全文获取类型
收费全文 | 2889篇 |
免费 | 175篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 31篇 |
儿科学 | 88篇 |
妇产科学 | 65篇 |
基础医学 | 277篇 |
口腔科学 | 54篇 |
临床医学 | 285篇 |
内科学 | 602篇 |
皮肤病学 | 44篇 |
神经病学 | 133篇 |
特种医学 | 99篇 |
外科学 | 494篇 |
综合类 | 48篇 |
一般理论 | 7篇 |
预防医学 | 309篇 |
眼科学 | 104篇 |
药学 | 291篇 |
中国医学 | 26篇 |
肿瘤学 | 126篇 |
出版年
2024年 | 8篇 |
2023年 | 33篇 |
2022年 | 105篇 |
2021年 | 115篇 |
2020年 | 84篇 |
2019年 | 123篇 |
2018年 | 139篇 |
2017年 | 105篇 |
2016年 | 112篇 |
2015年 | 111篇 |
2014年 | 144篇 |
2013年 | 206篇 |
2012年 | 257篇 |
2011年 | 270篇 |
2010年 | 149篇 |
2009年 | 131篇 |
2008年 | 180篇 |
2007年 | 156篇 |
2006年 | 148篇 |
2005年 | 122篇 |
2004年 | 90篇 |
2003年 | 85篇 |
2002年 | 56篇 |
2001年 | 22篇 |
2000年 | 12篇 |
1999年 | 9篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1987年 | 7篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1975年 | 5篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 3篇 |
1968年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有3083条查询结果,搜索用时 15 毫秒
91.
92.
Mohsen Rakhsha Rezvan Hosseinzadeh Dariush Hosseinzadeh Morteza Behnamfar Kataneh Kazemi 《Clinical Case Reports》2022,10(2)
Acute appendicitis can be associated with uncommon complications such as necrotizing fasciitis. We present a case of a 37‐year‐old woman referred to our hospital with a 1‐week history of significant weakness, anorexia, and mild abdominal pain. According to laboratory and radiographic data, the patient was diagnosed with perforated appendicitis and gangrene. 相似文献
93.
Eissa Soleymani Sohrab Sayyadi Hossein Pazoki Mahdi Fakhar Elham Sadat Banimostafavi Mohsen Kolivand Lotfollah Davoodi Mostafa Soleymani 《Clinical Case Reports》2022,10(2)
Cystic echinococcosis is one of the most important zoonotic parasitic diseases caused by the tapeworm Echinococcus granulosus. To date, the genotype of multivesicular CE has not been identified. In this regard, the genotyping of multivesicular types of CE could help clinicians understand and manage the disease effectively. 相似文献
94.
Mohsen Al-Qhtani Ghulam M. Mustafa Nasheeta Mazhar Sonia Bouzgarrou Qasim Mahmood Abeer Mera Zaki I. Zaki Nasser Y. Mostafa Saad H. Alotaibi Mohammed A. Amin 《Materials》2022,15(1)
In ferromagnetic semiconductors, the coupling of magnetic ordering with semiconductor character accelerates the quantum computing. The structural stability, Curie temperature (Tc), spin polarization, half magnetic ferromagnetism and transport properties of ZnX2Se4 (X = Ti, V, Cr) chalcogenides for spintronic and thermoelectric applications are studied here by density functional theory (DFT). The highest value of Tc is perceived for ZnCr2Se4. The band structures in both spin channels confirmed half metallic ferromagnetic behavior, which is approved by integer magnetic moments (2, 3, 4) μB of Ti, V and Cr based spinels. The HM behavior is further measured by computing crystal field energy crystal, exchange energies x(d), x (pd) and exchange constants (No and No ). The thermoelectric properties are addressed in terms of electrical conductivity, thermal conductivity, Seebeck coefficient and power factor in within a temperature range 0–400 K. The positive Seebeck coefficient shows p-type character and the PF is highest for ZnTi2Se4 (1.2 × 1011 W/mK2) among studied compounds. 相似文献
95.
Mohsen Raza Ryan Geleit James Houston Rachel Williams Alex Trompeter 《The British journal of radiology》2021,94(1125)
Objectives:Orthopaedic surgeons have a responsibility to minimise risks of ionising radiation to patients, themselves and staff. This study aims to establish the understanding of radiation practice, legislation and risk by orthopaedic surgeons.Methods:A nationwide online survey of UK-based orthopaedic surgeons was conducted. Participants answered 18 multiple-choice questions assessing level of radiation safety training, basic principles/knowledge of ionising radiation, relevant legislation and operating practice.Results:A total of 406 surgeons completed the survey. 92% reported using intraoperative ionising radiation at least once per week. 38% received no formal training on radiation safety. Knowledge of basic principles of radiation and legislation was limited. There was variable knowledge when labelling an image intensifier machine and choosing its safest orientation. Poor uptake of radiation protection equipment was noted. Only 19% agreed they had adequate training in ionising radiation safety and 27% reported receiving adequate training in equipment emitting ionising radiation in the operating theatre.Conclusion:Many orthopaedic surgeons in the UK do not believe they are adequately trained in radiation safety. There is a deficiency amongst practicing surgeons in basic knowledge, relevant legislation and practicalities of the use of ionising radiation in the operating room. This could potentially put patients and health-care professionals at additional risk. We recommend that a standardised national training programme on the basic principles and safety of ionising radiation is implemented for all practicing orthopaedic surgeons.Advances in knowledge:This paper is the first UK national survey amongst orthopaedic surgeons and is one of the largest reported internationally. 相似文献
96.
Elham Bahreini Yousef Rezaei-Chianeh Mohsen Nabi-Afjadi 《The review of diabetic studies : RDS》2021,17(1):1
Uncontrolled or chronic hyperglycemia causes kidney failure induced by the dysfunction of biomolecules and upregulation of inflammatory cytokines and growth factors. The reninangiotensin system (RAS) is incorporated in the regulation of renal hemodynamics. In a healthy state, local RAS is independent of systemic RAS. However, in pathological conditions such as chronic hyperglycemia, angiotensin II (Ang II) increases locally and causes tissue damage, mainly through the induction of oxidative stress, inflammation, and upregulation of some growth factors and their receptors. Such tissue events may cause disruption of the glomerular filtration barrier, thickening and hypertrophy of the glomerular basement membrane, microvascular hyperpermeability, proteinuria, and finally decrease in the glomerular filtration rate (GFR). Reduced GFR causes the kidney to sense falsely a low blood pressure condition and respond to it by stimulating systemic and local RAS. Therefore, patients with diabetic nephropathy (DN) suffer from chronic hypertension. In contrast to local RAS, there are alternative pathways in the kidney that act protectively by reducing tissue Ang II. Such autoregulatory and protective mechanisms are weakened in chronic kidney disease. Previously, it was presumed that systemic RAS inhibitors such as ACE inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) could prevent renal damage by controlling blood pressure and proteinuria. However, the progression of renal failure to end-stage renal disease (ESRD), despite such treatments, indicates the presence of factors other than Ang II. This review highlights the molecular mechanism in renal disease and discusses pharmaceutical and therapeutic approaches. 相似文献
97.
This work aimed at developing a natural compound-based hydrogel adsorbent to remove diclofenac as a model pharmaceutical from water. First, graphene oxide–chitosan (GO–CTS) and amine graphene oxide–chitosan (AGO–CTS) hydrogel adsorbents were synthesized via a facile mechanical mixing method. The synthesized materials were characterized through Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning and transmission electron microscopy (SEM and TEM), Raman spectroscopy, and thermogravimetric analysis (TGA) techniques. In the second stage, adsorption experiments were conducted to determine the best GO to CTS ratio and find the optimized adsorption parameters, including the initial drug concentration, adsorbent dosage, pH, and temperature. The results showed that the optimal GO to CTS mass ratio is 2 : 5 and thus the same ratio was selected as the AGO to CTS mass ratio to understand the effect of amine-functionalization on removal efficiency. The optimal adsorption parameters were determined to be pH of 5, Ci of 100 ppm and dosage of 1.5 g L−1, where 90.42% and 97.06% removal was achieved for optimal GO–CTS and AGO–CTS hydrogel adsorbents, respectively. Langmuir and Freundlich isotherms models were employed to investigate the adsorption behavior of diclofenac onto the synthesized hydrogels. The results revealed that the adsorption tends to be of the monolayer type and homogeneous, as the results were in better accordance with the Langmuir model than the Freundlich model. The thermodynamics of adsorption demonstrated that the adsorption is exothermic, exhibiting higher removal efficiency at lower temperatures. Furthermore, Gibb''s free energy change of adsorption (ΔG) suggested that the adsorption is spontaneous, being more spontaneous for AGO–CTS than GO–CTS hydrogels. Finally, the regeneration ability of the hydrogel adsorbents was studied in five consecutive cycles. The adsorbent maintained its efficiency at a relatively high level for three cycles but a considerable decrease was observed between the third and the fourth cycle, indicating that the hydrogels were recoverable for three cycles.This work aimed at developing a natural compound-based hydrogel adsorbent to remove diclofenac as a model pharmaceutical from water. 相似文献
98.
Dinesh Voruganti Ghanshyam Shantha Sushma Dugyala Alexander Bolton Ala Mohsen Subodh Devabhaktuni Hakan Paydak Jawahar L Mehta 《老年心脏病学杂志》2021,18(2):114-122
BACKGROUND Nonagenarians(NG),individuals aged≥90 years,constitute an increasing proportion of hospitalizations presenting with atrial fibrillation(AF).However,not much is known about demographics,clinical outcomes,and trends of hospitalizations.Therefore,we analyzed data about hospitalizations and clinical outcomes among NGs with AF over ten years from 2005 to 2014 using a publically available database,the National Inpatient Sample.METHODS All hospitalizations and major outcomes of subjects≥90 years with a primary diagnosis of AF(ICD-9-CM code 427.31)over a ten-year period were assessed in this study by multivariate logistic regression analysis.RESULTS There were more females than males(176,268 females,51,384 males)in this analysis.The number of hospitalizations for AF among NG increased by 50%(17,295 in 2005 to 25,830 in 2014).Males were more likely to undergo cardioversion(6.14%of males vs.5.06%of females,P<0.0001).Over this period,in-hospital mortality declined from 3.21%in 2005 to 2.38%in 2014(P=0.0041),with higher in-hospital mortality in males(3.23%in males vs.2.76%in females,P=0.0138),mean length of hospitalization decreased from 4.53 days to 4.13 days(P<0.0001),the prevalence of congestive heart failure fell from 0.48%to 0.23%(P=0.0257),and the use of anticoagulation increased from 6.09%to 14.54%(P<0.0001).In a multivariate analysis,hospital admission on the weekend,Elixhauser comorbidity index,CHA2DS2VASc score,acute respiratory failure,and the length of hospital stay were associated with a higher risk of in-hospital mortality.CONCLUSIONS From 2005 to 2014,AF-related hospitalizations among NGs increased,more so in in females population,mortality trends improved,rates of anticoagulation increased,and cardioversions increased.Despite the decreasing trend of in-hospital mortality since 2005,the relatively high mortality rate in males warrants further studies. 相似文献
99.
Abdel Mohsen Nomeir Robert A. Turner Lester E. Watts 《Arthritis \u0026amp; Rheumatology》1979,22(6):561-564
Initial studies from Bowman Gray School of Medicine showed that 18 of 30 patients with classic rheumatoid arthritis (RA) had cardiac involvement from their disease. These abnormalities were detected by echocardiography and consisted of mitral valve and/or pericardial abnormalities. All patients were followed for 4 years from the initial workup. Mitral valve abnormalities were seen on followup in 63% of the patients who initially showed this abnormality, while pericardial effusion remained in 20%. Pericardial thickening persisted in 6 of 7 patients. None of the patients developed constrictive pericarditis or heart failure. There was no definite correlation between persistence of these abnormalities and other clinical data, but it was noticed that patients who had persistent pericardial effusion and mitral valve abnormalities showed a higher number of involved joints and a higher erythrocyte sedimentation rate. The cardiac abnormalities described in this study have remained clinically insignificant in this population of RA patients. 相似文献
100.
Analyzing the structure and function of the brain from a network perspective has increased considerably over the past two decades, with regional subnetwork analyses becoming prominent in the recent literature. However, despite the fact that the brain, as a complex system of interacting subsystems (i.e., subnetworks), cannot be fully understood by analyzing its constituent parts as independent elements, most studies extract subnetworks from the whole and treat them as independent networks. This approach entails neglecting their interactions with other brain regions and precludes identifying potential compensatory mechanisms outside the analyzed subnetwork. In this study, using simulated and empirical data, we show that the analysis of brain subnetworks within the context of their whole‐brain networks, that is, including their interactions with other brain regions, can yield different outcomes when compared to analyzing them as independent networks. We also provide a multivariate mixed‐effects modeling framework that allows analyzing subnetworks within the context of their whole‐brain networks, and show that it can better disentangle global (whole‐brain) and local (subnetwork) differences when compared to standard t‐test analyses. T‐test analyses may produce misleading results in identifying complex global and local level differences. The provided multivariate model is an extension of a previously developed model for global, system‐level hypotheses about the brain. The modified version detailed here provides the same utilities as the original model—quantifying the relationship between phenotypes and brain connectivity, comparing brain networks among groups, predicting brain connectivity from phenotypes, and simulating brain networks—but for local, subnetwork‐level hypotheses. 相似文献