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101.
102.
Jacob G. Ghazarian Barbara Kream Kathleen M. Botham Michael W. Nickells Hector F. DeLuca 《Archives of biochemistry and biophysics》1978,189(1):212-220
An antibody was prepared from serum of rabbits injected with a pure inhibitor protein obtained from rat serum for chick renal 25-hydroxyvitamin D3-1α-hydroxylase. The antibody was separated from the endogenous inhibitor in rabbit serum. The antibody shows a single precipitin line with the rat serum antigen and with crude calf serum. Furthermore, the antibody removes the 4.0 S 25-hydroxyvitamin D3 binding protein from rat serum. The removal of the 25-hydroxyvitamin D3 binding protein from rat serum with antibody brings about a proportionate removal of inhibitor of the 25-hydroxyvitamin D3-1α-hydroxylase. The pure inhibitor binds 25-hydroxyvitamin D3, as demonstrated by sucrose density gradient sedimentation, and shows specificity of binding identical to the serum transport globulin for 25-hydroxyvitamin D3. Thus, the previously reported inhibitor of the 25-hydroxyvitamin D3-1α-hydroxylase in rat preparations is the serum 25-hydroxyvitamin D3 transport protein or some derivative thereof. The antibody added to rat renal mitochondrial preparations does increase the activity of the 1- and 24-hydroxylases slightly but not markedly. 相似文献
103.
In this review article we give an overview of current knowledge with respect to redox-sensitive alterations in Na+ and Ca2+ handling in the heart. In particular, we focus on redox-activated protein kinases including cAMP-dependent protein kinase A (PKA), protein kinase C (PKC), and Ca/calmodulin-dependent protein kinase II (CaMKII), as well as on redox-regulated downstream targets such as Na+ and Ca2+ transporters and channels. We highlight the pathological and physiological relevance of reactive oxygen species and some of its sources (such as NADPH oxidases, NOXes) for excitation—contraction coupling (ECC). A short outlook with respect to the clinical relevance of redox-dependent Na+ and Ca2+ imbalance will be given. 相似文献
104.
The 270 MHz 1H NMR spectra of rabbit skeletal long and short S2 were indistinguishable at 20°C and 30°C and contained only a small proportion of sharp peaks associated with flexible regions. At 60°C both proteins were denatured and had essentially identical spectra. At 40°C and 50°C the long S2 spectrum contained a marginally greater proportion of sharp peaks, representing not more than 25 residues/chain. Our results are consistent with the presence of a small hinge in long S2 but do not support its containing an extensive region which provides contractile force by a helix—coil transition. 相似文献
105.
106.
BRET A. COLLIER STEPHEN S. DITCHKOFF JOSHUA B. RAGLIN JORDAN M. SMITH 《The Journal of wildlife management》2007,71(1):277-281
Abstract: As a first step in understanding structure and dynamics of white-tailed deer (Odocoileus virginianus) populations, managers require knowledge of population size. Spotlight counts are widely used to index deer abundance; however, detection probabilities using spotlights have not been formally estimated. Using a closed mark—recapture design, we explored the efficiency of spotlights for detecting deer by operating thermal imagers and spotlights simultaneously. Spotlights detected only 50.6% of the deer detected by thermal imagers. Relative to the thermal imager, spotlights failed to detect 44.2% of deer groups (≥1 deer). Detection probabilities for spotlight observers varied between and within observers, ranging from 0.30 (SE = 0.053) to 0.66 (SE = 0.058). Managers commonly assume that although road counts based on convenience sampling designs are imperfect, observers can gather population-trend information from repeated counts along the same survey route. Our results indicate detection rate varied between and within observers and surveyed transects. If detection probabilities are substantially affected by many variables, and if transect selection is not based on appropriate sampling designs, it may be impractical to correct road spotlight counts for detection probabilities to garner unbiased estimates of population size. 相似文献
107.
Maciej Polak Aleksandra Anna Zasada Ewa Mosiej Katarzyna Krysztopa-Grzybowska Lucjan Witkowski Magdalena Rzeczkowska Katarzyna Piekarska Anna Lutyńska 《Microbes and infection / Institut Pasteur》2019,21(3-4):170-175
The introduction of pertussis vaccination in the 1950s resulted in a significant decrease in the incidence of disease. However, since the 1990s many highly vaccinated countries have observed the re-emergence of the disease. One of the causes of this phenomenon might be related to the adaptation of Bordetella pertussis to vaccination. The purpose of the presented study was an investigation of the emergence and spread of vaccine antigen-deficient B. pertussis isolates in Poland and genomic characterization of the currently circulating pathogen population using PFGE, MLVA and MAST. The results revealed that all tested isolates expressed Ptx, FHA and ACT antigens but 15.4% (4/26) of isolates from 2010 to 2016 were Prn-deficient. Moreover, one TcfA-deficient isolate was collected in 2015. The genotyping showed a genetic distinction between the isolates circulating in 2010–2016 and isolates from previous periods. The majority of currently circulating isolates belonged to PFGE group IV (96.2%), type MT27 (73.1%), and carried ptxA1-ptxC2-ptxP3-prn2-tcfA2-fim2-1-fim3-1 alleles (61.5%). The unique genetic structure of the B. pertussis population in Poland has changed since 2010 and became similar to that observed in countries with aP vaccination. This could be a result of increasing use of aP vaccines (60% of primary vaccination in 2013) over wP vaccines, which have been broadly used for primary vaccination in Poland for decades. 相似文献
108.
Toshiya Katano Shin-ichi Nakano Osamu Mitamura Haruko Yoshida Hisayuki Azumi Yoshiki Matsuura Yuji Tanaka Hiraku Maezono Yasuhiro Satoh Takeshi Satoh Yuko Sugiyama Yasunori Watanabe Tetsuro Mimura Yuki Akagashi Hiroshi Machida Valentin V. Drucker Irina Tikhonova Olga Belykh Vladimir A. Fialkov Myung-Soo Han Sung-Ho Kang Masahito Sugiyama 《Limnology》2008,9(2):105-114
In Lake Baikal, picocyanobacteria are the most important primary producers during the summer. Freshwater picocyanobacteria
are discriminated into either the phycoerythrin (PE)-rich or the phycocyanin (PC)-rich types according to their pigment composition.
The distributions of these two types of picocyanobacteria were investigated in Barguzin Bay. The PC-rich type accounted for
>98% of the total picocyanobacteria at the station near the shore of the bay where river water flows directly in. In the offshore
area of the lake, all of the picocyanobacteria cells were of the PE-rich type. In addition, the occurrence of the PC-rich
type was restricted to the station, where the attenuation coefficient exceeded 0.25 m−1. Near the shore, where the turbidity was high (>1 NTU), the cell densities of both the PE- and PC-rich types increased away
from the river mouth. This indicates that the PC-rich type cells grow near the shore of the bay where turbidity is high. Since
the PC-rich type could not grow well when cells were incubated in offshore lake water, restricted distribution of the PC-rich
type could also be explained by their growth capability. The present study clearly demonstrated the shift in the pigment type
composition of picocyanobacteria from the coastal to the pelagic zone of Lake Baikal. The co-existence of the two pigment
types probably enables the abundance of the picocyanobacterial community to be stable over a broader range of environmental
conditions than would be possible for a single pigment type. 相似文献
109.
Zhongfeng Ye Kazuya Nakagawa Masahiro Natsume Hideaki Nojiri 《Bioscience, biotechnology, and biochemistry》2017,81(6):1176-1184
Phytocassanes and momilactones are the major diterpenoid phytoalexins inductively produced in rice as bioactive substances. Regardless of extensive studies on the biosynthetic pathways of these phytoalexins, bioconversion of diterpene hydrocarbons is not shown in planta. To elucidate the entire biosynthetic pathways of these phytoalexins, uniformly 13C-labeled ent-cassadiene and syn-pimaradiene were enzymatically synthesized with structural verification by GC–MS and 13C-NMR. Application of the 13C-labeled substrates on rice leaves led to the detection of 13C-labeled metabolites using LC-MS/MS. Further application of this method in the moss Hypnum plumaeforme and the nearest out-group of Oryza species Leersia perrieri, respectively, resulted in successful bioconversion of these labeled substrates into phytoalexins in these plants. These results demonstrate that genuine biosynthetic pathways from these diterpene hydrocarbons to the end product phytoalexins occur in these plants and that enzymatically synthesized [U-13C20] diterpene substrates are a powerful tool for chasing endogenous metabolites without dilution with naturally abundant unlabeled compounds. 相似文献
110.
The seasonal distribution of the dinoflagellate genus, Dinophysis, in Maizuru Bay, Japan, was investigated from May 1997 to December 1999. Seven species of Dinophysis were detected, including the toxic species of Dinophysis acuminata and D. fortii. The most dominant species wasD. acuminata, detected year-around and more abundantly during periods when water temperatures were between 15 and 18 °C. No relationship was found between cell abundance of Dinophysis spp. and concentrations of dissolved inorganic nutrients. Phycoerythrin containing nano- and picophytoplankton (cryptophytes and cyanobacteria), suspected to be prey of mixotrophic Dinophysis, were enumerated simultaneously. A clear relationship was not found among the cell abundances of Dinophysis spp. and nano- and picophytoplankton. Autofluorescence of Dinophysis spp. (mainly D. acuminata and D. fortii) under blue-light excitation was usually of a yellow-orange color. Occasionally, Dinophysis spp. had red autofluorescencing and yellow-orange autofluorescencing particles. The proportion of cells possessing red autofluorescence tended to be higher in the warm season. Numerous coccoid cells of picophytoplankton (ca. 1–2 μm in diameter) were found attached to the cell surface of D. acuminata, D. fortii, etc. and food vacuole-like structures also observed. These observations suggest there is a close relationship between mixotrophic Dinophysis spp. and certain picophytoplankton. Based on our observations, the possibility that the picophytoplankton found to be attached onto Dinophysis cell surfaces are a food source for Dinophysis, and a source of DSP toxins, is discussed. 相似文献