BL19U2:Small-angle X-ray scattering beamline for biological macromolecules in solution at SSRF

The BL19U2 at the Shanghai Synchrotron Radiation Facility is a small-angle X-ray scattering beamline dedicated to structural studies pertaining to biological macromolecules in solution.The beamline has been officially opened to users in March 2015,and since then,a series of technological innovations has been developed to optimize beamline performance,thereby significantly improving the data collection efficiency and broadening the application scope of biological small-angle X-ray scattering.BL19U2 is ideal for the high-throughput screening of weakly scattered proteins,protein assemblies,nucleic acids,inorganic nanomaterials,and organic drug molecules.This paper describes the design and overview of the BL19U2 beamline.Versatile sample environments at the experimental station and some recent scientific highlights are presented.

心脏术后新发糖尿病的危险因素:进展与思考

心脏术后新发糖尿病是心脏手术常见的并发症之一,可增加术后死亡和排异事件的发生风险。对心脏术后新发糖尿病的早期发现和积极管理是促进心脏手术患者临床获益的重要内容。本文通过对冠脉血运重建术和心脏移植术两种重要心脏手术类型术后新发糖尿病的危险因素作一综述,以期为心脏术后新发糖尿病的早期综合化管理提供参考。

Photocatalytic dicarboxylation of strained C-C bonds with CO_(2) via consecutive visible-light-induced electron transfer

Dicarboxylic acids have a wide range of applications in the polymer industry to construct valuable materials.Photocatalysis has recently emerged as an efficient and sustainable strategy to generate dicarboxylic acids.However,photocatalytic dicarboxylation with CO_(2) is mainly limited to unsaturated bonds,and the dicarboxylation of C-C single bonds still remains a challenge.Herein,we report a photocatalytic dicarboxylation of C-C single bonds in strained rings with CO_(2) units via consecutive photo-induced electron transfer(ConPET).It is also the first photocatalytic reductive ring-opening reaction of cyclobutanes.Notably,this transition-metal-free protocol exhibits good functional group tolerance,broad substrate scope,facile scalability,and easy product derivatizations.Moreover,diacids can easily be derivatized to mainchain liquid crystalline polyesters.

New hybrid FDTD algorithm for electromagnetic problem analysis

Since the time step of the traditional finite-difference time-domain(FDTD) method is limited by the small grid size, it is inefficient when dealing with the electromagnetic problems of multi-scale structures.Therefore, the explicit and unconditionally stable FDTD(US-FDTD) approach has been developed to break through the limitation of Courant–Friedrich–Levy(CFL) condition.However, the eigenvalues and eigenvectors of the system matrix must be calculated before the time iteration in the explicit US-FDTD.Moreover, the eigenvalue decomposition is also time consuming, especially for complex electromagnetic problems in practical application.In addition, compared with the traditional FDTD method, the explicit US-FDTD method is more difficult to introduce the absorbing boundary and plane wave.To solve the drawbacks of the traditional FDTD and the explicit US-FDTD, a new hybrid FDTD algorithm is proposed in this paper.This combines the explicit US-FDTD with the traditional FDTD, which not only overcomes the limitation of CFL condition but also reduces the system matrix dimension, and introduces the plane wave and the perfectly matched layer(PML) absorption boundary conveniently.With the hybrid algorithm, the calculation of the eigenvalues is only required in the fine mesh region and adjacent coarse mesh region.Therefore, the calculation efficiency is greatly enhanced.Furthermore, the plane wave and the absorption boundary introduction of the traditional FDTD method can be directly utilized.Numerical results demonstrate the effectiveness, accuracy, stability, and convenience of this hybrid algorithm.

A novel heating area design of temperature-jump microfluidic chip for synchrotron radiation solution X-ray scattering

In this paper, we present a novel design scheme of temperature-jump(T-jump) area for microfluidic device.Numerical simulation and experimental research of thermal characteristics of the solution in microchannels is completed.Numerical simulation of the temperature-jump microchannel is analyzed to study the heat transfer characteristics by comparing performance of three proposed configurations.Calculation of the power requirement is discussed in the dimensional design of microheater. Temperature-sensitive fluorescent dye is applied to investigate the temperature field of microchannel heated by a designed microheater. It is found that the T-jump microfluidic device can provide rapid heating for solutions with strong convection heat transfer ability.

Accessibility in key areas of the Arctic in the 21st mid-century

The navigation potential of the Arctic has improved with the rapid retreat of sea ice under continuous warming.The comprehensive evaluation of Arctic accessibility for low ice-breaking ships(civil use)in the mid-century is important to support coordinated international decision-making.In this study,the hydrological conditions and navigation potential in key areas and crucial straits along the Northern Sea Route(NSR)and Northwest Passage(NWP)were assessed under Shared Socioeconomic Pathways(SSPs)using the Polar Operational Limit Assessment Risk Indexing System.The results showed that the most critical areas for navigation in the mid-century(2046-2055)are the waters around the New Siberian Islands and within the Parry Channel.Arctic navigability improves from SSP1-2.6 to SSP2-4.5 to SSP5-8.5,and the accessibility for PC7 ships under SSP2-4.5 is even better for OW ships under SSP5-8.5.The route on the north side of the New Siberian Islands is a relatively good choice within the NSR,and the southern route has a better navigation potential than the Parry Channel within the NWP.In addition,the accessibility of the Dmitri Laptev Strait is better than that of the Sannikov Strait at a monthly scale,although the latter has more navigable days.However,there is little difference in accessibility between the eastern and western parts of the Parry Channel.The best nav-igation potential through the above straits is in September for ordinary ships,and the optimal time window is delayed and extended for PC7 ships.The results can serve as references for policy-making and navigation planning in the Arctic.

Preparation of Polyaniline-coated Composite Aerogel of MnO2 and Reduced Graphene Oxide for High-performance Zinc-ion Battery

Aqueous zinc-ion batteries,especially Zn-Mn02 battery,have attracted intensive attention owing to their unique features of high capacity,environmental friendliness,and safety.However,the problem of Mn dissolution hinders the development of zinc-ion batteries with long-term usage and high-rate performance.In this work,a novel preparation method for the polyaniline(PANI)-coated composite aerogel of Mn02 and rGO(MnO2/rGO/PANI)electrode is reported.The obtained composite possesses high electrical conductivity,and also effectively suppresses the dissolution of Mn.The fabricated Mn02/rGO/PANI//Zn battery exhibits a high capacity of 241.1 mAh·g^-1 at 0.1 A·g^-1,and an excellent capacity retention of 82.7%after 600 charge/discharge cycles.In addition,the rapid diffusion coefficient of the Mn02/rGO/PANI electrode was further examined by galvanostatic intermittent titration technique.This work provides new insights into the development of high-performance Zn-Mn02 battery with a better understanding of its diffusion kinetics.