High pressure in situ diffraction studies of metal–hydrogen systems

“Hybrid” hydrogen storage, where hydrogen is stored in both the solid material and as a high pressure gas in the void volume of the tank can improve overall system efficiency by up to 50% compared to either compressed hydrogen or solid materials alone. Thermodynamically, high equilibrium hydrogen pressures in metal–hydrogen systems correspond to low enthalpies of hydrogen absorption–desorption. This decreases the calorimetric effects of the hydride formation–decomposition processes which can assist in achieving high rates of heat exchange during hydrogen loading—removing the bottleneck in achieving low charging times and improving overall hydrogen storage efficiency of large hydrogen stores. Two systems with hydrogenation enthalpies close to −20 kJ/mol H2 were studied to investigate the hydrogenation mechanism and kinetics: CeNi5–D2 and ZrFe2−xAlx (x = 0.02; 0.04; 0.20)–D2. The structure of the intermetallics and their hydrides were studied by in situ neutron powder diffraction at pressures up to 1000 bar and complementary X-ray diffraction. The deuteration of the hexagonal CeNi5 intermetallic resulted in CeNi5D6.3 with a volume expansion of 30.1%. Deuterium absorption filled three different types of interstices, Ce2Ni2 and Ni4 tetrahedra, and Ce2Ni3 half-octahedra and was accompanied by a valence change for Ce. Significant hysteresis was observed between deuterium absorption and desorption which profoundly decreased on a second absorption cycle. For the Al-modified Laves-type C15 ZrFe2−xAlx intermetallics, deuteration showed very fast kinetics of H/D exchange and resulted in a volume increase of the FCC unit cells of 23.5% for ZrFe1.98Al0.02D2.9(1). Deuterium content, hysteresis of H/D uptake and release, unit cell expansion and stability of the hydrides systematically change with the amount of Al content. In the deuteride D atoms exclusively occupy the Zr2(Fe,Al)2 tetrahedra. Observed interatomic distances are Zr–D = 1.98–2.11; (Fe, Al)–D = 1.70–1.75A˚ . Hydrogenation slightly increases the magnetic moment of the Fe atoms in ZrFe1.98Al0.02 and ZrFe1.96Al0.04 from 1.9 �B at room temperature for the alloy to 2.2 �B for its deuteride.

Matrix metalloproteinases 2 and 9 (gelatinases A and B) expression in malignant mesothelioma and benign pleura

Matrix metalloproteinases (MMPs), in particular the gelatinases (MMP-2 and -9), play a significant role in tumour invasion and angiogenesis. The expression and activities of MMPs have not been characterised in malignant mesothelioma (MM) tumour samples. In a prospective study, gelatinase activity was evaluated in homogenised supernatants of snap frozen MM (n = 35), inflamed pleura (IP, n = 12) and uninflammed pleura (UP, n = 14) tissue specimens by semiquantitative gelatin zymography. Matrix metalloproteinases were correlated with clinicopathological factors and with survival using Kaplan-Meier and Cox proportional hazard models. In MM, pro- and active MMP-2 levels were significantly greater than for MMP-9 (P = 0.006, P<0.001). Active MMP-2 was significantly greater in MM than in UP (P=0.04). MMP-2 activity was equivalent between IP and MM, but both pro- and active MMP-9 activities were greater in IP (P=0.02, P=0.009). While there were trends towards poor survival with increasing total and pro-MMP-2 activity (P=0.08) in univariate analysis, they were both independent poor prognostic factors in multivariate analysis in conjunction with weight loss (pro-MMP-2 P = 0.03, total MMP-2 P = 0.04). Total and pro-MMP-2 also contributed to the Cancer and Leukemia Group B prognostic groups. MMP-9 activities were not prognostic. Matrix metalloproteinases, and in particular MMP-2, the most abundant gelatinase, may play an important role in MM tumour growth and metastasis. Agents that reduce MMP synthesis and/or activity may have a role to play in the management of MM. © 2003 Cancer Research UK.

Inactivation and structural changes of E. Cloacae and B. Subtilis Endospores during IR laser water treatment

IR radiation has been studied for micro-organism inactivation of bacterial spores on metal substrates [1] and on metal and paper substrates [2]. A near-point near infrared laser water treatment apparatus for use in dental hand-pieces was also developed [3]. To date water sterilisation research using a mid-IR laser technique is very rare. According to the World Health Organisation [4], examinations for faecal indicator bacteria remain the most sensitive and specific way of assessing the hygienic quality of water. Bacteria that fall into this group are E. coli, other coliform bacteria (including E. cloacae) and to a lesser extent, faecal streptococci [5]. Protozoan cysts from organisms which cause giardiasis are the most frequently identified cause of waterborne diseases in developed countries [6,7]. The use of aerobic bacterial endospores to monitor the efficiency of various water treatments has been shown to provide a reliable and simple indicator of overall performance of water treatment[8,9].The efficacy of IR radiation for water disinfection compared to UV treatment has been further investigated in the present study. In addition FTIR spectroscopy in conjunction with Principle Component Analysis was used to characterise structural changes within the bacterial cells and endospores following IR laser treatment. Changes in carbohydrate content of E. cloacae following IR laser treatment were observed.

A facile chemical screening method for the detection of stress corrosion cracking in 9 carat gold alloys

Stress corrosion cracking (SCC) is a well known form of environmental attack in low carat gold jewellery. It is desirable to have a quick, easy and cost effective way to detect SCC in alloys and prevent them from being used and later failing in their application. A facile chemical method to investigate SCC of 9 carat gold alloys is demonstrated. It involves a simple application of tensile stress to a wire sample in a corrosive environment such as 1–10 % FeCl3 which induces failure in less than 5 minutes. In this study three quaternary (Au, Ag, Cu and Zn) 9 carat gold alloy compositions were investigated for their resistance to SCC and the relationship between time to failure and processing conditions is studied. It is envisaged that the use of such a rapid and facile screening procedure at the production stage may readily identify alloy treatments that produce jewellery that will be susceptible to SCC in its lifetime.

Epidemiological trend of hepatitis B, liver cirrhosis and liver cancer during 1990 - 2007 in Shandong province, China [山东省乙型肝炎、肝硬化及肝癌流行趋势分析]

Objective To analyze the epidemiological trend of hepatitis B, liver cirrhosis and liver cancer during 1990 to 2007 in Shandong province, and to evaluate the effectiveness of hepatitis B prevention and control measures, so as to provide evidence for policy-making. Methods Based on the routine incidence data of hepatitis B, mortality data of hepatitis B, liver cirrhosis, liver cancer and demographic data, the incidence rate, mortality rate and age-specific mortality rate were calculated and analyzed with simple linear regression model. Results A total of 437094 cases of hepatitis B were reported during 1990 - 2007 with an average yearly morbidity of 27.32 per 100 000 persons and a decreased trend for the 0-9 years old children. At the same time, the adjusted mortality rate for hepatitis B and liver cirrhosis showed a decreased trend and the combined mortality rate decreased from 17.55 /100 000 in 1990 to 4.01 /100 000 in 2007. The mortality of liver cancer was stable during this time (P = 0. 9998). Conclusion Immunization of hepatitis B vaccine may have lowered the incidence of hepatitis B in the target population and the overall mortality rates of liver cirrhosis and liver cancer. Abstract in Chinese 目的 了解山东省1990～2007年乙肝、肝硬化和肝癌的流行状况及变化趋势,初步评价乙肝预防控制措施的效果,为今后防治决策制定提供参考. 方法 根据报告的乙肝发病资料和乙肝、肝硬化、肝癌死亡资料以及历年人口资料,利用发病率、死亡率、年龄别死亡率等指标对上述3种疾病进行流行趋势的分析,并建立简单线性回归模型进行统计分析. 结果 1990～2007年山东省共报告乙肝病例437 094例,年均总发病率为27.32/10万,并呈上升趋势,而0～9岁年龄组的发病率呈显著下降趋势.乙肝和肝硬化调整死亡率下降趋势明显,两者合并死亡率由1990年的17.55/10万下降到2007年的4.01/10万.肝癌调整死亡率基本稳定(P=0.999 8). 结论 做好乙肝疫苗的免疫接种不仅可降低目标人群乙肝的发病,并将最终降低与此相关的肝硬化和肝癌的死亡率.

Epidemiological Trend of Hepatitis B in Shandong Province of China, 1990 - 2007 []

Objective To analyze the epidemiological trend of hepatitis B from 1990 to 2007 in Shandong province, and to find the high risk population so as to explore the further control strategy. Methods Based on the routine reporting incidence data of hepatitis B and demographic data of Shandong province, the incidence rates and sex - specific, age - specific incidence rates of hepatitis B were calculated and statistically analyzed in the simple linear regression model. Results The total number of hepatitis B was 437 094, the annual average morbidity was 27132 per 100 000 population during 1990 to 2007. The incidence of men (38142 per 100 000) was higher than that for women (15183 per 100 000) 1The annual incidence rate of hepatitis B indicated an increasing trend for the whole population, while a decreased trend for the 0～9 year - old children p resented in the past 18 years. It showed that the average age of onset moved to the older. Conclusion Young adult men are the high-risk groups for the onset of hepatitis B. For the prevention of hepatitis B, the immunization of hepatitis B vaccine should be enhanced for other groups, especially for the high - risk population on the basis of imp roving the immunization coverage rate for newborns.

Prevalence of depressive symptoms as elicited by Patient Health Questionnaire (PHQ-9) among medical trainees in Oman

Background Despite the increasing recognition that medical training tends to coincide with markedly high levels of stress and distress, there is a dearth of validated measures that are capable of gauging the prevalence of depressive symptoms among medical residents in the Arab/Islamic part of the world. Objective The aim of the present study is two-fold. First is to examine the diagnostic validity of the Patient Health Questionnaire (PHQ-9) using an Omani medical resident population in order to establish a cut-off point. Second is to compare gender, age, and residency level among Omani Medical residents who report current depressive symptomatology versus those who report as non-depressed according to PHQ-9 cut-off threshold. Results A total of 132 residents (42 males and 90 females) consented to participate in this study. The cut-off score of 12 on the PHQ-9 revealed a sensitivity of 80.6% and a specificity of 94.0%. The rate of depression, as elicited by PHQ-9, was 11.4%. The role of gender, age, and residency level was not significant in endorsing depression. Conclusion This study indicated that PHQ-9 is a reliable measure among this cross-cultural population. More studies employing robust methodology are needed to confirm this finding.

Clinical dyslipidaemia is associated with changes in the lipid composition and inflammatory properties of apolipoprotein-B-containing lipoproteins from women with type 2 diabetes

The aim of this study was to use lipidomics to determine if the lipid composition of apolipoprotein-B-containing lipoproteins is modified by dyslipidaemia in type 2 diabetes and if any of the identified changes potentially have biological relevance in the pathophysiology of type 2 diabetes. VLDL and LDL from normolipidaemic and dyslipidaemic type 2 diabetic women and controls were isolated and quantified with HPLC and mass spectrometry. A detailed molecular characterisation of VLDL triacylglycerols (TAG) was also performed using the novel ozone-induced dissociation method, which allowed us to distinguish vaccenic acid (C18:1 n-7) from oleic acid (C18:1 n-9) in specific TAG species. Lipid class composition was very similar in VLDL and LDL from normolipidaemic type 2 diabetic and control participants. By contrast, dyslipidaemia was associated with significant changes in both lipid classes (e.g. increased diacylglycerols) and lipid species (e.g. increased C16:1 and C20:3 in phosphatidylcholine and cholesteryl ester and increased C16:0 [palmitic acid] and vaccenic acid in TAG). Levels of palmitic acid in VLDL and LDL TAG correlated with insulin resistance, and VLDL TAG enriched in palmitic acid promoted increased secretion of proinflammatory mediators from human smooth muscle cells. We showed that dyslipidaemia is associated with major changes in both lipid class and lipid species composition in VLDL and LDL from women with type 2 diabetes. In addition, we identified specific molecular lipid species that both correlate with clinical variables and are proinflammatory. Our study thus shows the potential of advanced lipidomic methods to further understand the pathophysiology of type 2 diabetes.

A study of the effects metal residues in poly(9,9-dioctylfluorene) have on field-effect transistor device characteristics

The amount of metal residues from organometallic reagents used in preparation of poly(9,9-dioctylfluorene) by palladium catalysed Suzuki and nickel-induced Yamamoto polycondensations have been determined, and their effect upon the behaviour of the polymer in field-effect transistors (FETs) has been measured. The metal levels from material polymerised by Suzuki method were found to be much higher than from that made by the Yamamoto procedure. Simple treatment of the polymers with suitable metal trapping reagents lowered the metal levels significantly, with EDTA giving best results for nickel and triphenylphosphine for palladium. Comparison of the behaviour of FETs using polyfluorenes with varying levels of metal contamination, showed that the metal residues have little effect upon the mobility values, but often affect the degree of hysteresis, possibly acting as charge traps. Satisfactory device performances were obtained from polymer with palladium levels of 2000 μg/g suggesting that complete removal of metal residues may not be necessary for satisfactory device performance.

Elucidating the chromosome 9 association with AS; CARD9 is a candidate gene

Ankylosing spondylitis (AS) is polygenic with contributions from the immunologically relevant genes HLA-B27, ERAP1 and IL23R. A recent genome-wide association screen (GWAS) identified associations (P0.005) with the non-synonymous single-nucleotide polymorphisms (nsSNPs), rs4077515 and rs3812571, in caspase recruitment domain-containing protein 9 (CARD9) and small nuclear RNA-activating complex polypeptide 4 (SNAPC4) on chromosome 9q that had previously been linked to AS. We replicated these associations in a study of 730 AS patients compared with 2879 historic disease controls (rs4077515 P0.0004, odds ratio (OR)1.2, 95% confidence interval (CI)1.1-1.4; rs3812571 P0.0003, OR1.2, 95% CI1.1-1.4). Meta-analysis revealed strong associations of both SNPs with AS, rs4077515 P0.000005, OR1.2, 95% CI1.1-1.3 and rs3812571 P0.000006, OR1.2, 95% CI1.1-1.3. We then typed 1604 AS cases and 1020 controls for 13 tagging SNPs; 6 showed at least nominal association, 5 of which were in CARD9. We imputed genotypes for 13 additional SNPs but none was more strongly associated with AS than the tagging SNPs. Finally, interrogation of an mRNA expression database revealed that the SNPs most strongly associated with AS (or in strong linkage disequilibrium) were those most associated with CARD9 expression. CARD9 is a plausible candidate for AS given its central role in the innate immune response.

Localization of type 1 diabetes susceptibility to the MHC class I genes HLA-B and HLA-A

The major histocompatibility complex (MHC) on chromosome 6 is associated with susceptibility to more common diseases than any other region of the human genome, including almost all disorders classified as autoimmune. In type 1 diabetes the major genetic susceptibility determinants have been mapped to the MHC class II genes HLA-DQB1 and HLA-DRB1 (refs 1–3), but these genes cannot completely explain the association between type 1 diabetes and the MHC region4, 5, 6, 7, 8, 9, 10, 11. Owing to the region's extreme gene density, the multiplicity of disease-associated alleles, strong associations between alleles, limited genotyping capability, and inadequate statistical approaches and sample sizes, which, and how many, loci within the MHC determine susceptibility remains unclear. Here, in several large type 1 diabetes data sets, we analyse a combined total of 1,729 polymorphisms, and apply statistical methods—recursive partitioning and regression...