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   4987篇
  免费   334篇
  国内免费   29篇
耳鼻咽喉   37篇
儿科学   123篇
妇产科学   65篇
基础医学   780篇
口腔科学   77篇
临床医学   341篇
内科学   1324篇
皮肤病学   256篇
神经病学   332篇
特种医学   108篇
外科学   482篇
综合类   16篇
一般理论   1篇
预防医学   253篇
眼科学   147篇
药学   376篇
中国医学   15篇
肿瘤学   617篇
  2024年   5篇
  2023年   31篇
  2022年   93篇
  2021年   153篇
  2020年   102篇
  2019年   96篇
  2018年   167篇
  2017年   131篇
  2016年   156篇
  2015年   120篇
  2014年   172篇
  2013年   249篇
  2012年   362篇
  2011年   380篇
  2010年   208篇
  2009年   199篇
  2008年   354篇
  2007年   367篇
  2006年   340篇
  2005年   319篇
  2004年   323篇
  2003年   286篇
  2002年   280篇
  2001年   47篇
  2000年   37篇
  1999年   46篇
  1998年   53篇
  1997年   52篇
  1996年   33篇
  1995年   25篇
  1994年   20篇
  1993年   26篇
  1992年   19篇
  1991年   13篇
  1990年   7篇
  1989年   18篇
  1988年   11篇
  1987年   10篇
  1986年   4篇
  1985年   3篇
  1984年   6篇
  1983年   5篇
  1982年   7篇
  1981年   2篇
  1979年   2篇
  1972年   1篇
  1971年   1篇
  1955年   1篇
  1923年   4篇
  1922年   1篇
排序方式: 共有5350条查询结果,搜索用时 15 毫秒
1.
Although dose reduction of S‐1 is recommended for patients with impaired renal function, dose modification for such patients has not been prospectively evaluated. The aim of the present study was to investigate the pharmacokinetic parameters of 5‐fluorouracil, 5‐chloro‐2,4 dihydroxypyridine and oteracil potassium, and to review the recommended dose modification of S‐1 in patients with renal impairment. We classified patients receiving S‐1 into 4 groups according to their renal function, as measured using the Japanese estimated glomerular filtration rate (eGFR) equation. The daily S‐1 dose was adjusted based on the patient's eGFR and body surface area. Blood samples were collected for pharmacokinetic analysis. A total of 33 patients were enrolled and classified into 4 groups as follows: 10 patients in cohort 1 (eGFR ≥ 80 mL/min/1.73 m2), 10 patients in cohort 2 (eGFR = 50‐79 mL/min/1.73 m2), 10 patients in cohort 3 (eGFR = 30‐49 mL/min/1.73 m2), and 3 patients in cohort 4 (eGFR < 30 mL/min/1.73 m2). Those in cohorts 3 and 4 treated with an adjusted dose of S‐1 showed a similar area under the curve for 5‐fluorouracil (941.9 ± 275.6 and 1043.5 ± 224.8 ng/mL, respectively) compared with cohort 2 (1034.9 ± 414.3 ng/mL). Notably, while there was a statistically significant difference between cohort 1 (689.6 ± 208.8 ng/mL) and 2 (= 0.0474) treated with an equal dose of S‐1, there was no significant difference observed in the toxicity profiles of the cohorts. In conclusion, dose adjustment of S‐1 in patients with impaired renal function using eGFR is appropriate and safe.  相似文献   
2.
3.
4.
We report a case of a diaphragmatic hernia after a heart transplant operation. A 43-year-old woman, who underwent orthotropic heart transplantation for hypertrophic cadiomyopathy two year earlier, presented with vomiting and epigastric pain. A computed tomography scan showed that the stomach and transverse colon were dislocated in the left thoracic cavity. We diagnosed left diaphragmatic hernia incarceration and performed laparoscopic repair of the diaphragmatic hernia. A 12 × 8 cm diaphragmatic defect was found intraoperatively on the ventrolateral aspect of the left diaphragm, and the stomach with volvulus had herniated into the thorax through the defect. The hernia was considered to be iatrogenic. The diaphragmatic defect was large, and the diaphragm was thinning. We closed the defect by mesh repair. Laparoscopic mesh repair of the diaphragmatic hernia could be performed safely and with minimal invasiveness.  相似文献   
5.
6.
A 45-year-old man was referred to our department in March of 1989. Physical examination showed erythroderma, palmo-plantar hyperkeratosis, generalized lymphadenopathy, hepatosplenomegaly, and leukemic manifestation. The lymphocyte count in the peripheral blood before treatment was 1.7 × 104 cells/mm3. Atypical lymphocytes such as flower cells and lobulated cells were seen in the peripheral blood. A sample excised from a lymph node showed immunoblastic, pleomorphic T cells by a modified classification scheme of the Working Formulation. A high level of serum LDH was detected (2.1 times the upper normal limit). Anti HTLV-1 antibody was also detected in the serum. The atypical lymphocytes were positive for CD3, CD4, CD5, CD7 and HLA-DR, and negative for CD8. Thus, the clinical, pathologic and immunologic features were those of typical acute-type ATL. The patient was treated with VEPA-M for three months starting in March of 1989. Because of poor response, the patient was then treated with MACOP-B, M-FEPA, and VEPP-B for about one year from June of 1989 and has been free of disease up to the time of writing, March of 1993.  相似文献   
7.
A 57-year-old female presented with an abnormal Pap smear. Colposcopic examination of the cervix revealed white mucosa with erosion and several areas of black pigmentation. After a colposcopically directed biopsy and loop conization, radical hysterectomy and bilateral salpingo-oophorectomy with pelvic and paraaortic lymphadenectomy were performed. Pathological examination disclosed an invasive squamous cell carcinoma admixed with many dendritic melanocytes. Melanin granules were present within the melanocytes and tumor cells. Although similar tumors have been reported in other sites, this is the first report to our knowledge of a pigmented squamous cell carcinoma of the uterine cervix.  相似文献   
8.
BACKGROUND: Deposition of proteins on surfaces of medical devices has been recognized to putatively relate to the process of regulation of biomaterial-associated complications by attachment of fibrin clots, eukaryotic cells, and microbes. The molecules adsorb to a varying extent, depending not only on the physicochemical properties of the biomaterial, but also on the composition of the host fluid. OBJECTIVE: Adsorption of proteins on catheters exposed both ex vivo and in vitro to dialysate of patients on peritoneal dialysis (PD) was studied. METHODS: Peritoneal dialysis effluent was collected from 5 patients with end-stage renal disease on continuous ambulatory PD. Tenckhoff catheters were obtained from 16 patients. Deposition of proteins on excised Tenckhoff catheters and tubing of different materials exposed to PD effluent in vitro was studied using 125iodine-labeled antibodies. Adhesion of Staphylococcus aureus and Staphylococcus epidermidis strains was quantified on tubing exposed to PD effluent in vitro. RESULTS: The presence of albumin, transferrin, immunoglobulin G, fibrinogen, fibronectin, von Willebrand factor, vitronectin, and thrombospondin was determined at various concentrations in PD effluent. All proteins analyzed were detected on PD catheters removed from patients. The extent of protein deposition on Tenckhoff catheters exposed to PD effluent, in vitro, rapidly reached a plateau and remained constant, as it did on polyvinyl chloride and polyethylene tubing. Adhesion of staphylococci was enhanced on Tenckhoff catheters exposed to PD effluent compared to unused PD solution. CONCLUSIONS: The data identify surface exposed proteins that may serve as adhesion sites for microbes on peritoneal catheters indwelled in patients undergoing PD.  相似文献   
9.
Nuclear size and shape on histological specimens were used to quantify nuclear abnormality in gastric tubular tumors. A valid technique for this morphometrical analysis by image processing was developed. Furthermore, the present study examined the nuclear size and shape to determine if they were reliable criteria to be used for differential diagnosis. Nuclear area, maximum diameter and maximum width on the histological specimens were defined as factors to represent nuclear size. Nuclear aspect ratio represented nuclear shape. Histological features revealed varied degrees of condensation of nuclei; this was due to different protocols for preparing the histological specimens. This finding indicated that the size of intermediate lymphocytes on the same specimens should be measured as a control in order to estimate the degree of nuclear condensation. The present study also demonstrated that at least 200 nuclei should be measured on the histological specimens to obtain accurate nuclear size and shape. Histologically, the nuclei in benign tubular adenoma and borderline lesions tended to be spindle-shaped, while those in well-differentiated type tubular adenocarcinoma tended to be round and swollen. The nuclei in borderline lesions were larger than those in benign tubular adenoma and smaller than those in well-differentiated type tubular adenocarcinoma. Our results for the above 4 factors corresponded well with these histological findings. The nuclear size and shape on histological specimens were concluded to be reliable criteria for assessing nuclear abnormality in gastric tubular tumors and useful ones for differential diagnosis.  相似文献   
10.
Summary: Severe secondary hyperparathyroidism in chronic dialysis patients has been recently treated by supraphysiological concentration of calcitriol achieved through pulse therapy. However, there are many patients resistant to this therapy, who usually have larger parathyroid gland(s). to overcome this resistance, calcitriol was injected directly into the enlarged glands under ultrasonographic guidance. We injected 70–90% of the calculated gland volume of calcitriol solution (1 μg/mL) into the glands of 7 patients three times per week for 2 weeks. the parathyroid hormone (PTH) levels decreased significantly after 2 weeks of direct injections of calcitriol. Following a further 4 weeks of calcitriol pulse therapy, PTH levels remained suppressed and serum alkaline phosphatase activity and the volume of parathyroid glands also decreased. During the long-term follow up, five patients remained well controlled with calcitriol pulse therapy, while two patients needed ethanol injections to control hyperparathyroidism. Although we could not completely rule out a toxic effect of the vehicle, direct injection of calcitriol into parathyroid glands may be another treatment option for chronic dialysis patients. Our data further support the important role of resistance of parathyroid cells to calcitriol in the pathogenesis of parathyroid hyper function in uraemic patients.  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