全文获取类型
收费全文 | 2729篇 |
免费 | 142篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 70篇 |
妇产科学 | 94篇 |
基础医学 | 342篇 |
口腔科学 | 31篇 |
临床医学 | 260篇 |
内科学 | 653篇 |
皮肤病学 | 135篇 |
神经病学 | 209篇 |
特种医学 | 86篇 |
外科学 | 389篇 |
综合类 | 9篇 |
预防医学 | 178篇 |
眼科学 | 36篇 |
药学 | 161篇 |
肿瘤学 | 216篇 |
出版年
2024年 | 17篇 |
2023年 | 33篇 |
2022年 | 53篇 |
2021年 | 95篇 |
2020年 | 68篇 |
2019年 | 90篇 |
2018年 | 93篇 |
2017年 | 75篇 |
2016年 | 82篇 |
2015年 | 98篇 |
2014年 | 125篇 |
2013年 | 135篇 |
2012年 | 213篇 |
2011年 | 205篇 |
2010年 | 131篇 |
2009年 | 131篇 |
2008年 | 191篇 |
2007年 | 182篇 |
2006年 | 164篇 |
2005年 | 154篇 |
2004年 | 129篇 |
2003年 | 101篇 |
2002年 | 99篇 |
2001年 | 21篇 |
2000年 | 32篇 |
1999年 | 28篇 |
1998年 | 22篇 |
1997年 | 16篇 |
1996年 | 17篇 |
1995年 | 15篇 |
1994年 | 10篇 |
1993年 | 3篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1966年 | 1篇 |
排序方式: 共有2885条查询结果,搜索用时 15 毫秒
51.
PURPOSE: To characterize the surface properties of some modern resin composites employing a series of physicochemical methods. METHODS: Specimens from three microhybrid (Palfique Estellite-PE, Z250 Filtek-ZF, Tetric Ceram-TC) and one nanofilled (Supreme Filtek-SF) conventionally photo-cured resin composites polished with Soflex disks were studied for the following properties: Surface chemical composition and degree of C=C conversion (FTIR), surface energetics (contact angles), surface texture (AFM), surface roughness (AFM, stylus profilometry) and gloss (60 degrees-, 20 degrees-angle specular gloss). RESULTS: Polar and non polar molecular groups were identified in all products including NH and CONH (SF, ZF, TC). SF and ZF demonstrated higher conversion than PE and TC (P< 0.05). No significant differences (P> 0.05) were found in critical surface tension, total work of adhesion and its polar and dispersion components, the latter being the highest in all products. AFM showed the smoothest surface texture in PE. The ranking of Sa, Sq, Ra and Rz roughness parameters was PEZF>TC, P< 0.05) were more sensitive than 60 degree-angle measurements (PE, SF>TC, P< 0.05) in revealing gloss differences. A positive correlation was found between Sa and Ra and a negative one between Sa and 20 degree-angle gloss. 相似文献
52.
Korkontzelos I Antoniou N Stefos T Kyparos I Lykoudis S 《Clinical and experimental obstetrics & gynecology》2005,32(3):203-206
Emergency medicine has encountered in the last decades a gradual increase in cases of heterotopic pregnancy (HP) with rupture of the ectopic part. The rise of this entity is mainly due to ovulation induction performed in women undergoing assisted reproductive techniques (ART), but in natural cycles is still rare and unexpected. Diagnosis is often delayed especially in cases where no predisposing factors exist, causing life threatening situations. We report a case of a ruptured heterotopic pregnancy presenting at seven weeks of gestation that was treated with immediate laparotomy. The rest of the pregnancy course was uneventful with spontaneous vaginal delivery of a healthy infant at 39 weeks of gestation. A review of the diagnosis and management of heterotopic pregnancy is also given. 相似文献
53.
54.
Trichopoulou A Naska A Antoniou A Friel S Trygg K Turrini A 《International journal for vitamin and nutrition research. Internationale Zeitschrift für Vitamin- und Ern?hrungsforschung. Journal international de vitaminologie et de nutrition》2003,73(2):63-69
There is strong evidence that the intake of vegetables and fruits reduces the risk of cardiovascular disease (CVD) and is inversely associated with several forms of cancer. In contrast, information concerning specific macro- or micronutrients in relation to chronic diseases is limited and largely inconclusive. The beneficial role of vegetable and fruit consumption can also be inferred by considering the health effects of two dietary patterns, the Mediterranean and Japanese ones, in both of which the consumption of plant foods holds a prominent position. Time-trend data, retrieved from the DAFNE databank on the vegetable and fruit availability in four European countries (Greece, Ireland, Italy and Norway) indicate that, during the last decade, fruit availability decreased in Greece and Italy and increased in Ireland and Norway, whereas vegetable availability decreased only in Italy. In Greece, Italy and Norway, the daily fruit availability was higher than that of vegetables, a dietary pattern not in accordance to recommendations for higher vegetable consumption. This information, which is crucial for nutrition policies and health education, also demonstrates the value of the DAFNE surveillance system. 相似文献
55.
Tenofovir: a nucleotide analog for the management of human immunodeficiency virus infection 总被引:3,自引:0,他引:3
Tenofovir disoproxil fumarate, an acyclic nucleotide analog of adenosine monophosphate, is the most recent addition to the antiretroviral arsenal. After conversion to tenofovir by diester hydrolysis, subsequent phosphorylation by cellular enzymes to form the active tenofovir diphosphate is necessary for antiretroviral activity. Preliminary data suggest that tenofovir is as safe and efficacious as stavudine when given in combination with lamivudine and efavirenz for the treatment of antiretroviral-naïve patients. In antiretroviral-experienced patients, the addition of tenofovir to stable background antiretroviral therapy resulted in approximately a 0.6 log10 copies/ml reduction in viral load relative to placebo. Extended follow-up suggests that such virologic gains may be durable. In vitro, recombinant human immunodeficiency virus (HIV) expressing the K65R mutation showed a 3–4-fold increase in the 50% inhibitory concentrations of tenofovir when compared with wild type. In vivo, this mutation thus far appears to occur infrequently and is associated with variable virologic responses. Response rates to tenofovir vary with the number and pattern of thymidine analog mutations present before starting treatment with this agent. Tenofovir appears to be a well-tolerated agent in patients who are heavily pretreated and who have advanced disease. The main adverse effects appear to be gastrointestinal in nature and include nausea, vomiting, and diarrhea. In animals, osteomalacia and nephrotoxicity have occurred with tenofovir at exposures much higher than those observed in humans. Although no patient had to discontinue therapy as a result of elevated creatinine levels or hypophosphatemia through 58 weeks of treatment, the toxicities associated with long-term tenofovir therapy in humans are unknown. Concomitant administration of tenofovir and didanosine increases the area under the concentration-time curve of the latter by 44–60%; monitoring for signs and symptoms of didanosine toxicity is recommended. The approved dosage of tenofovir is 300 mg (one tablet) once/day with meals. Given the ease of administration and relative safety from the perspectives of adverse effects and drug interactions, tenofovir has the potential to assume a large role in the treatment of patients with HIV infection. 相似文献
56.
57.
Antoniou N Varras M Akrivis C Kitsiou E Stefanaki S Salamalekis E 《Clinical and experimental obstetrics & gynecology》2004,31(3):235-238
INTRODUCTION: Isolated torsion of the fallopian tube is a very rare condition. It occurs without ipsilateral ovarian involvement associated with pregnancy, haemosalpinx, hydrosalpinx, ovarian or paraovarian cysts and other adnexal alterations or even with an otherwise normal fallopian tube. We document a case of isolated torsion of the right fallopian tube associated with hydrosalpinx. CASE: The patient was a 39-year-old female, para 2, gravida 4, who was presented with acute pelvic pain, nausea and vomiting. Her medical history included an appendectomy and right hydrosalpinx diagnosed five months before admission by hysterosalpingography because of investigation for secondary infertility. The urinary pregnancy test was negative. Pelvic ultrasonography showed a dilated folded right tubular structure measuring 7.8 x 2.7 cm with thickened echogenic walls and mucosal folds protruding into the lumen; the ovaries and uterus were unremarkable. No free fluid in the cul-de-sac was noted. Preoperatively, a diagnosis of twisted right fallopian tube was suspected and an exploratory laparotomy confirmed the diagnosis of isolated torsion of the oviduct. The ipsilateral ovary appeared normal, but the fallopian tube was gangrenous and right salpingectomy was performed. The patient became pregnant three months after surgery. CONCLUSION: Isolated torsion of the fallopian tube should be considered in the differential diagnosis of patients with acute abdomen and previous medical history of hydrosalpinx. 相似文献
58.
Varras M Akrivis Ch Antoniou N Tolis C Stefanaki S Salamalekis E 《European journal of gynaecological oncology》2004,25(5):653-656
Primary ovarian carcinosarcoma is characterized by an admixture of malignant epithelial and stromal elements. This neoplasm is extremely rare with fewer than 400 cases reported in the English literature. Its histogenesis, clinical features and optimal treatment remain unclear because of the rarity of primary ovarian carcinosarcoma. This study focuses on the clinical, pathological, immunohistochemical features and survival of a 73-year-old patient with primary ovarian carcinocarcoma. The patient was treated with surgery followed by combined chemotherapy with carboplatin and taxol and assigned to FIGO Stage IIIc. She died from the disease 17 months after surgery. In conclusion, ovarian carcinosarcoma is a very aggressive tumor, especially when it is diagnosed at advanced stage. 相似文献
59.
Kreuter M Langer C Kerkhoff C Reddanna P Kania AL Maddika S Chlichlia K Bui TN Los M 《Archivum immunologiae et therapiae experimentalis》2004,52(3):141-155
Mapping of the human and other eukaryotic genomes has provided the pharmacological industry with excellent models for drug discovery. Control of cell proliferation, differentiation, activation and cell removal is crucial for the development and existence of multicellular organisms. Each cell cycle progression, with sequences of DNA replication, mitosis, and cell division, is a tightly controlled and complicated process that, when deregulated, may become dangerous not only to a single cell, but also to the whole organism. Regulation and the proper control of the cell cycle and of programmed cell death (apoptosis) is therefore essential for mammalian development and the homeostasis of the immune system. The molecular networks that regulate these processes are critical targets for drug development, gene therapy, and metabolic engineering. In addition to the primary, intracellular apoptotic suicide machinery, components of the immune system can detect and remove cells and tissue fragments that no longer serve their defined functions. In this review we will focus on apoptotic pathways converging on caspase family proteases, summarizing pharmacological attempts that target genes, proteins, and intermolecular interactions capable of modulating apoptosis and the inflammatory response. The upcoming pharmacological development for treatment of acute pathologies, such as sepsis, SIRS, stroke, traumatic brain injury, myocardial infarction, spinal cord injury, acute liver failure, as well as chronic disorders such as Huntington's disease, Parkinson's disease, ALS, and rheumatoid arthritis, will be discussed in details. We also suggest new potential molecular targets that may prove to be effective in controlling apoptosis and the immune response in vivo. 相似文献
60.