Background Atrial septal defect(ASD)is one of the most common congenital heart diseases.The diagnosis of ASD via transthoracic echocardiography is subjective and time-consuming.Methods The objective of this study was ...Background Atrial septal defect(ASD)is one of the most common congenital heart diseases.The diagnosis of ASD via transthoracic echocardiography is subjective and time-consuming.Methods The objective of this study was to evaluate the feasibility and accuracy of automatic detection of ASD in children based on color Doppler echocardiographic static images using end-to-end convolutional neural networks.The proposed depthwise separable convolution model identifies ASDs with static color Doppler images in a standard view.Among the standard views,we selected two echocardiographic views,i.e.,the subcostal sagittal view of the atrium septum and the low parasternal four-chamber view.The developed ASD detection system was validated using a training set consisting of 396 echocardiographic images corresponding to 198 cases.Additionally,an independent test dataset of 112 images corresponding to 56 cases was used,including 101 cases with ASDs and 153 cases with normal hearts.Results The average area under the receiver operating characteristic curve,recall,precision,specificity,F1-score,and accuracy of the proposed ASD detection model were 91.99,80.00,82.22,87.50,79.57,and 83.04,respectively.Conclusions The proposed model can accurately and automatically identify ASD,providing a strong foundation for the intelligent diagnosis of congenital heart diseases.展开更多
AIM: To investigate anti-tumor activities and apoptosis-regulated mechanisms of bufalin in the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice.METHODS: BEL-7402 cells of human hep...AIM: To investigate anti-tumor activities and apoptosis-regulated mechanisms of bufalin in the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice.METHODS: BEL-7402 cells of human hepatocellular carcinoma were inoculated to form subcutaneous tumors, and were implanted into the liver to establish orthotopic transplantation tumor models of human hepatocellular carcinoma in nude mice. Seventy-five animals were randomized divided into five groups (n = 15). Bufalin was injected intraperitoneally into three groups at doses of 1.5 mg/kg (BF1), 1 mg/kg (BF2) and 0.5 mg/kg (BF3) for d 15-24, respectively. The NS group was injected an equal volume of saline as above and adriamycin was injected intraperitoneally into the ADM group at a dose of 8.0 mg/kg for d 15. Ten mice in each group were killed at d 25 and the survival time in each group was calculated. We also observed the morphologic alterations in the myocardium, brain, liver, kidney and tumor tissues by pathology and electron microscopy, measured the apoptotic rate by TUNEL staining method, and detected the expression of apoptosis-regulated genes bcl-2 and bax by immunohistochemical staining and RT-PCR in tumor tissues. RESULTS: The tumor volumes in each group of bufalin were reduced significantly (35.21 ± 12.51 vs 170.39 ± 25.29; 49.83 ± 11.46 vs 170.39 ± 25.29; 83.99 ± 24.63 vs 170.39 ± 25.29, P < 0.01, respectively), and the survival times were prolonged in group BF1-2 (31.8 ± 4.2 vs 23.4 ± 2.1 and 29.4 ± 3.4 vs 23.4 ± 2.1, P < 0.05, respectively), and necrosis was mainly in severe or moderate degree in group BF1-2. No morphologicalchanges were detected in the myocardium, brain, liver and kidney tissues. Apoptotic characteristics could be seen in group BF1-2. The positive rates of bcl-2 and bax protein expression of each group by immunohistochemical staining were 10.0%, 10.0%, 20.0%, 10.0% and 20.0%; 90.0%, 80.0%, 80.0%, 40.0% and 30.0%, respectively. Loss of expression of bcl-2 mRNA in each group was to be found and the density of bax mRNA was increased progressively with increase of dose of bufalin by RT-PCR. CONCLUSION: Bufalin has significant anti-tumor activities in the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice with no marked toxicity and was able to induce apoptosis of transplanted tumor cells. This apoptosis may be mediated mainly via up-regulating the expression of apoptosis-regulated gene bax, which may be involved in its anti-tumor mechanism of bufalin.展开更多
AIM:To evaluate the significance ofγ-catenin in clinical pathology,cellular function and signaling mechanism in esophageal squamous cell carcinoma(ESCC).METHODS:The mRNA expression ofγ-catenin was detected by real-t...AIM:To evaluate the significance ofγ-catenin in clinical pathology,cellular function and signaling mechanism in esophageal squamous cell carcinoma(ESCC).METHODS:The mRNA expression ofγ-catenin was detected by real-time quantitative reverse transcription-polymerase chain reaction in 95 tissue specimens and evaluated for association with the clinicopathologic characteristics and survival time of patients with ESCC.siRNAs against humanγ-catenin were used to inhibitγ-catenin expression.Hanging drop aggregation assay and dispase-based dissociation assay were performed to detect the effect ofγ-catenin on ESCC cell-cell adhesion.Transwell assay was performed to determine cell migration.Luciferase-based transcriptional reporter assay(TOPflash)was used to measureβ-catenindependent transcription in cells with reducedγ-catenin expression.The expression and subcellular localizations ofβ-catenin and E-cadherin were examined using Western blot and immunofluorescence analysis.RESULTS:γ-catenin mRNA expression was significantly associated with tumor histological grade(P=0.017)in ESCC.Kaplan-Meier survival analysis showed thatγ-catenin expression levels had an impact on the survival curve,with lowγ-catenin indicating worse survival(P=0.003).The multivariate Cox regression analysis demonstrated thatγ-catenin was an independent prognostic factor for survival.Experimentally,silencingγ-catenin caused defects in cell-cell adhesion and a concomitant increase in cell migration in both KYSE150 and TE3 ESCC cells.Analysis of Wnt signaling revealed no activation event associated withγ-catenin expression.Totalβ-catenin and Triton X-100-insolubleβ-catenin were significantly reduced in theγ-catenin-specific siRNA-transfected KYSE150 and TE3 cells,whereas Triton X-100-solubleβ-catenin was not altered.Moreover,knocking downγ-catenin expression resulted in a significant decrease of E-cadherin and Triton X-100-insoluble desmocollin-2,along with reducedβ-catenin and E-cadherin membrane localization in ESCC cells.CONCLUSION:γ-catenin is a tumor suppressor in ESCC and may serve as a prognostic marker.Dysregulated expression ofγ-catenin may play important roles in ESCC progression.展开更多
Dragon Boat Festival herbal markets in the Qianxinan Buyi and Miao Autonomous Prefecture of southwestern Guizhou have a long well-conserved history.These markets,which are a feature of Buyi and Miao traditional medici...Dragon Boat Festival herbal markets in the Qianxinan Buyi and Miao Autonomous Prefecture of southwestern Guizhou have a long well-conserved history.These markets,which are a feature of Buyi and Miao traditional medicines,contain a rich diversity of medicinal plants and traditional medical knowledge.Today,people in southwestern Guizhou still believe that using herbs during the Dragon Boat Festival prevents and can treat disease.In this study,we identified the fresh herbal plants sold at the herbal markets of Xingren City and Zhenfeng County in Qianxinan Buyi and Miao Autonomous Prefecture and quantified their importance.We identified 141 plant species(belonging to 114 genera and 61 families).The plant family with the most species was Asteraceae(14 species).Informants reported that most medicinal plants are herbaceous,with 95.7%of plants used for decoction and 30.5%used for medicinal baths.Medicinal plants are most commonly used to treat rheumatism,injury,and abdominal diseases.The utilization frequency index and relative importance values indicated that Artemisia argyi and Acorus calamus are the most important plants sold at herbal markets during the Dragon Boat Festival.The price of medicinal materials sold in the market may serve as an indicator of the conservation status of species in the region.These findings indicate that the Dragon Boat Festival herbal markets in the Qianxinan Buyi and Miao Autonomous Prefecture fully embodies the characteristics of indigenous ethnomedicine and culture,and also exhibits the diversity of plant resources.We recommend that rare and endangered plants in this region be domesticated and protected.展开更多
Three new amide alkaloids piperlongumamides A-C(1-3),together with 12 known ones(4-15),were isolated from the fruits of Piper longum.The structures of the new isolates were determined using spectroscopic data analyses...Three new amide alkaloids piperlongumamides A-C(1-3),together with 12 known ones(4-15),were isolated from the fruits of Piper longum.The structures of the new isolates were determined using spectroscopic data analyses.Cytotoxic activity of these amides against HL-60(human leukemia),A-549(human lung cancer),MCF-7(human breast cancer),SMMC-7721(human liver cancer)and SW480(human rectal cancer)cell lines were evaluated.Piperchabamide B(11)exhibited weak inhibitory activity against HL-60(IC_(50)=21.32μM),A-549(IC_(50)=23.82μM)and MCF-7(IC_(50)=16.58μM)cell lines.展开更多
Limited by battery and computing re-sources,the computing-intensive tasks generated by Internet of Things(IoT)devices cannot be processed all by themselves.Mobile edge computing(MEC)is a suitable solution for this pro...Limited by battery and computing re-sources,the computing-intensive tasks generated by Internet of Things(IoT)devices cannot be processed all by themselves.Mobile edge computing(MEC)is a suitable solution for this problem,and the gener-ated tasks can be offloaded from IoT devices to MEC.In this paper,we study the problem of dynamic task offloading for digital twin-empowered MEC.Digital twin techniques are applied to provide information of environment and share the training data of agent de-ployed on IoT devices.We formulate the task offload-ing problem with the goal of maximizing the energy efficiency and the workload balance among the ESs.Then,we reformulate the problem as an MDP problem and design DRL-based energy efficient task offloading(DEETO)algorithm to solve it.Comparative experi-ments are carried out which show the superiority of our DEETO algorithm in improving energy efficiency and balancing the workload.展开更多
Although hydrophilic membranes are desired for reducing resistance to water permeation, hydrophilic surfaces are not used in the water-in-oil(W/O) membrane emulsification process because water spreads on the hydrophil...Although hydrophilic membranes are desired for reducing resistance to water permeation, hydrophilic surfaces are not used in the water-in-oil(W/O) membrane emulsification process because water spreads on the hydrophilic surface without forming droplets. Here, we report that a hydrophilic ceramic membrane can form a hydrophobic interface in diesel at a higher temperature;interestingly, the experiments show that the contact angle increases when the temperature rises. The hydrophilic membrane surface evolves into a hydrophobic interface, particularly near the boiling point of water, resulting in a water contact angle of 147.5° ± 1.2°. This work established a method for preparing W/O monodispersed emulsions by direct emulsification of hydrophilic ceramic membranes at a temperature close to the boiling point of water.Additionally, it made high flux of membrane emulsification of monodispersed W/O emulsions possible,which satisfied the industrial requirements of fluidized catalytic cracking in the petrochemical industry.展开更多
金属锂负极由于比容量高(3860 mAh·g^(-1))及氧化还原电位极低(-3.04 V vs.标准氢气电极(SHE)),被认为是实现高能量密度锂电池的理想负极。然而,金属锂电极与电解液反应剧烈,且锂离子在电极表面沉积不均匀容易产生枝晶,导致其循环...金属锂负极由于比容量高(3860 mAh·g^(-1))及氧化还原电位极低(-3.04 V vs.标准氢气电极(SHE)),被认为是实现高能量密度锂电池的理想负极。然而,金属锂电极与电解液反应剧烈,且锂离子在电极表面沉积不均匀容易产生枝晶,导致其循环稳定性和安全性都较差,限制了其应用推广。我们前期通过构建金属锂-碳纳米管(Li-CNT)复合结构,极大的提高了金属锂的比表面积,降低了电极电流密度,从而有效地抑制了锂枝晶的生长,提高了金属锂电极的循环稳定性和安全性能。本工作在前期工作基础上,采用简单的液相反应,利用4-氟苯乙烯(FPS)对Li-CNT进行表面修饰并进行原位聚合,得到了表面富含氟化锂(Li F)保护层的Li-CNT(FPS-Li-CNT)。该表面修饰层能够有效抑制电解液和空气对Li-CNT的侵蚀,显著的提高了LiCNT电极的界面稳定性。FPS-Li-CNT与磷酸铁锂正极(LFP)组成的LFP||FPS-Li-CNT全电池,在正负极容量配比为1:6条件下,能够稳定循环280圈,库伦效率达到97.7%。展开更多
Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascula...Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea.We found that sleep apnea aggravated brain edema,increased hippocampal neuron apoptosis,and worsened neurological function in this mouse model of subarachnoid hemorrhage.Then,we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died,and lactate dehydrogenase release increased,after 48 hours.We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1β,interleukin-18,inte rleukin-6,nuclear factorκB,pyro ptosis-related protein caspase-1,pro-caspase-1,and NLRP3,promoted the prolife ration of astrocytes,and increased the expression of hypoxia-inducible factor 1αand apoptosis-associated speck-like protein containing a CARD,which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.We also found that knockdown of hypoxia-inducible factor 1αexpression in vitro greatly reduced the damage to HY22 cells.These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis,at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.展开更多
Sea ice drift is mainly controlled by ocean currents, local wind, and internal ice stress. Information on sea ice motion, especially in situ synchronous observation of an ice velocity, a current velocity, and a wind s...Sea ice drift is mainly controlled by ocean currents, local wind, and internal ice stress. Information on sea ice motion, especially in situ synchronous observation of an ice velocity, a current velocity, and a wind speed, is of great significance to identify ice drift characteristics. A sea ice substitute, the so-called "modelled ice", which is made by polypropylene material with a density similar to Bohai Sea ice, is used to complete a free drift experiment in the open sea. The trajectories of isolated modelled ice, currents and wind in the Bohai Sea during non-frozen and frozen periods are obtained. The results show that the currents play a major role while the wind plays a minor role in the free drift of isolated modelled ice when the wind is mild in the Bohai Sea. The modelled ice drift is significantly affected by the ocean current and wind based on the ice–current–wind relationship established by a multiple linear regression. The modelled ice velocity calculated by the multiple linear regression is close to that of the in situ observation, the magnitude of the error between the calculated and observed ice velocities is less than12.05%, and the velocity direction error is less than 6.21°. Thus, the ice velocity can be estimated based on the observed current velocity and wind speed when the in situ observed ice velocity is missing. And the modelled ice of same thickness with a smaller density is more sensitive to the current velocity and the wind speed changes. In addition, the modelled ice drift characteristics are shown to be close to those of the real sea ice, which indicates that the modelled ice can be used as a good substitute of real ice for in situ observation of the free ice drift in the open sea, which helps solve time availability, safety and logistics problems related to in situ observation on real ice.展开更多
Lithium metal is regarded as the ultimate negative electrode material for secondary batteries due to its high energy density.However,it suffers from poor cycling stability because of its high reactivity with liquid el...Lithium metal is regarded as the ultimate negative electrode material for secondary batteries due to its high energy density.However,it suffers from poor cycling stability because of its high reactivity with liquid electrolytes.Therefore,continuous efforts have been put into improving the cycling Coulombic efficiency(CE)to extend the lifespan of the lithium metal negative electrode.Herein,we report that using dual-salt additives of LiPF_(6) and LiNO_(3) in an ether solvent-based electrolyte can significantly improve the cycling stability and rate capability of a Li-carbon(Li-CNT)composite.As a result,an average cycling CE as high as 99.30% was obtained for the Li-CNT at a current density of 2.5 mA cm^(-2) and an negative electrode to positive electrode capacity(N/P)ratio of 2.The cycling stability and rate capability enhancement of the Li-CNT negative electrode could be attributed to the formation of a better solid electrolyte interphase layer that contains both inorganic components and organic polyether.The former component mainly originates from the decomposition of the LiNO_(3) additive,while the latter comes from the LiPF_(6)-induced ring-opening polymerization of the ether solvent.This novel surface chemistry significantly improves the CE of Li negative electrode,revealing its importance for the practical application of lithium metal batteries.展开更多
The enzyme, dipeptidyl peptidase IV(DPP IV), is a novel target for the treatment of type 2 diabetes. Dipeptidyl peptidase IV inhibition improves the impaired insulin secretion and decrease postprandial concentration...The enzyme, dipeptidyl peptidase IV(DPP IV), is a novel target for the treatment of type 2 diabetes. Dipeptidyl peptidase IV inhibition improves the impaired insulin secretion and decrease postprandial concentrations of glucagon by enhancing the incretin hormone levels lucagon-like peptide-1(GLP-1) and glucose-dependent insulinotropic polypeptide/gastric inhibitory polypeptide(GIP). Recently, DPP IV inhibitors have attracted more and more attention, several of which have entered pre-clinical and clinical trials, and one has received approval for use as an anti-diabetic agent. Among the DPP IV inhibitors, two leading agents(sitagliptin and vildagliptin) have been shown to be effective in reducing glycosylated hemoglobin(HbAlc) and fasting plasma glucose(FPG) in patients with type 2 diabetes. This review summarizes the evidence supporting DPP IV inhibitors as potential antidiabetic agents.展开更多
Both a theoretical and an empirical model were developed for predicting the formation of soluble microbial products (SMP) during drinking water biofiltration. Four pilot-scale biofilters with ceramsite as the medium...Both a theoretical and an empirical model were developed for predicting the formation of soluble microbial products (SMP) during drinking water biofiltration. Four pilot-scale biofilters with ceramsite as the medium were fed with different acetate loadings for the determination of SMP formation. Using numerically simulated and measured parameters, the theoretical model was developed according to the substrate and biomass balance. The results of this model matched the measured data better for higher SMP formation but did not fit well when SMP formation was lower. In order to better simulate the reality and overcome the difficulties of measuring the kinetic parameters, a simpler empirical model was also developed. In this model, SMP formation was expressed as a function of fed organic loadings and the depth of the medium, and a much better fit was obtained.展开更多
BACKGROUND: The study aimed to explore the clinical presentations, laboratory findings, treatments and prognosis of patients with Haff disease after eating crayfi sh. METHODS: Sixteen patients with Haff disease after ...BACKGROUND: The study aimed to explore the clinical presentations, laboratory findings, treatments and prognosis of patients with Haff disease after eating crayfi sh. METHODS: Sixteen patients with Haff disease after eating crayfish were admitted to the Emergency Department of Beijing Chao-yang Hospital between June 2013 and August 2017. Clinical data was retrospectively analyzed. RESULTS: Alcohol consumption and exercise were found to be most commonly associated with the onset of rhabdomyolysis after consuming crayfi sh. Most patients were young adults and the symptoms mostly occurred within 24 hours of consumption of crayfi sh. Clinical symptoms included myalgia (100%), fatigue (87.5%), nausea (43.8%), dizziness (62.5%), chest distress (37.5%) and fever (18.8%). Also found after laboratory testing was elevations in the levels of creatine kinase (11,376±5,535 U/L), myoglobin (350±158 ng/mL), lactate dehydrogenase (6,539±3,180 U/L), alanine transaminase (174±71 U/L) and aspartate aminase (348±100 U/L). The incidence of renal dysfunction was low (6.25%), and all 16 patients had a good prognosis. CONCLUSION: Patients with Haff disease exhibited typical symptoms after consuming crayfish, and laboratory findings gave highly accurate diagnostic results. The development of rhabdomyolysis was considered to be associated with alcohol consumption and exercise, but further studies are needed to demonstrate its relationship with crayfi sh consumption. Compared with other causes of rhabdomyolysis, rhabdomyolysis after crayfi sh consumption has fewer complications and better prognosis.展开更多
BACKGROUND: Experimental data indicate that human growth-associated protein 43 mRNA expression coincides with axonal growth during nerve ganglion development; while neurocan, secreted from astrocytes, can inhibit spr...BACKGROUND: Experimental data indicate that human growth-associated protein 43 mRNA expression coincides with axonal growth during nerve ganglion development; while neurocan, secreted from astrocytes, can inhibit sprouting and elongation of the axonal growth cone. OBJECTIVE: To verify regulatory effects of cyclovirobuxine D (CVB-D) extracted from Chinese box branchlet on human growth-associated protein 43 (GAP-43), and neurocan expression in brain tissue of stroke-prone renovascular hypertensive (RHRSP) rats, at different time points after cerebral ischemia/reperfusion. DESIGN: Randomized grouping design and controlled animal study. SETTING: This study was performed at the Center of Guangdong Hospital of Traditional Chinese Medicine (a national key laboratory) from March 2003 to September 2006. MATERIALS: 100 healthy male Sprague-Dawley rats, aged 2 3 months and weighing 90-120 g, were selected for this study. CVB-D was provided by Nanjing Xiaoying Pharmaceutical Factory (Batch number: 307701). METHODS: The initial tip of renal arteries was clamped bilaterally for 10 weeks to establish the RHRSP model. 100 RHRSP rats were randomly divided into 4 groups: naive group (n = 10), sham surgery group (n = 10), CVB-D group (n = 40), and lesion group (n = 40). Rats in the naive group did not undergo any treatment, and cervical vessels of rats in the sham surgery group were exposed, but not blocked. The right middle cerebral artery of rats in the CVB-D group and lesion group were occluded to establish cerebral ischemia. Rats in the CVB-D group were intraperitoneally injected with CVB-D (6.48 mg/kg) every day and with saline (1.5 mL/injection) twice a day. Rats in the lesion group were intraperitoneally injected with saline (2 mL/injection). MAIN OUTCOME MEASURES: Immunohistochemistry was applied to detect GAP-43 and neurocan expression in the ischemic penumbra region of CVB-D and lesion brains at 2 hours post-cerebral ischemia and at 1, 7, 14, and 30 days post-perfusion (n = 10 at each time point). Similarly, GAP-43 and neurocan expression was detected in the right hemisphere of naive and sham-operated animals. The results were expressed as positive cells. RESULTS: A total of 100 rats were included in the final analysis. The number of GAP-43 positive cells increased in the CVB-D group 1, 7, 14, and 30 days post-cerebral ischemia/perfusion compared to the lesion group, as indicated by a significant difference between the CVB-D and lesion group (P 〈 0.054).01). The number of neurocan-positive cells decreased in the CVB-D group on the first day compared to the model group; however, there was no significant difference between the two groups (P 〉 0.05). On post-ischemia days 7, 14, and 30, the number of neurocan-positive cells in the CVB-D group was significantly less than in the lesion group (P 〈 0.05). Both, GAP-43 and neurocan expression was not detectable in brains of naive and sham-operated animals. CONCLUSION: CVB-D treatment up-regulated GAP-43 expression and down-regulated neurocan expression in the ischemic region of RHRSP rats.展开更多
The effect of dislocation structure evolution on low-angle grain boundary formation in 7050 aluminum alloy during aging was studied by using optical microscopy, transmission electron microscopy, and electron backscatt...The effect of dislocation structure evolution on low-angle grain boundary formation in 7050 aluminum alloy during aging was studied by using optical microscopy, transmission electron microscopy, and electron backscatter diffraction analysis of misorientation angle distribution, cumulative misorientation and geometrically necessary dislocation (GND) density. Experimental results indicate that coarse spindle-shaped grains with the dimension of 200 μm- 80 μm separate into fine equiaxed grains of 20μm in size as a result of newborn low-angle grain boundaries formed during the aging process. More specifically, the dislocation arrays, which are rearranged and formed due to scattered dislocations during earlier quenching, transform into low-angle grain boundaries with aging time. The relative frequency of 3°-5° low-angle grain boundaries increases to over 30%. The GND density, which describes low-angle grain boundaries with the misorientation angle under 3°, tends to decrease during initial aging. The inhomogeneous distribution of GNDs is affected by grain orientation. A decrease in GND density mainly occurs from 1.83 × 10^13 to 4.40 × 10^11 m^-2 in grains with 〈111〉 fiber texture. This is consistent with a decrease of unit cumulative misorientation. Precipitation on grain boundaries and the formation of a precipitation free zone (PFZ) are facilitated due to the eroding activity of the Graft etchant. Consequently, low-angle grain boundaries could be readily viewed by optical microscopy due to an increase in their electric potential difference.展开更多
基金the National Natural Science Foundation of China(61975056)the Shanghai Natural Science Foundation(19ZR1416000)+1 种基金the Science and Technology Commission of Shanghai Municipality(20440713100)the Scientific Development funds for Local Region from the Chinese Government in 2023(XZ202301YD0032C).
文摘Background Atrial septal defect(ASD)is one of the most common congenital heart diseases.The diagnosis of ASD via transthoracic echocardiography is subjective and time-consuming.Methods The objective of this study was to evaluate the feasibility and accuracy of automatic detection of ASD in children based on color Doppler echocardiographic static images using end-to-end convolutional neural networks.The proposed depthwise separable convolution model identifies ASDs with static color Doppler images in a standard view.Among the standard views,we selected two echocardiographic views,i.e.,the subcostal sagittal view of the atrium septum and the low parasternal four-chamber view.The developed ASD detection system was validated using a training set consisting of 396 echocardiographic images corresponding to 198 cases.Additionally,an independent test dataset of 112 images corresponding to 56 cases was used,including 101 cases with ASDs and 153 cases with normal hearts.Results The average area under the receiver operating characteristic curve,recall,precision,specificity,F1-score,and accuracy of the proposed ASD detection model were 91.99,80.00,82.22,87.50,79.57,and 83.04,respectively.Conclusions The proposed model can accurately and automatically identify ASD,providing a strong foundation for the intelligent diagnosis of congenital heart diseases.
文摘AIM: To investigate anti-tumor activities and apoptosis-regulated mechanisms of bufalin in the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice.METHODS: BEL-7402 cells of human hepatocellular carcinoma were inoculated to form subcutaneous tumors, and were implanted into the liver to establish orthotopic transplantation tumor models of human hepatocellular carcinoma in nude mice. Seventy-five animals were randomized divided into five groups (n = 15). Bufalin was injected intraperitoneally into three groups at doses of 1.5 mg/kg (BF1), 1 mg/kg (BF2) and 0.5 mg/kg (BF3) for d 15-24, respectively. The NS group was injected an equal volume of saline as above and adriamycin was injected intraperitoneally into the ADM group at a dose of 8.0 mg/kg for d 15. Ten mice in each group were killed at d 25 and the survival time in each group was calculated. We also observed the morphologic alterations in the myocardium, brain, liver, kidney and tumor tissues by pathology and electron microscopy, measured the apoptotic rate by TUNEL staining method, and detected the expression of apoptosis-regulated genes bcl-2 and bax by immunohistochemical staining and RT-PCR in tumor tissues. RESULTS: The tumor volumes in each group of bufalin were reduced significantly (35.21 ± 12.51 vs 170.39 ± 25.29; 49.83 ± 11.46 vs 170.39 ± 25.29; 83.99 ± 24.63 vs 170.39 ± 25.29, P < 0.01, respectively), and the survival times were prolonged in group BF1-2 (31.8 ± 4.2 vs 23.4 ± 2.1 and 29.4 ± 3.4 vs 23.4 ± 2.1, P < 0.05, respectively), and necrosis was mainly in severe or moderate degree in group BF1-2. No morphologicalchanges were detected in the myocardium, brain, liver and kidney tissues. Apoptotic characteristics could be seen in group BF1-2. The positive rates of bcl-2 and bax protein expression of each group by immunohistochemical staining were 10.0%, 10.0%, 20.0%, 10.0% and 20.0%; 90.0%, 80.0%, 80.0%, 40.0% and 30.0%, respectively. Loss of expression of bcl-2 mRNA in each group was to be found and the density of bax mRNA was increased progressively with increase of dose of bufalin by RT-PCR. CONCLUSION: Bufalin has significant anti-tumor activities in the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice with no marked toxicity and was able to induce apoptosis of transplanted tumor cells. This apoptosis may be mediated mainly via up-regulating the expression of apoptosis-regulated gene bax, which may be involved in its anti-tumor mechanism of bufalin.
基金Supported by the National Natural Science Foundation of China,No.81101613the Guangdong Provincial Natural Science Foundation of China,No.S2011040004363+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China,No.20114402120005the National Basic Research Program of China,No.2012CB526600the Natural Science Foundation of China-Guangdong Joint Fund,No.U0932001
文摘AIM:To evaluate the significance ofγ-catenin in clinical pathology,cellular function and signaling mechanism in esophageal squamous cell carcinoma(ESCC).METHODS:The mRNA expression ofγ-catenin was detected by real-time quantitative reverse transcription-polymerase chain reaction in 95 tissue specimens and evaluated for association with the clinicopathologic characteristics and survival time of patients with ESCC.siRNAs against humanγ-catenin were used to inhibitγ-catenin expression.Hanging drop aggregation assay and dispase-based dissociation assay were performed to detect the effect ofγ-catenin on ESCC cell-cell adhesion.Transwell assay was performed to determine cell migration.Luciferase-based transcriptional reporter assay(TOPflash)was used to measureβ-catenindependent transcription in cells with reducedγ-catenin expression.The expression and subcellular localizations ofβ-catenin and E-cadherin were examined using Western blot and immunofluorescence analysis.RESULTS:γ-catenin mRNA expression was significantly associated with tumor histological grade(P=0.017)in ESCC.Kaplan-Meier survival analysis showed thatγ-catenin expression levels had an impact on the survival curve,with lowγ-catenin indicating worse survival(P=0.003).The multivariate Cox regression analysis demonstrated thatγ-catenin was an independent prognostic factor for survival.Experimentally,silencingγ-catenin caused defects in cell-cell adhesion and a concomitant increase in cell migration in both KYSE150 and TE3 ESCC cells.Analysis of Wnt signaling revealed no activation event associated withγ-catenin expression.Totalβ-catenin and Triton X-100-insolubleβ-catenin were significantly reduced in theγ-catenin-specific siRNA-transfected KYSE150 and TE3 cells,whereas Triton X-100-solubleβ-catenin was not altered.Moreover,knocking downγ-catenin expression resulted in a significant decrease of E-cadherin and Triton X-100-insoluble desmocollin-2,along with reducedβ-catenin and E-cadherin membrane localization in ESCC cells.CONCLUSION:γ-catenin is a tumor suppressor in ESCC and may serve as a prognostic marker.Dysregulated expression ofγ-catenin may play important roles in ESCC progression.
基金This work was supported by the grants from the National Natural Science Foundation of China(31860074,U1812403)the Science and Technology project of Guizhou Province(QKHZC[2018]2799)and Guizhou Province Engineering Research Center for Natural Drugs.
文摘Dragon Boat Festival herbal markets in the Qianxinan Buyi and Miao Autonomous Prefecture of southwestern Guizhou have a long well-conserved history.These markets,which are a feature of Buyi and Miao traditional medicines,contain a rich diversity of medicinal plants and traditional medical knowledge.Today,people in southwestern Guizhou still believe that using herbs during the Dragon Boat Festival prevents and can treat disease.In this study,we identified the fresh herbal plants sold at the herbal markets of Xingren City and Zhenfeng County in Qianxinan Buyi and Miao Autonomous Prefecture and quantified their importance.We identified 141 plant species(belonging to 114 genera and 61 families).The plant family with the most species was Asteraceae(14 species).Informants reported that most medicinal plants are herbaceous,with 95.7%of plants used for decoction and 30.5%used for medicinal baths.Medicinal plants are most commonly used to treat rheumatism,injury,and abdominal diseases.The utilization frequency index and relative importance values indicated that Artemisia argyi and Acorus calamus are the most important plants sold at herbal markets during the Dragon Boat Festival.The price of medicinal materials sold in the market may serve as an indicator of the conservation status of species in the region.These findings indicate that the Dragon Boat Festival herbal markets in the Qianxinan Buyi and Miao Autonomous Prefecture fully embodies the characteristics of indigenous ethnomedicine and culture,and also exhibits the diversity of plant resources.We recommend that rare and endangered plants in this region be domesticated and protected.
基金This work was funded by the Natural Science Foundation of Yunnan Province,China(No.2011FZ205)the National Natural Science Foundation of China(Nos.31070288,31161140345)+1 种基金the Ministry of Education of China through its 111 and 985 projects(Nos.B08044,MUC98506-01000101&MUC985-9)the Japan Society for the Promotion of Science(No.JSPS/AP/109080).
文摘Three new amide alkaloids piperlongumamides A-C(1-3),together with 12 known ones(4-15),were isolated from the fruits of Piper longum.The structures of the new isolates were determined using spectroscopic data analyses.Cytotoxic activity of these amides against HL-60(human leukemia),A-549(human lung cancer),MCF-7(human breast cancer),SMMC-7721(human liver cancer)and SW480(human rectal cancer)cell lines were evaluated.Piperchabamide B(11)exhibited weak inhibitory activity against HL-60(IC_(50)=21.32μM),A-549(IC_(50)=23.82μM)and MCF-7(IC_(50)=16.58μM)cell lines.
基金This work was partly supported by the Project of Cultivation for young top-motch Talents of Beijing Municipal Institutions(No BPHR202203225)the Young Elite Scientists Sponsorship Program by BAST(BYESS2023031)the National key research and development program(No 2022YFF0604502).
文摘Limited by battery and computing re-sources,the computing-intensive tasks generated by Internet of Things(IoT)devices cannot be processed all by themselves.Mobile edge computing(MEC)is a suitable solution for this problem,and the gener-ated tasks can be offloaded from IoT devices to MEC.In this paper,we study the problem of dynamic task offloading for digital twin-empowered MEC.Digital twin techniques are applied to provide information of environment and share the training data of agent de-ployed on IoT devices.We formulate the task offload-ing problem with the goal of maximizing the energy efficiency and the workload balance among the ESs.Then,we reformulate the problem as an MDP problem and design DRL-based energy efficient task offloading(DEETO)algorithm to solve it.Comparative experi-ments are carried out which show the superiority of our DEETO algorithm in improving energy efficiency and balancing the workload.
基金the support from the National Key Research and Development Program of China (2021YFB3801303)the National Natural Science Foundation of China (21838005, 21921006)the Key Scientific Research and Development Projects of Jiangsu Province (BE201800901)。
文摘Although hydrophilic membranes are desired for reducing resistance to water permeation, hydrophilic surfaces are not used in the water-in-oil(W/O) membrane emulsification process because water spreads on the hydrophilic surface without forming droplets. Here, we report that a hydrophilic ceramic membrane can form a hydrophobic interface in diesel at a higher temperature;interestingly, the experiments show that the contact angle increases when the temperature rises. The hydrophilic membrane surface evolves into a hydrophobic interface, particularly near the boiling point of water, resulting in a water contact angle of 147.5° ± 1.2°. This work established a method for preparing W/O monodispersed emulsions by direct emulsification of hydrophilic ceramic membranes at a temperature close to the boiling point of water.Additionally, it made high flux of membrane emulsification of monodispersed W/O emulsions possible,which satisfied the industrial requirements of fluidized catalytic cracking in the petrochemical industry.
文摘金属锂负极由于比容量高(3860 mAh·g^(-1))及氧化还原电位极低(-3.04 V vs.标准氢气电极(SHE)),被认为是实现高能量密度锂电池的理想负极。然而,金属锂电极与电解液反应剧烈,且锂离子在电极表面沉积不均匀容易产生枝晶,导致其循环稳定性和安全性都较差,限制了其应用推广。我们前期通过构建金属锂-碳纳米管(Li-CNT)复合结构,极大的提高了金属锂的比表面积,降低了电极电流密度,从而有效地抑制了锂枝晶的生长,提高了金属锂电极的循环稳定性和安全性能。本工作在前期工作基础上,采用简单的液相反应,利用4-氟苯乙烯(FPS)对Li-CNT进行表面修饰并进行原位聚合,得到了表面富含氟化锂(Li F)保护层的Li-CNT(FPS-Li-CNT)。该表面修饰层能够有效抑制电解液和空气对Li-CNT的侵蚀,显著的提高了LiCNT电极的界面稳定性。FPS-Li-CNT与磷酸铁锂正极(LFP)组成的LFP||FPS-Li-CNT全电池,在正负极容量配比为1:6条件下,能够稳定循环280圈,库伦效率达到97.7%。
基金the Natural Science Foundation of Jiangsu Province(Youth Program),No.BK20190129National Scientific Program of Jiangsu Colleges and Universities of China,No.19KJB320012(both to LY)。
文摘Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea.We found that sleep apnea aggravated brain edema,increased hippocampal neuron apoptosis,and worsened neurological function in this mouse model of subarachnoid hemorrhage.Then,we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died,and lactate dehydrogenase release increased,after 48 hours.We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1β,interleukin-18,inte rleukin-6,nuclear factorκB,pyro ptosis-related protein caspase-1,pro-caspase-1,and NLRP3,promoted the prolife ration of astrocytes,and increased the expression of hypoxia-inducible factor 1αand apoptosis-associated speck-like protein containing a CARD,which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.We also found that knockdown of hypoxia-inducible factor 1αexpression in vitro greatly reduced the damage to HY22 cells.These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis,at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.
基金The National Natural Science Foundation of China under contract No.41571510the Fundamental Research Funds for the Central Universities of China under contract No.2014KJJCB02
文摘Sea ice drift is mainly controlled by ocean currents, local wind, and internal ice stress. Information on sea ice motion, especially in situ synchronous observation of an ice velocity, a current velocity, and a wind speed, is of great significance to identify ice drift characteristics. A sea ice substitute, the so-called "modelled ice", which is made by polypropylene material with a density similar to Bohai Sea ice, is used to complete a free drift experiment in the open sea. The trajectories of isolated modelled ice, currents and wind in the Bohai Sea during non-frozen and frozen periods are obtained. The results show that the currents play a major role while the wind plays a minor role in the free drift of isolated modelled ice when the wind is mild in the Bohai Sea. The modelled ice drift is significantly affected by the ocean current and wind based on the ice–current–wind relationship established by a multiple linear regression. The modelled ice velocity calculated by the multiple linear regression is close to that of the in situ observation, the magnitude of the error between the calculated and observed ice velocities is less than12.05%, and the velocity direction error is less than 6.21°. Thus, the ice velocity can be estimated based on the observed current velocity and wind speed when the in situ observed ice velocity is missing. And the modelled ice of same thickness with a smaller density is more sensitive to the current velocity and the wind speed changes. In addition, the modelled ice drift characteristics are shown to be close to those of the real sea ice, which indicates that the modelled ice can be used as a good substitute of real ice for in situ observation of the free ice drift in the open sea, which helps solve time availability, safety and logistics problems related to in situ observation on real ice.
基金the National Natural Science Foundation of China(Grant nos.21625304 and 21733012)the Ministry of Science and Technology(Grant No.2016YFA0200703).
文摘Lithium metal is regarded as the ultimate negative electrode material for secondary batteries due to its high energy density.However,it suffers from poor cycling stability because of its high reactivity with liquid electrolytes.Therefore,continuous efforts have been put into improving the cycling Coulombic efficiency(CE)to extend the lifespan of the lithium metal negative electrode.Herein,we report that using dual-salt additives of LiPF_(6) and LiNO_(3) in an ether solvent-based electrolyte can significantly improve the cycling stability and rate capability of a Li-carbon(Li-CNT)composite.As a result,an average cycling CE as high as 99.30% was obtained for the Li-CNT at a current density of 2.5 mA cm^(-2) and an negative electrode to positive electrode capacity(N/P)ratio of 2.The cycling stability and rate capability enhancement of the Li-CNT negative electrode could be attributed to the formation of a better solid electrolyte interphase layer that contains both inorganic components and organic polyether.The former component mainly originates from the decomposition of the LiNO_(3) additive,while the latter comes from the LiPF_(6)-induced ring-opening polymerization of the ether solvent.This novel surface chemistry significantly improves the CE of Li negative electrode,revealing its importance for the practical application of lithium metal batteries.
文摘The enzyme, dipeptidyl peptidase IV(DPP IV), is a novel target for the treatment of type 2 diabetes. Dipeptidyl peptidase IV inhibition improves the impaired insulin secretion and decrease postprandial concentrations of glucagon by enhancing the incretin hormone levels lucagon-like peptide-1(GLP-1) and glucose-dependent insulinotropic polypeptide/gastric inhibitory polypeptide(GIP). Recently, DPP IV inhibitors have attracted more and more attention, several of which have entered pre-clinical and clinical trials, and one has received approval for use as an anti-diabetic agent. Among the DPP IV inhibitors, two leading agents(sitagliptin and vildagliptin) have been shown to be effective in reducing glycosylated hemoglobin(HbAlc) and fasting plasma glucose(FPG) in patients with type 2 diabetes. This review summarizes the evidence supporting DPP IV inhibitors as potential antidiabetic agents.
基金supported by the National Natural Science Foundation of China (Grant No. 50408026)
文摘Both a theoretical and an empirical model were developed for predicting the formation of soluble microbial products (SMP) during drinking water biofiltration. Four pilot-scale biofilters with ceramsite as the medium were fed with different acetate loadings for the determination of SMP formation. Using numerically simulated and measured parameters, the theoretical model was developed according to the substrate and biomass balance. The results of this model matched the measured data better for higher SMP formation but did not fit well when SMP formation was lower. In order to better simulate the reality and overcome the difficulties of measuring the kinetic parameters, a simpler empirical model was also developed. In this model, SMP formation was expressed as a function of fed organic loadings and the depth of the medium, and a much better fit was obtained.
基金supported by the Beijing Natural Science Foundation(7182055)Beijing Municipal Administration of Hospitals Incubating Program(Px2016022)
文摘BACKGROUND: The study aimed to explore the clinical presentations, laboratory findings, treatments and prognosis of patients with Haff disease after eating crayfi sh. METHODS: Sixteen patients with Haff disease after eating crayfish were admitted to the Emergency Department of Beijing Chao-yang Hospital between June 2013 and August 2017. Clinical data was retrospectively analyzed. RESULTS: Alcohol consumption and exercise were found to be most commonly associated with the onset of rhabdomyolysis after consuming crayfi sh. Most patients were young adults and the symptoms mostly occurred within 24 hours of consumption of crayfi sh. Clinical symptoms included myalgia (100%), fatigue (87.5%), nausea (43.8%), dizziness (62.5%), chest distress (37.5%) and fever (18.8%). Also found after laboratory testing was elevations in the levels of creatine kinase (11,376±5,535 U/L), myoglobin (350±158 ng/mL), lactate dehydrogenase (6,539±3,180 U/L), alanine transaminase (174±71 U/L) and aspartate aminase (348±100 U/L). The incidence of renal dysfunction was low (6.25%), and all 16 patients had a good prognosis. CONCLUSION: Patients with Haff disease exhibited typical symptoms after consuming crayfish, and laboratory findings gave highly accurate diagnostic results. The development of rhabdomyolysis was considered to be associated with alcohol consumption and exercise, but further studies are needed to demonstrate its relationship with crayfi sh consumption. Compared with other causes of rhabdomyolysis, rhabdomyolysis after crayfi sh consumption has fewer complications and better prognosis.
基金the grants from Guangdong Province Administration of Traditional Chinese Medicine, No.103142
文摘BACKGROUND: Experimental data indicate that human growth-associated protein 43 mRNA expression coincides with axonal growth during nerve ganglion development; while neurocan, secreted from astrocytes, can inhibit sprouting and elongation of the axonal growth cone. OBJECTIVE: To verify regulatory effects of cyclovirobuxine D (CVB-D) extracted from Chinese box branchlet on human growth-associated protein 43 (GAP-43), and neurocan expression in brain tissue of stroke-prone renovascular hypertensive (RHRSP) rats, at different time points after cerebral ischemia/reperfusion. DESIGN: Randomized grouping design and controlled animal study. SETTING: This study was performed at the Center of Guangdong Hospital of Traditional Chinese Medicine (a national key laboratory) from March 2003 to September 2006. MATERIALS: 100 healthy male Sprague-Dawley rats, aged 2 3 months and weighing 90-120 g, were selected for this study. CVB-D was provided by Nanjing Xiaoying Pharmaceutical Factory (Batch number: 307701). METHODS: The initial tip of renal arteries was clamped bilaterally for 10 weeks to establish the RHRSP model. 100 RHRSP rats were randomly divided into 4 groups: naive group (n = 10), sham surgery group (n = 10), CVB-D group (n = 40), and lesion group (n = 40). Rats in the naive group did not undergo any treatment, and cervical vessels of rats in the sham surgery group were exposed, but not blocked. The right middle cerebral artery of rats in the CVB-D group and lesion group were occluded to establish cerebral ischemia. Rats in the CVB-D group were intraperitoneally injected with CVB-D (6.48 mg/kg) every day and with saline (1.5 mL/injection) twice a day. Rats in the lesion group were intraperitoneally injected with saline (2 mL/injection). MAIN OUTCOME MEASURES: Immunohistochemistry was applied to detect GAP-43 and neurocan expression in the ischemic penumbra region of CVB-D and lesion brains at 2 hours post-cerebral ischemia and at 1, 7, 14, and 30 days post-perfusion (n = 10 at each time point). Similarly, GAP-43 and neurocan expression was detected in the right hemisphere of naive and sham-operated animals. The results were expressed as positive cells. RESULTS: A total of 100 rats were included in the final analysis. The number of GAP-43 positive cells increased in the CVB-D group 1, 7, 14, and 30 days post-cerebral ischemia/perfusion compared to the lesion group, as indicated by a significant difference between the CVB-D and lesion group (P 〈 0.054).01). The number of neurocan-positive cells decreased in the CVB-D group on the first day compared to the model group; however, there was no significant difference between the two groups (P 〉 0.05). On post-ischemia days 7, 14, and 30, the number of neurocan-positive cells in the CVB-D group was significantly less than in the lesion group (P 〈 0.05). Both, GAP-43 and neurocan expression was not detectable in brains of naive and sham-operated animals. CONCLUSION: CVB-D treatment up-regulated GAP-43 expression and down-regulated neurocan expression in the ischemic region of RHRSP rats.
文摘The effect of dislocation structure evolution on low-angle grain boundary formation in 7050 aluminum alloy during aging was studied by using optical microscopy, transmission electron microscopy, and electron backscatter diffraction analysis of misorientation angle distribution, cumulative misorientation and geometrically necessary dislocation (GND) density. Experimental results indicate that coarse spindle-shaped grains with the dimension of 200 μm- 80 μm separate into fine equiaxed grains of 20μm in size as a result of newborn low-angle grain boundaries formed during the aging process. More specifically, the dislocation arrays, which are rearranged and formed due to scattered dislocations during earlier quenching, transform into low-angle grain boundaries with aging time. The relative frequency of 3°-5° low-angle grain boundaries increases to over 30%. The GND density, which describes low-angle grain boundaries with the misorientation angle under 3°, tends to decrease during initial aging. The inhomogeneous distribution of GNDs is affected by grain orientation. A decrease in GND density mainly occurs from 1.83 × 10^13 to 4.40 × 10^11 m^-2 in grains with 〈111〉 fiber texture. This is consistent with a decrease of unit cumulative misorientation. Precipitation on grain boundaries and the formation of a precipitation free zone (PFZ) are facilitated due to the eroding activity of the Graft etchant. Consequently, low-angle grain boundaries could be readily viewed by optical microscopy due to an increase in their electric potential difference.