全文获取类型
收费全文 | 3704篇 |
免费 | 216篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 97篇 |
妇产科学 | 93篇 |
基础医学 | 499篇 |
口腔科学 | 91篇 |
临床医学 | 237篇 |
内科学 | 1209篇 |
皮肤病学 | 76篇 |
神经病学 | 224篇 |
特种医学 | 169篇 |
外科学 | 525篇 |
综合类 | 4篇 |
一般理论 | 1篇 |
预防医学 | 131篇 |
眼科学 | 17篇 |
药学 | 188篇 |
中国医学 | 7篇 |
肿瘤学 | 328篇 |
出版年
2023年 | 26篇 |
2022年 | 46篇 |
2021年 | 83篇 |
2020年 | 43篇 |
2019年 | 73篇 |
2018年 | 76篇 |
2017年 | 66篇 |
2016年 | 59篇 |
2015年 | 66篇 |
2014年 | 98篇 |
2013年 | 115篇 |
2012年 | 206篇 |
2011年 | 213篇 |
2010年 | 108篇 |
2009年 | 101篇 |
2008年 | 194篇 |
2007年 | 180篇 |
2006年 | 177篇 |
2005年 | 207篇 |
2004年 | 212篇 |
2003年 | 147篇 |
2002年 | 164篇 |
2001年 | 147篇 |
2000年 | 122篇 |
1999年 | 108篇 |
1998年 | 42篇 |
1997年 | 34篇 |
1996年 | 32篇 |
1995年 | 32篇 |
1994年 | 32篇 |
1993年 | 28篇 |
1992年 | 73篇 |
1991年 | 78篇 |
1990年 | 60篇 |
1989年 | 60篇 |
1988年 | 47篇 |
1987年 | 44篇 |
1986年 | 41篇 |
1985年 | 34篇 |
1984年 | 36篇 |
1983年 | 39篇 |
1982年 | 24篇 |
1980年 | 12篇 |
1979年 | 29篇 |
1978年 | 13篇 |
1976年 | 14篇 |
1975年 | 15篇 |
1974年 | 9篇 |
1972年 | 10篇 |
1967年 | 11篇 |
排序方式: 共有3930条查询结果,搜索用时 15 毫秒
11.
Efficacy and safety of sublingual immunotherapy. 总被引:7,自引:0,他引:7
Giovanni Passalacqua Laura Guerra Mercedes Pasquali Carlo Lombardi Giorgio Walter Canonica 《Annals of allergy, asthma & immunology》2004,93(1):3-12; quiz 12-3, 103
OBJECTIVE: To review the available published data concerning the use of sublingual immunotherapy (SLIT) in respiratory allergy to primarily evaluate the clinical efficacy and safety of the treatment and to secondarily consider the mechanisms of action and any unresolved questions. DATA SOURCES: Articles in the medical literature (starting from 1986 up to November 2003) derived from searching the MEDLINE database with the keywords sublingual immunotherapy, respiratory allergy, asthma, and rhinitis. Sources included review articles, randomized controlled clinical trials, postmarketing surveillance studies, and relevant reports from meeting proceedings. STUDY SELECTION: Articles concerning safety, efficacy, and mechanisms of SLIT published in English-language, peer-reviewed journals. RESULTS: SLIT proved effective and safe in adults and children. As with traditional subcutaneous immunotherapy, SLIT has long-lasting efficacy and a preventive effect on new sensitizations. CONCLUSION: SLIT is a viable alternative to subcutaneous immunotherapy. Its use in pediatric patients seems to be particularly promising. 相似文献
12.
13.
Mitochondrial import and enzymatic activity of PINK1 mutants associated to recessive parkinsonism 总被引:17,自引:0,他引:17
Silvestri L Caputo V Bellacchio E Atorino L Dallapiccola B Valente EM Casari G 《Human molecular genetics》2005,14(22):3477-3492
Parkinson's disease (PD) is a progressive neurodegenerative illness associated with a selective loss of dopaminergic neurons in the nigrostriatal pathway of the brain. Despite the overall rarity of the familial forms of PD, the identification of single genes linked to the disease has yielded crucial insights into possible mechanisms of neurodegeneration. Recently, a putative mitochondrial kinase, PINK1, has been found mutated in an inherited form of parkinsonism. Here, we describe that PINK1 mutations confer different autophosphorylation activity, which is regulated by the C-terminal portion of the protein. We also demonstrate the mitochondrial localization of both wild-type and mutant PINK1 proteins unequivocally and prove that a short N-terminal part of PINK1 is sufficient for its mitochondrial targeting. 相似文献
14.
Identification of a 35-kilodalton Mycobacterium tuberculosis protein containing B- and T-cell epitopes. 下载免费PDF全文
D Vismara M F Mezzopreti M S Gilardini P Del Porto G Lombardi E Piccolella G Damiani R Rappuoli V Colizzi 《Infection and immunity》1990,58(1):245-251
Screening of a Mycobacterium tuberculosis genomic DNA library in the lambda gt11 expression vector was carried out by using, as probes, sera from tuberculous patients and murine monoclonal antibody H61.3 recognizing a mycobacterial 35-kilodalton protein present only on the M. tuberculosis complex. The recombinant beta-galactosidase-fused protein present in the crude lysate induced the proliferation of T lymphocytes from patients with tuberculous pleuritis. As the recombinant insert contains an internal EcoRI restriction site, it was possible to identify two fragments, one proximal to the lacZ gene and 1.7 kilobases (kb) in size and the other distal to the lacZ gene and 2.2 kb in size. Southern blot analysis showed that both of them hybridized with the genomic DNA from M. tuberculosis and M. bovis but not with the DNA from other mycobacterial species. To perform extensive immunological studies, the amount of beta-galactosidase-fused protein being very low, we fused the 1.7-kb fragment to the N-terminal part of the gene coding for the DNA polymerase of bacteriophage MS2 in the expression vector pEx34. The fusion protein was partially purified, and subsequent Western blotting (immunoblotting) and T-cell proliferation experiments confirmed the presence of B- and T-cell mycobacterial epitopes. Furthermore, to isolate the chromosomal region containing the 35-kilodalton gene, we constructed another mycobacterial genomic library in the lambda 2001 vector by cloning 15 to 20 kb of foreign DNA. Screening of this library was carried out by using 1.7- and 2.2-kb recombinant fragments as probes. Restriction maps of some clones isolated were determined. 相似文献
15.
Heterogeneous pattern of chromosomal breakpoints involving the MYC locus in multiple myeloma 总被引:2,自引:0,他引:2
Fabris S Storlazzi CT Baldini L Nobili L Lombardi L Maiolo AT Rocchi M Neri A 《Genes, chromosomes & cancer》2003,37(3):261-269
Chromosomal rearrangements of the MYC locus, which often involve the IG loci, are recurrent events in multiple myeloma (MM) and plasma cell leukemia (PCL). We used dual-color fluorescence in situ hybridization (FISH) to characterize the breakpoint locations of chromosomal translocations/rearrangements involving the MYC locus at 8q24 found in a panel of 14 MM cell lines and 70 primary tumors (66 MM and 4 PCL). MYC locus alterations were observed in 21 cases: MYC/IG (mainly IGH@) fusions in 11 cell lines and three patients (2 MM and 1 PCL), and extra signals and/or abnormal MYC localizations in seven patients (5 MM and 2 PCL). Fourteen of these cases were investigated by FISH analyses by use of a panel of BAC clones covering about 6 Mb encompassing the MYC locus. The breakpoints were localized in a region 100-250 kb centromeric to MYC in four cases, a region 500-800 kb telomeric to the gene in four cases, and regions > or = 2 Mb centromeric or telomeric to MYC in five cases. Two different breakpoints were detected in the KMS-18 cell line, whereas the insertion of a MYC allele was found in a complex t(16;22) chromosomal translocation in the RPMI8226 cell line. Our data document a relatively high dispersion of 8q24 breakpoints in MM. 相似文献
16.
17.
R Spaziante B Merola A Colao G Gargiulo T Cafiero C Irace E Rossi C Oliver G Lombardi B Mazzarella 《Journal of neurosurgical sciences》1990,34(2):99-106
The beta-endorphin-like-immunoreactivity (beta-ELI) has been evaluated both in plasma and in cerebrospinal fluid (CSF) in 30 patients during trans-sphenoidal surgery. Blood and liquoral samples were collected in five conditions: (1) "reference", (2) "pain", (3) "analgesia", (4) "end", and (5) "24th hour". A significant rise of both plasma and liquoral beta-ELI levels (p less than 0.00001 and p less than 0.08, respectively) when compared to basal ones occurred following the painful stimulation due to the divarication of the nasal mucosa by speculum. A significant decrease (p less than 0.01) was noticed for plasma concentrations at the third sample followed by a new significant increase at the end of the operation, (p less than 0.05 when compared to the third sample and p less than 0.01 when compared to the reference sample). In CSF, beta-ELI levels decreased at the third sample (p less than 0.01 when compared to the painful levels) and at the end of surgery (p less than 0.01, p less than 0.01 and p less than 0.05 vs first, second and third samples, respectively). Twenty-four hours after surgery either plasma and liquoral beta-ELI levels decreased (p less than 0.05). The modifications of the opiatergic system after acute painful stimuli should be, hence, characterized by an early rise followed by a progressive decrease of beta-ELI concentrations. The increase of plasma beta-ELI levels, at the end of surgery, could be due to pituitary manipulation with massive release in the peripheral blood. 相似文献
18.
The template bleeding time is still the screening test for defects of platelet function, although it is an invasive and poorly reproducible technique. The PFA-100 measures platelet function at high shear. Whole blood is aspirated through a capillary to an aperture of a membrane coated with platelet agonists. The system measures the time required to obtain occlusion of the aperture by a platelet plug (closure time). We measured the closure times in the PFA-100 system and the bleeding time in seven patients with delta-storage pool deficiency, 10 patients with "primary secretion defect" (not due to abnormalities of platelet granules or the arachidonate pathway), and 40 controls. Measurements were repeated I and 4 hours after intravenous infusion of desmopressin in six delta-storage pool deficiency and eight primary secretion defect patients. Baseline bleeding time and closure times with the collagen/epinephrine cartridge were longer in delta-storage pool deficiency and primary secretion defect patients than in controls. In contrast, closure times with the collagen/adenosine diphosphate cartridge were normal in both delta-storage pool deficiency and primary secretion defect patients. Treatment with desmopressin increased the plasma von Willebrand Factor levels, shortened the prolonged bleeding time, shortened the closure times with the collagen/adenosine diphosphate cartridge, and normalized the closure times with the collagen/ epinephrine cartridge. Therefore, the PFA-100 test may be a less invasive alternative to the bleeding time in the diagnosis and therapeutic monitoring of patients with platelet secretion defects. The collagen/epinephrine cartridge is more sensitive than the collagen/adenosine diphosphate cartridge to defects of platelet secretion. 相似文献
19.
Aesthesiometry of the cornea after refractive corneal surgery] 总被引:1,自引:0,他引:1
M Kohlhaas J Draeger A B?hm M Lombardi M Abbondanza M Zuppardo M G?rne 《Klinische Monatsbl?tter für Augenheilkunde》1992,201(4):221-223
The corneal sensibility was examined with the aesthesiometer of Draeger in 41 patients after refractive corneal surgery, 31 patients after radial keratotomy, 5 after epikeratophakia, 5 after excimer laser ablation. It could be shown that after radial corneal incisions the sensibility remains normal. After epikeratophakia the corneal sensibility is asensible even 3 years after operation. The lenticle periphery shows an increase of sensibility after 6 months. Excimer patients with "haze" showed a significant hyposensibility in the centre. The central sensibility showed normal values after a normal corneal wound healing. 相似文献
20.
P Gaetani R Rodriguez y Baena F Marzatico D Lombardi R Knerich P Paoletti 《Neurosurgery》1991,28(6):853-7; discussion 857-8
The specific mechanism underlying the genesis of vasogenic brain edema is still debated: the role of arachidonic acid is considered extremely important, as it is a possible activator of self-maintaining reactions enhancing the release of vasoactive and cytotoxic compounds. The relationship between arachidonic acid metabolism and brain edema has been studied primarily in brain tissue samples or in the extracellular fluid, whereas the residual capacity of perilesional tissue to synthesize and release eicosanoids has not been investigated. In the present study, perilesional samples of brain tissue were available from 4 patients operated on for brain metastasis, from 8 patients who had malignant neuroepithelial tumors, from 4 with meningiomas, and from 5 with subarachnoid hemorrhage. A brain edema index was calculated from the preoperative computed tomographic scan. The "ex vivo" method allowed determination of the residual capacity of endogenous arachidonic acid metabolism. The edema index is significantly higher in patients with brain metastasis (6.5 +/- 0.8) and neuroepithelial tumors (3.6 +/- 0.2) than in those with meningiomas (1.5 +/- 0.06), subarachnoid hemorrhage (1.7 +/- 0.18), and in controls. In patients with metastatic and neuroepithelial tumors there is a significant correlation between peritumoral brain edema and the capacity to synthesize leukotriene C4 (P less than 0.05); the capacity to synthesize leukotriene C4 is also significantly elevated after subarachnoid hemorrhage (13.91 +/- 2.6 ng/ml of incubation medium) when compared with control cases (5.56 +/- 0.91). The capacity to synthesize prostacyclin is significantly higher in patients with brain metastasis than in those with neuroepithelial tumors and meningiomas (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献