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Psychological stress causes structural and metabolic dysfunction of masseter muscles. The anti-inflammatory and anti-oxidative polyphenol curcumin plays a local antioxidant role in rat masseter muscles under psychological stress by an as-yet-unknown mechanism. The present study aimed to assess curcumin anti-inflammatory and anti-oxidative effects on masseter muscle and its possible molecular mechanisms.We constructed a rat model of chronic unpredictable moderate stress (CUMS). Psychological stress was assessed by determining the levels of adrenocorticotropic hormone (ACTH) and cortisol in serum. Enzyme-linked immunosorbent assays measured inflammatory cytokines and markers of oxidative stress in masseter muscles. Levels of high-mobility group box 1 (HMGB1), interleukin (IL)-1β, IL-6 and tumour necrosis factor-alpha (TNF-α) were determined using quantitative PCR analyses and immunofluorescent staining. Toll-like receptor 4 (TLR4) and nuclear factor kappa B (NF-κB) activation were examined using western blotting.The CUMS group showed increased serum cortisol and ACTH levels. Pathological changes in the ultrastructure, oxidative stress and inflammatory cytokines in the masseter muscles were also observed. Curcumin treatment (50, 100 mg/kg) ameliorated these changes significantly by varying degrees. Mechanistically, increased levels of phosphorylated NF-κB, toll-like receptor 4 and HMGB1 were observed, which were also ameliorated by curcumin treatment.Curcumin can reduce local pathological changes, levels of oxidative stress and inflammatory factors in masseter muscles. Psychological stress activates HMGB1 expression and increases the expression of downstream TLR4 and p-NF-κB, which could be reduced by curcumin. Thus, curcumin might exert anti-inflammatory and antioxidant effects in masseter muscles via the HMGB1/TLR4/NF-κB pathway.

Due to the complexity of the biomolecules and titanium (Ti) combination, it is a challenge to modify the implant surface with biological cytokines. The study proposed a new method for immobilizing cytokines on implant surface to solve the problem of low osseointegration under type 2 diabetes mellitus (T2DM) condition. This new modified protein that connected Ti-binding artificial aptamer minTBP-1 with Insulin-like growth factor I (IGF-I), had a special strong affinity with Ti and a therapeutic effect on diabetic bone loss. According to the copies of minTBP-1, three proteins were prepared, namely minTBP-1-IGF-1, 2minTBP-1-IGF-1 and 3minTBP-1-IGF-1. Compared with the other modified proteins, 3minTBP-1-IGF-1 adsorbed most on the Ti surface. Additionally, this biointerface demonstrated the most uniform state and the strongest hydrophilicity. In vitro results showed that the 3minTBP-1-IGF-1 significantly increased the adhesion, proliferation, and mineralization activity of osteoblasts under T2DM conditions when compared with the control group and the other modified IGF-1s groups. Real-time PCR assay results confirmed that 3minTBP-1-IGF-1 could effectively promote the expression of osteogenic genes, that is, ALP, BMP-2, OCN, OPG, and Runx2. All these data indicated that the 3minTBP-1-IGF-1 had the most efficacious effect in promoting osteoblasts osteogenesis in diabetic conditions, and may be a promising option for further clinical use.

The carrier type and concentration of a semiconductor are intimately associated with the kind and density of point defects possessed within itself. And two-dimensional SnS intrinsically exhibits a p-type semiconductor behavior, which is correlated with Sn vacancies. Here, we present tuning the hole concentration of SnS in a wide range of 1016–1019 cm−3 through a cationic lattice site vacancy engineering strategy, by simply changing the molar ratio of raw materials, i.e., SnCl2versus Na2S·9H2O. The thermoelectric properties of these Sn vacancy engineered SnS samples were investigated. Combining the significantly improved power factor due to the increased hole concentration with an intrinsically low lattice thermal conductivity arising from lattice anharmonicity, a respectable zT value up to 0.8 at 873 K could be achieved in polycrystalline SnS. This work demonstrates that low-cost and easily fabricated SnS is a promising candidate for thermoelectric application, despite it usually being considered as a low-asymmetrical crystal with a relatively large band gap (∼1.1 eV).

BackgroundDepression, one of the most frequently-occurring psychiatric disorders worldwide, is a significant inflammatory disorder. The polyphenol curcumin (Cur), which is extracted from Curcuma longa, has marked anti-inflammatory and anti‑oxidative effects against inflammatory diseases. However, whether Cur has antidepressant effects and the possible mechanisms, are unclear. The present study aimed to assess Cur’s beneficial effects on depressive-like behaviors using a chronic unpredictable mild stress (CUMS) model and its possible molecular mechanisms. MethodsWe performed CUMS treated Sprague Dawley (SD) rats as a model of depression. Behavioral observations were performed by sucrose preference test (SPT), force swimming test (FST) and tail suspension test (TST). Hippocampal expression of oxidative stress markers and inflammatory cytokines were measured with ELISA. Hippocampal expression of high-mobility group box 1 (HMGB1), IL-1β, TNF-α and IL-6 were determined with quantitative PCR analyses and immunofluorescent staining. Hippocampal Toll-like receptor 4 (TLR4) and NF-κB activation were examined with Western blotting analysis.ResultsRats subjected to CUMS demonstrated marked depressive-like behavior (decreased locomotor activity and sucrose intake, and prolonged immobility). Their levels of oxidative stress and inflammatory cytokines increased significantly, and their levels of phosphorylated nuclear factor kappa-B (NF-κB), toll-like receptor 4 (TLR4), and HMGB1, also increased in the hippocampus. The changes were ameliorated significantly by treatment with Cur (50, 100 mg/kg) to varying degrees.Conclusion This study demonstrated that Cur has a potent antidepressant effect via the HMGB1/TLR4/NF-κB pathway, suggesting that Cur might be a promising therapeutic drug for depression.

The rational design and fabrication of nanostructures has become a fashionable strategy for pursing high thermoelectric performance in solid-state materials. Here we report nanostructured Te–Sb2Te3 composites with significantly enhanced thermoelectric performance through a scalable bottom-up method followed by a rapid sintering process. The power factor along with the carrier concentration could be significantly enhanced by increasing the number of point defects of . Meanwhile, a great number of boundaries and hetero-interfaces between the Te and Sb2Te3 nanoparticles could play an important role in blocking phonons, resulting in the evident suppression of lattice thermal conductivity. Ultimately, a highest zT value close to 1.0 could be achieved at 623 K in samples with components of 2.6 mol% Sb2Te3 and 97.4 mol% Te. Such a peak zT value is comparable to that of doped Te materials synthesized by the conventional solid-state reaction process. This work reveals that high thermoelectric performance could be realized in an intentionally designed nanocomposite by synergistically improving the power factor and suppressing the lattice thermal conductivity.

It is commonly accepted that psychological stress is closely associated with the occurrence and development of chronic orofacial pain. However, the pathogenesis underlying this process has not been fully elucidated. In the present study, we explored the role of N-methyl-D-aspartate receptors (NMDARs) and Jun N-terminal kinase (JNK) mediated intercellular communication between neurons and astrocytes in the spinal trigeminal nucleus caudalis (Vc) in the induction of masseter hyperalgesia by psychological stress in rats. We found that subjecting rats to 14 days of restraint stress (8 h/d) caused a significant decrease in body weight gain, behavioral changes and marked masseter hyperalgesia in the rats. We also found that exposure to restraint stress for 14 days caused the expression of pJNK in astrocytes in the Vc to significantly increase, and intrathecally infusing a JNK inhibitor significantly prevented restraint stress-induced masseter hyperalgesia in the rats. In addition, after exposure to restraint stress for 14 days, the stressed group exhibited a noticeably increased expression level of pNR2B in neurons in the Vc. Then, we intrathecally injected MK-801 (an NMDAR inhibitor) and ifenprodil (a selective NR2B subunit antagonist) and observed that the two types of inhibitors not only alleviated masseter hyperalgesia but also significantly inhibited the phosphorylation of JNK in the Vc after restraint stress; this indicates that the effect of NMDAR antagonists may influence the activation of astrocytic JNK. Furthermore, inhibitors of neuronal nitric oxide synthase (nNOS) activation and guanylate cyclase (GC) inhibitor could not only inhibit the expression of pJNK in the Vc, but also effectively alleviate masseter hyperalgesia induced by restraint stress. Taken together, our results suggest that NMDAR activation could increase JNK phosphorylation in astrocytes after restraint stress, which may depend on the nNOS-GC pathway. The intercellular communication between neurons and astrocytes in the Vc may play a key role in the induction of masseter muscle hyperalgesia by psychological stress in rats.

Background Although tissue-engineered cartilage has been broadly studied, complete integration of regenerated cartilage with residual cartilage is still difficult for the inferior mechanical and biochemical feature of neocartilage. Chondrogenesis of mesenchymal stem cells can be induced by biophysical and biochemical factors. Methods In this study, autologous platelet-rich fibrin (PRF) membrane was used as a growth factor-rich scaffold that may facilitate differentiation of the transplanted bone marrow mesenchymal stem cells (BMSCs). At the same time, hydrostatic pressure was adopted for pre-adjustment of the seed cells before transplantation that may promote the mechanical flexibility of neocartilage. Results An in vitro study showed that the feasible hydrostatic pressure stimulation substantially promoted the chondrogenic potential of in vitro-cultured BMSC/PRF construct. In vivo results revealed that at every time point, the newborn tissues were the most favorable in the pressure-pretreated BMSC/PRF transplant group. Besides, the transplantation of feasible hydrostatic pressure-pretreated construct by BMSC sheet fragments and PRF granules could obviously improve the integration between the regenerated cartilage and host cartilage milieu, and thereby achieve boundaryless repair between the neocartilage and residual host cartilage tissue in rabbit temporomandibular joints. It could be concluded that feasible hydrostatic pressure may effectively promote the proliferation and chondrogenic differentiation of BMSCs in a BMSC/PRF construct. Conclusion This newly formed construct with biomechanical flexibility showed a superior capacity for cartilage regeneration by promoting the mechanical properties and integration of neocartilage.

In swallowing, the tongue contacts against the hard palate to generate pressure for propelling a bolus from the oral cavity into the pharynx. Meanwhile, the hyoid and larynx move upward and forward to facilitate the bolus from the pharynx into the esophagus. It has been well known that sequential coordination between those actions is critical for safety accomplishment of swallowing. However, the absence of noninvasive assessment for it limits the detection to the physiological symptom of dysphagia. We applied a sensor sheet on the hard palate to measure tongue contact pressure and a bend sensor on the frontal neck to monitor the laryngeal movement, which was synchronized with hyoid motion for assessing the coordination between both actions in 14 healthy male subjects when swallowing 5ml of water. The sequential order of tongue pressure and hyoid movement was successfully displayed. Tongue pressure was produced after slight movement of the hyoid and closely to the hyoid elevation, then reached a maximum when the hyoid stabilized in the most anterior-superior position, and ceased concurrently with the onset of hyoid descent. Additionally, the synchronized data from both sensors showed positive correlations between identified time points on the laryngeal signal waveform and onset, peak and offset of tongue pressure. Our sensing system successfully showed the coordination between tongue pressure production and hyoid motion, and could be a simple and noninvasive method for clinicians to evaluate the oral and pharyngeal stages of swallowing.

It is commonly accepted that psychological stress contributes to the development of temporomandibular joint disorders, in which chronic orofacial pain is the main symptom. However, the central mechanism underlying the development of these disorders has remained unclear. The current study was performed to determine the involvement of the glia in the trigeminal spinal subnucleus caudalis in stress-induced increases in masseter muscle hyperalgesia in rats. After being subjected to chronic restraint stress, the animals showed decreased body weight gain, behavioral changes and marked masseter allodynia. We also found that astrocytes, but not microglia, in the trigeminal subnucleus caudalis (Vc) were dramatically activated. A further analysis was undertaken to investigate the contribution of the glia; we intrathecally injected l-α-aminoadipate (astrocyte-specific inhibitor) and/or minocycline (microglia-specific inhibitor) into the stressed rats. Our results showed that l-α-aminoadipate (LAA), but not minocycline, could significantly attenuate the mechanical masseter allodynia and behavioral changes induced by restraint stress. In addition, the expression of interleukin-1β (IL-1β) and phosphorylated N-methyl-d-aspartic acid receptor 1 (p-NR1) in the Vc was significantly increased after chronic restraint stress, whereas LAA dramatically inhibited the overexpression of IL-1β and p-NR1. Taken together, these results suggest that activated astrocytes in the Vc may be one of the most important factors in the pathophysiology of masseter hyperalgesia induced by restraint stress and the following overexpression of IL-1β and excessive NMDAR phosphorylation may ultimately contribute to masseter hyperalgesia. Thus, inhibiting spinal astrocytic activation may represent a novel therapeutic strategy for the treatment of orofacial pain induced by stress.

Swallowing is a very important and complex physiological behaviour. The dynamic of swallowing has created great interest as any procedural abnormality will result in dysphagia and even lower quality of life. However, a non-invasive evaluation of biomechanical coordination during oropharyngeal swallowing, which includes the activities of the tongue, the hyoid and swallowing-related muscles, has not yet been achieved. In the present study, we recruited fifteen subjects, and a non-invasive sensing system composed of a pressure sensor, a bend sensor, surface electrodes and a microphone was created to simultaneously monitor tongue pressure, hyoid motion, and surface EMG of swallowing-related muscles, as well as take sound recordings, when the subjects swallowed 5 ml of water. In addition to obtaining the durations of certain motor events, the considerable time (beginning, peak and ending time) of tongue pressure production, suprahyoid and infrahyoid muscle activity and hyoid motion were successfully measured. Moreover, the significant correlations between swallowing-related muscles, tongue pressure, and the hyoid were confirmed. These findings suggest that the non-invasive sensing system has potential as a good candidate for monitoring and evaluating the oropharyngeal process of swallowing, which may be useful in clinical work involving dysphagia evaluation and rehabilitation.

To explore the effect of long-term stress on the temporomandibular joint (TMJ) condyle and its possible underlying mechanism.A 12-week, chronic unpredictable mild stress (CUMS) model was used to induce long-term psychological stress in rats. Rats were randomly divided into control group (CONT), chronic unpredictable mild stress group (CUMS) and chronic unpredictable mild stress with fluoxetine treatment group (CUMS + DT) (n = 30 per group). A 5 mg/kg dose of fluoxetine was intraperitoneally injected daily 0.5 h before stress. A sucrose preference test, plasma corticosterone test and open-field test were performed to verify the feasibility of the CUMS model. Histopathology was used to observe the pathological changes of condyle. The expression levels of inflammatory cytokines, matrix metalloproteases (MMPs) and extracellular matrix (ECM) were measured by real-time polymerase chain reaction, western blotting and immunohistochemistry.At 8 and 12 weeks after exposure to CUMS, the rats showed higher plasma corticosterone than the control rats. Additionally, for the open-field test, the rats exposed to CUMS spent more time in the centre zone and moved a shorter distance than the control and drug treatment rats. In addition, pathological changes in the condylar cartilage occurred in the 8-week CUMS subgroup and were more obvious in the 12-week CUMS subgroup. The CUMS caused an increase in the secretion of inflammatory cytokines, imbalanced expression of MMPs and tissue inhibitor of metalloproteinase-1 and accelerated degradation of ECM in condylar cartilage in a time-dependent manner.Osteoarthritis-like lesions can be caused by long-term CUMS in the mandibular condyles, which suggests that the imbalance in chondrocyte-secreted regulatory factors within the cartilage of the TMJ may play an important role in cartilage injury induced by psychological stress.

The present study aimed to analyze novel mechanisms underlying Nrf2-mediated anti-apoptosis in periodontal ligament stem cells (PDLSCs) in the periodontitis oxidative microenvironment. We created an oxidative stress model with H2O2-treated PDLSCs. We used real-time PCR, Western blotting, TUNEL staining, fluorogenic assay and transfer genetics to confirm the degree of oxidative stress and apoptosis as well as the function of nuclear factor-erythroid 2-related factor 2 (Nrf2). We demonstrated that with upregulated levels of reactive oxygen species (ROS) and malondialdehyde (MDA), the effect of oxidative stress was obvious under H2O2 treatment. Oxidative molecules were altered after the H2O2 exposure, whereby the signaling of Nrf2 was activated with an increase in its downstream effectors, heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1) and γ-glutamyl cysteine synthetase (γ-GCS). Additionally, the apoptosis levels gradually increased with oxidative stress by the upregulation of caspase-9, caspase-3, Bax and c-Fos levels in addition to the downregulation of Bcl-2. However, there was no alterations in levels of caspase-8. The enhanced antioxidant effect could not mitigate the occurrence of apoptosis. Furthermore, Nrf2 overexpression effectively improved the anti-oxidative levels and increased cell proliferation. At the same time, overexpression effectively restrained TUNEL staining and decreased the molecular levels of caspase-9, caspase-3, Bax and c-Fos, but not that of caspase-8. In contrast, silencing the expression of Nrf2 levels had the opposite effect. Collectively, Nrf2 alleviates PDLSCs via its effects on regulating oxidative stress and anti-intrinsic apoptosis by the activation of oxidative enzymes.

A reactive power optimization method based on interval arithmetic is presented to solve the uncertainty of the output of distributed generation (DG) and the effects of load fluctuation. The concept of interval number and interval arithmetic is introduced to model the interval power flow of distribution system, which is iterated by using the Krawczyk-Moore operator. The objective function is to minimize the interval midpoint value of system’s power loss, with taking the interval voltage constraints into consideration for the interval reactive power optimization model. A modified IEEE 14-bus system is used to validate the proposed model and its Particle Swarm Optimization (PSO) algorithm. The simulation results show that the proposed method is effective.

Objective To investigate the correlation between psychological stress and masseter muscle (MM) alterations, and explore the therapeutic agents for restoring the impaired masticatory muscle. Design We established a chronic unpredictable mild stress (CUMS) animal model and observed the changes of ultrastructure, redox homeostasis and energy metabolism in MM in rats with and without curcumin treatment. Results The depressive-like behavior in stressed rats was confirmed by the evidences of altered behaviors in sucrose preference test and open field test; while these phenomena were eased by curcumin. Except for the pathological changes in ultrastructure, decreased SOD, GSH-Px, CAT, Na+-K+ATPase, and Ca2+-Mg2+ATPase activities as well as increased MDA and LD content and LDH activity were also observed in MM in stressed rats. However, curcumin was capable of reversing CUMS-induced MM disorder by improving the activities of the examined anti-oxidant enzymes and energy metabolism enzymes. Additionally, the increased MDA content, LD content, and LDH activity in stressed rats were reduced by curcumin. Conclusion All the findings indicate the adverse effects of CUMS on MM function in rats, and raise the possibility of developing curcumin as a potential therapeutic agent for psychological stress-induced masseter dysfunction.

Ecohydrological research focuses on the relationship between changes in the hydrological conditions and the response of plant communities to those changes. To save the degraded riparian forests at the lower reaches of the Tarim River, water conveyance embankments (whose goal is to prevent water from overflowing the riverbanks) were constructed mid-stream in order to guide the watercourse down to the river's destination. To investigate and evaluate the influence of these embankments on the Tarim River's riparian forest communities, we prepared three monitoring sections (five others were added later) that included six monitoring wells, six vegetation sample plots and six soil profiles at each section. From 2001 to 2007, data on groundwater depth, vegetation coverage, species diversity, total dissolved solids and concentrations of ions were collected and analysed. The results indicate that groundwater depths gradually increased, total dissolved solids and major ions in groundwater sharply increased and vegetation coverage and species diversity declined. Moreover, at the start of our investigation, the hydrological connection extended more than 1000 m from the embankments; by 2007, however, the region beyond 800 m had become a water and salinity discharging area. On the basis of these findings, the removal of the embankments should be urgently considered to protect the riparian forest ecosystems. Copyright © 2013 John Wiley & Sons, Ltd.

Two glasses with different contents of fluorine were fabricated. A single phase, KMg 3.25 Si 3.625 O 10 F 2 , precipitated in both of the glass samples after heat treatment. Both the crystallization activation energy ( En ) and the frequency factor ( ν ) increased with increasing fluorine content. This means that the fluorine content has a dual effect on the crystallization of fluorosilicic mica glass; the effect on the frequency factor is predominant. The flexural strength of the as-cerammed glass ceramic containing more fluorine is larger than that containing less fluorine when heated to the same temperature.

Ge-Sb-Te alloys have been widely used in optical/electrical memory storage. Because of the extremely fast crystalline-amorphous transition, they are also expected to play a vital role in next generation nonvolatile microelectronic memory devices. However, the distribution and structural properties of vacancies have been one of the key issues in determining the speed of melting (or amorphization), phase-stability and heat-dissipation of rock-salt GeSbTe, which is crucial for its technological breakthrough in memory devices. Using spherical aberration-aberration corrected scanning transmission electron microscopy and atomic scale energy-dispersive X-ray mapping, we observe a new rock-salt structure with high-degree vacancy ordering (or layered-like ordering) at an elevated temperature, which is a result of phase transition from the rock-salt phase with randomly distributed vacancies. First-principles calculations reveal that the phase transition is an energetically favored process. Moreover, molecular dynamics studies suggest that the melting of the cubic rock-salt phases is initiated at the vacancies, which propagate to nearby regions. The observation of multi-rock-salt phases suggests another route for multi-level data storage using GeSbTe.

At the entrance temperature of 300°C, the effect of mill temperature on the texture and microstructure evolution was worked to 85/15 α-brass by two rollings with mill temperatures calibrated as 28°C for one rolling and 55°C for another, in which TEM was employed to reveal the microstructures, and ODF to represent the related textures. From the experiment evidence, a detailed discussion was made and led to a conclusion: in current rolling, with recovery, mill temperature influences the rolling texture and microstructure development through chilling and the working temperature induced deformation mechanisms change, the former one affecting B intensities, by contrast, the latter one leading to a texture transition.

In this study, SEM and Köhlhoff etching were employed to follow the rolling texture and microstructure development in 93/7 brass that had been homogeneously cold rolled to different plastic strains. Correlated with FEM to rolling process, the effect of strain field on rolling texture and microstructure development in rolled 93/7 brass is conducted and reasonable conclusion is obtained.

Psychological factors can be correlated with temporomandibular disorders (TMDs), but the mechanisms are unknown. In the present study, we examined the microstructural changes and expression of proinflammatory cytokines in mandibular condylar cartilage of the temporomandibular joint (TMJ) in a psychological stress animal model. Male Sprague-Dawley rats (8 weeks old, 210 ± 10 g) were randomly divided into 3 groups: psychological stress (PS, N = 48), foot shock (FS, N = 24), and control (N = 48). After inducing psychological stress using a communication box with the FS rats for 1, 3, or 5 weeks, PS rats were sacrificed and compared to their matched control littermates, which received no stress and were killed at the same times as the PS rats. Body and adrenal gland weight were measured and corticosterone and adrenocorticotropic hormone levels were determined by radioimmunoassay. After hematoxylin-eosin staining for histological observation, the ultrastructure of the TMJ was examined by scanning electron microscopy. Transcription and protein levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA and semi-quantitative RT-PCR. The PS group showed a significantly higher adrenal gland weight after 3 weeks of stress and higher hormone levels at weeks 1, 3, and 5. Histopathological changes and thinning cartilage were apparent at weeks 3 and 5. In the PS group, TNF-α increased at 1, 3, and 5 weeks and IL-1β increased significantly after 1 and 3 weeks of stress, and then decreased to normal levels by 5 weeks. Psychological stress increased plasma hormone levels and RT-PCR indicated increased IL-1β and TNF-α expression in the TMJ in a time-dependent manner. These results suggest that cytokine up-regulation was accompanied by stress-induced cartilage degeneration in the mandibular condyle. The proinflammatory cytokines play a potential role in initiating the cartilage destruction that eventually leads to the TMDs.

Jaw clenching (clenching) is the result of an isometric contraction of jaw closing muscles. Because of the location of working muscles and afferent information during tooth contact, the effect of clenching on the cerebral and systemic circulation might differ from that of isometric limb exercise. This study aimed to investigate the characteristic changes in cerebral and systemic circulation during jaw clenching by comparing those during handgrip exercise. Subjects were 17 right-handed men. Bilateral middle cerebral arterial blood flow velocity (MCAV), electromyography (EMG) of contracting muscles, heart rate (HR) and blood pressure (BP) were measured during unilateral handgrip exercise and clenching tasks. Autonomic nerve activity was evaluated by analyzing fluctuations in HR and BP. MCAV was significantly increased during the task with significantly higher values on the non-working than working side irrespective of unilateral handgrip or unilateral jaw clenching. Changes in HR during jaw clenching were lower than those during handgrip exercise, and changes in vaso-motor sympathetic nerve activity during left jaw clenching were lower than those during left handgrip exercise. The present results indicate that, compared with handgrip exercise, unilateral jaw clenching promotes bilateral activation of MCAV with smaller effects on cardiac output and sympathetic nervous system activity.

This study aimed to investigate the differential and synergistic effects of mechanical stimulation and estrogen on the proliferation and osteogenic or chondrogenic differentiation potential of bone marrow mesenchymal stem cells (BMSCs) and the roles of estrogen receptor (ER) in them. BMSCs were isolated and cultured using the whole bone marrow adherence method, and flow cytometry was used to identify the surface marker molecules of BMSCs. Cells were pre-treated with 1 nM 17β-estradiol or 1 nM of the estrogen receptor antagonist tamoxifen. Then, the cells were stimulated with hydrostatic pressure. Assessment included flow cytometry analysis of the cell cycle; immunofluorescent staining for F-actin; protein quantification for MAPK protein; and mRNA analysis for Col I, OCN, OPN and BSP after osteogenic induction and Sox-9, Aggrecan and Col-II after chondrogenic induction. Hydrostatic pressure (90 kPa/1 h) and 1 nM 17β-estradiol enhanced the cellular proliferation ability and the cytoskeleton activity but without synergistic biological effects. Estrogen activated ERKs and JNKs simultaneously and promoted the osteogenic differentiation, whereas the pressure just caused JNK-1/2 activation and promoted the chondrogenic differentiation of BMSCs. Estrogen had antagonism effect on chondrogenic promotion of hydrostatic pressure. Mechanobiological effects of hydrostatic pressure are closely associated with ERα activity. MAPK molecules and F-actin were likely to be important mediator molecules in the ER-mediated mechanotransduction of BMSCs.

Mechanical stimulation and estrogen have been proven to be two important factors in promoting mesenchymal stem cell activity, which is closely associated with bone formation, mass maintenance and remodeling. However, the superposition effects of mechanical stimulation and estrogen on stem cells remain unknown. It is also unclear if the estrogen receptor (ER) plays only a key role in estrogen signaling or if it is also involved in the mechanotransduction of stem cells. To investigate the role of estrogen and its receptors in the mechanobiological effects in bone mesenchymal stem cells (BMSCs), isolated mesenchymal stem cells from bone marrow were exposed to mechanical pressure under additional estrogen treatment or ER blockade. Cell proliferation was examined using an MTT assay and alkaline phosphatase (ALP) activity was determined by a modified enzyme kinetic method. Alignment of the cytoskeleton was observed by Coomassie brilliant blue staining and F-actin fluorescent staining. Cellular ultrastructure was observed under transmission electron microscope. Expression of ERα was investigated using Western blot analysis. Results indicated that mechanical pressure promoted cell proliferation, ALP activity, ERα expression and F-actin stress fiber formation. Overall, this effect was enhanced by the addition of estrogen and inhibited by ER blockade. We concluded that pressure stimulated proliferation and differentiation capability via F-actin transduction in BMSCs. The effects were enhanced by the addition of estrogen, and the ER plays an important role in regulating mechanobiological effects and the mechanotransduction processes of BMSCs.

To explore the relationship between psychological stress and masticatory muscle pain, we created a communication stress animal model to determine whether psychological stress could induce increased mechanical sensitivity in masticatory muscles and to study the changes of mechanical nociceptive thresholds after stress removal. Forty-eight male Sprague-Dawley rats were divided into a control group (CON), a foot-shocked group (FS, including 3 subgroups recorded as FS-1, FS-2, and FS-3), a psychological stress group (PS), and a drug treatment group (DT). PS and DT rats were confined in a communication box for one hour a day to observe the psychological responses of neighboring FS rats.Measurements of the mechanical nociceptive thresholds of the bilateral temporal and masseter muscles showed a stimulus-response relationship between psychological stress and muscle mechanical sensitivity. The DT rats, who received a diazepam injection, showed almost the same mechanical sensitivity of the masticatory muscles to that of the control in response to psychological stress. Fourteen days after the psychological stressor was removed, the mechanical nociceptive thresholds returned to normal. These findings suggest that psychological stress is directly related to masticatory muscle pain. Removal of the stressor could be a useful method for relieving mechanical sensitivity increase induced by psychological stress.

In the paper, the study was conducted on the characteristics of microstructures and orientations of UFG pure copper and 6061 aluminum alloy prepared by AARB, ECAP and CECC severe plastic deformation processes, in which SEM, TEM, EBSD and X-ray diffraction techniques were employed. The result of the study shows that microstructures, mainly composed of subgrains and dislocation kinks, are profuse in the UFG materials by the three SPDs. These kinds of microstructures have the strength of the materials much enhanced and the toughness heavily decreased. In these processes, shear deformation makes gains get finer and finer with the existence of the preferred orientations in the prepared UFG materials. Nevertheless, CECC shows the heaviest effect on the grain refining and the preferred orientation weakening.

The photosynthetic characterization of Populus euphratica and their response to increasing groundwater depth and temperature were analyzed based on net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 concentration (Ci), transpiration rate (E), water use efficiency (WUE) and stomatal limitation (Ls) measured by a portable gas-exchange system (LI-6400) in the lower reaches of the Tarim River. Light-response curves were constructed to obtain light-compensation and light-saturation points (LCP and LSP), maximum photosynthetic rates (Pmax), quantum yields (AQY), and dark respiration rates (RD). The growth condition of P. euphratica, soil moisture, and groundwater depth in the plots were analyzed by field investigation. The results showed that the growth condition and photosynthetic characterization of P. euphratica were closely related to groundwater depth. The rational groundwater depth for the normal growth and photosynthesis was 3–5 m, the stress groundwater depth for mild drought was more than 5 m, for moderate drought was more than 6 m, for severe drought was more than 7 m. However, P. euphratica could keep normal growth through a strong drought resistance depended on the stomatal limitation and osmotic adjustment when it faced mild or moderate drought stress, respectively, at a normal temperature (25°C). High temperature (40°C) significantly reduced PN and drought stress exacerbated the damage of high temperature to the photosynthesis. Moreover, P. euphratica would prioritize the resistance of high temperature when it encountered the interaction between heat shock and water deficit through the stomata open unequally to improve the transpiration of leaves to dissipate overheating at the cost of low WUE, and then resist water stress through the osmotic adjustment or the stomatal limitation.

With the entrance temperature at 300°C, cold mill rolling produced deformation texture transition from brass type to copper type in worked 85/15 α-brass. From the texture and TEM scale microstructure evidence, it is suggested that, rather than deformation twinning, recovery and easy cross slip favor in the deformation process, as the interior working temperature falls into the texture transition range proposed by Tranchant.

Based on the data of the depths and the chemical properties of groundwater, salinity in the soil profile, and the basic information on each delivery of water collected from the years 2000 to 2006, the varied character of groundwater chemistry and related factors were studied. The results confirmed the three stages of the variations in groundwater chemistry influenced by the intermittent water deliveries. The factors that had close relations to the variations in groundwater chemistry were the distances of monitoring wells from the water channel, the depths of the groundwater, water flux in watercourse, and the salinities in soils. The relations between chemical variation and groundwater depths indicated that the water quality was the best with the groundwater varying from 5 to 6 m. In addition, the constructive species in the study area can survive well with the depth of groundwater varying from 5 to 6 m, so the rational depth of groundwater in the lower reaches of the Tarim River should be 5 m or so. The redistribution of salts in the soil profile and its relations to the chemical properties and depths of groundwater revealed the linear water delivery at present combining with surface water supply in proper sections would promote water quality optimized and speed up the pace of ecological restoration in the study area.

The passive continental margin of West Africa is becoming an attractive area for hydrocarbon exploration, and it experienced four tectonic stages, i.e. pre-rift, syn-rift, transitional and post-rift (drifting) stages. The syn-rift and post-rift stages deposited deep lacustrine hydrocarbon sources and marine hydrocarbon sources of anoxic sediment, respectively, and the transitional stage deposited very thick evaporate rocks, which are very important for forming large traps. The outer basins in the passive margin are the main hydrocarbon-producers in West Africa. Several large rivers formed huge deltas and turbid fans such as Niger Delta, Congo Fan, Kwanza Fan, which contributed large amount of petroleum. Niger Delta and Lower Congo Basin are the most attractive areas in West Africa; Gabon Basin's and Rio Muni Basin's remained hydrocarbon resources are limited and the key problem is to find new targets; The exploration in the Kwanza Basin's deep sea is rare and has a certain risk. Key words: West Africa, petroleum geology, hydrocarbon potential, passive continental margin

Background A rodent occlusal hypofunction model has been widely established in jawbone-related studies. However, the effects of occlusal stimuli, with total elimination of molar contacts, and its rehabilitation on mandibular remodeling remain unclear. Materials and methods Forty-eight 5-wk-old Sprague–Dawley male rats were used. Twenty-four experimental rats underwent occlusal hypofunction by insertion of a bite-raising appliance. Twenty-four rats received no treatment (control group). Two weeks later, half the experimental rats (occlusal hypofunction group) were killed; the appliance was removed from the remaining experimental rats (recovery group) for two additional weeks before killing. Control animals were killed biweekly. Body weight and masseter muscle weight were measured, and the mandibles were subjected to micro-computed tomography to evaluate the mandibular morphology and cortical bone characteristics. The expressions of osteoblast- and osteoclast-related genes were evaluated with quantitative polymerase chain reaction. Results No significant body weight differences were observed between the experimental and control rats. However, lighter masseter muscle, shorter mandibular incisor crown, mandibular body and ramus, and higher mandibular alveolar process and first molar fossae were observed in the occlusal hypofunction group. Moreover, the cortical bone characteristics associated with the expression of osteoblast- and osteoclast-related genes were remarkably different in the central and posterior mandible in the occlusal hypofunction group. At the 2-wk recovery time point after occlusal stimuli, the altered parameters in the masseter and mandible returned to normal levels. Conclusions Mandibular remodeling via bone turnover is region specific for altered occlusal stimuli. Normal occlusion is an important determinant of the mandibular morphology and architecture.

Generally, in the mesoscopic simulation of polycrystalline materials, correctly establishing polycrystalline models is the key to numerical simulate rolling process. Based on the principle of Voronoi diagram, using MATLAB and ABAQUS Python script interface, the rolling process of pure copper plates in the Voronoi polycrystalline meso-structure model was finite element simulated on ABAQUS platform in this paper. The result shows that because internal each grain has different orientations and interactions with each other, polycrystalline plates display an uneven deformation field in the rolling process and there is obvious stress mutation at grain boundary. These are consistent with the relevant experimental research results and reasonably explain deformation process of polycrystalline materials in theory.

Our aim is to investigate the cytobiological effects of autologous platelet-rich fibrin (PRF) on dental pulp stem cells (DPSCs) and to explore the ectopic and orthotopic possibilities of dental pulp revascularization and pulp-dentin complex regeneration along the root canal cavities of the tooth by using a novel tissue-engineered transplant composed of cell-sheet fragments of DPSCs and PRF granules. Canine DPSCs were isolated and characterized by assaying their colony-forming ability and by determining their cell surface markers and osteogenic/adipogenic differentiation potential. The biological effects of autologous PRF on DPSCs, including cell proliferation, alkaline phosphatase (ALP) activity and odonto-/osteogenic gene expression, were then investigated and quantified. A novel transplant consisting of cell-sheet fragments of DPSCs and PRF granules was adopted to regenerate pulp-dentin-like tissues in the root canal, both subcutaneously in nude mice and in the roots of canines. PRF promoted the proliferation of DPSCs in a dose- and time-dependent manner and induced the differentiation of DPSCs to odonto-/osteoblastic fates by increasing the expression of the Alp, Dspp, Dmp1 and Bsp genes. Transplantation of the DPSC/PRF construct led both to a favorable regeneration of homogeneous and compact pulp-like tissues with abundantly distributed blood capillaries and to the deposition of regenerated dentin along the intracanal walls at 8 weeks post-operation. Thus, the application of DPSC/PRF tissue constructs might serve as a potential therapy in regenerative endodontics for pulp revitalization or revascularization.

Experimental and non-experimental stress significantly increase masseter muscle tone, which has been linked to the symptoms and pathogenesis of several stomatognathic system diseases. Until now, the mechanism underlying this phenomenon has remained unclear. The current study was performed to determine the mechanism of the stress-induced increase in masseter muscle tone and to investigate the effect of lamotrigine on this change. Animals challenged by repeated restraint stress received either saline as a vehicle or lamotrigine in doses of 20, 30 or 40 mg/kg body weight, whereas control animals received saline without stress treatment. Masseter muscle tone was assessed using electromyography. The activity of glutamate-related metabolic enzymes (glutaminase and glutamine synthetase) in the trigeminal motor nucleus was also investigated. Our results showed an interesting phenomenon: masseter muscle activity increased concurrently with the upregulation of the glutamate concentration after stress treatment. The activities of glutaminase and glutamine synthetase in the trigeminal motor nucleus were also upregulated and downregulated, respectively, when the rats were challenged by prolonged stress. The animals treated with lamotrigine at moderate and high doses had significantly decreased masseter muscle tone compared with stressed animals treated with vehicle. These results suggested that increased glutaminase activity and decreased glutamine synthetase activity increased glutamate production and decreased glutamate decomposition, causing an increase in glutamate levels in the trigeminal motor nucleus and eventually increasing masseter muscle tone. The administration of lamotrigine at doses of 30 or 40 mg/kg body weight effectively mitigated the adverse effects of stress on masseter muscle tone via inhibition of glutamate release.

To observe the protective effect of Shenfu Injection (SFI) pretreatment on brain of patients receiving aortic valve replacement (AVR) undergoing cardiopulmonary bypass (CPB).Thirty AVR patients undergoing CPB were randomly assigned to 2 groups, the control group and the experimental group, 15 cases in each group. SFI at 1.5 mL/kg (dissolved in 250 mL 5% glucose solution) was intravenously dripped to those in the experimental group 5 days before operation, once daily for 5 successive days. SFI at 1.5 mL/kg (dissolved in 250 mL 5% glucose solution) was intravenously dripped to those 30 min before anesthesia induction. Equal dose of normal saline was intravenously dripped to those in the control group, and the other procedures were the same as those for patients in the experimental group. The venous blood sample (2 mL) was drawn from the right internal carotid vein immediately after induction of anesthesia (T1),10 min after CPB (T2), 30 min after GPB (T3), 2 h after CPB (T4), 24 h after CPB (T5), and 48 h after CPB (T6), thus detecting the plasma levels of S100beta and neuron specific enolase (NSE). And patients' cognitive function was assessed with mini-mental state examination (MMSE) scale on the day before operation, the 2nd and the 7th day after operation.There was no statistical difference in the levels of S1001 and NSE between the two groups at T1 (P0.05). There was statistical difference in the levels of S100beta and NSE between the two groups at T2, T3, T4, T5, T6, when compared with those at T1 (P0.05). Besides, the levels of S100beta and NSE at T2, T3, T4, T5, T6 were lower in the experimental group than in the control group, showing statistical difference (P0.05). The MMSE scores decreased on the 2nd day after operation in the two groups, showing statistical difference when compared with those on the day before operation (P0.05). It was lowered more obviously in the control group. There was no statistical difference in the MMSE score between the 7th day post-operation and the day before operation (P0.05).SFI pretreatment had protective effect on brain in AVR patients undergoing CPB.

The aim of this study was to construct a cell transplant method consisting of cell sheet fragments of periodontal ligament stem cells (PDLSCs) and platelet-rich fibrin (PRF) granules to enhance periodontal healing in avulsed tooth reimplantation. To test this concept in vitro, human PDLSCs were isolated and characterized by colony forming unit assay, cell surface marker characterizations, and their osteogenic/adipogenic differentiation potential. The biological effects of autologous PRF as a growth factor-enriched endogenous scaffold on human PDLSCs were then investigated and quantified for statistical analyses, including cell viability and proliferation, alkaline phosphatase (ALP) activity, and the gene expression of bone sialoprotein (BSP), osteocalcin (OCN), collagen I (Col-I), and cementum protein 23 (CP23). It was found that the PRF induced a significant and continuous stimulation of proliferation in human PDLSCs throughout the 7-day incubation period. Furthermore, the PRF suppressed the osteoblastic differentiation of PDLSCs by decreasing ALP activity and the gene expression of BSP and OCN while up-regulating the mRNA expression levels of Col-I and CP23 during the testing period. To assess the potential application of the PDLSCs/PRF construct in tooth reimplantation, 36 incisors were extracted from 6 dogs. The incisors then underwent 2 h of dry storage and were randomly divided into four groups receiving different strategies of reimplantation, where the avulsed teeth were reimplanted with the use of the autologous PDLSCs/PRF construct (cell sheet fragments in combination with PRF granules), with the use of autologous PDLSCs or PRF alone, or without adjuvant use of PRF or PDLSCs. Eight weeks post-reimplantation, the PDLSCs/PRF group achieved a more effective periodontal healing, characterized by the regeneration of PDL-like tissues and a reduction of ankylosis and inflammation, compared with the other testing groups. These overall results suggest that the PDLSCs/PRF construct may be a useful tool for alveolar surgery that has the potential to improve the clinical outcomes in future avulsed tooth reimplantations.

Background Swallowing dysfunction (also known as dysphagia), which results in a deterioration of nutritional intake, slows rehabilitation and causes aspiration pneumonia, is very common following neurological impairments. Although videofluorographic (VF) examination is widely used for detecting aspiration, an objective and non-invasive method for assessing swallowing function has yet to be established because of a lack of adequate devices and protocols. In this paper, a bend sensor whose resistance is altered by bending was introduced to monitor swallowing-related laryngeal movement. Methods Six healthy male volunteers were recruited in the present study. Specific time points on the signal waveform produced by the bend sensor were defined to describe laryngeal movement by differential analysis. Additionally, the physiological significance of the obtained waveform was confirmed by analyzing the sequential correlations between the signal waveform from the bend sensor and hyoid bone kinetics simultaneously recorded by VF. Results Seven time points were successfully defined on the signal waveform to reference laryngeal movement. Each time point was well correlated with certain VF events, with evidence of no significant time lags, and there were positive correlations between waveform time points and matched VF events. Furthermore, obvious similarities were noticed between the duration of each phase on the signal waveform and the duration of the matched hyoid bone activity. Conclusions The present monitoring system using a bend sensor might be useful for observing the temporal aspects of laryngeal movement during swallowing, and it was well coordinated with hyoid bone movement.

Psychological stress plays an important role in the occurrence and development of temporomandibular joint disorder (TMD). The correlation between psychological factors and TMD has been clinically shown, but the influence of psychological stress on the temporomandibular joint (TMJ) structure still lacks direct evidence. Here, we used communication box to establish the rat model of psychological stress. The stress level of animals was estimated by the elevated plus maze (EPM) test and hormonal assays. The histomorphology andthree-dimensional microstructure of the rat condyles were observed by hematoxylin–eosin (HE) stainingand Micro-CT, respectively. Compared with control rats, the anxious state of the stressed rats was evidenced by higher plasma adrenocorticotropic hormone (ACTH) and corticosterone (CORT), as well as lower ratios of open arm entries and time and lower time spent in open arms after 1, 2, 3, 4 and 5 week(s) post-exposure to psychological stimuli. HE staining and histomorphometric data analysis showed decreased thicknesses of the central and posterior condylar cartilages in stressed rats at weeks 3, 4 and 5, with the most obvious changes in the posterior part characterized by debonding and thinned fibrous layer, thickened proliferative layer,thinned mature layer and hypertrophic layer. Moreover, Micro-CT scanning revealed local lesion of thesubchondral bone in the posterior condylar cartilages of stressed rats at week 5. Our findings indicate that pathologic changes of the histomorphology and three-dimensional microstructure occur in the condyles of stressed rats, hinting us a potential link between psychological factors and the pathogenesis or progression of TMD. Refereed/Peer-reviewed

To investigate the role of mechanical pressure on cartilage thickness and type II collagen synthesis, and the role of G protein in that process, in vitro organ culture of mandibular cartilage was adopted in this study. A hydraulic pressure-controlled cellular strain unit was used to apply hydrostatic pressurization to explant cultures. The explants were compressed by different pressure values (0 kPa, 100 kPa, and 300 kPa) after pretreatment with or without a selective and direct antagonist (NF023) for the G proteins. After 4, 8 and 12 h of cell culture under each pressure condition, histological sections of the explants were stained with hematoxylin-eosin to investigate the thickness of the cartilage. Immunohistochemical staining was used to observe type II collagen expressions. The results showed that a hydrostatic pressure of 100 kPa significantly reduced the thickness of the proliferative layer in condylar cartilage without affecting the thickness of the transitional layer. Hydrostatic pressures of 100 kPa and 300 kPa significantly enhanced the synthesis of type II collagen. G proteins are involved not only in the proliferation and differentiation of condylar cartilage regulated by prolonged pressure, but also in the process of collagen production in condylar cartilage stimulated by pressure.

Psychological stressors are generally associated with masseter muscle dysfunction and disorders in emotional response. In addition, oxidative states and HSP70 expression, which are involved in the physical and pathological changes of the masseter muscle, could be altered in the stressed tissues and organs. However, the link between psychological stress and the redox homeostasis or the expression of HSP70 in masseter muscles in rats has not been examined. Therefore, we used a communication box paradigm to induce psychological stress in rats. The successful establishment of the animal model was evidenced by an increase in plasma corticosterone and adrenocorticotropic hormone (ACTH). Meanwhile, the stressed rats showed a decrease in the number of entries on open arms, percentage of time spent in open arms, and distance moved in the elevated plus-maze test. The stressed rats also displayed a decrease in the time spent in the center zone, active velocity, and the distance moved in the open-field test. These results demonstrate affective-like behavioral changes in the stressed rats. Moreover, compared with the control rats, a decrease in SOD, GSH-Px and catalase activities and an increase in MDA content were observed in the masseter muscles in stressed rats after 3. weeks and 5. weeks, and the HSP70 expression was elevated in muscles in the rats exposed to stress for 5. weeks. These results indicate that psychological stress induces oxidative damage and up-regulates the expression of HSP70 in masseter muscles in rats, which are associated with behavior resembling anxiety. Refereed/Peer-reviewed