全文获取类型
收费全文 | 53696篇 |
免费 | 3594篇 |
国内免费 | 263篇 |
专业分类
耳鼻咽喉 | 521篇 |
儿科学 | 1920篇 |
妇产科学 | 1369篇 |
基础医学 | 8038篇 |
口腔科学 | 794篇 |
临床医学 | 5162篇 |
内科学 | 12142篇 |
皮肤病学 | 1178篇 |
神经病学 | 5907篇 |
特种医学 | 1124篇 |
外科学 | 4365篇 |
综合类 | 297篇 |
现状与发展 | 1篇 |
一般理论 | 43篇 |
预防医学 | 5028篇 |
眼科学 | 869篇 |
药学 | 4056篇 |
中国医学 | 136篇 |
肿瘤学 | 4603篇 |
出版年
2024年 | 91篇 |
2023年 | 682篇 |
2022年 | 1440篇 |
2021年 | 2428篇 |
2020年 | 1397篇 |
2019年 | 1789篇 |
2018年 | 1968篇 |
2017年 | 1595篇 |
2016年 | 1756篇 |
2015年 | 1905篇 |
2014年 | 2475篇 |
2013年 | 3103篇 |
2012年 | 4565篇 |
2011年 | 4563篇 |
2010年 | 2423篇 |
2009年 | 2067篇 |
2008年 | 3448篇 |
2007年 | 3438篇 |
2006年 | 3106篇 |
2005年 | 2825篇 |
2004年 | 2617篇 |
2003年 | 2333篇 |
2002年 | 2107篇 |
2001年 | 239篇 |
2000年 | 183篇 |
1999年 | 252篇 |
1998年 | 335篇 |
1997年 | 285篇 |
1996年 | 193篇 |
1995年 | 184篇 |
1994年 | 183篇 |
1993年 | 143篇 |
1992年 | 97篇 |
1991年 | 85篇 |
1990年 | 65篇 |
1989年 | 77篇 |
1988年 | 73篇 |
1987年 | 64篇 |
1986年 | 59篇 |
1985年 | 60篇 |
1984年 | 83篇 |
1983年 | 67篇 |
1982年 | 78篇 |
1981年 | 66篇 |
1980年 | 61篇 |
1979年 | 29篇 |
1978年 | 33篇 |
1977年 | 35篇 |
1976年 | 25篇 |
1975年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
281.
282.
Anna Korneva Boris Straumal Alena Gornakova Askar Kilmametov ukasz Gondek Lidia Lityska-Dobrzyska Robert Chulist Magorzata Pomorska Pawe Ziba 《Materials》2022,15(12)
This paper discusses the features of ω-phase formation and its thermal stability depending on the phase composition, alloying element and the grain size of the initial microstructure of Ti–Nb and Ti–Mo alloys subjected to high-pressure torsion (HPT) deformation. In the case of two-phase Ti–3wt.% Nb and Ti–20wt.% Nb alloys with different volume fractions of α- and β-phases, a complete β→ω phase transformation and partial α→ω transformation were found. The dependence of the α→ω transformation on the concentration of the alloying element was determined: the greater content of Nb in the α-phase, the lower the amount of ω-phase that was formed from it. In the case of single-phase Ti–Mo alloys, it was found that the amount of ω-phase formed from the coarse-grained β-phase of the Ti–18wt.% Mo alloy was less than the amount of the ω-phase formed from the fine α′-martensite of the Ti–2wt.% Mo alloy. This was despite the fact that the ω-phase is easier to form from the β-phase than from the α- or α′-phase. It is possible that the grain size of the microstructure also affected the phase transformation, namely, the fine martensitic plates more easily gain deformation and overcome the critical shear stresses necessary for the phase transformation. It was also found that the thermal stability of the ω-phase in the Ti–Nb and Ti–Mo alloys increased with the increasing concentration of Nb or Mo. 相似文献
283.
Sylwia Wieder-Huszla Anita Chudecka-Gaz Aneta Cymbaluk-Poska Beata Karakiewicz Mateusz Bosiacki Dariusz Chlubek Anna Jurczak 《Nutrients》2022,14(12)
(1) Background: The aim of this study was to assess the concentrations of selected elements in female patients with cancer of the reproductive organs, taking into account the stage of treatment. (2) Methods: The study sample consisted of 51 patients with advanced endometrial cancer and ovarian cancer, undergoing chemotherapy. The median age of the studied patients with endometrial cancer was 66.0 years (IQR: from 60.75 to 70.25), and with ovarian cancer―60.0 years (IQR: from 49.0 to 64.0). Each of the qualified women, after consent to participate in the study, had her blood drawn several times (before surgery, the first course of chemotherapy, the third course of chemotherapy, and the sixth course of chemotherapy) in order to determine serum levels of macro- and micronutrients (Na, Mg, Ca, Zn, P, Cu, Fe, Cd, Ni, and Sr). (3) Results: In the study group of patients with cancer of the reproductive tract, the concentrations of iron (<0.001), magnesium (0.038), sodium (0.014), and nickel (0.037) varied significantly over the course of the study. The analysis showed that the interaction between the stage of chemotherapy and the type of cancer had an effect on the concentrations of magnesium and cadmium (p < 0.05). (4) Conclusions: In the studied group of patients with ovarian and endometrial cancer, the applied chemotherapy significantly changed the concentrations of Fe, Na, and Ni, regardless of the type of tumor. Changes in Mg and Cd concentrations resulted from the interaction between the stage of chemotherapy and the type of cancer. The results of serum concentrations of selected elements in women with cancer of the reproductive organs may help understand the physiological changes resulting from the applied chemotherapy. 相似文献
284.
Edyta Wernio Anna Kosowska Agnieszka Kuchta Agnieszka wikliska Kornelia Saaga-Zaleska Maciej Jankowski Przemysaw Kosowski Piotr Winiewski Jolanta Wierzba Sylwia Magorzewicz 《Nutrients》2022,14(12)
Introduction: The risk of obesity in children with Down syndrome is high. Undoubtedly, proper nutrition plays an important role in the prevention of excess body weight and is associated with a reduction of metabolic complications. The aim of the study was to assess the problem of disturbances in the nutritional status and eating habits of children with DS. Methods: A total of 39 patients were included in the study. The nutritional status was assessed by anthropometric tests and Dual X-ray Absorptiometry. Eating habits were assessed using the Child Eating Behavior Questionnaire and the Food Frequency Questionnaire. Blood samples were taken to determine the oxidative stress and lipid parameters. Results: Obesity was recognized in 15% of subjects and 23% were overweight. Children that were overweight were characterized by higher levels of triglycerides, atherogenic index of plasma, and apoA2 and apoE levels. Fat mass, fat mass/height2 index, and visceral fat mass correlated with thiobarbituric acid reactive substances and advanced oxidative protein product level. The analysis of the Child Eating Behavior Questionnaire showed that children struggling with being overweight were more interested in food compared to those with normal body weight. A positive correlation was identified between waist circumference and food interest categories. Insufficient consumption of dairy products, vegetables, whole grain products, as well as fruits, seeds, nuts, and fatty fish was noted. Patients were less likely to consume products that are a good source of mono- and polyunsaturated fatty acids. Conclusions: In children with Down syndrome and obesity, disturbances in lipid and oxidative stress parameters are observed. Abnormal eating habits in all children with Down syndrome regardless of their nutritional status were noted. Proper nutritional education, nutritional control, and management of metabolic problems are essential in this group of patients. 相似文献
285.
Daria Matyushkina Varvara Shokina Polina Tikhonova Valentin Manuvera Dmitry Shirokov Daria Kharlampieva Vasily Lazarev Anna Varizhuk Tatiana Vedekhina Alexander Pavlenko Leonid Penkin Georgij Arapidi Konstantin Pavlov Dmitry Pushkar Konstantin Kolontarev Alexander Rumyantsev Sergey Rumyantsev Lyubov Rychkova Vadim Govorun 《Viruses》2022,14(6)
COVID-19 caused by SARS-CoV-2 is continuing to spread around the world and drastically affect our daily life. New strains appear, and the severity of the course of the disease itself seems to be decreasing, but even people who have been ill on an outpatient basis suffer post-COVID consequences. Partly, it is associated with the autoimmune reactions, so debates about the development of new vaccines and the need for vaccination/revaccination continue. In this study we performed an analysis of the antibody response of patients with COVID-19 to linear and conformational epitopes of viral proteins using ELISA, chip array and western blot with analysis of correlations between antibody titer, disease severity, and complications. We have shown that the presence of IgG antibodies to the nucleoprotein can deteriorate the course of the disease, induce multiple direct COVID-19 symptoms, and contribute to long-term post-covid symptoms. We analyzed the cross reactivity of antibodies to SARS-CoV-2 with own human proteins and showed that antibodies to the nucleocapsid protein can bind to human proteins. In accordance with the possibility of HLA presentation, the main possible targets of the autoantibodies were identified. People with HLA alleles A01:01; A26:01; B39:01; B15:01 are most susceptible to the development of autoimmune processes after COVID-19. 相似文献
286.
Galina V. Kurlyandskaya Luis Lezama Anna A. Pasynkova Stanislav O. Volchkov Vera A. Lukshina Aitor Larraaga Natalia V. Dmitrieva Anastasia V. Timofeeva Iaki Orue 《Materials》2022,15(12)
The ferromagnetic resonance (FMR) in the frequency range of 0.5 to 12.5 GHz has been investigated as a function of external magnetic field for rapidly quenched Fe3Co67Cr3Si15B12 amorphous ribbons with different features of the effective magnetic anisotropy. Three states of the ribbons were considered: as-quenched without any treatment; after relaxation annealing without stress at the temperature of 350 °C during 1 h; and after annealing under specific stress of 230 MPa at the temperature of 350 °C during 1 h. For FMR measurements, we adapted a technique previously proposed and tested for the case of microwires. Here, amorphous ribbons were studied using the sample holder based on a commercial SMA connector. On the basis of the measurements of the reflection coefficient S11, the total impedance including its real and imaginary components was determined to be in the frequency range of 0.5 to 12.5 GHz. In order to confirm the validity of the proposed technique, FMR was also measured by the certified cavity perturbation technique using a commercial Bruker spectrometer operating at X-band frequency of 9.39 GHz. As part of the characterization of the ribbons used for microwave measurements, comparative analysis was performed of X-ray diffraction, optical microscopy, transmission electron microscopy, inductive magnetic hysteresis loops, vibrating sample magnetometry, magneto-optical Kerr effect (including magnetic domains) and magnetoimpedance data for of all samples. 相似文献
287.
ObjectivesAccording to the EULAR recommendations, remission or low disease activity (LDA) in rheumatoid arthritis should be achieved by a maximum of 6 months (M6) of treatment. Data on the use of tocilizumab (TCZ) as first-line biologic treatment in rheumatoid arthritis (RA) in routine clinical practice in Poland are lacking.Material and methodsThis multicenter, non-interventional, prospective, observational study recruited adults, presenting with moderate-to-severe RA, showing an inadequate response or intolerance to disease-modifying antirheumatic drugs, where TCZ was the first-line biologic treatment. The effectiveness of TCZ was assessed by the proportion of patients achieving remission and low disease activity following 6 months of treatment with intravenous TCZ. The impact of comorbidities on treatment outcomes was measured using the Rheumatic Disease Comorbidity Index (RDCI).ResultsTotal remission rates at months 3 and 6 were 6% and 31%, respectively. Low disease activity was reported in 10% and 92% of the patients at 3 and 6 months, respectively. The response was comparable between TCZ as monotherapy and in combination with methotrexate. Mean DAS28 decreased from 6.61 at baseline to 4.27 at the scheduled time of the assessment (3 and 6 months). The Rheumatic Disease Comorbidity Index was not correlated with the number of patients achieving LDA at M3 and M6 or remission rates at M6. Remission rates correlated with RDCI at M3. A total of 114 adverse events were reported in 61 patients, among which five were considered as serious.ConclusionsThe study confirms the effectiveness and safety of TCZ in real-world settings as a first-line biologic treatment in patients with moderate-to-severe RA. Importantly, comorbidities do not affect the results of 6-month treatment with TCZ, that is, the optimal time to achieve at least LDA. Our results may improve the effects of RA therapy in Poland, especially in patients with comorbidities and those who, for various reasons, cannot receive optimal treatment with methotrexate. 相似文献
288.
Linda Su-Feher Anna N. Rubin Shanni N. Silberberg Rinaldo Catta-Preta Kenneth J. Lim Athena R. Ypsilanti Iva Zdilar Christopher S. McGinnis Gabriel L. McKinsey Thomas E. Rubino Jr. Michael J. Hawrylycz Carol Thompson Zev J. Gartner Luis Puelles Hongkui Zeng John L. R. Rubenstein Alex S. Nord 《Proceedings of the National Academy of Sciences of the United States of America》2022,119(15)
289.
Petronella Chirawu Jill Hanass-Hancock Toyin Janet Aderemi Liset de Reus Anna Sophie Henken 《Sexuality and disability》2014,32(3):259-277
Literature argues that people with disabilities have heightened risk of exposure to sexually transmitted infections, including HIV due to lack of HIV knowledge, access to health services, and increased risk of sexual abuse and poverty. People with disabilities lack access to sexuality education. Teachers should be at the forefront to address this; however there is little understanding of the knowledge, attitudes, practices and needs of teachers of learners with disabilities in regards to sexuality/HIV education in Africa. A pilot study was conducted in ten special schools (eight urban, two rural) representing four types of disabilities in South Africa. Data was collected from 99 teachers using scales investigating beliefs and practice in teaching sexuality education, perceived subjective norms, self-efficacy, and materials/professional preparation. Frequencies, means, standard deviations and Cronbach’s alphas were calculated for all scales. The data shows that overall teachers have positive attitudes towards teaching all elements of comprehensive sexuality education. However, they find it easier to discuss “soft topics” around relationships and personal skills (e.g., hygiene) than to talk about sexual behavior and functions. Teachers expressed confidence in their ability to teach sexuality education but indicated that their professional preparation and materials are not adequate to provide accessible sexuality education to their learners. The study highlights the need to develop appropriate materials and to build teachers’ capacity to deliver sexuality and HIV education to learners with disabilities. 相似文献
290.
Francesco Landi Riccardo Calvani Matteo Tosato Anna Maria Martone Domenico Fusco Alex Sisto Elena Ortolani Giulia Savera Sara Salini Emanuele Marzetti 《Journal of the American Medical Directors Association》2017,18(1):88.e17-88.e24