Analysis on Genetic Diversity of Radix Astragali by ISSR Markers

Radix Astragali has been an important traditional Chinese herbal medicine for over 2000 years. It is derived from two plant species, namely, Astragalus mongholicus [Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao] and Astragalus membranaceus [Astragalus membranaceus (Fisch.) Bge.] (Leguminosae ), according to the Pharmacopoeia of the People’s Republic of China. In this study, the genetic diversity and genetic relationships of Radix Astragali in China were analyzed by Inter-Simple Sequence Repeat (ISSR) markers. A total of 25 highly polymorphic ISSR primers were selected to amplify 95 Radix Astragali samples. Among 273 DNA bands amplified, 213 are polymorphic (percentage of polymorphic bands: 78%). The average value of the amplified bands was 10.9 for each primer, and the number varied from 4 to 20. The genetic diversity of the 95 Radix Astragali samples was analyzed by using POPGENE 1.32 software. The Nei’s genetic diversity index (h) and Shannon’s information index (I ) were 0.3590 and 0.5308, respectively, which indicated the abundant genetic diversity of Radix Astragali . The level of genetic diversity in A. membranaceus (h: 0.3109, I : 0.4657) was slightly lower than that in A. mongholicus (h: 0.3364, I : 0.4969). Considering the average genetic similarity coefficient by NTSYS analysis to cluster the A. membranaceus of nine habitats and A. mongholicus of five habitats, Radix Astragali samples were clustered into two groups according to place of origin. This clustering is different from traditional clustering, which divides groups according to species. Results obtained from this study will provide a theoretical basis for the molecular study on germplasm resources of Radix Astragali .

Neuroprotective effect of high-dose hyperbaric oxygenation on rats with acute cerebral infarction in super-early stage:Curative comparison between 9-hour and 18-hour therapeutic protocols

BACKGROUND： Previously, only single short-time low-dose hyperbaric oxygenation （HBO） protocol was administrated to treat acute ischemic stroke in early stage and the conflicting results were obtained. There are few studies to report the outcome of administering long-time （can cover all the natural pathologic progression period） high-dose HBO to treat the disease. OBJECTIVE： To evaluate the therapeutic effect between two kinds of high-dose hyperbaric oxygenation on super-early stage of acute permanent middle cerebral artery occlusion （MCAO） in rats. DESIGN： A randomized controlled experimental study. SETTING： Beijing Tiantan Hospital, Capital Medical University; Beijing Research Institute of Neurosurgery. MATERIALS： Seventy-four male SD rats, aged 2.5 months old, weighing （ 280 ＋ 20） g, were provided by the Animal Institute, Chinese Academy of Medical Sciences. Hyperbaric oxygenation device was hyperbaric air cabin in which there was a self-made pure oxygen animal experimental cabin （made in China）. METHODS： This experiment was carried out in the municipal laboratory of Beijing Tiantan Hospital affiliated to Capital Medical University and Beijing Research Institute of Neurosurgery. ① Experimental intervention： All the rats were developed into models of permanent MCAO by suture embolism. Then, they were randomly divided into two HBO groups （9 hours and 18 hours） and control group, with 24 rats in each as well as 3-hour ultrastructure control group, with 2 rats. After being modeled for 3 hours, rats in the two HBO groups stayed in the hyperbaric cabin for 9 hours and 18 hours, separately. Rats in the 9-hour HBO group inhaled pure oxygen at hours 1, 3, 5, 7 and 9, and hyperbaric air at hours 2, 4, 6 and 8. Rats in the 18-hour HBO group inhaled pure oxygen at hours l, 3, 5, 7, 9, 11, 13, 15 and 17, and hyperbaric air at hours 2, 4, 6, 8, l0 12, 14, 16 and 18. After being created into models, rats in the control group and 3-hour ultrastructure control group breathed room air. ② Experimental evaluation： Neurologic functions of rat models in the 9-hour and 18-hour HBO groups as well as control group were scored by Bederson and Garica two neurological grading systems at hours 14 and 28 and on day 5; Infarct volume of rat models in the two HBO groups and control group was measured at hour 24 and on day 5 with NIH image processing software Image J; The pathological changes of brain tissue in the brain infarct region and its opposite region of rat models in the two HBO groups and 3-hour ultrastructure control group were observed with a Philips EM 208S transmission electron microscope. MAIN OUTCOME MEASURES： ① Neurobehavioral outcome. ② Rat brain infarct volume. ③ Ultrastructure of brain tissue in the ischemic penumbra of infarct models at the different time points RESULTS： ① Neurobehavioral outcome： After treatment, Garica score in the 9-hour and 18-hour HBO groups was significantly higher than that in the control group （P 〈 0.01）. Bederson score on day 5 after modeling in the 9-hour and 18-hour HBO groups was significantly lower than that in the control group （P 〈 0.01）. ② Cerebral infarct volume： Cerebral infarct volume in the 9-hour and 18-hour HBO groups was significantly smaller than that in the control group at hour 24 and on day 5 after modeling （P 〈 0.01）. In the 18-hour HBO group, infarct volume on day 5 after modeling was significantly larger than that at hour 24 after modeling （P 〈 0.05）. ③In the 3-hour ultrastructure control group, astrocyte edema and neuron damage around the capillary in the infarct cerebral tissue significantly relieved in the rats which were subjected to HBO. CONCLUSION： High dose of HBO is highly efficient in reducing infarct volume and improving neurobehavioral outcome of rats with acute cerebral infarction, and also has an important role in inhibiting the pathological progression of ischemic brain tissue after cerebral infarction.

蒙古冰草咖啡酸氧甲基转移酶基因AmCOMT1的鉴定及功能分析

蒙古冰草(即沙芦草(Agropyron mongolicum))是我国北方代表性的多年生牧草之一,具有较强的耐寒和耐旱能力。在植物中,咖啡酸氧甲基转移酶基因(COMT)是参与木质素和褪黑素生物合成的关键基因,在调节植物生长、品质和抗逆性中发挥重要作用。通过分析蒙古冰草全长转录组数据,从蒙古冰草中克隆了COMT候选基因AmCOMT1。该基因在茎秆和根等木质素含量高的组织中高表达,且其表达受多种非生物胁迫诱导。在拟南芥(Arabidopsis thaliana)野生型(Col-0)和突变体(omt1-2)中过表达AmCOMT1,显著促进了转基因拟南芥的木质素合成,使突变体的木质素单体和组分恢复至野生型水平,同时Col-0/35S:AmCOMT1中木质素总量提高11%。此外, AmCOMT1过表达显著提高了Col-0/35S:AmCOMT1转基因拟南芥的褪黑素含量。在盐胁迫条件下,该株系平均根长相比野生型拟南芥提高20.3%,表现出更强的抗逆性。综上,蒙古冰草AmCOMT1基因在木质素和褪黑素合成中发挥关键作用,可提高转基因拟南芥的抗逆性,在蒙古冰草等单子叶牧草遗传改良方面具有重要应用潜力。

蒙古冰草肉桂醇脱氢酶基因序列鉴定及功能分析

肉桂醇脱氢酶(CAD)作为植物次生代谢尤其是木质素生物合成过程的关键酶,在调控植物生长发育和抵御生物/非生物胁迫等过程中发挥关键作用。蒙古冰草(即沙芦草(Agropyron mongolicum))耐旱耐寒,在我国北方荒漠草原区域广泛分布。为探讨CAD基因在蒙古冰草木质素合成和非生物胁迫抗性中的作用,从蒙古冰草全长转录组数据中筛选并克隆到1个CAD基因,序列长度1083 bp,命名为AmCAD。该基因编码361个氨基酸残基,同源序列比对发现蛋白质序列保守区域含有2个Zn^(2+)结合基序和NADP(H)辅因子结合基序,属于典型的CAD蛋白,且三维结构与AtCAD5相似。AmCAD在茎秆中高表达,对AmCAD重组蛋白的酶学性质分析表明,该蛋白对不同肉桂醛类底物均具有很强的催化能力,其中对松柏醛和芥子醛的底物亲和力更强。用不同浓度甘露醇模拟干旱胁迫,蒙古冰草AmCAD基因表达受到显著诱导。研究结果表明,AmCAD在蒙古冰草木质素合成和干旱胁迫抗性中发挥重要作用,可为提高蒙古冰草品质和抗逆性分子育种提供有价值的基因资源。

黄河流域旅游高质量发展空间差异、重心演化及优化路径

采用熵权TOPSIS法、标准差椭圆、模糊集定性比较分析等方法对2017—2021年黄河流域旅游高质量发展的空间演化及优化路径进行分析。结果表明:2017—2021年,黄河流域旅游高质量发展总体水平(相对贴近度)处于0.026~0.867,区域发展水平差异显著,呈现不平衡、不均匀的空间分布态势,东北-西南方向的空间集聚特征明显,西南部地区对黄河流域旅游高质量发展的拉动作用逐渐增强。2017—2021年,黄河流域旅游高质量发展空间重心向西南向移动,空间重心处于111.75°—111.16°E、36.02°—35.53°N,空间重心均呈集聚分布,移动距离较小,5年间共移动91.47 km。旅游生态治理是实现黄河流域旅游高质量发展的必要条件,存在市场—生态治理、资源—服务—生态治理、资源—服务—生态治理—市场3种条件组态。

Mace-like TTF-TCNQ/HKUST-1 composite structures for rapid NO_(2) detection: Synergistically induced ultrahigh sensitivity and outstanding selectivity

Integration and synergy of the unique functions of different components have been developed into one of the most convenient and effective ways to construct the composite advanced materials with collective properties and improved performances.In this work,the mace-like tetrathiafulvalene-tetracyanoquinodimethane(TTF-TCNQ)/HKUST-1 composite structures with single single-crystalline TTF-TCNQ submicrorods covered by ordered HKUST-1 nanosheet arrays were successfully constructed by an efficient TTF-TCNQ seed-mediated growth approach.Impressively,thanks to the synergetic and complementary effects between TTF-TCNQ and HKUST-1,the sensors based on such mace-like TTF-TCNQ/HKUST-1 composite structures not only displayed an experimental detection limit of 10 part per billion(ppb)for NO_(2) detection,but also exhibited outstanding selectivity even if the concentration of the interfering gases was 10 times that of NO_(2).Meanwhile,good reproducibility and rapid response were also achieved.This work opens the avenue for creation of novel high-performance sensing materials for application in gas sensing.

Determination of Coumoxystrobin Residue in Vegetables by QeEChERS-UPLC-MS/MS

[Objectives]This study was conducted to establish a method for determining residual coumoxystrobin in vegetables using QeEChERS-liquid chromatography-tandem mass spectrometry(QeEChERS-LC-MS/MS).[Methods]The sample was extracted by acetonitrile,and the extract was purified by QeEChERS,concentrated by nitrogen blowing,and then detected.[Results]Coumoxystrobin had a good linear relation in the range of 0.01-10.0 mg/kg,and the linear equation was y=4686.92×x+5683.28,R^(2)=0.999.The limit of detection was 0.001 mg/kg,and the limit of quantitation was 0.003 mg/kg.[Conclusions]The method has the advantages of convenient and fast operation and stable detection process,and can provide technical support for the supervision and monitoring of coumoxystrobin.

二维导电金属有机骨架材料

金属有机骨架(MOFs)是由金属离子或簇与有机配体以配位键组装而成的晶态多孔材料,其高的孔隙率及功能可设计性使其广泛应用于各种领域。然而,传统MOFs多数电导率非常低,这严重制约了其在电学相关领域的发展。近年来,导电金属有机骨架尤其是二维导电金属有机骨架(2D ECMOFs)材料因其结构中独特的π-π堆积及π-d共轭作用而呈现出半导体甚至类金属的电子输运性质而受到广泛关注,已在传感器、电子器件、电催化、电池和超级电容器等电学和能源相关领域展现出潜在的应用价值。本文将从2D ECMOFs的导电机理、结构、合成方法及应用等方面对近几年该领域的重要进展进行综述,并对其未来发展的挑战和机遇提出展望。

Coordination-responsive drug release inside gold nanorod @ metal-organic framework core-shell nanostructures for near-infrared-induced synergistic chemo-photothermal therapy

Multifunctional core-shell nanostructures formed by integration of distinct components have received wide attention as promising biological platforms in recent years. In this work, crystalline zeolitic imidazolate framework-8 （ZIF-8）, a typical metal-organic framework （MOF）, is coated onto single gold nanorod （AuNR） core for successful realization of synergistic photothermal and chemotherapy triggered by near-infrared （NIR） light. Impressivel）~ high doxorubicin hydrochloride （DOX） loading capacity followed by pH and NIR light dual stimuli-responsive DOX release can be easily implemented through formation and breakage of coordination bonds in the system. Moreover, under NIR laser irradiation at 808 nm, these novel AuNR@MOF core-shell nanostructures exhibit effective synergistic chemo-photothermal therapy both in vitro and in vivo, confirmed by cell treatment and tumor ablation via intravenous injection.

Climate change and its effect on reference crop evapotranspiration in central and western Inner Mongolia during 1961-2009

Water resource is one of the major constraints to agricultural production in central and western Inner Mongolia, where are characteristic by arid and semi-arid climate. Reference crop evapotranspiration （ETo） is an important part of water cycle in agricultural ecosystem, which has a direct effect on crop growth and yield. The implications of climate change on ETo are of high importance for agriculture regarding water management and irrigation scheduling. The aim of this study was to analyze the variations in climate and its effect on ETo in central and western Inner Mongolia over the period 1961 to 2009 For this purpose, data in ten meteorological stations across study area were collected and the FAO Penman-Monteith 56 method was used. Results showed that the average temperature, maximum temperature and minimum temperature increased by 0.49~C, 0.31~C and 0.70~C per decade during 1961-2009, respectively. In comparison, the daily temperature range decreased by 0.38~C per decade. The air relative humidity, sunshine hour, and 10-m wind speed decreased generally by 0.58%, 40.11 h, and 0.35 rrds per decade, respectively. Annual mean ETo decreased significantly at a rate of 12.2 mm per decade over the periods, this was mainly due to the decrease in wind speed in the study area. The decrease in wind speed may balance the effect of the increase in air temperature on ETo. Variations in spatial distribution of ETo and its main controlling factor were also detected among ten stations. Our results suggested that spatial and temporal distribution of ETo should be considered regarding the optimization of water resource management for agriculture in central and western Inner Mongolia under foreseen climate change.

Lung-protective Ventilation in Patients with Brain Injury： A Multicenter Cross-sectional Study and Questionnaire Survey in China

Background： Over the years, the mechanical ventilation （MV） strategy has changed worldwide. The aim of the present study was to describe the ventilation practices, particularly lung-protective ventilation （LPV）, among brain-injured patients in China. Methods： This study was a multicenter, 1-day, cross-sectional study in 47 Intensive Care Units （ICUs） across China. Mechanically ventilated patients （18 years and older） with brain injury in a participating ICU during the time of the study, including traumatic brain injury, stroke, postoperation with intracranial tumor, hypoxic-ischemic encephalopathy, intracranial infection, and idiopathic epilepsy, were enrolled. Demographic data, primary diagnoses, indications for MV, MV modes and settings, and prognoses on the 60th day were collected. Multivariable logistic analysis was used to assess factors that might affect the use of LPV. Results： A total of 104 patients were enrolled in the present study, 87 （83.7%） of whom were identified with severe brain injury based on a Glasgow Coma Scale 〈8 points. Synchronized intermittent mandatory ventilation （SIMV） was the most frequent ventilator mode, accounting for 46.2% of the entire cohort. The median tidal volume was set to 8.0 ml/kg （interquartile range [IQR], 7.0-8.9 ml/kg） of the predicted body weight; 50 （48.1%） patients received LPV. The median positive end-expiratory pressure （PEEP） was set to 5 cmH20 （IQR, 5-5 cmH20）. No PEEP values were higher than 10 cmH20. Compared with partially mandatory ventilation, supportive and spontaneous ventilation practices were associated with LPV. There were no significant differences in mortality and MV duration between patients subjected to LPV and those were not. Conclusions： Among brain-injured patients in China, SIMV was the most frequent ventilation mode. Nearly one-half of the brain-injured patients received LPV. Patients under supportive and spontaneous ventilation were more likely to receive LPV.

Tuning Reaction Processes for the Synthesis of Micron and Nanometer Sized, Single Crystalline Lamellae of Copper 7,7,8,8-tetracyano-p-quinodimethane (Phase II) with Large Area

Two simple methods have been demonstrated to obtain large area,single crystalline lamellae of copper-7,7,8,8-tetracyanoquinodimethane(CuTCNQ).The formation of the lamellae was a result of fine tuning of the processes during the synthesis processes of CuTCNQ phase II.This facile synthesis of large area single crystalline lamellae suggests bright prospects for the study and understanding of the electrical switching of CuTCNQ by using single crystals of its phase II,and future applications of the material in memory and switching devices.

Biosafety materials for tuberculosis treatment

Tuberculosis(TB)is among the deadliest infectious diseases worldwide.Although the existing antituberculosis(anti-TB)drugs remain to be effective,the administration of these complex anti-TB drug combinations with obvious toxicity often leads to patients’nonadherence.This may contribute toward the emergence of drug-resistant strains as well as lead to treatment failure and relapse.Therefore,in the past half century,the main focus of anti-TB drug research was to reduce the frequency of administration and toxicity and improve patients’compliance and drug sensitivity.Following these principles,the development of engineered biosafety materials is one of the most effective and promising methods in resolving these challenges.Compared with traditional drugs,biosafety materials provide a viable platform for treating TB,which are beneficial in reducing the frequency of drug administration and systemic toxicity,improving patients’compliance and drug sensitivity,and enhancing drug targeting.In this review,we summarized the application of biosafety materials in treatment of TB in recent years and discussed the challenges faced when developing a safe,more effective,and economical pharmacotherapy against TB.

根癌农杆菌介导的蒙古冰草稳定遗传转化体系建立

蒙古冰草(Agropyron mongolicum)亦称沙芦草,为禾本科(Poaceae)小麦族(Triticeae)冰草属(Agropyron)多年生疏丛型牧草,具有饲用价值高、抗寒耐旱以及耐盐、耐瘠薄、耐风沙等特性,是改良天然草场的适宜草种与挖掘优良耐逆基因资源的重要材料。然而,目前尚未建立蒙古冰草高效遗传转化体系,制约了该物种的基因资源鉴定与遗传改良应用。以蒙农1号蒙古冰草种子为来源的高再生效率的胚性愈伤系#89为外植体,建立了根癌农杆菌(Agrobacterium tumefaciens)EHA105介导的蒙古冰草稳定遗传转化体系,转化效率达30%。此外,针对多次继代后蒙古冰草愈伤系再生能力退化的难题,通过在再生培养基中添加1 mg·L^(-1) ABA或提高蔗糖浓度至45 g·L^(-1),成功将再生能力衰退的蒙古冰草愈伤系再生效率由5%分别提高至35%与42%。研究结果为后续蒙古冰草基因编辑体系建立、基因功能鉴定和新品种培育奠定了重要技术基础。