Crystal growth and negative thermal expansion properties of a Y2Mo4O15 single crystal.

A bulk-size single crystal of Y2Mo4O15 with 20 × 11 × 8 mm3 was successfully grown by the top-seed solution growth (TSSG) method. The full-width at half maximum of (100) and (010) crystal faces is 37 and 27 arcsec, respectively. The thermal conductivity coefficients κ 11, κ 22, κ 33, and κ 13 are determined to be 1.519, 2.097, 0.445, and 0.997 W m-1 K-1, respectively. It is worth noting that the Y2Mo4O15 crystal shows significant anisotropy thermal expansion properties, which exhibits a negative thermal expansion along the b-axis (α 22 = -5.11 × 10-6 K-1). The crystal structure analysis shows that the shrinking of Mo-O bond lengths along the b-axis with the increasing temperature would be the main origin of the negative thermal expansion properties for Y2Mo4O15 crystal, which does not comply with the current mechanism.

Activation of aldehyde dehydrogenase 2 protects ethanol-induced osteonecrosis of the femoral head in rat model.

OBJECTIVES: Osteonecrosis of the femoral head (ONFH) is a devastating disease characterized by destructive bone structures, enlarged adipocyte accumulation and impaired vascularization. The aldehyde dehydrogenase 2 (ALDH 2) is the limiting enzyme for ethanol metabolism with many physiological functions. The aim was investigated the potential protective role of activated ALDH 2 by Alda-1 for ethanol-induced ONFH. MATERIALS AND METHODS: The ethanol-induced ONFH in rat was performed to explore the protective of Alda-1 by various experimental methods. Subsequently, the effect of Alda-1 and ethanol on the osteogenic and adipogenic differentiation was investigated via multiple cellular and molecular methods. Finally, the effect of Alda-1 and ethanol on the neo-vascularization was detected in Human umbilical vein endothelial cells (HUVECs) and ONFH model. RESULTS: Firstly, radiographical and pathological measurements indicated that alda-1 protected ethanol-induced ONFH. Moreover, ethanol significantly inhibited the proliferation and osteogenic differentiation of BMSCs, whereas Alda-1 could distinctly rescue it by PI3K/AKT signalling. Secondly, ethanol remarkably promoted the lipid vacuoles formation of BMSCs, while Alda-1 significantly retarded it on BMSCs by AMPK signalling pathway. Finally, ethanol significantly inhibited proliferation and growth factor level resulting in reduced angiogenesis, whereas Alda-1 could rescue the effect of ethanol. Additionally, Alda-1 significantly reduced the occurrence of ONFH and promoted vessel number and distribution in alcoholic ONFH. CONCLUSIONS: Alda-1 activation of ALDH 2 was highly demonstrated to protect ethanol-induced ONFH by triggering new bone formation, reducing adipogenesis and stimulating vascularization.

MiR-151b inhibits osteoblast differentiation via downregulating Msx2.

PURPOSE: MicroRNA-151b (miR-151b) showed altered expression in ovariectomized rat model of osteoporosis. This study established an ovariectomy-induced osteoporotic rat model to investigate the role of miR-151b in osteoblasts. METHODS: Eighteen female Sprague-Dawley (SD) rats were divided randomly into Sham and OVX group (n = 9). The transfections with different miRNAs and expression vectors were confirmed by RT-qPCR. The protein expression of Msx2 was detected by Western blots. The interaction between miR-151b and Msx2D was evaluated by RNA pull-down and dual luciferase reporter assay. RESULTS: The expression of miR-151b was significantly increased in femoral tissues of ovariectomy-induced osteoporotic rats. The expression of osteogenesis marker genes including RUNX2, ALP, OCN, OSX, and Msx2 were all significantly increased in osteogenic medium (OM) incubated primary osteoblasts and MC3T3-E1 cells. The interaction between miR-151b and Msx2 was confirmed by luciferase reporter assay and RNA pull-down. Moreover, overexpression of miR-151b significantly inhibited Msx2 in both MC3T3-E1 cells and primary osteoblasts, while miR-151b inhibitor had the opposite effect on the expression of Msx2. In addition, in primary osteoblasts and MC3T3-E1 cells, miR-151b overexpression, or Msx2 silence significantly decreased the expression of OSX, ALP, RUNX2, and OCN. CONCLUSION: MiR-151b could inhibit osteoblast proliferation, differentiation, and mineralization via downregulating Msx2 in both MC3T3-E1 cells and primary osteoblasts. MiR-151b might serve as a novel therapeutic target for osteoporosis. ABBREVIATIONS: miR-151b: microRNA-151b; miRNAs: microRNAs; Msx2: Msh homeobox 2; MAPK: mitogen-activated protein kinase; STAT: signal transducer and activator of transcription; SD: Sprague-Dawley; BMD: bone mineral density; qRT-PCR: quantitative reverse transcription PCR; MTT: methyl thiazolyl tetrazolium; OVX: ovariectomy; ALP: alkaline phosphatase.

Li2 MTeO6 (M=Ti, Sn): Mid-Infrared Nonlinear Optical Crystal with Strong Second Harmonic Generation Response and Wide Transparency Range.

Oxide crystals have been widely used in nonlinear optics (NLO) in the ultraviolet-visible and near-infrared regions. Most traditional oxide crystals are restricted to the mid-infrared region due to their narrow transmission window. Hence, attempting to extend infrared cutoff wavelength of oxides has attracted much attention. Herein, we report two new tellurates Li2 TiTeO6 (LTT) and Li2 SnTeO6 (LST) with broad transparent regions of 0.38-6.72 and 0.38-6.86 µm, respectively, as excellent candidates for mid-infrared NLO applications. Both LTT and LST crystallize in the orthorhombic space group Pnn2. The LTT crystal exhibits intense powder second-order generation efficiency (26×KDP) under the fundamental wavelength of 1064 nm. First-principles calculations and dipole moments were used to illustrate the results of the powder second-harmonic generations based on the crystal structures. Our results provide a novel oxide NLO crystal with a strong SHG and wide transparency range. They also pave a way for the design of new oxide mid-IR NLO crystals.

Actively Q-switched and mode-locked all-fiber lasers with an α-BaTeMo2O9-based acousto-optical modulator.

In this work, a novel, to the best of our knowledge, α-BaTeMo2O9 crystal-based acousto-optical modulator is designed and successfully applied in actively Q-switched and mode-locked Er-doped fiber lasers (EDFLs) and Yb-doped fiber lasers (YDFLs) operating at 1.5 and 1.0 µm. The shortest pulse width of 429 ns and 1.37 µs are obtained in actively Q-switched EDFLs and YDFLs, respectively. For actively mode-locked operation, a pulse width of 11.32 ns at a modulation frequency of 3.19 MHz is obtained in EDFLs, while it is 29.9 ns at 1.036 MHz in YDFLs. The results indicate that the α-BaTeMo2O9 crystal is a promising candidate for all-fiber active modulators.

Remarkable reactivity of alkoxide/acetato-bridged binuclear copper(II) complex as artificial carboxylesterase.

Bromo-containing binuclear Schiff base copper(II) complex, Cu2L(OAc), with an alkoxo/acetato-bridged moiety was employed as a model of carboxylesterases to promote the hydrolytic cleavage of p-nitrophenyl picolinate (PNPP). Furthermore, the reactivity of a mononuclear complex (CuHL) was evaluated for comparing it with that of binuclear one. The results reveal that the as-prepared binuclear Cu2L(OAc) efficiently accelerated the hydrolysis of PNPP, giving rise to excess four orders of magnitude rate enhancement in contrast to the un-catalyzed reaction. Cu2L(OAc) represented an enzyme-like bell-shaped pH-responsive kinetic behavior. Moreover, the binuclear one is more reactive than its mononuclear analogue (CuHL) by two orders of magnitude. The total efficiency of Cu2L(OAc) is about 61-fold than that of its mononuclear analogue, CuHL. In addition, a contrast experiment reveals that binuclear Cu2L(OAc) displayed good activity in the hydrolysis of PNPP as well another active ester, i.e., S-2-benzothiazolyl 2-amino-alpha-(methoxyimino)-4-thiazolethiolacetate (AE-active ester). Noteworthyly, it was found that mononuclear one inspired more obvious rate enhancement in the hydrolysis of AE-active ester relative to PNPP hydrolysis. The estimated pK a1 of bound water on the binuclear Cu2L(OAc) using second derivative method (SDM) is relatively smaller than that for CuHL by a gap of about 0.8 pK unit, which facilitates the hydrolysis of PNPP. Four orders of magnitude rate enhancement was observed for the catalytic hydrolysis of p-nitrophenyl picolinate (PNPP) by one µ-alkoxide/acetato-bridged binuclear copper(II) complex under physiological conditions. Substrate specificity of the resulting binuclear complexes was observed for the hydrolysis of PNPP and AE-active ester.

Temporal and spatial variability of traffic-related noise in the City of Toronto, Canada.

The majority of studies that assessed population-level exposure to traffic-related noise were conducted in European countries and less is known about the exposure to traffic noise in North America, particularly in Canadian cities. This study explored the temporal and spatial variability of traffic noise in the City of Toronto, the largest city in Canada. We conducted two cycles of intensive field measurement campaign to collect real-time measurements of traffic noise at 554 locations across Toronto between June 2012 and January 2013. At each site, we collected measurements for a period of 30 min during daytime. Repeated measurements were made in cycle two at 62 locations randomly selected from cycle one, which exhibited high correlation (Pearson's correlation coefficient (r): 0.79). In addition, continuous measurements of noise were recorded for seven days at ten sites. We observed that noise variability was predominantly spatial in nature, rather than temporal: spatial variability accounted for 60% of the total observed variations in traffic noise. Traffic volume, length of arterial road, and industrial area were three most important variables, explaining the majority of the spatial variability of noise (R(2)=0.68 to 0.74, depending on the cycle). In comparison to the 16-h equivalent sound level guideline for outdoor locations set out by the Ministry of the Environment of the Province of Ontario, 80% of our sampled locations exceeded this guideline (i.e. 55 dBA,16 h). These findings suggested ubiquitous traffic noise exposure across Toronto and that noise variability was explained mostly by spatial characteristics.

SB203580, a p38 mitogen-activated protein kinase inhibitor, suppresses the development of endometriosis by down-regulating proinflammatory cytokines and proteolytic factors in a mouse model.

BACKGROUND: p38 mitogen-activated protein kinase (p38 MAPK), a regulator of inflammation, may play a role in the pathogenesis of endometriosis (EM). We studied the effect of SB203580, a p38 MAPK inhibitor, on the development of EM in a mouse model. METHODS: EM was induced in BALB/c mice by peritoneal injection of endometrium-rich fragments. Mice (n = 15) were injected i.p. for 24 days with SB203580 and 15 mice served as positive controls (EM group). Sham-operated mice received carrier only. Peritoneal fluid (PF) cells were collected for protein/mRNA analysis. Interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, matrix metalloproteinase-2 (MMP-2) and MMP-9 proteins were measured using enzyme-linked immunosorbent assay and mRNAs by RT-PCR. Phosphorylation of p38 MAPK was evaluated by western blotting. RESULTS: SB203580 decreased the weight and size (P < 0.05 versus EM) of endometriotic lesions in BALB/c mice. IL-1ß, TNF-α, MMP-2 and MMP-9 mRNA levels were decreased in peritoneal cells of the SB203580 versus EM group (P < 0.01, P < 0.05, P < 0.05 and P < 0.05, respectively). Concentrations of IL-1ß, TNF-α, MMP-2 and MMP-9 proteins in PF were reduced in the SB203580 versus EM group (P < 0.05, P < 0.01, P < 0.05 and P < 0.05, respectively). Compared with the sham-operated group, phosphorylation of p38 MAPK in the EM group was increased, and this was down-regulated by SB203580 (P < 0.01). CONCLUSIONS: SB203580 may suppress the development of EM by inhibiting expression of proinflammatory cytokines and proteolytic factors. p38 MAPK might play a key role in progression of EM.