Exploring the Impact of Active Site Structure on the Conversion of Methane to Methanol in Cu-Exchanged Zeolites.

In the past, Cu-oxo or -hydroxy clusters hosted in zeolites have been suggested to enable the selective conversion of methane to methanol, but the impact of the active site's stoichiometry and structure on methanol production is still poorly understood. Herein, we apply theoretical modeling in conjunction with experiments to study the impact of these two factors on partial methane oxidation in the Cu-exchanged zeolite SSZ-13. Phase diagrams developed from first-principles suggest that Cu-hydroxy or Cu-oxo dimers are stabilized when O2 or N2O are used to activate the catalyst, respectively. We confirm these predictions experimentally and determine that in a stepwise conversion process, Cu-oxo dimers can convert twice as much methane to methanol compared to Cu-hydroxyl dimers. Our theoretical models rationalize how Cu-di-oxo dimers can convert up to two methane molecules to methanol, while Cu-di-hydroxyl dimers can convert only one methane molecule to methanol per catalytic cycle. These findings imply that in Cu clusters, at least one oxo group or two hydroxyl groups are needed to convert one methane molecule to methanol per cycle. This simple structure-activity relationship allows to intuitively understand the potential of small oxygenated or hydroxylated transition metal clusters to convert methane to methanol.

Ghosts in the machinery: Living with and beyond radiotherapy treatment for gynaecological cancer.

This paper explores post-treatment experiences of women who have had radiotherapy for gynaecological cancer. Drawing on data from a project which explored post-treatment wellbeing, conceptual metaphors of ghosts/haunting are used to engage with enduring legacies of cancer and 'neglected matters' in post-treatment trajectories. Current arrangements of care contribute to the idea that participants are 'out of the other side of cancer' once active treatment completes. Despite broader ambitions for holistic cancer rehabilitation, fragilities of body and mind persist, even when the outward representation is one of health, of looking well, of moving on. We show how neglected matters of cancer (visceral late effects, psychological suffering and lives not lived) are part of living with and beyond cancer. These 'ghosts' manifest in chronic states of unsettledness that are temporarily relieved by individualised 'fixes', such as mobilisation of 'mind over matter' discourse and mindfulness. This discourse and its associated tools are a powerful yet impoverished framing of approaches to living with and beyond cancer. We argue for the need to attend to 'neglected matters' of post-treatment trajectories differently.

The ambivalence of radiotherapy: Re-framing effects and their temporalities in treatment for gynaecological cancer.

Within the biomedical paradigm, treatment effects are typically split into primary and secondary effects with temporality playing a key role in this separation. Yet, this kind of ordering of effects with some effects understood as happening on the 'side', secondary and temporary, does not fit with how they are experienced by many patients who undergo treatment for cancer. Drawing on empirical data from a research project that gathered narratives of women's experiences of radiotherapy for gynaecological cancer, we observe radiotherapeutic effects that are experienced as ambivalent and temporally diverse and as overlapping demands that the women endure and manage. We propose Derrida's concept of pharmakon as a relevant and useful analytic for understanding radiotherapy treatment, thus bringing into focus the ambivalent effects of radiotherapy - it is both therapeutic and toxic. Pharmakon, we argue, offers a way of disrupting the logics that govern current practices of therapeutic radiotherapy, and provides a way to re-negotiate the ordering and temporal understandings and practices of therapeutic efficacy, outcome and accountability of radiotherapy treatment - away from a temporal fragmentation of treatment effects and patients' bodily experiences to a focus on how best to support the whole patient in living with the ambivalent, temporally diverse and overlapping effects and demands of treatment.

Machine Learning-Based Prediction of Activation Energies for Chemical Reactions on Metal Surfaces.

In computational surface catalysis, the calculation of activation energies of chemical reactions is expensive, which, in many cases, limits our ability to understand complex reaction networks. Here, we present a universal, machine learning-based approach for the prediction of activation energies for reactions of C-, O-, and H-containing molecules on transition metal surfaces. We rely on generalized Bronsted-Evans-Polanyi relationships in combination with machine learning-based multiparameter regression techniques to train our model for reactions included in the University of Arizona Reaction database. In our best approach, we find a mean absolute error for activation energies within our test set of 0.14 eV if the reaction energy is known and 0.19 eV if the reaction energy is unknown. We expect that this methodology will often replace the explicit calculation of activation energies within surface catalysis when exploring large reaction networks or screening catalysts for desirable properties in the future.

Free and internal energies for the adsorption of short alkanes into the zeolite SSZ-13 from ab initio molecular dynamics simulations.

Electronic structure calculations have become a valuable tool in understanding chemical reactions of hydrocarbons in zeolite pores. However, commonly applied approaches to calculate free energies based on static electronic structure calculations significantly overestimate the entropic penalty for molecular adsorption into zeolite pores. Here, we use ab initio molecular dynamics (AIMD) simulations to model the adsorption of methane, ethane, and propane to purely siliceous and protonated SSZ-13. In our analyses we focus on the internal and Helmholtz free energies of adsorption of each molecule and compare our results to various approaches for the calculation of free energies based on static calculations. We find that only an approach that retains two thirds of the translational entropy of the adsorbate upon adsorption compares favorably with AIMD simulations. However, comparison to experimental measurements of Gibbs free energies of adsorption reported in the literature implies that we might not have captured the full complexity of alkane adsorption in our model. We expect that results in this work will help to develop a better understanding of alkane adsorption in zeolites, and that the provided data will serve as a benchmark for free energy calculations of alkane adsorption in zeolites in the future.

No Ifs, No Butts: Compliance with Smoking Cessation in Secondary Care Guidance (NICE PH48) by Providers of Cancer Therapies (Radiotherapy and Chemotherapy) in the UK.

Background: Legislation preventing smoking in public places was introduced in England in July 2007. Since then, smoke-free policies have been extended to the majority of hospitals including those providing cancer therapies. Whilst studies have been conducted on the impact and effectiveness of hospital smoke-free policy in the UK and other countries, there have not been any studies with a focus on cancer care providers. Cancer patients are a priority group for smoking cessation and support and this study aimed to examine implementation of the National Institute Clinical Excellence (NICE) guidance (PH48) in acute cancer care trusts in the UK. Methods: Participants were recruited from UK radiotherapy and chemotherapy departments (total 80 sites, 65 organisations) and asked to complete a 15 min online questionnaire exploring the implementation of NICE guidance at their hospital site. Results: Considerable variability in implementation of the NICE guidance was observed. A total of 79.1% trusts were smoke-free in theory; however, only 18.6% were described as smoke-free in practice. Areas of improvement were identified in information and support for patients and staff including in Nicotine Replacement Therapy (NRT) provision, staff training and clarity on e-cigarette policies. Conclusions: While some trusts have effective smoke-free policies and provide valuable cessation support services for patients, improvements are required to ensure that all sites fully adopt the NICE guidance.

Effect of pedal pump and thoracic pump techniques on intracranial pressure in patients with traumatic brain injuries.

CONTEXT: Although osteopathic manipulative treatment (OMT) is used to manage myriad conditions, there has been some hesitation regarding the safety of applying OMT to patients with intracranial injuries or elevated intracranial pressure (ICP). OBJECTIVE: To assess the safety of two OMT techniques--pedal pump and thoracic pump--on ICP and cerebral perfusion pressure (CPP) in patients with traumatic brain injuries (Glasgow Coma Scale score < or =8). METHODS: We prospectively enrolled consecutive patients admitted to the intensive care unit (ICU) for traumatic brain injury. Patients between the ages of 18 and 75 years and with abnormal CT scans were included in the present study. Patients with baseline ICP values of 20 mm Hg or lower were assigned to group 1, and those with ICP levels greater than 20 mm Hg, group 2. Patients underwent continuous ICP and CPP monitoring, with ICP measured using a ventricular catheter and fiber optic device. Values of ICP and CPP were recorded at baseline, during application of the OMT techniques, and 5 minutes after the two OMT techniques were completed. Patients received up to three treatment cycles. Ventricular drains remained open (stopcock open) during OMT, allowing continued cerebral spinal fluid drainage, except for brief periodic closures (stopcock closed) every minute to register accurate ICP values. Statistical analysis was performed using a dependent t test with repeated measures. RESULTS: Twenty-four comatose patients, aged 18 to 69 years, received a total of 50 sessions of pedal pump and thoracic pump techniques. In group 1 patients, a slight decrease in ICP values (mean, -0.586 mm Hg) and an increase in CPP values (mean, 1.1613 mm Hg) was noted post-OMT. Patients in group 2 also had decreased mean ICP values (-1.20 mm Hg) and increased mean CPP values (2.2105 mm Hg). Changes were not statistically significant in either group. CONCLUSION: According to the present limited study, pedal pump and thoracic pump techniques may be used safely in patients with severe brain injuries.