Nerve guidance conduits (NGCs) are tubular structures that are used to bridge the gap of a severed nerve, thereby acting as a guide and protective micro-environment for the regenerating axons and as a barrier against ...Nerve guidance conduits (NGCs) are tubular structures that are used to bridge the gap of a severed nerve, thereby acting as a guide and protective micro-environment for the regenerating axons and as a barrier against the in-growth of scar-forming tissue. In the last few decades, the concept of NGCs has evolved from a research tool to investigate nerve regeneration into a translational product that is now being used clinically as an alternative for autologous nerve graft repair, due to their availability and ease of fabrication.展开更多
In this study, we examined the effects of neuroglobin gene (Ngb) transfection into SH-SY5Y cells, using ultrasound-targeted microbubble destruction (UTMD), on cobalt chloride-induced hypoxia. With an ultrasound intens...In this study, we examined the effects of neuroglobin gene (Ngb) transfection into SH-SY5Y cells, using ultrasound-targeted microbubble destruction (UTMD), on cobalt chloride-induced hypoxia. With an ultrasound intensity of 0.8 W/cm2, a 60-second exposure duration, 50% duty cycle, and 20% microbubble concentration, pAcGFP1-C1-Ngb-transfected cells exhibited the highest cell viability and transfection efficiency. The efficiency of plasmid delivery was significantly higher with UTMD than transfection with plasmid alone, transfection with plasmid using microbubbles, or transfection of plasmid by ultrasound. In addition, during cobalt chloride-induced hypoxia, caspase-3 activity in pAcGFP1-C1-Ngb-transfected cells was significantly lower than in untransfected cells. Ngb protein and mRNA expression were significantly higher in cells transfected by UTMD than in cells transfected with the other methods. These results demonstrate that UTMD can very efficiently mediate exogenous gene delivery, and that Ngb overexpression protects cells against cobalt chloride-induced hypoxia.展开更多
Sluggish charge transfer in perovskite film induced by inherent defects such as uncoordinated Pb2+undoubtedly hinders the rapid response of self-powered photovoltaic-typed detector.Based on interaction between Lewis a...Sluggish charge transfer in perovskite film induced by inherent defects such as uncoordinated Pb2+undoubtedly hinders the rapid response of self-powered photovoltaic-typed detector.Based on interaction between Lewis acids and bases,herein,we employ thiourea molecule as a multifunctional Lewis base to significantly improve the quality of all-inorganic CsPbIBr2 perovskite film.After careful characterizations,the quality of perovskite film has been well regulated.Arising from the reduced defect and the reinforced the interfacial charge extraction owing to the strong interaction between uncoordinated Pb2+ions and the-C=S groups in thiourea and the formation of hydrogen bond at perovskite/TiO_(2) interface,an enhanced responsivity of 0.335 A W-1 and specific detectivity of 3.92×10^(12) Jones has been achieved for the self-powered,carbon-electrode based photodetector,which is comparable to the state-of-theart device based on CsPbIBr2 film.More importantly,the device free of encapsulation remains 82.8%of initial performance after storage over 56 days in ambient atmosphere,promoting the practical deployment of perovskite products.展开更多
Taking the scholarly activities of 73 doctoral program mentors working at the Chinese Academy of Medical Sciences&Peking Union Medical College(the CAMS&PUMC)as a sample of our investigative survey,we tried usi...Taking the scholarly activities of 73 doctoral program mentors working at the Chinese Academy of Medical Sciences&Peking Union Medical College(the CAMS&PUMC)as a sample of our investigative survey,we tried using such statistical methods as the analysis of variance(ANOVA),factor analysis and correlation analysis to compare the different characteristics of scholarship assessment of Chinese medical scholars as exhibited in their published papers in domestic and foreign journals.Our research findings show that citations per paper and A-index are more suitable for assessing the highly accomplished senior Chinese medical professionals(e.g.academicians)for their domestic and international scholarship attainment.In contrast,the m-quotient is not deemed appropriate to assess their academic influence both at home and abroad.Upon our further analysis of 6 evaluative indicators,we noticed that these indicators might be applied in two different aspects:One is from the viewpoint of Chinese scholars’academic influence at home,which has been evaluated mainly from the perspective of"total"amount and"average"amount of both publications and citations.The other is from their academic impact embodied by the means of documents retrieved from the Web of Science,which is mainly assessed from the two viewpoints of publications and citations.It is suggested that the accumulated time-length of a given scholar’s active engagement in professional practice in a specific subject area be taken into consideration while assessing a researcher’s performance at home and abroad.展开更多
Tumor proliferation,metabolism,metastasis,and chemoresistance are intimately related to the tumor microenvironment(TME).The metabolic reprogramming of tumor cells is a hallmark of their adaptation to hypoxic and nutri...Tumor proliferation,metabolism,metastasis,and chemoresistance are intimately related to the tumor microenvironment(TME).The metabolic reprogramming of tumor cells is a hallmark of their adaptation to hypoxic and nutrient-deficient TMEs.Exosomes,a type of extracellular vesicle,have been found to regulate the crosstalk between tumor cells and the TME,affecting tumor metabolic reprogramming.In this review,we introduce the metabolic characteristics of tumor cells;describe the crosstalk between tumor cells and the TME in terms of glucose metabolism,lipid metabolism,and amino acid metabolism through exosomes;and provide an overview of the diagnostic and therapeutic potential of exosomes.A better understanding of tumor metabolism would provide a broader perspective about the mechanisms underlying tumor pathology and would facilitate the search for therapeutic targets and guide more individualized tumor treatment.展开更多
Compared with the traditional train,the operational speed of the high-speed train has largely improved,and thedynamicenvironmentofthetrainhaschangedfromoneof mechanical domination to one of aerodynamic domination.The ...Compared with the traditional train,the operational speed of the high-speed train has largely improved,and thedynamicenvironmentofthetrainhaschangedfromoneof mechanical domination to one of aerodynamic domination.The aerodynamic problem has become the key technological challenge of high-speed trains and significantl affects the economy,environment,safety,and comfort.In this paper,the relationships among the aerodynamic design principle,aerodynamic performance indexes,and design variables are firs studied,and the research methods of train aerodynamics are proposed,including numerical simulation,a reducedscale test,and a full-scale test.Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface.Optimization design of the streamlined head includes conception design,project design,numerical simulation,and a reduced-scale test.Smooth design of the body surface is mainly used for the key parts,such as electric-current collecting system,wheel truck compartment,and windshield.The aerodynamic design method established in this paper has been successfully applied to various high-speed trains(CRH380A,CRH380 AM,CRH6,CRH2 G,and the Standard electric multiple unit(EMU)) that have met expected design objectives.The research results can provide an effective guideline for the aerodynamic design of high-speed trains.展开更多
Due to the deterioration of serious energy dilemma,energy-conservation and emission–reduction have been the strategic target in the past decades,thus people have identified the vital importance of higher energy effic...Due to the deterioration of serious energy dilemma,energy-conservation and emission–reduction have been the strategic target in the past decades,thus people have identified the vital importance of higher energy efficiency and the influence of lower carbon development.Since work exchange network is a significant part of energy recovery system,its optima design will have dramatically significant effect on energy consumption reduction in chemical process system.With an extension of the developed transshipment model in isothermal process,a novel step-wise methodology for synthesis of direct work exchange network(WEN)in adiabatic process involving heat integration is first proposed in this paper,where a nonlinear programming(NLP)model is formulated by regarding the minimum utility consumption as objective function and optimizing the initial WEN in accordance with the presented matching rules to get the optimized WEN configuration at first.Furthermore,we focus on the work exchange network synthesis with heat integration to attain the minimal total annual cost(TAC)with the introduction of heat-exchange equipment that is achieved by the following strategies in sequence:introducing heat-exchange equipment directly,adjusting the work quantity of the adjacent utility compressors or expanders,and approximating upper/lower pressure limits consequently to obtain considerable cost savings of expanders or compressors and work utility.Finally,a case taken from the literature is studied to illustrate the feasibility and effectiveness of the proposed method.展开更多
The prognosis of patients with previously treated tuberculosis (TB) was suggested to be dependent on whether the initial treatment was in compliance with the established guidelines. The aim of this retrospective multi...The prognosis of patients with previously treated tuberculosis (TB) was suggested to be dependent on whether the initial treatment was in compliance with the established guidelines. The aim of this retrospective multicenter study was to determine the proportion of new TB patients who received standard doses of rifampicin in multiple provinces of China, and the relationship between low doses of rifampicin and frequency of rifampicin-resistance as well as treatment outcomes. A total of 713 new TB patients were treated with either once-daily dose of bulk anti-TB drugs (group I) or every other day combination blister packs of anti-TB drugs containing rifampicin (group II) at more than 30 TB treatment centers/hospitals in China. Treatment history, therapeutic doses of rifampicin, and information about patients were extracted from their medical records and analyzed, and rifampicin-resistance of isolates collected from patients following the treatment as well as treatment outcomes were compared between two treatment groups. Among 522 patients in treatment group I, 154 (29.5%) received standard and 363 (69.5%) received low doses of rifampicin;238 (45.6%) isolates were rifampicin-resistant, and 243 (46.6%) were successfully treated. Among 191 patients in treatment group II, 175 (91.6%) received standard and 15 (7.9%) received low doses of rifampicin;72 (37.7%) isolates were rifampicin-resistant, and 105 (55%) were successfully treated. When patients who received low doses of rifampicin were compared to others within the same treatment group, increased rates for rifampicin-resistance and treatment failure were observed. Results from this study showed that most new TB patients in treatment group I (69.5%) received low doses of rifampicin, and their treatment outcomes were worse than those in treatment group II, indicating that low doses of rifampicin used for the initial treatment of new TB patients were correlated to increased frequency of rifampicin-resistance and poorer treatment outcomes.展开更多
Purpose:Given the information overload of scientific literature,there is an increasing need for computable biomedical knowledge buried in free text.This study aimed to develop a novel approach to extracting and measur...Purpose:Given the information overload of scientific literature,there is an increasing need for computable biomedical knowledge buried in free text.This study aimed to develop a novel approach to extracting and measuring uncertain biomedical knowledge from scientific statements.Design/methodology/approach:Taking cardiovascular research publications in China as a sample,we extracted subject-predicate-object triples(SPO triples)as knowledge units and unknown/hedging/conflicting uncertainties as the knowledge context.We introduced information entropy(IE)as potential metric to quantify the uncertainty of epistemic status of scientific knowledge represented at subject-object pairs(SO pairs)levels.Findings:The results indicated an extraordinary growth of cardiovascular publications in China while only a modest growth of the novel SPO triples.After evaluating the uncertainty of biomedical knowledge with IE,we identified the Top 10 SO pairs with highest IE,which implied the epistemic status pluralism.Visual presentation of the SO pairs overlaid with uncertainty provided a comprehensive overview of clusters of biomedical knowledge and contending topics in cardiovascular research.Research limitations:The current methods didn’t distinguish the specificity and probabilities of uncertainty cue words.The number of sentences surrounding a given triple may also influence the value of IE.Practical implications:Our approach identified major uncertain knowledge areas such as diagnostic biomarkers,genetic polymorphism and co-existing risk factors related to cardiovascular diseases in China.These areas are suggested to be prioritized;new hypotheses need to be verified,while disputes,conflicts,and contradictions need to be settled.Originality/value:We provided a novel approach by combining natural language processing and computational linguistics with informetric methods to extract and measure uncertain knowledge from scientific statements.展开更多
Purpose:This paper develops and validates a bibliometric framework for identifying the "princes"(PR) who wake up the "sleeping beauty"(SB) in challenge-type scientific discoveries,so as to figure o...Purpose:This paper develops and validates a bibliometric framework for identifying the "princes"(PR) who wake up the "sleeping beauty"(SB) in challenge-type scientific discoveries,so as to figure out the awakening mechanisms,and promote potentially valuable but not readily accepted innovative research.(A PR is a research study.)Design/methodology/approach:We propose that PR candidates must meet the following four criteria:(1) be published near the time when the SB began to attract a lot of citations;(2) be highly cited papers themselves;(3) receive a substantial number of co-citations with the SB;and(4) within the challenge-type discoveries which contradict established theories,the "pulling effect" of the PR on the SB must be strong.We test the usefulness of the bibliometric framework through a case study of a key publication by the 2014 chemistry Nobel laureate Stefan W.Hell,who negated Ernst Abbe's diffraction limit theory,one of the most prominent paradigms in the natural sciences.Findings:The first-ranked candidate PR article identified by the bibliometric framework is in line with historical facts.An SB may need one or more PRs and even "retinues" to be "awakened." Documents with potential awakening functionality tend to be published in prestigious multidisciplinary journals with higher impact and wider scope than the journals publishing SBs.Research limitations:The above framework is only applicable to transformative innovations,and the conclusions are drawn from the analysis of one typical SB and her awakening process.Therefore the generality of our work might be limited.Practical implications:Publications belonging to so-called transformative research,even when less frequently cited,should be given special attention as early as possible,because they may suddenly attract many citations after a period of sleep,as reflected in our case study.Originality/value:The definition of PR(s) as the first paper(s) that cited the SB article(selfciting excluded) has its limitations.Instead,the SB-PR co-citations should be given priority in current environment of scholarly communication.Since the "premature" or "transformative" breakthroughs in the challenge-type SB documents are either beyond the current knowledge domain,or violate established paradigms,people's psychological distance from the SB is larger than that from the PR,which explains why the annual citations of the PR are usually higher than those of the SB,especially prior to or during the SB's citation boom period.展开更多
Over the last three decades,flexibility and controllability considerations for heat exchanger networks(HENs)have received great attention,respectively.However,they should be simultaneously incorporated in HEN synthesi...Over the last three decades,flexibility and controllability considerations for heat exchanger networks(HENs)have received great attention,respectively.However,they should be simultaneously incorporated in HEN synthesis to allow the economic performance to be achievable in a practical operating environment.This paper proposes a method for simultaneous synthesis of flexible and controllable HEN by considering their coupling.The key idea is to add the bypasses with optimized initial fractions and positions to explore such coupling,and consequently enabling HENs to be operated successfully over a range of disturbance variations.These are implemented by identifying and quantifying disturbance propagations,and then examining the sensitivity of bypasses to the entire HEN.In this way,the superstructurebased mixed integer non-linear programming(MINLP)with objective function of minimizing the total annual cost is formulated.A case study is used to demonstrate the application of the proposed method.Quantitative measures and dynamic simulation show the ability to provide the satisfactory flexibility and controllability of the obtained HEN.展开更多
In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In co...In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In contrast with superstructure method, the transshipment model is easier to obtain the minimum utility consumption taken as the objective function and more convenient for us to attain the optimal network configuration for further minimizing the number of units. Different from division of temperature intervals in heat exchange networks,different pressure intervals are gained according to the maximum compression/expansion ratio in consideration of operating principles of indirect work exchangers and the characteristics of no pressure constraints for stream matches. The presented approach for WEN synthesis is a linear programming model applied to the isothermal process, but for indirect work exchange networks with adiabatic process, a nonlinear programming model needs establishing. Additionally, temperatures should be regarded as decision variables limited to the range between inlet and outlet temperatures in each sub-network. The constructed transshipment model can be solved first to get the minimum utility consumption and further to determine the minimum number of units by merging the adjacent pressure intervals on the basis of the proposed merging methods, which is proved to be effective through exergy analysis at the level of units structures. Finally, two cases are calculated to confirm it is dramatically feasible and effective that the optimal WEN configuration can be gained by the proposed method.展开更多
BACKGROUND:Glossy privet fruit inhibits neural cell apoptosis following the onset of vascular dementia. OBJECTIVE:To confirm glossy privet fruit effects on neural cell apoptosis in the cortical parietal lobe and hippo...BACKGROUND:Glossy privet fruit inhibits neural cell apoptosis following the onset of vascular dementia. OBJECTIVE:To confirm glossy privet fruit effects on neural cell apoptosis in the cortical parietal lobe and hippocampal CA1 region of rat models of vascular dementia using molecular biology techniques. DESIGN,TIME AND SETTING: The neural cell morphology experiment was performed at the Laboratory of Flow Cells and Biochemistry,Academy of Integrative Medicine,Fujian University of Traditional Chinese Medicine,and the Basic Room of Pathology,Academy of Chinese Medicine from December 2006 to May 2008. MATERIALS: A total of 60 Wistar rats were used to establish vascular dementia models using a photochemical reaction method. Glossy privet fruit was purchased from Fujian,China. Hydergine was co-produced by Sandoz,Switzerland and Huajin,China. METHODS: The 60 Wistar rats were randomly divided into 6 equal sized groups (n=10),i.e. model,blank,high,moderate and low doses of Chinese medicine,and hydergine control groups. Rats in the model group were treated with distilled water (1mL/100g) by gavage following model establishment. Rats in the blank group underwent experimental procedures as for the model group,except that rat models were created without illumination. Rats in the high,moderate and low doses of Chinese medicine groups,and the hydergine control group respectively received high,moderate and low doses of glossy privet fruit,and hydergine suspension (1 mL/100 g) by gavage,once a day,for 30 days. MAIN OUTCOME MEASURES: Morphology of neural cells from the rat cortical parietal lobe and hippocampal CA1 region of all groups was observed with an electron microscope. Positive neural cells in the injury site of the rat cortical parietal lobe and hippocampal CA1 region were investigated using the Fas immunohistochemical method. Absorbance of Fas-positive neurons was detected by the MPIAS-500 multimedia color imaging analysis system. RESULTS: Neural cells were normal,and nuclei were regular in the right cortical parietal lobe and hippocampal CA1 region in the blank group. Karyopyknosis,an integral nuclear membrane,vacuole and apoptotic bodies were presented in the model group. The quantity and morphology of neural cells were normal in all doses of Chinese medicine groups,and the hydergine control group. Compared with the model group,absorbance was reduced at the injury site of rat cortical parietal lobe and hippocampal CA1 region in the blank,high,moderate and low doses of Chinese medicine,and hydergine control groups (P<0.05). The decrease was particularly significant in the blank group (P<0.01),followed by the high dose of Chinese medicine group (P<0.01). Compared with the model group,the percentage of apoptosis was decreased at the injury site of the rat cortical parietal lobe and hippocampal CA1 region in the blank,high,moderate and low doses of Chinese medicine,and hydergine control groups (P<0.01) and this decrease was significant in the high dose of Chinese medicine group (P<0.01). CONCLUSION: Glossy privet fruit,a kidney-tonifying Chinese herbal medicine,can inhibit cell apoptosis by reducing apoptotic signals induced by cerebral ischemia/hypoxia.展开更多
BACKGROUND Uncarboxylated osteocalcin(GluOC)has been reported to improve glucose metabolism,prevent type 2 diabetes,and decrease the severity of obesity in mice with type 2 diabetes.GluOC can increase glucose uptake i...BACKGROUND Uncarboxylated osteocalcin(GluOC)has been reported to improve glucose metabolism,prevent type 2 diabetes,and decrease the severity of obesity in mice with type 2 diabetes.GluOC can increase glucose uptake in a variety of cells.Glucose metabolism is the main source of energy for osteoblast proliferation and differentiation.We hypothesized that decarboxylated osteocalcin(dcOC),a kind of GluOC,can increase glucose uptake in MG63 cells(osteoblast-like osteosarcoma cells)and influence their proliferation and differentiation.AIM To investigate the effects of dcOC on glucose uptake in human osteoblast-like osteosarcoma cells and the possible signaling pathways involved.METHODS MG63 cells(human osteoblast-like osteosarcoma cells)were treated with dcOC(0,0.3,3,10,or 30 ng/mL)for 1 and 72 h,and glucose uptake was measured by flow cytometry.The effect of dcOC on cell proliferation was measured with a CCK-8 assay,and alkaline phosphatase(ALP)enzyme activity was measured.PI3K was inhibited with LY294002,and hypoxia-inducible factor 1 alpha(HIF-1α)was silenced with siRNA.Then,GPRC6A(G protein-coupled receptor family C group 6 subtype A),total Akt,phosphorylated Akt,HIF-1α,and glucose transporter 1(GLUT1)levels were measured by Western blot to elucidate the possible pathways by which dcOC modulates glucose uptake.RESULTS The glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after short-term(1 h)treatment with dcOC at different concentrations(0.3,3,and 10 ng/mL groups,P<0.01;30 ng/mL group,P<0.05).Glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after long-term(72 h)treatment with dcOC at different concentrations(0.3,3,and 10 ng/mL groups,P<0.01;30 ng/mL group,P<0.05).DcOC triggered Akt phosphorylation in a dose-dependent manner,and the most effective stimulatory concentration of dcOC for short-term(1 h)was 3 ng/mL(P<0.01).LY294002 abolished the dcOC-mediated(1 h)promotion of Akt phosphorylation and glucose uptake without affecting GLUT1 protein expression.Long-term dcOC stimulation triggered Akt phosphorylation and increased the protein levels of HIF-1α,GLUT1,and Runx2 in a dose-dependent manner.Inhibition of HIF-1αwith siRNA abolished the dcOC-mediated glucose uptake and substantially decreased GLUT1 protein expression.DcOC interven-tion promoted cell proliferation in a time-and dose-dependent manner as determined by the CCK-8 assay.Treatment with both 3 ng/mL and 10 ng/mL dcOC affected the ALP activity in MG63 cells after 72 h(P<0.01).CONCLUSION Short-and long-term dcOC treatment can increase glucose uptake and affect proliferation and ALP activity in MG63 cells.This effect may occur through the PI3K/Akt,HIF-1α,and GLUT1 signaling factors.展开更多
Corn to sugar process has long faced the risks of high energy consumption and thin profits.However,it’s hard to upgrade or optimize the process based on mechanism unit operation models due to the high complexity of t...Corn to sugar process has long faced the risks of high energy consumption and thin profits.However,it’s hard to upgrade or optimize the process based on mechanism unit operation models due to the high complexity of the related processes.Big data technology provides a promising solution as its ability to turn huge amounts of data into insights for operational decisions.In this paper,a neural network-based production process modeling and variable importance analysis approach is proposed for corn to sugar processes,which contains data preprocessing,dimensionality reduction,multilayer perceptron/convolutional neural network/recurrent neural network based modeling and extended weights connection method.In the established model,dextrose equivalent value is selected as the output,and 654 sites from the DCS system are selected as the inputs.LASSO analysis is first applied to reduce the data dimension to 155,then the inputs are dimensionalized to 50 by means of genetic algorithm optimization.Ultimately,variable importance analysis is carried out by the extended weight connection method,and 20 of the most important sites are selected for each neural network.The results indicate that the multilayer perceptron and recurrent neural network models have a relative error of less than 0.1%,which have a better prediction result than other models,and the 20 most important sites selected have better explicable performance.The major contributions derived from this work are of significant aid in process simulation model with high accuracy and process optimization based on the selected most important sites to maintain high quality and stable production for corn to sugar processes.展开更多
Synthesis of heat exchanger networks including expansion process is a complex task due to the involvement of both heat and work.A stream that expands through expanders can produce work and cold load,while expansion th...Synthesis of heat exchanger networks including expansion process is a complex task due to the involvement of both heat and work.A stream that expands through expanders can produce work and cold load,while expansion through valves barely affects heat integration.In addition,expansion through expanders at higher temperature produces more work,but consumes more hot utility.Therefore,there is a need to weigh work production and heat consumption.To this end,an enhanced stage-wise superstructure is proposed that involves synchronous optimization of expander/valve placement and heat integration for each pressure-change sub-stream in stages.A mixed-integer nonlinear programming(MINLP)model is established for synthesizing sub and aboveambient heat exchanger networks with multi-stream expansion,which explicitly considers the optimized selection of end-heaters and end-coolers to adjust temperature requirement.Our proposed method can commendably achieve the optimal selection of expanders and valves in a bid for minimizing exergy consumption and total annual cost.Four example studies are conducted with two distinct objective function(minimization of exergy consumption and total annual cost,respectively)to illustrate the feasibility and efficacy of the proposed method.展开更多
基金partially supported by Maryland Stem Cell Research Fund(2018-MSCRFD-4271,to XJ)R01HL118084 and R01NS110387 from United States National Institutes of Health(both to XJ)
文摘Nerve guidance conduits (NGCs) are tubular structures that are used to bridge the gap of a severed nerve, thereby acting as a guide and protective micro-environment for the regenerating axons and as a barrier against the in-growth of scar-forming tissue. In the last few decades, the concept of NGCs has evolved from a research tool to investigate nerve regeneration into a translational product that is now being used clinically as an alternative for autologous nerve graft repair, due to their availability and ease of fabrication.
文摘In this study, we examined the effects of neuroglobin gene (Ngb) transfection into SH-SY5Y cells, using ultrasound-targeted microbubble destruction (UTMD), on cobalt chloride-induced hypoxia. With an ultrasound intensity of 0.8 W/cm2, a 60-second exposure duration, 50% duty cycle, and 20% microbubble concentration, pAcGFP1-C1-Ngb-transfected cells exhibited the highest cell viability and transfection efficiency. The efficiency of plasmid delivery was significantly higher with UTMD than transfection with plasmid alone, transfection with plasmid using microbubbles, or transfection of plasmid by ultrasound. In addition, during cobalt chloride-induced hypoxia, caspase-3 activity in pAcGFP1-C1-Ngb-transfected cells was significantly lower than in untransfected cells. Ngb protein and mRNA expression were significantly higher in cells transfected by UTMD than in cells transfected with the other methods. These results demonstrate that UTMD can very efficiently mediate exogenous gene delivery, and that Ngb overexpression protects cells against cobalt chloride-induced hypoxia.
基金supported by the National Natural Science Foundation of China(61774139,62004083,and U1802257)the Postdoctoral Research Foundation of China(2020 M683185 and 2019 M663379)+1 种基金the Fundamental Research Funds for the Central Universities(21620348,21618409 and 21619311)the Natural Science Foundation of Guangdong Province(2019B151502061,2020A1515011123)。
文摘Sluggish charge transfer in perovskite film induced by inherent defects such as uncoordinated Pb2+undoubtedly hinders the rapid response of self-powered photovoltaic-typed detector.Based on interaction between Lewis acids and bases,herein,we employ thiourea molecule as a multifunctional Lewis base to significantly improve the quality of all-inorganic CsPbIBr2 perovskite film.After careful characterizations,the quality of perovskite film has been well regulated.Arising from the reduced defect and the reinforced the interfacial charge extraction owing to the strong interaction between uncoordinated Pb2+ions and the-C=S groups in thiourea and the formation of hydrogen bond at perovskite/TiO_(2) interface,an enhanced responsivity of 0.335 A W-1 and specific detectivity of 3.92×10^(12) Jones has been achieved for the self-powered,carbon-electrode based photodetector,which is comparable to the state-of-theart device based on CsPbIBr2 film.More importantly,the device free of encapsulation remains 82.8%of initial performance after storage over 56 days in ambient atmosphere,promoting the practical deployment of perovskite products.
基金supported by the Institute of Medical Information,Library of Chinese Academy of MedicalSciences(Grant No.09R0216)
文摘Taking the scholarly activities of 73 doctoral program mentors working at the Chinese Academy of Medical Sciences&Peking Union Medical College(the CAMS&PUMC)as a sample of our investigative survey,we tried using such statistical methods as the analysis of variance(ANOVA),factor analysis and correlation analysis to compare the different characteristics of scholarship assessment of Chinese medical scholars as exhibited in their published papers in domestic and foreign journals.Our research findings show that citations per paper and A-index are more suitable for assessing the highly accomplished senior Chinese medical professionals(e.g.academicians)for their domestic and international scholarship attainment.In contrast,the m-quotient is not deemed appropriate to assess their academic influence both at home and abroad.Upon our further analysis of 6 evaluative indicators,we noticed that these indicators might be applied in two different aspects:One is from the viewpoint of Chinese scholars’academic influence at home,which has been evaluated mainly from the perspective of"total"amount and"average"amount of both publications and citations.The other is from their academic impact embodied by the means of documents retrieved from the Web of Science,which is mainly assessed from the two viewpoints of publications and citations.It is suggested that the accumulated time-length of a given scholar’s active engagement in professional practice in a specific subject area be taken into consideration while assessing a researcher’s performance at home and abroad.
基金This work was supported by grants from the National Natural Science Foundation of China(No.82173125 and 81974374).
文摘Tumor proliferation,metabolism,metastasis,and chemoresistance are intimately related to the tumor microenvironment(TME).The metabolic reprogramming of tumor cells is a hallmark of their adaptation to hypoxic and nutrient-deficient TMEs.Exosomes,a type of extracellular vesicle,have been found to regulate the crosstalk between tumor cells and the TME,affecting tumor metabolic reprogramming.In this review,we introduce the metabolic characteristics of tumor cells;describe the crosstalk between tumor cells and the TME in terms of glucose metabolism,lipid metabolism,and amino acid metabolism through exosomes;and provide an overview of the diagnostic and therapeutic potential of exosomes.A better understanding of tumor metabolism would provide a broader perspective about the mechanisms underlying tumor pathology and would facilitate the search for therapeutic targets and guide more individualized tumor treatment.
基金supported by the National Basic Research Program of China(973 program,2014CB239402)the National Natural Science Foundation of China(21476043)the Swedish Energy Agency and K&A Wallenberg Foundation~~
基金supported by the National Basic Research Program of China (973 Program, 2014CB239402)the National Natural Science Foundation of China (21476043)+1 种基金the Fundamental Research Funds for the Central Universities (DUT17ZD204)the Swedish Energy Agency and K&A Wallenberg Foundation~~
基金supported by the National Key Technology R&D Program of China (Grant 2013BAG22Q00)the China Railway Science and Technology R&D Program (2015J009-D)
文摘Compared with the traditional train,the operational speed of the high-speed train has largely improved,and thedynamicenvironmentofthetrainhaschangedfromoneof mechanical domination to one of aerodynamic domination.The aerodynamic problem has become the key technological challenge of high-speed trains and significantl affects the economy,environment,safety,and comfort.In this paper,the relationships among the aerodynamic design principle,aerodynamic performance indexes,and design variables are firs studied,and the research methods of train aerodynamics are proposed,including numerical simulation,a reducedscale test,and a full-scale test.Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface.Optimization design of the streamlined head includes conception design,project design,numerical simulation,and a reduced-scale test.Smooth design of the body surface is mainly used for the key parts,such as electric-current collecting system,wheel truck compartment,and windshield.The aerodynamic design method established in this paper has been successfully applied to various high-speed trains(CRH380A,CRH380 AM,CRH6,CRH2 G,and the Standard electric multiple unit(EMU)) that have met expected design objectives.The research results can provide an effective guideline for the aerodynamic design of high-speed trains.
基金Supported by the National Natural Science Foundation of China(21576036,21406026)
文摘Due to the deterioration of serious energy dilemma,energy-conservation and emission–reduction have been the strategic target in the past decades,thus people have identified the vital importance of higher energy efficiency and the influence of lower carbon development.Since work exchange network is a significant part of energy recovery system,its optima design will have dramatically significant effect on energy consumption reduction in chemical process system.With an extension of the developed transshipment model in isothermal process,a novel step-wise methodology for synthesis of direct work exchange network(WEN)in adiabatic process involving heat integration is first proposed in this paper,where a nonlinear programming(NLP)model is formulated by regarding the minimum utility consumption as objective function and optimizing the initial WEN in accordance with the presented matching rules to get the optimized WEN configuration at first.Furthermore,we focus on the work exchange network synthesis with heat integration to attain the minimal total annual cost(TAC)with the introduction of heat-exchange equipment that is achieved by the following strategies in sequence:introducing heat-exchange equipment directly,adjusting the work quantity of the adjacent utility compressors or expanders,and approximating upper/lower pressure limits consequently to obtain considerable cost savings of expanders or compressors and work utility.Finally,a case taken from the literature is studied to illustrate the feasibility and effectiveness of the proposed method.
文摘The prognosis of patients with previously treated tuberculosis (TB) was suggested to be dependent on whether the initial treatment was in compliance with the established guidelines. The aim of this retrospective multicenter study was to determine the proportion of new TB patients who received standard doses of rifampicin in multiple provinces of China, and the relationship between low doses of rifampicin and frequency of rifampicin-resistance as well as treatment outcomes. A total of 713 new TB patients were treated with either once-daily dose of bulk anti-TB drugs (group I) or every other day combination blister packs of anti-TB drugs containing rifampicin (group II) at more than 30 TB treatment centers/hospitals in China. Treatment history, therapeutic doses of rifampicin, and information about patients were extracted from their medical records and analyzed, and rifampicin-resistance of isolates collected from patients following the treatment as well as treatment outcomes were compared between two treatment groups. Among 522 patients in treatment group I, 154 (29.5%) received standard and 363 (69.5%) received low doses of rifampicin;238 (45.6%) isolates were rifampicin-resistant, and 243 (46.6%) were successfully treated. Among 191 patients in treatment group II, 175 (91.6%) received standard and 15 (7.9%) received low doses of rifampicin;72 (37.7%) isolates were rifampicin-resistant, and 105 (55%) were successfully treated. When patients who received low doses of rifampicin were compared to others within the same treatment group, increased rates for rifampicin-resistance and treatment failure were observed. Results from this study showed that most new TB patients in treatment group I (69.5%) received low doses of rifampicin, and their treatment outcomes were worse than those in treatment group II, indicating that low doses of rifampicin used for the initial treatment of new TB patients were correlated to increased frequency of rifampicin-resistance and poorer treatment outcomes.
基金funded by the National Natural Science Foundation of China(nos.71603280,72074006,and 82070235)the Beijing Municipal Natural Science Foundation(7191013)+1 种基金Research Unit of Medical Science Research Management/Basic and Clinical Research of Metabolic Cardiovascular Diseases,Chinese Academy of Medical Sciences(2021RU003)Peking University Health Science Center and the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2017QNRC001).
文摘Purpose:Given the information overload of scientific literature,there is an increasing need for computable biomedical knowledge buried in free text.This study aimed to develop a novel approach to extracting and measuring uncertain biomedical knowledge from scientific statements.Design/methodology/approach:Taking cardiovascular research publications in China as a sample,we extracted subject-predicate-object triples(SPO triples)as knowledge units and unknown/hedging/conflicting uncertainties as the knowledge context.We introduced information entropy(IE)as potential metric to quantify the uncertainty of epistemic status of scientific knowledge represented at subject-object pairs(SO pairs)levels.Findings:The results indicated an extraordinary growth of cardiovascular publications in China while only a modest growth of the novel SPO triples.After evaluating the uncertainty of biomedical knowledge with IE,we identified the Top 10 SO pairs with highest IE,which implied the epistemic status pluralism.Visual presentation of the SO pairs overlaid with uncertainty provided a comprehensive overview of clusters of biomedical knowledge and contending topics in cardiovascular research.Research limitations:The current methods didn’t distinguish the specificity and probabilities of uncertainty cue words.The number of sentences surrounding a given triple may also influence the value of IE.Practical implications:Our approach identified major uncertain knowledge areas such as diagnostic biomarkers,genetic polymorphism and co-existing risk factors related to cardiovascular diseases in China.These areas are suggested to be prioritized;new hypotheses need to be verified,while disputes,conflicts,and contradictions need to be settled.Originality/value:We provided a novel approach by combining natural language processing and computational linguistics with informetric methods to extract and measure uncertain knowledge from scientific statements.
基金supported by the National Natural Science Foundation of China(Grant No.:71373252)the Project from Institute of Medical Information of Chinese Academy of Medical Sciences(Grant No.:14R0106)
文摘Purpose:This paper develops and validates a bibliometric framework for identifying the "princes"(PR) who wake up the "sleeping beauty"(SB) in challenge-type scientific discoveries,so as to figure out the awakening mechanisms,and promote potentially valuable but not readily accepted innovative research.(A PR is a research study.)Design/methodology/approach:We propose that PR candidates must meet the following four criteria:(1) be published near the time when the SB began to attract a lot of citations;(2) be highly cited papers themselves;(3) receive a substantial number of co-citations with the SB;and(4) within the challenge-type discoveries which contradict established theories,the "pulling effect" of the PR on the SB must be strong.We test the usefulness of the bibliometric framework through a case study of a key publication by the 2014 chemistry Nobel laureate Stefan W.Hell,who negated Ernst Abbe's diffraction limit theory,one of the most prominent paradigms in the natural sciences.Findings:The first-ranked candidate PR article identified by the bibliometric framework is in line with historical facts.An SB may need one or more PRs and even "retinues" to be "awakened." Documents with potential awakening functionality tend to be published in prestigious multidisciplinary journals with higher impact and wider scope than the journals publishing SBs.Research limitations:The above framework is only applicable to transformative innovations,and the conclusions are drawn from the analysis of one typical SB and her awakening process.Therefore the generality of our work might be limited.Practical implications:Publications belonging to so-called transformative research,even when less frequently cited,should be given special attention as early as possible,because they may suddenly attract many citations after a period of sleep,as reflected in our case study.Originality/value:The definition of PR(s) as the first paper(s) that cited the SB article(selfciting excluded) has its limitations.Instead,the SB-PR co-citations should be given priority in current environment of scholarly communication.Since the "premature" or "transformative" breakthroughs in the challenge-type SB documents are either beyond the current knowledge domain,or violate established paradigms,people's psychological distance from the SB is larger than that from the PR,which explains why the annual citations of the PR are usually higher than those of the SB,especially prior to or during the SB's citation boom period.
基金Supported by the National Natural Science Foundation of China(21576036,21776035)
文摘Over the last three decades,flexibility and controllability considerations for heat exchanger networks(HENs)have received great attention,respectively.However,they should be simultaneously incorporated in HEN synthesis to allow the economic performance to be achievable in a practical operating environment.This paper proposes a method for simultaneous synthesis of flexible and controllable HEN by considering their coupling.The key idea is to add the bypasses with optimized initial fractions and positions to explore such coupling,and consequently enabling HENs to be operated successfully over a range of disturbance variations.These are implemented by identifying and quantifying disturbance propagations,and then examining the sensitivity of bypasses to the entire HEN.In this way,the superstructurebased mixed integer non-linear programming(MINLP)with objective function of minimizing the total annual cost is formulated.A case study is used to demonstrate the application of the proposed method.Quantitative measures and dynamic simulation show the ability to provide the satisfactory flexibility and controllability of the obtained HEN.
基金Supported by the National Natural Science Foundation of China(21576036 and 21776035)
文摘In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In contrast with superstructure method, the transshipment model is easier to obtain the minimum utility consumption taken as the objective function and more convenient for us to attain the optimal network configuration for further minimizing the number of units. Different from division of temperature intervals in heat exchange networks,different pressure intervals are gained according to the maximum compression/expansion ratio in consideration of operating principles of indirect work exchangers and the characteristics of no pressure constraints for stream matches. The presented approach for WEN synthesis is a linear programming model applied to the isothermal process, but for indirect work exchange networks with adiabatic process, a nonlinear programming model needs establishing. Additionally, temperatures should be regarded as decision variables limited to the range between inlet and outlet temperatures in each sub-network. The constructed transshipment model can be solved first to get the minimum utility consumption and further to determine the minimum number of units by merging the adjacent pressure intervals on the basis of the proposed merging methods, which is proved to be effective through exergy analysis at the level of units structures. Finally, two cases are calculated to confirm it is dramatically feasible and effective that the optimal WEN configuration can be gained by the proposed method.
基金the National Natural Science Foundation of China,No.30672729the Project Sponsored by Open Fund of Fujian Key Laboratory of Integrative Medicine on Geriatrics (Fujian University of TCM),No.2008J1004-18
文摘BACKGROUND:Glossy privet fruit inhibits neural cell apoptosis following the onset of vascular dementia. OBJECTIVE:To confirm glossy privet fruit effects on neural cell apoptosis in the cortical parietal lobe and hippocampal CA1 region of rat models of vascular dementia using molecular biology techniques. DESIGN,TIME AND SETTING: The neural cell morphology experiment was performed at the Laboratory of Flow Cells and Biochemistry,Academy of Integrative Medicine,Fujian University of Traditional Chinese Medicine,and the Basic Room of Pathology,Academy of Chinese Medicine from December 2006 to May 2008. MATERIALS: A total of 60 Wistar rats were used to establish vascular dementia models using a photochemical reaction method. Glossy privet fruit was purchased from Fujian,China. Hydergine was co-produced by Sandoz,Switzerland and Huajin,China. METHODS: The 60 Wistar rats were randomly divided into 6 equal sized groups (n=10),i.e. model,blank,high,moderate and low doses of Chinese medicine,and hydergine control groups. Rats in the model group were treated with distilled water (1mL/100g) by gavage following model establishment. Rats in the blank group underwent experimental procedures as for the model group,except that rat models were created without illumination. Rats in the high,moderate and low doses of Chinese medicine groups,and the hydergine control group respectively received high,moderate and low doses of glossy privet fruit,and hydergine suspension (1 mL/100 g) by gavage,once a day,for 30 days. MAIN OUTCOME MEASURES: Morphology of neural cells from the rat cortical parietal lobe and hippocampal CA1 region of all groups was observed with an electron microscope. Positive neural cells in the injury site of the rat cortical parietal lobe and hippocampal CA1 region were investigated using the Fas immunohistochemical method. Absorbance of Fas-positive neurons was detected by the MPIAS-500 multimedia color imaging analysis system. RESULTS: Neural cells were normal,and nuclei were regular in the right cortical parietal lobe and hippocampal CA1 region in the blank group. Karyopyknosis,an integral nuclear membrane,vacuole and apoptotic bodies were presented in the model group. The quantity and morphology of neural cells were normal in all doses of Chinese medicine groups,and the hydergine control group. Compared with the model group,absorbance was reduced at the injury site of rat cortical parietal lobe and hippocampal CA1 region in the blank,high,moderate and low doses of Chinese medicine,and hydergine control groups (P<0.05). The decrease was particularly significant in the blank group (P<0.01),followed by the high dose of Chinese medicine group (P<0.01). Compared with the model group,the percentage of apoptosis was decreased at the injury site of the rat cortical parietal lobe and hippocampal CA1 region in the blank,high,moderate and low doses of Chinese medicine,and hydergine control groups (P<0.01) and this decrease was significant in the high dose of Chinese medicine group (P<0.01). CONCLUSION: Glossy privet fruit,a kidney-tonifying Chinese herbal medicine,can inhibit cell apoptosis by reducing apoptotic signals induced by cerebral ischemia/hypoxia.
基金supported by the Taishan Scholar Program of Shandong (ts201511027)the Natural Science Foundation of Shandong Province (2018GGX102030)+1 种基金support from the “Hundred Talent Program” of Chinese academy of Sciences (CAS) (RENZI[2015] 70HAO, Y5100619AM),DICP and QIBEBT (UN201804),Dalian National Laboratory For Clean Energy (DNL),CASResearch Innovation Fund (QIBEBT SZ201801)~~
基金Supported by Provincial Science and Technology Department Natural Fund Guidance Project,No.2019-ZD-0774National Natural Science Foundation of China,No.81470998+1 种基金Liaoning Ministry of Education,No.LQNK201715and Liaoning Provincial Doctor Start up Fund,No.20180540008.
文摘BACKGROUND Uncarboxylated osteocalcin(GluOC)has been reported to improve glucose metabolism,prevent type 2 diabetes,and decrease the severity of obesity in mice with type 2 diabetes.GluOC can increase glucose uptake in a variety of cells.Glucose metabolism is the main source of energy for osteoblast proliferation and differentiation.We hypothesized that decarboxylated osteocalcin(dcOC),a kind of GluOC,can increase glucose uptake in MG63 cells(osteoblast-like osteosarcoma cells)and influence their proliferation and differentiation.AIM To investigate the effects of dcOC on glucose uptake in human osteoblast-like osteosarcoma cells and the possible signaling pathways involved.METHODS MG63 cells(human osteoblast-like osteosarcoma cells)were treated with dcOC(0,0.3,3,10,or 30 ng/mL)for 1 and 72 h,and glucose uptake was measured by flow cytometry.The effect of dcOC on cell proliferation was measured with a CCK-8 assay,and alkaline phosphatase(ALP)enzyme activity was measured.PI3K was inhibited with LY294002,and hypoxia-inducible factor 1 alpha(HIF-1α)was silenced with siRNA.Then,GPRC6A(G protein-coupled receptor family C group 6 subtype A),total Akt,phosphorylated Akt,HIF-1α,and glucose transporter 1(GLUT1)levels were measured by Western blot to elucidate the possible pathways by which dcOC modulates glucose uptake.RESULTS The glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after short-term(1 h)treatment with dcOC at different concentrations(0.3,3,and 10 ng/mL groups,P<0.01;30 ng/mL group,P<0.05).Glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after long-term(72 h)treatment with dcOC at different concentrations(0.3,3,and 10 ng/mL groups,P<0.01;30 ng/mL group,P<0.05).DcOC triggered Akt phosphorylation in a dose-dependent manner,and the most effective stimulatory concentration of dcOC for short-term(1 h)was 3 ng/mL(P<0.01).LY294002 abolished the dcOC-mediated(1 h)promotion of Akt phosphorylation and glucose uptake without affecting GLUT1 protein expression.Long-term dcOC stimulation triggered Akt phosphorylation and increased the protein levels of HIF-1α,GLUT1,and Runx2 in a dose-dependent manner.Inhibition of HIF-1αwith siRNA abolished the dcOC-mediated glucose uptake and substantially decreased GLUT1 protein expression.DcOC interven-tion promoted cell proliferation in a time-and dose-dependent manner as determined by the CCK-8 assay.Treatment with both 3 ng/mL and 10 ng/mL dcOC affected the ALP activity in MG63 cells after 72 h(P<0.01).CONCLUSION Short-and long-term dcOC treatment can increase glucose uptake and affect proliferation and ALP activity in MG63 cells.This effect may occur through the PI3K/Akt,HIF-1α,and GLUT1 signaling factors.
基金supports of Special Foundation for State Major Basic Research Program of China(Grant No.2021YFD2101000).
文摘Corn to sugar process has long faced the risks of high energy consumption and thin profits.However,it’s hard to upgrade or optimize the process based on mechanism unit operation models due to the high complexity of the related processes.Big data technology provides a promising solution as its ability to turn huge amounts of data into insights for operational decisions.In this paper,a neural network-based production process modeling and variable importance analysis approach is proposed for corn to sugar processes,which contains data preprocessing,dimensionality reduction,multilayer perceptron/convolutional neural network/recurrent neural network based modeling and extended weights connection method.In the established model,dextrose equivalent value is selected as the output,and 654 sites from the DCS system are selected as the inputs.LASSO analysis is first applied to reduce the data dimension to 155,then the inputs are dimensionalized to 50 by means of genetic algorithm optimization.Ultimately,variable importance analysis is carried out by the extended weight connection method,and 20 of the most important sites are selected for each neural network.The results indicate that the multilayer perceptron and recurrent neural network models have a relative error of less than 0.1%,which have a better prediction result than other models,and the 20 most important sites selected have better explicable performance.The major contributions derived from this work are of significant aid in process simulation model with high accuracy and process optimization based on the selected most important sites to maintain high quality and stable production for corn to sugar processes.
基金the financial support provided by the National Natural Science Foundation of China(No.21776035)China Postdoctoral Science Foundation(No.2019TQ0045)。
文摘Synthesis of heat exchanger networks including expansion process is a complex task due to the involvement of both heat and work.A stream that expands through expanders can produce work and cold load,while expansion through valves barely affects heat integration.In addition,expansion through expanders at higher temperature produces more work,but consumes more hot utility.Therefore,there is a need to weigh work production and heat consumption.To this end,an enhanced stage-wise superstructure is proposed that involves synchronous optimization of expander/valve placement and heat integration for each pressure-change sub-stream in stages.A mixed-integer nonlinear programming(MINLP)model is established for synthesizing sub and aboveambient heat exchanger networks with multi-stream expansion,which explicitly considers the optimized selection of end-heaters and end-coolers to adjust temperature requirement.Our proposed method can commendably achieve the optimal selection of expanders and valves in a bid for minimizing exergy consumption and total annual cost.Four example studies are conducted with two distinct objective function(minimization of exergy consumption and total annual cost,respectively)to illustrate the feasibility and efficacy of the proposed method.
