BACKGROUND & AIMS: :Radix astragali is a popular traditional herbal medicine that provides significant protection against tissue injury in various models of oxidative stress-related diseases. In this study, we aimed to investigate whether administration of Radix astragali prevented atrophy in both slow- and fast-twitch muscles following cast immobilization. Twenty-seven 12-week-old male F344 rats were divided into three experimental groups: control (CON), immobilized (IM), and immobilized with Radix astragali administration (IM+AR). Rats in the IM and IM+AR groups were subjected to immobilization of both lower extremities using casting-tape for 14 days. Rats in the IM+AR group were orally administered a decoction of Radix astragali daily for 21 days beginning 7 days before cast immobilization. As expected, rats in the IM group showed significant decreases (P < 0.05) in soleus and plantaris muscle-to-body weight ratios by 74.3% and 70.5%, respectively, compared with those in the CON group. Administration of Radix astragali significantly reversed (+35.5%) the weight reduction observed in soleus muscle, but not in the plantaris muscle, compared with that in the IM group. Furthermore, administration of Radix astragali inhibited MuRF1 mRNA expression only in the soleus muscle during cast immobilization. Our results demonstrated that administration of Radix astragali suppressed the immobilization-induced reductions in skeletal muscle mass and expression of MuRF1 mRNA in slow-twitch soleus muscles, but not in fast-twitch plantaris muscles.

背景与目标： 黄芪是一种流行的传统草药，可在各种氧化应激相关疾病模型中提供显着的保护，以防止组织损伤。在这项研究中，我们旨在调查黄芪注射液在石膏固定后是否能预防慢肌和快肌的萎缩。将27只12周大的雄性F344大鼠分成三个实验组：对照组（CON），固定化（IM）和黄芪给药（IM AR）固定化。 IM和IM AR组中的大鼠使用铸型带固定两个下肢14天。 IM AR组中的大鼠每天口服一次黄芪水煎汤，持续21天，开始施药固定7天。正如预期的那样，与CON组相比，IM组大鼠的比目鱼肌和plant肌与体重的比率分别显着降低（P <0.05）74.3％和70.5％。与IM组相比，黄芪注射液可显着逆转（35.5％）在比目鱼肌中观察到的体重减轻，但在the肌中观察不到。此外，黄芪的施用仅在石膏固定期间抑制比目鱼肌中的MuRF1 mRNA表达。我们的结果表明，黄芪能抑制固定化诱导的慢肌比目鱼肌骨骼肌质量的减少和MuRF1 mRNA的表达，但不能抑制快肌动的比目鱼肌。

BACKGROUND & AIMS: :Agmatine, an endogenous amine derived from decarboxylation of L-arginine catalyzed by arginine decarboxylase, has been proposed as a neurotransmitter or neuromodulator in the brain. In the present study, we examined whether agmatine has neuroprotective effects against repeated immobilization-induced morphological changes in brain tissues and possible effects of immobilization stress on endogenous agmatine levels and arginine decarboxylase expression in rat brains. Sprague-Dawley rats were subjected to 2h immobilization stress daily for 7 days. This paradigm significantly increased plasma corticosterone levels, and the glutamate efflux in the hippocampus as measured by in vivo microdialysis. Immunohistochemical staining with beta-tubulin III showed that repeated immobilization caused marked morphological alterations in the hippocampus and medial prefrontal cortex that were prevented by simultaneous treatment with agmatine (50mg/kg/day), i.p.). Likewise, endogenous agmatine levels measured by high-performance liquid chromatography in the prefrontal cortex, hippocampus, striatum and hypothalamus were significantly increased by immobilization, as compared to controls. The increased endogenous agmatine levels, ranging from 92 to 265% of controls, were accompanied by a significant increase of arginine decarboxylase protein levels in the same regions. These results demonstrate that the administration of exogenous agmatine protects the hippocampus and medial prefrontal cortex against neuronal insults caused by repeated immobilization. The parallel increase in endogenous brain agmatine and arginine decarboxylase protein levels triggered by repeated immobilization indicates that the endogenous agmatine system may play an important role in adaptation to stress as a potential neuronal self-protection mechanism.

背景与目标： ：胍丁胺，一种由精氨酸脱羧酶催化的L-精氨酸脱羧而衍生的内源性胺，已被提出作为大脑中的神经递质或神经调节剂。在本研究中，我们检查了胍丁胺是否对反复固定化引起的脑组织形态变化具有神经保护作用，以及固定化应激对大鼠脑中内源性胍丁胺水平和精氨酸脱羧酶表达的可能影响。每天对Sprague-Dawley大鼠进行2h固定应激，持续7天。通过体内微透析测量，该范例显着增加了血浆皮质酮水平和海马中的谷氨酸外排。用β-微管蛋白III进行的免疫组织化学染色显示，反复固定会引起海马和前额内侧皮层的明显形态学改变，这可以通过同时用胍丁胺（50mg / kg /天）腹膜内注射来预防。同样，与对照相比，通过高效液相色谱法测定的前额叶皮层，海马，纹状体和下丘脑中的内源胍丁胺水平由于固定而显着增加。内源性胍丁胺水平的升高，从对照的92％到265％不等，同时在相同区域中精氨酸脱羧酶蛋白水平也显着增加。这些结果表明，外源性胍丁胺的给药可保护海马和前额内侧皮层免受反复固定引起的神经元损伤。反复固定化触发内源性大脑胍丁胺和精氨酸脱羧酶蛋白水平的平行增加表明，作为潜在的神经元自我保护机制，内源性胍丁胺系统可能在适应压力中起重要作用。

BACKGROUND & AIMS: :Clinical and experimental studies have shown that the activation of corticotropin-releasing hormone (CRH) and noradrenergic systems mediate stress-induced anxiety. Repeated immobilization stress (RIS) has been shown to induce long-lasting anxiety behavior and changes in noradrenaline turnover. The present work was aimed at studying the effect of RIS on the in situ expression of CRH-LI in the central extended amygdala and paraventricular nucleus of the hypothalamus (PVN). Our results showed that RIS for 15 days induces a significant increase of CRH-LI expression in the central extended amygdala. The increase in CRH-LI expression in the central extended amygdala was sustained even after a 25-day stress-free period. The concomitant administration of desipramine (DMI), a specific noradrenaline uptake inhibitor, fully prevented the RIS-induced increase in CRH expression. RIS also induced an increase of CRH-LI expression in the PVN that was prevented by the concomitant DMI administration. In contrast to the sustained effect observed in the central extended amygdala, the RIS-induced increase of CRH-LI expression in the PVN was nonlasting. DMI administration also prevented the RIS-induced increase of adrenal gland weight. The present findings showing that RIS induces a sustained increase of CRH expression in the central extended amygdala suggest that the repeated activation of CRH neurons and CRH receptors in the central extended amygdala may underlie the long-lasting anxiety behavior induced by RIS. Further studies should address the mechanisms involved in the effect of DMI and its eventual relevance in the therapeutic actions of DMI.

背景与目标： ：临床和实验研究表明，促肾上腺皮质激素释放激素（CRH）和去甲肾上腺素能系统的激活介导了压力诱发的焦虑。反复的固定应激（RIS）已显示出引起长期的焦虑行为和去甲肾上腺素周转率的变化。目前的工作旨在研究RIS对下丘脑中央延伸杏仁核和室旁核（PVN）中CRH-LI原位表达的影响。我们的结果表明，RIS持续15天会导致中央中央杏仁核中CRH-LI表达的显着增加。即使在25天的无压力期后，中央延伸杏仁核中CRH-LI表达的增加仍然持续。伴随给药地昔帕明（DMI）（一种特定的去甲肾上腺素摄取抑制剂）的同时给药，完全可以防止RIS引起的CRH表达增加。 RIS还诱导了PVN中CRH-LI表达的增加，这可以通过同时给予DMI来预防。与在中央延伸杏仁核中观察到的持续作用相反，RIS诱导的PVN中CRH-LI表达的增加是持久的。 DMI管理还可以防止RIS引起的肾上腺重量增加。目前的发现表明，RIS诱导中央延伸杏仁核中CRH表达的持续增加，表明中央延伸杏仁核中CRH神经元和CRH受体的重复激活可能是RIS诱导的长期焦虑行为的基础。进一步的研究应解决DMI的作用及其最终与DMI的治疗作用相关的机制。

BACKGROUND & AIMS: :The spineboard (SB) and the vacuum mattress (VM) are utilized for prehospital and emergency department (ED) immobilization of the spine. While permitting excellent pictures to be taken, the SB is a very painful device that can only be used for a limited time. The current study investigated the feasibility of different models of the VM for radiography. Computed tomography for each of seven VMs showed different degrees of shadows from the sac containing the polystyrole balls. This was related first of all to a high contrast of the sac in comparison with its contents and to a sometimes considerable shrinkage of the latter that resulted in further folding into the sac and, secondly, also to very broad mattresses, additional chambers within the VM and various grips and supports for lifting the mattress. Therefore, some features designed for prehospital use of the VM are actually acting against its use for diagnostic purposes. The aim of this study was to discuss and identify possible properties of a device that is useful for both immobilization and diagnostic purposes.

背景与目标： ：脊柱板（SB）和真空床垫（VM）用于固定脊柱的院前和急诊科（ED）。 SB可以拍摄出色的照片，但它是一种非常痛苦的设备，只能在有限的时间内使用。当前的研究调查了用于放射线照相术的VM的不同模型的可行性。七个VM的每台计算机断层扫描显示来自包含聚苯乙烯球的囊的阴影程度不同。首先，这与囊的内容物相比具有较高的对比度，并且有时与囊的明显收缩有关，从而导致囊进一步折叠成囊，其次还与非常宽的床垫，VM内的其他腔室有关。以及各种用于提起床垫的把手和支撑。因此，为院前使用VM设计的某些功能实际上与出于诊断目的而使用VM的行为相反。这项研究的目的是讨论和确定可用于固定和诊断目的的设备的可能特性。

BACKGROUND & AIMS: :Immobilized antibody systems are the key to develop efficient diagnostics and separations tools. In the last decade, developments in the field of biomolecular engineering and crosslinker chemistry have greatly influenced the development of this field. With all these new approaches at our disposal, several new immobilization methods have been created to address the main challenges associated with immobilized antibodies. Few of these challenges that we have discussed in this review are mainly associated to the site-specific immobilization, appropriate orientation, and activity retention. We have discussed the effect of antibody immobilization approaches on the parameters on the performance of an immunoassay.

背景与目标： ：固定化的抗体系统是开发有效的诊断和分离工具的关键。在过去的十年中，生物分子工程和交联剂化学领域的发展极大地影响了该领域的发展。利用所有这些新方法，已经创建了几种新的固定方法来解决与固定抗体相关的主要挑战。我们在这篇综述中讨论的这些挑战中，很少有与特定地点的固定化，适当的方向定位和活动保留有关的。我们已经讨论了抗体固定方法对免疫测定性能参数的影响。

BACKGROUND & AIMS: :This contribution presents the possibility of application of natural sorbent (Transcarpathian clinoptylolite (KL)) for immobilization of selected heavy metals in the sewage sludge. The influence of ion-exchange parameters (e.g. time, amount of zeolite) were discussed. Process of immobilization was performed using a static method (Batch). It was found that best possible conditions for immobilization of heavy metal ions were as follows: zeolite fraction 0.7-1.0mm, 5h of shaking, zeolite/sewage sludge ratio 2/98.

背景与目标： ：该研究成果表明有可能应用天然吸附剂（喀尔巴阡型斜发沸石（KL））固定化污水污泥中的某些重金属。讨论了离子交换参数（例如时间，沸石量）的影响。固定过程使用静态方法（批处理）进行。发现固定重金属离子的最佳可能条件如下：沸石级分0.7-1.0mm，振动5h，沸石/污水污泥比2/98。

BACKGROUND & AIMS: :Polymer-associated infections are a major problem in implanted or intravascular devices. Among others, microorganisms of the staphylococcal family have been identified as the most important culprit. Prevention of bacterial adhesion and colonization of polymeric surfaces by release of antimicrobial agents incorporated into the polymers itself are currently under study. We have developed a novel method for the functionalization of a polymeric surface which is based on the deposition of covalently coupled lipid structures from antibiotic loaded vesicles. We have found that such process significantly reduces the bacterial growth on polystyrene material. In this work, lipid coverage obtained from multilamellar (MLVs) and extruded unilamellar (LUVs) vesicles were analyzed with respect to their adhesion efficiency on three types of polystyrene (PS) well-plates. Two methods of lipid deposition were characterized and compared in terms of surface lipid density and time stability: deposition of cationic vesicles on negatively charged surfaces and formation of covalent linkages between functionalized lipids and amines enriched surfaces. In order to study the antibiotic encapsulation efficiency we measured how the rifampicin (RIF) loading was affected by changes of liposome charge upon introduction of various amounts of stearylamine (SA), distearoyl-trimethylammonium propane (DSTAP) or dioleoyloxypropyl-trimethylammonium chloride (DOTAP) into the liposomal formulation. RIF-coated polymeric surfaces were also tested against a Staphylococcus epidermidis strain to evaluate their efficacy in vitro, showing that only approximately 2% of such bacteria inoculated on MLV-treated PS substrate were able to proliferate. Covalently immobilized lipid films showed about a tenfold increase in time stability compared to electrostatically bonded lipid films. Furthermore, substrates covalently modified with RIF-loaded MLVs retained an antibacterial activity for up to 12 days when aged in buffer at 37 degrees C. Such antimicrobial polymer coatings show promise for their use as antibacterial barrier for the prevention of catheter-related infections.

背景与目标： ：与聚合物相关的感染是植入式或血管内装置的主要问题。其中，葡萄球菌家族的微生物已被确定为最重要的罪魁祸首。目前正在研究通过释放掺入到聚合物本身中的抗微生物剂来防止细菌粘附和聚合物表面定居。我们已经开发了一种用于聚合物表面功能化的新方法，该方法基于从载有抗生素的囊泡中共价偶联的脂质结构的沉积。我们已经发现，这种方法显着减少了细菌在聚苯乙烯材料上的生长。在这项工作中，分析了从多层（MLV）和单层挤出（LUV）囊泡获得的脂质覆盖度，分析了它们在三种类型的聚苯乙烯（PS）孔板上的粘附效率。表征了两种脂质沉积的方法，并根据表面脂质密度和时间稳定性进行了比较：阳离子小泡在带负电荷的表面上的沉积以及功能化脂质和富含胺的表面之间形成共价键。为了研究抗生素的包封效率，我们测量了引入各种量的硬脂胺（SA），二硬脂酰三甲基铵丙烷（DSTAP）或二油酰氧基丙基三甲基氯化铵（DOTAP）时脂质体电荷的变化如何影响利福平（RIF）的负载量进入脂质体制剂。还用RIF涂层的聚合物表面针对表皮葡萄球菌菌株进行了测试，以在体外评估其功效，结果表明，仅约2％的此类细菌接种在MLV处理的PS底物上能够繁殖。与静电结合的脂质膜相比，共价固定的脂质膜显示出约10倍的时间稳定性。此外，当在37摄氏度的缓冲液中老化时，用RIF负载的MLV共价修饰的底物在长达12天的时间内仍保留了抗菌活性。此类抗菌聚合物涂层有望将其用作预防导管相关感染的抗菌屏障。

BACKGROUND & AIMS: :Klebsiella oxytoca (NRRL-B199), although able to produce 2, 3-butanediol from glucose, converted lactose mainly into acetic acid. By addition of a preparation of lactase (beta-galactosidase, EC 3.2.1.23), the fermentation of lactose in a stirred vessel was three-times faster and resulted in a high concentration of 2, 3-butanediol. The lactase confined in dead cells of Kluyveromyces lactis (CBS 683) was prepared by permeabilization with solvents and fixation with glutaraldehyde. The cells were coimmobilized by adhesion to glass wool after treatment of the latter with chitosan, which ensured cell-support electrostatic attraction. The cell loading (dry weight) was ca. 9 gL(-1) for the yeast and ca. 2 gL(-1) for the bacteria. In the presence of culture medium, the adhesion of both cells was stable and the bacteria tended to form biofilms. The stability of the coimmobilized cells was demonstrated by the continous conversion of lactose into 2, 3-butanediol at 30oC during 25 days. The coimmobilization system gave output concentrations (14 gL(-1)) and rate of production (1 gL(-1) h(-1)) of 2, 3-butanediol from lactose, similar to those obtained in the literature with immobilized cells and glucose. Compared to the literature data on direct conversion of lactose using pure cultures, the present results showed higher butanediol concentrations and 10 to 100 times higher rates of production.

背景与目标： 产酸克雷伯氏菌（KRLbsiella oxytoca）（NRRL-B199）尽管能够从葡萄糖中产生2,3-丁二醇，但主要将乳糖转化为乙酸。通过添加乳糖酶制剂（β-半乳糖苷酶，EC 3.2.1.23），在搅拌容器中进行乳糖发酵的速度加快了三倍，并产生了高浓度的2，3-丁二醇。限制在乳酸克鲁维酵母（CBS 683）死细胞中的乳糖酶是通过溶剂渗透和戊二醛固定制备的。在用壳聚糖处理玻璃棉后，通过将其粘附到玻璃棉上来共同固定细胞，从而确保细胞支持静电吸引。电池负荷（干重）约为1。酵母约9 gL（-1），细菌2 gL（​​-1）。在培养基的存在下，两个细胞的粘附是稳定的，细菌倾向于形成生物膜。共固定细胞的稳定性通过将乳糖在30oC下连续25天连续转化为2，3-丁二醇来证明。共固定系统产生了乳糖2,3,3-丁二醇的输出浓度（14 gL（-1））和产生速率（1 gL（-1）h（-1）），与文献中固定细胞获得的相似和葡萄糖。与使用纯培养物直接转化乳糖的文献数据相比，目前的结果显示出更高的丁二醇浓度和更高的10至100倍的生产率。

BACKGROUND & AIMS: :Fermentation rates and intracellular compositions have been determined for alginate-entrapped Saccharomyces cerevisiae and for identical cells in suspension. Glucose uptake and ethanol and glycerol production are approximately two times faster in immobilized cells than in suspended cells. Phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy of fermenting immobilized and suspended cells shows differences in intermediate metabolite levels such as fructose-1,6 diphosphate, glucose-6-phosphate, and 3-phosphoglycerate and in internal pH. Carbon-13 NMR shows an increase in polysaccharide production. These data suggest that immobilization has accelerated the rate of glucose transport or of glucose phosphorylation. These effects of immobilization upon cell metabolism are observed in a very short period of time under conditions in which negligible DNA, RNA, or protein synthesis takes place.

背景与目标： ：已确定了藻酸盐捕获的酿酒酵母和悬浮细胞中相同细胞的发酵速率和细胞内组成。固定细胞中的葡萄糖吸收以及乙醇和甘油的产生比悬浮细胞中快约两倍。发酵固定化和悬浮细胞的磷31核磁共振波谱显示中间代谢物水平（如果糖1,6二磷酸，葡萄糖6磷酸和3-磷酸甘油酸）和内部pH的差异。碳13 NMR显示多糖产量增加。这些数据表明固定化加速了葡萄糖转运或葡萄糖磷酸化的速率。固定化对细胞代谢的这些作用在很短的时间内，在发生可忽略的DNA，RNA或蛋白质合成的条件下观察到。

BACKGROUND & AIMS: :The enzyme penicillin G acylase (PGA) is not adsorbed at pH 7 on DEAE- or PEI-coated supports, neither is it adsorbed on carboxymethyl (CM)- or dextran sulfate (DS)-coated supports. The surface of the enzyme was chemically modified under controlled conditions: chemical amination of the protein surface of carboxylic groups (using soluble carbodiimide and ethylendiamine) and chemical succinylation (using succinic anhydride) of amino groups. The full chemical modification produced some negative effects on enzyme stability and activity, although partial modification (mainly succinylation) presented negligible effects on both enzyme features. The chemical amination of the protein surface permitted the immobilization of the enzyme on CM- and DS-coated support, while the chemical succinylation permitted the enzyme immobilization on DEAE- and PEI-coated supports. Immobilization was very strong on these supports, mainly in the polymeric ones, and dependent on the degree of modification, although the enzymes still can be desorbed after inactivation by incubation under drastic conditions. Moreover, the immobilization on ionic polymeric beds allowed a significant increase in enzyme stability against the inactivation and inhibitory effects of organic solvents, very likely by the promotion of a certain partition of the organic solvent out of the enzyme environment. These results suggest that the enrichment of the surface of proteins with ionic groups may be a good strategy to take advantage of the immobilization of industrial enzymes via ionic exchange on ionic polymeric beds.

背景与目标： ：青霉素G酰基转移酶（PGA）在pH 7时不吸附在DEAE或PEI包被的载体上，也不吸附在羧甲基（CM）或硫酸葡聚糖上（DS）的载体上。酶的表面在受控条件下进行了化学修饰：羧基的蛋白质表面化学胺化（使用可溶性碳二亚胺和乙二胺）和氨基的化学琥珀酰化（使用琥珀酸酐）。完全的化学修饰对酶的稳定性和活性产生了一些负面影响，尽管部分修饰（主要是琥珀酰化）对两种酶的特征影响可忽略不计。蛋白质表面的化学胺化使酶固定在CM和DS涂层的支持物上，而化学琥珀酰化使酶固定在DEAE和PEI涂层的支持物上。这些酶的固定化非常强，主要是在聚合的载体上，并且取决于修饰的程度，尽管在剧烈条件下孵育灭活后酶仍可以解吸。而且，固定在离子聚合物床上使得抵抗有机溶剂的失活和抑制作用的酶稳定性显着增加，这很可能是由于有机溶剂的一定分配的促进。这些结果表明，利用离子基团富集蛋白质表面可能是利用工业酶通过离子聚合床上的离子交换固定化酶的一种好策略。

BACKGROUND & AIMS: :Chondroitin-4-sulphate (ChS A) was immobilized by matrix assisted pulsed laser evaporation (MAPLE) with the aid of a UV KrF* excimer laser source. Distilled water was used as solvent for the preparation of the frozen composite MAPLE targets. The surface morphology, chemical structure and functional properties of laser transferred ChS A were investigated as a function of laser processing conditions. The results indicate that the amount of laser immobilized material, structure, and functional properties can be controlled by the laser fluence value used for the irradiation of the MAPLE targets. Under selected irradiation conditions besides the molecular structure, the functional properties of the laser processed ChS A molecules can be maintained.

背景与目标： ：借助紫外线KrF *受激准分子激光源，通过基质辅助脉冲激光蒸发（MAPLE）固定软骨素4-硫酸盐（ChS A）。蒸馏水用作制备冷冻复合材料MAPLE靶的溶剂。研究了激光转移的ChS A的表面形态，化学结构和功能特性随激光加工条件的变化。结果表明，激光固定材料的数量，结构和功能特性可以通过用于辐照MAPLE目标的激光通量值来控制。在选定的辐射条件下，除了分子结构外，还可以保持经过激光处理的ChS A分子的功能特性。

BACKGROUND & AIMS: :The remediation of heavy metal-contaminated soils has attracted increased attention worldwide. The immobilization of metals to prevent their uptake by plants is an efficient way to remediate contaminated soils. This work aimed to seek the immobilization of cadmium in contaminated soils via a combination method. Flask experiments were performed to investigate the effects of hydroxyapatite (HAP) and the Cupriavidus sp. strain ZSK on soil pH and DTPA-extractable cadmium. Pot experiments were carried out to study the effects of the combined amendment on three plant species. The results showed that HAP has no obvious influence on the growth of the strain. With increasing concentrations of HAP, the soil pH increased, and the DTPA-extractable Cd decreased. Via the combined amendment of the strain and HAP (SH), the DTPA-extractable Cd in the soil decreased by 58.2%. With the combined amendment of the SH, the cadmium accumulation in ramie, dandelion, and daisy decreased by 44.9%, 51.0%, and 38.7%, respectively. Moreover, the combined amendment somewhat benefitted the growth of the three plant species and significantly decreased the biosorption of cadmium. These results suggest that the immobilization by the SH combination is a potential method to decrease the available cadmium in the soil and the cadmium accumulation in plants.

背景与目标： ：重金属污染土壤的修复在全世界引起了越来越多的关注。固定金属以防止植物吸收金属是修复污染土壤的有效方法。这项工作旨在通过组合方法寻求将镉固定在受污染的土壤中。进行烧瓶实验以研究羟基磷灰石（HAP）和Cupriavidus sp。的作用。 ZSK菌株对土壤pH和DTPA可萃取镉的影响。进行盆栽试验以研究组合的改良剂对三种植物的影响。结果表明，HAP对菌株的生长没有明显的影响。随着HAP浓度的增加，土壤pH值升高，而DTPA可萃取的Cd降低。通过对菌株和HAP（SH）的联合改良，土壤中DTPA可萃取的Cd降低了58.2％。通过对SH的综合修正，麻，蒲公英和雏菊中的镉积累量分别下降了44.9％，51.0％和38.7％。此外，组合的改良剂在某种程度上有益于三种植物的生长，并显着降低了镉的生物吸收。这些结果表明，通过SH组合固定化是减少土壤中有效镉和植物中镉积累的潜在方法。

BACKGROUND & AIMS: :In this study, three pentachlorophenol (PCP) laboratory-spiked and one field-contaminated soil were amended with 2.0% char, humic acid (HA) and peat, respectively. The amended soils were aged for either 7 or 250 days. After amendment, CaCl(2) extractability of PCP was significantly decreased. Desorption kinetics indicated that the proposed amendment could lead to a strong binding and slow desorption of PCP in soils. Amendment with char reduced the bioaccumulation factor (BAF) of PCP most significantly for earthworms (Eisenia fetida) in all soils studied. The results of both physicochemical and biological tests suggested that amendment reduced PCP bioavailability quickly and enduringly, implying that carbonaceous material amendment, especially char amendment, was a potentially attractive in situ remediation method for sequestration of PCP in contaminated soil.

背景与目标： ：在这项研究中，分别用2.0％的炭，腐殖酸（HA）和泥炭对3种五氯酚（PCP）实验室加标的土壤和1种被田地污染的土壤进行了修正。修改过的土壤要老化7天或250天。修改后，PCP的CaCl（2）可萃取性显着降低。解吸动力学表明，拟议的修正可能导致土壤中五氯苯酚的牢固结合和缓慢解吸。在所有研究的土壤中，对炭黑的修正最大程度地降低了（（Eisenia fetida）的五氯苯酚的生物积累因子（BAF）。物理化学和生物学测试的结果均表明，改性剂快速而持久地降低了PCP的生物利用度，这意味着碳质材料改性剂（尤其是炭化剂改性剂）是一种潜在的有吸引力的原位修复方法，用于隔离受污染土壤中的PCP。

BACKGROUND & AIMS: :Herein, the zwitterionic material poly (carboxybetaine acrylamide) was grafted onto iron oxide to obtain biocompatible magnetic nanoparticles Fe3O4-pCBAA which were employed to immobilize enzymes. The nanocomplxes Fe3O4-pCBAA were characterized using scanning electron microscopy (SEM), dynamic light scattering (DLS), zeta potential, Fourier transform-infrared (FT-IR) spectra and energy dispersive X-ray spectrometry (EDX). The urease as a model enzyme was immobilized with the novel supports and the properties of immobilized urease were further investigated in comparison with the free urease counterpart. The immobilized urease exhibited excellent thermodynamic and chemical stability. Particularly, 60% of initial activity was remained after being stored at 70 °C for 2 h while the free urease only remained 30%. Besides, the relative activity of immobilized enzyme was 1.7 times that of free ones after disposed in ethanol and 2-propanol for 2 h, and 7 times in DMF. Moreover, immobilized urease retained >80% of its initial activity after 5 cycles. In addition, the immobilization carrier Fe3O4-pCBAA displayed famous biocompatibility, and the immobilized urease performed better in complex biological samples, which were >85% and <60% of its initial activity for the immobilized and dissociative urease, respectively, in 20% and 25% of serum. These results confirm that the nanoparticles Fe3O4-pCBAA are biofriendly and efficient supports for enzyme immobilization and potential for practical applications in bio-microenvironments.

背景与目标： ：在此，将两性离子材料聚（羧基甜菜碱丙烯酰胺）接枝到氧化铁上，获得生物相容性磁性纳米粒子Fe3O4-pCBAA，用于固定酶。使用扫描电子显微镜（SEM），动态光散射（DLS），ζ电势，傅立叶变换红外（FT-IR）光谱和能量色散X射线光谱（EDX）对Fe3O4-pCBAA纳米复合材料进行了表征。用新型载体固定了作为模型酶的脲酶，并与游离脲酶的对应物进行了比较，进一步研究了固定脲酶的性质。固定的脲酶表现出优异的热力学和化学稳定性。特别是，在70°C下保存2小时后，保留了60％的初始活性，而游离脲酶仅保留了30％。此外，固定化酶在乙醇和2-丙醇中放置2h后的相对活性是游离酶的1.7倍，在DMF中则为7倍。此外，固定的脲酶在5个循环后保留了其初始活性的80％以上。此外，固定化载体Fe3O4-pCBAA表现出著名的生物相容性，固定化脲酶在复杂的生物样品中表现更好，分别占固定化和解离脲酶初始活性的> 85％和<60％，分别为20％和70％。血清的25％。这些结果证实纳米颗粒Fe 3 O 4 -pCBAA是酶固定的生物友好且有效的载体，并且在生物微环境中的实际应用具有潜力。

BACKGROUND & AIMS: :In the present study, a facile functionalization of magnetic nanoparticles has been described for the immobilization of enzyme that offers many advantages for reuse and excellent efficiencies. The magnetic gold nanocomposites have been fabricated for the successful immobilization of an industrially important enzyme "papain". For immobilization of papain on magnetic gold nanocomposites, magnetic nanoparticles were modified with 3-(mercaptopropyl) trimethoxy silane (MPTS). Further, the citrate stabilized gold nanoparticles were chemisorbed on these thiol coated magnetic nanoparticles to fabricate the desired magnetic gold nanocomposites. Papain containing net positive charge (isoelectric point of papain=8.75) in PBS buffer (pH 7.4) has immobilized on the surface of the negatively charged magnetic gold nanocomposites through the ionic or electrostatic interaction. The Michaelis-Menten kinetic constant (K(m)) and maximum reaction velocity (V(max)) for free papain were 0.236×10(5) g ml(-1) and 4.08 g ml(-1)/s respectively whereas for immobilized papain, K(m) and V(max) values were 0.308×10(5) g ml(-1) and 5.4 g ml(-1)/s respectively. The loading amount of papain on magnetic gold nanocomposites was 54 mg/g support and the activity recovery of the immobilized papain reached to 47 (±5)% compared to native papain. The main advantage of this papain nanobiocatalyst is the easy isolation of enzyme from the reaction medium.

背景与目标： ：在本研究中，已描述了磁性纳米粒子的简便功能化，用于固定化酶，该酶具有许多可重复使用的优点和出色的效率。已经制造出磁性金纳米复合材料，以成功固定工业上重要的酶“木瓜蛋白酶”。为了将木瓜蛋白酶固定在磁性金纳米复合材料上，用3-（巯基丙基）三甲氧基硅烷（MPTS）修饰了磁性纳米粒子。此外，将柠檬酸盐稳定的金纳米颗粒化学吸附在这些硫醇涂覆的磁性纳米颗粒上，以制造所需的磁性金纳米复合材料。在PBS缓冲液（pH 7.4）中含有净正电荷的木瓜蛋白酶（木瓜蛋白酶的等电点= 8.75）已通过离子或静电相互作用固定在带负电荷的磁性金纳米复合材料的表面上。游离木瓜蛋白酶的Michaelis-Menten动力学常数（K（m））和最大反应速度（V（max））分别为0.236×10（5）g ml（-1）和4.08 g ml（-1）/ s固定化木瓜蛋白酶的K（m）和V（max）值分别为0.308×10（5）g ml（-1）和5.4 g ml（-1）/ s。木瓜蛋白酶在磁性金纳米复合材料上的负载量为54 mg / g载体，与天然木瓜蛋白酶相比，固定化木瓜蛋白酶的活性回收率达到47（±5）％。这种木瓜蛋白酶纳米生物催化剂的主要优点是易于从反应介质中分离出酶。