202 research outputs found
Influence of Stress on Electronic and Optical Properties of Rocksalt and Wurtzite MgO–ZnO Nanocomposites with Varying Concentrations of Magnesium and Zinc
The financial support of M-ERA.NET project “ZnMgO materials with tunable band gap for solar-blind UV sensors” (ZMOMUVS) is greatly acknowledged. The Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union’s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement no. 739508, project CAMART2. The calculations were performed at the Latvian SuperCluster (LASC) located at the Institute of Solid State Physics, University of Latvia.The structural, electronic and optical properties of stressed MgO–ZnO nanocomposite alloys with concentrations of Zn and Mg varying from 0.125 to 0.875 were studied using ab initio simulations. Two crystal structures are considered for the initial MgO–ZnO alloys: the rocksalt Mg (Formula presented.) Zn (Formula presented.) O and wurtzite Zn (Formula presented.) Mg (Formula presented.) O phases. For rocksalt Mg (Formula presented.) Zn (Formula presented.) O, the optimized structures are stable at pressures below 10 GPa. The larger the Mg concentration and pressure, the wider the (Formula presented.) of the rocksalt phase. In contrast, the optimal geometries of wurtzite Zn (Formula presented.) Mg (Formula presented.) O reveal a diversity of possibilities, including rocksalt, wurtzite and mixed phases. These effects lead to the fact that the optical properties of wurtzite Zn (Formula presented.) Mg (Formula presented.) O not only demonstrate the properties of the wurtzite phase but also indicate the optical features of the rocksalt phase. In addition, mixed phases of Zn (Formula presented.) Mg (Formula presented.) O simultaneously provide the characteristics of both wurtzite and rocksalt phases with the same structures in different dielectric matrices. © 2022 by the authors. --//-- This is an open access publication Lin Y.-P., Piskunov S., Trinkler L., Chou M.M.-C., Chang L. "Influence of Stress on Electronic and Optical Properties of Rocksalt and Wurtzite MgO–ZnO Nanocomposites with Varying Concentrations of Magnesium and Zinc" (2022) Nanomaterials, 12 (19), art. no. 3408, DOI: 10.3390/nano12193408 published under the CC BY 4.0 licence.M-ERA.NET project “ZnMgO materials with tunable band gap for solar-blind UV sensors” (ZMOMUVS); the Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement no. 739508, project CAMART2
Electronic and Optical Properties of Rocksalt Mg1−xZnxO and Wurtzite Zn1−xMgxO with Varied Concentrations of Magnesium and Zinc
The financial support of M-ERA.NET project “ZnMgO materials with tunable band gap for solar-blind UV sensors” (ZMOMUVS) is acknowledged. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2. The calculations were performed at the Latvian SuperCluster (LASC) located in Institute of Solid State Physics, University of Latvia.The structural, electronic and optical properties of rocksalt Mg (Formula presented.) Zn (Formula presented.) O and wurtzite Zn (Formula presented.) Mg (Formula presented.) O with the concentration of Zn and Mg varying from 0.125 to 0.875 were investigated using density functional theory (DFT), DFT+U, linear response theory and the Bethe–Salpeter equation. According to the experimental band gap for varied concentrations of magnesium and zinc, modeling the supercell was utilized for the varied concentrations of Mg/Zn/O compounds in order to not only avoid constructing the complicated interface systems that are observed in the experiments but also take into account the excitonic effects that usually require huge computational resources. From the calculated density of states, the Zn states are highly related to the edge of the conduction band minimum and responsible for the width of bandgap. In addition, the contribution of Zn–d states is below expectations as they are located away from the VBM. As for the optical response, an increase in Zn concentration would cause a red-shifted spectrum, on the whole. In contrast, the higher concentration of Mg also triggers the blue-shift of the optical spectrum. In addition, anisotropic properties could be found in the spectrum with consideration of the excitonic effects, whereas there is no apparent difference in optical response based on linear response theory. In addition, the optical features of this work reflect the characteristic peaks of the literature around the absorption onset. © 2022 by the authors.--//-- This is an open access article in Y.-P., Piskunov S., Trinkler L., Ming-Chi Chou M., Chang L. "Electronic and Optical Properties of Rocksalt Mg1−xZnxO and Wurtzite Zn1−xMgxO with Varied Concentrations of Magnesium and Zinc" (2022) Materials, 15 (21), art. no. 7689, DOI: 10.3390/ma15217689 published under the CC BY 4.0 licence.M-ERA.NET project ZMOMUVS; Institute of Solid-State Physics, University of Latvia has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-Teaming Phase 2 under grant agreement No. 739508, project CAMART2
Chlorine Adsorption on TiO2(110)/Water Interface: Nonadiabatic Molecular Dynamics Simulations for Photocatalytic Water Splitting
This study was financially supported M-ERA.NET project CatWatSplit. Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union’s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2. The calculations were performed at the Latvian SuperCluster (LASC) located in Institute of Solid State Physics, University of Latvia.Chloride is one of the most abundant ions in sea water, which is more available than fresh water. Due to lack of H2O adsorbate states near the valence band maximum (VBM) edge, the difficulty of water dissociation incidents has been reported on the rutile TiO2 surface as the excitation energy is around the band gap energy of TiO2. It is interesting whether the extra chloride can be a benefit to the water dissociation or not. In this study, the models of chlorine adatoms placed on the rutile TiO2 (110)/water interface are constructed using ab initio methods. The time-dependent spatial charges, bond-lengths of water molecules, and Hirshfeld charges are calculated by real-time time-dependent density functional theory and the Ehrenfest dynamics theory for investigating the excited state nonadiabatic dynamics of water dissociation. This study presents two photoinduced water-splitting pathways related to chlorine and analyzes the photogenerated hole along the reactions. The first step of water dissociation relies on the localized competition of oxygen charges between the dissociated water and the bridge site of TiO2 for transforming the water into hydroxyl and hydrogen by photoinduced driving force. --//-- This is an open access article Y.-P. Lin, D. Bocharov, I. Isakoviča, V. Pankratov, A.A. Popov, A.I. Popov, S. Piskunov; Chlorine adsorption on TiO2(110)/water interface: Nonadiabatic molecular dynamics simulations for potocatalytic water splitting; Electron. Mater., 2023, 4, pp. 33-48; DOI: 10.3390/electronicmat4010004; https://www.mdpi.com/2673-3978/4/1/4 published under the CC BY 4.0 licence.M-ERA.NET project CatWatSplit; Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union’s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2
Differentiating impacts of non‐pharmaceutical interventions on non‐coronavirus disease‐2019 respiratory viral infections: Hospital‐based retrospective observational study in Taiwan
Background
Physical distancing and facemask use are worldwide recognized as effective non-pharmaceutical interventions (NPIs) against the coronavirus disease-2019 (COVID-19). Since January 2020, Taiwan has introduced both NPIs but their effectiveness on non-COVID-19 respiratory viruses (NCRVs) remain underexplored.
Methods
This retrospective observational study examined electronic records at a tertiary hospital in northern Taiwan from pre-COVID (January–December 2019) to post-COVID period (January–May 2020). Patients with respiratory syndromes were tested for both enveloped (eg, influenza virus and seasonal coronavirus) and non-enveloped RVs (eg, enterovirus and rhinovirus) using multiplex reverse transcription polymerase chain reaction assays. Monthly positivity rates of NCRVs among adult and pediatric patients were analyzed with comparison between pre- and post-COVID periods.
Results
A total of 9693 patients underwent 12 127 multiplex RT-PCR tests. The average positivity rate of NCRVs reduced by 11.2% (25.6% to 14.4%) after nationwide PHIs. Despite the COVID-19 pandemic, the most commonly identified enveloped and non-enveloped viruses were influenza virus and enterovirus/rhinovirus, respectively. Observed reduction in NCRV incidence was predominantly contributed by enveloped NCRVs including influenza viruses. We did not observe epidemiological impacts of NPIs on non-enveloped viruses but an increasing trend in enterovirus/rhinovirus test positivity rate among pediatric patients. Our data were validated using Taiwan's national notification database.
Conclusions
Our frontline investigation suggests that the current NPIs in Taiwan might not effectively control the transmission of non-enveloped respiratory viruses, despite their protective effects against influenza and seasonal coronavirus. Health authorities may consider using hydrogen peroxide or chloride-based disinfectants as additional preventative strategies against non-enveloped respiratory viruses in the post-COVID-19 era
The Role of Age in Predicting the Outcome of Caustic Ingestion in Adults: A Retrospective Analysis
<p>Abstract</p> <p>Background</p> <p>Although the outcomes of caustic ingestion differ between children and adults, it is unclear whether such outcomes differ among adults as a function of their age. This retrospective study was performed to ascertain whether the clinical outcomes of caustic ingestion differ significantly between elderly and non-elderly adults.</p> <p>Methods</p> <p>Medical records of patients hospitalized for caustic ingestion between June 1999 and July 2009 were reviewed retrospectively. Three hundred eighty nine patients between the ages of 17 and 107 years were divided into two groups: non-elderly (< 65 years) and elderly (≥ 65 years). Mucosal damage was graded using esophagogastroduodenoscopy (EGD). Parameters examined in this study included gender, intent of ingestion, substance ingested, systemic and gastrointestinal complications, psychological and systemic comorbidities, severity of mucosal injury, and time to expiration.</p> <p>Results</p> <p>The incidence of psychological comorbidities was higher for the non-elderly group. By contrast, the incidence of systemic comorbidities, the grade of severity of mucosal damage, and the incidence of systemic complications were higher for the elderly group. The percentages of ICU admissions and deaths in the ICU were higher and the cumulative survival rate was lower for the elderly group. Elderly subjects, those with systemic complications had the greatest mortality risk due to caustic ingestion.</p> <p>Conclusions</p> <p>Caustic ingestion by subjects ≥65 years of age is associated with poorer clinical outcomes as compared to subjects < 65 years of age; elderly subjects with systemic complications have the poorest clinical outcomes. The severity of gastrointestinal tract injury appears to have no impact on the survival of elderly subjects.</p
Dielectrophoretically-assisted electroporation using light-activated virtual microelectrodes for multiple DNA transfection
The Time-resolved Atomic, Molecular and Optical Science Instrument at the Linac Coherent Light Source
The newly constructed Time-resolved atomic, Molecular and Optical science
instrument (TMO), is configured to take full advantage of both linear
accelerators at SLAC National Accelerator Laboratory, the copper accelerator
operating at a repetition rate of 120 Hz providing high per pulse energy, as
well as the superconducting accelerator operating at a repetition rate of about
1 MHz providing high average intensity. Both accelerators build a soft X-ray
free electron laser with the new variable gab undulator section. With this
flexible light sources, TMO supports many experimental techniques not
previously available at LCLS and will have two X-ray beam focus spots in line.
Thereby, TMO supports Atomic, Molecular and Optical (AMO), strong-field and
nonlinear science and will host a designated new dynamic reaction microscope
with a sub-micron X-ray focus spot. The flexible instrument design is optimized
for studying ultrafast electronic and molecular phenomena and can take full
advantage of the sub-femtosecond soft X-ray pulse generation program
Changes of T-lymphocyte subpopulation and differential expression pattern of the T-bet and GATA-3 genes in diffuse large B-cell lymphoma patients after chemotherapy
BACKGROUND AND OBJECTIVE: T cell-mediated immunity plays an important role in enhancing antitumor response.This study aimed to investigate the changes in the T-lymphocyte subpopulation and to characterize the differential expression pattern of corresponding regulatory genes in peripheral blood mononuclear cells (PBMCs) from diffuse large B cell lymphoma (DLBCL) patients before and after chemotherapy. METHODS: A total of 56 DLBCL patients were recruited for analysis of T-cell subset distribution in the peripheral blood using flow cytometry; serum interferon (IFN)-γ and interleukin (IL)-4 levels using enzyme-linked immunosorbent assays; and early growth response protein 1 (EGR-1), T-bet, GATA-binding protein 3 (GATA-3), and transforming growth factor (TGF)-β mRNA levels using quantitative reverse-transcription polymerase chain reaction. Twenty-six healthy subjects served as controls. RESULTS: The percentage of CD3(+)CD4(+)T lymphocytes in peripheral blood from DLBCL patients was significantly decreased, whereas the percentages of CD3(+)CD8(+)T and CD4(+)CD25(+)T cells were significantly increased compared to those in controls (p < 0.05). Serum levels of IFN-γ and IL-4 were also significantly lower in DLBCL patients than those in controls (p < 0.05), and the levels of EGR-1, T-bet, and GATA-3 mRNA in PBMCs were lower (2.69 ± 1.48, 9.43 ± 2.14, and 20.83 ± 9.05 fold, respectively) in DLBCL patients than those in controls. Furthermore, there was a positive association between the levels of EGR-1 and T-bet mRNA (p = 0.001). However, the level of TGF-β mRNA was significantly increased in DLBCL patients, which was inversely associated with the T-bet mRNA level (p = 0.008), but positively associated with the percentage of T regulatory cells in PBMCs (p = 0.011). After three cycles of chemotherapy, the distribution of T-lymphocyte subsets in DLBCL patients were changed, and the levels of EGR-1, T-bet, and GATA-3 mRNA were significantly increased (p < 0.05) compared to those before chemotherapy. CONCLUSIONS: These results demonstrate the changes in T-lymphocyte subpopulations and the altered expression 34 pattern of the corresponding regulatory genes in PBMCs from DLBCL patients after chemotherapy, which are associated with the response of patients to treatment. The preferential expression of the T-bet gene after chemotherapy was closely correlated with the increased expression of the EGR-1 gene and decreased expression of the TGF-β gene
The Role of Glypicans in Wnt Inhibitory Factor-1 Activity and the Structural Basis of Wif1's Effects on Wnt and Hedgehog Signaling
Proper assignment of cellular fates relies on correct interpretation of Wnt and Hedgehog (Hh) signals. Members of the Wnt Inhibitory Factor-1 (WIF1) family are secreted modulators of these extracellular signaling pathways. Vertebrate WIF1 binds Wnts and inhibits their signaling, but its Drosophila melanogaster ortholog Shifted (Shf) binds Hh and extends the range of Hh activity in the developing D. melanogaster wing. Shf activity is thought to depend on reinforcing interactions between Hh and glypican HSPGs. Using zebrafish embryos and the heterologous system provided by D. melanogaster wing, we report on the contribution of glypican HSPGs to the Wnt-inhibiting activity of zebrafish Wif1 and on the protein domains responsible for the differences in Wif1 and Shf specificity. We show that Wif1 strengthens interactions between Wnt and glypicans, modulating the biphasic action of glypicans towards Wnt inhibition; conversely, glypicans and the glypican-binding “EGF-like” domains of Wif1 are required for Wif1's full Wnt-inhibiting activity. Chimeric constructs between Wif1 and Shf were used to investigate their specificities for Wnt and Hh signaling. Full Wnt inhibition required the “WIF” domain of Wif1, and the HSPG-binding EGF-like domains of either Wif1 or Shf. Full promotion of Hh signaling requires both the EGF-like domains of Shf and the WIF domains of either Wif1 or Shf. That the Wif1 WIF domain can increase the Hh promoting activity of Shf's EGF domains suggests it is capable of interacting with Hh. In fact, full-length Wif1 affected distribution and signaling of Hh in D. melanogaster, albeit weakly, suggesting a possible role for Wif1 as a modulator of vertebrate Hh signaling
Deciphering colorectal cancer genetics through multi-omic analysis of 100,204 cases and 154,587 controls of European and east Asian ancestries
In the version of this article initially published, the author affiliations incorrectly listed “Candiolo Cancer Institute FPO-IRCCS, Candiolo (TO), Italy” as “Candiolo Cancer Institute, Candiolo, Italy.” The change has been made to the HTML and PDF versions of the article
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