全文获取类型
收费全文 | 1288篇 |
免费 | 57篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 24篇 |
妇产科学 | 27篇 |
基础医学 | 192篇 |
口腔科学 | 3篇 |
临床医学 | 89篇 |
内科学 | 405篇 |
皮肤病学 | 9篇 |
神经病学 | 114篇 |
特种医学 | 38篇 |
外科学 | 126篇 |
综合类 | 7篇 |
预防医学 | 60篇 |
眼科学 | 4篇 |
药学 | 152篇 |
中国医学 | 4篇 |
肿瘤学 | 72篇 |
出版年
2023年 | 14篇 |
2022年 | 43篇 |
2021年 | 69篇 |
2020年 | 24篇 |
2019年 | 32篇 |
2018年 | 34篇 |
2017年 | 28篇 |
2016年 | 28篇 |
2015年 | 40篇 |
2014年 | 51篇 |
2013年 | 59篇 |
2012年 | 122篇 |
2011年 | 122篇 |
2010年 | 49篇 |
2009年 | 44篇 |
2008年 | 83篇 |
2007年 | 84篇 |
2006年 | 67篇 |
2005年 | 81篇 |
2004年 | 56篇 |
2003年 | 66篇 |
2002年 | 36篇 |
2001年 | 7篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 11篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1971年 | 3篇 |
1937年 | 1篇 |
排序方式: 共有1349条查询结果,搜索用时 15 毫秒
71.
Wlazło A Kleszczyński J Błaszczyk A Tyfel P Jakubczyc A Morasiewicz J 《Psychiatria polska》2003,37(4):695-701
AIM: The analysis of the data from the psychiatric hospitals in Lubliniec (1894-1932, 1934-1936, 1970-1999) and Boles?awiec (1958-1999) proved a decrease in frequency of diagnosis of catatonic schizophrenia, what could testify to a decrease in morbidity with this form of schizophrenia. METHOD AND RESULTS: Basing on the facts from scientific literature there was ascertained that the decrease in frequency of diagnosis of catatonic schizophrenia is connected with following causes: firstly, with the changes in nozology, secondly, with the introduction of a new form of therapy and finally, with the fact that here psychological and sociological factors exist which eliminate catatonia as the most expressive form of schizophrenia. 相似文献
72.
The majority of antidepressants undergo the oxidative biotransformation catalysed by cytochrome P-450, particularly by izoenzyme CYP2D6, whose activity is genetically determined. In many cases poor tolerance of antidepressants depends on CYP2D6 activity. The aim of the study was the evaluation of the relationship between the CYP2Dg genotype and the occurrence of side effects during antidepressive pharmacotherapy. 相似文献
73.
Rudzki Z Matynia A Przybylik-Mazurek E Darczuk A Szybiński Z Piatkowska-Jakubas B Wójcik M Skotnicki AB 《Polskie Archiwum Medycyny Wewn?trznej》2003,110(3):1003-1011
Insufficiency of the pituitary gland and hematological abnormalities may coexist in the context of two syndromes. In the course of some hematopoietic neoplasms, particularly acute leukemias, the pituitary insufficiency may be caused by destruction of the gland either by direct neoplastic infiltration or occlusion of vessels. Alternatively, thy pituitary dysfunction may be associated with but not caused by hematological abnormalities, usually mild peripheral cytopenias. We present four cases of the latter type (1. M/33, pituitary tumor, hypogonadism, hyperprolactinemia, anemia, mild leukopenia with leukocytosis, 2. F/54, pituitary tumor, hyperprolactinemia, thyreotropic and corticotropic insufficiency, anemia, thrombocytopenia, mild neutropenia, 3. F/27, pituitary tumor, diabetes insipidus, hypogonadism, sideropenic anemia, leukopenia, thrombocytopenia, 4. M/24, primary multihormonal insufficiency of the anterior portion of the pituitary gland, neutropenia, microcytosis). Trephine and aspiration bone marrow biopsies revealed topographic and cytological abnormalities partially resembling these found in myelodysplastic syndromes (MDS). Bone marrow cellularity varied markedly between and within the cases, and in three patients abnormal aplastic areas were found. The percentage of hematopoietic stem cells (CD34+) was low in three cases and normal in one case. Pituitary dysfunction may be associated with hematological abnormalities simulating MDS, but showing different, less aggressive clinical course. The proliferative potential of hematopoietic cells is low, the peripheral blood abnormalities are stable, and no patient developed acute leukemia. Detailed bone marrow examination, including the trephine bone marrow biopsy, is useful in differentiation with true MDS, which was also reported in the literature in the patients with pituitary insufficiency. 相似文献
74.
OBJECTIVE: Our aim was to develop a mathematical model that describes the nitric oxide (NO) transport in and around capillaries. The model is used to make quantitative predictions for (1) the contribution of capillary endothelium to the nitric oxide flux into the parenchymal tissue cells; (2) the scavenging of arteriolar endothelium-derived NO by capillaries in the surrounding tissue; and (3) the role of myoglobin in tissue cells and plasma-based hemoglobin on NO diffusion in and around capillaries. METHODS: We used a finite element model of a capillary and surrounding tissue with discrete parachute-shape red blood cells (RBCs) moving inside the capillary to obtain the NO concentration distribution. An intravascular mass transfer coefficient is estimated as a function of RBC membrane permeability and capillary hematocrit. A continuum model of the capillary is also formulated, in which blood is treated as a homogeneous fluid; it uses the mass transfer coefficient and provides a closed-form analytic solution for the average exchange rate of NO in a capillary-perfused region. RESULTS: The NO concentration in the parenchymal cells depends on parameters such as RBC membrane permeability and capillary hematocrit; the concentration is predicted for a wide range of parameters. In the absence of myoglobin or plasma-based hemoglobin, the average tissue concentration generally ranges between 20 and 300 nM. In the presence of myoglobin or after transfusion of a hemoglobin-based blood substitute, there is minimal NO penetration into the tissue from the capillary endothelium. CONCLUSIONS: The model suggests that NO originating from the capillary wall can diffuse toward the parenchymal cells and potentially sustain physiologically significant concentrations. The model provides estimates of NO exchange and concentration level in capillary-perfused tissue, and it can be used in models of NO transport around arterioles or other NO sources. 相似文献
75.
Based on literature review the paper presents some clinical aspects of the genetically determined polymorphism of the CYP2D6. One of the main biotransformation processes of psychotropic drugs is oxidation catalysed by enzymes of cytochrome P-450. CYP2D6 is an isoenzyme of cytochrome P-450. Its activity is determined genetically and is characterised by interindividual variability. Genetically determined polymorphism of CYP2D6 is related to mutated alleles that code enzymatic proteins with different activity. Based on individual ability to oxidize drugs by CYP2D6 in population there are four phenotypically different groups: extensive (EM), ultra-rapid (UM), intermediate (IM) and poor metabolizers (PM). Each phenotype is determined by a given genotype. About 6-10% of the Caucasian population is known as PM phenotype. Drugs used in standard doses in this group may reach a markedly higher level in blood, even a toxic level. Compared to the group with EM phenotype persons with PM or IM phenotype are more likely to suffer from side effects that are related to impaired metabolic pathways that are catalyzed by CYP2D6. In the group with UM phenotype (1-7% of population) metabolism is very rapid, thus they need higher doses of psychotropic drugs to reach therapeutic blood level of drug. 相似文献
76.
77.
Susanne H.M. Gruber George G. Nomikos Aleksander A. Math 《European neuropsychopharmacology》2006,16(8):592-600
We have reported that acute d-amphetamine increases extracellular concentrations (efflux) of neurotensin-like immunoreactivity (NT-LI) and neuropeptide Y-LI (NPY-LI) in the ventral striatum (VSTR) of freely moving rats, effects that are abolished by chronic administration of haloperidol and risperidone admixed to food pellets. In this study we further investigated the d-amphetamine effects on NT-LI and NPY-LI efflux in VSTR and their content in selected brain regions. Rats received haloperidol, risperidone or vehicle for 30 days and saline or d-amphetamine either on days 22–29 and/or day 30. Seven day d-amphetamine administration decreased basal NT-LI and NPY-LI efflux in vehicle-treated rats; pretreatment with haloperidol counteracted these effects, while pretreatment with risperidone had effect only on NT-LI. Acute d-amphetamine after the seven day d-amphetamine increased NT-LI only. Pretreatment with haloperidol or risperidone abolished the effects of acute d-amphetamine on NT-LI and NPY-LI. Acute and seven day d-amphetamine increased NT-LI and NPY-LI contents in striatum; seven day d-amphetamine also increased NT-LI in frontal and occipital cortex and both NT-LI and NPY-LI in hippocampus. Our results suggest that NT and NPY are involved in both the pathophysiology and the therapeutics of schizophrenia. 相似文献
78.
Moreno FA McGavin C Malan TP Gelenberg AJ Heninger GR Mathé AA Delgado PL 《The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP)》2000,3(4):277-283
Plasma tryptophan (Trp) depletion is a commonly used tool for determining the role of brain serotonin (5-HT) function in a variety of psychiatric disorders. This study measured the cerebrospinal fluid (CSF) monoamine metabolite response to Trp depletion and control testing in five healthy subjects utilizing a single lumbar puncture. Testing was done in a placebo-controlled, double-blind, randomized, cross-over design. Plasma-free and total Trp levels and behavioural ratings were obtained prior to and 5 h after ingestion of each amino-acid drink. CSF was obtained by performing a standard lumbar puncture 7 h after ingestion of the drink. Compared to control testing, Trp depletion caused a significant decrease of CSF 5-hydroxyindoleacetic acid (5-HIAA) (p = 0.03), but not of homovanillic acid or 3-methoxy-4-hydroxy-phenylglycol. Behavioural ratings were minimally affected in all subjects. This confirms that plasma Trp depletion reduces central nervous system measures of 5-HT function and suggests that the single lumbar puncture technique may be sufficient to detect the extent of CSF 5-HIAA changes during Trp depletion studies. 相似文献
79.
Sileneoside H (1), a new phytoecdysteroid, has been isolated from the roots of Silene brahuica and identified as 22-O-alpha-D-galactosylintegristerone A 25-acetate by MS and NMR analysis. 相似文献
80.