全文获取类型
收费全文 | 1765篇 |
免费 | 115篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 41篇 |
妇产科学 | 69篇 |
基础医学 | 178篇 |
口腔科学 | 61篇 |
临床医学 | 167篇 |
内科学 | 306篇 |
皮肤病学 | 33篇 |
神经病学 | 105篇 |
特种医学 | 62篇 |
外科学 | 224篇 |
综合类 | 43篇 |
预防医学 | 139篇 |
眼科学 | 65篇 |
药学 | 202篇 |
中国医学 | 40篇 |
肿瘤学 | 94篇 |
出版年
2024年 | 4篇 |
2023年 | 29篇 |
2022年 | 79篇 |
2021年 | 98篇 |
2020年 | 73篇 |
2019年 | 86篇 |
2018年 | 96篇 |
2017年 | 79篇 |
2016年 | 67篇 |
2015年 | 68篇 |
2014年 | 85篇 |
2013年 | 92篇 |
2012年 | 145篇 |
2011年 | 125篇 |
2010年 | 71篇 |
2009年 | 55篇 |
2008年 | 109篇 |
2007年 | 71篇 |
2006年 | 82篇 |
2005年 | 58篇 |
2004年 | 44篇 |
2003年 | 46篇 |
2002年 | 44篇 |
2001年 | 20篇 |
2000年 | 16篇 |
1999年 | 17篇 |
1998年 | 12篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 13篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1973年 | 1篇 |
1969年 | 2篇 |
1928年 | 1篇 |
排序方式: 共有1894条查询结果,搜索用时 15 毫秒
991.
Parastoo Kheirandish SeyedAhmad SeyedAlinaghi MohammadReza Jahani Hadi Shirzad MohammadReza Seyed Ahmadian Ali Majidi AmirHoushang Sharifi Mostafa Hosseini Minoo Mohraz Willi McFarland 《Journal of urban health》2009,86(6):902-908
For the benefit of planning for the future care and treatment of people infected with hepatitis C virus (HCV) and to help
guide prevention and control programs, data are needed on HCV seroprevalence and associated risk factors. We conducted a cross-sectional
sero-behavioral survey of injection drug users (IDU) detained for mandatory rehabilitation during a police sweep of Tehran,
Iran, in early 2006. During the study period, a consecutive sample comprising 454 of 499 (91.0%) men arrested and determined
to be IDU by urine test and physical examination consented to a face-to-face interview and blood collection for HCV antibody
testing. Overall, HCV prevalence was 80.0% (95% confidence interval (CI) 76.2–83.6). Factors independently associated with
HCV infection included history of incarceration (adjusted OR 4.35, 95% CI 1.88–10.08), age of first injection ≤25 years (OR
2.72, 95% CI 1.09–6.82), and history of tattooing (OR 2.33, 95% CI 1.05–5.17). HCV prevalence in this population of IDU upon
intake to jail was extremely high and possibly approaching saturation. Findings support that incarceration is contributing
to the increased spread of HCV infection in Iran and calls for urgent increased availability of HCV treatment, long-term preparation
for the care of complications of chronic infection, and rapid scale-up of programs for the primary prevention of parenterally
transmitted infections among drug users. 相似文献
992.
Ang C O'Reilly EM Abou-Alfa GK Shamseddine A Skouri H Tawil A Eloubeidi MA Lowery M Kharfan-Dabaja M Kaprealian T Temraz S Sibai H Farran H Shah MA 《Journal of gastrointestinal cancer》2011,42(3):165-170
Introduction
Secondary malignancies and chronic end-organ sequelae are significant and steadily rising consequences of cancer therapy. The workup and management of a carcinoma of unknown primary must consider the patient’s clinical presentation, radiologic and pathologic findings, and comorbidities.Case Report
We present the case of a 50-year-old female survivor of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) with significant treatment-related end-organ sequelae who developed a metastatic adenocarcinoma of unknown primary 15 years following curative therapy for her ALL. The complex management issues related to the investigations and choice of therapy for this patient are reviewed.Discussion
This case discusses key issues related to the workup and management of a carcinoma of unknown primary. In addition, it illustrates the importance of taking patient comorbidities into consideration and tailoring investigations and therapy accordingly. 相似文献993.
Mohammad Hadi Sadeghian Mohammad Reza Keramati Hossein Ayatollahi Lida Manavifar Hoda Enaiati Masoumeh Mahmoudi 《Indian journal of hematology & blood transfusion》2010,26(2):45-48
Iron deficiency is a common cause of anemia worldwide. Documentation shows that these patients have impaired immunity and
are prone to infections. The aim of this study was to confirm whether serum immunoglobulins change in adult nonpregnant females
with iron deficiency anemia. Based on patients’ clinical history, CBC results, and serum ferritin, iron and total iron binding
capacity, 45 healthy patients and 45 iron deficiency anemia (hypochrom microcytic) patients were entered into this case–control
study. Serum IgG, IgA and IgM were measured in patient and control groups using the nephelometry method. Both of the groups
were compared using suitable statistical test. Mean serum values of IgG, IgA and IgM in the patient group were 12.47 ± 7.67,
1.93 ± 0.92 and 1.35 ± 0.90 g/l respectively. Mean serum values for the control group were 12.51 ± 6.85, 2.14 ± 0.88 and 1.49
± 0.73 g/l respectively. Although serum immunoglobulins were slightly lower in the patient group compared to the control group
these differences were not significant with the t test. Our study showed serum immunoglobulin levels did not change in iron deficiency anemia. 相似文献
994.
Mona Abdel‐Hadi Gehane F. Abdel‐Hamid Naglaa Abdel‐Razek Rawia K. Fawzy 《Diagnostic cytopathology》2010,38(12):880-889
Fine‐needle aspiration cytology (FNAC) of breast masses has been replaced by ultrasound‐guided core‐needle biopsy (USG‐CNB) in many countries. However, in Egypt, breast FNAC continues to play the major role in diagnosing breast masses. In this prospective study, we evaluated the efficacy of USG‐FNACs performed at a breast cancer screening center by comparing the FNAC results with the corresponding definitive histological examination outcome. We also investigated the role that CNB can play as a complementary diagnostic tool for FNAC in selected cases. A total of 229 consecutive nonpalpable breast masses were included in this study. Each FNAC was placed into one of four categories: 3.5% nondiagnostic, 13.5% benign, 12.3% atypical/suspicious (indeterminate), and 70.7% malignant. The overall diagnostic accuracy was 98.9%, with a specificity and sensitivity of 99.3 and 96.7%, respectively. The overall positive predictive values and negative predictive values were 99.3 and 96.7%, respectively. Only 37 masses (16%) were converted to CNB, with the indeterminate cytology being the most common cause (54%) for this conversion. Two cases demonstrating the superior benefit of FNAC over CNB are illustrated. Although we started the study by reserving CNB as a first choice to assess microcalcifications without architectural distortion, we ended the study by deciding to perform combined FNAC and CNB for this type of lesions. In conclusion, aiming to maximize the preoperative diagnosis of cancer, it would be cost efficient and time saving to use FNAC as a first‐line investigation to benefit from the wealth of cytological information yielded, followed by CNB in selected cases. Diagn. Cytopathol. 2010;38:880–889. © 2010 Wiley‐Liss, Inc. 相似文献
995.
996.
997.
Hadi Sarir Esmaeil Mortaz Willem. T. Janse Frans P. Nijkamp 《Biochemical pharmacology》2010,79(5):698-705
Macrophages are key inflammatory cells in chronic obstructive pulmonary disease (COPD). The pathophysiology of cigarette smoke-induced lung emphysema is complex but there is a clear role for reactive oxygen species (ROS, such as peroxynitrite), tumor necrosis factor (TNF-α) and interleukin (IL)-8. We investigated whether TNF-α or cigarette smoke medium (CSM) alone or in combination induces the production of IL-8 by human macrophages or monocyte lymphoma U937. CSM and TNF-α induce a dose- and time-dependent increase in IL-8 production. Interestingly, when sub-threshold concentrations of CSM and TNF-α were co-incubated, a 1500% increase in IL-8 production was observed compared to either of the compounds alone. Similar results were obtained with TNF-α and the peroxynitrite donor SIN-1. Moreover, the overproduction of IL-8 was associated with an enhanced increase in the translocation of NF-κB and an enhanced decrease in glutathione levels. Preincubation of the cells with antioxidants, such as N-acetyl-l-cysteine (NAC), prevented the overproduction of IL-8 and activation of NF-κB.In conclusion, CSM exposure of macrophages up-regulates the expression and the production of IL-8 via reactive oxygen species and NF-κB activation. Moreover, CSM dramatically enhances the production of IL-8 in combination with TNF-α. Based upon the strong synergistic action, a combination therapy directed against ROS and TNF-α could be a new approach to stop the progression in lung damage during emphysema. 相似文献
998.
Belinda G. Vermey Su Jen Chua Mohammad Hadi Zafarmand Rui Wang Salvatore Longobardi Evelyn Cottell Francois Beckers Ben W. Mol Christos A. Venetis Thomas DHooghe 《Reproductive biomedicine online》2019,38(5):751-763
This systematic review and meta-analysis determined the association between aspirated after ovarian stimulation and top/good quality embryos obtained in women undergoing ovarian stimulation for IVF/intracytoplasmic sperm injection (ICSI). MEDLINE, EMBASE, Scopus, CINAHL and Web of Science were searched for English-language publications on top/good-quality embryos at cleavage (day 2/3) and/or blastocyst (day 5/6) developmental stages, up to 18 November 2017. Twenty-eight studies (three prospective and 25 retrospective) reporting data on 291,752 assisted reproductive technology (ART) cycles were considered eligible. We confirmed a strong positive association between oocytes retrieved and top/good-quality day 2/3 embryos (weighted correlation coefficient [rw] = 0.791), day 5/6 embryos (rw = 0.901), metaphase II oocytes (rw = 0.988), oocytes exhibiting two pronuclei (rw = 0.987) and euploid embryos (rw = 0.851); P < 0.001 for all correlations (evaluated in subsets of the 17 studies). Data from 5657 cycles showed that the group with the most oocytes aspirated had the most top/good-quality day 2/3 embryos (pooled standardized mean differences (high [>15] versus low [<4] 1.91, 95% confidence interval [CI] 1.05–2.77, P < 0.0001; high versus medium [4–15] 1.15, 95% CI 0.74–1.55, P < 0.0001; medium versus low 1.41, 95% CI 0.79–2.03, P < 0.0001). Individual participant meta-analysis would enable accurate determination of these associations and other outcomes. 相似文献
999.
1000.
Masoomeh Mohammadzadeh Vahid Ramazani Mohammad Ali Khalili Hamed Hamishekar Laleh Dehghan Marvast Ali Reza Talebi Hadi Zare‐Zardini Saeed Ghasemi 《Andrologia》2019,51(4)
The aim of this study was to comprise the effect of catalase on sperm parameters and chromatin in normospermic persons. Semen samples were obtained from fertile men. A certain amount of different concentrations of catalase (0.1, 1, 10, 50, 100, 150 and 200 IU.ml) was added to each vial containing semen. Control group had similar condition to treated groups without treatment. Treatment was done for one hour in incubator and 4 and 24 hr in room temperature. Sperm parameters (motility, viability and morphology ) and chromatin were evaluated after incubation. The results show that percentage of motility was insignificantly increased at concentration of 100 IU.ml catalase. This increase was higher than other examined concentration in all incubation time. The increase in sperm motility had significant difference in concentrations of 100 IU.ml with other concentrations. Other parameters showed no significant difference in all concentrations. Regarding the health of sperm chromatin, low concentrations of catalase had significant effect on this variable. This effect was more in low concentrations than high concentrations. This study showed the use of lower concentrations of antioxidant can improve the sperm parameters and chromatin quality. The low concentrations of catalase led to protection of chromatin and optimisation of sperm parameters. 相似文献