Security Threats Classification in Blockchains

Blockchain, the foundation of Bitcoin, has become one of the most popular technologies to create and manage digital transactions recently. It serves as an immutable ledger which allows transactions take place in a decentralized manner. This expeditiously evolving technology has the potential to lead to a shift in thinking about digital transactions in multiple sectors including, Internet of Things, healthcare, energy, supply chain, manufacturing, cybersecurity and principally financial services. However, this emerging technology is still in its infancy. Despite the huge opportunities blockchain offers, it suffers from challenges and limitation such as scalability, security, and privacy, compliance, and governance issues that have not yet been thoroughly explored and addressed. Although there are some studies on the security and privacy issues of the blockchain, they lack a systematic examination of the security of blockchain systems. This research conducted a systematic survey of the security threats to the blockchain systems and reviewed the existing vulnerabilities in the Blockchain. These vulnerabilities lead to the execution of the various security threats to the normal functionality of the Blockchain platforms. Moreover, the study provides a case-study for each attack by examining the popular blockchain systems and also reviews possible countermeasures which could be used in the development of various blockchain systems. Furthermore, this study developed taxonomies that classified the security threats and attacks based on the blockchain abstract layers, blockchain primary processes and primary business users. This would assist the developers and businesses to be attentive to the existing threats in different areas of the blockchain-based platforms and plan accordingly to mitigate risk. Finally, summarized the critical open challenges, and suggest future research directions

Growth, Yield and Fruit Quality of Strawberry (Frageria ananasa Dutch) under Different Phosphorus Levels

Strawberry fruit takes less time for production and is easily multiplied. Fruiting is an exhaustive process and depletes nutrients especially phosphorus as it is highly immobile in the soil. An experiment was conducted in The University of Peshawar, Pakistan to evaluate different level of Phosphorous on growth, yield and fruit quality of Strawberry Cv Chandler. Results show that Phosphorus at 90 kg ha-1 significantly influenced the days to flowering (102.66) of strawberry plants while, at 80 kg ha-1 significantly affected days to fruit set (2.98), days to fruit maturity (20.05), Number of fruits (7.50) and Total fruit yield tons ha-1(3.61). Fruit size (6.42 cm3) was significantly affected at 70 kg ha-1. Similarly, Ascorbic acid (62.61), percent acidity (0.64) and Total soluble solids (7.83) were significantly affected by phosphorus at 60 kg ha-

Esophageal cooling for protection during left atrial ablation : a systematic review and meta-analysis

Thermal damage to the esophagus is a risk from radiofrequency (RF) ablation of the left atrium for the treatment of atrial fibrillation (AF). The most extreme type of thermal injury results in atrio-esophageal fistula (AEF) and a correspondingly high mortality rate. Various strategies for reducing esophageal injury have been developed, including power reduction, esophageal deviation, and esophageal cooling. One method of esophageal cooling involves the direct instillation of cold water or saline into the esophagus during RF ablation. Although this method provides limited heat-extraction capacity, studies of it have suggested potential benefit. We sought to perform a meta-analysis of published studies evaluating the use of esophageal cooling via direct liquid instillation for the reduction of thermal injury during RF ablation. We searched PubMed for studies that used esophageal cooling to protect the esophagus from thermal injury during RF ablation. We then performed a meta-analysis using a random effects model to calculate estimated effect size with 95% confidence intervals, with an outcome of esophageal lesions stratified by severity, as determined by post-procedure endoscopy. A total of 9 studies were identified and reviewed. After excluding preclinical and mathematical model studies, 3 were included in the meta-analysis, totaling 494 patients. Esophageal cooling showed a tendency to shift lesion severity downward, such that total lesions did not show a statistically significant change (OR 0.6, 95% CI 0.15 to 2.38). For high-grade lesions, a significant OR of 0.39 (95% CI 0.17 to 0.89) in favor of esophageal cooling was found, suggesting that esophageal cooling, even with a low-capacity thermal extraction technique, reduces the severity of lesions resulting from RF ablation. Esophageal cooling reduces the severity of the lesions that may result from RF ablation, even when relatively low heat extraction methods are used, such as the direct instillation of small volumes of cold liquid. Further investigation of this approach is warranted, particularly with higher heat extraction capacity techniques

Developmental Comparison of Ceramide in Wild-Type and Cln3Δex7/8 Mouse Brains and Sera

CLN3 disease is a neurodevelopmental disease leading to early visual failure, motor decline, and death. CLN3 pathogenesis has been linked to dysregulation of ceramide, a key intracellular messenger impacting various biological functions. Ceramide is upregulated in brains of CLN3 patients and activates apoptosis. Ceramide levels over the lifespan of WT and Cln3Δex7/8 mice were measured using the DGK assay. Ceramide subspecies were determined by LC-MS. Ceramide synthesis enzymes and pre- and post-synaptic mRNA expression was measured in Cln3Δex7/8 and normal mouse brains. Neuronal cell death was established by PARP cleavage and Caspases 3/6/9 and cytochrome C mRNA expression in Cln3Δex7/8 and normal mouse brains. In WT mouse, a ceramide peak was noted at 3 weeks of age. The absence of this peak in Cln3Δex7/8 mice might be related to early disease pathogenesis. Increase of ceramide in Cln3Δex7/8 mouse brain at 24 weeks of age precedes neuronal apoptosis. The correlation between serum and brain ceramide in WT mice, and dysregulation of ceramide in serum and brain of Cln3Δex7/8 mice, and the significant increase in ceramide in Cln3Δex7/8 mouse brains and sera argue for use of easily accessible serum ceramide levels to track response to novel therapies in human CLN3 disease

Budesonide orodispersible tablets for induction of remission in patients with active eosinophilic oesophagitis: A 6-week open-label trial of the EOS-2 Programme

BACKGROUND A novel budesonide orodispersible tablet (BOT) has been proven effective in adult patients with active eosinophilic oesophagitis (EoE) in a 6-week placebo-controlled trial (EOS-1). AIMS To report the efficacy of an open-label induction treatment with BOT in a large prospective cohort of EoE patients within the EOS-2 study. METHODS Patients with clinico-histological active EoE were treated with BOT 1 mg BID for 6 weeks. The primary endpoint was clinico-histological remission (≤2 points on numerical rating scales [0-10] each for dysphagia and odynophagia, and peak eosinophil count <16 eos/mm$^{2}$ hpf (corresponds to <5 eos/hpf)). Further study endpoints included clinical and histological remission rates, change in the EEsAI-PRO score, change in peak eosinophil counts, and deep endoscopic remission using a modified Endoscopic Reference Score. RESULTS Among 181 patients enrolled, 126 (69.6%) achieved clinico-histological remission (histological remission 90.1%, clinical remission 75.1%). The mean peak eosinophil counts decreased by 283 eos/mm$^{2}$ hpf (i.e., by 89.0%). Mean EEsAI-PRO score decreased from baseline by 29 points and deep endoscopic remission was achieved in 97 (53.6%) patients. The majority of patients judged tolerability as good or very good (85.6%) and compliance was high (96.5%). Local candidiasis was suspected in 8.3% of patients; all were of mild severity, resolved with treatment and none led to premature withdrawal from the study. CONCLUSIONS In this large prospective trial, a 6-week open-label treatment with BOT 1 mg BID was highly effective and safe in achieving clinico-histological remission of active EoE and confirmed the results of the placebo-controlled EOS-1 trial

Biallelic variants in CHST3 cause Spondyloepiphyseal dysplasia with joint dislocations in three Pakistani kindreds

Background Skeletal dysplasia is a heterogeneous group of disorders. Spondyloepiphyseal dysplasias comprise one subgroup. Deficiency of carbohydrate sulfotransferase 3 has been reported in a small number of patients with recessively inherited spondyloepiphyseal dysplasia with joint dislocation, short stature and scoliosis. We report here molecular and clinical findings of affected individuals in three consanguineous Pakistani families. Affected individuals in all three families had a uniform phenotype including severe short stature, multiple dislocated joints, progressive scoliosis and facial dysmorphism. Methods Clinical evaluation was done for three unrelated families. Radiological survey of bones was completed for patients from two of the families. Whole exome sequencing index patients from each family was performed followed by Sanger sequencing for validation of segregation of identified variants in respective families. In-silico analysis for determining pathogenicity of identified variants and conservation was done. Results Whole-exome sequencing revealed biallelic variants c.590 T > C;p.(Leu197Pro), c.603C > A;p.(Tyr201Ter) and c.661C > T;p.(Arg221Cys) in CHST3 (NM_004273.5) in the three families with eight, five and two affected individuals, respectively. Contrary to previous reports, affected individuals in none of the families exhibited a hearing loss. Conclusion We describe genotypic and phenotypic findings of three unrelated families with spondyloepiphyseal dysplasia. Our study confirms phenotypic variability and adds to the genotypic spectrum of spondyloepiphyseal dysplasia.Peer reviewe

Esophageal cooling for protection during left atrial ablation: a systematic review and meta-analysis.

PURPOSE: Thermal damage to the esophagus is a risk from radiofrequency (RF) ablation of the left atrium for the treatment of atrial fibrillation (AF). The most extreme type of thermal injury results in atrio-esophageal fistula (AEF) and a correspondingly high mortality rate. Various strategies for reducing esophageal injury have been developed, including power reduction, esophageal deviation, and esophageal cooling. One method of esophageal cooling involves the direct instillation of cold water or saline into the esophagus during RF ablation. Although this method provides limited heat-extraction capacity, studies of it have suggested potential benefit. We sought to perform a meta-analysis of published studies evaluating the use of esophageal cooling via direct liquid instillation for the reduction of thermal injury during RF ablation. METHODS: We searched PubMed for studies that used esophageal cooling to protect the esophagus from thermal injury during RF ablation. We then performed a meta-analysis using a random effects model to calculate estimated effect size with 95% confidence intervals, with an outcome of esophageal lesions stratified by severity, as determined by post-procedure endoscopy. RESULTS: A total of 9 studies were identified and reviewed. After excluding preclinical and mathematical model studies, 3 were included in the meta-analysis, totaling 494 patients. Esophageal cooling showed a tendency to shift lesion severity downward, such that total lesions did not show a statistically significant change (OR 0.6, 95% CI 0.15 to 2.38). For high-grade lesions, a significant OR of 0.39 (95% CI 0.17 to 0.89) in favor of esophageal cooling was found, suggesting that esophageal cooling, even with a low-capacity thermal extraction technique, reduces the severity of lesions resulting from RF ablation. CONCLUSIONS: Esophageal cooling reduces the severity of the lesions that may result from RF ablation, even when relatively low heat extraction methods are used, such as the direct instillation of small volumes of cold liquid. Further investigation of this approach is warranted, particularly with higher heat extraction capacity techniques

Budesonide orodispersible tablets maintain remission in a randomized, placebo-controlled trial of patients with eosinophilic esophagitis

Background & Aims: Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder. Swallowed topical-acting corticosteroids are effective in bringing active EoE into remission. However, it is not clear whether these drugs are effective for long-term maintenance of remission. Methods: We performed a double-blind trial to compare the efficacy and safety of 2 dosages of a budesonide orodispersible tablet (BOT) vs placebo in maintaining remission of EoE. Maintenance of remission was defined as absence of clinical and histologic relapse and no premature withdrawal for any reason. Two hundred and four adults with EoE in clinical and histologic remission, from 29 European study sites, were randomly assigned to groups given BOT 0.5 mg twice daily (n = 68), BOT 1.0 mg twice daily (n = 68), or placebo twice daily (n = 68) for up to 48 weeks. Results: At end of treatment, 73.5% of patients receiving BOT 0.5 mg twice daily and 75% receiving BOT 1.0 mg twice daily were in persistent remission compared with 4.4% of patients in the placebo group (P < .001 for both comparisons of BOT with placebo). Median time to relapse in the placebo group was 87 days. The frequency of adverse events was similar in the BOT and placebo groups. Morning serum levels of cortisol were in the normal range at baseline and did not significantly change during treatment. Four patients receiving BOT developed asymptomatic, low serum levels of cortisol. Clinically manifested candidiasis was suspected in 16.2% of patients in the BOT 0.5 mg group and in 11.8% of patients in the BOT 1.0 mg group; all infections resolved with treatment. Conclusions: In a phase 3 trial, up to 48 weeks of treatment with BOT (0.5 mg or 1.0 mg twice daily) was superior to placebo in maintaining remission of EoE. Both dosages were equally effective and well tolerated. EudraCT number; 2014-001485-99; ClinicalTrials.gov number, NCT02434029

Effect of dental trauma management resources on dental practitioners' confidence and knowledge: A pilot cross-sectional study

Background/Aim: The knowledge of standardized care guidelines is critical to the confidence of practitioners in managing dental trauma. Therefore, the aim of this study was to assess the awareness, use and impact of the International Association of Dental Traumatology guidelines, and the online Dental Trauma Guide on general dental practitioners' self-reported confidence and knowledge in managing traumatic dental injuries in the primary and permanent dentitions. Materials and Methods: A cross-sectional, pre-piloted, 27-item self-administered questionnaire survey was distributed electronically to general dental practitioners' working within five member states of the Gulf Cooperation Council countries (Kingdom of Bahrain, Kingdom of Saudi Arabia, Kuwait, Oman, and Qatar) between September and December 2020. Data were collected and analysed using descriptive statistics and Wilcoxon Signed Rank test analysis for relevant comparisons. Results: A total of 294 respondents completed the survey, with the majority being from the Kingdom of Saudi Arabia (47.4%) and Qatar (27.3%). A lack of evidence-based knowledge in managing traumatic dental injuries was evident among more than half of the respondents. Respondents who were cognizant of the recent International Association of Dental Traumatology guidelines (2020) and those who use the Dental Trauma Guide routinely demonstrated a higher self-reported confidence level in managing both simple and complex primary dentition trauma, as well as simple traumatic dental injuries in the permanent dentition (p <.05). Conclusion: This survey highlights critical deficiencies in the knowledge of a large number of the respondents in the management of dental trauma which is likely to cause irreversible long-term patient effects.Open Access funding provided by the Qatar National Library