RESUMEN

The use of acute carbon monoxide inhalation (COi) and hot water immersion (HWI) are of growing interest as interventions to stimulate erythropoietin (EPO) production. However, whether EPO production is further augmented when combining these stressors and whether there are sex differences in this response are poorly understood. Therefore, we measured circulating EPO concentration in response to acute COi and HWI independently and in combination and determined whether the responses were altered by sex. Participants completed three study visits-COi, HWI, and combined COi and HWI-separated by 1 week in a randomized, balanced, crossover design. Renal blood velocity was measured during all interventions, and carboxyhaemoglobin was measured during and after COi. Serum samples were analysed every hour for 6 h post-intervention for EPO concentration. HWI decreased renal blood velocity (46.2 cm/s to 36.2 cm/s) (P < 0.0001), and COi increased carboxyhaemoglobin (1.5%-12.8%) (P < 0.0001) without changing renal blood velocity (46.4-45.2 cm/s) (P = 0.4456). All three interventions increased peak EPO concentration from baseline (COi: 6.02-9.74 mIU/mL; HWI: 6.80-11.10 mIU/mL; COi + HWI: 6.71-10.91 mIU/mL) (P = 0.0048) and to the same extent (P = 0.3505). On average, females increased EPO while males did not in response to COi (females: 6.17 mIU/mL; males: 1.27 mIU/mL) (P = 0.0010), HWI (females: 6.47 mIU/mL; males: 2.14 mIU/mL) (P = 0.0104), and COi and HWI (females: 6.65 mIU/mL; males: 1.76 mIU/mL) (P = 0.0256). These data emphasize that combining these interventions does not augment EPO secretion and that these interventions may work better in females.

RESUMEN

Hot water treatment (HWT) is a versatile technique for synthesizing metal oxide nanostructures (MONSTRs) by immersing metal substrates in hot water, typically in glass beakers. The proximity of substrates to the heat source during HWT can influence the temperature of the substrate and subsequently impact MONSTR growth. In our study, zinc (Zn) substrates underwent HWT at the base of a glass beaker in contact with a hot plate and at four different vertical distances from the base. While the set temperature of deionized (DI) water was 75.0 °C, the substrate locations exhibited variations, notably with the base reaching 95.0 °C. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Raman spectroscopy showed stoichiometric and crystalline zinc oxide (ZnO) nanorods. ZnO rods on the base, exposed to higher temperatures, displayed greater growth in length and diameter, and higher crystallinity. Nanorods with increasing vertical distances from the base exhibited a logarithmic decrease in length despite identical temperatures, whereas their diameters remained constant. We attribute these findings to crucial HWT growth mechanisms like surface diffusion and "plugging", influenced by temperature and water flow within the beaker. Our results provide insights for optimizing synthesis parameters to effectively control MONSTR growth through HWT.

RESUMEN

BACKGROUND: Cannabis use in the general population is prevalent and is rising because of increased acceptance of its use, legalization in most US states, and perceived health benefits. Cannabis product potency has dramatically increased with higher delta-9-tetrahydrocannabinol content. Cannabis has documented antiemetic properties and cannabinoid pharmaceuticals are used in disorders like chemotherapy-induced nausea and vomiting. PURPOSE: Forty to eighty percent of cyclic vomiting syndrome (CVS) patients use cannabis products, which reportedly reduce stress as well as nausea and vomiting. Cannabinoid hyperemesis syndrome (CHS) has a presentation similar to CVS, but is associated with longstanding, high dose cannabis use, and is thought to be relieved by sustained cannabis abstinence. Most CHS patients have used cannabis on a daily or near-daily basis for more than 2 years. Compulsive hot-water bathing behaviors are reported by most CHS patients, but are not specific for this disorder as they are also noted by about half of CVS patients. Episodic vomiting associated with cannabis use contributes to extensive health resource use, including emergency department visits and inpatient hospitalizations, and impacts patients and their families negatively. Treatment for CHS overlaps with CVS although cannabis abstinence remains the cornerstone of its management. Challenges associated with cannabis use cessation in CHS include patient skepticism of the role of cannabis as a cause of symptoms, perceived benefits of cannabis, and a lack of other effective therapies. In this review, we highlight cannabis use patterns in the US and discuss diagnosis and management of CHS and gaps in knowledge about this disorder.

RESUMEN

OBJECTIVES: Hot water epilepsy (HWE) is a type of epilepsy that primarily affects children. This study was aimed to evaluate the clinical, electroencephalogram (EEG), neuroimaging findings, and treatment options in children with HWE. METHODS: The medical records of 24 patients who had HWE were evaluated retrospectively. RESULTS: There were 2767 patients diagnosed with epilepsy during the seven-year period, and 0.86 % of the patients had HWE. The median age of the patients was three (range 1.2-7 years), with a male predominance (male/female ratio: 7.1). Six patients (25 %) had HWE with spontaneous seizures (HWESS) and 18 patients (75 %) had HWE alone (HWEA). 11 patients had focal onset seizures, 13 patients had generalized onset seizures. EEG abnormalities were found in 7 patients (29.2 %). Three patients (12.5 %) had nonspecific MRI findings. Developmental abnormalities (autism spectrum disorder, learning disability and speech disturbance.) were detected in 8 patients (33.3 %). Only one patient's (4.2 %) seizure could be controlled by changing bathroom habits. Twenty-three patients (95.8 %) were given antiepileptic drugs. 18 of 24 patients had come for follow-up visits for two years, nine of them used monotherapy and seizures did not recur. The treatment response was 55.5 %. Oxcarbazepine (8 patients, 33.3 %) and valproic acid (7 patients, 29.2 %) were the most chosen two drugs for HWE. The genetic tests performed were not accepted relevant to the patients' clinical conditions and epilepsy. CONCLUSION: The frequency of the HWE was not as high in the literature. Male predominance, EEG abnormalities may be seen. Changing bath room habits did not improve the treatment as a first line management, all the patients except one used antiepileptic drug treatment. Until now, there has been no study in Turkey showing the frequency of HWE exclusively in children.

Asunto(s)

RESUMEN

Loss of sensitivity in the operated area is common after some plastic surgery procedures and promotes accidental trauma on a daily basis. Several studies showed that a loss of sensitivity is constant after an abdominoplasty. We report here the cases of three 3rd degree burns by contact, at the subumbilical level, with a hot water bottle soon after an abdominoplasty, responsible for significant aesthetic sequelae.

RESUMEN

A laboratory setup with two axis of manual sun-tracking was designed and built. To get the predicted values for a solar injera stove, a 20-min heating time to prepare it for baking, 3.1 kWh power in the first hour, and 5.8 kWh (with only an 87 percent increase) in the second hour were acquired to bake 9 and 28 injera using electric injera stove, respectively. The temperature distribution on the clay surface was the range of 180 °C-220 °C. Solar injera baking stove was designed and built using the average energy required to bake one injera from an electrical injera stove. The laboratory setup was put to the test, temperatures at the receiver's surface ranging from 315 to 318 °C and an average solar radiation of 1000 W/m2 was obtained on the first test. The injera stove inlet reached a maximum temperature of 180.92 °C with a pressure of 14.5 bars during a pressurized hot water production and circulation test (load test). The surface temperature of the solar injera stove clay plate reached a maximum of 62.69 °C. Temperature of more than 60 °C was maintained on the surface of the solar injera stove plate for nearly 2 h.

RESUMEN

Pearl millet bran is rich source of dietary fiber and several other bioactive compounds and is an unexploited by-product of millet processing industries. The utilization of pearl millet bran for extraction of dietary fiber can be an effective method for its valorization. Hydrothermal extraction of dietary fiber from pearl millet bran is a simple eco-friendly technique in terms of minimal consumption of toxic solvents, increased extraction yield, high purity and considered as an economically viable technique. In the present investigation, extraction and optimization of dietary fiber from pearl millet bran was performed using hydrothermal technique. The highest yield of dietary fiber (74.5%, w/w) was obtained under optimized conditions of water to solid ratio (20:1), temperature (90 °C) and time (15 min). The extracted dietary fiber from pearl millet bran was further assessed for its physico-chemical, functional and structural properties. The studies of functional and physico-chemical properties presented the water holding capacity (6.50 g/g and 3.99 g/g), swelling power (2.0 g/g and 2.05 g/g), oil holding capacity (4.91 g/g and 2.42 g/g), solubility (70%), total phenolic content of 4.24 mg GAE/g and 4.32 mg GAE/g, DPPH reduction of 86.6% and 83.9%, respectively. The results indicated that pearl millet bran can act as rich source of dietary fiber with health enhancing properties and can be utilized as potential food component in preparation of functional food products.

RESUMEN

This study aimed to develop an efficient method for the extraction of bioactive compounds from green tea waste (GTW) toward its potential application in the food industry. GTW, which is generated during the harvesting and processing of green tea products, accounts for a global annual loss of nearly 1 million tonnes. Notably, this waste is rich in polyphenolic compounds, particularly catechins, which are renowned for their significant health benefits. We assessed the optimization of catechin extraction from GTW employing hot water extraction (HWE), ultrasound-assisted extraction (UAE), and ethanol extraction (EthE) techniques at different sample-to-solvent ratios (1:100, 1:50, and 1:20 w/v). The extraction temperature was set at 80°C for both HWE and UAE; however, for EthE, the temperature was slightly lower at 70°C, adhering to the boiling point of ethanol. High-performance liquid chromatography was used to determine the extraction efficiency by quantifying various catechins (i.e., catechin, epicatechin [EC], epicatechin gallate [ECG], epigallocatechin [EGC], and epigallocatechin gallate [EGCG]). In terms of the concentration for individual catechins, EC was found to be the highest concentration detected, ranging from 30.58 ± 1.17 to 37.95 ± 0.84 mg/L in all extraction techniques and ratios of solvents, followed by EGCG (9.71 ± 1.40-20.99 ± 1.11 mg/L), EGC + C (7.95 ± 0.66-12.58 ± 0.56 mg/L), and ECG (1.85 ± 0.71-6.05 ± 0.06 mg/L). The findings of DPPH (2,2-diphenyl-1-picryl-hydrazyl) free radical assay illustrated that HWE demonstrated the highest extraction efficiency at all ratios, ranging from 61.41 ± 1.00 to 70.36 ± 1.47 mg/L. The 1:50 ratio exhibited the highest extraction yield (25.98% ± 0.75%) compared to UAE (24.16% ± 0.95%) and EthE (22.59% ± 0.26%). Moreover, this method of extraction (i.e., HWE) produced the highest total catechins and %DPPH reduction. Consequently, HWE was the most efficient method for extracting catechins from GTW, underscoring its potential for valorizing waste within the food manufacturing industry.

RESUMEN

In-shell pecans are typically harvested after falling from trees to the ground, presenting a potential route of contamination of foodborne pathogens from soil contact. In-shell pecans are often subjected to various processing or washing steps prior to being shelled. This study determined Shiga toxin-producing Escherichia coli (STEC) reductions after treatment with antimicrobial washes on direct and soil-inoculated in-shell pecans and evaluated the cross-contamination potential of the spent pecan washes after treatment. Pecans were directly and soil-inoculated with an STEC cocktail (O157:H7, O157:NM, O121, O26). Direct inoculation was achieved by spraying the STEC cocktail on the pecans. For soil-inoculation pecans, autoclaved soil was sprayed with the STEC cocktail, homogenized for 2 min, and used to coat in-shell pecans. Inoculated pecans were washed in treatments of 2% lactic acid (LA), 1,000 ppm free chlorine (sodium hypochlorite; NaClO), hot water (HW; 85 ± 2 °C), or ambient water (C [control]; 18 ± 2 °C) for 2, 5, and 10 min and diluted to enumerate STEC populations. After treatments, 100 mL of the spent wash was vacuum filtered through a 0.45-µm membrane and plated on selective agar. HW significantly reduced STEC populations from pecans with and without soil regardless of treatment time (p < 0.05), NaClO reduced STEC populations more than the ambient control wash on directly inoculated pecans, but there were no significant differences between STEC reductions from ambient water (C), LA, and NaClO treatments on soil-inoculated pecans (p > 0.05). Larger STEC populations were enumerated from ambient water wash compared to the antimicrobial washes (p < 0.05). The HW, LA, and NaClO treatments were effective at maintaining the quality of the wash water, with STEC levels being generally at or below the detection limit (<1 CFU/100 mL), while HW was the most effective at reducing STEC from in-shell pecans with and without a soil coating (>5-log CFU/mL reductions).

Asunto(s)

RESUMEN

This study examined the impact of different dipping pre-treatments (PO: potassium carbonate-olive oil emulsion, HW: hot water) and drying methods (sun, oven, hot air, and freeze) on aronia berry quality. Freeze-drying showed the highest process yield (29.07%-29.43%), while sun-drying had the lowest (24.60%-25.74%). PO pre-treatment showed superior moisture and water activity reductions across all drying methods. Notably, it enhanced carotenoid levels (PO: 399.5, HW: 371.4 mg BCE/kg), antioxidant activity (PO: 9602.8, HW: 9403.3 mg TE/kg), total phenolics (PO: 38176.5, HW: 34804.0 mg GAE/kg) and flavonoids (PO: 6537.1, HW: 6141.5 mg CE/kg) during freeze-drying. Additionally, PO-treated samples exhibited superior rehydration properties, with a ratio of 293.32% and a 1.01 g/g capacity. On the other hand, HW pre-treatment increased ascorbic acid levels (PO: 377.0, HW: 391.7 mg/kg). The highest quality dried aronia berries are generally observed in PO-treated samples, especially in freeze drying, followed by hot-air, oven, and sun drying processes.

Asunto(s)

RESUMEN

Envenomation by marine animals poses a significant health concern globally, affecting both local residents and tourists in coastal regions. The primary objective of this review is to critically evaluate the existing scientific literature to determine the most effective first-aid treatment for envenomations caused by marine animals, specifically whether hot-water immersion (HWI) or ice-pack treatment (IPT) provides the best immediate care. This comprehensive review covers a wide range of marine envenomations, from jellyfish stings to stingray injuries. While our focus is primarily on the efficacy of HWI and IPT, we also explore the role of cold-water treatment as a result of its relevance and similarity to ice-pack applications. In addition, we examine other treatments mentioned in the literature, such as medications or vinegar, and highlight their findings where applicable. To provide a clear and structured overview, we summarised the articles in separate tables. These tables categorise the type of research conducted, the marine species studied, the region of origin of the marine species, and the key findings of each study. Our analysis of the available evidence indicates a general consensus in the scientific community on the effectiveness of HWI or IPT for envenomation by marine animals. However, when treating those injuries, it is crucial to consider all factors since there is no universally superior treatment due to the diverse nature of marine habitats.

Asunto(s)

RESUMEN

This study investigated the effects of Cinnamomum osmophloeum leaf hot-water extract (CLWE) on nonspecific immune responses and resistance to Vibrio parahaemolyticus in white shrimp (Penaeus vannamei). Firstly, a cell viability assay demonstrated that the CLWE is safe to white shrimp heamocytes in the concentration of 0-500 mg L-1. Haemocytes incubated in vitro with 10 and 50 mg L-1 of CLWE showed significantly higher response in superoxide anion production, PO activity, and phagocytic activity. In the in vivo trials, white shrimp were fed with 0, 0.5, 1, 5, and 10 g kg-1 CLWE supplemented feeds (designated as CLWE 0, CLWE 0.5, CLWE 1, CLWE 5, and CLWE 10, respectively) over a period of 28 days. In vivo experiments demonstrated that CLWE 0.5 feeding group resulted in the highest total haemocyte count, superoxide anion production, phenoloxidase activity, and phagocytic activity. Moreover, CLWE 0.5 supplemented feed significantly upregulated the clotting system, antimicrobial peptides, pattern recognition receptors, pattern recognition proteins, and antioxidant defences in white shrimp. Furthermore, the shrimp were infected with V. parahaemolyticus injections after 14 days of feeding as challenge test. Based on the challenge test result, both CLWE 0.5 and CLWE 5 demonstrated a strong resistance to V. parahaemolyticus. These two dosages effectively reduced the number of nonviable cells and activated different haemocyte subpopulations. These findings indicated that treatment with CLWE 0.5 could promote nonspecific immune responses, immune-related gene expression, and resistance to V. parahaemolyticus in white shrimp.

Asunto(s)

RESUMEN

PURPOSE: There is emerging evidence that demonstrates the health benefits of hot water immersion including improvements to cardiovascular health and reductions in stress and anxiety. Many commercially available hot tubs offer underwater massage systems which purport to enhance many benefits of hot water immersion, however, these claims have yet to be studied. METHODS: Twenty participants (4 females) completed three, 30-min sessions of hot-water immersion (beginning at 39 °C) in a crossover randomized design: with air massage (Air Jet), water massage (Hydro Jet) or no massage (Control). Cardiovascular responses comprising; heart rate, blood pressure and superficial femoral artery blood flow and shear rate were measured. State trait anxiety, basic affect, and salivary cortisol were recorded before and after each trial. Data were analysed using a mixed effects model. RESULTS: Post immersion, heart rate increased (Δ31bpm, P < 0.001, d = 1.38), mean arterial blood pressure decreased (Δ16 mmHg, P < 0.001, d = -0.66), with no difference between conditions. Blood flow and mean shear rate increased following immersion (P < 0.001, Δ362 ml/min, d = 1.20 and Δ108 s-1, d = 1.00), but these increases were blunted in the Air Jet condition (P < 0.001,Δ171 ml/min, d = 0.43 and Δ52 s-1, d = 0.52). Anxiety and salivary cortisol were reduced (P = 0.003, d = -0.20, P = 0.014, d = -0.11), but did not vary between conditions. Enjoyment did not vary between conditions. CONCLUSION: These data demonstrate positive acute responses to hot water immersion on markers of cardiovascular function, anxiety, and stress. There was no additional benefit of water-based massage, while air-based massage blunted some positive vascular responses due to lower heat conservation of the water.

Asunto(s)

RESUMEN

This study describes the extraction and characterization of the hemicellulosic autohydrolysates (HAHs) derived from rice straw (RS) and vascular aquatic weeds like Typha angustifolia (TA) and Ceretophyllum demersum (CD). It further explores their capacity to sustain the proliferation of selected lactic acid bacteria (i.e., prebiotic activity) isolated from milk samples. To fractionate HAH from RS, TA and CD hot water extraction (HWE) method was used and RS, TA, and CD biomasses yielded 6.8, 4.99 and 2.98% of HAH corresponding to the hemicellulose extraction efficiencies of 26.15 ± 0.8%, 23.76 ± 0.6%, and 18.62 ± 0.4% respectively. The chemical characterization of HAH concentrates through HPLC showed that they comprised galactose, arabinose, xylose and glucose. The total phenol content of the RS, TA and CD-derived HAH concentrates were 37.53, 56.78 and 48.08 mg GAE/g. The five lactic acid bacteria (LAB) isolates Q1B, Q2A, Q3B, G1C and G2B selected for prebiotic activity assays generated mixed responses with the highest growth in RS-HAH for Q2A and the least in TA-HAH for Q3B. Further, the isolates Q2A, Q3B, G1C, and G2B, which showed the highest growth performance, were identified through MALDI-TOF and 16S rRNA sequencing as Lactobacillus brevis. All the tested LAB isolates showed diauxic growth in crude HAH preparations to maximize the utilization of carbon resources for their proliferation. This suggests that the selected LAB isolates are efficient degraders of hemicellulosic sugars. This paves the way for the valorization of lignocellulosic biomass to produce prebiotic hemicellulosic autohydrolysate and consequently enhances environmental sustainability by improving resource efficiency.

Asunto(s)

RESUMEN

In this research, the wetting behavior of SiO2 modified with dodecyltrimethoxysilane (DTMS) was explored using both experimental and molecular dynamics (MD) simulation approaches. The experimental results reveal that DTMS can chemically bond to the SiO2 surface, and the contact angle (CA) reaches the maximum value of 157.7° when the mass of DTMS is twice that of SiO2. The different wetting behaviors caused by DTMS grafting were analyzed by CA fitting, ionic pairs, concentration distribution, molecule orientation, and interfacial interaction energy. The results demonstrate that a 25 % DTMS grafting rate resulted in a maximum CA of 158.2°, which is ascribed to the disruption of interfacial hydrogen bonding and changes in the hydration structure caused by DTMS grafting. Moreover, the above hydrophobic SiO2 model shows a slight decrease in CA as the water temperature increases, which is consistent with the experimental findings. In contrast, an opposite change was observed for the pristine SiO2 model. Although the higher water temperature enhances the diffusion capacity of water molecules in both models, the difference in interfacial interactions is responsible for the change in CA. We hope this finding will contribute to a deeper understanding of the wetting adjustment of SiO2.

Asunto(s)

RESUMEN

Crystalline copper oxide (CuO) nanostructures with micro, nano, and micro-nano surface roughness were grown on Cu sheet substrates by a facile, scalable, low-cost, and low-temperature hot water treatment (HWT) method that simply involved immersing Cu sheet in DI water at 75 °C for 24 h without any chemical additives. Various morphological features and sizes of CuO nanostructures were tuned by using different surface pretreatment techniques including acid treatment, sandblasting, or a combination of those two. The surface morphology of the prepared samples was analyzed by scanning electron microscopy. The crystal structure of the CuO nanostructures was investigated by x-ray diffraction XRD and Raman spectroscopy. To study the pseudocapacitive behavior, their potential supercapacitor performance, and equivalent series resistance, electrochemical analysis was done by cyclic voltammetry and electrochemical impedance spectroscopy for all the CuO/Cu samples in 1 M of Na2SO4electrolyte. Among all, the best supercapacitive performance was achieved for CuO/Cu samples pretreated with Sandblasting followed by Acid treatment resulting in a specific capacitance of about 104 F g-1. The electrode with the sandblasted + acid pretreated sample showed a maximum of ∼69% capacitive retention after 2000 consecutive cycles. Our results indicate that CuO nanostructures on Cu substrates prepared with different surface pretreatment conditions and grown by HWT can be promising electrodes for supercapacitor device applications.

RESUMEN

There is little evidence of the long-term consequences of maintaining sanitary hot water at high temperatures on the persistence of Legionella in the plumbing system. The aims of this study were to describe the persistence and genotypic variability of L. pneumophila in a hospital building with two entirely independent hot water distribution systems, and to estimate the thermotolerance of the genotypic variants by studying the quantity of VBNC L. pneumophila. Eighty isolates from 55 water samples obtained between the years 2012-2017 were analyzed. All isolates correspond to L. pneumophila serogroup 6. The isolates were discriminated in four restriction patterns by pulsed-field gel electrophoresis. In one installation, pattern A + Aa predominated, accounting for 75.8 % of samples, while the other installation exhibited pattern B as the most frequent (81.8 % of samples; p < 0.001). The mean temperature of the isolates was: 52.6 °C (pattern A + Aa) and 55.0 °C (pattern B), being significantly different. Nine strains were selected as representative among patterns to study their thermotolerance by flow-cytometry after 24 h of thermic treatment. VBNC bacteria were detected in all samples. After thermic treatment at 50 °C, 52.0 % of bacteria had an intact membrane, and after 55 °C this percentage decreased to 23.1 %. Each pattern exhibited varying levels of thermotolerance. These findings indicate that the same hospital building can be colonized with different predominant types of Legionella if it has independent hot water installations. Maintaining a minimum temperature of 50 °C at distal points of the system would allow the survival of replicative L. pneumophila. However, the presence of Legionella in hospital water networks is underestimated if culture is considered as the standard method for Legionella detection, because VBNC do not grow on culture plates. This phenomenon can carry implications for the Legionella risk management plans in hospitals that adjust their control measures based on the microbiological surveillance of water.

Asunto(s)

RESUMEN

Hot water mound drench treatment has broad application prospects in the control of the red imported fire ant (RIFA), Solenopsis invicta Buren (Hymenoptera: Formicidae). However, much work still needs to be carried out to provide a theoretical basis and technical support for the use of this method against RIFAs under field conditions. In this study, we monitored the temperature changes at different depths within RIFA nests during laboratory-simulated hot water mound drench experiments and evaluated the lethal effect of hot water treatment on RIFAs. Furthermore, the targeted removal effect of hot water mound drench treatment on RIFA nests under field conditions was evaluated. Results indicated that the temperature at depths of 5, 15, and 25 cm inside the simulated ant nests was higher than 51.1 °C within 30 min after treatment, resulting in a 100% mortality rate for RIFAs at all tested depths. Under field conditions, when nests were disturbed, the percentage of RIFAs crawling out of their nests gradually increased with time after disturbance, reached its maximum value at 25 or 30 s after the disturbance, and then gradually decreased. Single hot water mound drench treatment (each ant nest was treated with 17.8-21.6 liter of hot water at a temperature of 97-100 °C) can significantly reduce the RIFA population in ant nests and lead to a 72.7% reduction in the number of surviving ant nests. However, the safety, operability, and timelines of hot water mound drench treatment for RIFA field control still need further investigation.

Asunto(s)

RESUMEN

Ultrasound assisted hot water extraction (UAHWE) was applied to extraction of polysaccharides from Taraxacum mongolicum with hot water as extract solvent. Experimental factors in UAHWE process were optimized by response surface methodology. The optimal extraction parameters to achieve the highest Taraxacum mongolicum polysaccharides (TMPs) yield (12.08 ± 0.14)% by UAHWE were obtained under the ultrasound power of 200 W, extraction temperature of 62°C, solid-to-liquid ratio of 1:20 g/mL, and extraction time of 40 min, and then the crude TMPs were further purified by DEAE-52 and Sephadex G-100 chromatography to obtain a homogenous polysaccharide fraction (TMPs-1-SG). Subsequently, the structure of TMPs-1-SG was characterized by UV-vis, Fourier transform infrared spectroscopy (FT-IR), high performance gel permeation chromatography (HPGPC), high performance liquid chromatography (HPLC), scanning electron microscope (SEM), transmission electron microscopy (TEM), and Congo red test. The results display that TMPs-1-SG with an average molecular weight of 5.49 × 104 Da was comprised of mannose (Man), galactose (Gal), xylose (Xyl), and arabinose (Ara) with a molar ratio of 39.85:52.61:27.14:6.30. Moreover, TMPs-1-SG did not contain a triple helix structure. Furthermore, TMPs-1-SG and TEM presented a sheet-like, rod-shaped, and irregular structure. Finally, the antioxidant activity of TMPs-1-SG was evaluated by in vitro experiment. The IC50 values of scavenging DPPH and OH radicals for TMPs-1-SG achieved 0.71 mg/mL and 0.75 mg/mL, respectively. The findings can provide an effective method for extracting polysaccharides from natural resources.

Asunto(s)

RESUMEN

The number of nontuberculous mycobacteria (NTM) lung disease cases is increasing in the United States (US). This respiratory disease is primarily caused by three NTM species: Mycobacterium avium, M. intracellulare, and M. abscessus. Since disease transmission could occur through water aerosolization, this study investigated these three species' occurrence (sporadic and persistent) in hot water samples collected from residences (n = 70) and office buildings (n = 30) across the US. A longitudinal survey design was used. Three quantitative Polymerase Chain Reaction (qPCR) assays were used to measure the mycobacterial species in the water samples. Additionally, the water's disinfectant residual was measured. A structure's age and square footage were evaluated to predict mycobacterial contamination. Also, the seasonal occurrence of each species was assessed by structure type. Residences had a 43 % (30/70), and office buildings had a 77 % (23/30) detection frequency of one or more Mycobacterium spp. in their hot water. The age of the structure influenced M. intracellulare detection frequency but not M. avium and M. abscessus. The structure's square footage affected M. avium and M. intracellulare detection frequency but not M. abscessus. In chlorinated water, M. intracellulare was detected 1.4× more often in office buildings' hot water than in chloraminated water. In chloraminated water, the Mycobacterium spp. were detected 2-2.5× more often in residences, while M. avium and M. abscessus were detected 1.5-2.3× more often in office buildings, compared to chlorinated water. Each Mycobacterium spp. had a different trend associated with the type of structure and disinfectant. Further research is needed to better understand NTM occurrence in the built environment to improve public health.

Asunto(s)