Effects of various dietary levels of copper hydroxychloride on growth performance and tissue response in Pacific white shrimp Litopenaeus vannamei fed practical diets

Two trials were conducted to evaluate the performance of Pacific white shrimp Litopenaeus vannamei offered diets containing various copper (Cu) levels from Cu hydroxychloride (Cu₂(OH)₃Cl) containing 58.81% copper in the clear water recirculating system. In both trials, the basal diet (360 g kg^?1 protein, 80 g kg^?1 lipid) containing approximately 10 mg Cu kg^?1 was primarily comprised of fishmeal, soybean meal, corn protein concentrate and whole wheat. In trial 1, test diets were produced supplementing the basal diet with 5, 10, 20, 40 and 60 mg Cu kg^?1 from Cu hydroxychloride. Four replicate groups of 15 shrimp per tank (initial weight 0.28 g) were offered diets in slight excess over 8 weeks. In trial 2, the basal diet was supplemented with 30, 90, 150, 210 and 270 mg Cu kg^?1 from Cu hydroxychloride. Seven replicate groups of 15 shrimp per tank (initial weight 0.22 g) were offered feed in slight excess over 7 weeks. At the end of the two growth trials, no significant differences were observed in final biomass, final mean weight, percentage weight gain, feed conversion ratio (FCR) and survival. In trial 1, the Cu concentrations of the carapace, hepatopancreas and whole shrimp linearly increased with increasing dietary Cu supplements. In trial 2, polynomial regression of Cu concentrations of the carapace, hepatopancreas and whole shrimp against analysed dietary Cu content indicated that a plateau was reached at 215 mg analysed Cu kg^?1. Results of this study indicate that there was no negative effect of high levels of Cu supplement with regard to growth and survival. Tissue levels generally increased up to around 200 mg Cu kg^?1 diet and then decreased, possibly indicating a shift in physiology.     

锌与吡虫啉配合喷施对小麦籽粒富锌效果及蛋白质组分的影响

[目的]探讨锌与杀虫剂配合喷施对小麦全粒及面粉富锌效果、蛋白质组分和人体每日吸收总锌(TAZ)的影响,阐明富锌效果存在差异的可能原因,以期为小麦农艺富锌方法提供可靠依据及高效可行的喷施方案.[方法]2016—2018年进行了两年田间试验,试验共设置了6个处理:喷蒸馏水(CK)、喷施0.1％吡虫啉(P)、喷施0.4％Zn...     

阿莫西林可溶性粉在猪体内的药代动力学和绝对生物利用度研究

研究阿莫西林可溶性粉在猪体内的药代动力学特征，并评价其与市售注射用阿莫西林钠的生物等效性。采用高效液相色谱法（HPLC）测定血浆中阿莫西林浓度，通过Data Analysis System（DAS 3.0）计算药动学参数，采用非房室模型分析方法对药代动力学参数进行评价，猪经内服给药后，药物平均滞留时间MRT(0-t)为3.12±0.41h，平均达峰时间Tmax为1.63±0.35h，平均达峰浓度Cmax为4101.35±631.55μg/L，平均药-时曲线下面积AUC(0-t)为13540.33±3445.51μg/L×h，消除速率常数λz为0.36±0.14/h，半衰期t1/2z为2.48±1.73h。 猪经静脉注射给药后，平均滞留时间MRT(0-t)为1.54±0.35h，平均药-时曲线下面积AUC(0-t)为8522.56±1430.51μg/L×h，消除速率常数λz为0.23±0.12/h，半衰期t1/2z为3.84±2.03h。 结果表明：受试制剂阿莫西林可溶性粉经内服给药后，具有较快的吸收速度，吸收进血液后在体内的停留时间较短，代谢较快，平均达峰时间短，药物消除速度较快，平均绝对生物利用度为79.44%，为临床制定合理用药方案提供科学依据。     

Effects of soil amendments, foliar sprayings of silicon and selenium and their combinations on the reduction of cadmium accumulation in rice

Agricultural soil contamination by cadmium (Cd) is becoming one of the most serious environmental issues and public concerns. In this study, factorial arrangements of treatments were designed to explore the effects of two soil amendments, sodium sulfide-biofuel ash (SSBA) and lime (0.1%), and three foliar applications, silicon (Si, 2.5 mmol L^-1), selenium (Se, 40 mg L^-1), and their combination (SS), on Cd reduction in rice (Oryza sativa L.) in a pot experiment, which were then verified in a field experiment. Compared with the control without amendment but with spraying of deionized water, both SSBA and lime significantly reduced concentrations of CaCl₂-extractable Cd in soil by 30%-39% and 31%-40% and Cd in brown rice by 44%-63% and 53%-72% in the pot and field experiments, respectively. Foliar Si, Se, and SS applications significantly reduced Cd accumulation in brown rice by 62%-64%, 72%-83%, and 39%-73%, respectively, increased rice grain yield, and improved antioxidant enzyme activities in rice leaves but with different trends in the pot and field experiments. Combinations of SSBA and lime with Si, Se, and SS had a non-significant synergistic effect on Cd reduction in brown rice compared to only foliar spraying or soil amendment in both pot and field experiments, although SSBA + Se and SSBA + Si reduced Cd concentration in brown rice by 16%-34% and 14%-24% compared to only foliar Si and Se and soil SSBA applications, respectively. Soil lime application and foliar Si spraying were the most cost-effective strategies to reduce Cd accumulation in brown rice in the field and pot experiments, respectively. Although soil amendments and foliar treatments were individually effective, their combinations failed to generate a significant synergistic reduction of Cd concentration in brown rice.     

阿苯达唑纳米混悬剂的研制及其评价

为了解决阿苯达唑的溶解性和口服吸收难题，借助高分子活性剂的稳定作用，利用反溶剂法-高压匀质法制备阿苯达唑纳米混悬剂，并考察该制剂的药学特征及稳定性；研究该制剂在大鼠体内的药代动力学。研究创制的纳米混悬液在电镜下药物形状大小均一，中位粒径为358.1nm。其药学特征符合《兽药质量标准》（2017版）中对混悬液的质量要求。6个月加速试验表明，该制剂外观色泽、含量、pH值、沉降体积比、重分散性均未发生明显变化，且放置6个月后粒径没有显著变化。该阿苯达唑纳米混悬液的Cmax为5.895μg/mL，显著高于参比制剂阿苯达唑伊维菌素粉、佛山正典阿苯达唑混悬液的2.804和2.053μg/mL。与阿苯达唑伊维菌素粉、佛山正典阿苯达唑混悬液相比，该制剂的相对生物利用度分别为214% 和299.74% ，表明该阿苯达唑纳米混悬液能显著提高阿苯达唑的吸收，将有助于提高临床治疗效果。     

钝化剂对土壤性质及镉生物有效性的影响研究

为研究土壤重金属钝化稳定化技术中钝化剂施加对土壤物理化学性质及镉生物有效性的影响,通过培养试验结合定期密集采样监测方法,研究羟基磷灰石(HAP)、小麦生物炭(WB)、巯基改性坡缕石(MPG)施加对镉污染碱性土壤pH值、EC值、团聚体组成和DTPA-Cd变化规律的影响,并分析不同因子间的相关关系。结果表明:HAP显著提高土壤pH值0.16～0.30个单位(P0.01),降低土壤EC值;WB则降低土壤pH值0.09～0.32个单位,显著提高土壤有机质、增加土壤EC值(P0.05);MPG处理对土壤pH值和EC值无显著影响。与对照组(不施加钝化剂)相比,3种钝化剂施加后短时间内(5 d)土壤中2mm和2～20mm团聚体比例增加,随着钝化稳定时间的延长,土壤中20mm团聚体占比逐渐增大;对比3种钝化剂对Cd2+的钝化效果,MPG钝化效果最佳,40d后DTPA-Cd含量较对照组降低3.01 mg·kg-1。相关性分析表明,HAP和WB通过改变土壤pH值影响土壤DTPA-Cd含量,XRD表明HAP通过磷酸镉沉淀降低土壤DTPA-Cd含量,HAP和MPG处理组土壤Cd2+的稳定化导致各粒径团聚体比例的变化。研究表明,MPG可显著降低镉的生物有效性且对土壤理化性质无显著影响,可作为碱性土壤原位钝化技术中钝化剂的优先选择。     

设施菜地利用强度对土壤磷形态分布及其有效性的影响——以江苏省水耕人为土和潮湿雏形土为例

以江苏省水耕人为土和潮湿雏形土两种土壤类型为对象,研究了设施菜地利用强度对土壤磷形态分布及其有效性的影响。结果表明:随利用强度增加,两种土壤类型的各磷形态含量均有所增加,以水溶态磷和铝结合态磷(Al-P)增加最为显著(P<0.05)。而水耕人为土闭蓄态磷(O-P)占总磷百分比和潮湿雏形土残渣态磷占总磷百分比随利用强度增加则表现出显著降低的趋势(P<0.05)。回归分析结果表明,水耕人为土有效磷主要来自于铁结合态磷(Fe-P)和Al-P;潮湿雏形土有效磷主要来自于水溶态磷和钙结合态磷(Ca-P),且以前者更为重要。另外,设施蔬菜生产增加了土壤磷淋失的风险,尤其是潮湿雏形土。水–旱轮作并结合减少施肥量可能是降低设施土壤磷淋失风险的一个有效措施。     

中药重金属生物可给性与生物有效性研究进展

中药作为我国传统医学的重要组成部分，在国内外深受关注。近年来，由中药重金属累积所致的人体健康风险为其推广、使用带来了一定的阻碍。重金属累积产生的人体健康风险不仅取决于其总量，与其生物可给性和生物有效性更是密切相关。因此，研究中药重金属生物可给性及生物有效性具有重要的科学意义和应用价值。本文综述了中药重金属污染现状与形势，阐述了中药重金属生物可给性与生物有效性的研究概况，以中药原药的生长环境、自身性质、加工过程及测定条件等方面为切入点，深入分析影响中药及其制品重金属生物可给性与生物有效性的关键因素，以期为中药重金属污染风险防控提供理论依据和技术支持。     

土壤中9-芴酮和9，10-蒽醌的分析方法及赋存形态

为探究含氧多环芳烃（oxygenated polycyclic aromatic hydrocarbon，OPAHs）在土壤中的赋存形态特征，以9-芴酮和9，10-蒽醌为OPAHs模式物，建立了其在不同基质中的提取及测定方法，分析了其在土壤中30 d内的赋存形态。结果表明：以甲醇-二氯甲烷（1∶1，V/V）溶液为萃取剂，采用超声-高效液相色谱法提取测定土壤中的9-芴酮和9，10-蒽醌，回收率为102.4%~104.2%。以二氯甲烷为萃取剂，通过液液萃取-高效液相色谱法测定水相及生物有效态相（羟丙基-β-环糊精）中的9-芴酮和9，10-蒽醌，回收率分别为87.2%~87.8%和78.7%~86.3%。采用连续提取方法，研究了这2种OPAHs在土壤中30 d内的形态分布，各形态9-芴酮和9，10-蒽醌含量之和的顺序为难解吸态>粗胡敏素结合态>干酪根结合态>生物有效态>胡敏酸结合态>富里酸结合态>矿物结合态。可提取态（生物有效态与难解吸态加和）为主要存在形态（58.0%），结合态亦占有相当大的比例（42.0%），有机质结合态较矿物结合态含量占比更高。土壤中9-芴酮和9，10-蒽醌在前15 d生物有效性降低较快，后15 d趋缓，9-芴酮较9，10-蒽醌生物有效性下降更快。     

富硒土壤中硒生物有效性的提取方法研究

为建立适用于酸性富硒土壤有效硒提取的方法，从湖北省恩施土家族苗族自治州建始县天然富硒区采集了40份土壤样品进行水稻盆栽试验，采用连续浸提法和10种常用的单步浸提法对土壤硒形态和有效硒进行了提取、测定，并分析了不同浸提方法提取的有效硒含量与植物硒的相关性。结果显示：建始县酸性富硒土壤中水溶态和交换态硒的含量较低，分别为0.12～46.0、0.58～197.35μg/kg；硒主要以有机结合态和残渣态等难以被植物利用的形态存在，铁锰氧化物结合态、有机结合态及残渣态硒含量分别为0.01～0.34、0.05～0.88、0.04～2.72 mg/kg；在10种单一浸提剂中，0.5 mol/L NaHCO₃和0.1 mol/L KH₂PO₄溶液对土壤有效硒的提取效率较高；在不同土壤硒形态中，交换态硒与植物硒的相关性最高(r=0.80,P<0.01)，其余形态硒与植物硒含量的相关性均低于交换态硒。在单一浸提法中，0.1 mol/L KH₂PO₄溶液和0.5 mol/L NaHCO3溶液提...