全文获取类型
收费全文 | 2533篇 |
免费 | 139篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 59篇 |
妇产科学 | 105篇 |
基础医学 | 164篇 |
口腔科学 | 77篇 |
临床医学 | 160篇 |
内科学 | 528篇 |
皮肤病学 | 40篇 |
神经病学 | 46篇 |
特种医学 | 113篇 |
外国民族医学 | 8篇 |
外科学 | 742篇 |
综合类 | 27篇 |
一般理论 | 3篇 |
预防医学 | 102篇 |
眼科学 | 66篇 |
药学 | 153篇 |
中国医学 | 8篇 |
肿瘤学 | 241篇 |
出版年
2024年 | 2篇 |
2023年 | 37篇 |
2022年 | 99篇 |
2021年 | 157篇 |
2020年 | 102篇 |
2019年 | 104篇 |
2018年 | 149篇 |
2017年 | 95篇 |
2016年 | 97篇 |
2015年 | 77篇 |
2014年 | 121篇 |
2013年 | 143篇 |
2012年 | 212篇 |
2011年 | 242篇 |
2010年 | 150篇 |
2009年 | 123篇 |
2008年 | 117篇 |
2007年 | 130篇 |
2006年 | 93篇 |
2005年 | 97篇 |
2004年 | 99篇 |
2003年 | 82篇 |
2002年 | 69篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1965年 | 2篇 |
排序方式: 共有2696条查询结果,搜索用时 15 毫秒
91.
Reham William Doss Abdel-Aziz A El-Rifaie Amr M Abdel-Wahab Yasser M Gohary Laila A Rashed 《Indian journal of dermatology》2016,61(4):408-412
Background:Vitiligo is a progressive depigmenting disorder characterized by the loss of functional melanocytes from the epidermis. The etiopathogenesis of vitiligo is still unclear. Heat shock proteins (HSPs) are prime candidates to connect stress to the skin. HSPs were found to be implicated in autoimmune diseases such as rheumatoid arthritis and other skin disorders as psoriasis.Results:Our analysis revealed a significantly higher expression of HSP-70 mRNA in lesional skin biopsies from vitiligo patients compared to nonlesional skin biopsies from vitiligo patients (P < 0.001) and compared to skin biopsies from healthy controls (P < 0.001). The level of HSP-70 was not found to be correlated with age, sex, or disease duration. The expression of HSP-70 was correlated with the disease activity and patients with active vitiligo showed higher mean HSP-70 level compared to those with inactive disease.Conclusions:HSP-70 plays a role in the pathogenesis of vitiligo and may enhance the immune response in active disease. 相似文献
92.
Objective
The aim of this study was to investigate the effect of dentin dryness on the variation in the probed nano-scale adhesion force between an AFM silicon nitride tip and demineralized intertubular dentin collagen fibrils network surface.Methods
Dentin specimens were etched with 37% phosphoric acid for 15 s and then divided into three groups. Specimens of the first two groups were air-dried for 5 or 10 s (DH5s and DH10s), respectively, whereas specimens of the third group were left in the hydrated condition (H). For each group, Force curves were characterized by contact-mode AFM and the adhesion force (Fad) was calculated. The structure of the demineralized collagen fibrils network was characterized by tapping mode AFM. The tensile bond strength (TBS) to dentin was evaluated using one alcohol-based dentin self-priming adhesive. The dentin/resin interface was investigated by SEM.Results
Dentin specimens in the wet-hydrated condition (H) showed significantly higher adhesion force and TBS values than dry-dehydrated specimens (DH5s and DH10s). AFM images showed open collagen fibrils network structure in wet-hydrated specimens (H), while the dry-dehydrated specimens (DH5s and DH10s) showed a collapsed appearance to varying degrees. SEM images revealed minimum resin infiltration in dry-dehydrated specimens.Significance
The nano-scale adhesion force between the AFM probe and demineralized intertubular dentin surface was shown to be sensitive to surface air-drying. The decrease in the nano-scale adhesion force with the increase in the time of air-dryness is related to dehydration of the demineralized collagen fibrils network surface. 相似文献93.
Rania H. Zakaria Nadine R. Barsoum Ramy E. Asaad Ayman A. El-Basmy Amr O. Azab 《The Egyptian Journal of Radiology and Nuclear Medicine》2011,42(3-4):289-295
PurposeTo demonstrate the superior role of multidetector computed tomography (MDCT) in delineation of the extracardiac vascular abnormalities including the pulmonary arterial tree, major aortopulmonary collateral arteries (MAPCAs), patent ductus arteriosus (PDA), and also the detection of the common and uncommon findings in Fallot Tetralogy cases for proper pre-surgical evaluation.Material and methodsA retrospective study of all multidetector CT images acquired to evaluate suspected cases of Tetralogy of Fallot sent by their respective referring physicians between April 2009 and August 2010. A total of 23 cases were included in this study. MDCT protocol, image analysis and calculations used in the diagnosis are explained in detail.ResultsDetailed explanation of the MDCT imaging findings in the 23 cases with Tetralogy of Fallot, as well as the common and uncommon associations of the disease, namely pulmonary atresia, MAPCAs, PDAs, atrial septal defects (ASDs), right sided aortic arch, and a few less common associations.ConclusionA customized approach to MDCT imaging improves the diagnostic accuracy and reduces unneeded prolongation of the study and sedation times. A careful preoperative perceptive of the complex cardiovascular anatomy in patients with Tetralogy of Fallot aids in exposing the patient to a directed and prepared surgical approach. 相似文献
94.
Manar Hussein Abdel-Sattar Omar Abdelaziz Amr Othman Othman Sherief Mohamed El-Refaei 《The Egyptian Journal of Radiology and Nuclear Medicine》2018,49(1):209-215
Objective
Our aim was evaluate the role the PET/CT in the assessment of response to therapy in patients with Non-Hodgkin extra-nodal lymphoma: in particular, a five-point scale (Deauville criteria), which can be employed for early- and late-therapeutic response assessment.Methods
Sixty patients with pathologically confirmed Non-Hodgkin lymphoma (NHL) were enrolled in this prospective study. All patients underwent the following PET/CT examinations: initial PET/CT for staging, interim PET/CT and end of treatment PET/CT. Response assessment was done using new Cheson’s guidelines and five-point scale (Deauville criteria).Results
All patients were evaluated for response to therapy in the early interim, followed by late interim, as well as end treatment assessment for the overall response. We found good concordance of response assessment according to the Deauville criteria classification with International Harmonization Project (IHP) classification. After early interim 48/60 patients had concordant designations (91.7%, 83.3%, 70%, and 33.3%) and 12 patients had discordant designations. After late interim, 56/60 patients had concordant designations (100%, 100%, 80%, and 50%) and four patients had discordant designations. After end of treatment, 54/60 patients had concordant designations (100%, 100% and 71.4%) and six patients has discordant designations.Conclusion
Response assessment according to the Deauville criteria classification showed good concordance with IHP classification. According to our findings, we recommend the use of Deauville criteria in reporting of PET/CT for staging and assessment of response to treatment. 相似文献95.
Mohamad F. Sherif Mohammed M. Dawoud Hanan A. Nagy Amr Abdelaziz Ghannam 《The Egyptian Journal of Radiology and Nuclear Medicine》2018,49(2):453-460
Aim and objectives
The aim of this study was to assess the role of 18-F FDG-PET/CT in evaluating the peripheral malignant neuronal affection as well as perineural tumoral spread that occurs in patients with cancers.Methodology
50 patients with clinical symptoms of neurological deficits (34 male and 16 female) were included, their ages ranged from 17 to 74 with a mean of 45?years. PET/CT was done for all patients followed by clinical correlation after anti-inflammatory drugs and chemotherapy.Results
Interpretation of the PET/CT studies and clinical correlation revealed 10 true positive cases with malignant neuronal involvement, 4 false positive cases diagnosed clinically as radiotherapy-induced neuropathy, 34 true negative cases and 2 false negative cases with negative PET/CT study and clinical evidence of nerve affection with sensitivity 83.33%, specificity 89.47%, PPV 71.43%, NPV 94.44% and diagnostic accuracy 88%. P-value?>?0.05 was considered statistically significant.Conclusion
PET/CT has a significant role in detection of neuronal involvement by malignancy in cancer patients. Correlation between PET/CT and clinical outcome after chemotherapy improves the accuracy of diagnosis. 相似文献96.
Maryline Beurg Lisa A. Schimmenti Alaa Koleilat Sami S. Amr Andrea Oza Amanda J. Barlow Angela Ballesteros Robert Fettiplace 《The Journal of neuroscience》2021,41(20):4378
Transmembrane channel-like protein isoform 1 (TMC1) is a major component of the mechano-electrical transducer (MET) channel in cochlear hair cells and is subject to numerous mutations causing deafness. We report a new dominant human deafness mutation, TMC1 p.T422K, and have characterized the homologous mouse mutant, Tmc1 p.T416K, which caused deafness and outer hair cell (OHC) loss by the fourth postnatal week. MET channels showed decreased Ca2+ permeability and resting open probability, but no change in single-channel conductance or expression. Three adjacent deafness mutations are TMC1 p.L416R, p.G417R, and p.M418K, the last homologous to the mouse Beethoven that exhibits similar channel effects. All substitute a positive for a neutral residue, which could produce charge screening in the channel pore or influence binding of an accessory subunit. Channel properties were compared in mice of both sexes between dominant (Tmc1 p.T416K, Tmc1 p.D569N) and recessive (Tmc1 p.W554L, Tmc1 p.D528N) mutations of residues near the putative pore of the channel. Tmc1 p.W554L and p.D569N exhibit reduced maximum current with no effect on single-channel conductance, implying a smaller number of channels transported to the stereociliary tips; this may stem from impaired TMC1 binding to LHFPL5. Tmc1 p.D528N, located in the pore''s narrowest region, uniquely caused large reductions in MET channel conductance and block by dihydrostreptomycin (DHS). For Tmc1 p.T416K and Tmc1 p.D528N, transduction loss occurred between P15 and P20. We propose two mechanisms linking channel mutations and deafness: decreased Ca2+ permeability, common to all mutants, and decreased resting open probability in low Ca2+, confined to dominant mutations.SIGNIFICANCE STATEMENT Transmembrane channel-like protein isoform 1 (TMC1) is thought to be a major component of the mechanotransducer channel in auditory hair cells, but the protein organization and channel structure are still uncertain. We made four mouse lines harboring Tmc1 point mutations that alter channel properties, causing hair cell degeneration and deafness. These include a mouse homolog of a new human deafness mutation pT416K that decreased channel Ca2+ permeability by introducing a positively-charged amino acid in the putative pore. All mutations are consistent with the channel structure predicted from modeling, but only one, p.D528N near the external face of the pore, substantially reduced channel conductance and Ca2+ permeability and virtually abolished block by dihydrostreptomycin (DHS), strongly endorsing its siting within the pore. 相似文献
97.
Amr Menshawy Hussien Ahmed Ammar Ismail Abdelrahman Ibrahim Abushouk Esraa Ghanem Ravikishore Pallanti Ahmed Negida 《Neurological sciences》2018,39(1):31-44
We performed this systematic review and meta-analysis to evaluate the tolerability and efficacy of intranasal sumatriptan, a selective serotonin agonist, compared to placebo or other migraine therapeutics for the treatment of acute migraine attacks. We searched PubMed, SCOPUS, Embase, and Cochrane CENTRAL for relevant randomized controlled trials (RCTs). Data were extracted from eligible studies and pooled as risk ratios (RR), using RevMan software. We performed subgroup and meta-regression analyses for different doses and treatment endpoints. Sixteen RCTs (n = 5925 patients) matched our inclusion criteria. The overall effect-estimate showed that intranasal sumatriptan was superior to placebo in terms of pain relief (RR = 1.70, 95% CI [1.31, 2.21], p < 0.0001) and headache relief (RR = 1.58, 95% CI [1.35, 1.84], p < 0.00001) at 2 h. Although sumatriptan was superior to placebo in terms of headache relief at 30 min (RR = 1.31, 95% CI [1.08, 1.59], p = 0.005), no significant difference was found between both groups in terms of the frequency of pain-free participants at 30 min (RR = 1.18, 95% CI [0.49, 2.88], p = 0.71). Subgroup analysis and meta-regression models showed that increasing the dose of sumatriptan reduced the time needed for headache relief; however, this clinical improvement with higher doses was associated with more frequent adverse events in comparison to smaller doses. In conclusion, intranasal sumatriptan is effective for the treatment of acute migraine attacks. However, it was associated with a six-fold increase in the risk of taste disturbance, compared to the placebo. Future RCTs are recommended to provide head-to-head comparison of different administration routes and drug formulations of sumatriptan. 相似文献
98.
Arafat Amr A. Rady Mustafa Ebrahim Mohamed Elmahrouk Ahmed F. 《International journal of mental health and addiction》2022,20(2):966-970
International Journal of Mental Health and Addiction - Pulmonary needle embolization in intravenous drug users is rarely reported in the literature. The management of these patients is... 相似文献
99.
Amr M. Salaheldin Abdelhamid 《Archives of gynecology and obstetrics》2013,288(3):673-678
Objective
The aim of this work was to compare the pregnancy rates during IUI cycles with or without endometrial sampling.Study design
A prospective, randomized study.Patients and methods
150 patients were recruited. They were classified into three groups. Each comprised 50 patients. Group 1 was considered the control group and underwent IUI with no endometrial sampling. Group 2 underwent Tao Brush endometrial sampling on day 8–9 of the uterine cycle that preceded the stimulation cycle, and finally, Group 3 underwent Tao Brush endometrial sampling on day 8–9 of the same IUI cycleOutcome of the study
A positive pregnancy test.Results
Pregnancy percentages were 18, 38, and 36 % for group 1, group 2, and group 3, respectively. The paired t test was used to compare each two individual group means. The results show a highly significant value for the paired t test of the control group and group 2 of the patients (p = 0.001), as well as a highly significant results (p = 0.002) for the group 3 and the control group. No significant value was present between the group 2 and 3 of patients (p = 0.322).Conclusion
Endometrial sampling significantly increases pregnancy rates in IUI procedures when it is done in the proliferative phase of the IUI cycle, or the cycle prior to IUI, than pregnancy rates with IUI alone. 相似文献100.
Powell Perng Wei Perng Twalib Ngoma Crispin Kahesa Julius Mwaiselage Sofia D. Merajver Amr S. Soliman 《International journal of gynaecology and obstetrics》2013