Large Birefringent Materials, Na₆Te₄W₆O₂₉ and Na₂TeW₂O₉: Synthesis, Structure, Crystal Growth, and Characterization

A new d⁰ transition metal tellurite, Na₆Te₄W₆O₂₉, was synthesized by solid-state methods. The material crystallizes in monoclinic space group <i>P</i>2₁/<i>c</i> (No. 14) with the following values: <i>a</i> = 7.3297(3) Å, <i>b</i> = 21.9057(9) Å, <i>c</i> = 10.2871(3) Å, β = 133.490(2)°, and <i>Z</i> = 2. Additionally, large crystals of Na₆Te₄W₆O₂₉ (13 mm × 11 mm × 10 mm) and Na₂TeW₂O₉ (23 mm × 5 mm × 3 mm) were grown by the top seeded solution growth method. In addition to the crystal growth, refractive indices were measured, and the Sellmeier equations were fitted by using the minimum deviation technique. Interestingly, the two reported compounds exhibit relatively large birefringences: Δ<i>n</i>₃ = <i>n</i>_<i>z</i> – <i>n</i>_<i>x</i> = 0.0828–0.1248 from 1062.6 to 450.2 nm for Na₆Te₄W₆O₂₉, and Δ<i>n</i>₃ = <i>n</i>_<i>z</i> <i>– n</i>_<i>x</i> = 0.1471–0.2069 from 1062.6 to 450.2 nm for Na₂TeW₂O₉. The results indicate that Na₆Te₄W₆O₂₉ and Na₂TeW₂O₉ may have uses in applications involving birefrigent materials

Assisting the Effective Design of Polar Iodates with Early Transition-Metal Oxide Fluoride Anions

Polar materials are of great technical interest but challenging to effectively synthesize. That is especially true for iodates, an important class of visible and mid-IR transparent nonlinear optical (NLO) materials. Aiming at developing a new design strategy for polar iodates, we successfully synthesized two sets of polymorphic early transition-metal (ETM) oxide-fluoride iodates, α- and β-Ba­[VFO₂(IO₃)₂] and α- and β-Ba₂[VO₂F₂(IO₃)₂]­IO₃, based on the distinct structure-directing properties of oxide-fluoride anions. α- and β-Ba­[VFO₂(IO₃)₂] contain the <i>trans</i>-[VFO₂(IO₃)₂]^2– polyanion and crystallize in the nonpolar space groups <i>Pbcn</i> and <i>P</i>2₁2₁2₁. In contrast, α- and β-Ba₂[VO₂F₂(IO₃)₂]­IO₃ contain the <i>cis</i>-[VO₂F₂(IO₃)₂]^3– Λ-shaped polyanion and crystallize in the polar space groups <i>Pna</i>2₁ and <i>P</i>2₁, respectively. Detailed structural analyses show that the variable polar orientation of <i>trans</i>-[VFO₂(IO₃)₂]^2– polyanions is the main cause of the nonpolar structures in α- and β-Ba­[VFO₂(IO₃)₂]. However, the Λ-shaped configuration of <i>cis</i>-[VO₂F₂(IO₃)₂]^3– polyanions can effectively guarantee the polar structures. Further property measurements show that polar α- and β-Ba₂[VO₂F₂(IO₃)₂]­IO₃ possess excellent NLO properties, including the large SHG responses (∼9 × KDP), wide visible and mid-IR transparent region (∼0.5–10.5 μm), and high thermal stability (up to 470 °C). Therefore, combining <i>cis</i>-directing oxide-fluoride anions and iodates is a viable strategy for the effective design of polar iodates

Assisting the Effective Design of Polar Iodates with Early Transition-Metal Oxide Fluoride Anions

Polar materials are of great technical interest but challenging to effectively synthesize. That is especially true for iodates, an important class of visible and mid-IR transparent nonlinear optical (NLO) materials. Aiming at developing a new design strategy for polar iodates, we successfully synthesized two sets of polymorphic early transition-metal (ETM) oxide-fluoride iodates, α- and β-Ba­[VFO₂(IO₃)₂] and α- and β-Ba₂[VO₂F₂(IO₃)₂]­IO₃, based on the distinct structure-directing properties of oxide-fluoride anions. α- and β-Ba­[VFO₂(IO₃)₂] contain the <i>trans</i>-[VFO₂(IO₃)₂]^2– polyanion and crystallize in the nonpolar space groups <i>Pbcn</i> and <i>P</i>2₁2₁2₁. In contrast, α- and β-Ba₂[VO₂F₂(IO₃)₂]­IO₃ contain the <i>cis</i>-[VO₂F₂(IO₃)₂]^3– Λ-shaped polyanion and crystallize in the polar space groups <i>Pna</i>2₁ and <i>P</i>2₁, respectively. Detailed structural analyses show that the variable polar orientation of <i>trans</i>-[VFO₂(IO₃)₂]^2– polyanions is the main cause of the nonpolar structures in α- and β-Ba­[VFO₂(IO₃)₂]. However, the Λ-shaped configuration of <i>cis</i>-[VO₂F₂(IO₃)₂]^3– polyanions can effectively guarantee the polar structures. Further property measurements show that polar α- and β-Ba₂[VO₂F₂(IO₃)₂]­IO₃ possess excellent NLO properties, including the large SHG responses (∼9 × KDP), wide visible and mid-IR transparent region (∼0.5–10.5 μm), and high thermal stability (up to 470 °C). Therefore, combining <i>cis</i>-directing oxide-fluoride anions and iodates is a viable strategy for the effective design of polar iodates

Presentation1_Causal effects of homocysteine levels on the components of sarcopenia: A two-sample mendelian randomization study.pdf

Background: Currently, it is unclear whether there is a causal association between genetically predicted plasma homocysteine (Hcy) levels and the risk of sarcopenia. We performed a Mendelian randomization (MR) study to assess the association between circulating Hcy levels and the components [grip strength, walking pace, and appendicular lean mass (ALM)] of sarcopenia.Methods: Independent single nucleotide polymorphisms (SNPs) significantly associated with plasma Hcy levels served as instrumental variables. Summary-level data regarding the components of sarcopenia. Were obtained from the UK Biobank. Inverse variance weighted (IVW) as the primary method was used for Mendelian randomization (MR) analysis. We also use four models, weighted median, MR-Egger regression, Maximum likelihood, and Penalised weighted median, as supplementary methods to IVW. The MR-Egger intercept test, Cochran’s Q test, and “leave-one-out” sensitivity analysis were performed to evaluate the horizontal pleiotropy, heterogeneities, and stability of the causal association between Hcy levels and the components of sarcopenia.Results: The IVW-MR analysis suggested significant negative associations of increased plasma Hcy levels with grip strength (right: effect = −0.036, SE = 0.032, p = 5.53E-4; left: effect = −0.045, SE = 0.010, p = 1.45E-5), walking pace (effect = −0.038, SE = 0.011, p = 3.18E-4), and ALM (effect = −0.058, 0.013, p = 1.03E-5). However, there were no significant associations of decreased plasma Hcy levels with grip strength (right: effect = 0.005, SE = 0.021, p = 0.82; left: effect = −0.006, SE = 0.014, p = 0.64), walking pace (effect = 0.01, 0.020, p = 0.61), or ALM (effect = -0.034, SE = 0.018, p = 0.06).The accuracy and robustness of these findings were confirmed by sensitivity tests.Conclusion: Increased circulating Hcy levels were associated with lower grip strength, slower walking pace, and decreased ALM.</p

Effects of temperature and competition treatments on measures of biomass and morphology of <i>E</i>. <i>densa</i>.

<p>(a) Ramet number, (b) Plant height, (c) Root length, (d) Total biomass, (e) Leaf biomass, (f) Stem biomass, (g) Root biomass (h) RGR, (i) R/S ratio. Values are mean ± SE. Means with different small letters are significantly different at <i>P</i><0.05 in different treatments.</p

Effects of temperature and competition treatments on measures of biomass, the R/S ratio and the RGR of <i>S</i>. <i>angustifolium</i>.

<p>(a) Total biomass, (b) Genet biomass, (c) R/S ratio, (d) Ramet biomass, (e) RGR. Values are mean ± SE. Means with different small letters are significantly different at <i>P</i><0.05 in different treatments.</p

Mean absolute competition intensity, relative competition intensity and the relative interaction index for the treatment combination of temperature and competition for each plant species.

<p>(a) Mean ACI, (b) Mean RCI, (c) Mean RII. Values are mean ± SE. Means with different small letters are significantly different at <i>P</i><0.05 in different treatments.</p

Physical and chemical factor of water and microclimate parameters of the experiment during the experimental period, the boldface of a and b showed the results of variance analysis.

<p>Physical and chemical factor of water and microclimate parameters of the experiment during the experimental period, the boldface of a and b showed the results of variance analysis.</p

Two-way ANOVA results for effects of temperature and competition on measures oyf growth and morphology of <i>S</i>. <i>angustifolium</i> and <i>E</i>.<i>densa</i>.

<p>Two-way ANOVA results for effects of temperature and competition on measures oyf growth and morphology of <i>S</i>. <i>angustifolium</i> and <i>E</i>.<i>densa</i>.</p

Phase-Matching in Nonlinear Optical Compounds: A Materials Perspective

Angle phase-matching in nonlinear optical (NLO) materials is critical for technological applications. The purpose of this manuscript is to describe the concept of phase-matching for the materials synthesis NLO community. Refractive index and birefringence are defined with respect to uniaxial and biaxial crystal systems. The phase-matching angle and wavelength range, Type I and Type II, are explained using real NLO materials, K₃B₆O₁₀Cl (KBOC) and Ba₃(ZnB₅O₁₀)­PO₄ (BZBP) In addition, we describe how refractive index measurements are performed on single crystals and how the resulting birefringence impacts the phase-matching. Our goal is to provide a description of phase-matching that is relevant for the materials synthesis NLO community