Back-streaming neutrons from the spallation target of the China Spallation Neutron Source(CSNS)that emit through the incoming proton channel were exploited to build a white neutron beam facility(the so-called Back-n w...Back-streaming neutrons from the spallation target of the China Spallation Neutron Source(CSNS)that emit through the incoming proton channel were exploited to build a white neutron beam facility(the so-called Back-n white neutron source),which was completed in March 2018.The Back-n neutron beam is very intense,at approximately 29107 n/cm2/s at 55 m from the target,and has a nominal proton beam with a power of 100 kW in the CSNS-I phase and a kinetic energy of 1.6 GeV and a thick tungsten target in multiple slices with modest moderation from the cooling water through the slices.In addition,the excellent energy spectrum spanning from 0.5 eV to 200 MeV,and a good time resolution related tothe time-of-flight measurements make it a typical white neutron source for nuclear data measurements;its overall performance is among that of the best white neutron sources in the world.Equipped with advanced spectrometers,detectors,and application utilities,the Back-n facility can serve wide applications,with a focus on neutron-induced cross-sectional measurements.This article presents an overview of the neutron beam characteristics,the experimental setups,and the ongoing applications at Backn.展开更多
Rubus chingii Hu, a member of the rosaceae family, is extensively distributed in China and Japan. Its unripe fruits(Fupenzi in Chinese) have a long history of use as an herbal tonic in traditional Chinese medicine for...Rubus chingii Hu, a member of the rosaceae family, is extensively distributed in China and Japan. Its unripe fruits(Fupenzi in Chinese) have a long history of use as an herbal tonic in traditional Chinese medicine for treating various diseases commonly associated with kidney deficiency, and they are still in use today. Phytochemical investigations on the fruits and leaves of R. chingii indicate the presence of terpenoids, flavonoids, steroids, alkaloids, phenylpropanoids, phenolics, and organic acids. Extracts or active substances from this plant are reported to have various pharmacological properties, including antioxidant, anti-inflammatory, antitumor, antifungal, antithrombotic, antiosteoporotic, hypoglycemic, and central nervous system-regulating effects. This review provides up-to-date information on the botanical characterizations, traditional usages, chemical constituents, pharmacological activities, toxicity,and quality control of R. chingii. Possible directions for future research are also briefly proposed. This review aims to supply fundamental data for the further study of R. chingii and contribute to the development of its clinical use.展开更多
Motor imagery is the mental representation of an action without overt movement or muscle activation. However, the effects of motor imagery on stroke-induced hand dysfunction and brain neural networks are still unknown...Motor imagery is the mental representation of an action without overt movement or muscle activation. However, the effects of motor imagery on stroke-induced hand dysfunction and brain neural networks are still unknown. We conducted a randomized controlled trial in the China Rehabilitation Research Center. Twenty stroke patients, including 13 males and 7 females, 32–51 years old, were recruited and randomly assigned to the traditional rehabilitation treatment group（PP group, n = 10） or the motor imagery training combined with traditional rehabilitation treatment group（MP group, n = 10）. All patients received rehabilitation training once a day, 45 minutes per session, five times per week, for 4 consecutive weeks. In the MP group, motor imagery training was performed for 45 minutes after traditional rehabilitation training, daily. Action Research Arm Test and the Fugl-Meyer Assessment of the upper extremity were used to evaluate hand functions before and after treatment. Transcranial magnetic stimulation was used to analyze motor evoked potentials in the affected extremity. Diffusion tensor imaging was used to assess changes in brain neural networks. Compared with the PP group, the MP group showed better recovery of hand function, higher amplitude of the motor evoked potential in the abductor pollicis brevis, greater fractional anisotropy of the right dorsal pathway, and an increase in the fractional anisotropy of the bilateral dorsal pathway. Our findings indicate that 4 weeks of motor imagery training combined with traditional rehabilitation treatment improves hand function in stroke patients by enhancing the dorsal pathway. This trial has been registered with the Chinese Clinical Trial Registry（registration number： Chi CTR-OCH-12002238）.展开更多
BACKGROUND Hypertensive cerebral hemorrhage(HICH)is a common clinical cerebrovascular disease and one of the most serious complications of hypertension.Early warning of the occurrence of infection during treatment and...BACKGROUND Hypertensive cerebral hemorrhage(HICH)is a common clinical cerebrovascular disease and one of the most serious complications of hypertension.Early warning of the occurrence of infection during treatment and timely anti-infective treatment are of great significance for the early prevention and treatment of postoperative infection in patients with HICH.Changes in the levels of inflammatory mediators,which are closely related to the occurrence and development of postoperative infection,and procalcitonin(PCT),which is a sensitive indicator for diagnosing bacterial infections,are widely used in clinical practice.AIM To explore the application value of inflammatory mediator profiles and PCT in predicting postoperative infection in patients with HICH.METHODS A total of 271 patients who underwent HICH surgery at our hospital between March 2019 and March 2021 were selected and divided into the infection(n=80)and non-infection(n=191)groups according to whether postoperative infection occurred.The postoperative infection status and etiological characteristics of the infective pathogens in the infection group were analyzed.Changes in inflammatory mediator profile indices and PCT levels were compared between the two groups,pre-and postoperatively.RESULTS A total of 109 strains of pathogenic bacteria were detected in the infection group,including 67 strains(61.47%)of gram-negative bacteria,32 strains(29.36%)of gram-positive bacteria,and 10 strains(9.17%)of fungi.The main infection site of the patients in the infection group was the respiratory system(63.75%).Preoperative interleukin(IL)-4,IL-6,IL-10,tumor necrosis factor-α,interferon-γ,and PCT levels were higher in the infection group than in the non-infection group(P<0.05),and there were no significant differences in the IL-2 Levels between the two groups(P>0.05).The inflammatory mediator profile indices and PCT levels were higher in the two groups of patients on the first postoperative day than preoperatively(P<0.05),and were higher than those in the non-infecti展开更多
Neutron-sensitive microchannel plates(nMCPs)have applications in neutron detection,including energy spectrum measurements,neutron-induced cross sections,and neutron imaging.10B-doped MCPs(B-MCPs)have attracted signifi...Neutron-sensitive microchannel plates(nMCPs)have applications in neutron detection,including energy spectrum measurements,neutron-induced cross sections,and neutron imaging.10B-doped MCPs(B-MCPs)have attracted significant attention owing to their potential for exhibiting a high neutron detection efficiency over a large neutron energy range.Good spatial and temporal resolutions are useful for neutron energy-resolved imaging.However,their practical applications still face many technical challenges.In this study,a B-MCP with 10 mol%10B was tested for its response to wide-energy neutrons from eV to MeV at the Back-n white neutron source at the China Spallation Neutron Source.The neutron detection efficiency was calibrated at 1 eV,which is approximately 300 times that of an ordinary MCP and indicates the success of 10 B doping.The factors that caused the reduction in the detection efficiency were simulated and discussed.The neutron energy spectrum obtained using B-MCP was compared with that obtained by other measurement methods,and showed very good consistency for neutron energies below tens of keV.The response is more complicated at higher neutron energy,at which point the elastic and nonelastic reactions of all nuclides of B-MCP gradually become dominant.This is beneficial for the detection of neutrons,as it compensates for the detection efficiency of B-MCP for high-energy neutrons.展开更多
The ^(232)Th(n,f)cross section is very important in basic nuclear physics and applications based on the Th/U fuel cycle.Using the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurem...The ^(232)Th(n,f)cross section is very important in basic nuclear physics and applications based on the Th/U fuel cycle.Using the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurement of the^(232)Th(n,f)cross sec-tion relative to^(235)U in the 1–200 MeV range was performed at the China Spallation Neutron Source Back-n white neutron source(Back-n).The fission event-neutron energy spectra of^(232)Th and^(235)U fission cells were measured in the single-bunch mode.Corrected 232Th/235U fission cross-sectional ratios were obtained,and the measurement uncertainties were 2.5–3.7%for energies in the 2–20 MeV range and 3.6–6.2%for energies in the 20–200 MeV range.The^(232)Th(n,f)cross section was obtained by introducing the standard cross section of^(235)U(n,f).The results were compared with those of previous theoreti-cal calculations,measurements,and evaluations.The measured 232Th fission cross section agreed with the main evaluation results in terms of the experimental uncertainty,and 232Th fission resonances were observed in the 1–3 MeV range.The present results provide^(232)Th(n,f)cross-sectional data for the evaluation and design of Th/U cycle nuclear systems.展开更多
Objective:To systematically evaluate the protective effects of Humulus lupulus L.extract(HLE)on osteoporosis mice.Methods:In vivo experiment,a total of 3512-week-old female ICR mice were equally divided into 5 groups:...Objective:To systematically evaluate the protective effects of Humulus lupulus L.extract(HLE)on osteoporosis mice.Methods:In vivo experiment,a total of 3512-week-old female ICR mice were equally divided into 5 groups:the sham control group(sham);the ovariectomy with vehicle group(OVX);the OVX with estradiol valerate[EV,0.2 mg/(kg·d)];the OVX with low-or high-dose HLE groups[HLE,1 g/(kg·d)and 3 g/(kg·d)],7 in each group.Treatment began 1 week after the ovariectomized surgery and lasted for 12 weeks.Bone mass and trabecular bone mircoarchitecture were evaluated by micro computed tomography,and bone turnover markers in serum were evaluated using enzyme-linked immunosorbent assay(ELISA)kits.In vitro experiment,osteoblasts and osteoclasts were treated with HLE at doses of 0,4,20 and 100μg/mL.Biomarkers for bone formation in osteoblasts and bone resorption in osteoclasts were analyzed.Results:Compared with the OVX group,HLE exerted bone protective effects by the increase of estradiol(P<0.05),the improvement of cancellous bone structure,bone mineral density(P<0.01)and the reduction of serum alkaline phosphatase(ALP),tartrate resistant acid phosphatase(TRAP),bone gla-protein,c-terminal telopeptides of typeⅠcollagen(CTX-Ⅰ)and deoxypyridinoline levels(P<0.01 for all).In vitro experiment,compared with the control group,HLE at 20μg/mL promoted the cell proliferation(P<0.01),and increased the expression of bone morphogenetic protein-2 and osteopontin levels in osteoblasts(both P<0.05).HLE at 100μg/mL increased the osteoblastic ALP activities,and HLE at all dose enhanced the extracellular matrix mineralization(both P<0.01).Furthermore,compared with the control group,HLE at 20μg/m L and 100μg/m L inhibited osteoclastic TRAP activity(P<0.01),and reduced the expression of matrix metalloproteinase-9 and cathepsin K(both P<0.05).Conclusion:HLE may protect against bone loss,and have potentials in the treatment of osteoporosis.展开更多
目的观察与探究他汀类药物在短暂性脑缺血发作预防中的效果及对脑血流参数的影响情况。方法选取2016年6月至2017年5月杭州师范大学附属医院收治的80例在短暂性脑缺血发作患者为研究对象,将所有患者按照治疗方式的不同分为对照组和观察组...目的观察与探究他汀类药物在短暂性脑缺血发作预防中的效果及对脑血流参数的影响情况。方法选取2016年6月至2017年5月杭州师范大学附属医院收治的80例在短暂性脑缺血发作患者为研究对象,将所有患者按照治疗方式的不同分为对照组和观察组,每组40例。对照组进行常规治疗干预,观察组则在对照组的基础上加用他汀类药物;比较两组患者不同时间短暂性脑缺血发作的发生率、脑梗死发生率及治疗前后的脂代谢指标、脑血流参数、不良反应发生率。结果治疗后不同时间段观察组的短暂性脑缺血发作发生率及脑梗死发生率均低于对照组(χ~2=4.211、6.275、5.698、4.211、5.333、6.135,P均<0.05),治疗前两组的脂代谢指标及脑血流参数(血流速、血流量及相关阻力指标)比较,差异无统计学意义(P>0.05),治疗后观察组的血流速及血流量、高密度脂蛋白胆固醇(high density liptein cholesterol,HDL-C)均高于对照组,相关阻力指标及其他脂代谢指标均低于对照组(P均<0.05),两组的不良反应发生率比较,差异无统计学意义(P>0.05)。结论他汀类药物在短暂性脑缺血发作预防中的效果较好,且对患者的脑血流参数具有积极的改善作用,因此在短暂性脑缺血发作患者治疗中有一定的应用价值。展开更多
基金This work was jointly supported by the National Key Research and Development Program of China(No.2016YFA0401600)National Natural Science Foundation of China(Nos.11235012 and 12035017)+1 种基金the CSNS Engineering Projectthe Back-n Collaboration Consortium fund。
文摘Back-streaming neutrons from the spallation target of the China Spallation Neutron Source(CSNS)that emit through the incoming proton channel were exploited to build a white neutron beam facility(the so-called Back-n white neutron source),which was completed in March 2018.The Back-n neutron beam is very intense,at approximately 29107 n/cm2/s at 55 m from the target,and has a nominal proton beam with a power of 100 kW in the CSNS-I phase and a kinetic energy of 1.6 GeV and a thick tungsten target in multiple slices with modest moderation from the cooling water through the slices.In addition,the excellent energy spectrum spanning from 0.5 eV to 200 MeV,and a good time resolution related tothe time-of-flight measurements make it a typical white neutron source for nuclear data measurements;its overall performance is among that of the best white neutron sources in the world.Equipped with advanced spectrometers,detectors,and application utilities,the Back-n facility can serve wide applications,with a focus on neutron-induced cross-sectional measurements.This article presents an overview of the neutron beam characteristics,the experimental setups,and the ongoing applications at Backn.
基金the National Natural Science Foundation of China(No.81803794)the Program for Excellent Talents in Zhejiang Chinese Medical University(No.112123A12201/001/004/019)。
文摘Rubus chingii Hu, a member of the rosaceae family, is extensively distributed in China and Japan. Its unripe fruits(Fupenzi in Chinese) have a long history of use as an herbal tonic in traditional Chinese medicine for treating various diseases commonly associated with kidney deficiency, and they are still in use today. Phytochemical investigations on the fruits and leaves of R. chingii indicate the presence of terpenoids, flavonoids, steroids, alkaloids, phenylpropanoids, phenolics, and organic acids. Extracts or active substances from this plant are reported to have various pharmacological properties, including antioxidant, anti-inflammatory, antitumor, antifungal, antithrombotic, antiosteoporotic, hypoglycemic, and central nervous system-regulating effects. This review provides up-to-date information on the botanical characterizations, traditional usages, chemical constituents, pharmacological activities, toxicity,and quality control of R. chingii. Possible directions for future research are also briefly proposed. This review aims to supply fundamental data for the further study of R. chingii and contribute to the development of its clinical use.
基金supported by the National Natural Science Foundation of China,No.U1613228a grant from the Sub-Project under National “Twelfth Five-Year” Plan for Science & Technology Support Project in China,No.2011BAI08B11+1 种基金a grant from the Beijing Municipal Science & Technology Commission in China,No.Z161100002616018the Special Fund for Basic Scientific Research Business of Central Public Scientific Research Institutes in China,No.2014CZ-5,2015CZ-30
文摘Motor imagery is the mental representation of an action without overt movement or muscle activation. However, the effects of motor imagery on stroke-induced hand dysfunction and brain neural networks are still unknown. We conducted a randomized controlled trial in the China Rehabilitation Research Center. Twenty stroke patients, including 13 males and 7 females, 32–51 years old, were recruited and randomly assigned to the traditional rehabilitation treatment group（PP group, n = 10） or the motor imagery training combined with traditional rehabilitation treatment group（MP group, n = 10）. All patients received rehabilitation training once a day, 45 minutes per session, five times per week, for 4 consecutive weeks. In the MP group, motor imagery training was performed for 45 minutes after traditional rehabilitation training, daily. Action Research Arm Test and the Fugl-Meyer Assessment of the upper extremity were used to evaluate hand functions before and after treatment. Transcranial magnetic stimulation was used to analyze motor evoked potentials in the affected extremity. Diffusion tensor imaging was used to assess changes in brain neural networks. Compared with the PP group, the MP group showed better recovery of hand function, higher amplitude of the motor evoked potential in the abductor pollicis brevis, greater fractional anisotropy of the right dorsal pathway, and an increase in the fractional anisotropy of the bilateral dorsal pathway. Our findings indicate that 4 weeks of motor imagery training combined with traditional rehabilitation treatment improves hand function in stroke patients by enhancing the dorsal pathway. This trial has been registered with the Chinese Clinical Trial Registry（registration number： Chi CTR-OCH-12002238）.
文摘BACKGROUND Hypertensive cerebral hemorrhage(HICH)is a common clinical cerebrovascular disease and one of the most serious complications of hypertension.Early warning of the occurrence of infection during treatment and timely anti-infective treatment are of great significance for the early prevention and treatment of postoperative infection in patients with HICH.Changes in the levels of inflammatory mediators,which are closely related to the occurrence and development of postoperative infection,and procalcitonin(PCT),which is a sensitive indicator for diagnosing bacterial infections,are widely used in clinical practice.AIM To explore the application value of inflammatory mediator profiles and PCT in predicting postoperative infection in patients with HICH.METHODS A total of 271 patients who underwent HICH surgery at our hospital between March 2019 and March 2021 were selected and divided into the infection(n=80)and non-infection(n=191)groups according to whether postoperative infection occurred.The postoperative infection status and etiological characteristics of the infective pathogens in the infection group were analyzed.Changes in inflammatory mediator profile indices and PCT levels were compared between the two groups,pre-and postoperatively.RESULTS A total of 109 strains of pathogenic bacteria were detected in the infection group,including 67 strains(61.47%)of gram-negative bacteria,32 strains(29.36%)of gram-positive bacteria,and 10 strains(9.17%)of fungi.The main infection site of the patients in the infection group was the respiratory system(63.75%).Preoperative interleukin(IL)-4,IL-6,IL-10,tumor necrosis factor-α,interferon-γ,and PCT levels were higher in the infection group than in the non-infection group(P<0.05),and there were no significant differences in the IL-2 Levels between the two groups(P>0.05).The inflammatory mediator profile indices and PCT levels were higher in the two groups of patients on the first postoperative day than preoperatively(P<0.05),and were higher than those in the non-infecti
基金supported by the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515030074)the National Natural Science Foundation of China(No.12035017)。
文摘Neutron-sensitive microchannel plates(nMCPs)have applications in neutron detection,including energy spectrum measurements,neutron-induced cross sections,and neutron imaging.10B-doped MCPs(B-MCPs)have attracted significant attention owing to their potential for exhibiting a high neutron detection efficiency over a large neutron energy range.Good spatial and temporal resolutions are useful for neutron energy-resolved imaging.However,their practical applications still face many technical challenges.In this study,a B-MCP with 10 mol%10B was tested for its response to wide-energy neutrons from eV to MeV at the Back-n white neutron source at the China Spallation Neutron Source.The neutron detection efficiency was calibrated at 1 eV,which is approximately 300 times that of an ordinary MCP and indicates the success of 10 B doping.The factors that caused the reduction in the detection efficiency were simulated and discussed.The neutron energy spectrum obtained using B-MCP was compared with that obtained by other measurement methods,and showed very good consistency for neutron energies below tens of keV.The response is more complicated at higher neutron energy,at which point the elastic and nonelastic reactions of all nuclides of B-MCP gradually become dominant.This is beneficial for the detection of neutrons,as it compensates for the detection efficiency of B-MCP for high-energy neutrons.
基金supported by the National Natural Science Foundation of China(Nos.11675155,11790321,and 12075216)the National Key Research and Development Plan(No.2016YFA0401603).
文摘The ^(232)Th(n,f)cross section is very important in basic nuclear physics and applications based on the Th/U fuel cycle.Using the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurement of the^(232)Th(n,f)cross sec-tion relative to^(235)U in the 1–200 MeV range was performed at the China Spallation Neutron Source Back-n white neutron source(Back-n).The fission event-neutron energy spectra of^(232)Th and^(235)U fission cells were measured in the single-bunch mode.Corrected 232Th/235U fission cross-sectional ratios were obtained,and the measurement uncertainties were 2.5–3.7%for energies in the 2–20 MeV range and 3.6–6.2%for energies in the 20–200 MeV range.The^(232)Th(n,f)cross section was obtained by introducing the standard cross section of^(235)U(n,f).The results were compared with those of previous theoreti-cal calculations,measurements,and evaluations.The measured 232Th fission cross section agreed with the main evaluation results in terms of the experimental uncertainty,and 232Th fission resonances were observed in the 1–3 MeV range.The present results provide^(232)Th(n,f)cross-sectional data for the evaluation and design of Th/U cycle nuclear systems.
基金Supported by the National Natural Science Foundation of China(No.U1603283)。
文摘Objective:To systematically evaluate the protective effects of Humulus lupulus L.extract(HLE)on osteoporosis mice.Methods:In vivo experiment,a total of 3512-week-old female ICR mice were equally divided into 5 groups:the sham control group(sham);the ovariectomy with vehicle group(OVX);the OVX with estradiol valerate[EV,0.2 mg/(kg·d)];the OVX with low-or high-dose HLE groups[HLE,1 g/(kg·d)and 3 g/(kg·d)],7 in each group.Treatment began 1 week after the ovariectomized surgery and lasted for 12 weeks.Bone mass and trabecular bone mircoarchitecture were evaluated by micro computed tomography,and bone turnover markers in serum were evaluated using enzyme-linked immunosorbent assay(ELISA)kits.In vitro experiment,osteoblasts and osteoclasts were treated with HLE at doses of 0,4,20 and 100μg/mL.Biomarkers for bone formation in osteoblasts and bone resorption in osteoclasts were analyzed.Results:Compared with the OVX group,HLE exerted bone protective effects by the increase of estradiol(P<0.05),the improvement of cancellous bone structure,bone mineral density(P<0.01)and the reduction of serum alkaline phosphatase(ALP),tartrate resistant acid phosphatase(TRAP),bone gla-protein,c-terminal telopeptides of typeⅠcollagen(CTX-Ⅰ)and deoxypyridinoline levels(P<0.01 for all).In vitro experiment,compared with the control group,HLE at 20μg/mL promoted the cell proliferation(P<0.01),and increased the expression of bone morphogenetic protein-2 and osteopontin levels in osteoblasts(both P<0.05).HLE at 100μg/mL increased the osteoblastic ALP activities,and HLE at all dose enhanced the extracellular matrix mineralization(both P<0.01).Furthermore,compared with the control group,HLE at 20μg/m L and 100μg/m L inhibited osteoclastic TRAP activity(P<0.01),and reduced the expression of matrix metalloproteinase-9 and cathepsin K(both P<0.05).Conclusion:HLE may protect against bone loss,and have potentials in the treatment of osteoporosis.
文摘目的观察与探究他汀类药物在短暂性脑缺血发作预防中的效果及对脑血流参数的影响情况。方法选取2016年6月至2017年5月杭州师范大学附属医院收治的80例在短暂性脑缺血发作患者为研究对象,将所有患者按照治疗方式的不同分为对照组和观察组,每组40例。对照组进行常规治疗干预,观察组则在对照组的基础上加用他汀类药物;比较两组患者不同时间短暂性脑缺血发作的发生率、脑梗死发生率及治疗前后的脂代谢指标、脑血流参数、不良反应发生率。结果治疗后不同时间段观察组的短暂性脑缺血发作发生率及脑梗死发生率均低于对照组(χ~2=4.211、6.275、5.698、4.211、5.333、6.135,P均<0.05),治疗前两组的脂代谢指标及脑血流参数(血流速、血流量及相关阻力指标)比较,差异无统计学意义(P>0.05),治疗后观察组的血流速及血流量、高密度脂蛋白胆固醇(high density liptein cholesterol,HDL-C)均高于对照组,相关阻力指标及其他脂代谢指标均低于对照组(P均<0.05),两组的不良反应发生率比较,差异无统计学意义(P>0.05)。结论他汀类药物在短暂性脑缺血发作预防中的效果较好,且对患者的脑血流参数具有积极的改善作用,因此在短暂性脑缺血发作患者治疗中有一定的应用价值。
