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   3412篇
  免费   153篇
  国内免费   19篇
耳鼻咽喉   12篇
儿科学   87篇
妇产科学   33篇
基础医学   504篇
口腔科学   93篇
临床医学   207篇
内科学   708篇
皮肤病学   138篇
神经病学   184篇
特种医学   71篇
外科学   718篇
综合类   25篇
预防医学   62篇
眼科学   171篇
药学   161篇
中国医学   3篇
肿瘤学   407篇
  2024年   5篇
  2023年   31篇
  2022年   65篇
  2021年   94篇
  2020年   42篇
  2019年   62篇
  2018年   72篇
  2017年   54篇
  2016年   69篇
  2015年   67篇
  2014年   119篇
  2013年   160篇
  2012年   220篇
  2011年   221篇
  2010年   124篇
  2009年   114篇
  2008年   167篇
  2007年   179篇
  2006年   205篇
  2005年   194篇
  2004年   253篇
  2003年   192篇
  2002年   213篇
  2001年   49篇
  2000年   52篇
  1999年   65篇
  1998年   51篇
  1997年   41篇
  1996年   39篇
  1995年   41篇
  1994年   37篇
  1993年   25篇
  1992年   33篇
  1991年   30篇
  1990年   22篇
  1989年   17篇
  1988年   20篇
  1987年   8篇
  1986年   13篇
  1985年   12篇
  1984年   10篇
  1983年   10篇
  1982年   7篇
  1981年   6篇
  1979年   9篇
  1978年   10篇
  1975年   6篇
  1974年   7篇
  1971年   7篇
  1970年   12篇
排序方式: 共有3584条查询结果,搜索用时 31 毫秒
21.
Summary An intravenous injection of 40 or 65 mg/kg streptozotocin induced not only diabetes but also severe hypertension in rats. Whereas the hyperglycemia developed fully within a few days after the injection of streptozotocin, the hypertension progressively advanced and reached maximum level several weeks after the treatment and lasted more than 20 weeks. Twenty mg/kg streptozotocin did not induce hyperglycemia but significantly increased blood pressure several weeks after the treatment. Arrest of growth, polyuria, glycosuria, hyperlipemia and lenticular cataracts developed in the animals treated with 40 or 65 mg/kg streptozotocin, but in none of the animals treated with 20 mg/kg. In histological examinations in the 24th week after the treatment, degranulation and necrosis in the pancreatic -cells, and vacuolization and deposition of PAS-positive materials in the renal proximal tubules were found in the animals treated with 40 or 65 mg/kg streptozotocin.  相似文献   
22.
The purposes of this study were to analyze the relationship between retroperitoneal lymph node (RLN) metastasis and clinical and pathologic risk factors in endometrial cancers, and to clarify the correlation between RLN metastasis and survival of patients with the disease. This analysis included 63 patients with endometrial cancer who underwent simultaneous pelvic lymph node (PLN) and paraaortic lymph node (PAN) dissection between April 1988 and December 1995. Patients with stage Ia grade 1 and stage IV disease were excluded from this analysis. Both PLN and PAN metastases were found in 10.0% (4/40) of patients with stage I (FIGO, 1988) disease. Of 14 cases with PLN metastases, 8 (57.1%) had PAN metastases simultaneously, whereas 4 (8.2%) of 49 cases without PLN metastases had PAN metastases. There was no significant relationship between the sites or numbers of positive PLN and PAN metastases. Multivariate analysis revealed that poor grade and deep myometrial invasion had an independent relationship with PAN metastases, whereas vascular space invasion and cervical invasion were independently associated with PLN metastases. When divided into the groups of stage I–II and stage III, the prognosis of patients with RLN metastases was significantly poorer than that of patients without RLN metastases in each stage. Furthermore, survival of patients with PAN metastases was significantly worse compared with that of patients with only PLN metastases (44.4 and 80.0%, respectively,P< 0.05). These results reveal that PLN and PAN metastases occur frequently even in early-stage endometrial cancer, and that RLN metastases, especially PAN metastases, have a serious impact on patient survival. In conclusion, systemically simultaneous pelvic and paraaortic lymphadenectomy is essential for all the patients with endometrial cancer except those with stage Ia grade 1 and stage IV to provide prognostic information and select suitable postoperative treatment as well as to perform accurate FIGO staging, provided the condition of the patient permits.  相似文献   
23.
Background Japanese surgeons have to macroscopically assess nodal metastasis from colon cancer according to the general rules established in Japan. Adjuvant therapy is sometimes started after macroscopic assessment of nodal metastasis. Macroscopic assessment, however, is difficult in many cases. Methods We evaluated the reliability of macroscopic assessment of nodal metastasis in colon cancer by (1) comparing the number of nodes picked up macroscopically with that of nodes recognized microscopically, and (2) by comparing the number of metastatic nodes found between macroscopic and microscopic examination. Results The number of nodes found during macroscopic examination was equal to that found in microscopic examination in only 52 of 206 cases (25%). Although 120 of 206 cases (58%) were judged macroscopically to have metastatic nodes, 61 had no metastatic nodes found microscopically. Sensitivity and specificity for the recognition of cases with nodal metastasis was 85.5% and 55.5%, respectively. The number of metastatic nodes in macroscopic examination was equal to that in microscopic examination in 90 cases (44%). Conclusion Because macroscopic assessment of nodal metastasis is not reliable, physicians should not rely on macroscopic assessment to indicate the need for further therapy, such as adjuvant chemotherapy. The recommendation for macroscopic assessment of nodal metastasis should be eliminated from the general rules in Japan.  相似文献   
24.
To elucidate the early events of blood-borne metastasis under actual blood flow, real-time trafficking of RAW117 large cell lymphoma cells, namely parental RAW117-P and liver-metastatic RAW117-H10 cells, was investigated using positron emission tomography (PET). Both types of cells accumulated in the liver immediately after injection via the portal vein, and were eliminated from the liver time-dependently. The elimination rate of RAW117-H10 cells, however, was slower than that of RAW117-P cells, suggesting that RAW117-H10 cells interact more strongly with hepatic sinusoidal endothelium than the parental cells. This result correlated with the metastatic potential of these cells: RAW117-H10 cells metastasized in the liver to a greater extent than RAW117-P cells after injection via this route. To investigate the role of sialylglycoconjugates in the interaction of RAW117-H10 cells with the hepatic endothelium after injection via the portal vein, the trafficking of RAW117-H10 cells was examined after the cells had been treated with sialidase. The elimination rate of RAW117-H10 cells from liver was observed to be greatly accelerated by sialidase treatment. To elucidate what kind of sialylglycoconjugates is related to this phenomenon, we analyzed the distribution of sialyl Lewis A and sialyl Lewis X antigens of both sublines of RAW117 by using flow cytometry. RAW117-H10 cells were found to express a much higher level of sialyl Lewis A than RAW117-P cells, whereas the amount of sialyl Lewis X did not differ significantly. These findings suggest that some sialylglycoconjugates, perhaps sialyl Lewis A in particular, play an important role in the initial interaction of RAW117-H10 cells with the hepatic endothelium, leading to metastasis.  相似文献   
25.
The biologic properties of adenomyosis and the effects of therapeutic agents on adenomyosis were evaluated with immunohistochemistry, terminal deoxy-nucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method, transmission electron microscopy, and analysis of genomic abnormality. In the adenomyotic endometrium, estrogen receptor (ER) expression was more intense than in the eutopic endometrium during the secretory phase, and bcl-2 was constantly expressed throughout the menstrual cycle. The expression of ER and bcl-2 was weaker in the adenomyotic endometrium treated with danazol than in that treated with gonadotro-pin-releasing hormone agonist (GnRHa), whereas bcl-2 phosphorylated on serine-87 was more intensely expressed in danazol-treated adenomyotic endometrium than in the GnRHa-treated one. The number of TUNEL-positive cells increased in the adenomyotic endometrium treated with danazol or GnRHa. Ultrastructurally, most of the adenomyotic endometrial cells treated with danazol underwent postapoptotic necrosis and formed a cluster of dead cells. In contrast, cells treated with GnRHa underwent typical apoptosis and were sparsely distributed in the adenomyotic endometrium. Analysis of several cancer-related genes showed no microsatellite instability or loss of heterozygosity in adenomyotic tissues. Therefore, we conclude that the occurrence of adenomyosis is correlated to bcl-2 expression regulated by estrogen and ER rather than genetic mutation.  相似文献   
26.
Tobacco smoke exposure is known to lower serum 25-hydroxyvitamin D (25(OH)D) concentrations. This study evaluated the association between passive smoking and vitamin D deficiency (VDD) in young children using data from the Japan Environment and Children’s Study (JECS), the largest birth cohort study in Japan. Information on parental smoking status was extracted from a survey of JECS for children aged 1.5 years and data for serum 25(OH)D concentrations were obtained from blood tests in the Sub-Cohort Study of JECS performed at age 2 years. Logistic regression and linear models were fitted to evaluate the association between these variables. Data were analyzed for 4593 children. After adjusting for covariates, smoke exposure was significantly associated with increased incidence of VDD (OR 1.35; 95% CI, 1.14–1.59) according to the logistic model. The linear model indicated that passive smoking negatively predicted de-seasonalized serum 25(OH)D concentrations (β −0.5; 95% CI −0.95 to −0.08) in children aged 2 years. The results suggest that smoke exposure is a risk factor for VDD in children. Given that VD plays a crucial role in bone metabolism and the immune system, our findings are significant for clinical and public health.  相似文献   
27.
Older people with chronic pain are at higher risk of developing sarcopenia. Central sensitization (CS) has been implicated in chronic pain among community-dwelling older adults. However, a relationship between CS and chronic pain with sarcopenia has not been established. This cross-sectional study aimed to clarify the relationship between chronic pain with sarcopenia or presarcopenia and CS among community-dwelling older adults. We assessed chronic pain and sarcopenia in 104 older adults participating in community health checks. We defined sarcopenia using the Asian Working Group for Sarcopenia (AWGS) consensus recommendations based on the following outcomes: low muscle mass, low muscle strength, and slow gait speed. Pain-related assessments included pain intensity, the Pain Catastrophizing Scale, the CS Inventory-9, the pressure pain threshold, the Tampa Scale of Kinesiophobia-11, and the EuroQol 5-dimension 5-level (EQ5D-5L). Chronic pain was defined by related symptoms within the month prior to the health check that had continued for ≥ 3 months and corresponded to a numerical rating scale score of ≥ 1 at the site of maximum pain. The prevalence of chronic pain was 43.3%. In addition, the prevalence of chronic pain with sarcopenia or presarcopenia was 29.8%. A logistic regression analysis revealed that the pressure pain threshold (odds ratio: 0.82, 95% CI: 0.95–1.02) and the EQ5D-5L (odds ratio: 0.58, 95% CI: 0.36–0.76) were significantly associated with the presence of chronic pain with sarcopenia or presarcopenia. Chronic pain with sarcopenia or presarcopenia was affected by central sensitization. Therefore, CS should be evaluated in the elderly.  相似文献   
28.
Cryopyrin-associated periodic syndrome (CAPS) is a spectrum of systemic autoinflammatory disorders in which the majority of patients have mutations in the cold-induced autoinflammatory syndrome (CIAS)1 gene. Despite having indistinguishable clinical features, some patients lack CIAS1 mutations by conventional nucleotide sequencing. We recently reported a CAPS patient with mosaicism of mutant CIAS1, and raised the possibility that CIAS1 mutations were overlooked in "mutation-negative" patients, due to a low frequency of mosaicism. To determine whether there were latent mutant cells in "mutation-negative" patients, we sought to identify mutation-associated biologic phenotypes of patients' monocytes. We found that lipopolysaccharide selectively induced necrosis-like cell death in monocytes bearing CIAS1 mutations. Monocyte death correlated with CIAS1 up-regulation, was dependent on cathepsin B, and was independent of caspase-1. Cell death was intrinsic to CIAS1-mutated monocytes, was not mediated by the inflammatory milieu, and was independent of disease severity or anti-IL-1 therapy. By collecting dying monocytes after lipopolysaccharide treatment, we succeeded in enriching CIAS1-mutant monocytes and identifying low-level CIAS1-mosaicism in 3 of 4 "mutation-negative" CAPS patients. Our findings reveal a novel effect of CIAS1 mutations in promoting necrosis-like cell death, and demonstrate that CIAS1 mosaicism plays an important role in mutation-negative CAPS patients.  相似文献   
29.
BACKGROUND: Decompensated hepatitis C virus (HCV)-related cirrhosis is the main indication for liver transplantation. We report the first successful living-related liver transplantation in a 49-year-old hemophilia A patient with end-stage HCV-related cirrhosis using a graft obtained from his 20-year-old daughter, an obligate carrier. METHODS: The donor's autologous fresh-frozen plasma rich in factor VIII (FVIII) by treatment with 1-deamino-8-D-arginine vasopressin was prepared before the operation. At induction, 1-deamino-8-D-arginine vasopressin was given to the donor to increase plasma FVIII level. In addition, autologous fresh-frozen plasma containing high FVIII concentrate was infused intraoperatively. The right lobe was harvested from the donor and transplanted orthotopically. The recipient was treated postoperatively with recombinant FVIII and immunosuppressive agents. RESULTS: The donor did not receive recombinant FVIII or allogenic blood during perioperative periods. No bleeding was encountered in the donor perioperatively. The recipient showed a steady increase in FVIII activity postoperatively and was discharged 40 days after transplantation. Ribavirin and interferon-alpha were provided for 3 months postoperatively to prevent potential recurrence of HCV infection. Serum HCV-RNA by RT-PCR became negative after such treatment. CONCLUSIONS: End-stage liver disease in patients with hemophilia A can be an indication for living-related liver transplantation. Furthermore, a graft from a living-related donor with hemophilia A carrier seems to be suitable provided such individuals receive adequate support for coagulopathies.  相似文献   
30.
PURPOSE: The incidence of testicular cancer is rare. However, it is a significant cancer in that it develops not only in old age but also in children and younger age. We investigated the epidemiological characteristics of testicular cancer in Japan, in order to elucidate its features and problems. PATIENTS AND METHODS: We surveyed hospitals and clinics in and around Gunma prefecture that treated patients with urologic diseases and reviewed the pathology records from 1985 to 1994, and calculated the annual age-adjusted incidence rates of testicular cancer. Incidence rates in Japan were taken from the estimates made by 'The Research Group for Population-based Cancer Registration in Japan'. The annual number of deaths, annual age-adjusted death rates from 1947 and 1998, the age-specific death rates and decrease rate of them, and the prefectural standardized mortality ratio (SMR) from 1973 and 1998 was calculated from the data reported by Ohno et al. and statistical tables kept in 'Statistics and Information Department, Minister's Secretariat, Ministry of Health and Welfare'. RESULTS: In Gunma Prefecture, the annual age-adjusted incidence rates tended to increase. In estimated data of national survey, it slightly increased from 1975-79 to 1980-84, and remained stable thereafter. The annual number of deaths and age-adjusted death rates tended to decrease from around 1980. The peak of age-specific death rates was seen in infants, age 20 to 40 and old age. The decrease in the age-specific death rate was prominent for age under 20 and old age, but not significant for age 25 to 34. Prefectures in which SMR was high (> or = 120) were distributed all over Japan, but prefectures in which SMR was low (< or = 80) were concentrated in western Japan. CONCLUSIONS: The annual number of deaths and age-adjusted death rates began to decrease from around 1980, which coincided with the time the clinical trial of cis-platinum began. More than 100 deaths of testicular cancer are reported even now, early diagnosis, early treatment, and improvement of treatment strategy to far-advanced cases are necessary.  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