全文获取类型
收费全文 | 9391篇 |
免费 | 577篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 193篇 |
儿科学 | 188篇 |
妇产科学 | 210篇 |
基础医学 | 1141篇 |
口腔科学 | 723篇 |
临床医学 | 734篇 |
内科学 | 2360篇 |
皮肤病学 | 204篇 |
神经病学 | 778篇 |
特种医学 | 196篇 |
外科学 | 1414篇 |
综合类 | 65篇 |
一般理论 | 1篇 |
预防医学 | 583篇 |
眼科学 | 230篇 |
药学 | 597篇 |
中国医学 | 21篇 |
肿瘤学 | 377篇 |
出版年
2023年 | 91篇 |
2022年 | 209篇 |
2021年 | 408篇 |
2020年 | 214篇 |
2019年 | 394篇 |
2018年 | 417篇 |
2017年 | 271篇 |
2016年 | 305篇 |
2015年 | 330篇 |
2014年 | 475篇 |
2013年 | 503篇 |
2012年 | 815篇 |
2011年 | 825篇 |
2010年 | 424篇 |
2009年 | 359篇 |
2008年 | 536篇 |
2007年 | 542篇 |
2006年 | 474篇 |
2005年 | 413篇 |
2004年 | 395篇 |
2003年 | 296篇 |
2002年 | 279篇 |
2001年 | 103篇 |
2000年 | 110篇 |
1999年 | 110篇 |
1998年 | 44篇 |
1997年 | 47篇 |
1996年 | 19篇 |
1995年 | 24篇 |
1994年 | 15篇 |
1993年 | 25篇 |
1992年 | 52篇 |
1991年 | 49篇 |
1990年 | 58篇 |
1989年 | 57篇 |
1988年 | 40篇 |
1987年 | 30篇 |
1986年 | 31篇 |
1985年 | 27篇 |
1984年 | 18篇 |
1983年 | 22篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 15篇 |
1979年 | 21篇 |
1977年 | 8篇 |
1976年 | 12篇 |
1975年 | 11篇 |
1970年 | 10篇 |
1969年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Samantha O. Brown Devin P. Effinger Rodrigo A. Montoro Nabil Daddaoua Zuzana Justinova Megan J. Moerke Charles W. Schindler Hank P. Jedema Charles W. Bradberry 《Neuropsychopharmacology》2022,47(7):1398
Traditional approaches for evaluating if compounds are reinforcing, and thus a risk for abuse, include preclinical self-administration procedures conducted in the absence of alternative reinforcers. While the track record of this approach for determining abuse potential is good, that for predicting efficacy of addiction treatments is not. An alternate approach would be economic choice between drug and nondrug rewards, with parametrically varied options from trial to trial. This would promote goal-directed decisions between reward modalities and should provide metrics that reflect changes in internal state that influence desirability of a given option. We report herein a high throughput economic choice procedure in which squirrel monkeys choose between a short-lived opiate, remifentanil, and a palatable food reward. Stimuli on touchscreens indicate the amount of each reward type offered by varying the number of reward-specific elements. The rapid clearance of remifentanil avoids accumulation of confounding levels of drug, and permits a large number of trials with a wide range of offers of each reward modality. The use of a single metric encompassing multiple values of each reward type within a session enables estimation of indifference values using logistic regression. This indifference value is sensitive to reward devaluation within each reward domain, and is therefore a useful metric for determining shifts in reward preference, as shown with satiation and pharmacological treatment approaches.Subject terms: Addiction, Decision 相似文献
42.
The obesity epidemic has serious implications for women of reproductive age; its rising incidence is associated not just with health implications for the mother but also has transgenerational ramifications for the offspring. Increased incidence of diabetes, cardiovascular disease, obesity, and kidney disease are seen in both the mothers and the offspring. Animal models, such as rodent studies, are fundamental to studying maternal obesity and its impact on maternal and offspring health, as human studies lack rigorous controlled experimental design. Furthermore, the short and prolific reproductive potential of rodents enables examination across multiple generations and facilitates the exploration of interventional strategies to mitigate the impact of maternal obesity, both before and during pregnancy. Given that obesity is a major public health concern, it is important to obtain a greater understanding of its pathophysiology and interaction with reproductive health, placental physiology, and foetal development. This narrative review focuses on the known effects of maternal obesity on the mother and the offspring, and the benefits of interventional strategies, including dietary intervention, before or during pregnancy on maternal and foetal outcomes. It further examines the contribution of rodent models of maternal obesity to elucidating pathophysiological pathways of disease development, as well as methods to reduce the impact of obesity on the mothers and the developing foetus. The translation of these findings into the human experience will also be discussed. 相似文献
43.
Effects of Osseodensification on Immediate Implant Placement: Retrospective Analysis of 211 Implants
Mrcio de Carvalho Formiga Kinga Grzech-Leniak Vittorio Moraschini Jamil Awad Shibli Rodrigo Neiva 《Materials》2022,15(10)
Osseodensification is a new method of bone instrumentation for dental implant placement that preserves bulk bone and increases primary implant stability, and may accelerate the implant rehabilitation treatment period and provide higher success and survival rates than conventional methods. The aim of this retrospective study was to evaluate and discuss results obtained on immediate implant placement with immediate and delayed loading protocols under Osseodensification bone instrumentation. This study included private practice patients that required dental implant rehabilitation, between February 2017 and October 2019. All implants were placed under Osseodensification and had to be in function for at least 12 months to be included on the study. A total of 211 implants were included in the study, with a 98.1% total survival rate (97.9% in the maxilla and 98.5% in the mandible). For immediate implants with immediate load, 99.2% survival rate was achieved, and 100% survival rate for immediate implant placement without immediate load cases. A total of four implants were lost during this period, and all of them were lost within two months after placement. Within the limitations of this study, it can be concluded that Osseodensification bone instrumentation provided similar or better results on survival rates than conventional bone instrumentation. 相似文献
44.
Magaly Martinez Phuong-Vi Nguyen Maxwell Su Ftima Cardozo Adriana Valenzuela Laura Franco María Eugenia Galeano Leticia Elizabeth Rojas Chyntia Carolina Díaz Acosta Jons Fernndez Joel Ortiz Florencia del Puerto Laura Mendoza Eva Nara Alejandra Rojas Jesse J. Waggoner 《Viruses》2022,14(5)
SARS-CoV-2 variant detection relies on resource-intensive whole-genome sequencing methods. We sought to develop a scalable protocol for variant detection and surveillance in Paraguay, pairing rRT-PCR for spike mutations with Nanopore sequencing. A total of 201 acute-phase nasopharyngeal samples were included. Samples were positive for the SARS-CoV-2 N2 target and tested with the Spike SNP assay to detect mutations associated with the following variants: alpha (501Y), beta/gamma (417variant/484K/501Y), delta (452R/478K), and lambda (452Q/490S). Spike SNP calls were confirmed using amplicon (Sanger) sequencing and whole-genome (Nanopore) sequencing on a subset of samples with confirmed variant lineages. Samples had a mean N2 Ct of 20.8 (SD 5.6); 198/201 samples (98.5%) tested positive in the Spike SNP assay. The most common genotype was 417variant/484K/501Y, detected in 102/198 samples (51.5%), which was consistent with the P.1 lineage (gamma variant) in Paraguay. No mutations (K417 only) were found in 64/198 (32.3%), and K417/484K was identified in 22/198 (11.1%), consistent with P.2 (zeta). Seven samples (3.5%) tested positive for 452R without 478K, and one sample with genotype K417/501Y was confirmed as B.1.1.7 (alpha). The results were confirmed using Sanger sequencing in 181/181 samples, and variant calls were consistent with Nanopore sequencing in 29/29 samples. The Spike SNP assay could improve population-level surveillance for mutations associated with SARS-CoV-2 variants and inform the judicious use of sequencing resources. 相似文献
45.
Maren Hedtke Rodrigo Pessoa Rejas Matthias F. Froelich Volker Ast Angelika Duda Laura Mirbach Victor Costina Uwe M. Martens RalfDieter Hofheinz Michael Neumaier Verena Haselmann 《Molecular oncology》2022,16(10):2042
The analysis of circulating tumor DNA (ctDNA) is at the threshold of implementation into standard care for colorectal cancer (CRC) patients. However, data about the clinical utility of liquid profiling (LP), its acceptance by clinicians, and its integration into clinical workflows in real‐world settings remain limited. Here, LP tests requested as part of routine care since 2016 were retrospectively evaluated. Results show restrained request behavior that improved moderately over time, as well as reliable diagnostic performance comparable to translational studies, with an overall agreement of 91.7%. Extremely low ctDNA levels at < 0.1% in over 20% of cases, a high frequency of concomitant driver mutations (in up to 14% of cases), and ctDNA levels reflecting the clinical course of disease were revealed. However, certain limitations hampering successful translation of ctDNA into clinical practice were uncovered, including the lack of clinically relevant ctDNA thresholds, appropriate time points of LP requests, and integrative evaluation of ctDNA, imaging, and clinical findings. In conclusion, these results highlight the potential clinical value of LP for CRC patient management and demonstrate issues that need to be addressed for successful long‐term implementation in clinical workflows. 相似文献
46.
Gaurav Singh Gaurav Singh Kushwah Tanvi Singh Rohit Kumar Thapa Urs Granacher Rodrigo Ramirez-Campillo 《Journal of Sports Science and Medicine》2022,21(2):277
This study aimed at examining the effects of nine weeks of sand-based plyometric-jump training (PJT) combined with endurance running on either outdoor or treadmill surface on measures of physical fitness. Male participants (age, 20.1 ± 1.7 years) were randomly assigned to a sand-based PJT combined with endurance running on outdoor surface (OT, n = 25) or treadmill surface (TT, n = 25). The endurance running intervention comprised a mixed training method, i.e., long slow distance, tempo, and interval running drills. A control group was additionally included in this study (CG, n = 25). Participants in CG followed their regular physical activity as OT and TT but did not receive any specific intervention. Individuals were assessed for their 50-m linear sprint time, standing long jump (SLJ) distance, cardiorespiratory fitness (i.e., Cooper test), forced vital capacity (FVC), calf girth, and resting heart rate (RHR). A three (groups: OT, TT, CG) by two (time: pre, post) ANOVA for repeated measures was used to analyze the exercise-specific effects. In case of significant group-by-time interactions, Bonferroni adjusted paired (within-group) and independent (between-group comparisons at post) t-tests were used for post-hoc analyses. Significant group-by-time interactions were found for all dependent variables (p < 0.001 – 0.002, ɳp2 = 0.16 – 0.78). Group-specific post-hoc tests showed improvements for all variables after OT (p < 0.001, Hedges’g effect size [g] = 0.05 – 1.94) and TT (p < 0.001, g = 0.04 – 2.73), but not in the CG (p = 0.058 – 1.000, g = 0.00 – 0.34). Compared to CG, OT showed larger SLJ (p = 0.001), cardiorespiratory fitness (p = 0.004), FVC (p = 0.008), and RHR (p < 0.001) improvements. TT showed larger improvements in SLJ (p = 0.036), cardiorespiratory fitness (p < 0.001), and RHR (p < 0.001) compared with CG. Compared to OT, TT showed larger improvements for SLJ (p = 0.018). In conclusion, sand-based PJT combined with either OT or TT similarly improved most measures of physical fitness, with greater SLJ improvement after TT. Coaches may use both concurrent exercise regimes based on preferences and logistical constrains (e.g., weather; access to treadmill equipment). Key points
- Concurrent training in the form of sand-based plyometric-jump training and endurance running exercise can enhance physical fitness in young individuals;
- Compared to treadmill running, rating of perceived exertion was higher in outdoor running sessions;
- Sand-based plyometric-jump training may induce greater standing long jump performance when combined with endurance running on treadmill surface as compared to outdoor surface.
47.
48.
Romeika Lorena Mendes da Silva Tmara Taynah Medeiros da Silva Renata Lima Pessoa Ayane Cristine Alves Sarmento Kleyton Santos Medeiros Daniele Vieira Dantas Rodrigo Assis Neves Dantas 《Medicine》2022,101(24)
Introduction:Uterine cervix tumors have an invasive nature, with the capacity to proliferate to surrounding organs such as the vagina, bladder, and rectum, as well as the capacity for dissemination and involvement of structures distant from its place of origin. According to the International Federation of Gynecology and Obstetrics, patients with stages IB I, IB I microscopic (small dimension <4 cm) are indicated for radiotherapy or adjuvant chemoradiotherapy with cisplatin (40 mg/m2). However, cisplatin has side effects such as hematological implications (anemia, neutropenia, and thrombocytopenia), gastrointestinal disorders (nausea, vomiting, diarrhea, constipation), and fatigue. Zingiber officinale contains bioactive compounds that act on pregnancy and postoperative nausea, chemotherapy-induced nausea and vomiting, and also in the management of fatigue, myalgia, and insomnia. This study aimed to evaluate the effects of ginger on chemotherapy-induced nausea and vomiting in patients with cervical cancer undergoing treatment with cisplatin and radiotherapy.Methods and analyses:A randomized intervention clinical and controlled trial with a triple-blind design is described, comparing the effects of institutional antiemetic therapy alone, as well as in combination with 2 different ginger concentrations.Ethics and dissemination:Due to the nature of the study, we obtained approval from the Division Ethics Committee of Liga Contra o Câncer. All participants signed an informed consent form prior to randomization. The results of this study will be published in peer-reviewed journals. The data collected will also be available in a public repository of data.Trial registration number:This study is registered in the Brazilian Registry of Clinical Trials under number RBR-47yx6p9. This study was approved by the Division Ethics Committee of Liga Contra o Câncer under CAAE 40602320.0.0000.5293. 相似文献
49.
Andrés Coca-Pelaz Juan P. Rodrigo Daniela Paccagnella Robert P. Takes Alessandra Rinaldo Carl E. Silver Julia A. Woolgar Michael L. Hinni Alfio Ferlito 《European archives of oto-rhino-laryngology》2013,270(2):417-423
Gastroesophageal reflux disease can present with a wide variety of extraesophageal symptoms. In particular, the type of disease characterized predominately by laryngopharyngeal reflux may be difficult to diagnose because of the absence of regurgitation or heartburn. The available battery of diagnostic tools is often insufficient to confirm a diagnosis of reflux, so the diagnosis is often made by elimination. In many cases, treatment with proton pump inhibitors will relieve symptoms and respiratory complications, despite the persistence of non-acidic reflux. Such treatment is often employed to “confirm” the diagnosis, as measured by patient response. Many diseases have been related to this condition in the literature. The authors review knowledge about these manifestations and their relationship with refluxed gastric content. Physiopathology, symptoms and treatment are reviewed in order to clarify our understanding of laryngopharyngeal reflux diseases and related manifestations. 相似文献
50.
Prada Diddier Baccarelli Andrea A. Terry Mary Beth Valdéz Leonora Cabrera Paula Just Allan Kloog Itai Caro Haydee García-Cuellar Claudia Sánchez-Pérez Yesennia Cruz Rodrigo Diaz-Chávez Jose Cortés Carlo Pérez Delia Meneses-García Abelardo Cantú-de-León David Herrera Luis A. Bargalló Enrique 《Breast cancer research and treatment》2021,187(2):525-533
Breast Cancer Research and Treatment - Many patients seek breast reconstruction following mastectomy. Debate exists regarding the best reconstructive option. The authors evaluate outcomes comparing... 相似文献