全文获取类型
收费全文 | 9974篇 |
免费 | 688篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 213篇 |
儿科学 | 262篇 |
妇产科学 | 181篇 |
基础医学 | 1378篇 |
口腔科学 | 148篇 |
临床医学 | 1011篇 |
内科学 | 2009篇 |
皮肤病学 | 97篇 |
神经病学 | 972篇 |
特种医学 | 312篇 |
外国民族医学 | 2篇 |
外科学 | 1349篇 |
综合类 | 88篇 |
一般理论 | 8篇 |
预防医学 | 923篇 |
眼科学 | 242篇 |
药学 | 719篇 |
中国医学 | 9篇 |
肿瘤学 | 756篇 |
出版年
2021年 | 127篇 |
2020年 | 67篇 |
2019年 | 133篇 |
2018年 | 161篇 |
2017年 | 119篇 |
2016年 | 134篇 |
2015年 | 166篇 |
2014年 | 240篇 |
2013年 | 398篇 |
2012年 | 564篇 |
2011年 | 564篇 |
2010年 | 339篇 |
2009年 | 363篇 |
2008年 | 615篇 |
2007年 | 601篇 |
2006年 | 639篇 |
2005年 | 674篇 |
2004年 | 641篇 |
2003年 | 611篇 |
2002年 | 709篇 |
2001年 | 118篇 |
2000年 | 99篇 |
1999年 | 132篇 |
1998年 | 147篇 |
1997年 | 102篇 |
1996年 | 99篇 |
1995年 | 105篇 |
1994年 | 87篇 |
1993年 | 84篇 |
1992年 | 63篇 |
1991年 | 73篇 |
1990年 | 49篇 |
1989年 | 47篇 |
1988年 | 49篇 |
1987年 | 52篇 |
1986年 | 55篇 |
1985年 | 76篇 |
1984年 | 78篇 |
1983年 | 93篇 |
1982年 | 90篇 |
1981年 | 98篇 |
1980年 | 101篇 |
1979年 | 40篇 |
1978年 | 51篇 |
1977年 | 65篇 |
1976年 | 40篇 |
1975年 | 40篇 |
1974年 | 39篇 |
1973年 | 32篇 |
1964年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Hui Yu Zhengming Chen Karla V. Ballman Mark A. Watson Ramaswamy Govindan Irena Lanc David G. Beer Raphael Bueno Lucian R. Chirieac Michael Herman Chui Guoan Chen Wilbur A. Franklin David R. Gandara Carlo Genova Kristine A. Brovsky Mary-Beth M. Joshi Daniel T. Merrick William G. Richards Fred R. Hirsch 《Journal of thoracic oncology》2019,14(1):25-36
Objectives
Anti–programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) immunotherapy has demonstrated success in the treatment of advanced NSCLC. Recently, PD-1/PD-L1 blockade also has demonstrated interesting results in small trials of neoadjuvant treatment in stage IB to IIIA NSCLC. In addition, several clinical trials using anti–PD-1/PD-L1 immunotherapy as an adjuvant or neoadjuvant treatment in patients with resectable stage NSCLC are ongoing. However, few analyses of anti–PD-1/PD-L1 immunotherapy–related biomarkers in early-stage squamous cell lung carcinoma (SqCLC) have been reported. In this study, we evaluated PD-L1 protein expression, tumor mutation burden, and expression of an immune gene signature in early-stage SqCLC, providing data for identifying the potential role for patients with anti–PD-1/PD-L1 treatment in early-stage SqCLC.Methods
A total of 255 specimens from patients with early-stage SqCLC were identified within participating centers of the Strategic Partnering to Evaluate Cancer Signatures program. PD-L1 protein expression by immunohistochemistry was evaluated by using the Dako PD-L1 22C3 pharmDx kit on the Dako Link 48 auto-stainer (Dako, Carpinteria, CA). Tumor mutation burden (TMB) was calculated on the basis of data from targeted genome sequencing. The T-effector and interferon gamma (IFN-γ) gene signature was determined from Affymetrix gene chip data (Affymetrix, Santa Clara, CA) from frozen specimens.Results
The prevalence of PD-L1 expression was 9.8% at a tumor proportion score cutoff of at least 50%. PD-L1 mRNA and programmed cell death 1 ligand 2 mRNA positively correlated with PD-L1 protein expression on tumor cells (TCs) and tumor-infiltrating immune cells. PD-L1 protein expression on tumor-infiltrating immune cells was correlated with the T-effector and IFN-γ gene signature (p < 0.001), but not with TMB. For TCs, all of these biomarkers were independent of each other and neither PD-L1 protein expression, TMB, or T-effector and IFN-γ gene signatures were independently prognostic for patient outcomes.Conclusions
Evaluation of PD-L1 expression, TMB, and T-effector and IFN-γ gene signatures in the cohort with early-stage SqCLC found them to be independent of each other, and none was associated with overall survival. Our results also support the hypothesis that PD-L1 expression is regulated by an intrinsic mechanism on TCs and an adaptive mechanism on immune cells. 相似文献2.
Marco Bandini Sebastiano Nazzani Michele Marchioni Felix Preisser Zhe Tian Marco Moschini Firas Abdollah Nazareno Suardi Markus Graefen Francesco Montorsi Shahrokh F. Shariat Fred Saad Alberto Briganti Pierre I. Karakiewicz 《Clinical genitourinary cancer》2019,17(1):72-78.e4
Background
The rate of noninterventional treatment (NIT) in prostate cancer (PCa) active surveillance (AS) candidates is on the rise. However, contemporary data are unavailable. We described community-based NIT rates within 16 Surveillance Epidemiology and End Results (SEER) registries between 2010 and 2014.Patients and Methods
We identified 23,360 PCa patients who fulfilled the University of California San Francisco AS criteria (prostate-specific antigen [PSA] < 10 ng/mL, clinical T stage ≤ T2a, Gleason score ≤ 6, and positive cores < 33%). Annual NIT rates as well as patient distribution according to PSA, age, number of positive cores, and clinical T stage were studied. Multivariable logistic regression analysis tested NIT predictors.Results
Between 2010 and 2014, the NIT rate increased from 30.2% to 57.5% (P = .004). Within 16 SEER registries, NIT rates ranged from 25.9% to 62%. NIT rate increased uniformly within all examined registries. Of patient and tumor characteristics (PSA > 4 ng/mL, cT2a and > 1 positive core) only the proportion of NIT patients aged < 65 years increased over time from 47.3% to 53.2% (P = .03). By multivariable logistic regression analysis predicting NIT rate, older age (odd ratio [OR] = 1.05), more contemporary year of diagnosis (OR = 1.41), and being unmarried (OR = 1.45) and uninsured (OR = 2.41) were independent predictors.Conclusion
The NIT rate has markedly increased across all examined SEER registries. Nonetheless, important differences distinguish those who received high-end NIT from low-end NIT. PCa characteristics of NIT patients remained unchanged over time. However, in addition to geographical differences in NIT rates, patient characteristics such as age, marital status, and insurance status represent potential NIT access barriers. 相似文献3.
Ritu R. Gill Anne S. Tsao Hedy L. Kindler William G Richards Samuel G. Armato Roslyn J. Francis Daniel R. Gomez Suzanne Dahlberg Andreas Rimner Charles B. Simone Marc de Perrot Gideon Blumenthal Alex A. Adjei Raphael Bueno David H. Harpole Mary Hesdorffer Fred R. Hirsch Harvey I. Pass Anna K. Nowak 《Journal of thoracic oncology》2019,14(10):1718-1731
Detailed guidelines pertaining to radiological assessment of malignant pleural mesothelioma are currently lacking due to the rarity of the disease, complex morphology, propensity to invade multiple planes simultaneously, and lack of specific recommendations within the radiology community about assessment, reporting, and follow-up. In March 2017, a multidisciplinary meeting of mesothelioma experts was co-sponsored by the National Cancer Institute Thoracic Malignancy Steering Committee, International Association for the Study of Lung Cancer, and the Mesothelioma Applied Research Foundation. One of the outcomes of this conference was the foundation of detailed, multidisciplinary consensus imaging and management guidelines. Here, we present the recommendations for radiologic assessment of malignant pleural mesothelioma in the setting of clinical trial enrollment. We discuss optimization of imaging parameters across modalities, standardized reporting, and response assessment within clinical trials. 相似文献
4.
Tryntsje Fokkema Robert Burggraaff Fred Hartgens Bas Kluitenberg Evert Verhagen Frank J.G. Backx Henk van der Worp Sita M.A. Bierma-Zeinstra Bart W. Koes Marienke van Middelkoop 《Journal of Science and Medicine in Sport》2019,22(3):259-263
Objectives
To investigate the prognosis and possible prognostic factors of running-related injuries (RRIs) in novice runners.Design
Prospective cohort study.Methods
Participants of Start to Run, a 6-weeks course for novice runners in The Netherlands, were asked to participate in this study. Before the start of the course a baseline questionnaire, on demographics, physical activity and perceived health, was sent to runners willing to participate. The 26- or 52-weeks follow-up questionnaires assessed information on RRIs and their duration. Only participants that sustained a RRI during follow-up were included in the analyses. An injury duration of 10 weeks or shorter was regarded as a relatively good prognosis, while an injury duration of more than 10 weeks was defined as a poor prognosis. To determine the associations between baseline characteristics and injury prognosis and between injury location and injury prognosis, multivariable logistic regression analyses were performed.Results
347 participants (48.8%) sustained an RRI during follow-up. The RRIs had an overall median duration of eight weeks (range: 1–52 weeks). Participants with a previous RRI were more likely to have a poor prognosis (OR 2.31; 95%CI 1.12–4.79), while a calf injury showed a trend towards an association with a relatively good prognosis (OR 0.49; 95%CI 0.22–1.11).Conclusions
The duration of RRIs in novice runners is relatively long, with only calf injuries being associated with a good prognosis. This emphasizes the need of injury prevention measures in novice runners and adequate support during and after an RRI, especially in runners with a previous injury. 相似文献5.
Rosiello Giuseppe Knipper Sophie Palumbo Carlotta Dzyuba-Negrean Cristina Pecoraro Angela Mazzone Elio Mistretta Francesco A. Tian Zhe Capitanio Umberto Montorsi Francesco Shariat Shahrokh F. Saad Fred Briganti Alberto Karakiewicz Pierre I. 《International urology and nephrology》2019,51(12):2181-2188
International Urology and Nephrology - We tested the effect of marital status on cytoreductive nephrectomy, metastasectomy, and systemic therapy rates, as well as on cancer-specific mortality (CSM)... 相似文献
6.
Tryntsje Fokkema Fred Hartgens Bas Kluitenberg Evert Verhagen Frank J.G. Backx Henk van der Worp Sita M.A. Bierma-Zeinstra Bart W Koes Marienke van Middelkoop 《Journal of Science and Medicine in Sport》2019,22(1):106-111
Objectives
To determine the proportion of participants of a running program for novice runners that discontinued running and investigate the main reasons to discontinue and characteristics associated with discontinuation.Design
Prospective cohort study.Methods
The study included 774 participants of Start to Run, a 6-week running program for novice runners. Before the start of the program, participants filled-in a baseline questionnaire to collect information on demographics, physical activity and perceived health. The 26-weeks follow-up questionnaire was used to obtain information on the continuation of running (yes/no) and main reasons for discontinuation. To determine predictors for discontinuation of running, multivariable logistic regression was performed.Results
Within 26 weeks after the start of the 6-week running program, 29.5% of the novice runners (n = 225) had stopped running. The main reason for discontinuation was a running-related injury (n = 108, 48%). Being female (OR 1.74; 95% CI 1.13–2.68), being unsure about the continuation of running after the program (OR 2.06; 95% CI 1.31–3.24) and (almost) no alcohol use (OR 1.62; 95%CI 1.11–2.37) were associated with a higher chance of discontinuation of running. Previous running experience less than one year previously (OR 0.46; 95% CI 0.26–0.83) and a higher score on the RAND-36 subscale physical functioning (OR 0.98; 95% CI 0.96–0.99) were associated with a lower chance of discontinuation.Conclusions
In this group of novice runners, almost one-third stopped running within six months. A running-related injury was the main reason to stop running. Women with a low perceived physical functioning and without running experience were prone to discontinue running. 相似文献7.
Dirk-Wouter Smits Frank Backx Henk Van Der Worp Marienke Van Middelkoop Fred Hartgens Evert Verhagen 《Research in sports medicine (Print)》2019,27(1):72-87
This study examined the criterion validity of self-reported running-related injuries (RRI) by novice runners. Fifty-eight participants (41 females; age 46 ± 11 yrs) of the “Start-to-Run” program provided self-reports on their RRIs using an online questionnaire. Subsequently, they attended injury consultations with sports medicine physicians who provided physician-reports (blinded for the self-reports) as a reference standard. Self-reports and physician-reports included information on injury location (i.e., hip/groin, upper leg, knee, lower leg, and ankle/foot) and injury type (i.e., muscle-tendon unit, joint, ligament, or bone). Sensitivity, specificity, and positive predictive values were 100% for all five injury locations. For injury type, sensitivity was low (66% for muscle-tendon unit, 50% for ligament, and 40% for bone) and lowest for joint injuries (17%). In conclusion, the validity of self-reported RRIs by novice runners is good for injury locations but not for injury types. In particular for joint injuries, the validity of novice runners’ self-reports is low.
Abbreviations: RRI: Running Related Injury; SMC: Sports Medicine Centre; MTU: Muscle Tendon Unit; PPV: Positive Predictive Value 相似文献
8.
Javier Baladron Atsushi Nambu Fred H. Hamker 《The European journal of neuroscience》2019,49(6):754-767
Theories and models of the basal ganglia have mainly focused on the role of three different corticothalamic pathways: direct, indirect and hyperdirect. Although the indirect and the hyperdirect pathways are linked through the bidirectional connections between the subthalamic nucleus (STN) and the external globus pallidus (GPe), the role of their interactions has been mainly discussed in the context of a dysfunction (abnormal oscillations in Parkinson's disease) and not of its function. We here propose a novel role for the loop formed by the STN and the GPe. We show, through a neuro‐computational model, that this loop can bias the selection of actions during the exploratory period after a change in the environmental conditions towards alternative responses. Testing well‐known alternative solutions before completely random actions can reduce the time required for the search of a new response after a rule change. Our simulations further show that the knowledge acquired by the indirect pathway can be transferred into a stable memory via learning in the hyperdirect pathway to establish the blocking of unwanted responses. After a rule switch, first the indirect pathway learns to inhibit the previously correct actions. Once the new correct association is learned, the inhibition is transferred to the hyperdirect pathway through synaptic plasticity. 相似文献
9.
10.
Annemarie E. M. Post Johan Bussink Fred C. G. J. Sweep Paul N. Span 《Oncology research》2020,28(1):33-40
Tamoxifen-induced radioresistance, reported in vitro, might pose a problem for patients who receive neoadjuvant tamoxifen treatment and subsequently receive radiotherapy after surgery. Previous studies suggested that
DNA damage repair or cell cycle genes are involved, and could therefore be targeted to preclude the occurrence
of cross-resistance. We aimed to characterize the observed cross-resistance by investigating gene expression
of DNA damage repair genes and cell cycle genes in estrogen receptor-positive MCF-7 breast cancer cells that
were cultured to tamoxifen resistance. RNA sequencing was performed, and expression of genes characteristic
for several DNA damage repair pathways was investigated, as well as expression of genes involved in different
phases of the cell cycle. The association of differentially expressed genes with outcome after radiotherapy was
assessed in silico in a large breast cancer cohort. None of the DNA damage repair pathways showed differential
gene expression in tamoxifen-resistant cells compared to wild-type cells. Two DNA damage repair genes were
more than two times upregulated (NEIL1 and EME2), and three DNA damage repair genes were more than two
times downregulated (PCNA, BRIP1, and BARD1). However, these were not associated with outcome after
radiotherapy in the TCGA breast cancer cohort. Genes involved in G1, G1/S, G2, and G2/M phases were lower
expressed in tamoxifen-resistant cells compared to wild-type cells. Individual genes that were more than two
times upregulated (MAPK13) or downregulated (E2F2, CKS2, GINS2, PCNA, MCM5, and EIF5A2) were not
associated with response to radiotherapy in the patient cohort investigated. We assessed the expression of DNA
damage repair genes and cell cycle genes in tamoxifen-resistant breast cancer cells. Though several genes in
both pathways were differentially expressed, these could not explain the cross-resistance for irradiation in these
cells, since no association to response to radiotherapy in the TCGA breast cancer cohort was found. 相似文献