The Function of Sialidase Revealed by Sialidase Activity Imaging Probe

Sialidase cleaves sialic acid residues from glycans such as glycoproteins and glycolipids. In the brain, desorption of the sialic acid by sialidase is essential for synaptic plasticity, learning and memory and synaptic transmission. BTP3-Neu5Ac has been developed for sensitive imaging of sialidase enzyme activity in mammalian tissues. Sialidase activity in the rat hippocampus detected with BTP3-Neu5Ac increases rapidly by neuronal depolarization. It is presumed that an increased sialidase activity in conjunction with neural excitation is involved in the formation of the neural circuit for memory. Since sialidase inhibits the exocytosis of the excitatory neurotransmitter glutamate, the increased sialidase activity by neural excitation might play a role in the negative feedback mechanism against the glutamate release. Mammalian tissues other than the brain have also been stained with BTP3-Neu5Ac. On the basis of information on the sialidase activity imaging in the pancreas, it was found that sialidase inhibitor can be used as an anti-diabetic drug that can avoid hypoglycemia, a serious side effect of insulin secretagogues. In this review, we discuss the role of sialidase in the brain as well as in the pancreas and skin, as revealed by using a sialidase activity imaging probe. We also present the detection of influenza virus with BTP3-Neu5Ac and modification of BTP3-Neu5Ac.     

Molecular Targeted Therapy for the Bone Loss Secondary to Pyogenic Spondylodiscitis Using Medications for Osteoporosis: A Literature Review

Pyogenic spondylodiscitis can cause severe osteolytic and destructive lesions in the spine. Elderly or immunocompromised individuals are particularly susceptible to infectious diseases; specifically, infections in the spine can impair the ability of the spine to support the trunk, causing patients to be bedridden, which can also severely affect the physical condition of patients. Although treatments for osteoporosis have been well studied, treatments for bone loss secondary to infection remain to be elucidated because they have pathological manifestations that are similar to but distinct from those of osteoporosis. Recently, we encountered a patient with severely osteolytic pyogenic spondylodiscitis who was treated with romosozumab and exhibited enhanced bone formation. Romosozumab stimulated canonical Wnt/β-catenin signaling, causing robust bone formation and the inhibition of bone resorption, which exceeded the bone loss secondary to infection. Bone loss due to infections involves the suppression of osteoblastogenesis by osteoblast apoptosis, which is induced by the nuclear factor-κB and mitogen-activated protein kinase pathways, and osteoclastogenesis with the receptor activator of the nuclear factor-κB ligand-receptor combination and subsequent activation of the nuclear factor of activated T cells cytoplasmic 1 and c-Fos. In this study, we review and discuss the molecular mechanisms of bone loss secondary to infection and analyze the efficacy of the medications for osteoporosis, focusing on romosozumab, teriparatide, denosumab, and bisphosphonates, in treating this pathological condition.     

Radiophotoluminescence phenomenon in copper-doped aluminoborosilicate glass

Radiophotoluminescence phenomena have been widely investigated on various types of materials for dosimetry applications. We report that an aluminoborosilicate glass containing 0.005 mol% copper exhibits intense photoluminescence in the visible region induced by X-ray and γ-ray irradiation. The luminescence is assigned to the 3d⁹4s¹ → 3d¹⁰ transition of Cu⁺. The proportionality of the intensity of the induced photoluminescence to the irradiation dose was confirmed up to 0.5 kGy using ⁶⁰Co γ-ray irradiation. Based on the spectroscopic results, a potential mechanism was proposed for the enhancement of the photoluminescence. The exposure to the ionizing radiation generates electron-hole pairs in the glass, and the electrons are subsequently captured by the Cu²⁺ ions, which are converted to Cu⁺ and emit the luminescence. For the glass containing 0.01 mol% copper, the pronounced enhancement of the photoluminescence was not observed because the reverse reaction, ie, the capture of the holes by the Cu⁺ ions, becomes prominent. The photoluminescence induced by the irradiation was stably observed for the glasses kept at room temperature and even for the glasses heat-treated at 150°C. However, the induced photoluminescence could be eliminated by the heat treatment at a temperature at 500°C, and the glass returned to the initial pre-irradiation state. The Cu-doped aluminoborosilicate glass is a potential candidate for use in dosimetry applications.     

Supramolecular Zn(II)-Dipicolylamine-Azobenzene-Aminocyclodextrin-ATP Complex: Design and ATP Recognition in Water

Cyclodextrins (CyDs) are water-soluble host molecules possessing a nanosized hydrophobic cavity. In the realm of molecular recognition, this cavity is used not only as a recognition site but also as a reaction medium, where a hydrophobic sensor recognizes a guest molecule. Based on the latter concept, we have designed a novel supramolecular sensing system composed of Zn(II)-dipicolylamine metal complex-based azobenzene (1-Zn) and 3A-amino-3A-deoxy-(2AS,3AS)-γ-cyclodextrin (3-NH₂-γ-CyD) for sensing adenosine-5′-triphosphate (ATP). 1-Zn showed redshifts in the UV-Vis spectra and induced circular dichroism (ICD) only when both ATP and 3-NH₂-γ-CyD were present. Calculations of equilibrium constants indicated that the amino group of 3-NH₂-γ-CyD was involved in the formation of supramolecular 1-Zn/3-NH₂-γ-CyD/ATP. The Job plot of the ICD spectral response revealed that the stoichiometry of 1-Zn/3-NH₂-γ-CyD/ATP was 2:1:1. The pH effect was examined and 1-Zn/3-NH₂-γ-CyD/ATP was most stable in the neutral condition. The NOESY spectrum suggested the localization of 1-Zn in the 3-NH₂-γ-CyD cavity. Based on the obtained results, the metal coordination interaction of 1-Zn and the electrostatic interaction of 3-NH₂-γ-CyD were found to take place for ATP recognition. The “reaction medium approach” enabled us to develop a supramolecular sensing system that undergoes multi-point interactions in water. This study is the first step in the design of a selective sensing system based on a good understanding of supramolecular structures.     

Understanding trust in ms-commerce: The roles of reported experience,linguistic style,profile photo,emotional, and cognitive trust

This paper examines what influences trust in mobile social commerce environment. Drawing on trust-based acceptance model (i.e. cognitive and emotional trust) and online review features (i.e. profile photo, linguistic style, and reported experience), we examine how these factors affect trust in mobile social commerce. Hypotheses were tested using survey data. The results of our model showed that there are significant influences of profile photo, reported experience, cognitive, and emotional trust towards trust in ms-commerce. This work contributes to existing literature by examining the roles of previous trust in mobile payments and online reviews on trust in mobile social commerce.     

Oxidation of Hastelloy-XR Alloy for Corrosion-Resistant Glass-Coating

The oxidation behavior of Hastelloy-XR alloy was investigated to obtain the optimum surface condition for corrosion-resistant glass-coatings. The surface morphology of oxide scales changed significantly with variation of temperatureand oxygen partial pressure (po2 ). The oxidation kinetics was mainly parabolic independent of oxidation conditions.The oxide scales were consisted of inner Cr2O3 and outer spinel layers. The phase component of spinel layers wereMn1.5Cr1.5O4 and (Mn,Ni)(Cr,Fe)2O4 for the oxygen partial pressures po2<10 kPa and po2>10 kPa, respectively.The optimum oxidation condition to obtain an oxide scale for well-adhered glass-coating to the substrate was 1248 Kand po2 =0.01 kPa for the oxidation time of 43 ks.     

A dual-mode bandpass filter with enhanced capacitive perturbation

A dual-mode ring bandpass filter with two pairs of capacitors has been designed. The capacitors are used to control the location of the even- and odd-mode frequencies independently, allowing weak coupling for narrow-band filter design with realizable capacitance values. Theoretical expressions have been derived for these frequencies. A 4% bandwidth bandpass filter centered at 1.9 GHz was designed and tested with good agreement between theoretical and measured results.     

Fracture toughness of short carbon fibre reinforced thermoplastic polyimide

The fracture toughness testing of short fibre reinforced thermoplastic materials were performed. Materials tested were the polyimide resin and also that reinforced with 20 wt% or 30 wt% short carbon fibre. For introducing the initial crack, the tapping method, the sliding method and the bridge indentation method were examined. Among them, the sliding method was found to be effective for every case. The fracture tests were conducted by the three-point bending test with several loading rates. Stable crack growth was observed for the neat material while unstable fracture occurred for the reinforced materials. The critical values of the stress intensity factor at crack initiation were greater for the reinforced materials than for the neat resin. The fracture toughness of the 30 wt% reinforced material was independent of loading rate while that of 20 wt% reinforced material increased with loading rate. In order to investigate the fracture mechanisms, fractographic observations were also performed.     

Longitudinal weight changes, length of survival, and energy requirements of long-term care residents with dementia

OBJECTIVE: We hypothesized that institutionalized patients with dementia, who frequently have feeding problems and require supervised and assisted feeding, would lose more weight during their residency than nondemented, independently functioning residents and have compromised survival. To test this hypothesis, we examined the survival and longitudinal changes in weight of two cohorts of institutionalized residents with dementia and compared these cohorts with a cohort of nondemented residents. We also measured the resting energy expenditures of a subset of the subjects with dementia as an indicator of their energy needs. DESIGN: A longitudinal cohort study with retrospective baseline chart review and subsequent follow-up of monthly weights and mortality over 4 years. SETTING: A 725-bed long-term care institution with specified levels of care. SUBJECTS: Two cohorts of residents with dementia, one consisting of subjects who required total care throughout their institutional stay (n = 31) and another group who did not initially require total care (n = 48); these were compared with a cohort with normal mentation who were functionally independent in their daily activities (n = 26). The total number of subjects was 105. MEASUREMENTS: Demographics, medical problems, and medications by chart review; functional and mental status evaluations; longitudinal monthly weights and mortality for the 48-month study period; and resting energy expenditures by indirect calorimetry. MAIN RESULTS: Residents with dementia had lower weights on admission and throughout their stay than nondemented, independently functioning residents, and they were more likely to have a weight loss of 10 lbs or more at some point during the 4-year study period. However, their mean weights did not change during the study period. The mean survival from admission of those demented residents who died was more than 3 years. Resting energy expenditures of women residents with advanced dementia were 12% lower than predicted from the Harris Benedict equations. CONCLUSION: Dementia is not necessarily associated with unremitting weight loss during institutionalization despite the frequent occurrence of feeding difficulties and temporary weight loss. This may be caused partly by the lower than expected resting energy expenditures and, hence, energy needs of affected residents as their dementia progresses. Demented residents weighed significantly less than nondemented, independently functioning residents throughout their institutional stay. Nevertheless, nursing staff are able to maintain weight and survival for extended periods even in very impaired residents.