RESUMO
Short-chain chlorinated paraffins (SCCPs) are an emerging class of persistent organic pollutants (POPs) that are widely detected in environmental matrices and human samples. Because of their environmental persistence, long-range transport potential, bioaccumulation potential, and biotoxicity, SCCPs pose a significant threat to human health. In this study, metabolomics technology was applied to reveal the metabolomic interference in human normal hepatic (L02) cells after exposure to low (1 µg/L), moderate (10 µg/L), and high (100 µg/L) doses of SCCPs. Principal component analysis (PCA) and metabolic effect level index (MELI) values showed that all three SCCP doses caused notable metabolic perturbations in L02 cells. A total of 72 metabolites that were annotated by MS/MS and matched with the experimental spectra in the Human Metabolome Database (HMDB) or validated by commercially available standards were selected as differential metabolites (DMs) across all groups. The low-dose exposure group shared 33 and 36 DMs with the moderate- and high-dose exposure groups, respectively. The moderate-dose exposure group shared 46 DMs with the high-dose exposure group. In addition, 33 DMs were shared among the three exposure groups. Among the 72 DMs, 9, 9, and 45 metabolites participated in the amino acid, nucleotide, and lipid metabolism pathways, respectively. The results of pathway enrichment analysis showed that the most relevant metabolic pathways affected by SCCPs were the lipid metabolism, fatty acid ß-oxidation, and nucleotide metabolism pathways, and that compared with low-dose exposure, moderate- and high-dose SCCP exposures caused more notable perturbations of these metabolic pathways in L02 cells. Exposure to SCCPs perturbed glycerophospholipid and sphingolipid metabolism. Significant alterations in the levels of phosphatidylcholines, phosphatidylethanolamines, and sphingomyelins indicated SCCP-induced biomembrane damage. SCCPs inhibited fatty acid ß-oxidation by decreasing the levels of short- and medium-chain acylcarnitines in L02 cells, indicating that the energy supplied by fatty acid oxidation was reduced in these cells. Furthermore, compared with low- and moderate-dose SCCPs, high-dose SCCPs produced a significantly stronger inhibition of fatty acid ß-oxidation. In addition, SCCPs perturbed nucleotide metabolism. The higher hypoxanthine levels observed in L02 cells after SCCP exposures indicate that SCCPs may induce several adverse effects, including hypoxia, reactive oxygen species production, and mutagenesis in L02 cells.
Assuntos
Hidrocarbonetos Clorados , Parafina , Humanos , Parafina/toxicidade , Parafina/análise , Espectrometria de Massas em Tandem , Hidrocarbonetos Clorados/toxicidade , Hidrocarbonetos Clorados/análise , Monitoramento Ambiental/métodos , Ácidos Graxos , Nucleotídeos , Hepatócitos/química , ChinaRESUMO
OBJECTIVE: Hand osteoarthritis (OA) is associated with considerable disability, especially in the elderly patient population. Paraffin wax (PW) and prolotherapy (P) are non-pharmacological treatment methods used in this setting. This study aimed to compare the therapeutic efficacy of P and PW in hand osteoarthritis. PATIENTS AND METHODS: This study was designed as a single-center, randomized-controlled trial conducted at our Physical Medicine and Rehabilitation Clinic between February 2019 and July 2020. Patients with bilateral hand OA were divided into PW and P treatment groups. The PW group was treated 5 days per week for 2 weeks. The P group received an injection of dextrose solution into the ligaments of painful joints once weekly for three weeks. Visual analog scale (VAS), Duruoz Hand Index (DHI) scale, hand dynamometer for grip strength, and pinch meter for lateral pinch were used for baseline and post-treatment follow-up assessments. RESULTS: Overall, 42 patients were included. The VAS scores significantly decreased in both PW and P groups (p=0.024 and p=0.014). Baseline and third-month post-treatment VAS scores did not significantly differ (p=0.581). The DHI scores improved significantly in both groups (p<0.001 and p<0.001), being higher in the P than in the PW group (p=0.042). Right- and left-hand grip strength increased significantly in PW and P groups (p<0.001, p=0.001; p=0.013, p=0.002, respectively). CONCLUSIONS: Both treatment methods were effective regarding pain and grip strength; however, P improved the hand functions more significantly.
Assuntos
Osteoartrite , Proloterapia , Humanos , Idoso , Parafina/uso terapêutico , Força da Mão , Proloterapia/métodos , Osteoartrite/tratamento farmacológico , Mãos , Resultado do TratamentoRESUMO
Oily sludge generated by the petroleum industry is not only an environmental hazard, but since it contains crude oil too, it is a valuable resource as well. This study demonstrates a methodology for the valorization of the oily sludge that allows the recovery of oil fractions by the action of microbes producing surface-active metabolites. Two bacterial isolates were used in the study that were producing different biosurfactants, identified via FTIR analysis as well as through genomic mapping of the biosurfactant pathways using RAST, ANTISMASH 7.0, STRING databases. Serratia spp. AKBS12, produced a mono-rhamnolipid, while Acinetobacter spp. AKBS16, produced emulsan. Although recovery efficiency of both biosurfactants was similar, the recovery profile with respect to the class of hydrocarbons differed. The rhamnolipid produced by Serratia spp. AKBS12 extracted mono-chained paraffins and linear alkanes, while emulsan, produced by Acinetobacter spp. AKBS16 could extract heavier paraffins. The extraction procedure is simple and involves mixing the biosurfactant with oily sludge at a temperature of 30 °C with an incubation of 9 days. Sulphuric acid precipitation releases the oil trapped in the oily sludge. The study is the first step in developing user-friendly, innovative technologies that can be linked to the concept of a circular economy.
Assuntos
Petróleo , Esgotos , Alcanos , Bactérias/genética , Bases de Dados Factuais , ParafinaRESUMO
Although peloid, paraffin, and exercise treatments are effective in patients with plantar fasciitis, there had been no comprehensive and comparative studies of these treatments for plantar fasciitis. The aim of our study was to evaluate the effects of peloid, paraffin, and exercise treatments on pain, functional status, and quality of life in patients with plantar fasciitis. A total of 104 patients, aged 18 years and over, who applied to our clinic with heel pain and were diagnosed with plantar fasciitis according to the American College of Foot and Ankle Surgeons Clinical Consensus Statement: Diagnosis and Treatment of Adult Acquired Infracalcaneal Heel Pain guideline, with pain at the level of 3 and more severe according to the visual analog scale were randomly divided into three groups: the peloid group (peloid therapy and home exercise), the paraffin group (paraffin therapy and home exercise), and the control group (home exercise). Peloid and paraffin applications were applied 5 days a week, a total of 15 sessions in 3 weeks. Participants were evaluated with the visual analog scale, heel tenderness index, and the foot and ankle outcome score before treatment, after treatment, and at the first month after treatment. Compared to pre-treatment evaluation, significant improvements were observed in all parameters after treatment and at the first month controls in all 3 groups (p < 0.05). In the peloidotherapy and paraffin therapy added groups, pain reduction and quality of life increase were higher than the exercise group (p < 0.05). Adding peloidotherapy or paraffin therapy to the home exercise program in the treatment of plantar fasciitis can further reduce pain and improve quality of life.
Assuntos
Fasciíte Plantar , Adulto , Humanos , Adolescente , Fasciíte Plantar/terapia , Parafina/uso terapêutico , Qualidade de Vida , Dor , Terapia por Exercício , Resultado do TratamentoRESUMO
Raw materials suitable for a sustainable society have attracted interest in the cosmetics industry. We focused on rice bran as a sustainable material and evaluated the gelation behavior of paraffin extracted from rice bran (rice paraffin) against liquid paraffin, squalane, jojoba oil, and silicone oil. In addition, the frictional properties of the prepared organogel on an artificial skin surface were evaluated using a sinusoidal motion friction evaluation system. Rice paraffin solidified all oils even at the lowest wax concentration of 5 wt%. The hardness and kinetic friction coefficient µ k increased with an increase in the wax composition. The hardness and µ k of organogels solidified with rice paraffin were smaller than those of gels solidified with petroleum-derived paraffin. These differences are caused by the smaller carbon amount of rice paraffin. The friction parameters depended on the type of oil: the µ k of RLG composed of rice and liquid paraffin was greater than that of the other three oils (R, L, and G denote rice paraffin, liquid paraffin, and gel, respectively). These findings promote the development of lipsticks and cleansing gels consisting of sustainable development goal-responsive raw materials.
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Oryza , Parafina , Óleo Mineral , Fricção , Óleos , Géis , Óleo de Farelo de ArrozRESUMO
The trace level detection of adulterants in food, nutritional supplements and medicinal herbs is highly challenging in the field of food processing and herbal industries. In addition, laborious sample processing procedures and well trained personnel are required to analyse the samples using conventional analytical equipments. In this study, a highly sensitive technique with minimal sampling processes and human intervention is proposed for the trace amount detection of pesticidal residues in centella powder. Herein, graphene oxide gold (GO-Au) nanocomposite coated parafilm is developed as substrate by simple dropcasting technique to facilitate dual surface enhanced Raman signal. The dual SERS enhancement involving chemical enhancement from graphene and electromagnetic signal enhancement from gold nanoparticles is utilized for detection of chlorpyrifos in the ppm level concentration. The flexible polymeric surfaces could be the better choice for SERS substrates due to their inherent properties such as flexibility, transparency, roughness and hydrophobicity. Among the various types of flexible substrates explored, GO-Au nanocomposites coated parafilm substrates showed better Raman signal enhancement. Parafilm coated with GO-Au nanocomposites is successful in achieving detection limits down to 0.1 ppm of chlorpyrifos in centella herbal powder sample. Thus, the fabricated parafilm based GO-Au SERS substrates could be used as a screening tool at quality control of herbal product manufacturing sectors for trace level detection of adulterants in herbal samples from their unique chemical and structural information.
Assuntos
Centella , Clorpirifos , Nanopartículas Metálicas , Humanos , Análise Espectral Raman/métodos , Ouro/química , Parafina , Pós , Nanopartículas Metálicas/químicaRESUMO
BACKGROUND/AIM: Post-stroke spasticity is a significant debilitating condition with negative consequences on individual functional independence and quality of life. This study aimed to identify the differences between transcutaneous electrical stimulation (TENS), ultrasound therapy and paraffin procedures on post-stroke upper extremity spasticity and dexterity. PATIENTS AND METHODS: Twenty-six patients were enrolled in the study, divided into three therapy groups: TENS (n=9), paraffin (n=10) and ultrasound therapy (n=7). For 10 days, the patients received specific group therapy and conventional physical therapy exercises for upper extremities. Modified Ashworth Scale, Functional Independence Measure, Functional Coefficient, Stroke Specific Quality of Life Scale, Activities of Daily Living score and ABILHAND questionnaire were used to assess the participants before and after therapy. RESULTS: The results of the group comparisons by analysis of variance showed no significant difference between outcomes by the applied treatments. In contrast, one-way analysis of variance suggested significant improvements in patients in all three groups after therapy. Step-wise regression results on functional independence measure and quality-of-life scales suggested that functional range of motion values for elbow and wrist influence individual independence and quality of life. CONCLUSION: TENS, ultrasound, and paraffin therapy bring equal benefits in the management of post-stroke spasticity.
Assuntos
Acidente Vascular Cerebral , Estimulação Elétrica Nervosa Transcutânea , Humanos , Parafina , Atividades Cotidianas , Qualidade de Vida , Modalidades de Fisioterapia , Extremidade Superior , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/terapiaRESUMO
Paraffin (petroleum) oils have been used for many years for their insecticidal properties, but relatively little research had been conducted towards their introduction into the agricultural praxis, due to their potential phytotoxic effects. In the recent years, however, there has been an increased interest in petroleum-based pesticides due to their compatibility with integrated pest management (IPM) programs. Various improvements in the refinement methods have enhanced the manufacture of commercial products with many advantageous features over the original oil formulas. However, literature is still lacking of a general overview about the applicability of newly introduced commercial petroleum oils in agriculture and their compatibility with modern pest management practices. Therefore, the present work aims to depict the current status of petroleum oils in arboriculture and beyond, providing an in-depth analysis of their insecticidal properties with respect to the knowledge gained over the years about the factors responsible for the pesticidal efficacy and the phytotoxic activity of petroleum-derived oil insecticides. Moreover, commercial aspects of petroleum oil formulations and their toxicological profile to non-target organisms have also been addressed through the current legislation in EU and the USA.
Assuntos
Inseticidas , Praguicidas , Petróleo , Parafina , Agricultura , ÓleosRESUMO
OBJECTIVE: This study aimed to compare the effects of therapeutic ultrasound and paraffin with or without vacuum massage on the biomechanical properties of grafted skin after a burn. METHODS: A total of 44 patients with deep second- and third-degree burns, with a mean age of 35.89 (±11.53) years, who visited the Hospital Burn Unity, were included in the study. The therapeutic interventions were randomly defined by drawing lots, with a crossover design (crossover), and a minimum interval of 7 days (washout) between interventions. Skin biomechanical parameters such as distensibility (R0) and viscoelasticity (R6) were noninvasively evaluated by Cutometer before and after 0, 10, 20, and 30 min of intervention with therapeutic ultrasound and paraffin alone, as well as associated with negative pressure therapy of the skin (vacuum therapy). In this study, all groups showed increased distensibility (R0) in the period immediately after the application of the resources and a progressive reduction in the effects in the consecutive tests. Participants with skin grafts showed a decrease in viscoelasticity (R6) in all groups, except therapeutic paraffin and therapeutic ultrasound and vacuum massage. CONCLUSION: The biomechanical properties of grafted skin after a burn are altered after therapeutic intervention with ultrasound alone or associated with vacuum massage, such as intervention with paraffin associated with vacuum massage, for both parameters evaluated, skin distensibility (R0) and skin viscoelasticity (R6). However, the same did not occur for the intervention with isolated paraffin. There was no significant difference between the interventions therapeutic ultrasound and therapeutic paraffin.
Assuntos
Queimaduras , Terapia por Ultrassom , Humanos , Adulto , Parafina , Pele , Queimaduras/terapia , MassagemRESUMO
In oral and maxillofacial surgery, flap repair is essential to the quality of postoperative life. Still, thrombosis is fatal for the survival of the flaps. Besides, some postoperative thrombotic diseases, such as pulmonary embolism, also intimidate patients' life. The traditional diagnostic methods are still limited by a large amount of hardware and suffer from inconvenience, delay, and subjectivity. Moreover, the treatments mainly rely upon thrombolytics, such as urokinase (UK) plasminogen activator, which may cause bleeding risk, especially intracerebral hemorrhage. Herein, a kind of poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) containing a first near-infrared window (NIR-I) phototheranostic agent Y8 and urokinase plasminogen activator (UK) as the core, and modified with the fibrin-targeting peptide Gly-Pro-Arg-Pro-Pro (GPRPP) were developed for the flap and postoperative thromboembolism treatment (named GPRPP-Y8U@P). The conjugated molecule Y8 endows GPRPP-Y8U@P with the capacity of NIR-II imaging and excellent photothermal/photodynamic therapeutic effects. In vivo experiments demonstrated that GPRPP-Y8U@P could quickly locate thrombus by NIR-II fluorescence imaging, and semi-quantitative analysis of the embolized blood vessels' paraffin section verified its thrombolytic efficiency. Additionally, the urokinase trapped in the NPs would not result in nonspecific bleeding, tremendously improving physical security and curative effects with minimizing side effects. Overall, the advantages of GPRPP-Y8U@P, such as precise localization of the thrombus, thrombus ablation in the site, and mild side effects, demonstrated the attractiveness of this approach for effective clinical monitoring of thrombus therapy.
Assuntos
Antineoplásicos , Nanopartículas , Tromboembolia , Trombose , Fibrina , Humanos , Nanopartículas/química , Nanopartículas/uso terapêutico , Imagem Óptica , Parafina , Fototerapia/métodos , Trombose/diagnóstico por imagem , Trombose/tratamento farmacológico , Ativador de Plasminogênio Tipo Uroquinase/uso terapêuticoRESUMO
Although peloid and paraffin treatments may have a positive effect in the short term on pain, functional status, hand grip strength, and quality of life in patients with hand osteoarthritis (HOA), there are no comprehensive and comparative studies of these therapies for HOA. The aim of our study was to evaluate the short-term effects of peloid and paraffin treatments in symptomatic HOA patients. Eighty female patients diagnosed with HOA were randomly divided into two equal groups: peloid group (peloid therapy and home exercise) and paraffin group (paraffin therapy and home exercise). Peloid and paraffin applications were performed over 3 weeks for a total of 15 sessions. Patients were evaluated with visual analog scale (VAS)-rest, -activity, and -handgrip for pain, Jamar hand dynamometer for grip strength, Australian/Canadian (AUSCAN) Osteoarthritis Hand Index for function, health assessment questionnaire (HAQ) for physical activity, Beck depression inventory (BDI) for depression, and short form-36 (SF-36) for quality of life. Evaluations were performed before treatment, in the 3rd week, and 1 month after treatment. For all parameters except SF-36, statistically significant improvements were observed in short-term evaluations compared to the baseline in both groups (p = .000). Reductions in HAQ scores in the 3rd week and 1st month (p = .001 and p = .003), and the decrease in BDI scores in the 3rd week (p = .005) was statistically significantly higher in the peloid group. Improvements in some subparameters of the SF-36 were statistically significant in favor of the peloid group. In female patients with HOA, both groups experienced similar positive effects on pain, functional status, and hand grip strength for up to one month, but the peloid group was found to be superior in the short term in terms of physical activity and some quality of life parameters. Peloid therapy can be preferred as a natural and reliable method for symptomatic HOA.
Assuntos
Força da Mão , Osteoartrite , Austrália , Canadá , Feminino , Mãos , Humanos , Dor , Parafina , Qualidade de Vida , Método Simples-Cego , Resultado do TratamentoRESUMO
Traditional Chinese medicine (TCM) provides therapeutic and health care effects through dietary intake. Owing to the susceptibility of plants to contaminations, a risk assessment system is urgently needed to ensure the safe use of TCMs. In this study, the contamination levels and risks associated with the dietary intake of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were investigated in six kinds of frequently-used TCM herbs. The concentrations varied from 144.4 to 1527.8 ng·g-1 dw for SCCPs and non-detect to 1214.1 ng·g-1 dw for MCCPs, with mean values of 551.5 and 259.8 ng·g-1 dw, respectively. A geographic distribution analysis indicated that the concentrations of CPs in TCMs were mainly associated with their levels of contamination in the ambient environment. Carbon atom-chlorine congener profiles of CPs were dominated by C10Cl7-8 and C14Cl7-8 congeners, accounting for 20.1% and 32.4% of the total SCCP and MCCP concentrations, respectively. Principal component analysis indicated that the TCM species might be the main factor influencing the accumulation of SCCPs congeners. Finally, a risk assessment reveals that the estimated daily intake and margin of exposure were far below levels that might pose a health risk, indicating an acceptable dietary intake of SCCPs and MCCPs in the studied TCMs. This is the first report of CPs in the TCM herbs and the obtained results are expected to aid in future evaluation of the quality of TCMs and ensuring diet and drug safety.
Assuntos
Hidrocarbonetos Clorados , Parafina , Parafina/análise , Exposição Dietética/análise , Hidrocarbonetos Clorados/análise , Cloro/análise , Rizoma/química , Medicina Tradicional Chinesa , Monitoramento Ambiental/métodos , Medição de Risco , Carbono/análise , ChinaRESUMO
Although it is thought that peloid and paraffin treatments may have positive effect on pain, functional status, and quality of life in patients with hallux rigidus (HR), there are no comprehensive and comparative studies with a high level of evidence. We aimed to compare peloid and paraffin treatments in symptomatic hallux rigidus patients. A total of 113 patients diagnosed with HR between May 2019 and June 2021 were included in the study. After exclusion criteria, the remaining 90 patients were randomly divided into two groups: the peloid therapy group (peloid therapy + home exercise) and the paraffin therapy group (paraffin therapy + home exercise). Peloid and paraffin treatments were applied for 2 weeks (5 days a week for a total of 10 sessions). Patients were evaluated before treatment, at the end of treatment, and one month after treatment. The groups were compared in terms of pain, functional status, quality of life, and joint range of motion. In the final analysis, 40 patients in each treatment group were compared. Statistically significant improvements were achieved for all parameters at the end of treatment and at follow-up, and the treatments were found to be highly effective. As a result of the comparison, the methods were not found to be superior to each other. The present study is the first randomized study comparing peloid therapy and paraffin therapy given as an adjuncts to exercise therapy. Exercise therapy plus peloid and exercise therapy plus paraffin treatments seem to have similar effects on HR; however, controlled trials are necessary for confirmation of our results.
Assuntos
Hallux Rigidus , Peloterapia , Terapia por Exercício , Hallux Rigidus/terapia , Humanos , Dor , Parafina/uso terapêutico , Estudos Prospectivos , Qualidade de Vida , Resultado do TratamentoRESUMO
This study aimed to assess different approaches for bone healing evaluation on histological images and to introduce a new automatic evaluation method based on segmentation with distinct thresholds. We evaluated the hyperbaric oxygen therapy (HBO) effects on bone repair in type 1 diabetes mellitus rats. Twelve animals were divided into four groups (n = 3): non-diabetic, non-diabetic + HBO, diabetic, and diabetic + HBO. Diabetes was induced by intravenous administration of streptozotocin (50 mg/kg). Bone defects were created in femurs and HBO was immediately started at one session/day. After 7 days, the animals were euthanized, femurs were removed, demineralized, and embedded in paraffin. Histological sections were stained with hematoxylin and eosin (HE) and Mallory's trichrome (MT), and evaluated using three approaches: (1) conventional histomorphometric analysis (HE images) using a 144-point grid to quantify the bone matrix; (2) a semi-automatic method based on bone matrix segmentation to assess the bone matrix percentage (MT images); and (3) automatic approach, with the creation of a plug-in for ImageJ software. The time required to perform the analysis in each method was measured and subjected to Bland-Altman statistical analysis. All three methods were satisfactory for measuring bone formation and were not statistically different. The automatic approach reduced the working time compared to visual grid and semi-automated method (p < .01). Although histological evaluation of bone healing was performed successfully using all three methods, the novel automatic approach significantly shortened the time required for analysis and had high accuracy.
Assuntos
Oxigenoterapia Hiperbárica , Parafina , Animais , Amarelo de Eosina-(YS) , Hematoxilina , Oxigenoterapia Hiperbárica/métodos , Ratos , EstreptozocinaRESUMO
Simultaneous renewable energy generation is an imperative part of sustainable hazardous waste management. Therefore, the present work explicates the co-pyrolysis of rice stubble (RS) waste biomass and spent motor oil (SMO) to upgrade the obtained bio-oil. Moreover, two different modes, namely, in-situ and ex-situ, were implemented to analyze the effect of physical inhibition. Monothetic analysis approach was followed to determine optimum process conditions. A substantial increment of â¼ 85% was observed in bio-oil yield for RS: SMO (1:1) in-situ operation whilst the only RS biomass pyrolysis. Moreover, the HHV increased by â¼ 2.15 times after co-pyrolysis with a considerable reduction (62.70%) in water content. Consequently, the paraffin content increased to 79.14 vol% with an iso-paraffin index of 0.285. Subsequently, a possible reaction mechanism is also proposed to evaluate results comprehensively. Altogether, the co-pyrolysis of these feedstocks resulted in improved aliphatic content and reduced oxygenates, encouraging its adequacy as an alternate fuel.
Assuntos
Petróleo , Pirólise , Biocombustíveis , Biomassa , Catálise , Temperatura Alta , ParafinaRESUMO
Chlorinated paraffins (CPs) are an emerging group of environmental pollutants associated with adverse effects on human health (such as endocrine disruption and possible carcinogenicity). CPs are classified into several groups: short- (SCCPs), medium- (MCCPs) and long-chain chlorinated paraffins (LCCPs). In this study, CPs were determined in fish oil-based omega-3 dietary supplements (DS) representing widely consumed products that might be contaminated with various lipophilic contaminants including CPs. The CPs were isolated from DS (n = 85) by solid phase extraction. The SCCPs and MCCPs were determined by gas chromatography coupled with high-resolution mass spectrometry operated in a negative chemical ionisation mode. The LCCPs (up to C21) were screened using supercritical fluid chromatography coupled with high-resolution mass spectrometry with electrospray ionisation operated in negative mode. The CP concentrations varied from <0.01 to 56.48 µg/g fat for SCCPs (median 0.12 µg/g fat; limit of quantification, LOQ, for SCCPs was exceeded in 51 out of 85 samples) and from <0.03-89.08 µg/g fat for MCCPs (median 0.26 µg/g fat; LOQ for MCCPs was exceeded in 66 out of 85 samples), respectively. The LCCPs were not quantified in this study, nevertheless their limit of detection (0.5 µg/g fat) was exceeded in 7 out of 85 samples. Due to high levels of CPs, DS might pose as a significant source of CPs exposure to some population groups.
Assuntos
Gorduras Insaturadas na Dieta , Hidrocarbonetos Clorados , China , Gorduras Insaturadas na Dieta/análise , Suplementos Nutricionais/análise , Monitoramento Ambiental , Óleos de Peixe , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos Clorados/análise , Parafina/análiseRESUMO
The addition of thermally conductive nanomaterials is an effective strategy for increasing the thermal conductivity of phase change materials (PCMs). However, nanomaterials are expensive and may significantly reduce the latent heat capacity of PCMs. In this study, low-cost and eco-friendly biochar microparticles were prepared from garlic stems, a common food waste in Singapore. The thermal properties of paraffin wax (PW) doped with 1, 3, and 5 wt% garlic stem biochar (GSB) microparticles were investigated. The GSB microparticles prepared at 700 °C had three-dimensional porous and two-dimensional flake-like structures, which contributed to the formation of additional heat transfer pathways in the PW. The addition of 5 wt% GSB microparticles enhanced the thermal conductivity of PW by 27.3% and 7.2% in the solid and liquid phases, respectively. The T-history test revealed that the melting and solidification rates of PW improved by 90 and 115 s, respectively. The improved heat transfer performance was mainly ascribed to the high degree of graphitization and the interconnected porous carbon structure of the GSB microparticles. The phase change temperatures of PW were slightly changed upon the addition of GSB microparticles, and the latent heat capacity was only reduced by 6.1%. These results suggest that the GSB microparticles can be used as a potential alternative to other nanoadditives such as metal- and metal oxide-based nanoadditives.
Assuntos
Alho , Eliminação de Resíduos , Carvão Vegetal , Alimentos , Parafina , Condutividade TérmicaRESUMO
Lecithin reverse wormlike micelles (LRWs) have been studied recently for dermal application dosage use but the effects of the physicochemical properties of oils on the formation and rheological properties of LRWs have not been investigated. We studied the effect of oil on the formation of LRWs using 5 types of liquid paraffin (LP) with kinematic viscosities ranging from 4.00 to 88.0 mm2/s. Partial phase diagrams of lecithin/water/LP systems indicated that LPs with low molecular weights could form LRWs with only a small amount of water, but LPs with high molecular weights could not form LRWs, regardless of the water concentration. The solubility of lecithin in LPs was higher for low molecular weight LPs, thus possibly affecting the formation of LRWs. The zero-shear viscosity and relaxation time of LRWs initially increased with increasing water concentration, and then decreased. The water concentration providing the maximum value was dependent on the molecular weight of the LP, whereas the maximum amount and length of the LRWs were independent of the water concentration. Our results indicate that the molecular weight of LP affects the ease of formation and the viscoelasticity of LRWs.
Assuntos
Lecitinas/química , Parafina/química , Físico-Química , Micelas , ReologiaRESUMO
Chlorinated paraffins (CPs) have been found to occur ubiquitously in foodstuff of both animal and plant origin. However, limited information is available on the content of CPs in green tea, one of the most commonly consumed beverages worldwide. Herein, 107 commercial green tea samples originating from 11 provinces of China, were collected to study the occurrence of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively). The concentration of SCCPs in all green tea samples ranged from 4.99 to 717 ng/g (mean: 55.7 ng/g), while MCCPs ranged from 2.55 to 543 ng/g (mean: 33.5 ng/g). CP profiles in green tea samples from different provinces exhibited no regional differences. To identify the potential sources of CPs in green tea, 19 tea packaging samples were collected and analyzed, showing that SCCPs and MCCPs existed at much higher concentrations in the tea packaging material than in the teas. Migration tests indicated that CPs could migrate from packaging into teas during storage, with the migration velocity and efficiency of SCCPs being higher than MCCPs.