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Carbon‐based materials have been utilized as effective catalysts for hydrogen peroxide electrosynthesis via two‐electron oxygen reduction reaction (2e ORR), however the insufficient selectivity and productivity still hindered the further industrial applications. In this work, we report the Fe−O4 motif activated graphitic carbon material which enabled highly selective H2O2 electrosynthesis operating at high current density with excellent anti‐poisoning property. In the bulk production test, the concentration of H2O2 cumulated to 8.6 % in 24 h and the corresponding production rate of 33.5 mol gcat−1 h−1 outperformed all previously reported materials. Theoretical model backed by in situ characterization verified α‐C surrounding the Fe−O4 motif as the actual reaction site in terms of thermodynamics and kinetics aspects. The strategy of activating carbon reaction site by metal center via oxo‐bridge provides inspiring insights for the rational design of carbon materials for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Carbon‐based materials have been utilized as effective catalysts for hydrogen peroxide electrosynthesis via two‐electron oxygen reduction reaction (2e ORR), however the insufficient selectivity and productivity still hindered the further industrial applications. In this work, we report the Fe−O4 motif activated graphitic carbon material which enabled highly selective H2O2 electrosynthesis operating at high current density with excellent anti‐poisoning property. In the bulk production test, the concentration of H2O2 cumulated to 8.6 % in 24 h and the corresponding production rate of 33.5 mol gcat−1 h−1 outperformed all previously reported materials. Theoretical model backed by in situ characterization verified α‐C surrounding the Fe−O4 motif as the actual reaction site in terms of thermodynamics and kinetics aspects. The strategy of activating carbon reaction site by metal center via oxo‐bridge provides inspiring insights for the rational design of carbon materials for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

The Shack–Hartmann wavefront sensor (SHWFS) is widely utilized for ocular aberration measurement. However, large ocular aberrations caused by individual differences can easily make the spot move out of the range of the corresponding sub-aperture in SHWFS, rendering the traditional centroiding method ineffective. This study applied a novel convolutional neural network (CNN) model to wavefront sensing for large dynamic ocular aberration measurement. The simulation results demonstrate that, compared to the modal method, the dynamic range of our method for main low-order aberrations in ocular system is increased by 1.86 to 43.88 times in variety. Meanwhile, the proposed method also has the best measurement accuracy, and the statistical root mean square (RMS) of the residual wavefronts is 0.0082 ± 0.0185 λ (mean ± standard deviation). The proposed method generally has a higher accuracy while having a similar or even better dynamic range as compared to traditional large-dynamic schemes. On the other hand, compared with recently developed deep learning methods, the proposed method has a much larger dynamic range and better measurement accuracy. [ABSTRACT FROM AUTHOR]

Objective: Regular monitoring of serum potassium after a total joint arthroplasty (TJA) is a form of routine examination that can help detect abnormal serum potassium levels and reduce the incidences of adverse events that may occur on account of postoperative hypokalemia. Previous studies rarely discussed hypokalemia after joint replacement. In the present study, our primary goal was to investigate the incidence and possible risk factors of hypokalemia after a total hip and knee replacement procedure was performed. Methods: This study included patients who underwent a unilateral total knee or hip arthroplasty in our department between April 2017 and March 2018. Serum potassium levels pre and post operation were collected and retrospectively analyzed. The differences in age, gender, body mass index (BMI), history of diseases, red blood cell (RBC), hemoglobin, hematocrit, glomerular filtration rate, ejection fraction, blood glucose, urine creatinine, urea nitrogen, intraoperative blood loss, operation time, drainage, preoperative potassium, surgery type, were compared between those patients diagnosed with hypokalemia and their non‐hypokalemia at different times post surgery. Thereafter, the risk factors of postoperative hypokalemia patients were analyzed using statistical procedure multiple logistic regression model. Results: The risk of hypokalemia after TJA was 53.1%, while, that on the first, third, and fifth day after operation was 12.5%, 40.7%, and 9.6% respectively. The serum potassium level on the first, third, and fifth postoperative days was 3.84 ± 0.32, 3.59 ± 0.34, and 3.80 ± 0.32 mmol/l, respectively. However, the level on the third day appeared to be the lowest (p = 0.015) of them all. The independent risk factors for hypokalemia after a total hip and knee replacement were the level of preoperative serum potassium concentration (p = 0.011), preoperative red blood cells counts (p = 0.027), and history of diabetes (p = 0.007). Conclusion: Regular monitoring of serum potassium concentration should be performed post TJA. We need to pay more attention to the patient's preoperative potassium levels along with their red blood cell counts especially in patients diagnosed with type 2 diabetes mellitus. [ABSTRACT FROM AUTHOR]

The ball screw is an essential component in feed drive systems whose accuracy is seriously affected by machine tool internal and external heat sources. In this paper, a thermal error compensation method for ball screws is proposed based on the extreme gradient boosting (XGBoost) algorithm and thermal expansion principle. An XGBoost predictive model is established using the time series temperature data collected from thermal characteristics experiments. Furthermore, the predictive performance between the XGBoost algorithm and BP neural network is compared to validate the effectiveness and robustness of the proposed model. The results show that the XGBoost model has better predictive performance. Based on this, the temperature of key points on the ball screw can be obtained, and thermal error (which is useful for pulse compensation) is predicted. Simultaneously, thermal error compensation experiments are carried out on the ball screw bench with average results of more than 45%. The presented thermal error compensation method proved effective and can provide a foundation for precision machining. [ABSTRACT FROM AUTHOR]

With the advancement of water conservancy projects around the world, several concrete-face rockfill dams (CFRDs) are being built in earthquake-prone areas. Among the many factors affecting the seismic safety of a CFRD, the dam–reservoir interaction is the most important one. Dam–reservoir interaction impacts the dynamic response and deformation of the dam and further influences the behavior of the face slab. This study conducted two centrifuge experiments to analyze the influence of dam–reservoir interaction on the behavior of a CFRD. Experimental models of concrete-face slab rockfill dams with and without an impoundment in four earthquake cases were established. In particular, a bidirectional earthquake motion was considered. The acceleration response and the settlement of the dam crest, bending moment and axial force of the facing slab, and the hydrodynamic pressure on the upstream slope of the dam were analyzed. The results showed that the dam–reservoir interaction increases the acceleration amplitude but decreases the progression of the dam crest settlement, enhances the dynamic axial force near the base, and reduces the bending moment near the dam crest of the face slab. Furthermore, the hydrodynamic pressure had a positive correlation with the dynamic axial force of the face slab. [ABSTRACT FROM AUTHOR]

The two-dimensional electron gas (2DEG) at the LaAlO3/SrTiO3 (LAO/STO) interface exhibits many emergent properties, such as high mobility, giant photoconductivity, the light-enhanced gating effect, etc., which are invaluable for basic research and potential applications. In this work, we report an unusual enhancement of persistent photoconductivity (PPC) by electrostatic gating (EG) at the LAO/STO interface. Under the influence of pre-EG processing, the 2DEG at the LAO/STO interface is triggered into a resistance state showing a more pronounced optical response and greatly enhanced PPC under light illumination (LI) at room temperature. These observations are found to be attributed to EG-induced interfacial polarization and the subsequent LI-accelerated depolarization at the interface. Based on these findings, a nonvolatile memory device made by this interface is proposed. Our work offers a new perspective for tuning the photoelectrical properties at the oxide interface, which is helpful for designing advanced photoelectric devices with high performance and multifunctionality. [ABSTRACT FROM AUTHOR]

High-quality Sr2CrWO6 (SCWO) films have been grown on SrTiO3 (STO) substrate by pulsed laser deposition under low oxygen pressure. With decrease of the film thickness, a drastic conductivity increase is observed. The Hall measurements show that the thicker the film, the lower the carrier density. An extrinsic mechanism of charge doping due to the dominance of oxygen vacancies at SCWO/STO interfaces is proposed. The distribution and gradient of carrier concentration in SCWO films are considered to be related to this phenomenon. Resistivity behavior observed in these films is found to follow the variable range hopping model. It is revealed that with increase of the film thickness, the extent of disorder in the lattice increases, which gives a clear evidence of disorder-induced localization charge carriers in these films. Magnetoresistance measurements show that there is a negative magnetoresistance in SCWO films, which is considered to be caused by the magnetic scattering of magnetic elements Cr3+ and W5+. In addition, a sign reversal of anisotropic magnetoresistance (AMR) in SCWO film is observed for the first time, when the temperature varies across a characteristic value, T M. Magnetizationâ€"temperature measurements demonstrate that this AMR sign reversal is caused by the direction transition of easy axis of magnetization from the in-plane ferromagnetic order at T > T M to the out-of-plane at T < T M. [ABSTRACT FROM AUTHOR]

This study aims to characterize the seismic responses of silt-interlayered stratified sandy tailings slopes. In order to achieve this, a series of model tests were carried out in an advanced centrifuge shaking table. The experimental results demonstrate that sandy tailings slopes interlayered with silts are more prone to flow failure compared with homogeneous slopes. The failure process of a steep silt-interlayered sandy slope is further elaborated in detail, and two modes of tailings release have been identified. The initial loading cycles may only lead to localized deformation near the relatively shallow silty layer; however, there is continuous build-up of excess pore water pressure in deeper sandy tailings. With increasing the number of loading cycles, more sandy tailings start to spread laterally, and ejection of tailings may occur. After ejection, the excess pore pressure turns to dissipate, while the tailings near slope crest become liquefied and then flow toward the downstream direction layer by layer, leading to tailings release. This is the first mode of tailings release. Due to the continuous lateral spreading, the displaced tailings eventually arrive at the crest of the starter dam and then flow along its slope at the downstream side, leading to tailings release. This is the second mode of tailings release. Those unique and invaluable observations can be used to improve the seismic design of tailings impoundments and to validate associated numerical methods. [ABSTRACT FROM AUTHOR]

The frequency-aliasing phenomenon, which can distort high-frequency harmonics in the analog input signal into low-frequency harmonics in the output digital signal, is widespread in the process of analog to digital conversions. The sorting-algorithm-based voltage-balance strategy is also such a conversion process. This strategy converts the analog-continuous-sinusoidal fundamental wave into the digital-discrete inserted-submodule number, deciding how many submodules are required to operate in modular multilevel converters (MMC). Thus, the frequency-aliasing phenomenon can occur in this strategy and deteriorate the performance of MMC as well. This article first proposes the mechanism of the frequency-aliasing phenomenon in the sorting-algorithm-based voltage-balance strategy. A quantitative analysis is then presented to indicate the root cause of the frequency-aliasing phenomenon in the voltage-balance strategy. This analysis also intuitively describes the frequency-aliasing phenomenon's effect, such as harmonic redistributions in the large-signal model, the phase delay in the small-signal model, and the associated deteriorations including the system stability's decrease and the power quality's reduction. Based on the above analysis, an optimal value design method is proposed to suppress the frequency-aliasing phenomenon by determining an appropriate voltage-balance frequency. A code restructuration method is further implemented to adapt the voltage-balance strategy to the optimal frequency and to avoid extra switching actions at the same time. The deteriorations caused by the frequency-aliasing phenomenon and the effectiveness of proposed methods are finally demonstrated via simulations experiments. [ABSTRACT FROM AUTHOR]

Underground structures in liquefiable ground are prone to severe earthquake damage, and the seismic responses of such underground structures can be affected by nearby superstructures. Two centrifuge shaking table tests on a precast underground structure with and without a superstructure above it in mildly inclined liquefiable ground were designed and conducted in this study. The seismic response of the underground structure was analyzed in terms of its acceleration, deformation, internal force, and waterproof performance. The influence of the superstructure on the underground structure seismic response, including the deformations and internal forces, was investigated by comparing the responses of the underground structure in the two tests. It was observed that the joints of the precast underground structure experienced greater deformations than the nonjoint positions and affected the overall seismic response of the underground structure. Among the nonjoint positions, the column and corners of the underground structure experienced relatively large deformations and internal forces. The joint-opening deformations and dynamic bending moments of the precast underground structure were mainly governed by soil shear deformation, and the increased soil lateral forces caused by excess pore pressure (EPP) accumulation increased the bending moment of the side walls. The superstructure could amplify the acceleration of the near-field soil and underground structure, thus intensifying the EPP accumulation and underground structure deformations and internal forces. The detrimental influence of superstructures on underground structures in liquefiable ground merits more attention in seismic design. [ABSTRACT FROM AUTHOR]

In recent years, probabilistic linguistic term set (PLT) is widely used in large group decision making (LGDM) for its integrity. However, the complexity of probabilistic linguistic LGDM and the large span of experts' profession cause two problems. On the one hand, it is difficult for all experts to give complete evaluation information in the form of PLTs. For this, we propose an expertise-based probabilistic linguistic evaluation information complement method. First, we identify authoritative experts under each attribute through professional hesitation and professional consistency. Then, we establish an optimization function to obtain the optimal missing value through the expectation score of authoritative experts and the linguistic term using habit of pending experts. On the other hand, the similarity between two experts cannot be fully represented by the sum of the distance of expert evaluation value. For this, we propose a two-stage similarity measurement method and introduce the distance weighting process, which not only measures the similarity between two expert evaluation values, but also measures the difference in degree of distance between two experts under different attributes. Finally, we apply this LGDM method to hot dry rock exploration site selection in southeast coast of China. [ABSTRACT FROM AUTHOR]

Brain‐derived neurotrophic factor (BDNF) has been reported to participate in fracture healing, whereas the mechanism is still unclear. Since osteoblast migration is important for fracture healing, investigating effects of BDNF on osteoblasts migration may help to reveal its mechanism. Here, MC3T3‐E1 cells were used in vitro while closed femur fracture mice were applied in vivo. Cells migration was assessed with Transwell assay. The protein expression was analysed by immunoblotting. X‐ray and Micro‐CT were performed at different time after fracture. Our results showed that BDNF promoted MC3T3‐E1 cells migration, integrin β1 expression and ERK1/2 and AKT phosphorylation. K252a, a specific inhibitor for TrkB, suppressed BDNF‐induced migration, integrin β1 expression and activation of ERK1/2 and AKT. PD98059 (an ERK1/2 inhibitor) and LY294002 (an AKT inhibitor) both inhibited BDNF‐induced migration and integrin β1 expression while integrin β1 blocking antibody only suppressed cell migration. X‐ray and Micro‐CT analyses showed that the adenoviral carried integrin β1 shRNA group had slower fracture healing at 7 and 21 days, but not 35 days compared to the control group. Thus, we proposed that BDNF stimulated MC3T3‐E1 cells migration by up‐regulating integrin β1 via TrkB mediated ERK1/2 and AKT signalling, and this may help to enhance the fracture healing. [ABSTRACT FROM AUTHOR]

For hydrogen evolution reaction (HER) in alkaline solution, the state‐of‐the‐art platinum(Pt)‐based electrocatalysts showed a bunch of drawbacks including high cost, poor durability and scarcity, making it essential to develop Pt‐free electrocatalysts. In this work, we employed a double‐solvent approach to prepare a ruthenium(Ru)‐dispersed metal‐organic framework composite, which was further pyrolyzed to obtain a novel Ru/C electrocatalyst with a Ru loading of 2.7 wt %. The target electrocatalyst showed ultrahigh activity for HER in 1 M KOH that outperformed commercial Pt/C catalyst (20 wt %) with an overpotential of 27 mV @ 25 mA cm−2 and 86 mV @ 100 mA cm−2. This work not only provides a promising electrocatalyst for highly efficient HER in alkaline solution, but also offers a double‐solvent strategy for the fabrication of various metal/carbon composites with uniform distribution of ultrafine metal nanoparticles. [ABSTRACT FROM AUTHOR]

Striking effects are expected in solid-solution alloying, which offers enormous possibilities for various applications, especially in industrial catalysis. However, phase diagrams have revealed that a wide range of metallic elements are immiscible with each other even above their melting points. Achieving such unknown alloying between different immiscible metallic elements is highly desirable but challenging. Here, for the first time, by using an innovative solid ligand-assisted approach, we achieve the solid-solution alloying between the bulk-immiscible Au and Rh in plenty of clean, ultrafine (∼ 1.6 nm) and highly dispersed nanoclusters. The solid-solution alloying of immiscible Au and Rh significantly enhances their catalytic performance toward the hydrogen evolution from formic acid in contrast to the monometallic Au and Rh nanoclusters. Moreover, the resultant binary solid-solution nanoclusters are stable without any segregation during catalytic reactions. The approach demonstrated here for homogeneously mixing the immiscible metals at the atomic scale will benefit the creation of advanced alloys and their catalytic applications in future. [ABSTRACT FROM AUTHOR]

Purpose: Infected nonunion after open reduction internal fixation (ORIF) is a serious complication. The aim of this study was to evaluate the usefulness of serum D-dimer for preoperative diagnosis of infected nonunion. Patients and methods: Patients undergoing debridement and external fixation for infected nonunion (n=32) and replacement of internal fixation due to aseptic failure (n=34) were enrolled and compared in this retrospective study. The optimum cutoff value of D-dimer for identification of infected nonunion was determined by calculating the Youden J statistic. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of four preoperative laboratory parameters—serum D-dimer level, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)—for diagnosis of infected nonunion were compared. Results: Serum D-dimer level was significantly higher in patients with infected nonunion than in patients with aseptic nonunion: 2.62 mg/mL (range, 0.13–11.90 mg/mL) vs 0.35 mg/mL (range, 0.07–6.46 mg/mL; p<0.001). WBC count, CRP, and ESR demonstrated sensitivity of 12.5% (95% CI: 4.08–29.93), 40.6% (95% CI: 24.22–59.21), and 56.3% (95% CI: 37.88–73.16), respectively, and specificity of 94.1% (95% CI: 78.94–98.97), 88.2% (95% CI: 71.61–96.16), and 85.3% (95% CI: 68.17–94.46), respectively. Using the Youden index, 1.70 mg/mL was determined as the optimal threshold value for serum D-dimer for the diagnosis of infected nonunion. The sensitivity and specificity of serum D-dimer (>1.70 mg/mL) were 75.0% (95% CI: 56.25–87.87) and 91.2% (95% CI: 75.19–97.69). Conclusions: Serum D-dimer level may be useful for preoperative prediction of infected nonunion in patients after ORIF. [ABSTRACT FROM AUTHOR]

Objectives:Deep surgical site infection (DSSI) is one of the most serious complications after open induction internal fixation (ORIF) for traumatic limb fractures. In this study, we aimed to investigate the diagnostic role of platelet indices (platelet count [PLT], mean platelet volume [MPV], and platelet distribution width [PDW]) in DSSI.Patients and methods:Data obtained between January 2011 and December 2017 in The Affiliated Drum Tower Hospital of Nanjing University Medical School from cases (n=29) with DSSI and fracture control subjects (n=29) matched for age, gender, and fracture type were analyzed. The white blood cell (WBC) count, neutrophil count, neutrophil percentage, and platelet indices from blood samples were compared between case and control groups. In addition, the cutoff value, sensitivity, and specificity were calculated by receiver-operating characteristic (ROC) curves.Results: No significant differences were detected in demographic features, the WBC count, neutrophil count, neutrophil percentage, and MPV values between two groups (P>0.05). The PLT values were significantly higher in the case group than in the control group (303.00±139.27 vs 196.10±59.61 [109/μL], P=0.001). The PDW values of the case and control groups were 11.77±2.71 and 13.19±2.39%, respectively, and were significantly lower in the case group (P=0.001). ROC curve analysis suggested a cutoff point for PLT as 215.50 (109/μL, larger values indicate pathology) for the diagnosis of DSSI with the sensitivity and specificity of 79.3 and 72.4%, respectively. For PDW, the cutoff point was 10.35% (smaller values indicate patients) for the diagnosis of DSSI with the sensitivity and specificity of 37.9 and 96.6%, respectively.Conclusion: Our results suggest that PDW combined with PLT can be used as an important additional test for the diagnosis of DSSI after ORIF for traumatic limb fractures, thus reducing the cost and loss of time. [ABSTRACT FROM AUTHOR]

Background: GIT1, a scaffold protein with ubiquitous multi-domain, is involved in many cellular processes. In recent years, it was proved that GIT1 participated in various tumors' growth or metastasis. However, the biological function of GIT1 in osteosarcoma is still unclear. In this study, we aimed to investigate the role and mechanism of GIT1 in osteosarcoma.Materials and methods: Human osteosarcoma tissues were obtained to investigate the distribution of GIT1. Adequate osteosarcoma cells were stably infected with lentivirus to knockdown GIT1 level and then was used to carry out cell invasion and vascular endothelial growth factor (VEGF) assay in vitro. Orthotopic femoral osteosarcoma model was constructed to investigate the growth, invasion, and angiogenesis in vivo. Western blot was used to detect extracellular signal-regulated kinase (ERK1/2) activation and hypoxia-inducible factor-1 (HIF-1α) expression.Results: In this study, we found that GIT1 was distributed in human osteosarcoma tissues and highly expressed in osteosarcoma (OS) cells. Knockdown of GIT1 inhibited cell invasion and VEGF release in vitro and suppressed tumor growth, invasion, and angiogenesis in vivo. Furthermore, knockdown of GIT1 substantially downregulated the protein levels of p-ERK and HIF-1α in OST cells and inhibition of p-ERK by PD98059 could significantly decrease the expression of HIF-1α and concentration of VEGF in GIT1-shRNA-treated cells.Conclusion: GIT1 knockdown can effectively inhibit the growth, invasion, and angiogenesis of osteosarcoma. Thus, GIT1 might act as an oncogenic factor in osteosarcoma and could be a potential molecular target for osteosarcoma gene therapy. [ABSTRACT FROM AUTHOR]

Background: Preoperative deep vein thrombosis (DVT) is a common complication in patients with hip fractures. Chronic kidney disease (CKD) as a frequent comorbidity in middle-aged and elderly patients with hip fractures is known to promote a proinflammatory and prothrombotic state. We aimed to identify whether CKD can increase the risk of DVT in middle-aged and elderly patients with hip fractures, as well as identify other risk factors.Patients and methods: We retrospectively studied 248 middle-aged and elderly patients with hip fractures who were admitted to our hospital from January 2016 to June 2017, meeting all the inclusion criteria. Doppler ultrasonography was used to diagnose DVT. Patients with CKD were classified into five stages according to the Kidney Diseases Outcomes Quality Initiative. We identified whether CKD could increase the occurrence of preoperative DVT in middle-aged and elderly patients with hip fractures and further investigated other independent risk factors for preoperative DVT by using univariate and multivariate analyses.Results: The mean estimated glomerular filtration rate was 125.7±41.4 mL/min/1.73 m2. Briefly, 82.3% (n=204) had been diagnosed with normal kidney function, 11.7% (n=29) with mildly decreased kidney function, and 6.0% (n=15) with stage 3 and 4 CKD. In addition, of the 248 patients, 11.7% (n=29) developed DVT before surgery. Independent predictors of preoperative DVT identified by multivariate analyses were age, prolonged bedridden time, increased levels of fibrinogen, and lower estimated glomerular filtration rate.Conclusion: CKD can increase the risk rate of preoperative DVT in middle-aged and elderly patients with hip fractures. Additionally, age, prolonged bedridden time, and increased levels of fibrinogen were also independent risk factors for preoperative DVT in these patients. We should take preventive measures for these patients with risk factors in order to reduce the incidence of preoperative DVT. [ABSTRACT FROM AUTHOR]

Aging- or creep-related phenomena in sand have been widely studied, and the discrete element method (DEM) has been frequently used to model the associated soil behavior and then to explore the associated underlying mechanisms. However, several difficulties involved in modeling still remain unsolved. To resolve these difficulties, a new approach based on the effect of the microfracturing of asperities is proposed in this study for the DEM modeling of the sand aging or creep process through several aging cycles of associated reduction in the mobilized friction resistance at particle contacts and subsequent particle rearrangement to reach a new equilibrium state. This approach can be easily incorporated into different contact models and DEM simulations of the loading, unloading, and/or reloading processes, in either drained or undrained conditions, before and/or after aging. This new approach is proven effective because the DEM simulations incorporated with this new approach can satisfactorily reproduce the experimental observations in the triaxial creep process, drained and undrained recompression after aging, and 1D secondary compression and rebound. The simulation results also indicate that, based on the stress-force-fabric relationship, the contribution from the contact normal anisotropy to the deviatoric stress q gradually increases, whereas the contribution from the tangential force anisotropy becomes less during triaxial creep under a constant q. Moreover, the contacts between particles are gradually away from the state where the frictional resistance is fully mobilized, and then become more stable. During the subsequent triaxial recompression after creep, the aged samples exhibit enhanced soil stiffness, which is also found to be associated with the evolution of the invariants of the anisotropy tensors. It is worthwhile noting that the aging or creep effects on the microstructural changes, e.g., the invariants of the anisotropy tensors, can be gradually erased upon further recompression. This explains why the stress-strain responses of the aged samples during recompression gradually rejoin the original stress-strain response obtained from the sample without being subjected to aging or creep. [ABSTRACT FROM AUTHOR]

Understanding the soil responses during monotonic jacking can help improve the estimation of axial capacity in pile foundation design. To examine the soil responses in terms of strain and stress distributions, stress paths, the movement of particles and contact force mobilization during monotonic jacking, a three-dimensional simulation of a centrifuge model pile test was performed using the discrete element method. The simulation results show great resemblance to the measurements from the centrifuge model pile test. The distribution of incremental deviatoric strain $$d\varepsilon _{q}$$ indicates the formation of a shear band in the shoulder of the 'nose cone' that is beneath the pile base. Based on this, the soil mass can be divided into three zones, i.e., the 'nose cone' (zone I), the shear band (zone II) and the surrounding soil beyond the shear band (zone III). The distributions of the radial stress $$\sigma _{r}^\prime $$ , hoop stress $$\sigma _{\theta }^\prime $$ , vertical stress $$\sigma _{v}^\prime $$ and shear stress $$\tau _{rv}^\prime $$ are in different modes and high-gradient distributions of mean stress $$ p^\prime $$ and deviatoric stress $$q$$ are found in zone II. As for the stress path, the surrounding soil experiences four phases in terms of changes in $$ p^\prime $$ and $$q$$ during monotonic jacking, and the change in the soil stress state decreases with increasing distance from the pile centerline. From a microscopic point of view, the particles in the shear band rotate strongly in a similar direction, fully mobilizing the frictions at the associated contacts. This provides a micromechanical explanation for the soil failure during monotonic jacking. [ABSTRACT FROM AUTHOR]

Edaravone, a free radical scavenger, has shown neuroprotection properties in both animals and humans. To evaluate the mechanisms involved, we obtained a culture of almost pure neurons. The neurons, either untreated or prophylactically treated with edaravone, were exposed to 300 μM hydrogen peroxide. We examined alterations in mitochondria, the percent of apoptotic cells and the immunoblots of key regulatory proteins, and the protein-protein interactions and the cellular locations of cytochrome c. The levels of p-JNK (Thr183/Tyr185) and cytochrome c in cytosol and BAX in heavy membrane (HM), respectively, were increased at 0.5 h and reached the peak at 12 h after stimulation with hydrogen peroxide. The levels of p-BAD and BAX in the cytosol and the interaction between BAD and 14-3-3 were decreased in the untreated neurons. However, edaravone could prevent these changes. In addition, mitochondrial morphology was better preserved and the percentage of apoptosis was lower under the treatment with edaravone. In summary, the present study indicates that edaravone could protect neurons by inhibiting: (1) the activity of JNK, (2) the disassociation of BAD from 14-3-3, and (3) the translocation of BAX from cytosol to mitochondria. [ABSTRACT FROM AUTHOR]

Osteoblast migration and proliferation are fundamental processes in bone healing. We demonstrated that the G-protein-coupled receptor kinase interacting protein 1(GIT1) is a key regulator of bone mass and osteoblast cell migration, but little is known about GIT1 regulation by upstream signaling systems or the impact of GIT1 on downstream effectors. We found that platelet-derived growth factor (PDGF) stimulated the GIT1 tyrosine phosphorylation in osteoblast cells and increased the association of GIT1 with focal adhesion kinase (FAK) at osteoblast focal adhesions. The Src inhibitor PP2 and FAK siRNA inhibited GIT1 tyrosine phosphorylation and the increased association between GIT1 and FAK following stimulation with PDGF. The spa2 homology domain (SHD) of GIT1 was required for association with FAK. Furthermore, phosphorylation of tyrosine 321 of GIT1, which is localized within the SHD, was critical for association with FAK. Mutagenesis analysis revealed that GIT1Y321F inhibited the increased association between GIT1 and FAK. Immunofluorescent staining revealed that GIT1Y321F inhibited FAK activation in focal adhesions after PGDF stimulation. A cell spreading assay demonstrated that GIT1Y321F also inhibited osteoblast cell motility, while the Boyden chamber assay demonstrated that the GIT1Y321F mutation inhibited PDGF-induced osteoblastic cell migration. Phosphorylation of tyrosine 321 of GIT1 is necessary for PDGF-induced association with FAK, FAK activation in focal adhesions, and for osteoblastic cell migration. [ABSTRACT FROM AUTHOR]