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   99篇
  免费   5篇
儿科学   1篇
妇产科学   2篇
基础医学   24篇
口腔科学   1篇
临床医学   9篇
内科学   29篇
神经病学   2篇
特种医学   3篇
外科学   12篇
预防医学   9篇
药学   6篇
肿瘤学   6篇
  2022年   5篇
  2021年   3篇
  2020年   2篇
  2019年   2篇
  2018年   1篇
  2016年   3篇
  2015年   3篇
  2014年   3篇
  2013年   2篇
  2012年   6篇
  2011年   6篇
  2010年   4篇
  2009年   5篇
  2008年   5篇
  2007年   5篇
  2006年   6篇
  2005年   5篇
  2004年   3篇
  2003年   2篇
  2002年   3篇
  2001年   3篇
  2000年   4篇
  1999年   4篇
  1997年   1篇
  1996年   1篇
  1994年   3篇
  1992年   2篇
  1989年   3篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1979年   1篇
  1972年   1篇
  1966年   2篇
排序方式: 共有104条查询结果,搜索用时 31 毫秒
91.
Primary pulmonary lymphoproliferative disorders (PLDs) are histologically divided into a neoplastic state of high and low grade malignant lymphoma (ML), and a reactive state of follicular bronchitis/bronchiolitis (FB) and lymphoid interstitial pneumonia (LIP). We reviewed 19 cases with PLDs, including 4 cases each of high and low grade B cell ML, 6 FB cases, and 5 cases of LIP. To clarify the clonality of the proliferating cells, we performed an immunohistochemical examination (IHC), in situ hybridization (ISH) for the immunoglobulin light chain and a polymerase chain reaction (PCR) analysis of the immunoglobulin heavy chain gene using DNA obtained from paraffin sections. In addition, a Southern blot analysis was also performed in 6 cases using fresh materials. In IHC, all ML were positive for L26 (CD20), while the monoclonality of the kappa light chain was observed in only one high grade case. However, using ISH we could detect the clonality in three of four high grade ML cases and in one of four low grade ML cases. In FB and LIP, no clonality of immunoglobulin by ISH was observed. In a PCR analysis for the immunoglobulin heavy chain gene, we could detect one or two prominent bands in all 8 cases of high and low grade ML. On the other hand, in all cases of FB and LIP, we could only detect either an oligoclonal or polyclonal population. In summary, the presence of monoclonality of ISH and/or PCR for the immunoglobulin heavy chain gene were limited in the neoplastic state, but not in the reactive state.  相似文献   
92.
Primary pulmonary lymphoproliferative disorders (PLDs) are histologically divided into a neoplastic state of high and low grade malignant lymphoma (ML), and a reactive state of fol-licular bronchitis/ bronchiolitis (FB) and lymphoid interstitial pneumonia (LIP). We reviewed 19 cases with PLDs, including 4 cases each of high and low grade B cell ML, 6 FB cases, and 5 cases of LIP. To clarify the clonality of the proliferating cells, we performed an immunohis-tochemical examination (IHC), in situ hybridization (ISH) for the immunoglobulin light chain and a polymerase chain reaction (PCR) analysis of the immunoglobulin heavy chain gene using DNA obtained from paraffin sections. In addition, a Southern blot analysis was also performed in 6 cases using fresh materials. In IHC, all ML were positive for L26 (CD20). while the monoclonality of the kappa light chain was observed in only one high grade case. However, using ISH we could detect the clonality in three of four high grade ML cases and in one of four low grade ML cases. In FE3 and LIP, no clonality of immunoglobulin by ISH was observed. In a PCR analysis for the immunoglobulin heavy chain gene, we could detect one or two prominent bands in all 8 cases of high and low grade ML. On the other hand, in all cases of FB and LIP, we could only detect either an oligoclonal or polyclonal population. In summary, the presence of monoclonality of ISH and/or PCR for the immunoglobulin heavy chain gene were limited in the neoplastic state, but not in the reactive state.  相似文献   
93.
We present an extremely rare case of an orbital melanocytoma that occurred in a 51-year-old man. The patient suffered from diplopia and mild exophthalmos of the right eye for 2 months. Brain magnetic resonance imaging showed a well-demarcated round mass 3.5 cm in diameter in the right orbit. We performed total resection of this tumor. Histological findings revealed a proliferation of large polygonal cells with fine pigment granules in the cytoplasm and prominent nucleoli. Although these tumor cells revealed immunohistochemical reactivity in HMB-1, there was no S-100 or Melan A antibody reactivity. Also, there were no malignant findings of nuclear polymorphism, mitoses, or necrosis. The brown pigments were confirmed to be melanin by bleaching and the Fontana-Masson silver stain method. The MIB-1 labeling index was less than 1%. This tumor also consisted of 50% melanophages, which revealed immunohistochemical reactivity in CD68, CD163, and in (1-AT antibodies. These histological findings led us to diagnose an orbital melanocytoma with partial tumor regression.  相似文献   
94.
Mammalian cardiomyocytes withdraw from the cell cycle soon after birth. This process is called terminal differentiation. The c-kit, a receptor tyrosine kinase, is expressed on cardiomyocytes immediately after birth but for only a few days. In mice with genetic c-kit dysfunction, adult cardiomyocytes are phenotypically indistinguishable from those of wild type mice, except that they are capable of proliferation in vivo after acute pressure overload. This review explores the idea that postnatal cardiomyocyte differentiation and cell cycle withdrawal are distinct processes and that terminal differentiation may not simply be due to altered expression of genes that regulate the cell cycle but could involve c-kit induced epigenetic change.  相似文献   
95.
OBJECTIVES: The purpose of this study was to clarify the relationship between the change of mental health and the improvement of lifestyle and physical health in the lifestyle intervention program. METHODS: The study was conducted using data from 126 persons (50 males and 76 females) who participated in the 6-month lifestyle intervention program. We used the result of the General Health Questionnaire (GHQ)-30 as the indicator of mental health, the number of steps, surveys concerning caloric intake, and sleeping hours as the indicator of lifestyle, and body weight, BMI, blood pressure, triglycerides, total cholesterol, LDL cholesterol, HDL cholesterol and HBA1c. The subjects were classified into four groups based on the change of mental health: Group-GG, change from good to good (n = 80); Group-PG, change from poor to good (n = 25); Group-PP, change from poor to poor (n = 13); and Group-GP, change from good to poor (n = 8). The changes between pre-intervention and post-intervention were compared for each group by the paired t-test, and among the 4 groups by ANCOVA. RESULTS: In Group-GG, the number of steps (p < 0.01), calorie intake (p < 0.05) and sleeping hours (p < 0.01) were significantly improved, triglyceride was significantly decreased (p < 0.01), and total and HDL cholesterol were significantly increased (p < 0.01). However there were no significant changes in Group-GP. CONCLUSION: The state and change of mental health were found to be significantly associated with the improvement of lifestyle and physical health.  相似文献   
96.
We have investigated the radiosensitizing effect of doranidazole, a hypoxic cells radiosensitizer, using SCCVII tumor cells of C3H mice and CFPAC-1 and MIA PaCa-2 human pancreatic tumor cells. The radiosensitivity of hypoxic SCCVII cells in vitro increased with 1 mM doranidazole by a factor of 1.34 and 1.68, when determined by clonogenic survival and micronucleus (MN) formation, respectively. The radiation-induced growth delay of SCCVII tumors was significantly enhanced and the TCD(50/120) was reduced by a factor of 1.33 when 200 mg/kg doranidazole was injected, i.v., 20 min prior to tumor irradiation. The in vivo-in vitro excision assay showed that radiosensitivity of SCCVII cells in vivo increased by a factor of 1.47 with 200 mg/kg doranidazole. The radiation-induced growth delay of CFPAC-1 xenografts in nude mice was significantly enhanced and the TCD(50/90) was reduced by a factor of 1.30 by 200 mg/kg doranidazole. On the other hand, 200 mg/kg of doranidazole exerted no influence on the radiation-induced growth delay in MIA PaCa-2 xenografts. The tumor oxygenation status, as determined with an oxygen sensitive needle probe and the immunohistological study using pimonidazole, indicated that MIA PaCa-2 tumors are better oxygenated than CFPAC-1 tumors. The relatively well-oxygenated status in MIA PaCa-2 tumor may account for the lack of radiosensitization by doranidazole. It is concluded that the magnitude of radiosensitization of tumors by doranidazole is dependent on the oxygenation status of the tumors and that doranidazole may be useful in increasing the response of hypoxic human pancreatic tumor to IORT.  相似文献   
97.
The effect of coprophagy on the 7 alpha-dehydroxylation of biliary bile acids was studied in the rabbit. Bile acid composition of bile and intestinal contents was analyzed by gas-liquid chromatography and thin layer chromatography. Biliary bile acid composition of normal rabbits (n = 5) was: deoxycholic acid, 95.3 +/- 1.0SE % and cholic acid, 2.3 +/- 1.1SE %. When coprophagy was prevented, significant alterations were observed in biliary bile acid composition, including a considerable decrease in deoxycholic acid (82.5 +/- 2.8SE %, p less than 0.01) and a marked increase in cholic acid (15.2 +/- 3.0SE %, p less than 0.002). These results indicate that coprophagy is a factor causing an increase of the 7 alpha-dehydroxylated bile acid, deoxycholic acid (and lithocholic acid when the animals were fed chenodeoxycholic acid) in rabbit bile.  相似文献   
98.
Subtilase cytotoxin (SubAB) is a recently identified AB5 subunit toxin produced by Shiga-toxigenic Escherichia coli. The A subunit is thought to be a subtilase-like, serine protease, whereas the B subunit binds to the toxin receptor on the cell surface. We cloned the genes from a clinical isolate; the toxin was produced as His-tagged proteins. SubAB induced vacuolation at concentrations greater than 1 microg/ml after 8 h, in addition to the reported cytotoxicity induced at a ng/ml level after 48 h. Vacuolation was induced with the B, but not the A, subunit and was dependent on V-type ATPase. The cytotoxicity of SubAB at low concentrations was associated with the inhibition of protein synthesis; the 50% inhibitory dose was approximately 1 ng/ml. The A subunit, containing serine 272, which is thought to be a part of the catalytic triad of a subtilase-like serine protease, plus the B subunit was necessary for this activity, both in vivo and in vitro. SubAB did not cleave azocasein, bovine serum albumin, ovalbumin, or synthetic peptides. These data suggest that SubAB is a unique AB toxin: first, the B subunit alone can induce vacuolation; second, the A subunit containing serine 272 plus the B subunit inhibited protein synthesis, both in vivo and in vitro; and third, the A subunit proteolytic activity may have a strict range of substrate specificity.  相似文献   
99.
100.
Treatment fidelity in behavior change research: a case example   总被引:1,自引:0,他引:1  
BACKGROUND: Treatment fidelity refers to the methodological strategies used to monitor and enhance the reliability and validity of behavioral interventions. Assuring optimal treatment fidelity also may decrease the costs of a study and help the research team explain findings. APPROACH: The Behavioral Change Consortium developed a comprehensive model of treatment fidelity that incorporates 5 areas: (a) study design, (b) training providers, (c) delivery of treatment, (d) receipt of treatment, and (e) enactment of treatment skills. The definitions of these areas and a case example (Testing the Effectiveness of the Exercise Plus Program) are provided. RESULTS: There was evidence of treatment fidelity related to delivery based on careful monitoring of the study implementation. A comprehensive plan for training of the interventionists was provided, although evidence of treatment fidelity to training was not quantified. There were evidence based on observations of treatment sessions of delivery and receipt of the intervention and evidence of enactments based on evaluation of exercise calendars. DISCUSSION: The development and implementation of a treatment fidelity plan requires a careful conceptualization of what is relevant to treatment fidelity in any given study. Monitoring of treatment fidelity ideally requires direct or indirect observations of sessions, which can be built into the study design so that costs are minimal in terms of time and resources. Monitoring treatment fidelity allows research teams to truly test interventions and to develop and implement interventions that ultimately improve the overall health and well-being of individuals.  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