首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   14976篇
  免费   725篇
  国内免费   89篇
耳鼻咽喉   127篇
儿科学   271篇
妇产科学   146篇
基础医学   1708篇
口腔科学   322篇
临床医学   1029篇
内科学   4421篇
皮肤病学   215篇
神经病学   949篇
特种医学   519篇
外科学   2821篇
综合类   31篇
一般理论   1篇
预防医学   281篇
眼科学   184篇
药学   928篇
中国医学   30篇
肿瘤学   1807篇
  2023年   104篇
  2022年   178篇
  2021年   386篇
  2020年   211篇
  2019年   265篇
  2018年   332篇
  2017年   263篇
  2016年   345篇
  2015年   334篇
  2014年   421篇
  2013年   536篇
  2012年   893篇
  2011年   1011篇
  2010年   585篇
  2009年   467篇
  2008年   827篇
  2007年   899篇
  2006年   849篇
  2005年   859篇
  2004年   832篇
  2003年   777篇
  2002年   766篇
  2001年   332篇
  2000年   367篇
  1999年   284篇
  1998年   175篇
  1997年   137篇
  1996年   89篇
  1995年   101篇
  1994年   101篇
  1993年   89篇
  1992年   186篇
  1991年   198篇
  1990年   163篇
  1989年   182篇
  1988年   135篇
  1987年   137篇
  1986年   156篇
  1985年   134篇
  1984年   80篇
  1983年   70篇
  1982年   47篇
  1979年   45篇
  1978年   34篇
  1977年   39篇
  1975年   31篇
  1971年   35篇
  1970年   33篇
  1969年   29篇
  1968年   35篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
We describe a case of 41-year-old Japanese man with Crohn's ileocolitis and cytomegalovirus infection, confirmed by histology of ileal ulcers. Although his colonoscopic and radiological features resembled those of intestinal tuberculosis, granulomas of typical Crohn's disease were evident on histology of biopsy specimens taken from the duodenum and colon. The lesions remain unchanged even after 1.5 years by oral administration of salazosulphapyridine 3g daily.  相似文献   
22.
Left ventricular (LV) remodeling after myocardial infarction (MI) is a maladaptive process that increases the risk of heart failure and death. The myocardial phosphoinositide cycle, which is located downstream from several neurohumoral factors, plays a crucial role in LV remodeling. Our animal studies demonstrated that 1-[1-11C]butyryl-2-palmitoyl-rac-glycerol (11C-DAG) can be used to visualize regions with an activated phosphoinositide cycle. Therefore, we examined whether myocardial 11C-DAG accumulation assessed by PET is relevant to LV enlargement and systolic dysfunction in post-MI patients. METHODS: We performed PET with 11C-DAG in 13 post-anteroseptal MI patients and 4 healthy volunteers. We placed regions of interest on the noninfarcted myocardium and calculated the myocardium-to-left atrial (LA) chamber ratio of 11C-DAG accumulation. RESULTS: The myocardium-to-LA chamber ratio of 11C-DAG was significantly higher in the post-MI patients (mean +/- SD, 1.73 +/- 0.35) compared with that of the healthy volunteers (mean +/- SD, 1.25 +/- 0.13; P < 0.05). In the post-MI patients, the myocardium-to-LA chamber ratio of (11)C-DAG was significantly correlated with the LV end-diastolic volume index (r = 0.79, P < 0.01) and the plasma concentration of brain natriuretic peptide (r = 0.85, P < 0.001) and negatively correlated with the LV ejection fraction (r = -0.69, P < 0.01). CONCLUSION: These findings suggest that the myocardial 11C-DAG accumulation assessed by PET is relevant to LV enlargement, LV systolic dysfunction, and humoral activation in post-MI patients. This new imaging strategy based on intracellular signaling may contribute to the assessment and treatment of post-MI patients.  相似文献   
23.
Isolated rupture of radial collateral ligament of the small finger DIP joint is a rare injury. We treated this lesion using a bone suture anchor with excellent results.  相似文献   
24.
Objective The objective of the present study was to compare long-term results of single aortic valve replacement (AVR) with mechanical (St. Jude Medical valves: standard) and biologic (the Carpentier-Edwards pericardial) prostheses. Method: Between 1995 and 2002, 95 patients who underwent single AVR with mechanical (n=46) or biologic (n=49) prostheses were enrolled in this study. The mean age at the operation was 54.0±9.6 years (range: 20 to 69 years) with the mechanical and 68.8±7.1 years (range: 44 to 85 years) with the biologic prosthesis. Results: The 9-year actuarial survival rate, which was calculated by taking perioperative mortality into account, was 90.3±4.6% for patients with mechanical valves and 87.6 ±4.8% for patients with bioprostheses, with no difference between the two groups (p=0.342). The 9-year freedom rate from thromboembolism, reoperation, endocarditis was 94.8+3.6%, 100% and 97.8 ±2.2% for patients with mechanical valves and 98.0 ±2.0%, 97.5 ±3.4% and 95.0 ±3.4% for those with bioprostheses, respectively. After 9 years, freedom from cardiac death averaged 97.8% in the group with mechanical valves compared with 95.3% in those with bioprostheses (p=0.541). Conclusion: We conclude that the mid-term durability of the Carpentier-Edwards pericardial valve in the aortic position for the elderly is excellent. Nevertheless, the risk of tissue valve reoperation progressively increases with time, and a longer follow-up may be necessary to provide its value compared with the mechanical valves in a country like Japan with a high life expectancy. (Jpn J Thorac Cardiovasc Surg 2005; 53:465-469)  相似文献   
25.
OBJECTIVE: To evaluate the initial results of brachytherapy for prostate cancer with permanent iodine-125 implant in Japan. METHODS: The results obtained with brachytherapy in the initial 100 Japanese patients treated at Nagano Municipal Hospital were reviewed. Patients with a prostate-specific antigen (PSA) level of less than 10 ng/mL and a Gleason's scores of 5, 6, 3 + 4 were classified as having a low risk of recurrence. Patients with a PSA level of 10-20 ng/mL and/or a Gleason's score of 4 + 3 were classified as having an intermediate risk for recurrence. Seventy-eight of the low-risk patients and 19 of the intermediate-risk patients were treated by seed implants alone, or seed implants combined with preceding external radiation, respectively. A total of 53 patients received neoadjuvant hormone therapy. The efficacy and morbidity of brachytherapy were investigated using the serum PSA, International Prostate Symptom Score, quality of life score and uroflowmetry data. RESULTS: The average V100 and D90 obtained by post-implant dosimetry was 94.3 and 113.7%, respectively. Serum PSA decreased gradually after treatment, although it had still not reached a nadir after 1 year. There was little difference of the PSA level between the patients with and without neoadjuvant hormone therapy even at 1 year after seed implantation. There were no PSA biochemical failure or clinical recurrence during the follow-up period. Voiding symptoms worsened until 3 months after treatment, and then gradually improved. Acute urinary retention occurred transiently in one patient (1%). Rectal bleeding and severe diarrhea did not occur. CONCLUSION: Brachytherapy is a feasible and effective option for the treatment of prostate cancer in Japanese men. Brachytherapy may have a different effect in Japanese patients with respect to voiding symptoms. Urinary retention was rare, but voiding symptoms were persistent in Japanese patients. Neoadjuvant hormone therapy deserves investigation to determine whether it can achieve better results, especially in patients with an intermediate risk.  相似文献   
26.
Abstract:   A 66-year-old man was referred to our hospital with chest discomfort and shortness of breath. Seven months previously he had undergone a laparoscopic left nephroureterectomy for a left renal pelvic tumor and was given two cycles of adjuvant chemotherapy (methotrexate, epirubicin and cisplatin). Echocardiogram showed an 8-mm sized mass extending from the right atrium into the right ventricle. On computed tomography, multiple lung tumors, as well as the right atrial and ventricular mass, were seen. The patient died of acute heart failure caused by right ventricular outflow obstruction. On autopsy, a right atrial and ventricular metastasis of the initial transitional cell carcinoma was found. The patient's cause of death was acute heart failure as a result of cardiac metastasis of his initial renal pelvic carcinoma.  相似文献   
27.
The current study was performed to understand the relationship between graft length placed within the bone tunnel and intraosseous graft healing in anterior cruciate ligament (ACL) reconstruction. Twenty-four adult beagle dogs were divided into two groups of 12 animals each. In each animal, ACL reconstruction using a 4-mm diameter autogenous flexor tendon graft was done in the left knee. In groups I and II, the graft having a length of 15 and 5 mm, respectively, was placed within the tibial tunnel. The proximal end of the graft was placed through the over-the-top route in all animals. In each group, five animals were sacrificed immediately after surgery, and the remaining seven were sacrificed at 6 weeks postoperatively. Biomechanical and histologic evaluations were performed. In pull out testing, the ultimate failure load and the linear stiffness of the graft-tibia complex harvested at 6 weeks were significantly greater than those harvested at the time-zero period. There were no significant differences in those parameters between groups I and II at 6 weeks. In each group, the perpendicular collagen fibers connecting the tendon to the bone tunnel wall were observed only in the narrow area located close to the intra-articular tunnel outlet. In conclusion, excessively long placement of the flexor graft within the bone tunnel does not result in an additional increase of anchoring strength and stiffness of the graft in ACL reconstruction.  相似文献   
28.
A total of 106 vascular reconstructions below the inguinal ligament including axillo-femoral and femoro-femoral bypasses were performed using 137 Dardik's human umbilical veins. The indication for surgery was limb salvage in 29%. The distal anastomosis was done with the popliteal artery above the knee in 53 cases, below the knee in 31, and with a tibial artery in 1. The axillo-femoral bypass was performed in 21 cases, and femoro-femoral bypass in 32. The accumulated graft patency rates of femoro-popliteal bypass at 1 yr./3 yrs./5 yrs. were 93%/75%/75%, those of femoro-femoral bypass were 85%/85%/85%, and those of axillo-femoral bypass were 54%/27%/27%. No special risk factor influencing patency rate was found from this study. In long term period, graft aneurysm was observed in 3 cases. It is concluded that the human umbilical vein is the graft material of choice for femoro-popliteal or femoro-femoral bypass when the saphenous vein is not available, and the careful follow-up is important because of the risk of graft aneurysm.  相似文献   
29.
Gamma seminoprotein (gamma Sm), a glycoprotein isolated from human seminal plasma with a molecular weight of 29,000 and possibly a serine protease, has been demonstrated to be one of the prostate organ-specific antigens. We established a murine monoclonal antibody (MoAb) to gamma-Sm in order to prove the presence and localization of this protein in the prostate. The hybrid clones were obtained by fusing mouse SP2/O-Ag-14 myeloma cells with splenocytes from Balb/c mouse immunized with the major fractions of gamma-Sm. The enzyme-linked immunosorbent assay was done for antibody screening. After cloning twice in soft agarose, the stable clone, termed 43-21-1-1, was finally chosen. This MoAb, IgG1(kappa), recognized gamma-Sm specifically, which was verified by an immunoblotting assay. The specificity of the MoAb was further evaluated by immunohistochemical study by the avidin biotin complex method. Periodate-lysine-paraformaldehyde-fixed surgical specimens, including the prostate associated with fibromuscular hyperplasia, seminal vesicles, bladder, testis and epididymis, were examined. Formaldehyde (10%)-fixed surgical specimens from patients with adenocarcinoma of the prostate and primary transitional cell carcinoma arising from the periurethral prostatic ducts were also examined. Positive reactions of gamma-Sm were recognized only in the cytoplasm of prostatic glandular epithelial cells and along the luminal surface. Fibrous and muscular tissues always given negative staining. Neither nonprostatic tissues nor transitional cell carcinoma of the prostate were stained positively for gamma-Sm. These results show that this MoAb (43-21-1-1) is quite specific to gamma-Sm and may be useful for the immunohistochemical study with prostatic tissue.  相似文献   
30.
Summary UFT, a combination of the masked compound of 5-fluorouracil (FT-207) and uracil, was given to head and neck cancer patients for 1 week preoperatively and for 8 weeks postoperatively. Drug concentrations were examined in the surgically removed tissues. The concentrations of FT-207, 5-fluorouracil, and uracil were higher in tumor tissues than in normal tissues. The lymphocyte subpopulations were assessed by cytofluorometry with monoclonal antibodies. There was no evidence that adjuvant chemotherapy with UFT specifically suppresses immunocompetent cells. We therefore conclude that further clinical evaluation of adjuvant chemotherapy with UFT would be worthwhile.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号