Observation of plaid-like spin splitting in a noncoplanar antiferromagnet.

Spatial, momentum and energy separation of electronic spins in condensed-matter systems guides the development of new devices in which spin-polarized current is generated and manipulated1-3. Recent attention on a set of previously overlooked symmetry operations in magnetic materials4 leads to the emergence of a new type of spin splitting, enabling giant and momentum-dependent spin polarization of energy bands on selected antiferromagnets5-10. Despite the ever-growing theoretical predictions, the direct spectroscopic proof of such spin splitting is still lacking. Here we provide solid spectroscopic and computational evidence for the existence of such materials. In the noncoplanar antiferromagnet manganese ditelluride (MnTe2), the in-plane components of spin are found to be antisymmetric about the high-symmetry planes of the Brillouin zone, comprising a plaid-like spin texture in the antiferromagnetic (AFM) ground state. Such an unconventional spin pattern, further found to diminish at the high-temperature paramagnetic state, originates from the intrinsic AFM order instead of spin-orbit coupling (SOC). Our finding demonstrates a new type of quadratic spin texture induced by time-reversal breaking, placing AFM spintronics on a firm basis and paving the way for studying exotic quantum phenomena in related materials.

Exercise is inversely associated with functional dyspepsia among a sample of Chinese male armed police recruits.

BACKGROUND: There is no study evaluating the association between exercise and functional dyspepsia (FD) based on the Rome IV criteria. We aimed to investigate the prevalence of FD and evaluate the association between exercise and FD based on Rome IV criteria among a sample of Chinese armed police recruits. METHODS: An on-site questionnaire survey on FD among a sample of Chinese armed police recruits was conducted based on the Rome IV criteria in 2021. Potential confounders included age, body mass index (BMI), race, marriage, education, smoking, and drinking variables were adjusted. RESULTS: A total of 2594 recruits were enrolled, including 46 FD participants and 2548 non-FD participants. In the model adjusted for all demographic variables among participants excluding irritable bowel syndrome (IBS) and functional constipation (FC), compared with no exercise participants, 1 h < each exercise time ≤ 2 h (OR = 0.15, 95% CI: 0.03-0.77, P = 0.0230) was inversely associated with FD and compared with no exercise participants, mild exercise (OR = 0.09, 95% CI: 0.01-0.71, P = 0.0220) was significantly inversely associated with FD. CONCLUSIONS: The incidence rate of FD in this sample Chinese armed police recruits was 1.77%, and 1 h < each exercise time ≤ 2 h and mild intensity exercise were independently inversely associated with FD. However, the causal relationship needs to be verified by further randomized controlled trials.

[Prevalence Survey of Functional Dyspepsia and Irritable Bowel Syndrome in Chinese College Students Based on Rome â £ Diagnostic Criteria].

Objective: To investigate the prevalence and risk factors of functional dyspepsia (FD) and irritable bowel syndrome (IBS) among college students in China. Methods: An online questionnaire survey of college students aged 17-35 from across China was conducted. The online questionnaire survey was supplemented by an offline survey. A total of 2025 valid samples were included for statistical analysis. χ 2 test and logistic regression were performed for statistical analysis. Results: The prevalence of FD among college students who met the Rome Ⅳ diagnostic criteria was 5.5% (112/2025), with most of them, or 66.1% (74/112), suffering from postprandial discomfort syndrome (PDS). Smoking (odds ratio [ OR]=2.334, 95% confidence interval [ CI]: 1.187-4.589, P=0.014), depression ( OR=2.447, 95% CI: 1.421-4.214, P=0.001), and insomnia ( OR=1.947, 95% CI: 1.291-2.937, P=0.001) were positively correlated with the prevalence of FD. The prevalence of IBS was 1.9% (38/2025), with IBS-diarrhea dominant (IBS-D) being the most important subtype that accounted for 44.7%. Anxiety ( OR=3.63, 95% CI: 1.34-9.88, P=0.012) and insomnia ( OR=2.35, 95% CI: 1.18-4.68, P=0.015) were positively correlated with the prevalence of IBS. Conclusion: Based on Rome Ⅳ criteria, IBS and FD are not uncommon among Chinese university students. Psychological disorders and some related lifestyle factors may be related to the development of the disease. In the future, more series of studies based on different diagnostic criteria, different regions, and multiple factors should be conducted in China.

Non-acid reflux and esophageal dysmotility is associated with early esophageal squamous cell carcinoma.

BACKGROUND: Studies have demonstrated that non-acid reflux (NAR) is associated with esophageal squamous cell carcinoma (ESCC). Esophageal dysmotility is associated with NAR but few studies have focused on the esophageal motility of ESCC patients. We explored the relationship between ESCC, NAR and esophageal dysmotility with the aid of multichannel intraluminal impedance and pH (MII-pH) and high-resolution manometry (HRM). METHODS: From Jan 2021 to Oct 2022, 20 patients with superficial ESCC were enrolled as the ESCC group, while 20 age and gender matched individuals without gastroesophageal reflux disease (GERD) symptoms and 20 age and gender matched patients with GERD symptoms were recruited as the control groups. Patients received 24 h MII-pH and HRM procedure before endoscopic submucosal dissection (ESD), and the data were then collected to identify the type of reflux and esophageal dysmotility. RESULTS: Prevalence of esophageal dysmotility was significantly different among the three groups, 75.0% in the ESCC group, 35.0% in the non-GERD group and 70.0% in the GERD group (P = 0.029). NAR episodes at 15 cm above the lower esophageal sphincter (LES) in the ESCC group were significantly higher than that in the non-GERD group (6.5 (3.5-9.3) vs 1.0 (0.8-4.0), P = 0.001) and were similar with that in the GERD group (6.5 (3.5-9.3) vs 5.5 (3.0-10.5), P > 0.05). NAR episodes at 5 cm above LES was significantly higher in the ESCC group than that in the non-GERD group (38.0 (27.0-60.0) vs 18.0 (11.8-25.8), P = 0.001) and was significantly higher than that in the GERD group (38.0 (27.0-60.0) vs 20.0 (9.8-30.5)), P = 0.010). Prevalence of pathologic non-acid reflux was significantly different among the three groups, 30.0% in the ESCC group, 0.0% in the non-GERD group and 10.0% in the GERD group (P < 0.001). CONCLUSION: Our study found NAR and esophageal dysfunction frequently occur in ESCC patients. NAR and esophageal dysmotility may be associated with ESCC. CLINICAL TRIAL REGISTRATION NUMBER: ChiCTR2200061456.

Bidirectional potential effects of DON transformation in vadose zones on groundwater nitrate contamination: Different contributions to nitrification and denitrification.

The main cause of groundwater nitrate contamination is the continual downward migration of dissolved nitrogen (N) in vadose zone with leachate. In recent years it has been found that dissolved organic N (DON) rise to forefront due to its great migration capacity and environmental effects. However, it remains unknown how the transformation behaviors of DONs with different properties in vadose zone profile may impact N forms distribution and groundwater nitrate contamination. To address the issue, we conducted a series of 60-day microcosm incubation experiments to investigate the effects of various DONs transformation behaviors on the distribution of N forms, microbial communities, and functional genes. The results revealed that urea and amino acids mineralized immediately after substrates addition. By contrast, amino sugars and proteins caused less dissolved N throughout entire incubation period. The transformation behaviors could substantially alter the microbial communities. Moreover, we discovered that amino sugars remarkably increased the absolute abundances of denitrification function genes. These results delineated that DONs with unique characteristics (such as amino sugar) promoted different N geochemical processes in distinct ways: different contributions to nitrification and denitrification. This can provide new insights for nitrate non-point source pollution control in groundwater.

The Effects of Psychological Interventions on Symptoms and Psychology of Functional Dyspepsia: A Systematic Review and Meta-Analysis.

Background: The effects of psychological interventions on symptoms and psychology of functional dyspepsia (FD) remain unclear. We aimed to comprehensively evaluate the effects of psychological interventions on symptoms and psychology of FD. Methods: We searched the PubMed, Cochrane Library, and Embase electronic databases for randomized controlled trials (RCTs) evaluating the role of psychological interventions in FD patients published before July 2021. Standardized mean differences (SMDs), risk ratios (RRs) and 95% confidence intervals (CIs) were calculated by a random effects model. Subgroup analyses and sensitivity analyses were also performed. Results: Fourteen RCTs with a total of 1,434 FD patients were included. Compared with the control group, psychological interventions were significantly more likely to symptom improvement [RR = 1.74, 95% CI (1.12, 2.72), p = 0.01], relieve gastrointestinal symptoms scores at follow up [SMD = -1.06, 95% CI (-1.55, -0.57), p < 0.0001], relieve gastrointestinal symptoms scores at end of treatment [SMD = -0.98, 95% CI (-1.29, -0.67), p < 0.001], decrease anxiety [SMD = -0.8, 95% CI (-1.38, -0.22), p = 0.006] and depression levels [SMD = -1.11, 95% CI (-1.62, -0.61), p < 0.001]. The results of the subgroup analysis showed that psychotherapy was more likely to symptom improvement, relieve gastrointestinal symptoms scores and decreased depression levels compared to the control. Conclusions: Psychological interventions may be effective in alleviating the symptoms and psychology of FD, but the effect appears to be limited to psychotherapy with fewer trials for other psychological interventions. More data from high-quality RCTs are needed to confirm their use in the treatment of FD.

Observation of Spin-Momentum-Layer Locking in a Centrosymmetric Crystal.

The spin polarization in nonmagnetic materials is conventionally attributed to the outcome of spin-orbit coupling when the global inversion symmetry is broken. The recently discovered hidden spin polarization indicates that a specific atomic site asymmetry could also induce measurable spin polarization, leading to a paradigm shift in research on centrosymmetric crystals for potential spintronic applications. Here, combining spin- and angle-resolved photoemission spectroscopy and theoretical calculations, we report distinct spin-momentum-layer locking phenomena in a centrosymmetric, layered material, BiOI. The measured spin is highly polarized along the Brillouin zone boundary, while the same effect almost vanishes around the zone center due to its nonsymmorphic crystal structure. Our work demonstrates the existence of momentum-dependent hidden spin polarization and uncovers the microscopic mechanism of spin, momentum, and layer locking to each other, thus shedding light on the design metrics for future spintronic materials.

Determination of the nitrogen isotope enrichment factor associated with ammonification and nitrification in unsaturated soil at different temperatures.

For nitrogen (N) migration and transformation from unsaturated soil to groundwater, the N stable isotope (δ15N) was modified due to the isotope fractionation effect. To quantitatively evaluate the N cycle in groundwater systems, the determination of isotope fractionation is decisive. In this research, for the first time, incubation experiments were conducted to quantitatively investigate the N isotope enrichment factor (ϵp/s) associated with ammonification in unsaturated soil. Under weak isotopic fractionation, the Rayleigh function cannot be directly applied during ammonification. Thus, we proposed a different method calculating the ϵp/s values during ammonification, which were -0.03‰ for 15 °C and -2.34‰ for 30 °C. Moreover, for the first time, experimental equipment is presented to explore the isotopic fractionation effects under the co-occurrence of nitrification and volatilization. The results indicated that the isotope effect of volatilization during nitrification can be ignored in this study, and the ϵp/s values during nitrification were -10.59 and -6.81‰ at 15 and 30 °C, respectively. This work provides a novel arrangement determining the crucial parameters for identifying nitrate pollution sources in groundwater systems.

Comparison of smear cytology with liquid-based cytology in pancreatic lesions: A systematic review and meta-analysis.

BACKGROUND: Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) is a safe and accurate technique to confirm the diagnosis of pancreatic cancers. Recently, numerous studies comparing the diagnostic efficacy of smear cytology (SC) and liquid-based cytology (LBC) for pancreatic lesions yielded mixed results. AIM: To compare and identify the better cytology method for EUS-FNA in pancreatic lesions. METHODS: A comprehensive search of PubMed, Embase, and Cochrane was undertaken through July 18, 2020. The primary endpoint was diagnostic accuracy (sensitivity and specificity). Secondary outcomes included sample adequacy and post procedure complications. In addition, factors affecting diagnostic efficacy were discussed. RESULTS: Data on a total of 1121 comparisons from 10 studies met the inclusion criteria. Pooled rates of sensitivity for SC and LBC were 78% (67%-87%) vs 75% (67%-81%), respectively. In any case, both SC and LBC exhibited a high specificity close to 100%. Inadequate samples more often appeared in LBC compared with SC. However, the LBC samples exhibited a better visual field than SC. Very few post procedure complications were observed. CONCLUSION: Our data suggested that for EUS-FNA in pancreatic lesions (particularly solid lesions), SC with Rapid On-Site Evaluation represents a superior diagnostic technique. If Rapid On-Site Evaluation is unavailable, LBC may replace smears. The diagnostic accuracy of LBC depends on different LBC techniques.

Fermi Velocity Reduction of Dirac Fermions around the Brillouin Zone Center in In2 Se3 -Bilayer Graphene Heterostructures.

Emergent phenomena such as unconventional superconductivity, Mott-like insulators, and the peculiar quantum Hall effect in graphene-based heterostructures are proposed to stem from the superlattice-induced renormalization of (moiré) Dirac fermions at the graphene Brillouin zone corners. Understanding the corresponding band structure commonly demands photoemission spectroscopy with both sub-meV resolution and large-momentum coverage, beyond the capability of the current state-of-the-art. Here the realization of moiré Dirac cones around the Brillouin zone center in monolayer In2 Se3 /bilayer graphene heterostructure is reported. The renormalization is evidenced by reduced Fermi velocity (≈23%) of the moiré Dirac cones and the reshaped Dirac point at the Γ point where they intersect. While there have been many theoretical predictions and much indirect experimental evidence, the findings here are the first direct observation of Fermi velocity reduction of the moiré Dirac cones. These features suggest strong In2 Se3 /graphene interlayer coupling, which is comparable with that in twisted bilayer graphene. The strategy expands the choice of materials in the heterostructure design and stimulates subsequent broad investigations of emergent physics at the sub-meV energy scale.

Te-Vacancy-Induced Surface Collapse and Reconstruction in Antiferromagnetic Topological Insulator MnBi2Te4.

MnBi2Te4 is an antiferromagnetic topological insulator that has stimulated intense interest due to its exotic quantum phenomena and promising device applications. The surface structure is a determinant factor to understand the magnetic and topological behavior of MnBi2Te4, yet its precise atomic structure remains elusive. Here we discovered a surface collapse and reconstruction of few-layer MnBi2Te4 exfoliated under delicate protection. Instead of the ideal septuple-layer structure in the bulk, the collapsed surface is shown to reconstruct as a Mn-doped Bi2Te3 quintuple layer and a MnxBiyTe double layer with a clear van der Waals gap in between. Combined with first-principles calculations, such surface collapse is attributed to the abundant intrinsic Mn-Bi antisite defects and the tellurium vacancy in the exfoliated surface, which is further supported by in situ annealing and electron irradiation experiments. Our results shed light on the understanding of the intricate surface-bulk correspondence of MnBi2Te4 and provide an insightful perspective on the surface-related quantum measurements in MnBi2Te4 few-layer devices.

Nitrate source apportionment in groundwater using Bayesian isotope mixing model based on nitrogen isotope fractionation.

Accurate identification of nitrate (NO3-) sources is critical to address the issue of groundwater pollution. The nitrogen (N) isotopic enrichment factor (ɛp/s) is an important parameter to explain the N cycle and determine the proportional contribution of NO3- sources. Considering the isotopic fractionation effects in N transformation processes, this study quantitatively analyzed the NO3- sources in groundwater using stable isotopes (δ15N-NO3- and δ18O-NO3-) and the Bayesian isotope mixing model (SIAR). For the first time, the ɛp/s values (0.0‰, -8.7‰, -8.7‰, and 14.7‰) of atmospheric deposition (AD), soil nitrogen (SN), chemical fertilizers (CF), and manure and sewage (M&S) were calculated to determine the NO3- source apportionment in groundwater. It was proved that the isotopic fractionation effect could produce a more accurate NO3- source apportionment. We also found that the NO3- source contributions were closely related to the cropping system. In the vegetable cultivation area, CF (54.32%) and SN (37.75%) were the dominant NO3- source, while in the grain cultivation area, NO3- pollution was largely influenced by SN (33.67%), CF (33.27%), and M&S (30.16%). According to this study, the isotope fractionation is strongly recommended for NO3- source apportionment in groundwater system.

High thermoelectric performance in low-cost SnS0.91Se0.09 crystals.

Thermoelectric technology allows conversion between heat and electricity. Many good thermoelectric materials contain rare or toxic elements, so developing low-cost and high-performance thermoelectric materials is warranted. Here, we report the temperature-dependent interplay of three separate electronic bands in hole-doped tin sulfide (SnS) crystals. This behavior leads to synergistic optimization between effective mass (m*) and carrier mobility (µ) and can be boosted through introducing selenium (Se). This enhanced the power factor from ~30 to ~53 microwatts per centimeter per square kelvin (µW cm-1 K-2 at 300 K), while lowering the thermal conductivity after Se alloying. As a result, we obtained a maximum figure of merit ZT (ZT max) of ~1.6 at 873 K and an average ZT (ZT ave) of ~1.25 at 300 to 873 K in SnS0.91Se0.09 crystals. Our strategy for band manipulation offers a different route for optimizing thermoelectric performance. The high-performance SnS crystals represent an important step toward low-cost, Earth-abundant, and environmentally friendly thermoelectrics.

A Design of Solid-State Li-S Cell with Evaporated Lithium Anode To Eliminate Shuttle Effects.

Li-S batteries hold great potential for energy storage systems due to their high theoretical capacity and low cost. However, the shuttle of polysulfides in conventional Li-S batteries with organic electrolyte results in severe problems, such as low Coulombic efficiency and poor cycling stability. Here, we developed a solid-state Li-S battery using Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid ceramic electrolyte instead of liquid electrolyte. Lithium film was deposited on one side of LAGP by an evaporation method to improve the contact between anode and LAGP. Sulfur-coated carbon nanotubes cathode (S-MWCNT) composition was casted on the other side of LAGP as the cathode and a small amount of ionic liquid was dropped in order to improve the ionic conductivity. This battery exhibited a high capacity of 1510 mAh g-1 in the first cycle and retained 1400 mAh g-1 after 30 cycles. Meanwhile, the Coulombic efficiency of the battery was almost 100% for each cycle, which indicated the shuttle effect was circumvented completely.

Preparation and in vitro study of hydrochloric norvancomycin encapsulated poly (d,l-lactide-co-glycolide, PLGA) microspheres for potential use in osteomyelitis.

HNV-loaded PLGA microspheres (HNV-PLGA MSs) were prepared by water-in-oil-in-water (w/o/w) double emulsion solvent evaporation technique. The surface of prepared HNV-PLGA MSs is smooth and nonporous with an average diameter of 69.9 µm. The drug-loading rate and encapsulation rate of HNV-PLGA MSs are 4.40 ± 0.26% and 48.51 ± 14.83%, respectively. Additionally, 43.36% of HNV was released from PLGA MSs after seven days of incubation. The antibacterial effects of HNV released from PLGA were as good as the pure HNV. HNV-loaded PLGA microspheres were successfully prepared using double emulsion solvent evaporation technique and their properties met the requirements for local anti-infection.

3,4-ethylenedioxythiophene as an electron donor to construct arylamine sensitizers for highly efficient iodine-free dye-sensitized solar cells.

The development of arylamine photosensitizers with high extinction coefficients, and suitable electronic structures and steric properties is necessary for improving the efficiency of dye-sensitized solar cells (DSCs) employing iodine-free redox shuttles. A new truxene-based organic sensitizer, M20, incorporating a 3,4-ethylenedioxythiophene (EDOT) moiety as an electron donor was synthesized and compared to its reference sensitizer, M4. M20 sensitized DSCs employing the Co(II/III) tris(1,10-phenanthroline)-based redox electrolyte exhibit a short circuit photocurrent of 11.8 mA cm(-2), an open circuit voltage of 903 mV, and a fill factor of 0.69, corresponding to an overall conversion efficiency of 7.35% under standard AM 1.5 sunlight, which is higher than that of 6.86% for equivalent M4 sensitized DSCs. The effects of 4-tert-butylpyridine (TBP) as an additive on the photovoltaic performance of truxene-dye-sensitized nanocrystallineTiO2 solar cells were also investigated.

New triphenylamine organic dyes containing dithieno[3,2-b:2',3'-d]pyrrole (DTP) units for iodine-free dye-sensitized solar cells.

Three dithieno[3,2-b:2',3'-d]pyrrole (DTP) units with different hexyloxyphenyl (HOP) substituents have been developed for triphenylamine organic dyes (XS54-XS56). The introduction of the 4-HOP-DTP unit has resulted in a stronger light harvesting capacity, accounting for the observed photocurrent enhancement in the case of XS54, while the 2-HOP-DTP/2,4-HOP-DTP units induce a strikingly large photovoltage improvement in the cases of XS55 and XS56 due to their higher steric hindrance.

Efficient expression of an alkaline pectate lyase gene from Bacillus subtilis and the characterization of the recombinant protein.

The gene encoding a novel alkaline pectate lyase (Apel) from Bacillus subtilis was cloned and expressed in B. subtilis WB600. Apel contained an ORF of 1,260 bp, encoding a signal peptide of 21 amino acids and a mature protein of 399 amino acids with a calculated molecular mass of 45497.9 Da. The mature Apel was structurally related to the enzymes in the polysaccharide lyase family 1. After purification, the recombinant Apel had a specific activity of 445 U mg(-1). The enzyme was optimally active at 50°C and pH 9.