全文获取类型
收费全文 | 1889篇 |
免费 | 90篇 |
国内免费 | 113篇 |
专业分类
耳鼻咽喉 | 99篇 |
儿科学 | 94篇 |
妇产科学 | 17篇 |
基础医学 | 190篇 |
口腔科学 | 32篇 |
临床医学 | 179篇 |
内科学 | 464篇 |
皮肤病学 | 54篇 |
神经病学 | 82篇 |
特种医学 | 371篇 |
外国民族医学 | 1篇 |
外科学 | 170篇 |
综合类 | 42篇 |
预防医学 | 81篇 |
眼科学 | 26篇 |
药学 | 104篇 |
中国医学 | 1篇 |
肿瘤学 | 85篇 |
出版年
2023年 | 7篇 |
2022年 | 12篇 |
2021年 | 18篇 |
2020年 | 14篇 |
2019年 | 27篇 |
2018年 | 31篇 |
2017年 | 11篇 |
2016年 | 25篇 |
2015年 | 31篇 |
2014年 | 32篇 |
2013年 | 66篇 |
2012年 | 47篇 |
2011年 | 54篇 |
2010年 | 59篇 |
2009年 | 74篇 |
2008年 | 60篇 |
2007年 | 101篇 |
2006年 | 61篇 |
2005年 | 77篇 |
2004年 | 53篇 |
2003年 | 54篇 |
2002年 | 41篇 |
2001年 | 37篇 |
2000年 | 54篇 |
1999年 | 46篇 |
1998年 | 96篇 |
1997年 | 99篇 |
1996年 | 106篇 |
1995年 | 64篇 |
1994年 | 64篇 |
1993年 | 65篇 |
1992年 | 13篇 |
1991年 | 37篇 |
1990年 | 28篇 |
1989年 | 50篇 |
1988年 | 42篇 |
1987年 | 49篇 |
1986年 | 29篇 |
1985年 | 46篇 |
1984年 | 20篇 |
1983年 | 18篇 |
1982年 | 27篇 |
1981年 | 23篇 |
1980年 | 33篇 |
1979年 | 9篇 |
1978年 | 13篇 |
1977年 | 17篇 |
1976年 | 26篇 |
1975年 | 16篇 |
1970年 | 2篇 |
排序方式: 共有2092条查询结果,搜索用时 15 毫秒
61.
Berge-Lefranc JL; Jay P; Massacrier A; Cau P; Mattei MG; Bauer S; Marsollier C; Berta P; Fontes M 《Human molecular genetics》1996,5(10):1637-1641
While constructing a cDNA library of human embryos, we have isolated a
clone homologous to jumonji, a mouse gene required for neural tube
formation. We have determined the complete coding sequence of the human
homologue (JMJ) and deduced the amino acid sequence of the putative
protein. We show here that human and mouse jumonji putative proteins are
homologous and present 90% identity. During human embryogenesis, JMJ mRNAs
are predominantly expressed in neurons and particularly in dorsal root
ganglion cells. They are also expressed in neurons of human adult cerebral
cortex. In view of these observations, we propose JMJ as a candidate gene
for developmental defects of the central nervous system in the human. The
human JMJ gene maps at position 6p24-6p23.
相似文献
62.
Screening for proteins with polyglutamine expansions in autosomal dominant cerebellar ataxias 总被引:2,自引:8,他引:2
Stevanin G; Trottier Y; Cancel G; Durr A; David G; Didierjean O; Burk K; Imbert G; Saudou F; Abada-Bendib M; Gourfinkel-An I; Benomar A; Abbas N; Klockgether T; Grid D; Agid Y; Mandel JL; Brice A 《Human molecular genetics》1996,5(12):1887-1892
Expansion of trinucleotide CAG repeats coding for polyglutamine has been
implicated in five neurodegenerative disorders, including spinocerebellar
ataxia (SCA) 1 and SCA3 or Machado-Joseph disease (SCA3/MJD), two forms of
type I autosomal dominant cerebellar ataxias (ADCA). Using the 1C2 antibody
which specifically recognizes large polyglutamine tracts, particularly
those that are expanded, we recently reported the detection of proteins
with pathological glutamine expansions in lymphoblasts from another form of
ADCA type I, SCA2, as well as from patients presenting with the distinct
phenotype of ADCA type II. We now have screened a large series of patients
with ADCA or isolated cases with cerebellar ataxia, for the presence of
proteins with polyglutamine expansions. A 150 kDa SCA2 protein was detected
in 16 out of 40 families with ADCA type I. This corresponds to 24% of all
ADCA type I families, which is much more frequent than SCA1 in this series
of patients (13%). The signal intensity of the SCA2 protein was negatively
correlated to age at onset, as expected for an expanded and unstable
trinucleotide repeat mutation. The disease segregated with markers closely
linked to the SCA2 locus in all identified SCA2 families. In addition, a
specific 130 kDa protein, which segregated with the disease, was detected
in lymphoblasts of patients from nine families with ADCA type II. It was
also visualized in the cerebral cortex of one of the patients,
demonstrating its translation in the nervous system. Finally, no new
disease-related proteins containing expanded polyglutamine tracts could be
detected in lymphoblasts from the remaining patients with ADCA or isolated
cases with cerebellar ataxia.
相似文献
63.
J. Cid G. Garc��a-Pardo R. Aguinaco R. S��nchez A. Llorente 《European journal of clinical microbiology & infectious diseases》2011,30(7):845-852
The purpose of this study was to evaluate the diagnostic accuracy and prognostic value of neutrophil CD64 expression for bacterial infection in febrile adult patients presenting to our hospital emergency department. We prospectively included 132 patients with fever ??8oC (??00.4oF) during the last 24 hours and we measured CD64 expression on neutrophils the day after admission at the emergency department. We followed the patients until full recovery or death. There were 115 (87%) patients with bacterial infection and 108 (94%) of them survived. There were 17 (13%) patients without bacterial infection and 12 (71%) of them survived. Patients with bacterial infection and patients who survived showed a CD64 index higher when compared with patients without bacterial infection and patients who died, respectively (3.7?±??.2 vs. 2.5?±??.3; p??/em>=??.03; and 3.7?±??.1 vs. 1.7?±??.6; p?????.002; Mann-Whitney U test). The receiver operating characteristic (ROC) curve analysis for detecting bacterial infection and predicting survival with the CD64 index showed an area under curve (AUC) of 0.66 (95% CI, 0.52??.8; p????.03) and 0.71 (95% CI, 0.57??.85; p??/em>=??.01), respectively. Diagnostic accuracy and prognostic value of CD64 expression was good in adult patients with fever. 相似文献
64.
Ramesh JL. Kandimalla Prabhakar S Binukumar BK Willayat Yousuf Wani Deep Raj Sharma V.K. Grover Neerja Bhardwaj Kajal Jain Kiran Dip Gill 《Neuroscience letters》2011
Alzheimer's disease (AD) is the most common form of dementia, and is characterized by the degeneration of neurons and their synapses, and a higher number of amyloid plaques and neurofibrillary tangles (NFTs) compared with that found in non-demented individuals. Amyloid-β-peptides (Aβ) are major components of amyloid plaques in AD brain whereas NFTs are composed of Tau and associated with ubiquitin. The aim of the present study was to analyze the levels of Aβ42, hTau (total Tau) and ubiquitin in CSF of North Indian population. CSF Aβ42, Tau and ubiquitin were measured in CSF of AD patients as well as controls using ELISA assays. Here we report low Aβ42 levels in AD patients (324.24 ± 76.38 pg/ml) as compared to those in non-AD (NAD) (668.34 ± 43.13 pg/ml), neurological controls (NCs) (727.28 ± 46.49 pg/ml) and healthy controls (HCs) (976.47 ± 124.46 pg/ml). In contrast, hTau and ubiquitin levels were significantly high (568.65 ± 48.89 pg/ml and 36.82 ± 4.34 ng/ml, respectively) in AD patients compared to those in NAD, NC and HC. The hTau levels were 267.37 ± 36.64 pg/ml, 167.34 ± 44.27 pg/ml and 107.62 ± 24.27 pg/ml in NAD, NC and HC, respectively. Similarly, ubiquitin levels were 23.57 ± 2.32 ng/ml, 19.76 ± 3.64 ng/ml and 13.24 ± 4.56 ng/ml in NAD, NC and HC, respectively. In conclusion, low Aβ42 and high Tau–ubiquitin levels were found in North Indian AD patients. 相似文献
65.
66.
67.
68.
Early transvaginal ultrasound following an accurately dated pregnancy: the importance of finding a yolk sac or fetal heart motion 总被引:1,自引:2,他引:1
Deaton JL; Honore GM; Huffman CS; Bauguess P 《Human reproduction (Oxford, England)》1997,12(12):2820-2823
Our goals were to determine the prognostic value of a yolk sac or fetal
heart motion seen during an early accurately dated transvaginal ultrasound
(TVU). We reviewed 225 consecutive pregnancies for fetal heart motion data.
Furthermore, 63 pregnancies following in-vitro fertilization were reviewed
for yolk sac information. The TVU was performed between 5 and 6 weeks
following presumed conception (heart motion data) and between 22 and 32
days following in-vitro fertilization (yolk sac data). Pregnancies were
followed until an ongoing pregnancy or spontaneous abortion was documented.
The presence of a yolk sac between 22 and 32 days from fertilization was
associated with the development of fetal heart motion in 94% of cases. The
absence of the yolk sac by 32 days after fertilization was always
associated with a poor outcome. In women < 36 years of age, the presence
of fetal heart motion was associated with a spontaneous abortion in only
4.5% of the cases. However, the incidence of spontaneous abortion following
fetal heart motion increased to 10% in women 36-39 years and 29% in women
> or = 40 years of age. The presence of heart motion should not be
considered a reassuring sign in the older woman. These data have
implications regarding early embryology and the counselling of infertility
patients.
相似文献
69.
Dongari-Bagtzoglou AI; Warren WD; Berton MT; Ebersole JL 《International immunology》1997,9(9):1233-1241
CD40, a member of the tumor necrosis factor-alpha receptor family, is
constitutively expressed by cells of hematopoietic and non- hematopoietic
origin, including fibroblasts. Signaling through this receptor molecule
regulates inflammatory cytokine secretion by many cell types. Based on the
recently described cytokine secretory heterogeneity of fibroblast cell
subsets, we hypothesized that secretion of inflammatory cytokines by
gingival fibroblast cultures may be dictated by the existence of
differential proportions of cytokine- secreting subpopulations which
express high levels of CD40. After examining a large number of gingival
fibroblast (GF) cultures we find that the frequency of IL-6- and
IL-8-secreting cells mirrors the frequency of cells expressing high levels
of CD40 in these cultures. In addition, we demonstrate a direct functional
relationship between CD40 expression and IL-6 or IL-8 secretion by showing
that ligation of this molecule on GF, and CD40+ fibroblast subsets in
particular, up- regulates secretion of these cytokines in vitro.
相似文献