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Two new scandium borate nonlinear optical crystal materials, Rb7SrSc2B15O30 and Rb7CaSc2B15O30, with typical B5O10 groups and short ultraviolet cutoff edges, were successfully obtained by spontaneous crystallization.

Gall stone disease was known to increase after bariatric surgery. Ursodeoxycholic acid (UDCA) might reduce the gallstone formation rate after bariatric surgery. However, other option for gallstone prevention was unclear. We reported the result of a randomized trial comparing the gallstone prevention efficacy of probiotics and digestive enzyme versus UDCA.This prospective, randomized trial was held in an institute of Taiwan. Patients were eligible for inclusion if their body-mass index (BMI) was 32.5 kg/m2 or higher with the presence of comorbidity, or 27.5 kg/mw or higher with not-well controlled type 2 diabetes, and were aged 18-65 years. Participant were randomized assigned (1:1:1) to probiotic, digestive enzyme or UDCA. The primary endpoint was assessed in the incidence of gallstone disease at 6 months after surgery. This study is registered with ClinicalTrials.gov. number NCT03247101, and is now completed.From January 2016 to December 2018, of 186 patients screened for eligibility, 152 were randomly assigned to probiotic (52) or digestive enzyme (52) or UDCA (52). In the per-protocol population, mean age was 35.9 years (SD 10.6), mean BMI was 40.3 kg/mProbiotic is not inferior to UDCA regarding gall bladder disease prevention after bariatric surgery at 6 months.

A new IR NLO crystal Sr3Ge2O4Te3 was successfully designed and synthesized by a “partial O-to-Te substitution” strategy. The bridging oxygen in [Ge2Te3O4] plays the most important role in the enhanced SHG effect of Sr3Ge2O4Te3.

In this study, a series of tetrafluoroborates with non-π-conjugated [BF

Birefringent materials are widely applied as photoelectric functional field devices to modulate the polarization of lasers. The introduction of a halogen into the structure of crystals could balance the relationship between the band gap Eg and nonlinear optical (NLO) coefficient owing to their outstanding electronegativity and control the optical anisotropy. In this work, the optical properties of phosphohalides α/β-Cd2P3X (X = Cl, Br, I) were studied. It was found that the birefringences of α/β-Cd2P3Cl (0.23/0.24 @ 1064 nm) are unexpectedly 8 times larger than those of α/β-Cd2P3I (0.04/0.03 @ 1064 nm). To find the optical property origins and explore the contributions of microscopic groups to the optical anisotropy and NLO responses in Cd–P–X (X = Cl, Br, I), the first-principles, real-space atom-cutting, and polarizability anisotropy analysis methods were used. This reveals that the electron distribution is susceptible to halogen electronegativity. Halogen atoms can modulate the polarization anisotropy of the active polyhedron and influence the birefringence significantly, owing to the synergistic effect of the anion size and strong covalent interactions between halogens and metal cations. This work clarifies the optical anisotropy origin mechanism and provides a general strategy for finding promising birefringent crystals in phosphohalide systems.

AIM To assess the outcomes of metabolic surgery in overweight and obese patients in Asia with type 2 diabetes (T2D). MATERIALS AND METHODS The treatment outcomes of 1999 patients from the Asian Diabetes Surgery Summit database were analysed. The changes in treatment effects across time were assessed with respect to the surgical procedures performed by using generalized estimating equations. RESULTS The most commonly performed procedure was the single-anastomosis gastric bypass (32.6%). Weight (from 106.2 ± 25.1 to 77.9 ± 18.8 kg), body mass index (BMI; from 38.7 ± 7.9 to 28.5 ± 5.9 kg/m2 ), blood sugar (from 9.3 ± 4.1 to 5.7 ± 1.8 mmol/L) and HbA1c (from 8.4% ± 1.8% to 6.0% ± 1.1%) significantly improved from baseline to 1 year (P

Owing to wide infrared transparency range, high laser damage thresholds, and easy to grow in open air, germanates are emerging as promising mid-infrared (mid-IR) nonlinear optical (NLO) materials. However, the germanates as NLO materials have not been investigated comprehensively and the crystals with large second harmonic generation (SHG) response have not been identified. Herein, we used the first-principles high-throughput screening pipeline for nonlinear optical materials (FHSP-NLO) to searching excellent NLO crystals from germanates collected in inorganic crystal structures database (ICSD). After two steps screening, three crystals are picked out from 128 structures based on their predicted energy gaps, birefringences and SHG coefficients. Subsequently, the three germanates are synthesized and measured. The results show that Pb3Ga2Ge4O14 and Ba2TiGe2O8exhibit wide energy gap (>3.1 eV) and strong phase-matchable SHG intensity that are comparable to the benchmark AgGaS2 (0.8 and 1.2 × AgGaS2, respectively). In addition, the statistical analyses to different categories classified according to their cations show that the d0-transition metal and lone pair cations are more conducive to achieving larger SHG response and birefringence compared other cations in germanates. It gives a guideline for exploring new mid-IR NLO materials.

Two new pyrophosphates nonlinear optical (NLO) materials, Rb3 PbBi(P2 O7 )2 (I) and Cs3 PbBi(P2 O7 )2 (II), were successfully designed and synthesized. Both compounds exhibit large NLO effects and birefringences. Material I presents the scarce case of possessing the coexistence of large birefringence (0.031 at 1064 nm and 0.037 at 532 nm) and second harmonic generation (SHG) response (2.8× potassium dihydrogen phosphate (KDP)) in ultraviolet NLO phosphates and its SHG is the largest in the phase-matching (PM) pyrophosphates. Both I and II have three-dimensional (3D) crystal structures composed of corner-shared RbO12 (CsO11 ), RbO10 (CsO10 ), BiO6 , PbO7 (PbO6 ) and P2 O7 groups, in which P2 O7 and PbO7 (PbO6 ) units form an alveolate [PbPO]∞ skeleton frame. Theoretical calculations reveal that the P-O, Bi-O and Pb-O units are mainly responsible for the moderate birefringence and large SHG efficiency of I.

Discovering new nonlinear optical (NLO) materials that require an optimization between multiple properties is a time-consuming and high-cost process. To speed up material development, a First-princ...

A new family of Na3AgSnQ4 (Q = S or Se) and Na3MIIInS4 (MII = Cd or Hg) was successfully synthesized in vacuum-sealed silica tubes for the first time. They exhibit similar isolated one-dimensional ...

Perovskite-related compounds are of vital significance in the optical element and laser industry and other fields. Exploring the contributions of microscopic units that form the perovskite framewor...

While clinical findings demonstrate a superior benefit of cardiovascular (CV) risk reduction in obese patients with type 2 diabetes mellitus (T2D) receiving bariatric surgery over non-T2D patients, the mechanism is unclear. This study aimed to investigate the changes in the CV risk score and five CV-associated biomarkers after gastric bypass surgery.We enrolled 80 obese subjects who underwent gastric bypass (40 T2D and 40 non-T2D). CV risks were assessed using the United Kingdom Prospective Diabetes Study (UKPDS) engine before and after surgery. Levels of five biomarkers -fasting serum fibroblast growth factor (FGF)-19, FGF-21, corin, oxidized low-density lipoprotein (ox-LDL), and soluble receptor for advanced glycation end-products (sRAGE)-were measured before surgery and one year after surgery.The T2D group was significantly older and had a higher CV risk score than the non-T2D group, but body mass index (BMI) was similar between the groups. Preoperative biomarker levels were similar in both the T2D and the non-T2D groups. One year after surgery, the percentage of total weight loss (%TWL) was similar between the two groups (32.2 ± 19.5% versus 34.1% ± 8.8%, p = 0.611). Complete T2D remission (hemoglobin A1c (HbA1c) 6.0%) was achieved in 29 patients (72.5%). The 10-year CV risk scores by the UKPDS risk engine reduced significantly in both the T2D and the non-T2D groups, but more in the T2D group. Three of five biomarkers changed significantly after surgery: the FGF-19 increased from 195.6 ± 249.1 pg/mL to 283.2 ± 211.8 pg/mL, corin increased from 3.3 ± 2.3 ng/mL to 4.6 ± 3.7 ng/mL, and ox-LDL decreased from 148.5 ± 71.7-107.9 U/L; the P values were 0.002, 0.002 and 0.001, respectively. The T2D group showed a significantly different change in FGF-19 increase and FGF-21 decrease compared to the non-T2D group. The changes in corin and ox-LDL levels were not different between the T2D and non-T2D groups.Gastric bypass surgery resulted in a higher UKPDS CV risk score reduction in obese T2D Asians than in those without. FGF-19 and FGF-21 may be associated with the underlying mechanism of this difference.

Factors controlling the nonlinear optical (NLO) responses of infrared materials remain unclear due to the complex systems spanning the whole main group elements and also transition elements. The microscopic mechanism of cation-affected optical properties is consequently necessary to the mid-infrared region. In this research work, the covalence, electronic structure and mechanism of nonlinear optical (NLO) responded for a typical IR system, In-containing chalcogenides with the formula MInS2 (M = Ag, Li), are systemically investigated. It reveals that the orbitals hybridization, size effect and the cation electronegativity induce the changes of band gaps. Via tailoring the A-site cations, the microscopic factors affecting the optical band gap are analyzed. In addition to the effect of anionic groups on optical properties, we have found that the contributions of the A-site cations are not negligible. Furthermore, the electronic structures of sulfur in the compounds are susceptible to the type of cations, and consequently affect the NLO properties.

The II-IV-V2 type nonlinear optical (NLO) materials with chalcopyrite structures have wide applications in infrared (IR) frequency conversion, optical parametric oscillation, and terahertz wave producing, which can be as references to explore IR NLO systems. The template effect, mainly the size effect of five II-IV-V2 type compounds (ZnGeP2, ZnSiP2, ZnSnP2, CdGeP2 and CdGeAs2) on the optical properties is analyzed in terms of microscopic structures and electronic structures. The mechanism for significant differences in the second harmonic generation (SHG) intensities from 2.8 to 15 × AgGaS2 (the IR benchmark) is clarified via the density functional theory, the real space atom-cutting method and SHG-weight density analysis. It is found that the size effect of ions in this family of crystals is mainly responsible for the decreases of band gaps, then leads to the enhancement of SHG intensities. Moreover, the real space atom-cutting calculations show that the [SiP4], [GeP4], [SnP4] and [GeAs4] dominate the contributions to SHG response, which are identified as the superior functional units and are conducive to enhancing the SHG effects. Therefore, one can select those NLO superior functional units that enlarge the cell size and SHG responses to obtain new IR NLO materials.

In this paper, the linear and second order nonlinear optical properties of CsGeX3 (X = Cl, Br, and I) compounds have been investigated using the finite field method combined with the density functional investigation. The obtained results are in good agreement with the experimental values. The electron density distribution nearby the fermi level is the lobe-like lone pair electrons which make the germanium-halogen polyhedron distorted. The atomic contribution to the birefringence and SHG response is analyzed using the Born effective charges, the variation of the atomic charges, and the SHG density method. The results show that the germanium and halogen atoms give main contribution to the optical anisotropic birefringence and the SHG response.

The first Ba-containing hydrated vanadate as nonlinear optical (NLO) material, BaV2O6·H2O, was synthesized by facile hydrothermal method. The single-crystal X-ray diffraction result shows that this compound crystallizes in the acentric orthorhombic space group of P212121 with cell parameters a = 7.3993(6) A, b = 8.9934(7) A, and c = 9.7206(8) A. UV–vis-IR diffuse reflectance spectrum shows that the compound has a large bandgap of 4.60 eV and moderate transparency range. The title compound shows second-harmonic generation (SHG) efficiency about 0.5 times of KH2PO4 (KDP). The structure-property relationship of BaV2O6·H2O was clarified by the first-principles studies.

The chalcopyrite structure is a rich source for the exploration of new IR materials. However, not all of the compounds with a chalcopyrite-type structure exhibit satisfactory optical properties, which may originate from their different microstructure features. In this work, we selected four classical chalcopyrite materials, AIGaS2 (AI = Ag, Cu) with normal structures and AIIGa2S4 (AII = Zn, Hg) with defect structures, to study their electronic structures, optical properties including the contribution of ions and ion groups to their band gaps, SHG responses and birefringences by the first-principles method. The results uncover that the different band gaps are mainly caused by the d orbitals of A* (A* = AI, AII)-site atoms and dp hybridizations between the A*-site and S atoms. In addition, the more powerful covalent bonds of AII–S and Ga–S in the AIIGa2S4 lead to the larger SHG responses of ZnGa2S4 and HgGa2S4. For the birefringences, the sizes of the A*-site atoms make sense, namely larger size will lead to higher distortion of tetrahedra, then result in large birefringences. All the above analyses conclude that the A*-site atoms in the chalcopyrite structures play a modulation role in determining the optical properties.

Screening a good-performance infrared (IR) nonlinear optical (NLO) material with a large band gap, appropriate second harmonic generation (SHG) response and moderate birefringence has inspired the study of A8BS6 (A = Cu, and Ag; B = Si, Ge, and Sn). The A8BS6 series exhibits apparently hierarchical changes in the optical properties with ion-substitution under the same symmetry. In this paper, by the first-principles method and SHG-density method, the electronic structure, the optical properties and the contribution of respective ions and ion groups have been investigated. This reveals that the substitution from Ag to Cu with isostructural compounds induces the apparent enhancement of the SHG responses, which is mainly attributed to the different intensity of dp hybridization between the A cation and S. In addition, tetrahedra formed by B-site cations contribute little to the SHG, mainly because they offset each other. For the tiny changes in band gaps, it is found that the synergetic effect of B-site ion size, compound volume size and dp hybridization of A–S plays an important role. This study provides a feasible way to design and synthesize good-performance IR NLO materials.

Oxonitridosilicates, in which O atoms in SiO4 are partially substituted by N atoms, are proposed to improve optical anisotropies of silicates as UV NLO materials. The optical properties calculation showed that the heteroleptic SiOxN4−x (x = 1–3) tetrahedra have strong polarizability anisotropy and large hyperpolarizability. Accordingly, nine noncentrosymmetric (NCS) oxonitridosilicate crystals collected in the inorganic crystal structural database (ICSD) are evaluated by using the first principles method. Finally, Si2N2O and LiSiON are screened out owing to wide band gaps (6.49 and 6.95 eV), large birefringences (0.102 and 0.060 at 1064 nm), and large SHG coefficients (3.3 and 2.2 times that of d36(KDP)). More importantly, the cation selection and structural characteristics that are beneficial for enhancing the band gap and birefringence are identified. This study provides a novel strategy to design and find UV NLO crystals.