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   11001篇
  免费   615篇
  国内免费   117篇
耳鼻咽喉   89篇
儿科学   210篇
妇产科学   83篇
基础医学   1276篇
口腔科学   313篇
临床医学   841篇
内科学   3126篇
皮肤病学   108篇
神经病学   757篇
特种医学   587篇
外科学   1768篇
综合类   60篇
预防医学   265篇
眼科学   133篇
药学   595篇
中国医学   31篇
肿瘤学   1491篇
  2023年   161篇
  2022年   284篇
  2021年   482篇
  2020年   245篇
  2019年   301篇
  2018年   400篇
  2017年   262篇
  2016年   295篇
  2015年   271篇
  2014年   392篇
  2013年   425篇
  2012年   718篇
  2011年   764篇
  2010年   431篇
  2009年   357篇
  2008年   615篇
  2007年   618篇
  2006年   574篇
  2005年   556篇
  2004年   543篇
  2003年   527篇
  2002年   466篇
  2001年   171篇
  2000年   176篇
  1999年   151篇
  1998年   134篇
  1997年   117篇
  1996年   108篇
  1995年   63篇
  1994年   59篇
  1993年   68篇
  1992年   94篇
  1991年   86篇
  1990年   97篇
  1989年   78篇
  1988年   60篇
  1987年   68篇
  1986年   53篇
  1985年   42篇
  1984年   47篇
  1983年   29篇
  1979年   27篇
  1978年   20篇
  1977年   19篇
  1976年   23篇
  1974年   21篇
  1972年   26篇
  1969年   20篇
  1968年   25篇
  1967年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Background Although extrahepatic metastasis occurs rarely after hepatic resection for hepatocellular carcinoma (HCC), the prognosis of these patients is extremely poor. Predictors of extrahepatic metastasis have not been fully investigated. Methods To identify predictors of extrahepatic metastasis after resection, we retrospectively investigated 77 patients with HCC tumors >50 mm in diameter who underwent hepatic resection. We investigated correlations between postoperative extrahepatic metastasis and clinicopathologic factors as well as extrahepatic metastasis-free survival rate by log rank test and predictors of extrahepatic metastasis by univariate and multivariate logistic regression models. Results Hepatitis B surface antigen (HBs-Ag) was found in 25 (32.5%) of 77 patients, and extrahepatic metastasis occurred in 26 (33.8%). Patients with extrahepatic metastasis showed better liver function and a high occurrence of HBs-Ag positivity than those without. The 5-year extrahepatic metastasis-free survival rate was worse in patients with HBs-Ag positivity, larger tumors (≥70 mm), higher alfa-fetoprotein level (≥300 ng/mL), and lower indocyanine green retention rate at 15 minutes (ICGR15) (<15%) than in those without. By univariate logistic regression analysis, HBs-Ag positivity, larger HCC tumor (≥70 mm), lower ICGR15 (<15%), and lower preoperative lymphocyte count (<1000/mm3) were predictors of extrahepatic metastasis (P < .1). By multivariate analysis, HBs-Ag positivity was an independent predictor of postoperative extrahepatic metastasis (P = .04). Conclusions In patients positive for HBs-Ag, radiologic examination of extrahepatic organs should be performed as a part of the postoperative surveillance. Hepatitis B virus infection may promote establishment of extrahepatic metastasis.  相似文献   
72.
We evaluated a 39-year-old pregnant woman with right temporal lobe epilepsy. During the second trimester, seizure deterioration was responsive to an increased daily dose of levetiracetam (LEV). However, immediately after delivery, new non-habitual seizures emerged along with a sharply increased LEV concentration. The frequency of habitual seizures also slightly increased. The non-habitual seizures completely disappeared, and the frequency of the habitual seizures improved to the baseline level after the LEV dosage was reduced. Thus, a paradoxical effect of an increased LEV blood concentration was assumed to be a potential cause of these events. Peripartum pharmacokinetic fluctuations in LEV levels should be monitored carefully.  相似文献   
73.
A 64-year-old Japanese man who worked at a butcher shop was hospitalized for a fever, headache, and deafness. We diagnosed him with sepsis and meningitis caused by Streptococcus suis infection. The patient''s renal function declined rapidly, and hemodialysis was performed temporarily. A renal biopsy was performed, and the renal function tended to improve with antimicrobial therapy. This case seemed rather similar to one of staphylococcal-associated nephritis in that it showed mesangial proliferative nephritis with immunoglobulin A deposition, even though the nephritis was caused by streptococci. Similarly, intramembranous electron-dense deposits were characteristic findings. We present new findings of an in vivo renal biopsy in a case of S. suis-associated glomerulonephritis.  相似文献   
74.
75.

Purpose  

The purpose of this retrospective study was to investigate the efficacy of transarterial chemoembolization (TACE) using cisplatin as a second-line treatment for advanced hepatocellular carcinoma (HCC) unresponsive to TACE using epirubicin–Lipiodol emulsion at our institution.  相似文献   
76.
Background: It has been reported that cystine and theanine, amino acids related to glutathione synthesis, have immunomodulatory effects, such as suppressing inflammation after strenuous exercise. In this study, we examined the effects of oral administration of cystine and theanine during the perioperative period as a pilot study. Methods: Forty‐three cases of distal gastrectomy for cancer conducted in our department were assigned to the cystine and theanine group (CT group) or to the placebo control group (P group), and a randomized, single‐blind, parallel‐group study was then performed. Cystine (700 mg) and theanine (280 mg) or a placebo was administered to participants for 10 continuous days (4 days before to 5 days after surgery). Changes in pre‐ and postoperative interleukin (IL)–6, C‐reactive protein (CRP), albumin, white blood cell (WBC) count, neutrophil count, total lymphocyte count, resting energy expenditure (REE), and body temperature were compared and examined. Results: Ten patients were excluded, leaving 33 patients in the study. The CT group had significantly lower IL‐6 values (postoperative day [POD] 4), CRP levels (POD 7), neutrophil counts (POD 4), and body temperatures (POD 5) than the P group (P < .05). In addition, REE in the P group peaked on day 1 (1.14 ± 0.16 [pre‐ and postoperative ratio]), whereas the CT group did not show any increase on POD 1 (0.99 ± 0.21, P < .05 vs P group). Conclusions: This study suggests that oral administration of cystine and theanine during the perioperative period may alleviate postgastrectomy inflammation and promote recovery after surgery.  相似文献   
77.
Depletion of plasma methionine is expected to inhibit or reverse growth of methionine‐dependent tumors; however, modulation of methionine and other sulfur amino acids is not a trivial task in experimental animals. l‐Methioninase from Pseudomonas putida at 1,000 U/kg causes acute reduction of plasma methionine by 80% in mice, but recovery occurs within 14 hours. Restriction of dietary choline and replacement of dietary methionine with homocystine results in 50% chronic reduction of plasma methionine. A >70% reduction can be accomplished with a diet deficient in methionine, homocystine, and choline, but ultimately this diet is lethal. Plasma methionine can be lowered to a steady state of <5 μM in mice with a combination of dietary restriction of methionine, homocysteine, and choline and synchronous treatments with intraperitoneal injections of 1,000 U/kg L‐methioninase and 25–50 mg/kg homocystine, each administered at 12‐hour intervals. Modulation of plasma methionine by this means causes no weight loss or pathologies in liver or pancreas, and it does not markedly alter levels of cysteine, homocysteine, or glutathione in plasma or in hepatic tissue. When this procedure is applied to athymic mice bearing human medulloblastoma (Daoy) tumors subcutaneously, tumor growth is inhibited. Methionine deprivation arrests mitosis by blocking the cell cycle in G2 and induces apoptosis. Tumor stasis was achieved in 100% of treated animals within 4 days of treatment, and regression was seen in one‐third of animals after a 10‐day period. These data strongly support the use of methionine‐depleting regimens for tumor treatments.  相似文献   
78.
Purpose: To ascertain the views of families living with TBI patients about the nature of the problems experienced as a result of TBI, and to compare the views of Japanese family members (J-FM) and British family members (B-FM) in order to find out whether there were cultural differences in family response to TBI. Methods: Family members involved in providing care were identified by the patients. Face to face interviews were conducted with all 18 carers in B-FM and four carers in J-FM. The remaining eight carers in J-FM participated in the postal questionnaire. Questionnaires were developed to explore the nature of problems and the involvement of family such as social embarrassment. Results: Problems arising in families were almost the same reported from both groups. However families in B-FM were likely to know more about how to cope with these problems. Family members in J-FM reported more statistically significant increases in social embarrassment than those in B-FM. Conclusion: The preliminary results showed that family members living with TBI patients in both groups had experienced problems. Appropriate rehabilitation services should be developed to help families as well as TBI patients in Japan.  相似文献   
79.
80.
We present a 44-year-old woman in whom a bronchialto-coronary artery communication via the conus branch was discovered after distal bronchial artery embolization with gelatin sponge for hemoptysis. If this bronchial-to-coronary artery anastomosis, not visible prior to embolization, had been inadvertently embolized, the patient could have developed a myocardial infarction. To reduce the likelihood of a serious complication, the possibility of this anastomosis should be kept in mind and angiography should be repeated before attempting proximal bronchial artery embolization.  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