Chiral Topological Superconductivity in Superconductor-Obstructed Atomic Insulator-Ferromagnetic Insulator Heterostructures.

Implementing topological superconductivity (TSC) and Majorana states (MSs) is one of the most significant and challenging tasks in both fundamental physics and topological quantum computations. In this work, taking the obstructed atomic insulator (OAI) Nb_{3}Br_{8}, s-wave superconductor (SC) NbSe_{2}, and ferromagnetic insulator (FMI) CrI_{3} as an example, we propose a new setup to realize the 2D chiral TSC and MSs in the SC/OAI/FMI heterostructure, which could avoid the subband problem effectively and has the advantage of huge Rashba spin-orbit coupling. As a result, the TSC phase can be stabilized in a wide region of chemical potential and Zeeman splitting, and four distinct TSC phases with superconducting Chern number N=-1,-2,-3, 3 can be achieved. Moreover, a 2D Bogoliubov-de Gennes Hamiltonian based on the triangular lattice of obstructed Wannier charge centers, combined with the s-wave superconductivity paring and Zeeman splitting, is constructed to understand the whole topological phase diagram analytically. These results expand the application of OAIs and pave a new way to realize the TSC and MSs with unique advantages.

Knowledge and belief of fecal occult blood screening: A systematic review.

INTRODUCTION: Colorectal cancer (CRC) is associated with a high incidence and mortality rate. Fecal occult blood test (FOBT) is effective in the prevention of CRC. OBJECTIVE: This study aimed to assess knowledge and beliefs regarding FOBT-based screening. METHODS: This study used PubMed, Cochrane Library, MEDLINE Complete, and Web of Science to search for articles. Original full-text studies in English language focusing on knowledge and beliefs of FOBT screening were included. RESULTS: A total of 32 articles were included. This study indicated that the population in most studies had inadequate knowledge and lacked beliefs toward FOBT-based screening. Most of the extracted studies showed that less than half of the participants had heard of FOBT-based screening. Six studies showed that less than 50% of participants had knowledge of FOBT age. Three studies found that less than 40% of participants were aware of the screening interval. Some participants perceived the benefits of FOBT-based screening, while others perceived many barriers to the test. CONCLUSION: Participants' knowledge and belief in FOBT-based screening were insufficient. This review highlights the importance of educational programs to increase knowledge and beliefs regarding FOBT-based screening. It is important to include FOBT-based screening in the health care system to promote the secondary prevention of CRC.

Efficient Method for Prediction of Metastable or Ground Multipolar Ordered States and Its Application in Monolayer α-RuX_{3} (X=Cl, I).

Exotic high-rank multipolar order parameters have been found to be unexpectedly active in more and more correlated materials in recent years. Such multipoles are usually dubbed "hidden orders" since they are insensitive to common experimental probes. Theoretically, it is also difficult to predict multipolar orders via ab initio calculations in real materials. Here, we present an efficient method to predict possible multipoles in materials based on linear response theory under random phase approximation. Using this method, we successfully predict two pure metastable magnetic octupolar states in monolayer α-RuCl_{3}, which is confirmed by self-consistent unrestricted Hartree-Fock calculations. We then demonstrate that these octupolar states can be stabilized in monolayer α-RuI_{3}, one of which becomes the octupolar ground state. Furthermore, we also predict a fingerprint of an orthogonal magnetization pattern produced by the octupole moment that can be easily detected by experiment. The method and the example presented in this Letter serve as a guide for searching multipolar order parameters in other correlated materials.

Photon-mediated electronic correlation effects in irradiated two-dimensional Dirac systems.

Periodically driven systems can host many interesting phenomena. Two-dimensional Dirac systems irradiated by circularly polarized light are especially attractive thanks to the special absorption and emission of photons near Dirac cones. Here, letting the light travel in the two-dimensional plane, we treat the light-driven Dirac systems by using a unitary transformation, instead of usual Floquet theory, to capture the photon-mediated electronic correlation effects. In this approach, the direct electron-photon interaction terms can be removed and the resulting effective electron-electron interactions can produce important effects. The effective interactions can produce topological band structure in the case of irradiated 2D Dirac fermion system, and can lift the energy degeneracy of the Dirac cones for irradiated graphene. This method can be applied to other light-driven Dirac systems to investigate their photon-mediated electronic effects. These phenomena would be observed with ultraviolet light in some effective two-dimensional Dirac systems of honeycomb long-period superstructures.

Intrinsic ferromagnetism and quantum anomalous Hall effect in a CoBr2 monolayer.

The electronic, magnetic, and topological properties of a CoBr2 monolayer are studied in the framework of density-functional theory (DFT) combined with tight-binding (TB) modeling in terms of the Wannier basis. Our DFT investigation and Monte Carlo simulation show that there exists intrinsic two-dimensional ferromagnetism in the CoBr2 monolayer, thanks to the large out-of-plane magnetocrystalline anisotropic energy. Our further study indicates that the spin-orbit coupling makes it become a topologically nontrivial insulator with a quantum anomalous Hall effect and topological Chern number [script C] = 4 and its edge states can be manipulated by changing the width of its nanoribbons and applying strains. The CoBr2 monolayer can be exfoliated from the layered CoBr2 bulk material because its exfoliation energy is between those of graphene and the MoS2 monolayer and it is dynamically stable. These results make us believe that the CoBr2 monolayer can make a promising spintronic material for future high-performance devices.

Identification of PP2Cs in six rosaceae species highlights RcPP2C24 as a negative regulator in rose drought tolerance.

Drought is a major environmental stress that limits plant growth, so it's important to identify drought-responsive genes to understand the mechanism of drought response and breed drought-tolerant roses. Protein phosphatase 2C (PP2C) plays a crucial role in plant abiotic stress response. In this study, we identified 412 putative PP2Cs from six Rosaceae species. These genes were divided into twelve clades, with clade A containing the largest number of PP2Cs (14.1%). Clade A PP2Cs are known for their important role in ABA-mediated drought stress response; therefore, the analysis focused on these specific genes. Conserved motif analysis revealed that clade A PP2Cs in these six Rosaceae species shared conserved C-terminal catalytic domains. Collinearity analysis indicated that segmental duplication events played a significant role in the evolution of clade A PP2Cs in Rosaceae. Analysis of the expression of 11 clade A RcPP2Cs showed that approximately 60% of these genes responded to drought, high temperature, and salt stress. Among them, RcPP2C24 exhibited the highest responsiveness to both drought and ABA. Furthermore, overexpression of RcPP2C24 significantly reduced drought tolerance in transgenic tobacco by increasing stomatal aperture after exposure to drought stress. The transient overexpression of RcPP2C24 weakened the dehydration tolerance of rose petal discs, while its silencing increased their dehydration tolerance. In summary, our study identified PP2Cs in six Rosaceae species and highlighted the negative role of RcPP2C24 on rose's drought tolerance by inhibiting stomatal closure. Our findings provide valuable insights into understanding the mechanism behind rose's response to drought.

Interventions to Improve Endoscopic Screening Adherence of Cancer in High-Risk Populations: A Scoping Review.

Background: Colorectal, and gastric cancers have the second, and fourth mortality rates worldwide, respectively. Endoscopic screening is a crucial diagnostic tool for colorectal, and gastric cancers. Effective interventions can improve adherence to endoscopic screening in high-risk populations, which is important for cancer prevention and mortality reduction. This study aimed to identify interventions that could improve adherence to endoscopic screening for cancer in high-risk populations. Methods: Combination keywords including colorectal cancer, gastric cancer, screening adherence, and interventions were used to search for articles in PubMed, Web of Science, Cochrane Library, and MEDLINE Complete. The review methodology was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-SCR). Results: A total of 12 articles were included in this review: 9 randomized controlled trials(RCT) and 3 quasi-experimental studies(QEDs). Among the extracted studies, 11 were about colorectal cancer, and 1 was about gastric cancer. Most studies used lecture-based or Information Technology-based health education interventions. Narrative interventions have proven to be novel and effective approaches for promoting adherence to endoscopic screening. Health education interventions included cancer epidemiology, cancer risk factors, warning symptoms, and screening methods. Conclusion: All interventions involved were effective in increasing individual knowledge of cancer-related endoscopic screening, willingness to undergo screening, and screening behaviors. These findings provide a reference for designing endoscopy-related cancer screening interventions.

What is the general Chinese public's awareness of and attitudes towards Helicobacter pylori screening and associated health behaviours? A cross-sectional study.

OBJECTIVE: To evaluate the general population's awareness of and attitudes toward Helicobacter pylori (HP) screening and health behaviours. DESIGN: Cross-sectional study. SETTING: Hengyang, Hunan Province, China. PARTICIPANTS: Using stratified cluster random sampling, a pretested structured questionnaire was used to interview members of the general population aged ≥18 years. PRIMARY AND SECONDARY OUTCOME MEASURES: Knowledge of and attitudes toward HP screening and associated health behaviours, sociodemographic factors associated with HP knowledge, and screening behaviours. RESULTS: This study featured 1042 participants. The average knowledge score was 11 (QL=4, QU=20, range 0-29). Approximately 68.9% of the participants said they had heard of HP, but 67.5% had never had an HP test. The most common reasons for not undergoing screening were 'no symptoms' (55.7%) and 'lack of knowledge regarding the benefits of the test' (21.1%). Independent factors related to knowledge included age, education level, occupation, HP infection, frequency of drinking unboiled water (p<0.05). Factors independently associated with screening behaviour included occupation, average monthly income, presence/absence of indigestion, stomach discomfort or pain, and/or stomach disease and knowledge score (p<0.05). Overall, 941 (90.3%) participants never used anti-HP toothpaste, and 442 (40.5%) never used serving spoons or chopsticks. The risk factors for HP infection included eating out and eating in groups (p<0.05). CONCLUSION: In China, the general population has poor knowledge of HP, but most people have a positive attitude towards HP screening. Being asymptomatic and lacking knowledge about testing were the main reasons for reluctance to be screened. These results highlight the urgent need for educational activities to raise awareness, enhance screening rates for HP, and encourage people to adopt a healthy lifestyle.

New types of topological superconductors under local magnetic symmetries.

We classify gapped topological superconducting (TSC) phases of one-dimensional quantum wires with local magnetic symmetries, in which the time-reversal symmetry [Formula: see text] is broken, but its combinations with certain crystalline symmetries, such as [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text], are preserved. Our results demonstrate that an equivalent BDI class TSC can be realized in the [Formula: see text] or [Formula: see text] superconducting wire, which is characterized by a chiral Z c invariant. More interestingly, we also find two types of totally new TSC phases in the [Formula: see text] and [Formula: see text] superinducting wires, which are beyond the known AZ class, and are characterized by a helical Z h invariant and Z h ⊕Z c invariants, respectively. In the Z h TSC phase, Z pairs of Majorana zero modes (MZMs) are protected at each end. In the [Formula: see text] case, the MZMs can be either chiral or helical, and even helical-chiral coexisting. The minimal models preserving [Formula: see text] or [Formula: see text] symmetry are presented to illustrate their novel TSC properties and MZMs.

Awareness, attitude and barriers of colorectal cancer screening among high-risk populations in China: a cross-sectional study.

OBJECTIVE: To assess the awareness, attitude and barriers of colorectal cancer screening among high-risk populations in China. DESIGN: A cross-sectional study was employed. SETTING: This study was conducted in nine hospitals in Hunan province, China. PARTICIPANTS: Individuals with a high-risk for colorectal cancer were interviewed using a pretested structured questionnaire. PRIMARY AND SECONDARY OUTCOME MEASURES: Knowledge, attitude towards colorectal cancer screening, sociodemographic factors associated with screening knowledge and behaviour and barriers of colorectal cancer screening. RESULTS: This study included 684 participants. The mean knowledge score was 11.86/24 (SD 4.84). But over 70% of them held a positive attitude towards screening. Only 13.3% had undergone colorectal cancer screening. Independent factors related to knowledge were education level of college or above, working as a white collar, higher income, having health insurance, having seen a doctor in the past year and with a high perceived risk (p<0.05). Factors independently associated with screening behaviour included personal history of colorectal disease, having seen a doctor in the past year, previous discussion of colorectal cancer screening, high perceived risk and better knowledge (p<0.05). Main reasons for not undergoing screening were no symptoms or discomfort (71.1%), never having thought of the disease or screening (67.4%) and no doctor advised me (29.8%). CONCLUSION: In China, the majority of high-risk people had deficient knowledge and had never undergone colorectal cancer screening. But most of them held a positive attitude towards the benefits of colorectal cancer screening. This has promising implications to design targeted educational campaigns and establish screening programmes to improve colorectal cancer awareness and screening participation. Healthcare professionals should advise high-risk individuals to participate in screening and inform them about cancer risk.

Directed evolution of an enantioselective epoxide hydrolase: uncovering the source of enantioselectivity at each evolutionary stage.

Directed evolution of enzymes as enantioselective catalysts in organic chemistry is an alternative to traditional asymmetric catalysis using chiral transition-metal complexes or organocatalysts, the different approaches often being complementary. Moreover, directed evolution studies allow us to learn more about how enzymes perform mechanistically. The present study concerns a previously evolved highly enantioselective mutant of the epoxide hydrolase from Aspergillus niger in the hydrolytic kinetic resolution of racemic glycidyl phenyl ether. Kinetic data, molecular dynamics calculations, molecular modeling, inhibition experiments, and X-ray structural work for the wild-type (WT) enzyme and the best mutant reveal the basis of the large increase in enantioselectivity (E = 4.6 versus E = 115). The overall structures of the WT and the mutant are essentially identical, but dramatic differences are observed in the active site as revealed by the X-ray structures. All of the experimental and computational results support a model in which productive positioning of the preferred (S)-glycidyl phenyl ether, but not the (R)-enantiomer, forms the basis of enhanced enantioselectivity. Predictions regarding substrate scope and enantioselectivity of the best mutant are shown to be possible.

A novel and conserved pocket of human kappa-Fab fragments: design, synthesis, and verification of directed affinity ligands.

Antibodies of type IgG may be divided into two classes, called lambda or kappa, depending on the type of light chain. We have identified a conserved pocket between the two domains CH1 and CL of human IgG kappa-Fab, which is not present in the lambda type. This pocket was used as a target docking site with the purpose of exploring the possibilities of designing affinity ligands that could function as such even after immobilization to gel. The idea of the design arose mainly from the results of the saturated transfer difference (STD-NMR) screening of 46 compounds identified by means of virtual docking of 60 K diverse compounds from the Available Chemicals Directory (ACD). Surface plasmon resonance (SPR) was used as an alternative method to monitor binding in solution. A total of 24 compounds belonging to a directed library were designed, synthesized, and screened in solution. They consist essentially of an amino acid condensed to a N,N'-methylated phenyl urea. STD-NMR results suggest that a small hydrophobic side chain in the condensed amino acid promotes binding, whereas a hydroxyl-group-containing side chain implies absence of STD-NMR signals. Three compounds of the directed library were immobilized and evaluated as chromatographic probes. In one case, using D-Pro as the condensed amino acid, columns packed with ligand-coupled Sepharose (Amersham Biosciences) retained two different monoclonal samples of kappa-Fab fragments with different variable regions, whereas a sample of monoclonal lambda-Fab fragments was not retained under similar chromatographic conditions.

Rapid screening of antibody aggregates and protein impurities using short gel filtration columns.

Gel filtration (GF) is an excellent tool to acquire information about sizing (identity), purity, and the multimeric state of a protein of interest. Superdex 200 and Superdex 75 are outstanding GF media for such analysis. To speed up analysis and keep sample and buffer consumption at minimum, two prepacked short GF columns have been developed, Superdex 200 5/150 GL and Superdex 75 5/150 GL. With lengths of only 15 cm and volume of 3 ml, these columns allow rapid analysis (6-12 min/run) with minimal sample (4-50microl) and buffer consumption.

Structure of Rhodococcus erythropolis limonene-1,2-epoxide hydrolase reveals a novel active site.

Epoxide hydrolases are essential for the processing of epoxide-containing compounds in detoxification or metabolism. The classic epoxide hydrolases have an alpha/beta hydrolase fold and act via a two-step reaction mechanism including an enzyme-substrate intermediate. We report here the structure of the limonene-1,2-epoxide hydrolase from Rhodococcus erythropolis, solved using single-wavelength anomalous dispersion from a selenomethionine-substituted protein and refined at 1.2 A resolution. This enzyme represents a completely different structure and a novel one-step mechanism. The fold features a highly curved six-stranded mixed beta-sheet, with four alpha-helices packed onto it to create a deep pocket. Although most residues lining this pocket are hydrophobic, a cluster of polar groups, including an Asp-Arg-Asp triad, interact at its deepest point. Site-directed mutagenesis supports the conclusion that this is the active site. Further, a 1.7 A resolution structure shows the inhibitor valpromide bound at this position, with its polar atoms interacting directly with the residues of the triad. We suggest that several bacterial proteins of currently unknown function will share this structure and, in some cases, catalytic properties.

The active site of cellobiohydrolase Cel6A from Trichoderma reesei: the roles of aspartic acids D221 and D175.

Trichoderma reesei cellobiohydrolase Cel6A is an inverting glycosidase. Structural studies have established that the tunnel-shaped active site of Cel6A contains two aspartic acids, D221 and D175, that are close to the glycosidic oxygen of the scissile bond and at hydrogen-bonding distance from each other. Here, site-directed mutagenesis, X-ray crystallography, and enzyme kinetic studies have been used to confirm the role of residue D221 as the catalytic acid. D175 is shown to affect protonation of D221 and to contribute to the electrostatic stabilization of the partial positive charge in the transition state. Structural and modeling studies suggest that the single-displacement mechanism of Cel6A may not directly involve a catalytic base. The value of (D2O)(V) of 1.16 +/- 0.14 for hydrolysis of cellotriose suggests that the large direct effect expected for proton transfer from the nucleophilic water through a water chain (Grotthus mechanism) is offset by an inverse effect arising from reversibly breaking the short, tight hydrogen bond between D221 and D175 before catalysis.