Search

Background: The aging-related disease and associated neurodegenerative complications, such as cognitive impairment, has received increasing attention.Objective: The aim of this study was to show changes in cognitive behavior and molecular related the synaptic plasticity in aged-induced cognitive deficits rats.Methods: We used novel object recognition testing and morphological staining as well as western blot to detect changes in cognitive behavior and molecular related the synaptic plasticity.Results: The morphological changes of synaptic structure and number on hippocampal neurons and learning and memory deficits were shown during natural aging. Moreover, learning and memory improvement was associated with alterations of hippocampal synaptic plasticity-related proteins, such as SNAP-25, synaptophysin, snapsoin-1 and so on, which distributes to cognitive decline in natural aging.Conclusions: Our study provides more behavior and molecular evidence on relationship of cognitive deficits and aging. [ABSTRACT FROM AUTHOR]

Microperforated panel (MPP) absorbers have been widely used in noise reduction and are regarded as a promising alternative to the traditional porous materials. However, the absorption bandwidth of a single-layer MPP is insufficient to compete with the porous materials. In order to improve the sound absorption ability of the single-layer MPP, a composite MPP sound absorber with membrane cells (MPPM) is introduced. Sound absorption properties of the MPPM are studied by the impedance tube experiment. Results show that the membranes have a significant influence on the sound impedance. The sound absorption performance of MPPM gradually increases with the increase of the membrane area. The single-layer MPP with some small area membrane cells may have the same effect and single large area membranes. By adjusting the size of the membrane cells, one can implement a sound absorber with a wider absorption bandwidth and higher absorption peaks than the single-layer MPP. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum (ER) stress is involved in neurodegenerative diseases including Alzheimer's disease (AD), in which dysregulation of double-stranded RNA-dependent protein kinase (PKR)-like ER-resident kinase (PERK) is considered to play a critical role. Allicin, a garlic extract, has been demonstrated a protective role in AD model. The present study was designed to investigate the possible protective effect of allicin on ER stress-induced cognitive deficits and underlying mechanisms in rats. In this study, 72 h of lateral ventricular infusion of tunicamycin (TM), an ER stress stimulator, induced significant cognitive deficits. TM increased tau phosphorylation, Aβ42 deposit, and oxidative stress, and reduced antioxidative enzymes activity in the hippocampus. TM moderately elevated the expression of PERK and its downstream substrate nuclear factor erythroid-derived 2-like 2 (Nrf2) in the hippocampus. All these impaired changes by TM were significantly improved by allicin pretreatment. Allicin markedly increased PERK and Nrf2 expression in the hippocampus. Thus, our data demonstrate the protective role of allicin in ER stress-related cognitive deficits, and suggest that PERK/Nrf2 antioxidative signaling pathway underlies the action mechanism. [ABSTRACT FROM AUTHOR]

Abstract: Pentamethylquercetin (PMQ) has been shown to possess glucose-lowering properties, but its effect on renal fibrosis in diabetes is still unclear. This study was designed to investigate the effect of PMQ on renal fibrosis and the underlying mechanisms in spontaneous type II diabetic Goto-Kakizaki rats and mesangial cells in high glucose. We found that in Goto-Kakizaki rats, PMQ treatment attenuated glomerular volume, glycogen deposition, renal collagen and fibronectin accumulation, in addition to amelioration of diabetic symptoms, including reduction of urine volume and urine glucose levels. In mesangial cells, PMQ remarkably inhibited the cell proliferation and total collagen accumulation, and suppressed cell hypertrophy. Further experiments showed that PMQ treatment down-regulated the expression of TGF-β1, up-regulated Smad7 and inhibited Smad2/3 activation in vivo and vitro. Our results demonstrated that PMQ ameliorated renal fibrosis in diabetes, which may be associated with suppressed TGF-β/Smads signaling. [Copyright &y& Elsevier]

Diabetic patients have a signifiantly higher risk of developing all forms of dementia. Pentamethylquercetin (PMQ) has been proven to have potential as an anti-diabetic agent. Nevertheless, whether PMQ can improve diabetes-induced cognitive dysfunction has not been investigated. To address this, we evaluated the effectiveness and underlying mechanisms of PMQ for ameliorating diabetes-related cognitive dysfunction in vivo and in vitro. Our results showed that Goto-Kakizaki (GK) rats displayed impairment in their learning abilities and memory capabilities. Furthermore, GK rats reflected cognitive dysfunction in proportion to the intensity of insulin resistance index. In addition, dendritic spine density and the % cell viability significantly decreased in hippocampus neurons. High glucose conditions induced hippocampal neurons damage, inflicted dendritic spine dysontogenesis, and reduced Akt/cAMP response element-binding protein activation. Treatment with PMQ in GK rats significantly ameliorated cognitive deficits and neuronal damage and increased dendritic spine density, at least in part, by improving insulin resistance and metabolic disorders. Furthermore, PMQ significantly activated the Akt/cAMP response element-binding protein pathway and increased the expression of memory-related proteins in the downstream part of the Akt/cAMP response element-binding protein pathway, such as synaptophysin and glutamate receptor 1. In addition, PMQ inhibited high glucose-induced cellular toxicity. LY294002 appeared to partly inhibit PMQ-mediated protective effects in hippocampal neurons. The results suggest that insulin resistance could predominantly reduce Akt/cAMP response element-binding protein activation in the brain, which is associated with a higher risk of cognitive dysfunction. PMQ could provide a new potential option for the prevention of cognitive dysfunction in diabetes. [ABSTRACT FROM AUTHOR]

Abstract: Numerous studies have demonstrated that learning and memory abilities in the course of normal aging cognitive abilities tend to decline and Nrf2 expression appears to decline with aging. So, Nrf2 pathway has been identified as a promising therapeutic target for neurodegenerative diseases. The organosulfur compounds, allicin can activate Nrf2, because it has an electrophilic center, which can serve as an attack site for nucleophiles, such as specific protein sulfhydryl groups present on Keap1. However, the influence of allicin on aging-induced cognitive deficits has not been examined. In this study, we assess the effects of allicin on endogenous antioxidant defenses in hippocampus of cognitively impaired aged mouse. Our results indicate that treatment of allicin significantly ameliorated ageing-induced cognitive dysfunction through enhancing of Nrf2 antioxidant signaling pathways. Therefore, allicin could be recommended as a possible candidate for the prevention and therapy of cognitive deficits in aging and Alzheimer''s disease. [Copyright &y& Elsevier]

Abstract: As the multimedia data increasing exponentially, how to get the video data we need efficiently become so important and urgent. In this paper, a novel method for shot retrieval is proposed, which is based on fuzzy evolutionary aiNet and hybrid features. To begin with, the fuzzy evolutionary aiNet algorithm proposed in this paper is utilized to extract key-frames in a video sequence. Meanwhile, to represent a key-frame, hybrid features of color feature, texture feature and spatial structure feature are extracted. Then, the features of key-frames in the same shot are taken as an ensemble and mapped to high dimension space by non-linear mapping, and the result obeys Gaussian distribution. Finally, shot similarity is measured by the probabilistic distance between distributions of the key-frame feature ensembles for two shots, and similar shots are retrieved effectively by using this method. Experimental results show the validity of this proposed method. [Copyright &y& Elsevier]

With the continuous advancement of medical technology, the survival rate of preterm infants is gradually improving, However, due to the underdeveloped function of various organs and systems, preterm infants are often exposed to light, noise, medical as well as nursing operations and other stimuli during their hospitalization in neonatal intensive care unit (NICU); it is highly susceptible to a number of problems, such as pain, unstable vital signs, growth retardation, and sleep disruption. This article reviews the research progress of music intervention in nursing of premature infants in NICU with both traditional and conventional care. This article reviews the research background, methodology/design, and measurement/application effects of music interventions, including Chinese and Western traditional music, in the care of preterm infants in NICU. All scholarly literature retrieved from MEDLINE\PubMed, Science Citation Index Expanded, Google scholar, CNKI scholar, Scopus and PubsHub. As a simple and effective non-pharmacological intervention, music intervention can effectively alleviate neonatal surgical pain, increase heart rate and oxygen saturation, promote sleep, growth and development, and improve neurological development. This review provide theoretical references for clinical practice. [ABSTRACT FROM AUTHOR]

Acoustic performance of an absorber without perforating holes, overlapping micro-gapped strips (OMGS), is studied in this paper. OMGS is made by overlapping and staggering two layers of plates, each layer of which is constituted by arranging an array of strip-shaped sheets separated by a micro gap. Micro slits are formed between those strips and the upper layer of slits intersects with the lower one forming micro apertures. The aperture sandwiched between the slits is just a layer of cross profile with zero geometrical thickness. Thermoviscous acoustic simulations of OMGS demonstrate the distribution of the pressure, velocity, and power dissipation at the cross profile and along the axial direction of the aperture. Empirical impedance correction models for the cross profile are proposed based on numerical simulations. Experimental examples validate that the proposed models offer an accurate prediction for the acoustic impedance and sound absorption coefficients of OMGS. [ABSTRACT FROM AUTHOR]

Microperforated plates (MPPs) are efficient sound absorbers typically made of thin panels, which restricts practical application in engineering. This paper investigates MPPs with stepwise apertures on thick panels to enhance acoustic performance and overcome the lack of appropriate strength. Thermoviscous acoustic simulations of the MPPs demonstrate that the acoustic pressure, local velocity, and the power dissipation change abruptly at the step edges, similar as the behaviors at the inlet and outlet ends of the uniform perforations. The step generates additional acoustic impedance, which has a strong relationship with cross section ratio. Empirical impedance correction models for sharp-edged circular holes located concentrically on square or circular end panel are derived based on numerical simulations. Experimental data validate that the proposed models offer accurate prediction for acoustic impedance of MPPs with stepwise apertures. [ABSTRACT FROM AUTHOR]

Objectives: Chronic hyperglycemia is considered as an important factor to promote the neurodegenerative process of brain, and the synaptic plasticity as well as heterogeneity of hippocampal cells are thought to be associated with cognitive dysfunction in the early process of neurodegeneration. To date, fibronectin type III domain‐containing protein 5 (FNDC5) has been highlighted its protective role in multiple neurodegenerative diseases. However, the potential molecular and cellular mechanisms of FNDC5 on synaptic plasticity regulation in cognitive impairment (CI) induced by diabetics are still need to known. Methods/Design: To investigate the heterogeneity and synaptic plasticity of hippocampus in animals with CI state induced by hyperglycemia, and explore the potential role of FNDC5 involved in this process. Firstly, the single cell sequencing was performed based on the hippocampal tissue from db diabetic mice induced CI and normal health control mice by ex vivo experiments; and then the integrated analysis and observations validation using Quantitative Real‐time PCR, western blot as well as other in vitro studies. Results: We observed and clarified the sub‐cluster of type IC spiral ganglion neurons expressed marker genes as Trmp3 and sub‐cluster of astrocytes with marker gene as Atp1a2 in hippocampal cells from diabetic animals induced CI and the effect of those on neuron‐glial communication. We also found that FNDC5\BDNF‐Trk axis was involved in the synaptic plasticity regulation of hippocampus. In high glucose induced brain injury model in vitro, we investigated that FNDC5 significantly regulates BDNF expression and that over‐expression of FNDC5 up‐regulated BDNF expression (p < 0.05) and can also significantly increase the expression of synapsin‐1 (p < 0.05), which is related to synaptic plasticity, In addition, the unbalanced methylation level between H3K4 and H3K9 in Fndc5 gene promoter correlated with significantly down‐regulated expression of FNDC5 (p < 0.05) in the hyperglycemia state. Conclusion: The current study revealed that the synaptic plasticity of hippocampal cells in hyperglycemia might be regulated by FNDC5\BDNF‐Trk axis, playing the protective role in the process of CI induced by hyperglycemia and providing a target for the early treatment of hyperglycemia induced cognitive dysfunction in clinic. Key points: The heterogeneity and synaptic plasticity of hippocampus between the db−/− diabetic mice with cognitive dysfunction and control groups were profiled by the single cell sequencing.FNDC5\BDNF‐Trk axis was involved in the synaptic plasticity regulation of hippocampus.Over‐expression of FNDC5 up‐regulated BDNF expression and can also increase the expression of synapsin‐1, which is related to synaptic plasticity.The unbalanced methylation level between H3K4 and H3K9 in Fndc5 gene promoter correlated with significantly down‐regulated expression of FNDC5 in the hyperglycemia state. [ABSTRACT FROM AUTHOR]

Ablation under oxyacetylene torch with heat flux of 4186.8 (10% kW/m2 for 20 s was performed to evaluate the ablation resistance of C/C–SiC composites fabricated by chemical vapor infiltration (CVI) combined with liquid silicon infiltration (LSI) process. The results indicated that C/C–SiC composites present a better ablation resistance than C/C composites without doped SiC. The doped SiC and the ablation products SiO2 derived from it play key roles in ablation process. Bulk quantities of SiO2 nanowires with diameter of 80 nm–150 nm and length of tens microns were observed on the surface of specimens after ablation. The growth mechanism of the SiO2 nanowires was interpreted with a developed vapor–liquid–solid (VLS) driven by the temperature gradient. [ABSTRACT FROM AUTHOR]

Microperforated panel (MPP) absorbers have been widely used in noise reduction and are regarded as a promising alternative to the traditional porous materials. However, the absorption bandwidth of a single-layer MPP is insufficient to compete with the porous materials. In order to improve the sound absorption ability of the single-layer MPP, membrane cell and mass blocks composite structure is introduced. Sound absorption properties of the MPP with membrane cell and mass blocks composite structure are studied by the impedance tube experiment. Results show that Membrane cell and mass blocks can change the sound absorption of MPP by introducing additional absorption peaks and valleys. To illustrate the role of membrane and mass in the sound absorption process, the acoustic properties of aluminum plate, aluminum plate with membrane, aluminum plate with membrane and mass are further investigated. When the membrane and mass are added, the sound resistance of the structure is increased and sound reactance of the structure jump abruptly near the sound absorption. This is mainly due to the local resonance of the membrane and mass. Therefore,combined with the characteristics of the sound absorption of MPP, the membrane and mass can further improve the sound absorption properties of the structure. Excellent performance of sound absorbing structure will be obtained by rational design of MPP, the size of membrane cell, the number, size and position mass blocks. [ABSTRACT FROM AUTHOR]

Microperforated panel (MPP) absorbers have been widely used in noise reduction and are regarded as a promising alternative to the traditional porous materials. However, the absorption bandwidth of a single-layer MPP with limited cavity space is insufficient to compete with the porous materials. In order to improve the sound absorption ability of the single-layer MPP with limited cavity space, MPP with L shape division cavity structure is introduced. Based on the MPP and electro-acoustical equivalent circuit principle, sound absorption properties of MPP with L shape division cavity are studied. Simulation and experimental results show that MPP with L shape division structure have better sound absorption performance than MPP with single cavity structure. Building on L shape division cavity, the extended plate can further improve the sound absorption of MPP. Wide band sound absorption of MPP can be realized with limited cavity space. [ABSTRACT FROM AUTHOR]

Microperforated panel (MPP) absorbers have been widely used in noise reduction and are regarded as a promising alternative to the traditional porous materials. However, the absorption bandwidth of a single-layer MPP is insufficient to compete with the porous materials. In order to improve the sound absorption ability of the single-layer MPP, MPP mounted with Helmholtz resonators (MPPHR) is introduced. Based on the MPP, Helmholtz resonators theory and electro-acoustical equivalent circuit principle, sound absorption properties of MPPHR are studied. Simulation and experimental results show that MPPHR have two peak frequencies and one anti-resonant frequency. The low-frequency peak is dependent on the Helmholtz resonators, while the high frequency peak is close to the peak of the single-layer MPP. The low-frequency sound absorption peaks move to low frequency with the neck length and the volume of Helmholtz resonators increasing. The high-frequency sound absorption peaks move to high frequency with the volume of Helmholtz resonators cavity increasing. Multiple Helmholtz resonator parallel MPP structure can provide more sound absorption than single MPPHR at low frequency range due to the introduction of more additional sound absorption peaks. [ABSTRACT FROM AUTHOR]

Partial microperforated panel (MPP) structures have been proposed for MPP with low sound absorption properties. Its purpose is to improve the sound absorption performance of the MPP in certain frequency bands. The structure was studied by the transfer matrix method, finite element simulation and experimental test. The results show that the three kinds of curves, that is, theoretical and simulation and experimental curves, are in good agreement. In the parallel structure of partial MPP and the cavity, the MPP structure occupying three-quarters of the total area makes perfect sound absorption at 1076 Hz. The sound absorption peak of the MPP structure which occupies half of the total area is 0.89 at 980 Hz. The theory of calculating the partial MPP, which is accurate for fast prediction of sound absorption peaks, is proposed. The sound absorption performance of the multi-partial MPP structure has also been theoretically verified. The acoustic siphon phenomenon of partial MPP is discussed. On this basis, a multi-Helmholtz resonance structure is designed to achieve high sound absorption effect. The sound absorption coefficient is greater than 0.87 at 488–712 Hz. [ABSTRACT FROM AUTHOR]

Changes in brain energy metabolism in diabetes mellitus, including increased insulin resistance and mitochondrial dysfunction, are critically involved in diabetes-related neurodegeneration, and associate with early cognitive impairment as well. The aim of this study is to detect the specific phosphorylated-Thr485- AMP-activated protein kinase (AMPK-α2), regulated by cyclin-dependent kinase 5 (Cdk5) paly the inhibitory functional role of AMPK-α2, Which is maybe the link to the accelerated diabetic brain damage progression. Here, we used GK rats, the type 2 diabetic animal model for in vivo studies and performed In vitro kinase assay, high glucose treatment, -phosphorylated mutation and protein expression in both HEK-293T and HT-22 cell lines. In vitro , the results show that murine wild-type AMPK-α2 was phosphorylated by Cdk5 at a (S/T)PX(K/H/R) phosphorylation consensus sequence, which was associated with decreased AMPK-α2 activity. Surprisingly, mutation of Thr485 to alanine in AMPK-α2 results in the abolished Cdk5 effects, demonstrating that Thr485-phosphorylation is critical to AMPK-α2 inhibition by Cdk5. In addition, these alterations in AMPK-α2-phosphorylation and -activity induced by Cdk5 is specific at Thr485. Furthermore, in GK rats, the increased phosphorylated- Thr 485 of AMPK-α2 results in the decreased AMPK-α2 activity, which is correlated with the apoptosis of neurons in hippocamps. After high glucose treatment, the decreased survival showed in AMPK-α2T485A HT-22 cells compared to AMPK-α2WT. The down-regulated of p-CREB, SNAP25, synaptophysin as well as synapsin-1were shown in both GK rats and HT-22 cell line. Meanwhile, pre-treated with either the specific Cdk5-inhibitor (roscovitine) or the antidiabetic AMPK-α2-inhibitor (metformin) could restore the alterations in neuronal protein expression. Our results suggest that Cdk5-mediated phosphorylated- Thr485 in AMPK-α2 may be involved in the pathogenesis of diabetic brain damage. • AMPK-α2 was phosphorylated by Cdk5 at a (S/T)PX(K/H/R) phosphorylation sequence. • Cdk5 activity induce an inhibition of AMPK-α2 via its specific phosphorylation site at Thr485. • Hyperglycemia in hippocampus results in the decreased neurons and down regulated cognitive-related proteins. • The study brings new insight in the molecular mechanism regarding brain damages induced by hyperglycemia. [ABSTRACT FROM AUTHOR]

Chronic hyperglycemia can cause changes in synaptic plasticity of hippocampal cells, which has accelerated the pathological process of cognitive dysfunction. However, the heterogeneity of the hippocampal cell populations under long term high glucose statement remains largely unknown. To mimic chronic hyperglycemia induced cognitive function deficit in vivo, db-/- diabetic mice was selected and Novel Object Recognition(NOR) behavior tests were performed. Based on diabetic induced cognitive impairment(CI) animal model, single-cell RNA sequencing was performed in the hippocampus of CI group (21,379 cells) or control group (20,045 cells), and single cell RNA sequencing was applied, and then the single cell atlas of gene expression was profiled. The comprehensive analysis explicated 18 nerve cell clusters, including 9 distinct sub-clusters, More in-depth analysis of oligodendrocyte precursor cells(OPCs) showed five distinct OPCs sub-clusters including expressing marker gene Lingo2 -OPCs, Kcnc1 -OPCs, Sst -OPCs, Slc6a1 -OPCs and Lhfpl3 -OPCs, which seems to be able to proliferate, migrate, and finally differentiate into mature oligodendrocytes and produce myelin. To be noted, differentially expressed genes(DEGs) of the Sst -OPCs sub-cluster indicated that the genes participating in neuroactive ligand-receptor interaction, nervous system development and inflammatory process were up-regulated in diabetic induced cognitive impairment(DCI) groups compared to normal control groups. Integrating the data of neuroplasticity regulation, the 20th top-enriched biological process was associated with neuroplasticity regulation in CI groups compared to control groups. Among these neuroplasticity-related genes, the intersectional gene Sstr2 may play an important role in neuroplasticity regulation. Focused on neuroplasticity regulation and its related specific genes may provide potential new clues for the treatment of diabetes mellitus complicated with cognitive impairment. In summary, we showed the comprehensively transcriptional landscape of hippocampal cells in the db-/- diabetic mice with cognitive dysfunction, distinctive cell sub-clusters and the gene expression characteristics were identified, and also their special functions were proposed, which may give new clues and potential targets for diagnosis and treatment of diabetic encephalopathy. • The transcriptional landscape of hippocampal cells between the db-/-mice with cognitive dysfunction and control were profiled. • Distinctive cell sub-clusters and gene expression characteristics were identified and functions as well as mechanism were proposed. • The study may give new clues and potential targets for diagnosis and treatment of diabetic encephalopathy. [ABSTRACT FROM AUTHOR]

Abstract Microperforated panel (MPP) absorber were proposed by Maa for situation where a robust sound absorber was needed, without fibrous or porous material. Nowadays, it is relatively easy to design a MPP for providing sound absorption in a frequency band of a couple of octaves. However, the widespread use of MPPs as sound absorbers in the noise control industry is far from occurring. Because it is very difficult to fabricate thousands of sub-millimetric holes in a small scale, and the cost of fabrication is quite expensive. According to the heat shrinkage characteristics of heat shrinkable materials, a manufacturing process of MPP with ultra-micro holes was developed in this paper. The holes were made on the heat shrinkable sheets by traditional technology. After heat shrinkage, the holes with 20–80% smaller than that of traditional technology were obtained, and the processing of ultra-micro holes was realized. Process flow for making MPP with heat shrinkable materials is introduced. The manufacturing sample is displayed. Sound absorption properties of the MPP making by heat shrinkable materials are studied by the impedance tube experiment. The experimental results show that the MPP making by heat shrinkable materials has good sound absorption properties. The tensile strength for the sample of the heat shrinkable forming MPP structure was tested. The stress-strain curves of the heat-shrinkable MPP shows that the stress and strain are proportional to each other. [ABSTRACT FROM AUTHOR]

The continuing emergence of drug-resistant Helicobacter pylori (HP) drives the ongoing need for the development of new and effective anti-HP drugs. Urease inhibitor has now gained strong interest as an alternative approach for HP infections. 3-Chlorophenyl-3-hydroxypropionylhydroxamic acid (CPH), a novel urease inhibitor identified in our group, shows impressive potency, which was optically separated for a further exploration. Here, we report in vitro / in vivo pharmacological evaluation of (±)-CPHs and the enantiomers. The raceme and the individual enantiomers significantly suppress gastritis at 32 mg/kg b.i.d dose with lower toxicity to mammalian cells (with CC 50 s ≥ 3.16 mM) and mice (LD 50 s ≥ 2338 mg/kg) than the clinically used agent acetohydroxamic acid. Furthermore, a significant increase of eradication of HP is observed for the combination of (±)-CPHs or the enantiomers with an antimicrobial. These studies revealed that CPH is a promising candidate for an alternative treatment of HP-dependent conditions by targeting virulence factor urease, and CPH may be used as a raceme. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus (S. aureus) is hard to be eradicated, not only due to the emergence of antibiotic resistant strains but also because of its ability to form biofilm. Antibiotics are the major approach to treating biofilm infections, but their effects are unsatisfactory. One of the potential alternative treatments for controlling biofilm infections is photodynamic therapy (PDT), which requires the administration of photosensitizer, followed by light activation. 5-aminolevulinic acid (ALA), a natural photosensitizer prodrug, presents favorable characteristics, such as easy penetration and rapid clearance. These advantages enable ALA-based PDT (ALA-PDT) to be well-tolerated by patients and it can be repeatedly applied without cumulative toxicity or serious side effects. ALA-PDT has been proven to be an effective treatment for multidrug resistant pathogens; however, the study of its effect on S. aureus biofilm is limited. Here, we established our PDT system based on the utilization of ALA and a light-emitting diode, and we tested the effect of ALA-PDT on S. aureus biofilm as well as the combined effect of ALA-PDT and antibiotics on S. aureus biofilm. Our results showed that ALA-PDT has a strong antibacterial effect on S. aureus biofilm, which was confirmed by the confocal laser scanning microscope. We also found that lethal photosensitization occurred predominantly in the upper layer of the biofilm, while the residual live bacteria were located in the lower layer of the biofilm. In addition, the improved bactericidal effect was observed in the combined treatment group but in a strain-dependent manner. Our results suggest that ALA-PDT is a potential alternative approach for future clinical use to treat S. aureus biofilm-associated infections, and some patients may benefit from the combined treatment of ALA-PDT and antibiotics, but drug sensitivity testing should be performed in advance. [ABSTRACT FROM AUTHOR]

Oxidative stress is generated in several peripheral nerve injury models.Nuclear factor erythroid 2-related factor 2 (Nrf2) is activated to have a role in antioxidant effect. After nerve injury, the severely painful behavior is also performed. However, little has been explored regarding the function of Nrf2 in this painful process. Therefore, in this study, we compared the effects of Nrf2 antibody administration following sciatic nerve-pinch injury on painful behavior induced in young mice and neurochemical changes in dorsal root ganglion neurons. After pinch nerve injury, we found that the magnitude of the thermal allodynia was significantly decreased after application of Nrf2 antibody (5ul, 1mg/ml) in such injured animals and phosphorylated ERK(p-ERK) as well as the apoptotic protein (i.e., Bcl-6) in DRG neurons were also down-regulated in the anti-Nrf2-treated injured groups compared to the saline-treated groups. Taken collectively, these data suggested that the Nrf2 antibody reduced thermal hyperalgesia via ERK pathway and the down regulation of Bcl-6 protein from the apoptosis pathway might be protecting against the protein deletions caused by anti-Nrf2 effect and suggested the new therapeutic strategy with Nrf2 inhibitor following nerve injury. [ABSTRACT FROM AUTHOR]

Low frequency noise has strong penetrability and has always been an important part of environmental pollution. Limited by the law of mass, traditional lightweight porous materials are difficult to effectively control low-frequency noise. Based on the characteristics of honeycomb structure, Helmholtz resonator and acoustic metamaterials, a kind of honeycomb like sandwich acoustic metamaterials is proposed. This structure combines the lightweight characteristics of honeycomb sandwich structure and Helmholtz resonance characteristics. The finite element models of honeycomb and Helmholtz resonators element are established. The transmission loss (TL) characteristic shows that Helmholtz resonators element will be a TL peak in a narrow frequency band than honeycomb element. The effects of neck diameter, neck length and cavity volume of Helmholtz resonator on its TL are analyzed. The TL of single and multiple Helmholtz resonators are compared. Furthermore, The TL of honeycomb panel and honeycomb like sandwich acoustic metamaterials are analyzed. The results show that the different TL peaks can be introduced into honeycomb like sandwich acoustic metamaterials with different neck diameters. Each Helmholtz resonators element plays an active role in its own frequency band. The sound insulation performance of the honeycomb like sandwich acoustic metamaterials is tested by impedance tube experiment. Excellent sound insulation ability is confirmed. The reasonable design of honeycomb like sandwich acoustic metamaterials structural parameters can solve the problem of low-frequency noise of thin-layer lightweight structure. [ABSTRACT FROM AUTHOR]

Herein we describe the synthesis and evaluation of a series of adenosine analogs for in vitro antibacterial activity against Staphylococcus aureus , Escherichia coli and Pseudomonas aeruginosa . Out of these compounds, compound c6 has much stronger antibacterial potency against Pseudomonas aeruginosa than ciprofloxacin, and was determined to target tyrosyl-tRNA synthetase with IC 50 of 0.8 ± 0.07 μM. Structure–activity relationship analysis suggested that introduction of a fluorine atom at the 3′-position of benzene ring of the phenylacetyl moiety significantly increased affinities to the enzyme. In comparison with isopropylidene analogs, 2′,3′-deprotected compounds displayed higher inhibitory activity. Molecular dockings provided an explanation for observations in biological assays. [ABSTRACT FROM AUTHOR]

Tyrosyl-tRNA synthetase (TyrRS), an essential enzyme in bacterial protein biosynthesis, is an attractive therapeutic target for finding novel antibacterial agents, and a series of N 2-(arylacetyl)glycinanilides has been herein synthesized and identified as TyrRS inhibitors. These efforts yielded several compounds, with IC 50 in the low micromolar range against TyrRS from Staphylococcus aureus . Out of the obtained compounds, 3ap is the most active and exhibits excellent activity against both Gram-positive ( S. aureus ) and Gram-negative ( Escherichia coli and Pseudomonas aeruginosa ) bacterial strains. In comparison with the parent scaffold 3-arylfuran-2(5 H )-one, N 2-(arylacetyl)glycinanilide significantly improved the potency against Gram-negative bacterial strains, indicating that this scaffold offers a significant potential for developing new antibacterial drugs. [ABSTRACT FROM AUTHOR]

3-Arylfuran-2(5 H )-one derivatives show good antibacterial activity and were determined as tyrosyl-tRNA synthetase (TyrRS) inhibitors. In a systematic medicinal chemistry exploration, we demonstrated chemical opportunities to treat infections caused by Helicobacter pylori . Twenty 3-arylfuran-2(5 H )-ones were synthesized and evaluated for anti- H. pylori , antioxidant and anti-urease activities which are closely interconnected with H. pylori infection. The results displayed that some of the compounds show excellent antioxidant activity, and good anti- H. pylori and urease inhibitory activities. Out of these compounds, 3-(3-methylphenyl)furan-2(5 H )-one ( b9 ) showed the most potent antioxidant activity (IC 50 = 8.2 μM) and good anti- H. pylori activity (MIC 50 = 2.6 μg/mL), and it can be used as a good candidate for discovering novel anti-gastric ulcer agent. [ABSTRACT FROM AUTHOR]

Our previous work has shown that somatostatin effectively inhibits neuropathic pain by activating its type 2 receptor (SSTR2) in the dorsal root ganglion (DRG) and spinal cord of mice. However, the underlying mechanism of this activation has not been elucidated. To explore further mechanisms, we examined pain behavior and the expression of neuropeptides such as calcitonin gene-related peptide (CGRP) in dorsal root ganglion neurons(DRGs) as well as the changes of the number of CGRP-IR DRGs in the mouse model of sciatic pinch nerve injury. In this model, the number of medium and small DRG neurons in ipsilateral CGRP-IR was slightly increased, but not significantly, compared with sham animals at 3, 7, and 9 days after pinch nerve injury. This correlated with the behavioral readouts of hypersensitivity at the same time points. However, the magnitude of the painful behavior (Autotomy) was observed after application of SSTR2 antagonist (CYN154806, 5 mg/kg) in the injured nerve groups compared to the saline-treated injured group as well as the sham-operated group. Following pinch nerve injury, there was a significant decrease in the number of ipsilateral CGRP-IR small and medium DRG neurons in SSTR2 antagonist (anti-SSTR2)- but not saline-treated mice. These data also correlated with painful behavioral readouts where hypersensitivity was significantly increased by anti-SSTR2 but not saline treatment. In all, application of the SSTR2 antagonist to the pinched sciatic nerve suppressed CGRP expression and aggravated painful behavior, suggesting that CGRP expression in DRG neurons can be an important component of the pain mechanism and an indicator of pain behavior. • A reduction of the number in ipsilateral CGRP-IR DRGs in the SSTR2 antagonist group. • Application of the SSTR2 antagonist to the pinched sciatic nerve suppressed CGRP expression. • The status of Pinch-induced pain could be maintain and advanced after SSTR2 antagonist application. • CGRP expression in DRG neurons can be an important component of the pain mechanism. [ABSTRACT FROM AUTHOR]

The periodic arrangement expansion chambers structure with built-in micro-perforated panel (MPP) is proposed. The transmission loss (TL) of expansion chambers before and after the introduction of MPP is analyzed by transfer matrix method and finite element method. In the low frequency range, the TL curves obtained by the transfer matrix method and finite element method are consistent. Both show that the first pass frequency of the structure disappears and the sound insulation bandwidth of the structure widens obviously after the introduction of MPP. The influences of the parameters of the periodic expansion chambers structure on the TL are numerically analyzed. By making hole on the inserted MPP, ventilation cooling function is realized. The result shows that the overall sound insulation effect is still satisfying after making appropriate hole. Additionally, expansion chambers and double MPP with hole insertion structure has been constructed. The result shows that the second pass frequency of expansion chambers structure also disappears. Therefore, the sound insulation performance of the expansion chambers structure is further improved by adding double-layer MPP. The sound insulation performance of the periodic expansion chambers structure with ventilation capability is tested by laboratory experiments. Excellent sound insulation ability is confirmed. [ABSTRACT FROM AUTHOR]

Microperforated panel (MPP) absorbers have been widely used in noise reduction and are regarded as a promising alternative to the traditional porous materials. However, the flat panel-like shape restricts their practical use in actual rooms or buildings. To overcome these limitations, three-dimensional MPP spatial sound absorbers have been proposed. MPP are mostly metal materials with high cost. It is relatively easy to make cylinders or cubes, and difficult to make other complex structures. In view of this, a kind of non-woven material which can replace micro-perforated board is proposed in this paper. This kind of non-woven material has the characteristics of low cost, flexibility, convenient moulding and good sound absorption performance. The impedance tube experiments has been employed to study the normal incidence sound absorption coefficient for the non-woven fabric materials. The experimental results show that the sound absorption properties of non-woven fabrics are similar to those of ultra-micro MPP. Three kinds of spatial sound absorbers have been made by non-woven materials. They are the hollow cylindrical, fan-shaped, and honeycomb-like spatial sound absorbers, respectively. The measurement of reverberation chamber results show that the sound absorption capacity of the honeycomb-like spatial sound absorber is better than the hollow cylindrical and fan-shaped spatial sound absorbers. Adding non-woven cylindrical boundary layer can further improve the sound absorption performance of the fan-shaped and honeycomb-like space absorber. [ABSTRACT FROM AUTHOR]