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91.
PL Gabbott BG Dickie RR Vaid AJ Headlam SJ Bacon 《Canadian Metallurgical Quarterly》1997,377(4):465-499
This paper is a light microscopical study describing the detailed morphology and quantitative distribution of local circuit neurones in areas 25, 32, and 24b of the medial prefrontal cortex (mPFC) in the rat. Cortical interneurones were identified immunocytochemically by their expression of calretinin (CR), parvalbumin (PV), and calbindin D-28k (CB) immunoreactivity. Neurones immunoreactive for gamma-aminobutyric acid (GABA) were also investigated, as were interneurones containing reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase activity. Several distinct classes of CR+, PV+, and CB+ neurones were identified; the most frequent were: bipolar/bitufted CR+ cells in upper layer 3; multipolar PV+ neurones in layers 3 and 5; and bitufted/multipolar CB+ neurones in lower layer 3. CB+ neurones resembling Martinotti and neurogliaform cells were also present in layers 5/6. The morphologies and depth distributions of each cell type were consistent across the three areas of mPFC studied. Seven classes of diaphorase-reactive mPFC neurone are described; these cells were composed about 0.8% of the total neurone population and had a peak distribution located in mid- to lower layer 5 in each area. In areas 32 and 25, three defined bands of diffuse NADPH diaphorase staining were located in layer 2 and in upper and deep layer 5. Diaphorase reactivity was very infrequently colocalised with either CR, PV, or CB immunoreactivities. The numerical densities of neurones (N(V), number of cells per mm3) in each layer were calculated stereologically. The mean total neuronal N(V) estimate for areas 25, 32, and 24b was 51,603 +/- 3,324 (mean +/- S.D.; n = 8). Significant interareal differences were detected. From cortical thickness data and neuronal N(V) estimates, the absolute number of neurones under 1 mm2 of cortical surface (N(C)) have been derived. The mean N(C) value for areas 25, 32, and 24b was 57,328 +/- 7,505 neurones. In immunolabelled Nissl-stained sections, CR+ neurones constituted an overall 4.0%, PV+ cells 5.6%, and CB+ 3.4% of the total neurone populations in mPFC. GABA+ cells represented a mean of 16.2% (14.8-17.2%) of neurones in areas 25, 32 and 24b. The absolute numbers of CR+, PV+, CB+, and GABA+ neurones within individual layers in a column of cortex under 1 mm2 of cortical surface (N(L)) have also been derived, with significant interareal differences in N(L) values being detected. The data provide the structural basis for a qualitative and quantitative definition of local cortical circuits in the rat mPFC. 相似文献
92.
In this paper we introduce new algorithm implementations of a new parametric image processing framework that will accurately process images and speed up computation for addition, subtraction, and multiplication. Its potential applications include computer graphics, digital signal processing and other multimedia applications. This Parameterized Digital Electronic Arithmetic (PDEA) model replaces linear operations with non-linear ones. The implementation of a parameterized model is presented. We also present the design of arithmetic circuits including parallel counters, adders and multipliers based in two high performance threshold logic gate implementations that we have developed. We will also explore new microprocessor architectures to take advantage of arithmetic. The experiments executed have shown that the algorithm provides faster and better enhancements from those described in the literature. The FPGA chips used is Spartan 3E from Xilinix. The critical length in the circuit implemented on the FPGA had the minimum period for the proposed subsystem is 10.209 ns (maximum frequency 97.957 MHz). Maximum power consumed is 2.4 mW using 32 nm process and we used parallelism and reuse of the Hardware components to accomplish and speed up the process. 相似文献
93.
Steep-front short-duration voltage surge tests were conducted on commercially available power-line filters and two types of transient voltage suppressors to determine their effectiveness for protection against nuclear electromagnetic pulse (EMP) induced power-line transients. The tested power line filters were single-phase industrial-type units in the 120/208 V and 277/480 V class rated at 100 or 200 A. It was found that the tested power-line filters provide from 38 to 54 dB of attenuation for steep front surges (20 to 40 ns rise time and 150 to 400 ns fall time to half-value waves for 2 to 20 kV peak voltage), and transient voltage suppressors add an additional 2 to 8 dB of attenuation. It was also found that while the tested power line filters provide good protection against EMP induced surges, degradation of the filter characteristics may occur and delayed failures of filter components are possible. Transient voltage suppressors reduce the EMP induced surge by 40% and thus provide some protection for the filter 相似文献
94.
Marcus V.J. Rocha Hudson W.P. de Carvalho Victor H.V. Sarmento Aldo F. Craievich Teodorico C. Ramalho 《Polymer Composites》2016,37(1):51-60
Maghemite (γ‐Fe2O3)‐poly(methyl methacrylate) (PMMA) nanocomposites were prepared by grafting 3‐(trimethoxy‐silyl) propyl methacrylate on the surface of maghemite nanoparticles, this process being followed by methyl methacrylate radical polymerization. Three different hybrids with 0.1, 0.5, and 2.5 wt% of maghemite nanoparticles were studied. The results indicate that these nanocomposites consist of a homogeneous PMMA matrix in which maghemite nanoparticles with a bimodal size distribution are embedded. The existence of covalent bonding between silane monomers and atoms on the maghemite surface was evidenced. AFM images showed a clear increase in surface roughness for increasing maghemite content. The thermal stability of PMMA‐maghemite nanocomposites is higher than that of pure PMMA and increases for increasing maghemite content. The results of our theoretical studies indicate that the electron density in the maghemite nanoparticle is not homogenous, the low electron density volumes being supposed to be radical trappers during PMMA decomposition, thus acting as a thermal stabilizer. POLYM. COMPOS., 51–60, 2016. © 2014 Society of Plastics Engineers 相似文献
95.
A series of hydroxy aromatic acids, esters and lactones have been evaluated as antioxidants for lard at 120°C at 0·025%, 0·05% and 0·1% concentrations. Most of the compounds studied are direct biochemical precursors of chalcones and these, in turn, of various flavonoids commonly occurring in plant material.Antioxidant efficiency has been shown to be very dependent on the number of phenolic hydroxyl groups in the molecule and also to be promoted by steric hindrance. Cinnamic acids are more effective than corresponding benzoic acids, and phenylacetic and phenylpropionic acids are even more effective. 3,4-Dihydroxy chalcone is more effective than the analogous caffeic acid. In general, the presence of a carbonyl group in the molecule appears to be necessary in this series for a high level of antioxidant activity. 相似文献
96.
Dr. Anders Højgaard Hansen Henriette B. Christensen Dr. Sunil K. Pandey Dr. Eugenia Sergeev Alice Valentini Julia Dunlop Domonkos Dedeo Simone Fratta Dr. Brian D. Hudson Prof. Graeme Milligan Prof. Trond Ulven Prof. Elisabeth Rexen Ulven 《ChemMedChem》2021,16(21):3326-3341
Free fatty acid receptor 2 (FFA2) is a sensor for short-chain fatty acids that has been identified as an interesting potential drug target for treatment of metabolic and inflammatory diseases. Although several ligand series are known for the receptor, there is still a need for improved compounds. One of the most potent and frequently used antagonists is the amide-substituted phenylbutanoic acid known as CATPB ( 1 ). We here report the structure-activity relationship exploration of this compound, leading to the identification of homologues with increased potency. The preferred compound 37 (TUG-1958) was found, besides improved potency, to have high solubility and favorable pharmacokinetic properties. 相似文献
97.
CF Verkoelen BG van der Boom FH Schr?der JC Romijn 《Canadian Metallurgical Quarterly》1997,15(4):229-235
Large bone flaps for free transfer can be successfully and safely harvested based on the deep branch of the superior gluteal artery. The anatomy is consistent, the vessels are large, and the complications of this technique are minimal. 相似文献
98.
Ahmad Jalloh Antwoine Flowers Charles Hudson Dale Chaput Jennifer Guergues Stanley M. Stevens Jr. Paula C. Bickford 《International journal of molecular sciences》2021,22(12)
Microglial activity in the aging neuroimmune system is a central player in aging-related dysfunction. Aging alters microglial function via shifts in protein signaling cascades. These shifts can propagate neurodegenerative pathology. Therapeutics require a multifaceted approach to understand and address the stochastic nature of this process. Polyphenols offer one such means of rectifying age-related decline. Our group used mass spectrometry (MS) analysis to explicate the complex nature of these aging microglial pathways. In our first experiment, we compared primary microglia isolated from young and aged rats and identified 197 significantly differentially expressed proteins between these groups. Then, we performed bioinformatic analysis to explore differences in canonical signaling cascades related to microglial homeostasis and function with age. In a second experiment, we investigated changes to these pathways in aged animals after 30-day dietary supplementation with NT-020, which is a blend of polyphenols. We identified 144 differentially expressed proteins between the NT-020 group and the control diet group via MS analysis. Bioinformatic analysis predicted an NT-020 driven reversal in the upregulation of age-related canonical pathways that control inflammation, cellular metabolism, and proteostasis. Our results highlight salient aspects of microglial aging at the level of protein interactions and demonstrate a potential role of polyphenols as therapeutics for age-associated dysfunction. 相似文献
99.
M Heinlein HS Padgett JS Gens BG Pickard SJ Casper BL Epel RN Beachy 《Canadian Metallurgical Quarterly》1998,10(7):1107-1120
Tobacco mosaic virus (TMV) derivatives that encode movement protein (MP) as a fusion to the green fluorescent protein (MP:GFP) were used in combination with antibody staining to identify host cell components to which MP and replicase accumulate in cells of infected Nicotiana benthamiana leaves and in infected BY-2 protoplasts. MP:GFP and replicase colocalized to the endoplasmic reticulum (ER; especially the cortical ER) and were present in large, irregularly shaped, ER-derived structures that may represent "viral factories." The ER-derived structures required an intact cytoskeleton, and microtubules appeared to redistribute MP:GFP from these sites during late stages of infection. In leaves, MP:GFP accumulated in plasmodesmata, whereas in protoplasts, the MP:GFP was targeted to distinct, punctate sites near the plasma membrane. Treating protoplasts with cytochalasin D and brefeldin A at the time of inoculation prevented the accumulation of MP:GFP at these sites. It is proposed that the punctate sites anchor the cortical ER to plasma membrane and are related to sites at which plasmodesmata form in walled cells. Hairlike structures containing MP:GFP appeared on the surface of some of the infected protoplasts and are reminiscent of similar structures induced by other plant viruses. We present a model that postulates the role of the ER and cytoskeleton in targeting the MP and viral ribonucleoprotein from sites of virus synthesis to the plasmodesmata through which infection is spread. 相似文献
100.