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991.
Dapeng Hao MD PhD Tao Ai MD MS Frank Goerner PhD Xuemei Hu MD PhD Michael Tweedle PhD 《Journal of magnetic resonance imaging : JMRI》2012,36(5):1060-1071
Magnetic resonance imaging (MRI) contrast agents are pharmaceuticals used widely in MRI examinations. Gadolinium‐based MRI contrast agents (GBCAs) are by far the most commonly used. To date, nine GBCAs have been commercialized for clinical use, primarily indicated in the central nervous system, vasculature, and whole body. GBCAs primarily lower the T1 in vivo to create higher signal in T1‐weighted MRI scans where GBCAs are concentrated. GBCAs are unique among pharmaceuticals, being water proton relaxation catalysts whose effectiveness is characterized by a rate constant known as relaxivity. The relaxivity of each GBCAs depends on a variety of factors that are discussed in terms of both the existing agents and future molecular imaging agents under study by current researchers. Current GBCAs can be divided into four different structural types (macrocyclic, linear, ionic, and nonionic) based on the chemistry of the chelating ligands whose primary purpose is to protect the body from dissociation of the relatively toxic Gd3+ ion from the ligand. This article discusses how the chemical structure influences inherent and in vivo stability toward dissociation, and how it affects important formulation properties. Although GBCAs have a lower rate of serious adverse events than iodinated contrast agents, they still present some risk. J. Magn. Reson. Imaging 2012;36:1060–1071. © 2012 Wiley Periodicals, Inc. 相似文献
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993.
目的腹腔镜下Sugarbaker修补手术是造口旁疝的主要手术方式,补片固定是手术的关键技术环节,本研究介绍一种新式补片固定方法,并探讨其在临床上的应用效果。 方法回顾性分析2017年6月至2019年6月在中山大学附属第六医院住院的66例造口旁疝患者临床资料,患者均行腹腔镜造口旁疝修补手术(Sugarbaker术式),根据补片固定方式的不同分为试验组(41例,采用"对位对线"补片固定法)和对照组(25例,采用传统疝钉双圈补片固定方法)。比较两组患者相关指标和治疗效果。 结果两组患者性别、年龄、体质指数、病程以及造口旁疝分型比较,差异均无统计学意义。试验组补片固定时间短于对照组[(32.6±9.0)min vs(38.7±11.0)min,P<0.05],两组在疝钉固定数量、血清肿、补片感染、术后住院时间指标方面,差异无统计学意义。试验组和对照组的平均随访时间差异无统计学意义[(37.6±14.8)个月vs(38.8±15.2)个月,P=0.687],试验组的造口旁疝复发率低于对照组(2.4% vs 20.0%,P<0.05),而两组术后慢性疼痛发生率差异无统计学意义(24.2% vs 24.0%,P=0.971)。 结论在腹腔镜造口旁疝Sugarbaker修补术中应用"对位对线"补片固定法,可以缩短补片固定时间并减少术后复发,值得临床上推广使用。 相似文献
994.
995.
本文较为详细地描述了我院在使用激光相机过程中遇到的2例故障和维修过程.在维修过程中首先认真观察故障表现,仔细分析故障成因,前后经过几次尝试,最终顺利解决了问题. 相似文献
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997.
Associations of functional single nucleotide polymorphisms in MIF-173G/C with early stage cervical cancer were investigated in a hospital-based case-control study on 250 patients with cervical cancer prior to surgery (including 49 cases with and 201 cases without lymphatic metastasis) and 147 healthy controls. The polymorphism was assessed using restriction fragment length polymorphism polymerase chain reaction, and the MIF serum concentration was examined using the enzyme-linked immunosorbent assay to analyze the correlation between the polymorphism and the MIF serum concentration. Carriers of the variant C allele in MIF-173 were at a significantly higher risk of cervical cancer compared to carriers of the wild-type allele (aOR=1.508; 95% CI, 1.128-2.016, p=0.05). The GC and CC genotypes may be the causative factors for cervical cancer (aOR=1.851; 95% CI, 1.132-3.027, p=0.013). Individuals with the GC+CC genotype and C allele at the MIF-173G/C site were at a significantly higher risk of cervical cancer and lymphatic metastasis. The risk of lymphatic metastasis in early stage cervical cancer was increased more than 1.6 times in patients with the CC and GC genotypes compared with those with the GG genotype. The genotype distribution and allele frequency of MIF-173G/C were statistically significant in the well-, moderately and poorly differentiated groups (P<0.05). Compared to the GG genotype and G allele, patients with GC and CC genotypes and C allele exhibited a lower degree of differentiation and a higher degree of malignancy. A significant difference was observed in MIF serum concentrations among the various subgroups (P<0.05). The early cervical cancer, lymphatic metastasis and poorly differentiated groups exhibited higher MIF levels in serum. Moreover, patients with the CC genotype exhibited higher MIF serum concentration, which could increase the risk of early stage cervical cancer and lymphatic metastasis. The results presented in this study provide the first evidence that the genetic polymorphism MIF-173 is associated with cervical cancer in humans. Detection of MIF serum concentration and genotyping may be used as biomarkers for early diagnosis and therapy for cervical cancer. 相似文献
998.
Yi FANG Tao YAN Xin-yu BI Hong-tu ZHANG Jian-guo ZHOU Zhen HUANG Yu-quan XIE Lei ZHANG Ping ZHAO Jian-qiang CAI 《中国肿瘤临床(英文版)》2011,8(4)
Low-grade myofibroblastic sarcoma is a recently characterized tumor showing features of myofibroblastic differentiation that is part of the spectrum of malignant mesenchymal tumors.This extremely rare ... 相似文献
999.
Liang Xu Lifeng Cai Xueliang Chen Xifeng Jiang Huihui Chong Baohua Zheng Kun Wang Junlin He Wei Chen Tao Zhang Maosheng Cheng Yuxian He Keliang Liu 《Antimicrobial agents and chemotherapy》2013,57(10):4963-4970
Discovery of new drugs for the treatment of AIDS typically possessing unique structures associated with novel mechanisms of action has been of great importance due to the quick drug-resistant mutations of HIV-1 strains. The work presented in this report describes a novel class of DNA duplex-based HIV-1 fusion inhibitors. Hydrophobic groups were introduced into a DNA duplex skeleton either at one end, at both ends, or in the middle. These modified DNA duplexes inhibited fusion between HIV-1 and human cell membranes at micro- or submicromolar concentrations. Respective inhibitors adopted an aptamer pattern instead of a base-pairing interaction pattern. Structure-activity relationship studies of the respective DNA duplexes showed that the rigid and negatively charged DNA skeletons, in addition to the presence of hydrophobic groups, were crucial to the anti-HIV-1 activity of these compounds. A fluorescent resonance energy transfer (FRET)-based inhibitory assay showed that these duplex inhibitors interacted with the primary pocket in the gp41 N-terminal heptad repeat (NHR) instead of interacting with the lipid bilayers. 相似文献
1000.
Lei Guo Nan Mei Qingsu Xia Tao Chen Po-Chuen Chan Peter P. Fu 《journal of environmental science and health part c-environmental carcinogenesis & ecotoxicology reviews》2013,31(1):60-87
Dietary supplements are consumed by more than 300 million people worldwide, and herbal dietary supplements represent the most rapidly growing portion of this industry. Even though adverse health effects of many herbal dietary supplements have been reported, safety assurances are not being addressed adequately. Toxicological data on the identification of genotoxic and tumorigenic ingredients in many raw herbs are also lacking. Currently, more than 30 herbal dietary supplements and active ingredients have been selected by the National Toxicology Program (NTP) for toxicity and tumorigenicity studies. Due to the complexity of the chemical components present in plant extracts, there are no established methodologies for determining the mechanisms of toxicity (particularly tumorigenicity) induced by herbs, such as Gingko biloba leaf extract (GBE) and other herbal plant extracts. Consequently, the understanding of toxicity of herbal dietary supplements remains limited. We have proposed that application of DNA microarrays could be a highly practical initial approach for revealing biological pathways and networks associated with toxicity induced by herbal dietary supplements and the generation of hypotheses to address likely mechanisms. The changes in expression of subsets of genes of interest, such as the modulation of drug metabolizing genes, can be analyzed after treatment with an herbal dietary supplement. Although levels of gene expression do not represent fully the levels of protein activities, we propose that subsequent biochemical and genomic experiments based on these initial observations will enable elucidation of the mechanisms leading to toxicity, including tumorigenicity. This review summarizes the current practices of microarray analysis of gene expressions in animals treated with herbal dietary supplements and discusses perspectives for the proposed strategy. 相似文献