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91.
The goal of this study was to determine the coefficient of permeability as well as the rate of carbonation of concrete constructed with rice husk ash (RHA) as a partial replacement for cement (i.e., 5%, 10%, and 15%) and two different concentrations of soap solutions (i.e., 1 percent and 2 percent). The microstructural studies of RHA, and carbonated samples have been conducted by using Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) analysis. According to this study, the carbonation depth of concrete made with 1% and 2% soap solution concentration and without rice husk ash decreased by 11.89% and 46.55%, respectively. From the results, it may also be observed that the carbonation depth of concrete made with up to 10% replacement of cement by rice husk ash led to maximum carbonation resistance, while more than 10% replacement of cement showed higher carbonation depth. It is also observed that the coefficient of permeability of concrete with 2% soap solution significantly decreased as compared to the 1% soap solution and control mix. It may be observed from the SEM images that 0% soap solution (M1) concrete has a very rough concrete surface which may indicate more voids. However, 2% soap solution concrete has a much smoother surface, which indicates a smaller number of voids. Furthermore, the SEM images showed that the soap solution helps in filling the voids of concrete which ultimately helps in reduction in permeability. Energy Dispersive X-Ray Analysis (EDX) of concrete with 0% (M1) and 2% (M6) soap solution disclosed that the concrete with 2% soap solution (M6) exhibited more silica element formation than the concrete with no soap solution (M1).  相似文献   
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93.
Left internal mammary artery (LIMA)-to-pulmonary artery fistulae rarely develop after coronary artery bypass grafting. Fewer than 30 cases of these fistulae have been reported since 1947. Nevertheless, this entity should be considered as a cause of recurrent angina after bypass surgery, in the absence of other causes. We present the case of a 67-year-old man with cardiac symptoms in whom multiple LIMA-to-pulmonary artery fistulae were found, 15 years after he had undergone coronary artery bypass grafting. The diagnosis was confirmed by means of coronary angiography with selective catheterization of the LIMA and by computed tomographic angiography of the heart. The patient underwent reoperative 2-vessel coronary artery bypass grafting and ligation of multiple fistulae; 16 months postoperatively, he was asymptomatic and doing well. In addition to reporting this case, we discuss relevant diagnostic and treatment considerations.Key words: Arteriovenous malformations/physiopathology, coronary artery bypass/adverse effects, fistula/etiology, internal mammary-coronary artery anastomosis/adverse effects, mammary arteries/surgery, myocardial ischemia/etiology, pulmonary artery/surgery, vascular fistula/complications/etiology/surgeryAs a bypass-graft conduit to the left anterior descending coronary artery (LAD), the left internal mammary artery (LIMA) is the vessel of choice because of its proven longevity and long-term patency. The formation of a LIMA-to-pulmonary artery (PA) fistula after coronary artery bypass grafting (CABG) is a rare complication: fewer than 30 reports have appeared in the medical literature.1 We report a case of multiple LIMA-to-PA fistulae that we found 15 years after a patient had undergone CABG.  相似文献   
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In-line X-ray phase-contrast imaging technique is an emerging method for the study of materials such as carbon fibers, carbon composite materials, polymers, etc. Similarly this technique is also well suited for the imaging of soft materials such as tissues, distinguishing between tumor and normal tissue. These represent the class of materials for which X-ray attenuation cross-section is very small. Thus this method promises a far better contrast for low X-ray absorbing substances than the conventional radiography method. We have set up an experimental facility using a combination of X-ray CCD detector and a microfocus X-ray source. This facility is dedicated to micro-imaging experiments such as microtomography and high-resolution phase-contrast experiments. In this paper, the results of X-ray phase-contrast imaging experiments are described.  相似文献   
96.
The degree of patient comfort and satisfaction with an inhaler can have an important effect on compliance with asthma treatment and, hence, therapeutic success. The objective of this study was to assess, from the patient's perspective, the importance of various inhaler characteristics and then evaluate patient satisfaction with a new breath-actuated powder inhaler (Diskhaler TM*) based on those characteristics. Self-administered patient satisfaction questionnaires were completed as part of a randomized, double-blind, placebo-controlled study of fluticasone propionate powder in the treatment of asthma. At baseline, patients rated the importance of five inhaler characteristics (convenient to carry, durability, easy to load, easy to hold and operate, and easy to clean). Following exposure to the Diskhaler over a period of 8 weeks, patients rated the inhaler on those same characteristics. They also rated their comfort using the inhaler and their overall satisfaction with the inhaler. Data were available from 274 patients, the majority of whom expressed a high or very high level of satisfaction with the Diskhaler on each of the five characteristics. These ratings were congruent with their ratings of the importance of those same characteristics; 80-90% rated “convenient to carry”, “durability”, “easy to load,” and “easy to hold and operate” as important or very important characteristics for an inhaler, while “easy to clean” was considered somewhat less important, with 63% rating this characteristic as important or very important. Following the initial exposure to the Diskhaler, 67% of patients were comfortable or very comfortable with the inhaler; that percentage increased to 79% after 8 weeks of use. Following 2 and 8 weeks of use, 61 and 62%, respectively, were satisfied or very satisfied with the Diskhaler. In general, satisfaction ratings were not affected by treatment, indicating that patients were evaluating only the inhaler and not the efficacy of the study drug they received. This study helped to identify which selected inhaler characteristics are most important to patients with asthma. The Diskhaler inhaler performed well on those characteristics deemed important to the patients. From their first exposure to the Diskhaler, patients were comfortable using the device, and this overall acceptance of the inhaler was maintained throughout the study.  相似文献   
97.
The treatment of central nervous system (CNS) disorders is particularly challenging because of a variety of formidable barriers to effective and persistent delivery of therapeutic compounds. This review discusses the potential of intranasal drug administration as a means to bypass a major barrier, the blood-brain barrier, and allow for direct delivery of drugs into the CNS. The article emphasizes physicochemical properties of intranasal drug formulations as well as relevant anatomical and physiological factors in intranasal delivery of drugs for CNS therapy. Published examples of intranasal administration of small molecular weight drugs, peptides and proteins, and novel formulations for delivering a broad spectrum of molecules are discussed. Finally, the article provides several strategies for effectively enhancing nose-to-brain transport of drug molecules through rational formulation design and optimization.  相似文献   
98.
Providing the optimum treatment of AIDS is a major challenge in the 21st Century. HIV is localised and harboured in certain inaccessible compartments of the body, such as the CNS, the cerebrospinal fluid, the lymphatic system and in the macrophages, where it cannot be reached by the majority of therapeutic agents in adequate concentrations or in which the therapeutic agents cannot reside for the necessary duration. Progression in HIV/AIDS treatment suggests that available therapy can lower the systemic viral load below the detection limit. However, on discontinuation of treatment, there is relapse of the infection from the reservoir sites and a potential for resistance development. This review discusses the aetiology and pathology of HIV, with emphasis on the viral reservoirs, current therapy of AIDS, and the opportunity for nanotechnology-based drug delivery systems to facilitate complete eradication of viral load from the reservoir sites. Literature-cited examples of drug delivery systems that are under investigation for the treatment of AIDS are discussed. The article also focuses on the future outlook and strategies for investigational drug formulations that use nanotherapeutic strategy for HIV/AIDS.  相似文献   
99.
We investigated the effect of maternal smoking during pregnancy on the relative risk of sudden infant death syndrome (SIDS) by linking data from Georgia birth and death certificates from 1997 to 2000. We estimated the effect of misclassifying smokers as non-smokers and the effect of being misclassified on SIDS rates, and we calculated the fraction of cases caused by exposure. Of all SIDS cases, 21% were attributable to maternal smoking; among smokers, 61% of SIDS cases were attributable to maternal smoking. Maternal smoking during pregnancy is associated with a significantly increased risk of SIDS.  相似文献   
100.
Thyroid disorders are common endocrine problem encountered in the paediatric and adolescent age group. Amongst the functional thyroid disorders hypothyroidism is far more common than hyperthyroidism. Though simple goitre is common in this age group, nodular goitre and in particular solitary thyroid nodule are uncommon. Appropriate use of thyroid function test can delineate practically all thyroid disorders. Functional thyroid disorders lend themselves to effective treatment and monitoring strategies. The basic management principles remain similar to adults with thyroid dysfunction; experience in management of paediatric and adolescent thyroid disorders is particularly necessary to safeguard against long term detrimental effects of under-or overtreatment as it can have repercussion on the growth of the child. Prognosis in majority of the children tends to be good provided that timely and appropriate management is undertaken.  相似文献   
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