Recovery of Metal Values from Useless Printed Circuit Boards

This study provides a hydrometallurgical method to recover copper, lead, tin and gold from useless printed circuit boards. Metals in the board were leached with different mineral acids. Gold, if present, was first recovered by filtering from the acid solution, washed and polished. Metal salts went into the acidic leachant were separately recovered, washed and dried. These were thermally reduced using carbon to obtain reduced metals. The polymeric base material was found safe for feasible for reuse in the manufacture of new printed circuit boards. Parameters affecting the recovery factor were studied. Results obtained showed that nitric acid was more effective compared to sulfuric or hydrochloric acid. The extent of metals dissolution increases with increase in acid molarity, stoichiometric ratio, temperature and time of leaching. With sulfuric acid, copper dissolved in > 6 M solution at > 75 °C whereas lead and tin did not. With nitric acid, all metals dissolved on hot conditions whereby tin deposited upon cooling as basic oxide. Lead was separated from copper as chloride. Copper was separated as solid sulfide. The recovered compounds were reduced with hydrogen gas or by carbon at temperatures up to 1000 °C. A separation factor of 98.4-96.2% was achieved

Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences

The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics

The effect of thrombocytopenia in coronavirus disease patients in comparison with patients with normal platelet count

Background Known as severe acute respiratory syndrome coronavirus 2, the severe acute respiratory syndrome coronavirus is a new coronavirus illness [coronavirus disease-2019 (COVID-19)], it spreads quickly over the world. Patients with COVID-19 frequently have changes in platelet count. The platelet count is a highly useful clinical tool for tracking patients with aggressive viral infections who have rapidly changing health conditions since it is a sensitive indicator of sickness severity. Aim To study thrombocytopenia as a prognostic factor in COVID-19 patients and its relation with the length of hospital stay and prognosis. Patients and methods A total of 60 COVID-19 patients were involved in the prospective study during the period from June 2020 to December 2020 who were admitted to the isolation hospital, Ain Shams University Hospitals. Then for each patient, complete blood count at admission was done, repeated on day 7, day 14, and day 21. Patients were followed regarding the length of hospital stay and mortality. Results Out of 60 patients, 10 (16.6%) patients were thrombocytopenic. The length of hospital stay was significantly higher in a thrombocytopenic group. There was a high statistically significant difference between the normal platelets count group and the thrombocytopenic groups regarding outcome (P<0.001). In thrombocytopenic patients, five (50%) showed deterioration, four (40%) patients died and one patient in this group showed complete recovery. Conclusion Thrombocytopenia is associated with increased length of hospital stay and poor prognosis in patients with COVID-19

Assessment of peripheral blood lymphocyte subsets in children with iron deficiency anemia

Abstract Background Iron plays an important role in body defense and essential for normal immune system development where its deficiency may result in an inadequate immune response. We aimed to assess the lymphocyte subsets in childhood iron deficiency anemia (IDA) with their laboratory correlations. Methods Fifty IDA (< 18 years) and 25 age and sex-matched healthy children were enrolled and a complete history was obtained and clinical examination was performed. Complete blood count, serum iron, total iron binding capacity and serum ferritin, were performed. Flow cytometric determination of peripheral blood CD3+, CD4+, CD8+ T-lymphocytes and CD19+ B-lymphocytes and CD4/CD8 ratio were done. Results Patients had significantly lower hemoglobin, Serum iron, ferritin levels and higher lymphocytic count in patients compared with controls (p = 0.001, 0.03, 0.001, 0.001 respectively). CD3 count and percentage were significantly lower in IDA patients compared to controls (p = 0.007 and 0.005 respectively). There was a Significant reduction in the CD4 count, percentage and CD4/CD8 ratio in patients compared with controls (p = 0.001, 0.001 and 0.005 respectively) while there was no significant difference regarding CD8 count and percentage. No significant difference between the two studied groups regarding either CD19 count or percentage (p = 0.28 and 0.18 respectively) were found. Conclusions IDA is associated with impaired cell-mediated immune response specifically T-cell mediated immunity

Echocardiography and N-terminal-pro-brain natriuretic peptide in assessment of left ventricular diastolic dysfunction in stable COPD in relation to disease severity

Introduction: Left ventricular diastolic dysfunction (LVDD) is found to be frequent in COPD patients. Relationship between airflow obstruction and cardiovascular risk can be explained by inflammation which is considered one of systemic manifestations of COPD. Objective: To assess the LVDD in COPD patients in relation to disease severity using echocardiography, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high sensitive C-reactive protein (hs-CRP). Patients and methods: This prospective study was carried out on 60 stable COPD patients who were recruited from outpatient chest clinics, Tanta University Hospitals. Diagnosis of COPD was made according to criteria of the Global Initiative for Chronic Obstructive Lung Disease. Patients were subjected to medical history and physical examination, chest X ray, pulmonary functions, ECG and echocardiography. Blood samples were withdrawn for assessment of NT-proBNP and hs-CRP. Results: Diastolic function of the heart was evaluated by echocardiography using: isovolumetric relaxation time (IVRT), deceleration time of early transmitral flow, ratio of the peak velocity of the early E wave/A wave which suggested that LVDD was recorded more in severe/very severe compared to mild/moderate COPD. Significant positive correlations were found between Nt-pro BNP and hs-CRP, IVRT, deceleration time of early transmitral flow and E/A wave ratio. Sensitivity, specificity and accuracy were 83.1, 90 and 0.94% for Nt-pro BNP. Conclusions: Evaluation of NT-proBNP was important for detection of LVDD in COPD patients, which was correlated with disease severity. Echocardiographic assessment of COPD patients, especially in combination with NT-proBNP can be considered as good diagnostic tools of LVDD in COPD

Task-oriented training for upper limb functions in patients with multiple sclerosis: Systematic review and meta-analysis

Patients with multiple sclerosis (MS) typically experience varying degrees of impairments and disabilities. Task-oriented training (TOT) has been used for those patients to improve their motor skills. This review aimed to evaluate the primary research on the effectiveness of TOT in improving upper limb functions in patients with MS. The systematic search was performed using PubMed, Cochrane library and Physical therapy Evidence Database (PEDro) databases up to 2022. Only randomized controlled trials that used TOT alone for UL functions of adult patients with MS were included. Two independent reviewers screened records, extracted data and assessed studies' quality by using PEDro scale. The meta-analysis was based on the standardized mean differences and the random effect. The search screened 9148 records; only five randomized controlled trials were eligible; four of them were of good quality. The trials included 147 patients with MS; 66% of them were females, their mean average age was 47 years. TOT duration ranged from 40 to 210 min with total period of 10 days to 8 weeks; it was applied alone without conventional physical therapy. Meta-analyses compared TOT alone versus control interventions revealed non-significant difference in the improvement of UL functions on Nine-Hole Peg Test, Action Reach Arm Test, Motor Activity Log-Amount Of Use scale, and Manual Ability Measurement. This review concluded that TOT alone can be effective for improving UL functions in patients with MS but meta-analyses showed non-significant differences when it was compared with conventional physical therapy

The uptake of Eriochrome Black T dye from aqueous solutions utilizing waste activated sludge: Adsorption process optimization using factorial design

In the present study, the sorption of Eriochrome Black T dye from aqueous solution on waste sludge was investigated by employing the factorial design method. Currently, there are worldwide interests to using inexpensive and commercially available adsorbent materials for contaminant removal. Design expert software was employed to examine the influence of different concentrations of dye, adsorbent dosage, contact time and pH on the removal efficiency of Eriochrome Black T using sludge. Additionally, the factorial design was applied to examine the interaction effect of these four variables on the adsorption process. The results were also subjected to examine the correlation between the actual and theoretical EBT dye removal efficiencies (%) which showed how closely the predicted distribution results followed the experimental values. Moreover, the experimental results were subjected to Halsey and Jovanovic adsorption isotherms to explain the adsorption process. The experimental data followed Jovanovic model with higher R2 (0.9997) than the Halsey model. Keywords: Factorial design, Adsorption, EBT, Sludge, Isotherm mode

Comparing conditional survival functions with missing population marks in a competing risks model

In studies involving nonparametric testing of the equality of two or more survival distributions, the survival curves can exhibit a wide variety of behaviors such as proportional hazards, early/late differences, and crossing hazards. As alternatives to the classical logrank test, the weighted Kaplan-Meier (WKM) type statistic and their variations were developed to handle these situations. However, their applicability is limited to cases where the population membership is available for all observations, including the right censored ones. Quite often, failure time data are confronted with missing population marks for the censored observations. To alleviate this, a new WKM-type test is introduced based on imputed population marks for the censored observations leading to fractional at-risk sets that estimate the underlying risk for the process. The asymptotic normality of the proposed test under the null hypothesis is established, and the finite sample properties in terms of empirical size and power are studied through a simulation study. Finally, the new test is applied on a study of subjects undergoing bone marrow transplantation