Enhanced Mechanical Properties of Ti/Mg Laminated Composites Using a Differential Temperature Rolling Process under a Protective Atmosphere.

Addressing the issue of low bonding strength in Ti/Mg laminated composites due to interfacial oxidation, this study employs a differential temperature rolling method using longitudinal induction heating to fabricate Ti/Mg composite plates. The entire process is conducted under an argon gas protective atmosphere, which prevents interfacial oxidation while achieving uniform deformation. The effects of reduction on the mechanical properties and microstructure of the composite plates are thoroughly investigated. Results indicate that as the reduction increases, the bonding strength gradually increases, mainly attributed to the increased mechanical interlocking area and a broader element diffusion layer. This corresponds to a transition from a brittle to a ductile fracture at the microscopic tensile-shear fracture surface. When the reduction reaches 47.5%, the Ti/Mg interfacial strength reaches 63 MPa, which is approximately a 20% improvement compared to the bonded strength with previous oxidation at the interface. Notably, at a low reduction of 17.5%, the bonding strength is significantly enhanced by about one time. Additionally, it was found that a strong bonded interface at a high reduction is beneficial in hindering the propagation of interfacial cracks during tensile testing, enhancing the ability of the Ti/Mg composite plates to resist interfacial delamination.

Visible light-promoted anti-biofouling performance of cellulose acetate membrane for reverse osmosis desalination.

Sea water desalination is regarded as a major solution that could alleviate the water scarcity problem. Reverse osmosis (RO) is typically employed to recover fresh water from sea and brackish water via economical means. RO membrane fouling remains a critical issue restricting their widespread application. In this work, a tertiary thiophenal quaternary ammonium salt-based antibacterial agent was covalently reacted with cellulose acetate (CA) to obtain contact-active antibacterial quaternized CA-RO membrane (QCA-RO). The membrane was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, water contact angle testing, and X-ray diffraction spectroscopy. The obtained QCA-RO membrane displayed good antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus and had bactericidal rates of 99 % in the presence of visible light. Results showed that embedding the quaternary ammonium salt did not cause any significant changes to the morphology, mechanical performance, and thermal stability of the RO membrane. The method described in this work not only produces QCA-RO membranes with good anti-biofilm performance but also presents great potential in seawater desalination.

The protective effects of EGCG was associated with HO-1 active and microglia pyroptosis inhibition in experimental intracerebral hemorrhage.

Intracerebral hemorrhage (ICH), which has high mortality and disability rate is associated with microglial pyroptosis and neuroinflammation, and the effective treatment methods are limited Epigallocatechin-3-gallate (EGCG) has been found to play a cytoprotective role by regulating the anti-inflammatory response to pyroptosis in other systemic diseases. However, the role of EGCG in microglial pyroptosis and neuroinflammation after ICH remains unclear. In this study, we investigated the effects of EGCG pretreatment on neuroinflammation-mediated neuronal pyroptosis and the underlying neuroprotective mechanisms in experimental ICH. EGCG pretreatment was found to remarkably improved neurobehavioral performance, and decreased the hematoma volume and cerebral edema in mice. We found that EGCG pretreatment attenuated the release of hemin-induced inflammatory cytokines (IL-1ß, IL-18, and TNF-α). EGCG significantly upregulated the expression of heme oxygenase-1 (HO-1), and downregulated the levels of pyroptotic molecules and inflammatory cytokines including Caspase-1, GSDMD, NLRP3, mature IL-1ß, and IL-18. EGCG pretreatment also decreased the number of Caspase-1-positive microglia and GSDMD along with NLRP3-positive microglia after ICH. Conversely, an HO-1-specific inhibitor (ZnPP), significantly inhibited the anti-pyroptosis and anti-neuroinflammation effects of EGCG. Therefore, EGCG pretreatment alleviated microglial pyroptosis and neuroinflammation, at least in part through the Caspase-1/GSDMD/NLRP3 pathway by upregulating HO-1 expression after ICH. In addition, EGCG pretreatment promoted the polarization of microglia from the M1 phenotype to M2 phenotype after ICH. The results suggest that EGCG is a potential agent to attenuate neuroinflammation via its anti-pyroptosis effect after ICH.

Simultaneous adsorption of As(III) and Pb(II) by the iron-sulfur codoped biochar composite: Competitive and synergistic effects.

Simultaneous elimination of As(III) and Pb(II) from wastewater is still a great challenge. In this work, an iron-sulfur codoped biochar (Fe/S-BC) was successfully fabricated in a simplified way and was applied to the remediate the co-pollution of As(III) and Pb(II). The positive enthalpy indicated that the adsorption in As-Pb co-pollution was an endothermic reaction. The mechanism of As(III) removal could be illustrated by surface complexation, oxidation and precipitation. In addition to precipitation and complexation, the elimination mechanism of Pb(II) also contained ion exchange and electrostatic interactions. Competitive and synergistic effects existed simultaneously in the co-contamination system. The suppression of As(III) was ascribed to competitive complexation of the two metals on Fe/S-BC, while the synergy of Pb(II) was attributed to the formation of the PbFe2(AsO4)2(OH)2. Batch experiments revealed that Fe/S-BC had outstanding ability to remove As(III) and Pb(II), regardless of pH dependency and interference by various coexisting ions. The maximum adsorption capacities of the Fe/S-BC for As(III) and Pb(II) were 91.2 mg/g and 631.7 mg/g, respectively. Fe/S-BC could be treated as a novel candidate for the elimination of As(III)-Pb(II) combined pollution.

A ReRAM-Based Non-Volatile and Radiation-Hardened Latch Design.

In aerospace environments, high reliability and low power consumption of chips are essential. To greatly reduce power consumption, the latches of a chip need to enter the power down operation. In this operation, employing non-volatile (NV) latches can retain circuit states. Moreover, a latch can be hit by a radiative particle in the aerospace environment, which can cause a severe soft error in the worst case. This paper presents a NV-latch based on resistive random-access memories (ReRAMs) for NV and robust applications. The proposed NV-latch is radiation-hardened with low overhead and can restore values after power down operation. Simulation results demonstrate that the proposed NV-latch can completely provide radiation hardening capability against single-event upsets (SEUs) and can restore values after power down operation. The proposed NV-latch can reduce the number of transistors in the storage cells by 50% on average compared with the other similar solutions.

Epigenetic regulation of synaptic disorder in Alzheimer's disease.

Synapses are critical structures involved in neurotransmission and neuroplasticity. Their activity depends on their complete structure and function, which are the basis of learning, memory, and cognitive function. Alzheimer's disease (AD) is neuropathologically characterized by synaptic loss, synaptic disorder, and plasticity impairment. AD pathogenesis is characterized by complex interactions between genetic and environmental factors. Changes in various receptors on the postsynaptic membrane, synaptic components, and dendritic spines lead to synaptic disorder. Changes in epigenetic regulation, including DNA methylation, RNA interference, and histone modification, are closely related to AD. These can affect neuronal and synaptic functions by regulating the structure and expression of neuronal genes. Some drugs have ameliorated synaptic and neural dysfunction in AD models via epigenetic regulation. We reviewed the recent progress on pathological changes and epigenetic mechanisms of synaptic dysregulation in AD to provide a new perspective on this disease.

Investigation on the binding of cyanobacterial metabolite calothrixin A with human serum albumin for evaluating its potential toxicology.

Calothrixin A (CLA), as a carbazole-1,4-quinone alkaloid with unique indolo [3,2-j] phenanthridine framework, is a natural metabolite from the Calothrix cyanobacteria. Since the interaction to the functional serum albumins may play an important role in estimating its potential physiological or toxicological effects in vivo, we here explored the binding information of CLA with human serum albumin (HSA) by multi-spectroscopic experiments and computational approaches. The molecular docking results showed that there was one binding site of CLA to the site I (subdomain IIA) of HSA, causing the spontaneous formation of the ground state complex of CLA-HSA through the integration of hydrogen bond, hydrophobic interaction, and electrostatic interaction. Moreover, CLA could effectively trigger the change of HSA's secondary structure because of an obvious decrease of α-helical content in HSA. Taking into consideration of the crucial role of HSA to transport extraneous functional small molecules in vivo, this study may provide a worthy theoretical basis to evaluate the in vivo toxicity of CLA, aiming to reduce/avoid the potential toxic side effects of CLA in the next hit-to-lead campaign.

Dihydroartemisinin inhibits endothelial cell migration via the TGF-ß1/ALK5/SMAD2 signaling pathway.

Anti-angiogenesis therapy is a novel treatment method for malignant tumors. Endothelial cell (EC) migration is an important part of angiogenesis. Dihydroartemisinin (DHA) exhibits strong anti-angiogenic and anti-EC migration effects; however, the underlying molecular mechanisms are yet to be elucidated. The TGF-ß1/activin receptor-like kinase 5 (ALK5)/SMAD2 signaling pathway serves an important role in the regulation of migration. The present study aimed to explore the effects of DHA treatment on EC migration and the TGF-ß1/ALK5/SMAD2 signaling pathway. The effects of DHA on human umbilical vein EC migration were assessed using wound healing and Transwell assays. The effects of DHA on the TGF-ß1/ALK5/SMAD2 signaling pathway were detected using western blotting. DHA exhibited an inhibitory effect on EC migration in the wound healing and Transwell assays. DHA treatment upregulated the expression levels of ALK5 and increased the phosphorylation of SMAD2 in ECs. SB431542 rescued the inhibitory effect of DHA during EC migration. DHA inhibited EC migration via the TGF-ß1/ALK5/SMAD2-dependent signaling pathway, and DHA may be a novel drug for the treatment of patients with malignant tumors.

Transforming growth factor­ß1 functions as a competitive endogenous RNA that ameliorates intracranial hemorrhage injury by sponging microRNA­93­5p.

Intracerebral hemorrhage (ICH) has the highest mortality rate of all stroke subtypes but an effective treatment has yet to be clinically implemented. Transforming growth factor­ß1 (TGF­ß1) has been reported to modulate microglia­mediated neuroinflammation after ICH and promote functional recovery; however, the underlying mechanisms remain unclear. Non­coding RNAs such as microRNAs (miRNAs) and competitive endogenous RNAs (ceRNAs) have surfaced as critical regulators in human disease. A known miR­93 target, nuclear factor erythroid 2­related factor 2 (Nrf2), has been shown to be neuroprotective after ICH. It was hypothesized that TGF­ß1 functions as a ceRNA that sponges miR­93­5p and thereby ameliorates ICH injury in the brain. Short interfering RNA (siRNA) was used to knock down TGF­ß1 and miR­93 expression was also pharmacologically manipulated to elucidate the mechanistic association between miR­93­5p, Nrf2, and TGF­ß1 in an in vitro model of ICH (thrombin­treated human microglial HMO6 cells). Bioinformatics predictive analyses showed that miR­93­5p could bind to both TGF­ß1 and Nrf2. It was found that neuronal miR­93­5p was dramatically decreased in these HMO6 cells, and similar changes were observed in fresh brain tissue from patients with ICH. Most importantly, luciferase reporter assays were used to demonstrate that miR­93­5p directly targeted Nrf2 to inhibit its expression and the addition of the TGF­ß1 untranslated region restored the levels of Nrf2. Moreover, an miR­93­5p inhibitor increased the expression of TGF­ß1 and Nrf2 and decreased apoptosis. Collectively, these results identified a novel function of TGF­ß1 as a ceRNA that sponges miR­93­5p to increase the expression of neuroprotective Nrf2 and decrease cell death after ICH. The present findings provided evidence to support miR­93­5p as a potential therapeutic target for the treatment of ICH.

Profiling the interaction of a novel toxic pyruvate dehydrogenase kinase inhibitor with human serum albumin.

To discover novel pyruvate dehydrogenase kinase (PDK) inhibitors, a new compound 2,2-dichloro-1-(4-((4-isopropylphenyl)amino)-3-nitrophenyl)ethan-1-one, namely XB-1 was identified, which inhibited PDK activity with a half maximal inhibitory concentration (IC50) value of 337.0 nM, and reduced A549 cell proliferation with a half maximal effective concentration (EC50) value of 330.0 nM. However, the compound appears to exhibit a negligible selectivity between cancer cell and normal one, indicating a potential toxicity existed for the compound. Herein, the interaction of the toxic XB-1 to human serum albumin (HSA) was firstly explored by spectroscopic approaches with the aim to reduce/avoid the toxicity of PDK inhibitors in the next hit-to-lead campaign. In detail, it was found that the XB-1 could effectively bind to HSA mainly via hydrogen bond interaction in PBS buffer (pH = 7.4, 10.0 mM), resulting in the formation of HSA-XB-1 complex. The negative value of ΔG showed that the binding of XB-1 to HSA is a spontaneous process. The result from site-selective binding assay suggested that the XB-1 bound to the site I of HSA by competing with warfarin, which was perfect in agreement with the molecular docking method. The results of this paper may offer a valuable theoretical basis to study the toxicity of biofunctional molecules and may offer thoughts about how to avoid/reduce toxicity for a small molecule.

Proximity hybridization triggered hybridization chain reaction for label-free electrochemical homogeneous aptasensors.

A label-free homogeneous electrochemical aptasensor was developed for detection of thrombin based on proximity hybridization triggered hybridization chain reaction induced G-quadruplex formation. Thrombin promoted the formation of a complex via the proximity hybridization of the aptamer DNA strands, which unfolded the molecular beacon, the stem part of molecular beacon as a primer to initiate the hybridization chain reaction process. Thus, with the electrochemical indicator hemin selectively intercalated into the multiple G-quadruplexes, a significant electrochemical signal drop is observed, which is dependent on the concentration of the target thrombin. Thus, using this"signal-off" mode, label-free homogeneous electrochemical strategy for sensitive thrombin assay with a detection limit of 44 fM is realized. Furthermore, this method also exhibits additional advantages of simplicity and low cost, since both expensive labeling and sophisticated probe immobilization processes are avoided. Its high sensitivity, acceptable accuracy, and satisfactory versatility of analytes led to various applications in bioanalysis.

Optimal transition paths of phenotypic switching in a non-Markovian self-regulation gene expression.

Gene expression is a complex biochemical process involving multiple reaction steps, creating molecular memory because the probability of waiting time between consecutive reaction steps no longer follows exponential distributions. What effect the molecular memory has on metastable states in gene expression remains not fully understood. Here, we study transition paths of switching between bistable states for a non-Markovian model of gene expression equipped with a self-regulation. Employing the large deviation theory for this model, we analyze the optimal transition paths of switching between bistable states in gene expression, interestingly finding that dynamic behaviors in gene expression along the optimal transition paths significantly depend on the molecular memory. Moreover, we discover that the molecular memory can prolong the time of switching between bistable states in gene expression along the optimal transition paths. Our results imply that the molecular memory may be an unneglectable factor to affect switching between metastable states in gene expression.

Key roles of the crystal structures of MgO-biochar nanocomposites for enhancing phosphate adsorption.

The affinity of biochar (BC) adsorbing phosphate was weak, while generation of magnesium oxide (MgO)-BC nanocomposites that transformed the crystal structures of BC would change the adsorption processes in improving the phosphate adsorption. Hereon, four different crystal structure of absorbents were selected to illustrate why the crystal structures and surface properties of absorbents were of great importance for the phosphate adsorption. The results showed that MgO/KBC with higher combination degree between MgO and KBC could change the normal crystal structure (MgO/KBC1, MgO phase (dominant)) to C-Mg-O phase (dominant). Therefore, MgO/KBC could achieve highest adsorption rate (k2, 8.059 g mg-1 min-1) and qm (maximal adsorption capacity, 121.950 mg g-1) for phosphate adsorption among absorbents, and even it had high anti-interference capacity for anions and natural organic matter (NOM). The mechanisms of MgO/KBC for phosphate adsorption were hydrogen-bond interaction, inner-sphere complexation and surface chemical adsorption; adsorption of phosphate on MgO/KBC1 was mainly controlled by inner-sphere complexation (Mg-O-PO3H2-, Mg-O-PO3H2- species). In addition, the adsorbability of MgO/KBC for phosphate could be restored after recalcination, which further proved that an efficient nanocomposite, calcinated from waste biomass (fallen leaves), was proposed to control eutrophication.

Proximity hybridization-triggered DNA assembly for label-free surface-enhanced Raman spectroscopic bioanalysis.

We have developed a versatile label-free surface-enhanced Raman spectroscopic platform for detecting various biotargets via proximity hybridization-triggered DNA assembly based on the 736 cm-1 Raman peak of adenine breathing mode. We initially immobilized the first probe to AuNPs and modified the second with poly adenine. Presence of target DNA or protein molecules assembled a sandwich complex that brought the poly adenine close to the AuNPs surface, generating Raman signals, that were proportional to target molecule concentration. These approach exhibits high sensitivity, with a detection limit of 5.4 pM, 47 fM, and 0.51 pg/mL for target DNA, thrombin and CEA, respectively. Owing to a one step proximity dependent complex formation, this technique is simple and can be completed within 40 min, making it a promising candidate for point-of-care testing applications.

Removal of Cu and Pb from contaminated agricultural soil using mixed chelators of fulvic acid potassium and citric acid.

This study investigated the application of a specific soil washing method to remove Cu and Pb from contaminated agricultural soil. To develop an efficient leaching agent of heavy metal compounds for use in farmland soil, a mixed chelator (MC) was prepared using potassium fulvic acid (PFA, 3.2%) and citric acid (CIT, 0.16 M) in a volume ratio of 4:1 (PFA:CIT = 4:1); the optimal solid-liquid ratio (S/L = 1:20), initial pH value (4.51) and contact time (360 min) were also explored. Under optimal conditions, the removal efficiencies of MC for Cu and Pb were 42.92% and 50.46%, respectively, both of which performed better than PFA (27.86% of Cu and 17.91% of Pb) and CIT (42.04% of Cu and 41.46% of Pb). The effective states, bioavailability and relative mobilities of Cu and Pb in soil were also efficiently reduced by MC, which also increased the stability of these elements, thereby lowering the risk to soil health. More importantly, MC not only had little effect on the soil physicochemical properties (e.g., pH, organic matter (OM), cation exchange capacity (CEC), ammonium nitrogen (AN), available phosphorus (AP) and rapidly available potassium (AK)), but also improved the restored soil. Furthermore, soil structure, surface elements and the enzyme activity did not exhibit significantly loss. Therefore, MC has great potential for remediating agricultural soil.

UV-Induced Photodegradation of Naproxen Using a Nano γ-FeOOH Composite: Degradation Kinetics and Photocatalytic Mechanism.

Naproxen (NPX) is one of the most common pharmaceutical and personal care products found in surface water, which is recalcitrant to degradation by biological treatment or complete removal via traditional sewage treatment processes. In this study, nanoscale γ-FeOOH was synthesized and characterized by X-ray diffraction, scanning electron microscopy, surface analysis, and analysis of the forbidden bandwidth. Under UV irradiation, γ-FeOOH had the capacity to rapidly photodegrade NPX. The photodegradation rate of NPX was dependent on the concentration of γ-FeOOH in solution, initial NPX concentration, and pH. By increasing the concentration of γ-FeOOH, the NPX photodegradation rate was increased and then remained stable. Furthermore, the highest photodegradation rate for NPX was observed under acidic conditions. Through the analysis of the active substances (such as h+, e-, OH, 1O2, and O 2 · - ) by electron spin resonance, the photocatalytic mechanism of NPX degradation on γ-FeOOH was determined to be semiconductor photocatalysis.

Pattern Formation through Temporal Fractional Derivatives.

It is well known that temporal first-derivative reaction-diffusion systems can produce various fascinating Turing patterns. However, it has been found that many physical, chemical and biological systems are well described by temporal fractional-derivative reaction-diffusion equations. Naturally arises an issue whether and how spatial patterns form for such a kind of systems. To address this issue clearly, we consider a classical prey-predator diffusive model with the Holling II functional response, where temporal fractional derivatives are introduced according to the memory character of prey's and predator's behaviors. In this paper, we show that this fractional-derivative system can form steadily spatial patterns even though its first-derivative counterpart can't exhibit any steady pattern. This result implies that the temporal fractional derivatives can induce spatial patterns, which enriches the current mechanisms of pattern formation.

Local accumulation time for the formation of morphogen gradients from a Lévy diffusion process.

Morphogen gradients provide very precise spatial information on the control of cell fate specification in many developing tissues. In previous studies, morphogen gradient formation was commonly modelled as Fickian diffusion. However, the complexity of morphogen transport and anisotropy of intracellular and extracellular environments in vivo can lead to Lévy flights of morphogens. In this case, a natural question is whether morphogen gradients reach steady states on timescales relevant to developmental patterning. Here, we build and analyse a Lévy diffusion model of morphogen transport, which is based on a continuous time random walk with a long-tailed jump length distribution. Importantly, we derive the analytical expression of local accumulation time that provides a time scale that characterizes relaxation to a steady state at an arbitrary position within the patterned field, and shows that this time depends on cell positions in a nonlinear and asymmetric manner. Our analytical result provides an explicit connection between the key parameters of the problem and the time needed to reach a steady state value at an arbitrarily given position, which is important for a better understanding of tissue patterning by morphogen gradients in a more real case.

Perceived peer engagement in HIV-related sexual risk behaviors and self-reported risk-taking among female sex workers in Guangxi, China.

Searching for modifiable perceptions that are associated with sexual risk behaviors among female sex workers (FSWs) are considered a priority in HIV/sexually transmitted disease preventions. Perception of peers' involvement in risk behaviors, a key correlate of individual risk behaviors, has barely been studied among FSWs. A self-administered questionnaire was completed by 1022 FSWs in Guangxi, China, a country with rapid growth in both HIV epidemic and commercial sex. Multiple imputation using chained equation (MICE) was applied to handle missing values (1-10%) in the data-set. Regression analysis that focused on relationship between perceived peers' risk involvement and FSWs' risk-taking was performed on full data-sets generated by MICE. FSWs who perceived more peer alcohol use was significantly more likely to have sex under the influence of alcohol. Those who perceived more unprotected sex among peers had a higher likelihood to use condom inconsistently with both stable and casual partners. Perceiving more peers engaging in sex after using alcohol was positively associated with having sex with clients who were intoxicated and/or high on drugs, and with having sex under the influence of alcohol. Perceived peer promiscuity, defined as having sex with any types of clients at any price offered, was positively associated with inconsistent condom use with casual partners, but negatively associated with having sex under the influence of alcohol. These data suggest that the potential for intervention programs to address behavioral change among FSWs through modifying perceptions of peer involvement in sexual risk behaviors. Longitudinal studies are needed to confirm these findings and qualitative researches will be essential for the clarification of mechanisms behind associations found in the current study and for the actual design of effective norm-based interventions among FSWs.

Alcohol consumption in relation to work environment and key sociodemographic characteristics among female sex workers in China.

The study explores the variation in pattern of alcohol use and related risk behaviors by types of sex work environments and sociodemographic characteristics among female sex workers (FSWs) in China. Data were collected from 1,022 FSWs in Guangxi, China, through a self-administered questionnaire. Chi-square and analysis of variance (ANOVA) were used to assess the variations. Results showed that younger FSWs were more susceptible than older FSWs to nearly all the risk drinking behaviors. FSWs of non-Han ethnicity as compared with those of Han ethnicity were more at risk of drinking large amounts of alcohol and having sex under the influence of alcohol. FSWs in entertainment establishments were most likely to have all kinds of risk drinking behaviors. Street-based FSWs were least likely to drink alcohol but more or equally likely to engage in alcohol-related sexual risk behaviors. The study highlights a need to develop tailored alcohol risk reduction intervention that takes into consideration these differences.