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排序方式: 共有729条查询结果,搜索用时 312 毫秒
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The definitions of invasive fungal diseases are intended to guide the appropriate use of clinical, radiologic, and various laboratory findings to increase diagnostic certainty in clinical research. The need for standardized definitions was the result of highly variable criteria used to diagnose invasive fungal diseases in epidemiologic and therapeutic studies. We review the original definitions published in 2002, and the need for revision. We also summarize the key changes in the revised 2008 definitions, discuss limitations and pitfalls, and comment on the potential impact of these changes. 相似文献
714.
Nikolaos Sfakianakis Niklas Kolbe Nadja Hellmann Mária Lukáčová-Medvid’ová 《Bulletin of mathematical biology》2017,79(1):209-235
We propose a multiscale model for the invasion of the extracellular matrix by two types of cancer cells, the differentiated cancer cells and the cancer stem cells. We investigate the epithelial mesenchymal-like transition between them being driven primarily by the epidermal growth factors. We moreover take into account the transdifferentiation program of the cancer stem cells towards the cancer-associated fibroblast cells as well as the fibroblast-driven remodelling of the extracellular matrix. The proposed haptotaxis model combines the macroscopic phenomenon of the invasion of the extracellular matrix by both types of cancer cells with the microscopic dynamics of the epidermal growth factors. We analyse our model in a component-wise manner and compare our findings with the literature. We investigate pathological situations regarding the epidermal growth factors and accordingly propose “mathematical-treatment” scenarios to control the aggressiveness of the tumour. 相似文献
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716.
Emmanouil H. Papaioannou Nikolaos G. Stoforos Maria Liakopoulou-Kyriakides 《World journal of microbiology & biotechnology》2011,27(4):851-858
Blakeslea trispora produces carotenoids mixtures consisting mainly of lycopene, γ-carotene and β-carotene, together with trace amounts of other
carotenoid precursors. The yield of these carotenoids and their composition are greatly affected by culture substrate. The
scavenging capacity of carotenoids extract from cultures of B. trispora growing in various substrates was estimated using the 2,2-diphenyl-1-picrylhydrazyl method. Fractions enriched in β-carotene,
γ-carotene and lycopene, obtained after column chromatography in alumina basic II, were also examined. Substrates containing
starch and oils mixture, Ni2+, and that with pantothenic acid presented higher antioxidant activity. An increase in the antioxidant activity of the crude
carotenoid extract compared to that of the isolated fractions enriched in β-carotene, γ-carotene and lycopene respectively,
observed in most samples, indicated a possible synergistic effect. The results are of interest and by expanding this study
to more substrates and other microorganisms- producing antioxidants, a formulation of extract with high free radical scavenging
potential could be produced. 相似文献
717.
Georgios Sylaios Nikolaos Kamidis Nikolaos Stamatis 《Soil & Sediment Contamination》2012,21(6):673-700
This study investigates the distribution of heavy metals in the suspended particulate matter and the sediments of Kavala Gulf, located in Northern Greece. Particulate trace metals were determined in accordance to water column physicochemical parameters. Metals in sediments were related to the textural characteristics, the organic matter, and carbonate contents of surficial sediments. Results illustrated that the diverse human coastal activities influence the distribution of particulate and sediment metal concentrations, since lower trace metal levels were detected along the western (tourism) and eastern (aquaculture) coast, while increased values were observed at the central (urban and industrial). Overall, particulate metals show moderately low levels compared to other similar sites, with the exception of Ni and Cd depicting local peaks along the industrial coastal zone. Significantly increased levels for particulate lead (123.1 μg/g) and chromium (113.9 μg/g) were detected at the sites near the industrial zone. Direct effluents from a fertilizer plant appeared responsible for the increased Pb, Cr, and Cd levels, while the increased values in Zn, Cu, and Hg appear related to phosphogypsum leaching. Sediment contamination assessment indicated that the Kavala Gulf is characterized by clean to marginally polluted sediments, with moderately severe pollution levels along the urban coastline. 相似文献
718.
Stoop D Baumgarten M Haentjens P Polyzos N Verheyen G Camus M Devroey P 《Reproductive biology and endocrinology : RB&E》2012,10(1):42
ABSTRACT: BACKGROUND: To investigate the obstetrical and perinatal impact of oocyte donation, a cohort of women who conceived after OD was compared with a matched control group of women who became pregnant through in vitro fertilisation with autologous oocytes (AO). METHODS: A matched-pair analysis has been performed at the Centre for Reproductive Medicine of the UZ Brussel, Dutch speaking Free University of Brussel. A total of 410 pregnancies resulted in birth beyond 20 weeks of gestation occurring over a period of 10 years, including 205 oocyte donation pregnancies and 205 ICSI pregnancies with autologous oocytes (AO). Patients in the OD group were matched on a one-to-one basis with the AO group in terms of age, ethnicity, parity and plurality. Matched groups were compared using paired t-tests for continuous variables and McNemar test for categorical variables. A conditional logistic regression analyses was performed adjusting for paternal age, age of the oocyte donor, number of embryos transferred, and singleton/twin pregnancy. RESULTS: Oocyte donation was associated with an increased risk of pregnancy induced hypertension (PIH) (matched OR: 1.502 CI: 1.024-2.204), and first trimester bleeding (matched OR: 1.493 CI: 1.036-2.15). No differences were observed between the two matched groups with regard to gestational age, mean birth weight and length, head circumference and Apgar scores. CONCLUSIONS: Oocyte donation is associated with an increased risk for PIH and first trimester bleeding independent of the recipients? age, parity and plurality, and independent of the age of the donor or the partner. However, oocyte donation has no impact on the overall perinatal outcome. 相似文献
719.
Nikolaos Friligos 《Hydrobiologia》1984,112(1):17-25
The nutrient distribution in relation to environmental characteristics of the Saronikos Gulf was studied at two stations for the period 1973–1976. The distribution of measured values and their spatiotemporal variations were compared with previous data for the same area. Winter convection resulted in a very weak gradient of temperature, salinity, oxygen and nutrients. Stratification started to develop in May and persisted. for about six months. Little seasonal variation of nutrients appeared to occur, with higher values generally in winter. It was found that the station in the vicinity of the outfall contained more phosphate and ammonia than the station in the source water. Their levels of nutrients were similar in both years, except in the case of phosphate and nitrite, which were double at the station near the outfall in 1975. Of the nutrients controlling productivity in the photic layer of the examined stations in the Saronikos Gulf, phosphate had a stronger limiting effect on plant growth than inorganic nitrogen. 相似文献
720.
Sheetal Kaw Swetha Ananth Nikolaos Tsopoulidis Katharina Morath Bahar M Coban Ralph Hohenberger Olcay C Bulut Florian Klein Bettina Stolp Oliver T Fackler 《The EMBO journal》2020,39(24)
Failures to produce neutralizing antibodies upon HIV‐1 infection result in part from B‐cell dysfunction due to unspecific B‐cell activation. How HIV‐1 affects antigen‐specific B‐cell functions remains elusive. Using an adoptive transfer mouse model and ex vivo HIV infection of human tonsil tissue, we found that expression of the HIV‐1 pathogenesis factor NEF in CD4 T cells undermines their helper function and impairs cognate B‐cell functions including mounting of efficient specific IgG responses. NEF interfered with T cell help via a specific protein interaction motif that prevents polarized cytokine secretion at the T‐cell–B‐cell immune synapse. This interference reduced B‐cell activation and proliferation and thus disrupted germinal center formation and affinity maturation. These results identify NEF as a key component for HIV‐mediated dysfunction of antigen‐specific B cells. Therapeutic targeting of the identified molecular surface in NEF will facilitate host control of HIV infection. 相似文献