Thermal stability and hot-stage Raman spectroscopic study of Ca-montmorillonite modified with different surfactants : a comparative study

Three long chain cationic surfactants were intercalated into Ca-montmorillonite through ion exchangeand the obtained organoclays were characterized by X-ray diffraction (XRD), high resolution thermo-gravimetric analysis (TG) and Raman spectroscopy. The intercalation of surfactants not only changes thesurface properties of clay from hydrophilic to hydrophobic but also greatly increases the basal spacing ofthe interlayers based on XRD analysis. The thermal stability of organoclays intercalated with three sur-factants (TTAB, DTAB and CTAB) and the different arrangements of the surfactant molecules intercalatedinto Ca-montmorillonite were determined by TG-DTG analysis. A Raman spectroscopic study on the Ca-montmorillonite modified by three surfactants prepared at different concentrations provided the detailedconformational ordering of different intercalated long-chain surfactants under different conditions. Thewavenumber of the antisymmetric stretching mode is more sensitive than that of the symmetric stretch-ing mode to the mobility of the tail of the amine chain. At room temperature, the conformational orderingis more easily affected by the packing density in the lateral model. With the increase of the temperature,the positions of both the antisymmetric and symmetric stretching bands shift to higher wavenumbers,which indicates a decrease of conformational ordering. This study offers new insights into the struc-ture and properties of Ca-montmorillonite modified with different long chain surfactants. Moreover, theexperimental results confirm the potential applications of organic Ca-montmorillonites for the removalof organic impurities from aqueous media.

Prevalence and correlates of sleep disturbance in post-menopausal Australian women : the Healthy Aging of Women (HOW) study

Background: Sleep disturbance in midlife women has been studied extensively, although less is known about sleep after menopause. This study examined the relative impact of socio-demographics, modifiable lifestyle factors, and health status on sleep disturbance in post-menopausal women from Queensland, Australia. Methods: The longitudinal Healthy Aging of Women (HOW) study examines health-related quality of life (HRQOL measured by SF-12©), chronic illness, modifiable lifestyle factors such as physical activity, alcohol consumption, smoking, and sleep disturbance (General Sleep Disturbance Scale, GSDS ≥ 43 represent poor sleep) in midlife and older women from low and high socio-economic, rural and urban areas of South-East Queensland, Australia. This paper presents cross-sectional data from the 322 women, aged 60-70 years, participating in the HOW study in 2011. Results: For women in this study, sleep disturbance was relatively common, with 23% (n = 83) reporting poor sleeping (GSDS ≥ 43). Sleep disturbance scores were strongly correlated with being unemployed or on a disability support pension (β = 18.69, P < 0.01), sedentary lifestyle (β = 23.84, P < 0.01), and lower mental (β = -0.60, P <0.01) and physical health-related quality of life scores (β = -0.32, P = 0.01), and these variables explained almost one third of variance in sleep disturbance scores (ηρ² = 29%). Conclusions: Multivariable analysis revealed that sleep disturbance was correlated with physical and mental health-related quality of life, disability, and sedentary lifestyle, but not other lifestyle and socio-demographic characteristics. It may be however, that modifiable lifestyle factors may indirectly impact on sleep by influencing health status.

Investigation of the low-density lipoprotein receptor gene and cholesterol as a risk factor for migraine

The Low-Density Lipoprotein Receptor (LDLR) gene is a cell surface receptor that plays an important role in cholesterol homeostasis. We investigated the (TA)n polymorphism in exon 18 of the LDLR gene on chromosome 19p13.2 performing an association analysis in 244 typical migraine-affected patients, 151 suffering from migraine with aura (MA), 96 with migraine without aura (MO) and 244 unaffected controls. The populations consisted of Caucasians only, and controls were age- and sex-matched. The results showed no significant difference between groups for allele frequency distributions of the (TA)n polymorphism even after separation of the migraine-affected individuals into subgroups of MA and MO affected patients. This is in contradiction to Mochi et al. who found a positive association of this variant with MO. Our study discusses possible differences between the two studies and extends this research by investigating circulating cholesterol levels in a migraine-affected population.

Porous graphene and nanomeshes

This chapter briefly introduces the concepts and modeling of gas/isotope separation by two dimensional carbon frameworks, i.e. porous graphene and carbon nanomeshes, on the basis of reviewing recent literatures. The small size of evenly distributed pores on these carbon frameworks make them ideal not only for the separation of small gas molecules but also for isotope separation by utilizing the different zero point energies induced by confinement of the pores. The related simulations were treated by transition state theory, an affordable yet precise method that could be adopted in combination with different levels of theory. Such method could be employed to evaluate the performance, as well as to aid the design, of other 2D carbon frameworks toward the goal of gas/isotope separation in the future.

Beyond “Beyondness”

When the term “anti-aesthetic” emerged thirty years ago, it was presumed to stand in stark opposition to the “aesthetic.” Today the situation is less clear. While the seminars aim to move beyond this dichotomy, many of the participants doubt whether the anti-aesthetic still holds as an absolute distinction. Over the course of the conversations, other oppositions arise—such as art theory and criticism versus philosophical aesthetics, art history versus visual culture—but it is the debate over Modernism that most complicates moving beyond, to the next aesthetic paradigm.

Removal of bisphenol A from wastewater by Ca-montmorillonite modified with selected surfactants

Organo Arizona SAz-2 Ca-montmorillonite was prepared with different surfactant (DDTMA and HDTMA) loadings through direct ion exchange. The structural properties of the prepared organoclays were characterized by XRD and BET instruments. Batch experiments were carried out on the adsorption of bisphenol A (BPA) under different experimental conditions of pH and temperature to determine the optimum adsorption conditions. The hydrophobic phase and positively charged surface created by the loaded surfactant molecules are responsible for the adsorption of BPA. The adsorption of BPA onto organoclays is well described by pseudo-second order kinetic model and the Langmuir isotherm. The maximum adsorption capacity of the organoclays for BPA obtained from a Langmuir isotherm was 151.52 mg/g at 297 K. This value is among the highest values for BPA adsorption compared with other adsorbents. In addition, the adsorption process was spontaneous and exothermic based on the adsorption thermodynamics study. The organoclays intercalated with longer chain surfactant molecules possessed a greater adsorption capacity for BPA even under alkaline conditions. This process provides a pathway for the removal of BPA from contaminated waters.

The relationship between angiogenesis and the immune response in carcinogenesis and the progression of malignant disease

Recent studies have demonstrated that angiogenesis and suppressed cell- mediated immunity (CMI) play a central role in the pathogenesis of malignant disease facilitating tumour growth, invasion and metastasis. In the majority of tumours, the malignant process is preceded by a pathological condition or exposure to an irritant which itself is associated with the induction of angiogenesis and/or suppressed CMI. These include: cigarette smoking, chronic bronchitis and lung cancer; chronic oesophagitis and oesophageal cancer; chronic viral infections such as human papilloma virus and ano-genital cancers, chronic hepatitis B and C and hepatocellular carcinoma, and Epstein- Barr virus (EBV) and lymphomas; chronic inflammatory conditions such as Crohn's disease and ulcerative colitis and colorectal cancer; asbestos exposure and mesothelioma and excessive sunlight exposure/sunburn and malignant melanoma. Chronic exposure to growth factors (insulin-like growth factor-I in acromegaly), mutations in tumour suppressor genes (TP53 in Li Fraumeni syndrome) and long-term exposure to immunosuppressive agents (cyclosporin A) may also give rise to similar environments and are associated with the development of a range of solid tumours. The increased blood supply would facilitate the development and proliferation of an abnormal clone or clones of cells arising as the result of: (a) an inherited genetic abnormality; and/or (b) acquired somatic mutations, the latter due to local production and/or enhanced delivery of carcinogens and mutagenic growth factors. With progressive detrimental mutations and growth-induced tumour hypoxia, the transformed cell, to a lesser or greater extent, may amplify the angiogenic process and CMI suppression, thereby facilitating further tumour growth and metastasis. There is accumulating evidence that long-term treatment with cyclo-oxygenase inhibitors (aspirin and indomethacin), cytokines such as interferon-α, anti-oestrogens (tamoxifen and raloxifene) and captopril significantly reduces the incidence of solid tumours such as breast and colorectal cancer. These agents are anti-angiogenic and, in the case of aspirin, indomethacin and interferon-α have proven immunomodulatory effects. Collectively these observations indicate that angiogenesis and suppressed CMI play a central role in the development and progression of malignant disease. (C) 2000 Elsevier Science Ltd.

TiO2 nanofibers of different crystal phases for transesterification of alcohols with dimethyl carbonate

TiO2 nanofibers with different crystal phases have been discovered to be efficient catalysts for the transesterification of alcohols with dimethyl carbonate to produce corresponding methyl carbonates. Advantages of this catalytic system include excellent selectivity (>99%), general suitability to alcohols, reusability and ease of preparation and separation of fibrous catalysts. Activities of TiO2 catalysts were found to correlate with their crystal phases which results in different absorption abilities and activation energies on the catalyst surfaces. The kinetic isotope effect (KIE) investigation identified the rate-determining step, and the isotope labeling of oxygen-18 of benzyl alcohol clearly demonstrated the reaction pathway. Finally, the transesterification mechanism of alcohols with dimethyl carbonate catalyzed by TiO2 nanofibers was proposed, in which the alcohol released the proton to form benzyl alcoholic anion, and subsequently the anion attacks the carbonyl carbon of dimethyl carbonate to produce the target product of benzyl methyl carbonate.

Plain facts about pleading : how to work with r 166

The decision of Durward SC DCJ in OSM Group Pty Ltd v Holden [2013] QDC 151 involves a useful consideration of the requirements relating to the pleading of denials and non-admissions under the Uniform Civil Procedure Rules 1999 (Qld) (UCPR). In particular, the decision examines the extent of the obligations when pleading in response to allegations of law, or of mixed fact and law.

Effect of chemical conjugation of L-leucine to chitosan on the dispersibility and drug release of a dry powder inhaler nanoparticle formulation

Purpose: This study investigated the effect of chemical conjugation of the amino acid L-leucine to the polysaccharide chitosan on the dispersibility and drug release pattern of a polymeric nanoparticle (NP)-based controlled release dry powder inhaler (DPI) formulation. Methods: A chemical conjugate of L-leucine with chitosan was synthesized and characterized by Infrared (IR) Spectroscopy, Nuclear Magnetic Resonance (NMR) Spectroscopy, Elemental Analysis and X-ray Photoelectron Spectroscopy (XPS). Nanoparticles of both chitosan and its conjugate were prepared by a water-in-oil emulsification – glutaraldehyde cross-linking method using the antihypertensive agent, diltiazem (Dz) hydrochloride as the model drug. The surface morphology and particle size distribution of the nanoparticles were determined by Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS). The dispersibility of the nanoparticle formulation was analysed by a Twin Stage Impinger (TSI) with a Rotahaler as the DPI device. Deposition of the particles in the different stages was determined by gravimetry and the amount of drug released was analysed by UV spectrophotometry. The release profile of the drug was studied in phosphate buffered saline at 37 ⁰C and analyzed by UV spectrophotometry. Results: The TSI study revealed that the fine particle fractions (FPF), as determined gravimetrically, for empty and drug-loaded conjugate nanoparticles were significantly higher than for the corresponding chitosan nanoparticles (24±1.2% and 21±0.7% vs 19±1.2% and 15±1.5% respectively; n=3, p<0.05). The FPF of drug-loaded chitosan and conjugate nanoparticles, in terms of the amount of drug determined spectrophotometrically, had similar values (21±0.7% vs 16±1.6%). After an initial burst, both chitosan and conjugate nanoparticles showed controlled release that lasted about 8 to 10 days, but conjugate nanoparticles showed twice as much total drug release compared to chitosan nanoparticles (~50% vs ~25%). Conjugate nanoparticles also showed significantly higher dug loading and entrapment efficiency than chitosan nanoparticles (conjugate: 20±1% & 46±1%, chitosan: 16±1% & 38±1%, n=3, p<0.05). Conclusion: Although L-leucine conjugation to chitosan increased dispersibility of formulated nanoparticles, the FPF values are still far from optimum. The particles showed a high level of initial burst release (chitosan, 16% and conjugate, 31%) that also will need further optimization.

Road crash risk after whiplash associated disorder

The future on-road safety of drivers affected by Whiplash Associated Disorder (WAD), the most common soft-tissue injury suffered in a traffic crash, has not been extensively explored. We obtained an anonymised file of 4280 insurance claimants with WAD and, as controls, 1116 claimants with comparably severe soft-tissue injuries who are considered to be at no increased risk than the general population. Their demographic information, road user type and traffic crash records both prior and subsequent to the traffic incident in which the injury occurred, the index crash, were obtained. Rates of subsequent crash involvement in these two groups were then compared, adjusting for age, sex, road user type and prior crash experience. The risk of a subsequent crash in the WAD group relative to controls was 1.14 (95% confidence interval, 0.87–1.48). To allow for differentially altered driving exposure after index crash we distributed a brief survey asking about changes in driving habits after a traffic crash involving injury via physiotherapy clinics and online through the electronic newsletter of a local motoring organisation. The survey yielded responses from 113 drivers who had experienced WAD in a traffic crash and 53 with other soft tissue injuries. There were no differences on average between the groups in their prior driving levels or their percentage change therein at one, three or six months after injury. There was thus no evidence that drivers with WAD are at any higher safety risk than drivers with other types of relatively minor post-crash soft tissue injury.

Incidental treatment effects of CBT on suicidal ideation and hopelessness

Background: Depression and alcohol misuse are among the most prevalent diagnoses in suicide fatalities. The risk posed by these disorders is exacerbated when they co-occur. Limited research has evaluated the effectiveness of common depression and alcohol treatments for the reduction of suicide vulnerability in individuals experiencing comorbidity. Methods: Participants with depressive symptoms and hazardous alcohol use were selected from two randomised controlled trials. They had received either a brief (1 session) intervention, or depression-focused cognitive behaviour therapy (CBT), alcohol-focused CBT, therapist-delivered integrated CBT, computer-delivered integrated CBT or person-centred therapy (PCT) over a 10-week period. Suicidal ideation, hopelessness, depression severity and alcohol consumption were assessed at baseline and 12-month follow-up. Results: Three hundred three participants were assessed at baseline and 12 months. Both suicidal ideation and hopelessness were associated with higher severity of depressive symptoms, but not with alcohol consumption. Suicidal ideation did not improve significantly at follow-up, with no differences between treatment conditions. Improvements in hopelessness differed between treatment conditions; hopelessness improved more in the CBT conditions compared to PCT and in single-focused CBT compared to integrated CBT. Limitations: Low retention rates may have impacted on the reliability of our findings. Combining data from two studies may have resulted in heterogeneity of samples between conditions. Conclusions: CBT appears to be associated with reductions in hopelessness in people with co-occurring depression and alcohol misuse, even when it is not the focus of treatment. Less consistent results were observed for suicidal ideation. Establishing specific procedures or therapeutic content for clinicians to monitor these outcomes may result in better management of individuals with higher vulnerability for suicide.

Physical activity promotion as a school priority : what do parents think?

The demands and responsibilities placed on schools in contemporary education systems are vast. However, with growing obesity levels and physical inactivity, the prevention of chronic disease has focused on youth populations, with schools playing the focal educative asset in this strategy. Parents play a decisive role in their child’s educational setting, and as fee and tax payers, are ultimately a consumer. Parents (82 males and 208 females) of secondary school children were recruited from three private (n=151) and two government schools (n=150) in Brisbane, Australia. The mean (standard deviation) age was 44.57 (6.21) years. Participants responded to a series of questions about physical activity at their child’s school, in addition to completing the International Physical Activity Questionnaire. Data were analysed using descriptive statistics, frequency distributions and logistic regressions. Parents were deemed sufficiently physically active if they participated in at least 150 minutes of moderate-to-vigorous physical activity per week. Overall, 83 (59.7%) parents from private and 60 (50.8%) parents from government schools were deemed sufficiently physically active. Concerning whether physical activity promotion should be a priority at their child’s school, 111 (73.5%) parents from private schools either agreed or strongly agreed, as opposed to 97 (64.7%) parents from government schools. Logistic regressions indicated that the concept of physical activity promotion being prioritised at schools was dependent on whether the child attended a private school (OR =1.34, z = 2.30, p = 0.02), and whether the participant was sufficiently active (OR =.71, z = -2.48, p = 0.01). Physical activity promotion within schools may provide substantial future benefits on a population scale. The demands on schools may need to be addressed to meet the needs of students and the desires of their parents.