AFM ultrastructural data of control chondrocytes.

<p>(A1–A3) Control chondrocytes. (B1–B3) Chondrocytes treated with 1.5 mM SNP for 12 h. (C1–C3) The chondrocytes were pretreated with 100 μM of RV for 24 h, and then treated with 1.5 mM of SNP for 12 h. Scanning area: 2×2 μm². (A1), (B1), (C1) was topography mode. (A2), (B2), (C2) 3-D mode of (A1), (B1) and (C1), respectively. (A3), (B3), (C3) was contour map of (A1), (B1) and (C1), respectively. (D1) and (D2) were histograms of average roughness (Ra) of chondrocytes which were analyzed in 5×5 μm² and 2×2 μm², respectively. In (D1) and (D2), ten cells in each group were selected to measure the values of Ra, statistical analysis was performed using Student's <i>t</i>-test. P<0.05 was regarded as statistically significant.</p

Reaction Kinetics of the Synthesis of Methyl Chloroacetate from Chloroacetic Acid and Methanol

The use of sulfuric acid to catalyze the synthesis of methyl chloroacetate from chloroacetic acid and methanol leads to equipment corrosion and separation difficulties. To solve the above problems and treat chloroacetic acid efficiently, the esterification of chloroacetic acid was catalyzed with a cation exchange resin in this work. The effects of the alcohol/acid molar ratio, catalyst dosage, reaction temperature, and reaction time were investigated by single-factor and orthogonal experiments. The excellent catalytic performance was reached with 70.11% chloroacetic acid conversion under the optimal reaction conditions of 1.4:1 alcohol/acid molar ratio, 3 wt % catalyst dosage, 70 °C reaction temperature, and 2 h reaction time. In addition, a power-law kinetic model for methyl chloroacetate was developed over a cation exchange resin. The activation energy and the pre-exponential factor were calculated by the Arrhenius equation: Ea+ = 38.83 kJ/mol, Ea– = 53.64 kJ/mol, A+ = 1.71 × 105 L0.84 mol–0.84 h–1, and A– = 1.15 × 105 L0.54 mol–0.54 h–1. After verification, the kinetic model can accurately predict the esterification reaction results of chloroacetic acid and methanol under experimental conditions, which provides theoretical guidance for the simulation of the chloroacetic acid esterification process

Cytotoxicity of SNP in chondrocytes.

<p>(A) <i>C</i>ell viability of chondrocytes treated by different concentrations of SNP for 24 h. (B) <i>C</i>ell viability of chondrocytes treated by 1.5 mM of SNP for different time periods (comparing with control group, *P<0.05, **P<0.01, ***P<0.001). The results indicated the killing effects of SNP on chondrocytes were in a dose- and time-dependent manner.</p

Alterations in nanobiotechnology of chondrocytes detected by AFM.

<p>(A1–A5) isolation of chondrocytes: (A1) Cartilage collected from the bilateral joints of the knees, hips, and shoulders. (A2) The joints were minced into small pieces, treated with 0.015% trypsin for 30 min, and subsequently digested. (A3) Morphology of primary joint chondrocytes. (A4) The morphology of primary joint chondrocytes cultured for 7 days. (A5) The AFM tip was employed to detect the morphology and biomechanics of chondrocytes. (A6) Typical force-distance curve detected using AFM: (1) The tip is approaching the surface of sample, (2) the tip is just in contact with the surface of cells, (3) the tip is further put into repulsive contact with the cellular surface, (4) lastly, the tip-sample contact is retracted. (A7–A9) are the representative force-distance curves obtained on control chondrocytes (A7), chondrocytes treated with 1.5 mM SNP for 12 h (A8), and chondrocytes pretreated with RV and the induce with SNP (A9), respectively. The elasticity maps, histogram of elasticity, adhesion force map and histogram of adhesion force of control chondrocytes (B1–B4), chondrocytes treated with 1.5 mM SNP for 12 h (C1–C4), and chondrocytes pretreated with RV and then cotreated with SNP (A4), respectively.</p

Protection effects of RV on SNP-induced apoptosis of chondrocytes.

<p>Cells were pretreated with different concentrations (0, 25, 50 and 100 mM) of RV for 24 h, and then treated with 1.5 mM of SNP for 12 h. After that, the cell viability was assayed using CCK-8 (comparing with control group, *P<0.05, **P<0.01; comparing with SNP treated group, #P<0.05, ##P<0.01, ###P<0.001).</p

Structural Characterization of β‑Agostic Bonds in Pd-Catalyzed Polymerization

β-agostic Pd complexes are critical intermediates in catalytic reactions, such as olefin polymerization and Heck reactions. Pd β-agostic complexes, however, have eluded structural characterization, due to the fact that these highly unstable molecules are difficult to isolate. Herein, we report the single-crystal X-ray and neutron diffraction characterization of β-agostic (α-diimine)­Pd–ethyl intermediates in polymerization. Short C_α–C_β distances and acute Pd–C_α–C_β bond angles combined serve as unambiguous evidence for the β-agostic interaction. Characterization of the agostic structure and the kinetic barrier for β-H elimination offer important insight into the fundamental understanding of agostic bonds and the mechanism of polymerization

LiCa₃As₂H and Ca₁₄As₆X₇ (X = C, H, N): Two New Arsenide Hydride Phases Grown from Ca/Li Metal Flux

The reaction of arsenic with sources of light elements in a Ca/Li melt leads to the formation of two new arsenide hydride phases. The predominant phase Ca₁₄As₆X₇ (X = C^4–, N^3–, H^–) exhibits a new tetragonal structure type in the space group <i>P</i>4<i>/mbm</i> (<i>a</i> = 15.749(1) Å, <i>c</i> = 9.1062(9) Å, Z = 4, R1 = 0.0150). The minor phase LiCa₃As₂H also has a new structure type in the orthorhombic space group <i>Pnma</i> (<i>a</i> = 11.4064(7) Å, <i>b</i> = 4.2702(3) Å, <i>c</i> = 11.8762(8)­Å, Z = 4, R1 = 0.0135). Both phases feature hydride and arsenide anions separated by calcium cations. The red color of these compounds indicates they should be charge-balanced. DOS calculations on LiCa₃As₂H confirm a band gap of 1.4 eV; UV–vis spectroscopy on Ca₁₄As₆X₇ shows a band gap of 1.6 eV. Single-crystal neutron diffraction studies were necessary to determine the mixed occupancy of carbon, nitrogen, and hydrogen anions on the six light-element sites in Ca₁₄As₆X₇; these data indicated an overall stoichiometry of Ca₁₄As₆C_0.445N_1.135H_4.915

Predicting Reoffending Using the Structured Assessment of Violence Risk in Youth (SAVRY): A 5-Year Follow-Up Study of Male Juvenile Offenders in Hunan Province, China

<div><p>Background</p><p>Juvenile violent offending is a serious worldwide public health issue.</p><p>Objective</p><p>The study examined whether the Structured Assessment of Violence Risk in Youth (SAVRY) can be used to predict violent reoffending in Chinese male juvenile offenders, and to determine which risk/protective domains (items) are associated with violent recidivism.</p><p>Methods</p><p>A total of 246 male juvenile offenders were recruited. SAVRY domains were scored by trained raters based on file review and interviews with participants and their legal guardians. Information on further arrests, charges, or convictions for violent offences were collected from police records over a five year follow-up.</p><p>Results</p><p>Over the course of the five year follow-up periods, 63 (25.6%) juvenile offenders were re-arrested for a further violent reoffence. Receiver Operating Characteristic (ROC) analyses showed Areas Under the Curve (AUCs) ranging from 0.60 to 0.68 for the SAVRY total, risk and protective score domains. Univariate logistic regression analysis showed that 7 of the 30 SAVRY items were significantly associated with reoffending; explaining 36.2% of the variance. Backward stepwise multiple logistic regression analysis showed the independently predictive items were items 2 (‘history of non-violent offending’), 17 (‘negative attitudes’), 18 (‘risk-taking/impulsivity’), and 20 (‘anger management problems’). Together these four items explained 25.0% of the variance in reoffending.</p><p>Conclusions</p><p>The results suggested that the SAVRY can be meaningfully used to inform the development and evaluation of effective violence risk assessment and management approaches for male juvenile offenders detained in a Youth Detention Center in Hunan province, China.</p></div