Mechanochemical treatment of kaolinite

Kaolinite surfaces were modified by mechanochemical treatment for periods of time up to 10 h. X-ray diffraction shows a steady decrease in intensity of the d(001) spacing with mechanochemical treatment, resulting in the delamination of the kaolinite and a subsequent decrease in crystallite size with grinding time. Thermogravimetric analyses show the dehydroxylation patterns of kaolinite are significantly modified. Changes in the molecular structure of the kaolinite surface hydroxyls were followed by infrared spectroscopy. Hydroxyls were lost after 10 h of grinding as evidenced by a decrease in intensity of the OH stretching vibrations at 3695 and 3619 cm−1 and the deformation modes at 937 and 915 cm−1. Concomitantly an increase in the hydroxyl stretching vibrations of water is found. The water-bending mode was observed at 1650 cm−1, indicating that water is coordinating to the modified kaolinite surface. Changes in the surface structure of the OSiO units were reflected in the SiO stretching and OSiO bending vibrations. The decrease in intensity of the 1056 and 1034 cm−1 bands attributed to kaolinite SiO stretching vibrations were concomitantly matched by the increase in intensity of additional bands at 1113 and 520 cm−1 ascribed to the new mechanically synthesized kaolinite surface. Mechanochemical treatment of the kaolinite results in a new surface structure.

Thermal treatment of weddellite—a Raman and infrared emission spectroscopic study

Thermal transformations of natural calcium oxalate dihydrate known in mineralogy as weddellite have been undertaken using a combination of Raman microscopy and infrared emission spectroscopy. The vibrational spectroscopic data was complimented with high resolution thermogravimetric analysis combined with evolved gas mass spectrometry. TG–MS identified three mass loss steps at 114, 422 and 592 °C. In the first mass loss step water is evolved only, in the second and third steps carbon dioxide is evolved. The combination of Raman microscopy and a thermal stage clearly identifies the changes in the molecular structure with thermal treatment. Weddellite is the phase in the temperature range up to the pre-dehydration temperature of 97 °C. At this temperature, the phase formed is whewellite (calcium oxalate monohydrate) and above 114 °C the phase is the anhydrous calcium oxalate. Above 422 °C, calcium carbonate is formed. Infrared emission spectroscopy shows that this mineral decomposes at around 650 °C. Changes in the position and intensity of the C=O and C---C stretching vibrations in the Raman spectra indicate the temperature range at which these phase changes occur.

Radiobiological model comparison of 3D conformal radiotherapy and IMRT plans for the treatment of prostate cancer

The main aim of radiotherapy is to deliver a dose of radiation that is high enough to destroy the tumour cells while at the same time minimising the damage to normal healthy tissues. Clinically, this has been achieved by assigning a prescription dose to the tumour volume and a set of dose constraints on critical structures. Once an optimal treatment plan has been achieved the dosimetry is assessed using the physical parameters of dose and volume. There has been an interest in using radiobiological parameters to evaluate and predict the outcome of a treatment plan in terms of both a tumour control probability (TCP) and a normal tissue complication probability (NTCP). In this study, simple radiobiological models that are available in a commercial treatment planning system were used to compare three dimensional conformal radiotherapy treatments (3D-CRT) and intensity modulated radiotherapy (IMRT) treatments of the prostate. Initially both 3D-CRT and IMRT were planned for 2 Gy/fraction to a total dose of 60 Gy to the prostate. The sensitivity of the TCP and the NTCP to both conventional dose escalation and hypo-fractionation was investigated. The biological responses were calculated using the Källman S-model. The complication free tumour control probability (P+) is generated from the combined NTCP and TCP response values. It has been suggested that the alpha/beta ratio for prostate carcinoma cells may be lower than for most other tumour cell types. The effect of this on the modelled biological response for the different fractionation schedules was also investigated.

Eye-movements and visual imagery : a working memory approach to the treatment of post-traumatic stress disorder

It has been claimed that the symptoms of post-traumatic stress disorder (PTSD) can be ameliorated by eye-movement desensitization-reprocessing therapy (EMD-R), a procedure that involves the individual making saccadic eye-movements while imagining the traumatic event. We hypothesized that these eye-movements reduce the vividness of distressing images by disrupting the function of the visuospatial sketchpad (VSSP) of working memory, and that by doing so they reduce the intensity of the emotion associated with the image. This hypothesis was tested by asking non-PTSD participants to form images of neutral and negative pictures under dual task conditions. Their images were less vivid with concurrent eye-movements and with a concurrent spatial tapping task that did not involve eye-movements. In the first three experiments, these secondary tasks did not consistently affect participants' emotional responses to the images. However, Expt 4 used personal recollections as stimuli for the imagery task, and demonstrated a significant reduction in emotional response under the same dual task conditions. These results suggest that, if EMD-R works, it does so by reducing the vividness and emotiveness of traumatic images via the VSSP of working memory. Other visuospatial tasks may also be of therapeutic value.

EMG biofeedback in the treatment of tinnitus : an experimental evaluation

26 tinnitus patients received either electromyogram (EMG) biofeedback with counterdemand instructions, EMG biofeedback with neutral demand instructions, or no treatment. Assessment was conducted on self-report measures of the distress associated with tinnitus, the loudness, annoyance and awareness of tinnitus, sleep-onset difficulties, depression, and anxiety. Audiological assessment of tinnitus was also conducted and EMG levels were measured (the latter only in the 2 treatment groups). No significant treatment effects were found on any of the measures. There was a significant decrease in the ratings of tinnitus awareness over the assessment occasions, but the degree of change was equivalent for treated and untreated groups. Results do not support the assertion that EMG biofeedback is an effective treatment for tinnitus.

What is the future for rimonabant in the treatment of obesity

Orlistat and sibutramine only cause modest reductions in body weight. Rimonabant, a cannabinoid receptor 1 antagonist, is a new approach to weight reduction, but is it safe, efficacious, and better than the existing agents?

Ticagrelor, a platelet aggregation inhibitor for the potential prevention and treatment of arterial thrombosis and acute coronary syndromes

Ticagrelor is an orally active ADP P2Y12 receptor antagonist in development by AstraZeneca plc for the reduction of recurrent ischemic events in patients with acute coronary syndromes (ACS). Prior to the development of ticagrelor, thienopyridine compounds, such as clopidogrel, were the focus of research into therapies for ACS. Although the thienopyridines are effective platelet aggregation inhibitors, they are prodrugs and, consequently, exert a slow onset of action. In addition, the variability in inter-individual metabolism of thienopyridine prodrugs has been associated with reduced efficacy in some patients. Ticagrelor is not a prodrug and exhibits a more rapid onset of action than the thienopyridine prodrugs. In clinical trials conducted to date, ticagrelor was a potent inhibitor of ADP-induced platelet aggregation and demonstrated effects that were comparable to clopidogrel. In a phase II, short-term trial, the bleeding profile of participants treated with ticagrelor was similar to that obtained with clopidogrel; however, an increased incidence of dyspnea was observed - an effect that has not been reported with the thienopyridines. Considering the occurrence of dyspnea, and the apparent non-superiority of ticagrelor to clopidogrel, it is difficult to justify a clear benefit to the continued development of ticagrelor. Outcomes from an ongoing phase III trial comparing ticagrelor with clopidogrel in 18,000 patients with ACS are likely to impact on the future development of ticagrelor.

Treatment of comorbidity

Cormorbity means the co-occurrence of one or more diseases or disorders in an individual. The National Comorbity Project aims to highlight this type of comorbity and identify appropriate strategies and policies responses.

Functional communication training for the treatment of multiply determined behaviour in two boys with autism

Functional communication training was used to replace multiply determined problem behaviour in two boys with autism. Experiment 1 involved a functional analysis of several topographies of problem behaviour using a variation of the procedures described by Iwata, Dorsey, Slifer, Bauman, and Richman. Results suggested that aggression, self-injury, and disruption were multiply determined (i.e., maintained by both attention and access to preferred objects). Experiment 2 involved a multiple-baseline design across subjects. The focus of intervention was to replace aggression, self-injury, and disruption with functionally equivalent communicative alternatives. Both boys were taught alternative “mands” to recruit attention and request preferred objects. Acquisition of these alternative communication skills was associated with concurrent decreases in aggression, self-injury, and disruption. Results suggest that multiply determined challenging behaviour can be decreased by teaching an alternative communication skill to replace each assessed function of the problem behaviour.

Continuous infusion of ticarcillin-clavulanate for home treatment of serious infections : clinical efficacy, safety, pharmacokinetics and pharmacodynamics

Continuous infusion (CI) ticarcillin–clavulanate is a potential therapeutic improvement over conventional intermittent dosing because the major pharmacodynamic (PD) predictor of efficacy of β-lactams is the time that free drug levels exceed the MIC. This study incorporated a 6-year retrospective arm evaluating efficacy and safety of CI ticarcillin–clavulanate in the home treatment of serious infections and a prospective arm additionally evaluating pharmacokinetics (PK) and PD. In the prospective arm, steady-state serum ticarcillin and clavulanate levels and MIC testing of significant pathogens were performed. One hundred and twelve patients (median age, 56 years) were treated with a CI dose of 9.3–12.4 g/day and mean CI duration of 18.0 days. Infections treated included osteomyelitis (50 patients), septic arthritis (6), cellulitis (17), pulmonary infections (12), febrile neutropenia (7), vascular infections (7), intra-abdominal infections (2), and Gram-negative endocarditis (2); 91/112 (81%) of patients were cured, 14 (13%) had partial response and 7 (6%) failed therapy. Nine patients had PICC line complications and five patients had drug adverse events. Eighteen patients had prospective PK/PD assessment although only four patients had sufficient data for a full PK/PD evaluation (both serum steady-state drug levels and ticarcillin and clavulanate MICs from a bacteriological isolate), as this was difficult to obtain in home-based patients, particularly as serum clavulanate levels were found to deteriorate rapidly on storage. Three of four patients with matched PK/PD assessment had free drug levels exceeding the MIC of the pathogen. Home CI of ticarcillin–clavulanate is a safe, effective, convenient and practical therapy and is a therapeutic advance over traditional intermittent dosing when used in the home setting.

The cost effectiveness of Naltrexone added to cognitive-behavioral therapy in the treatment of alcohol dependence

he purpose of this study was to evaluate the comparative cost of treating alcohol dependence with either cognitive behavioral therapy (CBT) alone or CBT combined with naltrexone (CBT+naltrexone). Two hundred ninety-eight outpatients dependent on alcohol who were consecutively treated for alcohol dependence participated in this study. One hundred seven (36%) patients received adjunctive pharmacotherapy (CBT+naltrexone). The Drug Abuse Treatment Cost Analysis Program was used to estimate treatment costs. Adjunctive pharmacotherapy (CBT+naltrexone) introduced an additional treatment cost and was 54% more expensive than CBT alone. When treatment abstinence rates (36.1% CBT; 62.6% CBT+naltrexone) were applied to cost effectiveness ratios, CBT+naltrexone demonstrated an advantage over CBT alone. There were no differences between groups on a preference-based health measure (SF-6D). In this treatment center, to achieve 100 abstainers over a 12-week program, 280 patients require CBT compared with 160 CBT+naltrexone. The dominant choice was CBT+naltrexone based on modest economic advantages and significant efficiencies in the numbers needed to treat.

The Treatment of Neonatal Seizures: A Critical Review of the Evidence

In a critical review of the literature to assess the efficacy of monotherapy and subsequent combinant anticonvulsant therapy in the treatment of neonatal seizures, four studies were examined; three randomised control trials and one retrospective cohort study. Each study used phenobarbital for monotherapy with doses reaching a maximum of 40mg/kg. Anticonvulsant drugs used in conjunction with phenobarbitone for combinant therapy included midazolam, clonazepam, lorazepam, phenytoin and lignocaine. Each study used an electroencephalograph for seizure diagnosis and neonatal monitoring when determining therapy efficacy and final outcome assessments. Collectively the studies suggest neither monotherapy nor combinant therapy are entirely effective in seizure control. Monotherapy demonstrated a 29% - 50% success rate for complete seizure control whereas combinant therapy administered after the failure of monotherapy demonstrated a success rate of 43% - 100%. When these trials were combined the overall success for monotherapy was 44% (n = 34/78) and for combinant therapy 72% ( n = 56/78). Though the evidence was inconclusive, it would appear that combinant therapy is of greater benefit to infants unresponsive to monotherapy. Further research such as multi-site randomised controlled trials using standardised criteria and data collection are required within this specialised area.