Chiral lanthanide-silver(I) cluster-based metal-organic frameworks exhibiting solvent stability, and tunable photoluminescence.

Due to the lack of effective synthetic strategies, the preparation of chemically stable chiral Ag(I) cluster-based materials for assembly remains challenging. Here, we have developed an approach to synthesize three pairs of chiral Ln-Ag(I) cluster-based metal-organic frameworks (MOFs) named l-LnAg5-3D (Ln = Gd for 1-L, Eu for 2-L, and Tb for 3-L) and d-LnAg5-3D (Ln = Gd for 1-D, Eu for 2-D, and Tb for 3-D) by employing a chiral Ag(I) cluster ({Ag5S6}) as the node and Ln3+ ion as the inorganic linker. Structural analysis revealed that the chiral ligands induced chirality through the entire structure, resulting in a chiral helix arrangement of the C3-symmetric chiral {Ag5S6} nodes and Ln3+ ions. These compounds showed high solvent stability in various polar organic solvents. The solid-state circular dichroism (CD) spectra of compounds l-LnAg5-3D and d-LnAg5-3D exhibited obvious mirror symmetrical peaks. The emission spectra in the solid state revealed that compound 1-L only exhibited the emission peak of {Ag5S6}, while compounds 2-L and 3-L exhibited overlapping peaks of Ln3+ and {Ag5S6} at different excitation wavelengths. This demonstrates the tunable photoluminescence from {Ag5S6} to Ln3+ by introducing different Ln3+ ions and manipulating the excitation wavelengths. The study underscores the enhanced stability of Ag(I) cluster-based MOFs achieved through the incorporation of Ln3+ ions and establishes chiral Ln-Ag(I) cluster-based MOFs as promising candidates for advanced materials with tunable photoluminescence.

Atom-Precise Chiral Lanthanide-Silver(I) Heterometallic Clusters Ln3Ag5.

Three pairs of chiral Ln-Ag(I) clusters d/l-Ln3Ag5 with C3 symmetry were prepared by d/l-penicillamine as multidentate ligand bridged Ln3+ and Ag(I) ions. The chiral ligand induced the molecular cluster to be chiral, and the CD spectra of the chiral compounds d/l-Ln3Ag5 were slightly blue-shifted due to the lanthanide contraction. The studies of optical properties indicated that tunable photoluminescence from {AgS}-to-Ln3+ was achieved by introducing Ln3+ ions with different emission bands or regulating various excitation light.

Family of Nanoclusters, Ln33 (Ln = Sm/Eu) and Gd32, Exhibiting Magnetocaloric Effects and Fluorescence Sensing for MnO4.

A family of nanoclusters, [Ln33(EDTA)12(OAc)2(CO3)4(µ3-OH)36(µ5-OH)4(H2O)38]·OAc·xH2O (x ≈ 50, Ln = Sm for 1; x ≈ 70, Ln = Eu for 2) and [Gd32(EDTA)12(OAc)2(C2O4)(CO3)2(µ3-OH)36(µ5-OH)4(H2O)36]·x(H2O) (x ≈ 70 for 3; H4EDTA = ethylene diamine tetraacetic acid), was prepared through the assembly of repeating subunits under the action of an anion template. The analysis of the structures showed that compounds 1 and 2 containing 33 Ln3+ ions were isostructural, which were constructed by three kinds of subunits in the presence of CO32- as an anion template, while compound 3 had a slightly different structure. Compound 3 containing 32 Gd3+ ions was formed by three types of subunits in the presence of CO32- and C2O42- as a mixed anion template. The CO32- anions came from the slow fixation of CO2 in the air. Meanwhile, one kind of high-nuclearity lanthanide clusters showed high chemical stability. The quantum Monte Carlo (QMC) calculation suggested that weak antiferromagnetic interactions were dominant between Gd3+ ions in 3. Magnetocaloric studies showed that compound 3 had a large entropy change of 43.0 J kg-1 K-1 at 2 K and 7 T. Surprisingly, compound 2 showed excellent recognition and detection effects for permanganate in aqueous solvents based on the fluorescence quenching phenomenon.

Nonlinear Association of Glycosylated Hemoglobin With Single Intracranial Aneurysm Rupture in Patients With Diabetes Mellitus: A Cross-Sectional Study.

Background: The published literature linking diabetes mellitus (DM) to intracranial aneurysm (IA) ruptured has been controversial and limited by methodology. Thus, this study was performed to examine whether hyperglycemia control status is independently associated with single IA rupture in patients with DM. Methods: We conducted a cross-sectional study on two Chinese hospitals between January 2010 and November 2017. Medical records of 223 patients with single IA and DM were reviewed and analyzed. We used glycosylated hemoglobin (GHB) as the independent variable of interest, and the outcome variable was ruptured status of IA. Covariates included data on demographics, morphological parameters, lifestyle habits, clinical features, and comorbidities. Results: Multivariable adjusted binary logistic regression and sensitivity analyses indicated that GHB was not associated with IA rupture (odds ratio OR, = 1.07, 95% CI 0.84-1.35). A nonlinear association between GHB and IA rupture was observed, whose inflection points were 5.5 and 8.9. The OR values (95% confidence intervals) were 0.38 (0.16-0.9) at the range of 1.88-5.5% of GHB, 1.6 (1.03, 2.5) at the range of 5.5-8.9%, and 0.56 (0.06-5.34) at the range of 8.9-10.1, respectively. Conclusion: The independent correlation between GHB and risk of IA rupture presented is nonlinear. The good glycemic control in single IA patients with DM can reduce the risk of IA rupture, and vice versa.

The complete mitochondrial genome of Oplophorus spinosus (Brullé, 1839) (Caridea, Oplophoridae).

We determined the complete mitochondrial genome of Oplophorus spinosus with a typical circular structure. The complete mitogenomes of O. spinosus was 17,346 bp in length, with 37 genes containing 13 protein-coding genes, 22 tRNAs, two rRNAs, and a confirmed D-loop zone. The GC content of O. spinosus was 34.39%. The phylogenetic results showed that O. spinosus was most closed to O. typus, providing useful mitochondrial information for its further evolutionary and taxonomy study.

Effect of iron loading on the performance and structure of Fe/ZSM-5 catalyst for the selective catalytic reduction of NO with NH3.

A series of Fe/ZSM-5 catalysts with different Fe contents were prepared by impregnation method. The catalysts were characterized by TEM, XRD, H2 temperature-programed reduction (H2-TPR), temperature-programed desorption of ammonia (NH3-TPD), and in situ diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS), and the catalytic activity test was also carried out on selective catalytic reduction (SCR) denitration device. Results showed that the single metal iron-supported ZSM-5 catalyst has high deNOx activity in the medium-high temperature range, and the optimal loading of Fe active component is 10 wt%; the deNOx efficiency over 80% at the range of 350-450 °C and 431 °C reaches the maximum of 96.91%. Iron species can be finely dispersed on the surface of the carrier as amorphous oxides, and the crystalline structure of zeolite is retained. The significant redox performance, highly dispersed nanoparticles, and rich Lewis acid sites on the surface of catalyst are favorable for the SCR denitration reaction. Fe/ZSM-5 10 wt% catalyst has rich Lewis acid sites and less B acid sites and Lewis acidic sites play an important role during the reaction. Only Eley-Rideal (E-R) mechanism existed during the NH3-SCR reaction process, and there is no denitration reaction being accomplished by L-H mechanism at 150 °C.

[Analysis of influencing factors on infrared spectroscopic determination of the content of free silica in quartz sand].

OBJECTIVE: To find a suitable method for detecting SiO2 in quartz sand and to analyze the influencing factors on infrared spectroscopic determination of the content of free silica in quartz sand. METHODS: The infrared spectroscopy was used to detect the free silica content of quartz sand, the various factors of influencing the results were analyzed and the control scheme was proposed. RESULTS: The number of particles less than 5 um and the proportion of free silica content increased with the grinding time. When the grinding time was 10-20 min, the results of detecting the free silica content tended to be stable. When the ashing temperature was below 550 degrees C, there was no effect on the free silica content. Although the silica content decreased slightly at ashing temperature 600 degrees C as compared to ashing temperature 550 degrees C, the difference of the free silica content between 550 degrees C and 600 degrees C was not significant (P > 0.05). When the ashing temperature was 600 degrees C, the free silica content in quartz sand samples did not change obviously in 1 h (F = 4.231, P > 0.05). The free silica content in quartz sand samples decreased significantly at 2 h of ashing time, as compared with 2 h of ashing time (F = 10.231, P < 0.05). The average content of free silica was 88.56% +/- 5.75% by pyrophosphate determination, which was significantly higher than that (21.23% +/- 11.25%) by infrared determination (P < 0.05). There was no significant correlation of the average content of free silica between pyrophosphate determination and infrared determination (r = 0.411, P > 0.05). CONCLUSION: The free silica contents detected by pyrophosphate determination were significantly higher than those detected by infrared determination for the same quartz sand samples. It is suggested that the method of detecting the free silica contents in quartz sand samples prefers the pyrophosphate determination to infrared determination.

Monte Carlo evaluations of the absorbed dose and quality dependence of AL2O3 in radiotherapy photon beams.

PURPOSE: The purpose of this work was to evaluate the absorbed dose to AL2O3 dosimeter at various depths of water phantom in radiotherapy photon beams by Monte Carlo simulation and evaluate the beam quality dependence. METHODS: The simulations were done using EGSnrc. The cylindrical Al2O3 dosimeter (Phi4 mm x 1 mm) was placed at the central axis of the water phantom (Phi16 cm x 16 cm) at depths between 0.5 and 8 cm. The incident beams included monoenergetic photon beams ranging from 1 to 18 MeV, 60Co gamma beams, Varian 6 MV beams using phase space files based on a full simulation of the linac, and Varian beams between 4 and 24 MV using Mohan's spectra. The absorbed dose to the dosimeter and the water at the corresponding position in the absence of the dosimeter, as well as absorbed dose ratio factor fmd, was calculated. RESULTS: The results show that fmd depends obviously on the photon energy at the shallow depths. However, as the depth increases, the change in fmd becomes small, beyond the buildup region, the maximum discrepancy of fmd to the average value is not more than 1%. CONCLUSIONS: These simulation results confirm the use of Al2O3 dosimeter in radiotherapy photon beams and clearly indicate that more attention should be paid when using such a dosimeter in the buildup region of high-energy radiotherapy photon beams.

[Application of active breathing control system to precise radiotherapy for non-small cell lung cancer].

BACKGROUND & OBJECTIVE: Breathing is one major factor which affects the dose used in the treatment of non-small cell lung cancer (NSCLC). This study was to observe the influence of active breathing control (ABC) system on the motion of primary tumor of non-small cell lung cancer and investigate the effect of ABC on the reduction of radioactive damage of lungs during precise radiotherapy. METHODS: Seven patients with stage IIIA and IV peripheral lung cancer, whose pathology were either squamous cell carcinoma or adenocarcinoma, were enrolled. The patients receiving three-dimensional conformal radiotherapy controlled by ABC system held their breath when their inspiratory volume reached 80% of the maximum. The moving ranges of tumor in intra-and inter-fractions during radiotherapy were calculated respectively. The tumor moving ranges of patients who accepted repeated CT scans when breathing freely in the same position were calculated. Internal margin, V2, D(mean), volume of GTV and total volume of bilateral lung were calculated by treatment planning system and compared by t-test. RESULTS: The mean ranges in left-right (X), superior-inferior (Y) and cranial-caudal (Z)directions were(0.79+/-0.45)mm, (0.98+/-0.52)mm, (0.50+/-0.75)mm in intra-fractional radiotherapy and (0.91+/-0.69)mm, (1.02+/-0.77)mm, (0.74+/-1.0)mm in inter-fractional radiotherapy respectively when patients used ABC system; while the ranges were (1.09+/-0.61)mm, (1.71+/-0.82)mm, (2.73+/-1.08)mm respectively when patients breathed freely. V20 were (10.0+/-3.7)% and (17.0+/-6.5)% (P=0.015); D(mean) were (539+/-247)cGy and (844+/-390)cGy (P=0.012); the volumes of GTV were (26.1+/-22)cm(3) and (30.0+/-23.9)cm(3) (P=0.02), and total bilateral lung volume were (3522.8+/-1020)cm(3) and (3240.7+/-876.7)cm(3) (P=0.045) respectively under ABC and free breathing condition. CONCLUSIONS: The tumor moving ranges and internal margins are reduced by holding the patients' breath by ABC system, which reduces the volume of normal tissues around peripheral lung tumor during radiotherapy. In addition, total lung volumes are enlarged when patients holding their breath while inhaling, which can reduce the density of irradiated lungs, and thus the incidence of radioactive lung damage is decreased accordingly.