肉毒毒素A对大鼠慢性神经源性疼痛镇痛作用的研究

目的观察肉毒毒素A(BoNT-A)对L5、L6脊神经结扎引起慢性神经源性疼痛模型大鼠行为学的影响。方法建立Wistar大鼠左侧L5、L6脊神经结扎模型(SNL模型)。SNL模型大鼠随机分为3组(n=8)。1)实验组:SNL术后第3天同侧足底皮下注射BoNT-A30U/kg;2)对照组:SNL术后同侧足底皮下注射相同容积生理盐水;3)假手术组:仅暴露而不结扎L5和L6脊神经。均分别测定术前、给药前、给药后1d、3d、5d、7d、14d、21d的机械缩足反射阈值(MWT)和热缩足反射潜伏期(TWL)。结果实验组手术同侧足底皮下注射BoNT-A可以增加大鼠的MWT和TWL,实验组手术对侧、对照组、假手术组应用BoNT-A对MWT和TWL无影响。结论足底皮下注射BoNTA能够改善SNL模型大鼠手术同侧肢体的MWT和TWL,有镇痛作用。     

Factors influencing the distribution of 99m-technetium methylene diphosphonate in bone and soft tissues.

The influences of dilution, storage and pH on the distribution of 99m-technetium methylene diphosphonate (99m-Tc-MDP) in bone and various soft tissues have been investigated in the rat. The results show a marked departure from normality when large dilution factors and very acidic or basic preparations are used.     

Effect of salinity on seed germination of Triglochin maritima under various temperature regimes

Triglochin maritima L. (arrow grass), an herbaceous perennial in the family Juncaginacea, is widely distributed in inland and coastal salt marshes of North America. Triglochin maritima seeds from a population growing in a salt marsh at Faust, Utah, were germinated at 4 temperature regimes (12-h night/12-h day, 5-15° C, 10-20° C, and 15-25° C) and 5 salinities (0, 100, 200, 300, 400, and 500 mol m -3 NaCl) to determine optimal conditions for germination and level of salt tolerance. Ungerminated seeds were returned to distilled water after 20 d to determine whether seeds could recover from salinity treatments. Maximum germination occurred in distilled water, and increases in NaCl concentration progressively inhibited seed germination. No seeds germinated at concentrations higher than 400 mol m -3 NaCl. A temperature regime of low night (5° C) and high day (25° C) temperature yielded maximum germination; all other temperature regimes significantly inhibited seed germination relative to this optimum. Recovery of germination was highest at 5-25° C and lowest at 5-15° C. Recovery of seed germination when seeds were transferred to distilled water from salt solutions was highest at 5-25° C (72%) for seeds exposed to the 500 mol m -3 NaCl pretreatment and significantly reduced at other temperature regimes. The recovery germination response indicates a synergistic inhibitory interaction effect on germination when seeds were exposed to high salinities at suboptimal thermoperiods.     

A Mal functional variant is associated with protection against invasive pneumococcal disease, bacteremia, malaria and tuberculosis

Toll-like receptors (TLRs) and members of their signaling pathway are important in the initiation of the innate immune response to a wide variety of pathogens. The adaptor protein Mal (also known as TIRAP), encoded by TIRAP (MIM 606252), mediates downstream signaling of TLR2 and TLR4 (refs. 4-6). We report a case-control study of 6,106 individuals from the UK, Vietnam and several African countries with invasive pneumococcal disease, bacteremia, malaria and tuberculosis. We genotyped 33 SNPs, including rs8177374, which encodes a leucine substitution at Ser180 of Mal. We found that heterozygous carriage of this variant associated independently with all four infectious diseases in the different study populations. Combining the study groups, we found substantial support for a protective effect of S180L heterozygosity against these infectious diseases (N = 6,106; overall P = 9.6 x 10(-8)). We found that the Mal S180L variant attenuated TLR2 signal transduction.     

铝合金上热沉积氧化铝–二氧化钛涂层的固体颗粒冲蚀研究

Thermal barrier coatings are widely used as surface modifications to enhance the surface properties of the material and protect from surface degradations such as erosion and corrosion. Ceramic-based coatings are highly recommended to increase wear resistance in the industrial sector. In this paper, an alumina–titania ceramic powder was deposited on an aluminum alloy using an atmospheric plasma spray technique. Experimental investigations were performed to study the behavior and erosion rate of the material. Solid particle erosion studies were performed by varying the particle velocity and particle flow rate. The angle impingement and stand-off distance were constant for comparison. The base metal has a clinging effect and the mass change was negative at a maximum particle flow rate of 4 g·min?1. Under the same process conditions, the coated sample had a reduced lifetime and reached a maximum erosion rate of 0.052 (Δg/g). The solid particle erosion studies confirmed that the base metal aluminum alloy had severe surface damage with erodent reinforcement when compared to the coated samples. The influence of the particle velocity, particle flow rate, and input process parameters were also identified.     

Dominant and recessive deafness caused by mutations of a novel gene, TMC1, required for cochlear hair-cell function

Positional cloning of hereditary deafness genes is a direct approach to identify molecules and mechanisms underlying auditory function. Here we report a locus for dominant deafness, DFNA36, which maps to human chromosome 9q13-21 in a region overlapping the DFNB7/B11 locus for recessive deafness. We identified eight mutations in a new gene, transmembrane cochlear-expressed gene 1 (TMC1), in a DFNA36 family and eleven DFNB7/B11 families. We detected a 1.6-kb genomic deletion encompassing exon 14 of Tmc1 in the recessive deafness (dn) mouse mutant, which lacks auditory responses and has hair-cell degeneration. TMC1 and TMC2 on chromosome 20p13 are members of a gene family predicted to encode transmembrane proteins. Tmc1 mRNA is expressed in hair cells of the postnatal mouse cochlea and vestibular end organs and is required for normal function of cochlear hair cells.