全文获取类型
收费全文 | 8303篇 |
免费 | 822篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 56篇 |
儿科学 | 319篇 |
妇产科学 | 211篇 |
基础医学 | 1242篇 |
口腔科学 | 142篇 |
临床医学 | 870篇 |
内科学 | 1832篇 |
皮肤病学 | 127篇 |
神经病学 | 661篇 |
特种医学 | 271篇 |
外科学 | 896篇 |
综合类 | 227篇 |
一般理论 | 5篇 |
预防医学 | 798篇 |
眼科学 | 105篇 |
药学 | 756篇 |
中国医学 | 9篇 |
肿瘤学 | 635篇 |
出版年
2021年 | 105篇 |
2020年 | 82篇 |
2019年 | 83篇 |
2018年 | 136篇 |
2017年 | 88篇 |
2016年 | 133篇 |
2015年 | 140篇 |
2014年 | 219篇 |
2013年 | 377篇 |
2012年 | 457篇 |
2011年 | 496篇 |
2010年 | 270篇 |
2009年 | 286篇 |
2008年 | 418篇 |
2007年 | 514篇 |
2006年 | 476篇 |
2005年 | 455篇 |
2004年 | 478篇 |
2003年 | 420篇 |
2002年 | 464篇 |
2001年 | 100篇 |
2000年 | 106篇 |
1999年 | 131篇 |
1998年 | 163篇 |
1997年 | 158篇 |
1996年 | 140篇 |
1995年 | 116篇 |
1994年 | 128篇 |
1993年 | 121篇 |
1992年 | 87篇 |
1991年 | 109篇 |
1990年 | 97篇 |
1989年 | 114篇 |
1988年 | 109篇 |
1987年 | 85篇 |
1986年 | 69篇 |
1985年 | 72篇 |
1984年 | 68篇 |
1983年 | 78篇 |
1982年 | 84篇 |
1981年 | 70篇 |
1980年 | 75篇 |
1979年 | 57篇 |
1978年 | 57篇 |
1977年 | 47篇 |
1976年 | 44篇 |
1975年 | 34篇 |
1974年 | 36篇 |
1973年 | 40篇 |
1972年 | 44篇 |
排序方式: 共有9162条查询结果,搜索用时 844 毫秒
81.
The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry 总被引:8,自引:1,他引:8
Nistico L; Buzzetti R; Pritchard LE; Van der Auwera B; Giovannini C; Bosi E; Larrad MT; Rios MS; Chow CC; Cockram CS; Jacobs K; Mijovic C; Bain SC; Barnett AH; Vandewalle CL; Schuit F; Gorus FK; Tosi R; Pozzilli P; Todd JA 《Human molecular genetics》1996,5(7):1075-1080
Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus
is determined by a combination of environmental and genetic factors, which
include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin
gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2
cannot explain the clustering of type 1 diabetes in families, and a role
for other genes is inferred. In the present report we describe linkage and
association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte
associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong
candidate gene for T cell- mediated autoimmune disease because it encodes a
T cell receptor that mediates T cell apoptosis and is a vital negative
regulator of T cell activation. In addition, we provide supporting evidence
that CTLA-4 is associated with susceptibility to Graves' disease, another
organ- specific autoimmune disease.
相似文献
82.
Cunliffe NA Dove W Gondwe JS Thindwa BD Greensill J Holmes JL Bresee JS Monroe SS Glass RI Broadhead RL Molyneux ME Hart CA 《Journal of medical virology》2002,67(4):563-566
In a 2-year hospital-based study of paediatric gastroenteritis in Blantyre, Malawi, astroviruses were detected by enzyme immunoassay in 15 (1.9%) of 786 inpatients and in 9 (2.3%) of 400 outpatients. Greater disease severity was noted in children coinfected with human immunodeficiency virus (HIV). Six human astrovirus (HAstV) genotypes were identified, including HAstV-1 (25%), HAstV-2 (21%), HAstV-3 (25%), HAstV-4 (13%), HAstV-5 (4%), and HAstV-8 (13%). Although astroviruses are not major causes of gastroenteritis among children admitted to hospital in Blantyre, concomitant HIV infection appears to be a risk factor for increased severity of disease. 相似文献
83.
Cooke MN Fisher JP Dean D Rimnac C Mikos AG 《Journal of biomedical materials research. Part B, Applied biomaterials》2003,64(2):65-69
A novel approach to the manufacture of biodegradable polymeric scaffolds for tissue-engineering utilizing stereolithography (SLA) is presented. SLA is a three-dimensional (3D) printing method that uses an ultraviolet laser to photo-crosslink a liquid polymer substrate. The current generation of SLA devices provide a 3D printing resolution of 0.1 mm. The experiments utilized a biodegradable resin mixture of diethyl fumarate (DEF), poly(propylene fumarate) (PPF), and a photoinitiator, bisacylphosphine oxide (BAPO). The PPF is crosslinked with the use of the SLA's UV laser (325-nm wavelength). An SLA device was retrofitted with a custom fixture build tank enclosing an elevator-driven build table. A 3D prototype model testing the manufacturing control this device provides was created in a computer-aided-design package. The resulting geometric data were used to drive the SLA process, and a DEF/PPF prototype part was successfully manufactured. These scaffolds have application in the tissue engineering of bony substrates. 相似文献
84.
Lovering Ruth; Middleton-Price Helen R.; O'Reilly Marie-Anne J.; Genet Sally A.; Parkar Mohammed; Sweatman Angela K.; Bradley Linda D.; Alterman Lesley A.; Malcolm Sue; Morgan Gareth; Levinsky Roland J.; Kinnon Christine 《Human molecular genetics》1993,2(2):139-141
Genetic linkage analysis has been instrumental in mapping thegene for X-linked agammaglobulinemia (XLA) to the proximal longarm of the human X chromosome, to Xq22. Due to the relativerarity of this disease the localization of the gene within Xq22has remained imprecise. We have investigated twenty-nine familiesaffected by XLA and have found no recombinants with the DXS178locus in over 30 informative meioses. DXS178 is now the mostreliable and informative locus for use in pre-natal diagnosisand carrier detection of XLA. In addition, we have identifiednew closely linked proximal and distal flanking markers forXLA, DXS442 and DXS101, respectively. These loci are separatedby 2cM, considerably reducing the extent of DNA within whichthe XLA locus can be contained. This will open up the way formore directed positional cloning efforts for the isolation ofthe XLA gene. 相似文献
85.
86.
Y chromosome microdeletions, in azoospermic or near-azoospermic subjects, are located in the AZFc (DAZ) subregion 总被引:9,自引:2,他引:9
Submicroscopic deletions of the Y chromosome and polymorphisms of the
androgen receptor (AR) gene in the X chromosome have been observed in men
with defective spermatogenesis. To further define the subregions/genes in
the Y chromosome causing male infertility and its relationship to
polymorphisms of the AR polyglutamine tract, we screened the genomic DNA of
202 subfertile males and 101 healthy fertile controls of predominantly
Chinese ethnic origin. Y microdeletions were examined with 16
sequence-tagged site (STS) probes, including the RBM and DAZ genes,
spanning the AZFb and AZFc subregions of Yq11, and related to the size of
trinucleotide repeat encoding the AR polyglutamine tract. Y microdeletions
were detected and confirmed in three out of 44 (6.8%) of azoospermic and
three out of 86 (3.5%) severely oligozoospermic patients. No deletions were
detected in any of the patients with sperm counts of >0.5 x 10(6)/ml,
nor in any of the 101 fertile controls. All six affected patients had
almost contiguous Y microdeletions spanning the entire AZFc region
including the DAZ gene. The AZFb region, containing the RBM1 gene, was
intact in five of the six subjects. Y deletions were not found in those
with long AR polyglutamine tracts. Our study, the first in a Chinese
population, suggest a cause and effect relationship between Y
microdeletions in the AZFc region (possibly DAZ), and azoospermia or
near-azoospermia. Y microdeletions and long AR polyglutamine tracts appear
to be independent contributors to male infertility.
相似文献
87.
88.
Sequence variation and size ranges of CAG repeats in the Machado-Joseph disease, spinocerebellar ataxia type 1 and androgen receptor genes 总被引:6,自引:0,他引:6
Rubinsztein David C.; Leggo Jayne; Coetzee Gerhard A.; Irvine Ryan A.; Buckley Michael; Ferguson-Smith Malcolm A. 《Human molecular genetics》1995,4(9):1585-1590
A subgroup of trinucleotide repeat diseases result from abnormalexpansions of CAG repeats which are translated into polyglutaminestretches. As yet there is little understanding of how the polyglutaminesfunction either normally, or when expanded. We have investigatedthese sequences in the Machado-Joseph disease, androgen receptorand spinocerebellar ataxia type 1 genes in humans and otherprimates. None of the 748 normal chromosomes that were examinedhad more than 34 uninterrupted gluta-mine codons in the Machado-Josephdisease gene. Similarly, no normal alleles with more than 39uninterrupted glutamine codons have been reported for the otherdisease genes associated with polyglutamine expansions. Sequenceanalyses of the repeats in primates revealed shorter polyglutaminestretches in some of the non-human primates at all three lociand marked diversions from the expected polyglutamines in theorang-utan Machado-Joseph gene and in the marmoset spinocerebellarataxia type 1 gene. These data suggest that conservation ofthese polyglutamine stretches may not always be necessary fornormal gene function. 相似文献
89.
Pain behaviors that are excessive for the degree of known physical disease are common in patients with chronic low back pain and are frequently assumed to arise from a comorbid depressive illness. Although some studies have confirmed an association between depression and excessive pain behavior, methodologic problems (such as the use of depression ratings that also recorded symptoms attributable to physical disease) make interpretation of this finding difficult. We recruited 54 consecutive patients with chronic (>6 months) low back pain from a hospital clinic. Subjects completed self-rated assessments of anxiety and depression (Hospital Anxiety and Depression Scale) designed to be minimally affected by physical symptoms, along with assessments of disability (ODQ), pain (visual analogue scale), pain behavior (Waddell checklist), and physical impairment. Seventeen subjects (31%) exhibited excessive pain behavior. Overall, they were no more depressed or anxious than the remainder, although men with excessive pain behavior showed a trend toward being more depressed. Patients with excessive pain behavior were more disabled (self-rated and observer-rated), reported greater pain, and were more likely to be female and to have pain of shorter duration. Pain behavior did not correlate with anxiety or depression, but correlated with measures of disability and pain intensity. Factor analysis revealed that physical disability, pain intensity, and pain behavior loaded heavily on the first factor. Anxiety and depression loaded together on a separate factor. We conclude that pain behaviors were not related to anxiety or depression in our group, although gender differences between groups could have contributed to our negative findings. Pain behaviors may influence other physical measures. Further studies are required to investigate the relation between depression and pain behavior while controlling for gender differences. 相似文献
90.
David Gompertz Patricia A. Goodey Hazel Thom George Russell Alan W. Johnston David H. Mellor Murdoch W. MacLean Marie E. Ferguson-Smith Malcolm A. Ferguson-Smith 《Clinical genetics》1975,8(4):244-250
In a family with a history of two neonatal deaths, propionicacidaemia was diagnosed retrospectively from stored plasma as the cause of the second death during the mother's next pregnancy. Amniocentesis was performed and a culture of amniotic cells was assayed for propionyl CoA carboxylase activity. The absence of any detectable propionyl CoA carboxylase activity allowed the prenatal diagnosis of propionicacidaemia to be made. Treatment with biotin and a modified aminoacid diet was started in the immediate postnatal period. Investigation of propionyl CoA carboxylase in leucocytes from the parents, siblings and other relations of the patient failed to demonstrate intermediate enzyme activities in even the parents, who were presumably heterozygotes for this condition. 相似文献