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61.
Hyperspectral and multispectral bioluminescence optical tomography for small animal imaging 总被引:4,自引:0,他引:4
Chaudhari AJ Darvas F Bading JR Moats RA Conti PS Smith DJ Cherry SR Leahy RM 《Physics in medicine and biology》2005,50(23):5421-5441
For bioluminescence imaging studies in small animals, it is important to be able to accurately localize the three-dimensional (3D) distribution of the underlying bioluminescent source. The spectrum of light produced by the source that escapes the subject varies with the depth of the emission source because of the wavelength-dependence of the optical properties of tissue. Consequently, multispectral or hyperspectral data acquisition should help in the 3D localization of deep sources. In this paper, we describe a framework for fully 3D bioluminescence tomographic image acquisition and reconstruction that exploits spectral information. We describe regularized tomographic reconstruction techniques that use semi-infinite slab or FEM-based diffusion approximations of photon transport through turbid media. Singular value decomposition analysis was used for data dimensionality reduction and to illustrate the advantage of using hyperspectral rather than achromatic data. Simulation studies in an atlas-mouse geometry indicated that sub-millimeter resolution may be attainable given accurate knowledge of the optical properties of the animal. A fixed arrangement of mirrors and a single CCD camera were used for simultaneous acquisition of multispectral imaging data over most of the surface of the animal. Phantom studies conducted using this system demonstrated our ability to accurately localize deep point-like sources and show that a resolution of 1.5 to 2.2 mm for depths up to 6 mm can be achieved. We also include an in vivo study of a mouse with a brain tumour expressing firefly luciferase. Co-registration of the reconstructed 3D bioluminescent image with magnetic resonance images indicated good anatomical localization of the tumour. 相似文献
62.
Usefulness of immunohistochemistry in delineating renal spindle cell tumours. A retrospective study of 31 cases 总被引:3,自引:0,他引:3
Wang J Weiss LM Hu B Chu P Zuppan C Felix D Rausei-Mills V Chase DR 《Histopathology》2004,44(5):462-471
AIMS: To assess the usefulness of immunohistochemistry in delineating tumour diagnoses on a series of morphologically diagnosed renal spindle cell tumours (RSCTs). METHODS AND RESULTS: Formalin-fixed paraffin-embedded tissues from 31 morphologically diagnosed tumours were reinterpreted in light of newly obtained immunohistochemical information. By morphology, six had originally been classified as sarcomatoid carcinoma, five as spindle cell tumour (NOS), four as sarcoma (NOS), three as leiomyoma, three as leiomyosarcoma, and one each as fibrous polyp, hamartoma, neurilemmoma, mesoblastic nephroma, medullary fibroma, angiomyolipoma, haemangiopericytoma, malignant rhabdoid tumour, malignant Triton tumour, and carcinosarcoma. The application of immunohistochemistry verified the original diagnosis in 18 cases (18/31, 58%), confirming the diagnosis of sarcomatoid renal carcinoma (4/6), leiomyoma (2/3), leiomyosarcoma (3/3), sarcoma (NOS) (2/4), carcinosarcoma (1/1), malignant rhabdoid tumour (1/1), malignant Triton tumour (1/1), fibrous polyp (1/1), mesoblastic nephroma (1/1), hamartoma (1/1), and angiomyolipoma (1/1). Different tumour designations were suggested in 13 cases (13/31, 42%), including carcinosarcoma, sarcoma (NOS), leiomyosarcoma, solitary fibrous tumour, monomorphic/biphasic angiomyolipoma, endometrial stromal tumour, and congenital mesoblastic nephroma. CONCLUSIONS: Our data indicate that although morphology is most important in formulating the initial differential diagnosis, the addition of immunohistochemistry is vital in arriving at the correct classification of RSCTs. 相似文献
63.
Ren A Tio Jasper S Wijpkema Eng S Tan Folkert W Asselbergs Geke A P Hospers Gillian A J Jessurun Felix Zijlstra 《Endothelium》2005,12(3):103-106
Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. VEGF gene therapy improves perfusion of ischemic myocardium in experimental models and possibly in patients with end-stage coronary artery disease. In addition to its proliferative and migratory effect on endothelial cells, it also activates and up-regulates endothelial nitric oxide synthase (eNOS). Therefore, the authors investigated coronary endothelium-dependent vasodilatation in patients before and after VEGF gene therapy. The effect of intracoronary acetylcholine infusion on coronary diameter was assessed at baseline and after 3 months follow-up in patients with end-stage coronary artery disease treated with VEGF gene and in controls scheduled for elective percutaneous transluminal coronary angioplasty (PTCA) (acetylcholine test at diagnostic angiography and before a subsequently scheduled PTCA). Five out of six VEGF patients experienced a reduction in anginal complaints. Angiographic evidence for improved collateral filling was evident in two out of six patients. The vasoconstrictive response to acetylcholine was partly converted into dilatation. In contrast, the acetylcholine response in control patients remained vasoconstrictive. In conclusion, VEGF gene therapy has an important beneficial effect on the functional characteristics of the myocardial vascular network. Therefore, this therapy can potentially play an important role in all stages of the atherosclerotic process. 相似文献
64.
Timo D Müller Anke Hinney André Scherag Thuy T Nguyen Felix Schreiner Helmut Schäfer Johannes Hebebrand Christian L Roth Thomas Reinehr 《BMC medical genetics》2008,9(1):85
Background
We have previously identified strong association of six single nucleotide polymorphisms (SNPs) in FTO (fat mass and obesity associated gene) to early onset extreme obesity within the first genome wide association study (GWA) for this phenotype. The aim of this study was to investigate whether the obesity risk allele of one of these SNPs (rs9939609) is associated with weight loss in a lifestyle intervention program. Additionally, we tested for association of rs9939609 alleles with fasting blood parameters indicative of glucose and lipid metabolism. 相似文献65.
66.
dos Santos CN Rocha CF Cordeiro M Fragoso SP Rey F Deubel V Desprès P 《Virus research》2002,90(1-2):197-205
We have investigated the genetic diversity of dengue type-1 (DEN-1) virus in Brazil. The full nucleotide sequences of three DEN-1 virus isolated from DEN fever (DF) and DEN hemorrhagic fever patients in northeastern Brazil in 1997 (BR/97) and one from a DF patient in the south of Brazil in 2001 (BR/01) were compared to that of the reference strain BR/90 obtained in the city of Rio de Janeiro in 1990. Sequence analysis showed that the structural proteins were remarkably conserved between all isolates. A total of 27 amino acid changes occurred throughout the non-structural proteins. Among them, nine amino acid substitutions were specific of BR/97 and BR/01 isolates, indicating that in situ evolution of these strains had occurred. Within the BR/97 and BR/01 samples, some amino acid substitutions have been previously identified in DEN-1 virus strains sequenced so far, suggesting that recombination events might have occurred. 相似文献
67.
Podlowski S Wenzel K Luther HP Müller J Bramlage P Baumann G Felix SB Speer A Hetzer R Köpke K Hoehe MR Wallukat G 《Journal of molecular medicine (Berlin, Germany)》2000,78(2):87-93
A substantial body of evidence suggests involvement of the human beta1-adrenoceptor (beta1-AR) gene in the pathophysiology of dilated cardiomyopathy (DCM), a severe heart disease of significant public health impact. Beta1-AR-mediated signal transduction is dramatically altered due to downregulation, resulting in an impairment of myocardial response. The important role of genetic factors in idiopathic dilated cardiomyopathy (IDCM) recently recognized, we analyzed this prime candidate gene for genetic variation in carefully selected patients and controls. In this preliminary study, 18 single nucleotide polymorphisms were observed, 17 of which were located in the N-terminal and C-terminal region of the coding exon, resulting in 7 amino acid exchanges: Ser-49-Gly, Ala-59-Ser, Gly-389-Arg, Arg-399-Cys, His-402-Arg, Thr-404-Ala, and Pro-418-Ala. These mutations resulted in 11 different beta1-AR genotypes. Importantly, the genotypes carrying the Ser-49-Gly mutation in the N-terminus of the molecule in a heterozygous or homozygous form were observed significantly more frequently in the group of IDCM patients. The present results may provide a clue on the molecular mechanisms involved in IDCM, and add moreover interesting information on nature, distribution, and evolutionary aspects of sequence variation in human adrenergic receptor genes. 相似文献
68.
Wayne C. Waltzer Radoslav J. Bachvaroff Angelo Arnold David Anaise Felix T. Rapaport 《Journal of clinical immunology》1985,5(2):78-83
The role and activity of natural killer (NK) cells following renal transplantation remain unknown. To monitor NK activity, a51Cr release of K-562 targets in prednisone-and azathioprine-treated patients receiving renal allografts was utilized. In 18 patients in whom NK activity was measured prior to and after transplantation, a significant diminution in NK activity within 3 weeks following transplantation was demonstrated compared to pretransplant values (34.71 vs 12.20%, respectively;P<0.001). In 11 subjects who had NK activity assayed at various intervals after transplantation but not prior to allografting, mean NK values were markedly lower (mean, 14.2%) than those of normal volunteers or patients maintained on hemodialysis (P<0.001). The latter two control groups demonstrated no difference (P = NS) in mean NK activity (39.46 vs 35.82%, respectively). In 5 of the 29 patients evaluated with good long-term graft function (mean, 2.7 years), restitution of normal NK activity was demonstrated. In two patients with bacterial infections, NK activity increased from 39.29 to 51.7% and from 13.54 to 20.00%. After infection, these values were 35.3% in the former and 3.39% in the latter. Viral infection did not appear to affect NK activity significantly. NK activity was increased in only one of seven patients with documented rejection episodes. In three of such patients, NK activity declined significantly following pulse methylprednisolone therapy. These results indicate that (1) NK-cell activity significantly decreases immediately after transplantation, probably as a result of immunosuppressive therapy; (2) NK activity does not appear to be stimulated by the alloreactive rejection process; (3) NK activity may be augmented in the course of bacterial but not viral infections; and (4) long-term allograft survival may be associated with a restoration of NK-cell levels in certain recipients. 相似文献
69.
Summary: Mucosal surfaces represent the entry route of a multitude of viral pathogens. For many of these viruses, such as the herpes simplex viruses and human immunodeficiency virus, no effective vaccine exists. Hence, it is important that prospective vaccines engender maximal immunity at these susceptible sites. Genetic vaccines encoding adjuvant molecules represent one approach to optimize mucosal as well as systemic immunity. Promising candidates include various inflammatory cytokines and chemokines that might be used to enhance the primary response to a level sufficient for protection. Encouraging studies involving cytokines such as granulocyte/macrophage colony‐stimulating factor, interleukin‐2 (IL‐2), IL‐12, IL‐18, and many others are examined. Notable chemokines that may offer hope in such efforts include IL‐8, RANTES, CCL19, CCL21, and a few others. Combinatorial approaches utilizing several cytokines and chemokines will most likely yield the greatest success. In addition, as more is discovered regarding the requirements for memory development of T cells, boosters involving key cytokines such as IL‐15 and IL‐23 may prove beneficial to long‐term maintenance of the memory pool. This review summarizes the progress in the use of genetic vaccines to achieve mucosal immunity and discusses the needed strategies to maximize long‐term prospective immunity at this vulnerable entry site. 相似文献
70.
Storlazzi CT Fioretos T Paulsson K Strömbeck B Lassen C Ahlgren T Juliusson G Mitelman F Rocchi M Johansson B 《Human molecular genetics》2004,13(14):1479-1485
Double minutes (dmin), the cytogenetic hallmark of genomic amplification, are found in approximately 1% of karyotypically abnormal acute myeloid leukemias (AML) and myelodysplastic syndromes (MDS). The MYC gene at 8q24 has been reported to be amplified in the majority of the cases, and generally it has been assumed that MYC is the target gene. However, only a few studies have focused on the extent of the amplicon or on the expression patterns of the amplified genes. We have studied six cases (five AML and one MDS) with MYC-containing dmin. Detailed fluorescence in situ hybridization analyses identified a common 4.3 Mb amplicon, with clustered proximal and distal breakpoints, harboring eight known genes (C8FW, NSE2, POU5FLC20, MYC, PVT1, AK093424, MGC27434 and MLZE). The corresponding region was deleted in one of the chromosome 8 homologues in five of the six cases, suggesting that the dmin originated through extra replication (or loop-formation)--excision--amplification. Northern blot analysis revealed that MYC was not overexpressed. Instead, the C8FW gene, encoding a phosphoprotein regulated by mitogenic pathways, displayed increased expression. These results exclude MYC as the target gene and indicate that overexpression of C8FW may be the functionally important consequence of 8q24 amplicons in AML and MDS. 相似文献