Ga intercalation in van der Waals layers for advancing p-type Bi_(2)Te_(3)-based thermoelectrics

Tetradymite-structured chalcogenides,such as Bi_(2)Te_(3) and Sb_(2)Te_(3),are quasi-two-dimensional(2D)layered compounds,which are significant thermoelectric materials applied near room temperature.The intercalation of guest species in van der Waals(vdW)gap implemented for tunning properties has attracted much attention in recent years.We attempt to insert Ga atoms in the vdW gap between the Te layers in p-type Bi_(0.3)Sb_(1.7)Te_(3)(BST)for further improving thermoelectrics.The vdW-related defects(including extrinsic interstitial and intrinsic defects)induced by Ga intercalation can not only modulate the carrier concentration but also enhance the texture,thereby yielding excellent electrical properties,which are reflected in the power factor PF~4.43 mW·m^(-1)·K^(-2).Furthermore,the intercalation of Ga produces multi-scale lattice imperfections such as point defects,Te precipitations,and nanopores,realizing the low lattice thermal conductivity in BST-Ga samples.Ultimately,a peak zT~1.1 at 373 K is achieved in the BST-1%Ga sample and greatly improved by~22%compared to the pristine BST.The weak bonding of vdW interlayer interaction can boost the synergistic effect for advancing BST-based or other layered thermoelectrics.

“一体化”共价有机框架光催化二氧化碳还原研究

自工业革命以来,温室气体CO_(2)大量排放使得环境问题日益突出,严重制约了人类的生存和发展.人工光合作用可利用取之不尽的阳光作为驱动力,将CO_(2)还原为可实际应用的化学燃料(CO、HCOOH等).人工光合作用体系通常包括两部分:光敏剂和催化剂.光敏剂吸收入射光的能量,电子由基态(价带)跃迁至激发态(导带);处于激发态的光敏剂将电子转移到催化剂上;最终由催化剂实现CO_(2)还原.对光敏剂和催化剂进行合理的调变可以构建更加高效、稳定的人工光合作用体系.共价有机框架(COFs)材料是由轻元素(C,H,O,N,B等)组成的有机小分子构筑单元通过动态共价键组装,所形成的具有预先设计的拓扑结构的一维、二维或三维的晶态有机多孔骨架材料.自从2005年首次报道COFs材料的成功合成以来,COFs逐渐地发展成为了一种具有高潜力和广泛的功能化应用前景的多孔骨架聚合物.特别是二维共价有机框架(2D-COFs).2D-COFs独特的平面扩展共轭π-π结构,使其具有较好的光吸收性能,轴向的π堆叠结构,有利于光生电荷的分离和转移,2D-COFs材料在光催化领域极具应用潜质.本文以四(4-氨基苯基)卟啉和Re(bpy)(CO)_(3)Cl为结构单元,通过希夫碱反应合成了一种集光敏剂和催化剂于一体的2D-COF.所制H_(2)PRebpy-COF不仅继承两种单体与COF的性能特点,并且使三者充分融合、相互促进:(1)卟啉对可见光具有较好的吸收能力,形成COF后扩展了其π-π共轭结构,从而增大了光吸收范围;(2)作为最常见的CO_(2)还原催化剂,大量内置的Re(bpy)(CO)_(3)Cl赋予了H_(2)PRebpy-COF催化CO_(2)还原的能力;(3)通过较为稳定的共价键和配位键将Re(bpy)(CO)_(3)Cl修饰在COF结构中,抑制了其在催化过程中发生的二聚失活.在可见光照射下,H_(2)PRebpy-COF光催化CO_(2)还原的产物为CO和HCOOH,其中CO的产率达到1200μmol g^(−1) h^(−1),选择性为78%.同等条件下,不含Re(bpy)(CO)_(3)Cl催化中心的参比物H_(2)Pbpy-COF则几乎没有催化活性.^(13)C同位素标记实验结果表明CO_(2)还原反应产物中的C来源于反应物CO_(2),而非催化体系中其他物质的分解.经过三次催化循环后,H_(2)PRebpy-COF的扫描电镜、红外光谱图与反应前基本一致,说明结构具有一定的稳定性.最后,结合实验和DFT计算对光催化CO_(2)还原过程提出了一种可能的催化机理:在可见光的驱动下,卟啉吸收光的能量,受激发的电子从卟啉(HOMO中心)转移到Re(bpy)(CO)_(3)Cl(LUMO中心);Re(bpy)(CO)_(3)Cl作为催化活性中心实现CO_(2)还原.综上,从微观到宏观,充分利用各结构的特点,合成具有特定结构的COFs,从而具有更优异的性能.

Umbilical cord-derived mesenchymal stem cells retain immunomodulatory and anti-oxidative activities after neural induction

The immunomodulatory and anti-oxidative activities of differentiated mesenchymal stem cells contribute to their therapeutic efficacy in cell-replacement therapy. Mesenchymal stem cells were isolated from human umbilical cord and induced to differentiate with basic fibroblast growth factor, nerve growth factor, epidermal growth factor, brain-derived neurotrophic factor and forskolin. The mesenchymal stem cells became rounded with long processes and expressed the neural markers, Tujl, neurofilament 200, microtubule-associated protein-2 and neuron-specific enolase. Nestin expression was significantly reduced after neural induction. The expression of immunoregulatory and anti-oxidative genes was largely unchanged prior to and after neural induction in mesenchymal stem cells. There was no significant difference in the effects of control and induced mesenchymal stem cells on lymphocyte proliferation in co-culture experiments. However, the expression of human leukocyte antigen-G decreased significantly in induced neuron-like cells. These results suggest that growth factor-based methods enable the differentiation of mesenchymal stem cell toward immature neuronal-like cells, which retain their immunomodulatory and anti-oxidative activities.

Numerical investigation of ocean waves generated by three typhoons in offshore China

The influences of the three types of reanalysis wind fields on the simulation of three typhoon waves occurred in2015 in offshore China were numerically investigated.The typhoon wave model was based on the simulating waves nearshore model(SWAN),in which the wind fields for driving waves were derived from the European Centre for Medium-Range Weather Forecasts(ECMWF)Re-Analysis-Interim(ERA-interim),the National Centers for Environmental Prediction climate forecast system version 2(CFSv2)and cross-calibrated multi-platform(CCMP)datasets.Firstly,the typhoon waves generated during the occurrence of typhoons Chan-hom(1509),Linfa(1510)and Nangka(1511)in 2015 were simulated by using the wave model driven by ERA-interim,CFSv2 and CCMP datasets.The numerical results were validated using buoy data and satellite observation data,and the simulation results under the three types of wind fields were in good agreement with the observed data.The numerical results showed that the CCMP wind data was the best in simulating waves overall,and the wind speeds pertaining to ERA-Interim and CCMP were notably smaller than those observed near the typhoon centre.To correct the accuracy of the wind fields,the Holland theoretical wind model was used to revise and optimize the wind speed pertaining to the CCMP near the typhoon centre.The results indicated that the CCMP wind-driven SWAN model could appropriately simulate the typhoon waves generated by three typhoons in offshore China,and the use of the CCMP/Holland blended wind field could effectively improve the accuracy of typhoon wave simulations.

Improved hemimorphite flotation using xanthate as a collector with S(Ⅱ) and Pb(Ⅱ) activation

The flotation of hemimorphite using the S(Ⅱ)–Pb(Ⅱ)–xanthate process,which includes sulfidization with sodium sulfide,activation by lead cations,and subsequent flotation with xanthate,was investigated.The flotation results indicated that hemimorphite floats when the S(Ⅱ)–Pb(Ⅱ)–xanthate process is used; a maximum recovery of approximately 90% was obtained.Zeta-potential,contact-angle,scanning electron microscopy–energy-dispersive spectrometry(SEM–EDS),and diffuse-reflectance infrared Fourier transform spectroscopy(DRIFTS) measurements were used to characterize the activation products on the hemimorphite surface and their subsequent interaction with sodium butyl xanthate(SBX).The results showed that a Zn S coating formed on the hemimorphite surface after the sample was conditioned in an Na2 S solution.However,the formation of a Zn S coating on the hemimorphite surface did not improve hemimorphite flotation.With the subsequent addition of lead cations,Pb S species formed on the mineral surface.The formation of the Pb S species on the surface of hemimorphite significantly increased the adsorption capacity of SBX,forming lead xanthate(referred to as chemical adsorption) and leading to a substantial improvement in hemimorphite flotation.Our results indicate that the addition of lead cations is a critical step in the successful flotation of hemimorphite using the sulfidization–lead ion activation–xanthate process.

Controllable Construction of Bifunctional CoxP@N,P-Doped Carbon Electrocatalysts for Rechargeable Zinc–Air Batteries

The exploration of cheap,efficient,and durable bifunctional electrocatalysts for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is highly desired to push forward the commercialization of rechargeable metal–air batteries.Here,bifunctional ORR/OER electrocatalysts based on CoxP(0<x<2,i.e.,Co_(2)P,Co_(2)P/CoP mixture,and CoP)nanoparticles(NPs)anchored on N,P-doped carbon framework(Co_(x)P@NPC)are developed via one-step carbonization of the mixture of as-synthesized ZIF-67 and melamine–phytic acid supermolecular aggregate(MPSA).The stoichiometric ratio of resultant Co_(x)P NPs can be rationally designed by adjusting the introduced ratio of ZIF-67 to MPSA,enabling their fabrication in a controlled manner.It is found that the as-synthesized Co_(2)P@NPC exhibits the best bifunctional ORR/OER activity among the Co_(x)P@NPC analogues,with a reversible oxygen electrode index(ΔE=E_(j10)−E_(1/2))down to~0.75 V.The constructed Zn–air battery based on Co_(2)P@NPC delivers a peak power density of 157 mW cm^(−2) and an excellent charge-discharge stability with negligible voltage decay for 140 h at 10 mA cm^(−2),superior to those based on Pt/C+RuO_(2) and most Co_(x)P-based electrodes ever reported.

Effect of deep oxidation of chalcopyrite on surface properties and flotation performance

In this study, chalcopyrite was oxidized in hydrogen peroxide(H_(2)O_(2)) solutions of different concentrations to simulate different degrees of oxidation in real ores, and the effects of H_(2)O_(2) treatment on chalcopyrite surface properties and flotation performance were investigated by surface analysis techniques and floatation experiments, which implied the reason for the poor grade and recovery of oxidized chalcopyrite concentrate in the production process of the ore. Flotation results showed that when the concentration of H_(2)O_(2) increased from 0%(by weight) to 5%, the flotation recovery of chalcopyrite decreased sharply.However, with increasing H_(2)O_(2) concentration from 5% to 30%, chalcopyrite recovery improved relatively to different degrees with different collector concentrations. Analyses of X-ray photoelectron spectroscopy(XPS) and inductively coupled plasma-atomic optical emission spectrophotometry(ICP-OES) results indicated that the pretreatment with H_(2)O_(2) caused that hydrophilic substance formed on chalcopyrite surface with the dissolution of copper ions, and the dissolution amount of copper increased with the increase of H_(2)O_(2) concentration. UV–visible spectrophotometer and Fourier transform infrared spectrum(FTIR) studies indicated that the pretreatment of chalcopyrite with H_(2)O_(2) had little effect on the adsorption amount of potassium butyl xanthate(PBX) on chalcopyrite surface. However, due to the dissolution of copper ions, PBX interacted with chalcopyrite mainly as buthyl dixanthogen(BX)_(2).

Prior transfusion of umbilical cord mesenchymal stem cells can effectively alleviate symptoms of motion sickness in mice through interleukin 10 secretion

BACKGROUND Motion sickness(MS)is a disease that occurs during unbalanced movement,characterized by gastrointestinal symptoms and autonomic nervous system activation.Current clinical treatments for MS are limited.Recent evidence indicates that the levels of pro-inflammatory cytokines increase during MS and are associated with an inner ear immune imbalance.In the present study,mesenchymal stem cells(MSCs)have been shown to exert strong immunosuppressive effects.AIM To explore whether umbilical cord-derived mesenchymal stem cells(UC-MSCs)can prevent the occurrence of MS,and the underlying mechanism regulated by MSCs in a mouse model of MS.METHODS A total of 144(equal numbers of males and females)5wkold BALB/c mice were randomly divided into five groups:Normal group(n=16),MS group(n=32),MSCs group(n=32),MS+MSCs group(n=32),and MS+AS101/MSCs group(n=32).The MSCs group(n=32),MS+MSCs group(n=32),and MS+AS101/MSCs group(n=32)were preventively transplanted with UC-MSCs or AS101-treated UC-MSCs(1×106 cells/mouse).Mice in the MS(n=32),MS+MSCs,and MS+AS101/MSCs groups were subjected to rotation on a centrifuge for 10 min at 8×g/min for MS model establishment on days 3,5,8,and 10 after UC-MSCs injection.The Morris water maze(MWM)test was used to observe the symptom of dizziness.Enzyme-linked immunosorbent assay(ELISA)and reverse transcription-quantitative polymerase chain reaction(RT-qPCR)were used to detect the levels of inflammatory cytokines in mice peripheral blood and the petrous part of the temporal bone samples.Western blot analysis was performed to analyze the JAK2/STAT3 signaling pathway in the cochlear tissues.Histological examination was performed by hematoxylin and eosin(HE)staining for conventional morphological evaluation in the petrous part of temporal bone samples.RESULTS The MWM test demonstrated that UC-MSCs improved the symptoms of MS.The MS+MSCs group was faster than the MS group on days 3 and 5(P=0.036 and P=0.002,respectively).ELISA and RT-qPCR showed that the serum and mRNA levels of interleukin-10(IL-10)in the cochlear tissues were increased after transplantation with UC-MSCs(MS+MSCs group vs MS group at 3 and 5 d,P=0.002 and cP<0.001,respectively).RT-qPCR results confirmed a significant increase in IL-10 levels at four time points(MS+MSCs group vs MS group,P=0.009,P=0.009,P=0.048,and P=0.049,respectively).This suggested that UCMSCs reduced the sensitivity of the vestibular microenvironment by secreting IL-10.Moreover,Western blot analysis showed that the MSCs activated the JAK2/STAT3 signaling pathway in the cochlear tissues.The levels of IL-10,IL-10RA,JAK2,STAT3,and phosphorylated JAK2 and STAT3 in the MS+MSCs group were increased compared to those of the MS group(P<0.05).The morphological changes in the four groups showed no significant differences.The role of IL-10 secretion on the ability of UC-MSCs to successfully improve the symptoms of MS was confirmed by the diminished therapeutic effects associated with treatment with the IL-10 inhibitor ammonium trichloro(dioxoethylene-o,o′)tellurate(AS101).CONCLUSION Prophylactic transplantation of UC-MSCs can alleviate the clinical symptoms of MS in mice,particularly at 3-5 d after preventive transplantation.The mechanism for UC-MSCs to reduce the sensitivity of vestibular cortex imbalance may be the secretion of IL-10.The next step is to demonstrate the possibility of curing MS in the vestibular environment by intermittent transplantation of MSCs.Above all,MSCs are expected to become a new method for the clinical prevention and treatment of MS.

Intratracheal administration of umbilical cord-derived mesenchymal stem cells attenuates hyperoxia-induced multi-organ injury via heme oxygenase-1 and JAK/STAT pathways

BACKGROUND Bronchopulmonary dysplasia(BPD)is not merely a chronic lung disease,but a systemic condition with multiple organs implications predominantly associated with hyperoxia exposure.Despite advances in current management strategies,limited progress has been made in reducing the BPD-related systemic damage.Meanwhile,although the protective effects of human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)or their exosomes on hyperoxia-induced lung injury have been explored by many researchers,the underlying mechanism has not been addressed in detail,and few studies have focused on the therapeutic effect on systemic multiple organ injury.AIM To investigate whether hUC-MSC intratracheal administration could attenuate hyperoxia-induced lung,heart,and kidney injuries and the underlying regulatory mechanisms.METHODS Neonatal rats were exposed to hyperoxia(80%O_(2)),treated with hUC-MSCs intratracheal(iT)or intraperitoneal(iP)on postnatal day 7,and harvested on postnatal day 21.The tissue sections of the lung,heart,and kidney were analyzed morphometrically.Protein contents of the bronchoalveolar lavage fluid(BALF),myeloper oxidase(MPO)expression,and malondialdehyde(MDA)levels were examined.Pulmonary inflammatory cytokines were measured via enzyme-linked immunosorbent assay.A comparative transcriptomic analysis of differentially expressed genes(DEGs)in lung tissue was conducted via RNA-sequencing.Subsequently,we performed reverse transcription-quantitative polymerase chain reaction and western blot analysis to explore the expression of target mRNA and proteins related to inflammatory and oxidative responses.RESULTS iT hUC-MSCs administration improved pulmonary alveolarization and angiogenesis(P<0.01,P<0.01,P<0.001,and P<0.05 for mean linear intercept,septal counts,vascular medial thickness index,and microvessel density respectively).Meanwhile,treatment with hUC-MSCs iT ameliorated right ventricular hypertrophy(for Fulton’s index,P<0.01),and relieved reduced nephrogenic zone width(P<0.01)and glomerular diameter(P<0.001)in kidneys.Among the beneficial effects,a reduction of BALF protein,MPO,and MDA was observed in hUC-MSCs groups(P<0.01,P<0.001,and P<0.05 respectively).Increased pro-inflammatory cytokines tumor necrosis factor-alpha,interleukin(IL)-1β,and IL-6 expression observed in the hyperoxia group were significantly attenuated by hUC-MSCs administration(P<0.01,P<0.001,and P<0.05 respectively).In addition,we observed an increase in anti-inflammatory cytokine IL-10 expression in rats that received hUC-MSCs iT compared with rats reared in hyperoxia(P<0.05).Transcriptomic analysis showed that the DEGs in lung tissues induced by hyperoxia were enriched in pathways related to inflammatory responses,epithelial cell proliferation,and vasculature development.hUC-MSCs administration blunted these hyperoxia-induced dysregulated genes and resulted in a shift in the gene expression pattern toward the normoxia group.hUC-MSCs increased heme oxygenase-1(HO-1),JAK2,and STAT3 expression,and their phosphorylation in the lung,heart,and kidney(P<0.05).Remarkably,no significant difference was observed between the iT and iP administration.CONCLUSION iT hUC-MSCs administration ameliorates hyperoxia-induced lung,heart,and kidney injuries by activating HO-1 expression and JAK/STAT signaling.The therapeutic benefits of local iT and iP administration are equivalent.

Learning Rat-Like Behavior for a Small-Scale Biomimetic Robot

Existing biomimetic robots can perform some basic rat-like movement primitives(MPs)and simple behavior with stiff combinations of these MPs.To mimic typical rat behavior with high similarity,we propose parameterizing the behavior using a probabilistic model and movement characteristics.First,an analysis of fifteen 10 min video sequences revealed that an actual rat has six typical behaviors in the open field,and each kind of behavior contains different bio-inspired combinations of eight MPs.We used the softmax classifier to obtain the behavior-movement hierarchical probability model.Secondly,we specified the MPs using movement parameters that are static and dynamic.We obtained the predominant values of the static and dynamic movement parameters using hierarchical clustering and fuzzy C-means clustering,respectively.These predominant parameters were used for fitting the rat spinal joint trajectory using a second-order Fourier series,and the joint trajectory was generalized using a back propagation neural network with two hidden layers.Finally,the hierarchical probability model and the generalized joint trajectory were mapped to the robot as control policy and commands,respectively.We implemented the six typical behaviors on the robot,and the results show high similarity when compared with the behaviors of actual rats.

Simplified algorithm for genetic subtyping in diffuse large B-cell lymphoma

Genetic classification helps to disclose molecular heterogeneity and therapeutic implications in diffuse large B-cell lymphoma(DLBCL).Using whole exome/genome sequencing,RNA-sequencing,and fluorescence in situ hybridization in 337 newly diagnosed DLBCL patients,we established a simplified 38-gene algorithm(termed‘LymphPlex’)based on the information on mutations of 35 genes and rearrangements of three genes(BCL2,BCL6,and MYC),identifying seven distinct genetic subtypes:TP53Mut(TP53 mutations),MCD-like(MYD88,CD79B,PIM1,MPEG1,BTG1,TBL1XR1,PRDM1,IRF4 mutations),BN2-like(BCL6 fusion,NOTCH2,CD70,DTX1,BTG2,TNFAIP3,CCND3 mutations),N1-like(NOTCH1 mutations),EZB-like(BCL2 fusion,EZH2,TNFRSF14,KMT2D,B2M,FAS,CREBBP,ARID1A,EP300,CIITA,STAT6,GNA13 mutations,with or without MYC rearrangement),and ST2-like(SGK1,TET2,SOCS1,DDX3X,ZFP36L1,DUSP2,STAT3,IRF8 mutations).Extended validation of 1001 DLBCL patients revealed clinical relevance and biological signature of each genetic subtype.TP53Mut subtype showed poor prognosis,characterized by p53 signaling dysregulation,immune deficiency,and PI3K activation.MCD-like subtype was associated with poor prognosis,activated B-cell(ABC)origin,BCL2/MYC double-expression,and NF-κB activation.BN2-like subtype showed favorable outcome within ABC-DLBCL and featured with NF-κB activation.N1-like and EZB-like subtypes were predominated by ABC-DLBCL and germinal center B-cell(GCB)-DLBCL,respectively.EZB-like-MYC+subtype was characterized by an immunosuppressive tumor microenvironment,while EZB-like-MYC-subtype by NOTCH activation.ST2-like subtype showed favorable outcome within GCB-DLBCL and featured with stromal-1 modulation.Genetic subtype-guided targeted agents achieved encouraging clinical response when combined with immunochemotherapy.Collectively,LymphPlex provided high efficacy and feasibility,representing a step forward to the mechanism-based targeted therapy in DLBCL.

Positron emission tomography-adapted therapy in low-risk diffuse large B-cell lymphoma:results of a randomized,phase Ⅲ,non-inferiority trial

Background:The current standard of care for non-bulky diffuse large B-cell lymphoma(DLBCL)patients with an International Prognostic Index(IPI)of 0 is four cycles of rituximab plus cyclophosphamide,doxorubicin,vincristine and prednisone(R-CHOP)but whether the same efficacy can be achieved with reduced chemotherapy regimen of four cycles for non-bulky DLBCL patients with an IPI of 1 remains unclear.This study compared four cycles versus six cycles of chemotherapy in non-bulky low-risk DLBCL patients with negative interim positron emission tomography with computed tomography(PET-CT,Deauville 1-3),irrespective of age and other IPI risk factors(IPI 0-1).Methods:This was an open-label,randomized,phaseⅢ,non-inferiority trial.Patients aged 14-75 years with newly diagnosed low-risk DLBCL,according to IPI,achieving PET-CT confirmed complete response(CR)after four cycles of R-CHOPwere randomized(1:1)between four cycles of rituximab(4R-CHOP+4R arm)or two cycles of R-CHOP plus two cycles of rituximab(6R-CHOP+2R arm).The primary endpoint was 2-year progression-free survival(PFS),conducted in the intention-to-treat population.Safety was assessed in patients with at least one cycle of assigned treatment.The non-inferiority margin was-8%.Results:A total of 287 patients were included in the intention-to-treat analysis,the median follow-up was 47.3 months,and the 2-year PFS rate was 95%(95%confidence interval[CI],92%to 99%)and 94%(95%CI,91%to 98%)for the 4R-CHOP+4R and 6R-CHOP+2R arm.The absolute difference in 2-year PFS between the two arms was 1%(95%CI,-5%to 7%),supporting the non-inferiority of 4R-CHOP+4R.Grade 3-4 neutropenia was lower in the last four cycles of rituximab alone in the 4R-CHOP+4R arm(16.7%versus 76.9%),with decreased risk of febrile neutropenia(0.0%versus 8.4%)and infection(2.1%versus 14.0%).Conclusions:For newly diagnosed low-risk DLBCL patients,interim PET-CT after four cycles of R-CHOP was effective in identifying patients with Deauville 1-3 who would have a good response and Deauville 4-5 patients who might have high-risk biological features or develop resistance.Reducing the standard six cycles to four cycles of chemotherapy had comparable clinical efficacy and fewer adverse events in low-risk,non-bulky DLBCL with interim PET-CT confirmed CR.

虚拟现实赋能未来教师培养:逻辑、场景与重塑

未来教师培养需要新范式赋能。虚拟现实为教师提供了“沉浸”“反思”“近迁移”的学习情境,为未来教师能力培养提供了新视角。本文阐释了虚拟现实促进未来教师培养的内在逻辑,从提升反思与移情能力、增强教学适应性、培养课堂管理能力以及促进教学互动等场景,描绘虚拟现实促进教师能力提升的进展;聚焦以学习者为中心的系统设计,从整体性设计框架、适应性干预方式、移情机制和职前教师整合示范体系等方面展开分析。虚拟现实赋能未来教师培养,需超越个别案例有效性的探索,使其在更广范围内体现适应性,着力构建沉浸式具身交互场景,促进教师在行动中认识以及在实践中反思,以实现对新教学样态的精熟掌握。自适应技术为虚拟环境中的个性化干预提供了新思路,有潜力成为支撑未来教师能力发展的创新数字底座。

Advances in targeted therapy for malignant lymphoma

The incidence of lymphoma has gradually increased over previous decades,and it ranks among the ten most prevalent cancers worldwide.With the development of targeted therapeutic strategies,though a subset of lymphoma patients has become curable,the treatment of refractory and relapsed diseases remains challenging.Many efforts have been made to explore new targets and to develop corresponding therapies.In addition to novel antibodies targeting surface antigens and small molecular inhibitors targeting oncogenic signaling pathways and tumor suppressors,immune checkpoint inhibitors and chimeric antigen receptor T-cells have been rapidly developed to target the tumor microenvironment.Although these targeted agents have shown great success in treating lymphoma patients,adverse events should be noted.The selection of the most suitable candidates,optimal dosage,and effective combinations warrant further investigation.In this review,we systematically outlined the advances in targeted therapy for malignant lymphoma,providing a clinical rationale for mechanism-based lymphoma treatment in the era of precision medicine.

Aryl C–H iodination: are there actual flavin-dependent iodinases in nature?

Flavin-dependent halogenases (FDHs) are well known to introduce carbon halide bonds (mainly C–Cl and C–Br) into natural products with the assistance of a partner protein flavin reductase to generate reduced flavin (FADH_(2)or FMNH_(2)).Compared with the common chloride-and bromide-containing natural products (approximately 5,000 compounds),iodinated natural products(approximately 100 compounds) are very limited.Specific iodinases have also rarely been identified in nature to date.This study discovered a novel relationship between iodination and flavin reductases for the first time.Through mechanistic studies,it was identified that peroxide (H_(2)O_(2)) was released from the uncoupling reaction of flavin reductases and then reacted with iodide ions(I^(-)) to produce hypoiodous acid (IOH) for the final iodination.Furthermore,this study also unintentionally verified that the recently reported flavin-dependent iodinase Vir X1 from the marine virus and its two homologs (MBG and NCV) did not catalyze iodination in the in vitro biochemical system but likely belonged to a new phylogenetic clade in the tryptophan halogenase superfamily.As a consequence,actual flavin-dependent iodinases in nature remain to be discovered by the scientific community in the future.

Terahertz superconducting kinetic inductance detectors demonstrating photon-noise-limited performance and intrinsic generation-recombination noise

The development of large-format detector arrays with background-limited performance is of particular interest at the terahertz(THz) band, which is a unique band in search of our cosmic origins. With high sensitivity and being more promising in the pixel number and multiplexing technology, superconducting kinetic inductance detectors(KID) are emerging as a major choice of detectors of this type. Here we fabricate three-THz-band(0.35/0.85/1.4 THz) KIDs on a single chip from a 120-nm-thick aluminum(Al) superconducting film and measure photon-noise-limited performance and intrinsic generation-recombination noise at high(>1 p W) and low(<1 f W) optical radiation power, respectively. Their responses to blackbody(optical) radiation are proven to be purely from photons compared with the responses of two dark KIDs intentionally arranged on the same detector chip. The lowest optical noise equivalent power(NEP) reaches 6×10^(-18)W/Hz^(0.5)and the optical coupling efficiency is in the range of 49%-56% for the three KIDs, which are in good agreement with the simulation results.

Accurate modulation of photoprinting under stiffness imaging feedback for engineering ECMs with high-fidelity mechanical properties

Engineered extracellular matrices(ECMs)that replicate complex in-vivo features have shown great potential in tissue engineering.Biocompatible hydrogel microstructures have been widely used to replace these native ECMs for physiologically relevant research.However,accurate reproduction of the 3D hierarchical and nonuniform mechanical stffness inside one integrated microstructure to mimic the complex mechanical properties of native ECMs presents a major challenge.Here,by using digital holographic microscopy(DHM)-based stffness imaging feedback,we propose a novel closed-loop control algorithm to achieve high-accuracy control of mechanical properties for hydrogel microstructures that recapitulate the physiological properties of native ECMs with high fidelity.During photoprinting,the photocuring area of the hydrogel is divided into microscale grid areas to locally control the photocuring process.With the assistance of a motorized microfluidic channel,the curing thickness is controlled with layer-by-layer stacking.The DHM-based stiffness imaging feedback allows accurate adjustment of the photocuring degree in every grid area to change the crosslinking network density of the hydrogel,thus enabling large-span and high-resolution modulation of mechanical properties.Finally,the gelatin methacrylate was used as a typical biomaterial to construct the highfidelity biomimetic ECMs.The Young's modulus could be flexibly modulated in the 10 kPa to 50 kPa range.Additionally,the modulus gradient was accurately controlled to within 2.9 kPa.By engineering ECM with locally different mechanical properties,cell spreading along the stff areas was observed successfully.We believe that this method can regenerate complex biomimetic ECMs that closely recapitulate in-vivo mechanical properties for further applications in tissue engineering and biomedical research.

Liquidity Shock,Credit Constraint and the Development of Private vs.State-Owned Enterprises

Based on firm level data for the period of 1998-2007,this paper attempts to explain the growth differences between private enterprises and state-owned enterprises(SOEs)in China,in the context of liquidity shocks,and institutional and financial environments.It is found that(1)when liquidity tightens,the private enterprises face stricter credit constraints than SOEs,which restricts the development of private enterprise;(2)when liquidity becomes abundant,private enterprises face fewer financial limitations and grow much faster than SOEs;(3)the effect of liquidity shocks on the growth rate gap between private enterprises and SOEs has weakened during the period 2002-2007.These findings reveal that the credit discrimination against private enterprises can be mitigated by improving institutional and financial environments,which weaken the effects of liquidity shocks on firm growth.

Comparative Analysis of CT Virtual Autopsy and Traditional Autopsy:A report of 3 Cases

The objective of the study is to compare the results of virtual autopsy and traditional autopsy and then to analyze the advantages and disadvantages of them.three cases with postmortem computed tomography(CT)examination and autopsy were selected.The CT images were sent to radiologists for interpretation and were compared with autopsy results.In the cases of death in traffic accidents,the two examination conclusions are relatively consistent;in the cases of sudden cardiac death,the information provided by virtual autopsy is limited;virtual autopsy has more strength on showing some lesions such as pneumatosis and fracture.Virtual autopsy has high application value in traffic accident cases,while its application in some sudden death cases remains to be improved.

POMDP-Based Real-Time Path Planning for Manipulation of Multiple Microparticles via Optoelectronic Tweezers

With high throughput and high flexibility,optoelectronic tweerers(OETs)hold huge potential for massively parallel micromanipulation.However,the trajectory of the virtual electrode has been planned in advance in most synchronous manipulations for multiple targets based on an optically induced dielectrophoresis(ODEP)mechanism,which is insuficient to ensure the stability and eficiency in an environment with potential collision risk.In this paper,a synchronously discretized manipulation method based on a centralized and decoupled path planner is proposed for transporting microparticles of diferent types with an OET platform.An approach based on the K uhn-Munkres algorithm is utilized to achieve the goal assignment between target microparticles and goal positions.With the assistance of a visual feedback module,a path planning approach based on the POMDP algorithm dynamically determines the motion strategies of the particle movement to avoid potential collisions.The geometrical parameters of the virtual electrodes are optimized for different types of particles with the goal of maximum transport speed.The experiments of micropatterning with different morphologies and transporting multiple micropartides(e.g,polystyrene microspheres and 3T3 cells)to goal positions are performed.These results demonstrate that the proposed manipulation method based on optoelectronic tweezers is effective for multicell transport and promises to be used in biomedical manipulation tasks with high flexibility and efficiency.