全文获取类型
收费全文 | 5234篇 |
免费 | 256篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 103篇 |
妇产科学 | 75篇 |
基础医学 | 627篇 |
口腔科学 | 86篇 |
临床医学 | 403篇 |
内科学 | 1487篇 |
皮肤病学 | 96篇 |
神经病学 | 292篇 |
特种医学 | 179篇 |
外科学 | 806篇 |
综合类 | 41篇 |
预防医学 | 171篇 |
眼科学 | 55篇 |
药学 | 360篇 |
中国医学 | 8篇 |
肿瘤学 | 656篇 |
出版年
2023年 | 35篇 |
2022年 | 35篇 |
2021年 | 143篇 |
2020年 | 69篇 |
2019年 | 67篇 |
2018年 | 79篇 |
2017年 | 61篇 |
2016年 | 55篇 |
2015年 | 69篇 |
2014年 | 83篇 |
2013年 | 131篇 |
2012年 | 207篇 |
2011年 | 195篇 |
2010年 | 127篇 |
2009年 | 139篇 |
2008年 | 191篇 |
2007年 | 257篇 |
2006年 | 222篇 |
2005年 | 212篇 |
2004年 | 203篇 |
2003年 | 187篇 |
2002年 | 201篇 |
2001年 | 183篇 |
2000年 | 214篇 |
1999年 | 210篇 |
1998年 | 78篇 |
1997年 | 82篇 |
1996年 | 65篇 |
1995年 | 55篇 |
1994年 | 39篇 |
1993年 | 34篇 |
1992年 | 147篇 |
1991年 | 149篇 |
1990年 | 143篇 |
1989年 | 135篇 |
1988年 | 126篇 |
1987年 | 111篇 |
1986年 | 94篇 |
1985年 | 99篇 |
1984年 | 72篇 |
1983年 | 59篇 |
1981年 | 27篇 |
1980年 | 23篇 |
1979年 | 61篇 |
1978年 | 31篇 |
1977年 | 35篇 |
1974年 | 45篇 |
1971年 | 23篇 |
1969年 | 22篇 |
1968年 | 22篇 |
排序方式: 共有5504条查询结果,搜索用时 265 毫秒
91.
Serial spirograms of 121 dust workers whose chest X-rays were found to be "class 1" of the diagnostic criteria for pneumoconiosis were obtained during 1978-80. Yearly changes of pulmonary function variables (%VC, FEV1, FEV1/FVC%,V25/H, and V50/V25) by age, smoking habit, total years of exposure to dust, and work history were evaluated. The average age of the dust workers was 48.0 +/- 5.5 years, and the average years of exposure to dust was 21.6 +/- 6.8 years in 1978. Eighty-two dust workers smoked with the mean smoking history of 24.7 pack-years. No significant differences of spirograms were found between the smoking and non-smoking groups. Among the smokers, however, linear regression of FEV1/FVC% by age gradually decreased during 1978-80. All the pulmonary function variables showed no correlation with smoking history as well as total years of dust exposure. All the dust workers were classified into eight types of work by their histories; crushing and quarrying operators, brick mason, foundry and grinding operators, asbestos workers, underground miners, refractory material workers, pyrites roasters, and welders. The underground miners showed lower FEV1/FVC% and V25 than the average. However, the difference of such pulmonary function variables by eight types of work was not significant by analysis of variance. Since aging is the most dominant factor for pulmonary dysfunction, a longer observation on this group will be needed. 相似文献
92.
Pterion and epipteric bones in Japanese adults and fetuses, with special reference to their formation and variations] 总被引:1,自引:0,他引:1
The formation and variations of the pterion and epipteric bones were examined in total of 614 Japanese skulls. The materials used consisted of 258 skulls of Japanese fetuses ranging from the fourth to the ninth month, 20 skulls of Japanese juveniles from the third month to 17 years of age, and 336 skulls of Japanese adults from 20 to 89 years of age. For the skulls examined the incidence of ossification in the fetal sphenoidal fontanelle was 3.6% on each side, whereas epipteric bones were observed in more than 10% of the juvenile and adult pteria. Great variation was seen in the form of the adult pterion. The most common form was a sphenoparietal contact in which the pteria were classified into usual (306 pteria), high (119), low (21), and narrow (32) types Another form of this type, a frontal process of the temporal bone without contact with frontal bone, was found in five pteria. The form of frontotemporal contact is classified into two types: One is with a frontal process of the temporal bone (17 pteria), and another is a K-shaped contact referred to as "stellate" (four). The two types were observable in adult skulls of all ages, although the fused pteria and fusing epipteric bones were most often seen in cases over 40 years of age. The results suggest that the pterion formation has two phases, the first occurring before the occlusion of sphenoidal fontanelle, and the second starting after 40 years of age. 相似文献
93.
S Mori H Ishihara T Sogabe Y Kodama H Hibino 《No shinkei geka. Neurological surgery》1977,5(4):385-392
So called intracerebral or subcortical meningioma with no relation to the ventricles is extremely rare. In 1938 Cushing and Eisenhardt reported two cases of this type of tumor as "Deep Sylvian Meningiomas" The authors reported a case of "deep sylvian meningioma" because of its rarity and interesting diagnostical questions, and 16 cases reported in the literature were reviewed. 相似文献
94.
We sought to determine whether a selection process for deployment had a measurable effect on psychological symptoms by comparing scores on the Yatabe-Guilford Personality Index, the Manifest Anxiety Scale, and the 30-item version of the General Health Questionnaire between deployed and nondeployed mission candidates from the Japan Self-Defense Forces. The studies were undertaken in Japan during education and training for the United Nations peacekeeping mission in the Golan Heights. The participants included 80 candidates for deployment. Personnel who were not deployed had significantly higher measures of manifest anxiety and general psychological distress than deployed personnel, whereas deployed personnel showed more symptoms suggesting somatization. The selection process and training for deployment appear to have been stressful for all personnel, whether deployed or not. 相似文献
95.
96.
97.
Identification of five novel SLC3A1 (rBAT) gene mutations in Japanese cystinuria. BACKGROUND: Cystinuria is an inheritable amino aciduria and has been classified into three subtypes: I, II, and III. One of the genes responsible for cystinuria has recently been identified as SLC3A1 or rBAT, but only type I cystinuria seems to be caused by genetic alterations in rBAT. To our knowledge, thus far 38 mutations in rBAT gene have been described. In this study, we investigated rBAT mutations in Japanese patients and compared the results with the previously reported mutations in other races. METHODS: We investigated 36 Japanese cystinuria patients by mutational analysis of rBAT gene. To identify newly mutated alleles, genomic DNA was analyzed by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). When an abnormal migration was observed on SSCP, a nucleotide sequence determination was performed. RESULTS: Five novel mutations were identified in five patients, three with missense mutations (L346P, I445T, C673R), one with a 1 bp deletion (1820delT), and one with a 2 bp insertion (1898insTA), and we detected three previously reported polymorphisms. Three of the mutations were homozygous, in whom parents had intermarried, and two were heterozygous for each mutations. Analysis of rBAT in family of the 1898insTA patient revealed that the patient had inherited the mutated allele from his parents. CONCLUSION: Five novel mutations in the rBAT gene have been identified in Japanese patients with cystinuria. A racial difference was not apparent in the position and frequency of the mutations. 相似文献
98.
Yoshie Nakanishi Junichi Kodama Keizo Tokumo Noriko Seki Yasunari Miyagi Mitsuo Yoshinouchi Hiroyuki Okuda Takafumi Kudo 《International journal of clinical oncology / Japan Society of Clinical Oncology》1997,2(4):219-223
Background The object of this study is to clarify the association of an angiogenic factor, PD-ECGF (platelet-derived endothelial cell
growth factor/thymidine phosphorylase), with clinicopathologic factors, in this case tumor angiogenesis, in epithelial ovarian
cancers.
Methods Tumor specimens were obtained at the time of surgery from the primary lesion in 60 patients with epithelial ovarian cancer.
Histologic cell types were assigned to tumors according to the World Health Organization classification: 26 were classified
as serous adenocarcinoma, 15 as endometrioid adenocarcinoma, 9 as mucinous adenocarcinoma, 9 as clear cell carcinoma, and
1 as undifferentiated carcinoma. Surgical staging was based on the international Federation of Gynecology and Obstetrics (FIGO)
staging system: 16 were stage I, 6 were stage II, 34 were stage III, and 4 were stage IV. Expression of PD-ECGF was evaluated
by immunohistochemical staining. Microvessel density was assessed by immunostaining for factor VIII-related antigen in the
most neovascularized area.
Results Stroma cells stained more strongly than cancer cells (80% vs. 33%). The immunopositivity of PD-ECGF in stroma cells was higher
in cases of advanced cancer. Expression of PD-ECGF in mucinous adenocarcinomas was significantly higher than that in serous
adenocarcinomas, while PD-ECGF expression in clear cell carcinomas was significantly lower. The microvessel density in the
cases with marked PD-ECGF-positive stroma cells was significantly higher than that in the cases with absent/minimal PD-ECGF-positive
stroma cells (P<0.05).
Conclusion The expression of PD-ECGF may play a crucial role in the promotion of angiogenesis in epithelial ovarian cancers. 相似文献
99.
Kasai T; Ohe Y; Nishio K; Kunitoh H; Tamura T; Sekine I; Kubota K; Yamamoto N; Nakamura Y; Shinkai T; Kodama T; Saijo N 《Japanese journal of clinical oncology》1998,28(3):214-221
BACKGROUND: It is important to minimize the incidence of ineligible cases
to improve the quality of clinical trials. To determine factors which may
influence the incidence of ineligible cases, the incidence of and reasons
for ineligibility in clinical trials were retrospectively analyzed.
METHODS: We retrospectively examined the incidence of and reasons for
ineligibility for inclusion in eight clinical trials conducted by the Lung
Cancer Chemotherapy Study Group of the Japan Clinical Oncology Group and
four trials financed by trust funds from a pharmaceutical company. RESULTS:
In these 12 clinical studies, the incidence of ineligibility was 4.2%
(32/762) (range 0-10.6%). Specific factors that might influence the
incidence of ineligible cases were then analyzed. There was a significant
difference in the incidence of ineligibility between the methods of
registration (P < 0.05). The incidences using a central registration and
without using a central registration system were 2.8% (9/322) and 5.2%
(23/440) respectively. We also analyzed ineligible cases in clinical
studies published in the Journal of Clinical Oncology. In clinical studies
published in the Journal of Clinical Oncology recently and 10 years ago,
the incidences of ineligible cases were 5.0% (942/18 878) and 4.1%
(206/4995) respectively. In clinical studies on lung cancer published in
the Journal of Clinical Oncology from 1984 to 1995, the incidence of
ineligible cases was 4.7% (900/19,116). There was no significant difference
in the incidence of ineligible cases between our 12 studies and the Journal
of Clinical Oncology clinical studies by the chi 2 test (P > 0.05).
CONCLUSIONS: We conclude that the incidence of ineligible cases in our
studies is similar to that in clinical trials published in the Journal of
Clinical Oncology. Central registration systems are useful for checking for
ineligibility, and to increase the quality of clinical trials.
相似文献
100.
We calculated the standardized mortality ratios (SMRs) of biliary tract cancer (BTC) in Japan from 1981 to 1990 and statistically analyzed the results according to 333 Secondary Areas of Medical Care, as well as sex and subsite [gallbladder cancer (GBC) and extrahepatic bile duct cancer (BDC)], in order to examine geographic clustering patterns of BTC. In GBC in both sexes, the Secondary Areas of Medical Care with high SMRs were clustered in the eastern part of Japan. In BDC in both sexes, the Areas with high SMRs were clustered between the northern and eastern parts of Japan. In comparison with GBC, this clustering favored the northern part of Japan. In males, the clustering pattern in mortality from BTC was mainly due to the occurrence of BDC. In females, the clustering pattern in mortality from BTC reflected that of GBC. The clustering of BTC, especially GBC, seems to be related to the distribution of plains, basins, and rivers. 相似文献