Electrostatic Gating of Spin Dynamics of a Quasi-2D Kagome Magnet.

Electrostatic gating has emerged as a powerful technique for tailoring the magnetic properties of two-dimensional (2D) magnets, offering exciting prospects including enhancement of magnetic anisotropy, boosting Curie temperature, and strengthening exchange coupling effects. Here, we focus on electrical control of the ferromagnetic resonance of the quasi-2D Kagome magnet Cu(1,3-bdc). By harnessing an electrostatic field through ionic liquid gating, significant shifts are observed in the ferromagnetic resonance field in both out-of-plane and in-plane measurements. Moreover, the effective magnetization and gyromagnetic ratios display voltage-dependent variations. A closer examination reveals that the voltage-induced changes can modulate magnetocrystalline anisotropy by several hundred gauss, while the impact on orbital magnetization remains relatively subtle. Density functional theory (DFT) calculations reveal varying d-orbital hybridizations at different voltages. This research unveils intricate physics within the Kagome lattice magnet and further underscores the potential of electrostatic manipulation in steering magnetism with promising implications for the development of spintronic devices.

Visual impairment burden in retinopathy of prematurity: trends, inequalities, and improvement gaps.

Retinopathy of prematurity (ROP) is an important cause of avoidable childhood visual impairment, and the increase in number and survival of premature infants may inflate its burden globally. We aimed to comprehensively assess the trends and inequalities in the burden of ROP-related visual impairment and to identify improvement gaps to facilitate appropriate actions in neonatal care systems. We obtained ROP data from the Global Burden of Disease 2019 study. We employed joinpoint regression analysis to assess the trends of the burden of ROP-related visual impairment, measured by age-standardised prevalence rates, health equity analysis methods to evaluate cross-country burden inequalities, and data envelopment and stochastic frontier analyses to identify improvement gaps based on the development status, i.e., sociodemographic index (SDI). Between 1990 and 2019, the age-standardised prevalence rates of ROP-related visual impairment significantly increased worldwide (average annual percentage change: 0.23 [95% confidence interval, 0.21-0.26] among males and 0.26 [0.25-0.27] among females), primarily in developed regions. Although significant SDI-related cross-country inequalities were identified, these reduced over time (slope index of inequality: -57.74 [-66.22 to -49.25] in 1990 to -29.68 [-38.39 to -20.97] in 2019; health concentration index: -0.11 [-0.13 to -0.09] in 1990 to -0.07 [-0.09 to -0.06] in 2019). Notably, some less-developed countries exhibited superior performance despite limited resources, whereas others with a higher SDI delivered lagging performance.  Conclusion: The global burden of ROP-related visual impairment has steadily increased between 1990 and 2019, with disproportionate burden concentration among less-developed countries, requiring appropriate preventive and intervention measures. What is Known: • Retinopathy of prematurity (ROP) is an important cause of avoidable childhood visual impairment. • The prevalence of ROP is anticipated to increase due to the growing number of extremely premature infants. What is New: • The prevalence of ROP-related visual impairment has increased worldwide, primarily in developed regions, with declining but persisting cross-country inequalities. • The increasing burden of ROP-related visual impairment should be considered as part of global and national health agendas, requiring interventions with proven efficacy.

N,N-Dimethyl-3ß-hydroxycholenamide attenuates neuronal death and retinal inflammation in retinal ischemia/reperfusion injury by inhibiting Ninjurin 1.

BACKGROUND: Retinal ischemia-reperfusion (RIR) injury refers to an obstruction in the retinal blood supply followed by reperfusion. Although the molecular mechanism underlying the ischemic pathological cascade is not fully understood, neuroinflammation plays a crucial part in the mortality of retinal ganglion cells. METHODS: Single-cell RNA sequencing (scRNA-seq), molecular docking, and transfection assay were used to explore the effectiveness and pathogenesis of N,N-dimethyl-3ß-hydroxycholenamide (DMHCA)-treated mice with RIR injury and DMHCA-treated microglia after oxygen and glucose deprivation/reoxygenation (OGD/R). RESULTS: DMHCA could suppress inflammatory gene expression and attenuate neuronal lesions, restoring the retinal structure in vivo. Using scRNA-seq on the retina of DMHCA-treated mice, we provided novel insights into RIR immunity and demonstrated nerve injury-induced protein 1 (Ninjurin1/Ninj 1) as a promising treatment target for RIR. Moreover, the expression of Ninj1, which was increased in RIR injury and OGD/R-treated microglia, was downregulated in the DMHCA-treated group. DMHCA suppressed the activation of the nuclear factor kappa B (NF-κB) pathways induced by OGD/R, which was undermined by the NF-κB pathway agonist betulinic acid. Overexpressed Ninj1 reversed the anti-inflammatory and anti-apoptotic function of DMHCA. Molecular docking indicated that for Ninj1, DMHCA had a low binding energy of - 6.6 kcal/mol, suggesting highly stable binding. CONCLUSION: Ninj1 may play a pivotal role in microglia-mediated inflammation, while DMHCA could be a potential treatment strategy against RIR injury.

Critical role of transcriptome-wide m6A methylation in the aqueous humor of patients with pseudoexfoliation glaucoma.

N6-methyladenosine (m6A) modification is one of the most common types of methylation modifications in eukaryotic mRNA. However, its role in the pathogenesis of pseudoexfoliation glaucoma (PXG) has not yet been reported. To enhance understanding in this regard, we assessed the m6A methylome in the aqueous humor of patients with PXG. MeRIP-Seq and RNA-Seq analyses were performed to compare the m6A methylomes and gene expression profiles of the aqueous humor of patients with PXG with those of patients with age-related cataract (ARC). Colorimetric m6A quantification was performed to detect global m6A levels. Quantitative reverse transcription PCR confirmed the expression of m6A-related enzymes and mRNAs in both groups. Results showed significantly higher aqueous humor m6A levels in the PXG group than in the ARC group. Five m6A-related enzymes, including METTL3, YTHDC2, HNRNPA2B1, HNRNPC, and LRPPRC, were significantly up-regulated in PXG specimens. We also observed 9728 m6A-modified peaks related to 6126 gene transcripts in the PXG group, with more than 250 genes containing one m6A peak (hypomethylated or hypermethylated). The distribution of the m6A peaks was enriched in coding sequences and 3'-untranslated regions for both groups. GGAC motif structures were also significantly enriched. Bioinformatics analysis further revealed that m6A plays a critical role in extracellular matrix formation and histone deacetylation. Additionally, MMP14, ADAMTSL1, FN1, and HDAC1 showed significant changes in m6A methylation and mRNA expression in the PXG group. Therefore, m6A methylation may regulate extracellular matrix composition in PXG and METTL3 may be a pivotal regulator of this process. In the future, it would be necessary to investigate MMP14, ADAMTSL1, FN1, and HDAC1, which are potential target genes.

Correlation between spherical equivalent and biometry parameters in adult Cynomolgus macaque.

PURPOSE: To characterize the distribution of refractive and ocular biometry parameters and analyze the effect factors of the refractive status in cynomolgus monkey colonies. METHODS: A Population-based cross-sectional study was conducted in adult cynomolgus macaque colonies. Animals were anesthetized with Zoletil 50. Intraocular pressure was measured using the Icare tonometer. Cycloplegic refraction (three drops of 1% tropicamide) and corneal radius of curvature (CRC) were measured using an autorefractor. The spherical equivalent (SE) was calculated. Biometric measurements, including the anterior chamber depth (ACD), lens thickness (LT), and axial length (AL), were obtained by A-scan ultrasonography. The AL-to-CR ratio (AL/CRC) was calculated. Central corneal thickness (CCT) and choroidal thickness (ChT) were measured using the Heidelberg Spectralis HRA OCT. Multiple regression analysis was performed to explore the association between refraction and ocular biometry. RESULTS: Among 263 cynomolgus monkeys (aged 5-26 years), which consisted of 520 eyes, 29.42% had hyperopia, 27.12% had emmetropia, 33.27% had mild-to-moderate myopia and 10.19% had high myopia. The mean SE was -1.27 ± 3.44 Diopters (D). The mean CRC, CCT, AL, and ChT was 5.70 ± 0.22 mm, 454.30 ± 32.40 µm, 18.76 ± 0.89 mm and 188.96 ± 38.19 µm, respectively. The LT was the thickest in the hyperopic eyes. CRC was the lowest, and CCT was the thickest in high myopic eyes. AL increased, while ChT decreased as SE decreased. For the SE variance, AL alone explained 40.5%; age, AL, and CRC together explained 57.5%. CONCLUSIONS: The refractive characteristics and biometry parameters of cynomolgus monkeys are highly comparable to those of humans. AL, CRC, and ChT showed the similar variation tendency in cynomolguses when compared to humans. Cynomolgus monkeys with naturally-occurring refractive errors may be a good animal model for refractive studies.

Design, methodology, and preliminary results of the non-human primates eye study.

PURPOSE: To describe the normative profile of ophthalmic parameters in a healthy cynomolgus monkey colony, and to identify the characteristic of the spontaneous ocular disease non-human primates (NHP) models. METHODS: The NHP eye study was a cross-sectional on-site ocular examination with about 1,000 macaques held in Guangdong Province, southeastern China. The NHPs (Macaca fascicularis, cynomolgus) in this study included middle-aged individuals with a high prevalence of the ocular disease. The NHP eye study (NHPES) performed the information including systematic data and ocular data. Ocular examination included measurement of intraocular pressure (IOP), anterior segment- optical coherence tomography (OCT), slit-lamp examination, fundus photography, autorefraction, electroretinography, etc. Ocular diseases included measurement of refractive error, anisometropia, cataract, pterygium, etc. RESULTS: A total of 1148 subjects were included and completed the ocular examination. The average age was 16.4 ± 4.93 years. Compared to the male participants, the females in the NHPES had shorter axial length and the mean Average retinal nerve fiber layer (RNFL) thickness (except for the nasal quadrants). The mean IOP, anterior chamber depth, lens thickness, axial length, central corneal thickness, choroid thickness and other parameters were similar in each group. CONCLUSION: The NHPES is a unique and high-quality study, this is the first large macaque monkey cohort study focusing on ocular assessment along with comprehensive evaluation. Results from the NHPES will provide important information about the normal range of ophthalmic measurements in NHP.

Discovery of Clinical Manifestations in Spontaneous Glaucoma Suspect Nonhuman Primates.

INTRODUCTION: The primary aim of this study was to assess the longitudinal changes in retinal nerve fiber layer (RNFL) thickness and relative ONH parameters using spectral-domain optical coherence tomography (SD-OCT) in the living eyes of nonhuman primates with spontaneous glaucoma. METHODS: Totally 9 macaque subjects underwent a standard fundus photo and OCT examination, including 3 adult monkeys with stable elevated intraocular pressure (IOP) as the glaucoma suspect group and 6 normal IOP monkeys as the control group. Each eye of primates with IOP measurement was repeated three times. OCT measurements recorded RNFL, Bruch's membrane opening (BMO) minimum rim width (MRW). The follow-up scan of glaucomatous subjects was undergone in 10 months. RESULTS: The mean ages of glaucoma and healthy subjects are 19.33 ± 0.33 and 20.5 ± 1.46 years. Elevated IOP was achieved in three nonhuman primate eyes with an average increase of 10 mm Hg over the study period. Elevated IOP was associated with decreased RNFL thickness in all the regions and decreased RNFL phase retardation in the superior and inferior regions. When averaged over the entire retinal area, only the whole RNFL and temporal regions showed a significant decrease. The mean IPL thicknesses are 87.17 ± 2.15 µm in glaucomatous and 93.33 ± 1.51 µm in healthy eyes (p = 0.03). Lamina cribrosa parameters are measured from the OCT images and showed significant differences between glaucoma primates and normal primates. CONCLUSIONS: Of the measured parameters, decreased RNFL and MRW were correlated with glaucomatous damage. Natural glaucoma primate can be a natural glaucoma model which is closer to glaucoma in humans.

Prevalence Patterns and Onset Prediction of High Myopia for Children and Adolescents in Southern China via Real-World Screening Data: Retrospective School-Based Study.

BACKGROUND: Patients with high myopia have an increased lifetime risk of complications. The prevalence patterns of high myopia in children and adolescents in southern China are unclear. Early identification of high-risk individuals is critical for reducing the occurrence and development of high myopia and avoiding the resulting complications. OBJECTIVE: This study aimed to determine the prevalence of high myopia in children and adolescents in southern China via real-world screening data and to predict its onset by studying the risk factors for high myopia based on machine learning. METHODS: This retrospective school-based study was conducted in 13 cities with different gross domestic products in southern China. Through data acquisition and filtering, we analyzed the prevalence of high myopia and its association with age, school stage, gross domestic product, and risk factors. A random forest algorithm was used to predict high myopia among schoolchildren and then assessed in an independent hold-out group. RESULTS: There were 1,285,609 participants (mean age 11.80, SD 3.07, range 6-20 years), of whom 658,516 (51.2%) were male. The overall prevalence of high myopia was 4.48% (2019), 4.88% (2020), and 3.17% (2021), with an increasing trend from the age of 11 to 17 years. The rates of high myopia increased from elementary schools to high schools but decreased at all school stages from 2019 to 2021. The coastal and southern cities had a higher proportion of high myopia, with an overall prevalence between 2.60% and 5.83%. Age, uncorrected distance visual acuity, and spherical equivalents were predictive factors for high myopia onset in schoolchildren. The random forest algorithm achieved a high accuracy of 0.948. The area under the receiver operator characteristic curve (AUC) was 0.975. Both indicated sufficient model efficacy. The performance of the model was validated in an external test with high accuracy (0.971) and a high AUC (0.957). CONCLUSIONS: High myopia had a high incidence in Guangdong Province. Its onset in children and adolescents was well predicted with the random forest algorithm. Efficient use of real-world data can contribute to the prevention and early diagnosis of high myopia.

Ammonia nitrogen recovery from biogas slurry by SCP production using Candida utilis.

The safe and robust yeast Candida utilis was employed for nitrogen recovery as single cell protein from biogas slurry. The maximum biomass of 6.2 g/L with protein content of 53.5% was produced in batch cultivation with glucose as the carbon source, C/N ratio of 3:1, NH4+-N concentration of 3000 mg/L, initial pH of 8.0, and the addition of 0.35% (w/v) Na2HPO4. It was speculated that C. utilis can grow well with free ammonia below 197 mg/L. In fed-batch fermentation, a biomass of 14.8 g/L was obtained, and the maintenance of aerobic conditions was critical to improving the production of single cell protein. The sterilized and non-sterilized biogas slurry can be used as an effective pH regulator. The obtained single cell protein was a nutritious, safe, and reliable protein source. This study provides novel insights into nitrogen recovery via C. utilis as a single cell protein from biogas slurry.

Molecular Dynamics Study on the Diffusion Mass Transfer Behaviour of CO2 and Crude Oil in Fluids Produced via CO2 Flooding.

Carbon dioxide flooding is one of the main methods used to improve crude oil recovery. It can not only improve oil recovery but also reduce greenhouse gas emissions. However, the addition of carbon dioxide makes crude oil become a more complex multiphase fluid; that is, carbon dioxide flooding-produced fluid, in which CO2 and various components in crude oil mass transfer each other. This results in significant changes in the structure and properties of crude oil that increase the hazards associated with its gathering and transportation. Therefore, it is very important to explore the microscopic mechanism for the diffusion mass transfer of CO2 and crude oil in this fluid, especially during its gathering and transportation. In this study, the diffusion mass transfer process of CO2 and crude oil in fluids produced via CO2 flooding is studied using molecular dynamics, and the influences of temperature, gas-oil ratio and water content are explored. Observations of the configuration and dynamic behaviour of the system show that after the system reaches equilibrium, the majority of the CO2 molecules are distributed at the oil-water interface, and CO2 is more prone to diffusing into the oil phase than the water phase. Increases in temperature and water content inhibit, while increases in the gas-oil ratio promote, the diffusion mass transfer of CO2 in the crude oil system. The results of this study reveal the mechanism for the diffusion mass transfer of CO2 and crude oil in fluids produced via CO2 flooding and account for the influence of the water phase, which is consistent with actual production conditions and has certain guiding significance for the safe operation of oil and gas gathering and transportation.

TET-dependent GDF7 hypomethylation impairs aqueous humor outflow and serves as a potential therapeutic target in glaucoma.

Glaucoma is the leading cause of irreversible vision loss, affecting more than 70 million individuals worldwide. Circulatory disturbances of aqueous humor (AH) have long been central pathological contributors to glaucomatous lesions. Thus, targeting the AH outflow is a promising approach to treat glaucoma. However, the epigenetic mechanisms initiating AH outflow disorders and the targeted treatments remain to be developed. Studying glaucoma patients, we identified GDF7 (growth differentiation factor 7) hypomethylation as a crucial event in the onset of AH outflow disorders. Regarding the underlying mechanism, the hypomethylated GDF7 promoter was responsible for the increased GDF7 production and secretion in primary open-angle glaucoma (POAG). Excessive GDF7 protein promoted trabecular meshwork (TM) fibrosis through bone morphogenetic protein receptor type 2 (BMPR2)/Smad signaling and upregulated pro-fibrotic genes, α-smooth muscle actin (α-SMA) and fibronectin (FN). GDF7 protein expression formed a positive feedback loop in glaucomatous TM (GTM). This positive feedback loop was dependent on the activated TET (ten-eleven translocation) enzyme, which kept the GDF7 promoter region hypomethylated. The phenotypic transition in TM fortified the AH outflow resistance, thus elevating the intraocular pressure (IOP) and attenuating the nerve fiber layer. This methylation-dependent mechanism is also confirmed by a machine-learning model in silico with a specificity of 84.38% and a sensitivity of 89.38%. In rhesus monkeys, we developed GDF7 neutralization therapy to inhibit TM fibrosis and consequent AH outflow resistance that contributes to glaucoma. The neutralization therapy achieved high-efficiency control of the IOP (from 21.3 ± 0.3 to 17.6 ± 0.2 mmHg), a three-fold improvement in the outflow facility (from 0.1 to 0.3 µL/min · mmHg), and protection of nerve fibers. This study provides new insights into the epigenetic mechanism of glaucoma and proposes an innovative GDF7 neutralization therapy as a promising intervention.

An Analytical Investigation of Anomaly Detection Methods Based on Sequence to Sequence Model in Satellite Power Subsystem.

The satellite power subsystem is responsible for all power supply in a satellite, and is an important component of it. The system's performance has a direct impact on the operations of other systems as well as the satellite's lifespan. Sequence to sequence (seq2seq) learning has recently advanced, gaining even more power in evaluating complicated and large-scale data. The potential of the seq2seq model in detecting anomalies in the satellite power subsystem is investigated in this work. A seq2seq-based scheme is given, with a thorough comparison of different neural-network cell types and levels of data smoothness. Three specific approaches were created to evaluate the seq2seq model performance, taking into account the unsupervised learning mechanism. The findings reveal that a CNN-based seq2seq with attention model under suitable data-smoothing conditions has a better ability to detect anomalies in the satellite power subsystem.

Study on cooperative constraint zoning of water environment.

This study comprehensively considers two elements of water environmental sensitivity and pressure using the combination of qualitative analysis and quantitative calculation. And it puts forward the water environmental collaborative constraint zoning method and focuses on the construction of the water environmental collaborative constraint zoning evaluation index system using the fuzzy optimization programming model to determine the index weight. This study takes the Liaohe River Basin in Liaoning Province as a study area through two-dimensional quadrant analysis of water environmental sensitivity and pressure; it is divided into four types of areas: high-pressure and high-sensitivity area (HP-HS area), high-pressure and low-sensitivity area (HP-LS area), low-pressure and high-sensitivity area (LP-HS area) and low-pressure and low-sensitivity area (LP-LS area), respectively. The results show that the proportion of HP-HS area is 28.4%, the proportion of HP-LS area is 10.1%, the proportion of LP-HS area is 22.2% and the proportion of LP-LS area is 39.3%, respectively. The evaluation results are in line with the actual situation of the Liaohe River Basin in Liaoning Province. According to the results of different zoning, this research puts forward the optimization and adjustment scheme of industrial layout to achieve the comprehensive and coordinated sustainable development of population, economy, society, and environment in the study area. The research results also have been applied to the formulation of '14th Five-Year Plan' for water ecological environment protection of key river basins in Liaoning Province.

Bioactivity-guided separation of antifungal compounds by preparative high-performance liquid chromatography.

Bioactivity-guided chromatographic methods are of great significance for the isolation of the active compounds in complex samples. In this study, four anti-fungal compounds were located by activity screening and successfully isolated from a microbial fermentation sample by preparative high-performance liquid chromatography. Separation performance of columns including C18, positively charged C18, negatively charged C18 and C8 were firstly investigated. And it showed a better capacity of mixed-mode stationary phases for retention and separation. Therefore, the positively charged C18 column was used to separate the sample into several fractions, among which the active one was identified by the antifungal test. And then the active fraction was enriched and separated again by successively using the negatively charged C18 and C8 columns to obtain four compounds, which were identified as polyoxins A, K, F and H. With activity verification, four polyoxins were found to have good inhibitory effects against the three fungal plant diseases including rice sheath blight, tomato grey mould disease, and apple spot leaf disease.

Isolation of three polyoxins by reversed-phase liquid chromatography with pure aqueous mobile phase.

Developing methods for the isolation of highly polar compounds from complex samples is of great significance. In this study, three polyoxins were successfully isolated from a complex sample (PN1-1# ) by preparative high-performance liquid chromatography. Separation was carried out on five polar reversed-phase stationary phases, using pure aqueous as mobile phase, where the C18HC column can provide the best performance for PN1-1# . Next, the effects of the mobile phase composition were studied. It was found that adding NaClO4 can enhance the retention and resolution, and adding NaH2 PO4 was beneficial to maintain good peak shapes when the sample loading increased. Therefore, the optimized mobile phase consisting of 20 mmol NaH2 PO4 and 20 mmol NaClO4 (adding H3 PO4 to adjust pH 2) was used to separate PN1-1# . This method of using 100% aqueous phase can effectively improve both the retention and the solubility of polar samples. Eventually, through further purification, three compounds, namely, polyoxins B, D, and G, were obtained. This paper provided an effective and eco-friendly strategy for the preparative-scale separation of polar samples.

Antennal transcriptome analysis and candidate olfactory genes in Crematogaster rogenhoferi.

Crematogaster rogenhoferi (Hymenoptera: Formicidae), an omnivorous ant, is one of the dominant predatory natural enemies of a soft scale pest, Parasaissetia nigra Nietner (Homoptera: Coccidae), and can effectively control P. nigra populations in rubber forests. Olfaction plays a vital role in the process of predation. However, the information about the molecular mechanism of olfaction-evoked behaviour in C. rogenhoferi is limited. In this study, we conducted antennal transcriptome analysis to identify candidate olfactory genes. We obtained 53,892 unigenes, 16,185 of which were annotated. Based on annotations, we identified 49 unigenes related to chemoreception, including four odourant-binding proteins, three chemosensory proteins, 37 odourant receptors, two odourant ionotropic receptors and three sensory neuron membrane proteins. This is the first report on the molecular basis of the chemosensory system of C. rogenhoferi. The findings provide a basis for elucidating the molecular mechanisms of the olfactory-related behaviours of C. rogenhoferi, which would facilitate a better application of C. rogenhoferi as a biological control agent.

Polybrominated Diphenyl Ethers and Heavy Metals in a Regulated E-Waste Recycling Site, Eastern China: Implications for Risk Management.

Serious pollution of multiple chemicals in irregulated e-waste recycling sites (IR-sites) were extensively investigated. However, little is known about the pollution in regulated sites. This study investigated the occurrence of 21 polybrominated diphenyl ethers (PBDEs) and 10 metals in a regulated site, in Eastern China. The concentrations of PBDEs and Cd, Cu, Pb, Sb, and Zn in soils and sediments were 1-4 and 1-3 orders of magnitude lower than those reported in the IR-sites, respectively. However, these were generally comparable to those in the urban and industrial areas. In general, a moderate pollution of PBDEs and metals was present in the vegetables in this area. A health risk assessment model was used to calculate human exposure to metals in soils. The summed non-carcinogenic risks of metals and PBDEs in the investigated soils were 1.59-3.27 and 0.25-0.51 for children and adults, respectively. Arsenic contributed to 47% of the total risks and As risks in 71.4% of the total soil samples exceeded the acceptable level. These results suggested that the pollution from e-waste recycling could be substantially decreased by the regulated activities, relative to poorly controlled operations, but arsenic pollution from the regulated cycling should be further controlled.

Systematic evaluation and optimization of high-performance liquid chromatography separation of polyoxins.

The chromatographic behavior of a kind of nucleoside peptides, polyoxins, was investigated in this study. Molecular simulation technique was used to elucidate the temperature-dependent peak sharpening of polyoxins. There was a relatively small energy barrier between the global minimum conformer and the local minimum conformer of polyoxin A and the high temperature helped to quickly cross the energy barrier and accelerate the conformational transformation for getting the global minimum, so that stationary phase could not identify these two conformations and presented a sharp peak. Two kinds of mixed-mode columns, strong cation exchange or strong anion exchange ligands bonded with C18 (C18SCX and C18SAX) were used to improve separation selectivity of four polyoxins (A, K, F, H). The electrostatic attraction was necessary to increase the retention to ensure that the alkyl chain can give better play to its hydrophobic effect. Therefore, four polyoxins were well separated on C18SCX at pH 2 and they were also well separated on C18SAX at pH 7. In the small-scale purification of polyoxins, the sample loading of the C18SCX was five times than that of the C18SAX and the purity of the collected four polyoxins was all over 90%.

A rapid UHPLC-MS/MS method for the quantification of ARQ531 in rat plasma: Validation and its application to a pharmacokinetic study.

A simple and sensitive ultra-high performance liquid chromatography-tandem mass spectrometric (UHPLC-MS/MS) method was developed and validated for the determination of ARQ531, a Bruton's tyrosine kinase inhibitor in rat plasma. After protein precipitation with acetonitrile, the samples were separated on a UPLC BEH C18 column with 0.1% formic acid in water and acetonitrile as mobile phase at a flow rate of 0.4 ml/min. The mass detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring with precursor-to-product ion transitions of m/z 479.1 > 365.1 and m/z 441.2 > 138.1 for ARQ531 and internal standard, respectively. Good linearity (correlation coefficient > 0.9988) was achieved over the concentration range of 0.5-1,000 ng/ml and the lower limit of quantitation was 0.5 ng/ml. The accuracy ranged from -13.50 to 11.35% and the precision was <8.87%. The extraction recovery was >85.56%. ARQ531 was demonstrated to be stable under the tested conditions. The validated method was further applied to a pharmacokinetic study of ARQ531 in rats after intravenous (1 mg/kg) and oral (1, 3 and 10 mg/kg) administration. The results demonstrated that ARQ531 displayed linear pharmacokinetic profiles over the oral dose range of 1-10 mg/kg and good oral bioavailability (>50%).

[Different Energy Spectrum CT Findings between Anterior Mediastinal Lymphoma and Thymic Carcinoma].

Objective To investigate the differences in energy spectrum CT findings between anterior mediastinal lymphoma and thymic carcinoma. Methods Twenty-two cases of anterior mediastinal lymphoma and 28 cases of thymic carcinoma confirmed by biopsy in Tangshan People's Hospital were selected.The CT values and changes of iodine content and water content in lesion sites were measured by energy spectrum analysis software.The differences between anterior mediastinal lymphoma and thymic carcinoma were compared. Results The single-energy CT value of 40-80 keV in thymus carcinoma was higher than that in anterior mediastinal lymphoma(P=0.001,P=0.037,P=0.042,P=0.034,P=0.002;P=0.016,P=0.013,P=0.018,P=0.024,P=0.012).The difference in the single-energy CT value of 90-110 keV between anterior mediastinal lymphoma and thymic carcinoma showed no statistical significance(all P>0.05).The concentrations of water in the arterial and venous stages of thymic carcinoma were significantly lower than those in the anterior mediastinal lymphoma(P=0.030,P=0.037),whereas the iodine concentrations were significantly higher(P=0.026,P=0.000). Conclusion Anterior mediastinal lymphoma and thymic carcinoma have remarkably different 40-80 keV single energy CT value and iodine concentration in arterial and venous phases,which may be helpful for the differential diagnosis of these two malignancies.