Potential of PAQosome as a therapeutic target for hepatic fibrosis.

BACKGROUND AND AIM: The condition of hepatic fibrosis is hazardous. Therefore, it is vital that we investigate the mechanism of hepatic fibrosis to provide new targets for treatment. METHODS: Preliminary screening and research was carried out based on our prior results and our speculated role of the particle with quaternary structure arrangement (PAQosome) in hepatic fibrosis. The experiments were conducted using LX-2 or HepG2 cell lines by western blotting, quantitative real-time polymerase chain reaction, luciferase assays, and co-immunoprecipitation and were further validated in the Gene Expression Omnibus (GEO) database. RESULTS: We screened and proved that several subunits of the PAQosome regulate the development of liver fibrosis, including the asparagine synthetase domain-containing 1 upstream open reading frame (ASDURF), prefoldin subunit 4 (PFDN4), prefoldin subunit 5 (PFDN5), unconventional prefoldin RNA polymerase II subunit 5 interactor (URI1), and ubiquitously expressed prefoldin-like chaperone (UXT). ASDURF promotes hepatic fibrosis through the transforming growth factor-ß1 (TGFß1)/Sekelsky mothers against decapentaplegic homologue 3 (Smad3) and NF-κB signaling pathways. ASDURF regulates the expression of asparagine synthetase domain-containing 1 (ASNSD1). PFDN4, PFDN5, URI1, and UXT regulate cell proliferation through the PI3K/AKT pathway, and thus regulate liver fibrosis. A hepatic fibrosis score ≥ F2 was selected as the diagnostic criteria for hepatic fibrosis in the GSE96971 database. The area under the receiver operating characteristic curve of PFDN4, PFDN5, UXT, and ASNSD1 were 0.862 (confidence interval [CI]: 0.6588-1.000), 0.538 (CI: 0.224-0.853), 0.708 (CI: 0.449-0.966), and 0.831 (CI: 0.638-1.000), respectively. CONCLUSIONS: These findings demonstrate that the PAQosome is a brand new target for hepatic fibrosis therapy.

Nutrient intake and risk of multimorbidity: a prospective cohort study of 25,389 women.

BACKGROUND: Multimorbidity is becoming an increasingly serious public health challenge in the aging population. The impact of nutrients on multimorbidity remains to be determined and was explored using data from a UK cohort study. METHOD: Our research analysis is mainly based on the data collected by the United Kingdom Women's Cohort Study (UKWCS), which recruited 35,372 women aged 35-69 years at baseline (1995 to 1998), aiming to explore potential associations between diet and chronic diseases. Daily intakes of energy and nutrients were estimated using a validated 217-item food frequency questionnaire at recruitment. Multimorbidity was assessed using the Charlson comorbidity index (CCI) through electronic linkages to Hospital Episode Statistics up to March 2019. Cox's proportional hazards models were used to estimate associations between daily intakes of nutrients and risk of multimorbidity. Those associations were also analyzed in multinomial logistic regression as a sensitivity analysis. In addition, a stratified analysis was conducted with age 60 as the cutoff point. RESULTS: Among the 25,389 participants, 7,799 subjects (30.7%) were confirmed with multimorbidity over a median follow-up of 22 years. Compared with the lowest quintile, the highest quintile of daily intakes of energy and protein were associated with 8% and 12% increased risk of multimorbidity respectively (HR 1.08 (95% CI 1.01, 1.16), p-linearity = 0.022 for energy; 1.12 (1.04, 1.21), p-linearity = 0.003 for protein). Higher quintiles of daily intakes of vitamin C and iron had a slightly lowered risk of multimorbidity, compared to the lowest quintile. A significantly higher risk of multimorbidity was found to be linearly associated with higher intake quintiles of vitamin B12 and vitamin D (p-linearity = 0.001 and 0.002, respectively) in Cox models, which became insignificant in multinomial logistic regression. There was some evidence of effect modification by age in intakes of iron and vitamin B1 associated with the risk of multimorbidity (p-interaction = 0.006 and 0.025, respectively). CONCLUSIONS: Our findings highlight a link between nutrient intake and multimorbidity risk. However, there is uncertainty in our results, and more research is needed before definite conclusions can be reached.

Deficiency of circ_0103809 Attenuates Non-small Cell Lung Cancer Malignant Progression by Controlling miR-153-3p/HDAC1 Network.

Circular RNAs are vital players in tumorigenesis. We held the purpose to investigate the role and mechanism of circ_0103809 in non-small cell lung cancer (NSCLC). The expressions of circ_0103809, miR-153-3p and HDAC1 mRNA were determined using quantitative real-time PCR assay, and HDAC1 protein was quantified using western blot analysis. MTT, EdU, flow cytometry, tube-formation, wound healing and tube-formation assays were conducted for functional analysis. The predicted relationship among circ_0103809, miR-153-3p and HDAC1 was ascertained using dual-luciferase analysis, RIP assay and pull-down analysis. Animal models were further constructed to realize circ_0103809's role in vivo. Circ_0103809 was upregulated NSCLC specimens, cells and serum-derived exosomes. Serum exosomal circ_0103809 had the potency to be a diagnostic biomarker for NSCLC. Circ_0103809 silencing inhibited NSCLC cell growth, metastasis and angiogenesis and triggered cell cycle arrest and apoptosis. Circ_0103809 deficiency also suppressed the growth of transplanted tumors. Circ_0103809 acted as the miR-153-3p sponge, and the biological effects of circ_0103809 knockdown were relieved by miR-153-3p inhibition. HDAC1 was directly targeted by miR-153-3p, and miR-153-3p enrichment inhibited NSCLC cell malignant phenotypes by sequestering HDAC1. Circ_0103809 knockdown repressed NSCLC malignant progression partly by regulating miR-153-3p/HDAC1 signaling.

Anti-Tumor Activity and Mechanism of Silibinin Based on Network Pharmacology and Experimental Verification.

Silibinin is a flavonoid compound extracted from the seeds of Silybum marianum (L.) Gaertn. It has the functions of liver protection, blood-lipid reduction and anti-tumor effects. However, the potential molecular mechanism of silibinin against tumors is still unknown. This study aimed to assess the anti-tumor effects of silibinin in adenoid cystic carcinoma (ACC2) cells and Balb/c nude mice, and explore its potential mechanism based on network pharmacology prediction and experimental verification. A total of 347 targets interacting with silibinin were collected, and 75 targets related to the tumor growth process for silibinin were filtrated. Based on the PPI analysis, CASP3, SRC, ESR1, JAK2, PRKACA, HSPA8 and CAT showed stronger interactions with other factors and may be the key targets of silibinin for treating tumors. The predicted target proteins according to network pharmacology were verified using Western blot analysis in ACC2 cells and Balb/c nude mice. In the pharmacological experiment, silibinin was revealed to significantly inhibit viability, proliferation, migration and induce the apoptosis of ACC2 cells in vitro, as well as inhibit the growth and development of tumor tissue in vivo. Western blot analysis showed that silibinin affected the expression of proteins associated with cell proliferation, migration and apoptosis, such as MMP3, JNK, PPARα and JAK. The possible molecular mechanism involved in cancer pathways, PI3K-Akt signaling pathway and viral carcinogenesis pathway via the inhibition of CASP3, MMP3, SRC, MAPK10 and CDK6 and the activation of PPARα and JAK. Overall, our results provided insight into the pharmacological mechanisms of silibinin in the treatment of tumors. These results offer a support for the anti-tumor uses of silibinin.

Multi-Carrier Generation in Organic-Passivated Black Silicon Solar Cells with Industrially Feasible Processes.

The innate inverse Auger effect within bulk silicon can result in multiple carrier generation. Observation of this effect is reliant upon low high-energy photon reflectance and high-quality surface passivation. In the photovoltaics industry, metal-assisted chemical etching (MACE) to afford black silicon (b-Si) can provide a low high-energy photon reflectance. However, an industrially feasible and cheaper technology to conformally passivate the outer-shell defects of these nanowires is currently lacking. Here, a technology is introduced to infiltrate black silicon nanopores with a simple and vacuum-free organic passivation layer that affords millisecond-level minority carrier lifetimes and matches perfectly with existing solution-based processing of the MACE black silicon. Advancements such as the demonstration of an excellent passivation effect whilst also being low reflectance provide a new technological route for inverse Auger multiple carrier generation and an industrially feasible technical scheme for the development of the MACE b-Si solar cells.

Cord blood metabolomics reveals gestational metabolic disorder associated with anti-thyroid peroxidase antibodies positivity.

BACKGROUND: Thyroid disease is one of the common endocrine disorders affecting the pregnant women, in which thyroid autoimmunity can alter the progress and the outcome of pregnancy. Women with euthyroid status but anti-thyroid peroxidase (anti-TPO) antibodies positivity before pregnancy are prone to subclinical gestational hypothyroidism. However, the connections between anti-TPO antibodies positivity and gestational hypothyroidism remain largely unknown. The aim of the present study is to investigate the differences of fetal metabolic profile at birth according to maternal anti-TPO status. METHODS: We performed 1H-NMR metabolomics on cord blood of a nested case control cohort of 22 pregnant women with matched thyroid hormone levels and demographic data, including 11 women with euthyroid status but anti-thyroid antibodies positivity (into the anti-TPO antibodies positivity group) and 11 matched women as controls with euthyroid status and negative anti-thyroid antibodies (into the control group). RESULTS: Distinct metabolic profiles were observed between the anti-TPO antibody positivity group and the nested control group, from which a total of 10 metabolites with between-group altered abundances were structurally identified. Five out of the 10 metabolites were up-regulated in the anti-TPO antibodies positivity group, including D-Glucose, L-Glutamine, 3-Hydroxybutyric acid, Myo-Inositol, Creatinine. The other 5 metabolites were down-regulated in the anti-TPO antibodies positivity group, including L-Leucine, L-Lysine, L-Glutamic acid, L-Tyrosine, and L-Phenylalanine. All the 10 metabolites have been previously reported to be correlated with hypothyroidism. Metabolite set enrichment analysis and pathway analysis suggested that amino acid metabolism pathways (especially the phenylalanine metabolism) were associated with anti-TPO antibodies positivity. CONCLUSION: The results of this study suggested that fetal metabolic disorder is correlated with anti-TPO antibodies positivity, representing by abundance alteration of hypothyroidism associated metabolites and the related disturbance of amino acid metabolism pathways.

Neurotoxicity of sanguinarine via inhibiting mitophagy and activating apoptosis in zebrafish and PC12 cells.

Sanguinarine, a plant-derived phytoalexin, displays various biological activities, such as insecticidal, antimicrobial, anti-inflammatory, anti-angiogenesis and antitumor effects. But its potential neurotoxicity and the underlying mechanisms has rarely been investigated. Therefore, we aimed to assess the neurotoxicity of sanguinarine using zebrafish model and PC12 cells in this study. The results showed that sanguinarine induced the reduction of the length of dopamine neurons and inhibited the blood vessel in the head area of the zebrafish. Further studies demonstrated that the behavioral phenotype of the larval zebrafish was changed by sanguinarine. In addition, there were more apoptotic cells in the larval zebrafish head area. The mRNA expression levels of ß-syn, th, pink1 and parkin, closely related to the nervous function, were changed after sanguinarine treatment. The in vitro studies show that notably increases of ROS and apoptosis levels in PC12 cells were observed after sanguinarine treatment. Moreover, the protein expression of Caspase3, Parp, Bax, Bcl2, α-Syn, Th, PINK1 and Parkin were also altered by sanguinarine. Our data indicated that the inhibition of mitophagy, ROS elevation and apoptosis were involved in the neurotoxicity of sanguinarine. These findings will be useful to understand the toxicity induced by sanguinarine.

Statistical Analysis on Rate Parameters of the H2-O2 Reaction System.

Quantitative rate determination of elementary reactions is a major task in the study of chemical kinetics. To ensure the fidelity of their determination, progressively tightened constraints need to be placed on their measurement, especially with the development of various notable experimental techniques. However, the evaluation of reaction rates and their uncertainties is frequently conducted with substantial subjectivity due to data source, thermodynamic conditions, sampling range, and sparsity. To reduce the extent of biased rate evaluation, we propose herein an approach of uncertainty-weighted statistical analysis, utilizing weighted average, and weighted least-square regression in statistical inference. Based on the backbone H2/O2 chemistry, rate data for each elementary reaction are collected from the time-history profile in shock tube experiments and high-level theoretical calculations, with their assigned weight inversely depending on uncertainty, which would overall avoid subjective assessments and provide more accurate rate evaluation. Aided by sensitivity analysis, the rates of a few key reactions are further constrained in the less investigated low- to intermediate-temperature conditions using high-fidelity flow reactor data. Good performance of the constructed mechanism is confirmed with validation against the target of the high-fidelity flow reactor data. This study demonstrates a systematic approach for reaction rate evaluation and uncertainty quantification.

Effects of streptozotocin on pancreatic islet ß-cell apoptosis and glucose metabolism in zebrafish larvae.

Type 1 diabetes is characterized by an increase in blood glucose levels resulting from damage to ß cells in pancreatic islets and the consequent absolute insufficiency of insulin. Animal models of type 1 diabetes were usually established using drugs toxic to ß cells, such as streptozotocin (STZ). To assess the application of zebrafish larvae in diabetes research, we explore the effects of STZ on pancreatic islets and glucose metabolism in zebrafish larvae. STZ was microinjected into the pericardial cavity of zebrafish larvae on alternate days for three times. At 2 days after the whole series of STZ injection (12 dpf), free-glucose level in larvae tissue shows a significant increase, and the fluorescence signal in immunohistochemistry, which indicates the insulin expression, was significantly weaker compared with the solution-injected control. Obvious apoptosis signals were also observed in the location of pancreatic islet, and insulin content decreased to be undetectable in STZ-injected larvae. Gene expression level of ins decreased to half of the solution injection control and that of casp3a was upregulated by 2.20-fold. Expression level of glut2 and gck decreased to 0.312-fold and 0.093-fold, respectively. pck1 was upregulated by 2.533-fold in STZ-injected larvae. By tracking detection, we found the free-glucose level in STZ-injected larvae gradually approached the level of the solution injection control and the insulin content recovered at 6 days post-STZ injection (16 dpf). Consistent with the change of the glucose level, the regeneration rate of the caudal fin in the STZ-injected group decreased initially, but recovered and accelerated gradually finally at 8 days post-amputation (20 dpf). These results indicate the generation of a transient hyperglycemia model due to ß-cell apoptosis caused by STZ, which is abated by the vigorous regeneration ability of ß cells in zebrafish larvae.

Study of the distribution of hepatitis B immunoglobulin in pregnant mice using small-animal imaging technology.

BACKGROUND: The safety and necessity of hepatitis B immunoglobulin (HBIG) in preventing the mother-to-child transmission of hepatitis B virus (HBV) are still controversial because of its unclear mechanism of action and the inconsistent injection programs used during gestation. OBJECTIVES: This study aimed to show the dynamic transportation and distribution of HBIG in the maternal body and to provide evidence for its clinical efficacy in preventing mother-to-child HBV transmission. STUDY DESIGN: Pregnant mice were injected with Cy7-labeled mouse anti-human monoclonal hepatitis B surface antibodies through the tail vein. In vivo imaging technology was used to observe the dynamic transportation and distribution of HBIG in the pregnant mice. RESULTS: HBIG fluorescence signals were higher in the uterus than in the liver, spleen, and kidneys. Fluorescence signals in the uterine region were obviously higher at the third trimester than at early and mid pregnancy. CONCLUSIONS: HBIG is gradually deposited in the mouse placenta during pregnancy, with the phenomenon being more significant in the third trimester.

Comparison of Two-Dimensional Shear Wave Elastography with Nine Serum Fibrosis Indices to Assess Liver Fibrosis in Patients with Chronic Hepatitis B: A Prospective Cohort Study.

PURPOSE: To prospectively assess liver fibrosis with two-dimensional shear wave elastography (2D-SWE) in patients with chronic hepatitis B (CHB) and to compare the performance of this modality with that of serum indices using Scheuer scoring from liver biopsies as the reference standard. MATERIALS AND METHODS: 123 patients with CHB underwent 2D-SWE measurements and serological tests between April 2016 and February 2018. The 2D-SWE and serum indices in the diagnosis of liver fibrosis were assessed using receiver operating characteristic (ROC) analyses. RESULTS: The areas under ROC (AUCs) for 2D-SWE, aspartate transaminase-to-platelet ratio index, fibrosis index based on the four factors, Forns score, King's score, FibroIndex, red cell distribution width-to-platelet ratio, Hepascore, type IV collagen, and hyaluronic acid were 0.851, 0.738, 0.701, 0.739, 0.734, 0.711, 0.692, 0.601, 0.640, and 0.522, respectively, in the diagnosis of substantial fibrosis, 0.975, 0.819, 0.792, 0.829, 0.818, 0.807, 0.732, 0.572, 0.676, and 0.544, respectively, in the diagnosis of severe fibrosis, and 0.972, 0.883, 0.862, 0.908, 0.889, 0.918, 0.808, 0.601, 0.807, and 0.775, respectively, in the diagnosis of cirrhosis. The AUCs of 2D-SWE in the diagnosis of substantial fibrosis, severe fibrosis, and cirrhosis were significantly higher than those of the serum indices (p < 0.05). CONCLUSION: 2D-SWE is a reliable noninvasive method for the assessment of liver fibrosis in patients with CHB with better diagnostic performance than that of nine serum fibrosis indices.

DKK4-knockdown enhances chemosensitivity of A549/DTX cells to docetaxel.

Drug resistance greatly limits docetaxel efficiency in the treatment of non-small cell lung cancer (NSCLC). Dickkopf 4 (DKK4), a negative regulator of Wnt/ß-catenin pathway, is believed to be involved in various human cancers; whereas the association of DKK4 with acquired docetaxel resistance in NSCLC remains unclear. In the present study, we investigated the involvement of DKK4 in the docetaxel-resistant human lung adenocarcinoma A549 (A549/DTX) cells. Our results showed that DKK4 expression was significantly increased in the A549/DTX cells compared with in the A549 cells, as well as in the culture supernatant of A549/DTX cells. DKK4 overexpression increased the resistance of A549 cells to docetaxel. DKK4-knockdown promoted inhibition of A549/DTX cell growth, and reduced the colony formation and invasion capacity of A549/DTX cells. Moreover, DKK4-knockdown promoted the pro-apoptotic effect of docetaxel characterized with caspase 3 activation and inhibition of BCL-2 expression in A549/DTX cells, which was possibly mediated by inducing the activation of c-Jun N-terminal kinase (JNK)-related signaling pathway. Thus, our results indicated that DKK4-knockdown promoted the cytotoxic and pro-apoptotic activity of A549/DTX cells, which suggests a critical role of DKK4 in docetaxel resistance of the A549 cells and provides the potential to combine docetaxel therapy with DKK4 depletion in treating NSCLC.

History of incomplete vaccination may associate with occurrence of hemorrhagic fever with renal syndrome with relieved clinical symptoms.

OBJECTIVE: This retrospective study is aimed to investigate the clinical features of the patients with history of incomplete vaccination against hemorrhagic fever with renal syndrome (HFRS). METHODS: Data of 140 cases of hospitalized patients with HFRS were collected. The patients were divided into incomplete vaccinated group (n = 10) and unvaccinated group (n = 130) according to vaccination status. Demographic, clinical, and laboratory characteristics of the two groups' patients were compared through t test, Pearson χ(2) test, and Mann-Whitney test. RESULTS: In comparison with the unvaccinated group, the incidence rate of vomiting and hypotensive-shock, the white blood cell (WBC) and platelet count, the level of blood urea nitrogen and albumin, total number of dialysis and hospitalization cost of patients in the incomplete vaccinated group have statistically significant differences. CONCLUSION: HFRS disease may still occur in individuals with a history of HFRS incomplete vaccination although the symptoms may be mild. Effective vaccination against HFRS needs sufficient doses and booster shot of the vaccine.

Ab initio kinetics studies of hydrogen atom abstraction from methyl propanoate.

The kinetics of hydrogen abstraction by five radicals (H, CH3, O((3)P), OH, and HO2) from a biodiesel surrogate, methyl propanoate (MP), is theoretically investigated. We employ high-level ab initio quantum chemistry methods, coupled-cluster singles and doubles with perturbative triples correction (CCSD(T)) and multi-reference singles and doubles configuration interaction (MRSDCI) with the Davidson-Silver (DS) correction, and obtain chemically accurate reaction energetics. Overall, MRSDCI + DS predicts comparable energetics to CCSD(T) for MP + H/CH3/O/OH. The rate constants are computed using transition state theory (TST-Rice-Ramsperger-Kassel-Marcus theory) in conjunction with the separable-hindered-rotor approximation, variable reaction coordinate TST, and the multi-structure all-structure (MS-AS) approach. A simplified method, semi-multi-structure, is also employed for MP + OH/HO2, and the rate coefficients with this less expensive method are in good agreement with the results obtained with the MS-AS method. The fitted modified Arrhenius expressions are provided over a temperature range of 250 to 2000 K. The predicted rate coefficients for MP + OH agree remarkably well with experimental data over a wide temperature range. Branching ratio analysis of all the studied reactions shows that abstractions of the secondary H atoms within MP are expected to dominate the consumption of fuel at low temperatures, and the contributions of abstractions from the two methyl groups increase with temperature for all abstracting radicals.

Ab initio pressure-dependent reaction kinetics of methyl propanoate radicals.

The unimolecular dissociation and isomerization kinetics of the three methyl propanoate (MP) radicals, CH3CH2C(=O)OCH2 (MP-m), CH3CHC(=O)OCH3 (MP-α), and CH2CH2C(=O)OCH3 (MP-ß), are theoretically investigated using high-level ab initio methods and the Rice-Ramsperger-Kassel-Marcus (RRKM)/master equation (ME) theory. Stationary-point energies are obtained using the coupled cluster singles and doubles with perturbative triples correction (CCSD(T)), multi-reference singles and doubles configuration interaction (MRSDCI) with the Davidson-Silver (DS) correction, and multi-reference averaged coupled pair functional (MRACPF2) theories. The isomerization barriers between the three radicals are predicted to be generally lower than the corresponding bond dissociation channels, leading to a strongly coupled reaction system in subsequent kinetics studies. The phenomenological temperature- and pressure-dependent rate coefficients are computed using the RRKM/ME theory over a temperature range of 500 to 2000 K and at a pressure range of 0.01 atm to the high-pressure limit, which are then fitted to modified Arrhenius expressions. The ß-scission rate coefficients of MP-α to CH3CHC(=O) and CH3O[combining dot above] are predicted to be the smallest because of its highest activation energy among all studied unimolecular reactions channels. Analysis of branching fractions shows that both MP-m and MP-α radicals mainly decompose to the bimolecular products CH3CH2C(=O) and H2CO, whereas the MP-ß radical primarily decomposes via cleavage of a C-C bond to form C2H4 and CH3OC(=O). The isomerization channels dominate at low temperatures, the branching fractions of which decrease with increasing temperature and become very minor at about 2000 K. Our accurate rate coefficients and branching fractions help to illuminate the unique combustion properties of MP.

Ab Initio Unimolecular Reaction Kinetics of CH2C(═O)OCH3 and CH3C(═O)OCH2 Radicals.

The unimolecular dissociation and isomerization kinetics of the methyl ester combustion intermediates methoxycarbonylmethyl (CH2C(═O)OCH3) and acetyloxylmethyl (CH3C(═O)OCH2) are theoretically investigated using high-level ab initio methods and the Rice-Ramsperger-Kassel-Marcus (RRKM)/master equation (ME) theory. Potential energy surfaces (PESs) are obtained using coupled cluster singles and doubles with perturbative triples correction (CCSD(T)), multireference singles and doubles configuration interaction (MRSDCI) with the Davidson-Silver (DS) correction, and multireference averaged coupled pair functional (MRACPF2) theory. The transition states exhibit high T1 diagnostics in coupled cluster calculations, suggesting the need for a multireference correlated wave function treatment. MRSDCI+DS and MRACPF2 capture their multiconfigurational character well, yielding lower barrier heights than CCSD(T) for these reactions. The rate coefficients are computed using the RRKM/ME theory over a 500-2500 K temperature range and at a pressure range of 0.01 atm to the high-pressure limit. The temperature- and pressure-dependent rate coefficients are given in modified Arrhenius expressions. The ß-scission of CH2C(═O)OCH3 is predicted to have a much higher barrier than the corresponding isomerization reaction and the ß-scission of CH3C(═O)OCH2. Consequently, the rate coefficients for ß-scission of CH2C(═O)OCH3 are the smallest among the three reactions and the isomerization followed by decomposition to CH3C(═O) and HCHO is the dominant reaction pathway for CH2C(═O)OCH3. Both radicals CH2C(═O)OCH3 and CH3C(═O)OCH2 are predicted to mainly decompose to CH3C(═O) + HCHO rather than to the bimolecular product CH2C(═O) + CH3O. A newly developed MA combustion mechanism, using our theoretical rate coefficients for the MA-related reactions, predicts combustion properties in good agreement with available experimental data.

Ab Initio Kinetics of Hydrogen Abstraction from Methyl Acetate by Hydrogen, Methyl, Oxygen, Hydroxyl, and Hydroperoxy Radicals.

The kinetics of hydrogen abstraction by five radicals (H, O((3)P), OH, CH3, and HO2) from methyl acetate (MA) is investigated theoretically in order to gain further understanding of certain aspects of the combustion chemistry of biodiesels, such as the effect of the ester moiety. We employ ab initio quantum chemistry methods, coupled cluster singles and doubles with perturbative triples correction (CCSD(T)) and multireference averaged coupled pair functional theory (MRACPF2), to predict chemically accurate reaction energetics. Overall, MRACPF2 predicts slightly higher barrier heights than CCSD(T) for MA + H/CH3/O/OH, but slightly lower barrier heights for hydrogen abstraction by HO2. Based on the obtained reaction energies, we also report high-pressure-limit rate constants using transition state theory (TST) in conjunction with the separable-hindered-rotor approximation, the variable reaction coordinate TST, and the multi-structure all-structure approach. The fitted modified Arrhenius expressions are provided over a temperature range of 250 to 2000 K. The predictions are in good agreement with available experimental results. Abstractions from both of the methyl groups in MA are expected to contribute to consumption of the fuel as they exhibit similar rate coefficients. The reactions involving the OH radical are predicted to have the highest rates among the five abstracting radicals, while those initiated by HO2 are expected to be the lowest.

Baicalein reduces the occurrence of cirrhotic endotoxemia by reducing intestinal mucosal apoptosis.

BACKGROUND: The dried roots of Scutellaria baicalensis Georgi, is known in traditional Chinese medicine as Huang Qin (H. qin), and it has been officially and traditionally used in treatment of various diseases such as hepatitis in China. Baicalein (BA), a flavonoid originally isolated from H. qin, has shown a wide range of biological activities. This study was to evaluate whether baicalein, can reduce the intestinal mucosal cell apoptosis caused by cirrhotic endotoxemia and its possible mechanisms. METHODS: For this purpose, compound factors modeling was used to establish endotoxemic cirrhotic rat model. Firstly, we evaluated endotoxin, ALT, AST and TBIL levels after the baicalein treatment (20 mg/kg, i.v.). To investigate the mechanism of baicalein effect on apoptosis, TUNEL assay was used to detect intestinal mucosal apoptosis. RT-PCR was used to detect the expression levels of gene Bcl-2 mRNA and Bax mRNA in intestinal mucosal tissues. Caspase-3 activity of intestinal tissue was detected with colorimetric method in our experiments. RESULTS: After treatment with BA, the serum endotoxin concentration, the intestinal mucosal apoptosis rate and the activity of caspase-3 of the baicalein group were significantly lower than that of the model and the glutamine group. The serum ALT, AST and TBIL concentration of the BA group were significantly lower than that of the model group. The body weight of the baicalein group was significantly lower than that of the normal group, but it was higher than that of the model group. Among the treatment groups, the mRNA level of anti-apoptotic gene Bcl-2 was the lowest in the model group and the highest in the baicalein group while the mRNA level of pro-apoptotic gene Bax was the lowest in the baicalein group and the highest in the model group. CONCLUSION: The present results demonstrated that baicalein could reduce the occurrence of cirrhotic endotoxemia partly by reducing intestinal mucosal apoptosis.

Effect of cooking methods on volatile compounds and texture properties in maize porridge.

To investigate the optimal processing of maize porridge, the volatile compounds and texture under different cooking methods and time have been studied. A total of 51 volatile compounds were identified in maize porridge. Notably, the major volatiles, aldehydes and esters exhibited a relatively high content in electric pressure cooker (EPC), and esters tend to significantly increase after cooking. Among aldehydes, nonanal and hexanal played a great role in flavor due to their relatively high content. Volatile compounds of maize porridge in different cooking methods could be clearly distinguished by multiple chemometrics. Furthermore, texture analysis revealed that almost all the indicators in the EPC can reach the lowest value at 60 min. To summarize, different cooking methods had a more significant influence on the volatile compounds and texture compared to time. This study helps to improve the sensory attributes of maize porridge, and thus contributes to healthier and more sustainable production.

Recombination of allyl radicals in the high temperature fall-off regime.

The recombination of allyl radicals (C3H5), generated from the dissociation of 1,5-hexadiene or allyl iodide dilute in krypton, has been investigated in a diaphragmless shock tube using laser schlieren densitometry, LS, (900-1700 K, 10 ± 1, 29 ± 3, 57 ± 3, and 120 ± 4 Torr). The LS density gradient profiles were simulated and excellent agreement was found between simulations and experimental profiles. Rate coefficients for C3H5I → C3H5 + I and C3H5 + C3H5 → C6H10 were obtained and showed strong fall-off. Second order rate coefficients for allyl radical recombination were determined as k(1a,124Torr) = (2.6 ± 0.8) × 10(55)T( -12.995) exp(-8426/T), k(1a,57Torr) = (1.7 ± 0.5) × 10(60)T( -14.49) exp(-9344/T), and k(1a,30Torr) = (7.5 ± 2.3) × 10(66)T( -15.935) exp(-10192/T) cm(3) mol(-1)s(-1). The contribution of a disproportionation channel in allyl radical reactions was assessed, and the best agreement was obtained with no more than 5% disproportionation. Notably, because both the forward and back reactions of C6H10 ⇌ C3H5 + C3H5 were measured, utilizing two different precursors, the equilibrium constant of this reaction could be found, suggesting an entropy of formation of 1,5-hexadiene, 87.3 cal mol(-1 )K(-1), which is significantly smaller than that group additivity predicts, but larger than other reference literature values.