全文获取类型
收费全文 | 893篇 |
免费 | 60篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 21篇 |
妇产科学 | 10篇 |
基础医学 | 133篇 |
口腔科学 | 11篇 |
临床医学 | 63篇 |
内科学 | 255篇 |
皮肤病学 | 13篇 |
神经病学 | 43篇 |
特种医学 | 20篇 |
外科学 | 127篇 |
综合类 | 23篇 |
预防医学 | 76篇 |
眼科学 | 3篇 |
药学 | 85篇 |
中国医学 | 5篇 |
肿瘤学 | 69篇 |
出版年
2024年 | 3篇 |
2023年 | 10篇 |
2022年 | 26篇 |
2021年 | 45篇 |
2020年 | 26篇 |
2019年 | 32篇 |
2018年 | 36篇 |
2017年 | 24篇 |
2016年 | 31篇 |
2015年 | 31篇 |
2014年 | 30篇 |
2013年 | 42篇 |
2012年 | 64篇 |
2011年 | 69篇 |
2010年 | 55篇 |
2009年 | 30篇 |
2008年 | 47篇 |
2007年 | 66篇 |
2006年 | 49篇 |
2005年 | 53篇 |
2004年 | 44篇 |
2003年 | 30篇 |
2002年 | 33篇 |
2001年 | 11篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 10篇 |
1997年 | 2篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1983年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有964条查询结果,搜索用时 15 毫秒
41.
Yahya Khosravi Ahmad Salimi Jalal Pourahmad 《Xenobiotica; the fate of foreign compounds in biological systems》2018,48(8):860-866
1. Today, diamond nanoparticles have several industrial applications. Nano diamond (ND) as a carbon allotrope diffuses in the air easily during producing and processing procedures.2. In this study, we investigated sub-acute exposed to ND at the exposure chamber in mice. The animals were divided into two groups (control and exposed group to ND at the concentration of 3?µg/m3 for 3?h/day, 5?days/week for 30?days) in a whole-body inhalation chamber.3. Our results showed that exposure to ND induced the hematological and biochemical changes. The target organs for ND were the lungs, brain and heart in the mice, respectively. Also, ND increased reactive oxygen species (ROS) generation, lipid peroxidation (LPO), the collapse of mitochondrial membrane potential (MMP), decreased a level of reduced glutathione (GSH) and finally increased a level of glutathione disulfide (GSSG) in lung, brain and heart tissues. Our results suggest that exposure to ND can induce oxidative stress in the tissue mentioned.4. These results suggest that exposure of researchers and workers with diamond nanoparticles probably increase a risk of respiratory, cardiovascular and cerebral disorders through oxidative stress. However, good ventilation, appropriate personal protective equipment and using of anti-oxidant compounds in daily diet of worker are suggested. 相似文献
42.
Mohammad Mahdi Majzoobi Seyyed Hamid Hashemi Mojgan Mamani Fariba Keramat Jalal Poorolajal Hamid Reza Ghasemi Basir 《International journal of antimicrobial agents》2018,51(3):365-369
Brucellosis is associated with a high recurrence rate and requires more than one course of standard treatment; therefore, more research is required to find more effective treatments that lead to prompt recovery, and reduce the relapse of disease. This single-blind, randomized study was designed to evaluate the effect of the standard treatment for brucellosis in combination with hydroxychloroquine.A total of 177 patients with acute brucellosis were randomly assigned to one of two treatment groups: doxycycline-streptomycin (DS) and doxycycline-streptomycin-hydroxychloroquine (DSH). Clinical symptoms and signs, serological tests, and side effects of therapy were compared between the two groups during the treatment course and at three and six months after the end of drug therapy. Of the 177 patients, with a mean age of 40.5?±?16.9 years, 66.1% were males. The mean duration of clinical signs prior to admission was 43.4?±?41.1 days. Appropriate clinical responses, relapse, treatment failure, and adverse drug reactions were seen in 98.9%, 1.2%, 0.0%, and 12.6% of patients, respectively, in the DSH group vs. 86.7%, 11.6%, 2.3%, and 19.8% of patients, respectively, in the DS group. There were significant differences in clinical response and relapse rates between the two groups. The addition of hydroxychloroquine to a doxycycline-streptomycin regimen appears to increase the efficacy of treatment, accelerate improvement of clinical symptoms, and significantly reduce the rate of relapse of brucellosis. 相似文献
43.
44.
Charles F. McTiernan Penelope Morel Leslie T. Cooper Navin Rajagopalan Vinay Thohan Mark Zucker John Boehmer Biykem Bozkurt Paul Mather John Thornton Jalal K. Ghali Karen Hanley-Yanez James Fett Indrani Halder Dennis M. McNamara 《Journal of cardiac failure》2018,24(1):33-42
Objective
The aim of this work was to evaluate the hypothesis that the distribution of circulating immune cell subsets, or their activation state, is significantly different between peripartum cardiomyopathy (PPCM) and healthy postpartum (HP) women.Background
PPCM is a major cause of maternal morbidity and mortality, and an immune-mediated etiology has been hypothesized. Cellular immunity, altered in pregnancy and the peripartum period, has been proposed to play a role in PPCM pathogenesis.Methods
The Investigation of Pregnancy-Associated Cardiomyopathy (IPAC) study enrolled 100 women presenting with a left ventricular ejection fraction of <0.45 within 2 months of delivery. Peripheral T-cell subsets, natural killer (NK) cells, and cellular activation markers were assessed by flow cytometry in PPCM women early (<6 wk), 2 months, and 6 months postpartum and compared with those of HP women and women with non–pregnancy-associated recent-onset cardiomyopathy (ROCM).Results
Entry NK cell levels (CD3–CD56+CD16+; reported as % of CD3– cells) were significantly (P?<?.0003) reduced in PPCM (6.6?±?4.9% of CD3– cells) compared to HP (11.9?±?5%). Of T-cell subtypes, CD3+CD4–CD8–CD38+ cells differed significantly (P?<?.004) between PPCM (24.5?±?12.5% of CD3+CD4–CD8– cells) and HP (12.5?±?6.4%). PPCM patients demonstrated a rapid recovery of NK and CD3+CD4–CD8–CD38+ cell levels. However, black women had a delayed recovery of NK cells. A similar reduction of NK cells was observed in women with ROCM.Conclusions
Compared with HP control women, early postpartum PPCM women show significantly reduced NK cells, and higher CD3+CD4–CD8–CD38+ cells, which both normalize over time postpartum. The mechanistic role of NK cells and “double negative” (CD4–CD8–) T regulatory cells in PPCM requires further investigation. 相似文献45.
Perfluorooctanoic acid (PFOA) is an octanoic acid and is found in wildlife and humans. We have investigated mitochondrial toxicity in isolated mitochondria from, placenta, brain, liver, and heart after oral exposure with PFOA in mice during gestational days (7‐15). Histopathological examination and mitochondrial toxicity parameters were assayed. Results indicated that PFOA decreased the weight of the fetus and placenta, the length of the fetus and the diameter of the placenta, dead fetuses and dead macerated fetuses in treated mice with 25 mg/kg. Histopathological examination showed that PFOA induced pathological abnormalities in liver, brain, heart, and placenta. Also, PFOA induced mitochondria toxicity in brain, liver, heart of mouse fetus. Our results indicate that PFOA up to 20 mg/kg exposure adversely affect embryofetal/developmental because for mitochondria dysfunction. These results suggested that mitochondrial dysfunction induced by PFOA in liver, heart, and brain lead to developmental toxicity and abnormality in tissues. 相似文献
46.
Cheerngod Shilpa Karunakaran Kavitha Nittur Sudheesh Sasidharanpillai Sabeena Varamballi Prasad Maity Hindol Govindakarnavar Arunkumar 《Journal of medical virology》2020,92(1):119-123
Chikungunya fever is a viral disease transmitted to humans by the bite of infected mosquitoes. The disease is characterized by fever, headache, rash, severe joint, and muscle pain. To evaluate the disease burden in the population and the effectiveness of public health measures, periodic seroprevalence surveys are essential. Chikungunya outbreaks were reported from many Asian countries since 2005, after more than three decades of disappearance. The study aimed to estimate the seroprevalence of the chikungunya virus in southern parts of Karnataka state, through demonstrating chikungunya virus-specific neutralizing antibodies. A cross-sectional study was carried out using 509 archived blood samples from a hospital-based acute febrile illness surveillance project, representative of the period between June 2014 and 2018. The study reported a 3.7% seroprevalence of chikungunya virus-neutralizing antibodies in Thirthahalli and Hosanagara taluks of South Karnataka. The low prevalence of chikungunya-neutralizing antibodies indicates that a major population is unexposed and prone to future outbreaks. 相似文献
47.
Santhosh Kuriakose MBBS MS Sasidharanpillai Sabeena MBBS DGO PhD Binesh Damodaran MBBS MD N. Ravishankar MSc PhD Amrutha Ramachandran MBBS MS Nurul Ameen MBBS MS 《Journal of medical virology》2020,92(12):3884-3888
One major advantage of molecular assays for human papillomavirus (HPV) DNA detection is that these assays can be performed on self-collected samples unlike cytology or visual inspection with acetic acid (VIA). This cross-sectional study was carried out between March 2017 and April 2019 to compare the diagnostic performance in self-collected urine and vaginal samples for HPV DNA detection. Viral DNA was extracted from processed samples using a Qiagen viral DNA extraction Kit (QIAamp DNA Mini Kit). To detect four common high-risk HPV types (16, 18, 31, 45), multiplex real-time polymerase chain reaction (PCR) targeting the LCR/E6/E7 region of the HPV genome was performed in ABI 7500 cycler (Applied Biosystems). The negative samples were screened by conventional PCR targeting the L1 capsid region to exclude other HPV types. The overall agreement between the two self-collecting sampling methods was 64.04% with a κ value of 0.29 pointing towards a fair agreement (P < .01). The sensitivity of HPV DNA detection in urine samples was 57.95% (47.52%, 67.72), and specificity was 84.6% (66.47%, 93.85%) when compared with vaginal samples. The study concludes that self-collected vaginal HPV DNA testing is more sensitive than unpreserved-urine samples for HPV DNA detection in a hospital-based setting. 相似文献
48.
Objective:
Enterobacter cowanii is a genus of common gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacterium of the Enterobacteriaceae family. This organism can be potentially a powdered infant milk formula-borne opportunistic pathogen. The aim of this study was to isolate and identify E. cowanii from consumed powdered infant formula milk (PIF) in intensive care units (NICU) and to determine antimicrobial susceptibility patterns of this bacterium.
Methods:
E. cowanii was isolated according to FDA method in 125 samples of PIF milk purchased from drug stores between Jun 2011 and March 2012. For final confirmation, biochemical tests embedded in API-20E system were used. The drug susceptibility test was performed using the disc diffusion method according to CLSI recommendations.
Findings
: Out of the 125 PIF samples investigated, 4 (3.2%) samples were positive for E. cowanii. All four isolates from PIF samples were uniformly susceptible to imipenem, meropenem, ceftazidime, ciprofloxacin, and colistin. Fifty percent of isolates were resistant to ampicillin, amoxicillin, and cotrimoxazole
Conclusion: Analysis of the results indicated that complementary studies are necessary to clarify the possible role of E. cowanii as a food contaminant, in common NICU infections and high risk groups including persons with underlying disease and immunocompromised individuals.Key Words: Powdered Infant Formula Milk; Neonatal Intensive Care Unit; E. Cowanii; Antimicrobial Susceptibility 相似文献
49.
50.
Jack L. Spurbeck Alan R. Zinsmeister Kevin J. Meyer Syed M. Jalal 《American journal of medical genetics. Part A》1996,61(4):387-393
Consistency of optimum chromosome spreading during harvest of cytogenetic specimens remains a major concern. We have tested the idea that a precise control of the drying rate (the time with which metaphase cells dry), as fixed cell suspension is placed on a slide or an in situ culture in last fixation, may be the answer. Amniocyte and lymphocyte cultures were allowed to dry at defined combinations of relative humidity (RH) and temperature (T) in a modified Thermotron environmental control unit. We were able to demonstrate, based on 2,250 amniocytes and 1,650 lymphocytes, that the metaphase area after drying was a function of RH and T for both in situ and non-in situ culture systems. As the RH and T increase, the metaphase area increases until a threshold is reached. Also, as RH increases, the slide drying time increases. Data obtained using a response surface regression, proportional hazards regression analysis and slide drying time studies are consistent with our model of chromosome spreading. Optimum metaphase areas can be achieved at various combinations of RH and T. We propose that the use of an environmental control unit is a practical way of achieving optimum chromosome spreading routinely and in a highly consistent manner. © 1996 Wiley-Liss, Inc. 相似文献