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101.
SOX8 expression during chick embryogenesis 总被引:4,自引:0,他引:4
We have isolated the SOX8 gene from the chicken embryo. This gene shows a high degree of sequence homology to SOX9 and SOX10. Detailed analysis of SOX8 expression by whole-mount in situ shows a dynamic and restricted expression pattern during chick development. SOX8 is expressed in the somitic derivative, the dermomyotome, the developing heart, pancreas, enteric neurone system, limb and the neural tube. This is the first detailed expression analysis of SOX8 in any species 相似文献
102.
ASW: a gene with conserved avian W-linkage and female specific expression in chick embryonic gonad 总被引:1,自引:0,他引:1
O'Neill M Binder M Smith C Andrews J Reed K Smith M Millar C Lambert D Sinclair A 《Development genes and evolution》2000,210(5):243-249
Vertebrates exhibit a variety of sex determining mechanisms which fall broadly into two classes: environmental or genetic.
In birds and mammals sex is determined by a genetic mechanism. In mammals males are the heterogametic sex (XY) with the Y
chromosome acting as a dominant determiner of sex due to the action of the testis-determining factor, SRY. In birds females
are the heterogametic sex (ZW); however, it is not known whether the W chromosome carries a dominant ovary-determining gene,
or whether Z chromosome dosage determines sex. Using an experimental approach, which assumes only that the sex-determining
event in birds is accompanied by sex-specific changes in gene expression, we have identified a novel gene, ASW (Avian Sex-specific W-linked). The putative protein for ASW is related to the HIT (histidine triad) family of proteins. ASW shows female-specific expression in genital ridges and maps to the chicken W chromosome. In addition, we show that, with
the exception of ratites, ASW is linked to the W chromosome in each of 17 bird species from nine different families of the class Aves.
Received: 18 October 1999 / Accepted: 10 January 2000 相似文献
103.
Hypoxia/hypoglycemia-induced amino acid release is decreased in vitro by preconditioning 总被引:1,自引:0,他引:1
Johns L Sinclair AJ Davies JA 《Biochemical and biophysical research communications》2000,276(1):134-136
The aim of this study was to investigate the effects of preconditioning on amino acid neurotransmitter release, induced by hypoxia/hypoglycaemia, from rat brain cortical slices. Tissue, perfused with artificial cerebrospinal fluid (aCSF) at 37 degrees C with zero glucose and gassed with 95% nitrogen and 5% carbon dioxide, showed a fivefold increase in glutamate release with little effect on gamma-aminobutyric acid (GABA) release. Preconditioning, with three 5-min periods of hypoxia/hypoglycaemia preceding continuous hypoxia/hypoglycaemia, significantly decreased glutamate release whilst significantly elevating GABA release. These results suggest that GABA may reduce the release of glutamate and consequently decrease the neurotoxic effects of glutamate. 相似文献
104.
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106.
J Frank S Sinclair S Hogg-Johnson H Shannon C Bombardier D Beaton D Cole 《CMAJ》1998,158(12):1625-1631
Despite the publication in the mid-1990s of comprehensive practice guidelines for the management of acute low-back pain, both in the United States and elsewhere, this ubiquitous health problem continues to be the main cause of workers'' compensation claims in much of the Western world. This paper represents a synthesis of the intervention studies published in the last 4 years and is based on a new approach to categorizing these studies that emphasizes the stage or phase of back pain at the time of intervention and the site or agent of the intervention. Current thinking suggests that medical management in the first 3-4 weeks after the onset of pain should be generally conservative. Several studies of rather heterogeneous interventions focusing on return to work and implemented in the subacute stage (3-4 to 12 weeks after the onset of pain) have shown important reductions in time lost from work (by 30% to 50%). There is substantial evidence indicating that employers who promptly offer appropriately modified duties can reduce time lost per episode of back pain by at least 30%, with frequent spin-off effects on the incidence of new back-pain claims as well. Finally, newer studies of guidelines-based approaches to back pain in the workplace suggest that a combination of all these approaches, in a coordinated workplace-linked care system, can achieve a reduction of 50% in time lost due to back pain, at no extra cost and, in some settings, with significant savings. 相似文献
107.
Hypohydration effects on skeletal muscle performance and metabolism: a 31P-MRS study 总被引:1,自引:0,他引:1
Montain Scott J.; Smith Sinclair A.; Mattot Ralph P.; Zientara Gary P.; Jolesz Ferenc A.; Sawka Michael N. 《Journal of applied physiology》1998,84(6):1889-1894
The purpose of this study was to determinewhether hypohydration reduces skeletal muscle endurance and whetherincreased H+ andPi might contribute to performancedegradation. Ten physically active volunteers (age 21-40 yr)performed supine single-leg, knee-extension exercise to exhaustion in a1.5-T whole body magnetic resonance spectroscopy (MRS) system wheneuhydrated and when hypohydrated (4% body wt).31P spectra were collected at arate of one per second at rest, exercise, and recovery, and weregrouped and averaged to represent 10-s intervals. The desired hydrationlevel was achieved by having the subjects perform 2-3 h ofexercise in a warm room (40°C dry bulb, 20% relative humidity)with or without fluid replacement 3-8 h before the experiment.Time to fatigue was reduced (P < 0.05) by 15% when the subjects were hypohydrated [213 ± 12 vs. 251 ± 15 (SE) s]. Muscle strength was generally notaffected by hypohydration. Muscle pH andPi/-ATP ratio were similarduring exercise and at exhaustion, regardless of hydration state. The time constants for phosphocreatine recovery were also similar betweentrials. In summary, moderate hypohydration reduces muscle endurance,and neither H+ norPi concentration appears to berelated to these reductions. 相似文献
108.
In vitro shoot culture and microtuber induction in the steroid yam Dioscorea composita Hemsl 总被引:4,自引:0,他引:4
Alizadeh Sedigeh Mantell Sinclair H. MariaViana Ana 《Plant Cell, Tissue and Organ Culture》1998,53(2):107-112
The individual effects of sucrose, plant growth regulators and basal salt media formulations were investigated on microtuber
induction and development in shoot cultures of the steroid yam Dioscorea composita. Sucrose at 8% (w/v) was the single most
significant medium constituent for microtuber induction. Of the four cytokinins tested, 6-benzyladenine at 1.25 and 2.5 μM
showed strong inhibitory effects on microtuber induction. By contrast, the auxins α-naphthaleneacetic acid and indole-3-butyric
acid at 5.0 μM showed striking promotive effects on microtuber induction and growth. In the presence of either one of these
auxins at 5.0 μM shoot cultures produced microtubers weighing 300–400 mg fresh weight whilst kinetin, 6-(γ,γ-dimethylallylamino)-purine,
6-benzyladenine and abscisic acid failed to promote microtuber growth (microtubers weighed generally <200 mg). Media formulations
Lloyd and MacCown and White supported the lowest frequencies of microtuber induction when kinetin was present at 2.5 μM. Anderson
Rhododendron was as effective as Murashige and Skoog overall in promoting both microtuber induction and growth. When removed
from cultures and planted in sterilized moist sand, microtubers sprouted readily (60–87% within 2 weeks) and produced vigorous
shoot growth and after 5–7 months minitubers of sizes (30–80 g) suitable for direct field planting.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
109.
110.
Clara?D. van?Karnebeek William?S. Sly Colin?J. Ross Ramona Salvarinova Joy Yaplito-Lee Saikat Santra Casper Shyr Gabriella?A. Horvath Patrice Eydoux Anna?M. Lehman Virginie Bernard Theresa Newlove Henry Ukpeh Anupam Chakrapani Mary?Anne Preece Sarah Ball James Pitt Hilary?D. Vallance Marion Coulter-Mackie Hien Nguyen Lin-Hua Zhang Amit?P. Bhavsar Graham Sinclair Abdul Waheed Wyeth?W. Wasserman Sylvia Stockler-Ipsiroglu 《American journal of human genetics》2014,94(3):453-461
Four children in three unrelated families (one consanguineous) presented with lethargy, hyperlactatemia, and hyperammonemia of unexplained origin during the neonatal period and early childhood. We identified and validated three different CA5A alterations, including a homozygous missense mutation (c.697T>C) in two siblings, a homozygous splice site mutation (c.555G>A) leading to skipping of exon 4, and a homozygous 4 kb deletion of exon 6. The deleterious nature of the homozygous mutation c.697T>C (p.Ser233Pro) was demonstrated by reduced enzymatic activity and increased temperature sensitivity. Carbonic anhydrase VA (CA-VA) was absent in liver in the child with the homozygous exon 6 deletion. The metabolite profiles in the affected individuals fit CA-VA deficiency, showing evidence of impaired provision of bicarbonate to the four enzymes that participate in key pathways in intermediary metabolism: carbamoylphosphate synthetase 1 (urea cycle), pyruvate carboxylase (anaplerosis, gluconeogenesis), propionyl-CoA carboxylase, and 3-methylcrotonyl-CoA carboxylase (branched chain amino acids catabolism). In the three children who were administered carglumic acid, hyperammonemia resolved. CA-VA deficiency should therefore be added to urea cycle defects, organic acidurias, and pyruvate carboxylase deficiency as a treatable condition in the differential diagnosis of hyperammonemia in the neonate and young child. 相似文献