RESUMEN

The increasing antibiotic resistance poses a significant global health challenge, threatening our ability to combat infectious diseases. The phenomenon of collateral sensitivity, whereby resistance to one antibiotic is accompanied by increased sensitivity to another, offers potential avenues for novel therapeutic interventions against infections unresponsive to classical treatments. In this study, we elucidate the emergence of tobramycin (TOB)-resistant small colony variants (SCVs) due to mutations in the hemL gene, which render S. Typhimurium more susceptible to nitrofurantoin (NIT). Mechanistic studies demonstrate that the collateral sensitivity in TOB-resistant S. Typhimurium SCVs primarily stems from disruptions in haem biosynthesis. This leads to dysfunction in the electron transport chain (ETC) and redox imbalance, ultimately inducing lethal accumulation of reactive oxygen species (ROS). Additionally, the upregulation of nfsA/B expressions facilitates the conversion of NIT prodrug into its active form, promoting ROS-mediated bacterial killing and contributing to this collateral sensitivity pattern. Importantly, alternative NIT therapy demonstrates a significant reduction of bacterial load by more than 2.24-log10 cfu/g in the murine thigh infection and colitis models. Our findings corroborate the collateral sensitivity of S. Typhimurium to nitrofurans as a consequence of evolving resistance to aminoglycosides. This provides a promising approach for treating infections due to aminoglycoside-resistant strains.

Asunto(s)

Antibacterianos , Nitrofurantoína , Salmonella typhimurium , Tobramicina , Nitrofurantoína/farmacología , Animales , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Tobramicina/farmacología , Ratones , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Farmacorresistencia Bacteriana/genética , Mutación , Femenino , Especies Reactivas de Oxígeno/metabolismo , Infecciones por Salmonella/microbiología , Infecciones por Salmonella/tratamiento farmacológico , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo

RESUMEN

BACKGROUND: Gamithromycin is an effective therapy for bovine and swine respiratory diseases but not utilized for rabbits. Given its potent activity against respiratory pathogens, we sought to determine the pharmacokinetic profiles, antimicrobial activity and target pharmacokinetic/pharmacodynamic (PK/PD) exposures associated with therapeutic effect of gamithromycin against Pasteurella multocida in rabbits. RESULTS: Gamithromycin showed favorable PK properties in rabbits, including high subcutaneous bioavailability (86.7 ± 10.7%) and low plasma protein binding (18.5-31.9%). PK analysis identified a mean plasma peak concentration (Cmax) of 1.64 ± 0.86 mg/L and terminal half-life (T1/2) of 31.5 ± 5.74 h after subcutaneous injection. For P. multocida, short post-antibiotic effects (PAE) (1.1-5.3 h) and post-antibiotic sub-inhibitory concentration effects (PA-SME) (6.6-9.1 h) were observed after exposure to gamithromycin at 1 to 4× minimal inhibitory concentration (MIC). Gamithromycin demonstrated concentration-dependent bactericidal activity and the PK/PD index area under the concentration-time curve over 24 h (AUC24h)/MIC correlated well with efficacy (R2 > 0.99). The plasma AUC24h/MIC ratios of gamithromycin associated with the bacteriostatic, bactericidal and bacterial eradication against P. multocida were 15.4, 24.9 and 27.8 h in rabbits, respectively. CONCLUSIONS: Subcutaneous administration of 6 mg/kg gamithromycin reached therapeutic concentrations in rabbit plasma against P. multocida. The PK/PD ratios determined herein in combination with ex vivo activity and favorable rabbit PK indicate that gamithromycin may be used for the treatment of rabbit pasteurellosis.

Asunto(s)

Enfermedades de los Bovinos , Lagomorpha , Infecciones por Pasteurella , Pasteurella multocida , Enfermedades de los Porcinos , Conejos , Animales , Bovinos , Porcinos , Antibacterianos/uso terapéutico , Antibacterianos/farmacocinética , Infecciones por Pasteurella/tratamiento farmacológico , Infecciones por Pasteurella/veterinaria , Infecciones por Pasteurella/microbiología , Macrólidos/uso terapéutico , Macrólidos/farmacocinética , Pruebas de Sensibilidad Microbiana/veterinaria , Enfermedades de los Bovinos/tratamiento farmacológico , Enfermedades de los Porcinos/tratamiento farmacológico

RESUMEN

We report an observation of quantum oscillations (QOs) in the correlated insulators with valley anisotropy of twisted double bilayer graphene (TDBG). The anomalous QOs are best captured in the magneto resistivity oscillations of the insulators at v = -2, with a period of 1/B and an oscillation amplitude as high as 150 kΩ. The QOs can survive up to ∼10 K, and above 12 K, the insulating behaviors are dominant. The QOs of the insulator are strongly D dependent: the carrier density extracted from the 1/B periodicity decreases almost linearly with D from -0.7 to -1.1 V/nm, suggesting a reduced Fermi surface; the effective mass from Lifshitz-Kosevich analysis depends nonlinearly on D, reaching a minimal value of 0.1 me at D = ∼ -1.0 V/nm. Similar observations of QOs are also found at v = 2, as well as in other devices without graphite gate. We interpret the D sensitive QOs of the correlated insulators in the picture of band inversion. By reconstructing an inverted band model with the measured effective mass and Fermi surface, the density of state at the gap, calculated from thermal broadened Landau levels, agrees qualitatively with the observed QOs in the insulators. While more theoretical understandings are needed in the future to fully account for the anomalous QOs in this moiré system, our study suggests that TDBG is an excellent platform to discover exotic phases where correlation and topology are at play.

Asunto(s)

Excipientes , Grafito , Humanos , Anisotropía , Inversión Cromosómica , Ambiente

RESUMEN

The seeds of Panax notoginseng (Burk.) F. H. Chen are typically characterized by their recalcitrance and after-ripening process and exhibit a high water content at harvest as well as a high susceptibility to dehydration. Storage difficulty and the low germination of recalcitrant seeds of P. notoginseng are known to cause an obstacle to agricultural production. In this study, the ratio of embryo to endosperm (Em/En) in abscisic acid (ABA) treatments (1 mg·l-1 and 10 mg·l-1, LA and HA) was 53.64% and 52.34%, respectively, which were lower than those in control check (CK) (61.98%) at 30 days of the after-ripening process (DAR). A total of 83.67% of seeds germinated in the CK, 49% of seeds germinated in the LA treatment, and 37.33% of seeds germinated in the HA treatment at 60 DAR. The ABA, gibberellin (GA), and auxin (IAA) levels were increased in the HA treatment at 0 DAR, while the jasmonic acid (JA) levels were decreased. ABA, IAA, and JA were increased, but GA was decreased with HA treatment at 30 DAR. A total of 4,742, 16,531, and 890 differentially expressed genes (DEGs) were identified between the HA-treated and CK groups, respectively, along with obvious enrichment in the ABA-regulated plant hormone pathway and the mitogen-activated protein kinase (MAPK) signaling pathway. The expression of pyracbactin resistance-like (PYL) and SNF1-related protein kinase subfamily 2 (SnRK2s) increased in the ABA-treated groups, whereas the expression of type 2C protein phosphatase (PP2C) decreased, both of which are related to the ABA signaling pathway. As a result of the changes in expression of these genes, increased ABA signaling and suppressed GA signaling could inhibit the growth of the embryo and the expansion of developmental space. Furthermore, our results demonstrated that MAPK signaling cascades might be involved in the amplification of hormone signaling. Meanwhile, our study uncovered that the exogenous hormone ABA could inhibit embryonic development, promote dormancy, and delay germination in recalcitrant seeds. These findings reveal the critical role of ABA in regulating the dormancy of recalcitrant seeds, and thereby provide a new insight into recalcitrant seeds in agricultural production and storage.

RESUMEN

BACKGROUND: Decrease in estimated glomerular filtration rate (eGFR) during Tenofovir disoproxil fumarate (TDF) treatment remains a concern, and few patients experience partial recovery of eGFR. This study aimed to investigate the risk factors for eGFR recovery in patients with and without hypertriglyceridemia. METHODS: A total of 203 patients with chronic HBV infection were prospectively recruited and followed up for three years. Data were collected at baseline, first, second, and third years during TDF treatment. RESULTS: Most patients achieved normal ALT (80.0% vs. 82.5%) and undetectable HBV DNA (95.0% vs. 95.6%) in both groups (p > 0.05). For patients with hypertriglyceridemia, eGFR and cholesterol did not change significantly during the 3-year follow-up, while triglyceride (TG) decreased significantly in the first year and persisted at a lower level in the subsequent two years. For patients without hypertriglyceridemia, eGFR declined significantly in the first year of treatment, then gradually recovered during the subsequent two years, and eGFR was negatively correlated with TG at the four time points. Fifteen (15/183, 8.2%) patients without hypertriglyceridemia experienced eGFR partial recovery in the third year. Univariate and multivariate analyses showed that baseline eGFR <90 mL/(min·1.73 m2) (p < 0.01; 95% CI: 0.019-0.284) and age (p < 0.01; 95% CI: 0.817-0.960) were independent risk factors for eGFR recovery. CONCLUSION: eGFR partially recovered in patients without hypertriglyceridemia during TDF treatment, and TG regulation might be a useful strategy to hinder renal function decline, although larger, confirmatory studies are necessary to validate our findings.Key messagesFor patients with normal triglyceride, eGFR declined significantly at the first year of TDF treatment, then gradually recovered during the subsequent two years, and eGFR was negatively correlated with TG. Baseline eGFR <90 mL/(min·1.73 m2) and age were independent risk factors for eGFR recovery.

Asunto(s)

Hipertrigliceridemia , Humanos , Tasa de Filtración Glomerular , Análisis Multivariante , Tenofovir , Triglicéridos

RESUMEN

PURPOSE: The Chronic Liver Disease Questionnaire (CLDQ)-Nonalcoholic Fatty Liver Disease (NAFLD) is a disease-specific instrument to assess the health-related quality of life (HRQL) of patients with NAFLD. In order to provide further evidence for the cross-cultural utility of this instrument in the Chinese population, we translated the CLDQ-NAFLD into Chinese and examined its reliability and validity. METHODS: Patients with NAFLD in 90 hospitals across China were enrolled in this multicenter cross-sectional survey. Eligible patients completed the Chinese version of CLDQ-NAFLD at enrollment to assess HRQL. Internal consistency of the questionnaire was assessed using Cronbach's alpha coefficient and split-half reliability. Convergent and discriminant validity were assessed using Spearman correlation coefficient. Factor analysis was used to test the construct validity. RESULTS: Between March and August 2019, 5181 patients with a mean age of 43.8 ± 13.3 years were enrolled. All domains exhibited good internal consistency, with Cronbach's alpha and split-half reliability greater than 0.70. The scaling success rate of all domains was 100% for convergent validity and 99.4% (179/180) for discriminant validity. The inter-scale correlations indicated a significant correlation between all CLDQ-NAFLD domains (r = 0.608 to 0.832, all p < 0.001). Factor analysis of 36 items extracted 6 factors, which explained 69.14% of the total variance. CONCLUSION: The Chinese version of CLDQ-NAFLD is a reliable and valid instrument for assessing the HRQL of Chinese patients with NAFLD.

Asunto(s)

Enfermedad del Hígado Graso no Alcohólico , Humanos , Adulto , Persona de Mediana Edad , Estudios Transversales , Calidad de Vida/psicología , Reproducibilidad de los Resultados , China , Encuestas y Cuestionarios , Psicometría

RESUMEN

BACKGROUND: Correlation between Triglyceride (TG) and estimated glomerular filtration rate (eGFR) remains largely unknown in overweight and non-overweight patients. AIM: To investigated the dynamic changes of eGFR and lipid profiles during 3-year tenofovir disoproxil fumarate (TDF) treatment in patients with chronic hepatitis B (CHB) and overweight. METHODS: A total of 202 CHB patients who received TDF treatment at the Third People's Hospital of Changzhou (Changzhou, China) and Nanjing Drum Tower Hospital (Nanjing, China) between January 2016 and May 2018 were retrospectively enrolled. According to the body mass index (BMI) at the initiation of TDF treatment, CHB patients were divided into overweight (BMI ≥ 25 kg/m2) and non-overweight (BMI < 25 kg/m2) groups. Logistic regression was applied for the analysis of risk factors for eGFR < 90 mL/(min·1.73 m2). RESULTS: There is no significant difference in hepatitis B virus DNA (HBV DNA) negativity and hepatitis Be antigen (HBeAg) loss between patients with overweight and non-overweight (both P > 0.05). More patients in non-overweight group achieved alanine aminotransferase normalization compared with those in overweight group (χ 2 = 11.036, P < 0.01). In non-overweight patients, the eGFR significantly declined in the 1st year (P < 0.01), then remained at a relatively lower level. TG significantly declined in the 2nd year (P = 0.02) and increased in the 3rd year. Moreover, TG was negatively correlated with GFR at the four-time points (P = 0.002, 0.030, 0.007, 0.008, respectively). In overweight patients, eGFR and TG remained relatively stable during the 3-year treatment, and eGFR showed no significant relationship with TG. Moreover, multivariate analysis showed that age [P < 0.01, 95%CI (0.97-1.005)] and baseline eGFR [P < 0.01, 95%CI (5.056-33.668)] were independent risk factors for eGFR < 90 mL/(min·1.73 m2) at the 3rd year. CONCLUSION: Dynamic changes in renal function were conversely related to TG during TDF treatment in patients with CHB and normal BMI, but not with overweight.

RESUMEN

BACKGROUND: Health Related Quality of Life (HRQL) is a multi-dimensional construct that can comprehensively evaluate the patient's health status, including physical, emotional, mental and social well-being. In this study, we aimed to evaluate the impact of non-alcoholic fatty liver disease (NAFLD) on HRQL in a Chinese population. METHODS: In this national multicenter cross-sectional survey, patients with NAFLD were enrolled. Chronic Liver Disease Questionnaire (CLDQ)-NAFLD was used to qualify HRQL. Univariate and multivariate analysis were used to identify independent risk factors of HRQL. RESULTS: A total of 5181 patients with NAFLD from 90 centers were enrolled in this study (mean age, 43.8 ± 13.3 years; male, 65.8%). The overall CLDQ score was 5.66 ± 0.89. Multivariate logistic regression analysis showed that body mass index (BMI: HR, 1.642; 95% CI, 1.330-2.026), alanine transaminase (ALT: HR, 1.006; 95% CI, 1.001-1.011), triglyceride (HR, 1.184; 95% CI, 1.074-1.305), disease severity (HR, 3.203; 95% CI, 1.418-7.232) and cardiovascular disease (HR, 4.305; 95% CI, 2.074-8.939) were independent risk factors for overall CLDQ score. In the logistic analyses of individual domain, BMI and triglyceride were independent risk factors of all domains. ALT, disease severity, diabetes, depression and cardiovascular disease were influencing factors for the CLDQ score of several domains. CONCLUSIONS: This national multicenter cross-sectional survey in China indicated that the HRQL in patients with NAFLD was impaired. HRQL was found to be significantly associated with sociodemographic and clinical factors. Attention should be paid to the optimally managing care of patients with NAFLD to improve their HRQL.

Asunto(s)

Pueblo Asiatico/psicología , Pueblo Asiatico/estadística & datos numéricos , Estado de Salud , Enfermedad del Hígado Graso no Alcohólico/psicología , Calidad de Vida/psicología , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios/normas , Adolescente , Adulto , China/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Adulto Joven

RESUMEN

BACKGROUND: Convalescent plasma (CP) transfusion was reported to be effective in treating critically ill patients with COVID-19, and hydroxychloroquine could potently inhibit SARS-CoV-2 in vitro. Herein, we reported a case receiving combination therapy with CP transfusion and hydroxychloroquine for the first time. CASE PRESENTATION: Laboratory findings showed high lactic acid level (2.1 mmol/L) and C-reactive protein (CRP, 48.8 mg/L), and low white blood cell count (1.96 × 109/L) in a 65-year-old Chinese man, who was diagnosed with severe COVID-19. CP was intravenously given twice, and hydroxychloroquine was orally administrated for a week (0.2 g, three times a day). The lactic acid and C-reactive protein levels remained high (2.1 mmol/L and 73.23 mg/L, respectively), while the arterial oxyhemoglobin saturation decreased to 86% with a low oxygenation index (OI, 76 mmHg) on day 4 after CP transfusion. His temperature returned to normal and the OI ascended above 300 on day 11. Moreover, the RNA test remained positive in throat swab, and computed tomography revealed severe pulmonary lesions on day 11 after admission. CONCLUSION: These findings suggested that the effectiveness of combination therapy with CP and hydroxychloroquine may be non-optimal, and specific therapy needs to be explored.

Asunto(s)

Transfusión de Componentes Sanguíneos/métodos , Infecciones por Coronavirus/terapia , Hidroxicloroquina/administración & dosificación , Neumonía Viral/terapia , Administración Oral , Anciano , Anticuerpos Neutralizantes/administración & dosificación , Anticuerpos Antivirales/administración & dosificación , Betacoronavirus/aislamiento & purificación , Proteína C-Reactiva/metabolismo , COVID-19 , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Humanos , Inmunización Pasiva/métodos , Ácido Láctico/sangre , Recuento de Leucocitos , Masculino , Oxihemoglobinas , Pandemias , Neumonía Viral/sangre , Neumonía Viral/tratamiento farmacológico , Neumonía Viral/virología , SARS-CoV-2 , Carga Viral , Sueroterapia para COVID-19

RESUMEN

The magnetic state of atomically thin semiconducting layered antiferromagnets such as CrI3 and CrCl3 can be probed by forming tunnel barriers and measuring their resistance as a function of magnetic field (H) and temperature (T). This is possible because the spins within each individual layer are ferromagnetically aligned and the tunneling magnetoresistance depends on the relative orientation of the magnetization in adjacent layers. The situation is different for systems that are antiferromagnetic within the layers in which case it is unclear whether magnetoresistance measurements can provide information about the magnetic state. Here, we address this issue by investigating tunnel transport through atomically thin crystals of MnPS3, a van der Waals semiconductor that in the bulk exhibits easy-axis antiferromagnetic order within the layers. For thick multilayers below T ∼ 78 K, a T-dependent magnetoresistance sets in at µ0H ∼ 5 T and is found to track the boundary between the antiferromagnetic and the spin-flop phases known from bulk measurements. We show that the magnetoresistance persists as thickness is reduced with nearly unchanged characteristic temperature and magnetic field scales, albeit with a different dependence on H, indicating the persistence of magnetism in the ultimate limit of individual monolayers.

RESUMEN

Electrons hopping in two-dimensional honeycomb lattices possess a valley degree of freedom in addition to charge and spin. In the absence of inversion symmetry, these systems were predicted to exhibit opposite Hall effects for electrons from different valleys. Such valley Hall effects have been achieved only by extrinsic means, such as substrate coupling, dual gating, and light illuminating. Here we report the first observation of intrinsic valley Hall transport without any extrinsic symmetry breaking in the non-centrosymmetric monolayer and trilayer MoS2, evidenced by considerable nonlocal resistance that scales cubically with local resistance. Such a hallmark survives even at room temperature with a valley diffusion length at micron scale. By contrast, no valley Hall signal is observed in the centrosymmetric bilayer MoS2. Our work elucidates the topological origin of valley Hall effects and marks a significant step towards the purely electrical control of valley degree of freedom in topological valleytronics.

RESUMEN

Two-dimensional transition metal dichalcogenides (TMDCs) are recently emerged electronic systems with various novel properties, such as spin-valley locking, circular dichroism, valley Hall effect, and superconductivity. The reduced dimensionality and large effective masses further produce unconventional many-body interaction effects. Here we reveal strong interaction effects in the conduction band of MoS2 by transport experiment. We study the massive Dirac electron Landau levels (LL) in high-quality MoS2 samples with field-effect mobilities of 24 000 cm2/(V·s) at 1.2 K. We identify the valley-resolved LLs and low-lying polarized LLs using the Lifshitz-Kosevitch formula. By further tracing the LL crossings in the Landau fan diagram, we unambiguously determine the density-dependent valley susceptibility and the interaction enhanced g-factor from 12.7 to 23.6. Near integer ratios of Zeeman-to-cyclotron energies, we discover LL anticrossings due to the formation of quantum Hall Ising ferromagnets, the valley polarizations of which appear to be reversible by tuning the density or an in-plane magnetic field. Our results provide evidence for many-body interaction effects in the conduction band of MoS2 and establish a fertile ground for exploring strongly correlated phenomena of massive Dirac electrons.

RESUMEN

Tenofovir disoproxil fumarate (TDF) is a potent nucleotide analogue with high barrier to resistance, which is recommended for multi-drug resistant hepatitis B virus (HBV) infection. However, nephrotoxicity has been reported during TDF treatment, and tenofovir alafenamide (TAF), which has comparable efficacy to TDF and improves bone and renal safety, can be used as a replacement strategy. Herein, we describe a clinical case concerning a 60-year-old individual suffering liver cirrhosis and renal dysfunction, and being infected with multidrug-resistant HBV. When failing treatment with TDF, he received TAF as a rescue therapy. TAF effectively inhibited HBV replication without worsening renal function or serum phosphorus abnormality. Furthermore, hepatocellular carcinoma (HCC) occurred during TAF treatment despite controlling the viral load. The risk of HCC could not be eliminated and should be monitored during TAF treatment.

RESUMEN

AIM: To understand the prevalence of hepatitis C virus (HCV) infection in blood donors over a nearly 27-year interval and to explore the factors that affect the outcome of HCV infection. METHODS: A retrospective and cross-sectional study was conducted. The participants, mostly plasma donors, were selected from three administrative villages in the Jiangsu province in Eastern China. A questionnaire was administered among the villagers who had a history of blood donation from the late 1980s to the early 1990s. All participants underwent physical examination, liver B-ultrasonography, and liver stiffness measurement. In addition, 10 mL of blood was collected from each participant to measure simple liver function parameters (albumin, alanine aminotransferase, aspirate aminotransferase), blood factors (platelet), and for hepatitis B surface antigen, antiHCV, and antihuman immunodeficiency virus detection. HCV RNA detection, HCV genotyping, and other tests were carried out in antiHCV-positive patients. RESULTS: After a median of 27 years (25-31 years) from the last blood donation to the time of survey, a total of 1694 participants were investigated, and the antiHCV-positive individuals were categorized into three groups: blood donors (n = 12, 3.3%), plasma donors (n = 534, 68.5%), and mixed donors (n = 324, 58.8%). A total of 592 (68.05%) patients had detectable HCV RNA, and 91.9% had genotype 1b. A total of 161 (27.2%, 161/592) patients with chronic HCV were considered to have cirrhosis with a liver stiffness measurement level higher than 12 kPa. Multiple logistic (binary) regression analysis results showed that platelet and IgG levels were associated with cirrhosis. CONCLUSION: The nearly 27-year interval investigation revealed that chronic hepatitis C infection is a very serious public health problem in Eastern China. Plasma donation and subsequent return of blood cells to the donor are the main causes of hepatitis C infection. The main HCV genotype is 1b. Nearly 28% of cases progressed to cirrhosis. Age, especially over 60 years, and regular drinking habits were risk factors associated with cirrhosis.

Asunto(s)

Donantes de Sangre/estadística & datos numéricos , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/epidemiología , Cirrosis Hepática/epidemiología , Obtención de Tejidos y Órganos/estadística & datos numéricos , Adulto , China/epidemiología , Estudios Transversales , Femenino , Técnicas de Genotipaje , Hepacivirus/genética , Hepatitis C Crónica/sangre , Hepatitis C Crónica/diagnóstico por imagen , Hepatitis C Crónica/virología , Humanos , Inmunoglobulina G/sangre , Hígado/diagnóstico por imagen , Hígado/virología , Cirrosis Hepática/sangre , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/virología , Pruebas de Función Hepática , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Prevalencia , ARN Viral/aislamiento & purificación , Factores de Riesgo , Encuestas y Cuestionarios , Ultrasonografía

RESUMEN

Morphology management for tailoring the properties of monolayer transition-metal dichalcogenides (TMDCs), that is, molybdenum disulfide (MoS2), has attracted great interest for promising applications such as in electrocatalysis and optoelectronics. Nevertheless, little progress has been made in engineering the shape of MoS2. Herein, we introduce a modified chemical vapor deposition method to grow monolayer MoS2 dendrites by pretreating substrates with adhesive tapes. The as-grown MoS2 crystals are featured with hexagonal backbones with fractal shapes and tunable degrees. By characterizing the atomic structure, it is found that these morphologies are mainly initiated from the twin defect derived growth and controlled by the S:Mo vapor ratio. Due to the accumulated sulfur vacancies in the cyclic twin regions, strong enhancement of photoluminescence emission is localized, which determines the shape dependency of optical property. This work not only enriches the understanding of the twin defects derived crystal growth mechanism and extends its applications from nanomaterials to two-dimensional crystals, but also offers a robust and controllable protocol for shape-engineered monolayer TMDCs in electrochemical and optoelectronic applications.

RESUMEN

Atomically-thin black phosphorus (BP) field-effect transistors show strong-weak localization transition, which is tunable through gate voltages. Hopping transports through charge impurity-induced localized states are observed at low carrier density regime. Variable-range hopping model is applied to simulate scattering behaviors of charge carriers. In the high carrier concentration regime, a negative magnetoresistance indicates weak localization effects. The extracted phase coherence length is power-law temperature-dependent [Formula: see text] and demonstrates inelastic electron-electron interactions and the 2D transport features in few-layer BP field-effect devices. The competition between localization and phase coherence lengths is investigated and analyzed based on observed gate-tunable strong-weak localization transition in few-layer BP.

RESUMEN

The objective of this study was to analyze the prevalence of drug-resistant HBV mutants in patients with treatment failure during the past seven years (2010-2016). 4055 HBV-infected patients who underwent HBV polymerase gene mutation test from 2010 to 2016 were enrolled. The nucleos(t)ide analogues (NAs) resistance mutation positions, including rtL180, rtA181, rtT184, rtS202, rtM204, rtI233, rtN236, rtI169, rtV173, and rtM250 were analyzed. Genotypic resistance mutations were detected in 30.8% (1248/4055) of the patients with treatment failure. Rates of drug-resistant mutations associated with LAM, ADV, ETV, and multidrug were 27.23% (1104/4055), 9.67% (392/4055), 3.69% (150/4055), and 0.79% (32/4055). Among the primary NA-resistant mutations, rtM204I (13.44%, 545/4055) occurred more frequently, followed by rtM204V, rtN236T, rtA181T, and rtA181V. For single-base mutations, rtL180M and rtA181V increased gradually during the past seven years, while rtM204I/V and rtN236T decreased after 2015. The development of drug-resistant mutations positively correlated with the consumption of ETV (r = 0.964, P = 0.002), and weakly correlated with that of LAM (r = 0.679, P = 0.109) and ADV (r = 0.429, P = 0.354). Moreover, single-base mutation rtA181V and multi-base mutations (rtL180M + M204I and rtL180M + M204V + M204I) were more common in HBV genotype C than those in genotype B (1.94% vs. 0.66%, 1.84% vs. 0.16%, 1.02% vs. 0.16%, respectively). NA-related mutations in HBV RT region increased in the past seven years, especially for LAM. Frequencies of rtL180M and rtA181T/V increased gradually in the past seven years, to which we should pay more attention.

Asunto(s)

Antivirales/uso terapéutico , Farmacorresistencia Viral , Evolución Molecular , Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/genética , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/virología , Frecuencia de los Genes , Genoma Viral , Virus de la Hepatitis B/aislamiento & purificación , Humanos , Mutación , Insuficiencia del Tratamiento

RESUMEN

This work reports an experimental study on an antiferromagnetic honeycomb lattice of MnPS3 that couples the valley degree of freedom to a macroscopic antiferromagnetic order. The crystal structure of MnPS3 is identified by high-resolution scanning transmission electron microscopy. Layer-dependent angle-resolved polarized Raman fingerprints of the MnPS3 crystal are obtained, and the Raman peak at 383 cm-1 exhibits 100% polarity. Temperature dependences of anisotropic magnetic susceptibility of the MnPS3 crystal are measured in a superconducting quantum interference device. Anisotropic behaviors of the magnetic moment are explored on the basis of the mean field approximation model. Ambipolar electronic conducting channels in MnPS3 are realized by the liquid gating technique. The conducting channel of MnPS3 offers a platform for exploring the spin/valleytronics and magnetic orders in 2D limitation.

RESUMEN

This study aimed to investigate the anti-oxidant and anti-hypertrophic effects of puerarin-7-O-glucuronide, a water-soluble puerarin metabolite. The anti-oxidant effects of puerarin-7-O-glucuronide were assessed by measurement of intracellular superoxide levels, total superoxide dismutase (SOD) activity, total anti-oxidant capacity, and glutathione (GSH)/glutathione disulfide (GSSG) ratio in cultured neonatal rat cardiomyocytes (NRCMs) stimulated with the xanthine oxidase (XO)/xanthine (X) system or angiotensin II. The activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and expression of NADPH oxidase subunits p22phox and p47phox were determined. The anti-hypertrophic effects of puerarin-7-O-glucuronide in angiotensin II-challenged NRCMs were characterized by changes in cell morphology and expression of hypertrophic genes. In the pharmacokinetic study, the plasma concentration of puerarin-7-O-glucuronide was determined by rapid resolution-liquid chromatography-tandem mass spectrometry (RR-LC-MS/MS). Puerarin-7-O-glucuronide prevented XO/X-induced increase in intracellular superoxide production and decreases in total SOD activity, GSH/GSSG ratio, and total anti-oxidant capacity. Puerarin-7-O-glucuronide also reversed angiotensin II-induced increases in intracellular superoxide production and NADPH oxidase activity and decreases in total SOD activity. These anti-oxidant effects of puerarin-7-O-glucuronide were accompanied by downregulation of p22phox and p47phox. Furthermore, puerarin-7-O-glucuronide prevented angiotensin II-induced increases in cell surface area and perimeter, as well as changes in Nppa, Myh7, and Myh6. In the pharmacokinetic study, puerarin-7-O-glucuronide was cleared with a half-life of 0.94 h after intravenous administration. Puerarin could be detected in rat plasma, albeit in low concentration, as early as 5 min after intravenous administration of puerarin-7-O-glucuronide. These anti-oxidant and anti-hypertrophic properties of puerarin-7-O-glucuronide were similar to those of its parent compound puerarin. These results support the development of puerarin-7-O-glucuronide as a novel pharmaceutical agent for therapeutic application.

Asunto(s)

Angiotensina II/toxicidad , Antioxidantes/farmacología , Cardiomegalia/prevención & control , Glucurónidos/farmacología , Isoflavonas/farmacología , Miocitos Cardíacos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Solventes/química , Agua/química , Animales , Animales Recién Nacidos , Antioxidantes/administración & dosificación , Antioxidantes/química , Antioxidantes/farmacocinética , Cardiomegalia/inducido químicamente , Cardiomegalia/genética , Cardiomegalia/metabolismo , Cardiomegalia/patología , Células Cultivadas , Femenino , Glucurónidos/administración & dosificación , Glucurónidos/química , Glucurónidos/farmacocinética , Glutatión/metabolismo , Disulfuro de Glutatión/metabolismo , Inyecciones Intravenosas , Isoflavonas/administración & dosificación , Isoflavonas/química , Isoflavonas/farmacocinética , Masculino , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , NADPH Oxidasas/genética , NADPH Oxidasas/metabolismo , Ratas Sprague-Dawley , Solubilidad , Superóxido Dismutasa/metabolismo , Superóxidos/metabolismo , Xantina/farmacología , Xantina Oxidasa/farmacología

RESUMEN

We fabricate high-mobility p-type few-layer WSe_{2} field-effect transistors and surprisingly observe a series of quantum Hall (QH) states following an unconventional sequence predominated by odd-integer states under a moderate strength magnetic field. By tilting the magnetic field, we discover Landau level crossing effects at ultralow coincident angles, revealing that the Zeeman energy is about 3 times as large as the cyclotron energy near the valence band top at the Γ valley. This result implies the significant roles played by the exchange interactions in p-type few-layer WSe_{2}, in which itinerant or QH ferromagnetism likely occurs. Evidently, the Γ valley of few-layer WSe_{2} offers a unique platform with unusually heavy hole carriers and a substantially enhanced g factor for exploring strongly correlated phenomena.