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811.
812.
813.
Evidence that eosinophils catalyze the bromide-dependent decarboxylation of amino acids 总被引:1,自引:0,他引:1
Human eosinophils from subjects with or without myeloperoxidase (MPO) deficiency and guinea pig eosinophils are able to decarboxylate L- alanine in the presence of the cationic detergent cetyltrimethylammonium bromide (CTAB) but not in the presence of the nonionic detergent Triton X-100. Instead, both normal human neutrophils and guinea pig neutrophils decarboxylate L-alanine in the presence of either detergent. When the non-bromide-containing cationic detergent cetyltrimethylammonium hydroxide (CTAOH) is used instead of CTAB, the eosinophils from MPO-deficient subjects are unable to decarboxylate L- alanine. Decarboxylation occurs with the combination CTAOH-Br-, but not with the combinations CTAOH-I-, CTAOH-CI-, or CTAOH-F-. Bromide in the absence of CTAOH does not promote decarboxylation. Triton X-100 and deoxycholate are much less effective in promoting decarboxylation in the presence of bromide. L-Lysine and L-aspartic acid are decarboxylated to a considerably lower rate than L-alanine in the presence of CTAOH and Br-. It is concluded that the eosinophils can catalyze the bromide-dependent decarboxylation of the apolar amino acid L-alanine in the presence of a cationic detergent. 相似文献
814.
Long-term follow-up of blood donors with indeterminate human immunodeficiency virus type 1 results on Western blot 总被引:3,自引:0,他引:3
JB Jackson ; MR Hanson ; GM Johnson ; TG Spahlinger ; HF Polesky ; RJ Bowman 《Transfusion》1995,35(2):98-102
BACKGROUND: At present, tens of thousands of United States blood donors who are at low risk for human immunodeficiency virus type 1 (HIV-1) infection are indefinitely deferred. These persons are repeatably reactive for HIV-1 antibody in enzyme immunoassay (EIA) and are indeterminate in Western blot. STUDY DESIGN AND METHODS: To determine the significance and persistence of anti-HIV-1 reactivity in plasma from volunteer blood donors with HIV-1-indeterminate Western blots, 66 donors were retested for HIV-1 antibody by the same manufacturers' EIA and Western blot 5 to 7 years after the initial Western blot. In addition, donors' peripheral blood mononuclear cells were tested by polymerase chain reaction (PCR) for HIV-1 DNA gag sequences. RESULTS: Thirty-five (53%) of 66 donors were still repeatedly reactive for HIV-1 on EIA and indeterminate on Western blot, 23 (35%) were negative on EIA and indeterminate on Western blot, 7 (11%) were negative in EIA and Western blot, and 1 (2%) was repeatedly reactive on EIA and negative on Western blot. Donors with persistently indeterminate Western blots had a band pattern nearly identical to that on the original Western blot. No donor was positive in Western blot, p24 antigen, or PCR testing. No donor had signs or symptoms of HIV-1 infection. CONCLUSION: Long-term follow-up of Western blot-indeterminate blood donors does not reveal evidence of HIV-infection. A mechanism to return these donors to the donor pool should be considered. 相似文献
815.
Two serologic markers to monitor the engraftment, growth, and treatment response of human leukemias in severe combined immunodeficient mice 总被引:3,自引:0,他引:3
We have investigated human lactate dehydrogenase (LDH) isoenzymes and human nuclear matrix protein 41/7 (NMP 41/7) as potential serologic markers to monitor the course of human leukemia in severe combined immunodeficient (SCID) mice. Following the transplantation of 10(6) human acute lymphoblastic leukemia (ALL) Nalm-6 cells, human specific LDH isoenzymes were measurable in the serum of SCID mice as early as 7 days after transplantation, although serum total LDH increased in some animals as early as 5 days after transplantation. Human NMP 41/7 was measurable in all animals at day 15 after leukemia cell injection. Serum levels of total LDH, human specific LDH and NMP 41/7 increased progressively over time, reaching total LDH levels as high as 50,000 U/L at day 25 after transplantation. To determine whether the levels of LDH and NMP 41/7 in serum were a reflection of human tumor burden, we studied these serologic markers in SCID mice bearing measurable subcutaneous human neuroblastoma tumors, or compared the serum levels of these markers with the number of human leukemia CD10+ cells in the bone marrow of the SCID mice. The serum levels of total LDH, human specific LDH isoenzymes, and NMP 41/7 correlated well with tumor burden, and they drastically decreased or disappeared from serum after the human leukemia or neuroblastoma cells were selectively killed with a single intravenous (IV) injection of 1 to 3 micrograms diphtheria toxin (DT) (the cellular receptor for DT is present on human cells, but not on mouse cells). Paraplegic mice with central nervous system leukemia completely recovered after DT treatment. We conclude that measurements of serum levels of total LDH, human LDH isoenzymes, and NMP 41/7 are sensitive, quantitative, rapid, and easy to perform serologic methods useful to monitor the engraftment, progression, and treatment response of human leukemia in SCID mice. 相似文献
816.
Felix CA; Hosler MR; Provisor D; Salhany K; Sexsmith EA; Slater DJ; Cheung NK; Winick NJ; Strauss EA; Heyn R; Lange BJ; Malkin D 《Blood》1996,87(10):4376-4381
We investigated the frequency of p53 mutations in 19 pediatric cases of therapy-related leukemia or myelodysplastic syndrome. Eleven children presented with acute myeloid leukemia, one with mixed-lineage leukemia, two with acute lymphoblastic leukemia, and five with myelodysplasia at times ranging from 11 months to 9 years after a primary cancer diagnosis. The primary cancers, which included 11 solid tumors and eight leukemias, were treated with various combinations of DNA topoisomerase II inhibitors, alkylating agents, or irradiation. Leukemic or myelodysplastic marrows were screened for possible mutations by single-strand conformation polymorphism (SSCP) analysis of p53 exons 4 to 8. The only observed mutation was an inherited 2- basepair deletion at codon 209 in exon 6 that would shift the open reading frame, create a premature termination codon, and foreshorten the resultant protein. Prior therapy in this patient included DNA topoisomerase II inhibitors, alkylating agents, and irradiation. The secondary leukemia presented as myelodysplasia with monosomies of chromosomes 5 and 7 and abnormalities of chromosome 17. Although the primary cancer was an embryonal rhabdomyosarcoma and there was a family history of cancer, the case did not fulfill the clinical criteria for Li-Fraumeni syndrome. This study suggests that germline p53 mutations may predispose some children to therapy-related leukemia and myelodysplasia, but that p53 mutations otherwise are infrequent in this setting. 相似文献
817.
Tumor-specific aneuploidy not detected in CD19+ B-lymphoid cells from myeloma patients in a multidimensional flow cytometric analysis 总被引:1,自引:0,他引:1
McSweeney PA; Wells DA; Shults KE; Nash RA; Bensinger WI; Buckner CD; Loken MR 《Blood》1996,88(2):622-632
Aneuploidy and lg light chain restriction were used as separate, independent tumor specific markers to study 26 patients with multiple myeloma to determine whether bone marrow B cells, as defined by CD19 expression, are clonally related to myeloma plasma cells. Specimens were characterized using multidimensional flow cytometry to identify the presence of clonality in both the B lymphoid and plasma cell populations using both surface and cytoplasmic staining with antibodies specific for kappa or lambda lg light chain In none of the patients with multiple myeloma were CD19+ cells found to be clonally restricted to kappa or lambda. The monoclonal plasma cells (MPC) were found to be uniformly negative for CD10, CD19, and CD34, while the CD19+ B lymphoid cells present within the samples expressed normal intensities and relationships of these antigens, which allowed them to serve as internal positive controls. Combined analysis of call surface antigen expression and DNA content allowed plasma cell populations to be characterized for aneuploidy without interference from normal bone marrow cells. The MPC, detected on the basis of bright CD38 expression (CD38+2), demonstrated DNA aneuploidy in 65% of cases (DNA index range of 0.9 to 1.3). These aneuploid DNA distributions had typical cell cycle profiles (including G1,S and G2+M) expected of a proliferating population. In all cases, DNA aneuploidy was confined almost entirely to the CD38+2, CD19- malignant plasma cells, while cells expressing CD19 were diploid. These results support the concept that myeloma is a disease process mediated by self-replicating, late compartments of B- cell ontogeny. 相似文献
818.
Decreased platelet thrombogenecity in association with increased platelet turnover and vascular damage 总被引:1,自引:0,他引:1
Platelet turnover is increased when platelets interact with prosthetic surfaces and damaged vessel wall. To determine whether the resulting increase in young platelets is associated with an increased tendency to thrombosis, we induced a state of increased platelet turnover in rabbits by inserting a sterile cannula into the abdominal aorta and tested for platelet thrombogenecity by measuring the deposition of circulating platelets onto a second injury site in the carotid arteries. Platelet half-life was decreased and platelet turnover was increased after the aortic cannulation, although the circulating platelet count remained unchanged. Platelet thrombogenecity determined 20 hr after cannulation was significantly decreased when compared to sham-operated animals. Ear bleeding studies demonstrated that the platelets circulating in cannulated animals were hemostatically less effective than those in sham-operated animals. This effect was intrinsic to the platelet and was associated with a platelet function defect. These data suggest that platelets exposed to a damaged or foreign surface interact with the surface and then circulate in a less reactive state. 相似文献
819.
有严重躯体疾病老年自杀死亡者的特征及其有无精神障碍者间的比较 总被引:1,自引:1,他引:1
目的了解有严重躯体疾病的老年自杀死亡者的特征并比较有无精神障碍者特征的异同。方法由精神科医师运用心理解剖方法对全国23个疾病监测点上报的≥55岁的304例自杀案例的家属和周围知情人进行调查,分析其中178例(58.6%)报告自杀死亡前1年内有严重躯体疾病者的自杀特征。结果178例自杀死亡者中,女性占41.6%;79.2%居住在乡村;58.4%从未上过学;38.8%丧偶;25.8%有自杀未遂既往史;10.7%一级血缘亲属有自杀行为;43.3%服农药或鼠药自杀,32.6%上吊;68.0%自杀当时有精神障碍,主要是重性抑郁障碍;仅5.1%自杀当时有人在场。有、无精神障碍者在社会人口经济学特征、有无自杀未遂史和自杀行为家族史、负性生活事件导致的慢性心理压力和急性应激强度以及自杀前一个月的生命质量等方面的差异无统计学意义(P均大于0.05)。结论有严重躯体疾病老年人自杀死亡最常见的两种方式是服毒和上吊,2/3有精神障碍,但有无精神障碍者的自杀相关特征无明显不同。 相似文献