Available Contents and Spatial Distribution of Soil Microelements of Tobacco Fields in Liupanshui City

The contents of soil microelements can affect the growth, yield and quality of tobacco, but it is not clear of the status quo of soil microelements in tobacco fields in Liupanshui city. In this study, soil samples of the plough layers (0 - 20 cm) were collected from January to March in 2021 from 500 typical tobacco fields in Liupanshui City (100, 180 and 220 fields in Zhongshan, Shuicheng and Panzhou, respectively), the particle size composition, pH, the contents of organic matter (OM), available boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn) were measured and discussed. the results show that the mean contents of B, Cu, Fe, Mn, Mo and Zn are 0.92, 2.55, 66.47, 47.26, 0.39 and 3.96 mg/kg, respectively, and among which, B, Cu and Zn are at the high grades while Fe, Mn and Mo are at the very-high grades. There are significant differences in B, Fe and Zn among the three regions, while Cu is significantly different between Zhongshan and Shuicheng, Mn is significantly different between Panzhou with Zhongshan and Shuicheng, and Mo is significantly different between Zhongshan and Panzhou. The proportions of fields deficient in microelements are relatively low, no field is Fe-deficient, and the fields deficient in Mo, B, Cu, Zn and Mn are only account for 10.40%, 9.40%, 7.40%, 2.80% and 2.00% of the total fields respectively. B-deficient fields (green and light green colors, the same below) are mainly scattered in the northwest of Zhongshan and in the north and south of Panzhou, Cu-deficient fields mainly in the middle of Shuicheng and Panzhou, Mn-deficient fields mainly in northern Zhongshan, central Shuicheng and north of Panzhou. Mo-deficient fields are mainly in the middle of Shuicheng and the middle and east of Panzhou, while Zn-deficient fields are mainly in the middle of Shuicheng and the middle and east of Panzhou. Altitude is negatively correlated with Mn (P < 0.05), pH is negatively correlated with B (P < 0.05), Fe and Mn (P < 0.01), and OM is positively correlated with Fe and Zn (P < 0.01). Sand is negatively correlated with B (P < 0.05), Mn and Mo (P < 0.01), but positively correlated with Zn (P < 0.01). Silt is positively correlated with Mo (P < 0.05);clay is positively correlated with B (P < 0.05) and Mn (P < 0.01), but negatively correlated with Zn (P < 0.01). In conclusion, most of the fields do not need to apply micro-fertilizers in Liupanshui, but the fields deficient in microelements should be considered to use the corresponding fertilizers.

基于集成学习算法构建有机化学品鱼体生物富集因子的QSAR预测模型

生物富集因子(BCF)是评价化学品生物累积能力的重要参数。目前全球市场上使用的化学品数量已超过了35万种,但是只有一千多种化学品具有BCF值。定量构效关系(QSAR)模型被认为是一种有效填补数据空缺的方法。目前大多数预测BCF的QSAR模型为单一模型,而集成模型可能会对BCF的预测效果有所改进。本研究建立了一个全面的鱼类BCF数据库,涵盖1300多种有机化学品的BCF实测值。基于此数据库,依据QSAR模型构建和验证导则,使用多种机器学习算法建立了预测鱼类BCF的5种单一模型和11种集成模型。结果表明,与单一模型相比,集成模型具有更好的拟合能力、稳健性、预测准确性以及更广泛的应用域。进一步使用最优集成模型对《中国现有化学物质清单》(IECSC)中化学物质的BCF进行了预测,结果表明该清单中有1066种化学物质具有生物累积性,86种化学物质具有强生物累积性。本研究所构建的模型可为化学品生物累积能力评估提供必要数据,支持化学品风险评价与管理工作。

Cycle-by-Cycle Queue Length Estimation for Signalized Intersections Using Multi-Source Data

In order to estimate vehicular queue length at signalized intersections accurately and overcome the shortcomings and restrictions of existing studies especially those based on shockwave theory,a new methodology is presented for estimating vehicular queue length using data from both point detectors and probe vehicles. The methodology applies the shockwave theory to model queue evolution over time and space. Using probe vehicle locations and times as well as point detector measured traffic states,analytical formulations for calculating the maximum and minimum( residual) queue length are developed. The proposed methodology is verified using ground truth data collected from numerical experiments conducted in Shanghai,China. It is found that the methodology has a mean absolute percentage error of 17. 09%,which is reasonably effective in estimating the queue length at traffic signalized intersections. Limitations of the proposed models and algorithms are also discussed in the paper.

The Water Quality Evaluation in Balihe Lake Based on Principal Component Analysis

The water pollution situation in Balihe Lake, the biggest tributary of Shaying River Basin in Anhui Province, China, has brought a huge pressure on the improvement of water quality in Huai River. On October 16th, 2017, 11 major pollution indexes were observed at 15 sampling points in Balihe Lake. Based on the data experimentally measured, the water quality in Balihe Lake was analyzed utilizing the Principal Component Analysis (PCA) of SPSS. The result suggested that the major components were oxygenated pollutants, water eutrophication pollutants and ammonia nitrogen, in which oxygenated pollutants played a dominant role. In addition, the upper part of Balihe Lake suffered serious situation and needed a focus on oxygenated pollutants.

Inhibition of apoptosis-regulatory protein Siva-1 reverses multidrug resistance in gastric cancer by targeting PCBP1

Introduction:Siva-1,as a pro-apoptotic protein,has been shown to induce extensive apoptosis in a number of different cell lines.In our previous study,we showed that overexpressed Siva-1 decreased the apoptosis of gastric cancer cells.So,we believe that it can also work as an anti-apoptotic protein.The present study aimed to determine the specific role of Siva-1 in anticancer drug resistance in gastric cancer in vivo and in vitro and preliminarily reveal the mechanism.Materials and Methods:A vincristine-resistant MKN-28/VCR gastric cancer cell line with stably downregulated Siva-1 was established.The effect of Siva-1 downregulation on chemotherapeutic drug resistance was assessed by measuring the IC50 and pump rate of doxorubicin.Proliferation,apoptosis of cells,and cell cycle were detected via colony formation assay andflow cytometry,respectively.Additionally,migration and invasion of cells was detected via wound healing and transwell assays.Moreover,we determined in vivo effects of LV-Siva-1-RNAi on tumor size,and apoptotic cells in tumor tissues were detected using TUNEL and hematoxylin and eosin staining.Results:Siva-1 downregulation reduced the pump rate of doxorubicin and enhanced the response to drug treatment.Siva-1 negatively regulated proliferation and promoted apoptosis of cells by potentiality G2-M phase arresting.Inhibition of Siva-1 expression in MKN-28/VCR cells significantly weakened wound healing ability and decreased invasion ability.Poly(C)-binding protein 1(PCBP1)was identified as a Siva-1-interacting protein in yeast two-hybrid screening.Semiquantitative RT-PCR and western blotting revealed that Siva-1 downregulation could inhibit expression of PCBP1,Akt,and NF-κB and eventually decrease the expression of MDR1 and MRP1.Conclusion:The current study demonstrated that the downregulation of Siva-1,which functions as a regulator of MDR1 and MRP1 gene expression in gastric cancer cells by inhibiting PCBP1/Akt/NF-κB signaling pathway expression,enhanced the sensitivity of gastric cancer cells to certain chemotherapies.

Analysis of Key Technologies in the Design of Small and Medium Span Basket Type Steel Box Tied Arch Bridge

In order to ensure the construction quality and safety of small and medium span basket type steel box tied arch bridge,this paper takes a practical project as an example to analyze the key technologies in its design process.It is hoped that this analysis can provide corresponding reference for the design and construction of this kind of arch bridge.

Analysis on Construction Technology of Reinforced Concrete Tied Arch Bridge

Bridge construction has received a lot of attention as transportation continues to improve.Reinforced concrete linked arch bridges are a common bridge style in today’s bridge construction.This type of bridge not only has a basic and generous shape,but it is also incredibly easy to construct,resulting in significant material and construction cost savings.This article analyzes the construction technology of a reinforced concrete linked arch bridge in order to achieve good construction and application.It is hoped that this analysis can provide a scientific reference for the guarantee of the construction quality and subsequent application effect of this kind of bridge.

Application Strategy of BIM Technology in Highway and Bridge Design

For the highway and bridge construction industry,the traditional management model has been difficult to adapt to the current information management background.In recent years,in order to comprehensively improve the information management level of highway and bridge engineering,the highway and bridge industry advocates the use of emerging technologies to achieve full-cycle dynamic management of highway and bridge engineering management,and try to ensure the quality of highway and bridge engineering management while improving The efficiency of highway and bridge design management.In view of this,this article is mainly based on the background of information management,researching and analyzing the application strategy of BIM technology in highway bridge design for reference.

Watt-level acousto-optically Q-switched Pr:YLF laser at 639 nm

We present a study on a watt-level acousto-optically Q-switched Pr:YLF laser at three different repetition rates(10 kHz,20 kHz,and 50 kHz)for the first time,to the best of our knowledge.The corresponding average output powers and pulse widths were measured to be 1.14 W,1.2 W,and 1.32 W,and 40 ns,52 ns,and 80 ns,respectively.A maximum pulse energy of0.11 mJ was obtained,corresponding to a peak power of up to 2.8 kW at a repetition rate of 10 kHz.The simulated dynamics of a fast Q-switched Pr:YLF laser is in agreement with the experiment.The laser's ability to generate stable pulses with high peak power and short pulse width makes it highly desirable for various practical applications,such as laser machining and material processing.

Subsequent strategies and underlying mechanism of acquired resistance to PD-1 axis inhibitors in advanced non-small cell lung cancer

To the Editor:With the widespread application of immune checkpoint inhibitors(ICIs)in clinical practice,acquired resistance(AR)to programmed death-1(PD-1)/programmed death ligand 1(PD-L1)axis inhibitors in advanced nonsmall cell lung cancer(NSCLC)develops and limits the durability of immunotherapy.AR is a clinical condition in which a patient initially responds to ICIs but relapses and progresses after a period of time.The rates of AR have not been routinely reported in lung cancer but typically range from 12.9%to 64%.[1]However,studies on subsequent management strategies and the mechanism of AR to PD-1/PD-L1 axis inhibitors in lung cancer are limited.The main exploratory strategies are immunotherapy rechallenge and the combination of ICIs with other therapies,including local therapy,chemotherapy,antiangiogenetic treatment,and cytotoxic T lymphocyte antigen 4(CTLA-4)inhibitors.[2]The purpose of this study was to characterize the clinical patterns of AR and compare different subsequent therapies and outcomes in NSCLC patients after AR to PD-1/PD-L1 inhibitors.Moreover,we explored the underlying mechanism of AR by analyzing the alterations in next-generation sequencing(NGS)data before and after AR.

Watt-level laser operation of Pr^(3+):YLF at 696 and 698 nm

We report continuous-wave deep red lasers at 696.6 and 698.6 nm in a Pr^(3+):YLF crystal pumped by an InGaN laser diode.A Lyot filter was inserted into the cavity as a birefringent filter to select wavelength;the lasers at 696.6 and 698.6 nm were obtained with a maximum output power of 1.36 and 3.11 W,separately.To the best of our knowledge,the output powers of these two lasers are the highest to date,and this is the first scaling of the output power of the Pr^(3+):YLF laser to the watt level at around 696 nm.In addition,the corresponding theoretical analysis and simulation were carried out to explain the experimental phenomena.

High performance visible generation of Ho^(3+)-doped all-fiber lasers

Direct generation of visible frequency from a compact all-fiber laser while preserving high output characteristics has been a subject of research in laser technology.We investigated the high output performance of all-fiber lasers based on Ho^(3+)-doped ZBLAN fluoride glass fiber especially operating in the deep-red band by pumping at 640 nm.Remarkably,we achieved a maximum continuous-wave output power of 271 m W at 750 nm with a slope efficiency of 45.1%,which represents,to our knowledge,the highest direct output power recorded in an all-fiber laser with a core diameter of less than 10μm in the deep-red band.Additionally,we successfully developed a 1.2μm all-fiber laser pumped by a 640 nm laser.We extensively investigated the correlation between these two-laser generation processes and their performances at 750 nm and 1.2μm wavelengths.By increasing the pumping rate,we observed an efficient recycling of population through a highly excited state absorption process,which effectively returned the population to the upper laser level of the deep-red transition.Moreover,we determined the optimized conditions for such lasers,identified the processes responsible for populating the excited state energy levels,and established the corresponding spectroscopic parameters.

Occurrence and Removal of Antibiotic Resistance in Nationwide Hospital Wastewater Deciphered by Metagenomics Approach-China,2018-2022

Summary What is already known about this topic?Hospital wastewater represents a significant conduit for the dissemination of antibiotic resistance genes(ARGs),including those that are of clinical importance.Yet,the variation in antibiotic resistance on a national level,which can be influenced by regional differences,has not been thoroughly elucidated.

QSAR模型应用域的表征方法

定量构效关系(QSAR)模型是填补化学品环境安全数据空缺的重要工具.QSAR模型需要明确定义的应用域,才能合理地用于化学品管理.本文回顾了应用域的3种概念:描述符域、结构域和机理域.基于案例,重点介绍了基于分子指纹与相似性度量指标而计算结构域的方法、结构域的特点和优势.讨论了结构-活性地貌(structure-activity landscape)中呈现的活性悬崖(activity cliffs)现象及其成因.为了更好地理解描述符的适用性,解释QSAR机制及合理选择应用域的表征方法,有必要认识预测终点(endpoint)本质上所描述的系统,该系统复杂性和空间异质性,以及预测终点是否考察了系统行为的涌现.

环境新污染物治理与化学品环境风险防控的系统工程

重视新污染物治理,是我国进入新发展阶段生态文明建设的必然要求.本文介绍了新污染物的概念、来源和特性,指出化学品管理不当及其环境释放是新污染物的主要来源.治理新污染物,需要分析化学品在人类社会子系统、新污染物在自然环境子系统中的源-流-汇;揭示化学品和新污染物对人类社会、生态系统、无机环境系统及各层次子系统造成的影响.以物质流分析、生命周期评价、计算毒理学、绿色化学等现代科技手段为核心要素的环境系统工程方法,有助于新污染物治理和化学品风险管理.物质流分析、生命周期评价可以追踪化学品在社会经济系统中循环流动的源-流-汇,进而定量其产生的潜在环境影响.计算毒理学通过计算机模型系统性地预测释放到环境中的化学污染物的分布和归趋,评估人类和生态物种暴露于新污染物的途径和水平,以及特定暴露条件下,化学污染物对人体和生态物种的有害影响.绿色化学则要求在开发全链条中减少有害原料使用和废物排放,并产出低危害性或无害的化学品.上述环境系统工程技术体系支撑化学品风险的源头防控,进一步结合过程控制和末端治理技术,有望实现对新污染物的有效治理.

Photoperiodism dynamics during the domestication and improvement of soybean

Soybean(Glycine max) is a facultative short-day plant with a sensitive photoperiod perception and reaction system, which allows it to adjust its physiological state and gene regulatory networks to seasonal and diurnal changes in environmental conditions. In the past few decades, soybean cultivation has spread from East Asia to areas throughout the world. Biologists and breeders must now confront the challenge of understanding the molecular mechanism of soybean photoperiodism and improving agronomic traits to enable this important crop to adapt to geographical and environmental changes. In this review, we summarize the genetic regulatory network underlying photoperiodic responses in soybean. Genomic and genetic studies have revealed that the circadian clock, in conjunction with the light perception pathways, regulates photoperiodic flowering. Here, we provide an annotated list of 844 candidate flowering genes in soybean, with their putative biological functions. Many photoperiod-related genes have been intensively selected during domestication and crop improvement. Finally, we describe recent progress in engineering photoperiod-responsive genes for improving agronomic traits to enhance geographic adaptation in soybean, as well as future prospects for research on soybean photoperiodic responses.

Efficient full-path optical calculation of scalar and vector diffraction using the Bluestein method

Efficient calculation of the light diffraction in free space is of great significance for tracing electromagnetic field propagation and predicting the performance of optical systems such as microscopy,photolithography,and manipulation.However,existing calculation methods suffer from low computational efficiency and poor flexibility.Here,we present a fast and flexible calculation method for computing scalar and vector diffraction in the corresponding optical regimes using the Bluestein method.The computation time can be substantially reduced to the sub-second level,which is 105 faster than that achieved by the direct integration approach(~hours level)and 102 faster than that achieved by the fast Fourier transform method(~minutes level).The high efficiency facilitates the ultrafast evaluation of light propagation in diverse optical systems.Furthermore,the region of interest and the sampling numbers can be arbitrarily chosen,endowing the proposed method with superior flexibility.Based on these results,full-path calculation of a complex optical system is readily demonstrated and verified by experimental results,laying a foundation for real-time light field analysis for realistic optical implementation such as imaging,laser processing,and optical manipulation.

Oxidation reactivity of 1,2-bis(2,4,6-tribromophenoxy)ethane(BTBPE)by CompoundⅠmodel of cytochrome P450s

Alternative brominated flame retardants（BFRs） have become prevalent as a consequence of restrictions on the use of polybrominated diphenyl ethers（PBDEs）. For risk assessment of these alternatives, knowledge of their metabolism via cytochrome P450 enzymes is needed.We have previously proved that density functional theory（DFT） is able to predict the metabolism of PBDEs by revealing the molecular mechanisms. In the current study, the reactivity of 1,2-bis（2,4,6-tribromophenoxy）ethane and structurally similar chemicals with the Compound I model representing the active site of P450 enzymes was investigated. The DFT calculations delineated reaction pathways which lead to reasonable explanations for products that were detected by wet experiments, meanwhile intermediates which cannot be determined were also proposed. Results showed that alkyl hydrogen abstraction will lead to bis（2,4,6-tribromophenoxy）ethanol, which may undergo hydrolysis yielding2,4,6-tribromophenol, a neurotoxic compound. In addition, a general pattern of oxidation reactivity regarding the 2,4,6-tribromophenyl moiety was observed among several model compounds. Our study has provided insights for convenient evaluation of the metabolism of other structurally similar BFRs.

Reply to Comments on “Efficient full-path optical calculation of scalar and vector diffraction using the Bluestein method”

Dear Editor,In ref.we present an efficient full-path optical calculation by using the Bluestein method.A real optical apparatus for laser processing,imaging,or optical tweezing normally involves diverse optical lenses with different physical and numerical apertures(NA).In such applications,the optical path is usually tortuous and long.To assist in the design,evaluation,and alignment of optical instruments,it is advantageous to retrieve the optical field in an arbitrary position along the entire optical path,which is termed the full-path calculation in our paper,with sufficient accuracy and efficiency.In particular,high flexibility is required to accommodate the mismatch between optical apertures of different components in the optical path.We present a fullpath optical calculation method by adopting the Bluestein method to address this realistic demand.