Physical properties, chemical composition, and cloud forming potential of particulate emissions from a marine diesel engine at various load conditions

Particulate matter (PM) emissions from one serial 4-stroke medium-speed marine diesel engine were measured for load conditions from 10% to 110% in test rig studies using heavy fuel oil (HFO). Testing the engine across its entire load range permitted the scaling of exhaust PM properties with load. Emission factors for particle number, particle mass and chemical compounds were determined. The potential of particles to form cloud droplets (cloud condensation nuclei, CCN) was calculated from chemical composition and particle size. Number emission factors are (3.43±1.26)x10^16 (kg fuel)–1 at 85-110% load, and (1.06±0.10)x10^16 (kg fuel)–1 at 10% load. CCN emission factors of 1-6 x 10^14 (kg fuel) -1 are at the lower bound of data reported in the literature. From combined thermal and optical methods, black carbon (BC) emission factors of 40 – 60 mg/(kg fuel) were determined for 85-100% load and 370 mg/(kg fuel) for 10% load. The engine load dependence of the conversion efficiency for fuel sulfur into sulfate of (1.08±0.15)% at engine idle to (3.85±0.41)% at cruise may serve as input to global emission calculations for various load conditions

Systematic review of existing literature regarding the prevalence of pediatric atopic dermatitis in HondurasCapsule Summary

Background: Atopic dermatitis (AD) is an inflammatory skin condition, often multifactorial in origin, and most commonly manifests during childhood. Although there remains a deficit in literature, current data suggest Honduras may have the highest prevalence and severity of AD among all Latin American countries. Objective: To assess the current prevalence of pediatric AD in Honduras and evaluate existing gaps in available literature to monitor disease burden. Methods: A comprehensive literature search was performed in March 2023. Articles were removed if they were published before 2007, were of the incorrect study design, or were focused on countries outside of Honduras. The articles were independently reviewed by 2 authors. Results: The initial literature search yielded 174 studies, of which 7 met inclusion criteria. AD prevalence rates in children in Honduras ranged from 0.7% to 40.0%. Limitations: Limitations include elements of study design, analytic methods, study populations, and limited articles. Conclusion: There appears to be a disproportionately higher prevalence and disease burden of pediatric AD in Honduras. Future research should acquire accurate data to further understand the prevalence, incidence, and severity of AD in Honduras

How proteins move lipids and lipids move proteins

Cells determine the bilayer characteristics of different membranes by tightly controlling their lipid composition. Local changes in the physical properties of bilayers, in turn, allow membrane deformation, and facilitate vesicle budding and fusion. Moreover, specific lipids at specific locations recruit cytosolic proteins involved in structural functions or signal transduction. We describe here how the distribution of lipids is directed by proteins, and, conversely, how lipids influence the distribution and function of proteins