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排序方式: 共有386条查询结果,搜索用时 31 毫秒
31.
Saunders PU Telford RD Pyne DB Peltola EM Cunningham RB Gore CJ Hawley JA 《Journal of strength and conditioning research / National Strength & Conditioning Association》2006,20(4):947-954
Fifteen highly trained distance runners VO(2)max 71.1 +/- 6.0 ml.min(-1).kg(-1), mean +/- SD) were randomly assigned to a plyometric training (PLY; n = 7) or control (CON; n = 8) group. In addition to their normal training, the PLY group undertook 3 x 30 minutes PLY sessions per week for 9 weeks. Running economy (RE) was assessed during 3 x 4 minute treadmill runs (14, 16, and 18 km.h(-1)), followed by an incremental test to measure VO(2)max. Muscle power characteristics were assessed on a portable, unidirectional ground reaction force plate. Compared with CON, PLY improved RE at 18 km.h(-1) (4.1%, p = 0.02), but not at 14 or 16 km.h(-1). This was accompanied by trends for increased average power during a 5-jump plyometric test (15%, p = 0.11), a shorter time to reach maximal dynamic strength during a strength quality assessment test (14%, p = 0.09), and a lower VO(2)-speed slope (14%, p = 0.12) after 9 weeks of PLY. There were no significant differences in cardiorespiratory measures or VO(2)max as a result of PLY. In a group of highly-trained distance runners, 9 weeks of PLY improved RE, with likely mechanisms residing in the muscle, or alternatively by improving running mechanics. 相似文献
32.
Neisseria meningitidis expressing lgtB lipopolysaccharide targets DC-SIGN and modulates dendritic cell function 总被引:2,自引:0,他引:2
Steeghs L van Vliet SJ Uronen-Hansson H van Mourik A Engering A Sanchez-Hernandez M Klein N Callard R van Putten JP van der Ley P van Kooyk Y van de Winkel JG 《Cellular microbiology》2006,8(2):316-325
Neisseria meningitidis lipopolysaccharide (LPS) has been identified as a major determinant of dendritic cell (DC) function. Here we report that one of a series of meningococcal mutants with defined truncations in the lacto-N-neotetraose outer core of the LPS exhibited unique strong adhesion and internalization properties towards DC. These properties were mediated by interaction of the GlcNAc(beta1-3)-Gal(beta1-4)-Glc-R oligosaccharide outer core of lgtB LPS with the dendritic-cell-specific ICAM-3 grabbing non-integrin (DC-SIGN) lectin receptor. Activation of DC-SIGN with this novel oligosaccharide ligand skewed T-cell responses driven by DC towards T helper type 1 activity. Thus, the use of lgtB LPS may provide a powerful instrument to selectively induce the desired arm of the immune response and potentially increase vaccine efficacy. 相似文献
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ABSTRACT: BACKGROUND: We have previously shown that an exclusively human milk-based diet is beneficial for extremely premature infants who are at risk for necrotizing enterocolitis (NEC). However, no significant difference in the other primary study endpoint, the length of time on total parenteral nutrition (TPN), was found. The current analysis re-evaluates these data from a different statistical perspective considering the probability or likelihood of needing TPN on any given day rather than the number of days on TPN. This study consisted of 207 premature infants randomized into three groups: one group receiving a control diet of human milk, formula and bovine-based fortifier ("control diet"), and the other two groups receiving only human milk and human milk-based fortifier starting at different times in the enteral feeding process (at feeding volumes of 40 or 100 mL/kg/day; "HM40" and "HM100", respectively). The counting process Cox proportional hazards survival model was used to determine the likelihood of needing TPN in each group. RESULTS: The two groups on the completely human-based diet had an 11-14 % reduction in the likelihood of needing nutrition via TPN when compared to infants on the control diet (p = 0.0001 and p = 0.001, respectively for the HM40 and HM100 groups, respectively). This was even more pronounced if the initial period of TPN was excluded (p < 0.0001 for both the HM40 and HM100 groups). CONCLUSIONS: A completely human milk-based diet significantly reduces the likelihood of TPN use for extremely premature infants when compared to a diet including cow-based products. This likelihood may be reduced even further when the human milk fortifier is initiated earlier in the feeding process. Trial registration This study was registered at www.clinicaltrials.gov reg. # NCT00506584. 相似文献
35.
ABSTRACT: BACKGROUND: Clinical and experimental studies have demonstrated that seizures can cause molecular and cellular responses resulting in neuronal damage. At present, there are no valid tests for assessing organic damage to the brain associated with seizure. The aim of this study was to investigate cerebrospinal fluid (CSF) and plasma concentrations of Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), a sensitive indicator of acute injury to brain neurons, in patients with tonic--clonic or partial secondarily generalized seizures due to various etiologies. METHODS: CSF and plasma concentrations of UCH-L1 were assessed in 52 patients within 48 hours after epileptic seizure and in 19 controls using ELISA assays. RESULTS: CSF obtained within 48 hours after seizure or status epilepticus (SE) presented significantly higher levels of UCH-L1 compared to controls (p = 0.008). Plasma UCH-L1 concentrations were negatively correlated with time to sample withdrawal. An analysis conducted using only the first 12 hours post-seizure revealed significant differences between concentrations of UCH-L1 in plasma and controls (p = 0.025). CSF and plasma concentrations were strongly correlated with age in patients with seizure, but not in control patients. Plasma UCH-L1 levels were also significantly higher in patients after recurrent seizures (n = 4) than in those after one or two seizures (p = 0.013 and p = 0.024, respectively). CONCLUSION: Our results suggest that determining levels of neuronal proteins may provide valuable information on the assessment of brain damage following seizure. These data might allow clinicians to make more accurate therapeutic decisions, to identify patients at risk of progression and, ultimately, to provide new opportunities for monitoring therapy and targeted therapeutic interventions. 相似文献
36.
Lei Lv Tianwei Zhang Qiyi Yi Yun Huang Zheng Wang Heli Hou Huan Zhang Wei Zhang Qiaomei Hao Zongyou Guo Howard J. Cooke Qinghua Shi 《Cell cycle (Georgetown, Tex.)》2012,11(15):2864-2875
Most ovarian cancers originate from the ovarian surface epithelium and are characterized by aneuploid karyotypes. Aneuploidy, a consequence of chromosome instability, is an early event during the development of ovarian cancers. However, how aneuploid cells are evolved from normal diploid cells in ovarian cancers remains unknown. In the present study, cytogenetic analyses of a mouse syngeneic ovarian cancer model revealed that diploid mouse ovarian surface epithelial cells (MOSECs) experienced an intermediate tetraploid cell stage, before evolving to aneuploid (mainly near-tetraploid) cells. Using long-term live-cell imaging followed by fluorescence in situ hybridization (FISH), we demonstrated that tetraploid cells originally arose from cytokinesis failure of bipolar mitosis in diploid cells, and gave rise to aneuploid cells through chromosome mis-segregation during both bipolar and multipolar mitoses. Injection of the late passage aneuploid MOSECs resulted in tumor formation in C57BL/6 mice. Therefore, we reveal a pathway for the evolution of diploid to aneuploid MOSECs and elucidate a mechanism for the development of near-tetraploid ovarian cancer cells. 相似文献
37.
Atwal GS Rabadán R Lozano G Strong LC Ruijs MW Schmidt MK van't Veer LJ Nevanlinna H Tommiska J Aittomäki K Bougeard G Frebourg T Levine AJ Bond GL 《PloS one》2008,3(4):e1951
Germline genetics, gender and hormonal-signaling pathways are all well described modifiers of cancer risk and progression. Although an improved understanding of how germline genetic variants interact with other cancer risk factors may allow better prevention and treatment of human cancer, measuring and quantifying these interactions is challenging. In other areas of research, Information Theory has been used to quantitatively describe similar multivariate interactions. We implemented a novel information-theoretic analysis to measure the joint effect of a high frequency germline genetic variant of the p53 tumor suppressor pathway (MDM2 SNP309 T/G) and gender on clinical cancer phenotypes. This analysis quantitatively describes synergistic interactions among gender, the MDM2 SNP309 locus, and the age of onset of tumorigenesis in p53 mutation carriers. These results offer a molecular and genetic basis for the observed sexual dimorphism of cancer risk in p53 mutation carriers and a model is proposed that suggests a novel cancer prevention strategy for p53 mutation carriers. 相似文献
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Samuli Helama Matti Vartiainen Taneli Kolström Heli Peltola Jouko Meriläinen 《Vegetation History and Archaeobotany》2008,17(6):675-686
A collection of subfossil wood of Pinus sylvestris (Scots pine) was exposed to X-ray densitometry. The collection of 64 samples from the southern boreal forest zone was dendrochronologically
cross-dated to a.d. 673-1788. Growth characteristics were determined by performing density profiles including the following parameters: minimum
density, earlywood and latewood boundary density, maximum density, earlywood width, earlywood density, latewood width, latewood
density, annual ring width and annual ring density. Seven out of the nine parameters were found to contain non-climatic growth
trends and six were found to be heteroscedastic in their variance. Tree-specific records were indexed, to remove the non-climatic
growth trends and stabilize the variance, and combined into nine parameter-specific tree-ring chronologies. Growth characteristics
of the pines changed in parallel with the generally agreed climatic cooling from the Medieval Warm Period to the Little Ice
Age: pine tree-rings showed decreasing maximum densities from the period a.d. 975-1150 to a.d. 1450–1625. A concomitant change in the intra-annual growth characteristics was detected between these periods. The findings
indicate that not only the trees growing near the species’ distributional limits are sensitive to large-scale climatic variations
but also the trees growing in habitats remote from the timberline have noticeably responded to past climate changes. 相似文献
40.
Joanna Peltola Alberto Ritieni Raimo Mikkola Pavel A. Grigoriev Gabriella Pcsfalvi Maria A. Andersson Mirja S. Salkinoja-Salonen 《Applied microbiology》2004,70(8):4996-5004
Trichoderma species isolated from water-damaged buildings were screened for toxicity by using boar sperm cells as indicator cells. The crude methanolic cell extract from Trichoderma harzianum strain ES39 inhibited the boar sperm cell motility at a low exposure concentration (50% effective concentration, 1 to 5 μg [dry weight] ml of extended boar semen−1). The same exposure concentration depleted the boar sperm cells of NADH2. Inspection of the exposed boar sperm cells by transmission electron microscopy revealed damage to the plasma membrane. By using the black lipid membrane technique, it was shown that the semipurified metabolites (eluted from a SepPak C18 cartridge) of T. harzianum strain ES39 induced voltage-dependent conductivity. The high-performance liquid chromatography-purified metabolites of T. harzianum strain ES39 dissipated the mitochondrial membrane potential (Δψm) of human lung epithelial carcinoma cells (cell line A549). The semipurified metabolites (eluted from a SepPak C18 cartridge) of T. harzianum strain ES39 were analyzed by mass spectrometry (MS). Matrix-assisted laser desorption ionization and nanoflow electrospray ionization MS revealed five major peptaibols, each of which contained 18 residues and had a mass ranging from 1,719 to 1,775 Da. Their partial amino acid sequences were determined by collision-induced dissociation tandem MS. 相似文献