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41.
This article reviews the mechanisms of pulmonary injury associated with hydrocarbon poisoning. The evolution of clinical and radiographic changes is discussed, along with appropriate treatment. Preventing aspiration in the emergency department is the most effective therapy for these children in the first few hours after ingestion. 相似文献
42.
Michael P. Savage M.D. Santiago J. Munoz M.D. Walter M. Herman M.D. Victoria M. Kusiak M.D. 《The American journal of gastroenterology》1987,82(10):1088-1090
Chylous ascites is an uncommon clinical entity associated with lymphatic obstruction usually caused by underlying malignancy. The authors describe a patient with chylous ascites caused by constrictive pericarditis in the absence of mechanical lymphatic obstruction. Pathophysiological mechanisms for the development of chylous ascites in constrictive pericarditis include augmented lymph production and high impedance to lymph drainage caused by central venous hypertension. After pericardiectomy, the patient's ascites and edema resolved. Constrictive pericarditis should be considered a rare but potentially curable cause of chylous ascites. 相似文献
43.
Susan K. Hummel DDS Victoria Marker PhD Larry Pace DDS Michael Goldfogle DDS 《The Journal of prosthetic dentistry》1997,77(6):568-572
Statement of problem. Controversy surrounds the use of hydrofluoric acid to prepare precementation surfaces of indirect composites.Purpose. This study was conducted to compare effects of combining hydrofluoric or orthophosphoric acid with microetching as precementation treatments.Material and methods. Nine specimens of three composite materials were prepared to simulate heat-cured indirect restorations. The specimen surfaces were prepared with one of three treatments. Adhesive Bond II and Twinlook cements were used to bond a phosphoric acid-etched disk of P50 to the treated surface. Analysis of variance and Scheffé tests were used to assess the bond strength data. Scanning electron microscopy and microscopic analysis of the fractured and treated surfaces were also performed.Results. Bond strengths for all surface treatments did not significantly differ. Hybrids had a higher bond strength with etching than microfills, and mechanical roughening produced the greatest bond strengths with microfills. Microetching with orthophosphoric acid produced higher bond strengths than microetching with hydrofluoric acid on hybrids.Conclusions. Acid etching alone is not sufficient to produce effective bond strengths, and hydrofluoric acid treatments are detrimental to the resin composite. (J Prosthet Dent 1997;77:568-72.) 相似文献
44.
Boxall S Stanton T Hirai K Ward V Yasui T Tahara H Tamori A Nishiguchi S Shiomi S Ishiko O Inaba M Nishizawa Y Dawes R Bodmer W Beverley PC Tchilian EZ 《Human molecular genetics》2004,13(20):2377-2384
The CD45 antigen is a haemopoietic cell specific tyrosine phosphatase essential for antigen receptor mediated signalling in lymphocytes. Expression of different patterns of alternatively spliced CD45 isoforms is associated with distinct functions. We recently identified a polymorphism in exon 6 (A138G) of the gene encoding CD45 (PTPRC) that results in altered CD45 splicing. The 138G allele is present at a high frequency among Japanese (23.7%), with 5.1% individuals homozygous for the G allele. In this study we show that the A138G polymorphism is the cause of altered CD45 isoform expression, promoting splicing towards low molecular weight CD45 isoforms. We further report that the frequency of A138G heterozygotes is significantly reduced in number in cohorts of patients with autoimmune Graves' disease or hepatitis B infection, whereas G138G homozygotes are absent from a cohort of Hashimoto's thyroiditis patients. We also show that 138G individuals exhibit altered cytokine production in vitro and an increased proportion of memory T cells. These data suggest that the 138G variant allele strongly influences these diseases by modulation of immune mechanisms and may have achieved its high frequency as a result of a natural selection probably related to pathogen resistance. 相似文献
45.
Over the past 100 years Drosophila has been developed into an outstanding model system for the study of evolutionary processes. A fascinating aspect of evolution
is the differentiation of sex chromosomes. Organisms with highly differentiated sex chromosomes, such as the mammalian X and
Y, must compensate for the imbalance in gene dosage that this creates. The need to adjust the expression of sex-linked genes
is a potent force driving the rise of regulatory mechanisms that act on an entire chromosome. This review will contrast the
process of dosage compensation in Drosophila with the divergent strategies adopted by other model organisms. While the machinery of sex chromosome compensation is different
in each instance, all share the ability to direct chromatin modifications to an entire chromosome. This review will also explore
the idea that chromosome-targeting systems are sometimes adapted for other purposes. This appears the likely source of a chromosome-wide
targeting system displayed by the Drosophila fourth chromosome. 相似文献
46.
Busse A Sánchez MA Monterroso V Alvarado MV León P 《American journal of medical genetics. Part A》2004,(2):190-194
Four affected siblings in a Costa Rican family presented an aggressive polyneuropathy with widespread involvement of many visceral organs and onset during the third decade of life with rapid loss of muscle mass in the lower limbs and severe dysautonomy. The medical histories include vitreous opacity, cardiac enlargement, dermal and gastrointestinal infiltration, and autonomic dysfunction including circulatory compromise and gastrointestinal disturbances. Histological studies using Congo red stain and immunohistochemical assays with antibodies against the transthyretin (TTR) protein showed widespread deposition of amyloid in extracellular areas, including dermis and gastrointestinal lamina propia, endo- and perineural spaces, and vascular walls. A mutation search in the transthyretin (ttr) gene was performed seeking the cause of this severe form of familial amyloidotic polyneuropathy (FAP). We applied single-stranded conformational polymorphism (SSCP)-analyses followed by sequencing of the four exons of the ttr gene, revealing a point mutation in exon 3, a G to A transition that causes a Glu54Lys codon change. Western blots of plasma proteins incubated with anti-transthyretin antibodies after gel electrophoresis provided separation of wild-type and mutant TTR protein in affected family members. 相似文献
47.
48.
Robinson VL Hickson JA Vander Griend DJ Dubauskas Z Rinker-Schaeffer CW 《Clinical & experimental metastasis》2003,20(1):25-30
MAP kinase kinase 4 (MKK4) is a member of the stress-activated protein kinase (SAPK) signaling cascade and is involved in the regulation of many cellular processes. We have recently demonstrated a functional role for MKK4 in the suppression of metastases. In this review, we discuss the established cellular and biochemical functions of MKK4, as well as a new function for MKK4 as a metastasis suppressor gene. Because of the importance of signaling studies to this translational work, a detailed example of the strategy and tools that can be employed to define the biochemical mechanism of MKK4-mediated metastasis suppression is presented. Finally, the potential therapeutic utility of these findings is discussed. 相似文献
49.
Event-related potentials (ERPs) from 134 children were obtained at 3 and 8 years of age and recorded to a series of consonant-vowel speech syllables and their nonspeech analogues. The HOME inventory was administered to these same children at 3 and 8 years of age and the sample was divided into 2 groups (low vs. high) based on their HOME scores. Discriminant functions analyses using ERP responses to speech and non-speech analogues successfully classified HOME scores obtained at 3 and 8 years of age and discriminated between children who received low vs. high levels of stimulation for language and reading. 相似文献
50.
The roles of individual eukaryotic translation initiation factors in ribosomal scanning and initiation codon selection 总被引:13,自引:0,他引:13
To elucidate an outline of the mechanism of eukaryotic translation initiation, 48S complex formation was analyzed on defined mRNAs in reactions reconstituted in vitro from fully purified translation components. We found that a ribosomal 40S subunit, eukaryotic initiation factor (eIF) 3, and the eIF2 ternary complex form a 43S complex that can bind to the 5'-end of an unstructured 5'-untranslated region (5'-UTR) and in the presence of eIF1 scan along it and locate the initiation codon without a requirement for adenosine triphosphate (ATP) or factors (eIF4A, eIF4B, eIF4F) associated with ATP hydrolysis. Scanning on unstructured 5'-UTRs was enhanced by ATP, eIFs 4A and 4B, and the central domain of the eIF4G subunit of eIF4F. Their omission increased the dependence of scanning on eIFs 1 and 1A. Ribosomal movement on 5'-UTRs containing even weak secondary structures required ATP and RNA helicases. eIF4F was essential for scanning, and eIFs 4A and 4B were insufficient to promote this process in the absence of eIF4F. We report that in addition to its function in scanning, eIF1 also plays a principal role in initiation codon selection. In the absence of eIF1, 43S complexes could no longer discriminate between cognate and noncognate initiation codons or sense the nucleotide context of initiation codons and were able to assemble 48S complexes on 5'-proximal AUG triplets located only 1, 2, and 4 nt from the 5'-end of mRNA. 相似文献