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621.
622.
Immunohistochemical localization of nerve growth factor (NGF) and NGF receptor (NGF-R) in the developing first molar tooth of the rat 总被引:9,自引:0,他引:9
Thimios A. Mitsiadis Eleni Dicou Annick Joffre Henri Magloire 《Differentiation; research in biological diversity》1992,49(1):47-61
Nerve growth factor (NGF) is a well established target-derived trophic factor supporting sympathetic and sensory innervation in the peripheral tissues as well as cholinergic innervation in the brain. Despite its name, NGF may have broader biological functions early in development in a wide range of non-neuronal differentiating cells. The many effects of NGF are directly dependent on initial binding of NGF to specific plasma membrane receptors on target cells. Here we use immunohistochemical methods to show that NGF and its receptor (NGF-R) are localized in a variety of embryonic epithelial and mesenchymal cells in the rat developing molar tooth. Dental cells known to play important roles in morphogenesis and inductive tissue interactions show NGF-like reactivity. Thus, labelling is seen in epithelial preameloblasts and mesenchymal odontoblasts. We also show a transient expression of NGF-R in restricted parts of the dental epithelium (inner dental epithelium) and dental mesenchyme differentiating cells (post-mitotic, polarizing odontoblasts). The expression patterns of NGF are different to those of NGF-R during embryogenesis and this is illustrated in detail in the developing tooth. The histochemical findings reported here support the notion that NGF may have multiple roles during morphogenetic and cytodifferentiation events in the tooth. 相似文献
623.
Omar Tanweer Eleni Metaxa Nicholas Liaw Daniel S. Sternberg Adnan H. Siddiqui John Kolega Hui Meng 《Journal of Biorheology》2010,24(2):77-83
Outward arterial remodeling is a physiological response to accommodate chronically elevated blood flow and requires endothelial cells (ECs) and expression of endothelial nitric oxide synthase (eNOS). ECs may sense elevated flow via stretch-activated ion channels (SACs). We evaluated the role of SACs in regulation of flow-induced arterial expansion and eNOS expression by ECs. A high-flow environment was created in the common carotid arteries (CCAs) of mice via contralateral common carotid artery (CCA) ligation. Either streptomycin for SAC blockade or saline for placebo was delivered to the mice. CCAs were harvested for morphometric analysis 7 days post procedure. Cultured ECs were exposed to flow with wall shear stresses (WSSs) of 1.5–10 Pa for 24 h in presence or absence of streptomycin. Immunofluorescent staining was used for eNOS quantification. In vivo, CCA expansion in streptomycin-treated mice (n = 7) was significantly less than in the placebo-treated group (n = 8) (p = 0.015). In vitro, streptomycin exposure significantly inhibited eNOS expression at WSS >2.5 Pa (p = 0.001) while not affecting eNOS expression at baseline WSS (1.5–2.5 Pa). Blockade of SACs with streptomycin impairs outward arterial remodeling and eNOS expression at high WSSs. Activation of SACs under elevated WSS may contribute to vessel expansion by upregulating eNOS in ECs. 相似文献
624.
Maria Eleni Kastriti Louis Faure Dorothea Von Ahsen Thibault Gerald Bouderlique Johan Bostrm Tatiana Solovieva Cameron Jackson Marianne Bronner Dies Meijer Saida Hadjab Francois Lallemend Alek Erickson Marketa Kaucka Viacheslav Dyachuk Thomas Perlmann Laura Lahti Jan Krivanek JeanFrancois Brunet Kaj Fried Igor Adameyko 《The EMBO journal》2022,41(17)
625.
Joanna Mercado Mary Carmen Valenzano Cameron Jeffers Jason Sedlak Marina K. Cugliari Eleni Papanikolaou Jacob Clouse Jingya Miao Nina E. Wertan James M. Mullin 《PloS one》2013,8(11)
Amid an increasing number of reports in the literature concerning epithelial barrier enhancement by various nutrient compounds, there has never been a study performing side-by-side comparisons of these agents in a single epithelial model. We compare five nutrient compounds (previously reported in various epithelial models to enhance barrier function) regarding their ability to increase transepithelial electrical resistance (Rt) and decrease transepithelial mannitol permeability (Jm) across LLC-PK1 renal epithelial cell layers. The effects of these nutrients on the abundance of various tight junctional proteins are also compared. In the overall group of nutrients tested - zinc, indole, quercetin, butyrate and nicotine - only nicotine failed to improve barrier function by either parameter. Nicotine also was without effect on tight junctional proteins. Quercetin simultaneously increased Rt and decreased Jm. Zinc, butyrate and indole only exhibited statistically significant enhancement of Rt. Each of these four effective nutrient compounds had unique patterns of effects on the panel of tight junctional proteins studied. No two compounds produced the same pattern of effects. This unique pattern of effects on tight junctional complex composition by each compound establishes the chance for additive or even synergistic improvement of barrier function by combinations of compounds. A synergistic effect of the combination of quercetin and zinc on Rt is shown. 相似文献
626.
Chih-Ko Yeh Prema M. Mertz Constance Oliver Bruce J. Baum Eleni E. Kousvelari 《In vitro cellular & developmental biology. Animal》1991,27(9):707-712
Summary We have successfully maintained and biochemically characterized differentiated rat parotid acinar cells cultured for long
periods (6 mo.). The cells were cultured on a reconstituted basement membrane matrix in a medium containing a variety of agents
that promote cellular proliferation and differentiation. The cultured cells retain the characteristics of the parental parotid
acinar cells. They exhibit both secretory granules and abundant cellular organelles required for protein synthesis and secretion.
In situ hybridization and immunocytochemistry demonstrate high levels of proline-rich protein mRNA and protein, and lower
levels of amylase mRNA and protein, in their cytoplasm. These findings suggest that rat parotid acinar cells can be maintained
in a differentiated state in vitro for long periods, and can serve as a useful model system for studying the regulation of
exocrine secretory processes. 相似文献
627.
628.
Mfn2 deletion in brown adipose tissue protects from insulin resistance and impairs thermogenesis 下载免费PDF全文
Kiana Mahdaviani Ilan Y Benador Shi Su Raffi A Gharakhanian Linsey Stiles Kyle M Trudeau Maria Cardamone Violeta Enríquez‐Zarralanga Eleni Ritou Tamar Aprahamian Marcus F Oliveira Barbara E Corkey Valentina Perissi Marc Liesa Orian S Shirihai 《EMBO reports》2017,18(7):1123-1138
BAT‐controlled thermogenic activity is thought to be required for its capacity to prevent the development of insulin resistance. This hypothesis predicts that mediators of thermogenesis may help prevent diet‐induced insulin resistance. We report that the mitochondrial fusion protein Mitofusin 2 (Mfn2) in BAT is essential for cold‐stimulated thermogenesis, but promotes insulin resistance in obese mice. Mfn2 deletion in mice through Ucp1‐cre (BAT‐Mfn2‐KO) causes BAT lipohypertrophy and cold intolerance. Surprisingly however, deletion of Mfn2 in mice fed a high fat diet (HFD) results in improved insulin sensitivity and resistance to obesity, while impaired cold‐stimulated thermogenesis is maintained. Improvement in insulin sensitivity is associated with a gender‐specific remodeling of BAT mitochondrial function. In females, BAT mitochondria increase their efficiency for ATP‐synthesizing fat oxidation, whereas in BAT from males, complex I‐driven respiration is decreased and glycolytic capacity is increased. Thus, BAT adaptation to obesity is regulated by Mfn2 and with BAT‐Mfn2 absent, BAT contribution to prevention of insulin resistance is independent and inversely correlated to whole‐body cold‐stimulated thermogenesis. 相似文献
629.
Gabriella Papastefanou Eleni Panayiotou Moisis Mylonas Stylianos Michail Simaiakis 《ZooKeys》2015,(510):163-179
Global urbanization is a major force that causes alteration and loss of natural habitats. Urban ecosystems are strongly affected by humans and there is a gradient of decreasing human influence from city centers to natural habitats. To study ecological changes along this continuum, researchers introduced the urban-rural gradient approach. The responses of centipedes to an urbanization gradient (urban-suburban-rural areas) were studied using pitfall traps in and near the city of Heraklion, in the island of Crete, Greece, from November 2010 to November 2011. Our results do not support the intermediate disturbance hypothesis, in which suburban areas located in the transitional zone between urban and rural habitats failed to indicate significant increase in terms of species richness and diversity. 相似文献
630.
The status of the Mediterranean and Black Sea fisheries was evaluated for the period 1970-2010 on a subarea basis, using various indicators including the temporal variability of total landings, the number of recorded stocks, the mean trophic level of the catch, the fishing-in-balance index and the catch-based method of stock classification. All indicators confirmed that the fisheries resources of the Mediterranean and Black Sea are at risk from overexploitation. The pattern of exploitation and the state of stocks differed among the western (W), central (C) and eastern (E) Mediterranean subareas and the Black Sea (BS), with the E Mediterranean and BS fisheries being in a worst shape. Indeed, in the E Mediterranean and the BS, total landings, mean trophic level of the catch and fishing-in-balance index were declining, the cumulative percentage of overexploited and collapsed stocks was higher, and the percentage of developing stocks was lower, compared to the W and C Mediterranean. Our results confirm the need for detailed and extensive stock assessments across species that will eventually lead to stocks recovering through conservation and management measures. 相似文献