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121.
Sam S Kucukasik F Yenigun O Nicolaus B Oner ET Yukselen MA 《Bioresource technology》2011,102(2):1788-1794
This study reports the first systematic investigation of the flocculation dynamics of exopolysaccharides (EPSs) produced by a halophilic bacterial strain grown on pretreated molasses as fermentation substrate. The potential use of these EPSs as an easily biodegradable, natural alternative for synthetic polyelectrolytes which are widely used and contain toxic and carcinogenic monomers was investigated. Flocculating activities of the EPS samples in synthetic water, synthetic sea water and natural sea water media which were used as model raw waters were monitored via the Photometric Dispersion Analyser (PDA 2000) instrument and removals were determined by measuring residual turbidities. One of the six EPS specimens, which formed the largest flocs thus performed highest turbidity removal, exhibited flocculation performance and particle removal efficiency comparable with commercial cationic, nonionic and anionic synthetic polyelectrolytes. 相似文献
122.
Chiral Schiff-bases 3a-f based on ferrocene were designed and synthesized using solvent-free methods by mixing ferrocene carbaldehyde 1 with amino alcohols and amines 2a-f under microwave irradiation and classical method for the enantioselective nitroaldol (Henry) reaction. The Schiff-bases were obtained in shorter reaction times and improved yield under microwave irradiation method over classical method. The highest enantioselectivity was observed in ligand 3e (95% ee) when CH(2)Cl(2) was used as solvent. 相似文献
123.
Although substantial advances have been made in behavioral and pharmacological treatments for addictions, moving treatment development to the next stage may require novel ways of approaching addictions, particularly ways based on new findings regarding the neurobiological underpinnings of addictions that also assimilate and incorporate relevant information from earlier approaches. In this review, we first briefly review theoretical and biological models of addiction and then describe existing behavioral and pharmacologic therapies for the addictions within this framework. We then propose new directions for treatment development and targets that are informed by recent evidence regarding the heterogeneity of addictions and the neurobiological contributions to these disorders. 相似文献
124.
Hussain AF Kampmeier F von Felbert V Merk HF Tur MK Barth S 《Bioconjugate chemistry》2011,22(12):2487-2495
Cancer cells can be killed by photosensitizing agents that induce toxic effects when exposed to nonhazardous light, but this also causes significant damage to surrounding healthy cells. The specificity of photodynamic therapy can be increased by conjugating photosensitizing agents to antibodies and antibody fragments that bind specifically to tumor cell antigens. However, standard conjugation reactions produce heterogeneous products whose targeting specificity and spectroscopic properties can be compromised. In this study, we used an antibody fragment (scFv-425) that binds to the epidermal growth factor receptor (EGFR) as a model to investigate the use of SNAP-tag fusions as an improved conjugation strategy. The scFv-425-SNAP-tag fusion protein allowed the specific conjugation of a chlorin e6 photosensitizer modified with O(6)-benzylguanine, generating a homogeneous product that was delivered specifically to EGFR(+) cancer cells and resulted in significant, tumor cell-specific cytotoxicity. The impact of our results on the development of photodynamic therapy is discussed. 相似文献
125.
Liong M Fernandez-Suarez M Issadore D Min C Tassa C Reiner T Fortune SM Toner M Lee H Weissleder R 《Bioconjugate chemistry》2011,22(12):2390-2394
The development of faster and more sensitive detection methods capable of identifying specific bacterial species and strains has remained a longstanding clinical challenge. Thus to date, the diagnosis of bacterial infections continues to rely on the performance of time-consuming microbiological cultures. Here, we demonstrate the use of bioorthogonal chemistry for magnetically labeling specific pathogens to enable their subsequent detection by nuclear magnetic resonance. Antibodies against a bacterial target of interest were first modified with trans-cyclooctene and then coupled to tetrazine-modified magnetic nanoprobes, directly on the bacteria. This labeling method was verified by surface plasmon resonance as well as by highly specific detection of Staphylococcus aureus using a miniaturized diagnostic magnetic resonance system. Compared to other copper-free bioorthogonal chemistries, the cycloaddition reaction reported here displayed faster kinetics and yielded higher labeling efficiency. Considering the short assay times and the portability of the necessary instrumentation, it is feasible that this approach could be adapted for clinical use in resource-limited settings. 相似文献
126.
The purpose of the present study was to determine the coping strategies of medical students and to investigate the effects of coping strategies on student satisfaction and academic achievement with different instruction methods. A total of 152 medical students was followed throughout the first 2 yr of medical education between 2008 and 2010. Students completed a sociodemographic questionnaire and revised form of the Ways of Coping questionnaire both at the beginning of the first year and at the end of the second year. These forms provided data about the characteristics and main coping strategies (problem focused or emotion focused) of the students and revealed the change over time. At the end of the second year, participants also completed a satisfaction questionnaire asking their satisfaction with lectures, problem-based learning, and practicals. The authors used block, problem-based learning, and practical exam scores of the students attained in the past 2 yr as academic achievement indicators. No sociodemographic variable was related to coping strategy. The majority of students (80.9%) adopted problem-focused coping. A shift occurred in the main coping strategies of some students in both sides. Problem-focused coping scores decreased over time. Problem-focused coping positively correlated with satisfaction with practicals and practical exam scores, whereas emotion-focused coping showed the same correlation negatively. The main coping strategy also predicted satisfaction and exam success in practicals. In conclusion, a main coping strategy may be helpful to predict student satisfaction and academic achievement with some student-centered instruction methods. Determining undesired coping strategies may provide an opportunity for intervention to prevent relevant dissatisfaction and failure. 相似文献
127.
Serdar Oztora Osman Korkmaz Nezih Dagdeviren Yahya Celik Ayse Caylan Mehmet S Top Talip Asil 《BMC neurology》2011,11(1):103
Background
Migraine is a significant health problem, especially for the young people, due to its frequency and accompanying morbidity, causing disability and loss of performance. In this study, our aim was to determine the prevalence of migraine headaches among university students in Edirne, a Turkish city. 相似文献128.
In this study, laboratory tests were performed in order to examine growth characteristics of floating aquatic macrophytes (Lemna gibba and Lemna minor) in the presence of wastewater with circulation. The results showed that circulation of the waste water enhanced the kinetics of the process, as compared to the control systems. However, prolonged application of high circulation level had a different effect. In the presence of circulation with aquatic plants, there was additional 85.3-88.2% for BODs and 59.6-66.8% for COD decreases in the water quality indicators. In this study, the effectiveness of L. gibba and L. minor with circulation addition for the removal of four heavy metals (Pb, Ni, Mn, and Cu) from waste water was also investigated. Results from analysis confirmed the accumulation of different metals within the plant and a corresponding decrease of metals in the waste water. At the end of the study of circulation, L. gibba provided the metal removal for Cu, Pb, Ni, and Mn in the waste water as the ratio of 57%, 60%, 60%, and 62%, respectively. In this context, the best results were obtained when the action of L. gibba and L. minor plants, was combined with that of circulation. It is shown that in the presence of L. gibba and L. minor plants that are supplemented with circulation, the national standards of biochemical oxygen demand (BOD5) 27-33 mgL(-1) and chemical oxygen demand (COD) 62-78 mgL(-1) for L. minor and L. gibba, respectively, were reached after treatment. The new results can be used for design calculations regarding expected removal of pollutants by aquatic floating plants. 相似文献
129.
The aim of this study was to demonstrate the role of curcumin on oxidative stress, cell proliferation and apoptosis in the
rat intestinal mucosa after ischemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into three groups:
sham, I/R and I/R+ curcumin; each group contain 10 animals. Sham group animals underwent laparotomy without I/R injury. After
I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In
the curcumin group, 3 days before I/R, curcumin (100 mg/kg) was administered by gastric gavage. All animals were sacrificed
at the end of reperfusion and intestinal tissues samples were obtained for biochemical and histopathological investigation
in all groups. Curcumin treatment significantly decreased the elevated tissue malondialdehyde levels and increased of reduced
superoxide dismutase, and glutathione peroxidase enzyme activities in intestinal tissues samples. I/R caused severe histopathological
injury including mucosal erosions and villous congestion and hemorrhage. Curcumin treatment significantly attenuated the severity
of intestinal I/R injury, with inhibiting of I/R-induced apoptosis and cell proliferation. These results suggest that curcumin
treatment has a protective effect against intestinal damage induced by intestinal I/R. This protective effect is possibly
due to its ability to inhibit I/R-induced oxidative stress, apoptosis and cell proliferation. 相似文献
130.
The aim of this study was to evaluate the possible protective effects of caffeic acid phenethyl ester (CAPE) against cholestatic
oxidative stress and liver damage in the common bile duct ligated rats. A total of 18 male Sprague–Dawley rats were divided
into three groups: control, bile duct ligation (BDL) and BDL + received CAPE; each group contain 6 animals. The rats in CAPE
treated groups were given CAPE (10 μmol/kg) once a day intraperitoneally (i.p) for 2 weeks starting just after BDL operation.
The changes demonstrating the bile duct proliferation and fibrosis in expanded portal tracts include the extension of proliferated
bile ducts into lobules, inflammatory cell infiltration into the widened portal areas were observed in BDL group. Treatment
of BDL with CAPE attenuated alterations in liver histology. The proliferating cell nuclear antigen and the activity of TUNEL
in the BDL were observed to be reduced with the QE treatment. The application of BDL clearly increased the tissue hydroxyproline
(HP) content, malondialdehyde (MDA) levels and decreased the antioxidant enzyme (superoxide dismutase (SOD), glutathione peroxidase
(GPx)) activities. CAPE treatment significantly decreased the elevated tissue HP content, and MDA levels and raised the reduced
of SOD, and GPx enzymes in the tissues. The data indicate that CAPE attenuates BDL-induced cholestatic liver injury, bile
duct proliferation, and fibrosis. The hepatoprotective effect of CAPE is associated with antioxidative potential. 相似文献