Kondragunta, Venkateswarlu

Conventional paints pose major environmental and health concerns due to their reliance on heavy-metal pigments and volatile organic compound (VOC)-emitting binders, emphasizing the need for sustainable alternatives. Previous formulations of biologic paints that combined bacteria-derived dsRED pigment protein and casein-based binders, while devoid of toxic components, suffered from prolonged drying times (~16 min), limiting their practical applicability. The present study addresses this key limitation by incorporating cellulose nanocrystals (CNC) and chitosan as biologic additives to enhance drying kinetics. Paint formulations containing 2%, 5%, and 10% of each additive were tested under controlled environmental conditions (20 °C, 60% relative humidity) following the GB/T 1728–2020 standard. Both CNC and chitosan significantly reduced drying time in a concentration-dependent manner (p < 0.001). The 10% CNC and 10% chitosan formulations achieved 61% and 44% reductions in drying time, respectively, relative to the unmodified biologic paint (12.96 ± 1.07 min at baseline). Regression analyses indicated that each 1% increase in CNC or chitosan concentration reduced drying time by 0.77 min and 0.58 min, respectively. The optimized paints exhibited acceptable drying times (5–7 min). These findings demonstrate an advancement in the development of biologically derived coatings, providing a feasible pathway toward safe and sustainable alternatives to conventional synthetic paints.

Abstract Myeloperoxidase (MPO) is an enzymatic mediator of several inflammatory cascades and higher serum levels have been associated with increased risk of adverse cardiovascular events. We investigated the association of serum MPO with the ankle–brachial index (ABI) and peripheral arterial disease (PAD) in a bi-ethnic cohort of African-Americans and non-Hispanic white individuals. Participants included 1324 African-Americans (mean age 64 years, 71% women) and 1237 non-Hispanic white individuals (mean age 59 years, 57% women) belonging to hypertensive sibships. Serum levels of MPO were measured by solid phase sandwich immunoassay. ABI was measured using a standard protocol and PAD was defined as an ABI < 0.90. Multivariable regression analysis using generalized estimating equations were performed to assess whether serum MPO levels were associated with ABI and the presence of PAD. After adjustment for age and sex, higher MPO levels were significantly associated with lower ABI and the presence of PAD in African-Americans ( p = 0.004 and p = 0.005, respectively) and in non-Hispanic white individuals ( p = 0.001 and p = 0.016, respectively). After additional adjustment for conventional risk factors (diabetes, smoking status, total and high-density lipoprotein cholesterol, waist circumference, hypertension), prior history of myocardial infarction or stroke, and medication use (statins, aspirin, estrogen), higher MPO levels remained significantly associated with lower ABI and the presence of PAD in both African-Americans ( p = 0.008 and p = 0.010, respectively) and non-Hispanic white individuals ( p = 0.001 and p = 0.018, respectively). We conclude that higher MPO levels are associated with lower ABI and the presence of PAD in African-Americans and non-Hispanic white individuals.

Vascular reactivity may affect the stiffness characteristics of the arterial wall. We investigated the association between forearm microcirculatory and conduit artery function and measures of arterial stiffness in 527 asymptomatic non-Hispanic white adults without known cardiovascular disease. High-resolution ultrasonography of the brachial artery (ba) was performed to assess forearm microcirculatory function (ba blood flow velocity, local shear stress, and forearm vascular resistance at rest and during reactive hyperemia) and conduit artery function (ba flow-mediated dilatation [baFMD] and ba nitroglycerin-mediated dilatation [baNMD]). Arterial stiffness was assessed by cuff-derived brachial pulse pressure and aortic pulse wave velocity (aPWV) measured by applanation tonometry. In regression analyses that adjusted for heart rate, mean arterial pressure, height, cardiovascular risk factors, and hypertension medication and statin use, higher baseline ba systolic velocity and systolic shear stress were associated with greater pulse pressure ( P =0.0002 and P =0.006, respectively) and higher aPWV (each P <0.0001). During hyperemia, lower ba mean velocity and lower mean shear stress were associated with higher pulse pressure ( P =0.045 and P =0.036, respectively), whereas both systolic and mean velocity ( P <0.0001 and P =0.002, respectively) and systolic and mean shear stress ( P <0.0001 and P =0.003, respectively) were inversely associated with aPWV. baFMD was not associated with pulse pressure but was inversely associated with aPWV ( P =0.011). baNMD was inversely associated with pulse pressure ( P =0.0002) and aPWV ( P =0.008). Our findings demonstrate that impaired forearm microvascular function (in the form of elevated resting blood flow velocity and impaired flow reserve) and impaired brachial artery reactivity are associated with increased arterial stiffness.