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51.
Paulo HG Mansur Lacordaire KP Cury José OB Leite Adriano A Pereira Nilson Penha-Silva Adriano O Andrade 《Biomedical engineering online》2010,9(1):29
Background
The main problem of tremor is the damage caused to the quality of the life of patients, especially those at more advanced ages. There is not a consensus yet about the origins of this disorder, but it can be examined in the correlations between the biological signs of aging and the tremor characteristics. 相似文献52.
A new immobilized biocatalyst for the racemization of L-glutamate on a preparative scale was developed. The gene encoding the glutamate racemase from Lactobacillus fermenti has been isolated by PCR amplification from its chromosomal DNA and overexpressed in Escherichia coli under the control of lac promoter. The recombinant enzyme (25-30% of total proteins) was rapidly immobilized on highly activated glyoxyl-agarose gels. The immobilized enzyme retained up to 80% of catalytic activity. In fact, 14 g of biocatalyst containing 20 mg of immobilized protein were able to racemize 90 mg of L-glutamic acid in less than 30 minutes. 相似文献
53.
Multiple Functions of Human Papillomavirus Type 16 E6 Contribute to the Immortalization of Mammary Epithelial Cells 总被引:9,自引:0,他引:9
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Yun Liu Jason J. Chen Qingshen Gao Sorab Dalal Yihui Hong Claire P. Mansur Vimla Band Elliot J. Androphy 《Journal of virology》1999,73(9):7297-7307
The E6 proteins from cervical cancer-associated human papillomavirus (HPV) types such as HPV type 16 (HPV-16) induce proteolysis of the p53 tumor suppressor protein through interaction with E6-AP. We have previously shown that human mammary epithelial cells (MECs) immortalized by HPV-16 E6 display low levels of p53. HPV-16 E6 as well as other cancer-related papillomavirus E6 proteins also binds the cellular protein E6BP (ERC-55). To explore the potential functional significance of these interactions, we created and analyzed a series of E6 mutants for their ability to interact with E6-AP, p53, and E6BP in vitro. While there was a similar pattern of binding among these E6 targets, a subset of mutants differentiated E6-AP binding, p53 binding, and p53 degradation activities. These results demonstrated that E6 binding to E6-AP is not sufficient for binding to p53 and that E6 binding to p53 is not sufficient for inducing p53 degradation. The in vivo activity of these HPV-16 E6 mutants was tested in MECs. In agreement with the in vitro results, most of these p53 degradation-defective E6 mutants were unable to reduce the p53 level in early-passage MECs. Interestingly, several mutants that showed severely reduced ability for interacting with E6-AP, p53, and E6BP in vitro efficiently immortalized MECs. These immortalized cells exhibited low p53 levels at late passage. Furthermore, mutants defective for p53 degradation but able to immortalize MECs were also identified, and the immortal cells retained normal levels of p53 protein. These results imply that multiple functions of HPV-16 E6 contribute to MEC immortalization. 相似文献
54.
The magnetohydrodynamic (MHD) stagnation point flow of a nanofluid over a permeable stretching/shrinking sheet is studied. Numerical results are obtained using boundary value problem solver bvp4c in MATLAB for several values of parameters. The numerical results show that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. A stability analysis is performed to determine the stability of the dual solutions. For the stable solution, the skin friction is higher in the presence of magnetic field and increases when the suction effect is increased. It is also found that increasing the Brownian motion parameter and the thermophoresis parameter reduces the heat transfer rate at the surface. 相似文献
55.
Renata Garcia Georgia Pacheco Erica Falcão Gabriela Borges Elisabeth Mansur 《Plant Cell, Tissue and Organ Culture》2011,106(1):47-54
Passiflora suberosa is used in popular medicine, improvement programs, and as an ornamental plant. The goal of this study was to establish efficient
protocols for plant regeneration and callus induction from nodal, internodal and leaf segments excised from in vitro-grown
plants. The different morphogenetic responses were modulated by the type and concentration of plant growth regulators, according
to the basal medium and light conditions. Shoot formation occurred through three pathways: (1) development of preexisting
meristems, (2) direct organogenesis, and (3) indirect organogenesis. Development of preexisting meristems was observed from
nodal segments (1 shoot/explant) in response to α-naphthaleneacetic acid (NAA), picloram (PIC), and 2,4-dichlorophenoxyacetic
acid (2,4-D), using two basal media (MS and MSM). Direct organogenesis in this species was obtained for the first time in
this work, through shoot development from internodal segments in the presence of 6-benzyladenine (BA). The highest regeneration
rates were achieved on MSM medium, regardless of the BA concentration. Indirect organogenesis was achieved from all explant
types on media supplemented with BA, used alone or in combination with NAA. The highest regeneration efficiency was obtained
from internodal segments cultured on MSM medium plus 44.4 μM BA. Compact, friable, or mucilaginous non-morphogenic calluses
were induced by thidiazuron, PIC, 2,4-D, and NAA. High-yielding friable calluses obtained on MSM medium supplemented with
28.9 μM PIC are being used for the establishment of suspension cultures and further analysis of the production of bioactive
compounds. 相似文献
56.
Simões-Gurgel Claudia Cordeiro Lívia da Silva de Castro Tatiana Carvalho Callado Cátia Henriques Albarello Norma Mansur Elisabeth 《Plant Cell, Tissue and Organ Culture》2011,106(3):537-545
The effects of different levels of Murashige and Skoog (MS) basal medium, 2,4-dichlorophenoxyacetic acid (2,4-D), and sucrose
on anthocyanin production and biomass accumulation of cell suspension cultures of Cleome rosea were investigated. Cultures were established in liquid MS medium containing 30 g l−1 sucrose and supplemented with 0.90 μM 2,4-D. Proliferating cell suspension cultures achieved the highest growth capacity,
a fourfold increase in biomass accumulation, following subculture at the exponential growth phase, 14–18 days of culture.
Moreover, the presence of 2,4-D was essential for anthocyanin production and biomass accumulation. On the other hand, increasing
levels of sucrose above 30 g l−1 resulted in a drastic reduction in biomass accumulation. Anthocyanin production was highest in cell suspension cultures grown
on half-strength MS medium (1/2 MS), 30 g l−1 sucrose, and 0.45 μM 2,4-D. These cell suspension cultures were mainly composed of small aggregates of spherical cells with
similar morphology observed in anthocyanin-producing and non-producing cultures. Moreover, microscopic analysis of anthocyanin-producing
cultures showed the presence of mixtures of non-pigmented, low-pigmented, and high-pigmented cells. 相似文献
57.
Activation of TLR2 and TLR4 by glycosylphosphatidylinositols derived from Toxoplasma gondii 总被引:2,自引:0,他引:2
Debierre-Grockiego F Campos MA Azzouz N Schmidt J Bieker U Resende MG Mansur DS Weingart R Schmidt RR Golenbock DT Gazzinelli RT Schwarz RT 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(2):1129-1137
GPIs isolated from Toxoplasma gondii, as well as a chemically synthesized GPI lacking the lipid moiety, activated a reporter gene in Chinese hamster ovary cells expressing TLR4, while the core glycan and lipid moieties cleaved from the GPIs activated both TLR4- and TLR2-expressing cells. MyD88, but not TLR2, TLR4, or CD14, is absolutely needed to trigger TNF-alpha production by macrophages exposed to T. gondii GPIs. Importantly, TNF-alpha response to GPIs was completely abrogated in macrophages from TLR2/4-double-deficient mice. MyD88(-/-) mice were more susceptible to death than wild-type (WT), TLR2(-/-), TLR4(-/-), TLR2/4(-/-), and CD14(-/-) mice infected with the ME-49 strain of T. gondii. The cyst number was higher in the brain of TLR2/4(-/-), but not TLR2(-/-), TLR4(-/-), and CD14(-/-), mice, as compared with WT mice. Upon infection with the ME-49 strain of T. gondii, we observed no decrease of IL-12 and IFN-gamma production in TLR2-, TLR4-, or CD14-deficient mice. Indeed, splenocytes from T. gondii-infected TLR2(-/-) and TLR2/4(-/-) mice produced more IFN-gamma than cells from WT mice in response to in vitro stimulation with parasite extracts enriched in GPI-linked surface proteins. Together, our results suggest that both TLR2 and TLR4 receptors may participate in the host defense against T. gondii infection through their activation by the GPIs and could work together with other MyD88-dependent receptors, like other TLRs or even IL-18R or IL-1R, to obtain an effective host response against T. gondii infection. 相似文献
58.
The objective of this paper is to determine the effect of ivermectin administration on cell mediated (CMI) and humoral immunity (HI) of rabbits. CMI against dinitrochlorobenzene (DNCB) and sheep red blood cells (SRBC) in rabbits was determined by delayed-type hypersensitivity and macrophage engulfment assay (MEA), respectively; whereas, HI to Pasteurella multocida B2 vaccine and SRBC was determined by indirect haemagglutination assay (IHA) and Jerne hemolytic plaque formation assay (JHPFA), respectively. The rabbits were divided into four major groups (A through D) each subdivided into four sub-groups (1 through 4). Rabbits of group A served as vehicle control while those of groups B, C and D were treated with ivermectin at the dose rates of 200 microg/kg, 400 microg/kg and 600 microg/kg b.w., respectively. Cellular immunity was determined in sub-groups 1 and 2 through DNCB and MEA, respectively while HI was determined in sub-groups 3 and 4 through IHA and JHPFA, respectively. The skin sensitivity to DNCB at 24 and 48 h and macrophage engulfment of SRBC were highest (P>0.05) in rabbits administered with 600 microg/kg b.w. The highest geometric mean titers (14.00+/-0.31) and number of plaque forming units (1860+/-0.75) were found in rabbits that received ivermectin at a dose of 600 microg/kg b.w. followed, in order by the groups that received 400 microg/kg, 200 microg/kg b.w. and controls. Leukocyte counts were significantly higher in ivermectin-treated groups (C and D) than group A (vehicle control) and B (ivermectin at the rate of 200 microg/kg). A graded dose immune response suggested an immunopotentiating effect of ivermectin at higher doses. 相似文献
59.
Determination of antioxidant activity and phenolic content of extracts from in vivo plants and in vitro materials of Passiflora alata Curtis 总被引:1,自引:0,他引:1
Danielle Lugato Mariela J. Simão Renata Garcia Elisabeth Mansur Georgia Pacheco 《Plant Cell, Tissue and Organ Culture》2014,118(2):339-346
Passiflora alata Curtis, commonly known as sweet passion fruit, is one of the commercially cultivated species of the genus Passiflora, whose fruits can be consumed in natura due to their sweet taste. It is also used worldwide as an ornamental and in folk medicine. The goal of this work was the evaluation of the antioxidant potential of extracts from in vivo plants, and in vitro-derived materials of P. alata. Leaves from in vivo plants were used for the optimization of parameters that affect the efficiency of extraction of antioxidant compounds (proportions of ethanol:water, maceration period, solvent:plant tissue ratio, and number of extraction stages), by employing the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The antioxidant activity and the extract yields were significantly influenced by the proportion of ethanol:water and maceration period. The optimized protocol was applied to obtain the extracts of in vitro-derived materials. Total phenolic content was determined using the Folin–Ciocalteu method. Higher antioxidant activities and phenolic contents were observed in extracts from leaves of in vivo-seed derived and from acclimatized plants when compared to in vitro plants, calluses and suspension cultures. Differences in the reaction kinetics of DPPH scavenging activity were also observed. 相似文献
60.
Chris Newby Liam G. Heaney Andrew Menzies-Gow Rob M. Niven Adel Mansur Christine Bucknall Rekha Chaudhuri John Thompson Paul Burton Chris Brightling 《PloS one》2014,9(7)