全文获取类型
收费全文 | 1262篇 |
免费 | 111篇 |
国内免费 | 19篇 |
专业分类
儿科学 | 80篇 |
妇产科学 | 4篇 |
基础医学 | 159篇 |
口腔科学 | 64篇 |
临床医学 | 127篇 |
内科学 | 256篇 |
皮肤病学 | 56篇 |
神经病学 | 28篇 |
特种医学 | 260篇 |
外科学 | 140篇 |
综合类 | 33篇 |
预防医学 | 72篇 |
眼科学 | 14篇 |
药学 | 32篇 |
1篇 | |
肿瘤学 | 66篇 |
出版年
2021年 | 8篇 |
2020年 | 13篇 |
2019年 | 12篇 |
2018年 | 14篇 |
2017年 | 8篇 |
2016年 | 16篇 |
2015年 | 29篇 |
2014年 | 25篇 |
2013年 | 44篇 |
2012年 | 30篇 |
2011年 | 33篇 |
2010年 | 58篇 |
2009年 | 52篇 |
2008年 | 25篇 |
2007年 | 37篇 |
2006年 | 32篇 |
2005年 | 27篇 |
2004年 | 23篇 |
2003年 | 36篇 |
2002年 | 33篇 |
2001年 | 33篇 |
2000年 | 12篇 |
1999年 | 28篇 |
1998年 | 83篇 |
1997年 | 79篇 |
1996年 | 62篇 |
1995年 | 53篇 |
1994年 | 39篇 |
1993年 | 48篇 |
1992年 | 19篇 |
1991年 | 29篇 |
1990年 | 23篇 |
1989年 | 46篇 |
1988年 | 38篇 |
1987年 | 26篇 |
1986年 | 27篇 |
1985年 | 21篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 15篇 |
1981年 | 17篇 |
1980年 | 19篇 |
1979年 | 9篇 |
1978年 | 15篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1975年 | 12篇 |
1970年 | 4篇 |
1968年 | 6篇 |
1967年 | 3篇 |
排序方式: 共有1392条查询结果,搜索用时 19 毫秒
31.
The t(X;1)(p11.2;q21.2) translocation in papillary renal cell carcinoma fuses a novel gene PRCC to the TFE3 transcription factor gene 总被引:4,自引:2,他引:4
32.
Somatic mutation processes at a human minisatellite 总被引:6,自引:3,他引:6
Germline instability at human minisatellites frequently involves complex
inter-allelic transfers of repeat units usually restricted to one end of
the repeat array and apparently regulated by flanking DNA. In contrast,
nothing is known about the structural basis of somatic instability at
minisatellites. An electrophoretic size-enrichment strategy was therefore
developed at minisatellite MS32 (D1S8) to enable rare abnormal-length
mutants to be detected, validated and quantitated in blood DNA by single
molecule PCR. Structural analysis of rare mutant alleles in blood revealed
simple deletions/duplications of repeat unit blocks located at random along
the tandem repeat array, a mode of mutation completely different from that
seen in sperm. Furthermore, allele-specific suppression of sperm
instability at MS32 did not affect somatic instability. These data suggest
that conversion-based minisatellite mutation in sperm is completely
germline-specific and most likely meiotic in origin. Somatic instability
appears to occur by a separate pathway involving replication slippage or,
more likely, intra-allelic unequal crossing over.
相似文献
33.
Mutations in the TSC2 gene: analysis of the complete coding sequence using the protein truncation test (PTT) 总被引:4,自引:0,他引:4
Mutations in the TSC2 gene on chromosome 16p13.3 are responsible for
approximately 50% of familial tuberous sclerosis (TSC). The gene has 41
small exons spanning 45 kb of genomic DNA and encoding a 5.5 kb mRNA. Large
germline deletions of TSC2 occur in <5% of cases, and a number of small
intragenic mutations have been described. We analysed mRNA from 18
unrelated cases of TSC for TSC2 mutations using the protein truncation test
(PTT). Three cases were predicted to be TSC2 mutations on the basis of
linkage analysis or because a hamartoma from the patient showed loss of
heterozygosity for 16p13.3 markers. Three overlapping PCR products,
covering the complete coding sequence of mRNA, were generated from
lymphoblastoid cell lines, translated into 35S-methionine labelled protein,
and analysed by SDS-PAGE. PCR products showing PTT shifts were directly
sequenced, and mutations confirmed by restriction enzyme digestion where
possible. Six PTT shifts were identified. Five of these were caused by
mutations predicted to produce a truncated protein: (i) a sporadic case
showed a 32 bp deletion in exon 11, and a mutant mRNA without exon 11 was
produced; the normal exon 10 was also spliced out; (ii) a sporadic case had
a 1 bp deletion in exon 12 (1634delT); (iii) a TSC2-linked mother and
daughter pair had a G-->T transversion in exon 23 (G2715T) introducing a
cryptic splice site causing a 29 bp truncation of mRNA from exon 23; (iv) a
sporadic case showed a 2 bp deletion in exon 36; (v) a sporadic case showed
a 1 bp insertion disrupting the donor splice site of exon 37 (5007+2insA),
resulting in the use of an upstream exonic cryptic splice site to cause a
29 bp truncation of mRNA from exon 37. In one case, the PTT shift was
explained by in-frame splicing out of exon 10, in the presence of a normal
exon 10 genomic sequence. Alternative splicing of exon 10 of the TSC2 gene
may be a normal variant. Three 3rd base substitution polymorphisms were
also detected during direct sequencing of PCR products. Confirmed mutations
were identified in 28% of the families studied and on the assumption that
half of the sporadic cases should have TSC2 mutations, a crude estimate of
the detection rate would be 60%. This compares favourably with other
screening methods used for TSC2, notably SSCP, and since PTT involves much
less work it may be the method of choice.
相似文献
34.
Detecting pre-ovulatory luteinizing hormone surges in urine 总被引:2,自引:1,他引:2
Kesner JS; Knecht EA; Krieg EF Jr; Wilcox AJ; O'Connor JF 《Human reproduction (Oxford, England)》1998,13(1):15-21
The study objectives were to determine (i) if pre-ovulatory luteinizing
hormone (LH) surges, undetected in urine by two immunoradiometric assays
(IRMA), were detectable by an ultrasensitive immunofluorometric assay
(IFMA) and (ii) the influence of creatinine adjustment on the detection and
timing of the urinary LH surges. Daily urine specimens were contributed by
healthy 25-36 year old volunteers during 14 ovulatory menstrual cycles for
an epidemiological study conducted in 1983-1985. Specimens were selected as
having been previously assayed by two IRMA without consistently detecting
LH surges. These urine specimens were remeasured using an IFMA and adjusted
for creatinine concentration. IFMA measurements revealed unambiguous LH
surges in all cycles. Adjusting IRMA urinary LH values for creatinine
concentrations revealed previously undetected LH surges in four of eight
cycles. Creatinine adjustment also altered the timing of IRMA and IFMA LH
surges by 1-5 days. These results demonstrate an IFMA that detects pre-
ovulatory LH surges in unpreserved, frozen urine from cycles where such
surges were previously undetectable. Further, creatinine adjustment can
markedly affect detection and timing of the onset and peak of the urinary
LH surge. While our analysis suggests that this adjustment improves the
validity of the LH measure, this requires further investigation.
相似文献
35.
We performed a randomized doubled-blind study to evaluate whether there was a benefit in delay in tourniquet deflation with intra-articular administration of morphine and bupivacaine following operative arthroscopic surgery. In 34 patients the tourniquet was deflated immediately and in 38 patients the tourniquet remained inflated for 10 min following injection. The analgesic efficacy was assessed using pain scores and the amount of supplementary analgesia required. The results demonstrate no benefit in delay in tourniquet deflation. 相似文献
36.
37.
38.
39.
Van der Wall H Frater CJ Magee MA Kannangara S Bruce W Murray IP 《Nuclear medicine communications》1999,20(11):1059-1065
Using any imaging modality, the elbow is a complex joint to evaluate. The use of scintigraphy in the evaluation of the effects of acute or chronic trauma has largely been confined to epicondylitis. We developed a skyline view of the elbow that minimized the effect of overlap and assessed its incremental value in the scintigraphic assessment of several pathological conditions. Thirty-four abnormalities were evaluated in 20 patients with a range of pathologies, including epicondylitis, ligamentous avulsion injury, articular injury, fractures and synovitis. The incremental value of addition of the skyline view to the standard views was assessed in addition to the overall accuracy of scintigraphy. Overall, scintigraphy detected 27 of 34 abnormalities, with the standard views of the elbow accurately identifying 15 and the skyline view 23 abnormalities. This gave the skyline view an incremental value of 24% over the standard views. In conclusion, scintigraphy has the potential to identify a greater range of pathologies in the elbow than previously reported, due to the addition of the skyline view to the standard views. 相似文献
40.