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51.
本文报道用中压柱色谱快速分离S或R-α-甲基苯乙胺及S或R-α-甲基苄胺缩(±)-棉酚的方法,可得光学活性胺缩(+)或(一)-棉酚非对映体,经水解分别得到(+)或(一)-棉酚。并证明胺缩光学活性棉酚非对映体之间有互相转化的性质,此特性可利用于棉酚对映体的转化。  相似文献   
52.
甘草叶中两个新异戊烯基黄酮类化合物   总被引:3,自引:0,他引:3  
自乌拉尔甘草(Glycyrrhiza uralensis Fisch.)的干燥叶中分离到三个黄酮类化合物。经化学方法和光谱(UV,MS,1HNMR)数据分析,分别确定为5,7,3′,4′-四羟基-3-甲氧基-5′-异戊烯基黄酮(Ⅰ),5,6,3′,4′-四羟基-3-甲氧基-6′-异戊烯基黄酮(Ⅱ)和槲皮素(Ⅲ)。Ⅰ和Ⅱ是新化合物,分别命名为乌拉尔醇-3-甲醚(uralenol-3-methylether)和乌拉尔素(uralene)。Ⅲ在本种植物中为首次报道。  相似文献   
53.
潘竞先  LAMY  K  ARISON  B  SMITH  J  韩桂秋 《药学学报》1987,22(5):380-384
Nine coumarins were isolated from dichloromethane extract of the roots of Angelica pubescens Maxim. Seven of them were identified as osthol (Ⅰ), columbianetin acetate (Ⅱ), columbianetin (Ⅲ), bergapten (Ⅳ), angelol (Ⅴ),xanthotoxin (Ⅵ) and isoimperatorin (Ⅶ). (Ⅵ) and (Ⅶ) were isolated for the first time from this plant. Two new coumarins were elucidated as isoangelol (Ⅷ), a geometric isomer of angelol C20H24O7 [α]D20-133.5 and anpubesol C20H26O7 [α]D20 -72.5 on the basis of spectral evidences.  相似文献   
54.
Purpose: To establish the prevalence and severity of myopia among the Chinese Hong Kong students and to study the relationship between myopia and optical components.Methods;One thousand and seventy-five freshmen of the 1993-1994 academic year in the Chinese University of Hong Kong underwent the eye examination including evaluation of refractive error, keratometry, and A-scan ultrasonic biometry. The data were analyzed with the SPSS/PC 4. 01 statistical package. Results: The prevalence of myopia was 91. 7% with the mean refraction being -4. 00 ± 2. 64D in this young adult population. The statistical analyses demonstrated a significant correlation between refractive value and axial length of the globe (r=-0. 78), vitreous length (r=-0. 76), anterior chamber depth (r=-0. 33), lens thickness (r = 0. 13) and corneal curvature (r = 0. 19). Conclusion: The refractive status is mainly dependent on the axial length. In general, the higher the myopia was, the longer the eyeball, the deeper the anterior chamber,  相似文献   
55.
A significant proportion of patients with skin diseases have associated psychosocial factors. Not only does psychopathology manifest on the skin in absence of any real skin disease, primary skin disorders can also be exacerbated by emotional stress adversely influencing the homeostasis of immunological and inflammatory processes in deeper layers of the skin. Furthermore, many patients develop emotional problems as a result of having disfiguring skin diseases. In addition, some patients having solely sensory disturbances in absence of primary dermatoses or identifiable medical or neurological conditions, as well as some purely dermatologic conditions such as post-herpetic neuralgia may preferentially need psychotherapeutic modalities to address their underlying psychopathology irrespective of the presenting dermatologic manifestation arising out of ‘somatisation’ of a psychopathology into physical problems. The most obvious course of action of referral to a psychiatrist or another mental health professional may unfortunately not be readily tenable either due to the perceived stigma associated with psychiatric illness or lack of insight on the part of patients. In the interregnum, effective management of the psychologic or/and psychiatric problems can only be done by the dermatologist provided he has an adequate knowledge base and experience to undertake psychotherapeutic modalities.Key Words: Denial, Psychodermatoses, Psychopathology, Psychopharmacotherapy, Somatisation  相似文献   
56.
Artifical Blood     
Elimination of unwanted side-effects, especially transfusion-transmitted diseases (HIV and hepatitis) and leucocyte-mediated allosensitisation, is an important goal of modern transfusion medicine. The problems and high cost factor involved in collecting and storing human blood and the pending world-wide shortages are the other driving forces contributing towards the development of blood substitutes. Two major areas of research in this endeavour are haemoglobin-based oxygen carriers (HBOCs) and perfluorochemicals. Even though they do not qualify as perfect red blood cell substitutes, these ‘oxygen carrying solutions’ have many potential clinical and non clinical usages. These can reach tissues more easily than normal red cells and can deliver oxygen directly. These are not without adverse effects, and extensive clinical trials are being conducted to test their safety and efficacy. New understandings on the mode of action of these products will help to define their utility and application. Only after successful clinical trials can they be used for patient management, after approval by the FDA.Key Words: Blood substitute, Haemoglobin solutions, Perfluorocarbons  相似文献   
57.
Increasing appreciation of tumor heterogeneity and the tumor-host interaction has stimulated interest in developing novel therapies that target both tumor cells and tumor microenvironment. Bone marrow derived cells (BMDCs) constitute important components of the tumor microenvironment. In this study, we aim to investigate the significance of VEGFR1- and VEGFR2-expressing non-tumor cells, including BMDCs, in esophageal cancer (EC) progression and in VEGFR1/VEGFR2-targeted therapies. Here we report that VEGFR1 or VEGFR2 blockade can significantly attenuate VEGF-induced Src and Erk signaling, as well as the proliferation and migration of VEGFR1+ and VEGFR2+ bone marrow cells and their pro-invasive effect on cancer cells. Importantly, our in vivo data show for the first time that systemic blockade of VEGFR1+ or VEGFR2+ non-tumor cells with neutralizing antibodies is sufficient to significantly suppress esophageal tumor growth, angiogenesis and metastasis in mice. Moreover, our tissue microarray study of human EC clinical specimens showed the clinicopathological significance of VEGFR1 and VEGFR2 in EC, which suggest that anti-VEGFR1/VEGFR2 therapies may be particularly beneficial for patients with aggressive EC. In conclusion, this study demonstrates the important contributions of VEGFR1+ and VEGFR2+ non-tumor cells in esophageal cancer progression, and substantiates the validity of these receptors as therapeutic targets for this deadly disease.  相似文献   
58.
59.
本文报道用中压柱色谱快速分离S或R-α-甲基苯乙胺及S或R-α-甲基苄胺缩(±)-棉酚的方法,可得光学活性胺缩( )或(一)-棉酚非对映体,经水解分别得到( )或(一)-棉酚。并证明胺缩光学活性棉酚非对映体之间有互相转化的性质,此特性可利用于棉酚对映体的转化。  相似文献   
60.
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