Nanocage-Confined Synthesis of Fluorescent Polycyclic Aromatic Hydrocarbons in Zeolite.

Polycyclic aromatic hydrocarbons (PAHs) attract much attention for applications to organic light-emitting diodes, field-effect transistors, and photovoltaic cells. The current synthetic approaches to PAHs involve high-temperature flash pyrolysis or complicated step-by-step organic reactions, which lead to low yields of PAHs. Herein, we report a facile and scalable synthesis of PAHs, which is carried out simply by flowing acetylene gas into zeolite under mild heating, typically at 400 °C and generates the products of 0.30 g g-1 zeolite. PAHs are synthesized via acetylene polymerization inside Ca2+-ion-exchanged Linde type A (LTA) zeolite, of which the α-cage puts a limit on the product molecular size as a confined-space nanoreactor. The resultant product after the removal of the zeolite framework exhibits brilliant white fluorescence emission in N-methylpyrrolidone solution. The product is separated into four different color emitters (violet, blue, green, and orange) by column chromatography. Detailed characterizations of the products by means of various spectroscopic methods and mainly mass spectrometric analyses indicate that coronene (C24H12) is the main component of the blue emitter, while the green emitter is a mixture of planar and curved PAHs. The orange can be attributed to curved PAHs larger than ovalene, and the violet to smaller molecules than coronene. The PAH growth mechanism inside Ca2+-exchanged LTA zeolite is proposed on the basis of mass spectral analyses and density functional theory calculations.

Minimal clinically important differences in Rowe and Western Ontario Shoulder Instability Index scores after arthroscopic repair of anterior shoulder instability.

BACKGROUND: The minimal clinically important difference (MCID) is the threshold value for a change that would be considered meaningful by the patient. The purpose of this study was to determine the MCIDs for the Rowe score and the Western Ontario Shoulder Instability Index (WOSI) score after arthroscopic repair of anterior shoulder instability. METHODS: The study enrolled 198 patients who underwent an arthroscopic stabilization procedure for anterior shoulder instability. Patients were assigned to no change and minimal change groups by a 15-item questionnaire at the 1-year postoperative visit. The Rowe and WOSI scores were assessed preoperatively and at a 1-year postoperative follow-up. The MCID was calculated using an anchor-based method and a distribution-based method. RESULTS: There were 9 patients in the no change group and 26 patients in the minimal change group. The MCID for the Rowe score was 9.7 according to the anchor-based method. By the anchor-based method, the authors could not calculate MCID for the WOSI score because of insignificant difference of the mean score changes between the no change and minimal change groups. By the distribution-based method, MCIDs for the Rowe and the WOSI scores were 5.6 and 151.9 with the standard deviation-based estimate and 2.2 and 60.7 with the effect size-based estimate, respectively. CONCLUSIONS: To assess the effectiveness of an arthroscopic stabilization procedure for anterior shoulder instability using the Rowe score, a difference of at least 9.7 in the score is clinically relevant. To compare clinical outcomes between different modalities, we should consider not only statistically significant differences but also the MCID.

Lanthanum-catalysed synthesis of microporous 3D graphene-like carbons in a zeolite template.

Three-dimensional graphene architectures with periodic nanopores­reminiscent of zeolite frameworks­are of topical interest because of the possibility of combining the characteristics of graphene with a three-dimensional porous structure. Lately, the synthesis of such carbons has been approached by using zeolites as templates and small hydrocarbon molecules that can enter the narrow pore apertures. However, pyrolytic carbonization of the hydrocarbons (a necessary step in generating pure carbon) requires high temperatures and results in non-selective carbon deposition outside the pores. Here, we demonstrate that lanthanum ions embedded in zeolite pores can lower the temperature required for the carbonization of ethylene or acetylene. In this way, a graphene-like carbon structure can be selectively formed inside the zeolite template, without carbon being deposited at the external surfaces. X-ray diffraction data from zeolite single crystals after carbonization indicate that electron densities corresponding to carbon atoms are generated along the walls of the zeolite pores. After the zeolite template is removed, the carbon framework exhibits an electrical conductivity that is two orders of magnitude higher than that of amorphous mesoporous carbon. Lanthanum catalysis allows a carbon framework to form in zeolite pores with diameters of less than 1 nanometre; as such, microporous carbon nanostructures can be reproduced with various topologies corresponding to different zeolite pore sizes and shapes. We demonstrate carbon synthesis for large-pore zeolites (FAU, EMT and beta), a one-dimensional medium-pore zeolite (LTL), and even small-pore zeolites (MFI and LTA). The catalytic effect is a common feature of lanthanum, yttrium and calcium, which are all carbide-forming metal elements. We also show that the synthesis can be readily scaled up, which will be important for practical applications such as the production of lithium-ion batteries and zeolite-like catalyst supports.

Wear of primary teeth caused by opposed all-ceramic or stainless steel crowns.

PURPOSE: This study was conducted to evaluate the effects of full-coverage all-ceramic zirconia, lithium disilicate glass-ceramic, leucite glass-ceramic, or stainless steel crowns on antagonistic primary tooth wear. MATERIALS AND METHODS: There were four study groups: the stainless steel (Steel) group, the leucite glass-ceramic (Leucite) group, the lithium disilicate glass-ceramic (Lithium) group, and the monolithic zirconia (Zirconia) group. Ten flat crown specimens were prepared per group; opposing teeth were prepared using primary canines. A wear test was conducted over 100,000 chewing cycles using a dual-axis chewing simulator and a 50 N masticating force, and wear losses of antagonistic teeth and restorative materials were calculated using a three-dimensional profiling system and an electronic scale, respectively. Statistical significance was determined using One-way ANOVA and Tukey's test (P<.05). RESULTS: The Leucite group (2.670±1.471 mm(3)) showed the greatest amount of antagonist tooth wear, followed by in decreasing order by the Lithium (2.042±0.696 mm(3)), Zirconia (1.426±0.477 mm(3)), and Steel groups (0.397±0.192 mm(3)). Mean volume losses in the Leucite and Lithium groups were significantly greater than in the Steel group (P<.05). No significant difference was observed between mean volume losses in the Zirconia and Steel groups (P>.05). CONCLUSION: Leucite glass-ceramic and lithium disilicate glass-ceramic cause more primary tooth wear than stainless steel or zirconia.

AFRICAN AMERICAN STEPFATHER-STEPCHILD RELATIONSHIPS, MARITAL QUALITY, AND MENTAL HEALTH.

This study examined associations between stepfather-stepchild relationship quality, stepfathers' depressive symptoms, and two aspects of marriage: marital quality and positive marital interactions. Marital quality was assessed in terms of commitment, trust, passionate and friendship-based love, and happiness. Marital interactions were assessed in terms of intimacy, shared activities, and verbal communication. Using data collected from 149 recently married African American stepfathers, structural equation modeling revealed that when stepfathers reported more positive relationships with their stepchildren, they also reported more positive marital quality and a higher frequency of positive marital interactions (relationship solidifying activities), and that, in turn, was associated with stepfathers experiencing fewer depressive symptoms.

Stressful life experiences in adolescence and cardiometabolic risk factors in young adulthood.

PURPOSE: An increasing number of studies have provided evidence for the persistent influence of childhood/adolescent socioeconomic adversities on subsequent health outcomes. However, less is known about the distinct and additive influences of these early socioeconomic adversities and adolescents' own stressful life experiences on health outcomes in young adulthood. METHODS: We used data from 11,030 adolescents who participated in the National Longitudinal Study of Adolescent Health at Waves 1, 3, and 4 and provided biomarker data at Wave 4. Three early socioeconomic adversities (community socioeconomic adversity, family economic hardship, and low parental education) were evaluated. Adolescents' stressful transition to young adulthood was captured by six specific precocious life events as follows: early sex, early marriage or cohabitation, early leaving home, early pregnancy, early employment, and truncated education. A summary measure of cardiovascular and metabolic disease risk was assessed using nine biomarkers. Univariate, bivariate, and multivariate regression analyses were employed. RESULTS: Early socioeconomic adversities and stressful life transition events were uniquely associated with elevated levels of cardiometabolic (CM) biomarkers and cumulative CM disease risk. For all of the biomarkers, young adults in high-adversity/stress groups were more likely to be in the high CM disease risk groups (>75th percentile) than in the low-adversity/stress groups. CONCLUSIONS: These findings provide support for the influence of multiple early socioeconomic adversities and adolescents' stressful life transitions on their CM disease risk as young adults. Increased efforts to prevent and mitigate these experiences may improve disease risks across a number of biomarkers.

Nitric oxide donor, (+/-)-S-nitroso-N-acetylpenicillamine, stabilizes transactive hypoxia-inducible factor-1alpha by inhibiting von Hippel-Lindau recruitment and asparagine hydroxylation.

We have confirmed that the NO donor (+/-)-S-nitroso-N-acetylpenicillamine (SNAP) stabilizes the transactive form of hypoxia-inducible factor-1alpha (HIF-1alpha), leading to the induction of HIF-1alpha target genes such as vascular endothelial growth factor and carbonic anhydrase 9. Activation of HIF-1alpha should require inhibition of the dual system that keeps it inactive. One is ubiquitination, which is triggered by hydroxylation of HIF-1alpha-proline and the subsequent binding of E3 ubiquitin ligase, the von Hippel Lindau (VHL) protein. The other is hydroxylation of HIF-1alpha-asparagine, which reduces the affinity of HIF-1alpha for its coactivator, cAMP responsive element binding protein/p300. We examined the effects of the NO donor SNAP on proline and asparagine hydroxylation of HIF-1alpha peptides by measuring the activities of the corresponding enzymes, HIF-1alpha-specific proline hydroxylase 2 (PHD2) and the HIF-1alpha-specific asparagine hydroxylase, designated factor inhibiting HIF-1alpha (FIH-1), respectively. We found that the SNAP did not prevent PHD2 from hydroxylating the proline of HIF-1alpha. Instead, it blocked the interaction between VHL and the proline-hydroxylated HIF-1alpha, but only when the reducing agents Fe(II) and vitamin C were limiting. The fact that the absence of cysteine 520 of HIF-1alpha abolishes its responsiveness to SNAP suggests that this residue mediates the inhibition by SNAP of the interaction between VHL and HIF-1alpha, presumably by S-nitrosylation of HIF-1alpha. Un-like PHD2, asparagine hydroxylation by FIH-1 was directly inhibited by SNAP, but again only when reducing agents were limiting. Substitution of cysteine 800 of HIF-1alpha with alanine failed to reverse the inhibitory effects of SNAP on asparagine hydroxylation, implying that FIH-1, not its substrate HIF-1alpha, is inhibited by SNAP.