排序方式: 共有277条查询结果,搜索用时 15 毫秒
61.
Lichens are valuable bio-indicators for evaluating the consequences of human activities that are increasingly changing the earth’s ecosystems. Since a major objective of national parks is the preservation of biodiversity, our aim is to analyse how natural resource management, the availability of lichen substrates and environmental parameters influence lichen diversity in Rodnei Mountains National Park situated in the Eastern Carpathians. Three main types of managed vegetation were investigated: the transhumance systems in alpine meadows, timber exploitation in mixed and pure spruce forests, and the corresponding conserved sites. The data were sampled following a replicated design. For the analysis, we considered not only all lichen species, but also species groups from different substrates such as soil, trees and deadwood. The lichen diversity was described according to species richness, red-list status and substrate-specialist species richness. The variation in species composition was related to the environmental variables. Habitat management was found to negatively influence species richness and alter the lichen community composition, particularly for threatened and substrate-specialist species. It reduced the mean level of threatened species richness by 59%, when all lichen species were considered, and by 81%, when only epiphytic lichens were considered. Management-induced disturbance significantly decreased lichen species richness in forest landscapes with long stand continuity. The diversity patterns of the lichens indicate a loss of species richness and change in species composition in areas where natural resources are still exploited inside the borders of the national park. It is thus imperative for protected areas, in particular old-growth forests and alpine meadows, to receive more protection than they have received in the past to ensure populations of the characteristic species remain viable in the future. 相似文献
62.
Photoacoustic and photothermal cytometry using photoswitchable proteins and nanoparticles with ultrasharp resonances
下载免费PDF全文
![点击此处可从《Journal of biophotonics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ekaterina I. Galanzha Dmitry A. Nedosekin Mustafa Sarimollaoglu Anamaria Ioana Orza Alexandru S. Biris Vladislav V. Verkhusha Vladimir P. Zharov 《Journal of biophotonics》2015,8(8):687-687
In the article by E. I. Galanzha et al. (doi: http://dx.doi.org/10.1002/jbio.201300140 ), published in J. Biophotonics 8, 81–93 (2015), the Conflict of Interest statement is missing. This erratum is published to correct this. 相似文献
63.
Multimode sensors as new tools for molecular recognition of testosterone,dihydrotestosterone and estradiol in children's saliva
下载免费PDF全文
![点击此处可从《Journal of molecular recognition : JMR》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Livia Alexandra Gugoasa Raluca‐Ioana Stefan‐van Staden Bogdan Calenic Juliette Legler 《Journal of molecular recognition : JMR》2015,28(1):10-19
Increased levels of testosterone (T2), dihydrotestosterone (DHT) and estradiol (E2) in children may be responsible for their early/delayed puberty and obesity conditions. Therefore, multimode sensors based on carbon matrices, such as graphite, graphene, fullerene C60 and multiwall carbon nanotubes modified with maltodextrin, were designed to assess reliably T2, DHT and E2 in children saliva. The modes used for the assay of hormones were stochastic mode (for qualitative and quantitative determination of hormones) and differential pulse voltammetry mode (for quantitative determination of hormones). The advantage of this type of sensors, for hormone analysis, is their possibility to reach low concentration levels— are placed for children saliva under the detection limit of standard methods (e.g. ELISA used for the determination of these hormones in saliva). This made the multimode sensors an excellent tool for clinical analysis and especially for determination of substances of clinical importance in saliva samples. The proposed method is fast and simple, and no sampling of saliva is required. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
64.
Cătană CS Cristea V Miron N Neagoe IB 《Roumanian archives of microbiology and immunology》2011,70(3):124-128
The importance of chronic inflammation in atherogenesis and cytokine involvement in all stages of atherosclerotic plaque development is now obvious. Our approach of the significant cytokines involved in atherogenesis or cardiovascular diseases is based on a correlation between clinical research and experiments on animal models. The contribution of IL-17 in atherogenesis remains controversial. In this study we investigated the role of IL-17 in cardiovascular diseases and in atherosclerosis associated with pathological aging. We performed a case-control study, enrolling subjects aged over 65 years in both groups. We included 40 patients with cardiovascular disorders and 10 healthy volunteers. IL-17 levels were measured in the serum of patients and healthy controls, along with serum total cholesterol and triglycerides. Significantly higher levels of IL-17 were obtained in patients compared to healthy controls (p<0.001). The level of this biomarker correlated significantly with two biochemical parameters - serum total cholesterol and triglycerides (the Pearson coefficient showed statistical significance, p=0.033, respectively p=0.043). We did not find any correlation between IL-17 and these two parameters in the control group. Our study is useful in understanding the physiopathological implications of IL-17 in the atherogenesis process. This could represent a starting point for future studies, including research regarding the therapeutic potential of IL-17 in pathological aging. 相似文献
65.
66.
Leiprecht N Munoz C Alesutan I Siraskar G Sopjani M Föller M Stubenrauch F Iftner T Lang F 《Biochemical and biophysical research communications》2011,404(2):695-700
Tumor cells utilize preferably glucose for energy production. They accomplish cellular glucose uptake in part through Na+-coupled glucose transport mediated by SGLT1 (SLC5A1). This study explored the possibility that the human papillomavirus 18 E6 protein HPV18 E6 (E6) participates in the stimulation of SGLT1 activity. E6 is one of the two major oncoproteins of high-risk human papillomaviruses, which are the causative agent for cervical carcinoma. According to Western blotting, SGLT1 is expressed in the HPV18-positive cervical carcinoma cell line HeLa. To explore whether E6 affects SGLT1 activity, SGLT1 was expressed in Xenopus oocytes with and without E6 and electrogenic glucose transport determined by dual electrode voltage clamp. In SGLT1-expressing oocytes, but not in oocytes injected with water or expressing E6 alone, glucose triggered a current (Ig). Ig was significantly increased by coexpression of E6 but not by coexpression of E2. According to chemiluminescence and confocal microscopy, coexpression of E6 significantly increased the SGLT1 protein abundance in the cell membrane. The decay of Ig following inhibition of carrier insertion by Brefeldine A (5 μM) was not significantly affected E6 coexpression. Accrodingly, E6 was not effective by increasing carrier protein stability in the membrane. In conclusion, HPV18 E6 oncoprotein participates in the upregulation of SGLT1. 相似文献
67.
Mihai Bogdan Preda Ana‐Mihaela Lupan Carmen Alexandra Neculachi Livia Ioana Leti Ioana Madalina Fenyo Sinziana Popescu Evelyn Gabriela Rusu Catalina Iolanda Marinescu Maya Simionescu Alexandrina Burlacu 《Journal of cellular and molecular medicine》2020,24(18):10889-10897
Subcutaneous transplantation of mesenchymal stromal cells (MSC) emerged as an alternative to intravenous administration because it avoids the pulmonary embolism and prolongs post‐transplantation lifetime. The goal of this study was to investigate the mechanisms by which these cells could affect remote organs. To this aim, murine bone marrow–derived MSC were subcutaneously transplanted in different anatomical regions and the survival and behaviour have been followed. The results showed that upon subcutaneous transplantation in mice, MSC formed multicellular aggregates and did not migrate significantly from the site of injection. Our data suggest an important role of hypoxia‐inducible signalling pathways in stimulating local angiogenesis and the ensuing modulation of the kinetics of circulating cytokines with putative protective effects at distant sites. These data expand the current understanding of cell behaviour after subcutaneous transplantation and contribute to the development of a non‐invasive cell‐based therapy for distant organ protection. 相似文献
68.
Raluca‐Ioana Stefan‐van Staden Iuliana Moldoveanu Daniel‐Florin Sava Constantina Kapnissi‐Christodoulou Jacobus Frederick van Staden 《Chirality》2013,25(2):114-118
Stochastic and potentiometric microsensors based on porphyrins and polymeric surfactants such as polysodium N‐undecanoyl‐ l ‐leucylvanilate and polysodium 相似文献
69.
Gabrovska K Ivanov J Vasileva I Dimova N Godjevargova T 《International journal of biological macromolecules》2011,48(4):620-626
A new matrix for enzyme immobilization of urease was obtained by incorporating rhodium nanoparticles (5% on activated charcoal) and chemical bonding of chitosan with different concentration (0.15%; 0.3%; 0.5%; 1.0%; 1.5%) in previously chemically modified AN copolymer membrane. The basic characteristics of the chitosan modified membranes were investigated. The SEM analyses were shown essential morphology change in the different modified membranes. Both the amount of bound protein and relative activity of immobilized enzyme were measured. A higher activity (about 77.44%) was measured for urease bound to AN copolymer membrane coated with 1.0% chitosan and containing rhodium nanoparticles. The basic characteristics (pH(opt), T(opt), thermal, storage and operation stability) of immobilized enzyme on this optimized modified membrane were also determined. The prepared enzyme membrane was used for the construction of amperometric biosensor for urea detection. Its basic amperometric characteristics were investigated. A calibration plot was obtained for urea concentration ranging from 1.6 to 23 mM. A linear interval was detected along the calibration curve from 1.6 to 8.2mM. The sensitivity of the constructed biosensor was calculated to be 3.1927 μAmM(-1)cm(-2). The correlation coefficient for this concentration range was 0.998. The detection limit with regard to urea was calculated to be 0.5mM at a signal-to-noise ratio of 3. The biosensor was employed for 10 days while the maximum response to urea retained 86.8%. 相似文献