全文获取类型
收费全文 | 1015篇 |
免费 | 74篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 16篇 |
妇产科学 | 11篇 |
基础医学 | 109篇 |
口腔科学 | 34篇 |
临床医学 | 90篇 |
内科学 | 244篇 |
皮肤病学 | 15篇 |
神经病学 | 57篇 |
特种医学 | 9篇 |
外科学 | 229篇 |
综合类 | 21篇 |
一般理论 | 3篇 |
预防医学 | 75篇 |
眼科学 | 23篇 |
药学 | 95篇 |
中国医学 | 24篇 |
肿瘤学 | 35篇 |
出版年
2023年 | 10篇 |
2022年 | 36篇 |
2021年 | 77篇 |
2020年 | 24篇 |
2019年 | 40篇 |
2018年 | 36篇 |
2017年 | 35篇 |
2016年 | 28篇 |
2015年 | 39篇 |
2014年 | 50篇 |
2013年 | 64篇 |
2012年 | 74篇 |
2011年 | 73篇 |
2010年 | 48篇 |
2009年 | 34篇 |
2008年 | 51篇 |
2007年 | 49篇 |
2006年 | 70篇 |
2005年 | 42篇 |
2004年 | 37篇 |
2003年 | 27篇 |
2002年 | 22篇 |
2001年 | 13篇 |
2000年 | 13篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1094条查询结果,搜索用时 156 毫秒
41.
Afak Yusuf Sherwani Abdul Qayoom Shah Abdul Majeed Wani Ahmad Chalkoo Bashir Ahmad Khan Bashir Farooq Ahmad Sofi Ashfaq Amin Wani Wasim Lone Ab Hamid Sherwani Mehmood Rashid Sheikh Raj Reshi Sharma 《International journal of surgery case reports》2014,5(12):1285-1287
INTRODUCTION
Persistent Mullerian duct syndrome is a rare form of male pseudo-hermaphroditism characterized by the presence of Mullerian duct structures in an otherwise phenotypically, as well as genotypically, normal man; only a few cases have been reported in the worldwide literature. A great variety of organs have been found in indirect inguinal hernial sacs.PRESENTATION OF CASE
We report a case of 70 year old man, father of 4 children with unilateral cryptorchidism on the right side and left-sided obstructed inguinal hernia containing uterus and fallopian tube (that is, hernia uteri inguinalis; type I male form of persistent Mullerian duct syndrome) coincidentally detected during an operation for an obstructed left inguinal hernia.DISCUSSION
PMDS is usually coincidently detected during surgical operation, as was in our case. However pre-operative ultrasonography, computerized tomography and MRI allow possible pre-operative diagnosis.3CONCLUSION
In cases of unilateral or bilateral cryptorchidism associated with hernia, as in our patient''s case, the possibility of PMDS should be kept in mind. 相似文献42.
Fawad Javed Hameeda Bashir Ahmed Anwar Saeed Abid Mehmood Crawford Bain 《Journal of periodontology》2014,85(5):e130-e135
Background: The cytokine profile in unstimulated whole saliva (UWS) of patients with prediabetes and chronic periodontitis (CP) remains uninvestigated. The aim of this study is to assess interleukin (IL)‐6 and matrix metalloproteinase (MMP)‐8 levels in UWS of patients with CP with and without prediabetes. Methods: Eighty‐eight males (aged 39 to 51 years) were divided into three groups: group 1: 28 patients with CP and prediabetes; group 2: 30 patients with CP and without prediabetes; and group 3: 30 controls. Fasting blood glucose (FBG) and hemoglobin A1c (HbA1c) levels, periodontal parameters (plaque index, bleeding on probing, probing depth, attachment loss, and marginal bone loss), and number of missing teeth were recorded. UWS samples were collected, and UWS flow rate (UWSFR) was measured. IL‐6 and MMP‐8 were measured in UWS using enzyme‐linked immunosorbent assay. P values <0.05 were considered statistically significant. Results: Mean FBG and HbA1c levels were significantly higher in group 1 (119.3 ± 3.1 mg/dL and 6.1% ± 0.2%) than group 2 (80.1 ± 3.5 mg/dL and 4.8% ± 0.5%; P <0.001) and group 3 (75.3 ± 2.2 mg/dL and 4.3% ± 0.2%; P <0.05). UWSFR was significantly higher in groups 2 (0.53 ± 0.1 mL/minute; P <0.05) and 3 (0.51 ± 0.1 mL/minute; P <0.01) than group 1 (0.33 ± 0.05 mL/minute). Periodontal parameters were worse in group 1 (P <0.05) and group 2 (P <0.05) than group 3. There was no difference in periodontal parameters, numbers of missing teeth, or salivary IL‐6 and MMP‐8 levels between patients in groups 1 and 2. Conclusion: Salivary IL‐6 and MMP‐8 levels are elevated in patients with CP with and without prediabetes. 相似文献
43.
Fawad Javed Ali Saad Thafeed AlGhamdi Toshinari Mikami Abid Mehmood Hameeda Bashir Ahmed Lakshman P. Samaranayake Howard C. Tenenbaum 《Journal of periodontology》2014,85(2):234-241
Background: The effect of glycemic control on severity of periodontal inflammatory parameters in patients with prediabetes is unknown. The aim of the present study is to assess the effects of glycemic control on self‐perceived oral health, periodontal parameters, and marginal bone loss (MBL) in patients with prediabetes. Methods: A total of 303 individuals were included. Hemoglobin A1c (HbA1c) and fasting blood glucose levels (FBGLs) were recorded. Participants were divided into three groups: 1) group A: 75 patients with prediabetes (FBGLs = 100 to 125 mg/dL [HbA1c ≥5%]); 2) group B: 78 individuals previously considered prediabetic but having FBGLs <100 mg/dL (HbA1c <5%) resulting from dietary control; and 3) control group: 150 medically healthy individuals. Self‐perceived oral health, socioeconomic status, and education status were determined using a questionnaire. Plaque index (PI), bleeding on probing (BOP), probing depth (PD), and clinical attachment loss (AL) were recorded. Premolar and molar MBLs were measured on panoramic radiographs. Results: Periodontal parameters (PI, BOP, PD, and AL) (P <0.01) and MBL (P <0.01) were worse among individuals in group A than those in group B. Self‐perceived gingival bleeding (P <0.001), pain on chewing (P <0.001), dry mouth (P <0.001), and oral burning sensations (P <0.05) were worse among patients in group A than those in group B. There was no difference in periodontal parameters, MBL, and self‐perceived oral symptoms among patients with prediabetes in group B and healthy controls. Conclusions: Self‐perceived oral health, severity of periodontal parameters, and MBL are worse in patients with prediabetes than controls. Glycemic control significantly reduces the severity of these parameters as well as the state of prediabetes in affected individuals. 相似文献
44.
Muhammad R.Baig Robert D.Beck Jennifer L.Wilson Jennifer A.Lemmer Adeel Meraj Eric C.Meyer Jim Mintz Alan L.Peterson John D.Roache 《军事医学研究(英文)》2021,8(1):121-131
Background:Selective serotonergic reuptake inhibitors(SSRIs)are first-line pharmacologic treatments for patients with posttraumatic stress disorder(PTSD),but must be given over extended period of time before the onset of action.The use of SSRIs in PTSD patients with mild traumatic brain injury(mTBI)is problematic since SSRIs could exacerbate post-concussion syndrome(PCS)symptoms.VA/DOD guidelines identify trauma-focused psychotherapy as the best evidence-based treatment for PTSD,but overall effectiveness is limited by reduced levels of patient engagement and retention.A previous study from this research group suggested that quetiapine monotherapy,but not risperidone or valproate,could increase engagement in trauma-focused psychotherapy.Methods:We report the study protocol of a pilot study funded under the South-Central Mental Illness Research,Education,and Clinical Center pilot study program from the U.S.Department of Veterans Affairs.This randomized,open-label study was designed to evaluate the feasibility of completing a randomized trial of quetiapine vs.treatment as usual to promote patient engagement in PTSD patients with a history of mTBI.Discussion:We expect that the success of this ongoing study should provide us with the preliminary data necessary to design a full-scale randomized trial.Positive efficacy results in a full-scale trial should inform new VA guidelines for clinical practice by showing that quetiapine-related improvements in patient engagement and retention may be the most effective approach to assure that VA resources achieve the best possible outcome for veterans. 相似文献
45.
Jalal Mohammed Zayan Abdul Khaliq Rasheed Akbar John Mohammad Khalid Ahmad Faris Ismail Abdul Aabid Muneer Baig 《Materials》2022,15(1)
This study presents the rheological behavior of water-based GO-TiO2-Ag and rGO-TiO2-Ag ternary-hybrid nanofluids. The impact of nanoparticles’ volumetric concentration and temperature on the rheological properties were studied. All experiments were performed under temperatures ranging from 25 to 50 °C in the solid volume concentration range of 0.5–0.00005%. The data optimization technique was adopted using the Taguchi method. The types of nanomaterials, concentration, temperature, and shear rate were chosen to optimize the viscosity and shear stress. The effect of shear stress, angular sweep, frequency sweep, and damping factor ratio is plotted. The experimental results demonstrated that the rheological properties of the ternary hybrid nanofluid depend on the ternary hybrid nanofluid’s temperature. The viscosity of ternary hybrid nanofluids (THNf) change by 40% for GO-TiO2-Ag and 33% for rGO-TiO2-Ag when temperature and shear rates are increased. All the ternary hybrid nanofluids demonstrated non-Newtonian behavior at lower concentrations and higher shear stress, suggesting a potential influence of nanoparticle aggregation on the viscosity. The dynamic viscosity of ternary hybrid nanofluid increased with enhancing solid particles’ volume concentration and temperature. 相似文献
46.
47.
Abdul Samad Mohammed Omar Saad Aljebreen Abbas Saeed Hakeem Tahar Laoui Faheemuddin Patel Mirza Murtuza Ali Baig 《Materials》2022,15(3)
Due to rapid technological advancements, the demand for lightweight materials with improved tribo-mechanical properties is continuously growing. The development of composite materials is one of the routes taken by researchers to meet these target properties. Aluminum (Al) is one of the most suitable materials used for developing composites for a wide range of applications because of its light weight, high conductivity, and high specific strength. In this study, aluminum hybrid nanocomposites with alumina (10 Vol% Al2O3) and varying loadings of graphene oxide (0.25, 0.5 and 1 wt% GO) were fabricated using the spark plasma sintering technique. The tribological properties of the developed hybrid composites were evaluated by conducting ball-on-disk wear tests at a normal load of 3N, with a sliding speed of 0.1 m/s, and for a sliding distance of 100 m. A 440C hardened stainless steel ball with a diameter of 6.3 mm and a hardness of 62 RC was used as a counterface. Scanning electron microscopy (SEM), elemental X-ray dispersive analysis (EDS), and optical profilometry were used to ascertain the involved wear mechanisms. The results revealed that Al-10 Vol%Vol% Al2O3-0.25 wt% GO hybrid nanocomposite showed an increase of 48% in the hardness, a reduction of 55% in the specific wear rate, and a reduction of 5% in COF compared with pure aluminum. 相似文献
48.
49.
R. M. Arif Khalil Muhammad Iqbal Hussain Nadia Luqman Fayyaz Hussain Anwar Manzoor Rana Muhammad Saeed Akhtar Rana Farhat Mehmood 《RSC advances》2022,12(7):4395
The first-principles approach has been used while employing the Perdew–Burke–Ernzerhof exchange-correlation functional of generalized gradient approximation (PBE-GGA) along with the Hubbard parameter to study the structural, optoelectronic, mechanical and magnetic properties of titanium-based MAX materials Ti3AC2 (A = P, As, Cd) for the first time. As there is no band gap found between the valence and conduction bands in the considered materials, these compounds belong to the conductor family of materials. A mechanical analysis carried out at pressures of 0 GPa to 20 GPa and the calculated elastic constants Cij reveal the stability of these materials. Elastic parameters, i.e., Young''s, shear and bulk moduli, anisotropy factor and Poisson''s ratio, have been investigated in the framework of the Voigt–Reuss–Hill approximation. The calculated values of relative stiffness are found to be greater than ½ for Ti3PC2 and Ti3AsC2, which indicates that these compounds are closer to typical ceramics, which possess low damage tolerance and fracture toughness. Optical parameters, i.e., dielectric complex function, refractive index, extinction coefficient, absorption coefficient, loss function, conductivity and reflectivity, have also been investigated. These dynamically stable antiferromagnetic materials might have potential applications in advanced electronic and magnetic devices. Their high strength and significant hardness make these materials potential candidates as hard coatings.The first-principles approach has used the Perdew–Burke–Ernzerhof exchange-correlation functional of generalized gradient approximation along with the Hubbard parameter to study various properties of titanium-based MAX materials Ti3AC2 (A = P, As, Cd). 相似文献
50.
Simultaneous transcatheter pulmonary and tricuspid valve‐in‐valve implantation for the treatment of failing pulmonary and tricuspid bioprostheses 下载免费PDF全文
Muhammad Baig MD Oluseun Alli MD James Davies MD 《Catheterization and cardiovascular interventions》2016,87(7):1352-1355
We report a case of a patient with a history of bioprosthetic pulmonary and tricuspid valve replacement who developed significant stenosis and regurgitation of the bioprosthetic valves. Due to multiple comorbidities, he was deemed high risk for redo‐valve replacement surgery. He subsequently underwent percutaneous transcatheter pulmonary and tricuspid valve‐in‐valve procedure at the same setting. This is the first of such that is reported in the literature. © 2015 Wiley Periodicals, Inc. 相似文献