全文获取类型
收费全文 | 4772篇 |
免费 | 362篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 84篇 |
妇产科学 | 135篇 |
基础医学 | 986篇 |
口腔科学 | 41篇 |
临床医学 | 415篇 |
内科学 | 1057篇 |
皮肤病学 | 51篇 |
神经病学 | 581篇 |
特种医学 | 113篇 |
外科学 | 501篇 |
综合类 | 15篇 |
一般理论 | 2篇 |
预防医学 | 293篇 |
眼科学 | 100篇 |
药学 | 379篇 |
中国医学 | 8篇 |
肿瘤学 | 378篇 |
出版年
2024年 | 3篇 |
2023年 | 49篇 |
2022年 | 123篇 |
2021年 | 220篇 |
2020年 | 99篇 |
2019年 | 142篇 |
2018年 | 163篇 |
2017年 | 97篇 |
2016年 | 129篇 |
2015年 | 158篇 |
2014年 | 186篇 |
2013年 | 227篇 |
2012年 | 364篇 |
2011年 | 422篇 |
2010年 | 238篇 |
2009年 | 219篇 |
2008年 | 367篇 |
2007年 | 362篇 |
2006年 | 345篇 |
2005年 | 288篇 |
2004年 | 259篇 |
2003年 | 247篇 |
2002年 | 208篇 |
2001年 | 30篇 |
2000年 | 14篇 |
1999年 | 28篇 |
1998年 | 36篇 |
1997年 | 33篇 |
1996年 | 19篇 |
1995年 | 19篇 |
1994年 | 6篇 |
1993年 | 10篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1974年 | 3篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有5160条查询结果,搜索用时 125 毫秒
991.
Zoia R. Korobova Elena V. Zueva Natalia A. Arsentieva Oleg K. Batsunov Natalia E. Liubimova Irina V. Khamitova Raisa N. Kuznetsova Artem A. Rubinstein Tikhon V. Savin Oksana V. Stanevich Alexandr N. Kulikov Dmitry E. Pevtsov Areg A. Totolian 《Viruses》2022,14(5)
IgG is the most prominent marker of post-COVID-19 immunity. Not only does this subtype mark the late stages of infection, but it also stays in the body for a timespan of at least 6 months. However, different IgG subclasses have different properties, and their roles in specific anti-COVID-19 responses have yet to be determined. We assessed the concentrations of IgG1, IgG2, IgG3, and IgG4 against different SARS-CoV-2 antigens (N protein, S protein RBD) using a specifically designed method and samples from 348 COVID-19 patients. We noted a statistically significant association between severity of COVID-19 infection and IgG concentrations (both total and subclasses). When assessing anti-N protein and anti-RBD IgG subclasses, we noted the importance of IgG3 as a subclass. Since it is often associated with early antiviral response, we presumed that the IgG3 subclass is the first high-affinity IgG antibody to be produced during COVID-19 infection. 相似文献
992.
Karim Ravilevich Muratov Timur Rizovich Ablyaz Evgeny Anatolevich Gashev Irina Georgievna Goryacheva 《Materials》2022,15(9)
The regularities of the formation of the resulting raster tool trajectories based on Lissajous figures for the lapping process of planes are established. This makes it possible to maximize the cutting ability of the tool, which contributes to its more uniform wear and increased productivity and processing quality. Optimal parameters of productivity and roughness of the treated surface during lapping of zirconium ceramics are achieved through the use of ASM paste 28/20 µm. Based on Preston’s hypothesis, an exponential dependence of the change in the contact area during the lapping of planes of different initial shape of the macrorelief is obtained. The obtained theoretical and practical results of the study of the process of flat lapping with constant and variable clamping force of the treated surface to the surface of the tool. The influence of the force factor on the formation of the surface in the process of abrasive lapping has been established. Studies have been carried out and the main technological recommendations of precision surface treatment of workpieces based on hard, brittle ceramic material and bronze samples on equipment with a raster trajectory of the tool movement are presented. The optimal pressure value when processing ceramics should be considered 203–270 kPa (2.1–2.8 kg/cm2). 相似文献
993.
The role of IL‐5 in chronic spontaneous urticarial (CSU) is unclear. It may be that benralizumab is an important bidirectional modifier of CSU; that is, blocking IL‐5 may improve CSU in some patients, but it is possible that it may worsen CSU in others. 相似文献
994.
Alexis Sentís Irina Kislaya Nathalie Nicolay Hinta Meijerink Jostein Starrfelt Ivn Martínez-Baz Jesús Castilla Katrine Finderup Nielsen Christian Holm Hansen Hanne-Dorthe Emborg Anthony Nardone Tarik Derrough Marta Valenciano Baltazar Nunes Susana Monge the VEBIS-Lot working group VEBIS-Lot working group Ausenda Machado Carlos Dias Itziar Casado Cristina Burgui Amparo Larrauri Clara Mazagatos 《Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin》2022,27(30)
By employing a common protocol and data from electronic health registries in Denmark, Navarre (Spain), Norway and Portugal, we estimated vaccine effectiveness (VE) against hospitalisation due to COVID-19 in individuals aged ≥ 65 years old, without previous documented infection, between October 2021 and March 2022. VE was higher in 65–79-year-olds compared with ≥ 80-year-olds and in those who received a booster compared with those who were primary vaccinated. VE remained high (ca 80%) between ≥ 12 and < 24 weeks after the first booster administration, and after Omicron became dominant. 相似文献
995.
目的 探讨控制营养状态(CONUT)评分对人表皮生长因子受体2(HER2)阳性早期乳腺癌患者复发转移中的预测价值。方法 将2012年1月至2020年10月于新疆医科大学附属肿瘤医院行手术切除并接受曲妥珠单抗治疗的154例HER2阳性早期乳腺癌患者为研究对象进行回顾性分析。基于患者术前血清白蛋白、总胆固醇水平及外周血淋巴细胞计数,计算CONUT评分。通过受试者操作特征曲线(ROC曲线)对CONUT评分截止点进行分类:高CONUT与低CONUT组。组间基线特征分布的比较采用卡方χ2检验或Fisher确切概率法。绘制Kaplan-Meier曲线,并通过单因素和多因素Cox回归分析确定CONUT评分与乳腺癌患者复发转移的关系。结果 ROC曲线表明CONUT评分预测乳腺癌患者术后复发转移的最佳截止点为2.5,曲线下面积(AUC)为0.689 (95%CI=0.577~0.801)。基于此截止点,将所有患者分为高CONUT组(≥3分)与低CONUT组(<3分)。Kaplan-Meier曲线展示两组患者的5年无复发生存(RFS)率分别为69.7%和86.9%,差异具有统计学意义(χ2=8.00... 相似文献
996.
Irina Stoian Bogdan Manolescu Valeriu Atanasiu Olivera Lupescu 《Central European Journal of Medicine》2007,2(4):361-378
Erythropoietin (EPO) is one of the main cytokines involved in the regulation of erythropoiesis. The main site of EPO production
are the kidneys. An altered EPO production leads to pathological conditions such as anemia and polycythaemia. Due to the progressive
loss of renal peritubular cells, patients with chronic kidney disease (CKD) have low EPO plasma levels. This decreases erythron
stimulation with the direct consequence of developing anemia. Before the introduction in the clinical practice of rHuEpo,
in the late 1980s, the only solution for treating this type of anemia were blood transfusions and anabolic steroids. Even
rHuEpo has proven to be safe and effective for treatment of anemias, there are some concerns about its cost, the need for
frequent parenteral administration, and development of anti-EPO antibodies. These inconveniences prompted the search for novel
erythropoiesis stimulating agents. Different strategies lead to isolation or chemical synthesis of such agents as darbepoetin
alfa and EPO mimetics. In this review, we present some general aspects of EPO biology, with emphasis on chronic renal failure,
and expose some of the alternatives to EPO used for anemia correction. 相似文献
997.
Marian Novac Adina Magdalena Musuc Emma Adriana Ozon Iulian Sarbu Mirela Adriana Mitu Adriana Rusu Simona Petrescu Irina Atkinson Daniela Gheorghe Dumitru Lupuliasa 《Materials》2022,15(15)
The development of new orally dispersible tablets containing amlodipine (AML) inclusion complexes in hydroxypropyl-β-cyclodextrin (HP-β-CD) and in methyl-β-cyclodextrin (Me-β-CD) was studied. The methods of obtaining amlodipine and the physical and chemical properties of the inclusion complexes using the two cyclodextrins was investigated separately. Solid inclusion complexes were obtained by three methods: kneading, coprecipitation, and lyophilization, at a molar ratio of 1:1. For comparison, a physical mixture in the same molar ratio was prepared. The aim of the complexation process was to improve the drug solubility. As the lyophilization method leads to a complete inclusion of the drug in the guest molecule cavity, for both used cyclodextrins, these types of compounds were selected as active ingredients for the design of orally dispersible tablets. Subsequently, the formulation of the orodispersible tablets containing AML-HP-β-CD and AML-Me-β-CD inclusion complexes and quality parameters of the final formulation were evaluated. The results prove that F1 and F4 formulations, based on silicified microcrystalline cellulose, which contains insignificant proportions of very small or very large particles, had the lowest moisture degree (3.52% for F1 and 4.03% for F4). All of these demonstrate their porous structure, which led to good flowability and compressibility performances. F1 and F4 formulations were found to be better to manufacture orally dispersible tablets. 相似文献
998.
Camelia Ungureanu Gratiela Teodora Tihan Roxana Gabriela Zgrian Irina Fierascu Anda Maria Baroi Silviu Rileanu Radu Claudiu Fierscu 《Materials》2022,15(15)
Nowadays, special importance is given to quality control and food safety. Food quality currently creates significant problems for the industry and implicitly for consumers and society. The effects materialize in economic losses, alterations of the quality and organoleptic properties of the commercial products, and, last but not least, they constitute risk factors for the consumer’s health. In this context, the development of analytical systems for the rapid determination of the sanitary quality of food products by detecting possible pathogenic microorganisms (such as Escherichia coli or Salmonella due to the important digestive disorders that they can cause in many consumers) is of major importance. Using efficient and environmentally friendly detection systems for identification of various pathogens that modify food matrices and turn them into food waste faster will also improve agri-food quality throughout the food chain. This paper reviews the use of metal nanoparticles used to obtain bio nanosensors for the purpose mentioned above. Metallic nanoparticles (Au, Ag, etc.) and their oxides can be synthesized by several methods, such as chemical, physical, physico-chemical, and biological, each bringing advantages and disadvantages in their use for developing nanosensors. In the “green chemistry” approach, a particular importance is given to the metal nanoparticles obtained by phytosynthesis. This method can lead to the development of good quality nanoparticles, at the same time being able to use secondary metabolites from vegetal wastes, as such providing a circular economy character. Considering these aspects, the use of phytosynthesized nanoparticles in other biosensing applications is also presented as a glimpse of their potential, which should be further explored. 相似文献
999.
Alexandra Mataleru Alexandra Sabina Cojocariu Andra Oancea Maria-Magdalena Leon-Constantin Mihai Roca Ioana Mdlina Zota Irina Mihaela Abdulan Cristina Rusu Laura Mihaela Trandafir Alexandru Dan Costache Elena Cojocaru Iulia Cristina Roca Florin Mitu 《Nutrients》2022,14(15)
(1) Background: Familial hypercholesterolemia (FH) is a genetic autosomal dominant disorder characterized by elevated levels of low-density lipoprotein cholesterol (LDL) that develops deposits of lipids in the arterial wall. Since it is underdiagnosed and undertreated, the disease has a high risk of premature cardiovascular disease and death. Patients are not always aware of the changes they should make in their diet. Thus, our study aimed to evaluate through a food frequency questionnaire their eating habits. (2) Methods: We included 70 patients with FH and 20 subjects in a control group that were evaluated through a physical examination and blood tests. They also completed a food frequency questionnaire. (3) Results: Throughout our study, we observed several aspects: regardless of age, patients with FH had higher carbohydrate intakes compared to the control group; from the same group, a positive correlation was observed between salami intake and the levels of glucose and glycated hemoglobin. Moreover, the sour cream preference was associated with higher liver function tests. In the control group, we observed a higher intake of pasta and fast food and fewer fruit portions. (4) Conclusions: As far as we know, this is the first study from Romania that evaluated the eating habits of patients diagnosed with FH. Our study reveals that, although patients with FH avoid junk food, they still have a high intake of carbohydrates when compared to the control group. Further research is needed in order to get a comprehensive nutritional evaluation of these patients. 相似文献
1000.
Alexey D. Sereda Mikhail E. Vlasov Galina S. Koltsova Sergey Y. Morgunov Dmitry A. Kudrjashov Irina P. Sindryakova Olga L. Kolbasova Valentina M. Lyska Andrei Y. Koltsov Sergey P. Zhivoderov Elena Y. Pivova Vladimir M. Baluishev Andrey E. Gogin Denis V. Kolbasov 《Viruses》2022,14(8)
The African swine fever virus (ASFV) is the cause of a recent pandemic that is threatening the global pig industry. The virus infects domestic and wild pigs and manifests with a variety of clinical symptoms, depending on the strain. No commercial vaccine is currently available to protect animals from this virus, but some attenuated and recombinant live vaccine candidates might be effective against the disease. This article describes the immunobiological characteristics of one such candidate—the laboratory-attenuated ASFV strain, Katanga-350—which belongs to genotype I. In this study, we assessed clinical signs and post-mortem changes, the levels of viremia and the presence of viral DNA caused by injection of ASF virus strains Katanga-350, Lisbon-57, and Stavropol 08/01. Intramuscular injection of this strain protected 80% of pigs from a virulent strain of the same genotype and seroimmunotype (Lisbon-57). At least 50% of the surviving pigs received protection from subsequent intramuscular infection with a heterologous (genotype II, seroimmunotype VIII) virulent strain (Stavropol 08/01). Virus-specific antibodies were detectable in serum and saliva samples between 8–78 days after the first inoculation of the Katanga-350 strain (the observational period). The results suggested that this strain could serve as a basis for the development of a recombinant vaccine against ASF viruses belonging to seroimmunotype I. 相似文献