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Hydrobiologia - In shallow lakes, macrophytes have important effects on food webs, community structure and nutrient dynamics. For this reason they play a significant role in the restoration of...  相似文献   
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The species composition of the damselfly assemblage and the life history patterns of two Coenagrionidae (Ischnura elegans and Cercion lindeni) were investigated along the urban tract of a river characterized by increasing organic pollution. The assemblage was dominated by generalist species, usually recorded in lentic habitats, rather than by typical riverine species and the proportion of the latter decrease at the most polluted sites. At the end of Winter, the mean size and in star distribution were different between the sampling sites showing that the life history of both species examined were influenced by a degradation of the environmental quality. A longer reproductive period, absence of diapause, and tolerance of low oxygen concentration appear to be key factors that allow generalist species I. elegans and C. lindeni to predominate at the polluted sites. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
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Ultra microscopic study of three glomic tumours established the presence in these of myoepithelial cells with a cytoplasma rich in fibrils and deprived of secretory granules. These typical cells are very different of these of chimioreceptors of chromophile system.  相似文献   
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Defects in telomere maintenance genes cause pathological telomere shortening, and manifest in syndromes which have prominent phenotypes in tissues of high turnover: the skin and bone marrow. Because the gastrointestinal (GI) epithelium is highly proliferative, we sought to determine whether telomere syndromes cause GI disease, and to define its prevalence, spectrum, and natural history. We queried subjects in the Johns Hopkins Telomere Syndrome Registry for evidence of luminal GI disease. In sixteen percent of Registry subjects (6 of 38), there was a history of significant GI pathology, and 43 additional cases were identified in the literature. Esophageal stenosis, enteropathy, and enterocolitis were the recurrent findings. In the intestinal mucosa, there was striking villous atrophy, extensive apoptosis, and anaphase bridging pointing to regenerative defects in the epithelial compartment. GI disease was often the first and most severe manifestation of telomere disease in young children. These findings indicate that telomere dysfunction disrupts the epithelial integrity in the human GI tract manifesting in recognizable disease processes. A high index of suspicion should facilitate diagnosis and management.  相似文献   
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A retrospective review of 16 cases of midline (dermoid) cysts of the floor of the mouth is presented, evaluating the different surgical approaches. Sixteen cases of patients with a diagnosis of midline cyst of the floor of the mouth, treated at the Maxillofacial Surgery Department of the School of Medicine and Surgery of the "Federico II" University of Naples (Naples, Italy), were observed over a 10-year period, between 1988 and 1998; age, sex, localization, diagnostic technique, and type of treatment were evaluated. Male patients were more frequently affected, with a male-to-female ratio of 3:1 (12:4 cases). Patients ranged in age from 5 to 51 years (average age, 27.8 years). The preoperative assessment was made using ultrasonography in all cases but one, computed tomography in eight cases, and magnetic resonance imaging in three cases. Regarding surgical techniques used, a transcutaneous approach was adopted for median geniohyoid cysts, an extended median glossotomy technique was used for very large median genioglossal cysts, a median glossotomy technique was used for median genioglossal cysts, and a midline incision of the oral mucosa along the lingual frenulum was used for sublingual cysts. During the postoperative course, there were no complications except for modest edema in three cases. Follow-up ranged between 24 months and 12 years; no relapses or malignant changes were observed. In the authors' experience, the intraoral approach was also effective for the treatment of large lesions and led to very good cosmetic and functional results, whereas the extraoral incision was necessary only when the cysts were under the geniohyoid muscle.  相似文献   
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The absence of a rapid and inexpensive method for estimating macroinvertebrate individual biomass is a limit to the study of freshwater communities, given that traditional methods are time- and money-consuming. We propose an inexpensive method to quickly estimate individual biomass from video-recorded images of pond macroinvertebrates. We used a software that automatically measures several body dimensions (area, perimeter, minor and major axes) on each individual and linear regression to relate these body dimensions to dry weight. Area was found to be the best predictor of dry weight. The method allows individual measures of macroinvertebrates at a reasonable speed and accuracy, and may be useful for biomass size spectra or secondary production studies.  相似文献   
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Head and Neck Squamous Cell Carcinoma (HNSCC) is the fifth most common cancer, annually affecting over half a million people worldwide. Presently, there are no accepted biomarkers for clinical detection and surveillance of HNSCC. In this work, a comprehensive genome-wide analysis of epigenetic alterations in primary HNSCC tumors was employed in conjunction with cancer-specific outlier statistics to define novel biomarker genes which are differentially methylated in HNSCC. The 37 identified biomarker candidates were top-scoring outlier genes with prominent differential methylation in tumors, but with no signal in normal tissues. These putative candidates were validated in independent HNSCC cohorts from our institution and TCGA (The Cancer Genome Atlas). Using the top candidates, ZNF14, ZNF160, and ZNF420, an assay was developed for detection of HNSCC cancer in primary tissue and saliva samples with 100% specificity when compared to normal control samples. Given the high detection specificity, the analysis of ZNF DNA methylation in combination with other DNA methylation biomarkers may be useful in the clinical setting for HNSCC detection and surveillance, particularly in high-risk patients. Several additional candidates identified through this work can be further investigated toward future development of a multi-gene panel of biomarkers for the surveillance and detection of HNSCC.  相似文献   
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