全文获取类型
收费全文 | 5120篇 |
免费 | 494篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 135篇 |
妇产科学 | 111篇 |
基础医学 | 590篇 |
口腔科学 | 94篇 |
临床医学 | 494篇 |
内科学 | 1010篇 |
皮肤病学 | 68篇 |
神经病学 | 251篇 |
特种医学 | 379篇 |
外科学 | 701篇 |
综合类 | 188篇 |
预防医学 | 468篇 |
眼科学 | 190篇 |
药学 | 407篇 |
中国医学 | 96篇 |
肿瘤学 | 474篇 |
出版年
2023年 | 40篇 |
2022年 | 47篇 |
2021年 | 104篇 |
2020年 | 67篇 |
2019年 | 111篇 |
2018年 | 103篇 |
2017年 | 93篇 |
2016年 | 93篇 |
2015年 | 135篇 |
2014年 | 163篇 |
2013年 | 196篇 |
2012年 | 269篇 |
2011年 | 270篇 |
2010年 | 188篇 |
2009年 | 187篇 |
2008年 | 271篇 |
2007年 | 293篇 |
2006年 | 244篇 |
2005年 | 280篇 |
2004年 | 209篇 |
2003年 | 215篇 |
2002年 | 170篇 |
2001年 | 136篇 |
2000年 | 126篇 |
1999年 | 136篇 |
1998年 | 100篇 |
1997年 | 96篇 |
1996年 | 84篇 |
1995年 | 79篇 |
1994年 | 64篇 |
1993年 | 63篇 |
1992年 | 100篇 |
1991年 | 90篇 |
1990年 | 84篇 |
1989年 | 97篇 |
1988年 | 97篇 |
1987年 | 92篇 |
1986年 | 62篇 |
1985年 | 61篇 |
1984年 | 37篇 |
1983年 | 33篇 |
1982年 | 41篇 |
1981年 | 35篇 |
1980年 | 29篇 |
1979年 | 29篇 |
1978年 | 20篇 |
1977年 | 23篇 |
1976年 | 27篇 |
1975年 | 15篇 |
1972年 | 12篇 |
排序方式: 共有5689条查询结果,搜索用时 31 毫秒
91.
Richard J Wong Mei-Ki Chan Zhenkun Yu Ronald A Ghossein Ivan Ngai Prasad S Adusumilli Brendon M Stiles Jatin P Shah Bhuvanesh Singh Yuman Fong 《Clinical cancer research》2004,10(13):4509-4516
PURPOSE: Oncolytic herpes simplex viruses (HSVs) may have significant antitumor effects resulting from the direct lysis of cancer cells. HSVs may also be used to express inserted transgenes to exploit additional therapeutic strategies. The ability of an interleukin (IL)-12-expressing HSV to treat squamous cell carcinoma (SCC) by inhibition of tumor angiogenesis is investigated in this study. EXPERIMENTAL DESIGN: A replication-competent, attenuated, oncolytic HSV carrying the murine IL-12 gene (NV1042), its non-cytokine-carrying analog (NV1023), or saline was used to treat established murine SCC flank tumors by intratumoral injection. The expression of secondary antiangiogenic mediators was measured. Angiogenesis inhibition was assessed by in vivo Matrigel plug assays, flank tumor subdermal vascularity, and in vitro endothelial cell tubule formation assay. RESULTS: Intratumoral injections of NV1042 (2 x 10(7) plaque-forming units) into murine SCC VII flank tumors resulted in smaller tumor volumes as compared with NV1023 or saline. IL-12 and IFN-gamma expression in tumors was 440 and 2.2 pg/mg, respectively, at 24 h after NV1042 injection, but both IL-12 and IFN-gamma were undetectable (<0.2 pg/mg) after NV1023 or saline injections. Expression of two antiangiogenesis mediators, monokine induced by IFN-gamma and IFN-inducible protein 10, was elevated after NV1042 treatment. Matrigel plug assays of NV1042-transfected SCC VII tumor cells demonstrated significantly decreased hemoglobin content and microvessel density as compared with NV1023 and PBS. Excised murine flank tumors treated with NV1042 had decreased subdermal vascularity as compared with NV1023 and PBS. Both splenocytes and IL-12 expression by NV1042 were required for in vitro inhibition of endothelial tubule formation. CONCLUSIONS: IL-12 expression by an oncolytic herpes virus enhances therapy of SCC through antiangiogenic mechanisms. Strategies combining HSV oncolysis with angiogenesis inhibition merit further investigation for potential clinical application. 相似文献
92.
Regional muramyl tripeptide phosphatidylethanolamine administration enhances hepatic immune function and tumor surveillance 总被引:4,自引:0,他引:4
BACKGROUND: Immune status of the liver may affect growth of liver metastases. We analyzed the ability of muramyl tripeptide phosphatidylethanolamine (MTP-PE), an immunomodulatory bacterial cell wall analog, to stimulate Kupffer cells (KCs) and protect against tumor growth, with or without an immunosuppressive partial hepatectomy (PH). Impact of MTP-PE's route of administration on KC function was assessed. METHODS: Buffalo rats (n = 7 to 12/group) were treated with saline, 40 microg MTP-PE intraportally (portal) or intravenously (IV) and challenged with 5 x 10(5) hepatoma cells, and tumors counted on day 21. To assess MTP-PE's impact on KC stimulation in animals undergoing PH, a known stimulant of tumor cell growth, groups were treated with saline or MTP-PE and challenged with tumor and underwent 30% PH. KCs were harvested and analyzed for superoxide production. Statistical analysis was performed with Mann-Whitney U test or chi-square test. RESULTS: MTP-PE-treated animals had fewer tumor nodules than control animals (19 vs 184, P <.005). MTP-PE-portal animals had fewer nodules than MTP-PE-IV (2 vs 36, P <.05). MTP-PE treatment before PH resulted in fewer tumor nodules compared with control animals (192 vs 276, P <. 05). MTP-PE administration increased macrophage superoxide production (20.6 +/- 2 vs 11.9 +/- 1.1 nmol/10(6) cells, P <.005). CONCLUSIONS: MTP-PE improved KC function and decreased growth of microscopic tumor cells. MTP-PE's effects persist after an immunosuppressive hepatectomy. Portal administration was the most effective. MTP-PE administration may be useful as a neoadjuvant therapy for patients undergoing resection of liver malignancies. 相似文献
93.
OBJECTIVES: To re-examine the potential influence of varicocelectomy on testicular volume using scrotal ultrasonography, because it has been reported that total testicular volume (assessed by physical examination) increases after adult varicocele ligation. METHODS: A retrospective review of the testicular volume and semen parameters of 61 men who underwent microsurgical varicocelectomy between 1996 and 1998 was performed. Ultrasound-derived testicular volumes and total motile sperm counts were compared before varicocelectomy and at a mean of 7.2 months postoperatively. RESULTS: Bilateral varicocelectomy was performed in 22 men; 39 men underwent a left-sided procedure only. Overall, no significant change was found in the mean total testicular volume after varicocelectomy compared with preoperatively (24.0 versus 23.9 mL, respectively; P = 0.74). Similarly, the testicular volumes did not change significantly after left or bilateral varicocelectomy (P >0.05). Overall, the mean total motile sperm count increased significantly after varicocelectomy (17. 9 to 25.4, P = 0.05). CONCLUSIONS: This was the first study to examine the effect of adult varicocelectomy on testicular volume using ultrasound-derived measurements of volume. Unlike previous findings, our data suggest that although adult varicocelectomy improves semen quality in most infertile men, it does not result in a significant increase in testicular volume. 相似文献
94.
A nationwide study of intracellular drug metabolite concentrations in children prescribed 6-mercaptopurine for the treatment of lymphoblastic leukaemia was carried out to assess interpatient variability at a standardised dose. Nine children (2% of the total) had completely undetectable metabolites, indicative of non-compliance. Five were adolescents, but otherwise they had no obvious distinguishing characteristics. Not taking any 6-mercaptopurine at all is uncommon, but the problem cannot be predicted. The total number of children who do not comply cannot be determined from this study, but the nine children described represent only a fraction of these. 相似文献
95.
Previous work has shown that sustained increased and decreased cell
proliferation, induced by dietary zinc deficiency and caloric restriction
respectively, influence the course of N- nitrosomethylbenzylamine
(NMBA)-induced esophageal carcinogenesis in rats. The present study
considered whether the increased cell proliferation and esophageal tumor
incidence induced by zinc deficiency are reversed upon zinc replenishment.
Weanling rats were maintained initially on a deficient diet containing 4
p.p.m. zinc. After 5 weeks, carcinogen-treated animals were given six
intragastric doses of NMBA (2 mg/kg twice weekly). Controls were untreated.
After the second NMBA dose, the rats were divided into three dietary
groups. One group was continued on the deficient diet, while the other two
groups were switched to diets containing either 75 or 200 p.p.m. zinc, with
half of the members in each group fed ad libitum and half pair-fed with
deficient rats. NMBA-untreated controls were similarly replenished. At
various time points, esophageal cell proliferation was assessed in five
animals from each group by immunohistochemical detection of cells in S
phase, with in vivo 5-bromo-2'deoxyuridine labeling. At 11 weeks after the
first dose, esophageal tumor incidence was greatly reduced, from 100% in
the deficient group to 26 and 14% respectively in the replenished groups
fed ad libitum 75 and 200 p.p.m. zinc and to 14 and 11% respectively in the
replenished groups pair-fed 75 and 200 p.p.m. zinc. In addition, the number
of tumors per esophagus was reduced from 9.93 +/- 4.25 in deficient rats,
to a range of 0.11 +/- 0.31-0.30 +/- 0.54 in replenished animals. Following
zinc replenishment, esophageal cell proliferation, as measured by labeling
index (LI), the number of labeled cells and the total number of cells, was
markedly decreased in NMBA-untreated and -treated esophagi as compared with
those in corresponding deficient esophagi. Thus, the esophageal cell
proliferation induced by zinc deficiency is reversed by zinc replenishment
and replenished animals have a markedly lower incidence of esophageal
tumors.
相似文献
96.
97.
Zhao P Cao J Zhao LJ Qin ZL Ke JS Pan W Ren H Yu JG Qi ZT 《第二军医大学学报》2006,27(5):506-506
The nucleocapsid (N) protein of SARS-coronavirus (SARS-CoV) is the key protein for the formation of the helical nucleocapsid during virion assembly. This protein is believed to be more conserved than other proteins of the virus, such as spike and membrane glycoprotein. In this study, the N protein of SARS-CoV was expressed in Escherichia coli DHSalpha and identified with pooled sera from patients in the convalescence phase of SARS. A plasmid pCI-N, encoding the full-length N gene of SARS-CoV, was constructed. Expression of the N protein was observed in COS1 cells following transfection with pCI-N. The immune responses induced by intramuscular immunization with pCI-N were evaluated in a murine model. Serum anti-N immunoglobutins and splenocytes proliferative responses against N protein were observed in immunized BALB/c mice. The major immunoglobulin G subclass recognizing N protein was immunoglobulin G2a, and stimulated splenocytes secreted high levels of gamma interferon and IL-2 in response to N protein. More importantly, the immunized mice produced strong delayed-type hypersensitivity (DTH) and CD^8+ CTL responses to N protein. 相似文献
98.
金银花药材中抗呼吸道病毒感染的咖啡酰奎宁酸类成分的定量研究 总被引:7,自引:3,他引:7
目的:寻找金银花中的抗呼吸道病毒感染的成分,并进行定量研究。方法:采用各种柱层析和制备薄层层析等方法分离、细胞病变法进行抗病毒作用的研究,采用RP-HPLC方法进行定量方法的研究。结果:分离得到了13种咖啡酰奎宁酸类化合物和咖啡酸、咖啡酸甲酯,确认咖啡酰奎宁酸类成分具有较强的抗呼吸道病毒作用,并采用HPLC方法测定了金银花中的 6种咖啡酰奎宁酸类成分和咖啡酸的含量。结论:咖啡酰奎宁酸类成分为金银花中的有效成分,定量方法准确、重复性好。 相似文献
99.
Nancy Kemeny William Jarnagin Philip Paty Mithat G?nen Lawrence Schwartz Mero? Morse Gregory Leonard Michael D'Angelica Ronald DeMatteo Leslie Blumgart Yuman Fong 《Journal of clinical oncology》2005,23(22):4888-4896
PURPOSE: To determine the maximum-tolerated dose (MTD) of concurrent systemic oxaliplatin (Oxal) combinations plus hepatic arterial infusion (HAI) in patients with unresectable hepatic metastases from colorectal cancer. PATIENTS AND METHODS: Thirty-six patients (89% previously treated) with unresectable liver metastases were treated with concurrent HAI and systemic Oxal plus irinotecan (CPT-11; group A) or Oxal, fluorouracil (FU), and leucovorin (LV; group B). Systemic chemotherapy was administered every 2 weeks concurrent with 2 weeks of HAI floxuridine (FUDR) and dexamethasone (Dex) every 28 days. RESULTS: The MTD for patients in group A was Oxal 100 mg/m(2), CPT-11 150 mg/m(2), and FUDR 0.12 mg/kg x 30 mL divided by pump flow rate. The MTD for group B was Oxal 100 mg/m(2), LV 400 mg/m(2), and FU 1,400 mg/m(2) by continuous infusion over 48 hours, with the same FUDR dose as in group A. Grade 3 or 4 toxicities in groups A and B included diarrhea (24% and 20%), neutropenia (10% and 7%), neurotoxicity (24% and 20%), and bilirubin more than 3 mg/mL (5% and 7%, respectively). The complete and partial response rate totaled 90% for group A and 87% for group B. Median survival time was 36 and 22 months for groups A and B, respectively. Seven patients in group A were ultimately able to undergo liver resection. CONCLUSION: Combination therapy with HAI FUDR and Dex plus systemic Oxal combinations may be safely administered to patients with colorectal cancer. The high response rate (88%) and the possibility of conversion to resectability, despite disease progression on prior systemic regimens, suggest that these combinations should be evaluated in larger studies as first- or second-line therapy in patients with hepatic metastases from colorectal cancer. 相似文献
100.