Numerical Study for the Performance of Viscoelastic Fluids on Displacing Oil Based on the Fractional-Order Maxwell Model.

In the study of polymer flooding, researchers usually ignore the genetic stress properties of viscoelastic fluids. In this paper, we investigate the process of viscoelastic fluid flooding the remaining oil in the dead end. This work uses the fractional-order Maxwell in the traditional momentum equation. Furthermore, a semi-analytic solution of the flow control equation for fractional-order viscoelastic fluids is derived, and the oil-repelling process of viscoelastic fluids is simulated by a secondary development of OpenFOAM. The results show that velocity fractional-order derivative α significantly affects polymer solution characteristics, and increasing the elasticity of the fluid can significantly improve the oil repelling efficiency. Compared to the Newtonian fluid flow model, the fractional order derivative a and relaxation time b in the two-parameter instanton equation can accurately characterize the degree of elasticity of the fluid. The smaller the a, the more elastic the fluid is and the higher the oil-repelling efficiency. The larger the b, the less elastic the fluid is and the lower the cancellation efficiency. Moreover, the disturbance of the polymer solution to the dead end is divided into two elastic perturbation areas. The stronger the elasticity of the polymer solution, the higher the peak value of the area in the dead end and the higher the final oil displacement efficiency.

Artemether Alleviates Diabetic Kidney Disease by Modulating Amino Acid Metabolism.

Diabetes is a worldwide metabolic disease with rapid growing incidence, characterized by hyperglycemia. Diabetic kidney disease (DKD), the leading cause of chronic kidney disease (CKD), has a high morbidity according to the constantly increasing diabetic patients and always develops irreversible deterioration of renal function. Though different in pathogenesis, clinical manifestations, and therapies, both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) can evolve into DKD. Since amino acids are both biomarkers and causal agents, rarely report has been made about its metabolism which lies in T1DM- and T2DM-related kidney disease. This study was designed to investigate artemether in adjusting renal amino acid metabolism in T1DM and T2DM mice. Artemether was applied as treatment in streptozotocin (STZ) induced T1DM mice and db/db T2DM mice, respectively. Artemether-treated mice showed lower FBG and HbA1c and reduced urinary albumin excretion, as well as urinary NAG. Both types of diabetic mice showed enlarged kidneys, as confirmed by increased kidney weight and the ratio of kidney weight to body weight. Artemether normalized kidney size and thus attenuated renal hypertrophy. Kidney tissue UPLC-MS analysis showed that branched-chain amino acids (BCAAs) and citrulline were upregulated in diabetic mice without treatment and downregulated after being treated with artemether. Expressions of glutamine, glutamic acid, aspartic acid, ornithine, glycine, histidine, phenylalanine and threonine were decreased in both types of diabetic mice whereas they increased after artemether treatment. The study demonstrates the initial evidence that artemether exerted renal protection in DKD by modulating amino acid metabolism.

Mental health status among prison officers in the process of enforcing the law during COVID-19epidemic: a cross-sectional survey from China.

BACKGROUND: A global public health emergency triggered by the Coronavirus Disease 2019 (COVID-19) epidemic may have are markable psychological impact on the population. There is still limited psychological research on police officers, especially prison officers in the process of enforcing the law. The present study aims to identify prevalence and influencing factors on mental health status among frontline prison officers in China during the prevention and control of the COVID-19 epidemic. METHODS: A cross-sectional survey with a sample of 981 frontline prison officers was conducted using snowball sampling approach. The self-administered questionnaire consisted of 4 parts: (i) informed consent form; (ii) socio-demographic section; (iii) work and life situations during the prevention and control of the COVID-19 epidemic; (iv) the Chinese version of the 12-item General Health Questionnaire (GHQ-12). Univariate analysis and multivariable logistic regression were performed to identify factors influencing mental health status. RESULTS: The prevalence of being prone to mental health problems (GHQ-12 score ≥ 4) was 33.43% among frontline prison officers. The results of GHQ-12 factors analysis indicated that the prison officers suffered from psychological issues was related to anxiety and depression, which main symptoms were unhappy and depressed, lost sleep over worry and constantly under strain. Multivariate logistic regression analysis revealed that male (OR = 1.573, 95% CI:1.385-1.853), lockdown shift inside the prison(OR = 2.203, 95% CI:2.139-2.297), more night shifts (OR = 2.163, 95% CI:2.031-2.317; OR = 2.749, 95% CI:2.194-2.901), more smoking (OR = 1.100, 95% CI:1.037-2.168), poor self-reported physical condition (OR = 1.947, 95% CI:1.478-2.250), chronic or serious illness history(OR = 1.870, 95% CI:1.314-2.660; OR = 2.214, 95% CI:1.460-2.812) were risk factors for mental health among frontline prison officers, while regular diet (OR = 0.779, 95% CI:0.539-0.928), more physical exercise (OR = 0.702, 95% CI:0.548-0.899; OR = 0.641, 95% CI:0.316-0.887), more communication with family members (OR = 0.437, 95% CI:0.295-0.616) were protective factors. CONCLUSION: Chinese frontline prison officers experienced different psychological stress coming from the prevention and control of this epidemic. Therefore, continued surveillance of psychological problems and targeted mental health care for frontline prison officers were urgent.

MRI-Based Machine Learning in Differentiation Between Benign and Malignant Breast Lesions.

BACKGROUND: Differential diagnosis between benign and malignant breast lesions is of crucial importance relating to follow-up treatment. Recent development in texture analysis and machine learning may lead to a new solution to this problem. METHOD: This current study enrolled a total number of 265 patients (benign breast lesions:malignant breast lesions = 71:194) diagnosed in our hospital and received magnetic resonance imaging between January 2014 and August 2017. Patients were randomly divided into the training group and validation group (4:1), and two radiologists extracted their texture features from the contrast-enhanced T1-weighted images. We performed five different feature selection methods including Distance correlation, Gradient Boosting Decision Tree (GBDT), least absolute shrinkage and selection operator (LASSO), random forest (RF), eXtreme gradient boosting (Xgboost) and five independent classification models were built based on Linear discriminant analysis (LDA) algorithm. RESULTS: All five models showed promising results to discriminate malignant breast lesions from benign breast lesions, and the areas under the curve (AUCs) of receiver operating characteristic (ROC) were all above 0.830 in both training and validation groups. The model with a better discriminating ability was the combination of LDA + gradient boosting decision tree (GBDT). The sensitivity, specificity, AUC, and accuracy in the training group were 0.814, 0.883, 0.922, and 0.868, respectively; LDA + random forest (RF) also suggests promising results with the AUC of 0.906 in the training group. CONCLUSION: The evidence of this study, while preliminary, suggested that a combination of MRI texture analysis and LDA algorithm could discriminate benign breast lesions from malignant breast lesions. Further multicenter researches in this field would be of great help in the validation of the result.

Effects of graphene on morphology, microstructure and transcriptomic profiling of Pinus tabuliformis Carr. roots.

Graphene has shown great potential for improving growth of many plants, but its effect on woody plants remains essentially unstudied. In this work, Pinus tabuliformis Carr. bare-rooted seedlings grown outdoors in pots were irrigated with a graphene solution over a concentration range of 0-50 mg/L for six months. Graphene was found to stimulate root growth, with a maximal effect at 25 mg/L. We then investigated root microstructure and carried out transcript profiling of root materials treated with 0 and 25 mg/L graphene. Graphene treatment resulted in plasma-wall separation and destruction of membrane integrity in root cells. More than 50 thousand of differentially expressed genes (DEGs) were obtained by RNA sequencing, among which 6477 could be annotated using other plant databases. The GO enrichment analysis and KEGG pathway analysis of the annotated DEGs indicated that abiotic stress responses, which resemble salt stress, were induced by graphene treatment in roots, while responses to biotic stimuli were inhibited. Numerous metabolic processes and hormone signal transduction pathways were altered by the treatment. The growth promotion effects of graphene may be mediated by encouraging proline synthesis, and suppression of the expression of the auxin response gene SMALL AUXIN UP-REGULATED RNA 41 (SAUR41), PYL genes which encode ABA receptors, and GSK3 homologs.

Oxidative degradation of tetramethylammonium hydroxide (TMAH) by UV/persulfate and associated acute toxicity assessment.

Tetramethylammonium hydroxide (TMAH) is widely used in high-tech industries as a developing agent. Ultraviolet (UV) light-activated persulfate (PS, S2O82-) can be used to generate strongly oxidative sulfate radicals, and it also exhibits the potential to treat TMAH-containing wastewater. This study initially investigated the effect of S2O82- concentration and UV strength on the UV/S2O82- process for the degradation of TMAH in a batch reactor. The results suggested that 15 watts (W) of UV-activated S2O82- at concentrations of 10 or 50 mM resulted in pseudo-first-order TMAH degradation rate constants of 3.1-4.2 × 10-2 min-1, which was adopted for determining the hydraulic retention time (HRT) in a continuous stirred tank reactor (CSTR). The operating conditions (15 W UV/10 mM S2O82-) with a HRT of 129 min resulted in stable residual concentrations of S2O82- and TMAH at approximately 2.6 mM and 20 mg L-1 in effluent, respectively. Several TMAH degradation intermediates including trimethylamine, dimethylamine, and methylamine were also detected. The effluent was adjusted to a neutral pH and evaluated for its biological acute toxicity using Cyprinus carpio as a bioassay organism. The "bio-acute toxicity unit" (TUa) was determined to be 1.41, which indicated that the effluent was acceptable for being discharged into an aquatic ecosystem.

Structural Pharmacokinetics of Polymethoxylated Flavones in Rat Plasma Using HPLC-MS/MS.

The purpose of this study was to investigate the pharmacokinetics of the polymethoxylated flavonoids kumatakenin, pachypodol, and retusin, which contain two, three, or four methoxy substitutions, using a validated ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method in rats. The pharmacokinetic results demonstrated that the elimination half-lives for kumatakenin, pachypodol, and retusin were 30 ± 11.6, 39.4 ± 19.5, and 106.9 ± 26 min, respectively, for the low dose group and 54.5 ± 16.5, 33.8 ± 10, and 134.6 ± 34.7 min for the high dose group. The results suggested that the area under the curve values (AUC) for the analytes did not correlate with the number of methoxy groups. Pachypodol had the lowest AUC, which may have been correlated with lipophilicity, for both the low and high dose groups. In conclusion, the polymethoxylated flavonoid pachypodol is more hydrophilic than kumatakenin or retusin, which were correlated with the pharmacokinetic results.