464 research outputs found
Adjustment formulae to improve the correlation of white-to-white measurement with direct measurement of the ciliary sulcus diameter by ultrasound biomicroscopy
Purpose: This study evaluates the correlation between horizontal white-to-white (WTW) distance using Caliper and Orbscan IIz with the ciliary sulcus diameter measured by high frequency ultrasound biomicroscopy (UBM) and presents an adjustment formula to improve the correlation. Methods: We measured horizontal sulcus-to-sulcus (STS) dimension of 273 right eyes of 273 high myopic patients with 35 MHz UBM and horizontal WTW using Orbscan IIz and Caliper. Mean WTW diameter, differences, and the correlation of measurement methods were evaluated. Results: The mean spherical equivalent was �8.79 ± 4.87 diopters. Mean horizontal STS dimension with UBM was 12.13 ± 0.45 mm (range, 10.81�13.42 mm). Mean WTW diameter in the Caliper method was 11.70 ± 0.40 mm (range, 10.6�12.8 mm) and 11.70 ± 0.40 mm (range, 10.5�13.1 mm) in the Orbscan method. Mean difference of UBM STS and WTW with Caliper was 0.48 ± 0.28 mm (range, �0.19 to 1.37 mm). Mean difference of UBM STS diameter and Orbscan WTW was 0.38 ± 0.31 mm (range, �0.64 to 1.29 mm). The Pearson correlations of WTW diameter measured by Caliper and Orbscan with UBM's STS diameter were 0.778 and 0.773, respectively. This difference diminished after adjustment. The 95 limit of agreement was almost the same in Caliper and Orbscan (�0.07 to 1.03 compared with �0.23 to 0.99). Conclusion: There is a significant difference in measurements between STS diameter using UBM and WTW diameter utilizing Caliper and Orbscan. This difference diminished after our recommended adjustment. © 2017 Iranian Society of Ophthalmolog
New instrumentation technologies for testing the bonding of sensors to solid materials
This report presents the results of a comprehensive research and development project that was conducted over a three-year period to develop new technologies for testing the attachment of sensors to solid materials for the following NASA applications: (1) testing the performance of composites that are used for the lining of solid rocket motor nozzles, (2) testing the bonding of surface-mounted platinum resistance thermometers that are used on fuel and oxidizer lines of the space shuttle to detect valve leaks by monitoring temperature, (3) testing the attachment of strain gages that are used in testing the performance of space shuttle main engines, and (4) testing the thermocouples that are used for determining the performance of blast tube liner material in solid rocket boosters
Solving boundary value problems via the Nyström method using spline Gauss rules
We propose to use spline Gauss quadrature rules for solving boundary value problems (BVPs) using the Nyström method. When solving BVPs, one converts the corresponding partial differential equation inside a domain into the Fredholm integral equation of the second kind on the boundary in the sense of boundary integral equation (BIE). The Fredholm integral equation is then solved using the Nyström method, which involves the use of a particular quadrature rule, thus, converting the BIE problem to a linear system. We demonstrate this concept on the 2D Laplace problem over domains with smooth boundary as well as domains containing corners. We validate our approach on benchmark examples and the results indicate that, for a fixed number of quadrature points (i.e., the same computational effort), the spline Gauss quadratures return an approximation that is by one to two orders of magnitude more accurate compared to the solution obtained by traditional polynomial Gauss counterparts
Solving Boundary Value Problems Via the Nyström Method Using Spline Gauss Rules
We propose to use spline Gauss quadrature rules for solving boundary value problems (BVPs) using the Nyström method. When solving BVPs, one converts the corresponding partial differential equation inside a domain into the Fredholm integral equation of the second kind on the boundary in the sense of boundary integral equation (BIE). The Fredholm integral equation is then solved using the Nyström method, which involves a use of a particular quadrature rule, thus, converting the BIE problem to a linear system. We demonstrate this concept on the 2D Laplace problem over domains with smooth boundary as well as domains containing corners. We validate our approach on benchmark examples and the results indicate that, for a fixed number of quadrature points (i.e., the same computational effort), the spline Gauss quadratures return an approximation that is by one to two orders of magnitude more accurate compared to the solution obtained by traditional polynomial Gauss counterparts
Inpatient opioid withdrawal management of street children and adolescents admitted to child and adolescent psychiatricward: A preliminary case series
Background: About 10 million children worldwide live or work on the street. International reports estimate the prevalence of substance use among street children to be between 25-90, which is who were referredntal disorders and high-risk behaviors. Objectives: The objective of this study was to report the outcomes of assisted withdrawal of opioid-dependent vulnerable children and adolescents who were referred to child and adolescent psychiatric ward of Ali Ebne Abitaleb hospital, an academic hospital in Zahedan city. Methods: Clinical chart abstractions were performed on a convenience sample of 40 serial opioid-dependent street children and adolescents (mean age: 11.14 ± 3.6 years) who were referred to child and adolescent psychiatric ward of Ali Ebne Abitaleb treatment and research center from November 2014 to May 2015. The demographic data, drug use history, comorbid physical and psychiatric conditions, symptomatology of opioid withdrawal syndrome, pharmacotherapiesandpsychosocial services, length of hospital stay, and any adverse events were extracted from the patients� files using a checklist developed by the authors. Results: Twenty-four (60) patients were male, and 16 (40) were female. The main drug used by all patients was opioids. Heroin Kerack (which has a street name of crystal in southeast Iran) was the most common (75) drug of use, followed by opium (10) and opium residue (7.5). None of the participants self-reported using injected drugs. The high rate of a lack of eligibility for guardianship was documented among parents (87.5) mainly due to their use of illegal drugs. Musculoskeletal pain and diarrhea were the most common withdrawal symptoms of the patients upon admission. The mean length of stay was 10.8 (± 7.30) days, and no significant adverse events were reported during the symptomatic treatment of opioid withdrawal syndrome. Conclusions: To our knowledge, this is the first study to report on the safety and feasibility of inpatient symptomatic pharmacological treatment for assisted withdrawal among opioid-dependent children and adolescents in Iran. More well-designed studies to investigate the long-term outcomes of opioid treatment among children are warranted. © 2016, Growth & Development Research Center
Mineral Intake and Cardiovascular Disease, Cancer, and All-Cause Mortality: Findings from the Golestan Cohort Study
Associations between mineral intake and mortality in non-Western countries have not been studied adequately. This study evaluated these associations in the Golestan Cohort Study, featuring a Middle Eastern population. The mineral intake was estimated from the baseline food frequency questionnaire, adjusted by using the nutrient density method, and divided into quintiles. We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the mortality. We analyzed 41,863 subjects with a mean age of 51.46 ± 8.73 years at the baseline. During 578,694 person-years of follow-up (median: 14.1 Years), 7217 deaths were recorded. Dietary calcium intake was inversely associated with the all-cause mortality (HRQ5 vs. Q1 = 0.91, 95%CI = 0.85–0.99). We observed significant associations between calcium (HRQ5 vs. Q1 = 0.82, 95% CI = 0.73–0.93), copper (HRQ5 vs. Q1 = 1.11, 95% CI = 0.99–1.26), and selenium intake (HRQ5 vs. Q1 = 1.14, 95% CI = 1.01–1.29) and CVD mortality. Dietary phosphorus (HRQ5 vs. Q1 = 0.81, 95%CI = 0.69–0.96) and copper intake (HRQ5 vs. Q1 = 0.84, 95%CI = 0.71–0.99) were inversely associated with cancer mortality. In this study within a Middle Eastern population, a higher dietary intake of calcium exhibited an inverse association with all-cause mortality. Furthermore, nuanced associations were observed in the cause-specific mortality, suggesting potential avenues for dietary interventions and emphasizing the importance of considering dietary factors in public health strategies
Incident cancers attributable to using opium and smoking cigarettes in the Golestan cohort study
Background: Opium consumption has recently been identified as a carcinogen, but the impact of opium use on cancer burden is unknown. We aimed to evaluate the fraction of cancers that could be attributed to opium use alone and in combination with cigarette smoking in a region where opium is widely used. Methods: 50,045 Iranian adults were recruited to this prospective cohort study between 2004 and 2008 and were followed through January 2022. We assessed the association between using opium and/or cigarette smoking and various cancers using proportional hazards regression models. We then calculated population attributable fractions (PAFs) for all cancers and for groups of cancers causally linked to opium and cigarette smoking. Findings: Of the total participants, 8% only used opium, 8.3% only smoked cigarettes, and 9% used both substances. During a median 14 years of follow-up, 2195 individuals were diagnosed with cancer, including 215 opium-related cancers (lung, larynx, and bladder) and 1609 tobacco-related cancers (20 types). Opium use alone was estimated to cause 35% (95% CI: 26%–45%) of opium-related cancers, while smoking cigarettes alone was estimated to cause 9% (6%–12%) of tobacco-related cancers in this population. Using opium and/or cigarettes was estimated to cause 13% (9%–16%) of all cancers, 58% (49%–66%) of opium-related cancers, and 15% (11%–18%) of tobacco-related cancers. Moreover, joint exposure to opium and cigarettes had the greatest impact on cancers of the larynx, pharynx, lung, and bladder, with PAFs ranging from 50% to 77%. Interpretation: Using opium and smoking cigarettes account for a large proportion of cancers in this population. To reduce the cancer burden, prevention policies should aim to decrease the use of both substances through public awareness campaigns and interventional efforts. Funding: The Golestan Cohort Study work was funded by the Tehran University of Medical Sciences, Cancer Research UK, U.S. National Cancer Institute, International Agency for Research on Cancer. The presented analysis was supported by the International HundredK+ Cohorts Consortium (IHCC)
One-carbon metabolism biomarkers and upper gastrointestinal cancer in the Golestan Cohort Study
Incidence of esophageal and gastric cancer has been linked to low B-vitamin status. We conducted matched nested case–control studies of incident esophageal squamous cell carcinoma (ESCC; 340 case–control pairs) and gastric cancer (GC; 352 case–control pairs) within the Golestan Cohort Study. The primary exposure was plasma biomarkers: riboflavin and flavin mononucleotide (FMN) (vitamin B2), pyridoxal phosphate (PLP) (B6), cobalamin (B12), para-aminobenzoylglutamate (pABG) (folate), and total homocysteine (tHcy); and indicators for deficiency: 3-hydroxykyurenine-ratio (HK-r for vitamin B6) and methylmalonic acid (MMA for B12). We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression adjusting for matching factors and potential confounders. High proportions of participants had low B-vitamin and high tHcy levels. None of the measured vitamin B levels was associated with the risk of ESCC and GC, but elevated level of MMA was marginally associated with ESCC (OR = 1.42, 95% CI = 0.99–2.04) and associated with GC (OR = 1.53, 95% CI = 1.05–2.22). Risk of GC was higher for the highest versus lowest quartile of HK-r (OR = 1.95, 95%CI = 1.19–3.21) and for elevated versus non-elevated HK-r level (OR = 1.59, 95% CI = 1.13–2.25). Risk of ESCC (OR = 2.81, 95% CI = 1.54–5.13) and gastric cancer (OR = 2.09, 95%CI = 1.17–3.73) was higher for the highest versus lowest quartile of tHcy. In conclusion, insufficient vitamin B12 was associated with higher risk of ESCC and GC, and insufficient vitamin B6 status was associated with higher risk of GC in this population with prevalent low plasma B-vitamin status. Higher level of tHcy, a global indicator of OCM function, was associated with higher risk of ESCC and GC
Customized clinical practice guidelines for management of adult cataract in Iran
Purpose: To customize clinical practice guidelines (CPGs) for cataract management in the Iranian population. Methods: First, four CPGs (American Academy of Ophthalmology 2006 and 2011, Royal College of Ophthalmologists 2010, and Canadian Ophthalmological Society 2008) were selected from a number of available CPGs in the literature for cataract management. All recommendations of these guidelines, together with their references, were studied. Each recommendation was summarized in 4 tables. The first table showed the recommendation itself in clinical question components format along with its level of evidence. The second table contained structured abstracts of supporting articles related to the clinical question with their levels of evidence. The third table included the customized recommendation of the internal group respecting its clinical advantage, cost, and complications. In the fourth table, the internal group their recommendations from 1 to 9 based on the customizing capability of the recommendation (applicability, acceptability, external validity). Finally, customized recommendations were sent one month prior to a consensus session to faculty members of all universities across the country asking for their comments on recommendations. Results: The agreed recommendations were accepted as conclusive while those with no agreement were discussed at the consensus session. Finally, all customized recommendations were codified as 80 recommendations along with their sources and levels of evidence for the Iranian population. Conclusion: Customization of CPGs for management of adult cataract for the Iranian population seems to be useful for standardization of referral, diagnosis and treatment of patients. © 2015 Journal of Ophthalmic and Vision Research | Published by Wolters Kluwer - Medknow
Synthesis, characterization, and biological evaluation of N-methyl derivatives of norbelladine
Abstract
Norbelladine derivatives have garnered attention in recent years due to their diverse biological activities and pivotal role in the biosynthetic pathway of Amaryllidaceae alkaloids. This study reports the synthesis and biological evaluation of four O,N-methylated derivatives of norbelladine. These derivatives were synthesized through a three-step process: forming imine intermediates from benzaldehydes with tyramine, hydrogenating them to secondary amines, and N-methylating these amines. The products were purified and characterized by 1H and 13C NMR spectroscopy. Their biological activities were assessed by evaluating their ability to inhibit Alzheimer’s disease-related enzymes acetylcholinesterase and butyrylcholinesterase. Additionally, the cytotoxic activity of the novel derivatives was tested against cancer cell lines derived from hepatocarcinoma (Huh7), adenocarcinoma (HCT-8), and acute myeloid leukemia (THP-1) cells, and their antiviral properties against a human coronavirus (HCoV-OC43), a flavivirus (dengue virus), and a lentivirus (pseudotyped HIV-1). Docking analysis was performed to understand the impact of the N-methylation on their pharmacological relevance. The results indicate that while N-methylation does not significantly affect antiviral activity, it enhances butyrylcholinesterase inhibition for N-methylnorbelladine and 4′-O,N-dimethylnorbelladine. Overall, this work enhances our understanding of norbelladine derivatives, provides new tools for Alzheimer’s disease research, and lays the groundwork for future pharmaceutical developments
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