[Application and optimization of CRISPRi to the biology of Mycobacterium tuberculosis].

Tuberculosis, caused by infection with Mycobacterium tuberculosis (MTB), remains a global public health challenge. Multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) strains make tuberculosis more difficult to control. New tools to study the biology of MTB can identify novel targets for drug discovery. Recently, the Clustered Regularly Interspaced Short Palindromic Repeats interference (CRISPRi) combined with next-generation sequencing has provided many novel insights into the physiology and genetics of MTB. This review summarizes the application and optimization of CRISPRi in MTB biology.

Adjustment of optical absorption in phosphorene through electron-phonon coupling and an electric field.

This study investigates the optical absorption of monolayer phosphorene, focusing on its response to the electron-phonon coupling (EPC) and an electric field. Using a tight-binding Hamiltonian model based on the Barisic-Labbe-Friedel-Su-Schrieffer-Heeger model and the Kubo formula, we calculate the electronic band structure and optical absorption characteristics. The anisotropic dispersion of carriers along armchair and zigzag directions leads to distinct optical responses. Positive and negative EPC effects increase and decrease hopping parameters, respectively, enlarging and reducing/closing the band gap. Moreover, both EPCs cause an admixture of blue and red shift spectrum along the armchair direction, while a red (blue) shift spectrum is observed for positive (negative) EPC along the zigzag direction. Incorporating electric field effects in the EPC increases band gaps for both positive and negative EPC activities, resulting in shifted optical peaks along both directions.

Morphological and molecular characterizations of Pratylenchus coffeae infecting Ming aralia and coffee in Vietnam.

Pratylenchus coffeae, belonging to the root-lesion nematode group, is a highly prevalent and destructive plant-parasitic nematode that is able to infest a wide range of host plants. Although this species' devastating impacts on coffee plantations across the world are widely known on other host plants, its association with Ming aralia has never been reported. Our study characterized two popu lations of P. coffeae (associated with Ming aralia and coffee) and compared them with other popu lations from previous studies in Vietnam and other countries in the world. The identification of P. coffeae in our study was confirmed by the comprehensive analysis encompassing morphological examination, morphometric data, and molecular characterizations of the COI mtDNA and D2D3 of 28S rRNA regions. The cluster and MDS analyses revealed that the two populations of P. coffeae from Vietnam are closely related to those from Japan and Indonesia. The D2-D3 sequences of 28S rRNA and COI mtDNA regions exhibited high similarity among these populations, indicating a stable genetic profile. Our research contributes to a better understanding of the distribution and genetic characterizations of P. coffeae by offering new morphological and molecular insights into the presence of this nematode in Vietnam. Additionally, this nematode species was found to be associated with host plant's symptoms such as chlorotic leaves, stunted growth and root lesion in both hosts. Given the economic significance of both Ming aralia and coffee crops in Vietnam, as well as the damaging potential of P. coffeae, this study emphasizes the need of proactive nematode management measures to control this destructive pest.

Radioactive seed localization is a safe and effective tool for breast cancer surgery: an evaluation of over 25,000 cases.

Radioactive seed localization (RSL) provides a precise and efficient method for removing non-palpable breast lesions. It has proven to be a valuable addition to breast surgery, improving perioperative logistics and patient satisfaction. This retrospective review examines the lessons learned from a high-volume cancer center's RSL program after 10 years of practice and over 25 000 cases. We provide an updated model for assessing the patient's radiation dose from RSL seed implantation and demonstrate the safety of RSL to staff members. Additionally, we emphasize the importance of various aspects of presurgical evaluation, surgical techniques, post-surgical management, and regulatory compliance for a successful RSL program. Notably, the program has reduced radiation exposure for patients and medical staff.

First-principles study of indium nitride monolayers doped with alkaline earth metals.

Element doping has been widely employed to modify the ground state properties of two-dimensional (2D) materials. In this work, the effects of doping with alkaline earth metals (AEMs) on the structural, electronic, and magnetic properties of indium nitride (InN) monolayers are investigated using first-principles calculations based on density functional theory. In a graphene-like honeycomb structure, the InN monolayer possesses good dynamical and thermal stability, and exhibits an indirect gap semiconductor character with a band gap of 0.37 (1.48) eV as determined by using the PBE(HSE06) functional. A single In vacancy leads to the emergence of a magnetic semiconductor character, where magnetic properties with a large total magnetic moment of 3.00 µB are produced mainly by the N atoms closest to the defect site. The incorporation of AEMs impurities causes local structural distortion due to the difference in atomic size, where Mg and Ca doping processes are energetically most favorable. Half-metallicity is induced by the partial occupancy of the N-2p orbital, which is a consequence of having one valence electron less. In these cases, the total magnetic moment of 1.00 µB mainly originates from N atoms neighboring the dopants. Further increasing the doping level preserves the half-metallic character, where N atoms play a key role on the magnetism of the highly doped systems. Results presented herein suggest the In replacement by AEMs impurities is an effective approach to make prospective spintronic 2D materials from InN monolayers.

Range area and the fast-slow continuum of life history traits predict pathogen richness in wild mammals.

Surveillance of pathogen richness in wildlife is needed to identify host species with a high risk of zoonotic disease spillover. While several predictors of pathogen richness in wildlife hosts have been proposed, their relative importance has not been formally examined. This hampers our ability to identify potential disease reservoirs, particularly in remote areas with limited surveillance efforts. Here we analyzed 14 proposed predictors of pathogen richness using ensemble modeling and a dataset of 1040 host species to identify the most important predictors of pathogen richness in wild mammal species. After controlling for research effort, larger species geographic range area was identified to be associated with higher pathogen richness. We found evidence of duality in the relationship between the fast-slow continuum of life-history traits and pathogen richness, where pathogen richness increases near the extremities. Taxonomic orders Carnivora, Proboscidea, Artiodactyla, and Perissodactyla were predicted to host high pathogen richness. The top three species with the highest pathogen richness predicted by our ensemble model were Canis lupus, Sus scrofa, and Alces alces. Our results can help support evidence-informed pathogen surveillance and disease reservoir management to prevent the emergence of future zoonotic diseases.

Biological Characterization and Genomic Analysis of Novel Phages DLDT_So2 and BHDT_So9 Against Pseudomonas solanacearum, an Infectious Agent in Tomato in Vietnam.

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.

Enhanced photocatalytic degradation of polycyclic aromatic hydrocarbon by graphitic carbonitride-nickel (g-C3N4-Ni) nanocomposite.

The objective of the present study is to synthesize g-C3N4-Ni nanocomposites composed of graphitic carbon nitride and magnetic nickel nanoparticles for benzopyrene degradation, which is one of the most potent polycyclic aromatic hydrocarbons (PAH) molecules. The concocted g-C3N4-Ni nanocomposites contained confined nanospheres with a mean particle dimension of 22 nm. Batch adsorption studies revealed that a rise in adsorbent dosage elevates benzopyrene degradation percentage in both water and soil samples with respect to time. The increase in the benzopyrene concentration did not have much influence on the degradation efficiency, and hence, the minimal concentration of PAH molecule is essential for the effective adsorption by g-C3N4-Ni nanocomposites. The rise in pH tends to increase the degradation of Benzopyrene till 3 h of the incubation period, and beyond 3 h, the degradation percentage declines. With regard to the effect of light source, UV light has been shown to accelerate the degradation of benzopyrene by g-C3N4-Ni nanocomposites than sunlight. The adsorption kinetic and isotherm investigations have proven that the Pseudo-second order kinetic model and Freundlich isotherm model were appropriate for our study. Thus, the g-C3N4-Ni nanocomposites were found to be efficient as a photocatalyst for the adsorption of benzopyrene from environmental samples.

Adjunctive Dexamethasone for Tuberculous Meningitis in HIV-Positive Adults.

BACKGROUND: Adjunctive glucocorticoids are widely used to treat human immunodeficiency virus (HIV)-associated tuberculous meningitis despite limited data supporting their safety and efficacy. METHODS: We conducted a double-blind, randomized, placebo-controlled trial involving HIV-positive adults (≥18 years of age) with tuberculous meningitis in Vietnam and Indonesia. Participants were randomly assigned to receive a 6-to-8-week tapering course of either dexamethasone or placebo in addition to 12 months of antituberculosis chemotherapy. The primary end point was death from any cause during the 12 months after randomization. RESULTS: A total of 520 adults were randomly assigned to receive either dexamethasone (263 participants) or placebo (257 participants). The median age was 36 years; 255 of 520 participants (49.0%) had never received antiretroviral therapy, and 251 of 484 participants (51.9%) with available data had a baseline CD4 count of 50 cells per cubic millimeter or less. Six participants withdrew from the trial, and five were lost to follow-up. During the 12 months of follow-up, death occurred in 116 of 263 participants (44.1%) in the dexamethasone group and in 126 of 257 participants (49.0%) in the placebo group (hazard ratio, 0.85; 95% confidence interval, 0.66 to 1.10; P = 0.22). Prespecified analyses did not reveal a subgroup that clearly benefited from dexamethasone. The incidence of secondary end-point events, including cases of immune reconstitution inflammatory syndrome during the first 6 months, was similar in the two trial groups. The numbers of participants with at least one serious adverse event were similar in the dexamethasone group (192 of 263 participants [73.0%]) and the placebo group (194 of 257 participants [75.5%]) (P = 0.52). CONCLUSIONS: Among HIV-positive adults with tuberculous meningitis, adjunctive dexamethasone, as compared with placebo, did not confer a benefit with respect to survival or any secondary end point. (Funded by the Wellcome Trust; ACT HIV ClinicalTrials.gov number, NCT03092817.).

Bacteriophage PVN06 protected catfish Pangasianodon hypophthalmus from Edwardsiella ictaluri infection.

Bacillary necrosis of pangasius (BNP) is a disease caused by Edwardsiella ictaluri bacteria in striped catfish Pangasianodon hypophthalmus that results in high mortality rates. To control this disease, bacteriophages have been considered as alternatives to antibiotics. In this study, we applied the lytic bacteriophage PVN06 in striped catfish fingerlings to prevent E. ictaluri infection. In an experimental trial, the phage was administered to fish by feeding phage-coated feed with doses of 7.17±0.09, 8.17±0.09 and 9.17±0.09 log PFU/g feed per day before bacterial infection. Fish were infected by bacteria once with concentrations ranging from 3.01 to 7.01 log CFU/ml tank water. A day after infection, phage treatment resumed at a rate of once per day until the end of the trial. The results of the trial show that bacterial infection caused typical symptoms of BNP in fish with the cumulative fish death rate of 36.7±2.9 to 75.0±5.0%, depending on the bacterial concentration used for infection. Phage treatment with 9.17±0.09 log PFU/g significantly reduced the mortality rate, while treatments with 8.17±0.09 and 7.17±0.09 log PFU/g did not. This phage dose resulted in a 61.7-fold reduction in the toxicity of the bacterial pathogen and the survival rate of 15-23.3% in fish. Our study has demonstrated that the bacteriophage PVN06 protected striped catfish from BNP.

Quantum magneto-transport properties of monolayers MoSi2N4, WSi2N4, and MoSi2As4.

We study the transport properties of monolayers MoSi2N4, WSi2N4, and MoSi2As4in a perpendicular magnetic field. The Landau level (LL) band structures including spin and exchange field effects are derived and discussed using a low-energy effective model. We show that the LLs band structures of these materials are similar to those of phosphorene and transition-metal dichalcogenides rather than graphene or silicene. The combination of strong spin-orbit coupling and exchange fields reduces the degradation of the LLs, leading to new plateaus in the Hall conductivity and Hall resistivity and new peaks in the longitudinal conductivity and longitudinal resistivity. The effect of the exchange field, carrier density, and LLs band structure on the conductivities and resistivities have been investigated. At high temperatures, the steps in Hall conductivity and resistivity plateaus disappear and reduce to their corresponding classical forms.

Rapid expansion of Neisseria gonorrhoeae ST7827 clone in Australia, with variable ceftriaxone phenotype unexplained by genotype.

BACKGROUND: Neisseria gonorrhoeae is identified as a priority pathogen due to its capacity to rapidly develop antimicrobial resistance (AMR). Following the easing of SARS-CoV-2 pandemic travel restrictions across international borders in the state of New South Wales (NSW), Australia, a surge of gonococcal isolates with raised ceftriaxone MIC values were detected. METHODS: All N. gonorrhoeae isolates (n = 150) with increased ceftriaxone MIC values in NSW between 1 January 2021 and July 2022 from males and females from all sites were sequenced. RESULTS: A new emergence and rapid expansion of an N. gonorrhoeae ST7827 clone was documented within NSW, Australia and provides further evidence of the ability of N. gonorrhoeae to undergo sufficient genomic changes and re-emerge as a geographically restricted subclone. Mapping AMR determinants to MIC results did not reveal any genomic pattern that correlated with MIC values. CONCLUSIONS: The rapid dissemination and establishment of this clone at the population level is a new and concerning demonstration of the agility of this pathogen, and underscores concerns about similar incursions and establishment of MDR clones. Moreover, it is notable that in this context the AMR genotype-phenotype correlates remain unclear, which requires further investigation to enable better understanding of genomic aspects of AMR in N. gonorrhoeae.

Simultaneous Measurement of Muon Neutrino ν_{µ} Charged-Current Single π

Neutrino-induced charged-current single π^{+} production in the Δ(1232) resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this Letter, high statistic differential cross sections are reported for the semiexclusive reaction ν_{µ}A→µ^{-}π^{+}+ nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wideband ν_{µ} beam with ⟨E_{ν}⟩≈6 GeV. Suppression of the cross section at low Q^{2} and enhancement of low T_{π} are observed in both light and heavy nuclear targets compared with phenomenological models used in current neutrino interaction generators. The cross sections per nucleon for iron and lead compared with CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.

A European-Japanese study on peach allergy: IgE to Pru p 7 associates with severity.

BACKGROUND: Pru p 3 and Pru p 7 have been implicated as risk factors for severe peach allergy. This study aimed to establish sensitization patterns to five peach components across Europe and in Japan, to explore their relation to pollen and foods and to predict symptom severity. METHODS: In twelve European (EuroPrevall project) and one Japanese outpatient clinic, a standardized clinical evaluation was conducted in 1231 patients who reported symptoms to peach and/or were sensitized to peach. Specific IgE against Pru p 1, 2, 3, 4 and 7 and against Cup s 7 was measured in 474 of them. Univariable and multivariable Lasso regression was applied to identify combinations of parameters predicting severity. RESULTS: Sensitization to Pru p 3 dominated in Southern Europe but was also quite common in Northern and Central Europe. Sensitization to Pru p 7 was low and variable in the European centers but very dominant in Japan. Severity could be predicted by a model combining age of onset of peach allergy, probable mugwort, Parietaria pollen and latex allergy, and sensitization to Japanese cedar pollen, Pru p 4 and Pru p 7 which resulted in an AUC of 0.73 (95% CI 0.73-0.74). Pru p 3 tended to be a risk factor in South Europe only. CONCLUSIONS: Pru p 7 was confirmed as a significant risk factor for severe peach allergy in Europe and Japan. Combining outcomes from clinical and demographic background with serology resulted in a model that could better predict severity than CRD alone.

Urban-rural disparities in acceptance of human papillomavirus vaccination among women in Can Tho, Vietnam.

Background: In Vietnam, cervical cancer is a significant public health concern for women. Unfortunately, despite the availability of the HPV vaccine, low vaccination rates persist. Objectives: This study investigates the discrepancy between urban and rural areas in the willingness to receive HPV vaccination with or without fees. Methods: A cross-sectional study was conducted on a sample of 648 women aged between 15 and 49, living in two urban and two rural Vietnamese districts of Can Tho, between May and December 2021. Results: The overall vaccination rate was 4%, with urban women having a higher rate of 4.9% compared to rural women at 3.1%. Among unvaccinated women, those from rural areas expressed a significantly higher desire to receive the free vaccine (91.4%) than urban women (84.4%). However, the intention to vaccinate declined when rural women and urban women were advised to pay the cost (63.4% and 57.1%, respectively). A strong correlation was found between a positive attitude and intention for vaccination, irrespective of its price or free availability. Education and access to information about the HPV vaccine were also identified as the most significant factors influencing the intention to vaccination among urban and rural women. Conclusion: The low HPV vaccination rates among women aged 15-49 living in both urban and rural regions of Vietnam are a notable public health concern. These outcomes emphasize the critical need for effective programs of vaccine laterization, as an introduction to the offer of affordable and accessible HPV vaccines for women in Can Tho, Vietnam.

Hooking the scientific community on thorny-headed worms: interesting and exciting facts, knowledge gaps and perspectives for research directions on Acanthocephala.

Although interest in Acanthocephala seems to have reached only a small community of researchers worldwide, we show in this opinion article that this group of parasites is composed of excellent model organisms for studying key questions in parasite molecular biology and cytogenetics, evolutionary ecology, and ecotoxicology. Their shared ancestry with free-living rotifers makes them an ideal group to explore the origins of the parasitic lifestyle and evolutionary drivers of host shifts and environmental transitions. They also provide useful features in the quest to decipher the proximate mechanisms of parasite-induced phenotypic alterations and better understand the evolution of behavioral manipulation. From an applied perspective, acanthocephalans' ability to accumulate contaminants offers useful opportunities to monitor the impacts - and evaluate the possible mitigation - of anthropogenic pollutants on aquatic fauna and develop the environmental parasitology framework. However, exploring these exciting research avenues will require connecting fragmentary knowledge by enlarging the taxonomic coverage of molecular and phenotypic data. In this opinion paper, we highlight the needs and opportunities of research on Acanthocephala in three main directions: (i) integrative taxonomy (including non-molecular tools) and phylogeny-based comparative analysis; (ii) ecology and evolution of life cycles, transmission strategies and host ranges; and (iii) environmental issues related to global changes, including ecotoxicology. In each section, the most promising ideas and developments are presented based on selected case studies, with the goal that the present and future generations of parasitologists further explore and increase knowledge of Acanthocephala.

Title: Accrocher la communauté scientifique à des vers à la tête pleine d'épines : faits intéressants et passionnants, lacunes dans les connaissances et perspectives pour des orientations de recherche sur les Acanthocéphales. Abstract: Bien que l'intérêt pour les acanthocéphales semble n'avoir atteint qu'un petit nombre de chercheurs dans le monde, nous montrons dans cet article que ce groupe de parasites est composé d'excellents organismes modèles pour étudier les questions en suspens en biologie moléculaire et cytogénétique, écologie évolutive et écotoxicologie. Leur ascendance partagée avec les rotifères en fait un groupe idéal pour explorer les origines du mode de vie parasitaire et les moteurs évolutifs des changements d'hôtes et des transitions environnementales. Ils présentent également des caractéristiques intéressantes pour l'étude des mécanismes proximaux sous-tendant les altérations phénotypiques induites par les parasites, et ainsi mieux comprendre l'évolution de la manipulation comportementale. D'un point de vue appliqué, la capacité des acanthocéphales à accumuler les contaminants offre des opportunités utiles pour surveiller les impacts - et évaluer les possibilités d'atténuation - des pollutions anthropiques sur la faune aquatique et développer le domaine de la parasitologie environnementale. Cependant, l'exploration de ces pistes de recherche passionnantes nécessitera de relier des connaissances fragmentaires en élargissant la couverture taxonomique des données moléculaires et phénotypiques. Dans cet article, nous présentons l'état actuel de la recherche sur les acanthocéphales selon trois axes principaux : (i) la taxonomie intégrative (y compris les outils non-moléculaires) et la phylogénie à des fins d'analyse comparative ; (ii) l'écologie et l'évolution des cycles de vie, des stratégies d'exploitation des hôtes et de transmission ; (iii) les questions environnementales liées aux changements globaux, y compris l'écotoxicologie. Dans chaque section, nous soulignons les besoins et les opportunités, en espérant que cela incitera une nouvelle génération de parasitologues à s'intéresser aux acanthocéphales.

Complete genome sequence of a novel lytic phage of Xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen in rice.

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.

Telehealth experiences in Canadian veterans: associations, strengths and barriers to care during the COVID-19 pandemic.

INTRODUCTION: Identifying barriers to care in veteran populations is critical, as veterans face increased social isolation, relationship strains and financial insecurities. For Canadian veterans experiencing barriers to accessing healthcare, telehealth may be a promising alternative with comparable effectiveness to in-person services; however, the potential benefits and limitations of telehealth require further examination to determine its long-term utility, and to inform health policy and planning. The goal of the present research was to identify predictors and barriers to telehealth usage in Canadian veterans in the context of the COVID-19 pandemic. METHODS: Data were drawn from baseline data of a longitudinal survey examining the psychological functioning of Canadian veterans during the COVID-19 pandemic. Participants were 1144 Canadian veterans aged 18-93 years (Mage=56.24, SD=12.92; 77.4% men). We assessed reported telehealth use (ie, for mental healthcare, physical healthcare), healthcare access (ie, difficulty accessing care, avoidance of care) and mental health and stress since the beginning of the COVID-19 pandemic, sociodemographic variables and open-ended responses about telehealth experiences. RESULTS: Findings suggest that sociodemographic factors and previous telehealth use were significantly associated with telehealth use during the COVID-19 pandemic. Qualitative evidence highlighted both the benefits (eg, reducing barriers of access) and drawbacks (eg, not all services can be delivered) of telehealth services. CONCLUSIONS: This paper provided a deeper understanding of Canadian veterans' experiences with accessing telehealth care during the COVID-19 pandemic. While for some, the use of telehealth mitigated perceived barriers (eg, safety concerns of leaving home), others felt that not all health services could be appropriately carried out through telehealth. Altogether, findings support the use of telehealth services in increasing care accessibility for Canadian veterans. Continued use of quality telehealth services may be a valuable form of care that extends the reach of healthcare professionals.

Diagnostic performance of magnetic resonance imaging for diagnosing acute appendicitis during pregnancy.

OBJECTIVE: This retrospective study evaluated the diagnostic efficacy of magnetic resonance imaging (MRI) for identifying acute appendicitis during pregnancy. PATIENTS AND METHODS: This retrospective study enrolled a total of 46 pregnant patients with clinically suspected acute appendicitis who underwent 1.5 T MRI and received a final pathological diagnosis. We evaluated the imaging characteristics associated with patients diagnosed with acute appendicitis, including the appendix diameter, the appendix wall thickness, intra-appendiceal fluid collection, and peri-appendiceal fat infiltration. A bright appendix on T1-weighted 3-dimensional imaging was identified as a negative sign for appendicitis. RESULTS: Peri-appendiceal fat infiltration had the highest specificity of 97.1% for diagnosing acute appendicitis, whereas increasing appendiceal diameter had the highest sensitivity of 91.7%. The cut-off values for increasing appendiceal diameter and appendiceal wall thickness were 6.55 mm and 2.7 mm, respectively. Using these cut-off values, appendiceal diameter had a sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of 91.7%, 91.2%, 78.4%, and 96.9%, respectively, whereas these values for appendiceal wall thickness were 75.0%, 91.2%, 75.0%, and 91.2%. The combination of increasing appendiceal diameter and appendiceal wall thickness resulted in an area under the receiver operating characteristic curve value of 0.958 with Se, Sp, PPV, and NPV values of 75.0%, 100.0%, 100.0%, and 91.9%, respectively. CONCLUSIONS: All five MRI signs examined in this study had significant diagnostic value for detecting acute appendicitis during pregnancy, with p-values <0.01. The combined use of increasing appendiceal diameter and appendiceal wall thickness displayed the excellent ability to diagnose acute appendicitis in pregnant women.

Janus structures of the C 2h polymorph of gallium monochalcogenides: first-principles examination of Ga2XY (X/Y = S, Se, Te) monolayers.

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.