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排序方式: 共有224条查询结果,搜索用时 15 毫秒
71.
Endometrial gene expression profiling of recurrent implantation failure after in vitro fertilization
Albayrak İrem Gülfem Azhari Fatemeh Çolak Ezgi Nur Balcı Burçin Karamustafaoğlu Ülgen Ege Sezerman Uğur Baştu Ercan Günel Tuba 《Molecular biology reports》2021,48(6):5075-5082
Molecular Biology Reports - Recurrent implantation failure (RIF) is diagnosed when good-quality embryos repeatedly fail to implant after transfer in several in vitro fertilization (IVF) treatment... 相似文献
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In this study, ethylcellulose (EC)-based microsphere formulations were prepared without and with triethyl citrate (TEC) content
of 10% and 30% by water-in-oil emulsion-solvent evaporation technique. Diltiazem hydrochloride (DH) was chosen as a hydrophilic
model drug and used at different drug/polymer ratios in the microspheres. The aim of the work was to evaluate the influence
of plasticizer ratio on the drug release rate and physicochemical characteristics of EC-based matrix-type microspheres. The
resulting microspheres were evaluated for encapsulation efficiency, particle size and size distribution, surface morphology,
total pore volume, thermal characteristics, drug release rates, and release mechanism. Results indicated that the physicochemical
properties of microspheres were strongly affected by the drug/polymer ratio investigated and the concentration of TEC used
in the production technique. The surface morphology and pore volume of microspheres significantly varied based on the plasticizer
content in the formulation. DH release rate from EC-based matrix-type microspheres can be controlled by varying the DH to
polymer and plasticizer ratios. Glass transition temperature values tended to decrease in conjunction with increasing amounts
of TEC. Consequently, the various characteristics of the EC microspheres could be modified based on the plasticized ratio
of TEC. 相似文献
75.
Evelin Ramóna Péli Nie Lei Tamás Pócs Zsanett Laufer Stefan Porembski Zoltán Tuba 《Central European Journal of Biology》2011,6(6):1065
Paper by Péli et al. “Ecophysiological responses of desiccation-tolerant cryptobiotic crusts” in Volume 6, Issue 5, 838–849 / October 2011; DOI:
10.2478/s11535-011-0049-1 contains incorrect graphic file inserted as Figure 6. The correct Figure 6, together with its caption
is presented below. 相似文献
76.
An optical trapping technique is implemented to investigate the chemotactic behavior of a marine bacterial strain Vibrio alginolyticus. The technique takes the advantage that the bacterium has only a single polar flagellum, which can rotate either in the counter-clock-wise or clock-wise direction. The two rotation states of the motor can be readily and instantaneously resolved in the optical trap, allowing the flagellar motor switching rate S(t) to be measured under different chemical stimulations. In this paper the focus will be on the bacterial response to an impulsive change of chemoattractant serine. Despite different propulsion apparati and motility patterns, cells of V. alginolyticus apparently use a similar response as Escherichia coli to regulate their chemotactic behavior. Specifically, we found that the switching rate S(t) of the bacterial motor exhibits a biphasic behavior, showing a fast initial response followed by a slow relaxation to the steady-state switching rate S0. The measured S(t) can be mimicked by a model that has been recently proposed for chemotaxis in E. coli. The similarity in the response to the brief chemical stimulation in these two different bacteria is striking, suggesting that the biphasic response may be evolutionarily conserved. This study also demonstrated that optical tweezers can be a useful tool for chemotaxis studies and should be applicable to other polarly flagellated bacteria. 相似文献
77.
Aydin Atakan Beyza Macunluoglu Yuksel Kaya Elif Ari Halit Demir Ebru Asicioglu Cigdem Kaspar 《Biological trace element research》2013,155(3):333-338
Cardiovascular diseases are the main reason of high mortality among hemodialysis patients. Decreased serum selenium levels may have a role in accelerated atherosclerosis in this patient group. The hypothesis of this study was to show a correlation between decreased serum selenium levels and coronary flow reserve as an indicator of endothelial dysfunction and atherosclerosis in HD patients. Seventy-one chronic hemodialysis patients and age 65 and sex-matched healthy controls were included in the study. Plasma selenium levels were measured by spectrophotometry, and coronary flow reserve was assessed by transthoracic Doppler echocardiography. Serum selenium levels (34.16?±?6.15 ng/ml vs. 52.4?±?5.51 ng/ml, P?<?0.001) and coronary flow reserve values (1.73?±?0.11 vs. 2.32?±?0.28, P?<?0.001) were significantly lower in hemodialysis patients compared with controls, respectively. There was a significant positive correlation between coronary flow reserve and serum levels of selenium (r?=?0.676, P?<?0.001). A linear regression analysis showed that serum levels of selenium were independently and positively correlated with coronary flow reserve (regression coefficient?=?0.650, P?<?0.05). This study was the first to show a positive and independent correlation between decreased selenium levels and diminished coronary flow reserve as an indicator of endothelial dysfunction and atherosclerosis in hemodialysis patients. Our data suggest that decreased serum selenium levels may facilitate the development of endothelial dysfunction and disruption of coronary flow reserve which occur before the development of overt atherosclerosis. 相似文献
78.
The size, shape, and number of chloroplasts in the palisade and spongy parenchyma layers of Haberlea rhodopensis leaves changed significantly during desiccation and following rehydration. The chloroplasts became smaller and more rounded during desiccation, and aggregated in the middle of the cell. The size and number of chloroplasts in the palisade parenchyma cells were higher than in spongy parenchyma. The good correlation observed between the size or number of chloroplasts and the cross-sectional area of mesophyll cells, the cross-sectional width of the leaf and its water content suggested that the palisade cells were more responsive to water availability than the spongy cells. Changes in chloroplast number during desiccation and rehydration process are characteristic features for desiccation-tolerant plants (especially in homoiochlorophyllous strategy). 相似文献
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Gunduz-Demir C 《Mathematical biosciences》2007,209(2):514-527
We report a novel computational method based on graph evolution process to model the malignancy of brain cancer called glioma. In this work, we analyze the phases that a graph passes through during its evolution and demonstrate strong relation between the malignancy of cancer and the phase of its graph. From the photomicrographs of tissues, which are diagnosed as normal, low-grade cancerous and high-grade cancerous, we construct cell-graphs based on the locations of cells; we probabilistically generate an edge between every pair of cells depending on the Euclidean distance between them. For a cell-graph, we extract connectivity information including the properties of its connected components in order to analyze the phase of the cell-graph. Working with brain tissue samples surgically removed from 12 patients, we demonstrate that cell-graphs generated for different tissue types evolve differently and that they exhibit different phase properties, which distinguish a tissue type from another. 相似文献