Search

2,6-Di-tert-butyl-4-methylphenol (BHT) is an excellent antioxidant that is easily oxidized to 2,6-di-tert-butyl-4-hydroperoxyl-4-methyl-2,5-cyclohexadienone (BHTOOH). For the safety of BHT production and usage, it is meaningful to study the thermal stability and decomposition properties of BHT and BHTOOH. In this paper, the thermal decomposition properties of BHT and BHTOOH were compared by the mini closed pressure vessel test (MCPVT) and differential scanning calorimetry (DSC). Their kinetics of thermal decomposition were studied using thermogravimetric analysis (TGA). The thermal decomposition products of BHT and BHTOOH were analyzed by gas chromatography-mass spectrometry (GC–MS). The results show that there was no significant change in temperature pressure when BHT was warmed up under a nitrogen atmosphere, indicating that BHT was stable within 400 K. The thermal decomposition reaction of BHTOOH was rapid with an initial reaction temperature of 375.2 K. The initial exothermic temperature (Ti) and heat release (QDSC) of DSC were 384.9 K and 865.0 J g−1, respectively. The apparent activation energies (Ea) for the thermal decomposition reactions of BHT and BHTOOH calculated by the Kissinger method were 151.8 kJ mol−1 and 66.07 kJ mol−1, respectively. The main decomposition products of BHT were isobutene and 2-tert-butyl-4-methylphenol. The thermal decomposition products of BHTOOH included BHT, 2,6-di-tert-butyl-4-ethylphenol, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, 4,4′-(1,2-ethanediyl) bis [2,6-bis (1,1-dimethylethyl) phenol, etc. Based on the thermal decomposition behavior and products, the reaction pathway has been described. These results indicate that BHT is a potential thermal hazard during production, storage and application. For the safety of the chemical industry, the oxidation of BHT should be avoided. [ABSTRACT FROM AUTHOR]

Propionic acidaemia is a rare disorder caused by defects in the propionyl-coenzyme A carboxylase α or β (PCCA or PCCB) subunits that leads to an accumulation of toxic metabolites and to recurrent, life-threatening metabolic decompensation events. Here we report interim analyses of a first-in-human, phase 1/2, open-label, dose-optimization study and an extension study evaluating the safety and efficacy of mRNA-3927, a dual mRNA therapy encoding PCCA and PCCB. As of 31 May 2023, 16 participants were enrolled across 5 dose cohorts. Twelve of the 16 participants completed the dose-optimization study and enrolled in the extension study. A total of 346 intravenous doses of mRNA-3927 were administered over a total of 15.69 person-years of treatment. No dose-limiting toxicities occurred. Treatment-emergent adverse events were reported in 15 out of the 16 (93.8%) participants. Preliminary analysis suggests an increase in the exposure to mRNA-3927 with dose escalation, and a 70% reduction in the risk of metabolic decompensation events among 8 participants who reported them in the 12-month pretreatment period.Interim data from a clinical trial of mRNA-3927—an mRNA therapeutic for propionic acidaemia—provide early indications of the safety and efficacy of the treatment, and suggest that this approach might be applicable to other rare diseases. [ABSTRACT FROM AUTHOR]

Myocardial remodeling and dysfunction are commonly observed in type 2 diabetes mellitus (T2DM). Aerobic exercise can partly alleviate diabetes-induced myocardial dysfunction through its antioxidant actions. MOTS-c is a potential exercise mimic. This study aimed to investigate the effects of MOTS-c on improving diabetic heart function and its mechanism and to identify whether MOTS-c improved antioxidant defenses due to aerobic exercise. Herein, we established a rat model of T2DM induced by high-fat diet combined with a low-dose streptozotocin injection. Interventions were performed using intraperitoneal injections of MOTS-c (i.p. 0.5 mg/kg/day, 7 days/week) or aerobic exercise training (treadmill, 20 m/min, 60 min/day, 5 days/week) for 8 weeks. Myocardial ultrastructure was assessed using transmission electron microscopy (TEM), myocardial lipid peroxidation levels (MDA), superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT) levels were assessed using colorimetric methods, and molecular analyses including MOTS-c, Kelch-like ECH-associated protein 1 (Keap1), Nuclear factor E2-related factor 2 (Nrf2), adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)and phospho-AMPK (p-AMPK) were examined using Western blot. The results showed that MOTS-c, with or without exercise, reduced myocardial ultrastructural damage and improved glucolipid metabolism and cardiac function in T2DM. Furthermore, MOTS-c increased antioxidant markers such as SOD, CAT, and the protein expression of myocardial MOTS-c, Keap1, Nrf2, and p-AMPK. MOTS-c with exercise treatment reduced myocardial MDA and increased p-AMPK significantly comparing to only exercise or MOTS-c alone. Our findings suggest that MOTS-c may be a helpful supplement for overcoming exercise insufficiency and improving myocardial structure and function in diabetes. [ABSTRACT FROM AUTHOR]

Small-cell lung cancer (SCLC) is an aggressive lung cancer subtype with an extremely poor prognosis. The 5-year survival rate for limited-stage (LS)-SCLC cancer is 10–13%, while the rate for extensive-stage SCLC cancer is only 1–2%. Given the crucial role of the tumor stage in the disease course, a well-constructed prognostic model is warranted for patients with LS-SCLC. The LS-SCLC patients' clinical data extracted from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2018 were reviewed. A multivariable Cox regression approach was utilized to identify and integrate significant prognostic factors. Bootstrap resampling was used to validate the model internally. The Area Under Curve (AUC) and calibration curve evaluated the model's performance. A total of 5463 LS-SCLC patients' clinical data was collected from the database. Eight clinical parameters were identified as significant prognostic factors for LS-SCLC patients' OS. The predictive model achieved satisfactory discrimination capacity, with 1-, 2-, and 3-year AUC values of 0.91, 0.88, and 0.87 in the training cohort; and 0.87, 0.87, and 0.85 in the validation cohort. The calibration curve showed a good agreement with actual observations in survival rate probability. Further, substantial differences between survival curves of the different risk groups stratified by prognostic scores were observed. The nomogram was then deployed into a website server for ease of access. This study developed a nomogram and a web-based predictor for predicting the overall survival of patients with LS-SCLC, which may help physicians make personalized clinical decisions and treatment strategies. [ABSTRACT FROM AUTHOR]

In this study, the oxidation characteristics of isoprene were investigated using a custom-designed mini closed pressure vessel test (MCPVT). The results show that isoprene is unstable and polymerization occurs under a nitrogen atmosphere. Under an oxygen atmosphere, the oxidation process of isoprene was divided into three stages: (1) isoprene reacts with oxygen to produce peroxide; (2) Peroxides produce free radicals through thermal decomposition; (3) Free radicals cause complex oxidation and thermal runaway reactions. The oxidation of isoprene conforms to the second-order reaction kinetics, and the activation energy was 86.88 kJ·mol−1. The thermal decomposition characteristics of the total oxidation product and purified peroxide mixture were determined by differential scanning calorimetry (DSC). The initial exothermic temperatures Ton were 371.17 K and 365.84 K, respectively. And the decomposition heat QDSC were 816.66 J·g−1 and 991.08 J·g−1, respectively. It indicates that high concentration of isoprene peroxide has a high risk of thermal runaway. The results of thermal runaway experiment showed that the temperature and pressure of isoprene oxidation were prone to rise rapidly, which indicates that the oxidation reaction was dangerous. The reaction products of isoprene were analyzed by gas chromatography-mass spectrometry (GC–MS). The main oxidation products were methyl vinyl ketone, methacrolein, 3-methylfuran, etc. The main thermal runaway products were dimethoxymethane, 2,3-pentanedione, naphthalene, etc. Based on the reaction products, the possible reaction pathway of isoprene was proposed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Vacuum brazing was used to join TC4 titanium alloy with self-designed and non-copper Ti–38Zr–24Ni (wt.%) filler metal. Variable brazing clearances were chosen to study their effect on the microstructural evolution and mechanical properties of the joints. The brazed joint with narrow brazing clearance only contained two reaction zones: the diffusion zone (α-Ti and (Ti, Zr)2Ni eutectoid structures and remained based metal) and the interface zone (α-Ti and (Ti,Zr)2Ni). However, the brazed joint with large brazing clearance had another reaction zone in the middle of the joint: the center zone (big block brittle (Ti,Zr)2Ni IMCs and some tiny phases: α-Ti and (Ti,Zr)2Ni eutectoid transformation phase). The width of center zone increased with the increase of the brazing clearance. The maximum shear strength of the brazed joint reached 872 MPa when brazing clearance was 0 μm. The brittleness of IMCs in center zone caused the low strength of the joint. Quasi-cleavage fracture occurred in the narrow brazing clearance (0 μm), while mixed quasi-cleavage and cleavage fractures occurred in the large brazing clearance (50-200 μm). [ABSTRACT FROM AUTHOR]

Introduction: Postoperative impaired sleep quality and pain are associated with adverse outcomes. Stellate ganglion block (SGB) has shown promising results in enhancing sleep quality and alleviating neuropathic pain. This study aimed to investigate the effects of ultrasound-guided SGB on postoperative sleep quality and pain in patients undergoing breast cancer surgery. Methods: This study is a parallel-group randomized controlled clinical trial with two groups: SGB and control. Fifty female patients undergoing breast cancer surgery were randomized in a 1:1 ratio to receive preoperative ultrasound-guided single-injection SGB (SGB group) or just an ultrasound scan (control group). All participants were blinded to the group assignment. The primary outcome was postoperative sleep quality, assessed by the St. Mary's Hospital Sleep Questionnaire and actigraphy 2 days postoperatively. The secondary outcome was postoperative pain, measured by the visual analog scale. Results: A total of 48 patients completed the study, with 23 patients in the control group and 25 in the SGB group. The postoperative St. Mary's Hospital Sleep Questionnaire scores were significantly higher in the SGB group than in the control group on 1 day postoperative (30.88 ± 2.44 versus 27.35 ± 4.12 points, P = 0.001). The SGB also increased the total sleep time and sleep efficiency (main actigraphy indicators) during the first two postoperative nights. Compared with the control group, preoperative SGB reduced postoperative pain and the incidence of breast cancer-related lymphedema (20% versus 52.2%, P = 0.02, odds ratio 0.229, 95% confidence interval 0.064–0.821). There were no adverse events related to SGB. Conclusion: Preoperative ultrasound-guided SGB improves postoperative sleep quality and analgesia in patients undergoing breast cancer surgery. SGB may be a safe and practical treatment to enhance the postoperative quality of life in patients with breast cancer. Trial Registration: The study was registered in the Chinese Clinical Trial Registry (ChiCTR2100046620, principal investigator: Kai Zeng, date of registration: 23 May 2021). [ABSTRACT FROM AUTHOR]

To suppress the accumulation of δ-ferrite and adjust the dilution of the Al-Si coating, 22MnB5 coated with Al-Si was laser lap welded with filler wire. The weld appearance, dilution of the coating, microstructure, and mechanical properties of the joints were studied. A mathematical model was established by energy conservation between the feeding speed and weld appearance and between the feeding speed and dilution of the base material. When the feeding speed was raised, the weld gradually changed from a tall cup shape to a bowl shape and the dilution of the coating decreased. This led to the reduction of the δ-ferrite. The fusion zone (FZ) was lath-like martensite (M). Four zones along the FZ to base material (BM) were formed in HAZ. The coarse grain heat-affected zone (CGHAZ) near FZ and the fine grain heat-affected zone (FGHAZ) consisted of martensite. The intercritical heat-affected zone (ICGHAZ) near BM consisted of martensite and a small amount of ferrite. The tempered zone (TZ) consisted of tempered martensite with the lowest hardness. Importantly, band-like (δ-ferrite) which had low strength and ductility occurred along the fusion boundary and became a weak region. The ultimate tensile strength was only 436 MPa without filler wire but reached 746 MPa with filler wire whose failure mode mixed dimpled and quasi-cleavage fracture. [ABSTRACT FROM AUTHOR]

Ti-6Al-4V alloy was brazed in vacuum using self-designed and non-copper Ti-38Zr-24Ni (wt.%) filler metal. The microstructural evolution and mechanical properties of the joints were researched. Ni and Zr atoms diffused into based material and led to β-Ti transformation, which formed the diffusion zone. Its microstructure was α-Ti and (Ti, Zr)2Ni eutectoid structures and remained based material. The interface zone was formed through isothermal solidification, which was composed of α-Ti and (Ti, Zr)2Ni by eutectoid transformation. The center zone was comprised of big block brittle (Ti, Zr)2Ni IMCs and some tiny phases: α-Ti and (Ti, Zr)2Ni by hypoeutectic and following eutectoid transformation. The maximum shear strength was 673MPa at 930°C for 45 min. The weak area was the center zone. Cracks initiated and propagated in the brittle (Ti, Zr)2Ni IMCs in the center zone and may be hindered by α-Ti which exhibited the mixed quasi-cleavage and cleavage fractures. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to identify the ferroptosis induced tumor microenvironment (FeME) landscape in bladder cancer (BCa) for mRNA vaccine development and selecting suitable patients for precision treatment. Methods: Gene expression profiles and clinical information of 1216 BCa patients were extracted from TCGA-BLCA, three GEO databases and IMvigor210 cohort. We comprehensively established the FeME landscape of 1216 BCa samples based on 290 ferroptosis related genes (FRGs), and systematically correlated these regulation patterns with TME cell-infiltrating characteristics. Besides, we identified the patients' ferroptosis risk index (FRI) to predict the prognosis of BCa for precise treatment. Results: Six over-expressed and mutated tumor antigens associated with poor prognosis and infiltration of antigen presenting cells were identified in BCa. Furthermore, we demonstrated the evaluation of FeME within individual tumors could predict stages of tumor inflammation, subtypes, genetic variation, and patient prognosis. Then, 5-lncRNA signature was mined to produce the FRI. Low FRI was also linked to increased mutation load, better prognosis and enhanced response to anti-PD-L1 immunotherapy. Besides, an immunotherapy cohort confirmed patients with lower FRI demonstrated significant therapeutic advantages and clinical benefits. Conclusions: TFRC, SCD, G6PD, FADS2, SQLE, and SLC3A2 are potent antigens for developing anti-BCa mRNA vaccine. Establishment of FRI will contribute to enhancing our cognition of TME infiltration characterization and guiding more effective immunotherapy strategies and selecting appropriate patients for tumor vaccine therapy. [ABSTRACT FROM AUTHOR]

The reaction process of gaseous 1,3-butadiene following ultraviolet irradiation at the temperature range from 298 to 323 K under nitrogen atmosphere was monitored by UV–vis spectrophotometry. A gaseous mini-reactor was used as a reaction vessel and could be directly monitored in a UV–vis spectrophotometer. We investigated the reactivity and kinetics of 1,3-butadiene under non-UV and UV irradiation to evaluate its photochemical stability. A second-order kinetic model with 50.48 kJ·mol–1 activation energy fitted the reaction data for non-UV irradiation, whereas a first-order kinetic model was appropriate in the case of UV irradiation with activation energies of 19.92–43.65 kJ mol–1. This indicates that ultraviolet light could accelerate the photolysis reaction rate of 1,3-butadiene. In addition, the reaction products were determined using gas chromatography-mass spectrometry (GC–MS), and the reaction pathways were identified. The photolysis of 1,3-butadiene gave rise to various volatile products by cleavage and rearrangement of single C–C bonds. The differences between dimerization and dissociation of 1,3-butadiene under ultraviolet irradiation were elucidated by combining experimental and theoretical methods. The present findings provide fundamental insight into the photochemistry of 1,3-butadiene compounds. [ABSTRACT FROM AUTHOR]

Laser welding of Al-Si coated 22MnB5 hot stamping steel/galvanized steel with different laser power, welding speed, and coating conditions were presented. The weld appearance, microstructure, and mechanical properties of the joints were investigated. With the increase of heat input (raising the laser power or lowering the welding speed), the welding seam changed from Y-shape to X-shape gradually, and the widths of the weld seam increased. The fusion zone (FZ) consisted of lath martensite (M). On the side of 22MnB5, the heat-affected zone (HAZ) was divided into coarse grain zone, refined zone, intercritical zone, and tempered zone along the direction from FZ to the base material (BM). Coarse grain zone and refined zone comprised martensite, intercritical zone comprised martensite and a little ferrite, and tempered zone comprised tempered martensite, which expressed obvious softening. On the side of galvanized steel, HAZ was mainly composed of ferrite and pearlite. Significantly, band-like δ-ferrite (a low ductility and low strength phase) was formed along the fusion boundary owing to the accumulation of the mixing of Al-Si coating and base metals. The maximum tensile shear strength of the joint was only 484 MPa in coated condition but increased to 700 MPa in de-coated condition because of the existence of δ-ferrite along the fusion boundary, which deteriorated the mechanical properties of the joints. The failure occurred at the fusion boundary (FB) in the coated conditions with a mixture of cleavage, quasi-cleavage, and dimpled fracture. However, the failure occurred at the interface in the de-coated condition with a dimpled fracture. In addition, for the coated condition, higher laser power or lower welding speeds led to wider bead width and more intense weld pool flow, which enhanced the diffusion of Al, resulted in alleviating the accumulation of Al at the fusion boundary, which increased the mechanical properties. [ABSTRACT FROM AUTHOR]

Blend films with poly(ε-caprolactone)(PCL) and poly(propylene carbonate)(PPC)with thickness of approximately 40 μm and 60 μm, respectively, were prepared using a uniaxial-stretching extrusion process to modify the property of PCL. PCL/PPC blend films with better comprehensive properties with thickness about 60 μm were used for equilibrium-modified atmosphere packaging of button mushrooms at 5 °C. The gas barrier property together with water vapor permeability were evaluated as well as its effects on the shelf life button mushrooms. The results showed that the PCL/PPC20 and PCL/PPC50 blend films have suitable gas barrier property and water vapor permeability, which was helpful to generate an appropriate storage environment and more importantly no condensation occurred in these two packages. The lower weight loss of button mushrooms was observed for PCL/PPC20 and PCL/PPC50 blend films 4.43 and 4.46, respectively. The PCL/PPC blend films was more effective in decreasing the activity of PPO and preserving the color of the button mushrooms. The over market acceptability of button mushrooms packaged in PCL/PPC blend films still maintained good and within the limit of marketability after 17 days of storage. [ABSTRACT FROM AUTHOR]

Cardiac remodeling is a physiological adaptation to aerobic exercise and which is characterized by increases in ventricular volume and the number of cardiomyocytes. The mitochondrial derived peptide MOTS-c functions as an important regulator in physical capacity and performance. Exercise elevates levels of endogenous MOTS-c in circulation and in myocardium, while MOTS-c can significantly enhance exercise capacity. However, the effects of aerobic exercise combined with MOTS-c on cardiac structure and function are unclear. We used pressure–volume conductance catheter technique to examine cardiac function in exercised rats with and without treatment with MOTS-c. Surprisingly, MOTS-c improved myocardial mechanical efficiency, enhanced cardiac systolic function, and had a tendency to improve the diastolic function. The findings suggest that using exercise supplements could be used to modulate the cardiovascular benefits of athletic training. [ABSTRACT FROM AUTHOR]

Introduction: The coronavirus disease 2019 (COVID-19) was defined as a species of beta coronavirus causing atypical respiratory disease in humans. The COVID-19 pandemic has resulted in an unprecedented health and economic crisis worldwide. Little is known about the specifics of its influence on people living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) (PLWHA). In this study, we aim to investigate the prevalence and mortality in PLWHA co-infected with COVID-19. Methods: The databases PUBMED, EMBASE, BioRxiv, and medRxiv were searched up to 9 March 2021 to explore the prevalence and mortality rate of COVID-19 in PLWHA. Cohort studies and case series meeting the inclusion criteria were included in this review. Results: We identified 14 eligible studies, 9 of which were cohort and 5 were case series. A total of 203,761 patients with COVID-19 were identified (7718 PLWHA vs. 196,043 non-PLWHA). Meta-analyses estimated the prevalence and mortality rate of COVID-19 in PLWHA was 0.774% [95% confidence interval (CI) 0.00393–0.01517] and 8.814% (95% CI 0.05766–0.13245) respectively. COVID-19 co-infected PLWHA do not seem to be associated with higher mortality, as compared to non-PLWHA [relative risk (RR) 0.96 (95% CI 0.88–1.06)]. The presence of comorbidities such as diabetes mellitus, RR 5.2 (95% CI 4.25–6.36), hypertension and chronic cardiac disease, RR 4.2 (95% CI 1.09–16.10), and chronic kidney disease, RR 8.43 (95% CI 5.49–12.93) were associated with an increased mortality in COVID-19 co-infected PLWHA. Conclusion: The estimated prevalence and mortality rate of COVID-19 in PLWHA were 0.774% and 8.814%, respectively. Since most of the included studies used unmatched populations, comparisons between PLWHA and non-PLWHA should be interpreted with caution. Further investigations are needed for a more comprehensive understanding of the relationship between cluster of differentiation 4 cell count, HIV viral load, antiretroviral therapy, and COVID-19 related prognosis in PLWHA. [ABSTRACT FROM AUTHOR]

Currently, there is tremendous interest in the development of surface coatings for outdoor applications that are self-cleaning with strong antibacterial properties. Herein, aniline was polymerized in situ with silver–N-doped TiO2 composites to fabricate PANI–Ag–N–TiO2 nanocomposites, which were then mixed with an acrylic resin to form coatings on type 316L stainless steel. Under UV–Vis light illumination, the PANI–Ag–N–TiO2 coatings delivered a stable photocathodic potential of − 0.79 V, a much larger negative potential than was realized using PANI–N–TiO2 (− 0.55 V) or PANI–TiO2 (− 0.40 V) coatings. The addition of Ag nanoparticles thus greatly enhanced the photo-cathodic response. Antimicrobial experiments demonstrated that the PANI–Ag–N–TiO2 coating offers good antibacterial activity (> 95% inhibition) against E. coli under UV–Vis light irradiation for 30 min, due to the generation of hydrogen peroxide or other reactive oxygen species capable of damaging the membrane of E. coli cells. Results suggest that PANI–Ag–N–TiO2 composite coatings offer good antifouling performance in marine environments. [ABSTRACT FROM AUTHOR]

Background: Skin injury is a kind of common tissue damage in daily life and war. Silk fibroin (SF) is becoming an engineered material for skin wound repair due to its superior unique physical and chemical properties. The present study aimed to illustrate mechanism of SF hydrogel promoting skin repair in the second degree burn mice. Methods: Heat shock models were established. In vitro, cells were culture for 50 min at 44 °C water bath; while in vivo, the skin of anesthetic mice were treat with soldering iron at 90 °C. Then, they divided into silk fibroin gel group, purilon gel group and control (blank) group. The cellular activity of proliferation and apoptosis was detected by Kit-8, flow cytometry and HE-staining, and the migration and adhesion were detected by scratch test. qRT-PCR and WB were employed to detected adhesion and migration related genes and proteins expression. TLN1 siRNA and overexpression technologies were also employed to illustrate the potential mechanism of SF effects. Results: Compared with the purilon gel group and control group, SF hydrogel could enhance cell proliferation, migration and adhesion and increase the expression of adhesion and migration related proteins (P < 0.05), which promote burn wound healing. Conclusions: Through the inhibition, overexpression and rescue experiments of Talin1, we proved that silk fibroin hydrogel promote burn wound healing through regulating TLN1 expression and affecting cell adhesion and migration. [ABSTRACT FROM AUTHOR]

As a crucial virulence factor of Porphyromonas gingivalis, gingipains play an important role in periodontal destruction. This study aimed to investigate the effect of gingipains on osteoclastogenesis. We used RAW264.7 cells as osteoclast precursors in our study. In experimental groups, cells were treated with gingipains and/or receptor activator of nuclear factor-κB ligand (RANKL). Tartrate-resistant acid phosphatase (TRAP) activity staining assay showed osteoclast precursors and RANKL-induced mature osteoclasts were increased in a gingipains dose-dependent manner. Real-time reverse transcription polymerase chain reaction analysis demonstrated that gingipains upregulated osteoclastic genes including the protease cathepsin K (Ctsk), matrix metalloprotein 9 (Mmp9), nuclear factor of activated T cells 1 (Nfatc1) and acid phosphatase 5, tartrate resistant (Acp5) in a time-dependent manner. Western blotting assays presented upregulated expressions of TNF receptor-activating factor 6 (TRAF6) and integrin β3 induced by gingipains and RANKL compared to RANKL alone. Enhanced integrin-related signaling was also demonstrated by elevated phosphorylations of FAK and paxillin compared to control. Moreover, the pit resorption assays showed that gingipains augmented bone resorptive function of osteoclasts induced by RANKL. When we used Cilengitide to block integrin αvβ3, gingipains reversed the reduction of formation and resorptive function in RANKL-induced osteoclasts, as they enhanced integrin αvβ3 levels more than RANKL treatment alone. In conclusion, our data suggest that gingipains augmented the differentiation and function of mature osteoclasts induced by RANKL through the increase in integrin αvβ3. [ABSTRACT FROM AUTHOR]

Nuclear factor I-C (NFIC) plays critical roles in the regulation of tooth development by influencing the biological behaviors of stem cells in the dental germ. This study aimed to investigate the effect of NFIC on the vitality and osteogenic/cementogenic differentiation of rat dental follicle cells (DFCs). DFCs were isolated from dental follicles in the first molars of neonatal rats. DFCs expressed mesenchymal stromal cell markers CD29, CD44 and CD90 and had capabilities for self-renewal and multipotent differentiation. Overexpression of NFIC promoted the proliferation of DFCs without markedly influencing the apoptosis of DFCs. Moreover, NFIC increased alkaline phosphatase (ALP) activity in DFCs and upregulated the mRNA levels of osteogenic-related markers, namely, collagen type I (Col I), Runt-related transcription factor 2 (Runx2) and ALP, as well as β-catenin. In contrast, silencing NFIC by siRNA increased the apoptosis of DFCs and downregulated the expression of osteogenic-related markers. In conclusion, these results suggested that upregulation of NFIC may promote the proliferation and osteogenic/cementogenic differentiation of DFCs. [ABSTRACT FROM AUTHOR]

Material-extrusion three-dimensional (3D) printing has recently attracted much interest because of its process flexibility, rapid response to design alterations, and ability to create structures 'on-the-go'. For this reason, 3D printing has possible applications in rapid creation of space-based devices, for example cube satellites (CubeSat). This work focused on fabrication and characterization of tungsten-doped polycarbonate polymer matrix composites specifically designed for x-ray radiation-shielding applications. The polycarbonate-tungsten polymer composite obtained intentionally utilizes low loading levels to provide x-ray shielding while limiting effects on other properties of the material, for example weight, electromagnetic functionality, and mechanical strength. The fabrication process, from tungsten functionalization to filament extrusion and material characterization, is described, including printability, determination of x-ray attenuation, tensile strength, impact resistance, and gigahertz permittivity, and failure analysis. The proposed materials are uniquely advantageous when implemented in 3D printed structures, because even a small volume fraction of tungsten has been shown to substantially alter the properties of the resulting composite. [ABSTRACT FROM AUTHOR]

Ballscrew is a precision mechanical component used to convert rotational motion to linear motion in the precision linear stage. The precision measuring system for the screw's cumulative-lead error is already well known. Up to now, however, there is no suitable measuring equipment for internal cumulative-lead error of the nut. For a matching pair, it is not reasonable to understand the quality of only one piece. This paper presents a developed automatic cumulative-lead error measuring system for ballscrew nuts. The nut is clamped by a rotational stage, in which the moving angle is detected by a rotary encoder. The probing ball is inserted into the nut and remains in contact with the thread groove of the nut. The probe arm is mounted on a linear slide so that when rotating the nut, the probing ball will be pushed by the groove wall and moved axially. A high-resolution diffraction scale is employed to detect the linear movement of the probe to nanometer resolution. Combining the angular and linear motions, the cumulative-lead error of the nut can be realized. In practice, however, the nut will cause typical spindle errors during rotating, including axial slip, radial run out, and tilt motions. These errors have to be compensated in order to guarantee the accuracy of measurement results. A multi-sensor error compensation system is thus developed. Experimental results show the applicability of this developed measuring system. [ABSTRACT FROM AUTHOR]

To investigate the pathophysiology of Leber's hereditary optic neuropathy (LHON), a cohort of 1164 Han Chinese subjects with LHON were screened for ND1 G3460A mutation. A total of 295 subjects from 16 Han Chinese families carrying the G3460A mutation underwent a clinical and genetic evaluation and molecular analysis of mitochondrial (mt)DNA. The incidence of G3460A mutation was 1.4% in this cohort of Chinese subjects with LHON. Twenty-seven (20 males/7 females) of 109 matrilineal relatives among 10 Chinese pedigrees carrying this mutation exhibited a wide range of severity and age-at-onset in visual impairment. Penetrances of optic neuropathy ranged from 7.1% to 50%, with the average of 24.5%. The age-at-onset of 27 affected matrilineal relatives varied from 10 to 40 years, with the average of 22 years. Molecular analysis identified the homoplasmic G3460A mutation and distinct sets of variants belonging to eight haplogroups. Haplogroup M with G3460A mutation was of higher frequency than those in controls. The penetrances of visual loss in families carrying mitochondrial DNA haplogroups A, B and M were higher than those in other families. Furthermore, haplogroup-specific variants tRNASer(AGY) A12223G, tRNAThr G15927A and tRNAGlu A14693G may enhance the penetrance of visual loss in these families. The G3460A mutation occurred through recurrent origins and founder events in Chinese population. Mitochondrial modifiers may modulate the penetrance and expressivity of optic neuropathy among Chinese pedigrees carrying the G3460A mutation. Thus, our findings may provide new insights into the understanding of pathophysiology and valuable information on the management of LHON. [ABSTRACT FROM AUTHOR]

The availability of uridine 5′-diphosphate N-acetylglucosamine (UDP-GlcNAc) is a prerequisite for the GlcNAc-transferase-catalyzed glycosylation reaction. UDP-GlcNAc has already been synthesized using an N-acetylhexosamine 1-kinase (NahK) and a GlcNAc-1-P uridyltransferase (truncated GlmU) and here, a fusion enzyme was constructed with truncated GlmU and NahK. After determination of the optimum catalytic condition (pH 8.0 at 40 °C), the fusion enzyme was used to synthesize UDP-GlcNAc in a single step with a yield of 88 % from GlcNAc, ATP and UTP. Furthermore, a simplified purification method was demonstrated using separation by gel filtration after by-product digestion with alkaline phosphatase. An overall yield of 77 % and a purity of over 90 % were achieved. [ABSTRACT FROM AUTHOR]

Agrobacterium tumefaciens-mediated transformation of tobacco leaves ( Nicotiana tabacum) is used to study gene expression in a heterologous genetic background. Here, the Cre- loxP recombination system was used to detect T-DNA transfer by two A. tumefaciens cells harboring different binary vectors. Cre, under the control of the CaMV 35S promoter, was cloned into one vector, and a loxP cassette into another vector. A mixture of A. tumefaciens, in which each cell contained either a Cre- or loxP-vector, was co-infiltrated into tobacco leaves. After two days, excision of loxP-flanked DNA was detected by PCR and used as an estimate for co-transformation events. Strongest excision (> 50%) was observed when the loxP cassette was cloned into vector pPZP112 and Cre into pISV2678. This fast and easy technique can be used to assess the co-transformation efficiency of tobacco cells in future studies. [ABSTRACT FROM AUTHOR]

Wireless sensor networks are often deployed in hostile and unattended environments. The nodes will be failure by fault, intrusion, and the battery exhaustion. Node-failure tolerance is an acceptable method to improve the networks' lifetime. Then two key problems for topology control are presented: first, how to get a node-failure topology when there is intrusion from the nodes of hostile enemies? second, how to sustain this node-failure topology with all deployed nodes being exhausted ultimately? We propose a novel approach for topology control and prove that it is node-failure tolerant. The approach contains three phases: topology discovery, topology update, and topology regeneration. A tricolor-based method is proposed to build architecture with high tolerance ability and some security protocols are employed to preclude the hostile nodes in discovery phase. In update and regeneration phases, the newly deployed nodes are regarded as renewable resource to fill in the consumed energy, enhance the debased node-failure tolerance ability, and prolong network lifetime, and a security protocol with forward and backward secrecy is devised to adapt the topology changed by node failure and node joining. Some attributes of the presented method are shown by simulations, and differences are given by comparison with related work. [ABSTRACT FROM AUTHOR]

Accumulation of plasma advanced oxidation protein products (AOPPs) promotes progression of proteinuria and glomerulosclerosis. To investigate the molecular basis of AOPPs-induced proteinuria, normal Sprague-Dawley rats were treated with AOPPs-modified rat serum albumin. The expression of glomerular podocyte slit diaphragm (PSD)-associated proteins, nephrin and podocin, was significantly decreased coincident with the onset of albuminuria in rats treated with AOPPs. Chronic inhibition of NADPH oxidase by apocynin prevented down-regulation of nephrin and podocin and decreased albuminuria in AOPPs-challenged rats. This suggested that accumulation of AOPPs promotes proteinuria, possibly via down-regulating the expression of PSD-associated proteins. [ABSTRACT FROM AUTHOR]

Recent studies have indicated that the four most common mutations account for 78% of mutant alleles in the glucose-6-phosphatase (G6Pase) gene. A significant fraction of mutant alleles remain unidentified. Thus, informative polymorphic markers are necessary for linkage analysis in carrier testing and prenatal diagnosis in families where mutations can not be identified. The common mutations appear to be ethnic-specific, suggesting that the individual mutations may have a common founder. With the recent discovery of the nucleotide 1176 polymorphism, we have studied whether these mutations are in linkage disequilibrium with the polymorphism. The results of polymerase chain reaction/allele-specific oligonucleotide analysis show that nucleotide 1176 C is in linkage disequilibrium with mutations R83 C and R83H, and with the splicing mutation 727G→T. The 1176 T polymorphism is in linkage disequilibrium with 459insTA. A GT repeat polymorphism has also been found. However, its heterozygosity is low. The 1176 nucleotide polymorphic marker can be used in carrier and prenatal diagnosis of GSD1a families that have unidentified mutations and are informative for this marker. [ABSTRACT FROM AUTHOR]