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1.
RSC Adv ; 14(44): 32053-32062, 2024 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-39391622

RESUMEN

In the present work, we propose GaGeX2 (X = N, P, As) monolayers and explore their structural, vibrational, piezoelectric, electronic, and transport characteristics for multifunctional applications based on first-principles simulations. Our analyses of cohesive energy, phonon dispersion spectra, and ab initio molecular dynamics simulations indicate that the three proposed structures have good energetic, dynamic, and thermodynamic stabilities. The GaGeX2 are found as piezoelectric materials with high piezoelectric coefficient d 11 of -1.23 pm V-1 for the GaGeAs2 monolayer. Furthermore, the results from electronic band structures show that the GaGeX2 have semiconductor behaviours with moderate bandgap energies. At the Heyd-Scuseria-Ernzerhof level, the GaGeP2 and GaGeAs2 exhibit optimal bandgaps for photovoltaic applications of 1.75 and 1.15 eV, respectively. Moreover, to examine the transport features of the GaGeX2 monolayers, we calculate their carrier mobility. All three investigated GaGeX2 systems have anisotropic carrier mobility in the two in-plane directions for both electrons and holes. Among them, the GaGeAs2 monolayer shows the highest electron mobilities of 2270.17 and 1788.59 cm2 V-1 s-1 in the x and y directions, respectively. With high electron mobility, large piezoelectric coefficient, and moderate bandgap energy, the GaGeAs2 material holds potential applicability for electronic, optoelectronic, piezoelectric, and photovoltaic applications. Thus, our findings not only predict stable GaGeX2 structures but also provide promising materials to apply for multifunctional devices.

4.
Nanoscale Adv ; 6(16): 4128-4136, 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-39114137

RESUMEN

Breaking structural symmetry in two-dimensional layered Janus materials can result in enhanced new phenomena and create additional degrees of piezoelectric responses. In this study, we theoretically design a series of Janus monolayers HfGeZ3H (Z = N, P, As) and investigate their structural characteristics, crystal stability, piezoelectric responses, electronic features, and carrier mobility using first-principles calculations. Phonon dispersion analysis confirms that HfGeZ3H monolayers are dynamically stable and their mechanical stability is also confirmed through the Born-Huang criteria. It is demonstrated that while HfGeN3H is a semiconductor with a large bandgap of 3.50 eV, HfGeP3H and HfGeAs3H monolayers have narrower bandgaps being 1.07 and 0.92 eV, respectively. When the spin-orbit coupling is included, large spin-splitting energy is found in the electronic bands of HfGeZ3H. Janus HfGeZ3H monolayers can be treated as piezoelectric semiconductors with the coexistence of both in-plane and out-of-plane piezoelectric responses. In particular, HfGeZ3H monolayers exhibit ultra-high electron mobilities up to 6.40 × 103 cm2 V-1 s-1 (HfGeAs3H), indicating that they have potential for various applications in nanoelectronics.

5.
Environ Monit Assess ; 196(8): 772, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39088135

RESUMEN

Every year, Hanoi suffers from several episodes (periods with daily concentration of PM2.5 higher than 50 µg m-3 during at least two consecutive days). These episodes are of health concern because of the high concentration of PM2.5 and/or PM0.1 and the presence of PM-bound toxic components, such as, PAHs. In this study, the concentrations of PAHs bound to PM2.5 and PM0.1 in night-time and day-time samples during episode and non-episode periods in December 2021 were determined. The concentrations of PAHs bound to PM2.5 were found to increase significantly from day-time samples of 3.24 ± 0.83 ng m-3 to night-time samples of 10.8 ± 4.45 ng m-3 in episode periods. However, PAHs bound to PM0.1 increased slightly from day-time samples of 0.58 ± 0.12 ng m-3 to night-time samples of 0.89 ± 0.30 ng m-3 in episode periods. Diagnostic ratios of PAHs indicate that biomass/coal combustion and vehicular emission are the primary sources of PAHs. The incremental lifetime cancer risk was estimated to vary from 8.7E-09 to 2.5E-08 for children and 6.7E-08 to 2.2E-07 for adults, respectively. Accordingly, loss of life expectancy was estimated at 0.11 min and 0.82 min for children and adults, respectively. These findings imply that the carcinogenic impact induced by PAHs via inhalation is negligible during the episode period.


Asunto(s)
Contaminantes Atmosféricos , Monitoreo del Ambiente , Material Particulado , Hidrocarburos Policíclicos Aromáticos , Hidrocarburos Policíclicos Aromáticos/análisis , Material Particulado/análisis , Contaminantes Atmosféricos/análisis , Humanos , Contaminación del Aire/estadística & datos numéricos , Ciudades , Tamaño de la Partícula
6.
RSC Adv ; 14(30): 21982-21990, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38993506

RESUMEN

In this article, an attempt is made to explore new materials for applications in piezoelectric and electronic devices. Based on density functional theory calculation, we construct three Janus ZrGeZ3H (Z = N, P, and As) monolayers and study their stability, piezoelectricity, Raman response, and carrier mobility. The results from phonon dispersion spectra, ab initio molecular dynamics simulation, and elastic coefficients confirm the structural, thermal, and mechanical stability of these proposed structures. The ZrGeZ3H monolayers are indirect band gap semiconductors with favourable band gap energy of 1.15 and 1.00 eV for the ZrGeP3H and ZrGeAs3H, respectively, from Heyd-Scuseria-Ernzerhof functional method. It is found that the Janus ZrGeZ3H monolayers possess both in-plane and out-of-plane piezoelectric coefficients, revealing that they are potential piezoelectric candidates. In addition, the carrier mobilities of electrons and holes along transport directions are anisotropic. Notably, the ZrGeP3H and ZrGeAs3H monolayers have high electron mobility of 3639.20 and 3408.37 cm2 V-1 s-1, respectively. Our findings suggest the potential application of the Janus ZrGeZ3H monolayers in the piezoelectric and electronic fields.

7.
Vaccine ; 42(9): 2200-2211, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38350768

RESUMEN

BACKGROUND: The Global COVID Vaccine Safety (GCoVS) Project, established in 2021 under the multinational Global Vaccine Data Network™ (GVDN®), facilitates comprehensive assessment of vaccine safety. This study aimed to evaluate the risk of adverse events of special interest (AESI) following COVID-19 vaccination from 10 sites across eight countries. METHODS: Using a common protocol, this observational cohort study compared observed with expected rates of 13 selected AESI across neurological, haematological, and cardiac outcomes. Expected rates were obtained by participating sites using pre-COVID-19 vaccination healthcare data stratified by age and sex. Observed rates were reported from the same healthcare datasets since COVID-19 vaccination program rollout. AESI occurring up to 42 days following vaccination with mRNA (BNT162b2 and mRNA-1273) and adenovirus-vector (ChAdOx1) vaccines were included in the primary analysis. Risks were assessed using observed versus expected (OE) ratios with 95 % confidence intervals. Prioritised potential safety signals were those with lower bound of the 95 % confidence interval (LBCI) greater than 1.5. RESULTS: Participants included 99,068,901 vaccinated individuals. In total, 183,559,462 doses of BNT162b2, 36,178,442 doses of mRNA-1273, and 23,093,399 doses of ChAdOx1 were administered across participating sites in the study period. Risk periods following homologous vaccination schedules contributed 23,168,335 person-years of follow-up. OE ratios with LBCI > 1.5 were observed for Guillain-Barré syndrome (2.49, 95 % CI: 2.15, 2.87) and cerebral venous sinus thrombosis (3.23, 95 % CI: 2.51, 4.09) following the first dose of ChAdOx1 vaccine. Acute disseminated encephalomyelitis showed an OE ratio of 3.78 (95 % CI: 1.52, 7.78) following the first dose of mRNA-1273 vaccine. The OE ratios for myocarditis and pericarditis following BNT162b2, mRNA-1273, and ChAdOx1 were significantly increased with LBCIs > 1.5. CONCLUSION: This multi-country analysis confirmed pre-established safety signals for myocarditis, pericarditis, Guillain-Barré syndrome, and cerebral venous sinus thrombosis. Other potential safety signals that require further investigation were identified.


Asunto(s)
COVID-19 , Síndrome de Guillain-Barré , Miocarditis , Pericarditis , Trombosis de los Senos Intracraneales , Humanos , Vacuna nCoV-2019 mRNA-1273 , Vacuna BNT162 , Estudios de Cohortes , COVID-19/prevención & control , Vacunas contra la COVID-19/efectos adversos , Síndrome de Guillain-Barré/inducido químicamente , Síndrome de Guillain-Barré/epidemiología , Vacunas de ARNm , Vacunación/efectos adversos , Masculino , Femenino
8.
Front Cardiovasc Med ; 11: 1291180, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38312233

RESUMEN

Background: Cancer therapy-related cardiac dysfunction due to trastuzumab has been well-known for many years, and echocardiographic surveillance is recommended every 3 months in patients undergoing trastuzumab treatment, irrespective of the baseline cardiotoxicity risk. However, the potential harm and cost of overscreening in low- and moderate-risk patients have become great concerns. Objectives: This study aimed to identify the incidence of early cancer therapy-related cardiac dysfunction (CTRCD) and the behaviours of left and right heart deformations during trastuzumab chemotherapy in low- and moderate-risk patients. Methods: We prospectively enrolled 110 anthracycline-naïve women with breast cancer and cardiovascular risk factors who were scheduled to receive trastuzumab. The left ventricular ejection fraction (LVEF), left ventricular global longitudinal strain (LV-GLS), and right ventricular and left atrial longitudinal strains were evaluated using echocardiography at baseline, before every subsequent cycle and 3 weeks after the final dose of trastuzumab. The baseline risk of CTRCD was graded according to the risk score proposed by the Heart Failure Association (HFA) Cardio-Oncology Working Group and the International Cardio-Oncology Society (ICOS). CTRCD and its severity were defined according to the current European Society of Cardiology (ESC) guidelines. Results: Twelve (10.9%) patients had asymptomatic CTRCD. All CTRCD occurred sporadically during the first 9 months of the active trastuzumab regimen in both low- and moderate-risk patients. While CTRCD was graded as moderate severity in 41.7% of patients and heart failure therapy was initiated promptly, no irreversible cardiotoxicity or trastuzumab interruption was recorded at the end of follow-up. Among the left and right heart deformation indices, only LV-GLS decreased significantly in the CTRCD group during the trastuzumab regimen. Conclusions: CTRCD is prevalent in patients with non-high-risk breast cancer undergoing trastuzumab chemotherapy. Low- and moderate-risk patients show distinct responses to trastuzumab. The LV-GLS is the only deformation index sensitive to early trastuzumab-related cardiac dysfunction.

9.
RSC Adv ; 14(7): 4966-4974, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38327810

RESUMEN

The auxetic materials have exotic mechanical properties compared to conventional materials, such as higher indentation resistance, more superior sound absorption performance. Although the auxetic behavior has also been observed in two-dimensional (2D) nanomaterials, to date there has not been much research on auxetic materials in the vertical asymmetric Janus 2D layered structures. In this paper, we explore the mechanical, electronic, and transport characteristics of Janus Si2OX (X = S, Se, Te) monolayers by first-principle calculations. Except for the Si2OTe monolayer, both Si2OS and Si2OSe are found to be stable. Most importantly, both Si2OS and Si2OSe monolayers are predicted to be auxetic semiconductors with a large negative Poisson's ratio. The auxetic behavior is clearly observed in the Janus Si2OS monolayer with an extremely large negative Poisson's ratio of -0.234 in the x axis. At the equilibrium state, both Si2OS and Si2OSe materials exhibit indirect semiconducting characteristics and their band gaps can be easily altered by the mechanical strain. More interestingly, the indirect-direct bandgap phase transitions are observed in both Si2OS and Si2OSe monolayers when the biaxial strains are introduced. Further, the studied Janus structures also exhibit remarkably high electron mobility, particularly along the x direction. Our findings demonstrate that Si2OS and Si2OSe monolayers are new auxetic materials with asymmetric structures and show their great promise in electronic and nanomechanical applications.

10.
Neurobiol Learn Mem ; 207: 107864, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38000462

RESUMEN

Animals rely on learned cues to guide their behaviour for rewards such as food. The Pavlovian-instrumental transfer (PIT) task can be used to investigate the influence of Pavlovian stimuli on instrumental responding. Ghrelin, an orexigenic peptide, and its receptor, growth hormone secretagogue receptor 1A (GHS-R1A), has received growing interest for its role in reward-motivated learning and behaviours. A significant population of GHS-R1A have been identified within the ventral tegmental area (VTA), a critical node in the mesolimbic reward circuit that is necessary for the expression of PIT. As ghrelin has been found to increase dopaminergic activity in the VTA, we predicted that GHS-R1A antagonism with JMV-2959 would attenuate PIT. Further, given the relationship between hunger levels and changes in ghrelin signalling, we sought to compare the effects GHS-R1A antagonism with those of satiety, hypothesizing parallel effects, with each attenuating PIT. Rats received daily sessions of Pavlovian and then instrumental training over 3 weeks. Across three experiments, we examined the effects of a shift to satiety, or treatment with the GHS-R1A antagonist JMV-2959, either peripherally or directly into the VTA. We found that presentations of a stimulus paired with food reward enhanced responding for food across all conditions, thus demonstrating the expected PIT effect. Further, GHS-R1A antagonism, both peripherally and within the VTA, as well as satiety significantly reduced the magnitude of the PIT effect compared to control conditions. These results clarify our understanding of ghrelin signalling in PIT and begin to elucidate the role of feeding-related peptides in the modulation of reward-related responding.


Asunto(s)
Ghrelina , Receptores de Ghrelina , Ratas , Animales , Ghrelina/farmacología , Área Tegmental Ventral , Motivación , Recompensa
11.
Sci Rep ; 13(1): 19559, 2023 11 10.
Artículo en Inglés | MEDLINE | ID: mdl-37950031

RESUMEN

Early detection of liver malignancy based on medical image analysis plays a crucial role in patient prognosis and personalized treatment. This task, however, is challenging due to several factors, including medical data scarcity and limited training samples. This paper presents a study of three important aspects of radiomics feature from multiphase computed tomography (CT) for classifying hepatocellular carcinoma (HCC) and other focal liver lesions: wavelet-transformed feature extraction, relevant feature selection, and radiomics features-based classification under the inadequate training samples. Our analysis shows that combining radiomics features extracted from the wavelet and original CT domains enhance the classification performance significantly, compared with using those extracted from the wavelet or original domain only. To facilitate the multi-domain and multiphase radiomics feature combination, we introduce a logistic sparsity-based model for feature selection with Bayesian optimization and find that the proposed model yields more discriminative and relevant features than several existing methods, including filter-based, wrapper-based, or other model-based techniques. In addition, we present analysis and performance comparison with several recent deep convolutional neural network (CNN)-based feature models proposed for hepatic lesion diagnosis. The results show that under the inadequate data scenario, the proposed wavelet radiomics feature model produces comparable, if not higher, performance metrics than the CNN-based feature models in terms of area under the curve.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Teorema de Bayes , Tomografía Computarizada por Rayos X , Pronóstico , Estudios Retrospectivos
12.
Nanoscale Adv ; 5(23): 6705-6713, 2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-38024315

RESUMEN

From the extending requirements for using innovative materials in advanced technologies, it is necessary to explore new materials for relevant applications. In this work, we design new two-dimensional (2D) Janus ZrSiSZ2 (Z = N, P, As) monolayers and investigate their crystal lattice and dynamic stability by using density functional theory investigations. The two stable structures of ZrSiSP2 and ZrSiSAs2 are then systematically examined for thermal, energetic, and mechanical stability, and electronic and transport properties. The calculation results demonstrate that both the ZrSiSP2 and ZrSiSAs2 monolayers have good thermal stability at room temperature and high energetic/mechanical stabilities for experimental synthesis. The studied structures are found to be in-direct semiconductors. Specifically, with moderate band-gap energies of 1.04 to 1.29 eV for visible light absorption, ZrSiSP2 and ZrSiSAs2 can be considered potential candidates for photovoltaic applications. The applied biaxial strains and external electric fields slightly change the band-gap energies of the monolayers. We also calculate the carrier mobilities for the transport properties based on the deformation potential method. Due to the lower effective masses, the carrier mobilities in the x direction are higher than those in the y direction. The carrier mobilities of the ZrSiSP2 and ZrSiSAs2 monolayers are anisotropic not only in transport directions but also for the electrons and holes. We believe that the results of our work may stimulate further studies to explore more new 2D Janus monolayers with novel properties of the MA2Z4 family materials.

13.
Indian J Microbiol ; 63(3): 386-394, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37781021

RESUMEN

Tomato (Solanum lycopersicum L.) is an important grown vegetable in Vietnam. Bacterial wilt caused by Pseudomonas solanacearum has been considered to be an important disease resulting in a harvest loss up to 90% and significant economic loss to farmers. In this study, two bacteriophages DLDT_So2 and BHDT_So9 specific to P. solanacearum were isolated. Morphological analysis indicated that DLDT_So2 and BHDT_So9 had podovirus morphology and were classified into Autographiviridae family. The latent period and burst size of DLDT_So2 was found to be approximately 120 min and 20.0 ± 2.4 virions per infected cell. Meanwhile, the latent period of BHDT_So9 was 140 min with a burst size of 11.5 ± 2.8 virions per infected cell. Of the 23 bacterial strains tested, the phages infected 7/11 strains of P. solanacearum and none of the other bacteria tested were susceptible to the phages. Stability of the phages at different temperatures, pHs, solvents was also investigated. The genomes of DLDT_So2 and BHDT_So9 are 41,341 bp and 41,296 bp and long with a total GC content of 63%, contains 48 and 46 predicted protein-encoding CDSs. No virulence or antibiotic resistance genes were found in the genomes, suggesting they would be useful biocontrol agents against P. solanacearum. Classification of the phage using average nucleotide identity, phylogenetic analysis was also carried out. The two phages represented new species when they had overall average nucleotide identity of < 95%. This is first report of the isolation and characterization of P. solanacearum-specific phages from tomato farms in Vietnam. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01090-9.

14.
Vaccine ; 41(42): 6227-6238, 2023 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-37673715

RESUMEN

BACKGROUND: The Global COVID Vaccine Safety (GCoVS) project was established in 2021 under the multinational Global Vaccine Data Network (GVDN) consortium to facilitate the rapid assessment of the safety of newly introduced vaccines. This study analyzed data from GVDN member sites on the background incidence rates of conditions designated as adverse events of special interest (AESI) for COVID-19 vaccine safety monitoring. METHODS: Eleven GVDN global sites obtained data from national or regional healthcare databases using standardized methods. Incident events of 13 pre-defined AESI were included for a pre-pandemic period (2015-19) and the first pandemic year (2020). Background incidence rates (IR) and 95% confidence intervals (CI) were calculated for inpatient and emergency department encounters, stratified by age and sex, and compared between pre-pandemic and pandemic periods using incidence rate ratios. RESULTS: An estimated 197 million people contributed 1,189,652,926 person-years of follow-up time. Among inpatients in the pre-pandemic period (2015-19), generalized seizures were the most common neurological AESI (IR ranged from 22.15 [95% CI 19.01-25.65] to 278.82 [278.20-279.44] per 100,000 person-years); acute disseminated encephalomyelitis was the least common (<0.5 per 100,000 person-years at most sites). Pulmonary embolism was the most common thrombotic event (IR 45.34 [95% CI 44.85-45.84] to 93.77 [95% CI 93.46-94.08] per 100,000 person-years). The IR of myocarditis ranged from 1.60 [(95% CI 1.45-1.76) to 7.76 (95% CI 7.46-8.08) per 100,000 person-years. The IR of several AESI varied by site, healthcare setting, age and sex. The IR of some AESI were notably different in 2020 compared to 2015-19. CONCLUSION: Background incidence of AESIs exhibited some variability across study sites and between pre-pandemic and pandemic periods. These findings will contribute to global vaccine safety surveillance and research.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19/efectos adversos , Incidencia , Vacunación , Vacunas/efectos adversos
15.
Eur Rev Med Pharmacol Sci ; 27(16): 7720-7727, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37667950

RESUMEN

OBJECTIVE: This study aimed to determine the rate of salvage chemotherapy and review associated factors in invasive mole patients treated by primary or delayed hysterectomy. PATIENTS AND METHODS: This study was carried out at the Tu Du Hospital, where a total of 189 patients were diagnosed with invasive mole based on histologic examination by hysterectomy between 01/2016 to 12/2020. We used the life table method to estimate the cumulative rate. We applied the Cox proportional hazard model to determine the factors associated with the need for salvage chemotherapy. RESULTS: At 12-month follow-up, 47 patients had required salvage chemotherapy. The incidence was 24.87% (95% CI: 18.88-31.66). Applying the multivariate model, prophylactic chemotherapy (HR = 2.75, 95% Cl: 1.20-6.30) and two weeks postoperative hCG value greater than 1,900 mIU/mL (HR = 4.30, 95% Cl: 2.08-8.87) increased the risk of requiring salvage chemotherapy. Postoperative chemotherapy decreased the risk of requiring salvage chemotherapy (HR = 0.43, 95% Cl: 0.22-0.83). CONCLUSIONS: Hysterectomy can be considered safe and effective in treating invasive mole patients. Although patients were treated by hysterectomy, 24.87% of patients needed salvage chemotherapy to achieve remission. This study affirms the malignant nature of invasive mole, a subtype of gestational trophoblastic neoplasia (GTN). It is not purely a local invasion of molar villi. Postoperative chemotherapy plays an essential role in reducing the risk of requiring salvage chemotherapy.


Asunto(s)
Mola Hidatiforme Invasiva , Neoplasias Uterinas , Femenino , Embarazo , Humanos , Vietnam , Duodeno , Histerectomía , Neoplasias Uterinas/cirugía
16.
Phys Chem Chem Phys ; 25(32): 21468-21478, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37539527

RESUMEN

Two-dimensional (2D) Janus materials with extraordinary properties are promising candidates for utilization in advanced technologies. In this study, new 2D Janus XWSiP2 (X = S, Se, Te) monolayers were constructed and their properties were systematically analyzed by using first-principles calculations. All three structures of SWSiP2, SeWSiP2, and TeWSiP2 exhibit high energetic stability for the experimental fabrication with negative and high Ecoh values, the elastic constants obey the criteria of Born-Huang, and no imaginary frequency exists in the phonon dispersion spectra. The calculated results from the PBE and HSE06 approaches reveal that the XWSiP2 are semiconductors with moderate direct band-gaps varying from 1.01 eV to 1.06 eV using the PBE method, and 1.39 eV to 1.44 eV using the HSE06 method. In addition, the electronic band structures of the three monolayers are significantly affected by the applied strains. Interestingly, the transitions from a direct to indirect semiconductor are observed for different biaxial strains εb. The transport parameters including the carrier mobility values along the x direction µx and y direction µy were also calculated to study the transport properties of the XWSiP2. The results indicate that the XWSiP2 monolayers not only have high carrier mobilities but also anisotropy in the transport directions for both holes and electrons. Together with the moderate and tunable energy gaps, the XWSiP2 materials are found to be potential candidates for application in the photonic, photovoltaic, optoelectronic, and electronic fields.

17.
Beilstein J Nanotechnol ; 14: 781-792, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37441001

RESUMEN

We present the in situ synthesis of silver nanoparticles (AgNPs) through ionotropic gelation utilizing the biodegradable saccharides lactose (Lac) and alginate (Alg). The lactose reduced silver ions to form AgNPs. The crystallite structure of the nanocomposite AgNPs@Lac/Alg, with a mean size of 4-6 nm, was confirmed by analytical techniques. The nanocomposite exhibited high catalytic performance in degrading the pollutants methyl orange and rhodamine B. The antibacterial activity of the nanocomposite is pH-dependent, related to the alterations in surface properties of the nanocomposite at different pH values. At pH 6, the nanocomposite demonstrated the highest antibacterial activity. These findings suggest that this nanocomposite has the potential to be tailored for specific applications in environmental and medicinal treatments, making it a highly promising material.

18.
Ultramicroscopy ; 250: 113750, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37178606

RESUMEN

X-ray photoelectron diffraction (XPD) is a powerful technique that yields detailed structural information of solids and thin films that complements electronic structure measurements. Among the strongholds of XPD we can identify dopant sites, track structural phase transitions, and perform holographic reconstruction. High-resolution imaging of kll-distributions (momentum microscopy) presents a new approach to core-level photoemission. It yields full-field kx-ky XPD patterns with unprecedented acquisition speed and richness in details. Here, we show that beyond the pure diffraction information, XPD patterns exhibit pronounced circular dichroism in the angular distribution (CDAD) with asymmetries up to 80%, alongside with rapid variations on a small kll-scale (0.1 Å-1). Measurements with circularly-polarized hard X-rays (hν = 6 keV) for a number of core levels, including Si, Ge, Mo and W, prove that core-level CDAD is a general phenomenon that is independent of atomic number. The fine structure in CDAD is more pronounced compared to the corresponding intensity patterns. Additionally, they obey the same symmetry rules as found for atomic and molecular species, and valence bands. The CD is antisymmetric with respect to the mirror planes of the crystal, whose signatures are sharp zero lines. Calculations using both the Bloch-wave approach and one-step photoemission reveal the origin of the fine structure that represents the signature of Kikuchi diffraction. To disentangle the roles of photoexcitation and diffraction, XPD has been implemented into the Munich SPRKKR package to unify the one-step model of photoemission and multiple scattering theory.

19.
Arch Virol ; 168(6): 157, 2023 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-37160612

RESUMEN

Bacteriophage L522, which infects Xanthomonas oryzae pv. oryzae, was isolated from a paddy leaf sample collected in Long An province, Vietnam. The phage shows myovirus morphology based on transmission electron microscopy. It displays a latent period and burst size of approximately 3 h and 63 new virions per infected cell (PFU/infected cell), respectively. The genome of L522 is 44,497 bp in length, with 52% GC content. Of the 63 genes identified, functions were predicted for 26. No virulence or antibiotic-resistance genes were detected. The results of a BLASTn search showed similarity to a previously reported Xanthomonas phage, with 85% average nucleotide sequence identity and 87.15% query coverage. Thus, this L522 is a representative of a new species in the genus Xipdecavirus.


Asunto(s)
Bacteriófagos , Oryza , Siphoviridae , Xanthomonas , Bacteriófagos/genética , Xanthomonas/genética
20.
RSC Adv ; 13(18): 12153-12160, 2023 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-37082371

RESUMEN

Group III monochalcogenide compounds can exist in different polymorphs, including the conventional D 3h and C 2h phases. Since the bulk form of the C 2h-group III monochalcogenides has been successfully synthesized [Phys. Rev. B: Condens. Matter Mater. Phys. 73 (2006) 235202], prospects for research on their corresponding monolayers have also been opened. In this study, we design and systematically consider a series of Janus structures formed from the two-dimensional C 2h phase of gallium monochalcogenide Ga2XY (X/Y = S, Se, Te) using first-principles simulations. It is demonstrated that the Janus Ga2XY monolayers are structurally stable and energetically favorable. Ga2XY monolayers exhibit high anisotropic mechanical features due to their anisotropic lattice structure. All Janus Ga2XY are indirect semiconductors with energy gap values in the range from 1.93 to 2.67 eV. Due to the asymmetrical structure, we can observe distinct vacuum level differences between the two surfaces of the examined Janus structures. Ga2XY monolayers have high electron mobility and their carrier mobilities are also highly directionally anisotropic. It is worth noting that the Ga2SSe monolayer possesses superior electron mobility, up to 3.22 × 103 cm2 V-1 s-1, making it an excellent candidate for potential applications in nanoelectronics and nanooptoelectronics.

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