Background: Patients on hemodialysis have a high-mortality risk. Tiffs study analyzed factors associated with death in patients on maintenance hemodialysis (MHD). While some studies used baseline data of MHD patien...Background: Patients on hemodialysis have a high-mortality risk. Tiffs study analyzed factors associated with death in patients on maintenance hemodialysis (MHD). While some studies used baseline data of MHD patients, this study used the most recent data obtained from patients just prior to either a primary endpoint or the end of the study period to iliad the characteristics of patients preceding death.Methods: Participants were selected from 16 blood purification centers in China from January 2012 to December 2014, Patients' data were collected retrospectively. Based on survival status, the participants were divided into two groups: survival group and the death group. Logistic regression analysis was performed to determine/'actors associated with all-cause mortality.展开更多
In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a ...In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a receptor of SARS-CoV-2,mediates the virus infection by binding to spike protein.Although ACE2 is expressed in the lung,kidney,and intestine,its expressing levels are rather low,especially in the lung.Considering the great infectivity of COVID-19,we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection.Here,we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein.The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody,Meplazumab,inhibits SARSCoV-2 amplification.Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells,which can be neutralized by CD147 extracellular fragment.Viral loads are detectable in the lungs of human CD147(hCD147)mice infected with SARS-CoV-2,but not in those of virus-infected wild type mice.Interestingly,virions are observed in lymphocytes of lung tissue from a COVID-19 patient.Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dosedependent manner,which is specifically inhibited by Meplazumab.Furthermore,CD147 mediates virus entering host cells by endocytosis.Together,our study reveals a novel virus entry route,CD147-spike protein,which provides an important target for developing specific and effective drug against COVID-19.展开更多
Objective: To observe wet cupping therapy(WCT) on local blood perfusion and analgesic effects in patients with nerve-root type cervical spondylosis(NT-CS). Methods: Fifty-seven NT-CS patients were randomly divid...Objective: To observe wet cupping therapy(WCT) on local blood perfusion and analgesic effects in patients with nerve-root type cervical spondylosis(NT-CS). Methods: Fifty-seven NT-CS patients were randomly divided into WCT group and Jiaji acupoint-acupuncture(JA) group according a random number table. WCT group(30 cases) was treated with WCT for 10 min, and JA group(27 cases) was treated with acupuncture for 10 min. The treatment efficacies were evaluated with a Visual Analogue Scale(VAS). Blood perfusion at Dazhui(GV 14) and Jianjing(GB 21) acupoints(affected side) was observed with a laser speckle flowmetry, and its variations before and after treatment in both groups were compared as well. Results: In both groups, the VAS scores significantly decreased after the intervention(P〈0.01), while the blood perfusion at the two acupoints significantly increased after intervention(P〈0.05); however, the increasement magnitude caused by WCT was obvious compared with JA(P〈0.05). Conclusion: WCT could improve analgesic effects in patients with NT-CS, which might be related to increasing local blood perfusion of acupunct points.展开更多
AIM: To screen and investigate the effective g RNAs against hepatitis B virus(HBV) of genotypes A-D.METHODS: A total of 15 g RNAs against HBV of genotypes A-D were designed. Eleven combinations of two above g RNAs(dua...AIM: To screen and investigate the effective g RNAs against hepatitis B virus(HBV) of genotypes A-D.METHODS: A total of 15 g RNAs against HBV of genotypes A-D were designed. Eleven combinations of two above g RNAs(dual-g RNAs) covering the regulatory region of HBV were chosen. The efficiency of each g RNA and 11 dual-g RNAs on the suppression of HBV(genotypes A-D) replication was examined by the measurement of HBV surface antigen(HBs Ag) or e antigen(HBe Ag) in the culture supernatant. The destruction of HBV-expressing vector was examined in Hu H7 cells co-transfected with dual-g RNAs and HBVexpressing vector using polymerase chain reaction(PCR) and sequencing method, and the destruction of ccc DNAwas examined in Hep AD38 cells using KCl precipitation, plasmid-safe ATP-dependent DNase(PSAD) digestion, rolling circle amplification and quantitative PCR combined method. The cytotoxicity of these g RNAs was assessed by a mitochondrial tetrazolium assay.RESULTS: All of g RNAs could significantly reduce HBs Ag or HBe Ag production in the culture supernatant, which was dependent on the region in which g RNA against. All of dual g RNAs could efficiently suppress HBs Ag and/or HBe Ag production for HBV of genotypes A-D, and the efficacy of dual g RNAs in suppressing HBs Ag and/or HBe Ag production was significantly increased when compared to the single g RNA used alone. Furthermore, by PCR direct sequencing we confirmed that these dual g RNAs could specifically destroy HBV expressing template by removing the fragment between the cleavage sites of the two used g RNAs. Most importantly, g RNA-5 and g RNA-12 combination not only could efficiently suppressing HBs Ag and/or HBe Ag production, but also destroy the ccc DNA reservoirs in Hep AD38 cells.CONCLUSION: These results suggested that CRISPR/Cas9 system could efficiently destroy HBV expressing templates(genotypes A-D) without apparent cytotoxicity. It may be a potential approach for eradication of persistent HBV ccc DNA in chronic HBV infection patients.展开更多
The accumulation of excessive reactive oxygen species can exacerbate any injury of retinal tissue because free radicals can trigger lipid peroxidation,protein damage and DNA fragmentation.Increased oxidative stress is...The accumulation of excessive reactive oxygen species can exacerbate any injury of retinal tissue because free radicals can trigger lipid peroxidation,protein damage and DNA fragmentation.Increased oxidative stress is associated with the common pathological process of many eye diseases,such as glaucoma,diabetic retinopathy and ischemic optic neuropathy.Many studies have demonstrated that Lycium barbarum polysaccharides(LBP)protects against oxidative injury in numerous cells and tissues.For the model of hypoxia we used cultured retinal ganglion cells and induced hypoxia by incubating with 200μM cobalt chloride(CoCl2)for 24 hours.To investigate the protective effect of LBP and its mechanism of action against oxidative stress injury,the retinal tissue was pretreated with 0.5 mg/mL LBP for 24 hours.The results of flow cytometric analysis showed LBP could effectively reduce the CoCl2-induced retinal ganglion cell apoptosis,inhibited the generation of reactive oxygen species and the reduction of mitochondrial membrane potential.These findings suggested that LBP could protect retinal ganglion cells from CoCl2-induced apoptosis by reducing mitochondrial membrane potential and reactive oxygen species.展开更多
清洁环保的燃料电池混合动力有轨电车近年来受到极大关注,其高效的能量管理方法对混合动力系统性能起到至关重要的作用。传统等效氢耗最小化方法的荷电状态(state of charge,SOC)平衡系数通常采用恒定值,而有轨电车在大功率峰值需求和...清洁环保的燃料电池混合动力有轨电车近年来受到极大关注,其高效的能量管理方法对混合动力系统性能起到至关重要的作用。传统等效氢耗最小化方法的荷电状态(state of charge,SOC)平衡系数通常采用恒定值,而有轨电车在大功率峰值需求和减速制动过程中,恒定的SOC平衡系数不能满足瞬时等效氢耗最小的指标要求,并且在未知有轨电车工况条件下最优SOC平衡系数无法确定。针对上述问题,建立基于燃料电池/锂电池的混合动力有轨电车动力系统模型,并通过分析SOC平衡系数与氢耗特性,提出一种基于运行模式和动态混合度的等效氢耗最小化能量管理控制方法。该方法通过划分有轨电车运行模式,分析不同运行模式下SOC平衡系数与瞬时氢耗的关系,在此基础上提出基于运行模式和动态混合度的等效氢耗瞬时优化方法。结合有轨电车典型工况,搭建RT-LAB实时仿真平台,开展有轨电车能量管理系统实时仿真,并与传统等效氢耗最小化方法进行对比分析。结果表明,所提出的能量管理方法能够根据有轨电车工况的实时变化而自动分配需求功率,并在不同初始SOC的情况下,满足等效氢耗量最小的性能指标要求,提高整车燃料经济性。展开更多
Background Ossification of the posterior longitudinal ligament (OPLL) has a strong genetic background. Previous studies have shown that bone morphogenetic protein-2 (BMP2) and BMP2 mRNA are expressed in ossifying ...Background Ossification of the posterior longitudinal ligament (OPLL) has a strong genetic background. Previous studies have shown that bone morphogenetic protein-2 (BMP2) and BMP2 mRNA are expressed in ossifying matrix and chondrocytes adjacent to cartilaginous areas of OPLL tissues and mesenchymal cells with fibroblastic features in the immediate vicinity of the cartilaginous areas. It is suggested that BMP2 plays different roles in the different stages of development of OPLL. However, it remains unknown which factors induce ligament cells to produce BMP2. Methods OPLL patients (n=-192) and non-OPLL controls (n=304) were studied. Radiographs of the cervical spine were analyzed for extent of OPLL. We investigated whether single nucleotide polymorphisms of exons 3(-726) T/C and 3(-583) NG in the BMP2 gene are statistically associated with genetic susceptibility to OPLL in Chinese Han subjects. Results There was no statistical difference between the occurrence of exons 3(-726) T/C and 3(-583) NG and the occurrence of OPLL in the cervical spine. However, there was a significant association between occurrence of exon 3(-726) T/C polymorphism and occurrence of OPLL in males of cases and controls in the cervical spine. In addition, no significant association was found between the exons 3(-726) T/C and 3(-583) A/G with number of ossified cervical vertebrae in OPLL patients. Conclusions Exon 3(-583) A/G polymorphism in BMP2 gene is not associated with the occurrence and the extent of OPLL in the cervical spine. Chinese Han male patients with TC and CC genotypes in exon 3(-726) T/C have genetic susceptibility to OPLL but not to more extensive OPLL in the cervical spine.展开更多
Summary What is known about this topic?Few major outbreaks of coronavirus disease 2019(COVID-19)have occurred in China after major nonpharmaceutical interventions and vaccines have been deployed and implemented.Howeve...Summary What is known about this topic?Few major outbreaks of coronavirus disease 2019(COVID-19)have occurred in China after major nonpharmaceutical interventions and vaccines have been deployed and implemented.However,sporadic outbreaks that had high possibility to be linked to cold chain products were reported in several cities of China..What is added by this report?In July 2020,a COVID-19 outbreak occurred in Dalian,China.The investigations of this outbreak strongly suggested that the infection source was from COVID-19 virus-contaminated packaging of frozen seafood during inbound unloading personnel contact.What are the implications for public health practice?Virus contaminated paper surfaces could maintain infectivity for at least 17–24 days at-25℃.Exposure to COVID-19 virus-contaminated surfaces is a potential route for introducing the virus to a susceptible population.Countries with no domestic transmission of COVID-19 should consider introducing prevention strategies for both inbound travellers and imported goods.Several measures to prevent the introduction of the virus via cold-chain goods can be implemented.展开更多
文摘以全球变暖为主要特征的气候变化已成为全球性环境问题,对全球可持续发展带来严峻挑战。2015年《巴黎协定》确定了自2020年后国家自主贡献的减排方式,并从2023年开始每5 a开展一次全球碳盘点。2019年第49届IPCC全会明确增加了基于卫星遥感的排放清单校验方法。欧盟、美国、日本、加拿大等正在大力发展温室气体排放的MVS(Monitoring and Verification Support)能力。本文调研分析了全球碳盘点对卫星遥感技术的需求,介绍了全球碳盘点卫星遥感的技术原理,梳理了温室气体卫星遥感、生态系统碳源汇卫星遥感估算、人为源碳排放卫星遥感、碳通量同化估算等全球碳盘点卫星遥感核心环节的研究现状与进展,分析了当前卫星遥感技术对全球碳盘点任务的支撑能力,并结合国内外发展趋势,针对性地提出中国的碳监测卫星计划方案,并展望了中国开展全球碳盘点卫星遥感监测重点任务,期望为中国全球碳盘点卫星遥感体系建设提供思路与方案。
文摘Background: Patients on hemodialysis have a high-mortality risk. Tiffs study analyzed factors associated with death in patients on maintenance hemodialysis (MHD). While some studies used baseline data of MHD patients, this study used the most recent data obtained from patients just prior to either a primary endpoint or the end of the study period to iliad the characteristics of patients preceding death.Methods: Participants were selected from 16 blood purification centers in China from January 2012 to December 2014, Patients' data were collected retrospectively. Based on survival status, the participants were divided into two groups: survival group and the death group. Logistic regression analysis was performed to determine/'actors associated with all-cause mortality.
基金supported by the National Science and Technology Major Project of China(2019ZX09732-001)the Key R&D Plan Projects in Shaanxi Province(2020ZDXM2-SF-01)Young Talent fund of the University Association for Science and Technology in Shaanxi,China(20200304).
文摘In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a receptor of SARS-CoV-2,mediates the virus infection by binding to spike protein.Although ACE2 is expressed in the lung,kidney,and intestine,its expressing levels are rather low,especially in the lung.Considering the great infectivity of COVID-19,we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection.Here,we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein.The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody,Meplazumab,inhibits SARSCoV-2 amplification.Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells,which can be neutralized by CD147 extracellular fragment.Viral loads are detectable in the lungs of human CD147(hCD147)mice infected with SARS-CoV-2,but not in those of virus-infected wild type mice.Interestingly,virions are observed in lymphocytes of lung tissue from a COVID-19 patient.Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dosedependent manner,which is specifically inhibited by Meplazumab.Furthermore,CD147 mediates virus entering host cells by endocytosis.Together,our study reveals a novel virus entry route,CD147-spike protein,which provides an important target for developing specific and effective drug against COVID-19.
基金Supported by National Natural Science Foundation of China(No.81273673)Integrated Chinese and Western Medicine,Tianjin Health Bureau,China(No.11027)
文摘Objective: To observe wet cupping therapy(WCT) on local blood perfusion and analgesic effects in patients with nerve-root type cervical spondylosis(NT-CS). Methods: Fifty-seven NT-CS patients were randomly divided into WCT group and Jiaji acupoint-acupuncture(JA) group according a random number table. WCT group(30 cases) was treated with WCT for 10 min, and JA group(27 cases) was treated with acupuncture for 10 min. The treatment efficacies were evaluated with a Visual Analogue Scale(VAS). Blood perfusion at Dazhui(GV 14) and Jianjing(GB 21) acupoints(affected side) was observed with a laser speckle flowmetry, and its variations before and after treatment in both groups were compared as well. Results: In both groups, the VAS scores significantly decreased after the intervention(P〈0.01), while the blood perfusion at the two acupoints significantly increased after intervention(P〈0.05); however, the increasement magnitude caused by WCT was obvious compared with JA(P〈0.05). Conclusion: WCT could improve analgesic effects in patients with NT-CS, which might be related to increasing local blood perfusion of acupunct points.
基金Supported by Natural Science Foundation of China,No.81471938the National S and T Major Project for Infectious Diseases,No.2013ZX10002-002 and No.2012ZX10002-005111 Project,No.B07001
文摘AIM: To screen and investigate the effective g RNAs against hepatitis B virus(HBV) of genotypes A-D.METHODS: A total of 15 g RNAs against HBV of genotypes A-D were designed. Eleven combinations of two above g RNAs(dual-g RNAs) covering the regulatory region of HBV were chosen. The efficiency of each g RNA and 11 dual-g RNAs on the suppression of HBV(genotypes A-D) replication was examined by the measurement of HBV surface antigen(HBs Ag) or e antigen(HBe Ag) in the culture supernatant. The destruction of HBV-expressing vector was examined in Hu H7 cells co-transfected with dual-g RNAs and HBVexpressing vector using polymerase chain reaction(PCR) and sequencing method, and the destruction of ccc DNAwas examined in Hep AD38 cells using KCl precipitation, plasmid-safe ATP-dependent DNase(PSAD) digestion, rolling circle amplification and quantitative PCR combined method. The cytotoxicity of these g RNAs was assessed by a mitochondrial tetrazolium assay.RESULTS: All of g RNAs could significantly reduce HBs Ag or HBe Ag production in the culture supernatant, which was dependent on the region in which g RNA against. All of dual g RNAs could efficiently suppress HBs Ag and/or HBe Ag production for HBV of genotypes A-D, and the efficacy of dual g RNAs in suppressing HBs Ag and/or HBe Ag production was significantly increased when compared to the single g RNA used alone. Furthermore, by PCR direct sequencing we confirmed that these dual g RNAs could specifically destroy HBV expressing template by removing the fragment between the cleavage sites of the two used g RNAs. Most importantly, g RNA-5 and g RNA-12 combination not only could efficiently suppressing HBs Ag and/or HBe Ag production, but also destroy the ccc DNA reservoirs in Hep AD38 cells.CONCLUSION: These results suggested that CRISPR/Cas9 system could efficiently destroy HBV expressing templates(genotypes A-D) without apparent cytotoxicity. It may be a potential approach for eradication of persistent HBV ccc DNA in chronic HBV infection patients.
基金supported by grants from Project of Administration of Traditional Chinese Medicine of Guangdong Province of China,No.20161071(to LL)Medical Scientific Research Foundation of Guangdong Province of China,No.A2019098(to LL)
文摘The accumulation of excessive reactive oxygen species can exacerbate any injury of retinal tissue because free radicals can trigger lipid peroxidation,protein damage and DNA fragmentation.Increased oxidative stress is associated with the common pathological process of many eye diseases,such as glaucoma,diabetic retinopathy and ischemic optic neuropathy.Many studies have demonstrated that Lycium barbarum polysaccharides(LBP)protects against oxidative injury in numerous cells and tissues.For the model of hypoxia we used cultured retinal ganglion cells and induced hypoxia by incubating with 200μM cobalt chloride(CoCl2)for 24 hours.To investigate the protective effect of LBP and its mechanism of action against oxidative stress injury,the retinal tissue was pretreated with 0.5 mg/mL LBP for 24 hours.The results of flow cytometric analysis showed LBP could effectively reduce the CoCl2-induced retinal ganglion cell apoptosis,inhibited the generation of reactive oxygen species and the reduction of mitochondrial membrane potential.These findings suggested that LBP could protect retinal ganglion cells from CoCl2-induced apoptosis by reducing mitochondrial membrane potential and reactive oxygen species.
文摘清洁环保的燃料电池混合动力有轨电车近年来受到极大关注,其高效的能量管理方法对混合动力系统性能起到至关重要的作用。传统等效氢耗最小化方法的荷电状态(state of charge,SOC)平衡系数通常采用恒定值,而有轨电车在大功率峰值需求和减速制动过程中,恒定的SOC平衡系数不能满足瞬时等效氢耗最小的指标要求,并且在未知有轨电车工况条件下最优SOC平衡系数无法确定。针对上述问题,建立基于燃料电池/锂电池的混合动力有轨电车动力系统模型,并通过分析SOC平衡系数与氢耗特性,提出一种基于运行模式和动态混合度的等效氢耗最小化能量管理控制方法。该方法通过划分有轨电车运行模式,分析不同运行模式下SOC平衡系数与瞬时氢耗的关系,在此基础上提出基于运行模式和动态混合度的等效氢耗瞬时优化方法。结合有轨电车典型工况,搭建RT-LAB实时仿真平台,开展有轨电车能量管理系统实时仿真,并与传统等效氢耗最小化方法进行对比分析。结果表明,所提出的能量管理方法能够根据有轨电车工况的实时变化而自动分配需求功率,并在不同初始SOC的情况下,满足等效氢耗量最小的性能指标要求,提高整车燃料经济性。
文摘Background Ossification of the posterior longitudinal ligament (OPLL) has a strong genetic background. Previous studies have shown that bone morphogenetic protein-2 (BMP2) and BMP2 mRNA are expressed in ossifying matrix and chondrocytes adjacent to cartilaginous areas of OPLL tissues and mesenchymal cells with fibroblastic features in the immediate vicinity of the cartilaginous areas. It is suggested that BMP2 plays different roles in the different stages of development of OPLL. However, it remains unknown which factors induce ligament cells to produce BMP2. Methods OPLL patients (n=-192) and non-OPLL controls (n=304) were studied. Radiographs of the cervical spine were analyzed for extent of OPLL. We investigated whether single nucleotide polymorphisms of exons 3(-726) T/C and 3(-583) NG in the BMP2 gene are statistically associated with genetic susceptibility to OPLL in Chinese Han subjects. Results There was no statistical difference between the occurrence of exons 3(-726) T/C and 3(-583) NG and the occurrence of OPLL in the cervical spine. However, there was a significant association between occurrence of exon 3(-726) T/C polymorphism and occurrence of OPLL in males of cases and controls in the cervical spine. In addition, no significant association was found between the exons 3(-726) T/C and 3(-583) A/G with number of ossified cervical vertebrae in OPLL patients. Conclusions Exon 3(-583) A/G polymorphism in BMP2 gene is not associated with the occurrence and the extent of OPLL in the cervical spine. Chinese Han male patients with TC and CC genotypes in exon 3(-726) T/C have genetic susceptibility to OPLL but not to more extensive OPLL in the cervical spine.
基金The National Key Research and Development Project,Ministry of Science and Technology of the People’s Republic of China(2021YFC0863000,2018ZX10713002,and 2020YFC0846900),National Natural Science Foundation of China(No.72042012,and No.82041032)and National Key Technology R&D Program of China(2017ZX10104001).
文摘Summary What is known about this topic?Few major outbreaks of coronavirus disease 2019(COVID-19)have occurred in China after major nonpharmaceutical interventions and vaccines have been deployed and implemented.However,sporadic outbreaks that had high possibility to be linked to cold chain products were reported in several cities of China..What is added by this report?In July 2020,a COVID-19 outbreak occurred in Dalian,China.The investigations of this outbreak strongly suggested that the infection source was from COVID-19 virus-contaminated packaging of frozen seafood during inbound unloading personnel contact.What are the implications for public health practice?Virus contaminated paper surfaces could maintain infectivity for at least 17–24 days at-25℃.Exposure to COVID-19 virus-contaminated surfaces is a potential route for introducing the virus to a susceptible population.Countries with no domestic transmission of COVID-19 should consider introducing prevention strategies for both inbound travellers and imported goods.Several measures to prevent the introduction of the virus via cold-chain goods can be implemented.