基于宏基因组技术研究哈蟆油对大鼠肠道菌群的影响

目的基于宏基因组技术研究哈蟆油(OR)对大鼠肠道菌群的影响,用组学技术表征OR的功效。方法雄性SD大鼠随机分为对照组和OR组。OR组大鼠以200 mg·kg^(-1)剂量的OR匀浆每日灌胃,对照组以等体积生理盐水灌胃。14 d后,采集大鼠粪便进行宏基因组测序,对测序结果进行基因预测、丰度分析、物种注释及京都基因与基因组百科全书(KEGG)功能注释。结果在门水平上OR可以显著升高放线菌门相对丰度(P<0.05),在纲水平上OR可以显著升高放线菌纲相对丰度(P<0.05),在目水平上OR可以显著升高双歧杆菌目相对丰度(P<0.05)。两组大鼠肠道菌群在门和属水平上的β多样性存在差异。线性判别效应大小分析(LEfSe)筛选出两组间35种显著差异菌种。KEGG功能注释结果显示,在Level 1层级上注释到新陈代谢类通路的基因最多。组间差异分析表明,OR组注释到免疫系统、环境适应及癌症相关通路的相对丰度产生变化。结论改变大鼠肠道菌群相对丰度及多样性、调节脂质及氨基酸代谢通路可能是OR营养保健和治疗疾病的潜在机制。

边疆刑事科学技术专业实验教学模式

为适应边疆地区公安技术专业人才培养需要,充分发挥校内实验教学效能,以培养学生核心能力为目标,对刑事科学技术专业实验教学模式进行综合设计。结合多民族学生的特点,以学生兴趣、能力、需要为出发点,探索模块分级、多平台的实验教学体系设计构建,运用线上线下立体化现代化教学手段完善实验教学内容。最终以分级化、互助化、多样化、充分化“四化”教学方式和计算机技术辅助管理选课及考核方式达成明确的实验教学效果,弥补基础实验教学短板,提升专业实验质量,提高实验教学效能。为边疆地区的应用型刑事科学技术专业民-汉学习者共融、共助、共进的人才培养总目标探索实践方法。

Suppressing by-product via stratified adsorption effect to assist highly reversible zinc anode in aqueous electrolyte

The development of promising zinc anodes mainly suffers from their low plating/stripping coulombic efficiencies when using aqueous electrolyte,which are mainly associated with the interfacial formation of irreversible by-products.It is urgent to develop technologies that can solve this issue fundamentally.Herein,we report an artificial Sc_(2)O_(3) protective film to construct a new class of interface for Zn anode.The density functional theory simulation and experimental results have proven that the interfacial side reaction was inhibited via a stratified adsorption effect between this artificial layer and Zn anode.Benefiting from this novel structure,the Sc_(2)O_(3)-coated Zn anode can run for more than 100 cycles without short circuit and exhibit low voltage hysteresis,and the coulombic efficiency increases by 1.2%.Importantly,it shows a good application prospect when matched with two of popular manganese-based and vanadium-based cathodes.The excellent electrochemical performance of the Sc_(2)O_(3)-coated Zn anode highlights the importance of rational design of anode materials and demonstrates a good way for developing high-performance Zn anodes with long lifespan and high efficiency.

Investigation of a non-explosive directional roof cutting technology for self-formed roadway

Traditional explosives have characteristics of high risk,large vibration,and poor directional fracturing.Consequently,an instantaneous expander with a single crack surface(IESCS),which is a novel nonexplosive directional rock-breaking technique,has been developed.The directional roof-cutting mechanism of the IESCS method,driven by high-pressure gas,was theoretically analyzed.Laboratory experiments and numerical simulations proved the directional slitting effect of the IESCS method to be excellent.Compared with shaped-charge blasting,the charge of IESCS was reduced by 8.9%,but the crack rate increased by 9%in field tests.After IESCS pre-splitting,the roof directionally collapsed along the cutting line,and the gangue filled the goaf.Moreover,the directional roof cutting by the IESCS could decrease roadway stress.The average pressure of hydraulic supports on the cutting side of the roof was 31%lower than that on the non-cutting side of the roof after pre-splitting.After the self-formed roadway constructed by the IESCS was stabilized,the final relative displacement of the roof and floor was 157.3 mm,meeting the required standard of the next working face.Thus,the IESCS was effectively applied to directional roof pre-splitting.The results demonstrate the promising potential of IESCS in the mining and geotechnical fields.

Layered hydrated vanadium oxide as highly reversible intercalation cathode for aqueous Zn-ion batteries

Aqueous Zn-ion batteries(ZIBs)hold great potential in large-scale energy storage systems due to the merits of low-cost and high safety.However,the unstable structure of cathode materials and sluggish(de)intercalation kinetics of Zn2+pose challenges for further development.Herein,highly reversible aqueous ZIBs are constructed with layered hydrated vanadium oxide as a cathode material.The electrochemical performances are further tested with the optimized electrolyte of 3M Zn(CF3SO3)2 and a cut-off voltage of 0.4 to 1.3 V,exhibiting a remarkable capacity of 290mAh g−1 at 0.5Ag−1,and long-term cycling stability at high current density.Furthermore,the Zn2+storage mechanism of V3O7⋅H2O is recognized as a highly reversible(de)intercalation process with good structural stability,implying the potential application in the field of large-scale energy storage.

Fundamental Understanding and Effect of Anionic Chemistry in Zinc Batteries

With the merit of high capacity,high safety,and low cost,zinc-ion batteries(ZIBs)possess huge application potential in the domain of large-scale energy storage.However,due to the relatively narrow voltage window and large lattice distortion of cationic redox reaction,ZIBs tend to present low energy density,poor kinetics,and unstable cyclic performance.Anion chemistry seems to provide a novel strategy to solve these issues from different aspects,such as enhanced operating voltage,extra capacity contribution,and boosted reaction kinetics.Considering the significance of this theory and the lack of relevant literatures,herein,in-depth comprehension of anionic chemistry and its positive effects on zinc storage performance have been emphasized and summarized.This review aims to present a full scope of anionic chemistry and furnish systematic cognition for rational design of advanced ZIBs with high energy density.Furthermore,insightful analysis and perspectives based on the current research status also have been proposed,which may point out some scientific suggestions and directions for the future research.

Experimental and numerical investigation into the non-explosive excavation of tunnels

The use of explosives is restricted on some important holidays,and the handling of unexploded charge is very dangerous.Therefore,an innovative non-explosive technology called instantaneous expansion(IE)was developed for tunneling.IE,whose components are derived from solid wastes such as coal gangue and straw conduces to realizing the reuse of waste.Moreover,its cost is lower than explosives.Blind guns of IE are easy to treat with water.The IE tunneling method is classified into two categories,i.e.IE with a single fracture(IESF)and IE with multiple fractures(IEMF),which are used to form the tunnel crosssection directionally cross-section and to fragment the rocks inside the cross-section,respectively.In this study,the principle of IE tunneling was elaborated first.Then,tunneling experiments and numerical simulations were performed on IE,conventional blasting(CB)and shaped charge blasting(SCB)in comparison.The experimental and numerical results show that IE achieved the best performance of directional rock breaking and corresponded to the most minor excavation-induced damage zone of the surrounding rock.Besides,the tunnel cross-section created by IE was flat and smooth.Comparing IE with CB and SCB,the over/under-excavation area decreased by 64%and 17%,and the excavation-induced damage zone fell by 26%and 11%,respectively.The range of the loose circle is reduced,which is conducive to improving the long-term stability of the roadway.The research provides a safe and economical tunneling method with excellent application prospects.

Acute myocardial infarction induced by eosinophilic granulomatosis with polyangiitis:A case report

BACKGROUND Eosinophilic granulomatosis with polyangiitis(EGPA)is a multisystem disease characterized by allergic rhinitis,asthma,and a significantly high eosinophil count in the peripheral blood.It mainly involves the arterioles and venules.When the coronary arteries are invaded,it can lead to acute myocardial infarction(AMI),acute heart failure,and other manifestations that often lead to death in the absence of timely treatment.CASE SUMMARY A 69-year-old man was admitted to the emergency department due to chest pain for more than 1 h.He had a past history of bronchial asthma and chronic obstructive pulmonary disease and was diagnosed with AMI and heart failure.Thrombus aspiration of the left circumflex artery and percutaneous transluminal coronary angioplasty were performed immediately.After surgery,the patient was admitted to the intensive care unit.The patient developed eosinophilia,and medical history taking revealed fatigue of both thighs 1 mo prior.Local skin numbness and manifestations of peripheral nerve involvement were found on the lateral side of the right thigh.Skin biopsy of the lower limbs pathologically confirmed EGPA.The patient was treated with methylprednisolone combined with intravenous immunoglobulin and was discharged after 21 d.On follow-up at 7 d after discharge,heart failure recurred.The condition improved after cardiotonic and diuretic treatment,and the patient was discharged.CONCLUSION Asthma,impaired cardiac function,and eosinophilia are indicative of EGPA.Delayed diagnosis often leads to heart involvement and death.

Development of a droplet digital polymerase chain reaction assay for the sensitive detection of total and integrated HIV-1 DNA

Background:Total human immunodeficiency virus(HIV)DNA and integrated HIV DNA are widely used markers of HIV persistence.Droplet digital polymerase chain reaction(ddPCR)can be used for absolute quantification without needing a standard curve.Here,we developed duplex ddPCR assays to detect and quantify total HIV DNA and integrated HIV DNA.Methods:The limit of detection,dynamic ranges,sensitivity,and reproducibility were evaluated by plasmid constructs containing both the HIV long terminal repeat(LTR)and human CD3 gene(for total HIV DNA)and ACH-2 cells(for integrated HIV DNA).Forty-two cases on stable suppressive antiretroviral therapy(ART)were assayed in total HIV DNA and integrated HIV DNA.Correlation coefficient analysis was performed on the data related to DNA copies and cluster of differentiation 4 positive(CD4^(+))T-cell counts,CD8^(+)T-cell counts and CD4/CD8 T-cell ratio,respectively.The assay linear dynamic range and lower limit of detection(LLOD)were also assessed.Results:The assay could detect the presence of HIV-1 copies 100%at concentrations of 6.3 copies/reaction,and the estimated LLOD of the ddPCR assay was 4.4 HIV DNA copies/reaction(95%confidence intervals[CI]:3.6-6.5 copies/reaction)with linearity over a 5-log_(10)-unit range in total HIV DNA assay.For the integrated HIV DNA assay,the LLOD was 8.0 copies/reaction(95%CI:5.8-16.6 copies/reaction)with linearity over a 3-log 10-unit range.Total HIV DNA in CD4^(+)T cells was positively associated with integrated HIV DNA(r=0.76,P<0.0001).Meanwhile,both total HIV DNA and integrated HIV DNA in CD4^(+)T cells were inversely correlated with the ratio of CD4/CD8 but positively correlated with the CD8^(+)T-cell counts.Conclusions:This ddPCR assay can quantify total HIV DNA and integrated HIV DNA efficiently with robustness and sensitivity.It can be readily adapted for measuring HIV DNA with non-B clades,and it could be beneficial for testing in clinical trials.

Impact of the Belt and Road Initiative:The case of Pakistan

This study investigates the macroeconomic impact of the Belt and Road Initiative(BRI)on Pakistan using the synthetic control method.Based on the panel data of 42 non-BRI countries,we construct a synthetic Pakistan to estimate the economic growth trend of the country without the BRI.By comparing the actual economy with the synthetic case,our results show that the BRI increases the annual per capita GDP growth rate of Pakistan from 3.04%to 4.69%for the period 2013-2018.Pakistan’s per capita GDP in 2018 would have been Int$5,022 instead of Int$5,567 if the BRI had not existed.The outcomes of the in-time placebo test,in-place placebo test,and dropping sample test all confirm the robust impact of the BRI on Pakistan.

循环肿瘤细胞体内检测技术及其应用研究

从实体瘤脱落进入血液循环系统的肿瘤细胞即循环肿瘤细胞(CTCs)与肿瘤转移密切相关,因此CTCs检测对癌症患者的诊断、治疗监测、病情评估以及肿瘤转移机制研究具有重要意义。由于CTCs在体内含量极少、异质性、分布不均一,通过体外采血发展的CTCs检测技术虽然已取得很大进展,但仍然面临肿瘤细胞损失、失活、失真以及灵敏度低等问题,因此亟需发展基于体内快速流动血液的肿瘤细胞检测技术,在真实生理状态下实时监测CTCs动态变化。在此,我们总结了CTCs体内检测技术及其相关应用的研究进展,分析了这些技术的优势和不足。最后,讨论并展望了CTCs体内检测技术的未来发展趋势。

Enlarged interlayer spacing and enhanced capacitive behavior of a carbon anode for superior potassium storage

Potassium-ion batteries(PIBs) hold great potential as an alternative to lithium-ion batteries due to the abundant reserves of potassium and similar redox potentials of K+/K and Li+/Li. Unfortunately, PIBs with carbonaceous electrodes present sluggish kinetics, resulting in unsatisfactory cycling stability and poor rate capability. Herein, we demonstrate that the synergistic effects of the enlarged interlayer spacing and enhanced capacitive behavior induced by the co-doping of nitrogen and sulfur atoms into a carbon structure(NSC) can improve its potassium storage capability. Based on the capacitive contribution calculations, electrochemical impedance spectroscopy, the galvanostatic intermittent titration technique, and density functional theory results, the NSC electrode is found to exhibit favorable electronic conductivity,enhanced capacitive adsorption behavior, and fast K+ ion diffusion kinetics. Additionally, a series of exsitu characterizations demonstrate that NSC exhibits superior structural stability during the(de)potassiation process. As a result, NSC displays a high reversible capacity of 302.8 mAh g-1 at 0.1 Ag-1 and a stable capacity of 105.2 m Ahg-1 even at 2 Ag-1 after 600 cycles. This work may offer new insight into the effects of the heteroatom doping of carbon materials on their potassium storage properties and facilitate their application in PIBs.

Tuning crystal structure and redox potential of NASICON-type cathodes for sodium-ion batteries

Sodium superionic conductor(NASICON)-type compounds have been regarded as promising cathodes for sodium-ion batteries(SIBs)due to their favorable ionic conductivity and robust structural stability.However,their high cost and relatively low energy density restrict their further practical application,which can be tailored by widening the operating voltages with earth-abundant elements such as Mn.Here,we propose a rational strategy of infusing Mn element in NASICON frameworks with sufficiently mobile sodium ions that enhances the redox voltage and ionic migration activity.The optimized structure of Na3.5Mn0.5V1.5(PO4)3/C is achieved and investigated systematically to be a durable cathode(76.6%capacity retention over 5,000 cycles at 20 C)for SIBs,which exhibits high reversible capacity(113.1 mAh·g^−1 at 0.5 C)with relatively low volume change(7.6%).Importantly,its high-areal-loading and temperature-resistant sodium ion storage properties are evaluated,and the full-cell configuration is demonstrated.This work indicates that this Na3.5Mn0.5V1.5(PO4)3/C composite could be a promising cathode candidate for SIBs.

Simultaneous regulation of cations and anions in an electrolyte for high-capacity, high-stability aqueous zinc–vanadium batteries

Safe,inexpensive aqueous zinc-ion batteries(AZIBs)are regarded as promising energy storage devices.However,they still face issues,including dissolution and collapse of the cathode as well as H_(2)evolution and the growth of Zn dendrites on the Zn anode.Herein,we simultaneously regulate the cations and anions in the electrolyte for high-capacity,high-stability aqueous zinc–vanadium(Zn–V)batteries based on a bimetallic cation-doped Na_(0.33)K_(0.1)V_(2)O_(5)·nH_(2)O cathode.We demonstrate that Na^(+) cations suppress cathode dissolution and restrain Zn dendrite growth on the anode via an electrostatic shield effect.We also illustrate that ClO_(4)^(-) anions participate in energy storage at the cathode and are reduced to Cl^(-),generating a protective layer on the Zn anode surface and providing a stable interface to decrease Zn dendrites and H_(2)evolution during long-term cycling.When Na^(+) and ClO_(4)^(-) are introduced into an aqueous ZnSO_(4) electrolyte,a Zn/Zn symmetric cell shows durable and reversible Zn stripping/plating for 1500 h at a current density of 1 mA cm^(-2) and with an area capacity of 1 mAh cm^(-2).Zn/Na_(0.33)K_(0.1)V_(2)O_(5)·nH_(2)O full batteries exhibit a high capacity of 600 mAh g^(-1)at 0.1 A g^(-1) and long-term cycling performance for 5000 cycles,with a capacity of 200 mAh g^(-1) at 20 Ag^(-1).

Programmable DNA-responsive microchip for the capture and release of circulating tumor cells by nucleic acid hybridization

The detection and analysis of circulating tumor cells （CTCs） from patients＇ blood is important to assess tumor status; however, it remains a challenge. In the present study, we developed a programmable DNA-responsive microchip for the highly efficient capture and nondestructive release of CTCs via nucleic acid hybridization. Transparent and patternable substrates with hierarchical architectures were integrated into the microchip with herringbone grooves, resulting in greatly enhanced cell-surface interaction via herringbone micromixers, more binding sites, and better matched topographical interactions. In combination with a high-affinity aptamer, target cancer cells were specifically and efficiently captured on the chip. Captured cancer cells were gently released from the chip under physiological conditions using toehold-mediated strand displacement, without any destructive factors for cells or substrates. More importantly, aptamercontaining DNA sequences on the surface of the retrieved cancer cells could be further amplified by polymerase chain reaction （PCR）, facilitating the detection of cell surface biomarkers and characterization of the CTCs. Furthermore, this system was extensively applied to the capture and release of CTCs from patients＇ blood samples, demonstrating a promising high-performance platform for CTC enrichment, release, and characterization.

Interfacial thermodynamics-inspired electrolyte strategy to regulate output voltage and energy density of battery chemistry

The electrochemical behaviors of battery chemistry,especially the operating voltage,are greatly affected by the complex electrode/electrolyte interface,but the corresponding basis understanding is still largely unclear.Herein,the concept of regulating electrode potential by interface thermodynamics is proposed,which guides the improvement of the energy density of Zn-MnO_(2) battery.A cationic electrolyte strategy is adopted to adjust the charge density of electrical double layer,as well as entropy change caused by desolvation,thus,achieving an output voltage of 1.6 V(vs.Zn^(2+)/Zn)and a capacity of 400 mAh g^(-1).The detailed energy storage behaviors are also analyzed in terms of crystal field and energy level splitting.Furthermore,the electrolyte optimization benefits the efficient operation of Zn-MnO_(2) battery by enabling a high energy density of 532 Wh kg^(-1) based on the mass of cathode and a long cyclic life of more than 500 cycles.This work provides a path for designing high-energy-density aqueous battery via electrolyte strategy,which is expected to be extended to other battery systems.

Local-scale systems input-output analysis of embodied water for the Beijing economy in 2007

Using the most detailed and recent statistics available for Beijing, a local-scale embodiment analysis on water use was conducted, employing a systems input- output analysis that integrates economic systems with natural resources data. Systems analysis for water research at the local scale is a crucial part of a systems oriented water accounting framework. To our knowledge, however, related works have not been thoroughly conducted. In this paper, a set of embodied water intensity inventory data is presented, which is applicable to both intermediate input and final demand. Also, detailed analyses of Beijing＇s embodied water use accounting are presented. The embodied water intensity of the. Water Production and Supply Industry Sector turns out to be the highest among the 42 sectors. For water embodied in final demand, the total amount is 3.48 km3, of which the water embodied in urban household consumption makes up nearly a half proportion. As a net virtual water importer, Beijing＇s water embodied in commodity trade totals 5.84× 10^8m3. As a result, in addition to improvements in technology and water use efficiency, adjustments in industrial structure and trade policies are algo of significant importance to water conservation efforts.

Visual inference of flow flux via free surface PDE model and image sequence assimilation

The free-surface flows,such as flows in rivers,lakes,and tides,play an important role in hydraulic engineering and environmental monitoring.However,due to their complex and changeable characters,the precise evolution procedure is quite difficult to reconstruct.In this study,the authors propose a novel framework to reconstruct the free-surface flow modelled by the shallow water equations by assimilating the images sequences.In particular,the ensemble Kalman filter framework is employed to implement the assimilation process.The efficiency of the proposed strategy has been verified through numerical simulations in which the accurate flow field in different situations could be obtained within limited assimilation steps.

Metabolic Labeling and Imaging of Cellular RNA via Bioorthogonal Cyclopropene−Tetrazine Ligation

RNA labeling is vital for the study of an RNA structure,cellular distribution,localization,and metabolism.Herein,we report N6 cyclopropane-modified adenosine(cpA)as a new analog for metabolic RNA labeling.We successfully applied inverse electrondemand Diels–Alder(iEDDA)chemistry to label cellular RNA with cpA.This labeling technique is practical and provides a new platform to study RNA roles in cells in a metal-free manner.This simple and robust assay represents a significant advancement in the profiling methods of the nascent transcriptome using chemical approaches.

Embodied exergy-based assessment of energy and resource consumption of buildings

As an effective approach to achieve a more unified and scientific assessment, embodied exergy-based analysis is devised to assess the energy and resource consumption of buildings. A systematic accounting of the landmark buildings in E-town, Beijing is performed, on the basis of raw project data in the Bill of Quantities （BOQ） and the most recent embodied exergy intensities for the Chinese economy in 2007 with 135 industrial sectors. The embodied exergy of the engineering structure of the case buildings is quantified as 4.95E ＋ 14 J, corresponding to an intensity of 8.25E ＋ 09 J/m2 floor area. Total exergy of 51.9% and 28.8% are embodied in the steel and concrete inputs, respectively, due to the fact that the case buildings are structured of reinforced-concrete. The fossil fuel source （coal, crude oil, and natural gas） is predominant among four categories of natural resources （fossil fuel, biological, mineral, and environmental）, accounting for 89.9% of the embodied exergy, with coal as the dominant energy resource （75.5%）. The material accounts for 89.5% of the embodied exergy, in contrast to 9.0%, 1.4%, and 0.1% for manpower, energy, and equipment respectively. This result indicates that great attention should be given to the use of various materials vs. their value of their contribution