类器官模型在膀胱癌中的研究进展

类器官是一种新型体外模型,能有效重现肿瘤微环境的复杂性。与传统的临床前模型相比,类器官保留了原发肿瘤的组织学和分子学特性,成为研究肿瘤异质性、功能通路和免疫微环境的重要工具,适用于生物标志物发现、药物筛选和个体化治疗。尽管类器官面临低建模成功率、高成本和缺乏标准化等问题,但生物工程技术不断创新、跨学科融合有望克服这些挑战。本文将对类器官在膀胱癌研究中的优势、建立过程和其临床应用前景与挑战进行综述。

In Situ X-ray Absorption Spectroscopy Studies of Nanoscale Electrocatalysts

Nanoscale electrocatalysts have exhibited promising activity and stability,improving the kinetics of numerous electrochemical reactions in renewable energy systems such as electrolyzers,fuel cells,and metal-air batteries.Due to the size effect,nano particles with extreme small size have high surface areas,complicated morphology,and various surface terminations,which make them different from their bulk phases and often undergo restructuring during the reactions.These restructured materials are hard to probe by conventional ex-situ characterizations,thus leaving the true reaction centers and/or active sites difficult to determine.Nowadays,in situ techniques,particularly X-ray absorption spectroscopy(XAS),have become an important tool to obtain oxidation states,electronic structure,and local bonding environments,which are critical to investigate the electrocatalysts under real reaction conditions.In this review,we go over the basic principles of XAS and highlight recent applications of in situ XAS in studies of nanoscale electrocatalysts.

Iron-Imprinted Single-Atomic Site Catalyst-Based Nanoprobe for Detection of Hydrogen Peroxide in Living Cells

Fe-based single-atomic site catalysts(SASCs),with the natural metalloproteases-like active site structure,have attracted widespread attention in biocatalysis and biosensing.Precisely,controlling the isolated single-atom Fe-N-C active site structure is crucial to improve the SASCs’performance.In this work,we use a facile ion-imprinting method(IIM)to synthesize isolated Fe-N-C single-atomic site catalysts(IIM-Fe-SASC).With this method,the ion-imprinting process can precisely control ion at the atomic level and form numerous well-defined single-atomic Fe-N-C sites.The IIM-Fe-SASC shows better peroxidase-like activities than that of non-imprinted references.Due to its excellent properties,IIM-Fe-SASC is an ideal nanoprobe used in the colorimetric biosensing of hydrogen peroxide(H_(2)O_(2)).Using IIM-Fe-SASC as the nanoprobe,in situ detection of H_(2)O_(2)generated from MDA-MB-231 cells has been successfully demonstrated with satisfactory sensitivity and specificity.This work opens a novel and easy route in designing advanced SASC and provides a sensitive tool for intracellular H_(2)O_(2)detection.

Dual-shell silicate and alumina coating for long lasting and high capacity lithium ion batteries

Here we demonstrate a theory-driven, novel dual-shell coating system of Li_(2)SrSiO_(4) and Al_(2)O_(3), achieved via a facile and scalable sol-gel technique on LiCoO_(2) electrode particles. The optimal thickness of each coating can lead to increased specific capacity(~185 m Ah/g at 0.5 C-rate) at a cut-off potential of 4.5 V, and greater cycling stability at very high C rates(up to 10 C) in half-cells with lithium metal. The mechanism of this superior performance was investigated using a combination of X-ray and electron characterization methods. It shows that the results of this investigation can inform future studies to identify still better dual-shell coating schemes, achieved by such industrially feasible techniques, for application on similar, nickel-rich cathode materials.

Deep-sea coral evidence for dissolved mercury evolution in the deep North Pacifi c Ocean over the last 700 years

The ocean is an important inventory of anthropogenic mercury(Hg),yet the history of anthropogenic Hg accumulation in the ocean remains largely unexplored.Deep-sea corals are an emerging archive of past ocean chemistry,which take in sinking or suspended particulate organic matter as their food sources.Such organic matter would exchange Hg with the local seawater before being consumed by the deepsea corals.As such,the organics preserved in the coral skeleton may record the Hg evolution of the ambient seawater during the time of coral growth.Here,we report the first data on Hg concentrations variability of a deep-sea proteinaceous coral in the oligotrophic North Pacific at the water depth of 1249 m,in attempt to understand the transfer of anthropogenic Hg into the deep Pacific ocean over the last seven centuries.We find that the Hg concentrations of different coral growth layers have remained relatively constant albeit with considerable short-term variability through time.The overall stable Hg concentration of the last seven centuries recorded in our sample suggests that anthropogenic pollution is not yet a clearly resolvable component in the deep oligotrophic North Pacific waters,in agreement with rece nt estimation from modelling works and observational studies of modern seawater profiles.As there is hardly an unambiguous way to separate anthropogenic Hg from the natural background based on recent seawater profiles,our historical data provide valuable information helping to understand the oceanic cycle of Hg through time.

Al_2O_3 coated LiCoO_2 as cathode for high-capacity and long-cycling Li-ion batteries

Lithium-ion batteries(LIBs) as energy storage devices play an important role in all aspects of our life. The increasing energy demand of the society requires LIBs with higher energy density and better performance. We here develop a new and easy-to-scaleup sol-gel method to coat a surface protection layer on commercial LiCoO2cathode. We demonstrate that a proper thickness can improve the cycling life with a higher cut-off potential(4.5 V), larger energy capacity(180 mAh/g at 0.5 C) and better energy density(35% more compared to non-coated LiCoO2). The mechanism of the protection layer is also revealed by a combination of electron microscopy and synchrotron X-ray spectroscopy.

俯冲带洋底玄武岩在晚更新世的风化与碳酸盐化

海底玄武岩风化及碳酸盐化是海洋的重要碳汇,调节了海洋和大气系统的碳循环.以往一般认为这一过程仅发生在年轻洋壳中,对俯冲带洋底玄武岩的风化和碳酸盐化几乎没有关注.本研究基于西太平洋Mussau海沟东侧崖壁的玄武岩样品,利用激光剥蚀原位铀系不平衡法对洋底玄武岩中的碳酸盐脉进行定年,发现其形成于(102±16)ka和(132±21)ka.通过矿物学、微形貌与稳定同位素手段,确认了碳酸盐脉的矿物相为方解石,并以侵染状分布于玄武岩中,无生物碳酸盐的形态,并沉淀于冷水环境中.这些证据综合表明碳酸盐脉很可能是玄武岩在海底风化,释放出碳酸氢根,局部方解石过饱和沉淀而成.该结果表明古老玄武岩在俯冲带的化学风化和碳酸盐化依然活跃,未来需进一步系统研究俯冲带的玄武岩风化通量.

Single-Atom Nanozymes Linked Immunosorbent Assay for Sensitive Detection of Aβ1-40:A Biomarker of Alzheimer’s Disease

Single-atom nanozymes(SANs)possess unique features of maximum atomic utilization and present highly assembled enzyme-like structure and remarkable enzyme-like activity.By introducing SANs into immunoassay,limitations of ELISA such as low stability of horseradish peroxidase(HRP)can be well addressed,thereby improving the performance of the immunoassays.In this work,we have developed novel Fe-N-C single-atom nanozymes(Fe-N_(x)SANs)derived from Fe-doped polypyrrole(PPy)nanotube and substituted the enzymes in ELISA kit for enhancing the detection sensitivity of amyloid beta 1-40.Results indicate that the Fe-N_(x)SANs contain high density of single-atom active sites and comparable enzyme-like properties as HRP,owing to the maximized utilization of Fe atoms and their abundant active sites,which could mimic natural metalloproteases structures.Further designed SAN-linked immunosorbent assay(SAN-LISA)demonstrates the ultralow limit of detection(LOD)of 0.88 pg/mL,much more sensitive than that of commercial ELISA(9.98 pg/mL).The results confirm that the Fe-N_(x)SANs can serve as a satisfactory replacement of enzyme labels,which show great potential as an ultrasensitive colorimetric immunoassay.

Isotopic fingerprinting of dissolved iron sources in the deep western Pacific since the late Miocene

Iron(Fe)is a productivity-limiting nutrient in the ocean.However,the sources of dissolved Fe(dFe)in the deep ocean and how they respond to tectonic and climate changes are still poorly understood.In the northern hemisphere,dust flux to the low-latitude western Pacific has increased dramatically since the late Miocene associated with intense aridification of the Asian inland.Meanwhile,the terrigenous material supply to the open ocean might have also changed as a result of the reorganization of the Pacific circulation due to the gradual closure of seaways in the low latitudes.Therefore,the western Pacific is a characteristic region for understanding the sources of dFe in the deep ocean and their responses to long term climate changes.Here,we present data on isotopic evolution of dFe and dissolved Pb since^8 Ma based on ferromanganese crust METG-03(16.0°N,152.0°E,3850 m water depth)in the western Pacific deep water.Our results show thatδ56Fe of the crust remains fairly stable since the late Miocene,i.e.,about-0.32±0.08‰(2SD).We infer thatδ56Fe of dFe in the deep western Pacific is relatively invariant at^0.45±0.1‰based on the Fe isotopic fractionation between hydrogenetic crust and the seawater dissolved component.The reconstructed isotope signature is similar to the measuredδ56Fe value(0.37±0.15‰)of the intermediate to deep waters in the modern low-latitude western Pacific region close to the island arcs,but is significantly higher than that of the eastern Pacific deep waters near South America which is controlled by the reductive dissolution of continental shelf sediments and the hydrothermal inputs(δ56Fe<-0.1‰).The deep-water 206Pb/204Pb ratio recorded by METG-03 displays systematic increase at about 8–4 Ma,reflecting increased input from sediment dissolution of low-latitude island arcs associated with reorganization of the western Pacific deep circulation.Notably,Fe isotopes of terrigenous materials from different sources are similar,while their dissolved Fe isotopic signatures released to the ocean are mainly controlled by the mechanism of particle dissolution.The stability ofδ56Fe and systematic changes in Pb isotopes over the last^8 Ma thus suggest that Asian dust dissolution and hydrothermal inputs are likely only minor sources of dFe in the low-latitude deep western Pacific,while the acquisition and transport of dFe from shelf sediments by organic ligand binding in the oxic environment is the major dFe source which keeps stable on tectonic time scales since the late Miocene.

Bioinspired Activation of N_(2) on Asymmetrical Coordinated Fe Grafted 1T MoS_(2) at Room Temperature

Main observation and conclusion Inspired by the nitrogen fixation process on MoFe nitrogenase,asymmetrical coordinated Fe grafted onto 1T MoS_(2) were successfully synthesized.The unique electron-rich structure with asymmetrical coordination made the 1T Fe_(0.1)Mo_(0.9)S_(2) layered material actively react with water and dinitrogen at room temperature and atmosphere pressure.

An on-line capacitor state identification method based on improved RLS

As an essential part of DC-Link in the power converter,capacitor plays a crucial role in absorbing ripple current and suppressing ripple voltage.The health and residual service life of the DC-Link capacitor is one of the decisive factors for the safety,stability,and efficiency of the system in which it is located.Aiming at the shortcomings of existing methods,such as low dynamic sensitivity of data update and fluctuation of identification results,a capacitor state identification method based on improved RLS is proposed in this paper.The proposed method is optimized by introducing the forgetting factor algorithm and root means square algorithm to modify the iterative formula and final identification results.Compared with existing methods,this method can identify the capacitor’s current state in real time and accurately.Finally,we successfully verified the accuracy,robustness,and adaptability of the proposed method by a series of experimental tests on a dSPACE platform.