Stability of loess high-fill slope based on monitored soil moisture changes

This paper aims to assess the influence of moisture content changes during rainfall on the stability of loess high-fill slopes by taking a loess high-fill slope in Lanzhou City as an example.First,according to the moisture content monitoring data collected from a slope online monitoring system,direct shear tests were performed on soil samples of different moisture content to determine the relationship between the shear strength parameters and moisture content.Next,a coupled hydro-mechanical model with soil shear strength related to moisture content was established and used to analyze 16 working conditions with various rainfall intensities and durations for two cases:shear strength parameters from the site exploration report and those from this study.Finally,the results from the two cases were compared regarding the changes in stresses and displacements after rainfall infiltration to analyze the influence of moisture content on the stability of loess high-fill slopes.The conclusions are as follows:(1)Segmental relationship equations of cohesion and angle of internal friction were established for loess with various moisture content.(2)Under the conditions of different rainfall intensities,significant differences were observed in the trends of slope stress and displacement changes.(3)The slope displacement occurred in the shallow soil layer within about 12.5 m from the slope top,and the plastic strain concentrated in the soil layer within about 6 m from the slope top.(4)The results of slope stability analyses based on moisture content monitoring data are more in line with the observed.

The zinc figure protein ZNF575 impairs colorectal cancer growth via promoting p53 transcription

Zinc-finger proteins play different roles in cancer;however,the function of zinc-finger protein ZNF575 in cancer remains unclear.In the present study,we aimed to determine the function and expression of ZNF575 in colorectal cancer.Proliferation assay,colony formation assay,and tumor model in mice were used to investigate the function of ZNF575 after ectopic expression of ZNF575 in colorectal cancer(CRC)cells.RNA sequencing,ChIP,and luciferase assays were used to investigate the mechanism behind ZNF575 regulation of CRC cell growth.The expression of ZNF575 was determined by IHC staining in 150 pairs of malignant CRC tissues,followed by prognosis analysis.We indicated that ectopic expression of ZNF575 inhibited CRC cell proliferation,colony formation and promoted cell apoptosis in vitro.Tumor growth in CRC was also impaired by ZNF575 in mice.RNA sequencing,follow-up western blotting,and qPCR results demonstrated the increase of p53,BAK,and PUMA in ZNF575-expressing CRC cells.Further results indicated that ZNF575 directly targeted the p53 promoter and promoted the transcription of p53.Downregulation of ZNF575 was confirmed in malignant tissues,and ZNF575 expression was positively correlated with the prognosis of CRC patients.The present study demonstrated the function,underlying mechanism,expression,and the prognosis-predicting role of ZNF575 in CRC,which indicated that ZNF575 would be a potential prognostic predictor and therapeutic target for CRC and other cancers.

Differential gene expression profiling of gastric intraepithelial neoplasia and early-stage adenocarcinoma

AIM:To investigate the differentiated whole genome expression profiling of gastric high-and low-grade intraepithelial neoplasia and early-stage adenocarcinoma.METHODS:Gastric specimens from an upper magnifying chromoendoscopic targeted biopsy were collected from March 2010 to May 2013.Whole genome expression profiling was performed on 19 low-grade intraepithelial neoplasia(LGIN),20 high-grade intraepithelial neoplasia(HGIN),19 early-stage adenocarcinoma(EGC),and 19 chronic gastritis tissue samples using Agilent 4×44K Whole Human Genome microarrays.Differentially expressed genes between different types of lesions were identified using an unpaired t-test and corrected with the Benjamini and Hochberg false discovery rate algorithm.A gene ontology(GO)enrichment analysis was performed using the Gene Spring software GX 12.6.The differentially expressed gene was verified using a real-time TaqManPCR assay with independent tissue samples,including 26 LGIN,15 HGIN,14 EGC,and 20 chronic gastritis.The expression of G0S2 were further validated by immunohistochemical staining(IHC)in 24 LGIN,40 HGIN,30 EGC and 61 chronic gastritis specimens.RESULTS:The gene expression patterns of LGIN and HGIN tissues were distinct.There were 2521 significantly differentially expressed transcripts in HGIN,with951 upregulated and 1570 downregulated.A GO enrichment analysis demonstrated that the most striking overexpressed transcripts in HGIN compared with LGIN were in the category of metabolism,defense response,and nuclear factorκB(NF-κB)cascade.While the vast majority of transcripts had barely altered expression in HGIN and EGC tissues,only 38 transcripts were upregulated in EGC.A GO enrichment analysis revealed that the alterations of the immune response were most prominent in the progression from HGIN to EGC.It is worth noting that,compared with LGIN,289 transcriptswere expressed at higher levels both in HGIN and EGC.A characteristic gene,G0/G1 switch 2(G0S2)was one of the 289 transcripts and related to metabolism,the immune response,and the NF-κB cascade,and its expression was validated in independent samples through real-time TaqManPCR and immunohistochemical staining.In real-time PCR analysis,the expression of G0S2 was elevated both in HGIN and EGC compared with that in LGIN(P<0.01 and P<0.001,respectively).In IHC analysis,G0S2 immunoreactivity was detected in the cytoplasmic of neoplastic cells,but was undetectable in chronic gastritis cells.The G0S2 expression in HGIN was higher than that of LGIN(P=0.012,χ2=6.28)and EGC(P=0.008,χ2=6.94).CONCLUSION:A clear biological distinction between gastric high-and low-grade intraepithelial neoplasia was identified,and provides molecular evidence for clinical application.

Variations of methane stable isotopic values from an Alpine peatland on the eastern Qinghai-Tibetan Plateau

Isotopic signature is a powerful tool to discriminate methane(CH_(4)) source types and constrain regional and global scale CH_(4) budgets.Peatlands on the Qinghai-Tibetan Plateau are poorly understood about the isotopic signature of CH_(4) due to the limited experimental conditions.In this study,three campaigns of diurnal air samples spacing 2-3 h were taken from an alpine peatland on the eastern Qinghai-Tibetan Plateau to investigate its source signal characteristics.Both CH_(4) concentration and its stable carbon isotope(δ^(13)C-CH_(4)) were measured to derive the carbon isotopic signature of the CH_(4) source using the Keeling plot technique.Diurnal variation patterns in CH_(4) concentration and δ^(13)C-CH_(4) were observed during summertime,with depleted δ^(13)C-CH_(4) signals and high CH_(4) concentration appearing at nighttime.The δ^(13)C-CH4 signature during summer was calculated to be-71 % ± 1.3%,which falls within the range of other wetland studies and close to high-latitude peatlands.The boundary layer dynamic and CH_(4) source were supposed to influence the measured CH_(4) concentration and δ^(13)C-CH_(4.)Further investigations of CH_(4) isotopic signals into the nongrowing season are still needed to constrain the δ^(13)C-CH_(4) signature and its environmental controls in this region.

Secure Mobile Crowdsensing Based on Deep Learning

To improve the quality of multimedia services and stimulate secure sensing in Internet of Things applications, such as healthcare and traffic monitoring, mobile crowdsensing(MCS) systems must address security threats such as jamming, spoofing and faked sensing attacks during both sensing and information exchange processes in large-scale dynamic and heterogeneous networks. In this article, we investigate secure mobile crowdsensing and present ways to use deep learning(DL) methods, such as stacked autoencoder, deep neural networks, convolutional neural networks, and deep reinforcement learning, to improve approaches to MCS security, including authentication, privacy protection, faked sensing countermeasures, intrusion detection and anti-jamming transmissions in MCS. We discuss the performance gain of these DLbased approaches compared to traditional security schemes and identify the challenges that must be addressed to implement these approaches in practical MCS systems.

Correction to:Variations of methane stable isotopic values from an Alpine peatland on the eastern Qinghai-Tibetan Plateau

Correction to:Acta Geochim https://doi.org/10.1007/S11631-021-00477-Z The article“Variations of methane stable isotopic values from an Alpine peatland on the eastern Qinghai-Tibetan Plaleau"written by Qian Guo,Haijun Peng,Bing Hong,Hu Yao,Yongxuan Zhu,Hanwei Ding,Ning An,Yetang Hong was originally published electronically on the publisher's internet portal(currently SpringerLink)on 3 June 2021.There were some errors in the published article which should be corrected.The authors apologize for these errors and any confusion caused.

Compact broadband high-resolution Compton spectroscopy for laser-driven high-flux gamma rays

A compact broadband Compton spectrometer with high spectral resolution has been designed to detect spectra of laser-driven high-flux gamma rays.The primary detection range of the gamma-ray spectrum is 0.5 MeV–13 MeV,although a secondary harder gamma-ray region of 13 MeV–30MeV can also be covered.The Compton-scattered electrons are spectrally resolved using a curved surface detector and a nonuniform magnetic field produced by a pair of step-like magnets.This design allows a compact structure,a wider bandwidth,especially in the lower-energy region of 0.5 MeV–2 MeV,and optimum spectral resolution.The spectral resolution is 5%–10%in the range 4 MeV–13 MeV and better than 25%in the range 0.5MeV–4MeV(with an Al converter of 0.25mmthickness and a collimator of 1 cm inner diameter).Low-Z plastic materials are used on the inner surface of the spectrometer to suppress noise due to secondary X-ray fluorescence.The spectrometer can be adjusted flexibly via a specially designed mechanical component.An algorithmbased on a regularizationmethod has also been developed to reconstruct the gamma-ray spectrum from the scattered electrons.

Deployment analysis of composite thin-walled lenticular tubes with effect of storage time and temperature

Composite Thin-walled Lenticular Tube(CTLT)is increasingly utilized in small satellites missions as a lightweight,foldable,and rollable structural material that facilitates the construction of large deployable systems.The CTLT is initially flattened and coiled around a central hub for storage before launch,during which elastic energy is stored as deformation energy,allowing it to be self-deployed on demand for use in orbit.This work presents a comprehensive investigation into the coiling,storage and deployment behaviors of CTLT that wraps around a central hub.A nonlinear explicit dynamic finite element model was developed with both deformable CTLT and rigidbodies mechanisms including the central hub and guide rollers,as well as the complex interactions among them.The coiling mechanics characteristics such as stored strain energy and rotational moment were presented and validated against experimental data in the literature.Then,the dynamic deployment behaviors were analyzed in terms of two different deployment methods,namely,controlled deployment and free deployment.The effect of material property change during storage was also discussed through numerical experiments.

与粉煤灰耦合增强碳掺杂TiO_2的可见光催化氧化能力（英文）

半导体光催化技术是利用太阳能消除有机污染物的最佳解决方案之一.二氧化钛(TiO_2)是在该领域应用最广泛的光催化剂,具有无毒、廉价、抗光致腐蚀等优异性能.然而,纯TiO_2在可见光下的光催化活性较差,这限制了TiO_2光催化技术的进一步发展和实际应用.对此,学者们进行了多方面研究来拓展TiO_2对可见光的吸收范围并提升其光催化活性.研究表明,对TiO_2进行碳掺杂是拓展其光吸收范围和增强其可见光催化活性的有效方法.粉煤灰是燃煤电厂原煤燃烧产生的一种固体废物.粉煤灰的随意堆积和不适当处置可导致土壤、空气、水甚至生态系统的严重污染.因此,粉煤灰的回收利用引起了许多研究者的关注.事实上,粉煤灰有其自身独特的优点,如无毒、低成本和化学/物理稳定性等.这些性质使得粉煤灰可以作为一种很有前景的催化剂载体材料.最近,很多学者以粉煤灰为载体合成了多种TiO_2/粉煤灰复合光催化剂,并对所制备催化剂的结构、性质及其光催化性能进行了研究.但是,将碳掺杂TiO_2与粉煤灰进行耦合的研究一直未见报道,而且关于粉煤灰载体对TiO_2光催化活性的促进机理,特别是粉煤灰负载对TiO_2能带结构及其光催化活性的影响仍缺乏深入和系统的研究.本文采用简单的溶胶浸渍+炭化的方法制备了碳掺杂TiO_2/粉煤灰载体(C-TiO_2/FAS)复合光催化剂.其中的碳掺杂组分源于合成过程中加入的有机成分(钛酸四丁酯、乙酸和乙醇),在负载及炭化过程中这些有机组分同步进入TiO_2体相及表面形成碳掺杂.采用多种表征方法对所制备的光催化剂进行了表征. XRD, SEM和XPS表征结果表明, C-TiO_2组分很好地包覆在粉煤灰球形颗粒表面.XPS和ATR-FTIR表征结果表明,随着C-TiO_2与FAS的耦合,C-TiO_2表面原有的羧基螯合结构被破坏,并在其界面上形成了Si–O–C和Al–O–Ti键.UV-VisDRS和VB-XPS表征结果表明,碳掺杂缩减了TiO_2的禁带宽度,显著拓展了光吸收范围.Si–O–C和Al–O–Ti键的存在引起了C-TiO_2价带边的正向移动,意味着光生空穴氧化能力增强.稳态PL及时间分辨PL表征结果表明, C-TiO_2/FAS光生载流子的复合率较低.在可见光催化活性测试中, C-TiO_2/FAS对甲基橙展示出较高的光催化降解效率,这主要是由于C-TiO_2/FAS较低的价带位置增强了光生空穴的氧化能力,进而提高了催化剂对甲基橙的降解效率.自由基捕获实验结果表明,在降解过程中光生空穴及超氧自由基是关键活性物种.此外,C-TiO_2/FAS可以很方便地通过自然沉降进行固液分离,并表现出很好的重复利用降解活性.

单细胞转录组测序在年龄相关性黄斑变性研究中的应用

年龄相关性黄斑变性(ARMD)是临床中常见的老年性致盲性眼病,可造成中心视力的不可逆丧失,其发病机制复杂,尚未阐明,治疗方法有限,诊疗效果不佳。传统的转录组测序方法基于细胞群体水平获得细胞群的平均差异,或反映数量占优势细胞的生物信息,而单细胞转录组测序(scRNA-seq)能对单个细胞的mRNA进行转录组分析,可用于发现新的细胞亚型、揭示细胞异质性、鉴定罕见细胞、理解细胞分化。本文简述了scRNA-seq的技术原理,及其在视网膜、脉络膜发育及ARMD研究中的应用,提出了该项技术的缺陷和新兴技术的发展趋势,为深入研究视网膜、脉络膜生理学、ARMD疾病病理生理学及其发病机制提供新的思路及视角,以期对ARMD的靶向治疗提供理论依据。

Recent progress on the recycling technology of Li-ion batteries

Lithium-ion batteries(LIBs)have been widely applied in portable electronic devices and electric vehicles.With the booming of the respective markets,a huge quantity of spent LIBs that typically use either LiFePO_(4) or Li N_(x)Co_(y)Mn_(z)O_(2) cathode materials will be produced in the very near future,imposing significant pressure for the development of suitable disposal/recycling technologies,in terms of both environmental protection and resource reclaiming.In this review,we firstly do a comprehensive summary of the-state-of-art technologies to recycle Li N_(x)Co_(y)Mn_(z)O_(2) and LiFePO_(4)-based LIBs,in the aspects of pretreatment,hydrometallurgical recycling,and direct regeneration of the cathode materials.This closed-loop strategy for cycling cathode materials has been regarded as an ideal approach considering its economic benefit and environmental friendliness.Afterward,as for the exhausted anode materials,we focus on the utilization of exhausted anode materials to obtain other functional materials,such as graphene.Finally,the existing challenges in recycling the LiFePO_(4) and Li N_(x)Co_(y)Mn_(z)O_(2) cathodes and graphite anodes for industrial-scale application are discussed in detail;and the possible strategies for these issues are proposed.We expect this review can provide a roadmap towards better technologies for recycling LIBs,shed light on the future development of novel battery recycling technologies to promote the environmental benignity and economic viability of the battery industry and pave way for the large-scale application of LIBs in industrial fields in the near future.

Climatology of Cloud-base Height from Long-term Radiosonde Measurements in China

Clouds are critical to the global radiation budget and hydrological cycle, but knowledge is still poor concerning the observed climatology of cloud-base height （CBH） in China. Based on fine-resolution sounding observations from the China Radiosonde Network （CRN）, the method used to estimate CBH was modified, and uncertainty analyses indicated that the CBH is good enough. The accuracy of CBH estimation is verified by the comparison between the sounding-derived CBHs and those estimated from the micro-pulse lidar and millimeter-wave cloud radar. As such, the CBH climatology was compiled for the period 2006-16. Overall, the CBH exhibits large geographic variability across China, at both 0800 Local Standard Time （LST） and 2000 LST, irrespective of season. In addition, the summertime cloud base tends to be elevated to higher altitudes in dry regions [i.e., Inner Mongolia and the North China Plain （NCP）]. By comparison, the Tibetan Plateau （TP）, Pearl River Delta （PRD） and Sichuan Basin （SCB） have relatively low CBHs （〈 2.4 km above ground level）. In terms of seasonality, the CBH reaches its maximum in summer and minimum in winter. A low cloud base tends to occur frequently （〉 70%） over the TP, PRD and SCB. In contrast, at most sites over the Yangtze River Delta （YRD） and the NCP, about half the cloud belongs to the high-cloud category. The CBH does not exhibit marked diurnal variation in summer, throughout all CRN sites, probably due to the persistent cloud coverage caused by the East Asia Summer Monsson. To the best of our knowledge, this is the first CBH climatology produced from sounding measurements in China, and provides a useful reference for obtaining observational cloud base information.

腓骨头上入路胫骨平台截骨联合外侧锁定钢板手术治疗胫骨平台骨折疗效研究

目的 探究腓骨头上入路胫骨平台截骨联合外侧锁定钢板手术对胫骨平台骨折患者膝关节功能及预后的影响,为临床选择治疗方案提供参考依据.方法 选择2016年4月至2019年5月在西安武警工程大学医院治疗的胫骨平台骨折患者48例为研究对象,按照随机数表法将患者分为对照组和观察组,每组24例.对照组仅使用传统手术治疗,观察组使用腓骨头上入路胫骨平台截骨联合外侧锁定钢板手术治疗.随访6个月,比较两组患者的膝关节功能恢复及预后情况.结果 6个月后,观察组患者的治疗总有效率为91.67%,明显优于对照组的75.00%,差异有统计学意义(P<0.05);6个月后,Rasmussen评分显示,观察组患者的膝关节功能优良率为83.33%,明显高于对照组的66.67%,差异有统计学意义(P<0.05);治疗前,两组患者膝关节功能HSS评分比较差异无统计学意义(P>0.05),6个月后,观察组患者的膝关节功能HSS评分为(91.03±10.72)分,明显高于对照组的(66.89±10.46)分,差异有统计学意义(P<0.05);观察组患者的骨折愈合率为91.67%,明显高于对照组的58.33%,差异有统计学意义(P<0.05).结论 腓骨头上入路胫骨平台截骨联合外侧锁定钢板手术治疗胫骨平台骨折,患者膝关节功能恢复效果明显,骨折愈合效果及预后效果良好,值得临床推广.

鄱阳县新报告晚期日本血吸虫病的时空分布特征分析

目的分析鄱阳县新报告晚期血吸虫病(晚血)病例的时空分布特征及规律,为控制晚血的发生提供科学依据。方法以基于行政村的空间数据库,利用SaTScan对2009-2019年晚血发病率按空间、时间和时间-空间3种扫描探测模式进行统计分析,并通过ArcMap将分析结果可视化。结果2009—2019年鄱阳县累计报告晚血病例932例,年报告晚血发病率呈逐年下降趋势,其中最高年份集中在2010—2013年,疫情控制阶段晚血发病率高于传播控制阶段(F=9.617,P=0.013);单纯空间扫描显示,疫情控制阶段出现2个一类聚集区域,传播控制阶段出现4个二类聚集区域;单纯时间扫描显示,疫情控制阶段晚血发病率高峰集中在2012—2013年(RR=64.44,P=0.001),传播控制阶段集中在2018年(RR=11.23,P=0.001);时间-空间扫描显示,2009—2019共探测到2个一类聚集区域和1个二类聚集区域,均沿鄱阳湖分布;在传播控制阶段无一类聚集区域。结论虽然随着疫情的降低,晚血发病率也逐年下降,但在空间分布上依然存在多个集聚区域,针对此类区域在今后的防治工作中,应进一步加大晚血筛查和救治力度。

鄱阳湖地区影响晚期日本血吸虫病发生的因素分析

目的分析鄱阳湖区晚期日本血吸虫病(晚血)发生的影响因素,为有效控制晚血的发生提供科学依据.方法收集2002年以后发生的晚血病例169例作为观察组,按性别相同、年龄和居住地相近等原则进行1∶1配对,以慢性血吸虫病病例(慢血)作为对照组;采用自行设计的问卷进行回顾性调查,内容包括研究对象基本信息、确诊慢血前后可能与晚血发生的相关因素,以及通过查治病分户册收集2002年以来的查、治病情况,共计20项指标.结果单因素分析显示,职业、职业改变、慢血后伴有消化系统疾病、查病间隔年限、服药依从性、累计服药次数、年间受检率、年间血阳检出率、年间粪阳检出率、年间治疗率等11项指标有统计学意义;logistic回归的多因素分析结果显示,离开疫源地累计年数越多、高暴露接触疫水方式的减少、累计服药次数越多是晚血发生的保护因素;而年间血阳检出率越高、高易感季节接触疫水、服药依从性越差、伴有乙肝是晚血发生的危险因素.结论在今后血吸虫病控制措施中,健全有效地血吸虫病病例追踪管理体系,改进影响晚血发生相关因素的干预措施.

Structure and strain tunings of topological anomalous Hall effect in cubic noncollinear antiferromagnet Mn3Pt epitaxial films

Antiferromagnets(AFMs)with chiral noncollinear spin structure have attracted great attention in recent years.However,the existing research has mainly focused on hexagonal chiral AFMs,such as Mn3Sn,Mn3Ga,Mn3Ge with low crystalline symmetry.Here,we present our systematical study for the face-centered cubic noncollinear antiferromagnetic Mn3Pt.By varying the alloy composition(x),we have successfully fabricated antiferromagnetic Mn1-xPtx epitaxial films on MgO substrates and have observed a crystalline structure transition from L10 MnPt to L12 Mn3Pt.The Mn3Pt exhibits a large anomalous Hall effect,which is in the same order of magnitude as those of ferromagnetic materials.Moreover,a large thickness-evolved strain effect is revealed in Mn3Pt films by X-ray diffraction(XRD)analysis based on the Scherrer method.Our work explores Mn3Pt as a promising candidate for topological antiferromagnetic spintronics.

Differential bone metabolism and protein expression in mice fed a high-fat diet versus Daurian ground squirrels following natural pre-hibernation fattening

This study compared the effects on bone metabolism and morphology of pathological obesity induced by excessive fat intake in a non-hibernator(mice)versus healthy obesity due to pre-hibernation fattening in a hibernator(ground squirrels).Kunming mice were fed a high-fat diet to provide a model of pathological obesity(OB group).Daurian ground squirrels fattened naturally in their pre-hibernation season(PRE group)were used as a healthy obesity model.Micro-computed tomography(micro-CT)and three-point bending tests were used to determine the microstructure and mechanical properties of bone.Western blots were used to analyze protein expression levels related to bone metabolism(Runt-related transcription factor 2(RunX2),osteocalcin(OCN),alkaline phosphatase(ALP),osteoprotegerin(OPG),receptor activator of nuclear factor-κB ligand(RANKL),cathepsin K,matrix metallopeptidase 9(MMP9),patched protein homolog 1(Ptch1),phosphorylatedβ-catenin(P-β-catenin),and glycogen synthase kinase-3β(GSK-3β)).Compared with controls,there was no obvious bone loss in the OB mice,and the stiffness of the femur was increased significantly.Compared with summer active squirrels,bone formation was enhanced but the mechanical properties did not change in the PRE group squirrels.In OB mice,western blots showed significantly increased expression levels of all proteins except RunX2,OPG,and Ptch1.PRE ground squirrels showed significantly increased expression of most proteins except OCN and Ptch1,which decreased significantly,and P-β-catenin and OPG,which did not change.In conclusion,for non-hibernating mice,moderate obesity had a certain protective effect on bones,demonstrating two-way regulation,increasing both bone loss and bone formation.For pre-hibernating ground squirrels,the healthy obesity acquired before hibernation had a positive effect on the microstructure of bones,and also enhanced the expression levels of proteins related to bone formation,bone resorption,and Wnt signaling.

A novel coumarin derivative DBH2 inhibits proliferation and induces apoptosis of chronic myeloid leukemia cells

With the development of tyrosine kinase inhibitor(TKI)resistance,finding the novel effective chemotherapeutic agent is of seminal importance for chronic myelogenous leukemia(CML)treatment.This study aims to find the effective anti-leukemic candidates and investigate the possible underlying mechanism.We synthesized the novel coumarin derivatives and evaluated their anti-leukemic activity.Cell viability assay revealed that compound DBH2 exhibited the potent inhibitory activity on the proliferation of CML K562 cells and TKI resistant K562 cells.Morphological observation and flow cytometry confirmed that DBH2 could selectively induce cell apoptosis and cell cycle arrest at G2/M phase of the K562 cells,which was further confirmed on the bone marrow cells from CML transgenic model mice and CD34+bone marrow leukemic cells from CML patients.Treatments of DBH2 in combination with imatinib could prolong the survival rate of SCL-tTA-BCR/ABL transgenic model mice significantly.Quantitative RT-PCR revealed that DBH2 inhibited the expression of STAT3 and STAT5 in K562 cells,and caspase-3 knockout alleviated the DBH2 induced apoptosis.Furthermore,DBH2 could induce the expression of PARP1 and ROCK1 in K562 cells,which may play the important role in caspase-dependent apoptosis.Our results concluded that coumarin derivative DBH2 serves as a promising candidate for the CML treatment,especially in the combination with imatinib for the TKI resistant CML,and STAT/caspase-3 pathway was involved in the molecular mechanism of anti-leukemic activity of DBH2.

基于次级梳的石墨烯功能化微球气体传感

光学微腔具有高品质因子和微小体积,为光学传感提供了理想平台.受限于微腔材料惰性和光源性能,基于光学微腔的高灵敏气体传感器的实现仍然是一个挑战.微腔光频梳具有等间距的频谱分量,被广泛用于大容量通信、高精密测量和光谱分析应用,已经成为通信和传感的新一代高性能光源.本文介绍了一种基于次级梳的石墨烯功能化微球气体传感器.相较于孤子态微梳,次级梳具有较高鲁棒性和更容易激发的特点,在气体传感方面展现出应用潜力.通过把次级梳的拍频作为传感探测信号,在石墨烯增敏作用下,实现了750 Hz/ppb的最大探测灵敏度和4 ppb的探测极限.该传感器保留了光频梳稳定性优势,同时避免了复杂的孤子激发和维持过程,为高性能实用化微型气体传感器的实现提供了新的技术路线.

Changing structures of summertime heatwaves over China during 1961–2017

Despite the prevalence of artificial separation of daytime and nighttime hot extremes, they may actually co-occur or occur sequentially. Considering their potential lead-lag configuration, this study identified an entire heatwave period as consecutive days with either daytime or nighttime hot extremes and investigated the changes of the prevalence and sequence of daytime and nighttime hot extremes during heatwaves over China from 1961 to 2017. It was found that the majority(82%) of heatwaves were compound heatwaves that had both daytime and nighttime hot extremes exceeding the 90 th percentile-based thresholds, while only 7%(11%) were purely daytime(nighttime) heatwaves that contained only daytime(nighttime) hot extremes. During the entire periods of compound heatwaves, daytime hot extremes usually occurred one day or a few days before nighttime hot extremes, which was in accordance with the daily variations in radiation and meteorological conditions, such as the increasing surface humidity and cloud cover, and decreasing solar radiation during the entire heatwave periods. From 1961 to2017, compound heatwave numbers exhibited the sharpest increase with a statistically significant trend of 0.44 times decade-1, in contrast to an insignificant trend of 0.00 times decade-1 for purely daytime heatwaves and a significant trend of 0.09 times decade-1 for purely nighttime heatwaves. Within the compound heatwave periods, hot nights were starting earlier and ending later, and numbers of concurrent daytime-nighttime hot extremes increased significantly at 0.20 days decade-1. In particular,urban area were not only subject to increasingly more frequent and longer compound heatwaves, but also to more occurrences of concurrent daytime-nighttime hot extremes with more serious impact. This study provides instructions for researchers to customize and select appropriate heatwave indices.