Tree crown injury from wildland fires: causes, measurement and ecological and physiological consequences.

The dead foliage of scorched crowns is one of the most conspicuous signatures of wildland fires. Globally, crown scorch from fires in savannas, woodlands and forests causes tree stress and death across diverse taxa. The term crown scorch, however, is inconsistently and ambiguously defined in the literature, causing confusion and conflicting interpretation of results. Furthermore, the underlying mechanisms causing foliage death from fire are poorly understood. The consequences of crown scorch - alterations in physiological, biogeochemical and ecological processes and ecosystem recovery pathways - remain largely unexamined. Most research on the topic assumes the mechanism of leaf and bud death is exposure to lethal air temperatures, with few direct measurements of lethal heating thresholds. Notable information gaps include how energy transfer injures and kills leaves and buds, how nutrients, carbohydrates, and hormones respond, and what physiological consequences lead to mortality. We clarify definitions to encourage use of unified terminology for foliage and bud necrosis resulting from fire. We review the current understanding of the physical mechanisms driving foliar injury, discuss the physiological responses, and explore novel ecological consequences of crown injury from fire. From these elements, we propose research needs for the increasingly interdisciplinary study of fire effects.

Skin color and tissue thickness effects on transmittance, reflectance, and skin temperature when using 635 and 808 nm lasers in low intensity therapeutics.

OBJECTIVE: To examine the role of skin color and tissue thickness on transmittance, reflectance, and skin heating using red and infrared laser light. METHODS: Forty volunteers were measured for skin color and skin-fold thickness at a standardized site near the elbow. Transmittance, reflectance and skin temperature were recorded for energy doses of 2, 6, 9, and 12 Joules using 635 nm (36 mW) and 808 nm (40 mW) wavelength laser diodes with irradiances within American National Standards Institute safety guidelines (4.88 mm diameter, 0.192 W/cm2 and 4.88 mm diameter, 0.214 W/cm2 , respectively). RESULTS: The key factors affecting reflectance to an important degree were skin color and wavelength. However, the skin color effects were different for the two wavelengths: reflectance decreased for darker skin with a greater decrease for red light than near infrared light. Transmittance was greater using 808 nm compared with 635 nm. However, the effect was partly lost when the skin was dark rather than light, and was increasingly lost as tissue thickness increased. Dose had an increasing effect on temperature (0.7-1.6°C across the 6, 9, and 12 J doses); any effects of wavelength, skin color, and tissue thickness were insignificant compared to dose effects. Subjects themselves were not aware of the increased skin temperature. Transmittance and reflectance changes as a function of energy were very small and likely of no clinical significance. Absorption did not change with higher energy doses and increasing temperature. CONCLUSION: Skin color and skin thickness affect transmittance and reflectance of laser light and must be accounted for when selecting energy dose to ensure therapeutic effectiveness at the target tissue. Skin heating appears not to be a concern when using 635 and 808 nm lasers at energy doses of up to 12 J and irradiance within American National Standards Institute standards. Photobiomodulation therapy should never exceed the American National Standards Institute recommendation for the maximum permissible exposure to the skin. Lasers Surg. Med. 50:291-301, 2018. © 2017 Wiley Periodicals, Inc.

Comparison of micronutrients in adult enteral formulas widely used in clinical practice.

In recent decades, great progress in the area of enteral nutrition has provided a large variety and commercial availability of enteral formulas, usually produced by the nutrition divisions of several pharmaceutical or dairy manufacturers, with specific compositions for each type of disease or patient condition. Despite the widespread use of enteral formulas, both in hospitals and at home, studies performed on the micronutrient compositions of adult enteral formulas are few in China. The content of micronutrients in 31 commercially available adult enteral formulas in the Chinese market was compared with the Chinese dietary reference intakes (DRIs), the tolerable upper limits (UL), the limit requirements in Food Safety National Standards General Rules of Foods for Special Medical Purposes (GB 29922-2013), and the European Society for Clinical Nutrition and Metabolism (ESPEN) micronutrient guideline (2022). The micronutrient content was calculated by multiplying the value provided on the nutrition label for each product by the daily energy dose of 1500 and 1800 Kcal/day. The research results showed that most adult enteral formulas were generally suitable for patients on long-term total enteral nutrition support in the Chinese market, and foods for special medical purpose (FSMP) formulas were more suitable than enteral nutrition preparation (ENP) formulas. However, the vitamin D, vitamin K, and iron content in these formulas should be appropriately increased to the limit recommended by the ESPEN micronutrient guideline. The results could provide a basis for manufacturers to research and develop more suitable enteral formulas and help clinical dietitians administer more effective enteral nutrition support for patients on long-term total enteral nutrition in clinical practice, especially individualized treatment.

Ceramics, Glass and Glass-Ceramics for Personal Radiation Detectors.

Different types of ceramics and glass have been extensively investigated due to their application in brachytherapy, radiotherapy, nuclear medicine diagnosis, radioisotope power systems, radiation processing of food, geological and archaeological dating methods. This review collects the newest experimental results on the thermoluminescent (TL) properties of crystalline and glassy materials. The comparison of the physico-chemical properties shows that glassy materials could be a promising alternative for dosimetry purposes. Furthermore, the controlled process of crystallization can enhance the thermoluminescent properties of glasses. On the other hand, the article presents information on the ranges of the linear response to the dose of ionizing radiation and on the temperature positions of the thermoluminescent peaks depending on the doping concentration with rare-earth elements for crystalline and glassy materials. Additionally, the stability of dosimetric information storage (fading) and the optimal concentration of admixtures that cause the highest thermoluminescent response for a given type of the material are characterized. The influence of modifiers addition, i.e., rare-earth elements on the spectral properties of borate and phosphate glasses is described.

Kinetic Energy Dose as a Unified Metric for Comparing Ball Mills in the Mechanocatalytic Depolymerization of Lignocellulose.

Mechanochemistry utilizes mechanical forces to activate chemical bonds. It offers environmentally benign routes for both (bio) organic and inorganic syntheses. However, direct comparison of mechanochemistry results is often very challenging. In mechanochemical synthetic protocols, ball mill setup (mechanical design and grinding vessel geometry) in addition to experimental parameters (milling frequency, duration, ball count and size) vary broadly. This fact poses a severe issue to further progress in this exciting research area because ball mill setup and experimental parameters govern how much kinetic energy is transferred to a chemical reaction. In this work, we address the challenge of comparing mechanochemical reaction results by taking the energy dose provided by ball mills as a unified metric into account. In this quest, we applied kinematic modeling to two ball mills functioning under distinct working principles to express the energy dose as a mathematical function of the experimental parameters. By examining the effect of energy dose on the extent of the mechanocatalytic depolymerization (MCD) of lignocellulosic biomass (beechwood), we found linear correlations between yield of water-soluble products (WSP) and energy dose for both ball mills. Interestingly, when a substrate layer is formed on the grinding jar wall and/or grinding medium, a weak non-linear correlation between water-soluble products yield and energy dose is identified. We demonstrate that the chemical reaction's best utilization of kinetic energy is achieved in the linear regime, which presents improved WSP yields for given energy doses. In the broader context, the current analysis outlines the usefulness of the energy dose as a unified metric in mechanochemistry to further the understanding of reaction results obtained from different ball mills operating under varied experimental conditions.

Comparative evaluation of 2-isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine, and 2,4,6-trichloroanisole degradation by ultraviolet/chlorine and ultraviolet/hydrogen peroxide processes.

2-Isopropyl-3-methoxypyrazine (IPMP), 2-Isobutyl-3-methoxypyrazine (IBMP), and 2,4,6-Trichloroanisole (TCA) are the primary emerging taste and odor (T&O) compounds in water systems with low thresholds (ng L-1). The selected T&O compounds are known to be difficult to remove using conventional water treatment processes. In this study, we compared the removal characteristics of the three T&O compounds using UV/Cl2 and UV/H2O2. The removal rates of the three compounds by direct photolysis at 254 nm were less than 10%, even at a high UV dose (approximately 1000 mJ cm-2). Under conditions of an oxidant injection volume of 5 mg L-1 and UV dose of 1000 mJ cm-2, the degradation rate of the target compounds in the UV/H2O2 process exceeded that of the UV/Cl2 process. Moreover, the results revealed that pH has a significant impact on the removal of the T&O compounds during the UV/Cl2 process. The IPMP, IBMP, and TCA were found to be more reactive with hydroxyl radicals than reactive chlorine species (RCS). A predictive tool was developed to determine the optimal operating condition using the generalized reduced gradient (GRG) nonlinear solver. In the UV/H2O2 process, the EED value for 90% removing rate was 0.156 kWh m-3 for the IPMP, 0.135 kWh m-3 for the IBMP, and 0.154 kWh m-3 for the TCA, respectively. In case of the UV/Cl2, the EED value for 50% removing rate was 0.174 kWh m-3 for the IPMP, 0.138 kWh m-3 for the IBMP, and 0.169 kWh m-3 for the TCA, respectively.

Role of timing and dose of energy received in patients with acute lung injury on mortality in the Intensive Nutrition in Acute Lung Injury Trial (INTACT): a post hoc analysis.

BACKGROUND: Our trial INTACT (Intensive Nutrition in Acute Lung Injury Trial) was designed to compare the impact of feeding from acute lung injury (ALI) diagnosis to hospital discharge, an interval that, to our knowledge, has not yet been explored. It was stopped early because participants who were randomly assigned to energy intakes at nationally recommended amounts via intensive medical nutrition therapy experienced significantly higher mortality hazards than did those assigned to standard nutrition support care that provided energy at 55% of recommended concentrations. OBJECTIVE: We assessed the influence of dose and timing of feeding on hospital mortality. DESIGN: Participants (n = 78) were dichotomized as died or discharged alive. Associations between the energy and protein received overall, early (days 1-7), and late (days ≥8) and the hazards of hospital mortality were evaluated between groups with multivariable analysis methods. RESULTS: Higher overall energy intake predicted significantly higher mortality (OR: 1.14, 95% CI: 1.02, 1.27). Among participants enrolled for ≥8 d (n = 66), higher early energy intake significantly increased the HR for mortality (HR: 1.17, 95% CI: 1.07, 1.28), whereas higher late energy intake was significantly protective (HR: 0.91, 95% CI: 0.83, 1.0). Results were similar for early but not late protein (grams per kilogram) exposure (early-exposure HR: 8.9, 95% CI: 2.3, 34.3; late-exposure HR: 0.15, 95% CI: 0.02, 1.1). Threshold analyses indicated early mean intakes ≥18 kcal/kg significantly increased subsequent mortality. CONCLUSIONS: Providing kilocalories per kilogram or grams of protein per kilogram early post-ALI diagnosis at recommended levels was associated with significantly higher hazards for mortality, whereas higher late energy intakes reduced mortality hazards. This time-varying effect violated the Cox proportionality assumption, indicating that feeding trials in similar populations should extend beyond 7 d and use time-varying statistical methods. Future trials are required for corroboration. INTACT was registered at clinicaltrials.gov as NCT01921101.