Catalytic dehydrogenation of propane by carbon dioxide: a medium-temperature thermochemical process for carbon dioxide utilisation

The dehydrogenation of C₃H₈ in the presence of CO₂ is an attractive catalytic route for C₃H₆ production. In studying the various possibilities to utilise CO₂ to convert hydrocarbons using the sustainable energy source of solar thermal energy, thermodynamic calculations were carried out for the dehydrogenation of C₃H₈ using CO₂for the process operating in the temperature range of 300–500 °C. Importantly, the results highlight the enhanced potential of C₃H₈ as compared to its lighter and heavier homologues (C₂H₆ and C₄H₁₀, respectively). To be utilised in this CO₂ utilisation reaction the Gibbs free energy (Δ_rGθm) of each reaction in the modelled, complete reacting system of the dehydrogenation of C₃H₈ in the presence of CO₂ also indicate that further cracking of C₃H₆ will affect the ultimate yield and selectivity of the final products. In a parallel experimental study, catalytic tests of the dehydrogenation of C₃H₈ in the presence of CO₂ over 5 wt%-Cr₂O₃/ZrO₂ catalysts operating at 500 °C, atmospheric pressure, and for various C₃H₈ partial pressures and various overall GHSV (Gas Hourly Space Velocity) values. The results showed that an increase in the C₃H₈ partial pressure produced an inhibition of C₃H₈ conversion but, importantly, a promising enhancement of C₃H₆ selectivity. This phenomenon can be attributed to competitive adsorption on the catalyst between the generated C₃H₆ and inactivated C₃H₈, which inhibits any further cracking effect on C₃H₆ to produce by-products. As a comparison, the increase of the overall GHSV can also decrease the C₃H₈ conversion to a similar extent, but the further cracking of C₃H₆ cannot be limited.

Genetic diversity and expression profiles of cysteine phytases in the sheep rumen during a feeding cycle

Cysteine phytase is the main phytate-degrading enzyme of ruminant animals. To explore the genetic diversity and dynamic expression profile of cysteine phytase in sheep rumen during a feeding cycle, four transcript (0, 4, 9 and 16 h after feeding) and one DNA (9 h after feeding) clone libraries were constructed, respectively. A total of 46 distinct gene fragments were identified, and most of these sequences had low identities (<60%) with known phytases. Great divergence was found in the constitution and abundance of genes at the genome and transcriptional levels, and the transcript data are more reliable to reflect the information of functional genes. Phylogenetic analysis indicated that the genes from uncultured bacteria instead of Firmicutes played the major phytate-degrading role. Further comparative analysis revealed the dynamic constitution of cysteine phytase genes in rumen at different time points.

SIGNIFICANCE AND IMPACT OF THE STUDY

Ruminal phytases, that are cysteine phytases, are novel in sequences and functions. Great divergence in the constitution and abundance of cysteine phytase genes at the genome and transcriptional levels suggested that transcript data are more reliable to reflect the information of functional genes. Phylogenetic and rarefaction analyses indicated that the cysteine phytase genes from uncultured bacteria instead of Firmicutes play the major phytate-degrading role in rumen, and their constitution is dynamic at different time points. This study provides a new insight into ruminal cysteine phytase genes and undermines their expression profiles over a whole feeding cycle.

Phase III study (MONET1) of motesanib plus carboplatin/paclitaxel in patients with advanced nonsquamous nonsmall-cell lung cancer (NSCLC): Asian subgroup analysis

BACKGROUND

This preplanned subset analysis of the phase III MONET1 study aimed to determine whether motesanib combined with carboplatin/paclitaxel (C/P) would result in improved overall survival (OS) versus chemotherapy alone, in a subset of Asian patients with nonsquamous nonsmall-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with nonsquamous NSCLC (stage IIIB/IV or recurrent) and no prior systemic therapy for advanced disease were randomized to IV carboplatin (AUC, 6 mg/ml min) and paclitaxel (200 mg/m2) for up to six 3-week cycles, plus either oral motesanib 125 mg q.d. or placebo. Primary end point was OS; secondary end points included progression-free survival (PFS), objective response rate (ORR), and safety.

RESULTS

Two hundred twenty-seven Asian patients from MONET1 were included in this descriptive analysis. Median OS was 20.9 months in the motesanib plus C/P arm and 14.5 months in the placebo plus C/P arm (P=0.0223); median PFS was 7.0 and 5.3 months, respectively, (P=0.0004); and ORR was 62% and 27%, respectively, (P<0.0001). Grade≥3 adverse events were more common in the motesanib plus C/P arm versus placebo plus C/P (79% versus 61%).

CONCLUSION

In this preplanned subset analysis of Asian patients with nonsquamous NSCLC, motesanib plus C/P significantly improved OS, PFS, and ORR versus placebo plus C/P.

CLINICAL TRIAL NUMBER

NCT00460317.

The incidence of posttransplantation diabetes mellitus during follow-up in kidney transplant recipients and relationship to Fok1 vitamin D receptor polymorphism

BACKGROUND

Posttransplantation diabetes mellitus (PTDM) is a common, serious complication of kidney transplantation. The purpose of this study was to investigate the incidence of and risk factors for PTDM in relationship to Fok1 vitamin D receptor (VDR) polymorphisms.

METHODS

One hundred five kidney transplant recipients with normal glucose values before transplantation were recruited for this study. All patients underwent fasting plasma glucose (FPG) determinations followed by oral glucose tolerance tests (OGTTs) among normal FPG recipients. Every recipient underwent Fok1 VDR polymorphism analysis using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP).

RESULTS

Among 105 recipients, 16 (15.24%) developed new-onset PTDM within 6 months after kidney transplantation. Compared with 89 non-PTDM recipients, the mean age was significantly higher among recipients with PTDM: 47.81 ± 15.54 vs 36.62 ± 11.43 years (P = .001). Patients treated with tacrolimus were more susceptible to PTDM (56.25% vs 28.09%; P = .027). The distribution frequencies of Fok1 genotypes in this cohort followed the Hardy-Weinberg equilibrium. The frequencies of 3 genotypes (FF/Ff/ff; P = .040) and 2 alleles (F/f; P = .009) differed between the 2 groups. Multivariate analysis by logistic regression showed age older than 40 years (odds ratio, 7.774; P = .005), VDR Fok1 f allele (odds ratio, 11.765; P = .012), and tacrolimus therapy (odds ratio, 7.499; P = .007) to be related to the development of PTDM.

CONCLUSIONS

The incidence of newly diagnosed PTDM in this study was 15.24%. Fok1 VDR polymorphism was a genetic marker predicting PTDM risk. Age older than 40 years and tacrolimus were independent risk factors for PTDM.

Grain boundary character distribution of nanocrystalline Cu thin films using stereological analysis of transmission electron microscope orientation maps

Stereological analysis has been coupled with transmission electron microscope (TEM) orientation mapping to investigate the grain boundary character distribution in nanocrystalline copper thin films. The use of the nanosized (<5 nm) beam in the TEM for collecting spot diffraction patterns renders an order of magnitude improvement in spatial resolution compared to the analysis of electron backscatter diffraction patterns in the scanning electron microscope. Electron beam precession is used to reduce dynamical effects and increase the reliability of orientation solutions. The misorientation distribution function shows a strong misorientation texture with a peak at 60°/[111], corresponding to the Σ3 misorientation. The grain boundary plane distribution shows {111} as the most frequently occurring plane, indicating a significant population of coherent twin boundaries. This study demonstrates the use of nanoscale orientation mapping in the TEM to quantify the five-parameter grain boundary distribution in nanocrystalline materials.

Associations between testosterone, bone mineral density, vitamin D and semen quality in fertile and infertile Chinese men

Testosterone (T) and vitamin D (VD) interact in androgen deficient men, however, this interaction and subsequent semen quality and bone mineral density (BMD) status is not clear in infertile men. Our objective was to investigate T, VD, semen quality, BMD and their relationships in Chinese infertile men. We conducted a cross-sectional study of 559 men aged 20-40 years, including 195 fertile men, 9 infertile men with known risk factors for osteoporosis (WR) and 355 infertile men without known risk factors for osteoporosis (WOR). WOR infertile men constituted 314 oligo-, astheno-, teratospermic or normospermic infertile men (OATN men) and 41 non-obstructive azoospermic men (NOA men). Differences of parameters were assessed, and the relationships were adjusted by multiple linear regression. WOR infertile men had significantly lower T, lumbar spine and total hip BMD than fertile men (all p < 0.05). Bioavailable T (Bio-T) and 25-hydroxyvitamin D [25(OH)D] were independent determinants of BMD in WOR infertile men (all p < 0.01) but not in fertile men. After stratifying Bio-T, WOR infertile men had lower BMD than fertile men (all p < 0.05) in low Bio-T subgroups (Bio-T ≤ 11.6 nmol/L), but not high Bio-T subgroups (Bio-T > 11.6 nmol/L). 25(OH)D was an independent determinant of sperm motility and morphology in WOR OATN men (all p < 0.05), with only borderline significance in fertile men(motility: p = 0.047; morphology: p = 0.056). T determined sperm concentration (square root) and morphology in WOR OATN men (all p < 0.001). No correlations between T and 25(OH)D were found in all groups. We suggest that infertile men have lower T and BMD than fertile men. 25(OH)D and T were associated with low BMD and poor semen quality in infertile men.

Growth and characterization of self-Q-switched Nd:Cr:YVO4 crystal

A Nd:Cr:YVO4 crystal was grown by the Czochralski method for the first time to our knowledge. Its structure and cell parameter have been studied by X-ray powder diffraction (XRPD) analysis. Polarized absorption spectra were measured at room temperature, which showed that the absorption bands display polarization character and an absorption band of Cr5+ ions at 1110 nm enables the crystal to be a self-Q-switched laser material. We also found that the absorption of Cr5+ ions became much larger and its self-Q-switched laser performance became much better when the Nd:Cr:YVO4 crystal was annealed because the annealing induces more Cr ions to become those with + 5 valence. In the self-Q-switched laser, the maximum output power, shortest pulse width, and largest pulse energy were obtained to be 120 mW, 85.8 ns, and 0.79 μJ, respectively.

Influence of canthaxanthin on broiler breeder reproduction, chick quality, and performance

To investigate the effect of canthaxanthin supplied via a maternal route on the production of both breeder hens and chickens, 270 Chinese Three-Yellow breeder hens were randomly divided into 2 groups consisting of 135 birds each (5 replicates of 27) for study. The breeder hens were fed either a basal diet or the basal diet supplemented with 6 mg of canthaxanthin/kg for 24 wk. At the end of the 24-wk breeder experiment, all hatching eggs laid in 5 consecutive days of each group were collected and incubated. For each breeder group, 100 newly hatched chicks (5 replicates of 20) were reared under environmentally controlled conditions for 21 d. Canthaxanthin supplementation resulted in the following outcomes: an enhancement of the serum total antioxidant capacity (TAC) of breeder hens (P = 0.029), a significant increase in the yolk colorimetric score of Roche Yolk Color Fan (RYCF; P < 0.001), and a significant improvement of the antioxidant status of the egg yolk (P < 0.05). The chicks that hatched from eggs laid by breeder hens fed the canthaxanthin supplementation diet demonstrated a higher pigmentation colorimetric score of RYCF for their shank skin (P < 0.05), and the antioxidant capacity of the newly hatched chicks was significantly increased (P < 0.05). Both of these positive effects on shank skin pigmentation colorimetric score of RYCF and antioxidant capacity were observed for at least 7 d posthatching, and the chicks that hatched from canthaxanthin-enriched eggs showed a lower mortality (0 vs. 4%) during the first 21 d posthatching. These findings support the hypothesis that canthaxanthin supplementation of the maternal diet enhances the protective capacity of tissues against oxidative stress in vivo, which might be beneficial for poultry producers.

An international, randomized, placebo-controlled, double-blind phase III study (MONET1) of motesanib plus carboplatin/paclitaxel (C/P) in patients with advanced nonsquamous non-small cell lung cancer (NSCLC)

LBA7512

Background: This study evaluated whether motesanib (a selective oral inhibitor of VEGFR 1, 2 and 3; PDGFR and Kit) plus C/P improved overall survival (OS) compared with placebo + C/P in patients (pts) with nonsquamous NSCLC and in a subset of pts with adenocarcinoma. Methods: Pts had stage IIIB/IV or recurrent nonsquamous NSCLC and no prior systemic therapy for advanced NSCLC. The study initially enrolled all histologies but was amended to exclude pts with squamous NSCLC owing to a high rate of hemoptysis. Pts were randomized 1:1 to receive up to six 3-wk cycles of C (AUC 6 mg/mL·min) and P (200 mg/m2) with either motesanib 125 mg QD (Arm A) or placebo QD (Arm B) orally continuously. The primary endpoint was OS; secondary endpoints included progression-free survival (PFS), adverse events (AEs), objective response rate (ORR) and association between placental growth factor (PLGF) change and OS. OS was evaluated using a stratified Cox model and 2-sided log-rank test (α=0.03 for nonsquamous pts and α=0.02 for adenocarcinoma pts). Results: 1090 pts with nonsquamous NSCLC were randomized (Arm A/B, n=541/549); 890 had adenocarcinoma (n=448/442). 61% were men; median age was 60 years (range 21–87); 83% had stage IV disease. At the time of analysis, 753 pts had died (608 pts with adenocarcinoma). Median follow-up was 10.6 mo. OS was not significantly improved in Arm A compared with Arm B (Table). In Arm A, PLGF analysis did not show an association with OS. The incidence of grade ≥3 AEs in Arms A/B was 73/59%. Grade ≥3 AEs occurring more frequently in Arm A than B included neutropenia (22/15%), diarrhea (9/1%), hypertension (7/1%) and cholecystitis (3/0%). The incidence of grade 5 AEs was 14/9% in Arms A/B. Conclusions: In pts with advanced nonsquamous NSCLC, treatment with motesanib + C/P did not significantly improve OS compared with C/P alone.

[Table: see text]

Optical properties of ZnMgO nanowalls grown by plasma-assisted molecular beam epitaxy

ZnMgO nanowalls were prepared by plasma-assisted molecular beam epitaxy without a catalyst on c-Al2O3 substrate. The obtained nanowalls have preferred orientation along c axis. The nanowalls are about 10 to 20 nm in thickness and about 50 nm in height. Only Zn, Mg, O and Al signals are detected in the nanowalls from the energy dispersive spectroscopy (EDS). The Mg content is about 3% in ZnMgO nanowalls. The room temperature photoluminescence (PL) spectra shows the emission peak of the ZnMgO nanowalls at 3.346 eV. The origin of the ultraviolet emission is discussed with the help of temperature-dependent PL spectra. The ultraviolet emission band is free exiton recombination observed in the low temperature PL spectra (at 81 K). We also observe the free-to-acceptor (FA) emission of the ZnMgO nanowalls. The acceptor binding energy obtained from photoluminescence studies is about 123 meV. The results show that Mg doping leads to an increase of the acceptor binding energy. The possible growth mechanism of the ZnMgO nanowall networks was discussed.