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Blastocyst implantation occurs in the progesterone-primed uterus of hamsters, but not in mice where the progesterone-primed uterus requires estrogen influence. Leukemia inhibitory factor (Lif), an estrogen-regulated gene in mice, is an absolutely needed cytokine for uterine receptivity and implantation in this species. This study aimed to evaluate the importance of Lif ligand-receptor signaling during uterine receptivity and implantation in hamsters. We investigated whether or not the uterine expression patterns of Lif and its receptors, Lif-r and gp130, during the periimplantation period of pregnancy and its hormonal regulation in the ovariectomized hamster correlate with some of the vital phases of uterine changes during early pregnancy. Uterine Lif, Lif-r, and gp130 mRNA expressions were examined by Northern and in situ hybridization. During the uterine preparatory phase for implantation, Lif, Lif-r, and gp130 were expressed either in the gland, luminal epithelium or both. As the implantation process began, Lif expression was minimal, but Lif-r and gp130 extended to the decidual areas. This decidual expression of Lif-r and gp130 was not dependent on the presence of the embryo since these genes were expressed in the suture-induced deciduomata. We also observed that, while the uterine Lif was induced by estrogen, Lif-r and gp130 were induced by progesterone in ovariectomized hamsters. Additionally, we show that a Lif antibody when instilled intraluminally on day 3 of pregnancy reduced the number of implantation sites. Taken together, these data suggest that Lif signaling is important for uterine receptivity and implantation in hamsters.  相似文献   
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Maternal infection-induced early pregnancy complications arise from perturbation of the immune environment at the uterine early blastocyst implantation site (EBIS), yet the underlying mechanisms remain unclear. Here, we demonstrated in a mouse model that the progression of normal pregnancy from days 4 to 6 induced steady migration of leukocytes away from the uterine decidual stromal zone (DSZ) that surrounds the implanted blastocyst. Uterine macrophages were found to be CD206+ M2-polarized. While monocytes were nearly absent in the DSZ, DSZ cells were found to express monocyte marker protein Ly6C. Systemic endotoxic lipopolysaccharide (LPS) exposure on day 5 of pregnancy led to: (1) rapid (at 2 h) induction of neutrophil chemoattractants that promoted huge neutrophil infiltrations at the EBISs by 24 h; (2) rapid (at 2 h) elevation of mRNA levels of MyD88, but not Trif, modulated cytokines at the EBISs; and (3) dose-dependent EBIS defects by day 7 of pregnancy. Yet, elimination of maternal neutrophils using anti-Ly6G antibody prior to LPS exposure failed to avert LPS-induced EBIS defects allowing us to suggest that activation of Tlr4-MyD88 dependent inflammatory pathway is involved in LPS-induced defects at EBISs. Thus, blocking the activation of the Tlr4-MyD88 signaling pathway may be an interesting approach to prevent infection-induced pathology at EBISs.  相似文献   
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Biosensing based on localized surface plasmon resonance (LSPR) relies on concentrating light to a nanometeric spot and leads to a highly enhanced electromagnetic field near the metal nanostructure. Here, a design of plasmonic nanostructures based on rationally structured metal–dielectric combinations is presented, called composite scattering probes (CSPs), to generate an integrated multimodal biosensing platform featuring LSPR and surface‐enhanced Raman spectroscopy (SERS). Specifically, CSP configurations are proposed, which have several prominent resonance peaks enabling higher tunability and sensitivity for self‐referenced multiplexed analyte sensing. Using electron‐beam evaporation and thermal dewetting, large‐area, uniform, and tunable CSPs are fabricated, which are suitable for label‐free LSPR and SERS measurements. The CSP prototypes are used to demonstrate refractive index sensing and molecular analysis using albumin as a model analyte. By using partial least squares on recorded absorption profiles, differentiation of subtle changes in refractive index (as low as 0.001) in the CSP milieu is demonstrated. Additionally, CSPs facilitate complementary untargeted plasmon‐enhanced Raman measurements from the sample's compositional contributors. With further refinement, it is envisioned that the method may lead to a sensitive, versatile, and tunable platform for quantitative concentration determination and molecular fingerprinting, particularly where limited a priori information of the sample is available.  相似文献   
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The development of high-efficiency photocatalysts is an attractive strategy for pollutants degradation under visible light. Herein, novel photocatalysts are reported through coupling Sb2MoO6 with g-C3N4 nanotube (abbreviated as GCN nanotube) by a simple reflux method. Also, the nanocomposites were defined by applying various analyses. Under visible-light excitation, the GCN nanotube/Sb2MoO6 systems had more photoactivity than g-C3N4 (abbreviated as GCN) and the rate constant for RhB removal on optimal GCN nanotube/Sb2MoO6 (30%) nanocomposite was 48.3 times premier than the GCN. Also, compared to the pristine GCN, the GCN nanotube/Sb2MoO6 (30%) sample demonstrated supreme photoactivity towards tetracycline degradation and Cr (VI) photoreduction, which was 88.5 and 21.8 times higher than the bulk GCN, respectively. These impressive enhancements were attributed to the quick segregation of charge carriers, boosted visible-light absorption, and extended specific surface area. Moreover, the photocatalyst has enough activity after four successive cycles. Finally, a conceivable charges transfer route is presented through n-n heterojunction constructed between Sb2MoO6 and GCN nanotube.  相似文献   
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Nanotechnology has provided tools for next generation biomedical devices which rely on nanostructure interfaces with living cells. In vitro biomimetic structures have enabled observation of cell response to various mechanical and chemical cues, and there is a growing interest in isolating and harnessing the specific cues that 3D microenvironments can provide without the requirement for such culture and the experimental drawbacks associated with it. Here, a randomly oriented gold coated Si nanowire substrate with patterned hydrophobic–hydrophilic areas for the differentiation of isogenic breast cancer cells of varying metastatic potential is reported. When considering synthetic surfaces for the study of cell-nanotopography interfaces, randomly oriented nanowires more closely resemble the isotropic architecture of a natural extracellular matrix. In the study reported here, the authors show that primary cancer cells preferably attach to the hydrophilic region of randomly oriented nanowire substrate while secondary cancer cells do not adhere. Using machine learning analysis of fluorescence images, cells are found to spread and elongate on the nanowire substrates as compared to a flat substrate, where they mostly remain round. Such platforms can not only be used for developing bioassays but also as stepping stones for tissue printing technologies where cells can be selectively patterned at desired locations.  相似文献   
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Terraced apartments as a typology of the buildings are new approaches to meet energy conservation targets. This principle in the form of interactive spaces contributes to an incorporation of interior and exterior, daylight addition and exploitation of natural ventilation. This study mainly investigates the natural ventilation exploitation of a terraced apartment in the hot and humid region. One solid block and 4 porous apartments with different terrace depths (TD) are evaluated using computational fluid dynamics (CFD) analysis. The k-ε turbulence model was adapted to simulate airflow in and around a mid-rise building with 42 residential blocks. CFD analysis compares the effect of permeability in the form of terraces on wind behaviour and natural ventilation efficiency in a mid-rise building. Ventilation assessment parameters such as mean air velocity and mean age of air are measured to compare the natural ventilation performance. The simulation results clearly indicate that the implementation of permeability in the form of terraces can enhance building natural ventilation performance significantly. However, it is proved that some physical configurations such as terrace depth can influence this performance greatly. According to the results, increasing the terrace depth up to 1.2 meters will enhance the mean wind velocity 40%–88% inside the room, 10.61%–12.29% near the window and 63.44% on the openings. Velocity diagram follows a descending process after TD 1.2. The mean wind speed decreases to 25.53% inside the room, 15.09% inside terraces and 1.09% near the window. The average wind velocity on the openings is revealed to be 1.54 to 1.64 times larger in the porous models than the solid one. On the other hand, porous cases indicate lower values for the mean age of air compared to the solid model. This study provides proper guidelines to predict ventilation performance and to improve the design of naturally ventilated mid-rise buildings in hot and humid regions.  相似文献   
8.
H S Maiti  M K Paria 《Sadhana》1988,13(1-2):59-71
A high temperature fuel cell using a solid oxide electrolyte, and operated at temperatures above 700°C, is a highly efficient energy conversion device utilizing primarily gaseous fuels like H2 and CO. It can also be operated in the reverse manner as a high temperature steam electrolyser to produce hydrogen. The operating principle and the construction details of different design concepts have been discussed. Nonavailability of suitable electrode and interconnection materials has hampered commercial exploitation. Recent trends in the development of these materials have been focussed upon, both in the national and the international context.  相似文献   
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Traditional dairy products are the main source of probiotic microorganisms. Hence, this study aimed to evaluate the safety and antimicrobial potential of Lactobacillus pentosus 22C, isolated from traditional yogurt from Kermanshah province, Iran. Strain 22C showed no undesirable amino acid decarboxylase and β-hemolytic activities. Virulence associated genes were detected in the isolate. The strain produced an antimicrobial molecule named pentocin 22C, a small peptide with a relative mass between 5 and 10 kDa. Bacterial inhibition was pH-independent, with greater activity at pH 4–6. Purified or semi-purified antimicrobial agents can be used as bio-preservatives, and the producing strain can be used as a starter culture to improve food safety. Therefore, a biosafety assessment should be conducted. L. pentosus 22C, isolated from a traditional dairy product, has antimicrobial ability, although its safety must be evaluated.  相似文献   
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