全文获取类型
收费全文 | 5189篇 |
免费 | 229篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 136篇 |
妇产科学 | 85篇 |
基础医学 | 688篇 |
口腔科学 | 47篇 |
临床医学 | 358篇 |
内科学 | 1406篇 |
皮肤病学 | 66篇 |
神经病学 | 638篇 |
特种医学 | 212篇 |
外科学 | 760篇 |
综合类 | 32篇 |
一般理论 | 1篇 |
预防医学 | 113篇 |
眼科学 | 47篇 |
药学 | 355篇 |
中国医学 | 3篇 |
肿瘤学 | 439篇 |
出版年
2023年 | 28篇 |
2022年 | 36篇 |
2021年 | 83篇 |
2020年 | 55篇 |
2019年 | 62篇 |
2018年 | 79篇 |
2017年 | 46篇 |
2016年 | 64篇 |
2015年 | 76篇 |
2014年 | 91篇 |
2013年 | 119篇 |
2012年 | 193篇 |
2011年 | 230篇 |
2010年 | 118篇 |
2009年 | 138篇 |
2008年 | 240篇 |
2007年 | 264篇 |
2006年 | 233篇 |
2005年 | 251篇 |
2004年 | 223篇 |
2003年 | 201篇 |
2002年 | 202篇 |
2001年 | 192篇 |
2000年 | 189篇 |
1999年 | 173篇 |
1998年 | 58篇 |
1997年 | 41篇 |
1996年 | 54篇 |
1994年 | 38篇 |
1993年 | 42篇 |
1992年 | 146篇 |
1991年 | 122篇 |
1990年 | 134篇 |
1989年 | 130篇 |
1988年 | 129篇 |
1987年 | 122篇 |
1986年 | 114篇 |
1985年 | 100篇 |
1984年 | 64篇 |
1983年 | 62篇 |
1982年 | 25篇 |
1981年 | 32篇 |
1979年 | 42篇 |
1977年 | 29篇 |
1972年 | 25篇 |
1970年 | 32篇 |
1969年 | 36篇 |
1968年 | 25篇 |
1967年 | 28篇 |
1966年 | 26篇 |
排序方式: 共有5439条查询结果,搜索用时 62 毫秒
71.
Nonspecific cross-reacting antigen (NCA) immunoreactivity was localized in normal and neoplastic human tissues using a monoclonal antibody to 55, 90 and 95 kDa molecules of NCA. This was compared to the localization of immunoreactive carcinoembryonic antigen (CEA) as demonstrated by polyclonal and monoclonal antibodies. In frozen sections, CEA was localized in normal surface epithelium of the stomach and colon where NCA was only weakly detected. Type 1 and type 2-like pneumocytes were positive for NCA, while CEA was localized only in type 2-like pneumocytes. CEA and NCA were both demonstrated in ductal cells of frozen pancreatobiliary and mammary tissues. The antigenicity of CEA and NCA in normal tissues was significantly lost after paraffin embedding as compared to frozen sections. NCA was consistently demonstrated in eccrine sweat glands embedded in paraffin. In various tumor tissues, CEA and NCA were colocalized and expression increased sufficiently to be detected in paraffin sections. Adenocarcinomas of the stomach and colon and cystadenocarcinoma of the pancreas, as well as neuroendocrine carcinomas of the lung and thyroid, showed a CEA predominance over NCA. In ductal adenocarcinomas of the pancreas and breast and in cholangiocarcinoma, NCA reactivity was greater than CEA. Keratinizing foci of most squamous cell carcinomas of mucosal origin and some adenocarcinomas equally expressed both. Hepatocellular carcinoma, lobular mammary carcinoma and papillary thyroid carcinoma were positive only with unabsorbed polyclonal antibody which widely recognizes CEA-related substances. Renal cell carcinoma, prostatic adenocarcinoma, transitional cell carcinoma, anaplastic carcinomas, choriocarcinoma and basal cell carcinomas showed little or no immunoreactivity. Hence the relative ratio of CEA/NCA expression in tumors was dependent on the tissue of origin and histologic type. The cytoplasmic granular staining of NCA in cancer cells was a noteworthy difference from the plasma membrane-associated localization of CEA. 相似文献
72.
Kunikata T Yamane H Segi E Matsuoka T Sugimoto Y Tanaka S Tanaka H Nagai H Ichikawa A Narumiya S 《Nature immunology》2005,6(5):524-531
Prostaglandins, including PGD(2) and PGE(2), are produced during allergic reactions. Although PGD(2) is an important mediator of allergic responses, aspirin-like drugs that inhibit prostaglandin synthesis are generally ineffective in allergic disorders, suggesting that another prostaglandin-mediated pathway prevents the development of allergic reactions. Here we show that such a pathway may be mediated by PGE(2) acting at the prostaglandin E receptor EP3. Mice lacking EP3 developed allergic inflammation that was much more pronounced than that in wild-type mice or mice deficient in other prostaglandin E receptor subtypes. Conversely, an EP3-selective agonist suppressed the inflammation. This suppression was effective when the agonist was administered 3 h after antigen challenge and was associated with inhibition of allergy-related gene expression. Thus, the PGE(2)-EP3 pathway is an important negative modulator of allergic reactions. 相似文献
73.
Motonobu Nishimura MD Takashi Nishimura MD Masayuki Ishikawa MD Ayumu Masuoka MD Nobuyuki Okamura MD Keiko Abe MD Takahiro Matsuoka MD Mika Iwazaki MD Kazuhito Imanaka MD Haruhiko Asano MD Shunei Kyo MD 《Journal of artificial organs》2006,9(4):209-213
The presence of a significant organ dysfunction does not immediately exclude patients from consideration for treatment with
a left ventricular assist system (LVAS). However, in treating morbid circulatory shock patients with multiple organ failure,
it is important to know the preoperative and postoperative factor or factors related to the recovery of the damaged organ
function. In this study, we retrospectively analyzed patients receiving a LVAS at our institution and tried to determine the
important factors related to the survival of patients with multisystem failure. Twenty-seven patients who underwent LVAS placement
at Saitama Medical School Hospital between 1993 and 2003 were included in this study. The preoperative risk factors analyzed
were renal dysfunction, respiratory dysfunction, hepatic dysfunction, the existence of active infection, and the combination
of all four factors. As a postoperative factor, the pump flow index (mean LVAS pump flow during the first 2 weeks after LVAS
surgery divided by the body surface area) was analyzed. None of the analyzed preoperative factors could predict survival after
LVAS surgery, but a pump flow index of less than 2.5 l/min/m2 had a significant relationship with death after LVAS surgery. Further analysis revealed that all the patients with a pump
flow index of 3.0 l/min/m2 or more could overcome preoperative organ dysfunction. Congestive heart failure patients with multisystem failure need luxury
pump flow for successful LVAS surgery; this factor could be especially important in device selection and postoperative management. 相似文献
74.
The prebiotic effect of high β-glucan barley (HGB) flour on the innate immune system of high-fat model mice was investigated. C57BL/6J male mice were fed a high-fat diet supplemented with HGB flour for 90 days. Secretory immunoglobulin A (sIgA) in the cecum and serum were analyzed by enzyme-linked immunosorbent assays (ELISA). Real-time PCR was used to determine mRNA expression levels of pro- and anti-inflammatory cytokines such as interleukin (IL)-10 and IL-6 in the ileum as well as the composition of the microbiota in the cecum. Concentrations of short-chain fatty acids (SCFAs) and organic acids were analyzed by GC/MS. Concentrations of sIgA in the cecum and serum were increased in the HGB group compared to the control. Gene expression levels of IL-10 and polymeric immunoglobulin receptor (pIgR) significantly increased in the HGB group. HGB intake increased the bacterial count of microbiota, such as Bifidobacterium and Lactobacillus. Concentrations of propionate and lactate in the cecum were increased in the HGB group, and a positive correlation was found between these organic acids and the IL-10 expression level. Our findings showed that HGB flour enhanced immune function such as IgA secretion and IL-10 expression, even when the immune system was deteriorated by a high-fat diet. Moreover, we found that HGB flour modulated the gut microbiota, which increased the concentration of SCFAs, thereby stimulating the immune system. 相似文献
75.
76.
The use of patient-controlled analgesia (PCA) to manage pain post-operatively is becoming increasingly popular. The potential for pharmacist involvement is larger. Traditional areas of pharmacy involvement include PCA pump evaluation and selection, choice of narcotic-analgesic to be used, education of other health care professionals on PCA use, and development of PCA protocol guidelines. Monitoring post-operative pain and adjusting the PCA dosage are not traditional areas of pharmacist involvement. The purpose of this report is to describe a protocol which allows hospital pharmacists in an inpatient setting to adjust the PCA dose so that postoperative pain relief is maximized and sedation is minimized. 相似文献
77.
Five patients with internal carotid artery occlusion were studied with MR imaging at 0.22 T. At the carotid siphon, occluded vessels showed absence of flow void in three patients. But two cases had "partial flow void" which mimicked small arterial caliber. In these patients angiography showed collateral circulation to the carotid siphon. So the partial flow void in the carotid siphon suggested internal carotid artery occlusion with collateral circulation. 相似文献
78.
In an attempt to further characterize non-irradiated contact-inhibited confluent monolayer of BALB/c 3T3 cells (= Contact-Sensitive Plates; CSP) as substrata for in vitro drug sensitivity testing, we compared the efficiency of colony formation with panels of cell lines on CSP with that on plastic dishes or in agar. Tumorigenicity in athymic nude mice was also examined. We found that: (1) HeLa cells, 2 esophageal cancer lines, rat 3Y1 fibroblasts transformed by either adenovirus type 12, mouse polyoma virus, Rous avian sarcoma virus, or plasmid DNA carrying v-Ha-ras oncogene all formed colonies on CSP and in agar and at the same time was tumorigenic. The efficiency of colony formation on CSP proved always to be higher than that in agar. (2) None of the 4 "normal" fibroplastic cell lines formed colonies on CSP or in agar and were tumorigenic. (3) Simian virus 40 and adenovirus E1A gene transformed rat 3Y1 fibroblasts formed colonies on CSP but not in agar, and were not tumorigenic. Therefore, CSP was found to provide selective and efficient growth of neoplastic cells when compared to other substrata and is also helpful in detecting incompletely transformed cells. 相似文献
79.
Karube Y Katsuno K Ito S Matsunaga K Takata J Kuroki M Murakami M Matsuoka Y 《Annals of nuclear medicine》1999,13(6):407-413
The method for subtracting the initial image from the localization image was evaluated for radioimmunoscintigraphy of tumors with technetium-99m (Tc-99m) labeled antibodies. Monoclonal antibodies were parental mouse and mouse-human chimeric antibodies to carcinoembryonic antigen (CEA), designated F11-39 and ChF11-39, respectively, both of which have been found to discriminate CEA in tumor tissues from the CEA-related antigens. After reduction of the intrinsic disulfide bonds, these antibodies were labeled with Tc-99m. In vivo studies were performed on athymic nude mice bearing the human CEA-producing gastric carcinoma xenografts. Though biodistribution results showed selective and progressive accumulation of Tc-99m labeled antibodies at the tumor site, high radioactivity in blood was inappropriate for scintigraphic visualization of the tumors within a few hours. We examined the subtraction of the initial Tc-99m image from the Tc-99m localization image after a few hours. Subtracted images of the same count reflected the in vivo behavior of the Tc-99m radioactivity. The subtracted scintigrams revealed excellent tumor images with no significant extrarenal background. Visualization of the tumor site was dependent on antigen-specific binding and nonspecific exudation. These results demonstrate that a method of subtraction of the initial image may serve as a potentially useful diagnostic method for an abnormal site for agents with a low pharmacokinetic value. 相似文献
80.
Miura H Arai H Matsuoka A Yazawa K Satoh E Nishimura K Honda M Fujioka H 《Hinyokika kiyo. Acta urologica Japonica》1999,45(2):79-83
Previously, we reported the short-term immunological effects of postoperative adjuvant interferon-gamma (IFN-gamma) administration to renal cell carcinoma patients as determined by three-color flow cytometry. We now report the results of a long-term study on a larger number of subjects. Thirty-three patients with renal cell carcinoma received a prophylactic intramuscular injection of IFN-gamma (300 x 10(4) units per week) after nephrectomy. We evaluated immunological changes by measuring peripheral blood lymphocyte subsets including activated cytotoxic T lymphocytes (ACTL), cytotoxic T lymphocytes (CTL), activated suppressor T lymphocytes (ASTL), helper T lymphocytes (HTL), activated suppressor-inducer T lymphocytes (AITL), and suppressor-inducer T lymphocytes (SITL). We also estimated the natural killer (NK) activity by a cytolytic test. All 33 patients were examined for at least 12 months after the start of IFN-gamma injection, and 18 patients were examined for 30 months including the 6-month period following discontinuation of IFN-gamma injection. We found significant enhancement of the ACTL subset from the second week to the sixth month after the start of IFN-gamma injection. On the other hand, we found a significant decrease in the percentage of the HTL and SITL subsets for a long time after the start of injection. NK activity significantly increased throughout the period of administration, and it continued to increase for six months after discontinuation of IFN-gamma injection. 相似文献