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81.
Nikolai Otmakhov Elena V. Gorbacheva Shaurav Regmi Ryohei Yasuda Andy Hudmon John Lisman 《PloS one》2015,10(3)
Over-activation of excitatory NMDA receptors and the resulting Ca2+ overload is the main cause of neuronal toxicity during stroke. CaMKII becomes misregulated during such events. Biochemical studies show either a dramatic loss of CaMKII activity or its persistent autonomous activation after stroke, with both of these processes being implicated in cell toxicity. To complement the biochemical data, we monitored CaMKII activation in living hippocampal neurons in slice cultures using high spatial/temporal resolution two-photon imaging of the CaMKIIα FRET sensor, Camui. CaMKII activation state was estimated by measuring Camui fluorescence lifetime. Short NMDA insult resulted in Camui activation followed by a redistribution of its protein localization: an increase in spines, a decrease in dendritic shafts, and concentration into numerous clusters in the cell soma. Camui activation was either persistent (> 1–3 hours) or transient (~20 min) and, in general, correlated with its protein redistribution. After longer NMDA insult, however, Camui redistribution persisted longer than its activation, suggesting distinct regulation/phases of these processes. Mutational and pharmacological analysis suggested that persistent Camui activation was due to prolonged Ca2+ elevation, with little impact of autonomous states produced by T286 autophosphorylation and/or by C280/M281 oxidation. Cell injury was monitored using expressible mitochondrial marker mito-dsRed. Shortly after Camui activation and clustering, NMDA treatment resulted in mitochondrial swelling, with persistence of the swelling temporarily linked to the persistence of Camui activation. The results suggest that in living neurons excitotoxic insult produces long-lasting Ca2+-dependent active state of CaMKII temporarily linked to cell injury. CaMKII function, however, is to be restricted due to strong clustering. The study provides the first characterization of CaMKII activation dynamics in living neurons during excitotoxic insults. 相似文献
82.
Coral Reefs - Pacific crown-of-thorns starfish (Acanthaster cf. solaris) are known to be widely distributed, and previous studies (showing limited genetic structure) suggest that there are high... 相似文献
83.
In this study, we studied the effects of cortisol and cortisone on the age-related decrease in locomotion in the nematode Caenorhabditis elegans and on the tolerance to heat stress at 35 °C and to oxidative stress induced by the exposure to 0.1% H2O2. Changes in mRNA expression levels of C. elegans genes related to stress tolerance were also analyzed. Cortisol treatment restored nematode movement following heat stress and increased viability under oxidative stress, but also shortened worm lifespan. Cortisone, a cortisol precursor, also restored movement after heat stress. Additionally, cortisol treatment increased mRNA expression of the hsp-12.6 and sod-3 genes. Furthermore, cortisol treatment failed to restore movement of daf-16-deficient mutants after heat stress, whereas cortisone failed to restore the movement of dhs-30-deficient mutants after heat stress. In conclusion, the results suggested that cortisol promoted stress tolerance via DAF-16 but shortened the lifespan, whereas cortisone promoted stress tolerance via DHS-30. 相似文献
84.
N. Yamaoka K. Inazawa S. Inagawa M. Yasuda K. Mawatari K. Nakagomi 《Nucleosides, nucleotides & nucleic acids》2013,32(12):1256-1259
Genetic mutations in the purine salvage enzyme, hypoxanthine-guanine phosphoribosyltransferase (HPRT), are known to cause Lesch–Nyhan syndrome and Kelley–Seegmiller syndrome. In patients, purine metabolism is different from that of normal persons. We have previously developed a method for simultaneously determining the concentration of purine and pyrimidine nucleosides and nucleotides. This system was applied to determine the concentrations of nucleosides and nucleotides in HPRT-deficient cell lines. The amount of inosine 5′-monophosphate (IMP) was different in Lesch–Nyhan syndrome, Kelley–Seegmiller syndrome, and control cell lines. The difference in the amount of IMP confirmed the mutation of the enzyme. 相似文献
85.
Kazuyo Yasuda Toshihiko Torigoe Rena Morita Takahumi Kuroda Akari Takahashi Junichi Matsuzaki Vitaly Kochin Hiroko Asanuma Tadashi Hasegawa Tsuyoshi Saito Yoshihiko Hirohashi Noriyuki Sato 《PloS one》2013,8(8)
Cancer stem-like cells (CSCs)/cancer-initiaiting cells (CICs) are defined as a small population of cancer cells that have self-renewal capacity, differentiation potential and high tumor-initiating ability. CSCs/CICs of ovarian cancer have been isolated by side population (SP) analysis, ALDEFLUOR assay and using cell surface markers. However, these approaches are not definitive markers for CSCs/CICs, and it is necessary to refine recent methods for identifying more highly purified CSCs/CICs. In this study, we analyzed SP cells and aldehyde dehydrogenese bright (ALDHBr) cells from ovarian cancer cells. Both SP cells and ALDHBr cells exhibited higher tumor-initiating ability and higher expression level of a stem cell marker, sex determining region Y-box 2 (SOX2), than those of main population (MP) cells and ALDHLow cells, respectively. We analyzed an SP and ALDHBr overlapping population (SP/ALDHBr), and the SP/ALDHBr population exhibited higher tumor-initiating ability than that of SP cells or ALDHBr cells, enabling initiation of tumor with as few as 102 cells. Furthermore, SP/ADLHBr population showed higher sphere-forming ability, cisplatin resistance, adipocyte differentiation ability and expression of SOX2 than those of SP/ALDHLow, MP/ALDHBr and MP/ALDHLow cells. Gene knockdown of SOX2 suppressed the tumor-initiation of ovarian cancer cells. An SP/ALDHBr population was detected in several gynecological cancer cells with ratios of 0.1% for HEC—1 endometrioid adenocarcinoma cells to 1% for MCAS ovary mucinous adenocarcinoma cells. Taken together, use of the SP and ALDHBr overlapping population is a promising approach to isolate highly purified CSCs/CICs and SOX2 might be a novel functional marker for ovarian CSCs/CICs. 相似文献
86.
Simon D. French Joanne E. McKenzie Denise A. O'Connor Jeremy M. Grimshaw Duncan Mortimer Jill J. Francis Susan Michie Neil Spike Peter Schattner Peter Kent Rachelle Buchbinder Matthew J. Page Sally E. Green 《PloS one》2013,8(6)
Introduction
This cluster randomised trial evaluated an intervention to decrease x-ray referrals and increase giving advice to stay active for people with acute low back pain (LBP) in general practice.Methods
General practices were randomised to either access to a guideline for acute LBP (control) or facilitated interactive workshops (intervention). We measured behavioural predictors (e.g. knowledge, attitudes and intentions) and fear avoidance beliefs. We were unable to recruit sufficient patients to measure our original primary outcomes so we introduced other outcomes measured at the general practitioner (GP) level: behavioural simulation (clinical decision about vignettes) and rates of x-ray and CT-scan (medical administrative data). All those not involved in the delivery of the intervention were blinded to allocation.Results
47 practices (53 GPs) were randomised to the control and 45 practices (59 GPs) to the intervention. The number of GPs available for analysis at 12 months varied by outcome due to missing confounder information; a minimum of 38 GPs were available from the intervention group, and a minimum of 40 GPs from the control group. For the behavioural constructs, although effect estimates were small, the intervention group GPs had greater intention of practising consistent with the guideline for the clinical behaviour of x-ray referral. For behavioural simulation, intervention group GPs were more likely to adhere to guideline recommendations about x-ray (OR 1.76, 95%CI 1.01, 3.05) and more likely to give advice to stay active (OR 4.49, 95%CI 1.90 to 10.60). Imaging referral was not statistically significantly different between groups and the potential importance of effects was unclear; rate ratio 0.87 (95%CI 0.68, 1.10) for x-ray or CT-scan.Conclusions
The intervention led to small changes in GP intention to practice in a manner that is consistent with an evidence-based guideline, but it did not result in statistically significant changes in actual behaviour.Trial Registration
Australian New Zealand Clinical Trials Registry ACTRN012606000098538 相似文献87.
Yasuda Tetsuya Mishiro Koji Kusunoki Mikio Fujiwara-Tsujii Nao Yasui Hiroe Uechi Nami Fujimura Takako Inokuchi Rika Fujita Kiwamu Kanegae Yasutada Miura Yasushi Kato Ichiro Mitsunaga Takayuki 《Applied Entomology and Zoology》2020,55(2):205-212
Applied Entomology and Zoology - To evaluate the infection risk of Anoplophora malasiaca (Thomson) (Coleoptera: Cerambycidae) in two species of Japanese pine bonsais (Japanese black pine and... 相似文献
88.
Kouichi Yasuda Yoko Nakayama Mizuho Tanaka Mikiko Tanaka Ryota Mori Kiyofumi Furusawa 《Somatosensory & motor research》2013,30(1):30-35
The present study was an attempt to identify the location of genioglossal respiratory and swallowing motoneuron cell bodies within the hypoglossal (XII) nucleus using both electrophysiological and morphological studies. The genioglossus muscle is innervated by the genioglossal branch of the medial XII nerve. At the entrance to the muscle, the genioglossal branch divides in the directions of the mandible and tongue. Five of five rats displayed both respiratory-related and swallowing-related bursts in the medial XII branch towards the mandible. All five rats also displayed swallowing-related bursts in the medial XII branch towards the tongue. In addition, horseradish peroxidase conjugated to wheatgerm agglutinin (HRP:WGA) was injected into the proximal cut ends of each branch. When HRP:WGA was injected into the branch in the direction of the mandible, HRP-labeled cells were detected in the lateral region of the ventromedial subnucleus in the XII nucleus, extending from 0.7 to 1.2 mm rostral to the obex. On the other hand, after injection into the branch in the direction of the mandible, HRP-labeled cells were detected in the ventromedial subnucleus of the XII nucleus, extending from 0.3 to 1.2 mm rostral to the obex. These results provide evidence that genioglossal respiration-related and swallowing-related motoneurons are located in different portions within the ventromedial subnucleus of the XII nucleus. 相似文献
89.
Yuriko Furuya Atsushi Inagaki Masud Khan Kaoru Mori Josef M. Penninger Midori Nakamura Nobuyuki Udagawa Kazuhiro Aoki Keiichi Ohya Kohji Uchida Hisataka Yasuda 《The Journal of biological chemistry》2013,288(8):5562-5571
To date, parathyroid hormone is the only clinically available bone anabolic drug. The major difficulty in the development of such drugs is the lack of clarification of the mechanisms regulating osteoblast differentiation and bone formation. Here, we report a peptide (W9) known to abrogate osteoclast differentiation in vivo via blocking receptor activator of nuclear factor-κB ligand (RANKL)-RANK signaling that we surprisingly found exhibits a bone anabolic effect in vivo. Subcutaneous administration of W9 three times/day for 5 days significantly augmented bone mineral density in mouse cortical bone. Histomorphometric analysis showed a decrease in osteoclastogenesis in the distal femoral metaphysis and a significant increase in bone formation in the femoral diaphysis. Our findings suggest that W9 exerts bone anabolic activity. To clarify the mechanisms involved in this activity, we investigated the effects of W9 on osteoblast differentiation/mineralization in MC3T3-E1 (E1) cells. W9 markedly increased alkaline phosphatase (a marker enzyme of osteoblasts) activity and mineralization as shown by alizarin red staining. Gene expression of several osteogenesis-related factors was increased in W9-treated E1 cells. Addition of W9 activated p38 MAPK and Smad1/5/8 in E1 cells, and W9 showed osteogenesis stimulatory activity synergistically with BMP-2 in vitro and ectopic bone formation. Knockdown of RANKL expression in E1 cells reduced the effect of W9. Furthermore, W9 showed a weak effect on RANKL-deficient osteoblasts in alkaline phosphatase assay. Taken together, our findings suggest that this peptide may be useful for the treatment of bone diseases, and W9 achieves its bone anabolic activity through RANKL on osteoblasts accompanied by production of several autocrine factors. 相似文献
90.
Eita Uenishi Tadao Shibasaki Harumi Takahashi Chihiro Seki Hitomi Hamaguchi Takao Yasuda Masao Tatebe Yutaka Oiso Tadaomi Takenawa Susumu Seino 《The Journal of biological chemistry》2013,288(36):25851-25864
Actin dynamics in pancreatic β-cells is involved in insulin secretion. However, the molecular mechanisms of the regulation of actin dynamics by intracellular signals in pancreatic β-cells and its role in phasic insulin secretion are largely unknown. In this study, we elucidate the regulation of actin dynamics by neuronal Wiskott-Aldrich syndrome protein (N-WASP) and cofilin in pancreatic β-cells and demonstrate its role in glucose-induced insulin secretion (GIIS). N-WASP, which promotes actin polymerization through activation of the actin nucleation factor Arp2/3 complex, was found to be activated by glucose stimulation in insulin-secreting clonal pancreatic β-cells (MIN6-K8 β-cells). Introduction of a dominant-negative mutant of N-WASP, which lacks G-actin and Arp2/3 complex-binding region VCA, into MIN6-K8 β-cells or knockdown of N-WASP suppressed GIIS, especially the second phase. We also found that cofilin, which severs F-actin in its dephosphorylated (active) form, is converted to the phosphorylated (inactive) form by glucose stimulation in MIN6-K8 β-cells, thereby promoting F-actin remodeling. In addition, the dominant-negative mutant of cofilin, which inhibits activation of endogenous cofilin, or knockdown of cofilin reduced the second phase of GIIS. However, the first phase of GIIS occurs in the G-actin predominant state, in which cofilin activity predominates over N-WASP activity. Thus, actin dynamics regulated by the balance of N-WASP and cofilin activities determines the biphasic response of GIIS. 相似文献