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991.
David Muehsam Parviz Lalezari Rukmani Lekhraj Provvidenza Abruzzo Alessandra Bolotta Marina Marini Ferdinando Bersani Giorgio Aicardi Arthur Pilla Diana Casper 《PloS one》2013,8(4)
The growing body of clinical and experimental data regarding electromagnetic field (EMF) bioeffects and their therapeutic applications has contributed to a better understanding of the underlying mechanisms of action. This study reports that two EMF modalities currently in clinical use, a pulse-modulated radiofrequency (PRF) signal, and a static magnetic field (SMF), applied independently, increased the rate of deoxygenation of human hemoglobin (Hb) in a cell-free assay. Deoxygenation of Hb was initiated using the reducing agent dithiothreitol (DTT) in an assay that allowed the time for deoxygenation to be controlled (from several min to several hours) by adjusting the relative concentrations of DTT and Hb. The time course of Hb deoxygenation was observed using visible light spectroscopy. Exposure for 10–30 min to either PRF or SMF increased the rate of deoxygenation occurring several min to several hours after the end of EMF exposure. The sensitivity and biochemical simplicity of the assay developed here suggest a new research tool that may help to further the understanding of basic biophysical EMF transduction mechanisms. If the results of this study were to be shown to occur at the cellular and tissue level, EMF-enhanced oxygen availability would be one of the mechanisms by which clinically relevant EMF-mediated enhancement of growth and repair processes could occur. 相似文献
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994.
Per K?hler Anette Wolff Fredrik Ejserholm Lars Wallman Jens Schouenborg Cecilia E. Linsmeier 《PloS one》2015,10(3)
To develop long-term high quality communication between brain and computer, a key issue is how to reduce the adverse foreign body responses. Here, the impact of probe flexibility and gelatine embedding on long-term (6w) tissue responses, was analyzed. Probes of same polymer material, size and shape, flexible mainly in one direction, were implanted in rat cerebral cortex (nimplants = 3 x 8) in two orientations with respect to the major movement direction of the brain relative to the skull: parallel to (flex mode) or transverse to (rigid mode). Flex mode implants were either embedded in gelatin or non-embedded. Neurons, activated microglia and astrocytes were visualized using immunohistochemistry. The astrocytic reactivity, but not microglial response, was significantly lower to probes implanted in flex mode as compared to rigid mode. The microglial response, but not astrocytic reactivity, was significantly smaller to gelatin embedded probes (flex mode) than non-embedded. Interestingly, the neuronal density was preserved in the inner zone surrounding gelatin embedded probes. This contrasts to the common reports of reduced neuronal density close to implanted probes. In conclusion, sheer stress appears to be an important factor for astrocytic reactivity to implanted probes. Moreover, gelatin embedding can improve the neuronal density and reduce the microglial response close to the probe. 相似文献
995.
996.
Devendra Kumar Maurya Tiago Henriques Monica Marini Nicoletta Pedemonte Luis J. V. Galietta Jason R. Rock Brian D. Harfe Anna Menini 《PloS one》2015,10(6)
TMEM16A/ANO1 is a calcium-activated chloride channel expressed in several types of epithelia and involved in various physiological processes, including proliferation and development. During mouse embryonic development, the expression of TMEM16A in the olfactory epithelium is dynamic. TMEM16A is expressed at the apical surface of the entire olfactory epithelium at embryonic day E12.5 while from E16.5 its expression is restricted to a region near the transition zone with the respiratory epithelium. To investigate whether TMEM16A plays a role in the development of the mouse olfactory epithelium, we obtained the first immunohistochemistry study comparing the morphological properties of the olfactory epithelium and nasal glands in TMEM16A-/- and TMEM16A+/+ littermate mice. A comparison between the expression of the olfactory marker protein and adenylyl cyclase III shows that genetic ablation of TMEM16A did not seem to affect the maturation of olfactory sensory neurons and their ciliary layer. As TMEM16A is expressed at the apical part of supporting cells and in their microvilli, we used ezrin and cytokeratin 8 as markers of microvilli and cell body of supporting cells, respectively, and found that morphology and development of supporting cells were similar in TMEM16A-/- and TMEM16A+/+ littermate mice. The average number of supporting cells, olfactory sensory neurons, horizontal and globose basal cells were not significantly different in the two types of mice. Moreover, we also observed that the morphology of Bowman’s glands, nasal septal glands and lateral nasal glands did not change in the absence of TMEM16A. Our results indicate that the development of mouse olfactory epithelium and nasal glands does not seem to be affected by the genetic ablation of TMEM16A. 相似文献
997.
Mariana Capurro Cecilia Ballaré Laura Bover Paula Portela Jesé Mordoh 《Cancer immunology, immunotherapy : CII》1999,48(2-3):100-108
The Lewisx (Lex) trisaccharide (CD15) linked to proteins and glycolipids is highly expressed on the surface of normal human polymorphonuclear
neutrophils (PMN) and several human neoplasias, such as breast and gastrointestinal carcinomas and chronic myeloid leukemias.
FC-2.15 is an IgM murine mAb that specifically recognizes Lex and has been previously shown to mediate the in vitro lysis of Lex(+) cells by human complement. In a phase I clinical trial of FC-2.15, a temporary neutropenia was the main toxicity, and
antitumor responses were observed. In order to characterize FC-2.15 further and determine the physiological relevance of Lex binding, the reactivity of FC-2.15 on PMN was investigated under several conditions. Flow cytometry revealed a strong reactivity
of FC-2.15 with almost 100% of PMN, and Scatchard analysis demonstrated an affinity constant of 5.14 × 109 M−1 and 1.11 × 106 antigen sites/cell. In vitro, the binding of Lex epitopes by FC-2.15 induced PMN homotypic aggregation, only 28.4 ± 4.1% remaining as single cells. When PMN and the Lex(+) MCF-7 breast cancer cells were co-incubated, FC-2.15 induced heterotypic aggregation. In 51Cr-release assays employing human complement, FC-2.15 lysed 93.4 ± 7.9% of PMN and 87.8 ± 10.7% of MCF-7 cells. However, when
the effect of FC-2.15 was tested in ex vivo circulating blood, no lytic activity against PMN was detected, whereas MCF-7 cells
were still lysed. Blood smears demonstrated that FC-2.15 induced PMN agglutination and heterotypic aggregates when MCF-7 cells
were present. A pre-treatment of PMN with colchicine impaired PMN agglutination both in vitro (single PMN = 81.15 ± 4.35%)
and in ex vivo circulating blood. In the latter condition, FC-2.15-lytic activity was restored, suggesting that PMN homotypic
aggregation by FC-2.15, but not lysis, is dependent on microtubule integrity and that PMN agglutination hinders their lysis.
Moreover, when 51Cr-release assays were performed following agglutination, FC-2.15 cytotoxicity was restricted to isolated PMN. It is suggested
that crosslinking of Lex epitopes by FC-2.15 induces PMN to form homotypic aggregates. It is suggested that the neutropenia observed in FC-2.15-treated
patients would be due to PMN agglutination and margination, rather than lysis. In addition, FC-2.15 appears to be able to
lyse Lex(+) tumor cells in circulation.
Received: 3 December 1998 / Accepted: 28 January 1999 相似文献
998.
An ex vivo technique for imaging mouse airway epithelia for quantitative analysis of motile cilia function important for insight into mucociliary clearance function has been established. Freshly harvested mouse trachea is cut longitudinally through the trachealis muscle and mounted in a shallow walled chamber on a glass-bottomed dish. The trachea sample is positioned along its long axis to take advantage of the trachealis muscle to curl longitudinally. This allows imaging of ciliary motion in the profile view along the entire tracheal length. Videos at 200 frames/sec are obtained using differential interference contrast microscopy and a high speed digital camera to allow quantitative analysis of cilia beat frequency and ciliary waveform. With the addition of fluorescent beads during imaging, cilia generated fluid flow also can be determined. The protocol time spans approximately 30 min, with 5 min for chamber preparation, 5-10 min for sample mounting, and 10-15 min for videomicroscopy. 相似文献
999.
Barry W. Festoff Jasti S. Rao Cecilia Maben Daniel Hantaï 《Journal of cellular physiology》1990,144(2):262-271
Plasminogen activators (PAs), were estimated qualitatively and quantitatively in two different clonal murine skeletal muscle cell lines. Both cell lines produced the two major types of PAs found in mammalian cells, urokinase-type (uPA) and tissue type (tPA). These two lines are models for the study of myogenesis in vitro, but differ in several growth and differentiation characteristics. Because of their possible involvement in these characteristics we assayed the expression of PAs in both cell systems during development in culture. Utilizing fibrin zymography two isoforms of tPA were detected. One co-migrated with human tPA at 75 kd and another may represent a tPA:inhibitor complex at 105 Kd. Several isoenzymes of uPA were detected and these changed depending on whether cell homogenates or conditioned medium was analyzed and whether myogenic cells were at single-cell myoblast or multi-nucleated myotube stage. Species-specific antisera to mouse uPA identified 4 uPA bands in muscle cell medium and 5 in cell layers. Antigenic uPA bands also varied depending on stage of myogenesis. Quantitative amidolytic studies using chromogenic substrates showed that maximal PA activity, both uPA and tPA, occurred at the time of myoblast fusion. Furthermore, uPA activity in membranes increased during myogenesis, while both uPA and tPA in medium decreased after fusion. These studies indicate that muscle PA expression is developmentally regulated and may correlate with growth and differentiation in skeletal muscle. 相似文献
1000.
Physical characterization of mitochondrial DNA from cotton 总被引:2,自引:0,他引:2