全文获取类型
收费全文 | 9598篇 |
免费 | 615篇 |
国内免费 | 199篇 |
专业分类
耳鼻咽喉 | 204篇 |
儿科学 | 101篇 |
妇产科学 | 50篇 |
基础医学 | 1774篇 |
口腔科学 | 177篇 |
临床医学 | 913篇 |
内科学 | 2325篇 |
皮肤病学 | 351篇 |
神经病学 | 715篇 |
特种医学 | 484篇 |
外科学 | 987篇 |
综合类 | 81篇 |
现状与发展 | 1篇 |
预防医学 | 369篇 |
眼科学 | 111篇 |
药学 | 945篇 |
中国医学 | 169篇 |
肿瘤学 | 655篇 |
出版年
2024年 | 3篇 |
2023年 | 57篇 |
2022年 | 300篇 |
2021年 | 490篇 |
2020年 | 213篇 |
2019年 | 275篇 |
2018年 | 324篇 |
2017年 | 235篇 |
2016年 | 356篇 |
2015年 | 457篇 |
2014年 | 570篇 |
2013年 | 619篇 |
2012年 | 1058篇 |
2011年 | 930篇 |
2010年 | 499篇 |
2009年 | 400篇 |
2008年 | 515篇 |
2007年 | 508篇 |
2006年 | 411篇 |
2005年 | 396篇 |
2004年 | 274篇 |
2003年 | 277篇 |
2002年 | 218篇 |
2001年 | 177篇 |
2000年 | 181篇 |
1999年 | 144篇 |
1998年 | 85篇 |
1997年 | 64篇 |
1996年 | 41篇 |
1995年 | 38篇 |
1994年 | 38篇 |
1993年 | 29篇 |
1992年 | 31篇 |
1991年 | 20篇 |
1990年 | 30篇 |
1989年 | 21篇 |
1988年 | 21篇 |
1987年 | 16篇 |
1986年 | 17篇 |
1985年 | 15篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1979年 | 7篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1939年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Jang SH Seol JY Kim CH Yoo CG Kim YW Han SK Shim YS Lee CT 《International journal of molecular medicine》2004,13(1):181-186
TRAIL is a cytokine that can induce tumor-specific apoptosis through its specific death receptors (DR4 and DR5) and p53 has been proven to increase the expression of death receptors. To examine their interaction in tumor suppression, p53 and TRAIL genes were inserted in recombinant adenovirus vectors and transferred simultaneously into non-small cell lung cancer cell lines (NCI-H157, NCI-H358, NCI-H460 and A549). Western blot assay demonstrated production of TRAIL protein in NCI-H157 and A549 cell lines. Increased expressions of DR4 and DR5 of NCI-H157 and DR4 of A549 after p53 overexpression were confirmed by flow cytometry. p53 or TRAIL gene transfer increased sub-G1 fraction in cell cycle analysis and inhibited the tumor growth dose-dependently and the degree was potentiated by co-transfer. But isobologram analysis indicated an additive effect. Together, these data indicate that p53 and TRAIL interact additively on tumor apoptosis despite theoretical synergism. 相似文献
42.
Damiani AM Matsumura T Jang HK Izumiya Y Mikami T Takahashi E 《Archives of virology》2000,145(7):1489-1496
Summary. In order to identify the products of the equine herpesvirus type 4 (EHV-4) gI and gE genes, we have constructed recombinant
vaccinia viruses containing the putative gI or gE genes. These recombinant viruses synthesized EHV-4 gI and gE with apparent
molecular masses of 75 and 80 kDa, respectively. Antibodies raised against both recombinant viruses detected a 75 kDa gI and
a 95 kDa gE in EHV-4-infected cells. The results also suggest that the EHV-4 gI and gE would form a complex like in other
herpesviruses.
Received October 29, 1999 Accepted January 21, 2000 相似文献
43.
44.
Various inhibitors of cyclooxygenase are known to mediate cancer chemopreventive effects. We currently describe two in vitro assay systems for measuring cyclooxygenase activity. These assays can be used in combination and thereby provide a rapid, reliable, and economical approach that is applicable for large-scale evaluation of test samples. This approach employs peroxidase co-substrate oxidation and oxygen consumption assays. The former system, adapted to a 96-well plate format, detects inhibitors that function as a radical scavengers or interact with the enzyme directly. The latter system specifically monitors cyclooxygenase inhibitors that interact with the enzyme itself. Thus, the peroxidase co-substrate oxidation assay serves as a pre-screening method, whereas the oxygen consumption assay is used subsequently to investigate the mode of action mediated by samples which test positive. 相似文献
45.
Mutation spectrum and genotype-phenotype analyses in Cowden disease and Bannayan-Zonana syndrome, two hamartoma syndromes with germline PTEN mutation 总被引:22,自引:1,他引:22
Marsh DJ; Coulon V; Lunetta KL; Rocca-Serra P; Dahia PL; Zheng Z; Liaw D; Caron S; Duboue B; Lin AY; Richardson AL; Bonnetblanc JM; Bressieux JM; Cabarrot-Moreau A; Chompret A; Demange L; Eeles RA; Yahanda AM; Fearon ER; Fricker JP; Gorlin RJ; Hodgson SV; Huson S; Lacombe D; Eng C 《Human molecular genetics》1998,7(3):507-515
The tumour suppressor gene PTEN , which maps to 10q23.3 and encodes a 403
amino acid dual specificity phosphatase (protein tyrosine phosphatase;
PTPase), was shown recently to play a broad role in human malignancy.
Somatic PTEN deletions and mutations were observed in sporadic breast,
brain, prostate and kidney cancer cell lines and in several primary tumours
such as endometrial carcinomas, malignant melanoma and thyroid tumours. In
addition, PTEN was identified as the susceptibility gene for two hamartoma
syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or
Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD
families and seven BZS families was screened for germline PTEN mutations.
PTEN mutations were identified in 30 of 37 (81%) CD families, including
missense and nonsense point mutations, deletions, insertions, a
deletion/insertion and splice site mutations. These mutations were
scattered over the entire length of PTEN , with the exception of the first,
fourth and last exons. A 'hot spot' for PTEN mutation in CD was identified
in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD
mutations identified in this exon. Seven of 30 (23%) were within the core
motif, the majority (five of seven) of which were missense mutations,
possibly pointing to the functional significance of this region. Germline
PTEN mutations were identified in four of seven (57%) BZS families studied.
Interestingly, none of these mutations was observed in the PTPase core
motif. It is also worthy of note that a single nonsense point mutation,
R233X, was observed in the germline DNA from two unrelated CD families and
one BZS family. Genotype-phenotype studies were not performed on this small
group of BZS families. However, genotype-phenotype analysis inthe group of
CD families revealed two possible associations worthy of follow-up in
independent analyses. The first was an association noted in the group of CD
families with breast disease. A correlation was observed between the
presence/absence of a PTEN mutation and the type of breast involvement
(unaffected versus benign versus malignant). Specifically and more
directly, an association was also observed between the presence of a PTEN
mutation and malignant breast disease. Secondly, there appeared to be an
interdependent association between mutations upstream and within the PTPase
core motif, the core motif containing the majority of missense mutations,
and the involvement of all major organ systems (central nervous system,
thyroid, breast, skin and gastrointestinal tract). However, these
observations would need to be confirmed by studying a larger number of CD
families.
相似文献
46.
Malgun (clear) cell change in Helicobacter pylori gastritis reflects epithelial genomic damage and repair
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jang J Lee S Jung Y Song K Fukumoto M Gould VE Lee I 《The American journal of pathology》2003,162(4):1203-1211
Cancers may develop in the background of genomic instability with accumulated mutations. Helicobacter pylori gastritis is characterized by acute foveolitis of the proliferative zone, which is found in any stage of the gastritis as long as the infection persists. Because acute foveolitis targets specifically the proliferative zone of pits, the proliferating epithelial cells are under severe and persistent mutagenic pressure. In H. pylori gastritis, a characteristic morphological change of epithelial cells, the malgun (clear) cell change is frequently present in association with acute foveolitis. Malgun cells have enlarged euchromatic nuclei and abundant cytoplasm. The expression of proliferating cell nuclear antigen and cytokeratin 8 are typically up-regulated in them indicating that they are mitotically and metabolically active. Here, we report evidence for DNA damage and repair in malgun cells. Significant double-strand DNA breaks were shown by the consistent terminal dUTP nick-end labeling in the nuclei of malgun cells. Proteins related to DNA damage and repair, such as Ku, poly(ADP-ribosyl) polymerase, OGG1, and MSH2 were selectively up-regulated in malgun cells. Inducible nitric oxide synthase was also up-regulated. There were occasional bcl2- and p53-expressing cells suggesting that further steps of carcinogenesis took place at the single cell level. Our results suggest that the malgun cell change represents a characteristic morphological sign of cellular genomic damage and repair, and may be implicated in an early stage of carcinogenesis. It is suggested that acute foveolitis of the proliferative zone is a major pathogenetic step of gastric carcinogenesis in H. pylori gastritis. 相似文献
47.
Jeong HJ Sung SH Hong SW Moon JI Kim SI Kim YS Park K 《Virchows Archiv : an international journal of pathology》2000,437(1):69-73
The distribution pattern of extracellular matrix (ECM) components in transplant glomerulopathy was studied in relation to
light microscopic features, actin expression of mesangial cells, and intraglomerular inflammatory cells. Nine cases of mild
(group I) and nine cases of severe (group II) transplant glomerulopathy were stained with antisera against fibronectin (FN),
tenascin (TN), collagen types III and IV, smooth muscle actin, CD45RO, CD68, and Ki-67 antigen. The composition of ECM was
similar in the two groups. The expanded mesangium was diffusely stained by type-IV collagen, FN and TN, and focally and weakly
stained by type-III collagen and smooth muscle actin. Type-IV collagen was linearly stained along the capillary walls, imparting
a double-contour feature, whereas FN and TN showed granular staining along the capillary walls. CD68 positive cells were increased
in severe transplant glomerulopathy, but this increase was not related to ECM deposition. These findings suggest that increased
glomerular deposition of normal and abnormal ECM components participate in the evolution of transplant glomerulopathy.
Received: 5 October 1999 / Accepted: 17 January 2000 相似文献
48.
Jang WJ Kim JH Choi YJ Jung KD Kim YG Lee SH Choi MS Kim IS Walker DH Park KH 《Journal of clinical microbiology》2004,42(5):2310-2313
To investigate the prevalence of spotted fever group rickettsioses in Korea, a serosurvey of Japanese spotted fever rickettsiosis in patients with acute febrile illness was conducted with an indirect immunofluorescence assay. Overall, 19.88% of the patients were found to have polyvalent antibody against Rickettsia japonica. This study is the first documentation of spotted fever group rickettsiosis in Korea. 相似文献
49.
The modifying potential of capsaicin (CAP) on lesion development was examined in a rat multiorgan carcinogenesis model. Groups 1 and 2 were treated sequentially with diethylnitrosamine (DEN) (100 mg/kg, ip, single dose at commencement), N-methylnitrosourea (MNU) (20 mg/kg, ip, 4 doses at days 2, 5, 8, and 11), and N,N-dibutylnitrosamine (DBN) (0.05% in drinking water during weeks 3 and 4). Group 3 received vehicles without carcinogens during the initiation period. Group 4 served as the untreated control. After this initiating procedure, Groups 2 and 3 were administered a diet containing 0.01% CAP. All surviving animals were killed 20 weeks after the beginning of the experiment and the target organs examined histopathologically. The induction of GST-P+ hepatic foci in rats treated with carcinogens was significantly inhibited by treatment with CAP. CAP treatment significantly decreased the incidence of adenoma of the lung but increased the incidence of papillary or nodular (PN) hyperplasia of the urinary bladder. The tumor incidence of other organs, such as the kidney and thyroid, was not significantly different from the corresponding controls. These results demonstrated that concurrent treatment with CAP not only can inhibit carcinogenesis but can also enhance it depending on the organ. Thus, this wide-spectrum initiation model could be used to confirm organ-specific modification potential and, in addition, demonstrate different modifying effects of CAP on liver, lung, and bladder carcinogenesis. 相似文献
50.
Seung Eun Lee Jin-Young Jang Kuhn Uk Lee Sun-Whe Kim 《Journal of Korean medical science》2008,23(6):1011-1014
The spleen may be preserved during distal pancreatectomy (DP) for benign disease. The aim of this study was to compare the perioperative and postoperative courses of patients with conventional DP and spleen-preserving distal pancreatectomy (SPDP) for benign lesions or tumors with low-grade malignant potential occurred at the body or tail of the pancreas. A retrospective analysis was performed for the hospital records of all the patients undergoing DP and SPDP between January 1995 and April 2006. One-hundred forty-three patients underwent DP and 37 patients underwent SPDP. There were no significant differences in age, sex, indications of operation, estimated blood loss, operative time, and postoperative hospital stay between the two groups. Pancreatic fistula occurred in 21 (13.3%) patients following DP and in 3 (8.1%) following SPDP without a significant difference (p=0.081). Portal vein thrombosis occurred in 4 patients after DP. Splenic infarction occurred in one patient after SPDP. Overwhelming postosplenectomy infection was observed in one patient after DP. SPDP can be achieved with no increase in complication rate, operative time, or length of postoperative hospitalization as compared to conventional DP. Additionally, it has the advantage of reducing the risk of overwhelming postsplenectomy infection and postoperative venous thrombosis. 相似文献