52±5.72 vs.4.76±2.36;P<0.01).Receiver operating curve showed that the cut-off NLR value was 5.76 with a sensitivity of 75.0%and a specificity of 77.3%.Conclusions:The NLR can be used as an independent prognostic marker in ACS.An elevated NLR value serves as a reliable predictor for short-term complications,notably in-hospital mortality.展开更多
Interest in metal nanoparticles as nanoscale drug-carrying vehicles has been increasing.In such an aspect,lanthanide metal nanoparticles are particularly intriguing.Herein,we report praseodymium nanoparticles as a nov...Interest in metal nanoparticles as nanoscale drug-carrying vehicles has been increasing.In such an aspect,lanthanide metal nanoparticles are particularly intriguing.Herein,we report praseodymium nanoparticles as a novel anticancer therapeutic transporting agent.The material was made as a composite with the supramolecular host polymer,poly-β-cyclodextrin.The praseodymium nanorods were characterized using standard analytical techniques,including X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and thermogravimetric analysis(TGA).In addition,they were imaged using transmission electron microscopy.The nanostructures are a long rod-shaped material with 2.0±0.1μm in length and 230±10 nm in width.The material shows a saturation magnetization value above 30 emu/g with a coercivity value of 130 Oe.The nanocarrier is freighted with the drug 5-fluorouracil,and the encapsulation efficiency is 76.09%.The drug release is continuous from the nanocarrier(polymer-containing praseodymium nanoparticles)and proceeds for above 250 h.The in vitro cytotoxicities of the blank nanocarrier and the 5-fluorouracil-loaded one are deduced by testing them on MCF-7 and Vero(non-cancerous)cell lines.The cytotoxicity on the cancerous cell lines is observed,whereas the non-cancerous cells are unaffected.The IC_(50)values on the cell lines are reported.展开更多
The ex-situ incorporation of the secondary SiC reinforcement,along with the in-situ incorporation of the tertiary and quaternary Mg_(3)N_(2) and Si_(3)N_(4) phases,in the primary matrix of Mg_(2)Si is employed in orde...The ex-situ incorporation of the secondary SiC reinforcement,along with the in-situ incorporation of the tertiary and quaternary Mg_(3)N_(2) and Si_(3)N_(4) phases,in the primary matrix of Mg_(2)Si is employed in order to provide ultimate wear resistance based on the laser-irradiation-induced inclusion of N_(2) gas during laser powder bed fusion.This is substantialized based on both the thermal diffusion-and chemical reactionbased metallurgy of the Mg_(2)Si–SiC/nitride hybrid composite.This study also proposes a functional platform for systematically modulating a functionally graded structure and modeling build-direction-dependent architectonics during additive manufacturing.This strategy enables the development of a compositional gradient from the center to the edge of each melt pool of the Mg_(2)Si–SiC/nitride hybrid composite.Consequently,the coefficient of friction of the hybrid composite exhibits a 309.3%decrease to–1.67 compared to–0.54 for the conventional nonreinforced Mg_(2)Si structure,while the tensile strength exhibits a 171.3%increase to 831.5 MPa compared to 485.3 MPa for the conventional structure.This outstanding mechanical behavior is due to the(1)the complementary and synergistic reinforcement effects of the SiC and nitride compounds,each of which possesses an intrinsically high hardness,and(2)the strong adhesion of these compounds to the Mg_(2)Si matrix despite their small sizes and low concentrations.展开更多
Heterogeneous and monolithic integration of the versatile low-loss silicon nitride platform with low-temperature materials such as silicon electronics and photonics,III–V compound semiconductors,lithium niobate,organ...Heterogeneous and monolithic integration of the versatile low-loss silicon nitride platform with low-temperature materials such as silicon electronics and photonics,III–V compound semiconductors,lithium niobate,organics,and glasses has been inhibited by the need for high-temperature annealing as well as the need for different process flows for thin and thick waveguides.New techniques are needed to maintain the state-of-the-art losses,nonlinear properties,and CMOS-compatible processes while enabling this next generation of 3D silicon nitride integration.We report a significant advance in silicon nitride integrated photonics,demonstrating the lowest losses to date for an anneal-free process at a maximum temperature 250℃,with the same deuterated silane based fabrication flow,for nitride and oxide,for an order of magnitude range in nitride thickness without requiring stress mitigation or polishing.We report record low anneal-free losses for both nitride core and oxide cladding,enabling 1.77 dBm-1 loss and 14.9 million Q for 80 nm nitride core waveguides,more than half an order magnitude lower loss than previously reported sub 300℃ process.For 800 nm-thick nitride,we achieve as good as 8.66 dBm-1 loss and 4.03 million Q,the highest reported Q for a low temperature processed resonator with equivalent device area,with a median of loss and Q of 13.9 dBm-1 and 2.59 million each respectively.We demonstrate laser stabilization with over 4 orders of magnitude frequency noise reduction using a thin nitride reference cavity,and using a thick nitride micro-resonator we demonstrate OPO,over two octave supercontinuum generation,and four-wave mixing and parametric gain with the lowest reported optical parametric oscillation threshold per unit resonator length.These results represent a significant step towards a uniform ultra-low loss silicon nitride homogeneous and heterogeneous platform for both thin and thick waveguides capable of linear and nonlinear photonic circuits and integration with low-temperature materials and pro展开更多
Reactive sputtered boron-doped zinc oxide(BZO) film was deposited from argon,hydrogen and boron gas mixture.The reactive sputtering technique provides us the flexibility of changing the boron concentration in the prod...Reactive sputtered boron-doped zinc oxide(BZO) film was deposited from argon,hydrogen and boron gas mixture.The reactive sputtering technique provides us the flexibility of changing the boron concentration in the produced films by using the same intrinsic zinc oxide target.Textured surface was obtained in the as-deposited films.The surface morphology and the opto-electronic properties of the films can be controlled by simply varying the gas concentration ratio.By varying the gas concentration ratio,the best obtained resistivity ~6.51×10^-4Ω-cm,mobility ~19.05 cm^2 V^-1 s^-1 and sheet resistance ~7.23Ω/□ were obtained.At lower wavelength of light,the response of the deposited films improves with the increase of boron in the gas mixture and the overall transmission in the wavelength region 350-1100 nm of all the films are>85 %.We also fabricated amorphous silicon(a-Si) thin film solar cell on the best obtained BZO layers.The overall efficiency of the a-Si solar cell is 8.14 %,found on optimized BZO layer.展开更多
This paper reviews gravitational wave sources and their detection. One of the most exciting potential sources of gravitational waves are coalescing binary black hole systems. They can occur on all mass scales and be f...This paper reviews gravitational wave sources and their detection. One of the most exciting potential sources of gravitational waves are coalescing binary black hole systems. They can occur on all mass scales and be formed in numerous ways, many of which are not understood. They are generally invisible in electromagnetic waves, and they provide opportunities for deep investigation of Einstein's general theory of relativity. Sect. 1 of this paper considers ways that binary black holes can be created in the universe, and includes the prediction that binary black hole coalescence events are likely to be the first gravitational wave sources to be detected. The next parts of this paper address the detection of chirp waveforms from coalescence events in noisy data.Such analysis is computationally intensive. Sect. 2 reviews a new and powerful method of signal detection based on the GPUimplemented summed parallel infinite impulse response filters. Such filters are intrinsically real time alorithms, that can be used to rapidly detect and localise signals. Sect. 3 of the paper reviews the use of GPU processors for rapid searching for gravitational wave bursts that can arise from black hole births and coalescences. In sect. 4 the use of GPU processors to enable fast efficient statistical significance testing of gravitational wave event candidates is reviewed. Sect. 5 of this paper addresses the method of multimessenger astronomy where the discovery of electromagnetic counterparts of gravitational wave events can be used to identify sources, understand their nature and obtain much greater science outcomes from each identified event.展开更多
As a hazard, flood is an extremely important indicator of how a city is resilient to waterborne diseases and epidemics. Over many decades, flood as a hazard has been a major factor in inducing displacement of marginal...As a hazard, flood is an extremely important indicator of how a city is resilient to waterborne diseases and epidemics. Over many decades, flood as a hazard has been a major factor in inducing displacement of marginalized section of the people. Austin city within Central Texas has been identified as one of the major hotspots for flooding in recent decades. Thus, the objectives of the paper are two folded: 1) Empirically, we analyzed and mapped out the susceptibility levels from the factors of physical environments to assess the risk of urban flooding (rainfall data, surface water bodies and topography);in Austin, Texas and 2) Methodologically, we created a re-useable ArcGIS scripting tool that can be used by researchers to automate the process of flood risk modelling with certain criteria. The paper showcases a novel time sensitive building of a tool which will enable better visibility of flood within the city of Austin.展开更多
BACKGROUND Cryoballoon ablation(CBA)is recommended for patients with paroxysmal atrial fibrillation(AF)refractory to antiarrhythmic drugs.However,only 80%of patients benefit from initial CBA.There is growing evidence ...BACKGROUND Cryoballoon ablation(CBA)is recommended for patients with paroxysmal atrial fibrillation(AF)refractory to antiarrhythmic drugs.However,only 80%of patients benefit from initial CBA.There is growing evidence that pretreatment with angiotensin-converting enzyme inhibitors(ACEIs)and angiotensin receptor blockers(ARBs)decreases the recurrence of AF postablation,particularly in nonparoxysmal AF undergoing radiofrequency ablation.The role of ACEIs and ARBs in patients with paroxysmal AF in CBA remains unknown.We decided to investigate the role of ACEIs and ARBs in preventing the recurrence of atrial arrhythmia(AA)following CBA for paroxysmal AF.AIM To investigate the role of ACEIs and ARBs in preventing recurrence of AA following CBA for paroxysmal AF.METHODS We followed 103 patients(age 60.6±9.1 years,29%women)with paroxysmal AF undergoing CBA 1-year post procedure.Recurrence was assessed by documented AA on electrocardiogram or any form of long-term cardiac rhythm monitoring.A multivariable Cox proportional hazard model was used to assess if ACEI or ARB treatment predicted the risk of AA recurrence.RESULTS After a 1-year follow-up,19(18.4%)participants developed recurrence of AA.Use of ACEI or ARB therapy was noted in the study population.Patients on ACEI/ARB had a greater prevalence of hypertension and coronary artery disease.On a multivariate model adjusted for baseline demographics and risk factors for AF,ACEI or ARB therapy did not prevent recurrence of AA following CBA(P=0.72).Similarly,on Kaplan–Meier analysis pretreatment with ACEI/ARB did not predict the time to first recurrence of AA(P=0.2173).CONCLUSION In our study population,preablation treatment with an ACEI or ARB had no influence on the recurrence of AA following CBA for paroxysmal AF.展开更多
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under Award Number R01 AR067306-01 and R01 AR078241(PI—Bandyopadhyay)。
文摘Porous and functionally graded materials have seen extensive applications in modern biomedical devices—allowing for improved site-specific performance;their appreciable mechanical,corrosive,and biocompatible properties are highly sought after for lightweight and high-strength load-bearing orthopedic and dental implants.Examples of such porous materials are metals,ceramics,and polymers.Although,easy to manufacture and lightweight,porous polymers do not inherently exhibit the required mechanical strength for hard tissue repair or replacement.Alternatively,porous ceramics are brittle and do not possess the required fatigue resistance.On the other hand,porous biocompatible metals have shown tailorable strength,fatigue resistance,and toughness.Thereby,a significant interest in investigating the manufacturing challenges of porous metals has taken place in recent years.Past research has shown that once the advantages of porous metallic structures in the orthopedic implant industry have been realized,their biological and biomechanical compatibility—with the host bone—has been followed up with extensive methodical research.Various manufacturing methods for porous or functionally graded metals are discussed and compared in this review,specifically,how the manufacturing process influences microstructure,graded composition,porosity,biocompatibility,and mechanical properties.Most of the studies discussed in this review are related to porous structures for bone implant applications;however,the understanding of these investigations may also be extended to other devices beyond the biomedical field.
文摘Corrosion behavior of 2024 Al-Cu-Mg alloy of different tempers was assessed by potentiodynamic polarization studies in 3.5% NaCl solution, 3.5% NaCI＋I.0% H2O2 solution and 3.5% NaCl solution at pH 12. Polarization curves showed shifting of corrosion potential （φPcor） towards more negative potential with increasing ageing time and shifting of φcorr in the positive direction with the addition of H2O2 in NaCl solution. Polarization curves in 3.5% NaCl solution at pH 12 exhibited distinct passivity phenomenon. Optical micrographs of the corroded surfaces showed general corrosion, extensive pitting and intergranular corrosion as well. Cyclic potentiodynamic polarization curves exhibited wide hysteresis loop and the mode of corrosion attack confirmed that the alloy states are susceptible to pit growth damage. Attempts were made to explain the observed corrosion behavior of the alloy of various tempers in different electrolytes with the help of microstructural features.
文摘Power systems are moving toward a low-carbon or carbon-neutral future where high penetration of renewables is expected.With conventional fossil-fueled synchronous generators in the transmission network being replaced by renewable energy generation which is highly distributed across the entire grid,new challenges are emerging to the control and stability of large-scale power systems.New analysis and control methods are needed for power systems to cope with the ongoing transformation.In the CSEE JPES forum,six leading experts were invited to deliver keynote speeches,and the participating researchers and professionals had extensive exchanges and discussions on the control and stability of power systems.Specifically,potential changes and challenges of power systems with high penetration of renewable energy generation were introduced and explained,and advanced control methods were proposed and analyzed for the transient stability enhancement of power grids.
基金Supported by The National Institutes of Health,NO.DK080812
文摘Approximately 170 million people worldwide are chronically infected with hepatitis C virus(HCV).Chronic HCV infection is the leading cause for the development of liver fibrosis,cirrhosis,hepatocellular carcinoma(HCC)and is the primary cause for liver transplantation in the western world.Insulin resistance is one of the pathological features in patients with HCV infection and often leads to development of typeⅡdiabetes.Insulin resistance plays an important role in the development of various complications associated with HCV infection.Recent evidence indicates that HCV associated insulin resistance may result in hepatic fibrosis,steatosis,HCC and resistance to anti-viral treatment.Thus,HCV associated insulin resistance is a therapeutic target at any stage of HCV infection.HCV modulates normal cellular gene expression and interferes with the insulin signaling pathway.Various mechanisms have been proposed in regard to HCV mediated insulin resistance,involving up regulation of inflammatory cytokines,like tumor necrosis factor-α,phosphorylation of insulin-receptor substrate-1,Akt,up-regulation of gluconeogenic genes like glucose 6 phosphatase,phosphoenolpyruvate carboxykinase 2,and accumulation of lipid droplets.In this review,we summarize the available information on how HCV infection interferes with insulin signaling pathways resulting in insulin resistance.
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under Award Numbers R01 AR067306 and R01 AR078241。
文摘Bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum(Ta)–Copper(Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological,mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta(10Ta) and 3 wt.% Cu(3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e.78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse infammatory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.
文摘The recent development of cloud computing offers various services on demand for organization and individual users,such as storage,shared computing space,networking,etc.Although Cloud Computing provides various advantages for users,it remains vulnerable to many types of attacks that attract cyber criminals.Distributed Denial of Service(DDoS)is the most common type of attack on cloud computing.Consequently,Cloud computing professionals and security experts have focused on the growth of preventive processes towards DDoS attacks.Since DDoS attacks have become increasingly widespread,it becomes difficult for some DDoS attack methods based on individual network flow features to distinguish various types of DDoS attacks.Further,the monitoring pattern of traffic changes and accurate detection of DDoS attacks are most important and urgent.In this research work,DDoS attack detection methods based on deep belief network feature extraction and Hybrid Long Short-Term Memory(LSTM)model have been proposed with NSL-KDD dataset.In Hybrid LSTM method,the Particle Swarm Optimization(PSO)technique,which is combined to optimize the weights of the LSTM neural network,reduces the prediction error.This deep belief network method is used to extract the features of IP packets,and it identifies DDoS attacks based on PSO-LSTM model.Moreover,it accurately predicts normal network traffic and detects anomalies resulting from DDoS attacks.The proposed PSO-LSTM architecture outperforms the classification techniques including standard Support Vector Machine(SVM)and LSTM in terms of attack detection performance along with the results of the measurement of accuracy,recall,f-measure,precision.
基金supported by the National Natural Science Foundation of China(51975112,52375412)Fundamental Research Funds for Central Universities(N2203011)。
文摘Additive manufacturing provides achievability for the fabrication of bimetallic and multi-material structures;however,the material compatibility and bondability directly affect the parts’formability and final quality.It is essential to understand the underlying printability of different material combinations based on an adapted process.Here,the printability disparities of two common and attractive material combinations(nickel-and iron-based alloys)are evaluated at the macro and micro levels via laser directed energy deposition(DED).The deposition processes were captured using in situ high-speed imaging,and the dissimilarities in melt pool features and track morphology were quantitatively investigated within specific process windows.Moreover,the microstructure diversity of the tracks and blocks processed with varied material pairs was comparatively elaborated and,complemented with the informative multi-physics modeling,the presented non-uniformity in mechanical properties(microhardness)among the heterogeneous material pairs was rationalized.The differences in melt flow induced by the unlike thermophysical properties of the material pairs and the resulting element intermixing and localized re-alloying during solidification dominate the presented dissimilarity in printability among the material combinations.This work provides an in-depth understanding of the phenomenological differences in the deposition of dissimilar materials and aims to guide more reliable DED forming of bimetallic parts.
文摘Objective:To explore correlation of neutrophil-to-lymphocyte ratio(NLR)to severity of coronary artery disease(CAD)and in-hospital clinical outcomes in patients with acute coronary syndrome(ACS).Methods:In this prospective and observational study,we recruited 500 patients with ACS.For all the eligible patients,demographic details were collected,and laboratory parameters were evaluated.The CAD severity was evaluated in terms of the number of involved vessels.The NLR was calculated based on neutrophils and lymphocytes and the correlation of various risk factors and severity and outcome of CAD was performed.Results:77.2%of Patients was male,and 52%of the patients aged between 55-70 years.Based on the type of ACS,396 out of 500 patients had ST-elevation myocardial infarction.An ascending trend in the white blood cell levels and NLR value was noted as the severity of the ACS increased and the highest white blood cell levels and NLR was noted among classⅣpatients.The mean NLR value among the non-survivors were higher compared to the survivors(9.52±5.72 vs.4.76±2.36;P<0.01).Receiver operating curve showed that the cut-off NLR value was 5.76 with a sensitivity of 75.0%and a specificity of 77.3%.Conclusions:The NLR can be used as an independent prognostic marker in ACS.An elevated NLR value serves as a reliable predictor for short-term complications,notably in-hospital mortality.
基金funding through the I-STEM program,organized by the Office of the Principal Scientific Adviser to the Government of India。
文摘Interest in metal nanoparticles as nanoscale drug-carrying vehicles has been increasing.In such an aspect,lanthanide metal nanoparticles are particularly intriguing.Herein,we report praseodymium nanoparticles as a novel anticancer therapeutic transporting agent.The material was made as a composite with the supramolecular host polymer,poly-β-cyclodextrin.The praseodymium nanorods were characterized using standard analytical techniques,including X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and thermogravimetric analysis(TGA).In addition,they were imaged using transmission electron microscopy.The nanostructures are a long rod-shaped material with 2.0±0.1μm in length and 230±10 nm in width.The material shows a saturation magnetization value above 30 emu/g with a coercivity value of 130 Oe.The nanocarrier is freighted with the drug 5-fluorouracil,and the encapsulation efficiency is 76.09%.The drug release is continuous from the nanocarrier(polymer-containing praseodymium nanoparticles)and proceeds for above 250 h.The in vitro cytotoxicities of the blank nanocarrier and the 5-fluorouracil-loaded one are deduced by testing them on MCF-7 and Vero(non-cancerous)cell lines.The cytotoxicity on the cancerous cell lines is observed,whereas the non-cancerous cells are unaffected.The IC_(50)values on the cell lines are reported.
基金supported by the Learning & Academic Research Institution for Master’s and Ph.D. Students and Postdocs (LAMP) Program of the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education (No. RS-2023-00285353)supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (NRF-2021R1A2C3006662, NRF-2022R1A5A1030054, and 2021R1A2C1091301)+3 种基金the support from Natural Sciences and Engineering Research Council of Canada (NSERC)Canada Foundation for Innovation (CFI)Atlantic Canada Opportunities Agency (ACOA)the New Brunswick Innovation Foundation (NBIF)
文摘The ex-situ incorporation of the secondary SiC reinforcement,along with the in-situ incorporation of the tertiary and quaternary Mg_(3)N_(2) and Si_(3)N_(4) phases,in the primary matrix of Mg_(2)Si is employed in order to provide ultimate wear resistance based on the laser-irradiation-induced inclusion of N_(2) gas during laser powder bed fusion.This is substantialized based on both the thermal diffusion-and chemical reactionbased metallurgy of the Mg_(2)Si–SiC/nitride hybrid composite.This study also proposes a functional platform for systematically modulating a functionally graded structure and modeling build-direction-dependent architectonics during additive manufacturing.This strategy enables the development of a compositional gradient from the center to the edge of each melt pool of the Mg_(2)Si–SiC/nitride hybrid composite.Consequently,the coefficient of friction of the hybrid composite exhibits a 309.3%decrease to–1.67 compared to–0.54 for the conventional nonreinforced Mg_(2)Si structure,while the tensile strength exhibits a 171.3%increase to 831.5 MPa compared to 485.3 MPa for the conventional structure.This outstanding mechanical behavior is due to the(1)the complementary and synergistic reinforcement effects of the SiC and nitride compounds,each of which possesses an intrinsically high hardness,and(2)the strong adhesion of these compounds to the Mg_(2)Si matrix despite their small sizes and low concentrations.
基金supported by DARPA GRYPHON contract number HR0011-22-2-0008ARL Award W911NF-22-2-0056.
文摘Heterogeneous and monolithic integration of the versatile low-loss silicon nitride platform with low-temperature materials such as silicon electronics and photonics,III–V compound semiconductors,lithium niobate,organics,and glasses has been inhibited by the need for high-temperature annealing as well as the need for different process flows for thin and thick waveguides.New techniques are needed to maintain the state-of-the-art losses,nonlinear properties,and CMOS-compatible processes while enabling this next generation of 3D silicon nitride integration.We report a significant advance in silicon nitride integrated photonics,demonstrating the lowest losses to date for an anneal-free process at a maximum temperature 250℃,with the same deuterated silane based fabrication flow,for nitride and oxide,for an order of magnitude range in nitride thickness without requiring stress mitigation or polishing.We report record low anneal-free losses for both nitride core and oxide cladding,enabling 1.77 dBm-1 loss and 14.9 million Q for 80 nm nitride core waveguides,more than half an order magnitude lower loss than previously reported sub 300℃ process.For 800 nm-thick nitride,we achieve as good as 8.66 dBm-1 loss and 4.03 million Q,the highest reported Q for a low temperature processed resonator with equivalent device area,with a median of loss and Q of 13.9 dBm-1 and 2.59 million each respectively.We demonstrate laser stabilization with over 4 orders of magnitude frequency noise reduction using a thin nitride reference cavity,and using a thick nitride micro-resonator we demonstrate OPO,over two octave supercontinuum generation,and four-wave mixing and parametric gain with the lowest reported optical parametric oscillation threshold per unit resonator length.These results represent a significant step towards a uniform ultra-low loss silicon nitride homogeneous and heterogeneous platform for both thin and thick waveguides capable of linear and nonlinear photonic circuits and integration with low-temperature materials and pro
基金The work has been supported by the Science and Engineering Research Board(SERB),Department of Science and Technology(SR/FTP/PS-175/2012)。
文摘Reactive sputtered boron-doped zinc oxide(BZO) film was deposited from argon,hydrogen and boron gas mixture.The reactive sputtering technique provides us the flexibility of changing the boron concentration in the produced films by using the same intrinsic zinc oxide target.Textured surface was obtained in the as-deposited films.The surface morphology and the opto-electronic properties of the films can be controlled by simply varying the gas concentration ratio.By varying the gas concentration ratio,the best obtained resistivity ~6.51×10^-4Ω-cm,mobility ~19.05 cm^2 V^-1 s^-1 and sheet resistance ~7.23Ω/□ were obtained.At lower wavelength of light,the response of the deposited films improves with the increase of boron in the gas mixture and the overall transmission in the wavelength region 350-1100 nm of all the films are>85 %.We also fabricated amorphous silicon(a-Si) thin film solar cell on the best obtained BZO layers.The overall efficiency of the a-Si solar cell is 8.14 %,found on optimized BZO layer.
基金supported by the NRF from the Korean government(Grant No.2006-00093852)the National Natural Science Foundation of China(Grant Nos.61440057,61272087,61363019,61073008 and 11303009)+4 种基金Beijing Natural Science Foundation(Grant Nos.4082016 and 4122039)the Sci-Tech Interdisciplinary Innovation and Cooperation Team Program of the Chinese Academy of Sciencesthe Specialized Research Fund for State Key Laboratories,National Science Foundation(Grant Nos.PHY-1206108 and PHY-1506497)the Perseus Computing Cluster at the Inter University Centre for Astronomy and Astrophysics(IUCAA),Pune,Indiathe hospitality and financial support provided by the Kavli Institute for Theoretical Physics in Beijing
文摘This paper reviews gravitational wave sources and their detection. One of the most exciting potential sources of gravitational waves are coalescing binary black hole systems. They can occur on all mass scales and be formed in numerous ways, many of which are not understood. They are generally invisible in electromagnetic waves, and they provide opportunities for deep investigation of Einstein's general theory of relativity. Sect. 1 of this paper considers ways that binary black holes can be created in the universe, and includes the prediction that binary black hole coalescence events are likely to be the first gravitational wave sources to be detected. The next parts of this paper address the detection of chirp waveforms from coalescence events in noisy data.Such analysis is computationally intensive. Sect. 2 reviews a new and powerful method of signal detection based on the GPUimplemented summed parallel infinite impulse response filters. Such filters are intrinsically real time alorithms, that can be used to rapidly detect and localise signals. Sect. 3 of the paper reviews the use of GPU processors for rapid searching for gravitational wave bursts that can arise from black hole births and coalescences. In sect. 4 the use of GPU processors to enable fast efficient statistical significance testing of gravitational wave event candidates is reviewed. Sect. 5 of this paper addresses the method of multimessenger astronomy where the discovery of electromagnetic counterparts of gravitational wave events can be used to identify sources, understand their nature and obtain much greater science outcomes from each identified event.
文摘As a hazard, flood is an extremely important indicator of how a city is resilient to waterborne diseases and epidemics. Over many decades, flood as a hazard has been a major factor in inducing displacement of marginalized section of the people. Austin city within Central Texas has been identified as one of the major hotspots for flooding in recent decades. Thus, the objectives of the paper are two folded: 1) Empirically, we analyzed and mapped out the susceptibility levels from the factors of physical environments to assess the risk of urban flooding (rainfall data, surface water bodies and topography);in Austin, Texas and 2) Methodologically, we created a re-useable ArcGIS scripting tool that can be used by researchers to automate the process of flood risk modelling with certain criteria. The paper showcases a novel time sensitive building of a tool which will enable better visibility of flood within the city of Austin.
文摘BACKGROUND Cryoballoon ablation(CBA)is recommended for patients with paroxysmal atrial fibrillation(AF)refractory to antiarrhythmic drugs.However,only 80%of patients benefit from initial CBA.There is growing evidence that pretreatment with angiotensin-converting enzyme inhibitors(ACEIs)and angiotensin receptor blockers(ARBs)decreases the recurrence of AF postablation,particularly in nonparoxysmal AF undergoing radiofrequency ablation.The role of ACEIs and ARBs in patients with paroxysmal AF in CBA remains unknown.We decided to investigate the role of ACEIs and ARBs in preventing the recurrence of atrial arrhythmia(AA)following CBA for paroxysmal AF.AIM To investigate the role of ACEIs and ARBs in preventing recurrence of AA following CBA for paroxysmal AF.METHODS We followed 103 patients(age 60.6±9.1 years,29%women)with paroxysmal AF undergoing CBA 1-year post procedure.Recurrence was assessed by documented AA on electrocardiogram or any form of long-term cardiac rhythm monitoring.A multivariable Cox proportional hazard model was used to assess if ACEI or ARB treatment predicted the risk of AA recurrence.RESULTS After a 1-year follow-up,19(18.4%)participants developed recurrence of AA.Use of ACEI or ARB therapy was noted in the study population.Patients on ACEI/ARB had a greater prevalence of hypertension and coronary artery disease.On a multivariate model adjusted for baseline demographics and risk factors for AF,ACEI or ARB therapy did not prevent recurrence of AA following CBA(P=0.72).Similarly,on Kaplan–Meier analysis pretreatment with ACEI/ARB did not predict the time to first recurrence of AA(P=0.2173).CONCLUSION In our study population,preablation treatment with an ACEI or ARB had no influence on the recurrence of AA following CBA for paroxysmal AF.
