Impact of the aqueous corrosion induced alteration layer on mechanical properties of pharmaceutical glasses.

It is known that network modifying ions (such as alkali or alkaline earth ions) make glasses susceptible to aqueous corrosion, resulting in the alteration of their surface layers. However, the effect of the altered layers on the mechanical properties of glasses has not been well understood. In this work we study this effect using the pharmaceutical boroaluminosilicate (BAS) glasses as objects by performing nano- and macroscale mechanical tests. The results show that extending the corrosion time increases the thickness of the alteration layer of the BAS glass. The water-related species in the alteration layer lowers the nanohardness, the reduced modulus, the nanowear resistance and Vickers hardness. The corrosion-induced “silica-like” structure in alteration layer benefits the densification of the subsurface caused by nanoindentation and nanowear, and thereby enhances the fracture toughness of the BAS glass. The correlation between the water content in the alteration layer and the mechanical properties has been revealed. This work is instrumental in the design of the next generation of pharmaceutical glasses with higher toughness

Elementary operations for quantum logic with a single trapped two-level cold ion beyond Lamb-Dicke limit

A simple alternative scheme for implementing quantum gates with a single trapped cold two-level ion beyond the Lamb-Dicke (LD) limit is proposed. Basing on the quantum dynamics for the laser-ion interaction described by a generalized Jaynes-Cummings model, one can introduce two kinds of elementary quantum operations i.e., the simple rotation on the bare atomic state, generated by applying a resonant pulse, and the joint operation on the internal and external degrees of the ion, performed by using an off-resonant pulse. Several typical quantum gates, including Hadamard gate, controlled-Z and controlled-NOT gates $etc.$, can thus be implemented exactly by using these elementary operations. The experimental parameters including the LD parameter and the durations of the applied laser pulses, for these implementation are derived analytically and numerically. Neither the LD approximation for the laser-ion interaction nor the auxiliary atomic level is needed in the present scheme.Comment: 5 pages, no figure, to appear in Opt. Com

Expression of anion exchanger 2 in human gastric cancer

Anion exchanger 2 (AE2), which mediates exchange of Cl-/HCO3- across the plasma membrane, is widely expressed in body tissues. It is most abundantly expressed in stomach and is responsible for the uptake of Cl- ions that are destined to become HCl molecules. Aim: To determine whether AE2 expression was altered in gastric tumors. Methods: We have studied AE2 expression in normal human gastric tissues (n =16) and in gastric tumors (n = 33) using immunohistochemistry and immunofluorescent labeling. Results: In normal gastric tissue positive staining was observed in gastric fundus gland, suggesting parietal cell-related expression of AE2, and AE2 expression was localized in the nuclear membrane and even in cell nuclei. For assay of cancerous gastric tissues, specimens of human gastric cancer arising from the region of the fundus (2 cases), the body (14 cases) and the antrum (17 cases) were randomly selected. Immunohistochemical staining has showed that AE2 was down-regulated in all 14 cancerous gastric body specimens, whereas staining for AE2 in cancerous antrum was less intense and had a diffuse profile. Conclusions: The data suggest that AE2 might be associated with gastric carcinogenesis and the achlorhydria experienced by gastric cancer patients.Анионный обменник 2 (АЕ2), который опосредует перенос Cl- /HCO3 - через плазматическую мембрану, экспрессируется клетками разных тканей. Самый высокий уровень экспрессии АЕ2 в желудке, поскольку этот белок отвечает за поглощение ионов Cl- , которые впоследствии используются для секреции HCl. Цель: Изучить изменения в экспрессии АЕ2 при раке желудка. Методы: исследована экспрессия АЕ2 в нормальных тканях (n = 16) и опухолях желудка (n = 33) с применением методов иммуногистохимии и иммунофлуоресценции. Результаты: в нетрансформированной ткани желудка в фундальной железе выявляли сильную положительную реакцию, что свидетельствует об экспрессии АЕ2 париетальными клетками, причем экспрессия АЕ2 была локализирована в ядерной мембране и в ядре. В опухолях желудка (фундального отдела (n = 2), тела (n = 14) и антрального отдела (n = 17)), отобранных случайным образом, был проведен анализ экспрессии АЕ2. Иммуногистохимическое исследование показало снижение экспрессии АЕ2 во всех 14 случаях рака тела желудка. Окрашивание АЕ2 в образцах рака антрального отдела желудка было менее интенсивным и диффузным. Выводы: полученные данные позволяют предположить наличие связи между экспрессией АЕ2 и развитием рака желудка, а также ахлоргидрией, отмечаемой у больных раком желудка

Frictional drag between non-equilibrium charged gases

The frictional drag force between separated but coupled two-dimensional electron gases of different temperatures is studied using the non-equilibrium Green function method based on the separation of center-of-mass and relative dynamics of electrons. As the mechanisms of producing the frictional force we include the direct Coulomb interaction, the interaction mediated via virtual and real TA and LA phonons, optic phonons, plasmons, and TA and LA phonon-electron collective modes. We found that, when the distance between the two electron gases is large, and at intermediate temperature where plasmons and collective modes play the most important role in the frictional drag, the possibility of having a temperature difference between two subsystems modifies greatly the transresistivity.Comment: 8figure

Combining nano-silicon with oxide glass in anodes for Li-ion batteries

Vanadium-tellurite glasses (VT) have emerged as promising anode materials for lithium-ion batteries (LIBs). Despite this, the Li-ion storage capacity of the VT glass anode is still insufficient to meet the demands for the next generation of advanced LIBs. Silicon (Si) anode has ultrahigh theoretical capacity but suffers from significant volume expansion during lithiation and delithiation. In this work, we combined Si nanoparticles with VT glass to prepare Si@VT composite anode for LIBs. The composite was produced through heat-treatment at different temperatures, some of which were hot-pressed under the isostatic pressure of 100 MPa. The Si@VT composite exhibited a synergistic effect that integrated the strengths of both VT glass and Si, resulting in a substantial enhancement of its electrochemical performance. The systematic characterizations of the composite-based anodes revealed the optimal conditions for fabricating the high-performance Si@VT composite: a silicon fraction of 10 wt% and a hot-pressing temperature of 620 K. This composite stood out as the optimal choice, exhibiting a capacity of 353 mA h g−1 at 1 A g−1 after 1000 cycles. This capacity surpasses that of VT glass anode by over threefold and that of pure Si anode by twelvefold.</p

Polyamine plays key role in different osmotic stress responses of wheat-rye 1BL/1RS translocation lines

It is well demonstrated that wheat-rye 1BL/1RS translocated chromosome leads to some valuable novel traits such as disease resistance, high yield and functional stay-green after anthesis. To understand the physiological mechanism of 1BL/1RS translocation responsible for osmotic stress, two wheat cultivars, CN12 and CN17, carrying the translocated chromosome and MY11 without the translocated chromosome were employed in the study. During 5-day osmotic stress, fresh weight inhibition, chlorophyll content, soluble protein content, MDA concentration, antioxidant enzymes activity and free polyamines content were examined. CN12 and CN17, especially cultivar CN17, registered greater biomass and minor oxidative damage compared with their wheat parent. Meanwhile, the concentration of Spd and Spm in CN17 was significantly higher than the others. In addition, we found a positive correlation of fresh weight inhibition (FWI) and Put concentration, and a negative one with the parameters (Spd + Spm): Put ratio, indicating the importance of higher polyamine (Spd and Spm) accumulation on the adaptation to osmotic stress. Therefore, we proposed that the accumulation of higher polyamines (Spd and Spm) should play an important role on the adaptation of 1BL/1RS translocation lines to osmotic stress and might be important factors for the origin of novel traits introduced by 1BL/1RS

Tracking echovirus eleven outbreaks in Guangdong, China

In April 2019, a suspect cluster of enterovirus cases was reported in a neonatology department in Guangdong, China, resulting in five deaths. We aimed to investigate the pathogen profiles in fatal cases, the circulation and transmission pattern of the viruses by combining metatranscriptomic, phylogenetic, and epidemiological analyses. Metatranscriptomic sequencing was used to characterize the enteroviruses. Clinical and environmental surveillance in the local population was performed to understand the prevalence and genetic diversity of the viruses in the local population. The possible source(s), evolution, transmission, and recombination of the viruses were investigated by incorporating genomes from the current outbreak, from local retrospective surveillance, and from public databases. Metatranscriptomic analysis identified Echovirus 11 (E11) in three fatal cases. Seroprevalence of neutralization antibody to E11 was 35 to 44 per cent in 3–15 age groups of general population, and the viruses were associated with various clinical symptoms. From the viral phylogeny, nosocomial transmissions were identified and all E11 2019 outbreak strains were closely related with E11 strains circulating in local population 2017–19. Frequent recombination occurred among the 2019 Guangdong E11 outbreak strains and various genotypes in enterovirus B species. This study provides an example of combining advanced genetic technology and epidemiological surveillance in pathogen diagnosis, source(s), and transmission tracing during an infectious disease outbreak. The result highlights the hidden E11 circulation and the risk of viral transmission and infection in the young age population in China. Frequent recombination between Guangdong-like strains and other enterovirus genotypes also implies the prevalence of these emerging E11 strains

Direct Measurements of the Branching Fractions for D0→K−e+νeD^0 \to K^-e^+\nu_e and D0→π−e+νeD^0 \to \pi^-e^+\nu_e and Determinations of the Form Factors f+K(0)f_{+}^{K}(0) and f+π(0)f^{\pi}_{+}(0)

The absolute branching fractions for the decays $D^0 \to K^-e ^+\nu_e$ and $D^0 \to \pi^-e^+\nu_e$ are determined using $7584\pm 198 \pm 341$ singly tagged $\bar D^0$ sample from the data collected around 3.773 GeV with the BES-II detector at the BEPC. In the system recoiling against the singly tagged $\bar D^0$ meson, $104.0\pm 10.9$ events for $D^0 \to K^-e ^+\nu_e$ and $9.0 \pm 3.6$ events for $D^0 \to \pi^-e^+\nu_e$ decays are observed. Those yield the absolute branching fractions to be $BF(D^0 \to K^-e^+\nu_e)=(3.82 \pm 0.40\pm 0.27)$ and $BF(D^0 \to \pi^-e^+\nu_e)=(0.33 \pm 0.13\pm 0.03)$. The vector form factors are determined to be $|f^K_+(0)| = 0.78 \pm 0.04 \pm 0.03$ and $|f^{\pi}_+(0)| = 0.73 \pm 0.14 \pm 0.06$. The ratio of the two form factors is measured to be $|f^{\pi}_+(0)/f^K_+(0)|= 0.93 \pm 0.19 \pm 0.07$.Comment: 6 pages, 5 figure