Transspinal direct current stimulation immediately modifies motor cortex sensorimotor maps

Motor cortex (MCX) motor representation reorganization occurs after injury, learning, and different long-term stimulation paradigms. The neuromodulatory approach of transspinal direct current stimulation (tsDCS) has been used to promote evoked cortical motor responses. In the present study, we used cathodal tsDCS (c-tsDCS) of the rat cervical cord to determine if spinal cord activation can modify the MCX forelimb motor map. We used a finite-element method model based on coregistered high-resolution rat MRI and microcomputed tomography imaging data to predict spinal current density to target stimulation to the caudal cervical enlargement. We examined the effects of cathodal and anodal tsDCS on the H-reflex and c-tsDCS on responses evoked by intracortical microstimulation (ICMS). To determine if cervical c-tsDCS also modified MCX somatic sensory processing, we examined sensory evoked potentials (SEPs) produced by wrist electrical stimulation and induced changes in ongoing activity. Cervical c-tsDCS enhanced the H-reflex, and anodal depressed the H-reflex. Using cathodal stimulation to examine cortical effects, we found that cervical c-tsDCS immediately modified the forelimb MCX motor map, with decreased thresholds and an expanded area. c-tsDCS also increased SEP amplitude in the MCX. The magnitude of changes produced by c-tsDCS were greater on the motor than sensory response. Cervical c-tsDCS more strongly enhanced forelimb than hindlimb motor representation and had no effect on vibrissal representation. The finite-element model indicated current density localized to caudal cervical segments, informing forelimb motor selectivity. Our results suggest that c-tsDCS augments spinal excitability in a spatially selective manner and may improve voluntary motor function through MCX representational plasticity.

A new ion exchange adsorption mechanism between carbonate groups and fluoride ions of basic aluminum carbonate nanospheres

Basic aluminum carbonate nanospheres exhibited excellent adsorption properties for fluoride, and a new ion exchange mechanism involving carbonate groups and fluoride ions was proposed.

Amines functionalized C60 as solid base catalysts for Knoevenagel condensation with high activity and stability

Amines functionalized C₆₀ were prepared through a simple amination reaction of C₆₀ with organic amines, and they showed high activity and stability for Knoevenagel condensation.

Genetic variation in COX-2 -1195 and the risk of endometriosis and adenomyosis

AIM

Ths study aims to explore the relationship between COX-2 gene polymorphism and the hereditary susceptibility or endoomeyriosis and adenomyosis.

MATERIALS AND METHODS

Gene polymorphism in COX-2 gene was genotyped in 170 cases of endometriosis, 150 cases of adenomyosis, and 240 matched non-endometriosis and non-adenomyosis controls.

RESULTS

Genotypic frequencies of GG, AG, and AA in COX-2 locus in endometriosis and adenomyosis were 16.5%, 51.2%, 32.4% and 16.0%, 49.3%, 34.7%, respectively. They were both significantly different from those in the control group (24.6%, 53.3%, and 22.1%) (p < 0.05). An allele frequency in endometriosis and adenomyosis were significantly higher than that in the control group. The risk of endometriosis or adenomyosis for those carrying two A alleles were 2.19 and 2.41 times to non-A genotype.

CONCLUSION

Genetic variation of G to A at -1195 locus in the promoter region of COX-2 gene increases the risk of endometriosis and adenomyosis, and the genetic susceptibility of these two diseases are similar.

NiO/nanoporous graphene composites with excellent supercapacitive performance produced by atomic layer deposition

Nickel oxide (NiO) is a promising electrode material for supercapacitors because of its low cost and high theoretical specific capacitance of 2573 F g(-1). However, the low electronic conductivity and poor cycling stability of NiO limit its practical applications. To overcome these limitations, an efficient atomic layer deposition (ALD) method is demonstrated here for the fabrication of NiO/nanoporous graphene (NG) composites as electrode materials for supercapacitors. ALD allows uniform deposition of NiO nanoparticles with controlled sizes on the surface of NG, thus offering a novel route to design NiO/NG composites for supercapacitor applications with high surface areas and greatly improved electrical conductivity and cycle stability. Electrochemical measurements reveal that the NiO/NG composites obtained by ALD exhibited excellent specific capacitance of up to ∼ 1005.8 F g(-1) per mass of the composite electrode (the specific capacitance value is up to ∼ 1897.1 F g(-1) based on the active mass of NiO), and stable performance after 1500 cycles. Furthermore, electrochemical performance of the NiO/NG composites is found to strongly depend on the size of NiO nanoparticles.

Ultrafast high-power microwave window breakdown: nonlinear and postpulse effects

The time- and space-dependent optical emissions of nanosecond high-power microwave discharges near a dielectric-air interface have been observed by nanosecond-response four-framing intensified-charged-coupled device cameras. The experimental observations indicate that plasma developed more intensely at the dielectric-air interface than at the free-space region with a higher electric-field amplitude. A thin layer of intense light emission above the dielectric was observed after the microwave pulse. The mechanisms of the breakdown phenomena are analyzed by a three-dimensional electromagnetic-field modeling and a two-dimensional electromagnetic particle-in-cell simulation, revealing the formation of a space-charge microwave sheath near the dielectric surface, accelerated by the normal components of the microwave field, significantly enhancing the local-field amplitude and hence ionization near the dielectric surface. The nonlinear positive feedback of ionization, higher electron mobility, and ultraviolet-driven photoemission due to the elevated electron temperature are crucial for achieving the ultrafast discharge. Following the high-power microwave pulse, the sheath sustains a glow discharge until the sheath collapses.

Recent progress in the research of small molecule HIV-1 RNase H inhibitors

Reverse transcription of human immunodeficiency virus type 1 (HIV-1) is a crucial step in the life cycle initiated by the viral-coded reverse transcriptase (RT), functioning as RNA- and DNA-dependent DNA polymerase (RDDP and DDDP) and the ribonuclease H (RNase H). The RNase H functions to degrade the RNA strand of the RNA:DNA heteroduplex, which makes it an attractive target for rational anti-HIV-1 drug design and development. Although development of drugs targeting the DNA polymerase have been highly successful, the discovery of drugable inhibitors of HIV RNase H is still in its infancy and none of RNase H inhibitors has reached the clinical development stage currently. This review describes the recent progress in the HIV-1 RNase H inhibitors, focusing on their chemical feature, mechanism and the structure-activity relationship (SAR).

Neural HO-1/sterol interactions in vivo: implications for Alzheimer's disease

BACKGROUND

Up-regulation of heme oxygenase-1 (HO-1) and altered cholesterol (CH) metabolism are characteristic of Alzheimer-diseased (AD) neural tissues. We previously provided evidence of significant HO-1/sterol interactions in vitro (cultured rat astroglia) and in post-mortem human AD brain (Religious Orders Study).

METHODS

The current experiments were designed to further delineate these interactions in vivo by comparing the behavior of HO-1/sterol interactions in two mouse models; (1) a novel HO-1 transgenic mouse (GFAP.HMOX1) engineered to selectively express human HO-1 in the astrocytic compartment and (2) the previously described triple transgenic AD mouse (3xTg-AD). In samples of frontal cortex, total CH, CH precursors and relevant oxysterols were quantified by gas chromatography-mass spectrometry (GC-MS) and HO-1 protein expression was assessed by ELISA. The relationships of HO-1 expression to total CH, CH precursors and total oxysterols were determined for both mouse models using linear regression analysis.

RESULTS

HO-1 expression is increased in GFAP.HMOX1 mice relative to wild type and in 11-12-month-old 3xTg-AD mice (with AD-like phenotype) relative to control mice and 5-6-month-old 3xTg-AD mice (no AD-like phenotype). Total oxysterols significantly decreased as HO-1 expression increased in GFAP.HMOX1 mice expressing high levels of HO-1, whereas total oxysterols increased as HO-1 expression increased in aged 3xTg-AD mice. Total CH and total CH precursors increased as HO-1 protein expression increased in 11-12-month-old 3xTg-AD mice relative to 5-6-month old 3xTg-AD mice.

CONCLUSIONS

Our findings indicate a differential impact of HO-1 on patterns of brain sterol and redox homeostasis that is contingent on the presence or absence of AD-like neuropathology. These data provide fresh insight concerning the regulation of sterol homeostasis within the aging and degenerating CNS which may inform the development of novel therapeutic and preventive strategies for the management of AD and related conditions.

Design, synthesis, and preliminary activity evaluation of novel pyrimidine derivatives as acid pump antagonists

Acid-related diseases of the upper gastrointestinal tract, especially gastroesophageal reflux disease (GERD), remain a widespread problem worldwide. In this paper, we reported the design, synthesis, and preliminary gastric antisecretory activity evaluation of novel pyrimidine derivatives as acid pump antagonists. The gastric antisecretory activity assay results showed that all compounds displayed potent gastric antisecretory activity when gastric secretion was stimulated by histamine. The most potent compound 5g exhibited even similar gastric antisecretory activity compared with the control revaprazan, and the relative inhibition rate was 93.0%, which was worthy of further investigation.