409 research outputs found
Transformational Leadership and R&D Workers' Multiple Commitments: Do Justice & Span of Control Matter?
Cataloged from PDF version of article.This study examines how transformational leaders influence research and development (R&D) workers' commitment
to their organizations and leaders. The study investigates the mediating role of organizational justice
(i.e., procedural and interactional) based on social exchange theory and the moderating role of span of
control in this relationship. In a sample of 445 Turkish R&D personnel, the study finds that transformational
leadership significantly influences followers' organizational commitment partially through procedural justice
and their supervisory commitment partially through interactional justice. Second, the findings reveal that
transformational leaders boost perceptions of procedural justice and organizational commitment when the
span of control is relatively narrow. Interestingly, when the span of control is large, transformational leadership
has significant positive effects on supervisory commitment, but no significant effects on organizational
commitment among R&D workers.
© 2012 Elsevier Inc. All rights reserved
A new nickel-based co-crystal complex electrocatalyst amplified by NiO dope Pt nanostructure hybrid; a highly sensitive approach for determination of cysteamine in the presence of serotonin.
A highly sensitive electrocatalytic sensor was designed and fabricated by the incorporation of NiO dope Pt nanostructure hybrid (NiO-Pt-H) as conductive mediator, bis (1,10 phenanthroline) (1,10-phenanthroline-5,6-dione) nickel(II) hexafluorophosphate (B,1,10,P,1,10, PDNiPF6), and electrocatalyst into carbon paste electrode (CPE) matrix for the determination of cysteamine. The NiO-Pt-H was synthesized by one-pot synthesis strategy and characterized by XRD, elemental mapping analysis (MAP), and FESEM methods. The characterization data, which confirmed good purity and spherical shape with a diameter of ⁓ 30.64 nm for the synthesized NiO-Pt-H. NiO-Pt-H/B,1,10, P,1,10, PDNiPF6/CPE, showed an excellent catalytic activity and was used as a powerful tool for the determination of cysteamine in the presence of serotonin. The NiO-Pt-H/B,1,10, P,1,10, PDNiPF6/CPE was able to solve the overlap problem of the two drug signals and was used for the determination of cysteamine and serotonin in concentration ranges of 0.003-200 µM and 0.5-260 µM with detection limits of 0.5 nM and 0.1 µM, using square wave voltammetric method, respectively. The NiO-Pt-H/B,1,10,P,1,10,PDNiPF6/CPE showed a high-performance ability for the determination of cysteamine and serotonin in the drug and pharmaceutical serum samples with the recovery data of 98.1-103.06%
Rosette based metamaterial for circularly polarized terahertz waves manipulation
Metamaterials that respond resonantly in interaction with the terahertz (THz) electromagnetic waves are significant for the achievement of diverse optical functionalities in THz spectral range [1]. Also, they are virtually desirable platforms for investigating chiral effects which rise due to different interaction of metamaterials with left and right circularly polarized light [2,3]. Light polarization is an important feature of electromagnetic waves and manipulation of polarization plays pivotal role in various areas such as communications, imaging and sensing. One of potential applications of the THz metadevices is for protein quality control in the biotechnology or food industries [4]. Chiral properties of metamaterial can be modified via different external influences, such as by changing the interlayer twist angle, adding a dielectric spacer, or modulating its thickness. Twisting or rotating achiral layered structures in parallel planes enables engineering of the extrinsic chirality and consequential optical performance. For example, the twist angle from counterclockwise rotation of an upper layer with respect to the one under it, leads to a left-handed stacking geometry [5]. In this study, we performed numerical simulations of the metamaterial structure in terahertz frequency range, 0.25-0.75 THz. The numerical simulations were done for the case of two parallel gold rosettes on sapphire substrates in which we analyzed the influence of rotating one rosette with respect to the another on chiral properties. Two geometries of the rosette based structures were studied. First geometry is based on resonator which consists of two same parallel rosettes and the second one of two parallel rosettes, but one of them is trimmed.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad
Realizing effectiveness across continents with hydroxyurea: Enrollment and baseline characteristics of the multicenter REACH study in Sub-Saharan Africa.
Despite its well-described safety and efficacy in the treatment of sickle cell anemia (SCA) in high-income settings, hydroxyurea remains largely unavailable in sub-Saharan Africa, where more than 75% of annual SCA births occur and many comorbidities exist. Realizing Effectiveness Across Continents with Hydroxyurea (REACH, ClinicalTrials.gov NCT01966731) is a prospective, Phase I/II open-label trial of hydroxyurea designed to evaluate the feasibility, safety, and benefits of hydroxyurea treatment for children with SCA in four sub-Saharan African countries. Following comprehensive training of local research teams, REACH was approved by local Ethics Committees and achieved full enrollment ahead of projections with 635 participants enrolled over a 30-month period, despite half of families living \u3e12 km from their clinical site. At enrollment, study participants (age 5.4 ± 2.4 years) had substantial morbidity, including a history of vaso-occlusive pain (98%), transfusion (68%), malaria (85%), and stroke (6%). Significant differences in laboratory characteristics were noted across sites, with lower hemoglobin concentrations (P \u3c .01) in Angola (7.2 ± 1.0 g/dL) and the DRC (7.0 ± 0.9 g/dL) compared to Kenya (7.4 ± 1.1 g/dL) and Uganda (7.5 ± 1.1 g/dL). Analysis of known genetic modifiers of SCA demonstrated a high frequency of α-thalassemia (58.4% with at least a single α-globin gene deletion) and G6PD deficiency (19.7% of males and 2.4% of females) across sites. The CAR β-globin haplotype was present in 99% of participants. The full enrollment to REACH confirms the feasibility of conducting high-quality SCA research in Africa; this study will provide vital information to guide safe and effective dosing of hydroxyurea for children with SCA living in Africa
Are children with SARS-CoV-2 infection at high risk for thrombosis? Viscoelastic testing and coagulation profiles in a case series of pediatric patients
© 2020 Wiley Periodicals LLC The coagulopathy of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is well documented in adults, with increases in D-dimer and prothrombin time found to be strong predictors of mortality, and anticoagulation shown to decrease this mortality. Viscoelastic parameters such as elevations in maximum clot firmness (MCF) on rotational thromboelastometry (ROTEM) have correlated with a hypercoagulable state in adults with SARS-CoV-2. We report our experience in children infected with SARS-CoV-2, with noted elevations in D-dimer and MCF on ROTEM (indicating hypercoagulability). Exploration of viscoelastic testing to provide additional laboratory-based evidence for pediatric-specific risk assessment for thromboprophylaxis in SARS-CoV-2 is warranted
Prevention of conversion to abnormal tcd with hydroxyurea in sickle cell anemia: A phase III international randomized clinical trial
Children with sickle cell anemia (SCA) and conditional transcranial Doppler (TCD) ultrasound velocities (170-199 cm/sec) may develop stroke. However, with limited available clinical data, the current standard of care for conditional TCD velocities is observation. The efficacy of hydroxyurea in preventing conversion from conditional to abnormal TCD (\u3e/=200 cm/sec), which confers a higher stroke risk, has not been studied prospectively in a randomized trial. Sparing Conversion to Abnormal TCD Elevation (SCATE #NCT01531387) was an NHLBI-funded Phase III multicenter international clinical trial comparing alternative therapy (hydroxyurea) to standard care (observation) to prevent conversion from conditional to abnormal TCD velocity in children with SCA. SCATE enrolled 38 children from the United States, Jamaica, and Brazil [HbSS (36), HbSbeta0 -thalassemia (1), and HbSD (1), median age 5.4 years (range, 2.7-9.8)]. Due to slow patient accrual and administrative delays, SCATE was terminated early. In an intention-to-treat analysis, the cumulative incidence of abnormal conversion was 9% (95% CI 0 to 35%) in the hydroxyurea arm and 47% (95% CI 6 to 81%) in observation arm at 15 months (p=0.16). In post-hoc analysis according to treatment received, significantly fewer children on hydroxyurea converted to abnormal TCD velocities, compared to observation (0% versus 50%, p=0.02). After a mean of 10.1 months, a significant change in mean TCD velocity was observed with hydroxyurea treatment (-15.5 versus +10.2 cm/sec, p=0.02). No stroke events occurred in either arm. Hydroxyurea reduces TCD velocities in children with SCA and conditional velocities. This article is protected by copyright. All rights reserved
Fast And Accurate Multiscale Electromagnetic Modeling Framework: An Overview
We present an overview of challenge problems in electromagnetic modeling of highly complex and multi-scale structures found in 3D IC, SiP, SoC, and electronic packaging necessary for signal integrity assessment. © 2013 IEEE
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