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61.
Human umbilical vein endothelial cells display high-affinity c-kit receptors and produce a soluble form of the c-kit receptor 总被引:4,自引:3,他引:4
Stem cell factor (SCF) is a hematopoietic growth factor produced by fibroblasts and endothelial cells that stimulates the growth of primitive hematopoietic cells. SCF triggers cell growth by binding to the c-kit receptor. Because endothelial cells can respond to certain hematopoietic growth factors, we tested human umbilical vein endothelial cells for display of the c-kit receptor and examined the effect of SCF on endothelial cell proliferation, adhesion molecule expression, and production of tissue factor. Quantitative binding experiments with 125I-SCF showed both high-affinity (Kd = 42 pmol/L) and low-affinity (Kd = 1.7 nmol/L) c-kit receptors. There were approximately 1,100 high-affinity c-kit receptors, and 5,400 low- affinity c-kit receptors per endothelial cell. Enzyme immunoassays showed that endothelial cells released soluble c-kit receptor and SCF. The transmembrane form of SCF was detected by indirect immunofluorescence analysis using monoclonal or polyclonal anti-SCF receptor antibodies. The addition of SCF (100 ng/mL) did not alter endothelial cell proliferation over a 7-day period. Similarly, there was no change in the release of tissue factor or expression of inducible endothelial adhesion molecules (intercellular adhesion molecule-1, endothelial-leukocyte adhesion molecule-1, and vascular cell adhesion molecule-1) measured by enzyme-linked immunosorbant assay at 4 and 24 hours after SCF addition. The neutralizing anti-c-kit receptor monoclonal antibody SR-1 blocked binding of 125I-SCF to the c- kit receptor by 98% but did not alter endothelial cell proliferation or adhesion-molecule expression. c-kit receptors were also detected on adult endothelial cells lining small blood vessels in normal human lymph nodes. These data indicate that normal human endothelial cells produce SCF and show high-affinity c-kit receptors that have the capacity to dimerize. The lack of response to exogenous SCF may be because of intracellular activation of the c-kit receptor via autocrine production of SCF. Alternatively, SCF and c-kit may play a role other than stimulation of proliferation, adhesion-molecule display, or tissue factor production by endothelial cells. The production of soluble c-kit receptors by normal human endothelial cells may serve to regulate the bioactivity of SCF within the bone marrow microenvironment. 相似文献
62.
63.
Grzegorzewski KJ; Komschlies KL; Franco JL; Ruscetti FW; Keller JR; Wiltrout RH 《Blood》1996,88(11):4139-4148
Administration of recombinant human interleukin-7 (rhIL-7) to mice increases the exportation of myeloid progenitors (colony-forming unit [CFU]-c and CFU-granulocyte erythroid megakaryocyte macrophage [CFU- GEMM]) from the bone marrow (BM) to peripheral organs, including blood, and also increases the number of primitive progenitor and stem cells in the peripheral blood (PB). We now report that combined treatment of mice with rhIL-7 and recombinant human granulocyte-colony stimulating factor (rhG-CSF) stimulates a twofold to 10-fold increase in the total number of PB CFU-c, and a twofold to fivefold increase in the total number of PB CFU-spleen at day 8 (CFU-S8) over the increase stimulated by rhIL-7 or rhG-CSF alone. In addition, the quality of mobilized cells with trilineage, long-term marrow-repopulating activity is maintained or increased in mice treated with rhIL-7 and rhG-CSF compared with rhIL- 7 or rhG-CSF alone. These differences in mobilizing efficiency suggest qualitative differences in the mechanisms by which rhIL-7 and rhG-CSF mobilize progenitor cells, in fact, the functional status of progenitor cells mobilized by rhIL-7 differs from that of cells mobilized by rhG- CSF in that the incidence of actively cycling (S-phase) progenitors obtained from the PB is about 20-fold higher for rhIL-7-treated mice than for mice treated with rhG-CSF. These results suggest the use of rhIL-7-mobilized progenitor/stem cells for gene-modification and tracking studies, and highlight different functions and rates of repopulation after reconstitution with PB leukocytes obtained from mice treated with rhIL-7 versus rhG-CSF. 相似文献
64.
65.
Jeroen Gerritsen Flip Van Der Made Jos Bloemers Diana Van Ham Gunilla Kleiverda Walter Everaerd Berend Olivier Roy Levin Adriaan Tuiten 《The journal of sexual medicine》2009,6(6):1678-1687
IntroductionIn the present study, we introduce clitoral photoplethysmography as an instrument to assess clitoral blood volume (CBV). In research on female sexual functioning, vaginal pulse amplitude (VPA), as measured using vaginal photoplethysmography, has been used extensively as a measure of vaginal vasocongestion. Measurement of clitoral blood flow has thus far been problematic, mainly because of methodological constraints.AimTo demonstrate that CBV is a valuable, easy to use complementary measure for the female sexual response, offering additional information to the VPA.MethodsThirty women with and without female sexual dysfunction (FSD) watched neutral and erotic film clips. At the end of the erotic clip, the session was interrupted to induce inhibition of the sexual response. Another neutral clip followed the interruption. VPA and CBV were measured simultaneously, as well as skin conductance levels (SCLs), to assess the amount of sympathetic activity.Main Outcome MeasuresVPA, CBV, SCL.ResultsFor both FSD and non-FSD women, VPA and CBV increased when sexually explicit material was presented. Changes in skin conductance significantly predicted changes in CBV (b = ?0.61, t[27] = ?3.88, P < 0.001), but not in VPA. A large increase in sympathetic activity was accompanied by a large decrease in CBV. Furthermore, a large increase in CBV at the end of the erotic film clip presentation, as compared with the neutral clip, was accompanied by a relatively small increase in VPA (b = ?0.39, t[29] = ?2.25, P < 0.033).ConclusionCBV is a valid and sensitive tool to measure the female genital response. In the present study, it was particularly useful in investigating sexual inhibition, when used in combination with SCL. Furthermore, high CBV appeared to inhibit VPA, suggesting that VPA reflects an automatic preparatory response rather than genital arousal per se. Gerritsen J, van der Made F, Bloemers J, van Ham D, Kleiverda G, Everaerd W, Olivier B, Levin R, and Tuiten A. The clitoral photoplethysmograph: A new way of assessing genital arousal in women. J Sex Med 2009;6:1678–1687. 相似文献
66.
V Wewer KM Christiansen LP Andersen FW Henriksen JP Hart Hansen M Tvede PA Krasilnikoff 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(12):1276-1281
Helicobacter pylori was cultured and Helicobacter-like organisms (HLO) were seen in 6 (16%) of 37 children with recurrent abdominal pain. Five children had concomitant histological inflammation, but none had endoscopic changes. All 6 children demonstrated positive serology. Compared with the total group, they were more often from developing countries, larger families and lower Social groups. Treatment with phenoxymethyl penicillin and colloidal bismuth subcitrate did not result in side effects or elevated serum levels of serum bismuth. Three children demonstrated metronidazole-resistant strains and the treatment of these children remained an unsolved problem. Among the 31 H. pylori/ HLO negative children 8 (26%) demonstrated histological changes, 5 (16%) endoscopic changes and 11 (35%) had positive serology. In conclusion, pathological findings at upper gastrointestinal endoscopy are common in children with recurrent abdominal pain. Because of disconcordance between endoscopy, histology and culture, we recommend that biopsies should always be taken to clarify the diagnosis. 相似文献
67.
R. van Erp T. C. J. Gribnau A. P. G. van Sommeren H. P. J. Bloemers 《Journal of immunological methods》1991,140(2):235-241
The interaction of some individual MAbs and human chrionic gonadotrophin (hCG) showed apparent positive cooperativity as observed by equilibrium binding studies. This form of cooperative interaction has now been further characterized. The main results were: (1) the apparent positive cooperativity was strongly dependent upon concentration and temperature; (2) the cooperativity was strongly reduced by using peptic F(ab′)2 fragments of IgG and became undetectable when the MAb was replaced by the corresponding Fab fragment; (3) the molecular weight of the complex changed from 226 kDa to 450 kDa upon increasing the hCG/MAb ratio.
From these and additional results it is hypothesized that the apparent positive cooperativity results from self (Fc-Fc) associations mediated or facilitated by prior antigen binding. 相似文献
68.
Basic fibroblast growth factor has a differential effect on MyoD conversion of cultured aortic smooth muscle cells from newborn and adult rats. 总被引:2,自引:1,他引:2 下载免费PDF全文
J. W. van Neck J. J. Medina C. Onnekink P. F. van der Ven H. P. Bloemers S. M. Schwartz 《The American journal of pathology》1993,143(1):269-282
MyoD is a master regulatory gene for myogenesis that also converts many mesoderm-derived cells into the skeletal muscle phenotype. Rat aortic smooth muscle cells do not contain MyoD homologous mRNA. However, expression of an exogenously supplied MyoD gene in aortic smooth muscle cells cultured from newborn and adult animals converts these cells to elongated myoblasts and myotubes expressing the skeletal muscle genes for titin, nebulin, myosin, and skeletal alpha-actin. The presence of basic fibroblast growth factor during growth and serum starvation completely inhibits MyoD-mediated conversion in cultures of newborn smooth muscle cells. However, in smooth muscle cell cultures derived from adult rats the presence of fibroblast growth factor increases the conversion frequency. The differential response of exogenous MyoD suggests that the two morphological types of aortic smooth muscle cells, one typical for the newborn rat, the other for the adult rat, represent two distinctive states of differentiation. 相似文献
69.
J J Van Groningen A M Van den Ouweland J S Verbeek A W van der Kemp H P Bloemers W J Van de Ven 《Virus research》1987,8(4):349-361
A variant clone of Snyder-Theilen feline sarcoma virus (ST-FeSV) encoding a polyprotein with a molecular weight of approximately 104 kDa (P104) was compared to the P85 encoding prototype clone of ST-FeSV. Analysis of chimeric genes constructed with the viral oncogenes of the two clones indicated that the variant clone coded for a larger polyprotein than the prototype clone because of genetic differences in its 3' portion. Comparative DNA sequence analysis revealed that one nucleotide just upstream of the termination condon TGA in the prototype proviral DNA was deleted from the variant clone resulting in a 468-bp larger open reading frame. Furthermore, it appeared that the U3 regions of the long terminal repeats (LTRs) of the variant clone contained an insertion of 71 bp as compared to the LTRs of the prototype clone. In addition, both clones differed also from each other with respect to genetic sequences deleted from their env gene regions. 相似文献
70.
Neuer A; Lam KN; Tiller FW; Kiesel L; Witkin SS 《Human reproduction (Oxford, England)》1997,12(5):925-929
Recent evidence suggests that Chlamydia trachomatis can persist in the
female upper genital tract in an unculturable state. Since unsuspected C.
trachomatis infection has been associated with adverse in-vitro
fertilization (IVF) outcome we sought to detect further evidence of C.
trachomatis in the genital tracts of women undergoing IVF. The prevalence
and distribution of antibodies to the major structural proteins of C.
trachomatis in paired follicular fluid and sera of women undergoing IVF
were examined. Sera and follicular fluid samples from 149 women were
assayed for immunoglobulin (Ig)G and IgA antibodies to two C. trachomatis
antigens, the major outer membrane protein (MOMP) and a recombinant
lipopolysaccharide (rLPS) fragment. Additionally, the expression of human
60 kDa heat shock protein (hsp 60) in follicular fluid was determined. All
cervical and follicular fluid samples were negative for C. trachomatis by
polymerase chain reaction, ligase chain reaction and DNA probe. Sera from
60% of the subjects were positive for antichlamydial rLPS IgG; 36% were
positive for anti-MOMP IgG. Similarly, rLPS-directed and MOMP-directed IgA
were detected in sera of 34 and 14% of the subjects respectively. IgG
antibodies to MOMP and rLPS were detected in 42 and 41% of the follicular
fluid examined respectively. Anti-MOMP IgA was identified in 8.7% of the
follicular fluid while 27.5% were positive for anti-rLPS IgA. Human hsp 60
expression was documented in 11.6% of the follicular fluid tested. IgA
antibodies to both MOMP (P = 0.03) and rLPS (P = 0.02) in follicular fluid
were associated with a failure to become pregnant after embryo transfer.
IgG antibodies in sera and follicular fluid and IgA antibodies in sera were
unrelated to IVF outcome. Similarly only anti- MOMP IgA (P = 0.02) and
anti-rLPS IgA (P = 0.04) in follicular fluid were correlated with human hsp
60 expression in follicular fluid. The unique association between IgA
antibodies to two chlamydial antigens in follicular fluid and both hsp 60
expression and IVF failure provides further support for the possibility
that a persistent upper genital tract chlamydial infection contributes to
IVF failure in some women.
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