全文获取类型
收费全文 | 13636篇 |
免费 | 761篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 153篇 |
儿科学 | 323篇 |
妇产科学 | 375篇 |
基础医学 | 1862篇 |
口腔科学 | 312篇 |
临床医学 | 1341篇 |
内科学 | 2800篇 |
皮肤病学 | 522篇 |
神经病学 | 841篇 |
特种医学 | 651篇 |
外科学 | 2209篇 |
综合类 | 155篇 |
现状与发展 | 1篇 |
一般理论 | 2篇 |
预防医学 | 582篇 |
眼科学 | 273篇 |
药学 | 1058篇 |
中国医学 | 150篇 |
肿瘤学 | 879篇 |
出版年
2023年 | 90篇 |
2022年 | 248篇 |
2021年 | 418篇 |
2020年 | 196篇 |
2019年 | 269篇 |
2018年 | 409篇 |
2017年 | 294篇 |
2016年 | 343篇 |
2015年 | 435篇 |
2014年 | 636篇 |
2013年 | 649篇 |
2012年 | 1039篇 |
2011年 | 1012篇 |
2010年 | 599篇 |
2009年 | 479篇 |
2008年 | 802篇 |
2007年 | 781篇 |
2006年 | 739篇 |
2005年 | 732篇 |
2004年 | 642篇 |
2003年 | 519篇 |
2002年 | 491篇 |
2001年 | 420篇 |
2000年 | 393篇 |
1999年 | 306篇 |
1998年 | 119篇 |
1997年 | 90篇 |
1996年 | 89篇 |
1995年 | 68篇 |
1994年 | 59篇 |
1993年 | 34篇 |
1992年 | 123篇 |
1991年 | 108篇 |
1990年 | 101篇 |
1989年 | 64篇 |
1988年 | 57篇 |
1987年 | 67篇 |
1986年 | 53篇 |
1985年 | 51篇 |
1984年 | 32篇 |
1980年 | 22篇 |
1979年 | 31篇 |
1977年 | 30篇 |
1976年 | 24篇 |
1975年 | 25篇 |
1974年 | 28篇 |
1973年 | 26篇 |
1972年 | 30篇 |
1970年 | 23篇 |
1969年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Sönmez AS Yasar L Savan K Koç S Ozcan J Toklar A Yazicioğu F Akgün A Sut N 《Human reproduction (Oxford, England)》2005,20(1):175-179
BACKGROUND: The aim of this study was to evaluate the effects of metformin and acarbose on insulin resistance, hormone profiles and ovulation rates in patients with clomiphene citrate-resistant polycystic ovary syndrome (PCOS). METHODS: Thirty clomiphene citrate-resistant patients were selected randomly and divided into two groups. Group I was treated with 100 mg/day clomiphene citrate and 300 mg/day acarbose 100 mg/day orally, for 3 months. Group II was treated with clomiphene citrate 100 mg/day and metformin 1700 mg/day orally, for 3 months. Serum fasting insulin and glucose, FSH, LH, estradiol, progesterone, prolactin and total testosterone levels plus body mass index (BMI) were measured before and after treatment. Follicle growth was followed by transvaginal ultrasonography. RESULTS: LH:FSH ratio and total testosterone concentrations decreased (P<0.05) and ovulation rates increased in both groups. Reduction in weight and BMI was only significant in the acarbose group. CONCLUSIONS: Both treatment modalities were effective in the treatment of insulin resistance and improving ovulation rates. Increase in the number of eumenorrhoeic and normoinsulinaemic cases and decrease in the number of insulin-resistant cases were significant in both groups (P<0.05). Ovulation rate was greater in the metformin group in the second month of therapy (P<0.05). Acarbose was found to be a safe and effective agent that could be used in cases with clomiphene-resistant PCOS. 相似文献
102.
Somatic mosaicism for a MECP2 mutation associated with classic Rett syndrome in a boy 总被引:4,自引:0,他引:4
Topçu M Akyerli C Sayi A Törüner GA Koçoğlu SR Cimbiş M Ozçelik T 《European journal of human genetics : EJHG》2002,10(1):77-81
Rett syndrome is a severe neurodevelopmental disorder that arises from mutations in the X-linked MECP2 gene. It is almost exclusively seen in girls due to the predominant occurrence of the mutations on the paternal X-chromosome, and also the early postnatal lethal effect of the disease causing mutations in hemizygous boys. We identified a boy with features of classic Rett syndrome who is mosaic for the truncating MECP2 mutation R270X. Chromosome analysis showed normal karyotype. These results indicate that a MECP2 mutation associated with Rett syndrome in females could lead to a similar phenotype in males as a result of somatic mosaicism. 相似文献
103.
Preferential expression of T(h)2-type chemokine and its receptor in atopic dermatitis 总被引:1,自引:0,他引:1
Lesional skin of patients with atopic dermatitis (AD) is histologically characterized by hypertrophy of the skin, and the infiltration of a large number of eosinophils and T cells into the dermis. Recent studies have indicated that Th2 cells play a crucial role in the pathogenesis of AD skin. Chemokines and their receptors are implicated in the development of symptoms of various skin diseases such as AD and psoriasis vulgaris (psoriasis). We have examined the in situ expression of a typical Th2-type chemokine, thymus- and activation-regulated chemokine (TARC), and its receptor (CCR4) using immunohistochemical techniques. TARC was found to be highly expressed in the basal epidermis of the lesional skin of AD patients and only slightly in the non-lesional skin. On the other hand, no positive cells were seen in the lesional skin of psoriasis. Consistently, CCR4+ cells were present predominantly in the lesional skin of AD patients, but not in the non-lesional skin. In contrast, in the lesional skin of psoriasis patients, cells positive for CCR5, which is expressed on Th1 cells, were abundantly present. Interestingly, psoralen plus ultraviolet A therapy reduced the number of CCR4+ cells in the AD skin lesions. These results suggest that Th2-type cytokines such as TARC are involved in the pathogenesis of skin lesions in AD patients through the preferential recruitment of Th2 cells. 相似文献
104.
Hsu SC Lin HP Wu JC Ko KL Sheen IJ Yan BS Chou CK Syu WJ 《Journal of virological methods》2000,87(1-2):53-62
Sequences of the hepatitis delta virus (HDV) vary to different degrees among isolates. A monoclonal antibody, designated as HP6A1, against the antigen of HDV (HDAg) has been characterized for its specificity. HP6A1 bound to HDAg of isolate 25 (genotype I) that was used for immunization, but not to others of both genotypes I and II. The epitope recognized by HP6A1 was then determined by a phage library displaying various heptapeptides. A consensus peptide deduced has the best match with that of residues 4-10 of HDAg (isolate 25). To confirm the phage mapping result, Escherichia coli recombinant proteins containing different lengths and various segments of HDAg (isolate 25) were constructed. The shortest HDAg segment contained in the fusion protein that reacted with HP6A1 was residues 1-10. When this peptide was added to the N-terminus of a heterologous protein engineered for eucaryotic expression, the fusion protein was detected by HP6A1. It is concluded that HP6A1 recognizes an epitope located at the N-terminus of HDAg (isolate 25). Since viruses of quasi-species exist in natural infections, a question of how different viral strains interact in vivo remains to be explored. The highly specific MAb opens a possibility to examine the fate of one strain in the presence of other related species in a cell transfection system. 相似文献
105.
M. Flesch A. Sachinidis Y. D. Ko K. Kraft H. Vetter 《Journal of molecular medicine (Berlin, Germany)》1994,72(12):944-950
In recent years there have been many studies demonstrating a correlation between increased arterial blood pressure and altered lipid profiles, and there has been an especially positive correlation between high cholesterol levels and blood pressure. There are differences between the various reports that are important. In our study the lipid distribution in 105 hypertensive patients with mild or moderate arterial hypertension according to WHO criteria without clinically or ultrasonographically apparent atherosclerosis was compared to the lipid distribution in 65 age-matched healthy persons. On the epidemiological level a significant, positive association was found between LDL serum levels (P 0.001), Apo B serum levels (P 0.001), serum triglyceride levels (P 0.05) and VLDL serum levels (P 0.01) and arterial hypertension. However, in contrast to recent reports, no significant difference was found between total serum cholesterol levels in normotensives and hypertensives, and there was no difference in HDL serum levels. No evidence could be found for a significant increase in lipoprotein (a) serum levels in hypertensives.Abbreviations LDL
low density lipoprotein
- VLDL
very low density lipoprotein
- HDL
high density lipoprotein
- Apo B 100
apolipoprotein B 100
- Apo A I
apolipoprotein A I
Correspondence to: H. Vetter 相似文献
106.
Michimasa Ebato Taizo Nitta Hideo Yagita Kiyoshi Sato Ko Okumura 《European journal of immunology》1994,24(12):2987-2992
The purpose of this study was to assess the V-(D)-J junctional region of the T cell receptor (TCR), the CDR3 region, which is responsible for glioma-specific antigen contact in αβ TCR-mediated recognition. We sequenced the TCR α and β chians of Vα7, and Vβ13.1 cDNA derived from tumor-infiltrating lymphocytes (TIL) of 12 glioma patients and also the corresponding clones from the patients' peripheral blood lymphocytes (PBL). A shared Vβ13.1 DJ sequence of the CDR3 region, NDβN, was demonstrated in 49 of 66 Vβ13.1+ clones (74.2 %) from the glioma TIL, whereas only 4 of 33 clones (12.1 %) were observed in the Vβ13.1+ clones from the PBL (p < 0.001). A common VDJ sequence, FCASS (Vβ13.1)-YRLPWGTSDS (NDβN)-GELFF(Jβ2.2), was observed not only in the gliomas from each patient, but also among all the patients with a preference for Vβ13.1. In contrast, the amino acid sequences of the Vβ13.1+ PBL clones were diverse and random. Next, we sequenced subclones from other Vβ subfamilies randomly selected to compare their VDJ region rearrangements (Vβ3 and Vβ5.1). In contrast to Vβ13.1, the amino acid sequences of these junctional regions were completely different in these subclones. The V-J junctional region of the α chain is dominated by a few clones in some patients, and no shared amino acid sequences were detected in the TCR Vα junctional region. However, in the Nα region of the Vα7-bearing TIL clones, arginine was used in 27 of 44 clones (61.4%) compared to only 3 of 12 clones from the PBL (p < 0.05). These results are consistent with the hypothesis that a clonal expansion/accumulation of glioma lineage-specific T cells occurred in vivo at the tumor site and that these T cells may be recognizing glioma-specific antigens. 相似文献
107.
Min-Seok Rha Hye Won Jeong Jae-Hoon Ko Seong Jin Choi In-Ho Seo Jeong Seok Lee Moa Sa A Reum Kim Eun-Jeong Joo Jin Young Ahn Jung Ho Kim Kyoung-Ho Song Eu Suk Kim Dong Hyun Oh Mi Young Ahn Hee Kyoung Choi Ji Hoon Jeon Jae-Phil Choi Eui-Cheol Shin 《Immunity》2021,54(1):44-52.e3
- Download : Download high-res image (218KB)
- Download : Download full-size image
108.
C M Teng F N Ko 《Research communications in molecular pathology and pharmacology》1998,102(3):211-225
Platelet-vessel wall interaction is an important process in physiological hemostasis and pathological thrombosis. In oriental countries, some medicinal plants have been claimed for uses to improve circulation, induce fibrinolysis or prevent thrombosis. In cooperation with chemists using bioassay-based step-by-step purification, some antiplatelet agents were isolated from plant sources. According to their effects on platelet aggregation, release reaction and signal transductions involved, these antiplatelet agents can be classified into eight groups: 1. platelet-activating factor (PAF) antagonists, 2. collagen-receptor antagonists, 3. thromboxane-receptor antagonists, 4. ADP-receptor agonists, 5. inhibitors of phosphoinositide breakdown, 6. inhibitors of thromboxane formation, 7. agents increasing cyclic nucleotides, and 8. protein kinase C activators. These new pharmacological agents derived from medicinal plant sources may be useful as leads to develop as effective cardiovascular drugs. 相似文献
109.
Frank E. Nulsen Albert Leung David G. Fleming Ronald J. Lorig John A. Bettice Kathleen A. Donlin Wen H. Ko 《Annals of biomedical engineering》1980,8(4-6):505-513
Intracranial pressure (ICP) monitoring is a critical measure for avoiding severe brain dysfunction or brain death by directing
supportive therapy so as to prevent ICP increase severe enough to reduce cerebral blood perfusion. Such situations occur with
brain swelling, increased cerebral vascular volume, and increase in cerebrospinal fluid (CSF) volume. Causes include ischemic
stroke, subarachnoid bleeding, brain contusion, encephalitis (as in Reye's syndrome), and hydrocephalus from meningitis or
neoplasm. When several days of ICP monitoring can direct resolution of the pressure crisis, the invasive direct connection
of an intracranial sensor with external recording device carries only minimal infection risk. Prolonged ICP monitoring for
weeks or months demands telemetry and becomes desirable in a number of chronic disease problems including both congenital
and acquired hydrocephalus where enlarged and pressurized cerebral ventricles develop with reduced absorption of continuously
secreted CSF. Although the primary disturbance in CSF circulation can remain incurable, its palliation by valve-regulated
CSF diversions or shunting can restore normal brain function and in infants permit normal brain development. Missing this
goal can result from failure to maintain a sufficiently normal pattern of CSF dynamics and ICP. Monitoring of the CSF pressure
fluctuations transmitted through an intraventricular catheter provides the most accurate record of ICP pulsations. Therefore,
a pressure sensing module can be “T'd” into an existing shunt system in continuity with the already placed ventricular tube.
The capacity to monitor ICP accurately by telemetry was first established in dogs made hydrocephalic to assure free CSF pulse
through a ventricular catheter (1,2,3, 4,5). The subsequent use of ICP monitoring by telemetry in three patients will be described. 相似文献
110.