全文获取类型
收费全文 | 1003篇 |
免费 | 62篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 47篇 |
妇产科学 | 10篇 |
基础医学 | 101篇 |
口腔科学 | 28篇 |
临床医学 | 91篇 |
内科学 | 206篇 |
皮肤病学 | 15篇 |
神经病学 | 45篇 |
特种医学 | 18篇 |
外科学 | 220篇 |
综合类 | 24篇 |
一般理论 | 3篇 |
预防医学 | 52篇 |
眼科学 | 29篇 |
药学 | 122篇 |
中国医学 | 7篇 |
肿瘤学 | 27篇 |
出版年
2024年 | 1篇 |
2023年 | 18篇 |
2022年 | 44篇 |
2021年 | 49篇 |
2020年 | 27篇 |
2019年 | 47篇 |
2018年 | 50篇 |
2017年 | 38篇 |
2016年 | 30篇 |
2015年 | 26篇 |
2014年 | 40篇 |
2013年 | 58篇 |
2012年 | 94篇 |
2011年 | 108篇 |
2010年 | 52篇 |
2009年 | 43篇 |
2008年 | 64篇 |
2007年 | 58篇 |
2006年 | 42篇 |
2005年 | 38篇 |
2004年 | 37篇 |
2003年 | 28篇 |
2002年 | 21篇 |
2001年 | 13篇 |
2000年 | 6篇 |
1999年 | 10篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1970年 | 1篇 |
1969年 | 2篇 |
排序方式: 共有1069条查询结果,搜索用时 15 毫秒
81.
Staal JA Sacks A Matheis R Collier L Calia T Hanif H Kofman ES 《International journal of psychiatry in medicine》2007,37(4):357-370
A randomized, controlled, single-blinded, between group study of 24 participants with moderate to severe dementia was conducted on a geriatric psychiatric unit. All participants received pharmacological therapy, occupational therapy, structured hospital environment, and were randomized to receive multi sensory behavior therapy (MSBT) or a structured activity session. Greater independence in activities of daily living (ADLs) was observed for the group treated with MSBT and standard psychiatric inpatient care on the Katz Index of Activities of Daily Living (KI-ADL; P = 0.05) than standard psychiatric inpatient care alone. The combination treatment of MSBT and standard psychiatric care also reduced agitation and apathy greater than standard psychiatric inpatient care alone as measured with the Pittsburgh Agitation Scale and the Scale for the Assessment of Negative Symptoms in Alzheimer's Disease (P = 0.05). Multiple regression analysis predicted that within the multi-sensory group, activities of daily living (KI-ADL) increased as apathy and agitation reduced (R2 = 0.42; p = 0.03). These data suggest that utilizing MSBT with standard psychiatric inpatient care may reduce apathy and agitation and additionally improve activities of daily living in hospitalized people with moderate to severe dementia more than standard care alone. 相似文献
82.
83.
Surbhi Shah M.B.B.S. Khaliqur Rahman M.D. Farhan Siddiqui M.D. Kafil Akhtar M.D. Sufian Zaheer M.D. Rana Sherwani M.D. 《Diagnostic cytopathology》2009,37(6):397-401
This study was conducted to evaluate the role of sediment cytology of biopsy specimen fixatives, which is usually discarded, in early diagnosis of bone lesions. Cytological smears prepared from sediments of biopsy specimen fixatives (sediment cytology) were used to study 65 bone specimens biopsied with suspicion of malignancy. The cytological diagnosis was then compared with histological diagnosis, taking the latter as gold standard. Smears were adequately cellular and showed good preservation of cellular morphology. Some of the smears showed microfragments of tissue. Cytology labeled 29 lesions as malignant, 26 lesions as benign, 3 as inflammatory, and 7 smears as inconclusive because of low cell yield. Sediment cytology was able to correctly diagnose 58 of 65 lesions. There was no false‐positive or false‐negative case. The sediment cytology could be considered as an easy and effective diagnostic tool that can provide early diagnosis for the lesion of bone. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc. 相似文献
84.
Ana A. Weil Mohammad Arifuzzaman Taufiqur R. Bhuiyan Regina C. LaRocque Aaron M. Harris Emily A. Kendall Azim Hossain Abdullah A. Tarique Alaullah Sheikh Fahima Chowdhury Ashraful I. Khan Farhan Murshed Kenneth C. Parker Kalyan K. Banerjee Edward T. Ryan Jason B. Harris Firdausi Qadri Stephen B. Calderwood 《Infection and immunity》2009,77(11):5090-5096
Vibrio cholerae O1 can cause diarrheal disease that may be life-threatening without treatment. Natural infection results in long-lasting protective immunity, but the role of T cells in this immune response has not been well characterized. In contrast, robust B-cell responses to V. cholerae infection have been observed. In particular, memory B-cell responses to T-cell-dependent antigens persist for at least 1 year, whereas responses to lipopolysaccharide, a T-cell-independent antigen, wane more rapidly after infection. We hypothesize that protective immunity is mediated by anamnestic responses of memory B cells in the gut-associated lymphoid tissue, and T-cell responses may be required to generate and maintain durable memory B-cell responses. In this study, we examined B- and T-cell responses in patients with severe V. cholerae infection. Using the flow cytometric assay of the specific cell-mediated immune response in activated whole blood, we measured antigen-specific T-cell responses using V. cholerae antigens, including the toxin-coregulated pilus (TcpA), a V. cholerae membrane preparation, and the V. cholerae cytolysin/hemolysin (VCC) protein. Our results show that memory T-cell responses develop by day 7 after infection, a time prior to and concurrent with the development of B-cell responses. This suggests that T-cell responses to V. cholerae antigens may be important for the generation and stability of memory B-cell responses. The T-cell proliferative response to VCC was of a higher magnitude than responses observed to other V. cholerae antigens.Vibrio cholerae is a gram-negative bacterium that can cause a severe, acute secretory diarrhea. Serological differentiation of V. cholerae strains is based on the O-side chain of the lipopolysaccharide (LPS) component of the outer membrane. Of the more than 200 serogroups of V. cholerae identified, only the O1 and O139 serogroups can cause epidemic cholera (44). These pathogens are noninvasive and colonize the mucosal surface of the small intestine (44).Natural infection with V. cholerae is known to provide protection against subsequent disease, but the mechanism of this protective immunity is not fully characterized. The vibriocidal antibody is a complement-dependent bactericidal antibody that is associated with protection from infection. However, no known threshold level of the vibriocidal antibody confers complete protection from V. cholerae infection, and some individuals with low serum vibriocidal antibody titers are still protected. This suggests that the vibriocidal titer may be a surrogate marker (16, 45). Elevated serum immunoglobulin A (IgA) antibody levels specific for the B subunit of cholera toxin (CTB), the major structural subunit of a type IV pilus (TcpA), and LPS are also associated with protective immunity in areas where cholera is endemic (19). However, after natural infection, the serum levels of these antibodies wane more rapidly than protective immunity (19). Patients with cholera develop memory B-cell responses of both the IgG and the IgA isotype to at least two V. cholerae protein antigens, CTB and TcpA. These responses are detectable for at least 1 year after infection and persist even after V. cholerae antigen-specific antibody-secreting cells and serum antibody titers have returned to baseline (18). B-cell memory responses also develop for the T-cell independent antigen LPS, but these responses wane more rapidly than memory B-cell responses to protein antigens, suggesting that durable memory B-cell responses to some V. cholerae antigens may be T-cell dependent (18).We have recently demonstrated that cholera patients mount a primed T-cell response in the mucosa after V. cholerae O1 infection (6). We hypothesize that protection from cholera may be mediated by memory B cells capable of an anamnestic response in the gut mucosa and that these memory B cells may depend on stimulation provided by memory T cells for their development and maintenance. T cells may contribute to the activation of B cells during V. cholerae infection by secreting stimulatory cytokines and direct contact with B cells in lymph nodes. Therefore, T cells may have an important role in protective immunity to V. cholerae infection.We characterized the memory T-cell responses to V. cholerae antigens following natural V. cholerae infection and compared these with serological responses to the same antigens. Previously, our group has studied various V. cholerae antigens, including mannose-sensitive hemagglutinin, TcpA, CTB, and LPS (22, 33, 37). We also included in the present study responses to a novel antigen, V. cholerae cytolysin/hemolysin (VCC) (31, 32). The hly gene that encodes the VCC protein is widespread across both pathogenic and environmental strains of V. cholerae, suggesting that VCC may impart an advantage to the organism (42). Although the precise role of VCC in V. cholerae infection is unknown, VCC is the primary virulence factor in V. cholerae infection with non-O1, non-O139 strains that do not produce cholera toxin (12, 46). The immune response to VCC is not well understood; however, recent studies suggest that VCC may promote a Th2 response in V. cholerae infection (2). In addition, the cytolytic activity of VCC may generate epithelial destruction that allows other V. cholerae antigens to penetrate the mucosa and promote the inflammatory response observed in V. cholerae infection (35, 39). 相似文献
85.
Akhtar N Ahad A Khar RK Jaggi M Aqil M Iqbal Z Ahmad FJ Talegaonkar S 《Expert opinion on therapeutic patents》2011,21(4):561-576
INTRODUCTION: The ATP-binding cassette superfamily contains membrane transporter proteins that transport a wide range of diverse compounds across cellular membranes. The P-glycoprotein (P-gp) is an important member of this family and a multi-specific drug efflux transporter that plays a significant role in governing the bioavailability of many clinically active drugs. The inhibition of this efflux transporter by various P-gp inhibitors forms a distinctive approach in improving bioavailability and conquering drug resistance. Most P-gp inhibitors exhibit limitations associated with their safety and unwanted pharmacokinetic interactions, thereby restraining their clinical applicability. AREAS COVERED: This review explores the investigations on the feasibility and applicability of various classes of P-gp inhibitors as described in recent patents for enhanced drug delivery. EXPERT OPINION: Several candidates presently under development look promising as P-gp inhibitors, e.g., tariquidar and elacridar. Pharmaceutical excipients currently constitute the most promising class of P-gp inhibitors and are considered safe and pharmaceutically acceptable for use in formulations. In addition, lipid-based excipients and thiolated polymers play an active role in affecting P-gp-mediated transport not only by altering the membrane fluidity or ATPase activity but by down regulating P-gp expression. An additional overture such as the prodrug derivatization of P-gp substrates is a feasible approach to bypass P-gp-mediated efflux. 相似文献
86.
5-Fluorouracil (5-FU) is a potent photosensitizer used in colon and rectal cancers. 5-FU on galvanostatic electrolysis or
radiation-induced oxidation of aqueous solution yields N1–C5-linked dimmer hydrate of 5-FU. Copper is presently associated with chromatin; in cancer cells the concentration of copper
is very high. It has been shown to be capable of mediating the action of several anticancer drugs through the production of
reactive oxygen species (ROS). The objective of the present study is to determine the Cu (II)-mediated anticancer mechanism
of 5-FU under photo-illumination as well as 5-FU alone. We have shown that a pro-oxidant action was enhanced when Cu (II)
was used with 5-FU as compared to 5-FU alone. This may be due to the inhibition of dimerization of 5-FU when present in combination
with Cu (II) under photo-illumination. It was also shown that 5-FU alone as well as in combination with Cu (II) was able to
generate oxidative stress in lymphocyte which is inhibited by scavengers of ROS. Moreover, the results of Fourier-transformed
infrared spectra lead to the conclusion that the dimerization of 5-FU was inhibited when used in combination with Cu (II).
It was due to the interaction of 5-FU with Cu (II). Hence, we propose that during chemoradiotherapy with 5-FU, the endogenous
copper is mobilized by 5-FU, leading to the generation of ROS which cause oxidative stress and possibly cancer cell death
by apoptosis. 相似文献
87.
Donohoe G Spoletini I McGlade N Behan C Hayden J O'Donoghue T Peel R Haq F Walker C O'Callaghan E Spalletta G Gill M Corvin A 《Psychiatry research》2008,161(1):19-27
Attributional style is defined as the pervasive tendency to explain the cause of social actions in terms of oneself, or others, or the context of the event. While the clinical correlates of this aspect of social cognition have been widely researched, its links with relationship style and neuropsychological performance, although hypothesised, have received less attention. This study investigated whether attributional style is predicted by variance in either relationship style or neuropsychological performance in schizophrenia. We assessed attributional style (using the Internal, Personal and Situational Attributions Questionnaire [IPSAQ]), relationship style (using Bartholomew and Horowitz's Relationship Questionnaire), and neuropsychological function (using the Wechsler Abbreviated Scale of Intelligence, the Wechsler Memory Test, and the Cambridge Automated Test Battery) in 73 stabilised outpatients with chronic schizophrenia and 78 controls matched for age and gender. 'Externalising bias' (attributing positive rather than negative events to oneself) was predicted by verbal ability in both patients and controls. 'Personalising bias' (attributing negative events to others rather than to situational factors) was predicted by higher secure relationship style ratings, but only in the patient group. This study highlights the importance of relationship style and neuropsychological performance for different aspects of attributional style in schizophrenia. 相似文献
88.
89.
90.
Endogenous endophthalmitis is a potentially blinding condition that occurs after the spread of organisms to the eye from a focus of infection elsewhere in the body. The holmium laser has gained increasing acceptance as being safe and effective for endoscopic lithotripsy. We report what we believe to be the first time endogenous endophthalmitis has been described as occurring after holmium laser lithotripsy, although it has been reported after extracorporeal shock wave lithotripsy. This 55-year-old woman developed infections in both eyes 2 to 3 weeks after the lithotripsy, with a good response to appropriate antibiotic treatment. 相似文献