Anisotropic Condensation of Helium in Nanotube Bundles

Helium atoms are strongly attracted to the interstitial channels within a bundle of carbon nanotubes. The strong corrugation of the axial potential within a channel can produce a lattice gas system where the weak mutual attraction between atoms in neighboring channels of a bundle induces condensation into a remarkably anisotropic phase with very low binding energy. We estimate the binding energy and critical temperature for 4He in this novel quasi-one-dimensional condensed state. At low temperatures, the specific heat of the adsorbate phase (fewer than 2% of the total number of atoms) greatly exceeds that of the host material.Comment: 8 pages, 3 figures, submitted to PRL (corrected typo in abstract

(Meta-)stable reconstructions of the diamond(111) surface: interplay between diamond- and graphite-like bonding

Off-lattice Grand Canonical Monte Carlo simulations of the clean diamond (111) surface, based on the effective many-body Brenner potential, yield the $(2\times1)$ Pandey reconstruction in agreement with \emph{ab-initio} calculations and predict the existence of new meta-stable states, very near in energy, with all surface atoms in three-fold graphite-like bonding. We believe that the long-standing debate on the structural and electronic properties of this surface could be solved by considering this type of carbon-specific configurations.Comment: 4 pages + 4 figures, Phys. Rev. B Rapid Comm., in press (15Apr00). For many additional details (animations, xyz files) see electronic supplement to this paper at http://www.sci.kun.nl/tvs/carbon/meta.htm

Rational synthesis of epoxy-functional spheres, worms and vesicles by RAFT aqueous emulsion polymerisation of glycidyl methacrylate

The rational synthesis of epoxy-functional diblock copolymer nano-objects has been achieved via RAFT aqueous emulsion polymerisation of glycidyl methacrylate (GlyMA; aqueous solubility ∼22 g dm-3 at 50 °C) by utilising relatively mild conditions (pH 7, 50 °C) to preserve the epoxy groups. High monomer conversions were achieved within 1 h when using a poly(glycerol monomethacrylate) chain transfer agent with a mean degree of polymerisation (DP) of 28, with GPC analysis indicating relatively narrow molecular weight distributions (Mw/Mn < 1.40) when targeting PGlyMA DPs up to 80. A phase diagram was constructed to identify the synthesis conditions required to access pure spheres, worms or vesicles. Transmission electron microscopy, dynamic light scattering and small-angle X-ray scattering (SAXS) studies indicated the formation of well-defined worms and vesicles when targeting relatively long PGlyMA blocks. These epoxy-functional nano-objects were derivatised via epoxy-thiol chemistry by reaction with l-cysteine in aqueous solution. Finally, an in situ SAXS study was conducted during the RAFT aqueous emulsion polymerisation of GlyMA at 50 °C to examine the nucleation and size evolution of PGMA48-PGlyMA100 diblock copolymer spheres using a bespoke stirrable reaction cell

Computer-supported collaborative learning with digital video cases in teacher education: the impact of teaching experience on knowledge convergence

Case-based learning is ascribed high potential with respect to the education of pre-service teachers as well as the further education of experienced in-service teachers, as it can provide opportunities for the application of professional knowledge to authentic classroom situations. In addition to the application and acquisition of knowledge, the aspect of knowledge convergence (i.e., increasing similarity of collaborative learners with respect to their knowledge) should be taken into account when homogeneous benefits are desired for all participants of a case-based training. A field study with 29 pre-service teachers and 24 in-service teachers from adult education was conducted to examine effects of different levels of teaching experience on knowledge application, knowledge acquisition, and knowledge convergence in a computer-supported collaborative case-based learning environment. An innovative approach to measuring knowledge convergence was introduced, using the positions of annotations (i.e., flags placed on the timeline of the case video) made by learners during their case analyses as an indicator of their shared focus of attention. This measure was found to positively correlate with the application and acquisition of professional knowledge. Teaching experience affected both processes and outcomes of case-based learning, suggesting different means of instructional support for pre-service and in-service teachers

The use of neuralgia medications to treat sensory neuropathic cough: our experience in a retrospective cohort of thirty-two patients

Objective. This study sought to: (1) quantify response rate and efficacy of amitriptyline, desipramine, and gabapentin in treating sensory neuropathic cough; and (2) describe an efficient treatment protocol.Study Design. This study is a retrospective case series.Methods. Persons diagnosed with sensory neuropathic cough during a one-year period were potential study candidates. To bolster the diagnosis credibility, only persons who had been treated elsewhere for gastroesophageal reflux disease, asthma, and allergy with no reduction of cough were included. Upon diagnosis of sensory neuropathic cough, each person was treated with either amitriptyline, desipramine, or gabapentin, titrating the dose upward to desired benefit or the dose limit. If the benefit was insufficient, another of the medications was used next, using a similar dose escalation strategy. Data points included patient demographics, initial and final medication, final dose, and degree of improvement.Results. 32 patients met the diagnostic and inclusion criteria and had a complete data set. 94% (30 of 32) of the patients responded to at least one of the medications. The 32 patients undertook a total of 45 single-medication trials. Patients reported symptom relief during 78% (14 of 18) of amitriptyline trials, 73% (11 of 15) of desipramine trials, and 83% (10 of 12) of gabapentin trials. At final dosage, symptom reduction averaged 77% on amitriptyline, 73% on desipramine, and 69% on gabapentin.Conclusion. Amitriptyline, desipramine, and gabapentin appear to vary in their effectiveness for individual cases of sensory neuropathic cough; across a whole cohort, symptom relief was similar in frequency and degree on any of the three medications. More evidence is needed to demonstrate more convincingly the effectiveness of these medications, but this data set suggests that each of these three medications deserves consideration in the codified treatment protocol presented here

Antiepileptic drugs’ tolerability and safety – a systematic review and meta-analysis of adverse effects in dogs

<p>Various anti-epileptic drugs (AEDs) are used for the management of idiopathic epilepsy (IE) in dogs. Their safety profile is an important consideration for regulatory bodies, owners and prescribing clinicians. However, information on their adverse effects still remains limited with most of it derived from non-blinded non-randomized uncontrolled trials and case reports.</p><p><span>This poster won third place, which was presented at the Veterinary Evidence Today conference, Edinburgh November 1-3, 2016. </span></p><br /> <img src="https://www.veterinaryevidence.org/rcvskmod/icons/oa-icon.jpg" alt="Open Access" /

Neuropsychological function in patients with a single gene mutation associated with autosomal dominant nocturnal frontal lobe epilepsy

Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is a nonlesional condition associated with mutation of the gene coding for the α4 nicotinic acetylcholine receptor (nAChR). The nAChR modulates aspects of memory and attention. We examined the neuropsychological phenotype of ADNFLE, with a particular emphasis on understanding the impact on frontal lobe functions. We used standard clinical tests as well as focused measures of frontal lobe function in a well-defined group of patients with ADNFLE. Their performance was compared with that of a group of age-, sex-, and education-matched control participants. Patients with ADNFLE showed impairments on tasks requiring cognitive flexibility against a background of well-preserved intellectual abilities. In accord with existing research, verbal memory impairments were identified in the patient group; the level of impairment on these tasks correlated with disease-related factors. In our study of ADNFLE associated with one mutation, cognitive flexibility appears to be the core cognitive deficit

Infection rates associated with epidural indwelling catheters for seven days or longer: systematic review and meta-analysis

BACKGROUND: To determine infection rate with use of epidural catheters in place for seven days or more. METHODS: Systematic review and pooled analysis of observational studies. RESULTS: Twelve studies with 4,628 patients (median 197 patients) provided information, of which nine (4,334 patients) were published after 1990. Eight studies (3,893 patients) were retrospective, and four studies (735 patients) prospective. Electronic searches identified three studies and searching reference lists nine. There were 257 catheter-related infections in total, of which 211 were superficial and 57 deep, giving rates of 6.1%, 4.6% and 1.2% respectively. Ten of the 12 studies had deep infection rates of 2% or less. The incidence of deep infection was 1 per 2391 days of treatment, or 0.4 per 1000 catheter treatment days. In nine studies (1503 patients), predominantly in cancer, and with average catheter duration of 74 days, the deep infection rate was 2.8%. The proportion of patients with infection of any type was higher in cancer patients with longer catheter duration. Limited numbers of events meant that no reliable estimate of the impact of prospective and retrospective design could be made. There appeared to be a relationship between catheter duration and infection rate from this and other recent estimates. Four of 57 (7%) patients with deep infection died. CONCLUSION: The best estimate is that one person in 35 with an epidural catheter in place for 74 days for relief of cancer pain can be expected to have a deep epidural infection, and that about 1 in 500 may die of infection-related causes. This is a most uncertain estimate given the limited nature of the evidence

Sildenafil (Viagra) for male erectile dysfunction: a meta-analysis of clinical trial reports

BACKGROUND: Evaluation of company clinical trial reports could provide information for meta-analysis at the commercial introduction of a new technology. METHODS: Clinical trial reports of sildenafil for erectile dysfunction from September 1997 were used for meta-analysis of randomised trials (at least four weeks duration) and using fixed or dose optimisation regimens. The main outcome sought was an erection, sufficiently rigid for penetration, followed by successful intercourse, and conducted at home. RESULTS: Ten randomised controlled trials fulfilled the inclusion criteria (2123 men given sildenafil and 1131 placebo). NNT or NNH were calculated for important efficacy, adverse event and discontinuation outcomes. Dose optimisation led to at least 60% of attempts at sexual intercourse being successful in 49% of men, compared with 11% with placebo; the NNT was 2.7 (95% confidence interval 2.3 to 3.3). For global improvement in erections the NNT was 1.7 (1.6 to 1.9). Treatment-related adverse events occurred in 30% of men on dose optimised sildenafil compared with 11% on placebo; the NNH was 5.4 (4.3 to 7.3). All cause discontinuations were less frequent with sildenafil (10%) than with placebo (20%). Sildenafil dose optimisation gave efficacy equivalent to the highest fixed doses, and adverse events equivalent to the lowest fixed doses. CONCLUSION: This review of clinical trial reports available at the time of licensing agreed with later reviews that had many more trials and patients. Making reports submitted for marketing approval available publicly would provide better information when it was most needed, and would improve evidence-based introduction of new technologies