聚乙二醇/蒙脱石插层复合物的制备及结构表征

通过X射线衍射、傅里叶变换红外光谱和差热分析表征聚乙二醇(PEG)／蒙脱石复合物的结构结果表明，PEG以单层或双层平卧于蒙脱石层间；PEG通过转换部分层间水进入蒙脱石层间通道内；大分子量的PEG与蒙脱石层间表面有更强的相互作用．     

蒙脱石/聚丙烯酰胺插层复合材料的制备及结构表征

利用蒙脱石层间域活性，合成蒙脱石／聚丙烯酰胺（Mntmorillonite-PAM)插层复合物，并用X－射线衍射，傅立叶变换红外光谱，差热分析等分析测试手段对插层复合物的结构进行表征。     

不同钝化机制矿物对土壤重金属的钝化效果及微生物响应

为探讨石灰石、蒙脱石两种不同钝化机制矿物施加对土壤重金属的钝化效果和土壤环境健康的影响,利用盆栽试验,通过常规测定方法和16S rRNA高通量测序手段,分析土壤酶活性和微生物群落结构的变化,并结合土壤重金属有效性、水稻富集系数和转运系数等指标,研究两种矿物施加后土壤的环境功能响应及其影响机制。结果表明:施加石灰石显著降低了土壤Cd、Cu、Pb、Zn的有效性,降低幅度依次为Zn(99.1%)Cd(91.4%)Cu(85.6%)Pb(46.1%),并显著降低了Cd、Zn的富集系数(43.4%～85.5%)和转运系数(Cd 62.5%、Zn 30.0%),而施加蒙脱石使土壤Pb的有效性降低幅度达19.5%,但其含量与对照差异不显著;施加石灰石显著提高了土壤过氧化氢酶和脲酶活性,均为对照(不施加钝化剂)的1.6倍,施加蒙脱石后土壤过氧化氢酶活性显著提高(为对照的1.4倍),但脲酶活性没有明显变化;施加蒙脱石对土壤微生物多样性和微生物群落结构影响较小,但施加石灰石后,土壤微生物多样性指数显著增加,且f_Gemmatimonadaceae、f_BIrii41和c_KD4-96等有益微生物属的丰度明显提高。研究表明,与通过吸附对重金属钝化的蒙脱石相比,石灰石通过提升土壤pH,不但能更有效地降低土壤中Cd、Cu、Pb、Zn等重金属的生物有效性,还能提升土壤酶活性和微生物的多样性,从而改善土壤健康状况,其中土壤pH、有效磷和有机质含量是影响微生物群落结构的关键因素。     

离子强度及pH对不同类型土壤中胶体释放的影响

采用实验室土柱纵向淋溶法,研究了离子强度及pH变化对常熟乌栅土原状、扰动土柱以及东北黑土、江西红壤扰动土柱土壤胶体释放的影响。结果表明离子强度变化对我国不同类型土壤胶体释放影响不同：淋洗液电解质为NaCl时,对于常熟乌栅土以及东北黑土,离子强度减小促进胶体的释放,反之抑制胶体的释放;对于江西红壤,离子强度变化对土壤胶体释放则不产生影响。淋洗液电解质为CaCl2条件下,土壤胶体的释放量低于淋洗液为NaCl,且离子强度变化对三种土壤胶体的释放均不产生明显影响。相同条件下,常熟乌栅土及东北黑土胶体释放量远远大于江西红壤,pH变化则对上述类型土壤胶体释放的影响不明显。研究结果有助于进一步阐明水化学条件的变化对我国不同类型土壤胶体释放的影响规律。     

基于Zeta电位法分析新生亚硫酸钙对蔗汁胶体的吸附特性

【目的】从Zeta电位的角度考察新生亚硫酸钙对蔗汁胶体的吸附规律,为适时监测和优化制糖澄清工艺提供新途径。【方法】通过模拟亚硫酸法制糖澄清工艺,探讨新生亚硫酸钙吸附蔗汁胶体过程中Zeta电位的变化规律及其与新生亚硫酸钙对蔗汁胶体吸附量（Qe）的相关性。【结果】随着p H和胶体浓度的升高,Zeta电位和新生亚硫酸钙对蔗汁胶体的Qe逐渐增大;随着Zeta电位的增大,新生亚硫酸钙对蔗汁胶体的Qe也逐渐增加。新生亚硫酸钙对胶体的吸附等温线采用Freundlich模型拟合时,其拟合参数R^2大于Langmuir模型的拟合参数R^2。【结论】新生亚硫酸钙对蔗汁胶体吸附特性更符合Freundlich等温吸附模型,且新生亚硫酸钙对蔗汁胶体的Qe与其Zeta电位呈正相关。     

一种新型肠粘膜保护剂——载铜蒙脱石对肠粘膜屏障功能影响的研究

以蒙脱石（MMT）为原料，通过阳离子交换反应合成载铜蒙脱石（MMT-Cu）。为探讨载铜蒙脱石对肠粘膜屏障功能的影响，采用体外培养的单层Caco-2细胞模型为研究对象，以细菌易位数量和肠绒毛损伤程度做为指标进行研究。结果表明：MMT-Cu可明显减少（P〈0．01）E．coilK88、S．choleraesuis侵入到Caco-2细胞内的数量，与对照组相比，下降了2logCFU／mL～3log CFU／mL；并能显著降低（P〈0．01）LDH的释放量。扫描电子显微镜下观察可见，加入MMT-Cu一段时间后，当E．coil K88和S．choleraesuis粘附Caco-2细胞时，微绒毛依旧排列整齐、致密，可见肠上皮细胞保持完好。结果表明，MMT-Cu对肠粘膜具有屏障作用，可作为一种消化道粘膜保护剂。     

Products to alleviate the effects of necrotic enteritis and aflatoxin on growth performance,lesion scores,and mortality in young broilers

This study investigated the effects of necrotic enteritis challenge or a necrotic enteritis challenge with an additional challenge from dietary aflatoxin B₁ compared to broilers that were unchallenged. Also tested were products designed to help alleviate those effects. Lesion scores were higher in broilers challenged to induce necrotic enteritis, but this did not increase with added aflatoxin. The presence of dietary aflatoxin during a necrotic enteritis challenge significantly increased the negative effects of the necrotic enteritis challenge. During the necrotic enteritis challenge virginiamycin, Calibrin-Z, or a blend of Calibrin-Z, an organic acid, and yucca, helped to decrease the effects of the challenge. When birds are challenged with necrotic enteritis and dietary aflatoxin is present, Calibrin-Z had an advantage over all other tested products.     

载菌蒙托石改善鲫养殖水质和生长性能的研究

以附载益生菌-沼泽红假单胞菌的蒙托石为研究对象,通过对鲫养殖水质指标和生长性能的测定,研究了其作用效果.试验分为1个对照组和3个试验组(T1、T2、T3分别添加一定量的沼泽红假单胞菌、蒙托石和载菌蒙托石).试验结果表明,与对照组相比,试验组T3显著降低了(P < 0.01)养殖水体后期氨氮、亚硝酸盐氮、硝酸盐氮、化学需氧量和硫化物的含量,提高了鲫的质量日增长和质量相对增长率(P < 0.01),改善效果优于T1和T2.试验组T1和T2在生长指标上与对照组比较,虽有不同程度的提高,但差异不显著(P > 0.01).     

The role of albumin replacement in the critically ill veterinary patient

Objective: To review the human and veterinary literature on the physiological role and effects of therapeutic albumin supplementation. Data sources: Data from human and veterinary literature was reviewed. Human data synthesis: Hypoalbuminemia often occurs in a variety of critical illnesses, and contributes to the development of life‐threatening complications, including pulmonary edema, delayed wound healing, feeding intolerance, hypercoaguability, and multiple organ dysfunction. Serum albumin concentration has been used as a prognostic indicator in cases of chronic hypoalbuminemia. The use of albumin replacement therapy in humans is sometimes controversial, but may be associated with improved morbidity and decreased mortality. Veterinary data synthesis: Unlike human literature, there is a paucity of controlled clinical studies in the literature regarding albumin supplementation in veterinary patients. Rather, the majority of published studies were performed in experimental animals or via retrospective analyses. One recent study evaluated the use of plasma to improve albumin concentration in dogs with hypoalbuminemia. Other older studies investigated wound healing in dogs with experimentally induced hypoalbuminemia. As in human medicine, serum albumin concentration may be helpful as a prognostic indicator in critically ill dogs. Conclusion: Albumin is one of the most important proteins in the body because of its role in maintenance of colloid oncotic pressure, substrate transport, buffering capacity, as a mediator of coagulation and wound healing, and free‐radical scavenging. Albumin replacement in veterinary medicine is difficult, but until prospective clinical trials determine the efficacy of albumin replacement are conducted, a suggested clinical guideline would be to maintain albumin concentration at or above 2.0 g/dl utilizing fresh frozen plasma.     

The effects of lactated Ringer's solution (LRS) or LRS and 6% hetastarch on the colloid osmotic pressure, total protein and osmolality in healthy horses under general anesthesia

ObjectiveTo investigate changes in colloid osmotic pressure (COP), total protein (TP) and osmolality (OSM) during anesthesia in horses given intravenous lactated Ringer’s solution (LRS) or LRS and hetastarch (HES).Study designProspective, clinical trial.AnimalsFourteen horses presented for surgery. Mean age 8.3 ± 1.9 years; mean weight 452 ± 25 kg.MethodsHorses were premedicated with xylazine intravenously (IV); anesthesia was induced with ketamine and diazepam IV, and maintained with sevoflurane. Butorphanol was administered IV with pre-medications or immediately after induction. Xylazine was administered IV for recovery if necessary. LRS was administered IV to all horses with a target rate of 5–10 mL kg^?1 hour^?1. Half of the horses also received 6% HES, 2.5 mL kg^?1 over 1 hour in addition to LRS. Horses that received LRS only were considered the LRS group. Horses that received both LRS and HES were considered the LRS/HES group. Blood was drawn pre- and post-anesthesia, immediately following induction, and every 30 minutes throughout anesthesia. COP, TP and OSM were measured.ResultsCOP and TP significantly decreased at similar rates for both treatment groups from pre-anesthetic values. Pre-anesthetic COP was significantly greater in the LRS group when compared to the LRS/HES group pre-, post- and throughout anesthesia. In the LRS group post-anesthetic OSM was significantly different than the pre-anesthesia value and that for the LRS/HES group.Conclusions and clinical relevanceAdministration of IV HES (2.5 mL kg^?1, over 1 hour) in combination with LRS does not attenuate the decrease in COP typically seen during anesthesia with crystalloid administration alone. Based on these results, administration of HES at this rate and total volume would not be expected to prevent fluid shifts into the interstitium through its effects on COP.