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11.
Background
During the development of the central nervous system (CNS), patterning processes along the dorsoventral (DV) axis of the neural tube generate different neuronal subtypes. As development progresses these neurons are arranged into functional units with varying cytoarchitecture, such as laminae or nuclei for efficient relaying of information. Early in development ventral and dorsal regions are similar in size and structure. Different proliferation rates and cell migration patterns are likely to result in the formation of laminae or nuclei, eventually. However, the underlying molecular mechanisms that establish these different structural arrangements are not well understood. 相似文献12.
Efficient four fragment cloning for the construction of vectors for targeted gene replacement in filamentous fungi 总被引:2,自引:0,他引:2
Rasmus JN Frandsen Jens A Andersson Matilde B Kristensen Henriette Giese 《BMC molecular biology》2008,9(1):70
Background
The rapid increase in whole genome fungal sequence information allows large scale functional analyses of target genes. Efficient transformation methods to obtain site-directed gene replacement, targeted over-expression by promoter replacement, in-frame epitope tagging or fusion of coding sequences with fluorescent markers such as GFP are essential for this process. Construction of vectors for these experiments depends on the directional cloning of two homologous recombination sequences on each side of a selection marker gene. 相似文献13.
Marjolein?Helder David?PBTB?StrikEmail author Hubertus?VM?Hamelers Cees?JN?Buisman 《Biotechnology for biofuels》2012,5(1):70
Due to a growing world population and increasing welfare, energy demand worldwide is increasing. To meet the increasing energy demand in a sustainable way, new technologies are needed. The Plant-Microbial Fuel Cell (P-MFC) is a technology that could produce sustainable bio-electricity and help meeting the increasing energy demand. Power output of the P-MFC, however, needs to be increased to make it attractive as a renewable and sustainable energy source. To increase power output of the P-MFC internal resistances need to be reduced. With a flat-plate P-MFC design we tried to minimize internal resistances compared to the previously used tubular P-MFC design. With the flat-plate design current and power density per geometric planting area were increased (from 0.15 A/m2 to 1.6 A/m2 and from 0.22 W/m2 to and 0.44 W/m2)as were current and power output per volume (from 7.5 A/m3 to 122 A/m3 and from 1.3 W/m3 to 5.8 W/m3). Internal resistances times volume were decreased, even though internal resistances times membrane surface area were not. Since the membrane in the flat-plate design is placed vertically, membrane surface area per geometric planting area is increased, which allows for lower internal resistances times volume while not decreasing internal resistances times membrane surface area. Anode was split into three different sections on different depths of the system, allowing to calculate internal resistances on different depths. Most electricity was produced where internal resistances were lowest and where most roots were present; in the top section of the system. By measuring electricity production on different depths in the system, electricity production could be linked to root growth. This link offers opportunities for material-reduction in new designs. Concurrent reduction in material use and increase in power output brings the P-MFC a step closer to usable energy density and economic feasibility. 相似文献
14.
Jouvin-Marche E; Cuddihy A; Butler S; Hansen JN; Fitch WM; Rudikoff S 《Molecular biology and evolution》1988,5(5):500-511
The immunoglobulin kappa light-chain constant region gene (C kappa) has
been cloned and sequenced from five wild mouse species. Analysis of these
data has permitted an assessment of single-copy gene evolution during a
limited time period as defined by the genus Mus. Sequence conservation was
found to be as high (or higher) in the 5' and enhancer regions as in the
coding region. The pattern of substitutions throughout these genes suggests
that parallel evolution has occurred frequently and that substitutions at
replacement sites have not decreased significantly, owing to saturation
during this period of approximately 10 Myr. Phylogenetic relationships have
been determined among these wild species as well as among members of the
genus Rattus.
相似文献
15.
Alan Winston Alejandro Arenas-Pinto Wolfgang St?hr Martin Fisher Chloe M. Orkin Kazeem Aderogba Andrew De Burgh-Thomas Nigel O'Farrell Charles JN. Lacey Clifford Leen David Dunn Nicholas I. Paton for the PIVOT Trial Team 《PloS one》2013,8(4)
Objective
To describe factors associated with neurocognitive (NC) function in HIV-positive patients on stable combination antiretroviral therapy.Design
We undertook a cross-sectional analysis assessing NC data obtained at baseline in patients entering the Protease-Inhibitor-Monotherapy-Versus-Ongoing-Triple therapy (PIVOT) trial.Main outcome measure
NC testing comprised of 5 domains. Raw results were z-transformed using standard and demographically adjusted normative datasets (ND). Global z-scores (NPZ-5) were derived from averaging the 5 domains and percentage of subjects with test scores >1 standard deviation (SD) below population means in at least two domains (abnormal Frascati score) calculated. Patient characteristics associated with NC results were assessed using multivariable linear regression.Results
Of the 587 patients in PIVOT, 557 had full NC results and were included. 77% were male, 68% Caucasian and 28% of Black ethnicity. Mean (SD) baseline and nadir CD4+ lymphocyte counts were 553(217) and 177(117) cells/µL, respectively, and HIV RNA was <50 copies/mL in all. Median (IQR) NPZ-5 score was −0.5 (−1.2/−0) overall, and −0.3 (−0.7/0.1) and −1.4 (−2/−0.8) in subjects of Caucasian and Black ethnicity, respectively. Abnormal Frascati scores using the standard-ND were observed in 51%, 38%, and 81%, respectively, of subjects overall, Caucasian and Black ethnicity (p<0.001), but in 62% and 69% of Caucasian and Black subjects using demographically adjusted-ND (p = 0.20). In the multivariate analysis, only Black ethnicity was associated with poorer NPZ-5 scores (P<0.001).Conclusions
In this large group of HIV-infected subjects with viral load suppression, ethnicity but not HIV-disease factors is closely associated with NC results. The prevalence of abnormal results is highly dependent on control datasets utilised.Trial registry
ClinicalTrials.gov, NCT01230580相似文献16.