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131.
In this experimental study, the effect of cadmium on cold and restraint stress-induced gastric lesions has been studied. Rats received 15 μg/mL cadmium-containing water for 30 d, and at the end of this period, they were subjected to cold and restraint stress. Cadmium accumulation in gastric mucosa was associated with increased mucosal lesions, as well as decreased mucin and PGE2 levels in rats exposed to cadmium. Stress-induced mucosal injury was more pronounced, and the hemoglobin leakage into gastric lumen owing to breakdown in the barrier was 17.30±3.45 μg/mL in control and 35.71±6.18 μg/mL in treated rats. Our data suggest that high cadmium intake facilitates the occurence of stress-induced mucosal lesions by diminishing the mucin content and PGE2 generation in gastric mucosa.  相似文献   
132.
An assessment of fertility in boron-exposed turkish subpopulations   总被引:3,自引:0,他引:3  
Summary In order to assess the effects of boron and its compounds on human health in a country with the world’s largest deposits, investigations were carried out on fertility and reproduction in the most highly exposed populations. The 927 probands, 697 male and 230 female, interviewed in the field were selected from six different areas of Turkey, in the provinces of Balikesir, Eskisehir, and Kutahya, with the highest boron deposits. These people are exposed to boron environmentally or occupationally or both. The drinking waters of high-boron soils contain 0.7–29 mg B/L compared with 0.05-0.45 mg B/L of low-boron soils. By the so-called pedigree technique 5,934 marriages were ascertained over three generations from all study areas. Childless families among 911 probands were 29 in number and 3.17% in frequency with minor variations from one area to the next, and 3.0% averaged over the generations. Infertility rates in a boron-free community near Ankara with 625 families studied over three generations was 4.48%, and in a larger population of 49,856 families randomly investigated by us throughout the country was 3.84%. No significant differences were observed in terms of marital status and childbearing between 222 and 399 occupationally boron-unrelated and boron-related men, respectively. Nor was there any difference with respect to other aspects studied. It was concluded that, within the limitations of this study, there was no evidence that boron interferes with human fertility and reproduction.  相似文献   
133.
Harboring many range‐restricted and specialized species, high elevation tropical cloud forests are diverse habitats represented in many protected areas. Despite this, many such areas receive little practical protection from deforestation and land conversion. Moreover, montane species may be more sensitive to climate change owing to various factors affecting community assembly across elevational gradients. Few studies have used annual monitoring to assess how biological communities in cloud forests may be shifting in response to habitat or climate change or assessed the efficacy of protected areas in buffering these effects. We analyzed avifaunal community trends in a 10‐yr dataset of constant‐effort bird point‐count data in a cloud forest national park in Honduras, Central America. We found that species richness and diversity increased at higher elevations, but decreased at lower elevations. Abundances of most dietary and forest‐dependency groups exhibited similar trends, and many key cloud forest species shifted upslope and/or increased in abundance. Taken together, our results suggest that the avian community is moving upslope and species composition is changing. Results for species richness and diversity were similar when only nondegraded transects were considered, suggesting the role of climate change as an important driver. At lower elevations, however, many species may be negatively affected by increased habitat degradation, favoring species with low forest dependency. Continued habitat conversion and climate change could push the cloud forest bird community further upslope, potentially resulting in increased competition, mortality, and even extirpation of some species. Increased protection is unlikely to mitigate the effects of climate change.  相似文献   
134.
The study objective was to investigate the chemical composition of otoliths of two Lessepsian fish migrants, namely, Champsodon nudivittis and Nemipterus randalli, which thrive in the Iskenderun Bay, Turkey. The study specifically investigated the age structure and explored differences in chemical otolith composition in relation to age. Samples were collected using a traditional Mediterranean bottom trawl (mesh size 44 mm) at depths of 45 to 90 m. A total of 78 Champsodon nudivittis (size range, 6.0 to 14.0 cm) and 60 Nemipterus randalli (size range, 6.1 to 17 cm) were captured in May 2012. Age readings were carried out (sectioning technique). Additionally, the concentrations of Na, K, Li, and Ca were determined using flame photospectrometry. The results revealed that the concentrations of Na (5.70 mg/g) and K (4.45 mg/g) in otoliths of Nemipterus randalli were predominant elements after Ca (128.71 mg/g). The concentration of Li in otoliths was also statistically different in the two species. This study contributes to the knowledge of the otolith chemistry in the two Lessepsian fish species now living in the same (but new) geographical region.  相似文献   
135.
We investigated the effects of different implant biomaterials on cultured canine bone marrow stromal cells (BMSC) undergoing differentiation into osteoblasts (dBMSC). BMSC were isolated from canine humerus by marrow aspiration, cultured and differentiated on calcium phosphate scaffold (CPS), hydroxyapatite, hydroxyapatite in gel form and titanium mesh. We used the MTT method to determine the effects of osteogenic media on proliferation. The characteristics of dBMSC were assessed using alizarin red (AR), immunocytochemistry and osteoblastic markers including alkaline phosphatase/von Kossa (ALP/VK), osteocalcin (OC) and osteonectin (ON), and ELISA. The morphology of dBMSC on the biomaterials was investigated using inverted phase contrast microscopy and scanning electron microscopy. We detected expression of ALP/VK, AR, OC and ON by day 7 of culture; expression increased from day 14 until day 21. CPS supported the best adhesion, cell spreading, proliferation and differentiation of BMSCs. The effects of the biomaterials depended on their surface properties. Expression of osteoblastic markers showed that canine dBMSCs became functional osteoblasts. Tissue engineered stem cells can be useful clinically for autologous implants for treating bone wounds.  相似文献   
136.
A new series of indolylhydrazones (6) and indole-based 4-thiazolidinones (7, 8) have been designed, synthesized and screened for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv. 4-Thiazolidinone derivatives 7g7j, 8g, 8h and 8j displayed notable antituberculosis (anti-TB) activity showing 99% inhibition at MIC values ranging from 6.25 to 25.0?µg/ml. Compounds 7g, 7h, 7i, 8h and 8j demonstrated anti-TB activity at concentrations 10-fold lower than those cytotoxic for the mammalian cell lines. The indolylhydrazone derivative 6b has also been evaluated for antiproliferative activity against human cancer cell lines at the National Cancer Institute (USA). Compound 6b showed an interesting anticancer profile against different human tumor-derived cell lines at sub-micromolar concentrations with obvious selectivity toward colon cancer cell line COLO 205.  相似文献   
137.
In recent years, various studies in the field of industrial enzymes of biotechnology have gained importance due to increasing development in enzyme technology. The different areas where enzymes are used and their economic value of biotechnological products further increases their importance. There are hundreds of different types of cheese but each is made by coagulating milk using rennet to give curds. Today, researchers have begun to develop alternative systems in the cheese industry related to milk-clotting enzymes. In this study, the nucleic acid sequence encoding the optimized chymosin enzyme was used and cloned by Not I and Mlu I restriction enzymes into pTOLT vector system. Then using this construct, the enzyme as a fusion with Tol-A-III protein was produced in Escherichia coli BL21 (DE3) cells. After disrupting the E. coli cell and separating from the constituents by high speed centrifugation, the enzyme was purified by affinity chromatography and fractions were analyzed by SDS–PAGE. Purified enzyme has shown its activity. Optimum temperature and pH of CHY-Tol-A-III protein were 40°C and 6.5, respectively.  相似文献   
138.
139.
Research on mycorrhizas in Romania started some 60 years ago, first in forestry, then in agriculture and finally in horticulture. The main studies have covered the following topics: (i) The mycorrhizal symbiosis; (ii) Ectomycorrhizas in natural forest ecosystems; (iii) Mycorrhizas in agriculture and forestry; (iv) Field methods, e.g., the development and strategies for obtaining high colonization rates in crops; interactions between mycorrhizal fungi, and soil microorganisms including Rhizobium spp.; factors influencing the efficiency of the mycorrhizas; (v) Management of mycorrhizas in agriculture, horticulture, and forestry as well as management of edible mycorrhizal mushrooms; (vi) Biological protection of crops against root pathogens (Pythium, Phytophthora, Fusarium etc.) using inoculation with mycorrhizal fungi; (vii) Architecture, anatomy and physiology of mycorrhizal plants; (viii) Isolation techniques; methods for investigating mycorrhizas; (ix) Identification by classical and modern methods and characterization of mycorrhizal fungi.  相似文献   
140.
In Vitro Cellular & Developmental Biology - Plant - Ajuga xylorrhiza Kit Tan is a rare endemic perennial species growing in the stony habitats in Southeastern Anatolia region, Turkey. An...  相似文献   
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