Competing risks for reliability analysis using Cox’s model

Purpose – Cox’s model with Weibull distribution and Cox’s with exponential distribution are the most important models in reliability analysis. This paper seeks to show that, with a large sample size based on expectation maximization (EM) algorithm, both models give similar results. Design/methodology/approach – The parameters of the models have been estimated by method of maximum likelihood based on EM algorithm. The objective of this analysis is to fit the modification of Cox’s model with Weibull distribution and Cox’s with exponential distribution, examine its performance and compare their results with Crowder et al. Findings – A simulation study indicates that the parametric Cox’s model with Weibull distribution gives similar results to Cox’s with exponential distribution, especially for a large sample size. Also, the modification of the two models showed better results compared with Crowder et al., especially for the second causes of failure. Originality/value – A modification of the two competing risk models has mostly been applied in failure time data and simulation data. The results of the simulation study indicate that the Weibull and exponential are suitable for Cox’s model as they are easy to use and it can achieve even higher accuracy compared with other distribution models

A NEW METHOD FOR THE DETERMINATION OF TOXIC DYE USING FTIR SPECTROSCOPY

A new method was developed to determine toxic dyes content in textile and other products using Fourier Transform Infrared (FTIR) spectroscopy with Attenuated Total Reflectance (ATR) element and KBr transmission cell. The wavelengths used were selected using pure dyes and dye mixtures. Transmittance values from the wavelengths regions 3500 – 2650 and 1675 – 1500 cm-1 and partial least square (PLS) regression method were used to derive FTIR spectroscopic calibration model for dyes containing –N=N– in their structure. The coefficient of determinations (R2) for the models were computed by comparing the results obtained from FTIR spectroscopy against the actual values of the dyes concentrations. R2 were 0.9321 and 0.9819 for two samples of toxic dyes respectively. The standard errors (SE) of calibrations were 1.84 and 1.36 respectively. The calibration model was cross validated within the same set of samples and the standard deviation (SD) of the difference for repeatability and accuracy of the FTIR method were determined. With its speed and ease of data manipulation, FTIR spectroscopy is a useful alternative method to wet chemical methods for rapid and routine detection of azo dyes as toxic dyes in such products for quality control

Follicular helper T cell profiles predict response to costimulation blockade in type 1 diabetes

Follicular helper T (TFH) cells are implicated in type 1 diabetes (T1D), and their development has been linked to CD28 costimulation. We tested whether TFH cells were decreased by costimulation blockade using the CTLA-4–immunoglobulin (Ig) fusion protein (abatacept) in a mouse model of diabetes and in individuals with new-onset T1D. Unbiased bioinformatics analysis identified that inducible costimulatory molecule (ICOS)+ TFH cells and other ICOS+ populations, including peripheral helper T cells, were highly sensitive to costimulation blockade. We used pretreatment TFH profiles to derive a model that could predict clinical response to abatacept in individuals with T1D. Using two independent approaches, we demonstrated that higher frequencies of ICOS+ TFH cells at baseline were associated with a poor clinical response following abatacept administration. Therefore, TFH analysis may represent a new stratification tool, permitting the identification of individuals most likely to benefit from costimulation blockade

Treatment-Based Strategy for the Management of Post-Kala-Azar Dermal Leishmaniasis Patients in the Sudan

Post-kala-azar dermal leishmaniasis (PKDL) is a dermatosis that affects more than 50% of successfully treated visceral leishmaniasis (VL) patients in Sudan. PKDL is considered an important reservoir for the parasite and its treatment may help in the control of VL. Currently, treatment is mainly with sodium stibogluconate (SSG), an expensive and fairly toxic drug and without universally in treatment protocols used. A literature review, a consensus of a panel of experts, and unpublished data formed the basis for the development of guidelines for the treatment of PKDL in the Sudan. Six treatment modalities were evaluated. Experts were asked to justify their choices based on their experience regarding of drug safety, efficacy, availability, and cost. The consensus was defined by assigning a categorical rank (first line, second line, third line) to each option. Regarding the use of AmBisome the presence of the drug in the skin was confirmed in smears from PKDL lesions. Recommendations: AmBisome at 2.5 mg/kg/day/20 days or SSG at 20 mg/kg/day/40 days plus four/weekly intradermal injection of alum-precipitated autoclave L. major vaccine are suggested as first-and second-treatment options for PKDL in the Sudan, respectively. SSG at 20 mg/Kg/day/60 or more days can be used if other options are not available

Multivariable regression analysis in Schistosoma mansoni-infected individuals in the Sudan reveals unique immunoepidemiological profiles in uninfected, egg+ and non-egg+ infected individuals

Background: In the Sudan, Schistosoma mansoni infections are a major cause of morbidity in schoolaged children and infection rates are associated with available clean water sources. During infection, immune responses pass through a Th1 followed by Th2 and Treg phases and patterns can relate to different stages of infection or immunity. Methodology: This retrospective study evaluated immunoepidemiological aspects in 234 individuals(range 4–85 years old) from Kassala and Khartoum states in 2011. Systemic immune profiles(cytokines and immunoglobulins) and epidemiological parameters were surveyed in n = 110 persons presenting patent S. mansoni infections (egg+), n = 63 individuals positive for S. mansoni via PCR in sera but egg negative (SmPCR+) and n = 61 people who were infection-free (Sm uninf). Immunoepidemiological findings were further investigated using two binary multivariable regression analysis. Principal Findings: Nearly all egg+ individuals had no access to latrines and over 90% obtained water via the canal stemming from the Atbara River. With regards to age, infection and an egg+ status was linked to young and adolescent groups. In terms of immunology, S. mansoni infection per se was strongly associated with increased SEA-specific IgG4 but not IgE levels. IL-6, IL-13 and IL-10 were significantly elevated in patently-infected individuals and positively correlated with egg load. In contrast, IL-2 and IL-1β were significantly lower in SmPCR+ individuals when compared to Sm uninf and egg+ groups which was further confirmed during multivariate regression analysis. Conclusions/Significance: Schistosomiasis remains an important public health problem in the Sudan with a high number of patent individuals. In addition, SmPCR diagnostics revealed another cohort of infected individuals with a unique immunological profile and provides an avenue for future studies on non-patent infection states. Future studies should investigate the downstream signalling pathways/mechanisms of IL-2 and IL-1β as potential diagnostic markers in order to distinguish patent from non-patent individuals

A new method for the determination of toxic dye using FTIR spectroscopy

A new method was developed to determine toxic dyes content in textile and other products using Fourier Transform Infrared (FTIR) spectroscopy with Attenuated Total Reflectance (ATR) element and KBr transmission cell. The wavelengths used were selected using pure dyes and dye mixtures. Transmittance values from the wavelengths regions 3500 – 2650 and 1675 – 1500 cm-1 and partial least square (PLS) regression method were used to derive FTIR spectroscopic calibration model for dyes containing –N=N– in their structure. The coefficient of determinations (R2) for the models were computed by comparing the results obtained from FTIR spectroscopy against the actual values of the dyes concentrations. R2 were 0.9321 and 0.9819 for two samples of toxic dyes respectively. The standard errors (SE) of calibrations were 1.84 and 1.36 respectively. The calibration model was cross validated within the same set of samples and the standard deviation (SD) of the difference for repeatability and accuracy of the FTIR method were determined. With its speed and ease of data manipulation, FTIR spectroscopy is a useful alternative method to wet chemical methods for rapid and routine detection of azo dyes as toxic dyes in such products for quality control

Psychological Resilience, Anxiety, and Well-Being of Health Care Providers During the COVID-19 Pandemic

Amani M AlQarni,1 Abdelaziz Elfaki,2 Moataza M Abdel Wahab,1 Yasser Aljehani,3 Auday A ALKhunaizi,4 Sharifah A Othman,5 Reem A AlShamlan2 1Family and Community Medicine Department, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 2Psychiatry Department, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 3Department of Surgery, King Fahd Hospital of the University, Imam Abdulrahman bin Faisal University, Dammam, Saudi Arabia; 4Emergency Department, Qatif Central Hospital, Qatif, Saudi Arabia; 5Obstetrics and Gynaecology Department, King Fahd Hospital of the University, Dammam, Saudi ArabiaCorrespondence: Reem A AlShamlan; Amani M AlQarni, Tel +966536353448 ; +966591775751, Email [email protected]; [email protected]: On the frontlines of the pandemic, healthcare providers (HCPs) are overworked, anxious, and fearful. Yet, despite all the fear and anxiety, the facilitation of protective resilience and psychological well-being has become crucial to ensure that minimal intangible psychological losses are incurred due to the pandemic.Aim: The present study aimed to examine the psychological resiliency, state anxiety, trait anxiety, and psychological well-being of frontline HCPs during the COVID-19 and to determine the association among resiliency, state-trait anxiety, and psychological well-being and their links with demographic and workplace factors.Design and Settings: A cross-sectional study concerning frontline HCPs was conducted at two of the largest hospitals in the eastern province of Saudi Arabia.Results: A significant inverse correlation was determined between resilience and state anxiety (r=− 0.417, p< 0.05) and between resilience and trait anxiety (r=− 0.536, p< 0.05). Likewise, a positive intermediate correlation between resilience and the age of the individual (r=0.263, p< 0.05) and a weak positive correlation with years of experience (r=0.211, p< 0.05) were established. Also, the resilience score of volunteer workers (50.9) was lower than that of regular staff (66.8) (p=0.028).Conclusion: Resilience is a crucial factor affecting the training of individuals, which will further promote their work output and mental health capacity, thus improving their overall concept of survival in adversity.Keywords: psychological distress, anxiety, resilience, well-being, COVID-19 pandemic, health care provider