全文获取类型
收费全文 | 24183篇 |
免费 | 1055篇 |
国内免费 | 116篇 |
专业分类
耳鼻咽喉 | 264篇 |
儿科学 | 483篇 |
妇产科学 | 253篇 |
基础医学 | 2988篇 |
口腔科学 | 684篇 |
临床医学 | 1497篇 |
内科学 | 6102篇 |
皮肤病学 | 280篇 |
神经病学 | 1890篇 |
特种医学 | 1024篇 |
外科学 | 4139篇 |
综合类 | 86篇 |
预防医学 | 731篇 |
眼科学 | 332篇 |
药学 | 1667篇 |
中国医学 | 34篇 |
肿瘤学 | 2900篇 |
出版年
2023年 | 141篇 |
2022年 | 271篇 |
2021年 | 437篇 |
2020年 | 253篇 |
2019年 | 313篇 |
2018年 | 441篇 |
2017年 | 322篇 |
2016年 | 397篇 |
2015年 | 431篇 |
2014年 | 561篇 |
2013年 | 705篇 |
2012年 | 1131篇 |
2011年 | 1219篇 |
2010年 | 761篇 |
2009年 | 674篇 |
2008年 | 1146篇 |
2007年 | 1184篇 |
2006年 | 1218篇 |
2005年 | 1202篇 |
2004年 | 1191篇 |
2003年 | 1201篇 |
2002年 | 1164篇 |
2001年 | 843篇 |
2000年 | 823篇 |
1999年 | 767篇 |
1998年 | 333篇 |
1997年 | 272篇 |
1996年 | 237篇 |
1995年 | 188篇 |
1994年 | 149篇 |
1993年 | 159篇 |
1992年 | 498篇 |
1991年 | 434篇 |
1990年 | 412篇 |
1989年 | 483篇 |
1988年 | 402篇 |
1987年 | 345篇 |
1986年 | 372篇 |
1985年 | 359篇 |
1984年 | 260篇 |
1983年 | 172篇 |
1982年 | 88篇 |
1980年 | 78篇 |
1979年 | 151篇 |
1978年 | 110篇 |
1977年 | 89篇 |
1975年 | 83篇 |
1974年 | 80篇 |
1969年 | 94篇 |
1967年 | 88篇 |
排序方式: 共有10000条查询结果,搜索用时 24 毫秒
31.
Masanori Hara M.D. Reiko Yoshida M.D. Susumu Inaba M.D. Akira Higuchi M.D. Yoshifumi Suzuki M.D. Toshio Okada M.D. Takakuni Tanizawa M.D. 《Pediatrics international》1991,33(3):335-344
The aim of this study was to assess the significance of C3 deposition in IgA nephropathy in children and adolescents. One hundred and two patients aged 5–21 years (57 male and 45 female) were studied. The findings of C3 deposition were classified into 8 groups by immunofluorescent (IF) pattern and intensity as follows: group MC3+ (N = 12): mesangiocapillary pattern and 3+ in intensity; group MC2+ (N = 13): mesangiocapillary and 2+; group MC1 + (N = 4): mesangiocapillary and 1 +; group M3+ (N = 11): mesangial and 3+; group M2+ (N = 24): mesangial and 2+; group M1 + (N=18): mesangial 1 +; group S (N = 12): only segmentally positive; and group N (N = 8): negative. Histological changes were scored semiquantitatively as an activity index (cellular proliferation, necrosis, interstitial cell infiltration, and cellular crescents) and a chronicity index (mesangial sclerosis, segmental and global glomerular sclerosis, fibrous crescents, adhesion and tubulo-interstitial change). IF findings were scored semiquantitatively and laboratory findings were also studied. The following results were obtained: 1) The scores of total activity index in MC groups were higher than in the M, S or N groups, and the greater the degree of C3 deposition, the higher the score; 2) Such result was not evident in the chronicity index; 3) High IF scores of IgG and IgM were found in the MC3+ and MC2+ groups; 4) Hematuria was more severe in MC3+ and MC2+ than in other groups, and proteinuria was more prominent in the MC than other groups. Thus the degree of C3 deposition was parallel with histological activity and urinary findings. 相似文献
32.
Masanori Hisaoka Takatoshi Aoki Hiromi Kouho Hirofumi Chosa Hiroshi Hashimoto 《Skeletal radiology》1997,26(3):191-194
The case of a 49-year-old man with Maffucci’s syndrome, who developed multiple spindle cell hemangioendotheliomas, is presented.
The case provides support for recent reports suggesting an association between this peculiar vascular lesion and skeletal
enchondromatosis. 相似文献
33.
Takao Hashimoto Osamu Sasaki Kunihiro Yoshida Yo-ichi Takei Shu-ichi Ikeda 《Movement disorders》2003,18(10):1201-1204
We report on a family with ataxia type 6 (SCA6) showing peculiar oculomotor symptoms. The proband presented with periodic alternating nystagmus (PAN), and her 2 brothers had rebound nystagmus and gaze-evoked nystagmus. They carried the identical mutation (the number of expanded CAG repeat, 24) in the CACNA1A gene. The intrafamilial variability of oculomotor symptoms may be ascribed to factors other than CAG repeat expansion size in SCA6. 相似文献
34.
A Sasaki K Matsumiya M Arao K Hasegawa N Horiuchi 《Rinsho byori. The Japanese journal of clinical pathology》1991,39(1):91-96
Screening methods for diabetes mellitus, based on fasting glucose (FPG), HbA1C and fructosamine (FRA) levels were compared with regard to their screening power. The subjects studied were 699 health examinees. A significant elevation of the mean level of each screening index was observed in diabetic subjects, but not in borderline cases compared with that of normal subjects. The FPG, HbA1C and FRA levels in diabetic subjects distributed over a wide range overlapping largely with the distributions of non-diabetic subjects. No appreciable difference in the screening power was observed between FPG and HbA1C but specificity was low in FRG for the comparable sensitivity level. In the screening methods based on the combination of two or more indices, elevation of the sensitivity was noted, but the specificity declined, resulting in an increase of re-examination rate. Among them, the combination of FPG and HbA1C indicated the highest sensitivity. 相似文献
35.
Yoshihiro Miyake Masashi Arakawa Keiko Tanaka Satoshi Sasaki Yukihiro Ohya 《Pediatric allergy and immunology》2007,18(5):433-440
Uncertainties remain as to whether breastfeeding is protective against childhood allergic disorders. Positive relationships of breastfeeding with asthma and atopic eczema were observed in two previous Japanese studies. This cross-sectional study investigated the association between the feeding pattern after birth and the prevalence of allergic disorders during the past 12 months in Japanese schoolchildren. Study subjects were 24,077 children aged 6-15 yr in Okinawa. The outcomes were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Allowance was made for age, sex, number of siblings, smoking in the household, paternal and maternal history of asthma, atopic eczema, and allergic rhinitis, and paternal and maternal educational level. Breastfeeding, regardless of exclusivity, for 13 months or longer and exclusive breastfeeding for 4-11 months were independently associated with a higher prevalence of atopic eczema, particularly among children without a parental allergic history. A clear positive dose-response relationship was observed between prolonged duration of breastfeeding, regardless of exclusivity, but not exclusive breastfeeding, and the prevalence of atopic eczema. We found a significant positive trend for atopic eczema across the three categories (formula milk, partial and exclusive breastfeeding) in the first 4 months of life although the odds ratio for exclusive breastfeeding was not statistically significant. No material association was found between the feeding pattern after birth and the prevalence of wheeze or allergic rhinoconjunctivitis. Prolonged breastfeeding may be associated with a higher prevalence of atopic eczema in Japanese children. 相似文献
36.
37.
C W Pinson R R Lopez K G Benner E B Keeffe M K Porayko A W Sasaki D K Bowers L J Wheeler R G Lee R S Johnson 《American journal of surgery》1991,161(5):606-611
During the first 24 months of the Oregon Liver Transplantation Program, which began in October 1988, 94 patients were formally evaluated and 47 adults underwent 54 liver transplantations. Thirty-four percent of patients were veterans. The recipient operation lasted a mean of 7.4 hours (range: 4 to 16 hours). Veno-venous bypass was used routinely at first but selectively later (7 of the last 26 cases), resulting in reduced operating time. Hepatic artery reconstruction was end-to-end anastomosis in 52 cases and iliac conduit in 2. No arterial thrombosis occurred. Biliary reconstruction was choledochocholedochostomy in 83% and choledochojejunostomy in 17%. Biliary complications occurred in 28%. Operative mortality was 2%, and 1-year actual survival was 80%. Patients with hepatitis B fared worse, with four of six dying at a mean of 7.6 months. Overall, the median hospital stay was 30 days. Patients surviving more than 3 months had a mean Karnofsky score of 82%. No significant difference in outcome was noted in patients receiving prophylactic OKT3 monoclonal antibody (used in 45%) versus conventional immunosuppressive therapy. Overall, allograft rejection occurred in 55% of patients. Retransplantation was required in seven patients, three for primary graft nonfunction, two for uncontrolled rejection during induction therapy with OKT3, and two for graft failure secondary to recurrent hepatitis B. 相似文献
38.
Effect of carbon dioxide and oxygen on endothelin production by cultured porcine cerebral endothelial cells 总被引:3,自引:0,他引:3
S Yoshimoto Y Ishizaki T Sasaki S Murota 《Stroke; a journal of cerebral circulation》1991,22(3):378-383
We have previously reported the production of endothelin, a potent vasoconstrictor peptide, by porcine cerebral microvessel endothelia and suggested its important role in the regulation of local blood flow within the brain. In our present study, radioimmunoassay with anti-porcine endothelin antiserum revealed that endothelin, produced by cerebral microvessel endothelia grown on a filter, is released mainly to the basement membrane side, not the vascular lumen side. This finding suggests that endothelin constricts arterioles locally where it is produced by endothelia. We also found that cerebral microvessel endothelia produce less endothelin under low oxygen pressure and more endothelin under low carbon dioxide pressure. Our results suggest that endothelin has a role in the regulation of cerebral blood flow in response to oxygen and carbon dioxide pressure. 相似文献
39.
40.
K Sekizawa Y Ujie H Nakazawa H Sasaki U Katsumata R Takasugi 《Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics》1991,28(3):308-310
Enzymes degrading peptides may participate in the regulation of the cough reflex. Thus, decreases in enzyme activities may enhance cough reflex and a decrease in cough reflex may lead to aspiration pneumonia. Down- and up-regulation of cough reflex is important for the understanding of cough reflex. 相似文献