Laterally unrestrained bearing strength of hot-wet conditioned pultruded FRP material

Presented in this paper are test results of a study pertaining to the reduction in bearing strength due to the effect of hot-wet conditioning on specimens cut from a polyester matrix based pultruded FRP structural shape. A total of 100 coupons (for 20 batches of five) were immersed in distilled water for three and six months at a constant temperature of 40°C. Subsequently, they were load tested using stainless steel ‘pins’ of M10 and M20 sizes with material orientations of 0o, 45o and 90o to the direction of pultrusion. Furthermore, this test series considered the effect of loading with and without bolt thread in the bearing zone. Testing employed a non-standard set-up that accommodates smaller test coupons, allowing material to be sourced from the web and flange of a 254×254×9.53 mm wide flange shape. An evaluation of the salient results provides characteristic bearing strength values (in accordance with Annex D of EN1990) and comparisons are drawn between equivalent strengths for non-aged (zero months) material from a previous test series. The degree of strength reduction is found to be influenced by both the ‘pin’ size and type, and observations are drawn towards the safe and reliable design of bolted connections

Investigation in optimisation of accuracy with non-contact systems by influencing variable processes

The use of 3D scanning systems is becoming increasingly popular and an essential tool for manufacturers for inspection and measurement. With such systems being utilised on the manufacturing shop floor due to their portability and ease of use, it is no doubt that such systems are designed to address a variety of users whom, with minimal training can operate the equipment. Due to continuing demands of high-quality products there is the need for manufacturers of 3D scanning systems to develop technologies that deliver fast and accurate information. However, one of the key challenges lies not in the training of people to use the equipment, but to develop engineers who can produce traceable, accurate and precise results with a declared statement of confidence quantifying the quality of the measurement. This statement of the quality of the output results relies on employing a set of workflow actions that involve planning, capture, processing and analysis, and finally output. This paper sets out to show how the results from a set of workflow actions from different categories of 3D scanning devices affects the quality of output

Cluster Headache: What's New?

BACKGROUND: Cluster headache is a highly disabling primary headache disorder which is widely described as the most painful condition a human can experience. AIM: To provide an overview of the clinical characteristics, epidemiology, risk factors, differential diagnosis, pathophysiology and treatment options of cluster headache, with a focus on recent developments in the field. METHODS: Structured review of the literature on cluster headache. RESULTS: Cluster headache affects approximately one in 1000 of the population. It is characterised by attacks of severe unilateral head pain associated with ipsilateral cranial autonomic symptoms, and the tendency for attacks to occur with circadian and circannual periodicity. The pathophysiology of cluster headache and other primary headache disorders has recently become better understood and is thought to involve the hypothalamus and trigeminovascular system. There is good quality evidence for acute treatment of attacks with parenteral triptans and high flow oxygen; preventive treatment with verapamil; and transitional treatment with oral corticosteroids or greater occipital nerve injection. New pharmacological and neuromodulation therapies have recently been developed. CONCLUSION: Cluster headache causes distinctive symptoms, which once they are recognised can usually be managed with a variety of established treatments. Recent pathophysiological understanding has led to the development of newer pharmacological and neuromodulation therapies, which may soon become established in clinical practice

Treatment of intractable hemicrania continua by occipital nerve stimulation

Hemicrania continua (HC) is characterised by a strictly unilateral continuous headache with ipsilateral autonomic features and migrainous symptoms that is exquisitely sensitive to indomethacin.1 As more than 30% of patients report side effects with indomethacin, there is need for an effective and safe alternative. Although several drugs have been used in open-label studies, none offer the same magnitude of response. Occipital nerve stimulation (ONS) has been performed in headache conditions such as chronic migraine and chronic cluster headache, both conditions with clinical similarities to HC and appears to be a safe, potentially efficacious treatment even in those failing all available medical treatments.2 We report the long-term follow-up of a new cohort of 16 patients with HC treated with ONS

Long-term follow up of intractable chronic short lasting unilateral neuralgiform headache disorders treated with occipital nerve stimulation

BACKGROUND: Occipital nerve stimulation is a potential treatment option for medically intractable short-lasting unilateral neuralgiform headache attacks. We present long-term outcomes in 31 patients with short-lasting unilateral neuralgiform headache attacks treated with occipital nerve stimulation in an uncontrolled open-label prospective study. METHODS: Thirty-one patients with intractable short-lasting unilateral neuralgiform headache attacks were treated with bilateral occipital nerve stimulation from 2007 to 2015. Data on attack characteristics, quality of life, disability and adverse events were collected. Primary endpoint was change in mean daily attack frequency at final follow-up. RESULTS: At a mean follow-up of 44.9 months (range 13-89) there was a 69% improvement in attack frequency with a response rate (defined as at least a 50% improvement in daily attack frequency) of 77%. Attack severity reduced by 4.7 points on the verbal rating scale and attack duration by a mean of 64%. Improvements were seen in headache-related disability and depression. Adverse event rates were favorable, with no electrode migration or erosion reported. CONCLUSION: Occipital nerve stimulation appears to offer a safe and efficacious treatment for refractory short-lasting unilateral neuralgiform headache attacks with significant improvements sustained in the long term. The procedure has a low adverse event rate when conducted in highly specialised units

OnabotulinumtoxinA for hemicrania continua: open label experience in 9 patients

BACKGROUND: Hemicrania continua is a strictly unilateral, continuous headache, typically mild to moderate in severity, with severe exacerbations commonly accompanied by cranial autonomic features and migrainous symptoms. It is exquisitely responsive to Indomethacin. However, some patients cannot tolerate treatment, often due to gastrointestinal side effects. Therapeutic alternatives are limited and controlled evidence lacking. METHODS: We present our experience of nine patients treated with OnabotulinumtoxinA for hemicrania continua. All patients were injected using the PREEMPT (Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy) protocol for migraine. RESULTS: Five of nine patients demonstrated a 50% or more reduction in moderate to severe headache days with OnabotulinumtoxinA with a median reduction in moderate to severe headache days of 80%. Patient estimate of response was 80% or more in five subjects. The median and mean duration of response in the five responders was 11 and 12 weeks (range 6-20 weeks). Improvements were also seen in headache-associated disability CONCLUSIONS: OnabotulinumtoxinA adds a potential option to the limited therapeutic alternatives available in hemicrania continua

Evolution of Surface Nanopores in Pressurised Gyrospun Polymeric Microfibers

The selection of a solvent or solvent system and the ensuing polymer–solvent interactions are crucial factors affecting the preparation of fibers with multiple morphologies. A range of poly(methylmethacrylate) fibers were prepared by pressurised gyration using acetone, chloroform, N,N-dimethylformamide (DMF), ethyl acetate and dichloromethane as solvents. It was found that microscale fibers with surface nanopores were formed when using chloroform, ethyl acetate and dichloromethane and poreless fibers were formed when using acetone and DMF as the solvent. These observations are explained on the basis of the physical properties of the solvents and mechanisms of pore formation. The formation of porous fibers is caused by many solvent properties such as volatility, solubility parameters, vapour pressure and surface tension. Cross-sectional images show that the nanopores are only on the surface of the fibers and they were not inter-connected. Further, the results show that fibers with desired nanopores (40–400 nm) can be prepared by carefully selecting the solvent and applied pressure in the gyration process

Current methodologies and approaches for the formation of core–sheath polymer fibers for biomedical applications

The application of polymer fibers has rocketed to unimaginable heights in recent years and occupies every corner of our day-to-day life, from knitted protective textile clothes to buzzing smartphone electronics. Polymer fibers could be obtained from natural and synthetic polymers at a length scale from the nanometer to micrometer range. These fibers could be formed into different configurations such as single, core–sheath, hollow, blended, or composite according to human needs. Of these several conformations of fibers, core–sheath polymer fibers are an interesting class of materials, which shows superior physical, chemical, and biological properties. In core–sheath fiber structures, one of the components called a core is fully surrounded by the second component known as a sheath. In this format, different polymers can be applied as a sheath over a solid core of another polymer, thus resulting in a variety of modified properties while maintaining the major fiber property. After a brief introduction to core–sheath fibers, this review paper focuses on the development of the electrospinning process to manufacture core–sheath fibers followed by illustrating the current methodology and approaches to form them on a larger scale, suitable for industrial manufacturing and exploitation. Finally, the paper reviews the applications of the core–sheath fibers, in particular, recent studies of core–sheath polymer fibers in tissue engineering (nerve, vascular grafts, cardiomyocytes, bone, tendons, sutures, and wound healing), growth factors and other bioactive component release, and drug delivery. Therefore, core–sheath structures are a revolutionary development in the field of science and technology, becoming a backbone to many emerging technologies and novel opportunities

Microvascular decompression or neuromodulation in patients with SUNCT and trigeminal neurovascular conflict?

Objectives To assess the effectiveness of neuromodulation and trigeminal microvascular decompression (MVD) in patients with medically-intractable short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). Methods Two patients with medically refractory SUNCT underwent MVD following beneficial but incomplete response to neuromodulation (occipital nerve stimulation and deep brain stimulation). MRI confirmed neurovascular conflict with the ipsilateral trigeminal nerve in both patients. Results Although neuromodulation provided significant benefit, it did not deliver complete relief from pain and management required numerous postoperative visits with adjustment of medication and stimulation parameters. Conversely, MVD was successful in eliminating symptoms of SUNCT in both patients with no need for further medical treatment or neuromodulation. Conclusion Neuromodulation requires expensive hardware and lifelong follow-up and maintenance. These case reports highlight that microvascular decompression may be preferable to neuromodulation in the subset of SUNCT patients with ipsilateral neurovascular conflict

Does regional anaesthesia reduce complications following total hip and knee replacement compared with general anaesthesia?:An analysis from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

Background Regional anesthesia is increasingly used in enhanced recovery programs following total hip replacement (THR) and total knee replacement (TKR). However, debate remains about its potential benefit over general anesthesia given that complications following surgery are rare. We assessed the risk of complications in THR and TKR patients receiving regional anesthesia compared with general anesthesia using the world’s largest joint replacement registry. Methods We studied the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man linked to English hospital inpatient episodes for 779,491 patients undergoing THR and TKR. Patients received either regional anesthesia (n = 544,620, 70%) or general anesthesia (n = 234,871, 30%). Outcomes assessed at 90 days included length of stay, readmissions, and complications. Regression models were adjusted for patient and surgical factors to determine the effect of anesthesia on outcomes. Results Length of stay was reduced with regional anesthesia compared with general anesthesia (THR = −0.49 days, 95% confidence interval [CI] = −0.51 to −0.47 days, P < .001; TKR = −0.47 days, CI = −0.49 to −0.45 days, P < .001). Regional anesthesia also had a reduced risk of readmission (THR odds ratio [OR] = 0.93, CI = 0.90-0.96; TKA OR = 0.91, CI = 0.89-0.93), any complication (THR OR = 0.88, CI = 0.85-0.91; TKA OR = 0.90, CI = 0.87-0.93), urinary tract infection (THR OR = 0.85, CI = 0.77-0.94; TKR OR = 0.87, CI = 0.79-0.96), and surgical site infection (THR OR = 0.87, CI = 0.80-0.95; TKR OR = 0.84, CI = 0.78-0.89). Anesthesia type did not affect the risk of revision surgery or mortality. Conclusion Regional anesthesia was associated with reduced length of stay, readmissions, and complications following THR and TKR when compared with general anesthesia. We recommend regional anesthesia should be considered the reference standard for patients undergoing THR and TKR