可用于环境修复的半导体光催化剂及其改性策略研究进展

多相光催化技术作为一种直接利用太阳光降解多种污染物的先进氧化工艺在环境修复领域的研究中引起了广泛关注.在多相光催化过程中,半导体材料在太阳光的激发下,其强大的氧化/还原能力可快速高效降解各种污染物.研究者通常根据环境中污染物的状态和种类选择合适的半导体材料及修饰策略,构建高效多相光催化体系,探究光催化材料在环境修复中的应用.多相光催化技术在环境修复方面的应用已取得了较大进展,但由于自然环境中污染物种类越来越多样和复杂,多相光催化技术尚未实现大规模的应用.此外,光催化过程中光生电子空穴的分离和转移效率、半导体材料寿命和成本等因素也制约其实际应用.因此,仍需要通过合适的修饰策略制备高催化活性、高稳定性且价格低廉的光催化材料,并借助DFT计算和原位表征等技术更深入地研究和理解多相光催化过程和机理,从而实现环境目标污染物的快速降解.本文首先介绍了环境修复中半导体多相光催化的基本原理,光催化过程中活性氧物种(ROS)的种类及其作用机制,以及潜在环境污染物和环境光催化面临的挑战.其次,系统地讨论了应用于环境修复中的多相光催化半导体材料(如:金属氧化物、银基、铋系、无金属和有机聚合物、金属有机骨架、金属硫化物、Mxenes基和双金属氢氧化物基半导体等)以及半导体修饰策略(如:异质结工程、缺陷工程、助催化剂体系、元素掺杂工程、金属磷化等).最后,总结了多相光催化技术在环境修复中的应用进展,并对多相光催化在环境修复领域的未来发展方向进行了展望.

Weekly albumin-bound paclitaxel/cisplatin versus gemcitabine/cisplatin as first-line therapy for patients with advanced non-small-cell lung cancer:A phase II open-label clinical study

Objective: The aim of this trial was to compare both the efficacy and the safety of a weekly nanoparticle albumin-bound paclitaxel(nab-paclitaxel) plus cisplatin vs. gemcitabine plus cisplatin in patients with advanced non-small-cell lung cancer(NSCLC).Methods: A total of 84 participants received either 100 mg/m^2 nab-paclitaxel each week on d 1, 8 and 15 of a 28 day cycle, as well as cisplatin 75 mg/m^2 on d 1 every three weeks(nab-TP arm); or gemcitabine 1,000 mg/m^2 on d 1 and 8, plus cisplatin 75 mg/m^2 on d 1 every three weeks(GP arm). The primary end point was progression-free survival(PFS). The secondary end points were overall response rate(ORR) and overall survival(OS).Results: According to our analysis, the median PFS was 4.8 months for the nab-TP arm vs. 5.2 months for the GP arm(P=0.55). Analysis showed the median OS was 14.6 months for participants who were in the nab-TP arm vs. 15.1 months for those in the GP arm(P=0.94). Besides, nab-TP showed OS advantages over GP in patients harboring epidermal growth factor receptor(EGFR) mutation(26.7 vs. 15.3 months, P=0.046) and patients with a performance status of 0(23.5 vs. 14.7 months, P=0.020). It was found that incidences of drug-related grade 3 or 4 toxicities were comparable between the two treatment arms.Conclusions: Therefore, it can be seen that weekly nab-TP treatment has a similar efficacy and tolerability to GP treatment for patients who are undergoing their first-line treatment for NSCLC. It could be that survival differences among platinum doublets in the context of both EGFR mutation and performance status have the potential to be the basis for our further clinical trials.

Typical Circulation Patterns and Associated Mechanisms for Persistent Heavy Rainfall Events over Yangtze–Huaihe River Valley during 1981–2020

Persistent heavy rainfall events(PHREs)over the Yangtze–Huaihe River Valley(YHRV)during 1981–2020 are classified into three types(type-A,type-B and type-C)according to pattern correlation.The characteristics of the synoptic systems for the PHREs and their possible development mechanisms are investigated.The anomalous cyclonic disturbance over the southern part of the YHRV during type-A events is primarily maintained and intensified by the propagation of Rossby wave energy originating from the northeast Atlantic in the mid–upper troposphere and the northward propagation of Rossby wave packets from the western Pacific in the mid–lower troposphere.The zonal propagation of Rossby wave packets and the northward propagation of Rossby wave packets during type-B events are more coherent than those for type-A events,which induces eastward propagation of stronger anomaly centers of geopotential height from the northeast Atlantic Ocean to the YHRV and a meridional anomaly in geopotential height over the Asian continent.Type-C events have“two ridges and one trough”in the high latitudes of the Eurasian continent,but the anomalous intensity of the western Pacific subtropical high(WPSH)and the trough of the YHRV region are weaker than those for type-A and type-B events.The composite synoptic circulation of four PHREs in 2020 is basically consistent with that of the corresponding PHRE type.The location of the South Asian high(SAH)in three of the PHREs in 2020 moves eastward as in the composite of the three types,but the position of the WPSH of the four PHREs is clearly westward and northward.Two water vapor conveyor belts and two cold air conveyor belts are tracked during the four PHREs in 2020,but the water vapor path from the western Pacific is not seen,which may be caused by the westward extension of the WPSH.

Nano Ag-enhanced photoelectric conversion efficiency in all-inorganic,hole-transporting-layer-free CsPbIBr_(2) perovskite solar cells

All-inorganic,hole-transporting-layer-free CsPbIBr_(2)perovskite solar cells have great potential for development,but their device performance needs to be further improved.Recently,metal nanostructures have been successfully applied in the field of solar cells to improve their performance.Nano Ag-enhanced power conversion efficiency(PCE)in one CsPbIBr_(2)perovskite solar cell utilizing localized surface plasmons of Ag nanoparticles(NPs)on the surface has been researched experimentally and by simulation in this paper.The localized surface plasmon resonance of Ag NPs has a near-field enhancement effect,which is expected to improve the light absorption of CsPbIBr_(2)perovskite photovoltaic devices.In addition,Ag NPs have a forward-scattering effect on the incident light,which can also improve the performance of CsPbIBr_(2)-based perovskite photovoltaic devices.By directly assembling Ag NPs(with a size of about 150 nm)on the surface of fluorine-doped tin oxide it is found when the particle surface coverage is 10%,the CsPbIBr_(2)perovskite photovoltaic device achieves a best PCE of 2.7%,which is 9.76%higher than that of the control group.Without changing any existing structure in the ready-made solar cell,this facile and efficient method has huge applications.To the best of our knowledge,this paper is the first report on nano Ag-enhanced photoelectric conversion efficiency in this kind of CsPbIBr_(2)perovskite solar cell.

Analysis of Genetic Relationship among Celery Germplasms by RAPD

In this study, forty celery cultivars introduced from different regions of China were used as experimental materials to verify and analyze the practicability of RAPD technology in the identification of celery cuhivars. The results showed that RAPD technology could distinguish accurately the genetic relationship among various celery cultivars as a simple and ideal DNA molecular marker technology suitable for genetic relationship analysis. To be specific, 13 RAPD primers with clear amplified bands and significantly different number of amplified bands were screened, which provided basis for the identification of genetic relationship among different celery cultivars.

自动驾驶开源数据体系:现状与未来

随着自动驾驶技术的不断成熟与应用,系统性梳理开源自动驾驶数据集有利于产业生态良性循环.现有自动驾驶数据集可大致分为两代,第一代数据集的传感模态复杂度相对较低、数据集规模相对较小,且大多局限于感知级任务,以发布于2012年的KITTI为代表.相比于第一代数据集,第二代数据集的特征为传感模态复杂度较高、数据集规模与多样性较丰富、所设置任务从感知扩展到预测、规控上,以2019年前后提出的nuScenes,Waymo为代表.本文联合学术界、产业界同仁,首次系统性梳理了国内外70余种开源自动驾驶数据集,对如何构建高质量数据集、数据在算法闭环体系中发挥的核心作用、如何利用生成式大模型规模化生产数据等进行了总结.此外,就未来第三代自动驾驶数据集应该具备的特质和数据规模,以及需要解决的科学与技术问题,进行了详细分析与讨论.希望本文的归纳与展望能促进新一代自动驾驶数据集与生态体系的建设、推动关键领域自主原创与科技自强的发展.

Thrombin is a therapeutic target for non-small-cell lung cancer to inhibit vasculogenic mimicry formation

Tumor cells transform into endothelial cells by epithelial-to-mesenchymal transition,which is characterized by vasculogenic mimicry(VM).VM not only accelerates tumor progression but also increases drug-induced resistance.However,very little is currently known about the molecular determinants that enable VM.Targeting VM might bring a new breakthrough in cancer treatment.Thrombin is the key enzyme of the blood coagulation system and could contribute to tumor progression.Nevertheless,the association between thrombin and VM formation remains largely unknown.We found that VM was associated with the overall survival of non-small-cell lung cancer(NSCLC)patients,and that thrombin expression was closely related to VM formation.This research revealed that thrombin induced VM formation via PAR-1-mediated NF-κB signaling cascades.The novel thrombin inhibitors r-hirudin and DTIP inhibited VM formation and spontaneous metastases in subcutaneous tumors.Clinical pathological analysis confirmed that NSCLC patients with thrombin-positive/PAR-1-high expression had the poorest prognosis and were the most likely to form VM.The promotional activity of thrombin in VM formation and tumor metastasis was abolished in PAR-1-deficient NSCLC cells.The EGFR inhibitor gefitinib had no effect on VM and increased VEGF expression in tumors.The combination therapy of DTIP and gefitinib achieved a better therapeutic effect than either agent alone.This study is the first to illustrate that thrombin substantially contributes,together with PAR-1,to VM formation and to illustrate that VM might be a target of r-hirudin and DTIP to suppress tumor progression.The anticoagulants r-hirudin and DTIP could be employed for antitumor therapy.Combination therapy with DTIP with an EGFR inhibitor might achieve superior therapeutic effects.

Advances in cost-effective integrated spectrometers

The proliferation of Internet-of-Things has promoted a wide variety of emerging applications that require compact,lightweight,and low-cost optical spectrometers.While substantial progresses have been made in the miniaturization of spectrometers,most of them are with a major focus on the technical side but tend to feature a lower technology readiness level for manufacturability.More importantly,in spite of the advancement in miniaturized spectrometers,their performance and the metrics of real-life applications have seldomly been connected but are highly important.This review paper shows the market trend for chip-scale spectrometers and analyzes the key metrics that are required to adopt miniaturized spectrometers in real-life applications.Recent progress addressing the challenges of miniaturization of spectrometers is summarized,paying a special attention to the CMOS-compatible fabrication platform that shows a clear pathway to massive production.Insights for ways forward are also presented.