Combinations of biomaterials and cells can effectively target delivery of cells or other therapeutic factors to the brain to rebuild damaged nerve pathways after brain injury.Porous collagen-chitosan scaffolds were pr...Combinations of biomaterials and cells can effectively target delivery of cells or other therapeutic factors to the brain to rebuild damaged nerve pathways after brain injury.Porous collagen-chitosan scaffolds were prepared by a freeze-drying method based on brain tissue engineering.The scaffolds were impregnated with rat bone marrow mesenchymal stem cells.A traumatic brain injury rat model was established using the 300 g weight free fall impact method.Bone marrow mesenchymal stem cells/collagen-chitosan scaffolds were implanted into the injured brain.Modified neurological severity scores were used to assess the recovery of neurological function.The Morris water maze was employed to determine spatial learning and memory abilities.Hematoxylin-eosin staining was performed to measure pathological changes in brain tissue.Immunohistochemistry was performed for vascular endothelial growth factor and for 5-bromo-2-deoxyuridine(BrdU)/neuron specific enolase and BrdU/glial fibrillary acidic protein.Our results demonstrated that the transplantation of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds to traumatic brain injury rats remarkably reduced modified neurological severity scores,shortened the average latency of the Morris water maze,increased the number of platform crossings,diminished the degeneration of damaged brain tissue,and increased the positive reaction of vascular endothelial growth factor in the transplantation and surrounding areas.At 14 days after transplantation,increased BrdU/glial fibrillary acidic protein expression and decreased BrdU/neuron specific enolase expression were observed in bone marrow mesenchymal stem cells in the injured area.The therapeutic effect of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds was superior to stereotactic injection of bone marrow mesenchymal stem cells alone.To test the biocompatibility and immunogenicity of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds,immunosuppressive cyclosporine was intravenously injected 12 hours before transplantation and 1-5 days after transplantation.The above indicators were similar to those of rats treated with bone marrow mesenchymal stem cells and collagen-chitosan scaffolds only.These findings indicate that transplantation of bone marrow mesenchymal stem cells in a collagen-chitosan scaffold can promote the recovery of neuropathological injury in rats with traumatic brain injury.This approach has the potential to be developed as a treatment for traumatic brain injury in humans.All experimental procedures were approved by the Institutional Animal Investigation Committee of Capital Medical University,China(approval No.AEEI-2015-035)in December 2015.展开更多
BACKGROUND： Previous studies have shown that autonomic dysfunction results in gastrointestinal motility disorders and ultimately results in bacterial translocation following acute spinal cord injury （SCI）. Intensiv...BACKGROUND： Previous studies have shown that autonomic dysfunction results in gastrointestinal motility disorders and ultimately results in bacterial translocation following acute spinal cord injury （SCI）. Intensive methylprednisolone dosing improves neurological recovery in SCI patients. However, it remains uncertain whether high-dose methylprednisolone inhibits bacterial translocation and endotoxin release following acute SCI. OBJECTIVE： To investigate the inhibitory effect of methylprednisolone on bacterial translocation and endotoxin release from the gut in paraplegic rats. DESIGN, TIME AND SETTING： The randomized, controlled study was performed at the Orthopedic Lab, First Affiliated Hospital, Nanchang University, China, from April to December 2008. MATERIALS： Methylprednisolone （Pfizer, USA）, automatic microbial identification instrument ATB Expression and reagent ID 32 system （BioMerieux, France）, Limulus test kit （ACC, USA）, and optical microscope （Olympus, Japan） were used in this study. METHODS： A paraplegia model was established following SCI in 48 Wistar rats, aged 7 weeks. The rats were equally and randomly assigned to saline and methylprednisolone groups. Immediately post-injury, the methylprednisolone group was administered 30 mg/kg methylprednisolone via caudal intravenous infusion, followed by a 23-hour infusion of 5.4 mg/kg per hour. The saline group received an equal volume of saline as placebo. MAIN OUTCOME MEASURES： At 24 hours, 72 hours, and 1 week after SCI, blood samples were collected for bacterial cultures, and bacteria and endotoxin were identified using ATB Expression and Limulus test kits. In addition, mesenteric lymph node, spleen, and liver samples were collected for bacterial cultures. Histological examinations of mesenteric lymph node, spleen, liver, jejunum, and ileum were performed 1 week post-injury. Locomotor function in the hind limb was evaluated using the Basso, Beattie, and Bresnahan score at pre-injury time point, as well as 24 hours, 72 hours, and 1 week post-injury. RESULTS： Endotoxemia and bacterial growth were identified at 24 hours post-injury in both groups. However, plasma endotoxin levels were significantly decreased in the methylprednisolone group compared with the saline group at 72 hours and 1 week post-injury （P 〈 0.05）. Translocated bacteria mainly comprised Bacillus coli, Enterobacter cloacae, Escherichia coli, Proteus vulgaris, and Enterococcus faecalis following SCI combined with paraplegia. Histological changes were not as severe in the methylprednisolone group compared with the saline group 1 week after injury. Basso, Beattie, and Bresnahan scores were significantly better in the methylprednisolone group compared with the saline group 1 week after injury （P 〈 0.05）. CONCLUSION： High-dose methylprednisolone inhibited bacterial translocation from the gut and endotoxin release in rats with SCI.展开更多
Peanut,sesame and other raw materials of food are allergens for special populations.In this study,specific primers and TaqMan probes labeled by different fluorescences were designed targeting Ara h 2 gene of peanut an...Peanut,sesame and other raw materials of food are allergens for special populations.In this study,specific primers and TaqMan probes labeled by different fluorescences were designed targeting Ara h 2 gene of peanut and Ses i 1 gene of sesame.After the optimization of reaction conditions,a real-time fluorescent PCR method was established for simultaneous detection of allergenic ingredients of peanut and sesame in food.Genomic DNA samples of peanut,sesame,rice,wheat,barley,soybean,celery,maize,potato,tomato,walnut,groundnut in shell,cashew nut,sunflower seed,almond,apple,pear and strawberry,pork,beef,mutton and fish were used as templates for PCR amplification with deionized water as negative control template.Results indicated that the established real-time fluorescent PCR method could specifically identify allergenic ingredients of peanut and sesame simultaneously.Sensitivity test showed that the minimum detection limit of this method was 0.01%.Therefore,the established real-time fluorescent PCR method is a specific,sensitive and effective assay for simultaneously detecting allergenic ingredients of peanut and sesame in food.展开更多
BAEKGROUND： Some experimental studies demonstrate that subcutaneous implant of allograft can significantly decrease lymphocyte infiltration and reduce immunological reaction. However, compared with autologous nerve g...BAEKGROUND： Some experimental studies demonstrate that subcutaneous implant of allograft can significantly decrease lymphocyte infiltration and reduce immunological reaction. However, compared with autologous nerve grafting, what is the effect of nerve regeneration after repair？OB]EETIVE： To observe the local nervous status of the detected part of sciatic nerve repaired through subcutaneously implanting peripheral nerve allograft, and compare the effect with fresh autologous nerve grafting.DESTGN ： Contrast observation.SETTING ： Departments of Orthopaedics of Zhengzhou Fifth People＇s Hospital and First Hospital Affiliated to Chongqing Medical University.MATEREALS ： Totally 30 healthy adult Wistar male rats, with body mass of （200±20）g, were enrolled. Optical microscope （Olympus biological microscope BHS, Japan）, Electron microscope （H-600, Japan）,CM-2000 biomedical image analysis system （CM-2000,Beihang） and myoelectricity scanner （KEYPOINT, Denmark） were used in this experiment.METHODS ： This experiment was carried out in the Orthopaedic Laboratory of Chongqing Medical University between October 2000 and April 2002. ① Six rats were chosen as the donors for allogenic nerve grafting, and 15 mm sciatic nerve segment was chosen as graft. The other rats were randomly divided into two groups： allogenic nerve grafting group and autologous nerve grafting group, with 12 rats in each group. In the allogenic nerve grafting group, a skin incision was made on the posterior side of right thigh, and subcutaneous blunt dissection was performed prorsally a little, then allograft was implanted. Two weeks later, sciatic nerve was exposed at the posterior side of left thigh and cut respectively at 5 mm and another 10 mm away from pelvis. The donor nerve （with connective tissue veil） implanted subcutaneously on the right thigh was taken out. Sectioned connective tissue at the proximal end was trimmed and that at the distal end as done but reserved 10 mm in length, and inosculated antegradely at the nerve defect on the left side with 11/0 nylon line. Twelve rats in autologous nerve grafting group underwent a 10 mm sciatic nerve defect inci- sion on the right thigh and implant of fresh sciatic nerve from left thigh. The incision on the left thigh was repaired in situ. ②2,4,8 and 14 weeks after grafting, the nerve specimen of anastomosis segment was observed under optical microscope. Fourteen weeks after grafting, the ultrathin section of distal sciatic nerve was observed under transmission electron microscope. The number and size of regenerated axons at the cross section of anastomosis of proximal and distal sciatic nerve were analyzed with biomedical image analysis system. Neuroelectrophysiological change of in vivo sciatic nerve was detected with myoelectricity scanner.③ t test was used in the comparison of difference of measurement data.MAZN OUTCOME MEASURES ： ① Observation of anastomosis part of sciatic nerve under optical and electron microscopes in the two groups. ② Comparison of motor nerve conduction velocity, latent period and action potential peak as well as the number and size of cross-section of anastomosis part of proximal and distal sciatic nerve between two groups.RESULTS： ①Observation under optical microscope：Two weeks after grafting, neve axon of repaired region broke and medullary sheath denatured in the allogenic nerve grafting group and autologous nerve grafting group. At the same time, vascular engorgement and a little lymphocytes infiltration were found in the autologous nerve grafting group, but those were found worsened in the allogenic nerve grafting group. Four weeks after grafting, the intensity of the inflammatory reaction was similar between two groups, some collagen fibers at the proximal end proliferated; 8 weeks after grafting, the inflammatory reaction ended basically and the collagen fibers proliferated obviously in the two groups. ② Observation under electron microscope： Fourteen weeks after grafting, the structure of epineurium was in integrity and there were no obvious differences in perineurium and endonurium between two groups. A large number of myelinated nerve fibers and a few unmyelinated nerve fibers regenerated. The structure of myelin sheath was in integrity. ③The number and size of regenerated axons of anastomosis of proximal and distal sciatic nerve had no significant difference 14 weeks after grafting [（575.500±7.495） vs（585.700±11.172） axons/visual field ; （389.300±49.073） vs （407.600±0.283） axons/visual field;（6 423.830±119.911 ） vs （6 695.36± 84.287） μm^2/visual field = （ 5 980.110±74.572） vs（5 980.110±74.572） μm^2/visual field] （P 〉 0.05）. ④ Neuroelectrophysiological examination showed that there were no significant differences in motor nerve evoked potential latent pedod[（1.420±0.346）vs （1.237±0.250） ms] , motor nerve conduction velocity [（ 12.120±0.906 ） vs（13.020±0.599） m/s]and latent period of sciatic nerve [（0.500±0.380）vs （1.250±1.067） mV] of rats between two groups （P 〉 0.05）.CONCLUSTON： Although subcutaneous implant of peripheral nerve allograft has some inflammatory reactions, no obvious rejection is found. Repair results of two groups show that subcutaneous implant of allograft can promote nerve regeneration, which is similar to autologous nerve grafting.展开更多
The prevalence of stroke displays obvious geographical variation and is higher on plateaus.Similarly,prolonged stay at high altitude is associated with higher incidence of stroke.High-altitude hypoxia can elicit vario...The prevalence of stroke displays obvious geographical variation and is higher on plateaus.Similarly,prolonged stay at high altitude is associated with higher incidence of stroke.High-altitude hypoxia can elicit various physiological dysfunctions,and hypoxia is suggested to be the principal contributing factor of stroke.In this brief review,the effects of hypoxia on the properties of the blood components such as erythrocytes,leukocytes and thrombocytes are presented,in an effort to inform the prevention and treatment of stroke in high-altitude areas.展开更多
Methylmalonic aciduria （MMA） is an autosomal recessive disorder of cobalamin （cbl） metabolism. Cobalamin C （cblC） disease is the most common type of MMA and is characteristically concurrent with homocystinemia ...Methylmalonic aciduria （MMA） is an autosomal recessive disorder of cobalamin （cbl） metabolism. Cobalamin C （cblC） disease is the most common type of MMA and is characteristically concurrent with homocystinemia （HCY） due to impaired synthesis of two active forms of cbl, namely adenosylcobalamin （AdoCbl） and methylcobalamin （MeCbl）. The estimated worldwide incidence of MMA ranges between 1：48,000 and 1：250,000. Mutations of the MMA and HCY type C protein （MMACtfC） gene are responsible for cblC disease and were first identified by Lerner-Ellis et aL in 2006.By the year 2016, more than 82 different MMACHC gene mutations have been reported （http：// www.hgmd.cf.ac.uk/ac/index.php）. Among these mutations, c.609G〉A （p.W203X） was reported to be the most frequent cblC mutation in Chinese patients.展开更多
Arthropod-borne viruses cause serious threats to human health and global agriculture by rapidly spreading via insect vectors. Southern rice black-streaked dwarf virus (SRBSDV) is the most damaging rice-infecting virus...Arthropod-borne viruses cause serious threats to human health and global agriculture by rapidly spreading via insect vectors. Southern rice black-streaked dwarf virus (SRBSDV) is the most damaging rice-infecting virus that is frequently transmitted by planthoppers. However, the molecular mechanisms underlying its propagation in the host plants and epidemics in the field are largely unknown. Here, we showed that the SRBSDV-encoded P6 protein is a key effector that regulates rice ethylene signaling to coordinate viral infection and transmission. In early SRBSDV infection, P6 interacts with OsRTH2 in the cytoplasm to activate ethylene signaling and enhance SRBSDV proliferation;this also repels the insect vector to reduce infestation. In late infection, P6 enters the nucleus, where it interacts with OsEIL2, a key transcription factor of ethylene signaling. The P6-OsEIL2 interaction suppresses ethylene signaling by preventing the dimerization of OsEIL2, thereby facilitating viral transmission by attracting the insect vector. Collectively, these findings reveal a novel molecular mechanism by which an arbovirus modulates the host defense system to promote viral infection and transmission.展开更多
High performance computing(HPC)is a powerful tool to accelerate the Kohn–Sham density functional theory(KS-DFT)calculations on modern heterogeneous supercomputers.Here,we describe a massively parallel implementation ...High performance computing(HPC)is a powerful tool to accelerate the Kohn–Sham density functional theory(KS-DFT)calculations on modern heterogeneous supercomputers.Here,we describe a massively parallel implementation of discontinuous Galerkin density functional theory(DGDFT)method on the Sunway Taihu Light supercomputer.The DGDFT method uses the adaptive local basis(ALB)functions generated on-the-fly during the self-consistent field(SCF)iteration to solve the KS equations with high precision comparable to plane-wave basis set.In particular,the DGDFT method adopts a two-level parallelization strategy that deals with various types of data distribution,task scheduling,and data communication schemes,and combines with the master–slave multi-thread heterogeneous parallelism of SW26010 processor,resulting in large-scale HPC KS-DFT calculations on the Sunway Taihu Light supercomputer.We show that the DGDFT method can scale up to 8,519,680 processing cores(131,072 core groups)on the Sunway Taihu Light supercomputer for studying the electronic structures of twodimensional(2 D)metallic graphene systems that contain tens of thousands of carbon atoms.展开更多
Orychophragmus violaceus is a Brassicaceae species widely cultivated in China,particularly as a winter cover crop in northern China because of its low-temperature tolerance and low water demand.Recently,O.violaceus ha...Orychophragmus violaceus is a Brassicaceae species widely cultivated in China,particularly as a winter cover crop in northern China because of its low-temperature tolerance and low water demand.Recently,O.violaceus has also been cultivated as a potential industrial oilseed crop because of its abundant 24-carbon dihydroxy fatty acids(diOH-FAs),which contribute to superior high-temperature lubricant properties.In this study,we performed de novo assembly of the O.violaceus genome.Whole-genome synteny analysis of the genomes of its relatives demonstrated that O.violaceus is a diploid that has undergone an extrawhole-genome duplication(WGD)after the Brassicaceae-specific a-WGD event,with a basic chromosome number of x=12.Formation of diOH-FAs is hypothesized to have occurred after the WGD event.Based on the genome and the transcriptome data from multiple stages of seed development,we predicted that OvDGAT1-1 and OvDGAT1-2 are candidate genes for the regulation of diOH-FA storage in O.violaceus seeds.These results may greatly facilitate the development of heat-tolerant and eco-friendly plant-based lubricants using O.violaceus seed oil and improve our understanding of the genomic evolution of Brassicaceae.展开更多
The short-range pair interaction consumes most of the CPU time in molecular dynamics(MD)simulations.The inherent computation sparsity makes it challenging to achieve high-performance kernel on the emerging many-core a...The short-range pair interaction consumes most of the CPU time in molecular dynamics(MD)simulations.The inherent computation sparsity makes it challenging to achieve high-performance kernel on the emerging many-core architecture.In this paper,we present a highly efficient short-range force kernel on the Sunway,a novel many-core architecture with many unique features.The parallel efficiency of this algorithm on the Sunway many-core processor is strongly limited by the poor data locality and write conflicts.To enhance the data locality,we adopt a super cluster based neighbor list with an appropriate granularity that fits in the local memory of computing cores.In the absence of a low overhead locking mechanism,using data-privatization force array is a more feasible method to avoid write conflicts,but results in the large overhead of data reduction.We adopt a dual-slice partitioning scheme for both hardware resources and computing tasks,which utilizes the on-chip data communication to reduce data reduction overhead and provide load balancing.Moreover,we exploit the single instruction multiple data(SIMD)parallelism and perform instruction reordering of the force kernel on this many-core processor.The experimental results show that the optimized force kernel obtains a performance speedup of 226x compared with the reference implementation and achieves 20%of peak flop rate on the Sunway many-core processor.展开更多
To the Editor：Hyperhomocysteinemia （HHcy） is an important risk factor for atherothrombotic disease and venous thrombosis.[1] Normally,homocysteine （Hcy） is either remethylated to methionine （Met） by a Vitamin B...To the Editor：Hyperhomocysteinemia （HHcy） is an important risk factor for atherothrombotic disease and venous thrombosis.[1] Normally,homocysteine （Hcy） is either remethylated to methionine （Met） by a Vitamin B12-dependent reaction or betaine as the methyl donor,or trans-sulfurated to cysteine through a pyridoxine-dependent reaction.Based on plasma level of total Hcy,HHcy is typically classified into three groups as follows：mild （tHcy 15-30 μmol/L）,moderate （tHcy 30-100 μmol/L）,and severe （tHcy 〉100 μmol/L）.[2] Severe HHcy is rare and most commonly caused by inherited deficiency of cystathionine beta-synthase （CBS）,or less frequently,ofmethylenetetrahydrofolate reductase （MTHFR） genes.The presentations of this metabolic disorder include developmental delay,intellectual disability,epilepsy,ectopia lentis,myopia,hypopigmentation of the skin and hair,marfanoid habitus,and thromboembolic disorders.[3] These manifestations are often overlooked in the early stage until the occur of thrombotic events like cerebral venous sinus thrombosis （CVST）.展开更多
To the Editor： Charcot-Marie-Tooth disease （CMT） is a clinically and genetically heterogeneous inherited neuropathy, with Type 1 A being the most common. CMT IA is characterized by progressive weakness and atrophy ...To the Editor： Charcot-Marie-Tooth disease （CMT） is a clinically and genetically heterogeneous inherited neuropathy, with Type 1 A being the most common. CMT IA is characterized by progressive weakness and atrophy of the distal limb muscles beginning in the peroneal group, mild distal sensory loss, diminished tendon reflexes, and slow nerve conduction velocity . Spinal nerve root hypertrophy is a distinct sign of CMT 1A. This sign can be detected on magnetic resonance images （MRI）, but it is often overlooked. Instead, diagnosis of this disease is often made basing on biopsy and genetic testing.展开更多
Processor specialization has become the development trend of modern processor industry. It is quite possible that this will still be the main-stream in the next decades of semiconductor era. As the diversity of hetero...Processor specialization has become the development trend of modern processor industry. It is quite possible that this will still be the main-stream in the next decades of semiconductor era. As the diversity of heterogeneous systems grows, organizing computation efficiently on systems with multiple kinds of heterogeneous processors is a challenging problem and will be a normality. In this paper, we analyze some state-of-the-art task scheduling algorithms of heterogeneous computing systems and propose a Degree of Node First (DONF) algorithm for task scheduling of fine-grained parallel programs on heterogeneous systems. The major innovations of DONF include: 1) simplifying task priority calculation for directed acyclic graph (DAG) based fine-grained parallel programs which not only reduces the complexity of task selection but also enables the algorithm to solve the scheduling problem for dynamic DAGs;2) building a novel communication model in the processor selection phase that makes the task scheduling much more efficient. They are achieved by exploring finegrained parallelism via a dataflow program execution model, and validated through experimental results with a selected set of benchmarks. The results on synthesized and real-world application DAGs show a very good performance. The proposed DONF algorithm significantly outperforms all the evaluated state-of-the-art heuristic algorithms in terms of scheduling length ratio (SLR) and efficiency.展开更多
During the era of global warming and highly urbanized development,extreme and high impact weather as well as air pollution incidents influence everyday life and might even cause the incalculable loss of life and prope...During the era of global warming and highly urbanized development,extreme and high impact weather as well as air pollution incidents influence everyday life and might even cause the incalculable loss of life and property.Despite the vast development of atmospheric models,there still exist substantial numerical forecast biases objectively.To accurately predict extreme weather,severe air pollution,and abrupt climate change,numerical atmospheric model requires not only to simulate meteorology and atmospheric compositions simultaneously involving many sophisticated physical and chemical processes but also at high spatiotemporal resolution.Global integrated atmospheric simulation at spatial resolutions of a few kilometers remains challenging due to its intensive computational and input/output(I/O)requirement.Through multi-dimension-parallelism structuring,aggressive and finer-grained optimizing,manual vectorizing,and parallelized I/O fragmenting,an integrated Atmospheric Model Across Scales(iAMAS)was established on the new Sunway supercomputer platform to significantly increase the computational efficiency and reduce the I/O cost.The global 3-km atmospheric simulation for meteorology with online integrated aerosol feedbacks with iAMAS was scaled to 39,000,000 processor cores and achieved the speed of 0.82 simulation day per hour(SDPH)with routine I/O,which enabled us to perform 5-day global weather forecast at 3-km horizontal resolution with online natural aerosol impacts.The results demonstrate the promising future that the increasing of spatial resolution to a few kilometers with online integrated aerosol feedbacks may significantly improve the global weather forecast.展开更多
基金financially supported by the Postdoctoral Research Foundation of Beijing of China,No.2017-ZZ-120(to FY)the Natural Science Foundation of Beijing of China,No.2164073(to ML)the Beijing Municipal Administration of Hospitals’ Youth Plan of China,No.QML20180804(to ML)
文摘Combinations of biomaterials and cells can effectively target delivery of cells or other therapeutic factors to the brain to rebuild damaged nerve pathways after brain injury.Porous collagen-chitosan scaffolds were prepared by a freeze-drying method based on brain tissue engineering.The scaffolds were impregnated with rat bone marrow mesenchymal stem cells.A traumatic brain injury rat model was established using the 300 g weight free fall impact method.Bone marrow mesenchymal stem cells/collagen-chitosan scaffolds were implanted into the injured brain.Modified neurological severity scores were used to assess the recovery of neurological function.The Morris water maze was employed to determine spatial learning and memory abilities.Hematoxylin-eosin staining was performed to measure pathological changes in brain tissue.Immunohistochemistry was performed for vascular endothelial growth factor and for 5-bromo-2-deoxyuridine(BrdU)/neuron specific enolase and BrdU/glial fibrillary acidic protein.Our results demonstrated that the transplantation of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds to traumatic brain injury rats remarkably reduced modified neurological severity scores,shortened the average latency of the Morris water maze,increased the number of platform crossings,diminished the degeneration of damaged brain tissue,and increased the positive reaction of vascular endothelial growth factor in the transplantation and surrounding areas.At 14 days after transplantation,increased BrdU/glial fibrillary acidic protein expression and decreased BrdU/neuron specific enolase expression were observed in bone marrow mesenchymal stem cells in the injured area.The therapeutic effect of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds was superior to stereotactic injection of bone marrow mesenchymal stem cells alone.To test the biocompatibility and immunogenicity of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds,immunosuppressive cyclosporine was intravenously injected 12 hours before transplantation and 1-5 days after transplantation.The above indicators were similar to those of rats treated with bone marrow mesenchymal stem cells and collagen-chitosan scaffolds only.These findings indicate that transplantation of bone marrow mesenchymal stem cells in a collagen-chitosan scaffold can promote the recovery of neuropathological injury in rats with traumatic brain injury.This approach has the potential to be developed as a treatment for traumatic brain injury in humans.All experimental procedures were approved by the Institutional Animal Investigation Committee of Capital Medical University,China(approval No.AEEI-2015-035)in December 2015.
基金a Grant from the Research Fund of Department of Health of Jiangxi Province,No.20061072
文摘BACKGROUND： Previous studies have shown that autonomic dysfunction results in gastrointestinal motility disorders and ultimately results in bacterial translocation following acute spinal cord injury （SCI）. Intensive methylprednisolone dosing improves neurological recovery in SCI patients. However, it remains uncertain whether high-dose methylprednisolone inhibits bacterial translocation and endotoxin release following acute SCI. OBJECTIVE： To investigate the inhibitory effect of methylprednisolone on bacterial translocation and endotoxin release from the gut in paraplegic rats. DESIGN, TIME AND SETTING： The randomized, controlled study was performed at the Orthopedic Lab, First Affiliated Hospital, Nanchang University, China, from April to December 2008. MATERIALS： Methylprednisolone （Pfizer, USA）, automatic microbial identification instrument ATB Expression and reagent ID 32 system （BioMerieux, France）, Limulus test kit （ACC, USA）, and optical microscope （Olympus, Japan） were used in this study. METHODS： A paraplegia model was established following SCI in 48 Wistar rats, aged 7 weeks. The rats were equally and randomly assigned to saline and methylprednisolone groups. Immediately post-injury, the methylprednisolone group was administered 30 mg/kg methylprednisolone via caudal intravenous infusion, followed by a 23-hour infusion of 5.4 mg/kg per hour. The saline group received an equal volume of saline as placebo. MAIN OUTCOME MEASURES： At 24 hours, 72 hours, and 1 week after SCI, blood samples were collected for bacterial cultures, and bacteria and endotoxin were identified using ATB Expression and Limulus test kits. In addition, mesenteric lymph node, spleen, and liver samples were collected for bacterial cultures. Histological examinations of mesenteric lymph node, spleen, liver, jejunum, and ileum were performed 1 week post-injury. Locomotor function in the hind limb was evaluated using the Basso, Beattie, and Bresnahan score at pre-injury time point, as well as 24 hours, 72 hours, and 1 week post-injury. RESULTS： Endotoxemia and bacterial growth were identified at 24 hours post-injury in both groups. However, plasma endotoxin levels were significantly decreased in the methylprednisolone group compared with the saline group at 72 hours and 1 week post-injury （P 〈 0.05）. Translocated bacteria mainly comprised Bacillus coli, Enterobacter cloacae, Escherichia coli, Proteus vulgaris, and Enterococcus faecalis following SCI combined with paraplegia. Histological changes were not as severe in the methylprednisolone group compared with the saline group 1 week after injury. Basso, Beattie, and Bresnahan scores were significantly better in the methylprednisolone group compared with the saline group 1 week after injury （P 〈 0.05）. CONCLUSION： High-dose methylprednisolone inhibited bacterial translocation from the gut and endotoxin release in rats with SCI.
基金Supported by Scientific Research Project of Anhui Bureau of Quality and Technical Supervision(13zj370033)
文摘Peanut,sesame and other raw materials of food are allergens for special populations.In this study,specific primers and TaqMan probes labeled by different fluorescences were designed targeting Ara h 2 gene of peanut and Ses i 1 gene of sesame.After the optimization of reaction conditions,a real-time fluorescent PCR method was established for simultaneous detection of allergenic ingredients of peanut and sesame in food.Genomic DNA samples of peanut,sesame,rice,wheat,barley,soybean,celery,maize,potato,tomato,walnut,groundnut in shell,cashew nut,sunflower seed,almond,apple,pear and strawberry,pork,beef,mutton and fish were used as templates for PCR amplification with deionized water as negative control template.Results indicated that the established real-time fluorescent PCR method could specifically identify allergenic ingredients of peanut and sesame simultaneously.Sensitivity test showed that the minimum detection limit of this method was 0.01%.Therefore,the established real-time fluorescent PCR method is a specific,sensitive and effective assay for simultaneously detecting allergenic ingredients of peanut and sesame in food.
文摘BAEKGROUND： Some experimental studies demonstrate that subcutaneous implant of allograft can significantly decrease lymphocyte infiltration and reduce immunological reaction. However, compared with autologous nerve grafting, what is the effect of nerve regeneration after repair？OB]EETIVE： To observe the local nervous status of the detected part of sciatic nerve repaired through subcutaneously implanting peripheral nerve allograft, and compare the effect with fresh autologous nerve grafting.DESTGN ： Contrast observation.SETTING ： Departments of Orthopaedics of Zhengzhou Fifth People＇s Hospital and First Hospital Affiliated to Chongqing Medical University.MATEREALS ： Totally 30 healthy adult Wistar male rats, with body mass of （200±20）g, were enrolled. Optical microscope （Olympus biological microscope BHS, Japan）, Electron microscope （H-600, Japan）,CM-2000 biomedical image analysis system （CM-2000,Beihang） and myoelectricity scanner （KEYPOINT, Denmark） were used in this experiment.METHODS ： This experiment was carried out in the Orthopaedic Laboratory of Chongqing Medical University between October 2000 and April 2002. ① Six rats were chosen as the donors for allogenic nerve grafting, and 15 mm sciatic nerve segment was chosen as graft. The other rats were randomly divided into two groups： allogenic nerve grafting group and autologous nerve grafting group, with 12 rats in each group. In the allogenic nerve grafting group, a skin incision was made on the posterior side of right thigh, and subcutaneous blunt dissection was performed prorsally a little, then allograft was implanted. Two weeks later, sciatic nerve was exposed at the posterior side of left thigh and cut respectively at 5 mm and another 10 mm away from pelvis. The donor nerve （with connective tissue veil） implanted subcutaneously on the right thigh was taken out. Sectioned connective tissue at the proximal end was trimmed and that at the distal end as done but reserved 10 mm in length, and inosculated antegradely at the nerve defect on the left side with 11/0 nylon line. Twelve rats in autologous nerve grafting group underwent a 10 mm sciatic nerve defect inci- sion on the right thigh and implant of fresh sciatic nerve from left thigh. The incision on the left thigh was repaired in situ. ②2,4,8 and 14 weeks after grafting, the nerve specimen of anastomosis segment was observed under optical microscope. Fourteen weeks after grafting, the ultrathin section of distal sciatic nerve was observed under transmission electron microscope. The number and size of regenerated axons at the cross section of anastomosis of proximal and distal sciatic nerve were analyzed with biomedical image analysis system. Neuroelectrophysiological change of in vivo sciatic nerve was detected with myoelectricity scanner.③ t test was used in the comparison of difference of measurement data.MAZN OUTCOME MEASURES ： ① Observation of anastomosis part of sciatic nerve under optical and electron microscopes in the two groups. ② Comparison of motor nerve conduction velocity, latent period and action potential peak as well as the number and size of cross-section of anastomosis part of proximal and distal sciatic nerve between two groups.RESULTS： ①Observation under optical microscope：Two weeks after grafting, neve axon of repaired region broke and medullary sheath denatured in the allogenic nerve grafting group and autologous nerve grafting group. At the same time, vascular engorgement and a little lymphocytes infiltration were found in the autologous nerve grafting group, but those were found worsened in the allogenic nerve grafting group. Four weeks after grafting, the intensity of the inflammatory reaction was similar between two groups, some collagen fibers at the proximal end proliferated; 8 weeks after grafting, the inflammatory reaction ended basically and the collagen fibers proliferated obviously in the two groups. ② Observation under electron microscope： Fourteen weeks after grafting, the structure of epineurium was in integrity and there were no obvious differences in perineurium and endonurium between two groups. A large number of myelinated nerve fibers and a few unmyelinated nerve fibers regenerated. The structure of myelin sheath was in integrity. ③The number and size of regenerated axons of anastomosis of proximal and distal sciatic nerve had no significant difference 14 weeks after grafting [（575.500±7.495） vs（585.700±11.172） axons/visual field ; （389.300±49.073） vs （407.600±0.283） axons/visual field;（6 423.830±119.911 ） vs （6 695.36± 84.287） μm^2/visual field = （ 5 980.110±74.572） vs（5 980.110±74.572） μm^2/visual field] （P 〉 0.05）. ④ Neuroelectrophysiological examination showed that there were no significant differences in motor nerve evoked potential latent pedod[（1.420±0.346）vs （1.237±0.250） ms] , motor nerve conduction velocity [（ 12.120±0.906 ） vs（13.020±0.599） m/s]and latent period of sciatic nerve [（0.500±0.380）vs （1.250±1.067） mV] of rats between two groups （P 〉 0.05）.CONCLUSTON： Although subcutaneous implant of peripheral nerve allograft has some inflammatory reactions, no obvious rejection is found. Repair results of two groups show that subcutaneous implant of allograft can promote nerve regeneration, which is similar to autologous nerve grafting.
文摘The prevalence of stroke displays obvious geographical variation and is higher on plateaus.Similarly,prolonged stay at high altitude is associated with higher incidence of stroke.High-altitude hypoxia can elicit various physiological dysfunctions,and hypoxia is suggested to be the principal contributing factor of stroke.In this brief review,the effects of hypoxia on the properties of the blood components such as erythrocytes,leukocytes and thrombocytes are presented,in an effort to inform the prevention and treatment of stroke in high-altitude areas.
文摘Methylmalonic aciduria （MMA） is an autosomal recessive disorder of cobalamin （cbl） metabolism. Cobalamin C （cblC） disease is the most common type of MMA and is characteristically concurrent with homocystinemia （HCY） due to impaired synthesis of two active forms of cbl, namely adenosylcobalamin （AdoCbl） and methylcobalamin （MeCbl）. The estimated worldwide incidence of MMA ranges between 1：48,000 and 1：250,000. Mutations of the MMA and HCY type C protein （MMACtfC） gene are responsible for cblC disease and were first identified by Lerner-Ellis et aL in 2006.By the year 2016, more than 82 different MMACHC gene mutations have been reported （http：// www.hgmd.cf.ac.uk/ac/index.php）. Among these mutations, c.609G〉A （p.W203X） was reported to be the most frequent cblC mutation in Chinese patients.
基金funded by the National Natural Science Foundation of China(31871928,31671993)the Guangdong Special Branch Plan for Young Talent with Scientific and Technological Innovation(2019TQ05N158)+2 种基金the Pearl River S&T Nova Program of Guangzhou(201906010093)the Research and Development Project in Major Fields of Guangdong(2019B020238001)the Guangdong Provincial Innovation Team for General Key Technologies in Modern Agricultural Industry(2019KJ133).
文摘Arthropod-borne viruses cause serious threats to human health and global agriculture by rapidly spreading via insect vectors. Southern rice black-streaked dwarf virus (SRBSDV) is the most damaging rice-infecting virus that is frequently transmitted by planthoppers. However, the molecular mechanisms underlying its propagation in the host plants and epidemics in the field are largely unknown. Here, we showed that the SRBSDV-encoded P6 protein is a key effector that regulates rice ethylene signaling to coordinate viral infection and transmission. In early SRBSDV infection, P6 interacts with OsRTH2 in the cytoplasm to activate ethylene signaling and enhance SRBSDV proliferation;this also repels the insect vector to reduce infestation. In late infection, P6 enters the nucleus, where it interacts with OsEIL2, a key transcription factor of ethylene signaling. The P6-OsEIL2 interaction suppresses ethylene signaling by preventing the dimerization of OsEIL2, thereby facilitating viral transmission by attracting the insect vector. Collectively, these findings reveal a novel molecular mechanism by which an arbovirus modulates the host defense system to promote viral infection and transmission.
基金partly supported by the Supercomputer Application Project Trail Funding from Wuxi Jiangnan Institute of Computing Technology(BB2340000016)the Strategic Priority Research Program of Chinese Academy of Sciences(XDC01040100)+6 种基金the National Natural Science Foundation of China(21688102,21803066)the Anhui Initiative in Quantum Information Technologies(AHY090400)the National Key Research and Development Program of China(2016YFA0200604)the Fundamental Research Funds for Central Universities(WK2340000091)the Chinese Academy of Sciences Pioneer Hundred Talents Program(KJ2340000031)the Research Start-Up Grants(KY2340000094)the Academic Leading Talents Training Program(KY2340000103)from University of Science and Technology of China。
文摘High performance computing(HPC)is a powerful tool to accelerate the Kohn–Sham density functional theory(KS-DFT)calculations on modern heterogeneous supercomputers.Here,we describe a massively parallel implementation of discontinuous Galerkin density functional theory(DGDFT)method on the Sunway Taihu Light supercomputer.The DGDFT method uses the adaptive local basis(ALB)functions generated on-the-fly during the self-consistent field(SCF)iteration to solve the KS equations with high precision comparable to plane-wave basis set.In particular,the DGDFT method adopts a two-level parallelization strategy that deals with various types of data distribution,task scheduling,and data communication schemes,and combines with the master–slave multi-thread heterogeneous parallelism of SW26010 processor,resulting in large-scale HPC KS-DFT calculations on the Sunway Taihu Light supercomputer.We show that the DGDFT method can scale up to 8,519,680 processing cores(131,072 core groups)on the Sunway Taihu Light supercomputer for studying the electronic structures of twodimensional(2 D)metallic graphene systems that contain tens of thousands of carbon atoms.
基金supported by the National Natural Science Foundation of China(U20A2034 and 31871659)the China Agriculture Research System(CARS-12)(to C.Z.)E.B.C.was supported by funding from the National Science Foundation(Plant Genome IOS-13-39385).
文摘Orychophragmus violaceus is a Brassicaceae species widely cultivated in China,particularly as a winter cover crop in northern China because of its low-temperature tolerance and low water demand.Recently,O.violaceus has also been cultivated as a potential industrial oilseed crop because of its abundant 24-carbon dihydroxy fatty acids(diOH-FAs),which contribute to superior high-temperature lubricant properties.In this study,we performed de novo assembly of the O.violaceus genome.Whole-genome synteny analysis of the genomes of its relatives demonstrated that O.violaceus is a diploid that has undergone an extrawhole-genome duplication(WGD)after the Brassicaceae-specific a-WGD event,with a basic chromosome number of x=12.Formation of diOH-FAs is hypothesized to have occurred after the WGD event.Based on the genome and the transcriptome data from multiple stages of seed development,we predicted that OvDGAT1-1 and OvDGAT1-2 are candidate genes for the regulation of diOH-FA storage in O.violaceus seeds.These results may greatly facilitate the development of heat-tolerant and eco-friendly plant-based lubricants using O.violaceus seed oil and improve our understanding of the genomic evolution of Brassicaceae.
基金The work was supported by the National Key Research and Development Program of China under Grant No. 2018YFB0204102。
文摘The short-range pair interaction consumes most of the CPU time in molecular dynamics(MD)simulations.The inherent computation sparsity makes it challenging to achieve high-performance kernel on the emerging many-core architecture.In this paper,we present a highly efficient short-range force kernel on the Sunway,a novel many-core architecture with many unique features.The parallel efficiency of this algorithm on the Sunway many-core processor is strongly limited by the poor data locality and write conflicts.To enhance the data locality,we adopt a super cluster based neighbor list with an appropriate granularity that fits in the local memory of computing cores.In the absence of a low overhead locking mechanism,using data-privatization force array is a more feasible method to avoid write conflicts,but results in the large overhead of data reduction.We adopt a dual-slice partitioning scheme for both hardware resources and computing tasks,which utilizes the on-chip data communication to reduce data reduction overhead and provide load balancing.Moreover,we exploit the single instruction multiple data(SIMD)parallelism and perform instruction reordering of the force kernel on this many-core processor.The experimental results show that the optimized force kernel obtains a performance speedup of 226x compared with the reference implementation and achieves 20%of peak flop rate on the Sunway many-core processor.
基金This work was supported by grants from Cheung Kong （Chang Jiang） Scholars Program （No. T2014251）, National Key R＆D Program of China （No. 2017YFC1308401）, Fundamental Clinical Research Cooperation Project of Capital Medical University （No： 17JL-02, 201611-201911）, and National Science Foundation for Distinguished Young Scholars （No. 81325007）.
文摘To the Editor：Hyperhomocysteinemia （HHcy） is an important risk factor for atherothrombotic disease and venous thrombosis.[1] Normally,homocysteine （Hcy） is either remethylated to methionine （Met） by a Vitamin B12-dependent reaction or betaine as the methyl donor,or trans-sulfurated to cysteine through a pyridoxine-dependent reaction.Based on plasma level of total Hcy,HHcy is typically classified into three groups as follows：mild （tHcy 15-30 μmol/L）,moderate （tHcy 30-100 μmol/L）,and severe （tHcy 〉100 μmol/L）.[2] Severe HHcy is rare and most commonly caused by inherited deficiency of cystathionine beta-synthase （CBS）,or less frequently,ofmethylenetetrahydrofolate reductase （MTHFR） genes.The presentations of this metabolic disorder include developmental delay,intellectual disability,epilepsy,ectopia lentis,myopia,hypopigmentation of the skin and hair,marfanoid habitus,and thromboembolic disorders.[3] These manifestations are often overlooked in the early stage until the occur of thrombotic events like cerebral venous sinus thrombosis （CVST）.
基金This work was supported by grants from the National Natural Science Foundation of China （No. 81470074 and No. 81401040）, Clinical Fund from Beijing Municipal Science and Technology Committee （No. Z 141107002514117）, and Beijing Municipal Government Fund （No. PXM2017_026283_000002）.
文摘To the Editor： Charcot-Marie-Tooth disease （CMT） is a clinically and genetically heterogeneous inherited neuropathy, with Type 1 A being the most common. CMT IA is characterized by progressive weakness and atrophy of the distal limb muscles beginning in the peroneal group, mild distal sensory loss, diminished tendon reflexes, and slow nerve conduction velocity . Spinal nerve root hypertrophy is a distinct sign of CMT 1A. This sign can be detected on magnetic resonance images （MRI）, but it is often overlooked. Instead, diagnosis of this disease is often made basing on biopsy and genetic testing.
文摘Processor specialization has become the development trend of modern processor industry. It is quite possible that this will still be the main-stream in the next decades of semiconductor era. As the diversity of heterogeneous systems grows, organizing computation efficiently on systems with multiple kinds of heterogeneous processors is a challenging problem and will be a normality. In this paper, we analyze some state-of-the-art task scheduling algorithms of heterogeneous computing systems and propose a Degree of Node First (DONF) algorithm for task scheduling of fine-grained parallel programs on heterogeneous systems. The major innovations of DONF include: 1) simplifying task priority calculation for directed acyclic graph (DAG) based fine-grained parallel programs which not only reduces the complexity of task selection but also enables the algorithm to solve the scheduling problem for dynamic DAGs;2) building a novel communication model in the processor selection phase that makes the task scheduling much more efficient. They are achieved by exploring finegrained parallelism via a dataflow program execution model, and validated through experimental results with a selected set of benchmarks. The results on synthesized and real-world application DAGs show a very good performance. The proposed DONF algorithm significantly outperforms all the evaluated state-of-the-art heuristic algorithms in terms of scheduling length ratio (SLR) and efficiency.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB41000000)the Research Funds of the Double First-Class Initiative of University of Science and Technology of China(YD2080002007)the National Natural Science Foundation of China(91837310,42061134009,and 41775146)。
文摘During the era of global warming and highly urbanized development,extreme and high impact weather as well as air pollution incidents influence everyday life and might even cause the incalculable loss of life and property.Despite the vast development of atmospheric models,there still exist substantial numerical forecast biases objectively.To accurately predict extreme weather,severe air pollution,and abrupt climate change,numerical atmospheric model requires not only to simulate meteorology and atmospheric compositions simultaneously involving many sophisticated physical and chemical processes but also at high spatiotemporal resolution.Global integrated atmospheric simulation at spatial resolutions of a few kilometers remains challenging due to its intensive computational and input/output(I/O)requirement.Through multi-dimension-parallelism structuring,aggressive and finer-grained optimizing,manual vectorizing,and parallelized I/O fragmenting,an integrated Atmospheric Model Across Scales(iAMAS)was established on the new Sunway supercomputer platform to significantly increase the computational efficiency and reduce the I/O cost.The global 3-km atmospheric simulation for meteorology with online integrated aerosol feedbacks with iAMAS was scaled to 39,000,000 processor cores and achieved the speed of 0.82 simulation day per hour(SDPH)with routine I/O,which enabled us to perform 5-day global weather forecast at 3-km horizontal resolution with online natural aerosol impacts.The results demonstrate the promising future that the increasing of spatial resolution to a few kilometers with online integrated aerosol feedbacks may significantly improve the global weather forecast.
