We performed a meta-analysis of 2 genome-wide association studies of
coronary artery disease comprising 1,515 cases with coronary artery disease and
5,019 controls, followed by de novo replication studies in
15,460 cases and 11,472 controls, all of Chinese Han descent. We successfully
identified four new loci for coronary artery disease reaching genome-wide
significance (P < 5 × 10−8),
which mapped in or near TTC32-WDR35, GUCY1A3,
C6orf10-BTNL2 and ATP2B1. We also
replicated four loci previously identified in European populations
(PHACTR1, TCF21, CDKN2A/B
and C12orf51). These findings provide new insights into
biological pathways for the susceptibility of coronary artery disease in Chinese
Han population.
Organic structure-directing agents (OSDAs) have been widely used for the synthesis of zeolites. In most cases, OSDAs are occluded in zeolites as an isolated cation or molecule geometrically fitted within the zeolite cavities. This is not the case for zeolite beta synthesized by using tetraethylammonium (TEA(+)) cation as an OSDA, in which a cluster/aggregate of ca. six TEA(+) cations is occluded intact in the cavity (i.e., the channel intersection) of zeolite beta. The structure direction of TEA(+) in such a nontypical, clustered mode has remained elusive. Here, zeolite beta was hydrothermally synthesized using TEA(+) in the absence of other alkali metal cations in order to focus on the structure-directing behaviors of TEA(+) alone. The solid products formed throughout the hydrothermal synthesis were analyzed by an array of characterization techniques including argon adsorption-desorption, high-energy X-ray total scattering, Raman and solid-state NMR spectroscopy, and high-resolution transmission electron microscopy. It was revealed that the formation of amorphous TEA(+)-aluminosilicate composites and their structural, chemical, and textural evolution toward the amorphous zeolite beta-like structure during the induction period is vital for the formation of zeolite beta. A comprehensive scheme of the formation of zeolite beta is proposed paying attention to the clustered behavior of TEA(+) as follows: (i) the formation of the TEA(+)-aluminosilicate composites after heating, (ii) the reorganization of aluminosilicates together with the conformational rearrangement of TEA(+), yielding the formation of the amorphous TEA(+)-aluminosilicate composites with the zeolite beta-like structure, (iii) the formation of zeolite beta nuclei by solid-state reorganization of such zeolite beta-like, TEA(+)-aluminosilicate composites, and (iv) the subsequent crystal growth. It is anticipated that these findings can provide a basis for broadening the utilization of OSDAs in the clustered mode of structure direction in more effective ways.
This study investigates the biochemical changes in a canine tibia lengthening model in comparison with a nonlengthened osteotomy model. The lengthened and the osteotomized callus and a contralateral corresponding segment were analyzed for their mineralization profile, collagen content, osteocalcin, insulin-like growth factor I (IGF-I), and transforming growth factor 1 (TGF-1). Examinations of bone samples were performed using specimens excised at different time intervals (respectively at 3, 5, 7, 9, and 13 weeks postoperatively). Several serum parameters (alkaline phosphatase [ALP], osteocalcin, IGF-I, and TGF-1) were also measured during the experimental period. A progressive increase in mineral parameters was noticed in both the lengthened and the osteotomized areas. A higher level of hydroxyproline and TGF-1 was observed in the lengthened area compared with the osteotomized area. IGF-I showed a significant increase in both the lengthened and contralateral control area at the later stage of the experimental period in the lengthened group. In serum, a high level of TGF-1 and a progressively increasing osteocalcin concentration were observed in the lengthened dogs in comparison with the osteotomized dogs. Serum ALP was significantly increased in both models during the experimental period. Serum IGF-I was increased in the lengthened models during the distraction period and decreased in the osteotomized models at the early stage of the experimental period. These results suggest that the mechanical strain induced by the Ilizarov distraction procedure stimulates osteoblast proliferation and promotes biosynthesis of bone extracellular matrix in distracted callus. Our data furthermore show that this process is different compared with normal fracture healing. (J Bone Miner Res 1998;13:279-286)
Shandong Province is located in the east of China. The province is characterized by robust economic development, with a rural population accounting for 56% of the total population. However, no data are available regarding temporal changes in the prevalence, awareness, treatment and control of hypertension among this population. Three independent cross-sectional surveys were performed in 1991 (n¼8359), 2002 (n¼18922) and 2007 (n¼20167) in the rural area population, aged 35-74 years. The sampling included a survey on blood pressure and associated risk factors. Although the rate of smoking and alcohol consumption decreased significantly from 1991 to 2007, the prevalence of overweight and obesity increased, whereas that of high-strength physical activity decreased remarkably. In 1991, 2002 and 2007, the prevalence of prehypertension was 33.8, 61.5 and 54.6%, respectively. The prevalence of hypertension was 20.4, 24.5 and 30.6%, respectively. Overall, the rate of hypertension awareness, treatment and control showed a steady increase over the 16-year period, although the control rate of hypertension is still far from being satisfactory. In conclusion, among the Chinese rural population, the prevalence of prehypertension and hypertension increased significantly from 1991 to 2007. Public health programs are required to improve this situation in Chinese rural populations.
Encapsulating metal nanoclusters into zeolites combines the superior catalytic activity of the nanoclusters with high stability and unique shape selectivity of the crystalline microporous materials. The preparation of such bifunctional catalysts, however, is often restricted by the mismatching in time scale between the fast formation of nanoclusters and the slow crystallization of zeolites. We herein demonstrate a novel strategy to overcome the mismatching issue, in which the crystallization of zeolites is expedited so as to synchronize it with the rapid formation of nanoclusters. The concept was demonstrated by confining Pt and Sn nanoclusters into a ZSM-5 (MFI) zeolite in the course of its crystallization, leading to an ultrafast, in situ encapsulation within just 5 min. The Pt/Sn-ZSM-5 exhibited exceptional activity and selectivity with stability in the dehydrogenation of propane to propene. This method of ultrafast encapsulation opens up a new avenue for designing and synthesizing composite zeolitic materials with structural and compositional complexity.
Copper-ion-exchanged
SSZ-13 has been demonstrated to be an effective
catalyst for the ammonia selective catalytic reduction of NO
x
. However, the Cu-SSZ-13 is still susceptible to
hydrothermal degradation, which reduces the catalyst lifetime. We
herein report that the hydrothermal stability of Cu-SSZ-13 can be
remarkably enhanced through loading with a small amount of cerium.
To clearly reveal the enhancement effect of cerium, we focused on
an aluminum-rich Cu-SSZ-13 zeolite (Si/Al ratio: 6.5) with copper
loadings ranging from ca. 3.4% to 4.1%, which was found to give high
hydrothermal stability while still suffering from considerable degradation
upon severe hydrothermal aging. Different cerium loadings were investigated,
and a cerium loading with a limited range of ca. 0.2–0.4 wt
% resulted in the best enhancement. The introduction of only a small
amount of cerium was beneficial because it enabled a high copper loading
and abundant Brønsted acidity sites that are needed for high
SCR activities over a broad temperature range. Various characterization
methods, including Rietveld refinement, transmission electron microscopy
with energy-dispersive X-ray spectroscopy, scanning electron microscopy,
and electron-spin resonance spectroscopy revealed that the small amount
of cerium ions loaded into the Cu-SSZ-13 occupied the ion-exchange
sites. The appropriate amount of cerium cations at the ion-exchange
sites better stabilized the framework of SSZ-13 and thus led to the
enhancement effect. By contrast, excessive ion-exchange with cerium
adversely affected the hydrothermal stability of the Cu-SSZ-13, resulting
in degraded SCR performance.
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