Circ_BLNK is a Unique Molecular Marker in Non-small Cell Lung Cancer.

Non-small cell lung cancer (NSCLC) patients are characterized by distant metastasis and poor prognosis. Growing evidence has implied that circular RNAs (circRNAs) are involved in multiple tumor progression, including NSCLC. The objective of the present study was to functionally dissect the role and mechanism of circ_BLNK in NSCLC development and progression. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression of circ_BLNK, miR-942-5p, and forkhead box protein O1 (FOXO1) in NSCLC tissues and cells. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay and colony formation assay detected cell proliferation; the protein expression levels were tested by western blot assay; cell apoptosis was measured by flow cytometry, and transwell assay detected cell migration and invasion. The molecular targeting relationship was determined by dual-luciferase reporter assay. The effect of circ_BLNK overexpression on tumor growth was detected by in vivo experiments and immunohistochemistry. Circ_BLNK was dramatically decreased in NSCLC, and overexpression of circ_BLNK inhibited proliferation, migration, and invasion of NSCLC cells and promoted cell apoptosis. Circ_BLNK level was negatively correlated with miR-942-5p expression and positively correlated with FOXO1 expression. Moreover, circ_BLNK acted as a sponge for miR-942-5p, which targeted FOXO1. Rescue assays presented that miR-942-5p reversed the anticancer action of circ_BLNK in NSCLC. Besides that, miR-942-5p inhibition suppressed the oncogenic behaviors, which were attenuated by FOXO1 knockdown. Animal experiments exhibited that circ_BLNK upregulation repressed tumor growth in vivo. Our study demonstrated a novel regulatory mechanism that circ_BLNK/miR-942-5p/FOXO1 axis adjusted non-small cell lung cancer development.

Effects of Bulk LPSO Phases on Mechanical Properties and Fracture Behavior of As-Extruded Mg-Gd-Y-Zn-Zr Alloys.

Despite the consensus on the constructive effect of LPSO (long-period stacking-ordered) phases, the true effect of bulk LPSO phases on strengthening and toughening in deformed magnesium alloys is still controversial. This article, which introduces the alloys Mg-8Gd-4Y-0.6Zn-0.5Zr, without bulk LPSO phases, and Mg-8Gd-4Y-1.6Zn-0.5Zr, containing bulk LPSO phases, details a systematically comparative analysis conducted to clarify the true contribution of bulk LPSO phases to the properties of as-extruded alloys. The results indicate that bulk LPSO phases significantly improve strength by refining grain sizes remarkably. But contrary to expectations, bulk LPSO phases themselves only provide a small strengthening effect and deteriorate plasticity, ascribed to the poor compatible plastic deformation of bulk LPSO phases. More importantly, this work may offer new insights into the strengthening and toughening of LPSO phases for further research and engineering applications of this series of alloys. Additionally, an example of a design strategy for Mg-Gd-Y-Zn alloys with superior strength and excellent plasticity is proposed at the end of this article.

Nitrite accumulation in activated sludge through cyclic anaerobic exposure with acetate.

Achieving nitrite accumulation still remains challenging for efficient short-cut biological nitrogen removal in municipal wastewater treatment. To tackle the problem of insufficient carbon in incoming wastewater for biological nutrient removal, a return activated sludge (RAS) fermentation method has been proposed and demonstrated to enable producing supplemental volatile fatty acids (VFAs) and enhance biological phosphorus removal via sludge cycling between mainstream and a sidestream anaerobic reactor. However, the impacts of long anaerobic exposure with acetate on nitrifying bacteria, known as the aerobic chemoautotrophic microorganisms, remains unexplored. In this study, the activated sludge underwent a cyclic anaerobic treatment with the addition of acetate (Ac), the effects on nitrification rate, abundance and microdiversity of nitrifying communities were comprehensively assessed. Firstly, batch activity tests proved the direct addition of high acetate (above 1000 mg/L) could cause inhibition on the nitrification rate, moreover, the inhibitory effect was stronger on nitrite-oxidizing bacteria (NOB) activity than that of ammonia-oxidizing bacteria (AOB). Then, a sequencing batch reactor (SBR) was applied to test the nitrogen conversion performance for low-strength ammonium wastewater. Nitrite accumulation could be achieved via the cyclic anaerobic exposure with 1000-5000 mg Ac/L. The maximum effluent concentration of nitrite was 40.8 ± 3.5 mg N/L with nitrite accumulation ratio (NAR) of 67.6 ± 3.5%. The decrease in NOB activity (72.7%) was greater than AOB of 42.4%, promoting nitrite accumulation via nitritation process. Furthermore, the cyclic anaerobic exposure with acetate can largely reshape the nitrifying communities. As the dominant AOB and NOB, the abundance of Nitrosomonas and Nitrospira were both decreased with species-level microdiversity in the nitrifying communities. However, the heterotrophic microorganism, Thauera, were found to be highly enriched (from 0 to 17.3%), which may act as the potential nitrite producer as proved by the increased nitrate reduction gene abundance. This study can provide new insights into achieving mainstream nitrite accumulation by involving sidestream RAS fermentation towards efficient wastewater treatment management.

Comparison of Thermal Deformation Behavior and Characteristics of Mg-Gd-Y-Zn Alloys with and without Bulk LPSO Phase.

Alloys Mg-8Gd-4Y-0.6Zn-0.5Zr (referred to as 0.6Zn) without the bulk long-period stacking ordered (LPSO) phase and Mg-8Gd-4Y-1.1Zn-0.5Zr (referred to as 1.1Zn) containing the bulk LPSO phase were prepared and a series of hot compression tests were conducted to examine and evaluate the influence of the bulk LPSO phase on the thermal deformation behavior and characteristics of the Mg-Gd-Y-Zn-Zr alloy. The bulk LPSO phase affects the dynamic recrystallization behavior, resulting in differences in flow stress between two alloys under different conditions. Specifically, in the temperature range of 380~460 °C, compression at lower strain rates is beneficial for the LPSO phase to promote dynamic recrystallization, while compression at a high strain rate inhibits the dynamic recrystallization due to the severe deformation of the bulk LPSO phase to release the stress concentration instead. The increase in temperature helps the LPSO promote dynamic recrystallization. As a result, the LPSO phase promotes dynamic recrystallization at all experimental strain rates at 500 °C. Furthermore, the thermal processing maps of the 0.6Zn and 1.1Zn alloys are established, and their optimal processing windows are located at 500 °C/0.001~0.01 s-1 and 500 °C/0.01 s-1, respectively. In addition, the instability zones for the 1.1Zn alloy are much larger than that for the 0.6Zn alloy, which corresponds to the microcracks generated at the interfaces between α-Mg and bulk LPSO phases.

Enhanced recovery after microdiscectomy: reductions in opioid use, length of stay and cost.

BACKGROUND: Enhanced recovery after surgery (ERAS) protocols are widely used worldwide. Recently, studies of the ERAS program in spinal surgery subspecialties have been reported. The aim of this study was to evaluate the impacts of ERAS in minimally invasive microdiscectomy (MD) surgery. METHODS: This was a retrospective cohort study of patients undergoing MD at a single center. From March 2018 to March 2021, 286 patients were in the ERAS group. A total of 140 patients from March 2017 to February 2018 were in the conventional group. The outcomes included length of stay (LOS), the postoperative numeric rating scale (NRS), complications, 30-day readmission rate, 30-day reoperation rate and cost. Moreover, perioperative factors were also evaluated. RESULTS: Compared with the conventional group, the LOS and cost were reduced in the ERAS group. There were no significant differences in the NRS, complication rate, 30-day readmission or reoperation rates between the groups. Furthermore, postoperative drainage volume, and postoperative opioid use were lower in the ERAS group. CONCLUSIONS: The ERAS protocol for MD surgery reduces LOS, cost and opioid use and accelerates patient recovery.

Textbook outcome in gallbladder carcinoma after curative-intent resection: a 10-year retrospective single-center study.

BACKGROUND: Textbook outcome (TO) can guide decision-making among patients and clinicians during preoperative patient selection and postoperative quality improvement. We explored the factors associated with achieving a TO for gallbladder carcinoma (GBC) after curative-intent resection and analyzed the effect of adjuvant chemotherapy (ACT) on TO and non-TO patients. METHODS: A total of 540 patients who underwent curative-intent resection for GBC at the Department of Hepatobiliary Surgery of the First Affiliated Hospital of Xi'an Jiaotong University from January 2011 to December 2020 were retrospectively analyzed. Multivariable logistic regression was used to investigate the factors associated with TO. RESULTS: Among 540 patients with GBC who underwent curative-intent resection, 223 patients (41.3%) achieved a TO. The incidence of TO ranged from 19.0% to 51.0% across the study period, with a slightly increasing trend over the study period. The multivariate analysis showed that non-TO was an independent risk factor for prognosis among GBC patients after resection ( P = 0.003). Age ≤60 years ( P = 0.016), total bilirubin (TBIL) level ≤34.1 µmol/L ( P <0.001), well-differentiated tumor ( P = 0.008), no liver involvement ( P <0.001), and T1-2 stage disease ( P = 0.006) were independently associated with achieving a TO for GBC after resection. Before and after propensity score matching (PSM), the overall survival outcomes of non-TO GBC patients who received ACT and those who did not were statistically significant; ACT improved the prognosis of patients in the non-TO group ( P <0.05). CONCLUSION: Achieving a TO is associated with a better long-term prognosis among GBC patients after curative-intent resection, and ACT can improve the prognosis of those with non-TO.

Redirecting carbon to recover VFA to facilitate biological short-cut nitrogen removal in wastewater treatment: A critical review.

Wastewater treatment plants (WWTPs) are facing a great challenge to transition from energy-intensive to carbon-neutral and energy-efficient systems. Biological nutrient removal (BNR) can be severely impacted by carbon limitation, particularly for wastewater with a low carbon-to-nitrogen (C/N) ratio, which can significantly increase the operational costs. Waste activated sludge (WAS) is a valuable byproduct of WWTPs, as it contains high levels of organic matter that can be utilized to improve BNR management by recovering and reusing the fermentative volatile fatty acids (VFAs). This review provides a comprehensive examination of the recovery and reuse of VFAs in wastewater management, with a particular focus on advancing the preferable biological short-cut nitrogen removal process for carbon-insufficient municipal wastewaters. First, the method of carbon redirection for recovering VFAs was reviewed. Carbon could be captured through the two-stage A/B process or via sludge fermentation with different sludge pretreatment and process control strategies to accelerate sludge hydrolysis and inhibit methanogens to enhance VFA production. Second, VFAs can support the metabolism of autotrophic N-cycling microorganisms involved in wastewater treatment, such as AOB, NOB, anammox, and comammox bacteria. However, VFAs can also cause inhibition at high concentrations, leading to the partition of AOB and NOB; and can promote partial denitrification as an efficient carbon source for heterotrophic denitrifiers. Third, the lab- and pilot-scale engineering practices with different configurations (i.e., A2O, SBR, UASB) were summarized that have shown the feasibility of utilizing the fermentate to achieve superior nitrogen removal performance without the need for external carbon addition. Lastly, the future perspectives on leveraging the relationships between mainstream and sidestream, nitrogen and phosphorus, autotrophs and heterotrophs were given for sustainable and efficient BNR management.

Noninvasive fluid bubble detection based on capacitive micromachined ultrasonic transducers.

Ultrasonic fluid bubble detection is important in industrial controls, aerospace systems and clinical medicine because it can prevent fatal mechanical failures and threats to life. However, current ultrasonic technologies for bubble detection are based on conventional bulk PZT-based transducers, which suffer from large size, high power consumption and poor integration with ICs and thus are unable to implement real-time and long-term monitoring in tight physical spaces, such as in extracorporeal membrane oxygenation (ECMO) systems and dialysis machines or hydraulic systems in aircraft. This work highlights the prospect of capacitive micromachined ultrasonic transducers (CMUTs) in the aforementioned application situations based on the mechanism of received voltage variation caused by bubble-induced acoustic energy attenuation. The corresponding theories are established and well validated using finite element simulations. The fluid bubbles inside a pipe with a diameter as small as 8 mm are successfully measured using our fabricated CMUT chips with a resonant frequency of 1.1 MHz. The received voltage variation increases significantly with increasing bubble radii in the range of 0.5-2.5 mm. Further studies show that other factors, such as bubble positions, flow velocities, fluid medium types, pipe thicknesses and diameters, have negligible effects on fluid bubble measurement, demonstrating the feasibility and robustness of the CMUT-based ultrasonic bubble detection technique.

Predicting Rural Women's Breast Cancer Screening Intention in China: A PLS-SEM Approach Based on the Theory of Planned Behavior.

Background: It was reported that the incidence of breast cancer (BC) was the highest among cancers worldwide. The breast cancer screening (BCS) program is regarded as an effective preventive measure. However, rural women's willingness to participate in the BCS program is relatively low. To provide measures to prevent BC, it is necessary for the government to identify the influencing factors of rural women's BCS intention. Methods: A cross-sectional study was conducted among 3,011 rural women by a convenience sampling method through face-to-face interviews on a self-designed questionnaire based on the theory of planned behavior (TPB). The partial least square structural equation model (PLS-SEM) was conducted to determine the predictors of BCS intention, and a multi-group analysis (MGA) of age was performed to identify if there were differences in all hypotheses between different age groups. Results: There were still rural women who have not been screened for BC in five years (41.7%). The research model of rural women's intention to accept this prevention against BC was rational. All of the hypotheses are supported. Especially, subjective norm (SN) (ß = 0.345, p < 0.001) is found to be the strongest predictor followed by the perceived behavioral control 1 (PBC 1) (personal factors, including distance, transportation, busyness, etc.) (ß = 0.165, p < 0.001), attitude (ß = 0.152, p < 0.001), past behavior (PB) (ß = 0.150, p < 0.001), knowledge (ß = 0.121, p < 0.001), and perceived behavioral control 2 (PBC 2) (pain and cultural-social factors including embarrassment from a physician, etc.) (ß = 0.042, p < 0.05). The advocacy and education (A&E), medical level and service attitude (ML&SA) of township health centers and village clinics can affect behavior intention (BI) via attitude, SN, and PBC. The results of MGA of age indicate that there are significant differences among rural women of different ages regarding the relationship between A&E and PBC 2 (p < 0.01) and the effect of PB on BI (p < 0.001). Conclusion: The TPB with the addition of PB, knowledge, ML&SA, and A&E can provide the theoretical basis for the policy intervention that aims to enhance the rural women's BCS willingness. MGA of age is conducive to promoting the implementation of the BCS policy. The findings are of great significance to improve rural women's health levels.

Robust Risley prism control based on disturbance observer for system line-of-sight stabilization.

In this paper, a robust control based on disturbance observer is proposed to improve the tracking accuracy of the Risley prism system (RPS). Applying the flexible thin-wall ring mechanism in the RPS causes a series of tracking and pointing challenges. Disturbances such as friction, shaft deformation, and model perturbation significantly deteriorate the tracking and pointing accuracy of the RPS. Two different observer-based control methods are proposed to guarantee the tracking precision of the RPS. Moreover, the disturbance observation and compensation (DOC) performance of the proposed methods is analyzed and compared. Finally, simulation and experiment results indicate that the proposed control methods, especially the DOC-expanded state observer control mode, obtain the best performance for disturbance rejection in the RPS.

An enhanced recovery after surgery pathway: LOS reduction, rapid discharge and minimal complications after anterior cervical spine surgery.

BACKGROUND: Enhance recovery after surgery (ERAS) is a new and promising paradigm for spine surgery. The purpose of this study is to investigate the effectiveness and safety of a multimodal and evidence-based ERAS pathway to the patients undergoing anterior cervical discectomy and fusion (ACDF). METHODS: The patients treated with the ACDF-ERAS pathway were compared with a historical cohort of patients who underwent ACDF before ERAS pathway implementation. Primary outcome was length of stay (LOS). Secondary outcomes included cost, MacNab grading, complication rates and 90-day readmission and reoperation. And perioperative factors and postoperative complications were reviewed. RESULTS: The ERAS protocol was composed of 21 components. More patients undergoing multi-level surgery (n ≥ 3) were included in the ERAS group. The ERAS group showed a shorter LOS and a lower cost than the conventional group. The postoperative satisfaction of patients in ERAS group was better than that in conventional group. In addition, the rate of overall complications was significantly higher in the conventional group than that in the ERAS group. There were no significant differences in operative time, postoperative drainage, or 90-day readmission and reoperation. CONCLUSIONS: The ACDF-tailored ERAS pathway can reduce LOS, cost and postoperative complications, and improve patient satisfaction without increasing 90-day readmission and reoperation.

Placebo response varies between different types of sham acupuncture: A randomized double-blind trial in neck pain patients.

BACKGROUND: In prospective experimental studies of neck pain patients, it is difficult to determine whether responses to sham acupuncture differ from responses to real acupuncture due to the heterogeneous methodologies in control/sham interventions. Here we aim to compare the specific and nonspecific effects of electroacupuncture with four types of sham acupuncture. METHODS: In this double-blind, sham-controlled study, we randomly assigned 175 patients with neck pain to receive 10 sessions of electroacupuncture, shallow puncture, nonacupoint deep puncture, nonacupoint shallow puncture, or nonpenetration acupuncture. We used the Northwick Park Neck Pain Questionnaire (NPQ) as our primary outcome, and Short-form McGill Pain Questionnaire, visual analog scale (VAS), and Pain Threshold as secondary outcomes to measure the changes from baseline to a 3-month follow up. RESULTS: All groups, except nonacupoint shallow puncture, had significant improvement in all outcome measurements. Electroacupuncture only showed superior improvements than the shallow puncture, nonacupoint shallow puncture, and nonpenetration groups when compared using the NPQ and VAS scale (*p < 0.001). Interestingly, the nonacupoint shallow puncture produced even less placebo response than nonpenetration acupuncture. CONCLUSION: Our study demonstrates the high variability of placebo response among different types of sham controls depending on the depth of needle insertion and the puncture location. An important implication of our results is nonacupoint deep puncture produced similar analgesic effects as electroacupuncture. Our study may shed a new light on the predominant underlying mechanisms among different types of sham acupuncture controls, which can help with interpreting the effect of acupuncture in other studies. TRIAL REGISTRATION: Chinese clinical trial registry (ChiCTR-IOR-15006886). SIGNIFICANCE: This study compared the observed specific and nonspecific analgesia effect in four different types of sham acupuncture stimulation with neck pain patients, assessed by four outcomes. Although all of the sham controls produced significant reduction in neck pain, electroacupuncture had superior significant improvement. Importantly, placebo responses differed significantly between the sham controls and responses were inconsistent according to different outcome assessments. This study emphasizes the importance of taking into consideration which sham control and method of outcome measurement were used in a pain research study when evaluating its results.

In silico study to predict potential precursors of human dipeptidyl peptidase-IV inhibitors from hazelnut.

Chinese hazelnut was chosen to become a probable precursor of biological active peptides via computer simulations in this article. There were a large number of bioactive peptides in Chinese hazelnut sequences according to analytical results from the BIOPEP database. The most prominent of these was the inhibitory peptide for dipeptidyl peptidase-IV (DPP-IV; EC 3.4.14.5), which can be used to treat type 2 diabetes, so the theoretical method to obtain DPP-IV inhibitory peptides by hydrolysis with a single or combination of enzymes was studied. Cytotoxicity analysis performed by ToxinPred showed that all of the DPP-IV inhibitory peptides generated from protein hydrolysis were not cytotoxic. Structural interaction fingerprint analysis revealed that Asp663 and Phe357 may be important residues for ligand binding. In order to further understand the inhibitory mechanism of peptide, VR with lowest half maximum inhibitory concentration (IC50) and IPI (inhibitors have been reported) were selected as ligand of DPP-IV to perform steered molecular dynamics simulations and PMF calculations. The results showed that P1 is the preferred (un)binding tunnel for the inhibitors obtained. Our findings help in the development of new DPP-IV inhibitors which were derived from common food.Communicated by Ramaswamy H. Sarma.

Distinct response patterns of bacterial communities in Ag- and ZnO-rGO nanocomposite-amended silt loam soils.

The widespread application of metal-based nanoparticle (MNPs)/reduced graphene oxide (rGO) composites inevitably leads to their release into soils. However, we lack a detailed understanding of the bacterial community response to MNPs-rGO exposure in farmland soils. Here, we conducted a soil microcosm experiment to analyze the potential impact of MNPs-rGO on bacterial communities in two field soils via high-throughput sequencing. The change in alpha diversity of bacterial communities was more susceptible to Ag-rGO and ZnO-rGO treatments than CuO-rGO. In both soils, MNPs-rGO significantly changed the bacterial community structure even at a low dose (1 mg kg-1). The bacterial community structure was most strongly affected by Ag-rGO at 30 days, but the greatest changes occurred in ZnO-rGO at 60 days. The differences in soil properties could shape bacterial communities to MNPs-rGO exposure. Distance-based redundancy analysis and functional annotation of prokaryotic taxa showed that some bacterial species associated with nitrogen cycling were greatly influenced by Ag-rGO and ZnO-rGO exposure. In sum, Ag-rGO and ZnO-rGO may potentially affect bacterial communities and nitrogen turnover under long-term realistic field exposure. These findings present a perspective on the response of bacterial communities to MNPs-rGO and provide a fundamental basis for estimating the ecological behavior of MNPs-rGO.

Synergy of Nitric Oxide and 1-Methylcyclopropene Treatment in Prolong Ripening and Senescence of Peach Fruit.

Peach is a putrescible fruit thus drastically restricting its postharvest storage life. In recent years, the application of 1-methylcyclopropene (1-MCP) and nitric oxide (NO) in postharvest fruit quality control has received considerable attention and investigative efforts due to the advantages of using relatively low concentrations and short-time treatment duration. In the present study, the effects of various 1-MCP and NO treatments on peach fruit (Prunus persica L. cv. Xiahui-8) stored at 25 °C were evaluated and compared. Results indicated that the combination treatment with both chemical agents (MN) was most effective in postponing peach ripening and preserving fruit quality, followed by 1-MCP and NO treatment alone. We also demonstrated that NO could delay fruit senescence mainly by stimulating antioxidant enzymes, while 1-MCP overly outperformed NO in the treatment of 'Xiahui-8' peach in slowing down respiration rate, inhibiting ethylene production, maintaining high firmness and reducing ROS content. NO treatment showed a greater influence on phenolic compounds than 1-MCP especially anthocyanins, flavanones and flavones according to LC/MS analysis. The phenolic change in MN group were highly associated to NO treatment. Through this study we provide informative physiological, biochemical and molecular evidence for the beneficial effects of the combined 1-MCP and NO treatment on peach fruit based on a functional synergy between these two chemical agents.

Selenomethionine-Dominated Selenium-Enriched Peanut Protein Ameliorates Alcohol-Induced Liver Disease in Mice by Suppressing Oxidative Stress.

Numerous natural compounds are considered as potential therapeutic agents against alcohol-induced liver disease (ALD). Research shows that selenium (Se) has a variety of bioactivities, including liver protecting ability. The present study based on in vitro cell culture models and in vivo mouse models was aimed at examining the contribution of selenomethionine (SeMet)-dominated Se-enriched peanut protein (SePP) to liver protection. SeMet and especially SePP reversed cell viability and cell death, inhibited ethanol induced CYP2E1 activation, decreased reactive oxygen species level, and restored GSH level. Hence, SeMet-dominated SePP alleviates alcohol-induced AML-12 cytotoxicity by suppressing oxidative stress. The p38-dependent mechanism was found to be responsible for SePP-induced Nrf-2 activation. Furthermore, supplementation with SePP and SeMet regulated lipid metabolism and reduced oxidative stress, minimizing liver damage in mice. Selenomethionine-dominated SePP possesses potential therapeutic properties and can be used to treat ALD through the suppression of oxidative stress.

Precipitation Behavior of Mg-7Gd-3Y-2Zn-0.5Zr Alloy during Isothermal Aging.

Precipitate phases in an Mg-7Gd-3Y-2Zn-0.5Zr alloy aged isothermally at 240 °C were examined using high-resolution transmission electron microscopy (TEM) and high-angle annular dark-field scanning TEM. The two types of precipitation sequence that involve Mg-Gd and long period stacking ordered (LPSO) type were found. The LPSO type sequence consisted of the precipitation of γ'', γ', 14H-LPSO/18R-LPSO. The Mg-Gd type precipitation sequence involved the formation of ß'(b.c.o.) and ß1(f.c.c.). The sequence, morphology, distribution, and crystal structure of these precipitates formed during isothermal aging were investigated. The results indicated that the priority precipitation of Mg-Gd and LPSO type sequences during aging can be affected by Nd, which has a higher diffusion coefficient than Gd and Y. The dislocation structures and strengthening mechanism were also discussed.

Microstructure, Hot Deformation Behavior, and Recrystallization Behavior of Zn-1Fe-1Mg Alloy under Isothermal Compression.

Nowadays, wrought zinc-based biodegradable alloys are favored by researchers, due to their excellent mechanical properties and suitable degradation rates. However, there are few research studies on their thermal deformation behavior at present. This study took Zn-1Fe-1Mg and explored its microstructural change, deformation, recrystallization behavior and processing map by means of the thermal simulation experiment, at temperatures ranging from 235 °C to 340 °C and strain rates ranging from 10-2 s-1 to 10 s-1. The constitutive model was constructed using the Arrhenius formula. The results indicated that the evolution of microstructure included the dynamic recrystallization (DRX) of the Zn matrix, the spheroidization of the Mg2Zn11 phase, and breaking of the FeZn13 phase. The subgrains observed within the deformed grain resulted mainly from continuous dynamic recrystallization (CDRX). The precipitated FeZn13 grains overlapped with the precipitated MgZn2 from the matrix, thus forming a spine-like structure at the phase interface. After compression, the alloy possessed a strong basal texture. Affected by the change of Zn twins, textural strength decreased at first and then increased as the deformation temperature rose. There was only a small unstable region in the processing map, indicating that the alloy exhibited good machinability.

Microstructure and Hot Deformation Behavior of the Mg-8 wt.% Sn-1.5 wt.% Al Alloy.

Mg-Sn-Al alloy is a new type of heat-resistant magnesium alloy with great potential and the hot deformation process of this alloy is of great significance for its application. The microstructure, hot deformation behavior, textural evolution, and processing map of a Mg-8 wt.% Sn-1.5 wt.% Al alloy were studied. A Gleeble 1500 D thermo-mechanical simulator was used. The temperature of deformation was 653 to 773 K, the strain rate was 0.001-1 s-1, and the maximum deformation degree was 60%. The obtained results show that the rheological stress of the alloy decreases with an increase in deformation temperature and increases with an increase in the strain rate. The alloy is completely dynamically recrystallized at 653 K, and the entire structure is formed of homogeneous crystals/grains, with small secondary phase particles distributed at the crystal boundary. The mean apparent activation energy of hot compression deformation is 153.5 kJ/mol. The Mg-8 wt.% Sn-1.5 wt.% Al alloy exhibits excellent plastic deformation properties, an expansive thermal processing interval, and a narrow instability zone under the test temperature and deformation rate. The optimal process parameters of the alloy comprise deformation temperatures between 603 and 633 K and strain rates of 0.03 to 0.005 s-1.

Conformational Changes of Glutamine 5'-Phosphoribosylpyrophosphate Amidotransferase for Two Substrates Analogue Binding: Insight from Conventional Molecular Dynamics and Accelerated Molecular Dynamics Simulations.

Glutamine 5'-phosphoribosylpyrophosphate amidotransferase (GPATase) catalyzes the synthesis of phosphoribosylamine, pyrophosphate, and glutamate from phosphoribosylpyrophosphate, as well as glutamine at two sites (i.e., glutaminase and phosphoribosylpyrophosphate sites), through a 20 Å NH3 channel. In this study, conventional molecular dynamics (cMD) simulations and enhanced sampling accelerated molecular dynamics (aMD) simulations were integrated to characterize the mechanism for coordination catalysis at two separate active sites in the enzyme. Results of cMD simulations illustrated the mechanism by which two substrate analogues, namely, DON and cPRPP, affect the structural stability of GPATase from the perspective of dynamic behavior. aMD simulations obtained several key findings. First, a comparison of protein conformational changes in the complexes of GPATase-DON and GPATase-DON-cPRPP showed that binding cPRPP to the PRTase flexible loop (K326 to L350) substantially effected the formation of the R73-DON salt bridge. Moreover, only the PRTase flexible loop in the GPATase-DON-cPRPP complex could remain closed and had sufficient space for cPRPP binding, indicating that binding of DON to the glutamine loop had an impact on the PRTase flexible loop. Finally, both DON and cPRPP tightly bonded to the two domains, thereby inducing the glutamine loop and the PRTase flexible loop to move close to each other. This movement facilitated the transfer of NH3 via the NH3 channel. These theoretical results are useful to the ongoing research on efficient inhibitors related to GPATase.