全文获取类型
收费全文 | 8596篇 |
免费 | 441篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 216篇 |
妇产科学 | 53篇 |
基础医学 | 1277篇 |
口腔科学 | 210篇 |
临床医学 | 449篇 |
内科学 | 2331篇 |
皮肤病学 | 162篇 |
神经病学 | 636篇 |
特种医学 | 352篇 |
外科学 | 1420篇 |
综合类 | 30篇 |
预防医学 | 194篇 |
眼科学 | 171篇 |
药学 | 503篇 |
中国医学 | 26篇 |
肿瘤学 | 1016篇 |
出版年
2023年 | 43篇 |
2022年 | 87篇 |
2021年 | 135篇 |
2020年 | 80篇 |
2019年 | 110篇 |
2018年 | 119篇 |
2017年 | 123篇 |
2016年 | 150篇 |
2015年 | 179篇 |
2014年 | 208篇 |
2013年 | 246篇 |
2012年 | 432篇 |
2011年 | 475篇 |
2010年 | 243篇 |
2009年 | 258篇 |
2008年 | 434篇 |
2007年 | 533篇 |
2006年 | 471篇 |
2005年 | 542篇 |
2004年 | 510篇 |
2003年 | 544篇 |
2002年 | 536篇 |
2001年 | 194篇 |
2000年 | 147篇 |
1999年 | 195篇 |
1998年 | 168篇 |
1997年 | 135篇 |
1996年 | 153篇 |
1995年 | 140篇 |
1994年 | 116篇 |
1993年 | 91篇 |
1992年 | 125篇 |
1991年 | 139篇 |
1990年 | 124篇 |
1989年 | 113篇 |
1988年 | 89篇 |
1987年 | 86篇 |
1986年 | 67篇 |
1985年 | 67篇 |
1984年 | 68篇 |
1983年 | 45篇 |
1982年 | 37篇 |
1981年 | 47篇 |
1980年 | 39篇 |
1979年 | 36篇 |
1978年 | 36篇 |
1977年 | 32篇 |
1976年 | 22篇 |
1975年 | 21篇 |
1974年 | 18篇 |
排序方式: 共有9089条查询结果,搜索用时 15 毫秒
21.
Fuyumi Yamamoto Hiroshi Kasai Tadayoshi Bessho Myung-Hee Chung Hideo Inoue Eiko Ohtsuka Tomokatsu Hori Susumu Nishimura 《Cancer science》1992,83(4):351-357
Here we report the finding of enzymatic activity that specifically cleaves DNA containing 8-hydroxyguanine (oh8 Gua) residues in various mammalian cells. To detect this activity, we used a synthetic double-stranded DNA containing a single oh8 Gua at a defined position as the substrate, and analyzed the products of enzymatic digestion by polyacrylamide gel electrophoresis. Two cleavage sites near the oh8 Gua residue were detected with partially purified fractions from cow brain and rat liver, and also with preparations from all mammalian tissues examined. These results suggest that enzymatic activity for the removal of oh8 Gua from DNA is widely distributed in mammalian cells. 相似文献
22.
Toshiharu Yamagishi Susumu Ishikawa Ichiro Yoshida Akio Ohtaki Toru Takahashi Satoshi Ohki Shuji Sakata Yasuo Morishita 《Surgery today》1997,27(9):874-875
We describe our technique for performing direct thoracoscopic closure of a congenital partial pericardial defect, which was
successfully employed in a 15-year-old boy. This is the first such report of a procedure that is noninvasive and may therefore
become the treatment of choice for patients with a small congenital pericardial defect. 相似文献
23.
Pyomyositis is a bacterial infection with abscess formation affecting large skeletal muscles. It is predominantly caused by Staphylococcus aureus. The disease is common in tropical areas, but rare in temperate climates. We report a patient with multiple myeloma who developed a giant elastic tumor on the right thigh and a hen egg-sized tumor on the right upper arm. MR imaging revealed cystic spaces in the femoral quadriceps and brachial biceps muscles. A large amount of pus with foul smell was removed by incision, drainage and aspiration of the two tumors. The lesions were successfully treated with intravenous administration of antibiotics. Repeated bacterial cultures yielded only Bacteroids fragilis. To our knowledge, this is the first report of pyomyositis due to Bacteroides fragilis. 相似文献
24.
A 62-year-old woman with diabetic triopathy developed widespread erythematous macules, numerous pustules, and a high fever after she underwent electric coagulation for vitreous hemorrhage. She was administered several drugs at that time. After discontinuation of the drugs, the eruption disappeared, and the fever returned to normal within two weeks. A positive patch test with isepamicin sulfate highly suggested that the symptoms described above were due to drug allergy. Cadralazine, which was positive in the drug lymphocyte stimulation test (DLST), could not be excluded from the causative drugs. A false-positive DLST with ofloxacin was confirmed by an accidental challenge test. To our knowledge, this is the first report of acute generalized exanthematous pustulosis due to isepamicin sulfate and/or cadralazine. 相似文献
25.
We studied choline acetyltransferase (CAT) activity in a rat model of brachial plexus injury. In experiment 1, we found that the CAT activity was remarkably high in the anterior roots and low in the posterior roots. In experiment 2, nerve root segments were extracted and examined for CAT activity in the root avulsion group (group A) and the plexus severance group (group B). CAT activity decreased day by day in group A, reaching about 1/20 of the normal 5 days postoperatively. By contrast, in group B activity decreased only slightly, and even at 90 days postoperatively was about 6,000 cpm (one-half normal level). As a result, CAT activity enabled us to distinghish postganglionic from preganglionic injury of the cervical roots. Furthermore, it was a useful adjunct for minimizing nerve loss in intercostal nerve transfer, distinguishing motor and sensory branches of the intercostal nerve, and evaluating the motor nerve activity. © 1995 Wiley-Liss, Inc. 相似文献
26.
Kazuhiro Sakata Akio Ohtaki Masaaki Aiba Susumu Ishikawa Yoshimi Otani Yasuo Morishita 《Surgery today》1997,27(1):88-89
We report herein the case of a 77-year-old man with a left ventricular tumor originating from the papillary muscle of the left ventricular wall, in whom a successful tumor resection with mitral valve replacement was performed. The pathological diagnosis of the tumor was confirmed as cardiac fibroma. His postoperative course was uneventful and he is currently well with no signs of recurrence 2 years after surgery. 相似文献
27.
Susumu Akimoto Yuzo Furuya Koichiro Akakura Jun Shimazaki Haruo Ito 《International journal of urology》1997,4(6):580-582
Background :
The aim of this study was to investigate the influence of osteoarthritis of lumbar vertebrae on serum bone formation and resorption marker levels of patients with benign prostatic hypertrophy (BPH).
Methods :
Serum levels of carboxyterminal propeptide of type I procollagen (PICP), alkaline phosphatase (ALP), carboxyterminaltelopeptide of type I collagen (ICTP), and prostate-specific antigen (PSA) were examined in 40 patients with BPH, and the presence of osteoarthritis at the lumbar vertebrae of the patients was evaluated by plain x-ray-p.
Results :
Findings of osteoarthritis were observed in 23 of the 40 patients (58%), and 10 of the patients had severe osteoarthritis (involving at least 2 lumbar vertebral bodies). The serum levels of PICP, ALP, ICTP, and PSA of the patients without osteoarthritis findings were not different from those of the patients with osteoarthritis or severe osteoarthritis.
Conclusion :
The influence of osteoarthritis on serum bone formation and resorption marker levels of patients with BPH appears to be rather slight, if there is any influence at all. 相似文献
The aim of this study was to investigate the influence of osteoarthritis of lumbar vertebrae on serum bone formation and resorption marker levels of patients with benign prostatic hypertrophy (BPH).
Methods :
Serum levels of carboxyterminal propeptide of type I procollagen (PICP), alkaline phosphatase (ALP), carboxyterminaltelopeptide of type I collagen (ICTP), and prostate-specific antigen (PSA) were examined in 40 patients with BPH, and the presence of osteoarthritis at the lumbar vertebrae of the patients was evaluated by plain x-ray-p.
Results :
Findings of osteoarthritis were observed in 23 of the 40 patients (58%), and 10 of the patients had severe osteoarthritis (involving at least 2 lumbar vertebral bodies). The serum levels of PICP, ALP, ICTP, and PSA of the patients without osteoarthritis findings were not different from those of the patients with osteoarthritis or severe osteoarthritis.
Conclusion :
The influence of osteoarthritis on serum bone formation and resorption marker levels of patients with BPH appears to be rather slight, if there is any influence at all. 相似文献
28.
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
29.
Y Ono M Sahashi H Suenaga S Ohshima 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1992,83(3):390-394
Laparoscopic surgery has been widely performed for removing the gallbladder and the pelvic lymph-nodes in recent years. We have applied laparoscopy technique to nephrectomy and here we describe our procedures and the clinical results. The patient is placed in the supine position under general anesthesia. After a 4 liter CO2 pneumoperitoneum is induced, five trocars are inserted into the abdominal cavity through the ipsilateral abdominal wall. The patient is then turned to the lateral position to displace the bowel medially. The ipsilateral colon is reflected medially after incision of the parietal peritoneum was made along the line of Todt to expose the retroperitoneum. The ureter was identified and dissected. It was secured with 4 clips (2 clips on the renal side and 2 on the distal side) and then cut with scissors. The renal vein and artery were then dissected and separately ligated with clips as described above. These vessels were also cut. The upper pole of the kidney was dissected out and the adrenal gland was left in place. The kidney thus became completely free within the abdomen. It was then grasped by the forceps through a 10 mm sheath positioned below the umbilicus. After incising the abdominal wall, the kidney was removed from the abdominal cavity with the grasping forceps and the sheath. By this procedure right nephrectomy was completely performed in a 56-year-old female patient and left nephrectomy in a 56-year-old male patient. The underlying disease was recurrent pyelonephritis secondary to renal calculi in both cases. The operative times were 221 min and 346 min, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
30.
K-ras activation and ras p21 expression in latent prostatic carcinoma in Japanese men. 总被引:11,自引:0,他引:11
Twenty-three clinically silent prostatic carcinomas discovered in Japanese men at autopsy were surveyed for ras proto-oncogene mutations by mutation-specific oligonucleotide probe hybridization after polymerase chain reaction (PCR) amplification from a section of formalin-fixed, paraffin-embedded tissue. Six of the 22 that were satisfactory amplified contained activating point mutations in codon 12 of K-ras, a significantly higher frequency than has been reported in patients with clinically advanced disease in the United States. Of the six cases with activating point mutations in codon 12 of K-ras, one had a GGT----GAT transition, four had GGT----GTT transversions, and one had both GGT----GAT and GGT----GTT mutations. Sections from the same tissues were immunohistochemically stained with an anti-ras p21 antibody. Carcinoma cells stained for ras p21 to some degree in 13 cases. Immunohistochemically detectable expression of p21 was always focal and was not necessarily associated with K-ras mutation. K-ras oncogene activation in prostatic carcinoma appears to merit additional study as a significant event in the pathogenesis of this neoplasm. 相似文献