The Clumpy Structure of Five Star-bursting Dwarf Galaxies in the MaNGA Survey

The star-forming clumps in star-bursting dwarf galaxies provide valuable insights into understanding the evolution of dwarf galaxies.In this paper,we focus on five star-bursting dwarf galaxies featuring off-centered clumps in the Mapping Nearby Galaxies at Apache Point Observatory survey.Using the stellar population synthesis software Fitting Analysis using Differential evolution Optimization,we obtain the spatially resolved distribution of the star formation history,which allows us to construct the g-band images of the five galaxies at different ages.These images can help us to probe the evolution of the morphological structures of these galaxies.While images of a stellar population older than 1 Gyr are typically smooth,images of a stellar population younger than 1 Gyr reveal significant clumps,including multiple clumps which appear at different locations and even different ages.To study the evolutionary connections of these five galaxies to other dwarf galaxies before their star-forming clumps appear,we construct the images of the stellar populations older than three age nodes,and define them to be the images of the"host"galaxies.We find that the properties such as the central surface brightness and the effective radii of the hosts of the five galaxies are in between those of dwarf ellipticals(dEs)and dwarf irregulars(dIrrs),with two clearly more similar to dEs and one more similar to dIrrs.Among the five galaxies,8257-3704 is particularly interesting,as it shows a previous starburst event that is not quite visible from its gri image,but only visible from images of the stellar population at a few hundred million years.The star-forming clump associated with this event may have appeared at around 600 Myr ago and disappeared at around 40 Myr ago.

A novel small-animal locomotor activity recording device for biological clock research

The rodent running-wheel recording apparatus is a reliable approach for studying cir-cadian rhythm.This study demonstrated how to construct a simple and intelligent running-wheel recording system.The running wheel was attached to the cage's base,whereas the Hall sensor was attached to the cage's cover.Then,the RJ25 adaptor relayed the running signal to the main control board.Finally,the main control board was connected to the USB port of the computer with the USB connection.Data were collected using the online-accessible,self-created software Magturning.Through Magturning,generated data were saved and exported in real time.Afterward,the device was validated by collecting data on the locomotor activities of mice under dif-ferent light conditions.In conclusion,this new device can record circadian activity of rodents.Our device is appropriate for interdisciplinary investigations related to biological clock research.

市场机制、社会资本与共同富裕——基于中国多维减贫政策目标的视角

党的十八大以来,中国开展的精准扶贫使得农村的多维贫困程度显著下降,继续改善农村多维贫困是新时期扎实推动共同富裕的重要环节和必要手段。本文在多维减贫政策目标下,考察了市场机制与社会资本的多维减贫效应及两者作用的关系。基于2014、2016及2018年北京大学中国家庭追踪调查数据(CFPS),采用内生Probit模型进行了实证分析。研究发现:以农地流转市场化为代表的市场机制与农村社会资本都表现出显著的多维减贫效应。进一步分析两者作用的关系发现,市场机制对社会资本的多维减贫效应具有显著替代作用,农地流转市场化水平越高,社会资本的多维减贫效应更弱,更具体地表现为对集体社会资本而非个体社会资本的替代效应。随着市场化转型的推进,集体社会资本的作用被弱化了,市场机制发挥着更为关键的多维减贫效应。异质性分析中,与区域市场化水平较低地区以及农地转入样本相比,区域市场化水平较高地区以及农地转出样本中市场机制对集体社会资本的替代作用更强。机制检验发现,市场机制和个体社会资本对各维度贫困都有一定的缓解作用,市场机制对集体社会资本的替代作用也较为稳健,但对个体社会资本的替代和互补作用在不同减贫渠道中均有体现。针对研究结论,本文提出了推动农地流转市场化、培育农村社会资本以及健全多维减贫机制的对策建议。

Numerical simulation and printability analysis of fused deposition modeling with dual-temperature control

Ideal tissue engineering scaffolds need interconnected pores and high porosity to enable cell survival,migration,proliferation,and differentiation.However,obtaining a high-resolution structure is difficult with traditional one-temperature control fused deposition modeling(FDM).In this study,we propose a dual-temperature control method to improve printability.A numerical model is developed in which the viscosity is a function of temperature and shear rate to study the influence of two different temperature control modes.Quantitative tests are used to assess filament formation and shape fidelity,including one-dimensional filament printing,deposition at corners,fusion,and collapse.By using dual-temperature control,the width of the deposited poly(ε-caprolactone)filament is reduced to 50μm.The comparative results of both the experimental method and numerical simulation suggest that the dual-temperature control FDM can manufacture spatially arranged constructs and presents a promising application in tissue engineering。

Simultaneous multi-material embedded printing for 3D heterogeneous structures

In order to mimic the natural heterogeneity of native tissue and provide a better microenvironment for cell culturing,multi-material bioprinting has become a common solution to construct tissue models in vitro.With the embedded printing method,complex 3D structure can be printed using soft biomaterials with reasonable shape fidelity.However,the current sequential multi-material embedded printing method faces a major challenge,which is the inevitable trade-off between the printed structural integrity and printing precision.Here,we propose a simultaneous multi-material embedded printing method.With this method,we can easily print firmly attached and high-precision multilayer structures.With multiple individually controlled nozzles,different biomaterials can be precisely deposited into a single crevasse,minimizing uncontrolled squeezing and guarantees no contamination of embedding medium within the structure.We analyse the dynamics of the extruded bioink in the embedding medium both analytically and experimentally,and quantitatively evaluate the effects of printing parameters including printing speed and rheology of embedding medium,on the 3D morphology of the printed filament.We demonstrate the printing of double-layer thin-walled structures,each layer less than 200μm,as well as intestine and liver models with 5%gelatin methacryloyl that are crosslinked and extracted from the embedding medium without significant impairment or delamination.The peeling test further proves that the proposed method offers better structural integrity than conventional sequential printing methods.The proposed simultaneous multi-material embedded printing method can serve as a powerful tool to support the complex heterogeneous structure fabrication and open unique prospects for personalized medicine.

Deep-ultraviolet photonics for the disinfection of SARS-CoV-2 and its variants(Delta and Omicron)in the cryogenic environment

Deep-ultraviolet(DUV)disinfection technology provides an expeditious and efficient way to suppress the transmission of coronavirus disease 2019(COVID-19).However,the influences of viral variants(Delta and Omicron)and low temperatures on the DUV virucidal efficacy are still unknown.Here,we developed a reliable and uniform planar light source comprised of 275-nm light-emitting diodes(LEDs)to investigate the effects of these two unknown factors and delineated the principle behind different disinfection performances.We found the lethal effect of DUV at the same radiation dose was reduced by the cryogenic environment,and a negative-U large-relaxation model was used to explain the difference in view of the photoelectronic nature.The chances were higher in the cryogenic environment for the capture of excited electrons within active genetic molecules back to the initial photo-ionised positions.Additionally,the variant of Omicron required a significantly higher DUV dose to achieve the same virucidal efficacy,and this was thanks to the genetic and proteinic characteristics of the Omicron.The findings in this study are important for human society using DUV disinfection in cold conditions(e.g.,the food cold chain logistics and the open air in winter),and the relevant DUV disinfection suggestion against COVID-19 is provided.

Improved microwave dielectric properties of MgAl_(2)O_(4)spinel ceramics through(Li_(1/3)Ti_(2/3))^(3+)doping

A series of nominal compositions MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)(x=0,0.04,0.08,0.12,0.16,and 0.20)ceramics were successfully prepared via the conventional solid-state reaction route.The phase compositions,microstructures,and microwave dielectric properties were investigated.The results of x-ray diffraction(XRD)and scanning electron microscopy(SEM)showed that a single phase of MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with a spinel structure was obtained at x≤0.12,whereas the second phase of MgTi_(2)O_(5)appeared when x>0.12.The cell parameters were obtained by XRD refinement.As the x values increased,the unit cell volume kept expanding.This phenomenon could be attributed to the partial substitution of(Li_(1/3)Ti_(2/3))^(3+)for Al^(3+).Results showed that(Li_(1/3)Ti_(2/3))^(3+)doping into MgAl_(2)O_(4)spinel ceramics effectively reduced the sintering temperature and improved the quality factor(Q_f)values.Good microwave dielectric properties were achieved for a sample at x=0.20 sintering at 1500℃in air for 4 h:dielectric constantε_(r)=8.78,temperature coefficient of resonant frequencyτ_(f)=-85 ppm/℃,and Q_(f)=62300 GHz.The Q_(f)value of the x=0.20 sample was about 2 times higher than that of pure MgAl_(2)O_(4)ceramics(31600 GHz).Thus,MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with excellent microwave dielectric properties can be applied to 5G communications.

Physics problems in bio or bioinspired additive manufacturing

Additive manufacturing,also known as three-dimensional(3D)printing,has attracted increasing attention due to the innovations in materials science and manufacturing over recent decades[1].Recently,innovations in biocompatible materials and biology have enabled the extension of 3D printing techniques into bioadditive manufacturing,which focuses on the fabrication of 3D engineered native-like tissues/organs[2].Currently,bioadditive manufacturing technologies can be categorized into inkjet-based bioprinting,microextrusion-based bioprinting,digital light processing(DLP)bioprinting,electric field-assisted bioprinting,and fused deposition modeling(FDM),to name a few[3,4](Fig.1).Artificial tissues and organs with delicate structures,such as the heart[5]and liver[6],have been successfully fabricated using various bioadditive manufacturing techniques.

塞瑞替尼450 mg随餐服用治疗中国ALK阳性非小细胞肺癌患者的安全性及近期疗效分析

背景与目的间变性淋巴瘤激酶(anaplastic lymphoma kinase,ALK)染色体易位为非小细胞肺癌(nonsmall cell lung cancer,NSCLC)常见的驱动基因。塞瑞替尼为第二代的ALK抑制剂,可为ALK阳性转移性NSCLC患者带来生存获益,但国内尚无塞瑞替尼用药安全性及疗效的研究报道。因此本研究拟通过真实世界研究来探讨塞瑞替尼450 mg随餐服用治疗中国ALK阳性NSCLC患者的安全性及近期疗效。方法回顾性分析2018年10月-2019年12月期间就诊于四川省8家医疗机构口服塞瑞替尼450 mg/d随餐治疗的ALK阳性NSCLC患者,收集患者基本信息、治疗期间不良事件(adverse effects,AEs)及疗效数据等资料,评价其安全性及初步疗效。结果研究共纳入109例患者,随访至2020年1月23日,中位服药时间为5.87个月(范围:0.4个月-15.7个月),总体不良事件发生率为89.9%,3级-4级不良事件发生率为22.9%。最常见AEs(主要为1级-2级)为腹泻(60.6%)、丙氨酸氨基转移酶(alanine aminotransferase,ALT)升高(38.5%)及门冬氨酸氨基转移酶(aspartate aminotransferase,AST)升高(37.6%)。至随访截止,共45例患者停药,总体客观缓解率(objective response rate,ORR)为37.6%(95%CI:28.5%-47.4%),疾病控制率(disease control rate,DCR)为86.2%(95%CI:78.3%-92.1%)。结论真实世界中,塞瑞替尼450 mg随餐服用的给药方式在中国ALK阳性NSCLC患者中具有良好的安全性及疾病控制率,但需要更大样本量的前瞻性研究来进一步验证。

长幼有序、董事权力的合法性与董事会治理效率——基于现金持有视角的经验证据

本文从现金持有视角考察了长幼有序文化对董事会治理的影响。我们发现,比公司最高管理者年长的董事比例增加降低了公司现金持有水平和超额现金持有水平,这种影响在儒家文化影响力较大的地区、董事会稳定性较强、董事会规模较大、国有控股、董事长与CEO两职分离的公司中更加明显;进一步研究还发现,年龄比公司最高管理者大的董事比例增加可以提高现金持有和超额现金持有的价值,且其作用在儒家文化影响力较大的地区、董事会稳定性较强、董事会规模较大、国有控股、董事长与CEO两职分离的公司中更加明显;相比独立董事,非独立董事比公司最高管理者年长能够更明显地降低公司现金持有水平和超额现金持有水平,提高现金持有和超额现金持有的价值。本文的证据表明,董事与公司管理者间的年龄关系通过影响他们间的权威结构,能够影响董事会治理效率。

甲醛荧光试纸的制备及其传感检测——推荐一个研究型大学综合化学实验

围绕甲醛的荧光检测,设计了一个研究型综合化学实验。本实验涵盖了基于光诱导电子转移的荧光传感机理、甲醛荧光传感器的合成、甲醛试纸的制备与应用等内容。同时,以科教融合的形式将具备应用前景的研究成果与日常生活中的甲醛污染与检测等实际应用相结合,能够提高学生的科研创新意识,并学以致用服务于日常生活。

Prognosis-related classifi cation and dynamic monitoring of immune status in patients with sepsis:A prospective observational study

BACKGROUND:The dynamic monitoring of immune status is crucial to the precise and individualized treatment of sepsis.In this study,we aim to introduce a model to describe and monitor the immune status of sepsis and to explore its prognostic value.METHODS:A prospective observational study was carried out in Zhongshan Hospital,Fudan University,enrolling septic patients admitted between July 2016 and December 2018.Blood samples were collected at days 1 and 3.Serum cytokine levels(e.g.,tumor necrosis factor-α[TNF-α],interleukin-10[IL-10])and CD14+monocyte human leukocyte antigen-D-related(HLA-DR)expression were measured to serve as immune markers.Classifi cation of each immune status,namely systemic inflammatory response syndrome(SIRS),compensatory anti-inflammatory response syndrome(CARS),and mixed antagonistic response syndrome(MARS),was defined based on levels of immune markers.Changes of immune status were classifi ed into four groups which were stabilization(SB),deterioration(DT),remission(RM),and non-remission(NR).RESULTS:A total of 174 septic patients were enrolled including 50 non-survivors.Multivariate analysis discovered that IL-10 and HLA-DR expression levels at day 3 were independent prognostic factors.Patients with MARS had the highest mortality rate.Immune status of 46.1%patients changed from day 1 to day 3.Among four groups of immune status changes,DT had the highest mortality rate,followed by NR,RM,and SB with mortality rates of 64.7%,42.9%,and 11.2%,respectively.CONCLUSIONS:Severe immune disorder defi ned as MARS or deterioration of immune status defi ned as DT lead to the worst outcomes.The preliminary model of the classifi cation and dynamic monitoring of immune status based on immune markers has prognostic values and is worthy of further investigation.

Two-way coupled analysis of lithium diffusion and diffusion induced finite elastoplastic bending of bilayer electrodes in lithium-ion batteries

A fully coupling model for the diffusion induced finite elastoplastic bending of bilayer electrodes in lithium-ion batteries is proposed. The effect of the mechanical stress on the lithium diffusion is accounted for by the mechanical part of the chemical potential derived from the Gibbs free energy along with the logarithmic stress and strain. Eight dimensionless parameters, governing the stress-assisted diffusion and the diffusion induced elastoplastic bending, are identified. It is found that the finite plasticity starting from the interface of the bilayer increases the chemical potential gradient and thereby facilitates the lithium diffusion. The full plastic flow makes the abnormal lithium concentration distribution possible, i.e., the concentration at the lithium inlet can be lower than the concentration at the interface(downstream). The increase in the thickness of the active layer during charging is much larger than the eigen-stretch due to lithiation, and this excess thickening is found to be caused by the lithiation induced plastic yield.

Trends on physical understanding of bioink printability

Recently, 3D bioprinting is developed as an emerging approach, increasingly applied to materials for healthcare;while, the precise placement of cells and materials, and the shape fidelity of forming constructs is of great importance for successful application of 3D bioprinting. Research efforts have been made to develop new bioinks as "raw materials" with better biocompatibility and biofunctionality, but the printability of bioinks is largely ignored and still needs to be carefully examined to enable robotic bioprinting. This article aims to introduce a recent published review (Appl. Phys. Rev. 2018, 5, 041304) on the evaluation of bioink printability by Huang's research group from University of Florida. Huang et al. comprehensively reviewed the bioink printability based on the physical point of view during inkjet printing, laser printing, and microextrusion, and a series of self-consistent time scales and dimensi on less quantities were utilized to physically understand and evaluate bioink printability. This article would be helpful to know the trends on physical understanding of bioink printability.

氨甲环酸不同给药方式对髋关节置换围手术期出血的影响研究

目的探讨3种不同给药方式应用氨甲环酸减少单侧全髋关节置换(THA)围手术期失血效率和安全性。方法选取2015年1月-2017年3月该院初次接受单侧THA的患者40例,将其随机分为3组。A组(12例):氨甲环酸(TXA)关节腔局部注射给药;B组(14例):TXA静脉滴注给药联合关节腔局部注射给药;C组(14例):术中喷洒和浸药纱布覆盖创面联合关节腔局部注射给药。比较3组围手术期显性失血量、隐性失血量、输血率、平均输血量、凝血功能及血栓性并发症的发生率。结果 3组间术前一般资料、住院时间、输血率、术前血红蛋白(HGB)含量及并发症发生率比较,差异无统计学意义(P>0.05)。C组失血量和平均输血量低于A、B组(P<0.05),A、B组间比较差异无统计学意义(P>0.05);3组术后HGB水平较术前降低(P<0.05),C组HGB高于A、B组(P<0.05);手术前后3组间D-二聚体(DD)、纤维蛋白素(FIB)、凝血酶原时间(PT)及活化部分凝血活酶时间(APTT)比较,差异无统计学意义(P>0.05),3组术后的FIB含量较术前降低(P<0.05),APTT较术前延长(P<0.05)。结论局部用药优于静脉给药,可安全有效减少THA围手术期出血。

Physical understanding of axonal growth patterns on grooved substrates:groove ridge crossing versus longitudinal alignment

Surface topographies such as micrometric edges and grooves have been widely used to improve neuron outgrowth.However,finding the mechanism of neuron–surface interactions on grooved substrates remains a challenge.In this work,PC12 cells and chick forebrain neurons(CFNs)were cultured on grooved and smooth polyacrylonitrile substrates.It was found that CFNs showed a tendency of growing across groove ridges;while PC12 cells were only observed to grow in the longitudinal direction of grooves.To further investigate these observations,a 3D physical model of axonal outgrowth was developed.In this model,axon shafts are simulated as elastic 3D beams,accounting for the axon outgrowth as well as the focal contacts between axons and substrates.Moreover,the bending direction of axon tips during groove ridge crossing is governed by the energy minimization principle.Our physical model predicts that axonal groove ridge crossing is contributed by the bending compliance of axons,caused by lower Young’s modulus and smaller diameters.This work will aid the understanding of the mechanisms involved in axonal alignment and elongation of neurons guided by grooved substrates,and the obtained insights can be used to enhance the design of instructive scaffolds for nerve tissue engineering and regeneration applications.

Scalable spray coated high performance sulfurized electron transporter for efficient and stable perovskite solar modules

The stability issue has been acknowledged as the bottleneck in the practical application of perovskite photovoltaics,while the stabilized interface between the perovskites and charge transport layers dominates their stability performance under different stresses.Here,we developed a high-performance sulfurized zinc-titanium mixed oxide(ZTO-S)electron transport layer(ETL)to fabricate large-area efficient and long-term 85℃/85%RH stable perovskite solar modules.The scalably prepared ZTO-S using the facile spray coating method demonstrates excellent electron mobility close to that of Zn O,in addition to promoting the uniform crystallization of perovskite film across the entire module via the interaction between surface S and Pb^(2+).Furthermore,this novel coordination stabilized the interface and reduced the interfacial non-radiative recombination defects within the devices,yielding an efficient and stable performance for the modules.High efficiency of 21.73%and 17.50%was achieved for blade-coated 36 cm^(2)and 100 cm^(2)perovskite solar modules,respectively.In addition,the encapsulated module(36 cm^(2))shows an attractive humidity and heat stability(85℃/85%RH)performance with a maintained 93.5%of the initial PCE over 1000 h.

Simultaneous multimaterial multimethod bioprinting

Bioprinting:a powerful tool to fabricate biomimetic tissues and organs Bioprinting is an important technology in the field of biofabrication that aims to create functional biomimetic structures.The flexibility,versatility and functionality of bioprinting enable the fabrication of intricate biological structures by combining cells,biomaterials or growth factors as printing bioinks[1,2].

Industry news:the additive manufacturing of nerve conduits for the treatment of peripheral nerve injury

Peripheral nerve injury and nerve conduit manufacturing The global nerve injury repair and regeneration market is expected to reach$9.7 billion by 2025,a compound annual growth rate of 9.1%between 2020 and 2025[1].One component alone,peripheral nerve injury(PNI),encompasses 5 million new cases worldwide every year[2].Although nerve autograft is considered the gold standard for PNI repair,this process sufers because of a short supply of autologous nerves as well as potential harm caused to the donor.In recent decades,as a promising alternative to autografts。