全文获取类型
收费全文 | 17896篇 |
免费 | 979篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 134篇 |
儿科学 | 420篇 |
妇产科学 | 257篇 |
基础医学 | 2242篇 |
口腔科学 | 470篇 |
临床医学 | 1250篇 |
内科学 | 4318篇 |
皮肤病学 | 860篇 |
神经病学 | 1293篇 |
特种医学 | 435篇 |
外科学 | 3182篇 |
综合类 | 68篇 |
一般理论 | 1篇 |
预防医学 | 480篇 |
眼科学 | 487篇 |
药学 | 1148篇 |
中国医学 | 46篇 |
肿瘤学 | 1860篇 |
出版年
2023年 | 73篇 |
2022年 | 188篇 |
2021年 | 313篇 |
2020年 | 171篇 |
2019年 | 234篇 |
2018年 | 321篇 |
2017年 | 273篇 |
2016年 | 327篇 |
2015年 | 303篇 |
2014年 | 430篇 |
2013年 | 478篇 |
2012年 | 750篇 |
2011年 | 775篇 |
2010年 | 544篇 |
2009年 | 440篇 |
2008年 | 748篇 |
2007年 | 809篇 |
2006年 | 880篇 |
2005年 | 904篇 |
2004年 | 821篇 |
2003年 | 811篇 |
2002年 | 799篇 |
2001年 | 680篇 |
2000年 | 686篇 |
1999年 | 646篇 |
1998年 | 206篇 |
1997年 | 149篇 |
1996年 | 171篇 |
1995年 | 138篇 |
1994年 | 98篇 |
1993年 | 113篇 |
1992年 | 420篇 |
1991年 | 361篇 |
1990年 | 385篇 |
1989年 | 402篇 |
1988年 | 362篇 |
1987年 | 326篇 |
1986年 | 325篇 |
1985年 | 275篇 |
1984年 | 217篇 |
1983年 | 163篇 |
1982年 | 70篇 |
1979年 | 147篇 |
1978年 | 103篇 |
1977年 | 106篇 |
1974年 | 105篇 |
1973年 | 82篇 |
1972年 | 95篇 |
1971年 | 84篇 |
1970年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
We have investigated DNA synthesis in hepatocytes after orthotopic liver transplantation in four rat combinations--DA into DA (isogeneic), DA into PVG (allogeneic, nonrejector), DA into BN (allogeneic, rejector), and DA into (BN X PVG)F1 (allogeneic, intermediate nonrejector). The methods used were assay of thymidine kinase activity in graft homogenate and staining of hepatocytes in liver sections by an antibromodeoxyuridine monoclonal antibody. Both demonstrated increased DNA synthesis in grafts in all combinations except isogeneic, and showed that its intensity and timing paralleled the occurrence of the rejection reaction. The significance of hepatocyte regeneration after liver grafting is discussed. 相似文献
92.
S Kobayashi M Miyazaki O Miyagi M Yodonawa S Shimizu 《No shinkei geka. Neurological surgery》1990,18(11):1065-1070
A 6-year-old boy was sent to us due to basal meningoencephalocele detected by MRI. He had had a past history of strabismus and morning glory syndrome since 6 months of age, as well as hypopituitary dwarfism since he was 3 years old. On admission, physical examination revealed hypertelorism and left coloboma. Laryngoscopic examination revealed a round mass covered by normal nasal mucose in the midline of the tegmen of the choana. X-ray tomogram and CT scan demonstrated an isodense mass protruding into the nasopharyngeal cavity through a bony defect of the sella turcica. Right carotid angiogram showed stenosis of the right internal carotid artery and abnormal fine vessels in the basal ganglia similar to basal Moyamoya network. There was an irregular filling of the right anterior cerebral artery. Left carotid angiogram showed an irregular filling of the left middle cerebral artery. MRI showed an anterior part of the third ventricle descending into, and the meningocele protruding into the nasopharyngeal cavity. It also showed a stalk extending from the hypothalamus into the meningocele, but the pituitary gland was not recognized. The meningocele was of the same signal intensity as CSF in both T1 and T2 weighted images. Growth hormone deficiency was confirmed by radioimmunoassay of the peripheral blood. An operation was scheduled transcranial to prevent snoring during sleep at age 9. The stalk was observed behind the chiasm during the operation, but a radical operation was not performed because of a possibility of postoperative hypothalamic-pituitary dysfunction. Transsphenoidal encephalocele is rare. So far as we could see, only 30 cases have been reported.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
93.
H Shimizu S Seki A Mizuguchi H Tsuchida H Watanabe A Namiki 《Masui. The Japanese journal of anesthesiology》1990,39(4):508-512
The cardiac output monitoring by impedance cardiography, NCCOM3, was evaluated in adult patients (n = 12) who were subjected to coronary artery bypass grafting. Values of cardiac output measured by impedance cardiography were compared to those by the thermodilution method. Changes of base impedance level used as an index of thoracic fluid volume were also investigated before and after cardiopulmonary bypass (CPB). Correlation coefficient (r) of the values obtained by thermodilution with impedance cardiography was 0.79 and the mean difference was 1.29 +/- 16.9 (SD)% during induction of anesthesia. During the operation, r was 0.83 and the mean difference was -14.6 +/- 18.7%. The measurement by impedance cardiography could be carried out through the operation except when electro-cautery was used. Base impedance level before CPB was significantly lower as compared with that after CPB. There was a negative correlation between the base impedance level and central venous pressure (CVP). No patients showed any signs suggesting lung edema and all the values of CVP, pulmonary artery pressure and blood gas analysis were within normal ranges. From the result of this study, it was concluded that cardiac output monitoring by impedance cardiography was useful in cardiac surgery, but further detailed examinations will be necessary on the relationship between the numerical values of base impedance and the clinical state of the patients. 相似文献
94.
H Sudo T Shimizu H Fukushima M Ishikawa S Ishimaru K Furukawa 《[Zasshi] [Journal]. Nihon Kyōbu Geka Gakkai》1992,40(1):96-101
A 65-year-old man was referred to our hospital because of fever and abnormal shadow in the left lung. An aortogram revealed a large artery arising from the descending aorta supplying the left basal segment and, which then flowed into the pulmonary vein. This artery had an aneurysm and 30 mm in diameter. Bronchography showed compression of the left basal branch. A clinical diagnosis of an aberrant left pulmonary basal aneurysm arising from descending aorta was made, and left lower lobectomy was performed, because of the danger apprehension of the aneurysmal rupture. The procedure was successful. There are only 15 case reports of a systemic artery supplying the lung with normal bronchial branch in Japan. Differences of this anomaly from pulmonary sequestration were discussed. 相似文献
95.
Shiro Saito Makoto Hata Ryuichi Fukuyama Kosuke Sakai Jun Kudoh Hiroshi Tazaki Nobuyoshi Shimizu 《International journal of urology》1997,4(2):178-185
Background Mutation converts the H-ras gene into an activated oncogene in about 10% of human bladder cancers. Codons 12 and 61 are the major "hot spots" for activation. A simple and accurate method to detect point mutations in these codons may be clinically useful for early diagnosis of bladder cancer.
Methods Bladder cancer samples from 50 patients, plus 10 samples of normal bladder mucosa, were analyzed for possible point mutation of the H-ras gene at either codon 12 or codon 61. The H-ras gene DNA segments that include these 2 codons were amplified by PCR methods, then the possible presence of a point mutation was evaluated at each codon by susceptibility of the respective DNA segments to digestion with the restriction enzyme and by dot blot hybridization assay. A bladder cancer patient who had an H-ras gene mutation was examined to see whether the mutation was also detectable in the cells released in the urine.
Results Definite or possible point mutations were found in 6 (1 2%) out of 50 bladder cancer patients, while no mutation was detected in normal mucosa. A point mutation could also be detected in cells isolated from the patient's urine sample.
Conclusion The prevalence of point mutations at codon 1 2 or codon 61 of the H-ras gene found in this study was similar to that previously estimated for human bladder cancer by DNA transfection assay. The method we have used for detecting point mutations of the H-ras gene provides a simple and highly accurate way to detect mutated cancer cells even in the urine. It may be clinically usable for early diagnosis of bladder cancer. 相似文献
Methods Bladder cancer samples from 50 patients, plus 10 samples of normal bladder mucosa, were analyzed for possible point mutation of the H-ras gene at either codon 12 or codon 61. The H-ras gene DNA segments that include these 2 codons were amplified by PCR methods, then the possible presence of a point mutation was evaluated at each codon by susceptibility of the respective DNA segments to digestion with the restriction enzyme and by dot blot hybridization assay. A bladder cancer patient who had an H-ras gene mutation was examined to see whether the mutation was also detectable in the cells released in the urine.
Results Definite or possible point mutations were found in 6 (1 2%) out of 50 bladder cancer patients, while no mutation was detected in normal mucosa. A point mutation could also be detected in cells isolated from the patient's urine sample.
Conclusion The prevalence of point mutations at codon 1 2 or codon 61 of the H-ras gene found in this study was similar to that previously estimated for human bladder cancer by DNA transfection assay. The method we have used for detecting point mutations of the H-ras gene provides a simple and highly accurate way to detect mutated cancer cells even in the urine. It may be clinically usable for early diagnosis of bladder cancer. 相似文献
96.
97.
Chiari pelvic osteotomy for osteoarthritis. The influence of the torn and detached acetabular labrum 总被引:2,自引:0,他引:2
T Nishina S Saito K Ohzono N Shimizu T Hosoya K Ono 《The Journal of bone and joint surgery. British volume》1990,72(5):765-769
We assessed the results of Chiari pelvic osteotomy in 64 hips with early osteoarthritis in terms of acetabular labral detachment detected pre-operatively by arthrography. At an average follow-up of four years, assessment by the Merle d'Aubigńe score showed 83% excellent or good results. These satisfactory results were achieved in only half the cases with a detached labrum, but in nearly all cases with normal or torn acetabular labra. Other factors such as the acetabular index, the level and angle of osteotomy, and the displacement following osteotomy did not affect the results. Chiari pelvic osteotomy is a worthwhile procedure for early osteoarthritis in selected cases, but a detached acetabular labrum increases the risk of clinical failure. 相似文献
98.
Seiitsu Ono Takashi Imai Shigeru Munakata Keiichi Takahashi Fumio Kanda Kazuki Hashimoto Takahiko Yamano Natsue Shimizu Koichi Nagao Mitsuo Yamauchi 《Journal of the neurological sciences》1998,160(2):565-147
During the last 10 years, we have demonstrated morphological and biochemical abnormalities of skin extracellular matrices in amyotrophic lateral sclerosis (ALS). However, currently little is known concerning collagen of the spinal cord in ALS. We measured the amount of collagen and characterized collagen at light and electron microscopic levels in posterior funiculus, posterior half of lateral funiculus and anterior horn of cervical enlargement of the spinal cord obtained from ten patients with ALS, 11 patients with other neurologic diseases (control group A), and ten patients without neurologic ones (control group B). In posterior half of lateral funiculus and anterior horn, (1) by light microscopy, there was no significant difference in vessel wall area between ALS patients and control groups A and B; (2) ultrastructurally, collagen bundles were more fragmented and widely separated, and the fibrils were randomly oriented in the perivascular space of capillaries in ALS patients, which were not observed in any areas of control groups or in posterior funiculus of ALS patients; and (3) the collagen contents in ALS were significantly lower (P<0.001 and P<0.001, respectively) than those in control groups A and B. Fragmented and widely separated collagen bundles in the interstitial tissue surrounding capillaries and markedly decreased amount of collagen in posterior half of lateral funiculus and in anterior horn of ALS could be related to the degeneration of the upper and lower motor neurons in the spinal cord in ALS, that is, selective neuronal vulnerability in ALS. 相似文献
99.
Yoko Matsumura Hiromi Kurosawa Kiyozo Morita Koji Nomura Shogo Shimizu Akira Tatara 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2002,50(4):173-177
Optimal initial palliation and a subsequent staged approach is mandatory for high-risk Fontan candidates. We describe the case of mitral atresia with severe tricuspid regurgitation and pulmonary hypertension successfully managed by repeated palliation from the neonatal period and 2-stage Fontan surgery. A 1-month-old boy diagnosed with mitral atresia and double-outlet right ventricle underwent pulmonary artery banding at 1 month of age, followed by repeated pulmonary artery banding accompanied by tricuspid annuloplasty and atrial septal defect enlargement at 6 months. Because of the presence of pulmonary artery distortion, right ventricular dysfunction, and borderline pulmonary vascular resistance, a hemi-Fontan procedure was conducted with extended pulmonary artery plasty when the boy was 3 years and 8 months old. Cardiac catheterization done 3 months after showed improvement in risk factors, and the final Fontan operation (total cavopulmonary connection) was successfully done in conjunction with repeated tricuspid annuloplasty when the boy was 4 years and 5 months old. The patient remains in excellent clinical condition at the last follow-up 5 years after the final Fontan procedure with sinus rhythm and good ventricular function. 相似文献
100.