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排序方式: 共有3762条查询结果,搜索用时 14 毫秒
81.
Liz Girardi Müller Camila Simonetti Pase Patrícia Reckziegel Raquel C.S. Barcelos Nardeli Boufleur Ana Cristina P. Prado Roseane Fett Jane Mara Block Maria Amália Pavanato Liliane F. Bauermann João Batista Teixeira da Rocha Marilise Escobar Burger 《Experimental and toxicologic pathology》2013,65(1-2):165-171
The hepatoprotective activity of the aqueous extract of the shells of pecan nut was investigated against ethanol-induced liver damage. This by-product of the food industry is popularly used to treat toxicological diseases. We evaluated the phytochemical properties of pecan shell aqueous extract (AE) and its in vitro and ex vivo antioxidant activity. The AE was found to have a high content of total polyphenols (192.4 ± 1.9 mg GAE/g), condensed tannins (58.4 ± 2.2 mg CE/g), and antioxidant capacity, and it inhibited Fe2+-induced lipid peroxidation (LP) in vitro. Rats chronically treated with ethanol (Et) had increased plasmatic transaminases (ALT, AST) and gamma glutamyl transpeptidase (GGT) levels (96%, 59.13% and 465.9%, respectively), which were effectively prevented (87; 41 and 383%) by the extract (1:40, w/v). In liver, ethanol consumption increased the LP (121%) and decreased such antioxidant defenses as glutathione (GSH) (33%) and superoxide dismutase (SOD) (47%) levels, causing genotoxicity in erythrocytes. Treatment with pecan shell AE prevented the development of LP (43%), GSH and SOD depletion (33% and 109%, respectively) and ethanol-induced erythrocyte genotoxicity. Catalase activity in the liver was unchanged by ethanol but was increased by the extract (47% and 73% in AE and AE + Et, respectively). Therefore, pecan shells may be an economic agent to treat liver diseases related to ethanol consumption. 相似文献
82.
Hassan Haji‐Valizadeh Li Feng Liliana E. Ma Daming Shen Kai Tobias Block Joshua D. Robinson Michael Markl Cynthia K. Rigsby Daniel Kim 《NMR in biomedicine》2020,33(5)
Retrospective electrocardiogram‐gated, 2D phase‐contrast (PC) flow MRI is routinely used in clinical evaluation of valvular/vascular disease in pediatric patients with congenital heart disease (CHD). In patients not requiring general anesthesia, clinical standard PC is conducted with free breathing for several minutes per slice with averaging. In younger patients under general anesthesia, clinical standard PC is conducted with breath‐holding. One approach to overcome this limitation is using either navigator gating or self‐navigation of respiratory motion, at the expense of lengthening scan times. An alternative approach is using highly accelerated, free‐breathing, real‐time PC (rt‐PC) MRI, which to date has not been evaluated in CHD patients. The purpose of this study was to develop a 38.4‐fold accelerated 2D rt‐PC pulse sequence using radial k‐space sampling and compressed sensing with 1.5 × 1.5 × 6.0 mm3 nominal spatial resolution and 40 ms nominal temporal resolution, and evaluate whether it is capable of accurately measuring flow in 17 pediatric patients (aortic valve, pulmonary valve, right and left pulmonary arteries) compared with clinical standard 2D PC (either breath‐hold or free breathing). For clinical translation, we implemented an integrated reconstruction pipeline capable of producing DICOMs of the order of 2 min per time series (46 frames). In terms of association, forward volume, backward volume, regurgitant fraction, and peak velocity at peak systole measured with standard PC and rt‐PC were strongly correlated (R2 > 0.76; P < 0.001). Compared with clinical standard PC, in terms of agreement, forward volume (mean difference = 1.4% (3.0% of mean)) and regurgitant fraction (mean difference = ?2.5%) were in good agreement, whereas backward volume (mean difference = ?1.1 mL (28.2% of mean)) and peak‐velocity at peak systole (mean difference = ?21.3 cm/s (17.2% of mean)) were underestimated by rt‐PC. This study demonstrates that the proposed rt‐PC with the said spatial resolution and temporal resolution produces relatively accurate forward volumes and regurgitant fractions but underestimates backward volumes and peak velocities at peak systole in pediatric patients with CHD. 相似文献
83.
Genotype-phenotype correlation for nucleotide substitutions in the IgII- IgIII linker of FGFR2 总被引:3,自引:3,他引:3
84.
Kelly M. Morgan Jada G. Hamilton Heather Symecko Daniella Kamara Colby Jenkins Jenny Lester Kelsey Spielman Lydia E. Pace Camila Gabriel Jeffrey D. Levin Prince Rainier Tejada Anthony Braswell Vanessa Marcell Temima Wildman Bryan Devolder Robin Camhi Baum Jeremy N. Block Yuri Fesko Kenneth Offit 《Genetics in medicine》2022,24(3):564-575
PurposeThis study aimed to evaluate uptake and follow-up using internet-assisted population genetic testing (GT) for BRCA1/2 Ashkenazi Jewish founder pathogenic variants (AJPVs).MethodsAcross 4 cities in the United States, from December 2017 to March 2020, individuals aged ≥25 years with ≥1 Ashkenazi Jewish grandparent were offered enrollment. Participants consented and enrolled online with chatbot and video education, underwent BRCA1/2 AJPV GT, and chose to receive results from their primary care provider (PCP) or study staff. Surveys were conducted at baseline, at 12 weeks, and annually for 5 years.ResultsA total of 5193 participants enrolled and 4109 (79.1%) were tested (median age = 54, female = 77.1%). Upon enrollment, 35.1% of participants selected a PCP to disclose results, and 40.5% of PCPs agreed. Of those tested, 138 (3.4%) were AJPV heterozygotes of whom 21 (15.2%) had no significant family history of cancer, whereas 86 (62.3%) had a known familial pathogenic variant. At 12 weeks, 85.5% of participants with AJPVs planned increased cancer screening; only 3.7% with negative results and a significant family history reported further testing.ConclusionAlthough continued follow-up is needed, internet-enabled outreach can expand access to targeted GT using a medical model. Observed challenges for population genetic screening efforts include recruitment barriers, improving PCP engagement, and increasing uptake of additional testing when indicated. 相似文献
85.
Block K Ricono JM Lee DY Bhandari B Choudhury GG Abboud HE Gorin Y 《Antioxidants & redox signaling》2006,8(9-10):1497-1508
Angiotensin II (Ang II) induces protein synthesis and hypertrophy through arachidonic acid (AA)- and redoxdependent activation of the serine-threonine kinase Akt/PKB in mesangial cells (MCs). The role of NAD(P)H oxidase component p22( phox ) was explored in this signaling pathway and in Ang II-induced expression of the extracellular matrix protein fibronectin. Ang II causes activation of Akt/PKB and induces fibronectin protein expression, effects abrogated by phospholipase A(2) inhibition and mimicked by AA. Ang II and AAalso elicited an increase in fibronectin expression that was reduced with a dominant negative mutant of Akt/PKB. Exposure of the cells to hydrogen peroxide stimulates Akt/PKB activity and fibronectin synthesis. The antioxidant N-acetylcysteine abolished Ang II- and AA-induced Akt/PKB activation and fibronectin expression. Western blot analysis revealed high levels of p22( phox ) in MCs. Antisense (AS) but not sense oligonucleotides for p22( phox ) prevented ROS generation in response to Ang II and AA. AS p22( phox ) inhibited Ang II- or AA-induced Akt/PKB as well as protein synthesis and fibronectin expression. These data provide the first evidence, in MCs, of activation by AAof a p22( phox )-based NAD(P)H oxidase and subsequent generation of ROS. Moreover, this pathway mediates the effect of Ang II on Akt/PKB-induced protein synthesis and fibronectin expression. 相似文献
86.
K.Y. Mumcuoglu L. Huberman R. Cohen V. Temper A. Adler R. Galun C. Block 《Clinical microbiology and infection》2010,16(6):563-567
The use of the medicinal leech (Hirudo medicinalis) in promoting venous drainage in tissues whose vitality is threatened by venous congestion and obstruction, especially in plastic and reconstructive surgery, has been complicated by infections caused by Aeromonas spp. These are leech endosymbionts for which patients undergoing hirudotherapy frequently receive systemic chemoprophylaxis. In order to evaluate the possibility of rendering leeches safe for use on patients, H. medicinalis were fed artificially with a 2 g/L arginine solution (used as a phagostimulant) supplemented with ciprofloxacin (100 mg/L). Aeromonads were detected in 57 out of 80 control leeches (71.3%), but in none of the 56 leeches treated with ciprofloxacin (p <0.001). Treated leeches survived for up to 4 months. Tested weekly, 61% of these leeches took human blood for at least 4 weeks after treatment and all remained negative for aeromonads. All water samples in which leeches were kept before treatment were contaminated with Aeromonas spp.; none were detected in any of the NaCl/arginine solutions with which treated animals were fed. Molecular characterization of two phenotypically distinct isolates using gyrB sequencing showed that one clustered tightly with A. veronii and the other was closely related to A. media. Other environmental bacteria and fungi were isolated from 26.5% of treated leeches that had taken a blood meal 1–4 weeks after treatment. Ciprofloxacin reduced the number of leech-associated aeromonads to undetectable levels for extended periods. Most treated leeches were ready to take a blood meal after treatment, suggesting the possibility of using ciprofloxacin-treated leeches instead of chemoprophylaxis in patients undergoing hirudotherapy. 相似文献
87.
Training medical students in community health: a novel required fourth-year clerkship at the University of Rochester. 总被引:1,自引:0,他引:1
Scott McIntosh Robert C Block Gabrielle Kapsak Thomas A Pearson 《Academic medicine》2008,83(4):357-364
In 2004, community health became the fourth mission of the University of Rochester Medical Center, along with education, clinical care, and research. In that same year, a novel clerkship was added to the fourth-year curriculum that focuses on the "practice" of community health and preventive medicine. The goal is to offer intensive experiential training to develop skills in community health improvement by partnering with community agencies involved in health promotion and disease prevention. The learning objectives addressed include community health assessment, risk behavior change, assurance of personal health services, advocacy and policy change, environmental interventions, community organization and partnership building, and program evaluation. The clerkship involves three full days of didactic instruction at the beginning of a four-week period of program development and implementation. Each student chooses a project that focuses on a specific target population, then designs it and incorporates public health knowledge, skills, and attitudes learned during the didactic component. Course directors then mentor students during project implementation. Students can begin "longitudinal" experiences in their first or second years to fold into the required clerkship. Innovations include a novel Advocacy and Policy Change module, a highly rated Cultural Determinants of Health lecture, and a resource-based course Web site. The clerkship was initially offered as an elective, and it has since become a required course. In the clerkship to date, 340 students have launched hundreds of community-level interventions within various settings locally, nationally, and internationally. Evaluation efforts to date indicate that the clerkship has been received favorably by both faculty and students. 相似文献
88.
G M Shepherd D P Corey S M Block 《Proceedings of the National Academy of Sciences of the United States of America》1990,87(21):8627-8631
The actin cores of hair-cell stereocilia were tested as a substrate for the movement of myosin-coated beads in an in vitro assay. Large numbers of stereocilia from bullfrog sacculi and semicircular canals were isolated by blotting onto coverglasses and were demembranated to expose the polar actin tracks of their cytoskeletal cores. Silica or polystyrene beads, coated with thick filaments of chicken skeletal muscle myosin, were added to this core preparation in the presence of ATP. Myosin-coated beads could reach some of the cores by diffusion alone, but the efficiency and precision of the assay were improved considerably by the use of "optical tweezers" (a gradient-force optical trap) to deposit the beads directly on the cores. Beads applied in this fashion bound and moved unidirectionally at 1-2 microns/s, escaping the retarding force of the trap. Actin filaments within the stereocilia are cross-linked by fimbrin, but this did not appear to interfere with the motility of myosin. Beads coated with optic-lobe kinesin were also tested for movement; these bound and moved unidirectionally at 0.1-0.2 microns/s when applied to microtubule-based kinociliary cores, but not when applied to actin-based stereociliary cores. Our results are consistent with, and lend support to, a model for hair cell adaptation in which a molecular motor such as myosin maintains tension on the mechanically gated transduction channels. Optical tweezers and video-enhanced differential interference contrast optics provide high efficiency and improved optical resolution for the in vitro analysis of myosin motility. 相似文献
89.
R A Goldstein P K Rohatgi E H Bergofsky E R Block R P Daniele D R Dantzker G S Davis G W Hunninghake T E King W J Metzger 《The American review of respiratory disease》1990,142(2):481-486
BAL remains a powerful investigative tool. In a short span of 20 yr, it has helped tremendously in understanding some of the aspects of the pathogenesis of diseases involving the lower respiratory tract. To realize its full potential in the diagnosis and management of diseases involving the lower respiratory tract, there is a great need for standardization of the technical aspects of BAL as well as processing and analysis of the BAL cellular- and fluid-phase components. Despite these hurdles, BAL has been found to be diagnostic in several infectious and noninfectious diseases involving the lower respiratory tract, and it provides valuable information that may be helpful in characterizing the prognosis and response to therapy in certain interstitial diseases of the lung. It is expected that with future research, in particular long-term prospective epidemiologic and clinical studies in pneumoconioses and in other interstitial lung disease, BAL will prove more valuable in the diagnosis and management of such disease. 相似文献
90.
Michael?Meier-SchroersEmail author Christian?Marx Frederic?Carsten?Schmeel Karsten?Wolter Jürgen?Gieseke Wolfgang?Block Alois?Martin?Sprinkart Frank?Traeber Winfried?Willinek Hans?Heinz?Schild Guido?Matthias?Kukuk 《European radiology》2018,28(1):24-30