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The trade-off between electrostrain and strain hysteresis for piezo/ferroelectric materials largely restrains the development of high precision actuators and remains unresolved over the past few decades. Here, a simple composition of (Bi0.5Na0.5)1-x/100Srx/100TiO3 in the ergodic relaxor state is collaboratively designed through the segregated domain structure with the ferroelectric core, local polarization heterogeneity, and defect engineering. The ferroelectric core can act as a seed to facilitate the field-induced nonpolar-to-polar transition. Together with the internal bias field caused by defect dipoles and adjusted through electric field cycling and heat treatment technology, a giant unipolar strain of 1.03% is achieved in the x = 30 ceramic with a low hysteresis of 27%, while the electric-field-independent large-signal piezoelectric strain coefficient of ~1000 pm/V and ultralow hysteresis of <10% can be obtained in the x = 35 ceramic. Intriguingly, the low-hysteresis high strain also exhibits near-zero remnant strain, excellent temperature and cycling stability. The development of precision piezo/ferroelectric actuators is hindered by the trade-off between electrostrain and strain hysteresis. Here, the authors report ferroelectric cores embedded into ergodic relaxor phase shells, showing giant unipolar strain and low hysteresis. [ABSTRACT FROM AUTHOR]

The hydrolysis behavior of U(IV) was preliminarily explored by experimental methods, and the hydrolysis characteristics of U(IV) were determined. The results show that the absorption characteristic peak of U(IV) hydrolyzed products is between 380 and 420 nm, the hydrolytic process is not linear and reversible, and the hydrolysis reaction of U(IV) includes multiple processes. There are 4 integer hydrolysis stability constants of U(IV) were experimentally analyzed. With the increasing of OH− concentration, the mean coordination number of OH− increases. [ABSTRACT FROM AUTHOR]

Currently, the dyeing processes between natural fibers and dyes heavily rely on inorganic electrolytes, posing significant challenges to ecological and sustainable development. In this work, zinc ion was used to modify the surface of Angora wool through high-voltage electrospray technology (HVET), aiming to enhance the binding capacity with natural dyes. The optimized zinc ion dosage and the treatment voltage have been explored and determined as 6% o.w.f and 25 kV. In addition, tannic acid, as a mordant, was implemented to achieve the complete coordination of metal ions while also imparting antibacterial properties to the fabric (above 90% of bacterial reduction). Thanks to the synergistic effect between zinc ions and tannic acid, the dyeing performances of modified Angora wool has been significantly improved. Density functional theory (DFT) calculations further support that the introduction of zinc ions enhances the reactivity of the modified fibers and lowers the energy barrier of dyeing reactions. The dyeing rate, the dyeing depth, and the dyeing fastness of the modified fabric/gardenia yellow dyes optimized can reach to 66.9%, 4.7, and grade 4–5, which is much better than untreated fibers. [ABSTRACT FROM AUTHOR]

Directed energy deposition (DED) provides the possibility of high-throughput synthesis by controlling the multi-channel powder feeders. However, the compositional accuracy of the targeted alloy is of concern due to the difficulty of adjusting the proportions. In this work, we present a method to improve the adjustment accuracy of the high-throughput DED technology by replacing the elemental powder with pre-alloyed powder, and binary Al–Mn alloys with different compositions were synthesized with a composition step of 1 wt.%. The effect of Mn content on the microstructure and mechanical properties of the alloys was characterized and analyzed, and the relationship between the Al6Mn phase and the yield strength was established. The results showed that the microstructures of DED-ed Al–Mn alloys are composed of Al and Al6Mn phases with Mn contents in the range of 2–10 wt.%. The Al–Mn alloy reaches a tensile strength of 165 MPa and maintains an elongation of 9% at Mn content of 4 wt.%. The improved controlling accuracy of composition step to 1 wt.% by pre-alloyed powder in this work provides a paradigm for high-throughput discovery of high-performance alloys. [ABSTRACT FROM AUTHOR]

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Sequential modulations have been found in both conflict and spatial orienting tasks. The former is called congruency sequence effects (CSE) and the latter is called validity sequence effects (VSE). Although the two effects have similar phenomenon descriptions, the relationship of the cognitive control mechanisms under the two effects is still unclear. Using a modified attentional network test (ANT), a flanker task and an arrow cueing task are integrated into a single task, which enables the test of the possible interactions between CSE and VSE. Since a confound-minimized design is used, the observed sequence effects cannot be attributed to the feature integration of low-level stimulus features or the contingency learning. It was found that the CSE are only significant when the arrow cue in preceding trial is invalid, and the VSE are only significant when the target letter in preceding trial is congruent with the distractor letters. The findings suggest that the sequential modulations during orienting and executive control of attention networks are highly interacted with each other, and the sequence effects in these networks are possibly controlled by a complex and multifaceted adaptive control mechanism. [ABSTRACT FROM AUTHOR]

Injecting fluids into deep underground geologic structures is a critical component to development of long-term strategies for managing greenhouse gas emissions and facilitating energy extraction operations. Recently, we reported that metal–organic frameworks are low-frequency, absorptive-acoustic metamaterial that may be injected into the subsurface to enhance geophysical monitoring tools used to track fluids and map complex structures. A key requirement for this nanotechnology deployment is transportability through porous geologic media without being retained by mineral-fluid interfaces. We used flow-through column studies to estimate transport and retention properties of five different polymer-coated MIL-101(Cr) nanoparticles (NP) in siliceous porous media. When negatively charged polystyrene sulfonate coated nanoparticles (NP-PSS-70K) were transported in 1 M NaCl, only about 8.4% of nanoparticles were retained in the column. Nanoparticles coated with polyethylenimine (NP-PD1) exhibited significant retention (> 50%), emphasizing the importance of complex nanoparticle-fluid-rock interactions for successful use of nanofluid technologies in the subsurface. Nanoparticle transport experiments revealed that nanoparticle surface characteristics play a critical role in nanoparticle colloidal stability and as well the transport. [ABSTRACT FROM AUTHOR]

The effect of severe plastic deformation applied through friction extrusion (FE) method on an Al-Ti composite billet is summarized. Formation of layered amorphous regions and specific atomic ratios (R) of Ti/Al, in addition to some crystalline Al-Ti intermetallic compounds (IMC), e.g., TiAl3 and TiAl forming et al./Ti interfaces, are noted after the deformation FE process. It seems that the amorphous regions form first and subsequently transform to corresponding Al-Ti IMCs. Semi-in situ heating demonstrated the thermal stability of such Al-Ti amorphous layered structures, with the phase transformation sequence being R = 1:3 (TiAl3, 250 °C) → R = 1:1 (TiAl, 400 °C) → R = 3:1 (Ti3Al, > 500 °C). [ABSTRACT FROM AUTHOR]

T-2 toxin is produced by the Fusarium genus. Ingestion of food or feed contaminated by T-2 toxin will cause damage to kidney. Selenium (Se), an essential trace element, showed the significant protective effects against kidney and renal cell damage induced by toxic substances. To explore the protective effects and mechanisms of Se against T-2-induced renal lesions, forty-eight male Kunming mice were exposed to T-2 toxin (1.0 mg/kg) and/or Se (0.2 mg/kg) for 28 days. In this study, we found that Se alleviated T-2-induced nephrotoxicity, presenting as increasing the body weight and kidney coefficient, relieving the renal structure injury, decreasing the contents of renal function-related biomarkers, decreasing the levels of reactive oxygen species (ROS), and increasing the mitochondrial membrane potential in T-2 toxin-treated mice. In addition, inhibition of renal cell apoptosis by Se was associated with blocking the mitochondrial pathway in T-2 toxin-treated mice, presenting as decreasing the protein expression of cytochrome-c, activities of caspase-3/9, as well as regulating the protein and mRNA expressions of Bax and Bcl-2. These results documented that the alleviating effect of Se on T-2-induced nephrotoxicity is related to the inhibition of ROS-mediated renal apoptosis. [ABSTRACT FROM AUTHOR]

Almost all proxy-based temperature reconstructions for East Asia have hitherto been designed to resolve summer or annual temperature variability. Reconstruction for the winter temperature is still lacking. Here, we report an annually resolved, winter-season (December-February, DJF) temperature field reconstruction for East Asia covering the period 1300–2000 CE, based on 260 temperature-sensitive tree-ring records. The most striking feature of our new reconstruction is a significant long-term warming trend since the 14th century, which is associated with winter solar insolation at mid-latitudes of the Northern Hemisphere and the global anthropogenic impact. The amplitude of reconstructed winter temperature change over the study period was ~4.7 times greater than that for summer temperature, and the rate of winter temperature increase was ∼6 times as much as that of summer temperature. The results from climate model simulations were consistent with the reconstruction, showing that the amplitude and rate of temperature change in winter were greater than those in summer. The reconstruction also suggests the possible influence of volcanic eruptions, anthropogenic activities and winter solar insolation on the winter temperature variations. Our result also suggests a long-term decrease in summer-to-winter temperature difference occurred in 1625 (±24 years) CE. [ABSTRACT FROM AUTHOR]

In phytopathogenic fungi, the Hog1 MAPK pathway plays roles in osmoregulation, oxidation responses, fungicide sensitivity, among others. However, how fungi depend on the HOG MAPK pathway to regulate their functions is poorly understood. To further elucidate the molecular mechanisms of the HOG MAPK pathway, a yeast two-hybrid (Y2H) system was adopted to screen interacting proteins of two key components (CsPbs2 and CsHog1) of the HOG MAPK pathway in a cDNA library of Colletotrichum siamense. The results showed that 19 proteins may interact with CsPbs2, including cytochrome P450 4F5, ceramide very-long-chain fatty acid hydroxylase SCS7, the oxidative stress response two-component system protein SSK1, and other proteins. Twenty-one proteins may interact with CsHog1, including the cell wall protein PhiA, acriflavine sensitivity control protein acr-2, arachidonate 15-lipoxygenase, respiratory supercomplex factor 2-like protein, and others. Five proteins interact with both CsHog1 and CsPbs2: antigenic thaumatin-like protein, aspirochlorine biosynthesis protein N, secreted beta-glucosidase sun 1, alcohol dehydrogenase 1, and hypothetical protein GQ607_005106. Furthermore, the interaction of CsSCS7 and CsCytP450 4F5 with CsPbs2 was verified by His pull-down. qPCR revealed significantly upregulated CsPbs2, CsHog1, CsSCS7 and CsCytP450 4F5 expression in Colletotrichum treated with 50 μg/mL fludioxonil for 2 h. This research identified candidate CsHog1- and CsPbs2-interacting proteins via a Y2H system and confirmed the interactions of CsSCS7 and CsCytP450 4F5 with CsPbs2. The findings lay the foundation for further studies of HOG MAPK pathway function and regulatory mechanisms, especially regarding fungicide sensitivity. [ABSTRACT FROM AUTHOR]

For the land shortage problem upon the city development in coastal areas, it is of great importance to improve the overall understanding of the settlement behavior of dredged slurry and determine the required site water storage capacity as well as the mechanical properties of the newly formed dredged slurry. This paper presents an experimental investigation on the effect of turbulent fluctuation on the settling behavior of dredged slurry in sheared condition via a self-developed testing apparatus namely double cylinder settling column. Test results showed that the settling velocity of the soil-water interface initially increased then decreased with the increasing rotation speed of the inner column. The interface would disappear and a stable suspended layer was observed when the rotation speed was greater than 20 rad/min, where water contents and grain composition were not changed over the depth. The particle content was closer to that of the original sample as the rotation speed kept increasing in the suspended layer. It was found that the stabilized flocs were gradually broken down by the turbulence effect existing in the sheared slurry. Moreover, the stabilized flocs were losing the stability gradually as the flowing velocity increased till 10 rad/min and the floc structure was broken down completely once the flowing velocity was greater than 20 rad/min. [ABSTRACT FROM AUTHOR]

Ductile fracture of metal often occurs in the plastic forming process of parts. The establishment of ductile fracture criterion can effectively guide the selection of process parameters and avoid ductile fracture of parts during machining. The 3D ductile fracture envelope of AA6063-T6 was developed to predict and prevent its fracture. Smooth round bar tension tests were performed to characterize the flow stress, and a series of experiments were conducted to characterize the ductile fracture firstly, such as notched round bar tension tests, compression tests and torsion tests. These tests cover a wide range of stress triaxiality (ST) and Lode parameter (LP) to calibrate the ductile fracture criterion. Plasticity modeling was performed, and the predicted results were compared with corresponding experimental data to verify the plasticity model after these experiments. Then the relationship between ductile fracture strain and ST with LP was constructed using the modified Mohr–Coulomb (MMC) model and Bai-Wierzbicki (BW) model to develop the 3D ductile fracture envelope. Finally, two ductile damage models were proposed based on the 3D fracture envelope of AA6063. Through the comparison of the two models, it was found that BW model had better fitting effect, and the sum of squares of residual error of BW model was 0.9901. The two models had relatively large errors in predicting the fracture strain of SRB tensile test and torsion test, but both of the predicting error of both two models were within the acceptable range of 15%. In the process of finite element simulation, the evolution process of ductile fracture can be well simulated by the two models. However, BW model can predict the location of fracture more accurately than MMC model. [ABSTRACT FROM AUTHOR]

This study investigates the elemental composition and surface morphology of solid tribochemical films formed on steel surfaces. The reversible addition-fragmentation chain transfer (RAFT) method was used to synthesize nine different metal-free polymers, which were blended into commercial base oils. The polymers were either homopolymers of dodecyl methacrylate and ethylhexyl methacrylate or were co-polymers of these monomers with six polar monomers. After tribological testing at 100 °C using the ball-on-flat geometry, the resulting tribochemical films were imaged using scanning electron microscopy (SEM) and optical microscopy. The resulting tribochemical films have thicknesses around 50–100 nm. Two of the films corresponding to small (P1—imidazole-containing copolymer) and large (P3—less polar homopolymer) wear were cross-sectioned using focused ion beam (FIB) and analyzed for elemental composition using energy-dispersive X-Ray (EDX) mapping. Oxygen and nitrogen enrichment was observed, consistent with the relative chemical composition of the precursor polymers. Transmission electron microscopy (TEM) evidence suggests that at the worn surface, some organic elements penetrate or are mixed into the steel substrate giving an interlocking appearance. The two samples examined with TEM showed that P1 tribofilm is diffused or mixed with the steel substrate more so than P3, suggesting a stronger affinity and contact during tribofilm formation. [ABSTRACT FROM AUTHOR]

Crystallization by particle attachment (CPA) is a frequently occurring mechanism of colloidal crystallization that results in hierarchical morphologies1–4. CPA has been exploited to create nanomaterials with unusual properties4–6 and is implicated in the development of complex mineral textures1,7. Oriented attachment7,8—a form of CPA in which particles align along specific crystallographic directions—produces mesocrystals that diffract as single crystals do, although the constituent particles are still discernible2,9. The conventional view of CPA is that nucleation provides a supply of particles that aggregate via Brownian motion biased by attractive interparticle potentials1,9–12. However, mesocrystals often exhibit regular morphologies and uniform sizes. Although many crystal systems form mesocrystals1–9 and individual attachment events have been directly visualized10, how random attachment events lead to well defined, self-similar morphologies remains unknown, as does the role of surface-bound ligands, which are ubiquitous in nanoparticle systems3,9,11. Attempts to understand mesocrystal formation are further complicated in many systems by the presence of precursor nanoparticles with a phase distinct from that of the bulk1,13,14. Some studies propose that such particles convert before attachment15, whereas others attribute conversion to the attachment process itself16 and yet others conclude that transformation occurs after the mesocrystals exceed a characteristic size14,17. Here we investigate mesocrystal formation by iron oxides, which are important colloidal phases in natural environments18,19 and classic examples of systems forming ubiquitous precursor phases and undergoing CPA accompanied by phase transformations15,19–21. Combining in situ transmission electron microscopy (TEM) at 80 degrees Celsius with ‘freeze-and-look’ TEM, we tracked the formation of haematite (Hm) mesocrystals in the presence of oxalate (Ox), which is abundant in soils, where iron oxides are common. We find that isolated Hm particles rarely appear, but once formed, interfacial gradients at the Ox-covered surfaces drive Hm particles to nucleate repeatedly about two nanometres from the surfaces, to which they then attach, thereby generating mesocrystals. Comparison to natural and synthetic systems suggests that interface-driven pathways are widespread.Mesocrystal formation is investigated for haematite in the presence of oxalate, showing that chemical gradients at interfaces cause nucleation near surfaces rather than in the bulk, followed by particle attachment. [ABSTRACT FROM AUTHOR]

Aluminum (Al)-induced bone metabolism disorder is a primary cause of osteoporosis. Ginsenoside Rg3 (Rg3) has demonstrated therapeutic properties in the treatment of osteoporosis. The present study aimed to identify potential bone protection mechanisms of Rg3 against Al-induced osteoporosis in rats. In this study, forty healthy male Sprague-Dawley rats were randomly allocated into groups in which they were treated with AlCl3 (64 mg/kg/day) and/or Rg3 (20 mg/kg/day). AlCl3 was given orally to rats for 120 days, and from the 91st day, treated orally with Rg3 for 30 days. Rg3 attenuated AlCl3-induced accumulation of Al by decreasing the bone mineral density in the lumbar spines, femoral metaphysis, and tibia, and inhibited AlCl3-induced oxidative stress in rat bone by decreasing the levels of reactive oxygen species and malondialdehyde, while increasing glutathione peroxidase and superoxide dismutase activity. Rg3 facilitated bone formation by increasing the concentration of calcium, phosphorus, amino-terminal propeptide of type I procollagen, and carboxyl-terminal propeptide of type I procollagen, bone alkaline phosphatase activity in serum, and type I collagen, osteocalcin, and osteopontin protein expressions. Rg3 inhibited bone resorption by decreasing the content of N-terminal cross-linking telopeptide of type I collagen, C-terminal cross-linking telopeptide of type I collagen, and tartrate-resistant acid phosphatase 5b activity in serum. Rg3 promoted the mRNA expression of growth regulation factors by increasing transforming growth factor-β1, bone morphogenetic protein-2, insulin-like growth factor I, and core-binding factor α1. The results demonstrate that Rg3 can significantly attenuate Al accumulation, facilitate bone formation, inhibit bone resorption, resist oxidative stress, and promote the expression of factors that regulate growth. The results indicate that Rg3 is effective in alleviating AlCl3-induced osteoporosis. [ABSTRACT FROM AUTHOR]

The thermal stability of dislocation cellular structures in three additively manufactured (AM) austenitic stainless steels (SSs), 316L SS, 304L SS, and Al modified 316L SS (316L(Al)), were studied. Minor alloying elements, Mo and Al, were found affecting the stability of the cellular structures in AM austenitic SS, resulting in a stability ranking of AM 316L SS > AM 304L SS > AM 316L(Al) SS. As a result, their abilities towards recrystallization also differed. Owing to the high stacking fault energy (SFE) due to Al addition, AM 316L(Al) SS had the least stable subgrain cellular structure and exhibited the lowest recovery temperature. Although 316L SS possessed slightly higher SFE than 304L SS, the pinning effect due to Mo segregation at the cellular walls in AM 316L SS significantly enhanced its thermal stability. While the low-SFE AM 316L SS and AM 304L SS recovered their cellular structures via the equiaxed cell growth, the dislocation cellular walls in high-SFE AM 316L(Al) SS continuously vanished along a preferred direction. The fast recovery of cellular structures led to recrystallization retardation. The Hall–Petch model was found incapable of correlating cell size to strength because of the continuous weakening of cellular walls during heat treatment. [ABSTRACT FROM AUTHOR]

Two novel two-dimensional (2D) Zn coordination polymers,namely [Zn(qnl)2]n (Zn-qnl) and [Zn2(tpp)(OH)2(H2O)]n (Zn-tpp) (qnl = quinoline-3-carboxylate anion, tpp = tetraphenyl phthalate anion) have been hydrothermally synthesized and discussed their solid state photoluminescent properties. Two novel Zn coordination polymers with ligands quinoline-3-carboxylic acid (Hqnl) and tetraphenylphthalic acid (H2tpp) have been prepared and characterized by X-ray crystallography. Zn-tpp and Zn-qnl show a 2D hinge layer and a 2D layer with quadrilateral meshes, respectively. [ABSTRACT FROM AUTHOR]

Aluminum (Al) exposure has adverse effects on osteoblasts, and the effect might be through autophagy-associated apoptosis. In this study, we showed that aluminum trichloride (AlCl3) could induce autophagy in MC3T3-E1 cells, as demonstrated by monodansylcadaverine (MDC) staining and the expressions of the ATG3, ATG5, and ATG9 genes. We found AlCl3 inhibited MC3T3-E1 cell survival rate and caused apoptosis, as evidenced by CCK-8 assay, Annexin V/PI double staining, and increased expressions of Bcl-2, Bax, and Caspase-3 genes. In addition, increased autophagy induced by rapamycin further attenuated the MC3T3-E1 cell apoptosis rate after AlCl3 exposure. These results support the hypothesis that autophagy plays a protective role in impeding apoptosis caused by AlCl3. Activating autophagy may be a strategy for treatment of Al-induced bone disease. [ABSTRACT FROM AUTHOR]

Aluminum (Al) is known to induce apoptosis of osteoblasts (OBs). However, the mechanism is not yet established. To investigate the apoptotic mechanism of OBs induced by aluminum trichloride (AlCl3), the primary OBs from the craniums of fetal Wistar rats were exposed to 0 mg/mL (control group, CG), 0.06 mg/mL (low-dose group, LG), 0.12 mg/mL (mid-dose group, MG), and 0.24 mg/mL (high-dose group, HG) AlCl3 for 24 h, respectively. We observed that AlCl3 induced OB apoptosis with the appearance of apoptotic morphology and increase of apoptosis rate. Additionally, AlCl3 treatment activated mitochondrial-mediated signaling pathway, accompanied by mitochondrial membrane potential (ΔΨm) depolarization, release of cytochrome c from the mitochondria to the cytoplasm, as well as survival signal-related factor caspase-9 and caspase-3 activation. AlCl3 exposure also activated Fas/Fas ligand signaling pathway, presented as Fas, Fas ligand, and Fas-associated death domain expression enhancement and caspase-8 activation, as well as the hydrolysis of Bid to truncated Bid, suggesting that the Fas-mediated signaling pathway might aggravate mitochondria-mediated OB apoptosis through hydrolyzing Bid. Furthermore, AlCl3 exposure inhibited Bcl-2 protein expression and increased the expressions of Bax, Bak, and Bim in varying degrees. These results indicated that AlCl3 exposure induced OB apoptosis through activating Fas- and mitochondria-mediated signaling pathway and disrupted B-cell lymphoma-2 family proteins. [ABSTRACT FROM AUTHOR]

The orienting of attention has been found to be influenced by the previous cueing status in a spatial-cueing paradigm. The explanation for this sequence effect remains uncertain. This study separated the involuntary and the voluntary components of arrow cueing by manipulating the predicted target locations. For example, a left arrow cue may have indicated that the target was more likely to appear at the up location. Therefore, three trial types were repeated or switched between trials: cued (targets appeared along the direction of the arrows), predicted (targets appeared at the locations predicted by the arrows), and unrelated (targets appeared at the other two locations, neither cued nor predicted). RTs of cued trials were found to be significantly facilitated after a previous cued trial; however, the same effect was not observed for predicted trials. The results suggest that significant sequence effects are induced only in the involuntary component of arrow cueing. The findings support the feature-integration hypothesis for the sequence effect of symbolic cueing. [ABSTRACT FROM AUTHOR]

Aluminum (Al) exposure inhibits bone formation. Osteoblastic proliferation promotes bone formation. Therefore, we inferred that Al may inhibit bone formation by the inhibition of osteoblastic proliferation. However, the effects and molecular mechanisms of Al on osteoblastic proliferation are still under investigation. Osteoblastic proliferation can be regulated by Wnt/β-catenin signaling pathway. To investigate the effects of Al on osteoblastic proliferation and whether Wnt/β-catenin signaling pathway is involved in it, osteoblasts from neonatal rats were cultured and exposed to 0, 0.4 mM (1/20 IC), 0.8 mM (1/10 IC), and 1.6 mM (1/5 IC) of aluminum trichloride (AlCl) for 24 h, respectively. The osteoblastic proliferation rates; Wnt3a, lipoprotein receptor-related protein 5 (LRP-5), T cell factor 1 (TCF-1), cyclin D1, and c-Myc messenger RNA (mRNA) expressions; and p-glycogen synthase kinase 3β (GSK3β), GSK3β, and β-catenin protein expressions indicated that AlCl inhibited osteoblastic proliferation and downregulated Wnt/β-catenin signaling pathway. In addition, the AlCl concentration was negatively correlated with osteoblastic proliferation rates and the mRNA expressions of Wnt3a, c-Myc, and cyclin D1, while the osteoblastic proliferation rates were positively correlated with mRNA expressions of Wnt3a, c-Myc, and cyclin D1. Taken together, these findings indicated that AlCl inhibits osteoblastic proliferation may be associated with the inactivation of Wnt/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

Aluminum (Al) is considered to be a potentially toxic metal and inhibits cartilage formation. Transforming growth factor β1 (TGF-β1) and bone morphogenetic protein 2 (BMP-2) are cartilage stimulatory growth factors, which play important roles in regulating the cartilage formation. To investigate the effects of aluminum trichloride (AlCl) on the regulation of cartilage formation. Eighty Wistar rats were orally exposed to 0 (control group), 0.4 g/L (low-dose group), 0.8 g/L (mid-dose group) and 1.6 g/L (high-dose group) AlCl for 120 days, respectively. The rats body weight were decreased, the cartilage histological structure were disrupted, the cartilage and serum contents of Al and the serum level of C-telopeptide of type II collagen were all increased, the serum level of type II collagen (Col II) and alkaline phosphatase (ALP), and the mRNA expressions of TGF-β1, BMP-2, ALP and Col II were all decreased in the AlCl-treated groups compared with those in control group. These results indicate that AlCl inhibits the cartilage formation through inhibition of the cartilage stimulatory growth factors expressions. [ABSTRACT FROM AUTHOR]

Aluminum (Al) is an accumulative toxic metal. Excessive Al accumulation inhibits osteoblasts mineralization and induces osteoporosis. However, the inhibition mechanism of Al on the mineralization is not fully understood. Thus, in this study, the rat osteoblasts were cultured and exposed to 0 mmol L (control group, CG) and 0.52 mmol L aluminum trichloride (AlCl, treatment group, TG) for 7, 14, and 21 days, respectively. We found that mineralized matrix nodules, the activity of bone alkaline phosphatase, the concentration of extracellular calcium, the mRNA expression of type-I collagen, the mRNA and protein expressions of osteopontin, osteocalcin, and bone sialoprotein were all decreased, while the concentration of extracellular phosphorus was increased in TG compared with CG with time prolonged. Taken together, these results indicated that AlCl inhibited osteoblasts mineralization in vitro. [ABSTRACT FROM AUTHOR]

Aluminum (Al) exposure is toxic to immune system. Studies have implicated that glucocorticoids (GCs) exert the dual regulation effect on the immune function depending on the concentration. However, it is unknown whether a dual effect of GCs exists in the AlCl-treated lymphocytes. Corticosterone (Cort) is one kind of GCs. To investigate the effect of different concentration Cort on AlCl-treated lymphocytes, rat splenic lymphocyte was isolated and cultured with 0.55 mmol/L AlCl, simultaneously administrated Cort at final concentration of 0 (control group, CG), 10 (low-level group, LG), and 10 (high-level group, HG) mol/L, respectively. Another group without AlCl and Cort served as the blank group (BG). We found that low concentration Cort increased the T and B lymphocyte proliferation rate, proportions of CD4 T lymphocyte subset, IgG, IL-2, and TNF-α contents, whereas high concentration Cort decreased those in AlCl-treated lymphocytes. In conclusion, the results of this study indicated that low concentration Cort relieves the immunotoxicity of AlCl on the splenic lymphocytes, whereas high concentration Cort aggravates it. [ABSTRACT FROM AUTHOR]

The healing kinetics of nanometer-scale voids in Al-Mg-Er and Al-Mg-Zn-Er alloy systems were investigated with a combination of in situ transmission electron microscopy and electron tomography at different temperatures. Mg was observed completely healing the voids, which were then rejuvenated to the alloy composition with further aging, in the Al-Mg-Er alloy. On the contrary, MgZn intermetallic compound was formed in voids in the Al-Mg-Zn-Er alloy, which leads to complete filling of the voids but not rejuvenation for the material. For voids with different geometrical aspects, different evolution processes were observed, which are related to the competition between bulk and surface diffusion of the alloys. For voids with a large size difference in their two ends, a viscous flow of surface atoms can be directly observed with in situ electron microscopy, when the size of one end becomes less than tens of nanometers. [ABSTRACT FROM AUTHOR]

To explore the apoptosis mechanism in lymphocytes of rats induced by aluminum chloride (AlCl) by activating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling pathway, the splenic lymphocytes of rats were cultured and exposed to different concentrations of AlCl for 24 h. The final concentrations of AlCl (AlCl · 6HO) in supernatant were 0 (control group, CG), 0.3 mmol/L (low-dose group, LG), 0.6 mmol/L (mid-dose group, MG), and 1.2 mmol/L (high-dose group, HG), respectively. Lymphocytes Apoptosis rate, intracellular cAMP content, PKA, survivin, B cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2-associated X protein (Bax) mRNA expressions, and the mRNA and protein expressions of nuclear factor-κ-gene binding (NF-κB, p65) were detected, respectively. The results showed that apoptosis index of lymphocytes, cAMP content in intracellular and PKA mRNA expression were significantly upregulated, whereas NF-κB and survivin mRNA expressions, nuclear NF-κB (p65) protein expression, and the ratio of Bcl-2 and Bax mRNA expression were downregulated in the AlCl-treated groups compared with those in CG. The results indicated that the activated cAMP/PKA signaling pathway induces apoptosis by inhibited NF-κB in AlCl-treated lymphocytes in vitro. [ABSTRACT FROM AUTHOR]

Recent studies have shown that chemical immiscibility is important to achieve enhanced radiation tolerance in metallic multilayers as immiscible layer interfaces are more stable against radiation induced mixing than miscible interfaces. However, as most of these immiscible systems have incoherent interfaces, the influence of coherency on radiation resistance of immiscible systems remains poorly understood. Here, we report on radiation response of immiscible Cu/Fe multilayers, with individual layer thickness h varying from 0.75 to 100 nm, subjected to He ion irradiation. When interface is incoherent, the peak bubble density decreases with decreasing h and reaches a minimum when h is 5 nm. At even smaller h when interface is increasingly coherent, the peak bubble density increases again. However, void swelling in coherent multilayers with smaller h remains less than those in incoherent multilayers. Our study suggests that the coherent immiscible interface is also effective to alleviate radiation induced damage. [ABSTRACT FROM PUBLISHER]

Previous studies have shown that attention orienting is influenced by the orienting processes of previous trials in a spatial-cueing paradigm. This sequence effect is due to the fact that performance is facilitated when cue validity (valid or invalid) repeats between trials. In this study, we investigated the influences of cue direction and target location on the sequence effect of symbolic cueing with a nonpredictive central arrow cue. The cue direction was manipulated to always point in a certain direction in one condition, and to always point in the opposite direction in a second condition. The results showed that sequence effects were enhanced by the alternation of cue direction and target location and were impaired by the repetition of cue direction and target location. The same result pattern was found when the cue direction was chosen randomly in the third condition. The results suggested that both the repetition advantage effect of cue validity and the alternation advantage effect of cue direction and target location are involved in the sequence effect within the symbolic-cueing paradigm. [ABSTRACT FROM AUTHOR]

Previous studies have found that attention orienting is influenced by the orienting processes of previous trials in a spatial cueing paradigm. This study mainly investigated whether this sequence effect could happen for a non-predictive arrow cue and whether it was influenced by the cue-target SOAs in previous and current trials. A significant sequence effect was observed for arrow cues even when voluntary control was not required, and it was significantly influenced by the SOAs of previous trials. The present results support the automatic memory check hypothesis and may reflect some temporal characteristics of the memory mechanism in sequential processes. In addition, contrary to the previous findings, we found an overall response facilitation following a catch trial, suggesting that the influence of preceding catch trials may be sensitive to experimental contexts. [ABSTRACT FROM AUTHOR]

Cognitive control has been investigated in attentional conflict tasks for a long time. One representative phenomenon of adaptive cognitive control in these tasks is the congruency sequence effect (CSE), which means that a previous conflict will lead to reduced congruency effects at the current moment, reflecting increased control of attention toward the task at hand. One debating question is whether CSE can generalize between different conditions. Since a similar phenomenon (i.e., validity sequence effect, VSE) has been found in spatial cueing tasks, this study investigated whether the two sequential effects could generalize between each other. A cross-task sequence effect is found from previous flanker trials to current cueing trials when the task sets of the two tasks are either very similar or sufficiently dissimilar, and this C-VSE effect is influenced by the response mode of the experimental design. In addition, the VSE between trial n-2 and trial n is eliminated by the existence of an intermediate flanker trial, but the CSE between trial n-2 and trial n is still significant even with an intermediate cueing trial. Possible explanations of these findings are discussed. The findings suggest a close connection between orienting and executive control processes in attention networks and provide a new perspective and method for investigating the potential mechanisms of cognitive control. [ABSTRACT FROM AUTHOR]

States that near-total depletion of the ozone in surface air is often observed in the Arctic spring along with high atmospheric concentrations of inorganic bromine. Suggestion by Barrie, et al, that the ozone depletion was due to a catalytic cycle involving the radicals Br and BrO; Proposal of a mechanism, based on known aqueous-phase chemistry, which rapidly converts HBr, HOBr and BrNO3 back to Br and BrO radicals; Details.