Effects of leaf N concentration and leaf area index on determining rice tillering

Relative tillering rate(RTR)increased linear-ly with the increasing of leaf N concentration(NLV)has been already reported.To testwhether this relationship could be used toquantitatively explain the difference in tilleringamong a wide range of N application,field ex- periments were conducted at the IRRI farm,Los Banos,Laguna,the Philippines.Two in- dica cultivars,IR 72 and IR68284H wereused.For each cultivar,12 treatments includ- ing 4 N levels(0,60,120,and 180kgN·ha)and 3 transplanting spacing(30×20,20×20,and 10×20cm)were arranged in a ran-domized split-plot design with 4 replications.The N treatments were designated as mainplots and spacings as subplots.Fourteen-day-old seedlings were transplanted with 3seedlings per hill.The subplot area was 20m~2.Nitrogen fertilizer was applied as basal,atmidtillering,and at panicle initiation in threeequal splits.P,K,and Zn were applied asbasal at normal dosage.The field was flooded.Plant samples were taken every 7-14 d from 14d after transplanting to flower

Clinical significance of melatonin concentrations in predicting the severity of acute pancreatitis

AIM: To assess the value of plasma melatonin in pre-dicting acute pancreatitis when combined with the acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) and bedside index for severity in acute pancreatitis (BISAP) scoring systems. METHODS: APACHEⅡ and BISAP scores were calculated for 55 patients with acute physiology (AP) in the first 24 h of admission to the hospital. Additionally, morning (6:00 AM) serum melatonin concentrations were measured on the first day after admission. According to the diagnosis and treatment guidelines for acute pancreatitis in China, 42 patients suffered mild AP (MAP). The other 13 patients developed severe AP (SAP). A total of 45 healthy volunteers were used in this study as controls. The ability of melatonin and the APACHEⅡ and BISAP scoring systems to predict SAP was evaluated using a receiver operating characteristic (ROC) curve. The optimal melatonin cutoff concentration for SAP patients, based on the ROC curve, was used to classify the patients into either a high concen-tration group (34 cases) or a low concentration group (21 cases). Differences in the incidence of high scores, according to the APACHEⅡ and BISAP scoring sys- tems, were compared between the two groups. RESULTS: The MAP patients had increased melatonin levels compared to the SAP (38.34 ng/L vs 26.77 ng/L) (P = 0.021) and control patients (38.34 ng/L vs 30.73 ng/L) (P = 0.003). There was no significant difference inmelatoninconcentrations between the SAP group and the control group. The accuracy of determining SAP based on the melatonin level, the APACHEⅡ score and the BISAP score was 0.758, 0.872, and 0.906, respectively, according to the ROC curve. A melatonin concentration ≤ 28.74 ng/L was associated with an increased risk of developing SAP. The incidence of high scores (≥ 3) using the BISAP system was significantly higher in patients with low melatonin concentration (≤ 28.74 ng/L) compared to patients with high melatonin concentration (> 28.74 ng/L) (42.9% vs 14.7%, P = 0.02). The incidence of high APACHEⅡ scores (≥ 10) between the two groups was not significantly different. CONCLUSION: The melatonin concentration is closely related to the severity of AP and the BISAP score. Therefore, we can evaluate the severity of disease by measuring the levels of serum melatonin.

Er^(3+) ion concentration effect on transient and steady-state behavior in Er^(3+):YAG crystal

The effect of Er3＋ ion concentration on transient and steady-state behavior in 45-nm Er3＋ ：YAG crystal is investigated. It is shown that by changing the signal field, the coherent field and the concentration of Er3＋ ions in the crystal, the absorption, dispersion, and group index of the weak probe field can be adjusted. Also, it is found that the probe absorption occurs in the presence of population inversion and probe amplification is obtained in the absence of population inversion.

Characteristics Analysis of Chemical Concentration Sensor Based on Three-layer FBG

The three-layer structure model of the fiber Bragg grating is proposed in this paper. And through experimental study and reasoning calculation to verify the three layer structure of the optical waveguide model, so the sensitivity characteristic of the Bragg wavelength to the refractive index of chemical solution is obtained. And the relationships between the concentration and the shift of Bragg wavelength of sucrose, ethanol, and Nacl solution are achieved. Finally the shifts of the Bragg wavelength with the external concentration are obtained by experiments. A kind of simple structure, small size, good stability, high sensitivity chemical concentration sensor is obtained.

A Self-Organizing RBF Neural Network Based on Distance Concentration Immune Algorithm

Radial basis function neural network(RBFNN) is an effective algorithm in nonlinear system identification. How to properly adjust the structure and parameters of RBFNN is quite challenging. To solve this problem, a distance concentration immune algorithm(DCIA) is proposed to self-organize the structure and parameters of the RBFNN in this paper. First, the distance concentration algorithm, which increases the diversity of antibodies, is used to find the global optimal solution. Secondly,the information processing strength(IPS) algorithm is used to avoid the instability that is caused by the hidden layer with neurons split or deleted randomly. However, to improve the forecasting accuracy and reduce the computation time, a sample with the most frequent occurrence of maximum error is proposed to regulate the parameters of the new neuron. In addition, the convergence proof of a self-organizing RBF neural network based on distance concentration immune algorithm(DCIA-SORBFNN) is applied to guarantee the feasibility of algorithm. Finally, several nonlinear functions are used to validate the effectiveness of the algorithm. Experimental results show that the proposed DCIASORBFNN has achieved better nonlinear approximation ability than that of the art relevant competitors.

The Activity Concentrations, Radiation Contamination, and Hazards from Wastes and Soil Samples in Nasirabad Industrial Area, Chattogram, Bangladesh

Soils and other solid wastes from industrial areas of Nasirabad, Chattogram are usually dumped or used for land development. Information about the radioactivity level presented on these soil and wastes enables one to assess any possible radiological hazard to humankind by the use of such materials. A total of 37 (31 soils and 6 solid waste) samples near from different types of industries along four kilometre range were collected. The presence and activity concentrations of naturally occurred radioactive materials (NORM) and anthropogenic radionuclides in the samples were estimated using HPGe detector of 40% relative efficiency. The activity concentration of 226Ra, 232Th and 40K were found to be ranging from 8 ± 2 to 131 ± 18.33 with an average of 21 Bq·kg-1, 10 ± 2.69 to 133 ± 15.96 with an average of 40 Bq·kg-1 and 81 ± 22.68 to 930 ± 260.40 with an average of 449 Bq·kg-1 respectively. Besides this, some hazard indices like, the radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), and the activity concentration index (Iy) were calculated to assess the radiation hazard in this region. The averages of calculated hazard indices were within the normal limits, except the activity concentration index, which shows elevated values. The outcomes of this study could serve as important baseline radiological data for future epidemiological studies and environmental monitoring initiatives in the study area.

Assessment of Heavy Metal Concentration and Evaluation of Health Risk of Some Vegetables Cultivated in Loumbila Farmland, Burkina Faso

Vegetables such as spinach, African eggplant, cabbage, eggplant, okra, chili peppers and tomatoes are found in our everyday foods and are the most important dietary source of nutrient. But, it becomes deleterious to human as well as animals as it accumulates toxic metals in their tissue when grown in contaminated soil. The mostly consumed vegetables like spinach, African eggplant (fruit and leaves), Corchorus olitorius leaf, Amaranthus hybridus leaf, cabbage, eggplant, okra, pepper and tomato were collected from Loumbila market gardening. Heavy metals copper (Cu), nickel (Ni), lead (Pb), chromium (Cr), cadmium (Cd) and zinc (Zn) were measured using atomic absorption spectrophotometer (AAS) model AANALYST 200 from PERKIN ELMER. The results of this study showed that the concentrations of lead (0.49 to 8.59 mg/kg) and zinc (20.73 to 71.29 mg/kg) in spinach, African eggplant (fruit and leaves), Corchorus olitorius leaf, Amaranthus hybridus leaf, cabbage, eggplant, okra, pepper and tomato exceeded the permissible level of FAO and WHO standard. The daily plant metal intake for Cd (0.001 - 0.015 mg/kg), Pb (0.041 - 0.730 mg/kg), and Cu (0.703 - 1.543 mg/kg) is higher than the recommended daily intake of metals but does not exceed the tolerable limit. The calculated values of the health risk indices show high values for Cd, Pb, Zn, Ni and Cu while low values are observed for Cr. Except for Cr, the IRS evaluated for all the studied metals were greater than one (IRS > 1). This implies that exposed populations are susceptible to developing diseases linked to the following metals: Cd, Pb, Zn, Ni and Cu.

Study of the relationship between dosage of oral progesterone and concentration of serum progesterone

Objective:To explore the relationship among body mass index(BMI),dosage of progesterone(P) and serum progesterone concentration,and provide reference for the clinical use of oral progesterone. Methods:This was a random,open-label,prospective clinical trial.Eighty women meeting the criteria for enrollment were recruited from July 2010 to March 2011 in outpatient clinic of Peking Union Medical College Hospital and given oral progesterone therapy for consecutive 10 days.They were randomly assigned into four groups according to the different doses of progesterone:group A 100 mg/day,group B 200 mg/day,group C 300 mg/day and group D 400 mg/day. Results:Seventy four patients(92.5%,74/80) accomplished the study.It can be observed that administration of different dosage of P could significantly increase serum P concentration(all P<0.001).And there was a positive correlation between the increase of P concentration and dosage(r_p=0.613,P<0.001).Furthermore,the medians of the increase of serum P concentration in 4 groups were 14.71 nmol/L in group A,28.47 nmol/L in group B, 58.89 nmol/L in group C,72.69 nmol/L in group D.When BMI<24 kg/m^2(42 cases),the median of the increase of P levels was 13.90 nmol/L,37.22 nmol/L,62.55 nmol/L,and 119.02 nmol/L in group A,B,C and D, respectively,while BMI≥24 kg/m^2(32 cases),the median of increase was 8.93 nmol/L,24.82 nmol/L,24.87 nmol/L,and 63.48 nmol/L,respectively.In addition,significant difference was found only in group D between women with BMI<24 kg/m^2 and with BMI≥24 kg/m^2(P = 0.010). Conclusions;Serum progesterone levels go up linearly with the dosage increasing.The greater BMI the patient have,the larger dosage may be needed to achieve the same serum progesterone concentration.The individual dosage of oral progesterone needed can be roughly calculated in the light of the result of this study.

一种基于迈克尔逊干涉仪的浓度/折射率在线测量系统的研究

浓度是表征溶液性质的重要物理参数之一。本文设计了一种基于旋转比色皿结合迈克尔逊干涉仪的浓度/折射率在线测量系统。将液体加入比色皿并旋转5°,利用CCD采集光强数据和自编的计数程序,可实时测量旋转前后干涉条纹移动数目之差,并由此计算NaCl和葡萄糖溶液的折射率和浓度。对质量百分比浓度为0、10%和20%的NaCl溶液进行了折射率测量和误差分析,发现与相关理论值的相对误差仅为0.61%、0.63%和2.2%。葡萄糖溶液的浓度—折射率关系曲线也呈现出线性良好、可靠性高的特点。总之,基于迈克尔逊干涉仪的浓度/折射率在线测量系统具有测量非接触、结果可靠、高效实用的特点。

煤自燃程序升温实验及其在实验教学中的应用

该文利用程序升温实验系统,对三种氧气浓度(20.9%、10%和7%)所代表的采空区散热带、氧化带、窒息带进行了煤样自燃发火实验,采集了不同温度阶段的气体产物,分析了温度及氧气浓度对气体产物浓度的影响,并对指标气体进行了详细分类和评估。实验结果表明:交叉点温度CPT随着氧气浓度的升高而降低,干空气的交叉点温度为144.6℃,由经验关系计算得到的CPT值与实验数据相差仅6.08%;氧气浓度越高,临界温度越低,所产生的气体浓度越高;CO气体在不同的含氧环境下都是主要的氧化产物,可作为判断煤自燃发火的主要指标,C_(2)H_(4)和C_(3)H_(6)的产生表示煤体进入加速氧化状态,可作为判断煤自燃发火的辅助指标。

福建省县域人口-经济时空分异及影响因素研究

根据人口、经济及其相关指标数据,运用人口地理集中度、经济地理集中度和人口-经济匹配指数,对福建省人口与经济之间耦合关系和空间差异进行研究,并对其影响因素进行分析。结果表明:人口地理集中度在阈值为1时呈现东—西两级分异;经济地理集中度在阈值为1时呈现闽东和闽东南集聚态势,将人口-经济匹配指数按3类划分,2010—2021年期间同类型县域逐渐呈现集聚效应,福建省县域人口-经济匹配度整体有趋好态势,但匹配程度仍有待提高,人口-经济稳定型逐渐形成一个“U”字形,与福建省“十四五”规划较为吻合,说明该划分有利于宏观决策。在今后的发展中,福建省仍要注重区域间人口与经济发展水平相协调。

干旱半干旱地区城市公园绿地空气负离子浓度特征及影响因素

为研究干旱半干旱地区城市公园绿地空气负离子浓度(NAIC)特征及影响因素,以呼和浩特市敕勒川公园为对象,于2020—2021年,每个季节选取晴天、晴间多云为主的天气各10 d,同步监测07:00—19:00时段,5种不同结构绿地(乔草型、乔灌型、乔木型、灌草型、乔灌草型)及对照区(CK)空气负离子浓度及PM10、PM2.5、温度、湿度、风速、大气压强、噪声等环境指标。结果表明:不同结构绿地空气负离子浓度季节日变化有所差异;同一季节,复杂结构绿地空气负离子浓度均值较高,不同结构绿地之间空气负离子浓度均值差异不显著;同一结构绿地,夏、秋季空气负离子浓度均值显著高于春、冬季;不同结构绿地空气清洁度夏、秋季较高,空气清洁度评价指数均值分别为0.58~0.78、0.52~0.80。绿地结构、季节对空气负离子浓度影响为主效应,绿地结构×季节对空气负离子浓度交互作用不显著;除此之外,相对湿度、PM10、PM2.5是影响空气负离子浓度的主要因素。

基于分子动力学聚合物改性沥青黏附性能研究

为了增强基质沥青与集料之间界面黏附性,选取PE、SBS、SBR、PU 4种代表性聚合物对其进行改性,采用分子动力学模拟法对沥青-集料和沥青-水-集料模型进行不同工况模拟,并通过室内试验验证模拟结果。通过分析相对浓度分布曲线得到沥青极性组分的变化规律,研究不同温度下各改性沥青混合料黏附性并根据相对浓度参数对其机理进行分析,通过聚合物改性性能对比,得出其适用条件。结果表明:PE与沥青相溶性好,但PE改性沥青混合料水稳定性较差;SBS改性沥青能在温差较大的环境中保持较高的黏附性;SBR改性沥青低温条件下黏附性突出,且水稳定性优越,适用于低温多雨的地区;PU改性沥青综合性能较好,在高温多雨等气候条件复杂的环境中适用性较强。

中国农业废弃物源活性氮排放特征、驱动因素及差异性分析

旨在研究农业废弃物源活性氮排放规律和监测活性氮污染,进而为减少活性氮排放量和提高氮污染治理公平提供理论依据,研究首先采用排放因子法测算了1990—2019年全国农业废弃物源活性氮排放量,并分析确定了我国(除港澳台之外)31个省级行政区域的活性氮排放特征。然后利用LMDI模型和集中指数法分别研究农业废弃物源活性氮排放变化量的驱动因素和活性氮排放量的地区差异性。结果发现,1990—2019年,全国农业废弃物源活性氮排放量在1996年达到峰值,整体呈现“M”型变化趋势;全国范围内人均活性氮排放强度呈现以胡焕庸线为界的西北低密度—东南高密度的格局。基于农产品前端消费及其农业废弃物末端处置2个维度来考察活性氮的排放特征,从农产品消费端来看,消费肉类农产品生产活性氮排放量占比(36.75%)最高,其中,牛羊肉类农产品占比高达22%;从农业废弃物末端处置来看,处置畜禽粪尿产生的活性氮占比较高,且对畜禽粪尿和秸秆而言直接排放与燃烧还田均是活性氮排放量较高的2种处置方式。国家层面农业废弃物源活性氮排放量的驱动因素为经济发展效应,而省级层面农业废弃物源活性氮排放变化量的主要驱动因素为经济发展效应、购买能力效应和消费结构效应。活性氮排放总量、人均活性氮和地均活性氮排放量均是农业经济强省较高,这些省份承担了更多的氮污染环境压力。

2005-2021年我国卫生人力资源发展趋势及公平性分析

背景“健康中国2030”战略对卫生人力资源配置提出了更高需求,国内开展了较多地区卫生人力资源公平性的评价研究,但尚无从全国视角对我国多种医疗机构、多类别卫生人力资源进行的概述。目的对2005—2021年全国31省(自治区、直辖市)12类医疗卫生机构、5类卫生人力资源进行趋势描述和公平性分析,为未来各卫生机构人力资源配置优化提供参考。方法全国卫生人力资源数据来自《中国卫生统计年鉴(2006—2012)》《中国卫生和计划生育统计年鉴(2013—2017)》《中国卫生健康统计年鉴(2018—2022)》,人口数据和经济数据来自《中国统计年鉴(2006—2022)》。计算2005—2021年各省(自治区、直辖市)各类医疗卫生机构、各类卫生人力资源的人均占有量,计算年均增长率和集中指数(CI)以描述发展趋势,并根据经济发展水平进行公平性分析。结果2005—2021年,我国卫生人员总量持续上升,年均增长率为5.58%,农村地区增长较快,年均增长率达10.87%。在各类医疗卫生机构中,社区卫生服务中心(站)的卫生人员数增速最快(年均增长率达18.05%),卫生监督所(中心)的人员数增速较低(年均增长率为0.18%),疾病预防控制中心的卫生人员数总体呈下降趋势(年均增长率为-0.39%)。除社区卫生服务中心(站)外,各类医疗机构卫生人员总数的CI<0.20。结论我国各类医疗卫生机构人力资源人均占有量在农村地区增长较快,地区间人均资源分配的公平性尚佳,但总量不足,重要机构和人员类别需要注意。要继续加强农村卫生人力资源的投入,国家和各省(自治区、直辖市)要稳定公共卫生队伍,健全基层医疗卫生服务发展,提高公平性与可及性。

重庆市绿色空间景观格局与PM_(2.5)浓度时空相关性

空气中的细颗粒物对人民群众身体健康产生严重威胁,探究绿色空间景观格局对PM_(2.5)浓度的影响,有助于通过调整绿色空间格局降低PM_(2.5)浓度。以重庆市1980~2020年土地利用遥感监测数据和PM_(2.5)浓度数据作为基础数据,通过景观格局指数法、空间自相关分析研究绿色空间景观格局及PM_(2.5)浓度变化特征,再通过时空地理加权回归(GTWR)模型研究绿色空间景观格局指数变化对PM_(2.5)浓度的影响及其时空异质性。结果表明:①重庆市PM_(2.5)浓度从1980年至2010年逐渐上升,2010年至今逐渐降低;同时,其空间分布具有显著聚集特征,主要显示为东部低-低聚集、西部高-高聚集的特征。②林地、草地和耕地的面积指数(TA)、斑块密度指数(PD)和斑块连接度指数(COHESION)与PM_(2.5)浓度具有显著的相关性。其中,林地面积指数呈负影响,耕地、草地面积指数呈正影响;林地、草地斑块密度指数呈正影响,耕地斑块密度指数呈负影响;林地、草地和耕地斑块连接度指数均呈负影响。③主城都市区内,草地面积指数和耕地斑块密度指数对PM_(2.5)浓度的负影响较强。渝东北三峡库区城镇群和渝东南武陵山区城镇群内,林地聚合度指数(AI)、斑块密度指数和斑块连接度指数以及耕地面积指数对PM_(2.5)浓度的影响较强。

不同镁硼浓度配比营养液对静止水培番茄幼苗生长的影响

以樱桃番茄幼苗为试验材料,采用静止水培的方式,研究以山崎番茄专用配方为基础,添加不同浓度镁硼的营养液对番茄幼苗生长的影响。试验设6个不同镁硼配比浓度(mmol/L),分别为0.5∶0.014、0.5∶0.018、0.5∶0.023、1.0∶0.014、1.0∶0.018、1.0∶0.023。试验结果表明:不同镁硼浓度配比的营养液对番茄幼苗的株高、根系长度、鲜重、干重、壮苗指数、叶绿素含量、根系活力及可溶性糖含量的提高均有促进作用;镁硼浓度配比为1.0∶0.018时,番茄幼苗的根系长度、茎粗、鲜重干重、壮苗指数及叶绿素含量等指标表现最佳,利于培育番茄优质壮苗。

耐碳青霉烯类鲍曼不动杆菌联合药敏试验研究

目的了解耐碳青霉烯类鲍曼不动杆菌(CRAB)的分布特征和耐药状况,评价以黏菌素(COL)为基础,分别与头孢哌酮/舒巴坦(SCF)、替加环素(TGC)、亚胺培南(IPM)、美罗培南(MEM)、阿米卡星(AK)和左氧氟沙星(LEV)联合的体外抗菌效果,为临床抗感染治疗提供参考。方法收集2022年我院75株非重复分离的CRAB菌株,用WHONET 5.6软件分析其临床分布和耐药情况。从中筛选25株,采用微量肉汤稀释法测定各药物单独及联合时的最低抑菌浓度(MIC),用棋盘法抑菌试验计算部分抑菌浓度指数(FIC)判定联合效应。结果2022年我院共分离鲍曼不动杆菌145株,其中CRAB 75株,检出率51.7%。CRAB在>70岁老年患者中检出率最高(40.0%),主要来源于血液(41.3%)和痰液(37.3%)标本,ICU是主要分离科室。75株CRAB对5种抗菌药物哌拉西林(PRL)、哌拉西林/他唑巴坦(TZP)、头孢曲松(CRO)、IPM和MEM均100%耐药;对3种药物氨苄西林/舒巴坦(SAM)、头孢吡肟(FEP)和复方磺胺甲噁唑(SXT)的耐药率均>95%;对LEV、SCF、AK、TGC和COL的耐药率分别为86.7%、82.7%、77.4%、2.4%和0.0%。25株CRAB的联合药敏试验显示,COL分别与SCF和TGC的协同率最高(92%和80%),协同率与相加率之和均为100%;COL与IPM、MEM、AK、LEV联合的协同率依次为64%、72%、56%和48%,均无拮抗作用。结论CRAB呈高度耐药,老年和ICU患者是高危人群。COL与SCF联合具有最佳协同作用,COL与LEV联合效果最差,值得临床参考。

基于全球视角下的口腔癌疾病负担公平性分析

目的研究1990—2019年由社会经济发展水平差异所致的全球口腔癌疾病负担不平等情况,为制定有效的预防和控制政策提供科学依据。方法本研究的疾病负担数据来源于2019年全球疾病负担研究,人类发展指数(human development index,HDI)来自于《2020年人类发展报告》,采用线性回归分析年龄标化的伤残调整寿命年(disability-adjusted life yeas,DALY)率与HDI的相关性,使用不平等斜率指数(slope index of inequality,SII)和集中指数(concentration index,CI)评价1990—2019年全球口腔癌疾病负担的不公平情况及发展趋势。结果本研究共纳入189个国家和地区,2019年口腔癌DALY率为46.61[IQR(30.70,64.97)],线性回归结果显示口腔癌DALY率与HDI水平呈显著负相关(ρ=-0.06,P<0.001)。口腔癌DALY负担在189个国家和地区间表现出显著的不平等性,2019年SII值为-107.16[95%CI(-127.60,-90.69)],1990—2019年SII值<0且绝对值呈上升趋势;2019年口腔癌CI值为-1.35[95%CI(-2.88,-1.01)],1990—2015年CI值>0且呈下降趋势,而2016—2019年CI值<0且绝对值呈上升趋势。结论1990—2019年全球口腔癌疾病负担存在明显的社会不公平现象,口腔癌疾病负担更集中在低社会经济发展水平国家,且随着时间变化呈现出加重趋势。因此,未来应注重发展中国家的医疗资源分配问题,采取更有针对性的措施,有效控制口腔癌疾病负担的不平等现状。