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991.
Evidence of Increased Oxidative Damage in Both Sporadic and Familial Amyotrophic Lateral Sclerosis 总被引:22,自引:13,他引:9
Robert J. Ferrante Susan E. Browne Leslie A. Shinobu Allen C. Bowling M. Jay Baik Usha MacGarvey Neil W. Kowall †Robert H. Brown Jr. M. Flint Beal 《Journal of neurochemistry》1997,69(5):2064-2074
Abstract: Some cases of autosomal dominant familial amyotrophic lateral sclerosis (FALS) are associated with mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1), suggesting that oxidative damage may play a role in ALS pathogenesis. To further investigate the biochemical features of FALS and sporadic ALS (SALS), we examined markers of oxidative damage to protein, lipids, and DNA in motor cortex (Brodmann area 4), parietal cortex (Brodmann area 40), and cerebellum from control subjects, FALS patients with and without known SOD mutations, SALS patients, and disease controls (Pick's disease, progressive supranuclear palsy, diffuse Lewy body disease). Protein carbonyl and nuclear DNA 8-hydroxy-2'-deoxyguanosine (OH8 dG) levels were increased in SALS motor cortex but not in FALS patients. Malondialdehyde levels showed no significant changes. Immunohistochemical studies showed increased neuronal staining for hemeoxygenase-1, malondialdehyde-modified protein, and OH8 dG in both SALS and FALS spinal cord. These studies therefore provide further evidence that oxidative damage may play a role in the pathogenesis of neuronal degeneration in both SALS and FALS. 相似文献
992.
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994.
Cristiana Leslie Corrêa Rosemary Custdio Pedroso 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,704(1-2)
A headspace gas chromatographic method using a fused-silica capillary column Poraplot Q has been developed and validated for the detection and quantification of ethanol in urine. Under optimized conditions, ethanol was properly separated from acetaldehyde, acetone, isopropanol, methanol and n-propanol. Limits of detection (LODs) and quantification (LOQs) were 0.008 and 0.010 g/l, respectively. The precision studies within-run and between-run, using spiked urine samples (0.08, 0.8 and 2.0 g/l) showed maximum coefficients of variation 5.9 and 6.5%, respectively. Results of ethanol recovery varied from 91.6±0.8 to 103.3±1.8% over the concentration range from 0.01 to 3.20 g/l. The method was appropriate for the detection of ethanol in urine samples. This matrix can be used for monitoring alcohol abuse in the workplace and used in alcohol rehabilitation programs. 相似文献
995.
Cremona George; Higenbottam Tim; Takao Motoshi; Bower Edward A.; Hall Leslie W. 《Journal of applied physiology》1997,82(1):23-31
Cremona, George, Tim Higenbottam, Motoshi Takao, Edward A. Bower, and Leslie W. Hall. Nature and site of action of endogenousnitric oxide in vasculature of isolated pig lungs. J. Appl. Physiol. 82(1): 23-31, 1997.The site ofaction of endogenous and exogenous nitric oxide (NO) in isolated piglungs was investigated by using arterial, double, and venous occlusion,which allowed precapillary, postcapillary, and venous segments to bepartitioned into arterial, precapillary, postcapillary, and venoussegments. NG-nitro-L-arginine(L-NNA;105 M) increased resistancein the arterial (35 ± 6.6%, P = 0.003), precapillary (39.3 ± 5.1%,P = 0.001), and venous (18.3 ± 4.8%, P = 0.01) segments,respectively. Sodium nitroprusside(105 M) and NO (80 parts/million) reversed the effects ofL-NNA. Total pulmonary vascularresistance fell with increasing flow, due to a fall in precapillaryresistance and dynamic resistance, and was significantlylower than mean total resistance.L-NNA increased the resistancesbut did not alter the pattern of the pressure-flow relationships. It isconcluded that, in isolated pig lungs, the effect of endogenous NOseems to be dependent on flow in the arterial segment and independentof flow in the precapillary segment, but variation of its release doesnot appear to be fundamental to accommodation to changes in steadyflow. 相似文献
996.
Yi Ning Marjorie Rosenberg David H. Ledbetter Leslie G. Biesecker 《Human genetics》1996,97(6):765-769
A number of human telomeres have been successfully cloned using a modified yeast artificial chromosome (YAC) vector (half-YAC)
cloning strategy, but to date, human chromosome 22q has not been identified by this approach. We used an alternative approach
of genomic walking, starting from a subtelomeric sequence, TelBam3.4, present on a number of human chromosomes including 22q.
This approach was successful in the development of a cosmid contig representing the terminal 140 kb of human chromosome 22q,
providing telomeric closure of the genetic and physical maps for 22q. The most distal region of the contig contains subtelomeric
repeats which crosshybridize to a number of chromosomes, while the proximal sequences are unique for 22q. The unique sequence
cosmid was used as a 22qter-specific probe for fluorescence in situ hybridization (FISH) analysis, which confirmed that this
cosmid was distal to the most telomeric marker previously available for chromosome 22. In addition, this cosmid was used to
document a 22q terminal deletion that was not detectable by conventional cytogenetic analysis. Unique telomere-specific FISH
probes such as this one will have significant diagnostic value in the detection of cryptic deletions and translocations in
patients with unexplained mental retardation and other patient populations.
Received: 21 November 1995 相似文献
997.
The gating properties and current amplitudes of mammalian voltage-activatedShakerpotassium channels are modulated by at least two associated β subunits (Kvβ1.1 and Kvβ1.2). The human Kvβ1.1 gene (KCNA1B) resides on chromosome 3, as indicated by somatic cell hybrid mapping. More precise localization of KCNA1B to 3q26.1 was obtained with fluorescencein situhybridization (FISH) and was corroborated by PCR screening of the CEPH YAC library. The human Kvβ1.2 gene (KCNA2B) resides on chromosome 1, as indicated by somatic cell hybrid mapping, and has been localized by FISH to 1p36.3. 相似文献
998.
Kenneth R. Johnson Leslie Smith Dabney K. Johnson Jennifer Rhodes Eugene M. Rinchik Mathew Thayer Elaine J. Lewis 《Genomics》1996,33(3):527
The recently described homeodomain protein ARIX is expressed specifically in noradrenergic cell types of the sympathetic nervous system, brain, and adrenal medulla. ARIX interacts with regulatory elements of the genes encoding the noradrenergic biosynthetic enzymes tyrosine hydroxylase and dopamine β-hydroxylase, suggesting a role for ARIX in expression of the noradrenergic phenotype. In the study described here, the mouse and human ARIX genes are mapped. Using segregation analysis of two panels of mouse backcross DNA, mouseArixwas positioned approximately 50 cM distal to the centromere of chromosome 7, nearHbb.HumanARIXwas positioned through analysis of somatic cell hybrids and fluorescencein situhybridization of human metaphase chromosomes to chromosome 11q13.3–q13.4. These map locations extend and further define regions of conserved synteny between mouse and human genomes and identify a new candidate gene for inherited developmental disorders linked to human 11q13. 相似文献
999.
Information transfer from DNA to peptide nucleic acids by template-directed syntheses. 总被引:1,自引:1,他引:0
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Peptide nucleic acids (PNAs) are analogs of nucleic acids in which the ribose-phosphate backbone is replaced by a backbone held together by amide bonds. PNAs are interesting as models of alternative genetic systems because they form potentially informational base paired helical structures. Oligocytidylates have been shown to act as templates for formation of longer oligomers of G from PNA G2 dimers. In this paper we show that information can be transferred from DNA to PNA. DNA C4T2C4 is an efficient template for synthesis of PNA G4A2G4 using G2 and A2 units as substrates. The corresponding synthesis of PNA G4C2G4 on DNA C4G2C4 is less efficient. Incorporation of PNA T2 into PNA products on DNA C4A2C4 is the least efficient of the three reactions. These results, obtained using PNA dimers as substrates, parallel those obtained using monomeric activated nucleotides. 相似文献
1000.
Site-directed mutations in the Escherichia coli ssb gene were tested for the ability to complement a chromosomal ssb deletion for viability, and only the ssb W54→G mutation failed to do so at the pSC101 copy level. Non-aromatic amino acid substitutions for SSB Trp-54 ( ssb W54→L and ssb W54→S) produced the greatest effects on in vivo protein function including altered marker linkage subsequent to generalized transduction, extreme UV sensitivity, and a lack of ability to support SOS induction. Additionally, the ssb-113 ( ssb P176→S) mutation demonstrated the existence of both uvrA -dependent and uvrA -independent components of SOS induction. Although nucleotide excision repair appeared unaffected by alterations in the SSB protein, the mutational analysis suggests a direct role for SSB in recombinational repair. 相似文献