全文获取类型
收费全文 | 18955篇 |
免费 | 1145篇 |
国内免费 | 137篇 |
专业分类
耳鼻咽喉 | 160篇 |
儿科学 | 422篇 |
妇产科学 | 362篇 |
基础医学 | 2179篇 |
口腔科学 | 765篇 |
临床医学 | 1816篇 |
内科学 | 4096篇 |
皮肤病学 | 394篇 |
神经病学 | 1167篇 |
特种医学 | 436篇 |
外国民族医学 | 6篇 |
外科学 | 2483篇 |
综合类 | 491篇 |
一般理论 | 15篇 |
预防医学 | 1566篇 |
眼科学 | 744篇 |
药学 | 1802篇 |
中国医学 | 215篇 |
肿瘤学 | 1118篇 |
出版年
2024年 | 31篇 |
2023年 | 252篇 |
2022年 | 694篇 |
2021年 | 1086篇 |
2020年 | 715篇 |
2019年 | 854篇 |
2018年 | 1015篇 |
2017年 | 722篇 |
2016年 | 778篇 |
2015年 | 789篇 |
2014年 | 1065篇 |
2013年 | 1230篇 |
2012年 | 1676篇 |
2011年 | 1712篇 |
2010年 | 1011篇 |
2009年 | 770篇 |
2008年 | 1128篇 |
2007年 | 1001篇 |
2006年 | 847篇 |
2005年 | 722篇 |
2004年 | 560篇 |
2003年 | 465篇 |
2002年 | 396篇 |
2001年 | 48篇 |
2000年 | 60篇 |
1999年 | 59篇 |
1998年 | 51篇 |
1997年 | 45篇 |
1996年 | 45篇 |
1995年 | 38篇 |
1994年 | 18篇 |
1993年 | 33篇 |
1992年 | 24篇 |
1991年 | 17篇 |
1990年 | 19篇 |
1989年 | 21篇 |
1988年 | 18篇 |
1987年 | 12篇 |
1986年 | 13篇 |
1985年 | 14篇 |
1984年 | 23篇 |
1983年 | 20篇 |
1982年 | 18篇 |
1981年 | 13篇 |
1980年 | 13篇 |
1979年 | 13篇 |
1978年 | 11篇 |
1976年 | 11篇 |
1975年 | 8篇 |
1974年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
Mohammad Hajiha Marq-André DuBord Hattie Liu Richard L. Horner 《The Journal of physiology》2009,587(11):2677-2692
Opioids can modulate breathing and predispose to respiratory depression by actions at various central nervous system sites, but the mechanisms operating at respiratory motor nuclei have not been studied. This study tests the hypotheses that (i) local delivery of the μ-opioid receptor agonist fentanyl into the hypoglossal motor nucleus (HMN) will suppress genioglossus activity in vivo , (ii) a component of this suppression is mediated by opioid-induced acetylcholine release acting at muscarinic receptors, and (iii) δ- and κ-opioid receptors also modulate genioglossus activity. Seventy-two isoflurane-anaesthetised, tracheotomised, spontaneously breathing rats were studied during microdialysis perfusion into the HMN of (i) fentanyl and naloxone (μ-opioid receptor antagonist), (ii) fentanyl with and without co-application of muscarinic receptor antagonists, and (iii) δ- and κ-opioid receptor agonists and antagonists. The results showed (i) that fentanyl at the HMN caused a suppression of genioglossus activity ( P < 0.001) that reversed with naloxone ( P < 0.001), (ii) that neither atropine nor scopolamine affected the fentanyl-induced suppression of genioglossus activity, and (iii) that δ-, but not κ-, opioid receptor stimulation also suppressed genioglossus activity ( P = 0.036 and P = 0.402 respectively). We conclude that μ-opioid receptor stimulation suppresses motor output from a central respiratory motoneuronal pool that activates genioglossus muscle, and this suppression does not involve muscarinic receptor-mediated inhibition. This μ-opioid receptor-induced suppression of tongue muscle activity by effects at the hypoglossal motor pool may underlie the clinical concern regarding adverse upper airway function with μ-opioid analgesics. The inhibitory effects of μ- and δ-opioid receptors at the HMN also indicate an influence of endogenous enkephalins and endorphins in respiratory motor control. 相似文献
962.
Terry Kwok Hanspeter Helfer Mohammad Intakhab Alam Jochen Heinrich Jovan Pavlovic Karin Moelling 《Archives of virology》2009,154(1):109-114
Influenza A virus causes prevalent respiratory tract infections in humans. Small interfering RNA (siRNA) and antisense oligonucleotides
(asODNs) have been used previously for silencing the RNA genome of influenza virus. Here, we explored the use of partially
double-stranded oligodeoxynucleotides (dsODNs) to suppress the production of influenza A virus in cell cultures and animal
models. We were able to inhibit influenza A virus replication in cultured human lung cells as well as in the lungs of infected
C57BL/6 mice by treatment with dsODN 3-h post-infection. In about 20% of the cases (15/77) the titer was reduced by 10- to
100-fold and in 10% up to 1,000-fold. The antiviral effects of dsODNs were dose-dependent, sequence-dependent and comparable
to those of its antisense and siRNA analogues. Thus, dsODNs may be developed as an additional class of nucleic acids for the
inhibition of influenza virus replication. 相似文献
963.
964.
Andrology is a medical specialty which is concerned with male reproductive andsexual functions. There are several peer-reviewed andrology journals.1-9 As shown in Table 1, we highlighted alphabetically on some selected andrology periodicals. However, there are additional periodicals which are not included in Table 1. For example: 相似文献
965.
Mohammad Esmaeillou Mohammad Moharamnejad Ramin Hsankhani Ali Asghar Tehrani Hamid Maadi 《Environmental toxicology and pharmacology》2013,35(1):67-71
In this study, we extended previous work to evaluate the oral toxicity of ZnO nanoparticles and their possible effects on different serum-elements and sexual hormones in the mouse. The histopathological changes have also been examined. Significant recorded increases in alanine aminotransferase and aspartate aminotransferase activity in all mice exposed to ZnO nanoparticles suggest that these nanoparticles can cause hepatic injury. Hepatocyte necrosis and other pathological observations also confirmed liver damage. Moreover, Glomeruli segmentation, hydropic degeneration in epithelial cells, necrosis of epithelial cells in tubules and swelling in epithelial cells of proximal tubules were found in all kidney tissues, which demonstrated that ZnO nanoparticles have severe toxicological effects on kidney. Serous inflammation, severe hyperemia in alveoli, and edema were observed as pathological findings in the lung which suggest that the lung is the third target tissue of the ZnO nanoparticles. 相似文献
966.
“Mo'ez Al-Islam” E. Faris Safia Kacimi Ref'at A. Al-Kurd Mohammad A. Fararjeh Yasser K. Bustanji Mohammad K. Mohammad Mohammad L. Salem 《Nutrition Research》2012
Intermittent fasting and caloric restriction have been shown to extend life expectancy and reduce inflammation and cancer promotion in animal models. It was hypothesized that intermittent prolonged fasting practiced during the month of Ramadan (RIF) could positively affect the inflammatory state. To investigate this hypothesis, a cross-sectional study was designed to investigate the impact of RIF on selected inflammatory cytokines and immune biomarkers in healthy subjects. Fifty (21 men and 29 women) healthy volunteers who practiced Ramadan fasting were recruited for the investigation of circulating proinflammatory cytokines (interleukin [IL]-1β, IL-6, and tumor necrosis factor α), immune cells (total leukocytes, monocytes, granulocytes, and lymphocytes), and anthropometric and dietary assessments. The investigations were conducted 1 week before Ramadan fasting, at the end of the third week of Ramadan, and 1 month after the cessation of Ramadan month. The proinflammatory cytokines IL-1β, IL-6, and tumor necrosis factor α; systolic and diastolic blood pressures; body weight; and body fat percentage were significantly lower (P < .05) during Ramadan as compared with before Ramadan or after the cessation of Ramadan fasting. Immune cells significantly decreased during Ramadan but still remained within the reference ranges. These results indicate that RIF attenuates inflammatory status of the body by suppressing proinflammatory cytokine expression and decreasing body fat and circulating levels of leukocytes. 相似文献
967.
968.
Mohammad Abdulwahab Fatima Al-Sayegh Sean G Boynes Hawra Abdulwahab Jayme Zovko John Close 《Anesthesia progress》2010,57(3):91-95
The objective of this study was to examine the public health relevance of the prevalence of dental fear in Kuwait and the resultant barrier that it creates regarding access to dental care. The study analysis demonstrated a high prevalence of dental fear and anxiety in the Kuwaiti population and a perceived need for anesthesia services by dental care providers. The telephone survey of the general population showed nearly 35% of respondents reported being somewhat nervous, very nervous, or terrified about going to the dentist. In addition, about 36% of the population postponed their dental treatment because of fear. Respondents showed a preference to receive sedation and anesthesia services as a means of anxiety relief, and they were willing to go to the dentist more often when such services were available. People with high fear and anxiety preferred to receive some type of medication to relieve their anxiety. In conclusion, the significance and importance of the need for anesthesia services to enhance the public health of dental patients in Kuwait has been demonstrated, and improvements are needed in anesthesia and sedation training of Kuwaiti dental care providers. 相似文献
969.
Mohammad Reza Hasanjani Roushan Mohammad Jafar Soleimani Amiri Abolghasem Laly Amrollah Mostafazadeh A. Bijani 《International journal of infectious diseases》2010,14(3):e250-e253
BackgroundThe standard agglutination (SAT) and 2-mercaptoethanol (2-ME) tests are usually used in the follow-up of treated cases of human brucellosis. The purpose of this study was to monitor the levels of these tests, two years after clinical cure in cases of brucellosis.MethodsFrom April 2003 to September 2008, 175 clinically cured cases of brucellosis (103 males, 72 females) were evaluated. Diagnosis of brucellosis was established with a SAT of ≥1:320 and a 2-ME of ≥1:80, with clinical symptoms and signs compatible with brucellosis. SAT and 2-ME were retested at the end of therapy and at 3-monthly intervals for two years. Serologic cure was considered in the event of a SAT titer decrease to ≤1:160 or a 2-ME decrease to < 1:80.ResultsThe mean age of study patients was 31 ± 13.5 years. At 6, 12, 18, and 24 months after treatment, SAT titers ≥1:320 were seen in 41 (23.4%), 22 (12.6%), 7 (4%), and 6 (3.4%) cases, respectively, whereas 2-ME titers ≥1:80 were seen in 51 (29.1%), 24 (13.7%), 12 (6.9%), and 8 (4.6%) cases, respectively. The probability of serologic cure for patients with SAT titers ≤1:640 was higher than for those >1:640 (95% confidence interval (CI) 2.5–3.47, p = 0.023). The probability of serologic cure for patients with 2-ME titers ≤1:320 was higher than for those >1:320 (95% CI 2.48–3.5, p = 0.04).ConclusionsSAT and 2-ME may be found in significant titers in less than 5% of clinically treated cases after two years. Serologic cure for both tests with lower titers were higher than with higher titers. 相似文献
970.
Husain A. Saleh M.D. F.I.A.C. M.B.A. Mohammad El‐Fakharany M.D. Hassan Makki M.D. F.C.C.P. Ahmad Kadhim M.D. Shahla Masood M.D. 《Diagnostic cytopathology》2009,37(5):324-332
Differentiating reactive mesothelial cells (RMs) from metastatic adenocarcinoma cells (MAC) in serous fluids based on cytomorphologic features alone can be very challenging. Various immunocytochemical (ICC) markers have been used to maximize the diagnostic accuracy, however, cytopathologists still encounter difficulties in effusion cytologic diagnosis. The aim of this study was to evaluate previous and recent ICC stains to identify the most sensitive and specific markers and the best panel for differentiating RM from MAC. Cell block sections from 41 MAC and 43 RM effusions cases were subjected to ICC staining for MOC‐31, BerEp4, carcinoembryonic antigen (CEA), calretinin, HBME‐1, CK5/6, and D2‐40. For the MAC cases, the sensitivity of BerEp4, MOC‐31, and CEA was 82.9, 92.6, and 17%, respectively, and the specificity was 95.3, 93, and 100%, respectively. For the RM cases, the sensitivity of calretinin, CK5/6, D2‐40, and HBME‐1 was 95.3, 27.9, 58.1, and 93%, respectively, and the specificity was 70.7, 73.1, 75.6, and 82.9%, respectively. The results show that BerEp4 and MOC‐31 are highly sensitive and specific for detecting MAC, whereas calretinin and HBME1 are highly sensitive but only modestly specific for detecting RM cases (P < 0.05). Forced entry logistic regression revealed that using MOC‐31, BerEp4, HBME‐1, and calretinin, is an excellent panel for making correct diagnosis with 97.6% sensitivity in detecting MAC and 90.7% specificity in detecting RM. We conclude that adding a panel of MOC‐31, BerEp4, calretinin, and HBME‐1 immunostains to routine cytomorphologic features can greatly enhance the diagnostic accuracy of serous effusions. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc. 相似文献