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81.
Human lymphocytes were cultured for two cell cycles in the presence of bromodeoxyuridine (BrdU), and the resulting metaphase chromosomes were first stained with quinacrine mustard (QM) and then, immediately afterwards, with Hoechst 33258, without any intermediate destaining. Both Q-banding patterns and sister chromatid differential staining were photographed subsequently on the same metaphase using two different filter blocks of the fluorescence microscope. 相似文献
82.
Establishment and Functional Implications of B-cell Connectivity 总被引:7,自引:0,他引:7
83.
Serotonin transporter binding in Tourette Syndrome 总被引:5,自引:0,他引:5
Müller-Vahl KR Meyer GJ Knapp WH Emrich HM Gielow P Brücke T Berding G 《Neuroscience letters》2005,385(2):120-125
Recent studies provided evidence for an involvement of the dopaminergic system in the pathophysiology of Tourette Syndrome (TS). However, little is known about possible impairment of other neurotransmitter systems. In obsessive-compulsive disorder (OCD), a common comorbidity in TS, it is suggested that the serotonergic system plays a major role in the pathogenesis. We, therefore, used [I-123]2[beta]-carbomethoxy-3[beta]-(4-iodophenyl)tropane ([123I]beta-CIT) and single photon emission computed tomography (SPECT) to investigate serotonin transporter (SERT) binding capacity in 12 patients with TS with various degrees of associated obsessive compulsive behaviour (OCB) and 16 age-matched healthy controls. Binding ratios in TS patients not receiving serotonin reuptake inhibitors (SSRI) (n=8) were significantly reduced compared to age-adjusted ratios from normal controls (2.8 versus 3.2, p=0.003). Treatment with SSRI resulted in a significant reduction of SERT availability. Performing linear regression analysis for this small group, SSRI-free patients indicated trends for a negative correlation between [123I]beta-CIT binding on SERT and OCB (r=-0.78, p=0.023) as well as complex motor tics (r=-0.68, p=0.064). In healthy controls, but not in the TS group, we found an age-related decline in SERT binding capacity (0.28% decrease per year, p=0.038). Our data are in agreement with previous results suggesting an impairment of the serotonergic system in TS. It can be speculated that the reduction in SERT binding capacity is associated with the degree of comorbid OCB. 相似文献
84.
Genetic and epigenetic modification of MLH1 accounts for a major share of microsatellite-unstable colorectal cancers 总被引:16,自引:0,他引:16 下载免费PDF全文
Kuismanen SA Holmberg MT Salovaara R de la Chapelle A Peltomäki P 《The American journal of pathology》2000,156(5):1773-1779
Microsatellite instability (MSI) is a hallmark of hereditary nonpolyposis colorectal cancer, and in these patients, results from inherited defects in DNA mismatch repair genes, mostly MSH2 and MLH1. MSI also occurs in 15% of sporadic colorectal cancers, but in these tumors, its basis is less well characterized. We investigated 46 sporadic MSI+ colorectal cancers for changes in MSH2 and MLH1 protein expression, followed by the analysis of somatic mutation, loss of heterozygosity (LOH), and promoter hypermethylation as possible underlying defects. Most cases (36/46, 78%) showed lost or reduced MLH1 expression. Among these, a majority (83%) was associated with MLH1 promoter hypermethylation, whereas the rates of LOH and somatic mutation of MLH1 were 24% and 13%, respectively. Hypermethylation and LOH were inversely correlated, suggesting that they had alternative functions in the inactivation of MLH1. MSH2 expression was lost in 7/46 (15%), and of these, 2 (29%) showed LOH and/or somatic mutation of MSH2. We conclude that most sporadic MSI+ colorectal cancers have an MLH1-associated etiology and that epigenetic modification is a major mechanism of MLH1 inactivation. Moreover, we found a significantly lower prevalence for MLH1 promoter hypermethylation in hereditary nonpolyposis colorectal cancer tumors with MLH1 germline mutations (12/26, 46%), which might explain some differences that are known to occur in the clinicopathological characteristics and tumorigenic pathways between sporadic and hereditary MSI+ colorectal cancers. 相似文献
85.
Teun P De Boer Bart Kok Kirsten I E Neuteboom Nicole Spieker Jochum De Graaf Olivier H J Destrée Martin B Rook Toon A B Van Veen Habo J Jongsma Marc A Vos Jacques M T De Bakker Marcel A G Van Der Heyden 《Developmental dynamics》2005,233(3):864-871
Connexin-containing gap junctions play an essential role in vertebrate development. More than 20 connexin isoforms have been identified in mammals. However, the number identified in Xenopus trails with only six isoforms described. Here, identification of a new connexin isoform from Xenopus laevis is described. Connexin40.4 was found by screening expressed sequence tag databases and carrying out polymerase chain reaction on genomic DNA. This new connexin has limited amino acid identity with mammalian (<50%) connexins, but conservation is higher (approximately 62%) with fish. During Xenopus laevis development, connexin40.4 was first expressed after the mid-blastula transition. There was prominent expression in the presomitic paraxial mesoderm and later in the developing somites. In adult frogs, expression was detected in kidney and stomach as well as in brain, heart, and skeletal muscle. Ectopic expression of connexin40.4 in HEK293 cells, resulted in formation of gap junction like structures at the cell interfaces. Similar ectopic expression in neural N2A cells resulted in functional electrical coupling, displaying mild, asymmetric voltage dependence. We thus cloned a novel connexin from Xenopus laevis, strongly expressed in developing somites, with no apparent orthologue in mammals. 相似文献
86.
During hypoxic exercise some vasoconstriction is needed to match O2 delivery with O2 demand at the microcirculatory level. 总被引:1,自引:0,他引:1
Carsten Lundby Robert Boushel Paul Robach Kirsten M?ller Bengt Saltin José A L Calbet 《The Journal of physiology》2008,586(1):123-130
To test the hypothesis that the increased sympathetic tonus elicited by chronic hypoxia is needed to match O(2) delivery with O(2) demand at the microvascular level eight male subjects were investigated at 4559 m altitude during maximal exercise with and without infusion of ATP (80 mug (kg body mass)(-1) min(-1)) into the right femoral artery. Compared to sea level peak leg vascular conductance was reduced by 39% at altitude. However, the infusion of ATP at altitude did not alter femoral vein blood flow (7.6 +/- 1.0 versus 7.9 +/- 1.0 l min(-1)) and femoral arterial oxygen delivery (1.2 +/- 0.2 versus 1.3 +/- 0.2 l min(-1); control and ATP, respectively). Despite the fact that with ATP mean arterial blood pressure decreased (106.9 +/- 14.2 versus 83.3 +/- 16.0 mmHg, P < 0.05), peak cardiac output remained unchanged. Arterial oxygen extraction fraction was reduced from 85.9 +/- 5.3 to 72.0 +/- 10.2% (P < 0.05), and the corresponding venous O(2) content was increased from 25.5 +/- 10.0 to 46.3 +/- 18.5 ml l(-1) (control and ATP, respectively, P < 0.05). With ATP, leg arterial-venous O(2) difference was decreased (P < 0.05) from 139.3 +/- 9.0 to 116.9 +/- 8.4(-1) and leg .VO(2max) was 20% lower compared to the control trial (1.1 +/- 0.2 versus 0.9 +/- 0.1 l min(-1)) (P = 0.069). In summary, at altitude, some degree of vasoconstriction is needed to match O(2) delivery with O(2) demand. Peak cardiac output at altitude is not limited by excessive mean arterial pressure. Exercising leg .VO(2peak) is not limited by restricted vasodilatation in the altitude-acclimatized human. 相似文献
87.
Thy Thy Vanem Tordis Böker Gunhild F. Sandvik Eva Kirkhus Hans‐Jørgen Smith Kai Andersen Liv Drolsum Rigmor Lundby Cecilie Røe Kirsten Krohg‐Sørensen Odd R. Geiran Benedicte Paus Svend Rand‐Hendriksen 《American journal of medical genetics. Part A》2020,182(2):397-408
The age‐dependent penetrance of organ manifestations in Marfan syndrome (MFS) is not known. The aims of this follow‐up study were to explore how clinical features change over a 10‐year period in the same Norwegian MFS cohort. In 2003–2004, we investigated 105 adults for all manifestations in the 1996 Ghent nosology. Ten years later, we performed follow‐up investigations of the survivors (n = 48) who consented. Forty‐six fulfilled the revised Ghent criteria. Median age: females 51 years, range 32–80 years; males 45 years, range 30–67 years. New aortic root dilatation was detected in patients up to 70 years. Ascending aortic pathology was diagnosed in 93 versus 72% at baseline. Sixty‐five percent had undergone aortic surgery compared to 39% at baseline. Pulmonary trunk mean diameter had increased significantly compared to baseline. From inclusion to follow‐up, two patients (three eyes) developed ectopia lentis, four developed dural ectasia, four developed scoliosis, three developed incisional or recurrent herniae, and 14 developed hindfoot deformity. No changes were found regarding protrusio acetabuli, spontaneous pneumothorax, or striae atrophicae. The study confirms that knowledge of incidence and progression of organ manifestations throughout life is important for diagnosis, treatment, and follow‐up of patients with verified or suspected MFS. 相似文献
88.
Johannes Jrhult Jan Holmberg Jan Lundvall Stefan Mellander 《Acta physiologica (Oxford, England)》1976,97(4):470-475
Changes of the arterial plasma osmolality and of the glucose concentration were followed during a 30 min period of graded hemorrhagic hypotension (80, 50, and 30 mmHg) in the cat. Bleeding evoked a significant plasma hyperosmolality at all three hypotension levels and the responses were quantitatively related to the degree of hypotension. An approximate steady state increase in the arterial plasma osmolality was reached about 20 min after the start of the bleeding and it then averaged 8, 20, and 25 mOsm/kg H2O at 80, 50, and 30 mmHg, respectively. Bleeding also evoked an increase in the plasma glucose concentration, which almost entirely accounted for the observed hyperosmolality, especially at 80 and 50 mmHg. In late stages of hypotension at 30 mmHg, elevated plasma lactate and potassium concentrations contributed to the overall hyperosmolality. — Previous hemorrhagic hypotension experiments at 50 mmHg (Järhult 1975 b) have shown that hyperosmolality serves as an important regulator of the plasma and extracellular fluid volumes during bleeding. The present results indicate that such an osmolar compensatory mechanism is operating over wide ranges of hemorrhagic hypotension. 相似文献
89.
Amy A. Eapen Kirsten M. Kloepfer Frederick E. Leickly James E. Slaven Girish Vitalpur 《Annals of allergy, asthma & immunology》2019,122(2):193-197
Background
Recent studies have suggested that removing foods from the diet to manage atopic dermatitis (AD), based on positive allergy test results, may lead to immediate allergic reactions on reintroduction of that food.Objective
To examine the frequency of oral food challenge (OFC) failures among foods removed from the diet as suspected AD triggers, focusing on the 5 major food allergens in the United States.Methods
OFCs to egg, milk, peanut, soy, and wheat, performed from 2008 to 2014, at a children's hospital's allergy clinics, were reviewed. OFCs were offered based on history and laboratory values. Reasons for food avoidance were classified as food allergy (IgE-mediated reaction occurring within 2 hours); sensitization only (lack of introduction because of positive test results); and removal because of test results during AD evaluation.Results
There were 442 OFCs performed, with 89 failures (20.1%). Reasons for OFCs included a history of food allergy (320 of 442 [72.4%]), food sensitization without any introduction (77 of 442 [17.4%]), and AD (45 of 442 [10.2%]). OFC failures among those who had food allergy (70 of 320 [21.9%]), sensitization only (13 of 77 [16.9%]), and suspected AD trigger (6 of 45 [13.3%]) did not significantly differ (P?=?.63). Wheat was more likely to be avoided than the other 4 foods for AD concerns (P < .001).Conclusion
The frequency of OFC failure among those who removed foods suspected as AD triggers was 13.3%, indicating a loss of tolerance. Restriction of foods to manage AD must be done with caution and close monitoring. 相似文献90.
P. Ljungberg C. Holmberg H. Jalanko I. Virtanen 《Virchows Archiv : an international journal of pathology》1996,428(6):333-346
The aim of this study was to examine the distribution of 1 and v integrins (Ints) and some of their ligands in the kidneys of patients with congenital nephrotic syndrome of the Finnish type (CNF) and in controls using indirect immunofluorescence with monoclonal antibodies. The mesangial reactivity of Int 1 and Int 1 subunits was more variable and an increased glomerular reactivity with Int 3 and Int-6 antibodies was found in CNF kidneys than in controls. Int 2 subunit was either completely missing from or found in significantly lesser amounts in CNF kidney glomeruli. The immunoreactivity for Int v was more variable, fainter and also more granular in CNF samples than in control kidneys. The glomerular reactivity for Int 5 was more diffuse and weaker, and in sclerotic Bowman's capsules more intense in CNF kidneys than in controls. Immunoreactivity for Int 6 was restricted and was comparable in extent in CNF and control kidneys. Of the extracellular matrix components studied, the expression of EDAFn, EDBFn, OncFn, Ln 2 chain, Ln 1 chain and tenascin was increased. This is also seen in several glomerular diseases with inflammation and sclerosis. Immunoreactivity for vitronectin was decreased. Several differences were found in the intensity or location of the immunostaining for the 1 and v Ints and their ligands in CNF kidneys compared with controls, which have not been found in any other proteinuric disease. Disturbed Int expression pattern in CNF may specifically reflect the disturbance of glomerular function caused by the primary defect in this disease. 相似文献