Enhancing I^(0)/I^(-)Conversion Efficiency by Starch Confinement in Zinc-lodine Battery

The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle life and efficiency of these batteries remain unsatisfactory due to the uncontrolled shuttling of polyiodide(I_(3)^(-)and I_(5)^(-))and side reactions on the Zn anode.Starch is a very low-cost and widely sourced food used daily around the world.“Starch turns blue when it encounters iodine”is a classic chemical reaction,which results from the unique structure of the helix starch molecule–iodine complex.Inspired by this,we employ starch to confine the shuttling of polyiodide,and thus,the I^(0)/I^(-)conversion efficiency of an I^(2)-Zn battery is clearly enhanced.According to the detailed characterizations and theoretical DFT calculation results,the enhancement of I^(0)/I^(-)conversion efficiency is mainly originated from the strong bonding between the charged products of I_(3)^(-)and I_(5)^(-)and the rich hydroxyl groups in starch.This work provides inspiration for the rational design of high-performance and low-cost I^(2)-Zn in AZIBs.

Prevention of Nosocomial COVID-19 Infections in a Designated Hospital for Children in Guangzhou, China

Background: Guangzhou Women and Children’s Medical Center was chosen as the designated facility for screening, diagnosing, and treating children in Guangzhou with SARS-CoV-2 infection after the COVID-19 outbreak in China. From January 23 to March 20, 2020, the center opened new wards for screening and treatment, taking measures to prevent and control nosocomial infections. This article summarizes and evaluates measures for preventing and controlling nosocomial infections to provide reference information during the pandemic. Methods: The COVID-19 nosocomial infection prevention and control strategies were summarized and analyzed, including the formulation of the hospital partition, the improvement of the hospitalization process, environmental cleaning and disinfection, graded protection based on risk assessment, enhanced training on-site quality control inspection, data monitoring and evaluation, among others, and evaluating the effects by comparing before and after the intervention. Results: There were 159 patients admitted to the screening wards, including 98 males and 61 females, with a median age of 34 years (interquartile range (IQR): 15, 60) months. There were no abnormal findings in these patients and their families during follow-up. During the screening ward opening period, hand hygiene compliance was significantly improved. Fifty staff members in close contact with the contaminated area had tested for SARS-CoV-2 nucleic acid by polymerase chain reaction (PCR), which showed zero infections and no nosocomial infections occurred. Conclusions: For SARS-CoV-2 nosocomial infections, taking the “standard prevention & contact isolation & droplet isolation & air isolation” strategies can prevent patients and staff effectively.

Defect-induced electron rich nanodomains in CoSe_(0.5)S_(1.5)/GA realize fast ion migration kinetics as sodium-ion capacitor anode

Optimizing charge migration and alleviating volume expansion in anode materials are the key to improve the electrochemical performance for sodium-ion storage devices.Herein,a hierarchical porous conducting matrix confining defect-rich selenium doped cobalt dichalcogenide(CoSe_(0.5)S_(1.5)/GA)is constructed as a promising SICs anode based on the guidance of theoretical calculation analysis.The increased defect concentration significantly enhanced the disorder degree of the compound and presented electron aggregation around the S atoms,which effectively modulated the electronic structure,further enabling high rate and ultra-capacity sodium storage.Moreover,strong interfacial coupling could construct spatial constraint to alleviate volume expansion as well as maintain electrode integrity and stability.The CoSe_(0.5)S_(1.5)/GA electrode can deliver a high capacity of 310.1 mA h g^(-1)after 2000 cycles at 1 A g^(-1),and the CoSe_(0.5)S_(1.5)/GA//AC sodium ion capacitor can exhibit an outstanding energy density of 237.5 W h kg^(-1).A series of characterization and theoretical calculation convincingly reveal that the defect moieties can regulate the Na^(+)storage and diffusion kinetics,which prove that our defect manufacture coupling with space-confined strategy can provide deep insights into the development of high-performance Na^(+)storage devices.

单模具多规格聚乳酸微管挤出成型工艺

系统研究了聚乳酸微管的挤出成型工艺,获得了注气量、螺杆转速、牵引速度对微管外径、壁厚和椭圆度的影响规律。实验结果表明,注气量、螺杆转速、牵引速度对微管外径和壁厚的影响显著,且呈非线性变化。其中,牵引速度和螺杆转速相对于注气量对微管外径的影响程度较大;螺杆转速、牵引速度和注气量对微管壁厚的影响程度依次减弱。注气量直接影响微管截面的椭圆度,注气量越大,椭圆度越小,在注气量较小时,注气量增大1倍,椭圆度可降低68%。通过改变牵引速度、螺杆转速、注气量及其组合,可以达到采用1套模具顺序挤出4种规格聚乳酸微管的目的。

Neural cell injury microenvironment induces neural differentiation of human umbilical cord mesenchymal stem cells

This study aimed to investigate the neural differentiation of human umbilical cord mesenchymal stem cells （hUCMSCs） under the induction of injured neural cells. After in vitro isolation and culture, passage 5 hUCMSCs were used for experimentation, hUCMSCs were co-cultured with normal or AI31.4o-injured PC12 cells, PC12 cell supernatant or PC12 cell lysate in a Transwell co-culture system. Western blot analysis and flow cytometry results showed that choline acetyltransferase and microtubule-associated protein 2, a specific marker for neural cells, were expressed in hUCMSCs under various culture conditions, and highest expression was observed in the hUCMSCs co-cultured with injured PC12 cells. Choline acetyltransferase and microtubule-associated protein 2 were not expressed in hUCMSCs cultured alone （no treatment）. Cell Counting Kit-8 assay results showed that hUCMSCs under co-culture conditions promoted the proliferation of injured PC12 cells. These findings suggest that the microenvironment during neural tissue injury can effectively induce neural cell differentiation of hUCMSCs. These differentiated hUCMSCs likely accelerate the repair of injured neural ceils.

Study of extrudability and standoff distance effect during nanoclay-enabled direct printing

Nanoclay-enabled self-supporting printing has been emerging as a promising filament-based extrusion fabrication approach for different biomedical and engineering applications including tissue engineering. With the addition of nanoclay powders, liquid build materials may exhibit solid-like behavior upon extrusion and can be directly printed in air into complex three-dimensional structures. The objective of this study is to investigate the effect of nanoclay on the extrudability of N-isopropylacrylamide （NIPAAm） and the effect of standoff distance on the print quality during nanoclay-enabled direct printing. It is found that the addition of nanoclay can significantly improve the NIPAAm extrudability and effectively eliminate die swelling in material extrusion. In addition, with the increase of standoff distance, deposited filaments change from over-deposited to well-defined to stretched to broken, the filament width decreases, and the print fidelity deteriorates. A mathematical model is further proposed to determine the optimal standoff distance to achieve better print fidelity during nanoclay-enabled direct printing. Based on the extrudability and standoff distance knowledge from this study, NIPAAm-Laponite nanoclay and NIPAAm-Laponite nanoclay-graphene oxide nanocomposite hydrogel precursors are successfully printed into a three-layered one-dimensional responsive pattern, demonstrating the good extrudability and print quality during nanoclay-enabled printing under optimal printing conditions.

Advances in friction of aluminium alloy deep drawing

Broad use of lightweight aluminium alloy parts in automobile manufacturing,aerospace,electronic communication,and rail transit is mainly formed through deep drawing process.Deep drawing friction is a key boundary condition for controlling the forming quality of aluminium alloy parts.However,due to the oxidation and adhesion tendency of aluminium alloys,the tribological situations of aluminium alloy deep drawing(AADD)system is more complicated than those of traditional deep drawing of steel sheets.Therefore,the study of AADD friction is essential for manufacturing high-performance aluminium alloy parts.Herein,aiming to provide a valuable reference for researchers in related fields,a comprehensive review of AADD friction is provided,including friction mechanism,influencing factors,friction measurement,friction model,friction simulation,and lubrication-free friction control.Finally,a brief conclusion and several current challenges were discussed.

Microfluidic separation of particles by synergistic effect of geometry-induced hydrodynamics and magnetic field

Microfluidic combined with magnetic field have been demonstrated to be the promising solutions for fast and low-damage particles separation.However,the difficulties in the precise layout of magnets and accurate prediction of particle trajectories lead to under and over separation of target particles.A novel particle separation lab-on-chip(LOC)prototype integrated with microstructures and micropolar arrays is designed and characterized.Meanwhile,a numerical model for the separation of magnetic particles by the synergistic effect of geometry-induced hydrodynamics and magnetic field is constructed.The effect of geometry and magnetic field layout on particle deflection is systematically analyzed to implement accurate prediction of particle trajectories.It is found that the separation efficiency of magnetic particles increased from 50.2%to 91.7%and decreased from 88.6%to 85.7%in the range of depth factors from 15µm to 27µm and width factors from 30µm to 60µm,respectively.In particular,the combined effect of the offset distance of permanent magnets and the distance from the main flow channel exhibits a significant difference from the conventional perception.Finally,the developed LOC prototype was generalized for extension to arbitrary systems.This work provides a new insight and robust method for the microfluidic separation of magnetic particles.

A robust indium-organic framework with open tubular channels for efficient separation of acetylene

Considering the tremendous applications and purification requirement of acetylene(C_(2)H_(2)),seeking appropriate adsorbents with high capacity and selectivity is a vital task and remains an enduring challenge.Herein,we designed and synthesized a robust three-dimensional(3D)indium-organic framework([(Me)_(2)NH_(2)][In(L6)_(0.5)(IPA)_(0.5)]·DMA·2H_(2)O(In-L6-IPA,DMA=dimethylammonium,IPA=isopropyl alcohol))featuring two types of one-dimensional(1D)tubular channels.The activated In-L6-IPA displayed high loading for C_(2)H_(2)(104.4 cm^(3)·g^(-1),the second highest value among all reported indium-based metal-organic frameworks(MOFs))and simultaneously selective adsorption for C_(2)H_(2) over CO_(2),C_(2)H_(6),and ethylene(C_(2)H_(4))at 298 K under 100 kPa.Molecular modelling revealed that the porous wall of In-L6-IPA provides more and stronger multiple interactions for C_(2)H_(2) than CO_(2),C_(2)H_(6),and C_(2)H_(4) containing C–H···π,C–H···O,and O···πinteractions.Breakthrough experiments validated the actual separation ability for various ratios of binary C_(2)H_(2)/C_(2)H_(4) and C_(2)H_(2)/CO_(2) mixtures as well as equimolar ternary C_(2)H_(2)/C_(2)H_(4)/CO_(2) and C_(2)H_(2)/C_(2)H_(4)/C_(2)H_(6) mixtures with excellent reusability.

Erratum to: A robust indium-organic framework with open tubular channels for efficient separation of acetylene

Erratum to Nano Research,2024,17(4):3139–3146 https://doi.org/10.1007/s12274-023-6061-8 In the first page of the original version of this paper,the corresponding authors should be“Yanwei Sui”and“Lei Hou”,instead of“Lei Hou”and“Yao-Yu Wang”.And“Address correspondence to:Lei Hou,lhou2009@nwu.edu.cn;Yao-Yu Wang,wyds123456@outlook.com”should be corrected to“Address correspondence to:Lei Hou,lhou2009@nwu.edu.cn;Yanwei Sui,wyds123456@outlook.com”.

Epidemiology and control measures of an outbreak of neonatal echovirus 11 infections in Guangdong, China: A retrospective analysis

The objective of this study was to investigate the outbreak of echovirus 11 (ECHO 11) infection in newborns at a hospital in Guangdong Province, China, and to study the effectiveness of prevention and control measures to infer the epidemiological characteristics of ECHO 11 and explore the effective measures for its prevention and control. We performed retrospective analyses of hospital records and laboratory test data. In this outbreak, ten cases of ECHO 11 infection were identified, of which nine cases were nosocomial infections. Most of the cases (90%) were severe, and three died. The onset time interval of 10 patients was 1-4 days, most of which occur in 1-2 days. There were eight (80%) males and two females (20%). The gestational age of the patients was 31 to 40 weeks (mean, 35+4 weeks;median, 35+4 weeks). The onset time was 3-26 days (average 9 days;median 8 days). The birth weights of the patients ranged from 1,650 g to 3,450 g (mean 2,385 g;median 2,250 g). We concluded that neonatal infection with ECHO 11 will lead to serious symptoms and high mortality, and is prone to outbreaks of nosocomial infection. We speculate that ECHO 11 is most likely to spread via contact transmission;however, we do not rule out the possibility of droplet transmission. Prevention and control measures can effectively prevent and control hospital enteroviral infections.

A first comprehensive evaluation of China's GNSS-R airborne campaign:part Ⅱ—river remote sensing

The Global Navigation Satellite System Reflectometry(GNSS-R) has been proven to be a powerful technique for retrieving geophysical parameters of ocean and land. Airborne GNSS-R is an important experimental platform, because it is not only needed as validation for spaceborne application, but also possesses the advantages to be capable of remote sensing of small and medium scale targets, such as rivers and lakes. This paper presents an overview of China's airborne GNSS-R campaign conducted on May 30, 2014, in Henan. The campaign has two objectives, i.e.:(1) to examine the capability of a GNSS-R payload developed by National Space Science Center,Chinese Academy of Sciences(NSSC, CAS) for airborneobservations and(2) to study the algorithms for soil moisture and river remote sensing, including altimetry and flow velocity measurement. A previous paper has presented results of soil moisture retrieval as part I, and in this paper,initial results of the Yellow River remote sensing are presented as part II. This paper presents the river altimetry results and explores a new potential application of GNSS-R technology, which is used to detect the flow velocity of the river. The river surface height results observed by code delay altimetry method were consistent with the height results of GPS dual-frequency differential positioning altimetry. The GNSS-R altimetry results showed that decimeter level heights were achieved in 1-min sliding average. Comparing with in situ measurements, the GNSSR flow velocity result was reasonable; the error was about0.027 m/s, which indicated the validity and feasibility of using GNSS-R technique to detect river flow velocity.

3D Printing of Biodegradable Polymer Vascular Stents:A Review

Biodegradable polymer vascular stents(BPVSs)have been widely used in percutaneous coronary interventions for the treatment of coronary artery diseases.The development of BPVSs is an integrated process that combines material design/selection,manufacturing,and performance characterization.Three-dimensional(3D)printing technology is a powerful tool for polymer stent fabrication.Current review studies have focused primarily on the material and structural design of polymer stents but have failed to comprehensively discuss different 3D printing approaches and stent characterization techniques.In this paper,we address these shortcomings by discussing 3D printing methods and their application in BPVSs.First,some commonly used 3D printing methods(including material extrusion,vat polymerization,and powder bed fusion)and potential 3D printing strategies(including material jetting and binder jetting)for fabricating BPVSs are discussed;furthermore,the main post-treatments are summarized.Then,techniques to characterize the morphology,mechanical properties,and biological prop-erties of the printed BPVSs are introduced.Subsequently,representative commercial BPVSs and lab-grade BPVSs are compared.Finally,based on the limitations of stent printing and characterization processes,future perspec-tives are proposed,which may help develop new techniques to fabricate more customized stents and accurately evaluate their performance.