438 research outputs found
Recurrence of intestinal metaplasia and early neoplasia after endoscopic eradication therapy for Barrett’s esophagus: A systematic review and meta-analysis
Abstract
Background Conflicting data exist with regard to recurrence rates of intestinal metaplasia (IM) and dysplasia after achieving complete eradication of intestinal metaplasia (CE-IM) in Barrett’s esophagus (BE) patients.
Aim (i) To determine the incidence of recurrent IM and dysplasia achieving CE-IM and (ii) to compare recurrence rates between treatment modalities [radiofrequency ablation (RFA) with or without endoscopic mucosal resection (EMR) vs stepwise complete EMR (SRER)].
Methods A systematic search was performed for studies reporting on outcomes and estimates of recurrence rates after achieving CE-IM. Pooled incidence [per 100-patient-years (PY)] and risk ratios with 95 %CI were obtained. Heterogeneity was measured using the I
2 statistic. Subgroup analyses, decided a priori, were performed to explore heterogeneity in results.
Results A total of 39 studies were identified (25-RFA, 13-SRER, and 2 combined). The pooled incidence of any recurrence was 7.5 (95 %CI 6.1 – 9.0)/100 PY with a pooled incidence of IM recurrence rate of 4.8 (95 %CI 3.8 – 5.9)/100 PY, and dysplasia recurrence rate of 2.0 (95 %CI 1.5 – 2.5)/100 PY. Compared to the SRER group, the RFA group had significantly higher overall [8.6 (6.7 – 10.5)/100 PY vs. 5.1 (3.1 – 7)/100 PY, P = 0.01] and IM recurrence rates [5.8 (4.3 – 7.3)/100 PY vs. 3.1 (1.7 – 4)/100 PY, P < 0.01] with no difference in recurrence rates of dysplasia. Significant heterogeneity between studies was identified. The majority of recurrences were amenable to repeat endoscopic eradication therapy (EET).
Conclusion The results of this study demonstrate that the incidence rates of overall, IM, and dysplasia recurrence rates post-EET are not inconsiderable and reinforce the importance of close surveillance after achieving CE-IM.</jats:p
Population-based cross-sectional study of barriers to utilisation of refraction services in South India: Rapid Assessment of Refractive Errors (RARE) Study
AIM: To assess the barriers to the uptake of refraction services in the age group of 15-49 years in rural Andhra Pradesh, India. METHODS: A population-based cross-sectional study was conducted using cluster random sampling to enumerate 3300 individuals from 55 clusters. A validated questionnaire was used to elicit information on barriers to utilisation of services among individuals with uncorrected refractive error (presenting visual acuity 35 years with binocular distance visual acuity of ≥6/12). RESULTS: 3095 (94%) were available for examination. Those with uncorrected refractive errors cited affordability as the main barrier to the uptake of eye-care services. Among people with uncorrected presbyopia, lack of 'felt need' was the leading barrier. CONCLUSION: The barriers that were 'relatively easy to change' were reported by those with uncorrected refractive errors in contrast to 'difficult to change' barriers reported by those with uncorrected presbyopia. Together, the data on prevalence and an understanding of the barriers for the uptake of services are critical to the planning of refractive error services
Effect of Steric Constraint at the γ-Backbone Position on the Conformations and Hybridization Properties of PNAs
Conformationally preorganized peptide nucleic acids (PNAs) have been synthesized through backbone modifications at the γ-position, where R = alanine, valine, isoleucine, and phenylalanine side chains. The effects of these side-chains on the conformations and hybridization properties of PNAs were determined using a combination of CD and UV-Vis spectroscopic techniques. Our results show that the γ-position can accommodate varying degrees of sterically hindered side-chains, reaffirming the bimodal function of PNAs as the true hybrids of “peptides” and “nucleic acids.
Advancing cybersecurity and privacy with artificial intelligence: current trends and future research directions
IntroductionThe rapid escalation of cyber threats necessitates innovative strategies to enhance cybersecurity and privacy measures. Artificial Intelligence (AI) has emerged as a promising tool poised to enhance the effectiveness of cybersecurity strategies by offering advanced capabilities for intrusion detection, malware classification, and privacy preservation. However, this work addresses the significant lack of a comprehensive synthesis of AI's use in cybersecurity and privacy across the vast literature, aiming to identify existing gaps and guide further progress.MethodsThis study employs the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework for a comprehensive literature review, analyzing over 9,350 publications from 2004 to 2023. Utilizing BERTopic modeling, 14 key themes in AI-driven cybersecurity were identified. Topics were clustered and validated through a combination of algorithmic and expert-driven evaluations, focusing on semantic relationships and coherence scores.ResultsAI applications in cybersecurity are concentrated around intrusion detection, malware classification, federated learning in privacy, IoT security, UAV systems and DDoS mitigation. Emerging fields such as adversarial machine learning, blockchain and deep learning are gaining traction. Analysis reveals that AI's adaptability and scalability are critical for addressing evolving threats. Global trends indicate significant contributions from the US, India, UK, and China, highlighting geographical diversity in research priorities.DiscussionWhile AI enhances cybersecurity efficacy, challenges such as computational resource demands, adversarial vulnerabilities, and ethical concerns persist. More research in trustworthy AI, standardizing AI-driven methods, legislations for robust privacy protection amongst others is emphasized. The study also highlights key current and future areas of focus, including quantum machine learning, explainable AI, integrating humanized AI and deepfakes
A Prospective Multicenter Study Evaluating Learning Curves and Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography Among Advanced Endoscopy Trainees: The Rapid Assessment of Trainee Endoscopy Skills (RATES) Study
Background and aims
Based on the Next Accreditation System, trainee assessment should occur on a continuous basis with individualized feedback. We aimed to validate endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) learning curves among advanced endoscopy trainees (AETs) using a large national sample of training programs and to develop a centralized database that allows assessment of performance in relation to peers.
Methods
ASGE recognized training programs were invited to participate and AETs were graded on ERCP and EUS exams using a validated competency assessment tool that assesses technical and cognitive competence in a continuous fashion. Grading for each skill was done using a 4-point scoring system and a comprehensive data collection and reporting system was built to create learning curves using cumulative sum analysis. Individual results and benchmarking to peers were shared with AETs and trainers quarterly.
Results
Of the 62 programs invited, 20 programs and 22 AETs participated in this study. At the end of training, median number of EUS and ERCP performed/AET was 300 (range 155-650) and 350 (125-500). Overall, 3786 exams were graded (EUS:1137; ERCP–biliary 2280, pancreatic 369). Learning curves for individual endpoints, and overall technical/cognitive aspects in EUS and ERCP demonstrated substantial variability and were successfully shared with all programs. The majority of trainees achieved overall technical (EUS: 82%; ERCP: 60%) and cognitive (EUS: 76%; ERCP: 100%) competence at conclusion of training.
Conclusions
These results demonstrate the feasibility of establishing a centralized database to report individualized learning curves and confirm the substantial variability in time to achieve competence among AETs in EUS and ERCP
Oligomeric Hsp33 with enhanced chaperone activity
Hsp33, an Escherichia coli cytosolic chaperone, is inactive under normal conditions but becomes active upon oxidative stress. It was previously shown to dimerize upon activation in a concentration- and temperature-dependent manner. This dimer was thought to bind to aggregation-prone target proteins, preventing their aggregation. In the present study, we report small angle x-ray scattering (SAXS), steady state and time-resolved fluorescence, gel filtration, and glutaraldehyde cross-linking analysis of full-length Hsp33. Our circular dichroism and fluorescence results show that there are significant structural changes in oxidized Hsp33 at different temperatures. SAXS, gel filtration, and glutaraldehyde cross-linking results indicate, in addition to the dimers, the presence of oligomeric species. Oxidation in the presence of physiological salt concentration leads to significant increases in the oligomer population. Our results further show that under conditions that mimic the crowded milieu of the cytosol, oxidized Hsp33 exists predominantly as an oligomeric species. Interestingly, chaperone activity studies show that the oligomeric species is much more efficient compared with the dimers in preventing aggregation of target proteins. Taken together, these results indicate that in the cell, Hsp33 undergoes conformational and quaternary structural changes leading to the formation of oligomeric species in response to oxidative stress. Oligomeric Hsp33 thus might be physiologically relevant under oxidative stress
All-Male Groups in Asian Elephants: A Novel, Adaptive Social Strategy in Increasingly Anthropogenic Landscapes of Southern India
Male Asian elephants are known to adopt a high-risk high-gain foraging strategy by venturing into agricultural areas and feeding on nutritious crops in order to improve their reproductive fitness. We hypothesised that the high risks to survival posed by increasingly urbanising and often unpredictable production landscapes may necessitate the emergence of behavioural strategies that allow male elephants to persist in such landscapes. Using 1445 photographic records of 248 uniquely identified male Asian elephants over a 23-month period, we show that male Asian elephants display striking emergent behaviour, particularly the formation of stable, long-term all-male groups, typically in non-forested or human-modified and highly fragmented areas. They remained solitary or associated in mixed-sex groups, however, within forested habitats. These novel, large all-male associations, may constitute a unique life history strategy for male elephants in the high-risk but resource-rich production landscapes of southern India. This may be especially true for the adolescent males, which seemed to effectively improve their body condition by increasingly exploiting anthropogenic resources when in all-male groups. This observation further supports our hypothesis that such emergent behaviours are likely to constitute an adaptive strategy for male Asian elephants that may be forced to increasingly confront anthropogenically intrusive environments
Surgical versus non-surgical interventions in people with adolescent idiopathic scoliosis
BACKGROUND
Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine. While AIS can progress during growth and cause a surface deformity, it is usually not symptomatic. However, if the final spinal curvature surpasses a certain critical threshold, the risk of health problems and curve progression is increased. Interventions for the prevention of AIS progression include scoliosis-specific exercises, bracing, and surgery. The main aims of all types of interventions are to correct the deformity and prevent further deterioration of the curve and to restore trunk asymmetry and balance, while minimising morbidity and pain, allowing return to full function. Surgery is normally recommended for curvatures exceeding 40 to 50 degrees to stop curvature progression with a view to achieving better truncal balance and cosmesis. Short-term results of the surgical treatment of people with AIS demonstrate the ability of surgery to improve various outcome measures. However there is a clear paucity of information on long-term follow-up of surgical treatment of people with AIS.
OBJECTIVES
To examine the impact of surgical versus non-surgical interventions in people with AIS who have severe curves of over 45 degrees, with a focus on trunk balance, progression of scoliosis, cosmetic issues, quality of life, disability, psychological issues, back pain, and adverse effects, at both the short term (a few months) and the long term (over 20 years).
SEARCH METHODS
We searched the Cochrane Back Review Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, four other databases, and three trials registers up to August 2014 with no language limitations. We also checked the reference lists of relevant articles and conducted an extensive handsearch of the grey literature.
SELECTION CRITERIA
We searched for randomised controlled trials (RCTs) and prospective controlled trials comparing spinal fusion surgery with non-surgical interventions in people with AIS with a Cobb angle greater than 45 degrees. We were interested in all types of instrumented surgical interventions with fusion that aimed to provide curve correction and spine stabilisation.
DATA COLLECTION AND ANALYSIS
We found no RCTs or prospective controlled trials that met our inclusion criteria.
MAIN RESULTS
We did not identify any evidence comparing surgical to non-surgical interventions for AIS with severe curves of over 45 degrees.
AUTHORS' CONCLUSIONS
We cannot draw any conclusions
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Conformationally preorganized peptide nucleic acids (PNAs) have been synthesized through backbone modifications at the γ-position, where R = alanine, valine, isoleucine, and phenylalanine side chains. The effects of these side-chains on the conformations and hybridization properties of PNAs were determined using a combination of CD and UV-Vis spectroscopic techniques. Our results show that the γ-position can accommodate varying degrees of sterically hindered side-chains, reaffirming the bimodal function of PNAs as the true hybrids of "peptides" and "nucleic acids."
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