61 research outputs found
Comprehensive review of various corrosion behaviours on 316 stainless steel
Corrosion is a destructive process that converts the pure metal into a chemically stabled form by hydroxide or sulphide and it is a slow process of destruction on the material by the chemical or electrochemical reaction in the environmental space. This kind of destruction has been typically produced from oxides or salt content on the material and it results in distinctive orange coloration. The classifications of corrosion act on atmospheric air and liquids as well as on contact of two solids. To resist the corrosion rate, stainless steel 316 has been chosen because of the presence of 2-3% molybdenum content and the presence of molybdenum plays a vital role in corrosion resistance. In this study, literature related to various works has been reviewed to explain the corrosion behaviour on cavitation, crevice, electrochemical, erosion, fatigue, galvanic, uniform, pitting, and stress corrosion which act on 316 stainless steel. In the present work, several coating processes and the additives, that have been added to SS 316 to enhance the outcomes according to various corrosion causes, are discussed
Radiofrequency denervation of the lumbar facet joints: guidelines for the RADICAL randomised controlled trial
X-ray diffraction from single Al<SUB>6</SUB>CuLi<SUB>3</SUB> grains showing five-fold symmetry
We present here the detailed results of X-ray diffraction from single quasicrystals of Al6CuLi3. X-ray precession photographs taken down the two-, three- and five-fold axes along with rotation and zero-level Weissenberg photographs are shown. Preliminary analysis of the diffraction data rules out the twin hypothesis
Durability of Evoked Compound Action Potential (ECAP)-Controlled, Closed-Loop Spinal Cord Stimulation (SCS) in a Real-World European Chronic Pain Population
Introduction: Closed-loop spinal cord stimulation (CL-SCS) is a recently introduced system that records evoked compound action potentials (ECAPs) from the spinal cord elicited by each stimulation pulse and uses this information to automatically adjust the stimulation strength in real time, known as ECAP-controlled SCS. This innovative system compensates for fluctuations in the distance between the epidural leads and the spinal cord by maintaining the neural response (ECAP) at a predetermined target level. This data collection study was designed to assess the performance of the first CL-SCS system in a real-world setting under normal conditions of use in multiple European centers. The study analyzes and presents clinical outcomes and electrophysiological and device data and compares these findings with those reported in earlier pre-market studies of the same system. Methods: This prospective, multicenter, observational study was conducted in 13 European centers and aimed to gather electrophysiological and device data. The study focused on the real-world application of this system in treating chronic pain affecting the trunk and/or limbs, adhering to standard conditions of use. In addition to collecting and analyzing basic demographic information, the study presents data from the inaugural patient cohort permanently implanted at multiple European centers. Results: A significant decrease in pain intensity was observed for overall back or leg pain scores (verbal numerical rating score [VNRS]) between baseline (mean ± standard error of the mean [SEM]; n = 135; 8.2 ± 0.1), 3 months (n = 93; 2.3 ± 0.2), 6 months (n = 82; 2.5 ± 0.3), and 12 months (n = 76; 2.5 ± 0.3). Comparison of overall pain relief (%) to the AVALON and EVOKE studies showed no significant differences at 3 and 12 months between the real-world data release (RWE; 71.3%; 69.6%) and the AVALON (71.2%; 73.6%) and EVOKE (78.1%; 76.7%) studies. Further investigation was undertaken to objectively characterize the physiological parameters of SCS therapy in this cohort using the metrics of percent time above ECAP threshold (%), dose ratio, and dose accuracy (µV), according to previously described methods. Results showed that a median of 90% (40.7–99.2) of stimuli were above the ECAP threshold, with a dose ratio of 1.3 (1.1–1.4) and dose accuracy of 4.4 µV (0.0–7.1), based on data from 236, 230, and 254 patients, respectively. Thus, across all three metrics, the majority of patients had objective therapy metrics corresponding to the highest levels of pain relief in previously reported studies (usage over threshold > 80%, dose ratio > 1.2, and error < 10 µV). Conclusions: In conclusion, this study provides valuable insights into the real-world application of the ECAP-controlled CL-SCS system, highlighting its potential for maintaining effective pain relief and objective neurophysiological therapy metrics at levels seen in randomized control trials, and potential for quantifying patient burden associated with SCS system use via patient–device interaction metrics. Clinical Trial Registration: In the Netherlands, the study is duly registered on the International Clinical Trials Registry Platform (Trial NL7889). In Germany, the study is duly registered as NCT05272137 and in the United Kingdom as ISCRTN27710516 and has been reviewed by the ethics committee in both countries.</p
Appropriate referral and selection of patients with chronic pain for spinal cord stimulation: European consensus recommendations and e-health tool
Background: Spinal cord stimulation (SCS) is an established treatment for chronic neuropathic, neuropathic-like and ischaemic pain. However, the heterogeneity of patients in daily clinical practice makes it often challenging to determine which patients are eligible for this treatment, resulting in undesirable practice variations. This study aimed to establish patient-specific recommendations for referral and selection of SCS in chronic pain. Methods: A multidisciplinary European panel used the RAND/UCLA Appropriateness Method (RUAM) to assess the appropriateness of (referral for) SCS for 386 clinical scenarios in four pain areas: chronic low back pain and/or leg pain, complex regional pain syndrome, neuropathic pain syndromes and ischaemic pain syndromes. In addition, the panel identified a set of psychosocial factors that are relevant to the decision for SCS treatment. Results: Appropriateness of SCS was strongly determined by the neuropathic or neuropathic-like pain component, location and spread of pain, anatomic abnormalities and previous response to therapies targeting pain processing (e.g. nerve block). Psychosocial factors considered relevant for SCS selection were as follows: lack of engagement, dysfunctional coping, unrealistic expectations, inadequate daily activity level, problematic social support, secondary gain, psychological distress and unwillingness to reduce high-dose opioids. An educational e-health tool was developed that combines clinical and psychosocial factors into an advice on referral/selection for SCS. Conclusions: The RUAM was useful to establish a consensus on patient-specific criteria for referral/selection for SCS in chronic pain. The e-health tool may help physicians learn to apply an integrated approach of clinical and psychosocial factors. Significance: Determining the eligibility of SCS in patients with chronic pain requires careful consideration of a variety of clinical and psychosocial factors. Using a systematic approach to combine evidence from clinical studies and expert opinion, a multidisciplinary European expert panel developed detailed recommendations to support appropriate referral and selection for SCS in chronic pain. These recommendations are available as an educational e-health tool (https://www.scstool.org/)
Does a Screening Trial for Spinal Cord Stimulation in Patients with Chronic Pain of Neuropathic Origin have Clinical Utility and Cost-Effectiveness? (TRIAL-STIM Study): study protocol for a randomised controlled trial
Abstract Background The TRIAL-STIM Study aims to assess the diagnostic performance, clinical outcomes and cost-effectiveness of a screening trial prior to full implantation of a spinal cord stimulation (SCS) device. Methods/design The TRIAL-STIM Study is a superiority, parallel-group, three-centre, randomised controlled trial in patients with chronic neuropathic pain with a nested qualitative study and economic evaluation. The study will take place in three UK centres: South Tees Hospitals NHS Foundation Trust (The James Cook University Hospital); Basildon and Thurrock University Hospitals NHS Foundation Trust; and Leeds Teaching Hospitals NHS Trust. A total of 100 adults undergoing SCS implantation for the treatment of neuropathy will be included. Subjects will be recruited from the outpatient clinics of the three participating sites and randomised to undergo a screening trial prior to SCS implant or an implantation-only strategy in a 1:1 ratio. Allocation will be stratified by centre and minimised on patient age (≥ 65 or < 65 years), gender, presence of failed back surgery syndrome (or not) and use of high frequency (HF10™) (or not). The primary outcome measure is the numerical rating scale (NRS) at 6 months compared between the screening trial and implantation strategy and the implantation-only strategy. Secondary outcome measures will include diagnostic accuracy, the proportion of patients achieving at least 50% and 30% pain relief at 6 months as measured on the NRS, health-related quality-of-life (EQ-5D), function (Oswestry Disability Index), patient satisfaction (Patients’ Global Impression of Change) and complication rates. A nested qualitative study will be carried out in parallel for a total of 30 of the patients recruited in each centre (10 at each centre) to explore their views of the screening trial, implantation and overall use of the SCS device. The economic evaluation will take the form of a cost–utility analysis. Discussion The TRIAL-STIM Study is a randomised controlled trial with a nested qualitative study and economic evaluation aiming to determine the clinical utility of screening trials of SCS as well as their cost-effectiveness. The nested qualitative study will seek to explore the patient’s view of the screening trials, implantation and overall use of SCS. Trial registration ISRCTN, ISRCTN60778781. Registered on 15 August 2017
Profile of the capsaicin 8% patch for the management of neuropathic pain associated with postherpetic neuralgia: safety, efficacy, and patient acceptability
Muhammad Laklouk,1 Ganesan Baranidharan2 1Department of Anaesthesia, Bradford Teaching Hospitals NHS Foundation Trust, 2Leeds Pain and Neuromodulation Centre, Leeds Teaching Hospitals NHS Trust, Seacroft Hospital, Leeds, UK Abstract: Capsaicin is a naturally occurring irritant active ingredient found in hot peppers. It is a ligand for transient receptor potential channel vanilloid receptors, which are found in nociceptive nerve terminals in the skin. Initial exposure to topical capsaicin leads to excitation of these receptors, release of vasoactive mediators, erythema, intense burning, pain, and thereafter desensitization of sensory neurons resulting in inhibition of pain transmission. Capsaicin 8% has been licensed for the treatment of postherpetic neuralgia pain in recent years. A single application of high-concentration capsaicin for 60 minutes for postherpetic neuralgia has been robustly evaluated. Capsaicin 8% patches are applied to the most painful areas of healthy skin and allowed to remain for 60 minutes. Treatment can be repeated every 90 days if the pain persists or returns. The patches are usually applied in specialist pain clinics where patients can be pretreated and monitored. Health care staff need to take certain precautions before administering these patches to avoid unintentional contact. Common adverse effects of the capsaicin 8% patch are transient mild-to-moderate self-limiting application-site burning, pain, erythema, pruritus, papules, swelling, dryness, and hypertension. To manage local pain from capsaicin application, the skin is pretreated with a local anesthetic such as topical lidocaine or an oral analgesic such as oxycodone for up to 5 days. A transient increase in pain is usually seen within 48 hours of patch application before the pain-relieving effect starts. Systemic absorption is minimal and clinically insignificant. The nature of administration and relatively high cost of capsaicin patches can significantly limit their use to a small number of patients with severe refractory symptoms. This review highlights recent evidence related to the use and effectiveness of the 8% capsaicin patch for Postherpetic Neuralgia and discusses its safety and side-effect profiles. Keywords: capsaicin, efficacy, safety, tolerability, high-dose patch, postherpetic neuralgi
Analysis of the effects of amino acid sequence on the structure of proteins
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