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1.
Int J Biol Macromol ; : 132129, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38718994

RESUMO

This Review presents an overview of all-organic nanocomposites, a sustainable alternative to organic-inorganic hybrids. All-organic nanocomposites contain nanocellulose, nanochitin, and aramid nanofibers as highly rigid reinforcing fillers. They offer superior mechanical properties and lightweight characteristics suitable for diverse applications. The Review discusses various methods for preparing the organic nanofillers, including top-down and bottom-up approaches. It highlights in situ polymerization as the preferred method for incorporating these nanomaterials into polymer matrices to achieve homogeneous filler dispersion, a crucial factor for realizing desired performance. Furthermore, the Review explores several applications of all-organic nanocomposites in diverse fields including food packaging, performance-advantaged plastics, and electronic materials. Future research directions-developing sustainable production methods, expanding biomedical applications, and enhancing resistance against heat, chemicals, and radiation of all-organic nanocomposites to permit their use in extreme environments-are explored. This Review offers insights into the potential of all-organic nanocomposites to drive sustainable growth while meeting the demand for high-performance materials across various industries.

2.
Chemosphere ; 354: 141729, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38492680

RESUMO

The accumulation of petroleum-based plastics on our planet is causing serious environmental pollution. Biodegradable plastics, promoted as eco-friendly solutions, hold the potential to address this issue. However, their impact on the environment and the mechanisms of their natural degradation remain inadequately understood. Furthermore, the specific conditions set forth in international standards for evaluating the biodegradability of biodegradable plastics have led to misconceptions about their real-world behavior. To properly elucidate the relationship between their degradability and structure, this study mimics the thermal effect on poly(lactic acid) (PLA) under standardized composting temperature. The higher the crystallinity of PLA, the lower the degradation rate, which suggests that crystallinity is a key factor in determining degradation. The composting temperature of 58 °C induces crystallization by having a structural effect on the polymer, which in turn reduces the degradation rate of PLA. Therefore, control over temperature and crystallization during the processing and degradation of PLA is crucial, as it not only determines the biodegradability but also enhances the utility.


Assuntos
Plásticos Biodegradáveis , Compostagem , Temperatura , Poliésteres/química
3.
Adv Sci (Weinh) ; 11(16): e2302463, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38361378

RESUMO

Self-healing polymeric materials, which can repair physical damage, offer promising prospects for protective applications across various industries. Although prolonged durability and resource conservation are key advantages, focusing solely on mechanical recovery may limit the market potential of these materials. The unique physical properties of self-healing polymers, such as interfacial reduction, seamless connection lines, temperature/pressure responses, and phase transitions, enable a multitude of innovative applications. In this perspective, the diverse applications of self-healing polymers beyond their traditional mechanical strength are emphasized and their potential in various sectors such as food packaging, damage-reporting, radiation shielding, acoustic conservation, biomedical monitoring, and tissue regeneration is explored. With regards to the commercialization challenges, including scalability, robustness, and performance degradation under extreme conditions, strategies to overcome these limitations and promote successful industrialization are discussed. Furthermore, the potential impacts of self-healing materials on future research directions, encompassing environmental sustainability, advanced computational techniques, integration with emerging technologies, and tailoring materials for specific applications are examined. This perspective aims to inspire interdisciplinary approaches and foster the adoption of self-healing materials in various real-life settings, ultimately contributing to the development of next-generation materials.

4.
Nat Mater ; 23(3): 414-423, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38182810

RESUMO

The structure-property paradox of biological tissues, in which water-rich porous structures efficiently transfer mass while remaining highly mechanically stiff, remains unsolved. Although hydrogel/sponge hybridization is the key to understanding this phenomenon, material incompatibility makes this a challenging task. Here we describe hydrogel/sponge hybrids (hydrospongels) that behave as both ultrastiff water-rich gels and reversibly squeezable sponges. The self-organizing network of cyano-p-aramid nanofibres holds approximately 5,000 times more water than its solid content. Hydrospongels, even at a water concentration exceeding 90 wt%, are hard as cartilage with an elastic modulus of 50-80 MPa, and are 10-1,000 times stiffer than typical hydrogels. They endure a compressive strain above 85% through poroelastic relaxation and hydrothermal pressure at 120 °C. This performance is produced by amphiphilic surfaces, high rigidity and an interfibrillar, interaction-driven percolating network of nanofibres. These features can inspire the development of future biofunctional materials.

5.
Int J Biol Macromol ; 254(Pt 2): 127790, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37926305

RESUMO

Growing concerns regarding plastic waste have prompted various attempts to replace plastic packaging films with biodegradable alternatives such as poly(lactic acid) (PLA). However, their low hydrolysis resistance owing to the presence of aliphatic polyesters limits the shelf life of biodegradable polymers. Hydrolysis leads to the deterioration of mechanical performance, which is a key disadvantage of biodegradable plastics. In this study, a layer-by-layer (LBL) assembly method was used for the dip-coating of biorenewable, biodegradable nanocellulose/nanochitin on the PLA surface. Additional crosslinking and compression of the coated nanofibers, each containing carboxylic acid and amine groups, respectively, were induced through electromagnetic microwave irradiation to protect the PLA film by improving hydrolysis resistance. The coatings were examined by morphological observations and water contact angle measurements. The LBL coatings of differently charged nanofibers of 10.6 µm were reduced to 40 % after microwave treatment, and the thickness does not vary after the hydrolysis experiment. Microwave irradiation increased the water contact angle owing to amide linkage formation, thereby preventing the peeling off of coating layers. Improved hydrolysis resistance inhibited the reduction in molecular weight and tensile strength. These findings could be used to develop sustainable and biodegradable plastic packaging films with a prolonged shelf life.


Assuntos
Embalagem de Alimentos , Poliésteres , Hidrólise , Embalagem de Alimentos/métodos , Água
6.
Waste Manag ; 171: 568-579, 2023 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-37812971

RESUMO

Bioplastics offer a promising solution to plastic pollution, however, their production frequently relies on edible biomass, and their degradation rates remain inadequate. This study investigates the potential of superworms (Zophobas atratus larvae) for polybutylene succinate (PBS) waste management, aiming to achieve both resource recovery and biodegradation. Superworms exclusively fed on PBS for a month exhibited the same survival rate as those on a standard bran diet. PBS digestion yielded a 5.13% weight gain and a 23.23% increase in protein composition in superworms. Additionally, carbon isotope analyses substantiated the conversion of PBS into superworm components. Gut microbes capable of PBS biodegradation became progressively prominent, further augmenting the degradation rate of PBS under composting conditions (ISO 14855-1). Gut-free superworms fed with PBS exhibited antioxidant activities comparable to those of blueberries, renowned for their high antioxidant activity. Based on these findings, this study introduces a sustainable circular solution encompassing recycling PBS waste to generate insect biomass, employing insect gut and frass for PBS degradation and fertilizer, and harnessing insect residue as a food source. In essence, the significance of this research extends to socio-economic and environmental spheres, impacting waste management, resource efficiency, circular economy promotion, environmental preservation, industrial advancement, and global sustainability objectives. The study's outcomes possess the potential to reshape society's approach to plastic waste, facilitating a shift toward more sustainable paradigms.

7.
Plast Reconstr Surg Glob Open ; 11(5): e5029, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37250837

RESUMO

Facial skin quality profoundly influences an individual's perceived appearance and is an important aspect of facial rejuvenation. Facial pore enlargement is one of the most common concerns among Asian individuals that adversely impacts perceived skin surface evenness and affects overall skin quality. One of the major causes of enlarged pores is facial skin laxity. Microfocused ultrasound with visualization (MFU-V; Ultherapy; Merz North America, Inc., Raleigh, N.C.) is indicated for lifting and tightening of the face and neck, and improving the appearance of wrinkles on the décolletage. In addition, it is useful for addressing several aspects of facial rejuvenation, including facial pores, skin laxity, skin unevenness, etc., but there is limited literature on these applications. Thus, we present our proposed MFU-V treatment protocol for achieving a harmonious outcome for attractive skin, along with practical strategies for its application, illustrated in patients presenting with enlarged pores as their main concern. Drawing on our collective experience in using MFU-V for facial rejuvenation and the recently published skin quality framework that advocates addressing interrelated attributes of skin quality for optimal outcomes, we developed a treatment protocol for improving skin quality using MFU-V. This MFU-V treatment protocol reliably improves overall skin quality in patients presenting with enlarged pores, through MFU-V's effects on skin lifting and tightening, and consequent improvement in facial pores and skin texture. This treatment protocol can be readily used as part of a multimodal layering approach to yield successful outcomes in patients with various facial skin concerns.

8.
Clin Cosmet Investig Dermatol ; 16: 1249-1255, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37215534

RESUMO

Background: Despite the increasing need for the improvement of enlarged facial pores, the treatment remains challenging. A few previous studies have reported the effects of micro-focused ultrasound with visualization (MFU-V) or intradermal incobotulinumtoxin-A (INCO) on enlarged facial pores. Objective: To evaluate the efficacy and safety of combined treatment with superficial MFU-V and intradermal INCO for enlarged facial pores. Methods: This single-center retrospective study included 20 patients treated with MFU-V and intradermal INCO to improve enlarged facial pores. Outcomes were evaluated 1, 4, 12, and 24 weeks after a single session of the combined procedure. Pore count and density were objectively quantitated using a three-dimensional scanner, and improvement was assessed using the physician and patient Global Aesthetic Improvement Scale (GAIS). Results: The mean pore count and density decreased after one week and decreased by up to 62% until 24 weeks. After one week, almost all patients (100% in physician GAIS and 95% in patient GAIS) showed improvement with a grade 3 (much improved) or higher. All adverse events were transient. Conclusion: Combined treatment with MFU-V and intradermal INCO could be effective and safe for reducing enlarged facial pores; the improvements can be sustained for up to 24 weeks.

9.
Chemosphere ; 330: 138695, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37080474

RESUMO

Along with bisphenol-A (BPA), conventional phthalate esters (PAEs) have been reported as environmental hormones, despite their functional usefulness as plasticizers. Nevertheless, they are frequently found in various products, including children's utensils and toys made of poly (vinyl chloride). This is tremendously important because PAEs are harmful to infants. In addition, gel/slime-type toys made of poly (vinyl alcohol) are currently popular for developing infant' tactile senses. In this study, we developed a method to qualitatively and quantitatively detect PAEs in gel/slime-type toys mimicking, infants playing with them in a bathtub. As a result, 1,2-cyclohexanedicarboxylic acid diisononyl ester (DINCH), one of the PAE alternatives, transferred into the water from the toys and was detected most commonly (108-719 µg g-1; 0.01-0.07 wt%) among PAEs. The detected DINCH levels were below the universally accepted levels for PAEs (0.1 wt%). However, the amount of DINCH detected could still be toxic, in accordance with toxicity tests using water fleas. Furthermore, unpleasant odors were emitted when the toys containing toxic volatile organic compounds were unpacked. This is the first study to develop a method to analyze PAE in gel/slime-type toys and determine that alternatives to conventional PAEs cannot be unconditionally regarded as safe chemicals. Therefore, the revised standards for regulating PAEs and their alternatives must be reconsidered.


Assuntos
Ácidos Ftálicos , Criança , Humanos , Lactente , Plastificantes , Jogos e Brinquedos , Produtos Domésticos , Ésteres , Dibutilftalato , China
10.
J Cosmet Dermatol ; 22(6): 1805-1813, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37102267

RESUMO

BACKGROUND: The unique anatomy of the Asian face, along with the influence of cultural forces and regional preferences, has led to the development of specialized approaches to rejuvenation and beautification that are applicable to the aesthetic practice within Asia as well as those who serve these patients internationally. AIMS: To discuss similarities and differences in anatomy and treatment preferences of Asian patients and explore how these differences may influence aesthetic practices. PATIENTS/METHODS: In support of clinicians who wish to serve a diverse patient population, a six-part international roundtable series focused on diversity in aesthetics was conducted from August 24, 2021 to May 16, 2022. RESULTS: The results of the sixth and final roundtable in the series, the Asian Patient, are described here. Anatomical differences and their influence on treatment preferences are discussed, and specific procedural information provided for management of facial shape and projection, including advanced injection techniques for the eyelid-forehead complex. CONCLUSIONS: The continued exchange of ideas and treatment techniques support not only optimal aesthetic outcomes for a diverse range of patients within a given practice, but also the evolution of aesthetic medicine. The expert approaches detailed here may be used to inform treatment plans tailored to the Asian population.


Assuntos
Toxinas Botulínicas Tipo A , Técnicas Cosméticas , Humanos , Face , Testa , Estética
11.
Aesthet Surg J ; 43(9): 1015-1024, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-36857534

RESUMO

BACKGROUND: In aesthetic clinical practice, botulinum toxin type A (BoNT-A) is best known for its use as a neuromodulator for the treatment of dynamic facial lines; however, when injected intradermally as microdroplets, BoNT-A can improve skin quality and overall skin appearance. OBJECTIVES: To discuss key aspects of microtoxin use in clinical practice and provide expert guidance on utilization. METHODS: As part of a continuing medical education lecture series and roundtable, the authors discussed key aspects of microtoxin patient selection, injection technique, and safety. RESULTS: The experiences of expert faculty are shared here. Clinical experience is consistent with reported data. Microtoxin can be used to reduce pore size, sebum production, rosacea, acne, and fine lines, and to improve jawline and neck definition. Intradermal injection can also be employed for the improvement of transverse neck lines as well as for the safe prevention and management of scars and keloids. CONCLUSIONS: Expanding the use of BoNT-A, a predictable, minimally invasive, and affordable treatment to address commonly encountered complaints is appealing. The authors have found that making patients aware of microtoxin as a treatment option results in an increased interest in and utilization of BoNT-A, and high satisfaction among appropriately selected patients.


Assuntos
Toxinas Botulínicas Tipo A , Queloide , Humanos , Sebo , Pele , Injeções Intradérmicas
12.
Chemosphere ; 320: 138089, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36754297

RESUMO

Human society has become increasingly reliant on plastic because it allows for convenient and sanitary living. However, recycling rates are currently low, which means that the majority of plastic waste ends up in landfills or the ocean. Increasing recycling and upcycling rates is a critical strategy for addressing the issues caused by plastic pollution, but there are several technical limitations to overcome. This article reviews advancements in polymer technology that aim to improve the efficiency of recycling and upcycling plastic waste. In food packaging, natural polymers with excellent gas barrier properties and self-cleaning abilities have been introduced as environmentally friendly alternatives to existing materials and to reduce food-derived contamination. Upcycling and valorization approaches have emerged to transform plastic waste into high-value-added products. Recent advancements in the development of recyclable high-performance plastics include the design of super engineering thermoplastics and engineering chemical bonds of thermosets to make them recyclable and biodegradable. Further research is needed to develop more cost-effective and scalable technologies to address the plastic pollution problem through sustainable recycling and upcycling.


Assuntos
Plásticos , Polímeros , Humanos , Plásticos/química , Instalações de Eliminação de Resíduos , Poluição Ambiental , Tecnologia , Reciclagem
13.
Adv Mater ; 35(4): e2203325, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35639091

RESUMO

Nanochitin and nanochitosan (with random-copolymer-based multiscale architectures of glucosamine and N-acetylglucosamine units) have recently attracted immense attention for the development of green, sustainable, and advanced functional materials. Nanochitin and nanochitosan are multiscale materials from small oligomers, rod-shaped nanocrystals, longer nanofibers, to hierarchical assemblies of nanofibers. Various physical properties of chitin and chitosan depend on their molecular- and nanostructures; translational research has utilized them for a wide range of applications (biomedical, industrial, environmental, and so on). Instead of reviewing the entire extensive literature on chitin and chitosan, here, recent developments in multiscale-dependent material properties and their applications are highlighted; immune, medical, reinforcing, adhesive, green electrochemical materials, biological scaffolds, and sustainable food packaging are discussed considering the size, shape, and assembly of chitin nanostructures. In summary, new perspectives for the development of sustainable advanced functional materials based on nanochitin and nanochitosan by understanding and engineering their multiscale properties are described.


Assuntos
Quitosana , Nanofibras , Nanopartículas , Nanoestruturas , Quitina/química , Quitosana/química , Nanoestruturas/química , Nanofibras/química
14.
Polymers (Basel) ; 14(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36559855

RESUMO

Composite materials have been extensively studied to optimize properties such as lightness and strength, which are the advantages of plastics. We prepared a highly concentrated (30 wt %) nylon/chitosan nanowhisker (CSW) masterbatch by blending nylon 6,10 and CSW by solvent casting to achieve high dispersion efficiency while considering an industrial setting. Subsequently, 0.3 wt % nylon/CSW nanocomposites were prepared with a large quantity of nylon 6,10 via melt blending. During preparation, the materials were stirred in the presence of formic acid at different times to investigate the effect of stirring time on the structure of the CSW and the physical properties of the composite. The formation of nanocomposites by the interactions between nylon and CSW was confirmed by observing the change in hydrogen bonding using FT-IR spectroscopy and the rise in melting temperature and melting enthalpy through differential scanning calorimetry. The results demonstrated increases in complex viscosity and shear thinning. The rheological properties of the composites changed due to interactions between CSW and nylon, as indicated by the loss factor. The mechanical properties produced by the nanocomposite stirred for 1.5 h were superior, suggesting that formic acid caused minimal structural damage, thus verifying the suitability of the stirring condition.

15.
Adv Sci (Weinh) ; : e2205554, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-36403230

RESUMO

Among plastic items, single-use straws are particularly detrimental to marine ecosystems because such straws, including those made of poly(lactic acid) (PLA), are sharp and extremely slowly degradable in the ocean. While paper straws are promising alternatives, they exhibit hydration-induced swelling even when coated with a non-degradable plastic coating and promote effervescence (fizzing) in soft drinks owing to their surface heterogeneities. In this study, upgraded paper straw is coated with poly(butylene succinate) cellulose nanocrystal (PBS/CNC) composites. CNC increases adhesion to paper owing to their similar chemical structures, optimizes crystalline PBS spherulites through effective nucleation, and reinforces the matrix through its anisotropic and rigid features. The straws are not only anti-fizzing when used with soft drinks owing to their homogeneous and seamless surface coatings, but also highly water-resistant and tough owing to their watertight surfaces. All degradable components effectively decompose under aerobic composting and in the marine environment. This technology contributes to United Nations Sustainable Development Goal 14 (Life Below Water).

16.
J Clin Aesthet Dermatol ; 15(6): 10-21, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35783570

RESUMO

Objective: We sought to examine the current skin quality trends and gaps in clinical practice in the Asia Pacific region and develop a practical guide to improve skin quality. Methods: Medical practitioners from 11 countries in the Asia Pacific region completed an online survey on current trends in skin quality treatment. A panel of 12 leading experts convened for a virtual meeting to develop a practical guide for skin quality improvement. Results: A total of 153 practitioners completed the survey. The four most common skin quality issues were uneven skin tone, skin surface unevenness, skin laxity, and sebaceous gland hyperactivity and enlarged pores. Most practitioners reported using a combination of treatment modalities for each skin quality issue. It was also observed that each treatment modality could be used to treat several skin quality issues. A multimodal approach targeting different interrelated issues across the tissue planes was recommended for balanced results. The panel developed a practical guide for the appropriate combinations and sequence of treatments, and created treatment protocols for specific skin quality outcome goals. The guide employed an "inside-out" approach, treating the deeper tissue planes prior to the superficial layers to achieve harmonious results. Limitations: Future studies are needed to support the recommended treatment protocols for skin quality improvement. Conclusion: These findings provide valuable insights on current skin quality trends and gaps in clinical practice. The practical guide provides a framework for practitioners to customize their treatment plan according to each patient's needs.

17.
Plast Reconstr Surg Glob Open ; 10(6): e4407, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35747253

RESUMO

Botulinum neurotoxin A (BoNT-A) injection is the most widely performed aesthetic procedure and a first-line therapeutic option for various medical conditions. The potential for BoNT-A immunoresistance and secondary nonresponse related to neutralizing antibody (NAb) formation warrants attention as the range of BoNT-A aesthetic applications continues to expand. Methods: An international multidisciplinary panel reviewed published evidence on BoNT-A immunoresistance in aesthetic and therapeutic applications and discussed best practices integrating clinical, ethical, and aesthetic considerations. Consensus statements relating to awareness, assessment, and management of the risk of NAb-related secondary nonresponse in aesthetic practice were developed. Results: There was a consensus that, as doses used in aesthetic practice become like those in therapeutics, rates of NAb formation may be expected to increase. However, the true extent of NAb formation in aesthetics is likely underestimated due to limitations of published evidence and variability in treatment patterns of aesthetic patients. Since BoNT-A therapy is often lifelong, practitioners need to recognize immunogenicity as a potential complication that might affect future therapeutic use and strive to minimize modifiable risk factors. The selection and use of a BoNT-A product with the least immunogenic potential from the beginning may thus be advantageous, especially when treatment with high doses is planned. Conclusions: In view of current trends in BoNT-A aesthetic use, it is essential for practitioners to conduct thorough clinical assessments, inform patients of treatment risks, and develop BoNT-A treatment plans to minimize immunogenicity. This can help preserve the option of continued or future BoNT-A treatment with satisfactory outcomes.

18.
J Cosmet Dermatol ; 21(9): 3779-3786, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35699355

RESUMO

BACKGROUND: The use of hyaluronic acid (HA) fillers for medical aesthetic purposes is increasing worldwide. Nonetheless, adverse events do occur because of patient-specific issues, injection technique, or product factors. It would be mandatory to consider cultural and anatomical features of Asians in preventing and managing the complications of HA injections. METHODS: Literature search of studies looking at current evidence and guidelines on the management of complications following HA filler injections in Asian patients was conducted. This was followed by an expert group discussion that was convened to reach consensus recommendations on the best clinical practices. RESULTS: The expert panel provided specific recommendations focusing on the safe use of soft tissue fillers in Asian patients, including early identification of adverse events and how to prevent and comprehensively manage these outcomes. CONCLUSIONS: Here, we provide consensus statements of Asian experts in dermatology, plastic surgery, ophthalmology, and aesthetic medicine mainly focusing on AEs with higher risk for Asians and can be used to guide physicians in treating Asian population.


Assuntos
Técnicas Cosméticas , Preenchedores Dérmicos , Povo Asiático , Técnicas Cosméticas/efeitos adversos , Preenchedores Dérmicos/efeitos adversos , Estética , Humanos , Ácido Hialurônico/efeitos adversos , Injeções
19.
Chemosphere ; 303(Pt 1): 134946, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35569634

RESUMO

As plastic consumption has increased, environmental problems associated with the accumulation of plastic wastes have started to emerge. These include the non-degradability of plastic and its disintegration into sub-micron particles. Although some biodegradable plastic products have been developed to relieve the landfill and leakage burden, a significant portion of discarded plastics are inevitably still incinerated. The concern here is that incinerating plastics may result in the emission of toxic volatile organic compounds (VOCs). Moreover, lack of policy and the limited market share contributes to the indiscriminate discarding of biodegradable plastics, whereby it is mixed and subsequently incinerated with non-degradable plastics. The aim of this study was therefore to qualitatively and quantitatively analyze the VOCs emitted from both non-degradable and biodegradable plastics during combustion employing gas chromatography mass spectrometry. Here, non-degradable poly(vinyl chloride) and poly(ethylene terephthalate) emitted 10-115 and 6-22 ppmv of VOCs, respectively. These emission levels were more than 100 times higher than the VOC concentrations of 0.1-0.5 and 0.1-1.8 ppmv obtained for biodegradable polyhydroxyalkanoate and polylactic acid, respectively. Notably, due to the presence of a repeating butylene group in both non-degradable and biodegradable plastics, 1,3-butadiene accounted for the highest concentration among the VOCs identified, with concentrations of 6-116 ppmv and 0.5-558 ppmv obtained, respectively. During the evaluation of gas barrier films employed for food packaging purposes, non-degradable aluminum-coated multilayered films emitted 9-515 ppmv of VOCs, compared to the 2-41 ppmv VOCs emitted by biodegradable nanocellulose/nanochitin-coated films. Despite the significantly lower levels of VOCs emitted during the incineration of biodegradable plastics, this does not represent suitable waste treatment solution because VOCs are still emitted during incomplete combustion. This study aims to encourage further research into diverse combustion conditions for plastics and stimulate discussions on the fate of discarded plastics.


Assuntos
Plásticos Biodegradáveis , Compostos Orgânicos Voláteis , Cromatografia Gasosa-Espectrometria de Massas , Incineração , Plásticos/química , Compostos Orgânicos Voláteis/análise
20.
Plast Reconstr Surg Glob Open ; 10(4): e4217, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35450268

RESUMO

Background: Most botulinum toxin A (BoNT/A) products contain unnecessary bacterial components that increase the risk of developing neutralizing antibodies (nAbs). Reports of secondary nonresponse and treatment failures (STF) due to nAbs have accompanied a surge in new BoNT/A products. Methods: To formulate recommendations on managing toxin resistance, we reviewed the evidence on BoNT/A-associated immunogenicity and evaluated Asian physicians' current BoNT/A practices, knowledge, and real-world experiences, as provided by survey outcomes conducted with 128 Asian experts (regular botulinum toxin injectors). Results: Most doctors believe STF occurs, some patients exhibit partial symptoms, and impurities (eg, complexing proteins) in BoNT/A preparations risk STF. Bioassays that distinguish non-nAbs from nAbs that hinder toxin function remain unavailable to most doctors, though most would perform testing if given the option. Doctors in the Asia-Pacific region have differing strategies for managing STF, depending on the availability of alternatives or tests. They recommended switching to a highly-purified formulation free of complexing proteins and other impurities to lower the risk of immunogenicity, or offering treatment holidays of 2 -2.5 years. They suggested restarting treatment with the same highly purified formulation, especially for repeated treatments, large-dose injections, and younger patients who will accumulate higher lifetime doses, so as to minimize immunogenic risks and preserve long-term treatment outcomes. Importantly, doctors should always initiate patients on pure formulations rather than switching to these only after resistance develops. Conclusion: Choosing highly purified BoNT/A products at treatment initiation enhances long-term efficacy and patient satisfaction while minimizing the risk of immune activation and nAb formation.

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