BACKGROUND The treatment of acute respiratory distress syndrome(ARDS)complicated by sepsis syndrome(SS)remains challenging.AIM To investigate whether combined adipose-derived mesenchymal-stem-cells(ADMSCs)-derived exo...BACKGROUND The treatment of acute respiratory distress syndrome(ARDS)complicated by sepsis syndrome(SS)remains challenging.AIM To investigate whether combined adipose-derived mesenchymal-stem-cells(ADMSCs)-derived exosome(EXAD)and exogenous mitochondria(mitoEx)protect the lung from ARDS complicated by SS.METHODS In vitro study,including L2 cells treated with lipopolysaccharide(LPS)and in vivo study including male-adult-SD rats categorized into groups 1(sham-operated-control),2(ARDS-SS),3(ARDS-SS+EXAD),4(ARDS-SS+mitoEx),and 5(ARDS-SS+EXAD+mitoEx),were included in the present study.RESULTS In vitro study showed an abundance of mitoEx found in recipient-L2 cells,resulting in significantly higher mitochondrial-cytochrome-C,adenosine triphosphate and relative mitochondrial DNA levels(P<0.001).The protein levels of inflammation[interleukin(IL)-1β/tumor necrosis factor(TNF)-α/nuclear factor-κB/toll-like receptor(TLR)-4/matrix-metalloproteinase(MMP)-9/oxidative-stress(NOX-1/NOX-2)/apoptosis(cleaved-caspase3/cleaved-poly(ADP-ribose)polymerase)]were significantly attenuated in lipopolysaccharide(LPS)-treated L2 cells with EXAD treatment than without EXAD treatment,whereas the protein expressions of cellular junctions[occluding/β-catenin/zonula occludens(ZO)-1/E-cadherin]exhibited an opposite pattern of inflam-mation(all P<0.001).Animals were euthanized by 72 h post-48 h-ARDS induction,and lung tissues were harvested.By 72 h,flow cytometric analysis of bronchoalveolar lavage fluid demonstrated that the levels of inflam-matory cells(Ly6G+/CD14+/CD68+/CD11b/c+/myeloperoxidase+)and albumin were lowest in group 1,highest in group 2,and significantly higher in groups 3 and 4 than in group 5(all P<0.0001),whereas arterial oxygen-saturation(SaO2%)displayed an opposite pattern of albumin among the groups.Histopathological findings of lung injury/fibrosis area and inflammatory/DNA-damaged markers(CD68+/γ-H2AX)displayed an identical pattern of SaO2%among the groups(all P<0.0001).The protein expressions of inflammatory(TLR-4/MMP-9/IL-1β/TNF-α)/oxidative stress(NOX-1/NOX-2/p22phox/oxidized protein)/mitochondrial-damaged(cytosolic-cytochrome-C/dynamin-related protein 1)/autophagic(beclin-1/Atg-5/ratio of LC3B-II/LC3B-I)biomarkers exhibited a similar manner,whereas antioxidants[nuclear respiratory factor(Nrf)-1/Nrf-2]/cellular junctions(ZO-1/E-cadherin)/mitochondrial electron transport chain(complex I-V)exhibited an opposite manner of albumin among the groups(all P<0.0001).CONCLUSION Combined EXAD-mitoEx therapy was better than merely one for protecting the lung against ARDS-SS induced injury.展开更多
AIM To examine the accuracy of machine learning to relate particulate matter(PM) 2.5 and PM10 concentrations to upper respiratory tract infections(URIs).METHODS Daily nationwide and regional outdoor PM2.5 and PM10 con...AIM To examine the accuracy of machine learning to relate particulate matter(PM) 2.5 and PM10 concentrations to upper respiratory tract infections(URIs).METHODS Daily nationwide and regional outdoor PM2.5 and PM10 concentrations collected over 30 consecutive days obtained from the Taiwan Environment Protection Administration were the inputs for machine learning, using multilayer perceptron(MLP), to relate to the subsequent one-week outpatient visits for URIs. TheURI data were obtained from the Centers for Disease Control datasets in Taiwan between 2009 and 2016. The testing used the middle month dataset of each season(January, April, July and October), and the training used the other months' datasets. The weekly URI cases were classified by tertile as high, moderate, and low volumes.RESULTS Both PM concentrations and URI cases peak in winter and spring. In the nationwide data analysis, MLP machine learning can accurately relate the URI volumes of the elderly(89.05% and 88.32%, respectively) and the overall population(81.75% and 83.21%, respectively) with the PM2.5 and PM10 concentrations. In the regional data analyses, greater accuracy is found for PM2.5 than for PM10 for the elderly, particularly in the Central region(78.10% and 74.45%, respectively), whereas greater accuracy is found for PM10 than for PM2.5 for the overall population, particularly in the Northern region(73.19% and 63.04%, respectively).CONCLUSION Short-term PM2.5 and PM10 concentrations were accurately related to the subsequent occurrence of URIs by using machine learning. Our findings suggested that the effects of PM2.5 and PM10 on URI may differ by age, and the mechanism needs further evaluation.展开更多
Background and Aims:As practice patterns and hepatitis C virus(HCV)genotypes(GT)vary geographically,a global real-world study from both East and West covering all GTs can help inform practice policy toward the 2030 HC...Background and Aims:As practice patterns and hepatitis C virus(HCV)genotypes(GT)vary geographically,a global real-world study from both East and West covering all GTs can help inform practice policy toward the 2030 HCV elimination goal.This study aimed to assess the effectiveness and tolerability of DAA treatment in routine clinical practice in a multinational cohort for patients infected with all HCV GTs,focusing on GT3 and GT6.Methods:We analyzed the sustained virological response(SVR12)of 15,849 chronic hepatitis C patients from 39 Real-World Evidence from the Asia Liver Consortium for HCV clinical sites in Asia Pacific,North America,and Europe between 07/01/2014–07/01/2021.Results:The mean age was 62±13 years,with 49.6%male.The demographic breakdown was 91.1%Asian(52.9%Japanese,25.7%Chinese/Taiwan residents,5.4%Korean,3.3%Malaysian,and 2.9%Vietnamese),6.4%White,1.3%Hispanic/Latino,and 1%Black/African-American.Additionally,34.8%had cirrhosis,8.6%had hepatocellular carcinoma(HCC),and 24.9%were treatment-experienced(20.7%with interferon,4.3%with direct-acting antivirals).The largest group was GT1(10,246[64.6%]),followed by GT2(3,686[23.2%]),GT3(1,151[7.2%]),GT6(457[2.8%]),GT4(47[0.3%]),GT5(1[0.006%]),and untyped GTs(261[1.6%]).The overall SVR12 was 96.9%,with rates over 95%for GT1/2/3/6 but 91.5%for GT4.SVR12 for GT3 was 95.1%overall,98.2%for GT3a,and 94.0%for GT3b.SVR12 was 98.3%overall for GT6,lower for patients with cirrhosis and treatment-experienced(TE)(93.8%)but≥97.5%for tretment-naive patients regardless of cirrhosis status.On multivariable analysis,advanced age,prior treatment failure,cirrhosis,active HCC,and GT3/4 were independent predictors of lower SVR12,while being Asian was a significant predictor of achieving SVR12.Conclusions:In this diverse multinational realworld cohort of patients with various GTs,the overall cure rate was 96.9%,despite large numbers of patients with cirrhosis,HCC,TE,and GT3/6.SVR12 for GT3/6 with cirrhosis and TE was lower but still excellent(>91%).展开更多
In this paper,a decision-making problem with a q-rung orthopair fuzzy hypersoft environment is developed,and two operators of ordered weighted average and induced ordered weighted average are developed.Several fundame...In this paper,a decision-making problem with a q-rung orthopair fuzzy hypersoft environment is developed,and two operators of ordered weighted average and induced ordered weighted average are developed.Several fundamental features are also derived.The induced ordered weighted average operator is essential in a q-ROFH environment as the induced ordered aggregation operators are special cases of the existing aggregation operators that already exist in q-ROFH environments.The main function of these operators is to help decision-makers gain a complete understanding of uncertain facts.The proposed aggregation operator is applied to a decision-making problem,with the aim of selecting the most promising real estate project for investment.展开更多
Salt marshes are important carbon and nutrient sinks that are threatened by climate changes and human activities.In this study,the accumulation rates of sedimentary total organic carbon(TOC),total nitrogen(TN),and tot...Salt marshes are important carbon and nutrient sinks that are threatened by climate changes and human activities.In this study,the accumulation rates of sedimentary total organic carbon(TOC),total nitrogen(TN),and total phosphorus(TP)from two cores in the Andong salt marsh,Hangzhou Bay,were investigated to determine whether TOC,TN,and TP show increasing or decreasing trends toward the present.The TOC accumulation rates at the relatively lower marsh were lower during 1990-1996(1.63-2.37 g/(cm^(2)·a))than 1997-2014(1.15-4.30 g/(cm^(2)·a)).The TN accumulation rates increased from 1990(0.14 g/(cm^(2)·a))toward 2012(0.40 g/(cm^(2)·a)),then decreased toward 2014(0.16 g/(cm^(2)·a)).The TP accumulation rates were lower during 1990-1999(0.10-0.21 mg/(cm^(2)·a)),and decreased from 2000(0.32 mg/(cm^(2)·a))toward 2014(0.15 mg/(cm^(2)·a)).The TOC accumulation rates along the relatively upper marsh during 1982-1992(1.18-3.25 g/(cm^(2)·a))were lower than during 1998-2010(2.30-4.20 g/(cm^(2)·a)),and then decreased toward 2015(2.15 g/(cm^(2)·a)).TN increased from 1982(0.18 g/(cm^(2)·a))to 2005(0.41 g/(cm^(2)·a)),then decreased toward 2015(0.22 g/(cm^(2)·a)).TP accumulation rates fluctuated within a narrow range during 1982-1997(0.21-0.41 mg/(cm^(2)·a)),increased from 1998(0.50 mg/(cm^(2)·a))to 2004(0.87 mg/(cm^(2)·a)),then decreased to 2015(0.38 mg/(cm^(2)·a)).Thus,increases in accumulation rates of TOC,TN,and TP from the 1980s to 1990s indicates that the marsh likely served as carbon and nutrient sinks,then the rates decreased during 2000-2015 due probably to the reduced sediment inputs from rivers and intensified sea level rise.展开更多
BACKGROUND Previous studies that compared the postoperative health-related quality of life(HRQoL)outcomes after receiving laparoscopic resection(LR)or open resection(OR)in patients with colorectal cancer(CRC)have diff...BACKGROUND Previous studies that compared the postoperative health-related quality of life(HRQoL)outcomes after receiving laparoscopic resection(LR)or open resection(OR)in patients with colorectal cancer(CRC)have different conclusions.AIM To explore the medium-term effect of postoperative HRQoL in such patients.METHODS This study randomized 567 patients undergoing non-metastatic CRC surgery managed by one surgeon to the LR or OR groups.HRQoL was assessed during the preoperative period and 3,6,and 12 mo postoperative using a modified version of the 36-Item Short Form(SF-36)Health Survey questionnaire,emphasizing eight specific items.RESULTS This cohort randomly assigned 541 patients to receive LR(n=296)or OR(n=245)surgical procedures.More episodes of postoperative urinary tract infection(P<0.001),wound infection(P<0.001),and pneumonia(P=0.048)were encountered in the OR group.The results demonstrated that the LR group subjectively gained mildly better general health(P=0.045),moderately better physical activity(P=0.006),and significantly better social function recovery(P=0.0001)3 mo postoperatively.Only the aspect of social function recovery was claimed at 6 mo,with a significant advantage in the LR group(P=0.001).No clinical difference was found in HRQoL during the 12 mo.CONCLUSION Our results demonstrated that LR resulted in better outcomes,including intra-operative blood loss,surgery-related complications,course of recovery,and especially some health domains of HRQoL at least within 6 mo postoperatively.Patients should undergo LR if there is no contraindication.展开更多
Objective:To study whether the infection of Schistosomiasis japanicum(S.japanicum) is related to enhanced proliferation and migration of cancer cells,and the molecular mechanism pertains to cancer cell metastasis in h...Objective:To study whether the infection of Schistosomiasis japanicum(S.japanicum) is related to enhanced proliferation and migration of cancer cells,and the molecular mechanism pertains to cancer cell metastasis in human host.Methods:The gene of S.japanicum glutathione transferase(sjGST) cloned from 5.japanicum was expressed,purified and applied in a series of assays to explore the effect of sjGST on proliferation and migration of MDA-MB-435S,and the expression of MMP2 and MMP9.Immunofluorescence assay for the binding of sjGST to MDA-MB-435S was also carried out.Results:Results showed that sjGST enhanced proliferation and migration in human breast cancer cell MDA-MB-435S signifycantly at 50-200 nM,but did not enhance them in human lung cancer cell A549.Immunofluorescence assay for the binding of sjGST to MDA-MB-435S and A549 showed that GST was readily hound to the breast cancer cells,but showed almost no binding to human lung cancer cells.The assays for gelatinase activity showed that both MMP2 and MMP9 activities were increased significantly in the presence of sjGST(50-200 nM) in MDA-MB-435S, but they were not significant in A549.Conclusions:Our current results show strongly that S. japanicum GST binds to MDA-MB-435S probably via its i'eceptor,and enhances proliferation and migration of the cancer cells by up-regulatory expression of MMP2 and MMP9.展开更多
Multiphase flows are ubiquitous in our daily life and engineering applications. It is important to investigate the flow structures to predict their dynamical behaviors ef- fectively. Lagrangian coherent structures (...Multiphase flows are ubiquitous in our daily life and engineering applications. It is important to investigate the flow structures to predict their dynamical behaviors ef- fectively. Lagrangian coherent structures (LCS) defined by the ridges of the finite-time Lyapunov exponent (FTLE) is utilized in this study to elucidate the multiphase interactions in gaseous jets injected into water and time-dependent turbu- lent cavitation under the framework of Navier-Stokes flow computations. For the gaseous jets injected into water, the highlighted phenomena of the jet transportation can be observed by the LCS method, including expansion, bulge, necking/breaking, and back-attack. Besides, the observation of the LCS reveals that the back-attack phenomenon arises from the fact that the injected gas has difficulties to move toward downstream re- gion after the necking/breaking. For the turbulent cavitating flow, the ridge of the FTLE field can form a LCS to capture the front and boundary of the re-entraint jet when the ad- verse pressure gradient is strong enough. It represents a bar- rier between particles trapped inside the circulation region and those moving downstream. The results indicate that the FFLE field has the potential to identify the structures of mul- tiphase flows, and the LCS can capture the interface/barrier or the vortex/circulation region.展开更多
BACKGROUND Although important for determining long-term outcome, pathologic stage of hepatocellular carcinoma (HCC) is difficult to predict before surgery. Current state-of-the-art magnetic resonance imaging (MRI) usi...BACKGROUND Although important for determining long-term outcome, pathologic stage of hepatocellular carcinoma (HCC) is difficult to predict before surgery. Current state-of-the-art magnetic resonance imaging (MRI) using gadoxetic acid provides many imaging features that could potentially be used to classify single HCC as pT1 or pT2. AIM To determine which gadoxetic acid-enhanced MRI (EOB-MRI) findings predict pathologic stage T2 in patients with solitary HCC (cT1). METHODS Pre-operative EOB-MRI findings were reviewed in a retrospective cohort of patients with solitary HCC. The following imaging features were examined: Hyperintensity in unenhanced T2-weighted images, hypointensity in unenhanced T1-weighted images, arterial enhancement, corona enhancement, washout appearance, capsular appearance, hypointensity in the tumor tissue during the hepatobiliary (HB) phase, peritumoral hypointensity in the HB phase, hypointense rim in the HB phase, intratumoral fat, hyperintensity on diffusionweighted imaging, hypointensity on apparent diffusion coefficient map, mosaic appearance, nodule-in-nodule appearance, and the margin (smooth or irregular). Surgical pathology was used as the reference method for tumor staging. Univariate and multivariate analyses were performed to identify predictors of microvascular invasion or satellite nodules. RESULTS There were 39 (34.2%;39 of 114) and 75 (65.8%;75 of 114) pathological stage T2 and T1 HCCs, respectively. Large tumor size (≥ 2.3 cm) and two MRI findings, i.e., corona enhancement [odds ratio = 2.67;95% confidence interval: 1.101-6.480] and peritumoral hypointensity in HB phase images (odds ratio = 2.203;95% confidence interval: 0.961-5.049) were associated with high risk of pT2 HCC. The positive likelihood ratio was 6.25 (95% confidence interval: 1.788-21.845), and sensitivity of EOB-MRI for detecting pT2 HCC was 86.2% when two or three of these MRI features were present. Small tumor size and hypointense rim in the HB phase were regarded as benign features. Small HCCs with hypointense rim but not associated with aggressive features were mostly pT1 lesions (specificity, 100%). CONCLUSION Imaging features on EOB-MRI could potentially be used to predict the pathologic stage of solitary HCC (cT1) as pT1 or pT2.展开更多
Laboratory experiments were conducted in a wave flume on internal solitary wave (ISW) of depression and elevation types propagating over a submarine ridge in semicircular/triangular shape. Tests were arranged in ser...Laboratory experiments were conducted in a wave flume on internal solitary wave (ISW) of depression and elevation types propagating over a submarine ridge in semicircular/triangular shape. Tests were arranged in series for combinations of submarine ridges of different heights and ISW of different amplitudes. The resuhant wave motions were found differing from thee of surface gravity waves. In deeper water, where an ISW of depression-type prevailed, the process of wave breaking displayed downward motion with continuous eddy on the front face of the ridge followed by upward motion towards the apex of the obstacle. Experimental results also suggested that blockage parameter ξ could be applied to classify various degrees of ISW-ridge interaction, i.e., ξ 〈 0.5 for weak interaction, 0.5 〈 ξ 〈 0.7 for moderate interaction, and 0.7 〈 ξ for wave breaking.展开更多
In the present study a numerical model developed by Lynett and Liu (2002) is modified to include density difference in a stratified two-layer fluid in a three-dimensional internal wave domain. The internal solitary ...In the present study a numerical model developed by Lynett and Liu (2002) is modified to include density difference in a stratified two-layer fluid in a three-dimensional internal wave domain. The internal solitary wave (ISW) in the model is assumed to be weakly nonlinear and weakly dispersive, and the viscosity effects at all boundaries are ignored. The governing equations based on the Navier-Stokes and Euler equations are solved for internal solitary wave propagation over variable seabed topography. Theoretical formulations are established, from which analytical solutions are obtained, in addition to numerical results. Wave profiles from previous experimental studies are compared with the numerical results from the present analytical solutions. Numerical models developed on the basis of the present analytical solutions are better than those developed by Lynett and Liu (2002). The results of numerical modeling agree well with the experimental data.展开更多
The retrieval of dissolved organic carbon (DOC) distribution by remote sensing is mainly based on the em- pirical relationship of DOC concentration and colored dissolved organic matter (CDOM) concentration in many...The retrieval of dissolved organic carbon (DOC) distribution by remote sensing is mainly based on the em- pirical relationship of DOC concentration and colored dissolved organic matter (CDOM) concentration in many literatures. To investigate the nature of this relationship, the distributions and mixing behaviors of DOC and CDOM are reviewed in the world's major estuaries and bays. It is found that, generally, the C- DOM concentration is well correlated with the salinity in most estuaries, while DOC usually shows a non- conservative behavior which leads to a weak correlation between the DOC concentration and the CDOM concentration. To establish a good satellite reversion of the DOC concentration, the East China Sea(ECS) was taken as an example, and the mixing behavior of DOC and CDOM as well as the influence of biogeo- chemical processes were analyzed except for the physical mixing process with the data from late autumn (November, 2010) and winter (December, 2009) cruises. In the two ECS cruises, the CDOM concentration was found to be tightly correlated with the salinity, influenced little by the photochemical or biological pro- cesses. The data from the winter cruise show that DOC followed a conservative mixing along the salinity gradient, while in the late autumn cruise it was significantly affected by the biological activities, resulting in a poor correlation between the DOC and the CDOM. Accordingly, an improved DOC algorithm (CSDM) was proposed: when the biological influence was significant (Chl a greater than 0.8 μg/dm3), DOC was retrieved by the conservative and biological model, and if the conservative mixing was dominant (Chl a less than 0.8 μg/dm3), the direct DOC concentration and CDOM concentration relationship was used. Based on the pro- posed algorithm, a reasonable DOC distribution for the ECS from satellite was obtained in this study, and the proposed method can be applied to the other large river-dominant marginal sea.展开更多
We show that closed shrinking gradient Ricci solitons with positive Ricci curvature and sufficiently pinched Weyl tensor are Einstein. When Weyl tensor vanishes, this has been proved before but our proof here is much ...We show that closed shrinking gradient Ricci solitons with positive Ricci curvature and sufficiently pinched Weyl tensor are Einstein. When Weyl tensor vanishes, this has been proved before but our proof here is much simpler.展开更多
The contradiction between manufacturing accuracy and manufacturing efficiency is discussed in this paper.In order to solve this problem,a novel droplet-targeting laser hybrid indirect arc for additive manufacturing te...The contradiction between manufacturing accuracy and manufacturing efficiency is discussed in this paper.In order to solve this problem,a novel droplet-targeting laser hybrid indirect arc for additive manufacturing technology is proposed in which a couple of wires are melted using the alternating current with interwire indirect arc to achieve high deposition rate.On the other hand,droplets actively target the laser beam and detach from wire tip under the recoil pressure subjected to pulsed laser irradiating at desired position and with controlled mass for a precise bead forming.The process of alternative droplet growing at desired position are mathematically analyzed and then preliminary verified by experiment.By precisely controlling the wire feed speed and current frequency,the melting process at desired position and mass of wire is successfully obtained which is the fundamental for next-step for the droplet actively targeting laser.展开更多
BACKGROUND Barrett’s esophagus(BE)is a pre-malignant condition associated with the development of esophageal adenocarcinoma.The prevalence of BE in the general populations of Asian countries ranges from 0.06%to 1%.Ho...BACKGROUND Barrett’s esophagus(BE)is a pre-malignant condition associated with the development of esophageal adenocarcinoma.The prevalence of BE in the general populations of Asian countries ranges from 0.06%to 1%.However,with lifestyle changes in Asian countries and adoption of western customs,the prevalence of BE might have increased.AIM To determine the current prevalence of BE in Taiwan,and to investigate risk factors predicting the presence of BE.METHODS This retrospective study was conducted at the Health Evaluation Center of Kaohsiung Veterans General Hospital in Taiwan.Between January 2015 and December 2015,3385 subjects undergoing routine esophagogastroduodenoscopy examinations as part of a health check-up at the Health Evaluation Center were included.Patient characteristics and endoscopic findings were carefully reviewed.Lesions with endoscopic findings consistent with BE awaiting histological evaluation were judged as endoscopically suspected esophageal metaplasia(ESEM).BE was defined based on extension of the columnar epithelium≥1 cm above the gastroesophageal junction and was confirmed based on the presence of specialized intestinal metaplasia(IM)in the metaplastic esophageal epithelium.Clinical factors of subjects with BE and subjects without BE were compared,and the risk factors predicting BE were analyzed.RESULTS A total of 3385 subjects(mean age,51.29±11.42 years;57.1%male)were included in the study,and 89 among them were confirmed to have IM and presence of goblet cells via biopsy examination.The majority of these individuals were classified as short segment BE(n=85).The overall prevalence of BE was 2.6%.Multivariate analysis disclosed that old age[odds ratio(OR)=1.033;95%confidence interval(CI):1.012-1.055;P=0.002],male gender(OR=2.106;95%CI:1.145-3.872;P=0.017),ingestion of tea(OR=1.695;95%CI:1.043-2.754;P=0.033),and presence of hiatal hernia(OR=3.037;95%CI:1.765-5.225;P<0.001)were significant risk factors predicting BE.The independent risk factor for the presence of IM in ESEM lesions was old age alone(OR=1.029;95%CI:1.006-1.053;P=0.014).CONCLUSION Current prevalence of BE among the general population in Taiwan is 2.6%.Old age,male gender,ingestion of tea and hiatal hernia are significant risk factors for BE.展开更多
Owing to the dramatic mobile IP growth,the emerging Internet of Things,and cloud-based applications,wireless networking is witnessing a paradigm shift.By fully exploiting spatial degrees of freedom,massive multiple-in...Owing to the dramatic mobile IP growth,the emerging Internet of Things,and cloud-based applications,wireless networking is witnessing a paradigm shift.By fully exploiting spatial degrees of freedom,massive multiple-input-multiple-output(MIMO) systems promise significant gains in data rates and link reliability.Although the research community has recognized the theoretical benefits of these systems,building the hardware of such complex systems is a challenge in practice.This paper presents a time division duplex(TDD)-based 128-antenna massive MIMO prototype system from theory to reality.First,an analytical signal model is provided to facilitate the setup of a feasible massive MIMO prototype system.Second,a link-level simulation consistent with practical TDDbased massive MIMO systems is conducted to guide and validate the massive MIMO system design.We design and implement the TDDbased 128-antenna massive MIMO prototype system with the guidelines obtained from the link-level simulation.Uplink real-time video transmission and downlink data transmission under the configuration of multiple single-antenna users are achieved.Comparisons withstate-of-the-art prototypes demonstrate the advantages of the proposed system in terms of antenna number,bandwidth,latency,and throughput.The proposed system is also equipped with scalability,which makes the system applicable to a wide range of massive scenarios.展开更多
Resulting from the rising levels of atmospheric carbon, ocean acidification has become a global problem. It has significant impacts on the development, survival, growth and physiology of marine organisms. Therefore, a...Resulting from the rising levels of atmospheric carbon, ocean acidification has become a global problem. It has significant impacts on the development, survival, growth and physiology of marine organisms. Therefore, a high- precision sensor is urgently needed to measure the pH of sea-water. Iridium wire with a diameter of 0.25 mm is used as the substrate, and an Ir/Ir(OH)x pH electrode is prepared by a one-step electrochemical method in a LiOH solution at the room temperature. A scanning electron microscope (SEM) observation reveals that it is coated with nanoscale particles. In laboratory tests, the electrode exhibits a very promising pH response, with an ideal Nernst slope (56.14-59.52), fast response, good stability and long fife-span in tested pH buffer solutions. For a sea trial, four pH electrodes and one Ag/AgC1 reference electrode are integrated with a self-made chemical sensor, and a profile detection of nearly 70 m is implemented near Newport Harbor, California on August 3, 2015. The results reflect that the pH value measured by the sensor is very close to the data given by Sea-Bird 911 plus CTD, with a difference value ranging from 0.000 075 to 0.064 719. And the sensor shows a better data matching degree in 0-40 m water depth. In addition, the high precision and accuracy of the sensor make it possible to use in the ocean observation field.展开更多
Investigations of the diffusion activities both within and outside the seafloor hydrothermal vents, as well as related mineral genesis, have been one of the key focuses of ocean biogeochemistry studies. Many hy- droth...Investigations of the diffusion activities both within and outside the seafloor hydrothermal vents, as well as related mineral genesis, have been one of the key focuses of ocean biogeochemistry studies. Many hy- drothermal vents are distributed close to the southern Okinawa Trough on the less-than-30-m deep shallow seafloor off Kueishan Tao, northeast of Taiwan Island. Investigations of temperature, pH and Eh at four depths of hydrothermal plume were carried out near Kueishan Tao at the white (24.83°N, 121.9°E) and yellow (24.83°N, 121.96°E) vents. An 87 h of temperature time series observation-undertaken near the white vent showed that tide is the main factor affecting the background environment. Based on the observed data, 3-dimensional sliced diffusion fields were obtained and analyzed. It was concluded that the plume diffused mainly from north to south due to ebb tide. The yellow vent's plume could effect as far as the white vent surface. From the temperature diffusion field, the vortices of the plume were observed. The Eh negative abnormality was a better indicator to search for hydrothermal plumes and locate hydrothermal vents than high temperature and low pH abnormalities.展开更多
Successful modeling and/or design of engineering systems often requires one to address the impact of multiple "design variables" on the prescribed outcome.There are often multiple,competing objectives based on which...Successful modeling and/or design of engineering systems often requires one to address the impact of multiple "design variables" on the prescribed outcome.There are often multiple,competing objectives based on which we assess the outcome of optimization.Since accurate,high fidelity models are typically time consuming and computationally expensive,comprehensive evaluations can be conducted only if an efficient framework is available.Furthermore,informed decisions of the model/hardware's overall performance rely on an adequate understanding of the global,not local,sensitivity of the individual design variables on the objectives.The surrogate-based approach,which involves approximating the objectives as continuous functions of design variables from limited data,offers a rational framework to reduce the number of important input variables,i.e.,the dimension of a design or modeling space.In this paper,we review the fundamental issues that arise in surrogate-based analysis and optimization,highlighting concepts,methods,techniques,as well as modeling implications for mechanics problems.To aid the discussions of the issues involved,we summarize recent efforts in investigating cryogenic cavitating flows,active flow control based on dielectric barrier discharge concepts,and lithium(Li)-ion batteries.It is also stressed that many multi-scale mechanics problems can naturally benefit from the surrogate approach for "scale bridging."展开更多
Hepatitis B virus(HBV)reactivation can lead to severe acute hepatic failure and death in patients with HBV infection.HBV reactivation(HBVr)most commonly develops in patients undergoing cancer chemotherapy,especially B...Hepatitis B virus(HBV)reactivation can lead to severe acute hepatic failure and death in patients with HBV infection.HBV reactivation(HBVr)most commonly develops in patients undergoing cancer chemotherapy,especially B cell-depleting agent therapy such as rituximab and ofatumumab for hematological or solid organ malignancies and that receiving hematopoietic stem cell transplantation without antiviral prophylaxis.In addition,the potential consequences of HBVr is particularly a concern when patients are exposed to either immunosuppressive or biologic therapies for the management of rheumatologic diseases,inammatory bowel disease and dermatologic diseases.Thus,screening with HBV serological markers and prophylactic or pre-emptive antiviral treatment with nucleos(t)ide analogues should be considered in these patients to diminish the risk of HBVr.This review discusses the clinical manifestation,prognosis and management of HBVr,risk stratifications of cancer chemotherapy and immunosuppressive therapy and international guideline recommendations for the prevention of HBVr in patients with HBV infection and resolved hepatitis B.展开更多
文摘BACKGROUND The treatment of acute respiratory distress syndrome(ARDS)complicated by sepsis syndrome(SS)remains challenging.AIM To investigate whether combined adipose-derived mesenchymal-stem-cells(ADMSCs)-derived exosome(EXAD)and exogenous mitochondria(mitoEx)protect the lung from ARDS complicated by SS.METHODS In vitro study,including L2 cells treated with lipopolysaccharide(LPS)and in vivo study including male-adult-SD rats categorized into groups 1(sham-operated-control),2(ARDS-SS),3(ARDS-SS+EXAD),4(ARDS-SS+mitoEx),and 5(ARDS-SS+EXAD+mitoEx),were included in the present study.RESULTS In vitro study showed an abundance of mitoEx found in recipient-L2 cells,resulting in significantly higher mitochondrial-cytochrome-C,adenosine triphosphate and relative mitochondrial DNA levels(P<0.001).The protein levels of inflammation[interleukin(IL)-1β/tumor necrosis factor(TNF)-α/nuclear factor-κB/toll-like receptor(TLR)-4/matrix-metalloproteinase(MMP)-9/oxidative-stress(NOX-1/NOX-2)/apoptosis(cleaved-caspase3/cleaved-poly(ADP-ribose)polymerase)]were significantly attenuated in lipopolysaccharide(LPS)-treated L2 cells with EXAD treatment than without EXAD treatment,whereas the protein expressions of cellular junctions[occluding/β-catenin/zonula occludens(ZO)-1/E-cadherin]exhibited an opposite pattern of inflam-mation(all P<0.001).Animals were euthanized by 72 h post-48 h-ARDS induction,and lung tissues were harvested.By 72 h,flow cytometric analysis of bronchoalveolar lavage fluid demonstrated that the levels of inflam-matory cells(Ly6G+/CD14+/CD68+/CD11b/c+/myeloperoxidase+)and albumin were lowest in group 1,highest in group 2,and significantly higher in groups 3 and 4 than in group 5(all P<0.0001),whereas arterial oxygen-saturation(SaO2%)displayed an opposite pattern of albumin among the groups.Histopathological findings of lung injury/fibrosis area and inflammatory/DNA-damaged markers(CD68+/γ-H2AX)displayed an identical pattern of SaO2%among the groups(all P<0.0001).The protein expressions of inflammatory(TLR-4/MMP-9/IL-1β/TNF-α)/oxidative stress(NOX-1/NOX-2/p22phox/oxidized protein)/mitochondrial-damaged(cytosolic-cytochrome-C/dynamin-related protein 1)/autophagic(beclin-1/Atg-5/ratio of LC3B-II/LC3B-I)biomarkers exhibited a similar manner,whereas antioxidants[nuclear respiratory factor(Nrf)-1/Nrf-2]/cellular junctions(ZO-1/E-cadherin)/mitochondrial electron transport chain(complex I-V)exhibited an opposite manner of albumin among the groups(all P<0.0001).CONCLUSION Combined EXAD-mitoEx therapy was better than merely one for protecting the lung against ARDS-SS induced injury.
基金Supported by Hualien Armed Forces General Hospital,No.805-C107-14Ministry of Science and Technology,Taiwan,R.O.C.,No.MOST 107-2221-E-899-002-MY3
文摘AIM To examine the accuracy of machine learning to relate particulate matter(PM) 2.5 and PM10 concentrations to upper respiratory tract infections(URIs).METHODS Daily nationwide and regional outdoor PM2.5 and PM10 concentrations collected over 30 consecutive days obtained from the Taiwan Environment Protection Administration were the inputs for machine learning, using multilayer perceptron(MLP), to relate to the subsequent one-week outpatient visits for URIs. TheURI data were obtained from the Centers for Disease Control datasets in Taiwan between 2009 and 2016. The testing used the middle month dataset of each season(January, April, July and October), and the training used the other months' datasets. The weekly URI cases were classified by tertile as high, moderate, and low volumes.RESULTS Both PM concentrations and URI cases peak in winter and spring. In the nationwide data analysis, MLP machine learning can accurately relate the URI volumes of the elderly(89.05% and 88.32%, respectively) and the overall population(81.75% and 83.21%, respectively) with the PM2.5 and PM10 concentrations. In the regional data analyses, greater accuracy is found for PM2.5 than for PM10 for the elderly, particularly in the Central region(78.10% and 74.45%, respectively), whereas greater accuracy is found for PM10 than for PM2.5 for the overall population, particularly in the Northern region(73.19% and 63.04%, respectively).CONCLUSION Short-term PM2.5 and PM10 concentrations were accurately related to the subsequent occurrence of URIs by using machine learning. Our findings suggested that the effects of PM2.5 and PM10 on URI may differ by age, and the mechanism needs further evaluation.
基金partially supported by an investigator-initiated research grant(IN-US-334-4309)from Gilead Sciences to Stanford University.
文摘Background and Aims:As practice patterns and hepatitis C virus(HCV)genotypes(GT)vary geographically,a global real-world study from both East and West covering all GTs can help inform practice policy toward the 2030 HCV elimination goal.This study aimed to assess the effectiveness and tolerability of DAA treatment in routine clinical practice in a multinational cohort for patients infected with all HCV GTs,focusing on GT3 and GT6.Methods:We analyzed the sustained virological response(SVR12)of 15,849 chronic hepatitis C patients from 39 Real-World Evidence from the Asia Liver Consortium for HCV clinical sites in Asia Pacific,North America,and Europe between 07/01/2014–07/01/2021.Results:The mean age was 62±13 years,with 49.6%male.The demographic breakdown was 91.1%Asian(52.9%Japanese,25.7%Chinese/Taiwan residents,5.4%Korean,3.3%Malaysian,and 2.9%Vietnamese),6.4%White,1.3%Hispanic/Latino,and 1%Black/African-American.Additionally,34.8%had cirrhosis,8.6%had hepatocellular carcinoma(HCC),and 24.9%were treatment-experienced(20.7%with interferon,4.3%with direct-acting antivirals).The largest group was GT1(10,246[64.6%]),followed by GT2(3,686[23.2%]),GT3(1,151[7.2%]),GT6(457[2.8%]),GT4(47[0.3%]),GT5(1[0.006%]),and untyped GTs(261[1.6%]).The overall SVR12 was 96.9%,with rates over 95%for GT1/2/3/6 but 91.5%for GT4.SVR12 for GT3 was 95.1%overall,98.2%for GT3a,and 94.0%for GT3b.SVR12 was 98.3%overall for GT6,lower for patients with cirrhosis and treatment-experienced(TE)(93.8%)but≥97.5%for tretment-naive patients regardless of cirrhosis status.On multivariable analysis,advanced age,prior treatment failure,cirrhosis,active HCC,and GT3/4 were independent predictors of lower SVR12,while being Asian was a significant predictor of achieving SVR12.Conclusions:In this diverse multinational realworld cohort of patients with various GTs,the overall cure rate was 96.9%,despite large numbers of patients with cirrhosis,HCC,TE,and GT3/6.SVR12 for GT3/6 with cirrhosis and TE was lower but still excellent(>91%).
文摘In this paper,a decision-making problem with a q-rung orthopair fuzzy hypersoft environment is developed,and two operators of ordered weighted average and induced ordered weighted average are developed.Several fundamental features are also derived.The induced ordered weighted average operator is essential in a q-ROFH environment as the induced ordered aggregation operators are special cases of the existing aggregation operators that already exist in q-ROFH environments.The main function of these operators is to help decision-makers gain a complete understanding of uncertain facts.The proposed aggregation operator is applied to a decision-making problem,with the aim of selecting the most promising real estate project for investment.
基金Supported by the Zhejiang University Self Program Fund for the Research of Heavy Metal Geochemical Characteristics in Sediments of Hangzhou Baythe Zhejiang University Fundamental Research Funds for the Central Universities(No.2013QNA4037)+1 种基金the National Key Research and Development Plan of China(No.2016YFC1401603)the National Natural Science Foundation of China(No.41876031)。
文摘Salt marshes are important carbon and nutrient sinks that are threatened by climate changes and human activities.In this study,the accumulation rates of sedimentary total organic carbon(TOC),total nitrogen(TN),and total phosphorus(TP)from two cores in the Andong salt marsh,Hangzhou Bay,were investigated to determine whether TOC,TN,and TP show increasing or decreasing trends toward the present.The TOC accumulation rates at the relatively lower marsh were lower during 1990-1996(1.63-2.37 g/(cm^(2)·a))than 1997-2014(1.15-4.30 g/(cm^(2)·a)).The TN accumulation rates increased from 1990(0.14 g/(cm^(2)·a))toward 2012(0.40 g/(cm^(2)·a)),then decreased toward 2014(0.16 g/(cm^(2)·a)).The TP accumulation rates were lower during 1990-1999(0.10-0.21 mg/(cm^(2)·a)),and decreased from 2000(0.32 mg/(cm^(2)·a))toward 2014(0.15 mg/(cm^(2)·a)).The TOC accumulation rates along the relatively upper marsh during 1982-1992(1.18-3.25 g/(cm^(2)·a))were lower than during 1998-2010(2.30-4.20 g/(cm^(2)·a)),and then decreased toward 2015(2.15 g/(cm^(2)·a)).TN increased from 1982(0.18 g/(cm^(2)·a))to 2005(0.41 g/(cm^(2)·a)),then decreased toward 2015(0.22 g/(cm^(2)·a)).TP accumulation rates fluctuated within a narrow range during 1982-1997(0.21-0.41 mg/(cm^(2)·a)),increased from 1998(0.50 mg/(cm^(2)·a))to 2004(0.87 mg/(cm^(2)·a)),then decreased to 2015(0.38 mg/(cm^(2)·a)).Thus,increases in accumulation rates of TOC,TN,and TP from the 1980s to 1990s indicates that the marsh likely served as carbon and nutrient sinks,then the rates decreased during 2000-2015 due probably to the reduced sediment inputs from rivers and intensified sea level rise.
基金Supported by The Research Foundation of E-Da Cancer Hospital and E-Da Hospital,Kaohsiung,Taiwan,No.EDCHI111002 and NCKUEDA11110.
文摘BACKGROUND Previous studies that compared the postoperative health-related quality of life(HRQoL)outcomes after receiving laparoscopic resection(LR)or open resection(OR)in patients with colorectal cancer(CRC)have different conclusions.AIM To explore the medium-term effect of postoperative HRQoL in such patients.METHODS This study randomized 567 patients undergoing non-metastatic CRC surgery managed by one surgeon to the LR or OR groups.HRQoL was assessed during the preoperative period and 3,6,and 12 mo postoperative using a modified version of the 36-Item Short Form(SF-36)Health Survey questionnaire,emphasizing eight specific items.RESULTS This cohort randomly assigned 541 patients to receive LR(n=296)or OR(n=245)surgical procedures.More episodes of postoperative urinary tract infection(P<0.001),wound infection(P<0.001),and pneumonia(P=0.048)were encountered in the OR group.The results demonstrated that the LR group subjectively gained mildly better general health(P=0.045),moderately better physical activity(P=0.006),and significantly better social function recovery(P=0.0001)3 mo postoperatively.Only the aspect of social function recovery was claimed at 6 mo,with a significant advantage in the LR group(P=0.001).No clinical difference was found in HRQoL during the 12 mo.CONCLUSION Our results demonstrated that LR resulted in better outcomes,including intra-operative blood loss,surgery-related complications,course of recovery,and especially some health domains of HRQoL at least within 6 mo postoperatively.Patients should undergo LR if there is no contraindication.
基金Supported by grants from National Science Council(NSC98-2314-B-110-001-MY3)
文摘Objective:To study whether the infection of Schistosomiasis japanicum(S.japanicum) is related to enhanced proliferation and migration of cancer cells,and the molecular mechanism pertains to cancer cell metastasis in human host.Methods:The gene of S.japanicum glutathione transferase(sjGST) cloned from 5.japanicum was expressed,purified and applied in a series of assays to explore the effect of sjGST on proliferation and migration of MDA-MB-435S,and the expression of MMP2 and MMP9.Immunofluorescence assay for the binding of sjGST to MDA-MB-435S was also carried out.Results:Results showed that sjGST enhanced proliferation and migration in human breast cancer cell MDA-MB-435S signifycantly at 50-200 nM,but did not enhance them in human lung cancer cell A549.Immunofluorescence assay for the binding of sjGST to MDA-MB-435S and A549 showed that GST was readily hound to the breast cancer cells,but showed almost no binding to human lung cancer cells.The assays for gelatinase activity showed that both MMP2 and MMP9 activities were increased significantly in the presence of sjGST(50-200 nM) in MDA-MB-435S, but they were not significant in A549.Conclusions:Our current results show strongly that S. japanicum GST binds to MDA-MB-435S probably via its i'eceptor,and enhances proliferation and migration of the cancer cells by up-regulatory expression of MMP2 and MMP9.
文摘Multiphase flows are ubiquitous in our daily life and engineering applications. It is important to investigate the flow structures to predict their dynamical behaviors ef- fectively. Lagrangian coherent structures (LCS) defined by the ridges of the finite-time Lyapunov exponent (FTLE) is utilized in this study to elucidate the multiphase interactions in gaseous jets injected into water and time-dependent turbu- lent cavitation under the framework of Navier-Stokes flow computations. For the gaseous jets injected into water, the highlighted phenomena of the jet transportation can be observed by the LCS method, including expansion, bulge, necking/breaking, and back-attack. Besides, the observation of the LCS reveals that the back-attack phenomenon arises from the fact that the injected gas has difficulties to move toward downstream re- gion after the necking/breaking. For the turbulent cavitating flow, the ridge of the FTLE field can form a LCS to capture the front and boundary of the re-entraint jet when the ad- verse pressure gradient is strong enough. It represents a bar- rier between particles trapped inside the circulation region and those moving downstream. The results indicate that the FFLE field has the potential to identify the structures of mul- tiphase flows, and the LCS can capture the interface/barrier or the vortex/circulation region.
文摘BACKGROUND Although important for determining long-term outcome, pathologic stage of hepatocellular carcinoma (HCC) is difficult to predict before surgery. Current state-of-the-art magnetic resonance imaging (MRI) using gadoxetic acid provides many imaging features that could potentially be used to classify single HCC as pT1 or pT2. AIM To determine which gadoxetic acid-enhanced MRI (EOB-MRI) findings predict pathologic stage T2 in patients with solitary HCC (cT1). METHODS Pre-operative EOB-MRI findings were reviewed in a retrospective cohort of patients with solitary HCC. The following imaging features were examined: Hyperintensity in unenhanced T2-weighted images, hypointensity in unenhanced T1-weighted images, arterial enhancement, corona enhancement, washout appearance, capsular appearance, hypointensity in the tumor tissue during the hepatobiliary (HB) phase, peritumoral hypointensity in the HB phase, hypointense rim in the HB phase, intratumoral fat, hyperintensity on diffusionweighted imaging, hypointensity on apparent diffusion coefficient map, mosaic appearance, nodule-in-nodule appearance, and the margin (smooth or irregular). Surgical pathology was used as the reference method for tumor staging. Univariate and multivariate analyses were performed to identify predictors of microvascular invasion or satellite nodules. RESULTS There were 39 (34.2%;39 of 114) and 75 (65.8%;75 of 114) pathological stage T2 and T1 HCCs, respectively. Large tumor size (≥ 2.3 cm) and two MRI findings, i.e., corona enhancement [odds ratio = 2.67;95% confidence interval: 1.101-6.480] and peritumoral hypointensity in HB phase images (odds ratio = 2.203;95% confidence interval: 0.961-5.049) were associated with high risk of pT2 HCC. The positive likelihood ratio was 6.25 (95% confidence interval: 1.788-21.845), and sensitivity of EOB-MRI for detecting pT2 HCC was 86.2% when two or three of these MRI features were present. Small tumor size and hypointense rim in the HB phase were regarded as benign features. Small HCCs with hypointense rim but not associated with aggressive features were mostly pT1 lesions (specificity, 100%). CONCLUSION Imaging features on EOB-MRI could potentially be used to predict the pathologic stage of solitary HCC (cT1) as pT1 or pT2.
基金The work was supported bythe National Science Council ,Taiwan,China (Grant No. NSC93-2611-M-110-001)
文摘Laboratory experiments were conducted in a wave flume on internal solitary wave (ISW) of depression and elevation types propagating over a submarine ridge in semicircular/triangular shape. Tests were arranged in series for combinations of submarine ridges of different heights and ISW of different amplitudes. The resuhant wave motions were found differing from thee of surface gravity waves. In deeper water, where an ISW of depression-type prevailed, the process of wave breaking displayed downward motion with continuous eddy on the front face of the ridge followed by upward motion towards the apex of the obstacle. Experimental results also suggested that blockage parameter ξ could be applied to classify various degrees of ISW-ridge interaction, i.e., ξ 〈 0.5 for weak interaction, 0.5 〈 ξ 〈 0.7 for moderate interaction, and 0.7 〈 ξ for wave breaking.
文摘In the present study a numerical model developed by Lynett and Liu (2002) is modified to include density difference in a stratified two-layer fluid in a three-dimensional internal wave domain. The internal solitary wave (ISW) in the model is assumed to be weakly nonlinear and weakly dispersive, and the viscosity effects at all boundaries are ignored. The governing equations based on the Navier-Stokes and Euler equations are solved for internal solitary wave propagation over variable seabed topography. Theoretical formulations are established, from which analytical solutions are obtained, in addition to numerical results. Wave profiles from previous experimental studies are compared with the numerical results from the present analytical solutions. Numerical models developed on the basis of the present analytical solutions are better than those developed by Lynett and Liu (2002). The results of numerical modeling agree well with the experimental data.
基金The National Basic Research Program of China (973 Program) under contract No.2009CB421202the Public Science and Technology Research Funds Projects of Ocean of China under contract No. 200905012the National Natural Science Foundation of China under contract Nos 40976110 and 40706061
文摘The retrieval of dissolved organic carbon (DOC) distribution by remote sensing is mainly based on the em- pirical relationship of DOC concentration and colored dissolved organic matter (CDOM) concentration in many literatures. To investigate the nature of this relationship, the distributions and mixing behaviors of DOC and CDOM are reviewed in the world's major estuaries and bays. It is found that, generally, the C- DOM concentration is well correlated with the salinity in most estuaries, while DOC usually shows a non- conservative behavior which leads to a weak correlation between the DOC concentration and the CDOM concentration. To establish a good satellite reversion of the DOC concentration, the East China Sea(ECS) was taken as an example, and the mixing behavior of DOC and CDOM as well as the influence of biogeo- chemical processes were analyzed except for the physical mixing process with the data from late autumn (November, 2010) and winter (December, 2009) cruises. In the two ECS cruises, the CDOM concentration was found to be tightly correlated with the salinity, influenced little by the photochemical or biological pro- cesses. The data from the winter cruise show that DOC followed a conservative mixing along the salinity gradient, while in the late autumn cruise it was significantly affected by the biological activities, resulting in a poor correlation between the DOC and the CDOM. Accordingly, an improved DOC algorithm (CSDM) was proposed: when the biological influence was significant (Chl a greater than 0.8 μg/dm3), DOC was retrieved by the conservative and biological model, and if the conservative mixing was dominant (Chl a less than 0.8 μg/dm3), the direct DOC concentration and CDOM concentration relationship was used. Based on the pro- posed algorithm, a reasonable DOC distribution for the ECS from satellite was obtained in this study, and the proposed method can be applied to the other large river-dominant marginal sea.
基金supported by National Natural Science Foundation of China(11301191)supported by MOST(MOST107-2115-M-110-007-MY2)
文摘We show that closed shrinking gradient Ricci solitons with positive Ricci curvature and sufficiently pinched Weyl tensor are Einstein. When Weyl tensor vanishes, this has been proved before but our proof here is much simpler.
基金supported by National Natural Science Foundation of China(51475009)National Natural Science Funded Youth Projects(51505009)+1 种基金Natural Science Foundation of Beijing Projects(3162004)China Postdoctoral Science Foundation Program(2015M570021)。
文摘The contradiction between manufacturing accuracy and manufacturing efficiency is discussed in this paper.In order to solve this problem,a novel droplet-targeting laser hybrid indirect arc for additive manufacturing technology is proposed in which a couple of wires are melted using the alternating current with interwire indirect arc to achieve high deposition rate.On the other hand,droplets actively target the laser beam and detach from wire tip under the recoil pressure subjected to pulsed laser irradiating at desired position and with controlled mass for a precise bead forming.The process of alternative droplet growing at desired position are mathematically analyzed and then preliminary verified by experiment.By precisely controlling the wire feed speed and current frequency,the melting process at desired position and mass of wire is successfully obtained which is the fundamental for next-step for the droplet actively targeting laser.
基金Supported by the In-Hospital Research Project Funding of Kaohsiung Veterans General Hospital,No.VGHKS107-040
文摘BACKGROUND Barrett’s esophagus(BE)is a pre-malignant condition associated with the development of esophageal adenocarcinoma.The prevalence of BE in the general populations of Asian countries ranges from 0.06%to 1%.However,with lifestyle changes in Asian countries and adoption of western customs,the prevalence of BE might have increased.AIM To determine the current prevalence of BE in Taiwan,and to investigate risk factors predicting the presence of BE.METHODS This retrospective study was conducted at the Health Evaluation Center of Kaohsiung Veterans General Hospital in Taiwan.Between January 2015 and December 2015,3385 subjects undergoing routine esophagogastroduodenoscopy examinations as part of a health check-up at the Health Evaluation Center were included.Patient characteristics and endoscopic findings were carefully reviewed.Lesions with endoscopic findings consistent with BE awaiting histological evaluation were judged as endoscopically suspected esophageal metaplasia(ESEM).BE was defined based on extension of the columnar epithelium≥1 cm above the gastroesophageal junction and was confirmed based on the presence of specialized intestinal metaplasia(IM)in the metaplastic esophageal epithelium.Clinical factors of subjects with BE and subjects without BE were compared,and the risk factors predicting BE were analyzed.RESULTS A total of 3385 subjects(mean age,51.29±11.42 years;57.1%male)were included in the study,and 89 among them were confirmed to have IM and presence of goblet cells via biopsy examination.The majority of these individuals were classified as short segment BE(n=85).The overall prevalence of BE was 2.6%.Multivariate analysis disclosed that old age[odds ratio(OR)=1.033;95%confidence interval(CI):1.012-1.055;P=0.002],male gender(OR=2.106;95%CI:1.145-3.872;P=0.017),ingestion of tea(OR=1.695;95%CI:1.043-2.754;P=0.033),and presence of hiatal hernia(OR=3.037;95%CI:1.765-5.225;P<0.001)were significant risk factors predicting BE.The independent risk factor for the presence of IM in ESEM lesions was old age alone(OR=1.029;95%CI:1.006-1.053;P=0.014).CONCLUSION Current prevalence of BE among the general population in Taiwan is 2.6%.Old age,male gender,ingestion of tea and hiatal hernia are significant risk factors for BE.
基金supported in part by the National Science Foundation(NSFC) for Distinguished Young Scholars of China with Grant 61625106the National Natural Science Foundation of China under Grant 61531011the Hong Kong,Macao and Taiwan Science and Technology Cooperation Program of China(2016YFE0123100)
文摘Owing to the dramatic mobile IP growth,the emerging Internet of Things,and cloud-based applications,wireless networking is witnessing a paradigm shift.By fully exploiting spatial degrees of freedom,massive multiple-input-multiple-output(MIMO) systems promise significant gains in data rates and link reliability.Although the research community has recognized the theoretical benefits of these systems,building the hardware of such complex systems is a challenge in practice.This paper presents a time division duplex(TDD)-based 128-antenna massive MIMO prototype system from theory to reality.First,an analytical signal model is provided to facilitate the setup of a feasible massive MIMO prototype system.Second,a link-level simulation consistent with practical TDDbased massive MIMO systems is conducted to guide and validate the massive MIMO system design.We design and implement the TDDbased 128-antenna massive MIMO prototype system with the guidelines obtained from the link-level simulation.Uplink real-time video transmission and downlink data transmission under the configuration of multiple single-antenna users are achieved.Comparisons withstate-of-the-art prototypes demonstrate the advantages of the proposed system in terms of antenna number,bandwidth,latency,and throughput.The proposed system is also equipped with scalability,which makes the system applicable to a wide range of massive scenarios.
基金The Key Laboratory Project of State Oceanic Administration for Marine Ecosystem and Biogeochemistry of China under contract No.529101-X21601the Foundation from Wendy Schmidt Ocean Health XPRIZE and the Southern California Coastal Water Research Project
文摘Resulting from the rising levels of atmospheric carbon, ocean acidification has become a global problem. It has significant impacts on the development, survival, growth and physiology of marine organisms. Therefore, a high- precision sensor is urgently needed to measure the pH of sea-water. Iridium wire with a diameter of 0.25 mm is used as the substrate, and an Ir/Ir(OH)x pH electrode is prepared by a one-step electrochemical method in a LiOH solution at the room temperature. A scanning electron microscope (SEM) observation reveals that it is coated with nanoscale particles. In laboratory tests, the electrode exhibits a very promising pH response, with an ideal Nernst slope (56.14-59.52), fast response, good stability and long fife-span in tested pH buffer solutions. For a sea trial, four pH electrodes and one Ag/AgC1 reference electrode are integrated with a self-made chemical sensor, and a profile detection of nearly 70 m is implemented near Newport Harbor, California on August 3, 2015. The results reflect that the pH value measured by the sensor is very close to the data given by Sea-Bird 911 plus CTD, with a difference value ranging from 0.000 075 to 0.064 719. And the sensor shows a better data matching degree in 0-40 m water depth. In addition, the high precision and accuracy of the sensor make it possible to use in the ocean observation field.
基金The National Natural Science Foundation of China under contract No.40637037the Natural Science Foundation of Zhejiang Province under contract No.Y5080084+3 种基金the Science and Technology Project of Zhejiang Province under contract No.2009C31153the Youth Foundation for Marine Science of State Oceanic Administration,Public Research Institutes(Second Institute of Oceanography,State Oceanic Adminstration,PRC)under contract No.2013529the Special Fund for Central Universities Fundamental Researchthe Fundamental Research Fund of Second Institute of Oceanography,State Oceanic Administration,PRC
文摘Investigations of the diffusion activities both within and outside the seafloor hydrothermal vents, as well as related mineral genesis, have been one of the key focuses of ocean biogeochemistry studies. Many hy- drothermal vents are distributed close to the southern Okinawa Trough on the less-than-30-m deep shallow seafloor off Kueishan Tao, northeast of Taiwan Island. Investigations of temperature, pH and Eh at four depths of hydrothermal plume were carried out near Kueishan Tao at the white (24.83°N, 121.9°E) and yellow (24.83°N, 121.96°E) vents. An 87 h of temperature time series observation-undertaken near the white vent showed that tide is the main factor affecting the background environment. Based on the observed data, 3-dimensional sliced diffusion fields were obtained and analyzed. It was concluded that the plume diffused mainly from north to south due to ebb tide. The yellow vent's plume could effect as far as the white vent surface. From the temperature diffusion field, the vortices of the plume were observed. The Eh negative abnormality was a better indicator to search for hydrothermal plumes and locate hydrothermal vents than high temperature and low pH abnormalities.
文摘Successful modeling and/or design of engineering systems often requires one to address the impact of multiple "design variables" on the prescribed outcome.There are often multiple,competing objectives based on which we assess the outcome of optimization.Since accurate,high fidelity models are typically time consuming and computationally expensive,comprehensive evaluations can be conducted only if an efficient framework is available.Furthermore,informed decisions of the model/hardware's overall performance rely on an adequate understanding of the global,not local,sensitivity of the individual design variables on the objectives.The surrogate-based approach,which involves approximating the objectives as continuous functions of design variables from limited data,offers a rational framework to reduce the number of important input variables,i.e.,the dimension of a design or modeling space.In this paper,we review the fundamental issues that arise in surrogate-based analysis and optimization,highlighting concepts,methods,techniques,as well as modeling implications for mechanics problems.To aid the discussions of the issues involved,we summarize recent efforts in investigating cryogenic cavitating flows,active flow control based on dielectric barrier discharge concepts,and lithium(Li)-ion batteries.It is also stressed that many multi-scale mechanics problems can naturally benefit from the surrogate approach for "scale bridging."
文摘Hepatitis B virus(HBV)reactivation can lead to severe acute hepatic failure and death in patients with HBV infection.HBV reactivation(HBVr)most commonly develops in patients undergoing cancer chemotherapy,especially B cell-depleting agent therapy such as rituximab and ofatumumab for hematological or solid organ malignancies and that receiving hematopoietic stem cell transplantation without antiviral prophylaxis.In addition,the potential consequences of HBVr is particularly a concern when patients are exposed to either immunosuppressive or biologic therapies for the management of rheumatologic diseases,inammatory bowel disease and dermatologic diseases.Thus,screening with HBV serological markers and prophylactic or pre-emptive antiviral treatment with nucleos(t)ide analogues should be considered in these patients to diminish the risk of HBVr.This review discusses the clinical manifestation,prognosis and management of HBVr,risk stratifications of cancer chemotherapy and immunosuppressive therapy and international guideline recommendations for the prevention of HBVr in patients with HBV infection and resolved hepatitis B.