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81.
Bacterial contamination of touch surfaces poses a serious threat for public health. The use of bactericidal surface materials, such as copper and its alloys, might constitute a way to aid the use of antibiotics and disinfectants, thus minimizing the risk of emergence and spread of multiresistant germs. The survival of Escherichia coli on metallic copper surfaces has been studied previously; however, the mechanisms underlying bacterial inactivation on copper surfaces have not been elucidated. Data presented in this study suggest that bacteria are killed rapidly on dry copper surfaces. Several factors, such as copper ion toxicity, copper chelators, cold, osmotic stress, and reactive oxygen species, but not anaerobiosis, influenced killing rates. Strains deleted in copper detoxification systems were slightly more sensitive than was the wild type. Preadaptation to copper enhanced survival rates upon copper surface exposure. This study constitutes a first step toward understanding the reasons for metallic copper surface-mediated killing of bacteria.  相似文献   
82.
A survey of Connecticut lakes and rivers revealed the presence of 7 species of freshwater sponge: Spongilla lacustris, Ephydatia muelleri, Eunapius fragilis, Anheteromeyenia ryderi, A. argyrosperma, Corvomeyenia carolinensis, and Corvospongilla novaeterrae in order of decreasing frequency of occurrence. Corvomeyenia carolinensis has not been reported previously beyond its type locality in South Carolina. In addition, microscleres of Spongilla lacustris, Anheteromeyenia-like megascleres, Ephydatia muelleri-like megascleres, and smooth megascleres (amphioxeas), which could not be assigned to a particular species, were found in surface sediments from lake cores. Spongilla lacustris inhabiting small rivers produced brown, thick-capsuled gemmules during the summer and yellow, thin-capsuled gemmules during the fall. The thick-capsuled gemmules, but not the thin-capsuled gemmules, are tolerant of desiccation; and populations of Spongilla lacustris and Ephydatia muelleri survived severe drying of their habitats during the summer.  相似文献   
83.
Cancer morbidity and mortality are on a steady increase in Croatia. Technologic possibilities for appropriate management are available for four cancer sites, i.e. cancer of the breast, cervix uteri, colorectum and prostate, and include cancer prevention and early detection in individuals yet free from manifest signs of the disease. The magnitude of the problem, the experience acquired to date, health care personnel available, and additional resources required to launch a systematic program of early detection of the disease are presented. The program should be initially launched in a county with greatest experience in early detection of cancer, where health care service is ready to immediately start its implementation. The role of family physician, gynecologic service at primary health care level, and polyclinic-consultation hospital service in program implementation is described. The following three possible options for early detection of cancer are analyzed and proposed: minimal program (early detection every 3 years), medium program (the same individuals examined every 2 years), and optimal program proposed by the American Cancer Society and other national and international organizations.  相似文献   
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A PstI DNA family was isolated from the genome of a lacertid, Lacerta graeca. The 185-bp monomeric unit (pGPS) was cloned and hybridized to DNAs and chromosomes of several lacertid species. The data showed that pGPS hybridizes to the (1) centromeric or pericentromeric heterochromatin of almost all the chromosomes of L. graeca and (2) genomic DNA of species phylogenetically related and unrelated to L. graeca. The presence of pGPS even in species immunologically apart more than 30 million years suggests that this repeated family might be either very ancient or have been conserved during evolution due to its functional role. The latter hypothesis might be supported by the results of sequence analysis which showed some homology with both several alphoid sequences of primates and the CDEIII centromeric sequence of yeast. Segments of the satellite sequence are similar to the mammalian CENP-B box. These observations suggest that pGPS might have a role in determining the centromeric function in lacertid lizards. Received: 6 February 1997 / Accepted: 14 May 1997  相似文献   
87.

Background

The role of cardiac natriuretic peptides in the management of patients with chronic heart failure (HF) remains uncertain. The purpose of this study was to evaluate whether natriuretic peptide-guided therapy, compared to clinically-guided therapy, improves mortality and hospitalization rate in patients with chronic HF.

Methodology/Principal Findings

MEDLINE, Cochrane, ISI Web of Science and SCOPUS databases were searched for articles reporting natriuretic peptide-guided therapy in HF until August 2012. All randomized trials reporting clinical end-points (all-cause mortality and/or HF-related hospitalization and/or all-cause hospitalization) were included. Meta-analysis was performed to assess the influence of treatment on outcomes. Sensitivity analysis was performed to test the influence of potential effect modifiers and of each trial included in meta-analysis on results. Twelve trials enrolling 2,686 participants were included. Natriuretic peptide-guided therapy (either B-type natriuretic peptide [BNP]- or N-terminal pro-B-type natriuretic peptide [NT-proBNP]-guided therapy) significantly reduced all-cause mortality (Odds Ratio [OR]:0.738; 95% Confidence Interval [CI]:0.596 to 0.913; p = 0.005) and HF-related hospitalization (OR:0.554; CI:0.399 to 0.769; p = 0.000), but not all-cause hospitalization (OR:0.803; CI:0.629 to 1.024; p = 0.077). When separately assessed, NT-proBNP-guided therapy significantly reduced all-cause mortality (OR:0.717; CI:0.563 to 0.914; p = 0.007) and HF-related hospitalization (OR:0.531; CI:0.347 to 0.811; p = 0.003), but not all-cause hospitalization (OR:0.779; CI:0.414 to 1.465; p = 0.438), whereas BNP-guided therapy did not significantly reduce all-cause mortality (OR:0.814; CI:0.518 to 1.279; p = 0.371), HF-related hospitalization (OR:0.599; CI:0.303 to 1.187; p = 0.142) or all-cause hospitalization (OR:0.726; CI:0.609 to 0.964; p = 0.077).

Conclusions/Significance

Use of cardiac peptides to guide pharmacologic therapy significantly reduces mortality and HF related hospitalization in patients with chronic HF. In particular, NT-proBNP-guided therapy reduced all-cause mortality and HF-related hospitalization but not all-cause hospitalization, whereas BNP-guided therapy did not significantly reduce both mortality and morbidity.  相似文献   
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Abstract

Photosynthesis and photoprotective mechanisms were investigated in the field on Laurus nobilis L. and Quercus ilex L. leaves exposed to summer drought (July) and winter cold (February) conditions compared with no-stress conditions (May). In July, net photosynthetic rate (A) and stomatal conductance (g s) decreased significantly compared with May in both species; conversely the highest ETR/A ratio and no difference in non-photochemical quenching (NPQ) was observed. In February A, g s and ETR/A declined compared with May but the highest NPQ were found in both species. Our data suggest that during summer, an increase of photochemical alternative pathways to carbon reduction, were able to effectively protect the photosynthetic apparatus under drought. In winter, the thermal dissipation of excess absorbed light constitutes the main safety valve for the photosynthetic apparatus.  相似文献   
90.
The toxicity of ochratoxin A (OTA), a mycotoxin produced by fungi ofAspergillus orPenicillium genera is now well documented. Its nephrotoxicity, immunosuppression, teratogenicity, and carcinogenicity have been widely studied. Physical and biochemical methods have been studied to prevent these toxinogenicAspergillus andPenicillium from producing OTA, and/or to destroy the mycotoxin when already produced in a liquid or a solid medium. Repeated freezing at ? 20?C and thawing at + 26?C aleatory reduce OTA production in a liquid medium. Exposure to UV B for different periods of time is efficient in preventing OTA production in a liquid medium. Gamma-irradiation from 2 to 5 kGy gives good results in preventing the production of OTA or destroying it when already produced. Carboxypeptidase is very efficient at 5 units/50 ml in a liquid medium for cleaving the OTA already produced.  相似文献   
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