Post cardiac surgery sternal wound sepsis burden, risk factors and outcomes at Red Cross War Memorial Children’s Hospital, Cape Town, South Africa: A five-year experience

Purpose: Sternal wound infection (SWI) is associated with significant morbidity and mortality in post-operative cardiac patients. We aimed to describe the burden, risk factors and outcomes of SWI in post-operative paediatric cardiac patients at a tertiary children’s hospital.Methods: We conducted a retrospective record review of cardiac surgeries via median sternotomy over a 5-year period to identify cases of SWI.Results: Between 2011 and 2016, 1 319 patients underwent median sternotomy. Thirty four (2.6%) patients developed SWI; 18 (13%) patients developed deep sternal wound infection (DSWI), and 16 (12%) developed superficial sternal wound infections (SSWI). Twenty two (16%) of SWIs were apparent within a week postsurgery before discharge, and the remaining were readmitted post-discharge. Seven (0.5%) patients died from complications.Conclusion: Significant morbidity was associated with SWI. Furthermore, with a mortality rate of 20% in the case of DSWI, we strongly support quality improvement procedures such as the Sternal Wound Prevention Bundle (SWPB) that was introduced in late 2014. However, the rate of SWI implies that ongoing monitoring and evaluation of the SWPB is necessary and more stringent adherence to the protocol may result in better outcomes

LEIDENFROST DROPLET MICROFLUIDICS

Systems and methods are described for propelling a liquid droplet in a Leidenforst state. A microfluidic device embodiment includes, but is not limited to, a solid structure having a patterned surface, the patterned surface including at least a first patterned region having a first Leidenfrost temperature with respect to a fluid, the first patterned region adjacent to the second patterned region, the first patterned region defining a path over which a droplet of the fluid is configured to travel in a Leidenfrost state

Condensation and subsequent freezing delays as a result of using femtosecond laser functionalized surfaces

In this paper, the authors report on the use of femtosecond laser surface processing (FLSP) to enhance the anti-icing properties of a commonly used aircraft alloy, Al 7075-O Clad. By changing the surface morphology through FLSP and the surface chemistry through siloxane vapor deposition, the wettability of Al 7075-O Clad was altered. Tall mound and short mound FLSP functionalized surfaces were created through two sets of laser parameters. Condensation and the subsequent freezing of condensates on FLSP Al 7075-O Clad was studied. Both structure height and surface wettability were shown to play a role in the delay of freezing. Freezing occurred on the FLSP superhydrophilic surface faster than on the unprocessed Al 7075-O Clad surface; however, freezing was delayed for all superhydrophobic FLSP surfaces. Tall structure height FLSP functionalized surfaces delayed freezing time longer than short structure height FLSP functionalized surfaces although all were superhydrophobic. It was shown that FLSP functionalized surfaces were able to delay freezing by up to 530 s compared with unprocessed Al 7075-O Clad. The authors also report on self-propelled condensate jumping on FLSP surfaces during the condensing process. The selfpropelled jumping phenomena provide a means to promote anti-icing of materials, especially where jumping drops can be swept away in flow conditions

Generating evidence from contextual clinical research in low- to middle income countries: A roadmap based on theory of change

Along with inadequate access to high-quality care, competing health priorities, fragile health systems, and conflicts, there is an associated delay in evidence generation and research from LMICs. Lack of basic epidemiologic understanding of the disease burden in these regions poses a significant knowledge gap as solutions can only be developed and sustained if the scope of the problem is accurately defined. Congenital heart disease (CHD), for example, is the most common birth defect in children. The prevalence of CHD from 1990 to 2017 has progressively increased by 18.7% and more than 90% of children with CHD are born in Low and Middle-Income Countries (LMICs). If diagnosed and managed in a timely manner, as in high-income countries (HICs), most children lead a healthy life and achieve adulthood. However, children with CHD in LMICs have limited care available with subsequent impact on survival. The large disparity in global health research focus on this complex disease makes it a solid paradigm to shape the debate. Despite many challenges, an essential aspect of improving research in LMICs is the realization and ownership of the problem around paucity of local evidence by patients, health care providers, academic centers, and governments in these countries. We have created a theory of change model to address these challenges at a micro- (individual patient or physician or institutions delivering health care) and a macro- (government and health ministries) level, presenting suggested solutions for these complex problems. All stakeholders in the society, from government bodies, health ministries, and systems, to frontline healthcare workers and patients, need to be invested in addressing the local health problems and significantly increase data to define and improve the gaps in care in LMICs. Moreover, interventions can be designed for a more collaborative and effective HIC-LMIC and LMIC-LMIC partnership to increase resources, capacity building, and representation for long-term productivity

Monolithic Heat-Transfer Device

A monolithic heat-transfer device can include a container wall configured to retain a working fluid, where the container wall is formed of a single material. The container wall also includes an interior surface configured to be in fluid communication with the working fluid. The monolithic heat-transfer device also includes a channel disposed in the interior surface of the container wall, where the channel comprises a microstructure and a nanostructure. The microstructure and the nanostructure are materially contiguous with the single material forming the container wall. In some embodiments, the nanostructure comprises one or more layers of nanoparticles. The monolithic heat-transfer device can be configured as a heat pipe, which can be constructed from the container wall and a second container wall joined together and sealed to one another to contain the working fluid (e.g., using laser welding, electron beam welding (EBW), and so forth)

Quantifying Wicking in Functionlized Surfaces

Wicking remains the enigmatic key factor in many research areas. From boiling in power plants, to anti-icing on plane wings, to medical instruments, to heat pipes, efficiency and safety depend on how quickly a surface becomes wet. Yet wicking remains difficult to quantify and define as a property of the surface. This experiment strives to measure the wicking property by examining the rate that a liquid can be pulled out of a container. A superhydrophilic surface is placed in contact with the liquid at the bottom of a tube so that the volume flow rate across the surface can be monitored by a camera. By tracking the liquid level in the tube as a function of time, the wicking property of the surface can be quantified. Different tube sizes were compared to ensure that a property of the surface was being accurately measured

Generating Evidence From Contextual Clinical Research in Low- to Middle Income Countries: A Roadmap Based on Theory of Change

Along with inadequate access to high-quality care, competing health priorities, fragile health systems, and conflicts, there is an associated delay in evidence generation and research from LMICs. Lack of basic epidemiologic understanding of the disease burden in these regions poses a significant knowledge gap as solutions can only be developed and sustained if the scope of the problem is accurately defined. Congenital heart disease (CHD), for example, is the most common birth defect in children. The prevalence of CHD from 1990 to 2017 has progressively increased by 18.7% and more than 90% of children with CHD are born in Low and Middle-Income Countries (LMICs). If diagnosed and managed in a timely manner, as in high-income countries (HICs), most children lead a healthy life and achieve adulthood. However, children with CHD in LMICs have limited care available with subsequent impact on survival. The large disparity in global health research focus on this complex disease makes it a solid paradigm to shape the debate. Despite many challenges, an essential aspect of improving research in LMICs is the realization and ownership of the problem around paucity of local evidence by patients, health care providers, academic centers, and governments in these countries. We have created a theory of change model to address these challenges at a micro- (individual patient or physician or institutions delivering health care) and a macro- (government and health ministries) level, presenting suggested solutions for these complex problems. All stakeholders in the society, from government bodies, health ministries, and systems, to frontline healthcare workers and patients, need to be invested in addressing the local health problems and significantly increase data to define and improve the gaps in care in LMICs. Moreover, interventions can be designed for a more collaborative and effective HIC-LMIC and LMIC-LMIC partnership to increase resources, capacity building, and representation for long-term productivity.publishedVersio

Emissivity prediction of functionalized surfaces using artificial intelligence

Tuning surface emissivity has been of great interest in thermal radiation applications, such as thermophotovoltaics and passive radiative cooling. As a low-cost and scalable technique for manufacturing surfaces with desired emissivities, femtosecond laser surface processing (FLSP) has recently drawn enormous attention. Despite the versatility offered by FLSP, there is a knowledge gap in accurately predicting the outcome emissivity prior to fabrication. In this work, we demonstrate the immense advantage of employing artificial intelligence (AI) techniques to predict the emissivity of complex surfaces. For this aim, we used FLSP to fabricate 116 different aluminum samples. A comprehensive dataset was established by collecting surface characteristics, laser operating parameters, and the measured emissivities for all samples. We demonstrate the successful application of AI in two distinct scenarios: (1) effective emissivity classification solely based on 3D surface morphology images, and (2) emissivity prediction based on surface characteristics and FLSP parameters. These findings open new pathways towards extended implementation of AI to predict various surface properties in functionalized samples or extract the required fabrication parameters via reverse engineering