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1.
Brain Cogn ; 180: 106205, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39053200

ABSTRACT

Team-based physical activity (PA) can improve social cognition; however, few studies have investigated the neurobiological mechanism underlying this benefit. Accordingly, a hyper-scanning protocol aimed to determine whether the interbrain synchrony (IBS) is influenced by an acute bout of team-based PA (i.e., tandem rope skipping). Specifically, we had socially avoidant participants (SOA, N=15 dyads) and their age-matched controls (CO, N=16 dyads) performed a computer-based cooperative task while EEG was recorded before and after two different experimental conditions (i.e., 30-min of team-based PA versus sitting). Phase locking value (PLV) was used to measure IBS. Results showed improved frontal gamma band IBS after the team-based PA compared to sitting when participants received successful feedback in the task (Mskipping = 0.016, Msittting = -0.009, p = 0.082, ηp2 = 0.387). The CO group showed a larger change in frontal and central gamma band IBS when provided failure feedback in the task (Mskipping = 0.017, Msittting = -0.009, p = 0.075, ηp2 = 0.313). Thus, results suggest that socially avoidant individuals may benefit from team-based PA via improved interbrain synchrony. Moreover, our findings deepen our understanding of the neurobiological mechanism by which team-based PA may improve social cognition among individuals with or without social avoidance.


Subject(s)
Electroencephalography , Humans , Male , Female , Adult , Young Adult , Electroencephalography/methods , Exercise/physiology , Social Cognition , Friends , Cooperative Behavior , Gamma Rhythm/physiology , Brain/physiology
2.
Nutr Metab Cardiovasc Dis ; 34(8): 1922-1931, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38866613

ABSTRACT

BACKGROUND AND AIMS: The systemic inflammation response index (SIRI) is associated with various diseases with inflammatory components, but its relationship with the progression of hepatic fibrosis and survival outcomes in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) is still unclear. This study was designed to investigate the potential associations between the SIRI and advanced hepatic fibrosis (AHF) as well as between the SIRI and long-term outcomes in individuals with MASLD. METHODS AND RESULTS: A prospective cohort study was conducted using data gathered from the National Health and Nutrition Examination Survey (NHANES) spanning from 2005 to 2016. Weighted binary logistic regression, the Cox proportional hazards model, and time-dependent receiver operating characteristic (ROC) analyses were employed to assess the relationships among the SIRI, AHF, and mortality in patients with MASLD. Our study included a total of 5126 patients with MASLD. A higher SIRI was significantly associated with increased odds of AHF (OR 1.55, 95% CI 1.22, 1.96). According to the survival analyses, a higher SIRI was associated with greater all-cause (HR 1.19, 95% CI 1.15, 1.22) and cardiovascular mortality (HR 1.25, 95% CI 1.19, 1.32) after adjustment. The time-dependent ROC analysis indicated that the SIRI had a modest predictive value for discriminating MASLD individuals at higher versus lower mortality risk over 3-year, 5-year, and 10-year follow-up. CONCLUSIONS: The SIRI is a promising tool for identifying MASLD individuals at risk of progressing to AHF and for predicting mortality outcomes.


Subject(s)
Liver Cirrhosis , Nutrition Surveys , Predictive Value of Tests , Humans , Male , Female , Middle Aged , Prospective Studies , Liver Cirrhosis/mortality , Liver Cirrhosis/diagnosis , Liver Cirrhosis/blood , Risk Factors , Risk Assessment , Time Factors , Prognosis , United States/epidemiology , Adult , Aged , Inflammation/mortality , Inflammation/diagnosis , Inflammation/blood , Inflammation Mediators/blood , Cause of Death , Disease Progression
3.
J Orthop Sci ; 2023 Jul 25.
Article in English | MEDLINE | ID: mdl-37500402

ABSTRACT

BACKGROUND: Bone graft fusion is a major concern among surgeons after Anterior Cervical Discectomy and Fusion (ACDF) surgery as non-fusion may lead to further physical and drug therapies. METHODS: The related risk elements of non-fusion of bone graft in ACDF surgery were retrospectively assessed. Patients receiving ACDF operation in our hospital from January 2015 to December 2019 were retrospectively analyzed. According to the criteria, 107 study subjects were recruited with a total of 164 surgical segments. The general information of patients, bone graft materials, imaging parameters, and clinical efficacy was recorded. T-test, chi-square test and binary logistic regression evaluation were employed to explore the risk factors of bone graft nonunion. RESULTS: Low housefield unit (HU) value, diabetes, allogeneic bone, and hydroxyapatite (HA) artificial bone could be risk factors for bone graft fusion in ACDF surgery. Further multivariate analysis was performed and confirmed those related factors of bone graft non-fusion including low HU value (non-fusion rate: 32.53% [27/83], OR = 5.024, p = 0.025), diabetes (non-fusion rate: 53.33% [8/15], OR = 4.776, p = 0.031), allogeneic bone (18.57% [13/70], OR = 3.964, p = 0.046), and artificial bone (68.29% [28/41], OR = 50.550, p < 0.01). CONCLUSION: By looking at bone graft fusion, selecting autologous iliac bone is an ideal selection to avoid non-fusion of bone graft in ACDF. Diabetes was more important predictor of bone graft nonunion than low HU value. Larger sample size and longer follow-up are required to further confirm these findings in the future.

4.
Eur Spine J ; 31(3): 678-684, 2022 03.
Article in English | MEDLINE | ID: mdl-35094163

ABSTRACT

Pseudoaneurysms of the lumbar arteries following transforaminal lumbar interbody fusion (TLIF) are rare postoperative complications that usually occur around the transverse process. However, there are few detailed descriptions of the transverse branch and other branches of the dorsal branches at the L1-L4 disks. STUDY DESIGN: Ten adult embalmed cadavers were anatomically studied. OBJECTIVES: The purposes of the study were to describe the vascular distribution of the dorsal branches, especially the transverse branches, at the L1-L4 levels and provide information useful for TLIF. METHODS: Ten embalmed cadavers studied after their arterial systems were injected with red latex. The quantity, origin, pathway, distribution range and diameter of the branches were recorded and photographed. RESULTS: The transverse branch appeared in all 80 intervertebral foramina. The transverse branch was divided into 2 types: In type 1, the arteries divided into superior branches and inferior branches; the arteries in type 2 divided into 3 branches (superior, intermedius and inferior branches). CONCLUSIONS: The transverse branches of the dorsal arteries are common structures from L1 to L4, and 2 types of transverse branches were found. A thorough understanding of the dorsal branches, especially the transverse branches of the lumbar artery, may be very important for reducing both intraoperative bleeding during the surgery and the occurrence of pseudoaneurysms after transforaminal lumbar interbody fusion.


Subject(s)
Lumbar Vertebrae , Spinal Fusion , Adult , Aorta, Abdominal , Arteries , Cadaver , Humans , Lumbar Vertebrae/blood supply , Lumbar Vertebrae/surgery
5.
Chemistry ; 26(45): 10191-10194, 2020 Aug 12.
Article in English | MEDLINE | ID: mdl-32220132

ABSTRACT

Dynamic covalent polymers-dynamers-are adaptive materials that offer timely variant adaptive macroscopic organization across extended scales. In the current study, imine exchange reactions and fluorescence transfer can occur at the interfaces between various solutions and solid state dynameric films. The fluorescence quenching upon imine formations for designed fluorogen was successfully demonstrated, and this tunable fluorescence was further used to study the re-composition of a solid film. Moreover, the dynamic covalent films also exhibited responsiveness to competing amines and acid/base conditions, both in solutions and solid film-solution interface. This work can provide more insights into interface dynamic chemistry and holds great potential for further applications in optical and biomedical materials.

6.
Virol J ; 17(1): 36, 2020 03 16.
Article in English | MEDLINE | ID: mdl-32178702

ABSTRACT

OBJECTIVE: The prevalence of hepatitis C virus (HCV) infection is typically evaluated based on the current rate of positivity of anti-HCV antibody; however, HCV RNA positivity is considered the main criterion for antiviral treatment of HCV infection in the clinical setting. In this study, we evaluated the prevalence of HCV infection based on anti-HCV and HCV RNA detection in the population of Liaoning Province, and investigated the correlation between serum HCV RNA positivity and anti-HCV levels. METHODS: A total of 192,202 patients who underwent serum anti-HCV examination at Shengjing Hospital in 2018 were enrolled in the study. Anti-HCV production was tested using a chemiluminescence assay, and serum HCV RNA detection was performed with Roche COBAS TaqMan (CTM) Analyzer. RESULTS: The prevalence of anti-HCV was 1.21 and 0.93% among male and female patients in Liaoning Province, respectively. The positive rates of anti-HCV and serum anti-HCV levels were both age-related, in which patients over 40 years of age had a significantly higher anti-HCV positive rate than those younger than 40 years. Among the anti-HCV-positive patients, the average HCV RNA positive rate was 51.66 and 35.93% in males and females, respectively. Spearman rank analysis showed a significantly positive correlation between serum HCV RNA positivity and the level of anti-HCV. The best cut-off value using serum anti-HCV levels to predict the positivity of HCV RNA was determined to be 9.19 signal-to-cut-off ratio (s/co) in males and 10.18 s/co in females. CONCLUSION: The prevalence of anti-HCV in the general population of Liaoning Province was around 1.04%, which was higher than that previously reported from a national survey of HCV infection in China. Approximately 42.9% of the anti-HCV-positive patients also tested positive for HCV RNA. However, the positive correlation between the serum anti-HCV and HCV RNA levels suggests that the positivity of serum HCV RNA can be predicted according to the anti-HCV level in anti-HCV-positive patients, which can improve screening and facilitate timely intervention to prevent the spread of infection.


Subject(s)
Hepatitis C Antibodies/blood , Hepatitis C/epidemiology , Hospitals/statistics & numerical data , RNA, Viral/blood , Adolescent , Adult , Child , Child, Preschool , China/epidemiology , Cities/epidemiology , Female , Hepacivirus , Humans , Infant , Infant, Newborn , Male , Middle Aged , Prevalence , Retrospective Studies , Young Adult
7.
J Biol Chem ; 288(30): 22111-27, 2013 Jul 26.
Article in English | MEDLINE | ID: mdl-23744079

ABSTRACT

Bid is a Bcl-2 family protein that promotes apoptosis by activating Bax and eliciting mitochondrial outer membrane permeabilization (MOMP). Full-length Bid is cleaved in response to apoptotic stimuli into two fragments, p7 and tBid (p15), that are held together by strong hydrophobic interactions until the complex binds to membranes. The detailed mechanism(s) of fragment separation including tBid binding to membranes and release of the p7 fragment to the cytoplasm remain unclear. Using liposomes or isolated mitochondria with fluorescently labeled proteins at physiological concentrations as in vitro models, we report that the two components of the complex quickly separate upon interaction with a membrane. Once tBid binds to the membrane, it undergoes slow structural rearrangements that result in an equilibrium between two major tBid conformations on the membrane. The conformational change of tBid is a prerequisite for interaction with Bax and is, therefore, a novel step that can be modulated to promote or inhibit MOMP. Using automated high-throughput image analysis in cells, we show that down-regulation of Mtch2 causes a significant delay between tBid and Bax relocalization in cells. We propose that by promoting insertion of tBid via a conformational change at the mitochondrial outer membrane, Mtch2 accelerates tBid-mediated Bax activation and MOMP. Thus the interaction of Mtch2 and tBid is a potential target for therapeutic control of Bid initiated cell death.


Subject(s)
BH3 Interacting Domain Death Agonist Protein/metabolism , Cell Membrane/metabolism , Mitochondrial Membrane Transport Proteins/metabolism , bcl-2-Associated X Protein/metabolism , Animals , Apoptosis/physiology , BH3 Interacting Domain Death Agonist Protein/chemistry , BH3 Interacting Domain Death Agonist Protein/genetics , Caspase 8/metabolism , Fluorescence Resonance Energy Transfer , HeLa Cells , Humans , Kinetics , Liposomes/metabolism , Mice , Mice, Knockout , Mitochondria/metabolism , Mitochondria/physiology , Mitochondrial Membrane Transport Proteins/chemistry , Mitochondrial Membrane Transport Proteins/genetics , Mitochondrial Membranes/physiology , Models, Biological , Models, Molecular , Mutation , Permeability , Protein Binding , Protein Conformation , Time Factors , bcl-2-Associated X Protein/chemistry , bcl-2-Associated X Protein/genetics
8.
J Cell Sci ; 125(Pt 11): 2615-25, 2012 Jun 01.
Article in English | MEDLINE | ID: mdl-22375065

ABSTRACT

E-cadherin is synthesized as a precursor and then undergoes cleavage by proprotein convertases. This processing is essential for E-cadherin maturation and cell adhesion. Loss of cell adhesion causes detachment-induced apoptosis, which is called anoikis. Anoikis can be inhibited despite loss of cell-matrix interactions by preserving E-cadherin-mediated cell-cell adhesion. Conversely, acute loss of E-cadherin sensitizes cells to apoptosis by unknown post-translational mechanisms. After treatment of breast cancer cells with drugs, we found that two independent modifications of E-cadherin inhibit its cell surface transport. First, O-linked ß-N-acetylglucosamine (O-GlcNAc) modification of the cytoplasmic domain retains E-cadherin in the endoplasmic reticulum. Second, incomplete processing by proprotein convertases arrests E-cadherin transport late in the secretory pathway. We demonstrated these E-cadherin modifications (detected by specific lectins and antibodies) do not affect binding to α-catenin, ß-catenin or γ-catenin. However, binding of E-cadherin to Type I gamma phosphatidylinositol phosphate kinase (PIPKIγ), a protein required for recruitment of E-cadherin to adhesion sites, was blocked by O-GlcNAc glycosylation (O-GlcNAcylation). Consequently, E-cadherin trafficking to the plasma membrane was inhibited. However, deletion mutants that cannot be O-GlcNAcylated continued to bind PIPKIγ, trafficked to the cell surface and delayed apoptosis, confirming the biological significance of the modifications and PIPKIγ binding. Thus, O-GlyNAcylation of E-cadherin accelerates apoptosis. Furthermore, cell-stress-induced inactivation of proprotein convertases, inhibited E-cadherin maturation, further exacerbating apoptosis. The modifications of E-cadherin by O-GlcNAcylation and lack of pro-region processing represent novel mechanisms for rapid regulation of cell surface transport of E-cadherin in response to intoxication.


Subject(s)
Apoptosis , Cadherins/metabolism , Protein Processing, Post-Translational , Acetylglucosamine/metabolism , Animals , Antigens, CD , Apoptosis/drug effects , Cadherins/chemistry , Cell Membrane/metabolism , Dogs , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum/metabolism , Glycosylation/drug effects , HEK293 Cells , Humans , MCF-7 Cells , Madin Darby Canine Kidney Cells , Models, Biological , Peptides/metabolism , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Protein Processing, Post-Translational/drug effects , Protein Transport/drug effects , Sequence Deletion/genetics , Stress, Physiological/drug effects , Thapsigargin/pharmacology , Transfection
9.
Chembiochem ; 15(18): 2703-9, 2014 Dec 15.
Article in English | MEDLINE | ID: mdl-25358737

ABSTRACT

Detecting RNA-partner interactions in cells is often difficult due to a lack of suitable tools. Here we describe a dual reporter system capable of detecting intracellular interactions in which one of the partners is an RNA. The system utilizes two fluorescent proteins with similar maturation rates but distinct spectral properties, specifically cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP). By placing the CFP gene upstream and the YFP gene downstream of an RNA gene of interest, the production of YFP becomes sensitive to RNA-partner interaction, whereas the synthesis of CFP is not disturbed. Therefore, the RNA-partner interaction can be simply measured by the change in the ratio of fluorescence of YFP over CFP. The utility of our approach is demonstrated through verification of three known RNA-partner interactions in the model bacterium Escherichia coli. Our two-reporter strategy should be broadly useful to the study of RNA-targeted interactions in bacteria.


Subject(s)
Bacterial Proteins/metabolism , Escherichia coli/metabolism , Fluorescent Dyes/metabolism , Green Fluorescent Proteins/metabolism , Luminescent Proteins/metabolism , RNA, Bacterial/metabolism , Bacterial Proteins/analysis , Bacterial Proteins/genetics , Base Sequence , Cloning, Molecular , Escherichia coli/genetics , Escherichia coli Proteins/metabolism , Fluorescent Dyes/analysis , Green Fluorescent Proteins/analysis , Green Fluorescent Proteins/genetics , Luminescent Proteins/analysis , Luminescent Proteins/genetics , RNA, Bacterial/genetics , Spectrometry, Fluorescence
10.
Int J Biol Macromol ; 279(Pt 3): 135399, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39245095

ABSTRACT

Acidic xylanase PjxA from Penicillium janthinellum MA21601, with good eosinophilic and enzymatic activity, is an excellent candidate for xylan degradation to achieve effective utilization of biomass materials. However, the low thermal stability of PjxA has become a major bottleneck in its application. In this study, the flexible sites of PjxA were identified and rigidified through computational simulations of structure and sequence analysis combined with folding free energy calculations. Finally, a combined mutase PjxA-DS was constructed by rational integration of the two single mutants S82N and D45N. Compared to PjxA, PjxA-DS showed a 115.11-fold longer half-life at 50 °C and a 2.02-fold higher specific enzyme activity. Computer simulation analysis showed that S82N and D45N acted synergistically to improve the thermostability of PjxA. The stabilization of the N-terminus and the active center of PjxA, the increase in surface positive charge and hydrophilicity are the main reasons for the improved thermostability and catalytic activity of PjxA. Rigidification of the flexible site is an effective method for improving the thermostability of enzymes, S82N and D45N can be used as effective targets for the thermostability engineering modification of GH11 acidic xylanase.


Subject(s)
Endo-1,4-beta Xylanases , Enzyme Stability , Penicillium , Penicillium/enzymology , Penicillium/genetics , Endo-1,4-beta Xylanases/chemistry , Endo-1,4-beta Xylanases/genetics , Endo-1,4-beta Xylanases/metabolism , Temperature , Catalytic Domain , Models, Molecular , Kinetics , Mutation
11.
Biochem Pharmacol ; : 116560, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39343180

ABSTRACT

The escalating prevalence of obesity presents a formidable global health challenge, underscoring the imperative for efficacious pharmacotherapeutic interventions. However, current anti-obesity medications often exhibit limited efficacy and adverse effects, necessitating the exploration of alternative therapeutic approaches. Growth differentiation factor 15 (GDF15) has emerged as a promising target for obesity management, given its crucial role in appetite control and metabolic regulation. In this study, we aimed to investigate the efficacy of curcumol, a sesquiterpene compound derived from plants of the Zingiberaceae family, in obesity treatment. Our findings demonstrate that curcumol effectively induces the expression of GDF15 through the activation of the endoplasmic reticulum stress pathway. To confirm the role of GDF15 as a critical target for curcumol's function, we compared the effects of curcumol in wild-type mice and Gdf15-knockout mice. Using a high-fat diet-induced obese murine model, we observed that curcumol led to reduced appetite and altered dietary preferences mediated by GDF15. Furthermore, chronic curcumol intervention resulted in promising anti-obesity effects. Additionally, curcumol administration improved glucose tolerance and lipid metabolism in the obese mice. These findings highlight the potential of curcumol as a GDF15 inducer and suggest innovative strategies for managing obesity and its associated metabolic disorders. In conclusion, our study provides evidence for the efficacy of curcumol in obesity treatment by inducing GDF15 expression. The identified effects of curcumol on appetite regulation, dietary preferences, glucose tolerance, and lipid metabolism emphasize its potential as a therapeutic agent for combating obesity and related metabolic disorders.

12.
Complement Ther Clin Pract ; 57: 101895, 2024 Aug 13.
Article in English | MEDLINE | ID: mdl-39180951

ABSTRACT

BACKGROUND: and Purpose: Outdoor play is widely acknowledged for its benefits to physical health and psychological well-being, yet its relationship with school readiness remains understudied in preschoolers. To address this gap in the literature, this study investigated how outdoor play relates to cognitive and psychosocial development among a nationally representative sample of preschoolers. MATERIALS AND METHOD: Data on the duration of outdoor play (on weekdays and weekends) and specific cognitive and psychosocial outcome variables (i.e., early learning skills, self-regulation, social-emotional development, and flourishing) were collected via questionnaires provided to the caregivers of preschoolers. Logistic regressions were performed to examine the associations between outdoor play with cognitive and psychosocial outcomes while adjusting for covariates and calculate the odds ratio with 95 % confidence intervals (CI). RESULTS: Among the 10,682 preschoolers (i.e., 3-5y) included in this study (i.e., 5558 boys, Mage = 3.98 ± 0.99 years), there was a lower percentage of preschoolers engaged in outdoor play for over 3 h per day on weekdays (33.39 %) compared to weekends (56.85 %). Outdoor play in preschoolers is positively associated with various domains of school readiness, and engaging in outdoor play for more than 3 h per day is associated with more beneficial outcomes. CONCLUSION: The findings of this cross-sectional study suggest that promoting outdoor play among preschoolers can be an effective strategy for enhancing cognitive, social, and emotional development in this age group although further intervention studies are required to buttress this assumption empirically.

13.
Medicine (Baltimore) ; 102(45): e36039, 2023 Nov 10.
Article in English | MEDLINE | ID: mdl-37960792

ABSTRACT

BACKGROUND: Anti-mitochondrial antibodies (AMA) and the M2 subtype are considered serological hallmarks in the diagnosis of primary biliary cholangitis (PBC). However, these autoantibodies may be undetectable in some patients. This meta-analysis aimed to evaluate the diagnostic accuracy of serum AMA and M2 for PBC. METHODS: We systematically searched PubMed, Embase, Web of Science, and the Cochrane Library for relevant studies. Pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) were calculated using a random-effects model. We also constructed hierarchical summary receiver operating characteristic curves and calculated the area under the curve values. RESULTS: Our meta-analysis included 28 studies, of which 24 examined the diagnostic accuracy of AMA for PBC. Pooled sensitivity and specificity of AMA were 84% (95% confidence intervals [CI] 77-90%) and 98% (96-99%), respectively. Pooled LR+, LR-, and DOR were 42.2 (22.1-80.5), 0.16 (0.11-0.24), and 262 (114-601), respectively. Sixteen studies explored the diagnostic value of the M2 subtype, demonstrating pooled sensitivity and specificity of 89% (81-94%) and 96% (93-98%), respectively. Pooled LR+, LR-, and DOR were 20.3 (8.0-51.1), 0.12 (0.05-0.26), and 169 (41-706), respectively. The hierarchical summary receiver operating characteristic curves for both of serum AMA and M2 subtype lie closer to the upper left corner of the plot with area under the curve values of 0.98 (95% CI = 0.96-0.99) and 0.98 (95% CI = 0.96-0.99) respectively. CONCLUSION: This meta-analysis provides evidence affirming the utility of AMA and M2 as sensitive and specific serological hallmarks that can facilitate early screening and diagnosis of PBC.


Subject(s)
Liver Cirrhosis, Biliary , Humans , Mitochondria , Autoantibodies , Sensitivity and Specificity , ROC Curve
14.
ACS Omega ; 8(48): 46292-46299, 2023 Dec 05.
Article in English | MEDLINE | ID: mdl-38075784

ABSTRACT

Due to their high toxicity and ongoing bioaccumulation, mercury ions (Hg2+) can cause significant harm to both the environment and human health. Therefore, rapid, accurate, and selective methods for Hg2+ detection are highly desirable. Herein, we present a simple method for depositing platinum nanoparticles (PtNPs) on graphene oxide (GO) to obtain graphene oxide-PtNPs (GO-PtNPs). The fabricated GO-PtNPs exhibit excellent peroxidase-like activity and high stability. Further, the GO-PtNPs nanozymes preferentially reduced Hg2+, thereby inhibiting the catalytic activity. By monitoring the color change in the chromogenic substrate, Hg2+ can be detected within 15 min. With a detection limit of 88.3 pM, the GO-PtNPs system may be employed to detect Hg2+ in a linear range of 0.1 nM to 10 µM. The simplicity and low cost of the proposed approach as well as its applicability to complicated samples demonstrate its capacity for mercury sensing in environmental samples.

15.
J Plant Physiol ; 287: 154022, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37301036

ABSTRACT

Salinity is poisonous to various plant physiological processes and poses an increasingly severe threat to agricultural productivity worldwide. As a tactic to mitigate this issue, the hunt for salt-tolerance genes and pathways is intensifying. The low-molecular-weight proteins known as metallothioneins (MTs) can effectively reduce salt toxicity in plants. In seeking concrete evidence of its function under salt stress conditions, a unique salt-responsive metallothionein gene, LcMT3, was isolated from the extremely salt-enduring Leymus chinensis and heterologously characterized in Escherichia coli (E. coli), yeast (Saccharomyces cerevisiae), as well as Arabidopsis thaliana. Overexpression of LcMT3 imparted resistance to salt in E. coli cells and yeast, while the development of control cells was completely inhibited. Besides, transgenic plants expressing LcMT3 exhibited significantly enhanced salinity tolerance. They had higher germination rates and longer roots than their nontransgenic counterparts during NaCl tolerance. For several physiological indices of salt tolerance, transgenic lines reduced the accumulation of malondialdehyde (MDA), relative conductivity, and reactive oxygen species (ROS) in comparison to nontransgenic Arabidopsis. They also possessed increased concentrations of proline (Pro), relative water content, chlorophyll content, coupled with three more active antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)). Transgenic plants also accumulated less Na+ and maintained a lower Na+/K+ ratio than control, which can be attributable to the transgene's regulatory effect on transporter proteins such as salt overly sensitive (SOS) and Na+/H+ antiporter (NHX1), as demonstrated by qPCR experiments. Collectively, LcMT3 could have a vital function in salinity resistance and be an essential candidate protein for abiotic stress.


Subject(s)
Arabidopsis , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genetics , Arabidopsis/metabolism , Escherichia coli/genetics , Metallothionein/genetics , Poaceae/genetics , Plants, Genetically Modified/metabolism , Salt Tolerance/genetics , Gene Expression Regulation, Plant , Stress, Physiological/genetics , Plant Proteins/metabolism
16.
Enzyme Microb Technol ; 162: 110143, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36335858

ABSTRACT

The N-terminal of xylanase from 11 family of glycoside hydrolases (GH11 xylanase) has an important effect on its thermostability and catalytic properties. Previous studies have unearthed five important residues located in the N-terminal and successfully improved the thermostability of several GH11 xylanases using amino acid substitutions. In the present study, we applied this tactic to construct a mutant of XynA from Streptomyces rameus L2001, XynAR, and studied its biochemical, catalytic and hydrolytic properties. The results showed that thermostability, acid tolerance as well as catalytic efficiency of XynAR significantly improved compared to those of XynA, while the hydrolytic characteristics changed. Computer simulation analysis showed that this tactic created new hydrogen bonds and electrostatic interactions in the N-terminal, resulting in decrease in the flexibility of N-terminal and surface electrostatic potential as well as a change in the profile of hydrogen bonds between the subsites and substrate in the cleft region of xylanase. This study showed that amino acid substitutions at the key sites of the N-terminal of GH11 xylanase can improve its thermostability and catalytic properties.


Subject(s)
Endo-1,4-beta Xylanases , Endo-1,4-beta Xylanases/metabolism , Enzyme Stability , Computer Simulation , Kinetics
17.
Foods ; 12(4)2023 Feb 18.
Article in English | MEDLINE | ID: mdl-36832954

ABSTRACT

Glycoside hydrolase family 11 (GH11) xylanases are the preferred candidates for the production of functional oligosaccharides. However, the low thermostability of natural GH11 xylanases limits their industrial applications. In this study, we investigated the following three strategies to modify the thermostability of xylanase XynA from Streptomyces rameus L2001 mutation to reduce surface entropy, intramolecular disulfide bond construction, and molecular cyclization. Changes in the thermostability of XynA mutants were analyzed using molecular simulations. All mutants showed improved thermostability and catalytic efficiency compared with XynA, except for molecular cyclization. The residual activities of high-entropy amino acid-replacement mutants Q24A and K104A increased from 18.70% to more than 41.23% when kept at 65 °C for 30 min. The catalytic efficiencies of Q24A and K143A increased to 129.99 and 92.26 mL/s/mg, respectively, compared with XynA (62.97 mL/s/mg) when using beechwood xylan as the substrate. The mutant enzyme with disulfide bonds formed between Val3 and Thr30 increased the t1/260 °C by 13.33-fold and the catalytic efficiency by 1.80-fold compared with the wild-type XynA. The high thermostabilities and hydrolytic activities of XynA mutants will be useful for enzymatic production of functional xylo-oligosaccharides.

18.
Polymers (Basel) ; 14(13)2022 Jul 05.
Article in English | MEDLINE | ID: mdl-35808795

ABSTRACT

To promote the performance of perovskite solar cells (PSCs), its theoretical power conversion efficiency (PCE) and high stability, elaborative defect passivation, and interfacial engineering at the molecular level are required to regulate the optoelectric properties and charge transporting process at the perovskite/hole transport layer (HTL) interfaces. Herein, we introduce for the first time a multifunctional dipole polymer poly(2-ethyl-2-oxazoline) (PEOz) between the perovskite and Spiro-OMeTAD HTL in planar n-i-p PSCs, which advances the PSCs toward both high efficiency and excellent stability by stimulating three beneficial effects. First, the ether-oxygen unshared electron pairs in PEOz chemically react with unsaturated Pb2+ on the perovskite surfaces by forming a strong Pb-O bond, which effectively reduces the uncoordinated defects on the perovskite surfaces and enhances the absorption ability of the resulting PSCs. Second, the dipole induced by PEOz at the perovskite/HTL interface can decrease the HOMO and LUMO level of Spiro-OMeTAD and optimize the band alignment between these layers, thereby suppressing the interfacial recombination and accelerating the hole transport/extraction ability in the cell. Third, the hygroscopic PEOz thin film can protect perovskite film from water erosion by absorbing the water molecules before perovskite does. Finally, the PEOz-modified PSC exhibits an optimized PCE of 21.86%, with a high short-circuit current density (Jsc) of 24.88 mA/cm2, a fill factor (FF) of 0.79, and an open-circuit voltage (Voc) of 1.11 V. The unencapsulated devices also deliver excellent operation stability over 300 h in an ambient atmosphere with a humidity of 30~40% and more than 10 h under thermal stress.

19.
Complement Ther Clin Pract ; 49: 101670, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36182711

ABSTRACT

PURPOSE: The integrated model of flow and clutch provides a multistate perspective to the optimal experiences during physical exercises. Based on this model, the Flow-Clutch Scale (FCS) was developed. The current study is the first step to test the psychometric properties of a Chinese version of the FCS (FCS-C). METHOD: A confirmatory factor analysis (CFA) with Maximum Likelihood estimate was performed in Chinese athletes (N = 426) to explore the structural validity of the FCS-C . The Pearson correlations between the subscales of the FCS-C and "non-reactivity to inner experiences", "cognitive flexibility", and "self-consciousness" were explored to examine the concurrent validity. Cronbach's alpha coefficients were used to assess the internal consistency of the total scale and subscales. Moreover, the test-retest reliability was examined in a subsample (N = 53) using a two-week interval. RESULTS: The results of CFA suggested that the three-factor model showed an acceptable model fit (χ2 = 459.40, df = 120, CFI = 0.95, GFI = 0.90, SRMR = 0.03, RMSEA = 0.082 [90% CI = 0.074-0.09]). Concerning the correlations between the factor "characteristics of flow" and "self-consciousness", the concurrent validity was not satisfactory. Moreover, the test-retest coefficients ranged from 0.75 to 0.78 (p < .01) and Cronbach's alpha ranged from 0.87 to 0.96. CONCLUSION: Results indicated that the three-factor model of FCS-C is acceptable, whereas its validity is not satisfactory to appropriately examine flow and/or clutch states in Chinese athletes. In summary, the current translation and validation study of the FCS-C allows for future research on optimal exercise experiences in Chinese-speaking cohorts including a further cultural adaptation of the questionnaire.


Subject(s)
Translations , Humans , Reproducibility of Results , Likelihood Functions , Psychometrics/methods , Surveys and Questionnaires , China
20.
Int J Biol Macromol ; 222(Pt A): 868-879, 2022 Dec 01.
Article in English | MEDLINE | ID: mdl-36167104

ABSTRACT

Polymers synthesized from green resources have many advantages in food packaging and hence their development is very important. Herein, starch/polyvinyl alcohol (PVA) nanofibrous composite films were fabricated by electrospinning technology. Steam-induced cross-linking reaction with glutaraldehyde (GTA) and silver sodium zirconium phosphate (Ag-ZrP) was employed to improve the hydrophobic and antibacterial properties of the constructed nanofibrous films, respectively. The effects of starch/PVA ratio on the micro-morphology and mechanical properties of the binary composite film were investigated. The composite film showed optimal uniformity, bead-free electrospun nanofibers, with enhanced mechanical strength for the 60/40 (v/v) starch/PVA composite. Moreover, the crystallinity of PVA was reduced during the electrospinning process, whereas the introduction of PVA strengthened the hydrogen interactions and improved the thermal stability of the composite films. After the cross-linking with GTA, the starch/PVA films became more hydrophobic. Furthermore, the starch/PVA films embedded with Ag-ZrP had outstanding antibacterial property against both Gram-negative and Gram-positive bacteria. This work demonstrated the potential prospects of electrospun starch nanofibrous films in the food packaging field.


Subject(s)
Food Packaging , Nanofibers , Nanofibers/chemistry , Starch/chemistry , Polyvinyl Alcohol/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Glutaral
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