Two-Dimensional Perovskite Single Crystals for High-Performance X-ray Imaging and Exploring MeV X-ray Detection

Scintillation semiconductors play increasingly important medical diagnosis and industrial inspection roles.Recently,two-dimensional(2D)perovskites have been shown to be promising materials for medical X-ray imaging,but they are mostly used in low-energy(≤130 keV)regions.Direct detection of MeV X-rays,which ensure thorough penetration of the thick shell walls of containers,trucks,and aircraft,is also highly desired in practical industrial applications.Unfortunately,scintillation semiconductors for high-energy X-ray detection are currently scarce.Here,This paper reports a 2D(C_(4)H_(9)NH_(3))_(2)PbBr_(4)single crystal with outstanding sensitivity and stability toward X-ray radiation that provides an ultra-wide detectable X-ray range of between 8.20 nGy_(air)s^(-1)(50 keV)and 15.24 mGy_(air)s^(-1)(9 MeV).The(C_(4)H_(9)NH_(3))_(2)PbBr_(4)single-crystal detector with a vertical structure is used for high-performance X-ray imaging,delivering a good spatial resolution of 4.3 Ip mm^(-1)in a plane-scan imaging system.Low ionic migration in the 2D perovskite enables the vertical device to be operated with hundreds of keV to MeV X-ray radiation at high bias voltages,leading to a sensitivity of 46.90μC Gy_(air)-1 cm^(-2)(-1.16 Vμm^(-1))with 9 MeV X-ray radiation,demonstrating that 2D perovskites have enormous potential for high-energy industrial applications.

Deep Learning Recognition for Arabic Alphabet Sign Language RGB Dataset

This paper introduces a Convolutional Neural Network (CNN) model for Arabic Sign Language (AASL) recognition, using the AASL dataset. Recognizing the fundamental importance of communication for the hearing-impaired, especially within the Arabic-speaking deaf community, the study emphasizes the critical role of sign language recognition systems. The proposed methodology achieves outstanding accuracy, with the CNN model reaching 99.9% accuracy on the training set and a validation accuracy of 97.4%. This study not only establishes a high-accuracy AASL recognition model but also provides insights into effective dropout strategies. The achieved high accuracy rates position the proposed model as a significant advancement in the field, holding promise for improved communication accessibility for the Arabic-speaking deaf community.

A 5G Perspective of an SDN-Based Privacy-Preserving Scheme for IoT Networks

The ever-increasing needs of Internet of Things networks (IoTn) present considerable issues in computing complexity, security, trust, and authentication, among others. This gets increasingly more challenging as technology advances, and its use expands. As a consequence, boosting the capacity of these networks has garnered widespread attention. As a result, 5G, the next phase of cellular networks, is expected to be a game-changer, bringing with it faster data transmission rates, more capacity, improved service quality, and reduced latency. However, 5G networks continue to confront difficulties in establishing pervasive and dependable connections amongst high-speed IoT devices. Thus, to address the shortcomings in current recommendations, we present a unified architecture based on software-defined networks (SDNs) that provides 5G-enabled devices that must have complete secrecy. Through SDN, the architecture streamlines network administration while optimizing network communications. A mutual authentication protocol using elliptic curve cryptography is introduced for mutual authentication across certificate authorities and clustered heads in IoT network deployments based on IoT. Again, a dimensionality reduction intrusion detection mechanism is introduced to decrease computational cost and identify possible network breaches. However, to leverage the method’s potential, the initial module's security is reviewed. The second module is evaluated and compared to modern models.

长链非编码RNA-p21调控微小RNA-9/去乙酰化酶1信号通路逆转结直肠癌细胞奥沙利铂耐药性

目的探讨长链非编码RNA(LncRNA)-p21调控微小RNA-9(miR-9)/去乙酰化酶1(SIRT1)信号通路逆转结直肠癌(CRC)奥沙利铂相关的细胞自噬及耐药性的分子机制。方法采用qPCR方法LncRNA-p21的表达检测,Westbloting blotting法检测细胞自噬相关蛋白(微管相关蛋白1轻链3-Ⅰ((LC3-I)、微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)),自噬底物(P62)、去乙酰化酶1(Sirtuin-1,SIRT1)、miR-9的表达水平;克隆形成实验检测细胞活性。结果(1)LncRNA-p21在奥沙利铂耐药的结直肠肿瘤细胞HCT116,SW620中高表达,差异有统计学意义(P<0.001);(2)敲降LncRNA-p21可抑制细胞自噬,改善HCT116细胞对奥沙利铂的化疗敏感性;(3)敲降LncRNA-p21后miR-9表达上调,而miR-9过表达可增强HCT116细胞对奥沙利铂的化疗敏感性,差异有统计学意义(P<0.001);(4)同时,SIRT1的表达受到LncRNA-p21和miR-9的调控。结论结直肠肿瘤对于化疗药奥沙利铂抵抗可能由LncRNA-p21诱导细胞自噬增强而引起,其过程可能通过LncRNA-p21调控miR-9/SIRT1信号通路而实现。

A Bandwidth-Link Resources Cooperative Allocation Strategy of Data Communication in Intelligent Transportation Systems

The bandwidth resources allocation strategies of the existing Internet of Vehicles(IoV) are mainly base on the communication architecture of the traditional 802.11 x in the wireless local area network(WLAN). The traditional communication architecture of IoV will easily cause significant delay and low Packet Delivery Ratio(PDR) for disseminating critical security beacons under the condition of high-speed movement, distance-varying communication, and mixed traffic. This paper proposes a novel bandwidth-link resources cooperative allocation strategy to achieve better communication performance under the road conditions of intelligent transportation systems(ITS). Firstly, in traffic scenarios, based on the characteristic to predict the relative position of the mobile transceivers, a strategy is developed to cooperate on the mobile cellular network and the Dedicated Short-Range Communications(DSRC). Secondly, by adopting the general network simulator NS3, the dedicated mobile channel models that are suitable for the data interaction of ITS, is applied to confirm the feasibility and reliability of the strategy. Finally, by the simulation, comparison, and analysis of some critical performance parame-ters, we conclude that the novel strategy does not only reduce the system delay but also improve the other communication performance indicators, such as the PDR and communication capacity.

The absorption kinetics of Antarctic krill oil phospholipid liposome in blood and the digestive tract of healthy mice by single gavage

Antarctic krill(Euphausia superba)oil has been gaining increasing attention due to its nutritional and functional potentials.Krill oil usually contains a high concentration(about 50%)of phospholipids(AKOP)rich in DHA and EPA accompanied with 30%–40%triacylglycerols.Phospholipids can be made into liposomes without emulsifiers due to its amphiphilic characteristics.However,the absorption kinetics of AKOP liposome in vivo is not clear,which restrict the molecular mechanism analysis related to its distinct bioactivities.The lipid analysis in serum,small intestinal content and wall was carried out after oral administration of AKOP liposome to illustrate its absorption kinetics in blood and the digestive tract of healthy mice by single gavage.The major type of the obtained AKOP was phosphatidylcholine,and the total contents of the DHA and EPA were 29.31%.AKOP liposome was almost completely digested in the small intestine in 1 h and the hydrolysis products could be quickly absorbed by intestinal enterocytes.The DHA in serum peaked at 2 h after administration of AKOP liposome.AKOP liposome could be quickly digested and absorbed in vivo.The obtained results might provide a scientific basis for the molecular mechanism analysis related to distinct bioactivities of Antarctic krill oil phospholipid.

Efficient Splitting of Trans-/Cis-Olefins Using an Anion-Pillared Ultramicroporous Metal-Organic Framework with Guest-Adaptive Pore Channels

Trans-/cis-olefin isomers play a vital role in the petrochemical industry.The paucity of energy-efficient technologies for their splitting is mainly due to the similarities of their physicochemical properties.Herein,two new tailor-made anion-pillared ultramicroporous metal–organic frameworks(MOFs),ZU-36-Ni and ZU-36-Fe(GeFSIX-3-Ni and GeFSIX-3-Fe)are reported for the first time for the efficient trans-/cis-2-butene(trans-/cis-C_(4)H_(8))mixture splitting by enhanced molecular exclusion.Notably,ZU-36-Ni unexpectedly exhibited smart guest-adaptive pore channels for trapping trans-C_(4)H_(8)with a remarkable adsorption capacity(2.45 mmol∙g^(−1))while effectively rejecting cis-C_(4)H_(8)with a high purity of 99.99%.The dispersion-corrected density functional theory(DFT-D)calculation suggested that the guest-adaptive behavior of ZU-36-Ni in response to trans-C_(4)H_(8)is derived from the organic linker rotation and the optimal pore dimensions,which not only improve the favorable adsorption/diffusion of trans-C_(4)H_(8)with optimal host–guest interactions,but also enhance the size-exclusion of cis-C_(4)H_(8).This work opens a new avenue for pore engineering in advanced smart or adaptive porous materials for specific applications involving guest molecular recognition.

Study on Technical Schemes for Major Pollutants Emission Reduction in Beijing North Canal River Basin Based on Watershed Water Quality Target Management

Water quality target management in watershed is the fundamental choice of city rivers suffering both serious pollution and severe water shortage. In this study, we performed a case study regarding river pollution control plan based on water quality target management in the North Canal River catchment of Beijing section, in order to obtain effective water quality improvement programs. The ammonia nitrogen (NH3-N) and chemical oxygen demand (COD) were taken as the main controlling pollutants. Water quality targets and basic water quality improvement scenarios were set up considering different intensities of population regulation scenarios and gradually strengthening emission control measures. The MIKE11 model was adopted to simulate the effects of a range of water quality improvement scenarios. Results indicated that the basic scenarios could dramatically improve the surface water environment. However, additional intensive and combined measure programs should be implemented to ensure that the water quality would basically meet the targets of corresponding water function zones. The results highlight the need to implement water conservation in water shortage urban river basin and show the importance of enhancing drainage communication and conducting ecological water replenishment in such kind basins. It is expected to provide a reference for the water environment management practice of other metropolis in the world facing both crisis of water resource shortage and water environment pollution.

雅鲁藏布江中下游底栖动物物种多样性及其影响因素

雅鲁藏布江流域维系着丰富而独特的生物资源,是全球生物多样性研究的热点区域。然而,该流域底栖动物多样性的调查却极不充分。本文于2015年10月和2016年3月对雅鲁藏布江干流(朗县至墨脱段)和主要支流的底栖动物进行了调查,并采用单因素方差分析(one-way ANOVA)和典范对应分析(canonical correspondence analysis)等对群落多样性格局进行解析。共采集到底栖动物270种,隶属于5门8纲20目92科,包括昆虫纲246种,寡毛纲14种,腹足纲4种,其他动物6种。春季和秋季分别采集到底栖动物184种和214种,优势种均以喜清洁和冷水的水生昆虫为主,包括四节蜉属一种(Baetissp.)、花翅蜉属一种(Baetiella sp.)、蚋属一种(Simulium sp.)、小突摇蚊属一种(Micropsetra sp.)和短石蛾属一种(Brachycentrus sp.)等。全流域平均密度为939.1 ind./m^(2),平均生物量为5.44 g/m2。底栖动物的物种组成、密度和多样性在季节和区域之间存在一定差异,支流的多样性显著高于干流。典范对应分析显示,海拔、流速、河宽和底质类型等环境因子是影响雅鲁藏布江流域底栖动物群落结构的关键环境因素,而大峡谷地区多变的气候类型和地理阻隔是造成群落变化的根本原因。本研究可为雅鲁藏布江流域底栖动物多样性评估和环境监测提供重要的基础和参考。

Assessment of heavy metal accumulation in freshwater fish of Dongting Lake,China:Effects of feeding habits,habitat preferences and body size

We measured the concentrations of Cr,Fe,Ni,Cu,Zn,Cd,Pb and Hg,and the stable isotope ratios(δ^(13)C and δ^(15)N)in 87 fish samples within 12 economic fish species collected from the Dongting Lake,the second largest freshwater lake in China.With few exceptions in concentration of Cr,most of fish species showed lower concentrations of the 8 metals than legislation thresholds.Piscivorous fishes had significantly higher values of δ^(15)N(possessing higher trophic level)and metal concentrations than planktivorous and herbivorous fishes.Moreover,demersal fishes showed higher concentrations of Cu,Zn,Cd and Pb than pelagic and benthopelagic fishes.We found positive correlations between concentrations of Fe,Pb and Hg and δ^(15)N ratio,confirming the biomagnification of the three metals through trophic transfer.In contrast,fishes showed clear growth dilution effect for Ni,Zn,Cu,Pb and Hg,indicated by the negative correlations between their concentrations and fish weight or length.Multiple regression analysis demonstrated that growth dilution and biomagnification effects simultaneously governed the metal concentrations in fish muscle,and the two effects'importance varied among different metals.The human health risk assessment indicated that all 8 metals gave target hazard quotient(THQ)values<1.0,i.e.,the estimated daily intake(EDI)of metals did not exceed the oral reference dose(Rf D),indicating a safe consumption of these fish species for consumer.Our study provides comprehensive approaches to better understand the determining processes and potential risk of heavy metals in freshwater lake fishes.

Fructose and fructose kinase in cancer and other pathologies

Fructose metabolism and fructose kinase KHKe C/A are key factors in the development of lipid oversynthesis-promoted metabolic disorders and cancer.Here,we summarize and discuss the current knowledge about the specific features of fructose metabolism and the distinct roles of KHKe C and KHKe A in metabolic liver diseases and their relevant metabolic disorders and cancer,and we highlight the specific protein kinase activity of KHKe A in tumor development.In addition,different approaches that have been used to inhibit KHK and the exploration of KHK inhibitors in clinical treatment are introduced.

Open science as a better gatekeeper for science and society: a perspective from neurolaw

In 2011,a court near Milan,Italy,reduced the sentence of a convicted murderer from life to 20years in jail,after considering results from neuroimaging and genetic tests.These tests had been used to convince the judge that the trial's female defendant,Stefania Albertani,was suffering from partial mental illness (http:// blogs.nature.com/news/2011/09]italian_court_reduces_murde_s. html).The structural MRI images showed that Albertani's grey matter volume was different from the average volume of a randomly-selected group -10healthy women with no history of mental or neurological disorders -in brain areas including the anterior cingulate gyrus (ACC)and insula.The expert testimony concluded that "these alterations (of brain structures)have to be considered in causal relation to the psychiatric symptomatology of the murderer."

Organolead trihalide perovskite materials for efficient light emitting diodes

Organolead trihalide perovskite materials have been attracting increasing attention due to their promising role in solid solar cells. Several advantages make them potential candidates for optoelectronics:(1) solution- or/and vapor-processed preparation at low temperature;(2) tunable optical bandgap, wide absorption spectrum but narrow photoluminescence peaks;(3) long car-rier life time, large diffusion length and high charge mobility;(4) various nanostructures via tuning capping agents and sol-vents. In this review, we summarize recent attempts toward efficient LEDs based on organolead trihalide perovskite materials. The strategies of materials science, device design and interface engineering are highlighted. Recent development and future perspectives are summarized for practical perovskite light technologies.

Wearing Face Masks--the Simple and Effective Way to Block the Infection Source of COVID-19

The key difference between the coronavirus disease 2019(COVID-19)and previous coronaviruses such as SARS and MERS is that some infected people do not display obvious symptoms but are contagious during the incubation period for 14 days(1)or longer.Recently,there are many discussions about whether all persons should wear masks when they go out during the COVID-19 pandemic.The main reasons for the opposition are that the effectiveness of masks in preventing infection is not clear,ordinary people rarely wear masks correctly,everyone wearing masks may cause social panic,there are not enough masks,etc.(2–3).

Exploring potential of different X-ray imaging methods for early-stage lung cancer detection

Purpose To explore the potential of X-ray imaging for early-stage lung cancer screening and to help finding an optimal lung cancer screening method.Methods Experimentally and simulatively comparing performances of different X-ray techniques(absorption-contrast imaging and phase-contrast imaging)for model lung cancer samples.Results Absorption imaging shows performance equal to or better than that of low-radiation dose.Conclusion Absorption imaging is still the most promising imaging method for early lung cancer detection.

Effective Antarctic krill oil extraction using switchable hydrophilicity solvents

Antarctic krill has been widely studied because of its abundant biomass,rich nutritional value,and great production potential.Notably,krill oil(KO)is rich in phospholipids(PLs),polyunsaturated fatty acids(PUFAs),and astaxanthin.A method based on a green switchable hydrophilicity solvent N,7V-dimethyIcyclohexylamine(DMCHA),which can reversibly change from oil soluble to water soluble in the presence of CO2 was used to extract KO from frozen Antarctic krill as it consumes less energy than traditional methods.We showed that DMCHA destroyed the surface structure of Antarctic krill and accelerated the dissolution of KO.In addition,this method enabled the PL extraction to reach up to 80.2%of total PLs,among which PC accounted for the highest proportion,up to 90.91%in PL.In fact,the astaxanthin extraction reached up to 81.44%of total astaxanthin while the fatty acid(FA)extraction up to 84.35%.The KO extracted through DMCHA was rich in PUFA,up to 47.74%,and the content of EPA+DHA reached 42.16%of total FA content.Furthermore,the amount of residual solvent in the lipid phase was just 0.23%of the DMCHA used for the extraction and the recovery rate of solvent was up to 93.2%.Our results demonstrated the high efficiency of oil extraction and the environmental friendliness of this method.

CO-HCCA:Bandwidth Allocation Strategy in Internet of Vehicles with Dynamically Segmented Congestion Control

Hybrid coordination function controlled channel access(HCCA)applied in wireless ad hoc network systems is the strategy to allocate the bandwidth resources of control channel(CCH)and service channels(SCHs).With the continuous development of Internet of vehicles(IoV)technologies,it is difficult for HCCA to support traffic information services,such as low delay along with high-frequency dissemination of security beacons and large capacity interaction of image data.Fusing the fundamental theories of No.7 signaling system and 5G-IoV technologies,this paper proposes a novel channel bandwidth allocation strategy named CO-HCCA,which matches CCH time slot numbers with on board units(OBUs)numbers to reduce the congestion of channel access demand information(CADI);and also illustrates a dynamic segment adjusting algorithm of the time slots.On one hand,in the channel reservation stage of CCH control cycle,OBUs are sorted according to the priority of data transmission,and then the corresponding transmission slots are adopted orderly according to the OBUs numbers,so as to decrease the collision probability of high-frequency dissemination of CADI.On the other hand,for the quickly arriving and leaving OBUs in coverage of roadside base station(RBS),the prediction of bandwidth segments is dynamically adjusted to adapt to the time-varying characteristic of the connected vehicle scenarios.Modeling calculation and objective comparison on OMNeT++computing platform show that the proposed CO-HCCA strategy can effectively reduce the channel congestion of IoV,and in the scenario of high-density data interaction,it is beneficial to promote the transmission timeliness of security beacons and the package delivery rate(PDR)of high bit-rate multiple information.

Coldness impedes tumor growth

The Warburg effect is critical for tumor growth.A new study showed that cold acclimatization activates brown adipose tissue(BAT),reduces blood glucose levels,and subsequently blunts aerobic glycolysis in cancer and tumor growth.Tumor cells preferentially use glucose as an energy resource even in the presence of ample oxygen,to generate ATP and metabolic intermediates for the production of amino acids,fatty acids and cholesterol,and nucleotides.This Warburg effect or aerobic glycolysis occurring in various types of solid tumors has been used for cancer diagnosis and monitoring tumor progression and response to therapies by positron emission tomography–computed tomography(PET–CT)imaging analysis,which detects the substantially enhanced uptake of ^(18)F-fluorodeoxyglucose(^(18)FFDG)of tumor cells[1].