全文获取类型
收费全文 | 599篇 |
免费 | 33篇 |
国内免费 | 1篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 7篇 |
2021年 | 17篇 |
2020年 | 14篇 |
2019年 | 10篇 |
2018年 | 12篇 |
2017年 | 12篇 |
2016年 | 18篇 |
2015年 | 28篇 |
2014年 | 46篇 |
2013年 | 34篇 |
2012年 | 55篇 |
2011年 | 55篇 |
2010年 | 28篇 |
2009年 | 30篇 |
2008年 | 43篇 |
2007年 | 35篇 |
2006年 | 23篇 |
2005年 | 18篇 |
2004年 | 21篇 |
2003年 | 19篇 |
2002年 | 15篇 |
2001年 | 18篇 |
2000年 | 17篇 |
1999年 | 14篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1973年 | 4篇 |
1972年 | 7篇 |
1971年 | 4篇 |
1970年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有633条查询结果,搜索用时 125 毫秒
141.
142.
143.
Introducing pulsed low-intensity ultrasound to culturing human umbilical cord-derived mesenchymal stem cells 总被引:1,自引:0,他引:1
Yoon JH Roh EY Shin S Jung NH Song EY Lee DS Han KS Kim JS Kim BJ Jeon HW Yoon KS 《Biotechnology letters》2009,31(3):329-335
The human umbilical cord (hUC) is a source of adult tissue-derived mesenchymal stem cells (MSCs). A pulsed low-intensity ultrasound
(PLIUS) method is described for increasing the yield of MSCs from whole hUC without enzymatic digestion or growth factor supplementation.
Analysis of the immunophenotype of cells and a differentiation study were performed to show the compatibility of MSCs. The
mean number of cells recovered from primocultures of hUC was 6 × 105 cells/cm. PLIUS resulted in a 3.3-fold increase in MSC yield at passage 0. PLIUS exposure increases the yield of hUC-MSCs
by promoting release and enhancing proliferation.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
144.
Zhe-Xue?Quail Dan-Ning?Zeng Yi-Ping?Xiao Seong?Woon?Roh Young-Do?Nam Ho-Won?Chang Jung-Hoon?Yoon Hee-Mock?Oh Jin-Woo?BaeEmail author 《Journal of microbiology (Seoul, Korea)》2009,47(2):156-161
A bacterial strain, designated Iso4T, was isolated from the East Sea of Korea and was subjected to a poly-phasic taxonomy study including phenotypic and chemotaxonomic
characteristics as well as 16S rRNA gene sequence analysis. Cells of the strain were Gram-negative, motile, non-budding, non-stalked,
and strictly aerobic. Strain Iso4T grew optimally at 20°C in the presence of 1∼2% (w/v) NaCl and at pH 6.9∼7.6. The major respiratory quinone was Q-10 and the
major cellular fatty acids were C18:1 ω7c (53.5%), C17:1 ω5c (11.7%), C17:1 ω6c (8.1%), C16:0 (7.8%), C17:0 (4.8%), C15:0 (2.9%), and C16:1 ω5c (2.2%). The DNA G+C content of strain Iso4T was 56.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Iso4T formed a monophyletic clade in the family Hyphomonadaceae, supported by high bootstrap value and was most closely related to the genus Hyphomonas (92∼94%), a member of marine bacteria in the family. The phenotypic, genotypic, and chemotaxonomic evidences also suggest
strain Iso4T represents a novel genus and species in the family Hyphomonadaceae, for which the name Henriciella gen. nov., sp. nov. is proposed. The type strain is Iso4T (=KCTC 12513T =DSM 19595T =JCM 15116T). 相似文献
145.
Temperature and nutrition are two prominent environmental variables influencing juvenile growth rate in ectotherms. These two factors interact in complex ways. Here, we present a comprehensive analysis of the interactive effects of temperature and nutrition on various components of fitness (growth rate, survival), food intake, and level of energy storage in an insect herbivore, caterpillars of Spodoptera exigua Hübner (Lepidoptera: Noctuidae). In a factorial experimental design, final‐instar caterpillars (i.e., fifth instars) were individually reared at one of three constant temperatures (18, 26, and 34 °C), in which they received one of six diets differing in their ratio of protein and digestible carbohydrate [P:C mixture, expressed as the percentage of diet by dry mass: protein 42%:carbohydrate 0% (42:0), 35:7, 28:14, 21:21, 14:28, and 7:35]. Within the range of test temperatures, larval growth rate increased with rising temperature and was strongly affected by P:C mixture, reaching a maximum on moderate P:C diets at each temperature and falling at very high and low P:C mixtures. There was a significant temperature*diet interaction, such that the difference in growth rates between temperatures was greatest on moderate P:C diets and least on the most extreme diets (42:0 and 7:35). Food intake rate patterns followed a similar trend to growth rate. Rapidly growing animals at high ambient temperature suffered high mortality across all dietary P:C mixtures, but to a greater extent on the extremely unbalanced diets. This suggests that there are developmental and physiological costs associated with fast growth at high temperature, as indicated by high rate of pupation failure and reduced lipid storage efficiency. Our study shows how temperature and nutrition interplay to mediate phenotypic variations in growth rates and energy utilization in an insect ectotherm. 相似文献
146.
Gyeongwha Kim Younghyurk Lee Eun Young Jeong Soonwoong Jung Hyeonwi Son Dong Hoon Lee Gu Seob Roh Sang Soo Kang Gyeong Jae Cho Wan Sung Choi Hyun Joon Kim 《Molecules and cells》2010,30(2):161-165
Regulator of G-protein signaling (RGS) proteins play an important role in G-protein coupled receptor (GPCR) signaling and the activity of some GPCRs is modulated via RGS protein levels during stress response. The aim of this study was to investigate changes in RGS protein mRNA expressions in the mouse brain after 2h restraint stress. The mRNA level of 19 RGS proteins was analyzed using real-time PCR in six brain regions, which included the prefrontal cortex, amygdala, hippocampus, hypothalamus, striatum, and pituitary gland, from control and stressed mouse. We found that the level of mRNA of each RGS varied according to brain region and that two to eight RGS proteins exhibited changes in mRNA levels in each brain region by restraint stress. It was also revealed that RGS4 protein amount was consistent with mRNA level, indicating RGS4 protein may have regulatory roles in the acute stress response. 相似文献
147.
Darren E. Casteel Eric V. Smith-Nguyen Banumathi Sankaran Sung H. Roh Renate B. Pilz Choel Kim 《The Journal of biological chemistry》2010,285(43):32684-32688
Cyclic GMP-dependent protein kinase (PKG) is a key mediator of the nitric oxide/cGMP signaling pathway and plays a central role in regulating cardiovascular and neuronal functions. The N-terminal ∼50 amino acids of the kinase are required for homodimerization and association with isoform-specific PKG-anchoring proteins (GKAPs), which target the kinase to specific substrates. To understand the molecular details of PKG dimerization and gain insight into its association with GKAPs, we solved a crystal structure of the PKG Iβ dimerization/docking domain. Our structure provides molecular details of this unique leucine/isoleucine zipper, revealing specific hydrophobic and ionic interactions that mediate dimerization and demonstrating the topology of the GKAP interaction surface. 相似文献
148.
A moderate halophilic, Gram-negative, non-motile, rod-shape, and aerobe designated as strain HwaT was isolated from traditional fermented Korean seafood, which presented as a single cell or paired cells. Optimal growth
occurred at 25°C in 10% (w/v) salts at pH 7.0–8.0; however, growth occurred in a temperature range of 10–32°C, a salts concentration
of 5–25% (w/v) and pH 5.0–10.0. Tests for oxidase and catalase were positive. The cells produced poly-β-hydroxybutyric acid, but not exopolysaccharide. Based on the 16S rRNA gene sequence, not only was there low similarity between
strain HwaT and all other species (94.1% similarity with H. subglaciescola DSM 4683T, 94.0% similarity with H. sulfidaeris Esulfide1T, 93.6% similarity with H. cerina SP4T and 93.0% similarity with H. halodurans DSM 5160T), but the phylogenetic analysis revealed that the isolate may be classified as a novel species belonging to the genus Halomonas in the class Gammaproteobacteria. The predominant fatty acids of strain HwaT were C18:1
ω7c, C16:0, C12:0 3-OH and C16:1
ω7c/C15:0 iso 2-OH. The DNA G+C content was calculated as 61.7 mol%. Based on phenotypic, genotypic, and phylogenetic characteristics,
it is proposed that the strain designated as HwaT be assigned to the genus Halomonas as Halomonas jeotgali sp. nov. (=KCTC 22487T =JCM 15645T). 相似文献
149.
Tae Woong Whon Mi-Ja Jung Seong Woon Roh Young-Do Nam Eun-Jin Park Kee-Sun Shin Jin-Woo Bae 《Journal of microbiology (Seoul, Korea)》2010,48(6):862-866
A moderate halophile, strain X50T, was isolated from mustard kimchi, a traditional Korean fermented food. The organism grew under conditions ranging from 0–15.0%
(w/v) NaCl (optimum: 3.0%), pH 7.0–10.0 (optimum: pH 9.0) and 15–45°C (optimum: 37°C). The morphological, physiological, and
biochemical features and the 16S rRNA gene sequences of strain X50T were characterized. Colonies of the isolate were creamcolored and the cells were rod-shaped. Phylogenetic analysis based
on the 16S rRNA gene sequence indicated that strain X50T belongs to the genus Oceanobacillus and is closely related phylogenetically to the type strain O. iheyensis HTE831T (98.9%) and O. oncorhynchi subsp. oncorhynchi R-2T (97.0%). The cellular fatty acid profiles predominately included anteiso-C15:0 and iso-C15:0. The G+C content of the genomic DNA of the isolate was 37.9 mol% and the major isoprenoid quinone was MK-7. Analysis of the
16S rRNA gene sequences, DNA-DNA relatedness and physiological and biochemical tests indicated genotypic and phenotypic differences
among strain X50T and reference species in the genus Oceanobacillus. Therefore, strain X50T was proposed as a novel species and named Oceanobacillus kimchii. The type strain of the new species is X50T (=JCM 16803T =KACC 14914T =DSM 23341T). 相似文献
150.
The supernatant of Beauveria bassiana SFB-205 reduced the population of cotton aphid, Aphis gossypii Glover, with a dosage-dependent manner, which allowed a quality control (QC) factor to be determined for the evaluation of the supernatant as the first step of a development. Enzymes were assumed as possible QC factors based on 1) the comparable aphicidal activity of the supernatant protein pellet to the raw supernatant, 2) the supernatant-induced degradation of the insect cuticles, observed by transmission electron microscopy, and 3) the confirmation of enzymes related to the fungal penetration - chitinase, and the Pr1- and Pr2 proteases - in the supernatant. Finally, from the bioassay with the enzyme-inhibited supernatants processed by substrate inhibition one by one, decreased aphicidal activities were observed for all three enzyme-inhibited treatments. This phenomenon, furthermore, was more remarkable in the chitinase-inhibited supernatant. This finding provides that those enzymes (and most particularly the chitinase) in the supernatant were strongly involved in the aphicidal activity. Consequently, the amount of the chitinase may be used as one of the QC factors to determine the insecticidal activity of the supernatant of B. bassiana SFB-205 in the optimization of mass production. 相似文献