Effective Degradation of Brewer Spent Grains by a Novel Thermostable GH10 Xylanase.

Brewer spent grains (BSGs) are one of the most abundant by-products in brewing industry. Due to microbiological instability and high perishability, the efficient degradation of BSGs is of environmental and economic importance. Streptomyces sp. F-3 could grow in the medium with BSGs as the only carbon and nitrogen source. Proteome mass spectrometry revealed that a GH10 xylanase SsXyn10A could be secreted in large quantities. SsXyn10A showed optimum activity at pH 7.0 and 60 °C. SsXyn10A exhibited excellent thermostability which retained approximately 100% and 58% after incubation for 5 h at 50 and 60 °C. SsXyn10A displayed high activity to beechwood xylan (BX) and wheat arabinoxylan (WAX). SsXyn10A is active against xylotetracose (X4), xylopentose (X5), and xylohexose (X6) to produce main products xylobiose (X2) and xylotriose (X3). Ssxyn10A showed synergistic effects with commercial cellulase on BSGs hydrolyzing into soluble sugar. In addition, the steam explosion pretreatment of BSGs as the substrate produced twice as much reducing sugar as the degradation of the original substrate. This study will contribute to efficient utilization of BSGs and provide a thermostable GH10 xylanase which has potential application in biomass hydrolysis.

Investigating the effect of exercise on the expression of genes related to cardiac physiological hypertrophy.

Physiological hypertrophy of the heart is associated with an increase in the normal function of the heart, and it directly relates to regular exercise, especially among elite athletes. Researches about special signaling pathways that create physiological hypertrophy have recently received more attention. As a result, the present study was conducted to investigate the effect of aerobic exercise intensity on the expression of genes involved in heart physiological hypertrophy. For this purpose, 30 male Wistar rats were prepared and randomly divided into three groups: control, intense intermittent training, and submaximal continuous training. The intensive intermittent training protocol included 30 minutes of intermittent running, each interval including 4 minutes of running with an intensity of 85-90% VO2max and 2 minutes of active recovery with an intensity of 50-60% VO2max three days a week for 8 weeks. Also, the submaximal continuous exercise group had activity intensity equal to 50-55% of the maximum oxygen consumption. The expression of genes related to cardiac hypertrophy such as MMP-I, TGF-ß1, and TIMP was evaluated through real-time PCR technique. The results showed that the expression of studied genes in the three groups had significant differences (p<0.05). Both training methods led to a significant increase in TGF-ß1 and TIMP gene expression in the heart of rats. But the changes in MMP-I in the intermittent group were not significant compared to the control group. In general, it seems that exercise leads to the improvement of the factors involved in the physiological hypertrophy of the heart. Therefore, the findings of the current research are expressed with caution and more research is needed in the future.

Prediction of MAFLD and NAFLD using different screening indexes: A cross-sectional study in U.S. adults.

Introduction: Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as non-alcoholic fatty liver disease (NAFLD), has become the most common chronic liver disease worldwide. We aimed to explore the gender-related association between nine indexes (BMI/WC/VAI/LAP/WHtR/TyG/TyG-BMI/TyG-WC/TyG-WHtR) and MAFLD/NAFLD and examine their diagnostic utility for these conditions. Methods: Eligible participants were screened from the 2017-2018 cycle data of National Health and Nutrition Examination Survey (NHANES). Logistic regression and receiver operating characteristic (ROC) curve were used to assess the predictive performance of 9 indexes for MAFLD/NAFLD. Results: Among the 809 eligible individuals, 478 had MAFLD and 499 had NAFLD. After adjusting for gender, age, ethnicity, FIPR and education level, positive associations with the risk of MAFLD/NAFLD were found for all the nine indexes. For female, TyG-WHtR presented the best performance in identifying MAFLD/NAFLD, with AUC of 0.845 (95% CI = 0.806-0.879) and 0.831 (95% CI = 0.791-0.867) respectively. For male, TyG-WC presented the best performance in identifying MAFLD/NAFLD, with AUC of 0.900 (95% CI = 0.867-0.927) and 0.855 (95% CI = 0.817-0.888) respectively. Conclusion: BMI/WC/VAI/LAP/WHtR/TyG/TyG-BMI/TyG-WC/TyG-WHtR are important indexes to identify the risk of MAFLD and NAFLD.

A thermostable and CBM2-linked GH10 xylanase from Thermobifida fusca for paper bleaching.

Xylanases have the potential to be used as bio-deinking and bio-bleaching materials and their application will decrease the consumption of the chlorine-based chemicals currently used for this purpose. However, xylanases with specific properties could act effectively, such as having significant thermostability and alkali resistance, etc. In this study, we found that TfXyl10A, a xylanase from Thermobifida fusca, was greatly induced to transcript by microcrystalline cellulose (MCC) substrate. Biochemical characterization showed that TfXyl10A is optimally effective at temperature of 80 °C and pH of 9.0. After removing the carbohydrate-binding module (CBM) and linker regions, the optimum temperature of TfXyl10A-CD was reduced by 10°C (to 70°C), at which the enzyme's temperature tolerance was also weakened. While truncating only the CBM domain (TfXyl10AdC) had no significant effect on its thermostability. Importantly, polysaccharide-binding experiment showed that the auxiliary domain CBM2 could specifically bind to cellulose substrates, which endowed xylanase TfXyl10A with the ability to degrade xylan surrounding cellulose. These results indicated that TfXyl10A might be an excellent candidate in bio-bleaching processes of paper industry. In addition, the features of active-site architecture of TfXyl10A in GH10 family were further analyzed. By mutating each residue at the -2 and -1 subsites to alanine, the binding force and enzyme activity of mutants were observably decreased. Interestingly, the mutant E51A, locating at the distal -3 subsite, exhibited 90% increase in relative activity compared with wild-type (WT) enzyme TfXyl10A-CD (the catalytic domain of TfXyl110A). This study explored the function of a GH10 xylanase containing a CBM2 domain and the contribution of amino acids in active-site architecture to catalytic activity. The results obtained provide guidance for the rational design of xylanases for industrial applications under high heat and alkali-based operating conditions, such as paper bleaching.

Functional Specificity of Three α-Arabinofuranosidases from Different Glycoside Hydrolase Families in Aspergillus niger An76.

α-l-Arabinofuranosidase (Abf), a debranching enzyme that can remove arabinose substituents from arabinoxylan, promotes the hydrolysis of hemicellulose in plant biomass. However, the functional specificity of Abfs from different glycoside hydrolase (GH) families on the digestion of arabinoxylan and their synergistic interaction with xylanase have not been systematically studied. In this work, we characterized three Abfs (AxhA, AbfB, and AbfC) from GH62, GH54, and GH51 families in Aspergillus niger An76. Quantitative transcriptional analysis showed that expression of the axhA gene was upregulated as a result of induction by xylose substrates, whereas expression of the abfB gene was mainly induced by arabinose. Recombinant AxhA, AbfB, and AbfC exhibited different hydrolytic performances. AxhA showed the highest catalytic activity toward wheat arabinoxylan (WAX) and tended to hydrolyze monosubstituted arabinofuranose units, whereas AbfB had higher catalytic activity on AN and debranched arabinan (DAN), having the ability to cope with mono- and disubstituted arabinofuranose units. Furthermore, AbfC had greater arabinofuranosidase activity on p-nitrophenyl-α-l-arabinofuranoside (pNP-AraF) than on other substrates. Moreover, three Abfs displayed obvious synergistic action with GH11 xylanase XynB against WAX and barley husk residues. The elucidation of the degradation mechanisms of Abfs will lay a theoretical foundation for the efficient industrialized transformation of arabinoxylans.

Amplitude-integrated electroencephalography improves the predictive ability of acute bilirubin encephalopathy.

BACKGROUND: To establish a clinical prediction model of acute bilirubin encephalopathy (ABE) using amplitude-integrated electroencephalography (aEEG). METHODS: A total of 114 neonatal hyperbilirubinemia patients in the Beijing Chaoyang Hospital from August 2015 to October 2018 were enrolled in this study. There were 62 (54.38%) males, and the age of patients undergoing aEEG examination was 2-23 days, with an average of 7.61±4.08 days. Participant clinical information, peak bilirubin value, albumin value, hyperbilirubinemia, and the graphic indicators of aEEG were extracted from medical records, and ABE was diagnosed according to a bilirubin-induced neurological dysfunction (BIND) score >0. Multivariable logistic regression was used to establish a clinical prediction model of ABE. Furthermore, decision curve analysis (DCA) was performed to evaluate the model's predictive value. RESULTS: According to the BIND score, there were a total of 23 (20.18%) ABE cases. The multivariable logistic regression analysis showed that the value of bilirubin/albumin (B/A), presence of hyperbilirubinemia risk factors, number of sleep-wake cycling (SWC) within 3 hours, widest bandwidth, duration of SWC, and type of SWC were significantly associated with ABE. A clinical prediction model was developed as: p=ex/ (1+ex), X=0.278+0.713*B/A+2.602*with risk factors (with risk factors equals 1) - 1.500*SWC number within 3 hours + 0.219*the widest bandwidth-0.065*the duration of one SWC + 1.491* SWC (mature SWC equals 0, immature SWC equals 1). The area under the curve (AUC) was 0.85 [95% confidence interval (CI): 0.75-0.94], which was significantly higher than the AUC only based on conventional clinical information of B/A (AUC: 0.58, 95% CI: 0.45-0.72). The DCA also showed good predictive ability compared to B/A. CONCLUSIONS: A clinical prediction model can be established based on the patients' B/A, presence of risk factors for hyperbilirubinemia, number of SWC within 3 hours, widest bandwidth, duration of 1 SWC, and the type of SWC. It has good predictive ability and may improve the diagnostic accuracy of ABE.

Attentional bias of subliminal emotional faces in adolescents with obsessive-compulsive disorder.

Attentional bias to threatening information may play a vital role in the onset and maintenance of obsessive-compulsive disorder (OCD). This study aimed to explore whether adolescents with OCD exhibited attentional bias toward faces that express disgust or fear. Participants were 27 adolescents with a first-time primary diagnosis of OCD and 27 healthy controls. To assess OCD, depression, and anxiety symptoms, all participants completed the Yale-Brown Obsessive Compulsive Scale, the Hamilton Depression Scale, and the Hamilton Anxiety Scale, respectively, followed by the modified dot probe task. Repeated measures ANOVA revealed a main effect of validity type and a significant group × validity type interaction effect. The results of one sample t-tests showed that participants in the OCD group had an attentional bias toward both disgusted and fearful faces. Further analysis indicated that adolescents in the OCD group showed facilitated attention toward the fearful faces and difficulty disengaging from disgusted faces. Adolescents with OCD exhibited facilitated attention toward threat stimuli, and when they allocated attention to threat, they experienced difficulty disengaging from it. Treatment procedures to modify the attentional bias may be effective.

Biophysical signal transduction in cancer cells: Understanding its role in cancer pathogenesis and treatment.

Signaling between cells can promote both the development and progression of cancer. It has been found that chemical and physical signals, together with extracellular factors, can influence cancer progression. In this review, we focus on the physical microenvironment of cancer cells and examine the action of mechanical, electromagnetic, thermal, and acoustic signals on cancer cells, which may provide new directions for cancer research and treatment.

Blind Estimation of the PN Sequence of A DSSS Signal Using A Modified Online Unsupervised Learning Machine.

Direct sequence spread spectrum (DSSS) signals are now widely used in air and underwater acoustic communications. A receiver which does not know the pseudo-random (PN) sequence cannot demodulate the DSSS signal. In this paper, firstly, the principle of principal component analysis (PCA) for PN sequence estimation of the DSSS signal is analyzed, then a modified online unsupervised learning machine (LEAP) is introduced for PCA. Compared with the original LEAP, the modified LEAP has the following improvements: (1) By normalizing the system state transition matrices, the modified LEAP can obtain better robustness when the training errors occur; (2) with using variable learning steps instead of a fixed one, the modified LEAP not only converges faster but also has excellent estimation performance. When the modified LEAP is converging, we can utilize the network connection weights which are the eigenvectors of the autocorrelation matrix of the DSSS signal to estimate the PN sequence. Due to the phase ambiguity of the eigenvectors, a novel approach which is based on the properties of the PN sequence is proposed here to exclude the wrong estimated PN sequences. Simulation results showed that the methods mentioned above can estimate the PN sequence rapidly and robustly, even when the DSSS signal is far below the noise level.

An Improved Velocity Estimation Method for Wideband Multi-Highlight Target Echoes in Active Sonar Systems.

In active sonar systems, the target echoes are usually equivalent to a superposition of the Doppler-scaled reflections from multiple highlights. The reflections overlap with each other both in the time and frequency domain, which results in a decreased velocity estimation performance. Recently, the hyperbolic-frequency modulated signal has been widely employed in sonar systems for moving targets due to its Doppler tolerance, while the precise velocity estimation becomes a great challenge under such conditions. In this paper, the echo c is modeled onsidering a target with a constant velocity and multi-highlights. The velocity estimation performance is analyzed though the signal's matched filter and the wideband ambiguity function. An improved method based on the sliding window matching algorithm is proposed to improve the performance. The method controls the energy of environmental noise and interference by focusing on the dominant target highlight, and applying a designed window which utilizes the Doppler characteristics of hyperbolic-frequency modulated signals. Simulations and lake experiment allow us to compare between the improved method and the conventional matched filter method. The results verify the influence of the multi-highlights in velocity estimation and indicate that the improved method has more effective performance.

Effect of Hydraulic Retention Time on Anaerobic Digestion of Wheat Straw in the Semicontinuous Continuous Stirred-Tank Reactors.

Three semicontinuous continuous stirred-tank reactors (CSTR) operating at mesophilic conditions (35°C) were used to investigate the effect of hydraulic retention time (HRT) on anaerobic digestion of wheat straw. The results showed that the average biogas production with HRT of 20, 40, and 60 days was 46.8, 79.9, and 89.1 mL/g total solid as well as 55.2, 94.3, and 105.2 mL/g volatile solids, respectively. The methane content with HRT of 20 days, from 14.2% to 28.5%, was the lowest among the three reactors. The pH values with HRT of 40 and 60 days were in the acceptable range compared to that with HRT of 20 days. The propionate was dominant in the reactor with HRT of 20 days, inhibiting the activities of methanogens and causing the lower methane content in biogas. The degradation of cellulose, hemicellulose, and crystalline cellulose based on XRD was also strongly influenced by HRTs.

Immobilization of proline-specific endoprotease on nonporous silica nanoparticles functionalized with amino group.

Enzyme immobilization is believed to provide an excellent base for increasing environmental tolerance of enzyme and considerable period of time. In this work, a kind of nonporous silica nanoparticles functionalized with amino group was synthesized to immobilize proline-specific endoprotease (PSEP). PSEP is known to specifically cleave peptides (or esters) at the carboxyl side of proline, thus can prevent the formation of haze and prolong the shelf life of beer. After immobilization, the environmental tolerance (temperature and pH, respectively) was obviously improved, and the immobilized enzyme can retain above 90 % of its original activity after 6 uses. Moreover, the immobilized enzyme can effectively prevent the formation of chill-haze using fresh beer fermentation liquid.

Prevention of toxigenic fungal growth in stored grains by carbon dioxide detection.

The growth of toxigenic fungi can adversely affect grain quality and even produce mycotoxins of food safety concern, which should be sensitively monitored and controlled during grain storage. To establish the relationship between the growth of toxigenic fungi and their carbon dioxide (CO2) production, the pattern of CO2 concentration changes was studied during the fungal growth in grain. The results showed the CO2 concentrations increased exponentially (r ≥ 0.96) during the growth of toxigenic fungi Aspergillus flavus, Penicillium sp. and Aspergillus ochraceus, which was different from the linear increase of CO2 concentration produced by the non-toxigenic xerophilic fungi Aspergillus glaucus and Aspergillus restrictus. The acceleration of CO2 concentration was found much earlier than the growth of toxigenic fungi, which would be useful for the prevention of grain spoilage. In addition, the CO2 concentration changes were also determined in storage containers loaded with grain of different moisture content and significant correlation (p < 0.05) was found between changes of CO2 concentration and fungal growth as well as mycotoxin production. The nonlinear increase of CO2 concentration in stored grains could be considered as an indication of the rapid growth of toxigenic fungi and greater risk of microbial spoilage of grains. The results can provide a valid foundation for the prevention of toxigenic fungi and mycotoxin production in stored grains through monitoring the CO2 concentration changes.