全文获取类型
收费全文 | 1965篇 |
免费 | 93篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 86篇 |
妇产科学 | 71篇 |
基础医学 | 341篇 |
口腔科学 | 9篇 |
临床医学 | 109篇 |
内科学 | 454篇 |
皮肤病学 | 34篇 |
神经病学 | 284篇 |
特种医学 | 26篇 |
外科学 | 92篇 |
综合类 | 20篇 |
预防医学 | 147篇 |
眼科学 | 102篇 |
药学 | 154篇 |
中国医学 | 2篇 |
肿瘤学 | 112篇 |
出版年
2023年 | 6篇 |
2022年 | 49篇 |
2021年 | 101篇 |
2020年 | 36篇 |
2019年 | 51篇 |
2018年 | 73篇 |
2017年 | 45篇 |
2016年 | 43篇 |
2015年 | 61篇 |
2014年 | 71篇 |
2013年 | 92篇 |
2012年 | 145篇 |
2011年 | 143篇 |
2010年 | 76篇 |
2009年 | 45篇 |
2008年 | 128篇 |
2007年 | 142篇 |
2006年 | 156篇 |
2005年 | 132篇 |
2004年 | 142篇 |
2003年 | 109篇 |
2002年 | 90篇 |
2001年 | 14篇 |
2000年 | 14篇 |
1999年 | 17篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 9篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有2069条查询结果,搜索用时 93 毫秒
81.
82.
Frequent occurrence of BCL6 rearrangements in nodular lymphocyte predominance Hodgkin lymphoma but not in classical Hodgkin lymphoma 总被引:2,自引:0,他引:2
Wlodarska I Nooyen P Maes B Martin-Subero JI Siebert R Pauwels P De Wolf-Peeters C Hagemeijer A 《Blood》2003,101(2):706-710
We studied the genomic status of BCL6 in 23 cases of nodular lymphocyte predominance Hodgkin lymphoma (NLPHL) and 40 cases of classical Hodgkin lymphoma (cHL), using dual-color interphase fluorescence in situ hybridization (FISH). The BCL6 rearrangement was identified in 48% of NLPHL cases and was not detected in cHL cases. As a confirmation, sequential or simultaneous immunohistochemistry (IHC) and FISH using CD20 or BCL6 antibodies and BCL6 DNA probes was performed in 8 NLPHL cases. The BCL6-associated translocations, t(3;22)(q27;q11), t(3;7)(q27;p12), and the most probable t(3;9)(q27;p13), were identified in 3 cases. A consistent expression of BCL6 protein in popcorn cells with the highest number of intensely stained cells in cases with a genomic BCL6 rearrangement was shown by IHC. These findings support the hypothesis of a germinal center B cell-derived origin of NLPHL, indicate a significant role of BCL6 in the pathogenesis of NLPHL, and provide further evidence of the genetic diversity underlying the pathogenesis of NLPHL and cHL. 相似文献
83.
Bruggemann H Baumer S Fricke WF Wiezer A Liesegang H Decker I Herzberg C Martinez-Arias R Merkl R Henne A Gottschalk G 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(3):1316-1321
Tetanus disease is one of the most dramatic and globally prevalent diseases of humans and vertebrate animals, and has been reported for over 24 centuries. The manifestation of the disease, spastic paralysis, is caused by the second most poisonous substance known, the tetanus toxin, with a human lethal dose of approximately 1 ng/kg. Fortunately, this disease is successfully controlled through immunization with tetanus toxoid; nevertheless, according to the World Health Organization, an estimated 400,000 cases still occur each year, mainly of neonatal tetanus. The causative agent of tetanus disease is Clostridium tetani, an anaerobic spore-forming bacterium, whose natural habitat is soil, dust, and intestinal tracts of various animals. Here we report the complete genome sequence of toxigenic C. tetani E88, a variant of strain Massachusetts. The genome consists of a 2,799,250-bp chromosome encoding 2,372 ORFs. The tetanus toxin and a collagenase are encoded on a 74,082-bp plasmid, containing 61 ORFs. Additional virulence-related factors could be identified, such as an array of surface-layer and adhesion proteins (35 ORFs), some of them unique to C. tetani. Comparative genomics with the genomes of Clostridium perfringens, the causative agent of gas gangrene, and Clostridium acetobutylicum, a nonpathogenic solvent producer, revealed a remarkable capacity of C. tetani: The organism can rely on an extensive sodium ion bioenergetics. Additional candidate genes involved in the establishment and maintenance of a pathogenic lifestyle of C. tetani are presented. 相似文献
84.
Iwona Cygankiewicz Jerzy Krzysztof Wranicz Janusz Zaslonka Halina Bolinska Wojciech Zareba 《Annals of noninvasive electrocardiology》2003,8(4):289-295
Background: The aim of this study is to evaluate the association between heart rate turbulence (HRT) parameters and clinical characteristics of coronary artery disease (CAD) patients. Methods and Results: In 122 patients (mean age 62 ± 9 years) with angiographically documented CAD, 24‐hour Holter monitoring with HRT analysis was performed to evaluate turbulence onset (TO) and turbulence slope (TS). There was a significant correlation between TO and TS (P =?0.31; P < 0.001) . According to quartile values, TO ≥?0.37% and TS ≤ 4.25 ms/RR were considered as abnormal in this patient population. Average values of TO were higher and TS lower in patients over 60 years, in patients with a past history of myocardial infarction and in those with EF < 40%. Considering pharmacotheraphy, higher (better) values of TS were observed in patients on statins, nitrates, and beta‐blockers while lower TS values were noted in patients on calcium blockers. Patients with abnormal parameters of HRT compared to group with normal HRT values were characterized by features of more advanced CAD: age over 60 years (75% vs 49%), past history of MI (75% vs 64%), and EF < 40% (25% vs 3%). Multivariate analysis revealed age > 60 years (OR 1.27; P = 0.002) and EF < 40% (OR 1.39; P = 0.001) as independent clinical factors associated with abnormal HRT parameters. Conclusions: HRT parameters are influenced by clinical characteristics and pharmacotherapy of studied patients with TS more than abnormal TO depending on clinical characteristics of patients. Advanced age, prior myocardial infarction and left ventricular dysfunction are key factors influencing values of HRT parameters. 相似文献
85.
The applicability of antisense technology to suppress the expression of myelin associated glycoprotein (MAG) in cultured oligodendrocytes was evaluated. Differentiating oligodendrocyte precursor cells obtained by the shake-off method were exposed to nine unmodified antisense oligodeoxynucleotides (ODNs) targeted to the first seven exons of MAG mRNA. After four days, steady-state levels of MAG, proteolipid protein (PLP) and basic protein (BP) mRNAs were determined by Northern blot analysis. Only ODN annealing to 599-618 nt of the MAG mRNA (the junction of exon 5 and 6) resulted in a significant, 75% decrease in the MAG mRNA level. Unexpectedly, six other anti-MAG ODNs which had no significant effect on the MAG message, greatly increased the level of BP mRNA. The highest upregulation of approximately 12 fold was observed with ODN annealing to 139-168 nt (junction of exon 3 and 4). On the other hand, the 997-1016 ODN decreased the levels of BP and PLP messages by 70-80%. The 599-618 ODN also decreased the PLP mRNA by 85%. The results demonstrate that antisense ODNs targeted to one gene may profoundly alter the expression of other genes, and hence, complicate functional analysis of the targeted protein. 相似文献
86.
Li Tang Xujuan Yang Qian Yin Kaimin Cai Hua Wang Isthier Chaudhury Catherine Yao Qin Zhou Mincheol Kwon James A. Hartman Iwona T. Dobrucki Lawrence W. Dobrucki Luke B. Borst Stéphane Lezmi William G. Helferich Andrew L. Ferguson Timothy M. Fan Jianjun Cheng 《Proceedings of the National Academy of Sciences of the United States of America》2014,111(43):15344-15349
Nanomedicines (NMs) offer new solutions for cancer diagnosis and therapy. However, extension of progression-free interval and overall survival time achieved by Food and Drug Administration-approved NMs remain modest. To develop next generation NMs to achieve superior anticancer activities, it is crucial to investigate and understand the correlation between the physicochemical properties of NMs (particle size in particular) and their interactions with biological systems to establish criteria for NM optimization. Here, we systematically evaluated the size-dependent biological profiles of three monodisperse drug–silica nanoconjugates (NCs; 20, 50, and 200 nm) through both experiments and mathematical modeling and aimed to identify the optimal size for the most effective anticancer drug delivery. Among the three NCs investigated, the 50-nm NC shows the highest tumor tissue retention integrated over time, which is the collective outcome of deep tumor tissue penetration and efficient cancer cell internalization as well as slow tumor clearance, and thus, the highest efficacy against both primary and metastatic tumors in vivo.Over the last two to three decades, consensus has been reached that the size of anticancer nanomedicines (NMs) plays a pivotal role in determining their biodistribution, tumor penetration, cellular internalization, and clearance from blood plasma and tissues as well as excretion from body, and thus, it has significant impact on overall therapeutic efficacy against cancers (1–7). Although most clinically approved anticancer NMs have size ranging from 100 to 200 nm (8, 9), recent studies showed that anticancer NMs with smaller sizes exhibited enhanced performance in vivo, such as greater tissue penetration and enhanced tumor inhibition, particularly those with size around or smaller than 50 nm (5–7, 10–12). As such, there has been a major push recently in the field of anticancer NM to miniaturize nanoparticle (NP) size using novel chemistry and engineering design (13–17). One unanswered question, however, is whether additional miniaturization of NM size would be necessary and result in additional improved anticancer efficacy. Widely evaluated small molecular therapeutics (<1,500 Da and <2 nm) can traverse most tumor tissues freely (18). However, they diffuse away from tumor tissues rapidly and get cleared primarily into tumor blood capillaries, leading to minimal tumor accumulation (18). Macromolecules of relatively low molecular masses (<40,000 Da and <10 nm) were also shown to have low overall tumor retention because of both rapid permeation into and clearance from tumor tissues, behaving to some extent like small molecule drugs (18, 19). In conjunction with the renal clearance threshold (<10–15 nm) (20, 21) and interstitial/lymphatic fenestration (<20 nm) (22) for NPs, it becomes essential to carefully and comprehensively evaluate the in vivo behavior and anticancer efficacy of NMs in the size range of 20–50 nm to determine the optimal size of NM for cancer therapy.In this study, we used monodisperse drug–silica nanoconjugates (NCs) that have identical physiochemical properties, except for size, to investigate the size-dependent biodistribution and tumor tissue penetration and clearance as well as the overall efficacy. We focused on the NCs of 20 and 50 nm in this particularly interesting size range as well as the NC of 200 nm, the upper size limit of systemic NM to extravasate leaky tumor vasculature, which has a cutoff pore size larger than 200 nm for most tumors (23). Among these three representative sizes, the 50-nm NC showed the optimal balance of deep tissue penetration and high retention in tumors, which is in contrast with its larger counterpart (the 200-nm NC) of limited tumor tissue penetration and smaller counterpart (the 20-nm NC) of fast clearance from tumors, leading to overall low tumor retention for both. Therefore, 50 nm could be or could be close to the optimal size of NCs in the studied size range of 20–200 nm, ensuring not only the efficient distribution in, but also the protracted availability of drug-containing NC to the tumor tissues, resulting in superior anticancer efficacy against both primary and metastatic tumors. 相似文献
87.
Grzegorz Wozniak Maciej Misioek Adam Idasiak Iwona Dbosz-Suwiska Magdalena Jaworska Wieslaw Bal Boguslaw Maciejewski Leszek Miszczyk Krzysztof Skadowski Rafal Suwinski 《The British journal of radiology》2020,93(1116)
Objective:To compare the efficacy and tolerance of 7-days-a-week accelerated postoperative radiotherapy (p-CAIR) vs postoperative radio-chemotherapy (p-RTCT)Methods:Between September 2007 and October 2013, 111 patients were enrolled and randomly assigned to receive 63 Gy in 1.8 Gy fractions 7-days-a-week (n = 57, p-CAIR) or 63 Gy in 1.8 Gy fractions 5-days-a-week with concurrent cisplatin 80–100 mg per square meter of body-surface area on days 1, 22 and 43 of the radiotherapy course (p-RTCT). It represents approximately 40% of the intended trial size, that was closed prematurely due to slowing accrual. Only high-risk patients with squamous cell cancer of the oropharynx/oral cavity, considered fit for concurrent treatment were enrolled.Results:The rate of locoregional control (LRC) did not differ significantly between treatment arms (p = 0.18, HR = 0.56), 5 year LRC tended, however, to favour p-RTCT (81%) vs p-CAIR (62%). There was no difference in overall survival between treatment arms (p = 0.90, HR = 1.03).The incidence and severity of acute mucosal reactions and late reactions did not differ significantly between treatment arms. Haematological toxicity of p-RTCT was, however, considerably increased compared to p-CAIRConclusion:Concurrent postoperative RTCT tended to improve locoregional control rate as compared to p-CAIR. This, however, did not transferred into improved overall survival. Postoperative RTCT was associated with a substantial increase in haematological toxicity that negatively affected treatment compliance in this arm.Advances in knowledge:To our knowledge, this is the first trial that compares accelerated radiotherapy and radio-chemotherapy in postoperative treatment for oralcavity/oropharyngeal cancer 相似文献
88.
Mari Aikio Harri Elamaa David Vicente Valerio Izzi Inderjeet Kaur Lotta Seppinen Helen E. Speedy Dorota Kaminska Sanna Kuusisto Raija Sormunen Ritva Heljasvaara Emma L. Jones Mikko Muilu Matti Jauhiainen Jussi Pihlajam?ki Markku J. Savolainen Carol C. Shoulders Taina Pihlajaniemi 《Proceedings of the National Academy of Sciences of the United States of America》2014,111(30):E3043-E3052
89.
Malgorzata Gawel MD PhD Elzbieta Szmidt‐Salkowska MD PhD Anna Lusakowska MD PhD Monika Nojszewska MD PhD Anna Sulek MSc PhD Wioletta Krysa MSc PhD Marta Rajkiewicz MSc PhD Andrzej Seroka TECH Anna M. Kaminska MD PhD 《Muscle & nerve》2014,49(2):277-283
Introduction: Standard electromyography (EMG) is useful in the diagnosis of myotonic dystrophy type 1 (DM1) and type 2 (DM2), but it does not differentiate between them. The aim of this study was to estimate the utility of the short exercise test (SET) and short exercise test with cooling (SETC) in differentiating between DM1 and DM2. Methods: SET and SETC were performed in 32 patients with DM1 (mean age 35.8 ± 12.7 years) and 28 patients with DM2 (mean age 44.5 ± 12.5 years). Results: We observed a significant decline in compound motor action potential (CMAP) amplitude in DM1 with both SET and SETC immediately after effort. In DM2, there was no marked change in CMAP amplitude with either SET or SETC. Conclusions: SET and SETC may serve as useful tools for clinical differentiation between DM1 and DM2, and they may be used as a guide for molecular testing. Muscle Nerve 49 : 277–283, 2014 相似文献
90.
Magdalena Kraft Macarena Pia Knop Jean-Marie Renaudin Kathrin Scherer Hofmeier Claudia Pföhler Maria Beatrice Bilò Roland Lang Regina Treudler Nicola Wagner Thomas Spindler Jonathan O'B Hourihane Ioana Maris Alice Koehli Andrea Bauer Lars Lange Sabine Müller Nikolaos G. Papadopoulos Bettina Wedi Anne Moeser Luis F. Ensina Montserrat Fernandez-Rivas Ewa Cichocka-Jarosz George Christoff Blanca E. Garcia Iwona Poziomkowska-Gęsicka Victoria Cardona Tihomir B. Mustakov Uta Rabe Vera Mahler Linus Grabenhenrich Sabine Dölle-Bierke Margitta Worm The Network for Online Registration of Anaphylaxis 《Allergy》2020,75(4):901-910