全文获取类型
收费全文 | 10421篇 |
免费 | 996篇 |
国内免费 | 393篇 |
专业分类
耳鼻咽喉 | 116篇 |
儿科学 | 204篇 |
妇产科学 | 179篇 |
基础医学 | 1500篇 |
口腔科学 | 137篇 |
临床医学 | 1232篇 |
内科学 | 1622篇 |
皮肤病学 | 448篇 |
神经病学 | 540篇 |
特种医学 | 508篇 |
外国民族医学 | 7篇 |
外科学 | 928篇 |
综合类 | 845篇 |
现状与发展 | 1篇 |
一般理论 | 4篇 |
预防医学 | 662篇 |
眼科学 | 284篇 |
药学 | 1353篇 |
5篇 | |
中国医学 | 479篇 |
肿瘤学 | 756篇 |
出版年
2024年 | 20篇 |
2023年 | 138篇 |
2022年 | 371篇 |
2021年 | 456篇 |
2020年 | 319篇 |
2019年 | 371篇 |
2018年 | 387篇 |
2017年 | 334篇 |
2016年 | 433篇 |
2015年 | 590篇 |
2014年 | 700篇 |
2013年 | 651篇 |
2012年 | 1022篇 |
2011年 | 965篇 |
2010年 | 553篇 |
2009年 | 470篇 |
2008年 | 603篇 |
2007年 | 559篇 |
2006年 | 433篇 |
2005年 | 439篇 |
2004年 | 316篇 |
2003年 | 297篇 |
2002年 | 238篇 |
2001年 | 131篇 |
2000年 | 134篇 |
1999年 | 151篇 |
1998年 | 90篇 |
1997年 | 95篇 |
1996年 | 61篇 |
1995年 | 67篇 |
1994年 | 41篇 |
1993年 | 33篇 |
1992年 | 54篇 |
1991年 | 36篇 |
1990年 | 34篇 |
1989年 | 30篇 |
1988年 | 26篇 |
1987年 | 25篇 |
1986年 | 14篇 |
1985年 | 18篇 |
1983年 | 14篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 9篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1970年 | 7篇 |
1966年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Christoph A. Binder Herminia Mi?o de Kaspar V. Klau? Anselm Kampik 《Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft》1999,247(7):663-667
Background: Most germs causing postoperative endophthalmitis derive from the conjunctival bacterial normal flora. Postoperative endophthalmitis
is often induced by staphylococcal germs. The application of polyvidone-iodine solution to the conjunctiva is one possibility
to reduce potential endophthalmitis-causing bacteria. The aim of this study was to evaluate the effectiveness of 1 % polyvidone-iodine
solution concerning the reduction of colonization with staphylococci in the course of intraocular surgery. This is to evaluate
the effectiveness of 1 % polyvidone-iodine solution concerning coagulase-negative and positive staphylococci. 相似文献
92.
分离性垂直偏斜(简称DVD)亦称上隐斜。该病病因不清,治疗方法亦各不相同,临床较多采用上直肌减弱术。下斜肌止端转位术是KratZ1989年报道的一种新的DVD矫正术。近三年我们采用上直肌后徙术及下斜肌止端转位术治疗DVD,取得较好疗效。现报告如下,l临床资料11对象本组16例,年龄7一月岁,男6例,女10例,合并内斜9例,合并外斜5例,Helveston综合征2例。患者术前均行视力、屈光状态、眼位、注视性质、眼底、三棱镜及同视机检查。1.2手术设计及效果DVD手术定量主要根据第一眼位用交替遮盖试验测量最大斜视程度来决定,一般在Drp影… 相似文献
93.
Byong Kak Kim Eung Chil Choi Kyeong Soo Chung Hee Ju Park Hye Ryoung Kim Yang Sup Kim Yong Hwan Park Mi Ja Shim 《Archives of pharmacal research》1983,6(2):141-142
To find antitumor metabolites in Korean basidiomycetes, the shake-cultured mycelia of eight of the higher fungi were extracted with hot water and the extracts, after being partially purified, were subjected toin vivo antitumor test. When administeredi.p. at the dose of 30mg/kg/day for ten consecutive days into the female ICR mice, which had been implanted with 1×105 cells of sarcoma 180 twenty-four hours before the first injection, the extracts ofAgaricus campestris, Lyophyllum decastes, Lyophyllum ulmarium, Armillaria tabescence andCalvatia exipulitormis respectively showed inhibition ratios of 64.1%, 65.4%, 60.0%, 53.0% and 49.3%. These five species were selected for further study, whereas the extracts ofPhallus impudicus, Coprinus comatus andPholiota squarrosa which showed the inhibition ratios of 31.2%, 33.5% and 19.0% were discontinued. 相似文献
94.
95.
The effects of intracerebroventricular (i.c.v.) and intrathecal (i.t.) 3-isobutyl-1-methylxanthine (IBMX), cholera toxin (CTX) and pertussis toxin (PTX) administration on immobilization-induced antinociception were studied in ICR mice. Antinociception was assessed by the tail-flick assay. Immobilization of the mouse increased inhibition of the tail-flick response for at least 1 h. The pretreatment with i.t. IBMX (0.01-1 ng), but not i.c.v. IBMX, significantly attenuated immobilization-induced inhibition of the tail-flick response. The pretreatments with i.c.v. PTX (0.05-0.5 microg) as well as i.t. CTX, but neither i.c.v. CTX (0.05-0.5 microg) nor i.t. PTX, potentiated the inhibition of the tail-flick response induced by immobilization stress. Our results suggest that spinally located phosphodiesterase appears to be involved in the production of immobilization stress-induced antinociception. In addition, inactivation of supraspinally located PTX-sensitive G-proteins and spinally located CTX-sensitive G-proteins may modulate immobilization stress-induced antinociception. 相似文献
96.
Prognostic significance of c-kit mutation in localized gastrointestinal stromal tumors. 总被引:16,自引:0,他引:16
Tae Won Kim Hyoungnam Lee Yoon-Koo Kang Mi Sun Choe Min-Hee Ryu Heung Moon Chang Jung Sun Kim Jeong Hwan Yook Byung Sik Kim Jung Shin Lee 《Clinical cancer research》2004,10(9):3076-3081
PURPOSE: Constitutive mutational activation of c-kit has been found to be associated with the pathogenesis of gastrointestinal stromal tumors (GISTs). The prognostic significance of c-kit mutations, however, is still controversial. EXPERIMENTAL DESIGN: We examined 86 patients curatively resected for localized GIST. Genomic DNA was extracted from paraffin-embedded tumor tissues. Exons 9, 11, 13, and 17 of the c-kit gene were amplified by PCR and sequenced. RESULTS: Mutations in exon 11 were detected in 61 tumors, and mutations in exon 9 were observed in three tumors, whereas no mutations were detected in exons 13 or 17. The overall c-kit mutation frequency was 74%. Amino acid alterations in the 61 tumors with exon 11 mutations were deletion in 33 tumors, substitution in 20, both deletion and substitution in 4, insertion in 1, and duplication in 3. Histologically, tumors with c-kit mutations showed higher mitotic counts and higher cellularity. The 5-year relapse-free survival (RFS) in patients having GISTs with c-kit mutations was 21%, compared with 60% in those without c-kit mutations. Significantly higher RFS rates were observed in patients with tumors having mitotic counts < 5 mitoses/50 high power field, spindle-cell histology, tumor size < 5 cm, or gastric GISTs. Multivariate analyses indicated association of poorer RFS with a higher mitotic count > or = 5 of 50 high power fields; odds ratio (OR) = 3.0], presence of c-kit mutations (OR = 5.6), and a larger tumor size (> or = 5 cm; OR = 4.2). CONCLUSIONS: The presence of c-kit mutation, along with high mitotic count and larger tumor size, was an independent factor for poor prognosis in patients with localized GISTs. 相似文献
97.
Feliciano García-Vicente Angel Mi?ambres Inmaculada Jerez Ignaci Modolell Leopoldo Pérez Juan Jose Torres 《Radiotherapy and oncology》2003,67(2):239-249
BACKGROUND AND PURPOSE: Modern conformal radiotherapy treatments require accurate dose calculation in any relevant clinical situation. One of these situations is the treatment of lung tumors, where irradiation has to be planned under challenging conditions for dose calculation. In this study we assess the errors in dose values predicted by fast Fourier transform convolution (FFTC) and multigrid superposition (MGS) algorithms implemented in a commercial treatment planning system (TPS). MATERIALS AND METHODS: FFTC and MGS algorithms were used in a FOCUS 3.0.0 (Computerized Medical Systems, USA) to calculate doses in treatment plans using photon beams of 6 and 25 MV nominal energy from a Saturne 43 linac (GE Medical Systems, USA). A 10x10-cm beam irradiating a mediastinum-lung and a thoracic wall-lung-thoracic wall modeled geometry was assessed. The calculated data were compared with measurements performed with radiographic films and ionization chamber. RESULTS: FFTC algorithm leads to an average deviation from ionometric dose measurements of over 10%. Discrepancies between measured and calculated beam fringe values (distance between 50 and 90% isodose lines) of up to 8 mm were observed. For MGS algorithm, all the points assessed in both geometries fulfilled the 3%-3 mm accuracy criteria and the average deviation of absolute dose was about 1%. A maximum of 3 mm deviation in the beam fringe for any depth was found and was within 2 mm beyond the buildup region. Deviations between ionometric and film measurements were within 3%. CONCLUSIONS: MGS algorithm assesses with reasonable accuracy dose distributions and absolute dose in inhomogeneous regions like the lung region. Therefore, and respecting the inhomogeneity dose calculation, the system could be used in routine clinical practice and in dose-escalation programs. This is not true in the case of FFTC algorithm which leads to errors greater than 10% in the absolute dose calculation and underestimates the beam fringe by up to 8 mm. 相似文献
98.
从羊红膻(Pimpinella thellungiana Wolff.)根中分得四个化合物,经理化常数测定和光谱数据解析证明为棕榈酸(Ⅰ)、4-丙烯基苯酚(Ⅱ)、松酯酚(Ⅲ)和新化合物2-甲基-2-羟基-5-甲氧基苯并[d]氢化呋喃-3-酮(Ⅳ)。 相似文献
99.
Byung Mu Lee Ja-June Jang Joung-Soon Kim Young Chan You Sun Ah Chun Hyung Sik Kim Hyung Mee Han Mi Young Ahn Soo Hyun Byun 《Cancer science》1998,89(6):597-603
Gastric adenocarcinoma is the most prevalent cancer in South Korea, and Helicobacter pylori (H. pylori) infection is also common. This study was performed to examine the association between H. pylori infection and gastric cancer, taking into account various other factors. To investigate the association between gastric adenocarcinoma and H. pylori infection, determined by urease-positive reaction in the CLO test, a total of 175 paired specimens (175 tumor and 175 tissues adjacent to tumor) of stomach cancer patients and a total of 113 control specimens were obtained. The positive H. pylori infection rates were 78.9% (138/175) among the patients in specimens of tumor or tissues adjacent to the tumor and 41.6% (47/113) among controls in the CLO test. A positive correlation between H. pylori infection and gastric cancer was observed (age-adjusted odds ratio, 7.0; MH χ2 =34.5 with P <0.0005). These data suggest that stomach cancer patients in Korea have high infection rates of H. pylori regardless of site specificity, and this infection might be causally associated with stomach cancer. 相似文献
100.
人急性早幼粒细胞性白血病细胞诱导分化生成树突状细胞的体外研究 总被引:3,自引:1,他引:3
树突状细胞(dendritic cells,DC)在激发机体抗白血病T细胞免疫应答中具有重要作用,有报道DC可以由单核细胞及粒细胞分化生成,本研究应用细胞因子在体外诱导了急性早幼粒细胞性白血病(APL)细胞向DC的分化.从M3型APL患者外周血分离白血病细胞,加入GM-CSF(100ng/ml)或GM-CSF(100ng/ml) rhIL-4(500U/ml)体外培养14天,并于培养结束前3天加人TN-α(100ng/ml).结果表明,GM-CSF可以促进白血病细胞体外增殖,并从幼稚状态逐渐分化成熟,表达高水平的CD45分子,其中部分为CD14~ 的单核细胞,部分为CDla~ 的DC(M3DC);培养后期加入TNF-α,可以促进DC生成,约占35%;以GM-CSF IL-4培养也诱导了幼稚细胞的成熟,2周后DC约占10%,但较少单核细胞生成,培养至3周时DC约占60%;而在培养后第11天加入TNF-α则可以加速DC生成,3天后生成的白血病型DC达90%.电镜观察到M3DC具有与单核细胞来源的DC相似的超微结构,但具有的突出特征是部分细胞存在少量胞浆颗粒;M3DC高表达HLA-DR、B7-2、CD40、CD54分子,体外可以强烈刺激同种T细胞增殖.此类由白血病细胞诱导生成的DC可被用于体内外诱导生成肿瘤特异性CTL,在APL的免疫治疗中具有一定的应用价值. 相似文献