BiGa(SeO3)3: A Phase Matchable SHG Material Achieved by Cation Substitution.

The search of novel second-harmonic generation crystals in gallium selenite systems results in three new compounds of MGa2(SeO3)4 (M = Sr, Pb) and BiGa(SeO3)3. The isostructural MGa2(SeO3)4 (M = Sr, Pb) are centrosymmetric (P1̅, no. 2). The structures represent a complicated three-dimensional skeleton containing two different types of Ga4Se4 8-member polyhedral ring tunnels with the counter cations located at the broad ones. When the divalent counter cations were substituted by a trivalent lone pair cation of Bi(III), a novel noncentrosymmetric compound of BiGa(SeO3)3 was achieved. BiGa(SeO3)3 displays a 3D gallium selenite framework with 1D bismuth oxide chains filling in the 12-member polyhedral ring tunnels. Frequency doubling measurements showed that BiGa(SeO3)3 presented an apparent SHG signal comparable to the commercial KDP and can realize phase matching. The lone pair anionic groups of SeO32- made the major contribution according to the SHG density analyses. BiGa(SeO3)3 exhibits a wide transparent range and large optical bandgap (3.90 eV). The laser-induced damage threshold of BiGa(SeO3)3 was estimated to be 98.68 MW/cm2, about 44 × AGS.

Two Indium Sulfate Tellurites: Centrosymmetric In2(SO4)(TeO3)(OH)2(H2O) and Non-centrosymmetric In3(SO4)(TeO3)2F3(H2O).

Two new indium sulfate tellurites, namely, In2(SO4)(TeO3)(OH)2(H2O) and In3(SO4)(TeO3)2F3(H2O), were synthesized by hydrothermal method in a one-pot reaction. Their pure phase yields have been successfully optimized to 76% and 21%, respectively. In2(SO4)(TeO3)(OH)2(H2O) crystallized in centrosymmetric (CS) space group P21/n, while In3(SO4)(TeO3)2F3(H2O) formed a non-centrosymmetric (NCS) and chiral space group P212121. The CS compound features a 2D layered structure composed of 2D indium oxide layers decorated by sulfate tetrahedra and tellurite groups. The NCS compound displays a 3D network consisting of indium tellurite layers bridged by sulfate tetrahedra. Powder second harmonic generation measurements disclosed that In3(SO4)(TeO3)2F3(H2O) exhibits a weak frequency-doubling efficiency about 11% of the commercial KDP. Its powder laser damage threshold quantity was estimated to be 79.6 MW/cm2, which is about 36 times that of AGS. The two samples present wide optical band gaps of 4.86 and 4.10 eV, respectively, which were determined by Te, In, and O atoms based on density functional theory calculations.

PbCdF(SeO3)(NO3): A Nonlinear Optical Material Produced by Synergistic Effect of Four Functional Units.

A new nonlinear optical material, the first fluoride selenite nitrate PbCdF(SeO3)(NO3), was successfully synthesized by traditional solid state reactions. This compound crystallizes in the polar space group of Pca21, and its structure features a novel 2D layered structure consisting of 1D lead nitrate chains and 2D cadmium selenite layers. PbCdF(SeO3)(NO3) exhibits a phase-matchable SHG efficiency of about 2.6 times that of KDP and a wide band gap of 4.42 eV. Its laser damage threshold was measured to be 135.6 MW/cm2, which is comparative to that of the reported Li7(TeO3)3F with a short ultraviolet cutoff edge. Theoretical calculation confirmed that the synergistic effects of all the four functional units make PbCdF(SeO3)(NO3) a remarkable SHG material.

A Dynamic Three-Dimensional Covalent Organic Framework.

A guest-induced reversible crystal-structure transformation is identified in a new 3D covalent organic framework (COF) by comprehensive analyses using powder X-ray diffraction, organic vapor sorption isotherm, and 129Xe NMR spectroscopy. The revolving imine bond in interpenetrating 3D networks is uncovered as the key to the dynamic behavior, the potential applications of which are illustrated by gas separation and heterogeneous catalysis, thus paving the way to the design of stimuli-responsive and multifunctional COF materials.

Salen-Based Covalent Organic Framework.

The Salen unit represents one of the most important ligands in coordination chemistry. We report herein the first example of a Salen-based covalent organic framework (COF), in which both the construction of the COF structure and the functionalization with Salen moieties have been realized in a single step. Due to its structural uniqueness, the obtained COF material, Salen-COF, possesses high crystallinity and excellent stability. Based on this, a series of metallo-Salen-based COFs were prepared via metalation for further applications.

Ln2 F2 (OH2 )(MoO3 )2 (SeO3 )2 : Promising Multifunctional Nonlinear Optical Materials Created by Partial Fluorination Strategy under Corrosion Resistant Supercritical Reactions.

It has historically been exceedingly challenging to create physically and chemically stable lanthanide compounds with strong second harmonic generation (SHG) due to their strong preference to central symmetry. In this work, five new non-centrosymmetric lanthanide selenites, namely, Ln2 F2 (OH2 )(MoO3 )2 (SeO3 )2 (Ln = Sm, Eu, Gd, Tb and Dy), are achieved by partial fluorination of the lanthanide oxygen polyhedron. An HF corrosion resistant supercritical hydrothermal method is developed, which is a facile and universal method for HF corrosion and high-temperature high-pressure environment. The title compounds displayed a novel 3D framework composed of 1D molybdenum selenite chains bridged by Ln2 F2 O12 (OH2 ) dimers. Their powder SHG responses showed a large difference, ranging from 1.0 to 9.0 × KH2 PO4 (KDP) at 1064 nm. The half-filled Gd compound exhibited very strong SHG efficiency of up to 1.2 × KTP (KTiOPO4 ) at 2050 nm. Compounds Tb and Gd are the first lanthanide selenites with SHG intensity reaching KTP level, which is very rare in this system. Furthermore, these compounds can also possess excellent physicochemical stability and strong luminescence emission, indicating that they are promising multifunctional nonlinear optical materials. This work offered an effective way for design and synthesis of multifunctional and high-performant nonlinear optical materials.

Macrocycle-Based Metal-Organic Frameworks with NO2-Driven On/Off Switch of Conductivity.

Conductive metal-organic frameworks (MOFs) have a wide range of applications in supercapacitors, electrocatalysts, and fuel cells, while gas-driven conductive MOFs have not yet been synthesized so far. Herein, we report a gas-driven conductive MOF (A) constructed from calix[4]resorcinarene macrocycle and Co(II) cations, which shows the conductivity enhancement by about eight orders of magnitude through NO2 adsorption. The conductivities of MOF A before and after the adsorption of NO2 were calculated to be about 1.3 × 10-11 and 8.4 × 10-4 S/cm, respectively. MOF A realizes the conversion from an insulator to a conductor by adsorbing NO2. When NO2 is evacuated, MOF A quickly changes from a conductor back to an insulator in 42 s. In the crystal structure of NO2-adsorbed MOF (termed as A-NO2), NO2 molecule connects Co(II) and uncoordinated carboxylate groups through hydrogen-bonding interactions to form a conductive pathway, greatly reducing the electron transmission distance between each two metal clusters. In addition, NO2 molecule and H3O+ may also form a conductive pathway by hydrogen-bonding interactions. This work presents an interesting macrocycle-based MOF with a NO2-driven on/off conductivity switch, proving the possibility for designing advanced gas-driven conductive systems.

[Effects of combined application of xuezhikang capsule with hypotensive drugs on arterial compliance and smoothness of the dynamic blood pressure].

OBJECTIVE: To investigate the effects of combined application of Xuezhikang Capsule (XZK) and hypotensive drugs on the dynamic blood pressure (DBP), pulse pressure index (PPI), pulse wave velocity (PWV) and smoothness index (SI), and to study the relationship between SI and related factors (age, BP, dynamic PPI, and vascular elasticity). METHODS: One hundred and ten patients with essential hypertension were randomly assigned to 2 groups: 54 in the control group and 56 in the treated group. Both were treated with hypertensive drugs, but with oral medication of XZK given additionally to the treated group at the dose of 60 mg, twice a day. PWV and DBP were measured before treatment and at the terminal of a 6-month treatment. Meantime, the 24-h average systolic and diastolic pressures were recorded to calculate the 24-h dynamic pulse pressure (24 hPP), PPI, SI of systolic and diastolic blood pressure (SISBP and SIDBP) for comparing the changes between groups and analyzing the SI related factors. RESULTS: All patients' blood pressure levels were well controlled; after a 6-month treatment, the PP and PPI in the treated group were 45 +/- 8 mm Hg and 0.35 +/- 0.08 respectively, which were significantly lower than those in the control group (51 +/- 10 mm Hg and 0.38 +/- 0.05, P < 0.05); while SISBP and SIDBP in the treated group were higher than those in the control group (1.37 +/- 0.16 vs 1.26 +/- 0.20, P < 0.01; and 1.28 +/- 0.14 vs 1.18 +/- 0.23, P < 0.05) respectively; and PWV in the former was significantly lower than that in the latter group (10.4 +/- 3.68 m/s vs 12.5 +/- 4.27 m/s, P < 0.05). Multiple factor stepwise regression analysis showed that the SISBP was negatively correlated with age, PPI and PWV, while the SIDBP was negatively correlated with PPI (P < 0.01). CONCLUSION: The combined application of XZK and hypotensive drugs can decrease PP and PPI, improve the endothelial function and arterial elasticity, enhance the efficacy of treatment on SI. After treatment SI shows a significant negative correlation with PPI, PWV and age in patients.

Dual-Functionalized Fluorescent Cationic Organic Network: Highly Efficient Detection and Removal of Dichromate from Water.

Dichromate is a widespread contaminant in wastewater, threatening the health of humans and other organisms. Therefore, effective detection and removal of dichromate from water is of great significance. Herein, a tetraphenylethylene functionalized cationic organic network (CON-LDU2) was constructed via a facile quaternization reaction. CON-LDU2 was successfully integrated with both detection and removal functionalities toward dichromate. On the one hand, benefiting from the strong fluorescence, CON-LDU2 was employed as a chemosensor, it could efficiently and selectively probe Cr2O72- in water with "turn-off" fluorescent response. On the other hand, the cationic skeleton and free anions inside framework make CON-LDU2 an excellent adsorbent for Cr2O72-, it could capture Cr2O72- from water with rapid kinetics and high capacity. The kinetic constant for adsorption of Cr2O72- can reach up to 1.784 g mg-1 min-1, while the capacity is determined as 325 mg g-1. Furthermore, CON-LDU2 displayed good recyclability and can be reused for at least 5 cycles. Therefore, CON-LDU2 can serve as an ideal candidate not only in detection but also in removal of Cr2O72- in water medium.

A(VO2F)(SeO3) (A = Sr, Ba) and Ba(MOF2)(TeO4) (M = Mo, W): first examples of alkali-earth selenites/tellurites with a fluorinated d0-TM octahedron.

Four new compounds of A(VO2F)(SeO3) (A = Sr 1, Ba 2) and Ba(MOF2)(TeO4) (M = Mo 3, W 4) oxyfluorides have been synthesized successfully by hydrothermal reactions. They represent the first examples of alkali-earth selenites or tellurites with a fluorinated d0-TM octahedron. Their crystal structures were determined by single-crystal X-ray diffraction. They exhibit two different types of structures. Compounds 1 and 2 are isostructural and crystallize in the orthorhombic crystal system with the space group of Pbca (no. 61). Their structures feature a 3D network composed of 0D [V2O4F2(SeO3)2]4- dimers which are further bridged by Sr2+ or Ba2+ cations. Isostructural compounds 3 and 4 are crystallized in the monoclinic crystal system with the space group of P21/c (no. 14). Their structures can be described as 2D [(MOF2)(TeO4)]2- (M = Mo, W) anionic layers separated by Ba2+ cations. Out-of-center distortion studies show that the magnitude of the distortion of the (MOxF6-x) octahedron is comparable to that of MO6 (M = d0 transition metal). Infrared spectroscopy, thermal stability, optical property studies and theoretical calculations based on density functional theory methods were also performed.

[Study on number and mature rate of eggs in gravid proglottids of Taenia solium].

OBJECTIVE: To investigate the number and mature rate of eggs in gravid proglottids of Taenia solium. METHODS: Ten worms of Taenia solium, expelled from patients, were detected. Eggs were collected from the last 10 gravid proglottids of each worm. RESULTS & CONCLUSION: The egg number in each mature proglottids varied from 3,900 to 126,520, and the mean number was 28,332. The mature rate of eggs was from 7.00% to 36.00% with an average of 29.12%, which was lower than that in proglottids naturally excreted with feces. With suitable temperature and humidity, the proglottids developed continually after excreted out of host body. Two to three days later, the mature rate of their eggs increased to 85%-90%.