ZnO/g-C3N4 photocatalyst activated by low-pressure ultraviolet for restoring the SWASV signals: A fast pretreatment method for electrochemically detecting Cd2+ and Pb2+ in soil extracts.

Soil organic matter (SOM) significantly impacts the detection accuracy of Cd2+ and Pb2+ using square wave anodic stripping voltammetry (SWASV) due to the complexation of SOM to heavy metal ions (HMIs), thereby attenuating SWASV signals. This study explored an effective pretreatment method that combined low-pressure ultraviolet (LPUV) photolysis with the ZnO/g-C3N4 photocatalyst, activating the photocatalyst to generate highly oxidative •OH radicals and O2•- radicals, which effectively disrupted this complexation, consequently restoring the electroactivity of HMIs and achieving high-fidelity SWASV signals. The parameters of the LPUV-ZnO/g-C3N4 photocatalytic system were meticulously optimized, including the pH of photolysis, duration of photolysis, g-C3N4 mass fraction, and concentration of the photocatalyst. Furthermore, the ZnO/g-C3N4 photocatalyst was thoroughly characterized, with an in-depth investigation on the synergistic interaction between ZnO and g-C3N4 and the mechanisms contributing to the restoration of SWASV signals. This synergistic interaction effectively separated charge carriers and reduced charge transfer resistance, enabling photogenerated electrons (e-) from the conduction band of g-C3N4 to be quickly transferred to the conduction band of ZnO, preventing the recombination of e- and h+ and generating more radicals to disrupt complexation and restore the SWASV signals. Finally, the analysis of HMIs in real soil extracts using the proposed pretreatment method demonstrated high detection accuracy of 94.9% for Cd2+ and 99.8% for Pb2+, which validated the feasibility and effectiveness of the proposed method in environmental applications.

Age-Related Effect of Uric Acid on Contrast-Induced Acute Kidney Injury of Patients Undergoing Coronary Angiography.

Background: The association between uric acid (UA) and contrast-induced acute kidney injury (CI-AKI) following coronary angiography (CAG) has been established. However, whether the association would vary with age remained undetermined. Methods: We performed the retrospective analysis based on the Cardio-renal Improvement II study, (ClinicalTrials.gov NCT05050877), which enrolled consecutive patients undergoing coronary angiography in 5 teaching hospitals in China from 2007 to 2020. The primary outcome was CI-AKI defined as the rise of serum creatinine (SCr) ≥ 0.5 mg/dL or 25% compared with the baseline value within 48 hours following CAG. The effect of age on the association between uric acid and CI-AKI was assessed by the logistic regression model. Results: A total of 36,550 patients (mean age 63.08±5.6-year-old, 41.7% men) were included in the study. After adjusting for the confounders, the risk of CI-AKI between each quartile of uric acid was insignificant in the young group. In patients of the middle group, lower UA was associated with a lower risk of CI-AKI while higher UA was associated with a higher risk (Q1 OR: 0.853, 95% CI: 0.734-0.993; Q4 OR: 1.797, 95% CI: 1.547-2.09). In patients of the elder group, lower and higher UA were both associated with a higher risk of CI-AKI (Q1 OR: 1.247, 95% CI: 1.003-1.553; Q4 OR: 1.688, 95% CI: 1.344-2.124). The restricted cubic spline indicated a non-linear association between UA and CI-AKI in middle and elder age groups but a linear association in the young age group. Conclusion: The association between uric acid and CI-AKI vary in patients of different age. Patients with elder age should maintain a middle level of uric acid while patients with middle age should consider a lower level of uric acid to reduce the risk of CI-AKI. The level of UA was an insignificant risk factor for CI-AKI in young patients.

Epsilon-near-zero material-based bi-layer metamaterials for selective mid-infrared radiation.

Selective mid-infrared (MIR) radiation is highly desirable in many applications. However, there are still great challenges to simultaneously achieve MIR camouflage and radiative cooling utilizing simple structure. This work theoretically and experimentally proposes a bi-layer metamaterial composed of aluminum doped zinc oxide (AZO) nanoparticles embedded in Al2O3matrix on the aluminum film. The bi-layer metamaterial exhibits high performance in MIR camouflage with radiative cooling, a low emissivity (ε3-5µm= 0.11,ε8-14µm= 0.20) in atmospheric windows and a high emissivity (ε5-8µm= 0.81) in non-atmospheric windows. The interaction of the epsilon-near-zero (ENZ) mode and localized surface plasmon resonance (LSPR) mode is responsible for the perfect emission over the wavelength range of 5-8µm. Additionally, the proposed selective MIR emitter supports large-angle incidence and has great polarization insensitivity. This demonstrates that epsilon-near-zero material-based bi-layer metamaterial is highly promising for the development of selective mid-infrared radiation.

Analysis of Drug-Resistance Characteristics and Genetic Diversity of Multidrug-Resistant Tuberculosis Based on Whole-Genome Sequencing on the Hainan Island, China.

Purpose: Given the high burden of Tuberculosis (TB) in China, the prevalence of multidrug-resistant tuberculosis (MDR-TB) is significant. Whole-genome sequencing (WGS) of Mycobacterium tuberculosis (MTB) enables the identification of lineages, drug-resistant mutations, and transmission patterns, offering valuable insights for TB control, clinical diagnosis, and treatment. Methods: We collected 202 MDR-MTB strains from 3519 suspected pulmonary TB patients treated at The Second Affiliated Hospital of Hainan Medical University between July 2019 and June 2021. Proportional drug-susceptibility testing was performed using 8 common anti-tuberculosis drugs. Subsequently, the genotypic drug resistance and genetic characteristics were analyzed by the WGS. Results: Lineages are identified by TB-profiler revealed 202 MDR-MTB strains, showcasing three predominant lineages, with lineage 2 being the most prevalent. Close genomic relatedness analysis and evidence of MTB transmission led to the formation of 15 clusters comprising 42 isolates, resulting in a clustering rate of 20.8%. Novelty, lineage 2.1 (non-Beijing) accounted for 27.2% of the MDR-MTB strains, which is rare in China and Neighboring countries. Regarding first-line anti-TB drugs, genes associated with rifampicin resistance, primarily the rpoB gene, were detected in 200 strains (99.0%). Genes conferring resistance to isoniazid, ethambutol, and streptomycin were identified in 191 (94.5%), 125 (61.9%), and 100 (49.5%) strains, respectively. Among the second-line drugs, 97 (48.0%) strains exhibited genes encoding resistance to fluoroquinolones. Comparing the results to phenotypic drug susceptibility-based testing, the sensitivity of WGS for detecting resistance to each of the six drugs (rifampicin, isoniazid, ethambutol, ofloxacin, kanamycin, capreomycin) was 90% or higher. With the exception of ethambutol, the specificity of WGS prediction for the remaining drugs exceeded 88%. Conclusion: Our study provides crucial insights into genetic mutation types, genetic diversity, and transmission of MDR-MTB on Hainan Island, serving as a significant reference for MDR-MTB surveillance and clinical decision-making.

An efficient pretreatment method based on AgNPs-doped SnO2 photocatalyst for the accurate detection of heavy metals in organic-rich water samples.

Humic acid (HA), the primary composition of natural organic matter (NOM) widely distributed in water and soil, can complex with heavy metal ions (HMIs), i.e., Cd(II) and Pb(II) in this study, which deters the accurate detection of HMIs using square wave anodic stripping voltammetry (SWASV). Hence, in this study, an efficient pretreatment method was proposed to restore the electrochemical signal of Cd(II) and Pb(II) by breaking the complexation based on AgNPs-doped SnO2 photocatalyst combined with LP/UV irradiation. Optimization of the key parameters for electrochemical signal restoration including pH for photolysis, AgNPs doping rate, photocatalyst dosage and photolysis time were performed to further elevating the accuracy in the proposed pretreatment method over 96.9% for Cd(II) and Pb(II) in 15 min. The effect of different HA concentrations on SWASV signal of Cd(II) and Pb(II) was also investigated adopting the optimal parameters. Then, the UV-vis absorption spectra, crystal structure, and the morphology of AgNPs-doped SnO2 photocatalyst were investigated to excavate the reasons behind the most excellent AgNPs doping rate to SnO2 in signal restoration. Moreover, the behavior of HA degradation and transformation under LP/UV irradiation was studied to investigate the mechanism of electrochemical signal restoration. Finally, the feasibility of the proposed method was testified by comparing detection results with ICP-MS results using real water samples extracted from aquaculture water.

Quantum metric nonlinear Hall effect in a topological antiferromagnetic heterostructure.

Quantum geometry in condensed-matter physics has two components: the real part quantum metric and the imaginary part Berry curvature. Whereas the effects of Berry curvature have been observed through phenomena such as the quantum Hall effect in two-dimensional electron gases and the anomalous Hall effect (AHE) in ferromagnets, the quantum metric has rarely been explored. Here, we report a nonlinear Hall effect induced by the quantum metric dipole by interfacing even-layered MnBi2Te4 with black phosphorus. The quantum metric nonlinear Hall effect switches direction upon reversing the antiferromagnetic (AFM) spins and exhibits distinct scaling that is independent of the scattering time. Our results open the door to discovering quantum metric responses predicted theoretically and pave the way for applications that bridge nonlinear electronics with AFM spintronics.

Comparative analysis of the gut microbiota of wild adult rats from nine district areas in Hainan, China.

BACKGROUND: Wild rats have the potential to hold zoonotic infectious agents that can spread to humans and cause disease. AIM: To better understand the composition of gut bacterial communities in rats is essential for preventing and treating such diseases. As a tropical island located in the south of China, Hainan province has abundant rat species. Here, we examined the gut bacterial composition in wild adult rats from Hainan province. METHODS: Fresh fecal samples were collected from 162 wild adult rats, including three species (Rattus norvegicus, Leopoldamys edwardsi, and Rattus losea), from nine regions of Hainan province between 2017-2018. RESULTS: We analyzed the composition of gut microbiota using the 16S rRNA gene amplicon sequencing. We identified 4903 bacterial operational taxonomic units (30 phyla, 175 families, and 498 genera), which vary between samples of different rat species in various habitats at various times of the year. In general, Firmicutes were the most abundant phyla, followed by Bacteroidetes (15.55%), Proteobacteria (6.13%), and Actinobacteria (4.02%). The genus Lactobacillus (20.08%), unidentified_Clostridiales (5.16%), Romboutsia (4.33%), unidentified_Ruminococcaceae (3.83%), Bacteroides (3.66%), Helicobacter (2.40%) and Streptococcus (2.37%) were dominant. CONCLUSION: The composition and abundance of the gut microbial communities varied between rat species and locations. This work provides fundamental information to identify microbial communities useful for disease control in Hainan province.

Predictors of mortality in heart failure with reduced ejection fraction: interaction between diabetes mellitus and impaired renal function.

BACKGROUND: The harmful effect of diabetes mellitus (DM) on mortality in patients with heart failure with reduced ejection fraction (HFrEF) remains controversial. Furthermore, it seems that no consistent conclusion on whether chronic kidney disease (CKD) modifies the relationship of DM and poor prognosis in patients with HFrEF. METHODS: We analyzed the individuals with HFrEF from the Cardiorenal ImprovemeNt (CIN) cohort between January 2007 and December 2018. The primary endpoint was all-cause mortality. The patients were divided into four groups (control vs. DM alone vs. CKD alone vs. DM and CKD). Multivariate Cox proportional hazards analysis was conducted to examine the association among DM, CKD and all-cause mortality. RESULTS: There were 3,273 patients included in this study (mean age: 62.7 ± 10.9 years, 20.4% were female). During a median follow-up of 5.0 years (interquartile range: 3.0-7.6 years), 740 (22.6%) patients died. Patients with DM have a higher risk of all-cause mortality (HR [95% confidence interval (CI)]:1.28[1.07-1.53]) than those without DM. In patients with CKD, DM had a 61% (HR [95% CI]:1.61[1.26-2.06]) increased adjusted risk of death relative to non-DM, while in patients with non-CKD, there was no significantly difference in risk of all-cause mortality (HR [95% CI]:1.01[0.77-1.32]) between DM and non-DM (p for interaction = 0.013). CONCLUSIONS: Diabetes is a potent risk factor for mortality in patients with HFrEF. Furthermore, DM had a substantially different effect on all-cause mortality depending on CKD. The association between DM and all-cause mortality was only observed in patients with CKD.

Disseminated Talaromyces marneffei infection after renal transplantation: A case report and literature review.

We reported a 31-year-old man who received renal transplantation for more than 2 years. He was admitted to our hospital on 9 March 2022 due to intermittent diarrhea accompanied by leukopenia for more than 1 month. The patient successively developed high fever, cough, anemia, weight loss, gastrointestinal bleeding, and liver function impairment. Computed tomography (CT) revealed a slight inflammation in the lower lobes of both lungs, enlargement of the lymph nodes in the retroperitoneal and the root of mesenteric areas, and hepatosplenomegaly. Talaromyces marneffei was detected by metagenomics next-generation sequencing (mNGS) in blood and bronchoalveolar lavage fluid, and the pathogen was subsequently verified by blood culture. After endoscopic hemostatic therapy and antifungal therapy with voriconazole and amphotericin B cholesteryl sulfate complex, the patient was successfully discharged. Oral voriconazole was given regularly after discharge. Diarrhea, fever, enlargement of the lymph nodes, and endoscopic evidence of erosion may indicate intestinal T. marneffei infection. Although the mortality of T. marneffei infection after renal transplantation is very high, timely and effective antifungal therapy with amphotericin B cholesteryl sulfate complex is still expected to improve its prognosis.

Screening and Drug Resistance Analysis of Non-Tuberculous Mycobacteria in Patients with Suspected Pulmonary Tuberculosis on the Hainan Island, China.

Background: China has seen a drastic increase in the incidence of non-tuberculous mycobacteria (NTM) infection, which is a notable public health issue. Due to a lack of reliable epidemiological surveillance information, there is a need to gather accurate epidemiological and surveillance data, which can help clinicians effectively treat NTM patients. Moreover, drug susceptibility testing for NTM is not frequently performed in China. This retrospective study, therefore, determined the prevalence and resistance characteristics of NTM to provide a reference to control the NTM epidemic. Methods: Sputum, alveolar lavage fluid, and other respiratory specimens were collected from 3025 patients with suspected pulmonary tuberculosis attending The Second Affiliated Hospital of Hainan Medical University from January 2014 to December 2021. Strain identification and species distribution of NTM were performed by DNA chip technology and gene sequencing, and the drug resistance of NTM isolates was evaluated by calculating the minimum inhibitory concentration through antimicrobial susceptibility testing for NTM. Results: From 2014 to 2021, 373 strains of NTM were isolated and identified from respiratory specimens of 3025 suspected tuberculosis patients. Except in 2014, NTM-infected patients accounted for more than 10% of suspected tuberculosis patients in other years. The median age of patients with NTM infection was 62.0 years (53.0, 71.0), and the male-to-female ratio among these patients was 0.79:1. Among culture-positive strains, 12.3% (373/3040; 95% CI 11.1-13.4%) were identified as NTM comprising forty species of NTM. The forty species of NTM included 23 slow-growing mycobacteria (SGM) and 17 rapidly-growing mycobacteria (RGM). Among the NTM isolates, 58.7% (219/373; 95% CI 53.7-63.7%) were SGM and 41.3% (154/373; 95% CI 36.3-46.3%) were RGM. M.avium complex(MAC)(41.3%; 95% CI 36.3-46.3%) and M.abscessus complex (MABC)(33.2%; 95% CI 28.4-38.0%) were the most frequently detected species, followed by M.simiae Complex (11.8%; 95% CI 8.5-15.1%), M.fortuitum group (5.1%; 95% CI 2.9-7.3%), and others. Drug sensitivity test results showed that most of the NTM isolates were susceptible to amikacin and clarithromycin with a drug resistance rate of less than 10%. However, clarithromycin could induce drug resistance, followed by linezolid and moxifloxacin, and their drug resistance rate was less than 50%. Conclusion: During 2014-2021, the number of NTM isolates detected in the respiratory specimens of the study patients in The Second Affiliated Hospital of Hainan Medical University increased year by year. M. intracellulare is the most common pathogenic NTM species, and there is a high incidence of NTM infection on Hainan Island. Our findings might be of great importance for diagnosing and treating this patient population in Hainan.

Epidemiological characteristics and antimicrobial resistance of 151 cases of melioidosis in Hainan Province / 中国热带医学

@#Abstract: Objective　To analyze the epidemiological characteristics of 151 cases of melioidosis and the drug resistance of Burkholderia pseudomallei (BP), in order to provide the basis for diagnosis, treatment and reasonable prevention of melioidosis. Methods　A total of 151 inpatients and outpatients from the Second Affiliated Hospital of Hainan Medical University from January 1, 2013 to August 31, 2022 were collected, and clinical specimens were submitted for examination to isolate and identify BP strains. The clinical data of 151cases of melioidosis and the drug resistance characteristics of pathogenic bacteria were retrospectively analyzed, and using SPSS26.0 software for statistical analysis. Results　Among 151 cases with BP infection, there were 138 males (91.4%) and 13 females (8.6%); the most patients were aged from 45-<60 years old, accounting for 74 cases (49.0%); melioidosis incidence was concentrated in October (19.2%), November (19.2%), August (9.9%) and July (8.6%), and; the number of confirmed cases showed an increasing trend and the time for confirmation was <10 d; Internal medicine system (31.1%), surgery system (26.5%) and intensive care department (20.5%) were the common departments for treating melioidosis; blood (49.0%), sputum (9.9%) and wound secretion (8.6%) were the main clinical specimens for detecting BP; pulmonary infection (68.2%), sepsis (35.1%) and local suppurative infection (23.8%) were the top clinical manifestations in patients with BP infection; the effective rate of treating melioidosis was 74.8%; abnormal liver function was a risk factor for the curative effect of melioidosis (χ2=5.010, P<0.05); the sensitivity rates of BP strains to sulfamethoxazole-trimethoprim (SXT), doxycycline (DOX), imipenem(IPM), ceftazidime (CAZ), amoxicillin/clavulanate (AMC) and tetracycline (TCY) were generally more than 90%, with sensitivities of 98.7%, 97.2%, 96.7%, 94.0%, 93.2% and 90.7%, respectively. Conclusions　It can be concluded that misdiagnosis or missed diagnosis of melioidosis is easy to occur, and the understanding of the epidemiological characteristics and risk factors in this area should be strengthened. The sensitivity of BP to commonly used antibiotics has shown a certain downward trend, clinical use should be standardized, and drug resistance monitoring should be strengthened to improve the efficacy of melioidosis treatment.

Diagnostic value of cross-primer isothermal amplification technology in tuberculosis and its related influencing factors / 中国热带医学

@#Abstract： Objective　To analyze the value and influencing factors of cross-primer isothermal amplification technology(CPA) in clinical screening and diagnosis of tuberculosis (TB). Methods　We collected 543 inpatients in the Second Affiliated Hospital of Hainan Medical College from January 1, 2018 to December 31, 2021, including 179 patients with tuberculosis, 187 patients with pneumonia and 177 patients with other diseases. The patients' sputum, alveolar lavage fluid, pleural effusion and midstream urine were detected by CPA, smear microscopy, culture method and gene detection. The value of CPA detection in the diagnosis of tuberculosis and its influencing factors were evaluated. Statistical analysis was performed using SPSS 26.0. Results　The total positive rate of CPA was 14.4% (78/543), and the positive rate of sputum samples accounted for 29.1% (39/134). Among the 78 cases of CPA positive patients, the tuberculosis group accounted for 69.2% (54/78), followed by pneumonia group 21.8% (17/78), and other diseases group accounted for 9.0% (7/78). Taking CPA test as the reference method, the "sensitivity" of smear microscopy was lower than that of genetic testing and culture, while the "specificity" was higher than that of culture and gene testing, and the "missed diagnosis rate" of smear microscopy was higher than that of genetic testing and culture. CPA test positive was related to gender, ESR and pneumonia. There is a good agreement between CPA test and culture method and gene test (Kappa>0.9), and a moderate agreement between CPA test and smear microscopy (Kappa=0.616). Conclusions　Sputum specimen is the best choice for CPA detection, while the value of pleural effusion detection is relatively limited. Sputum, alveolar lavage fluid and midcourse urine can be used as clinical specimens for screening and diagnosis of "tuberculosis group and other disease group", while sputum can be used for screening and diagnosis of "tuberculosis group and pneumonia group". Gender, ESR and pneumonia are the influencing factors of CPA positive patients. Therefore, CPA testing is worthy of clinical promotion, but more clinical research data are needed.

Diagnostic value and analysis of two cases with Mucor infection after renal transplantation / 中国热带医学

@#Abstract: To report the diagnosis and treatment of Mucor infection in two cases of renal transplantation, and to provide reference for diagnosis and treatment of Mucor infection. Case 1, a male patient, who underwent allogeneic kidney transplantation due to increased creatinine for more than 8 years. The renal function had partially recovered 25 days after the operation, but then the patient suddenly got worse epigastric pain. Pathogen culture, smear microscopy, mass spectrometry identification and next-generation metagenomic sequencing (mNGS) were performed on the peritoneal drainage, with the result pointing to Rhizopus microsporus. The patient's condition improved after antifungal treatment using amphotericin B lipid complex (ABLC) and was discharged. Case 2, a male patient with hypertension and increased creatinine for more than 7 years was admitted to the hospital. After allograft kidney transplantation, tissue culture smear and histopathological examination suggested Mucor infection. The patient then underwent a "hand muscle debridement surgery + closed negative pressure drainage (VSD)" procedure, and amphotericin B was given postoperative treatment against Mucor infection and debridement. Subsequent retesting with mNGS showed no signs of Mucor infection. In the course of treatment, two patients developed abdominal pain after treatment with tegacycline, which was immediately diagnosed as pancreatitis and recovered after withdrawal. Both patients being male, with one case associated with hypertension. After initially guiding the diagnosis with traditional smear tests, final confirmation was done using histopathological examination, mNGS and mass spectrometry. One case was infected by Rhizopus microspora, and the other was infected by Rhizopus oryzae and Cunninghamia microbicans. The causes leading to Mucor infection in patients post renal transplantation varied greatly. Early diagnosis is the key to treatment of patients with Mucor infection after renal transplantation. Treatment with amphoteric B and its liposome is an effective means to improve mucormycosis patients after renal transplantation. The use of amphotericin B lipid complex treatment proved to be an effective treatment method for patients with Mucor infection after renal transplantation.

Analysis of drug resistance and its influencing factors in different infection sites of patients / 中国热带医学

@#Abstract： Objective　To analyze the characteristics and corresponding drug resistance of pathogenic bacterial spectrum in eight major infection sites of hospitalized patients, and to provide epidemiological data for the rational selection of antibiotics in clinical practice. Methods　A total of 396 bacterial strains isolated from clinical specimens of hospitalized patients in member institutions of the Hainan Provincial Bacterial Resistance Monitoring Network from September 1, 2020, to September 30, 2022, were included in this study. Data were screened and filtered from the database of MH120 Microbial Identification and Drug Sensitivity Analysis System based on the technical scheme of the National Bacterial Drug Resistance Surveillance Network and Science and Technology Basic Resources Investigation Project research plan in 2020. The testing data were integrated, summarized, and analyzed using EXCEL and WHONET 5.6 software, and statistical analysis was conducted using SPSS 26.0 software. Results　Among of 396 strains of bacteria, 78 (19.7%) were isolated from respiratory tract specimens, 74 (18.7%) from urinary tract specimens, 72 (18.2%) from blood specimens, 54 (13.6%) from abdominal cavity specimens, 48 (12.1%) from skin and soft tissue specimens 48 strains (12.1%), 30 (7.6%) from reproductive tract specimens, 22 (5.6%) from central nervous system specimens, 18 (4.5%) from digestive tract specimens. Gram-negative bacteria accounted for 69.4% of the isolates, while gram-positive bacteria accounted for 30.6%. The top five gram-negative bacteria isolated were Klebsiella pneumoniae (14.9%), Escherichia coli (14.4%), Pseudomonas aeruginosa (10.4%), Acinetobacter baumannii (5.3%), and Salmonella species (4.5%). The top five gram-positive bacteria were Staphylococcus aureus (11.1%), Streptococcus agalactis (7.8%), Enterococcus faecalis (3.0%), Enterococcus faecium (2.8%), and Streptococcus suis (1.8%). Respiratory failure and bloodstream infection were independent influencing factors of treatment response (P<0.01). The resistance rate of Escherichia coli to ampicillin was 81.4%, and the resistance rate of Staphylococcus aureus to gentamicin and levofloxacin were both below 7%. Conclusions　The pathogen spectra vary with different infection sites of patients, and rational selection of antibiotics based on drug susceptibility testing is crucial to shorten the treatment time of patients and avoid the unnecessary emergence of drug-resistant strains caused by drug abuse.

Unusual magnetotransport in twisted bilayer graphene.

SignificanceWhen two sheets of graphene are twisted to the magic angle of 1.1∘, the resulting flat moiré bands can host exotic correlated electronic states such as superconductivity and ferromagnetism. Here, we show transport properties of a twisted bilayer graphene device at 1.38∘, far enough above the magic angle that we do not expect exotic correlated states. Instead, we see several unusual behaviors in the device's resistivity upon tuning both charge carrier density and perpendicular magnetic field. We can reproduce these behaviors with a surprisingly simple model based on Hofstadter's butterfly. These results shed light on the underlying properties of twisted bilayer graphene.

[Effects of whole body vibration on bone strength and physical fitness in elderly COPD patients complicated with osteoporosis].

Objective: To investigate the effects of adding whole body vibration (WBV) to routine exercise regimen of pulmonary rehabilitation (PR) on bone strength, lung function and exercise ability of elderly patients with stable chronic obstructive pulmonary disease (COPD) complicated with osteoporosis (OP). Methods: Thirty seven elderly patients with stable COPD were randomly divided into control group (group C, n=12, age: 64.6±3.8 years), conventional PR group (PR group, n=12, age: 66.1±4.9 years), and whole body vibration combined PR group (WP group, n=13, age: 65.5±3.3 years). Before intervention, X-ray and computerized tomography bone scan, bone metabolic markers, pulmonary function, cardiopulmonary exercise, 6-minute walking and isokinetic muscle strength were performed, and then intervened for 36 weeks, three times/week, among which group C subjects were given routine treatment, PR group added aerobic running and static weight resistance on the basis of routine treatment, and WP group added WBV on the basis of PR group intervention. After the intervention, the same indicators were detected. Results: Compared with before the intervention, the pulmonary function indexes of each group were significantly improved after the intervention (P＜0.05), and the bone mineral density and bone microstructure indexes of the patients in the WP group were also significantly improved (P＜0.05). Compared with group C and group PR, the bone mineral density, bone microstructure, parathyroid hormone (PTH), insulin-like growth factor-1 (IGF-1), interleukin-6 (IL-6), osteocalcin (OCN) and other bone metabolism indexes, knee flexion, peak extension torque, fatigue index and muscle strength of patients in WP group were significantly improved (P＜0.05). Conclusion: Adding WBV to the conventional PR regimen can improve the bone strength, lung function and exercise capacity of elderly patients with COPD complicated with OP, and may be able to make up for the deficiency of the current conventional PR regimen for insufficient muscle and bone stimulation.

Analysis of the etiological characteristics and drug resistance of adult patients with bloodstream infection in a hospital in Hainan, 2018-2020 / 中国热带医学

@#Abstract: Objective　To analyze the etiological characteristics and drug resistance of patients with bloodstream infection (BSI) in the bacterial resistance monitoring network in Hainan Province from 2018 to 2020, so as to provide laboratory data for clinical diagnosis and treatment. Methods　The clinical data of the subjects were collected, and the etiological characteristics of BSI patients and drug resistance of commonly used drugs in clinical treatment were analyzed retrospectively. SPSS 26.0 software was used for statistical analysis. Results　A total of 877 strains were isolated, including Gram-negative bacteria (584 strains, 66.6%), Gram-positive bacteria (239 strains, 27.2%) and fungi (54 strains, 6.2%); male patients (591 cases, 67.4%), female patients (286 cases, 32.6%); inpatients (780 cases, 88.9%), outpatient and emergency patients (97 cases, 11.1%); the main primary diseases of BSI patients were hypertension, cerebral infarction and type 2 diabetes, and the main primary infections were pulmonary infection and urinary system infection. Intensive care unit (25.2%, 221 cases), emergency department (10.9%, 96 cases), oncology department (9.1%, 80 cases), nephrology department (6.8%, 60 cases) and hepatobiliary and pancreatic surgery department (4.3%, 38 cases) had the highest proportion of pathogenic bacteria. Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, coagulase-negative Staphylococcus, Viridans group streptococci and Candida albicans were the most frequently isolated pathogens. The detection rates of carbapenem-resistant Klebsiella pneumoniae, carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Acinetobacter baumannii were 3.4%, 15.2% and 36.4% respectively. The carbapenem-resistant Escherichia coli was not checked out. The detection rates of methicillin resistant Staphylococcus aureus and methicillin resistant coagulase negative Staphylococcus were 18.5% and 79.1% respectively. Conclusions　Gram-negative bacteria are the most common pathogens of BSI, and inpatients are the main source of BSI. Age, underlying diseases and primary infection are the risk factors of BSI. Clinical laboratories should strengthen the etiological monitoring of high-risk patients with BSI, and the resistance analysis of common antibiotics can provide a basis for the rational use of antibiotics in clinical practice.

Fractional Chern insulators in magic-angle twisted bilayer graphene.

Fractional Chern insulators (FCIs) are lattice analogues of fractional quantum Hall states that may provide a new avenue towards manipulating non-Abelian excitations. Early theoretical studies1-7 have predicted their existence in systems with flat Chern bands and highlighted the critical role of a particular quantum geometry. However, FCI states have been observed only in Bernal-stacked bilayer graphene (BLG) aligned with hexagonal boron nitride (hBN)8, in which a very large magnetic field is responsible for the existence of the Chern bands, precluding the realization of FCIs at zero field. By contrast, magic-angle twisted BLG9-12 supports flat Chern bands at zero magnetic field13-17, and therefore offers a promising route towards stabilizing zero-field FCIs. Here we report the observation of eight FCI states at low magnetic field in magic-angle twisted BLG enabled by high-resolution local compressibility measurements. The first of these states emerge at 5 T, and their appearance is accompanied by the simultaneous disappearance of nearby topologically trivial charge density wave states. We demonstrate that, unlike the case of the BLG/hBN platform, the principal role of the weak magnetic field is merely to redistribute the Berry curvature of the native Chern bands and thereby realize a quantum geometry favourable for the emergence of FCIs. Our findings strongly suggest that FCIs may be realized at zero magnetic field and pave the way for the exploration and manipulation of anyonic excitations in flat moiré Chern bands.

RRM2 Improves Cardiomyocyte Proliferation after Myocardial Ischemia Reperfusion Injury through the Hippo-YAP Pathway.

OBJECTIVE: Ribonucleotide reductase M2 (RRM2) as an enzyme that catalyzes the deoxyreduction of nucleosides to deoxyribonucleoside triphosphate (dNTP) has been extensively studied, and it plays a crucial role in regulating cell proliferation. However, its role in ischemia-reperfusion injury (I/RI) is still unclear. METHODS: SD rats were used as the research object to detect the expression of RRM2 in the myocardium by constructing an I/RI model. At the same time, primary SD neonatal rat cardiomyocytes were extracted, and hypoxia/reoxygenation (H/R) treatment simulated the I/RI model. Using transfection technology to overexpress RRM2 in cardiomyocytes, quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) was used to detect the expression of RRM2, Cell Counting Kit-8 (CCK-8) assay was used to detect cell viability, and immunofluorescence staining was used to detect Ki67 and EdU-positive cells. Western blot (WB) technology was used to detect YAP and its phosphorylation expression. RESULTS: qRT-PCR results indicated that the expression of RRM2 was inhibited in the model group, and cardiomyocytes overexpressing RRM2 can obviously promote the proliferation of primary cardiomyocytes and improve the damage of cardiac structure and function caused by I/R. At the same time, RRM2 can promote the increase of YAP protein expression and the increase of Cyclin D1 mRNA expression. CONCLUSION: RRM2 expression was downregulated in myocardial tissue with I/R. After overexpression of RRM2, cardiomyocyte proliferation was upregulated and the Hippo-YAP signaling pathway was activated.

Broadband RCS Reduction by a Quaternionic Metasurface.

A quaternionic metasurface consisting of two pairs of units with destructive phase difference is proposed to extend the bandwidth of radar cross section (RCS) reduction. The two pairs of units are designed to have complementary phase-different bandwidth, which extends the bandwidth of RCS reduction. The overlaps of their bandwidth enhance the RCS reduction, resulting in a metasurface having broadband and strong RCS reduction. This design and the wideband RCS reduction of the quaternionic metasurface were verified by analytical calculation with superposition principle of electric field, numerical simulation with commercial software package CST Microwave Studio and experiment in microwave anechoic chamber. The scattering mechanism and the angular performance of the quaternionic metasurface were also investigated.