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101.
Hideaki Matsuoka Yasushi Kazuno Takuji Horie Tomoo Homma Yasuyuki Nemoto 《Cytotechnology》1993,11(1):59-65
Possible roles of coexisting cells in inducing neurite growth from a nerve cell were studied. Nerve growth factor (NGF)-inducing neurite growth from PC12h-R (a cell line derived from cultured nerve cells) was investigated at various cell densities. At the cell density 102104 cells/ml neurites appeared even without NGF. In contrast, no neurite appeared without NGF in single cell culture. The neurite growth observed in plural cell culture without NGF was only partially inhibited by antibody to NGF receptor (Ab-NGFR). However, the effect of the used medium alone was mostly inhibited by Ab-NGFR. These results suggest that the neurite inducing potency of coexisting cells is via different sites than the NGF receptor.Abbreviations Ab-IgG-FITC
anti-mouse-IgG labeled with fluorescein isothiocyanate
- Ab-NF
monoclonal antibody to neurofilament 160 kD
- Ab-NGFR
monoclonal antibody to NGF receptor
- BDNF
brain-derived neurotrophic factor
- D-medium
medium for differentiation culture
- DMEM
Dulbecco's modified Eagle's medium
- M-medium
medium for multiplication culture
- NGF
nerve growth factor
- NGFR
NGF receptor
- NT-3
neurotrophin-3
- PC12
pheochromocytoma cell line
- PC12h-R
subclone of PC12
- Sup-D
supernatant of D-medium 相似文献
102.
Hyung Suk Kim Karen M. Lyons Eiichi Saitoh Edwin A. Azen Oliver Smithies Nobuyo Maeda 《Mammalian genome》1993,4(1):3-14
We present the nucleotide sequences of four members of the six-member human salivary prolinerich protein (PRP) gene family. The four genes are PRB1 and PRB2, which encode basic PRPs, and PRB3 and PRB4, which encode glycosylated PRPs. Each PRB gene is approximately 4.0 kb in length and contains four exons, the third of which is entirely composed of 63-bp tandem repeats and encodes the proline-rich portion of the protein products. Exon 3 contains different numbers of tandem repeats in the different PRB genes. Variation in the numbers of these repeats is also responsible for length variations in different alleles of the PRB genes. We have determined a probable evolutionary history of the human PRP gene family by comparing the nucleotide sequences of the six PRP genes. The present-day six PRP loci probably evolved from a single ancestral gene by four sequential gene duplications, leading to six genes that fall into three subsets, each consisting of two genes. During this evolutionary process, multiple rearrangements and gene conversion occurred mainly in the region from the 3 end of IVS2 and the 3 end of exon 3. 相似文献
103.
Yoshihiro Kuroda Yoshitaka Maeda Shinichi Sawa Kiyohiro Shibata Kazuhide Miyamoto Terumichi Nakagawa 《Journal of peptide science》2003,9(4):212-220
Pathogenic prion proteins (PrP(Sc)) are thought to be produced by alpha-helical to beta-sheet conformational changes in the normal cellular prion proteins (PrP(C)) located solely in the caveolar compartments. In order to inquire into the possible conformational changes due to the influences of hydrophobic environments within caveolae, the secondary structures of prion protein peptides were studied in various kinds of detergents by CD spectra. The peptides studied were PrP(129-154) and PrP(192-213); the former is supposed to assume beta-sheets and the latter alpha-helices, in PrP(Sc). The secondary structure analyses for the CD spectra revealed that in buffer solutions, both PrP(129-154) and PrP(192-213) mainly adopted random-coils (approximately 60%), followed by beta-sheets (30%-40%). PrP(129-154) showed no changes in the secondary structures even in various kinds of detergents such as octyl-beta-D-glucopyranoside (OG), octy-beta-D-maltopyranoside (OM). sodium dodecyl sulfate (SDS), Zwittergent 3-14 (ZW) and dodecylphosphocholine (DPC). In contrast, PrP(192-213) changed its secondary structure depending on the concentration of the detergents. SDS, ZW, OG and OM increased the alpha-helical content, and decreased the beta-sheet and random-coil contents. DPC also increased the alpha-helical content, but to a lesser extent than did SDS, ZW, OG or OM. These results indicate that PrP(129-154) has a propensity to adopt predominantly beta-sheets. On the other hand, PrP(192-213) has a rather fickle propensity and varies its secondary structure depending on the environmental conditions. It is considered that the hydrophobic environments provided by these detergents may mimic those provided by gangliosides in caveolae, the head groups of which consist of oligosaccharide chains containing sialic acids. It is concluded that PrP(C) could be converted into a nascent PrP(Sc) having a transient PrP(Sc) like structureunder the hydrophobic environments produced by gangliosides. 相似文献
104.
105.
Yoshikazu Horie Toshimitu Fukiharu Kazuko Nishimura Hideaki Taguchi Duan Li Wang Ruoyu Li 《Mycoscience》1996,37(3):323-329
Emericella miyajii, a new species isolated from Chinese soil, is described and illustrated. It is characterized by pale orange to brownish orange
colonies on malt extract agar, subglobose to broadly elliptical ascospores with defective four equatorial crests and smooth
convex walls, and with anAspergillus anamorph.Emericella undulata is also described as an uncommon species from Chinese soil. 相似文献
106.
Anwaruzzaman ; Sawada Shinichi; Usuda Hideaki; Yokota Akiho 《Plant & cell physiology》1995,36(3):425-433
The mechanism of the regulation of the activation of ribulose1,5-bisphosphate carboxylase/ oxygenase (RuBisCO) by inorganicphosphate (Pi) in the presence of limiting concentrations ofCO2 was explored. The activation state of RuBisCO increasedsigmoidally following a biphasic kinetics against the concentrationof Pi in the activation mixture with an intermediary plateauat 2 to 3 mM Pi when the enzyme was activated for 30 min. Theintermediary plateau could not be seen when the preincubationtime was 10 min and the activation was completed at 10 mM Pi.RuBisCO from Euglena also showed a quite similar activationkinetics. The activation was not due to the contaminating CO2included in the stock Pi solution or in the activation buffercontaining the enzyme. The experiments with 2-carboxyarabinitol1,5-bisphosphate showed that the Pi stimulated activation wasdue to the promotion of binding of the activator CO2 to theactivation sites. It was also found that Pi increased the affinityof RuBisCO for the activator CO2 5.4-fold accompanied by a decreaseof the half-saturating concentration of CO2 to 1.6 µMat 20 mM MgCl2. Physiological significance of the effects ofPi on the activation of RuBisCO is discussed.
2Present address: Laboratory of Plant Molecular Physiology,Research Institute of Innovative Technology for the Earth (RITE),9-2 Kizugawadai, Kizu-cho, Soraku-gun, Kyoto, Japan. 相似文献
107.
Nanosecond time-resolved infrared spectroscopy distinguishes two K species in the bacteriorhodopsin photocycle. 总被引:1,自引:1,他引:0 下载免费PDF全文
The photochemical reaction process of bacteriorhodopsin in the nanosecond time range (-120-860 ns) was measured in the 1400-900 cm-1 region with an improved time resolved dispersive-type infrared spectrometer. The system is equipped with a newly developed detection unit whose instrumental response to a 5-ns laser pulse has a full width of the half-maximum of 60 ns. It provides highly accurate data that enabled us to extract a kinetic process one order of magnitude faster than the instrumental response. The spectral changes in the 1400-900 cm-1 region were analyzed by singular value decomposition and resolved into three components. These components were separated by fitting with 10- and 1000-ns exponential functions and a step function, which were convoluted with the instrumental response function. The components with decay time constants of 10 and 1000 ns are named K and KL, respectively, on the basis of previous visible spectroscopy. The spectral shapes of K and KL are distinguishable by their hydrogen-out-of-plane (HOOP) modes, at 958 and 984 cm-1, respectively. The former corresponds to the K intermediate recorded at 77 K and the latter to a K-like photoproduct at 135 K. On the basis of published data, these bands are assigned to the 15-HOOP mode, indicating that the K and KL differ in a twist around the C14-C15 bond. 相似文献
108.
Takashi Hirayarna Tatsuya Maeda Haruo Saito Kazuo Shinozaki 《Molecular & general genetics : MGG》1995,249(2):127-138
Yeast cells can respond and adapt to osmotic stress. In our attempt to clarify the molecular mechanisms of cellular responses to osmotic stress, we cloned seven cDNAs for hyperosmolarity-responsive (HOR) genes from Saccharomyces cerevisiae by a differential screening method. Structural analysis of the clones revealed that those designated HOR1, HORS, HOR4, HOR5 and HOR6 encoded glycerol-3-phosphate dehydrogenase (Gpd1p), glucokinase (Glklp), hexose transporter (Hxtlp), heat-shock protein 12 (Hsp12p) and Na+, K+, Li+-ATPase (Enalp), respectively. HOR2 and HOR7 corresponded to novel genes. Gpdlp is a key enzyme in the synthesis of glycerol, which is a major osmoprotectant in S. cerevisiae. Cloning of HOR1/GPD1 as a HOR gene indicates that the accumulation of glycerol in yeast cells under hyperosmotic stress is, at least in part, caused by an increase in the level of GPDH protein. We performed a series of Northern blot analyses using HOR cDNAs as probes and RNAs prepared from cells grown under various conditions and from various mutant cells. The results suggested that all the HOR genes are regulated by common signal transduction pathways. However, the fact that they exhibited certain distinct responses indicated that they might also be regulated by specific pathways in addition to the common pathways. Ca2+ seemed to be involved in the signaling systems. In addition, Hog1p, one of the MAP kinases in yeast, appeared to be involved in the regulation of expression of HOR genes, although its function seemed to be insufficient for the overall regulation of expression of these genes. 相似文献
109.
The effects of 24 hr light-dark cycles on the circadian conidiation rhythm inNeurospora crassa were compared among will-typefrq
+ and clock mutantsfrq
+,frq
3,frq
7,frq
9 andfrq
11. The minimum length of the light period necessary for complete entrainment to the light-dark cycles was almost 2 hr infrq
+,frq
3 andfrq
7 strains. The minimum duration of the dark period necessary for the appearance of circadian conidiation was almost 4 hr in
all of the strains except thefrq
11 strain. The phase of the conidiation rhythm was dependent on the light to dark transition in thefrq
1 strain in all light-dark cycles examined and in thefrq
+ andfrq
3 strains when the light period was shorter than 16 hr. In contrast, the phase of thefrq
7 strain was dependent on the light to dark transition when the light period was shorter than 10 hr. 相似文献
110.
An algal suspension containing protoplasmic detritus [termed, single cell detritus (SCD)] was prepared from freeze-dried fronds
of Ulva and its dietary value to Artemia nauplii was tested after size fractionation. The dissolved fraction (<0.22 μm) ofthe
Ulva suspension contained ca. 48% of theoriginal protein in the Ulva, but had no dietaryvalue to Artemia, which is a suspension
feeder. In contrast, the fraction passing through a 100-μm meshand containing SCD of 2–14 μm in diameter, contributedto the
survival of Artemia. The fraction remaining on the 100 μm mesh was further incubated with and without the bacterium Pseudoalteromonas
espejiana strain AR06 FERM BP-5024. The bacterium degraded
Ulva forming new SCD over 106 mL -1 level as rapidly as by 16 h of incubation. The dietary
value of Ulva for Artemia growth was elevated over four times by the incubation. The protein content of the SCD
was approximately doubled by the attaching of bacteria, suggesting the enhanced Artemia growth is attributable to
the combined effect of the SCD and the bacteria. Development of a hatchery diet from Ulva , a resource with a low
commercial value, is suggested utilizing the degrading and attaching ability of P. espejiana.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献