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1.
Contact Dermatitis ; 90(3): 273-279, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38164086

RESUMO

BACKGROUND: The growing popularity of nail techniques based on acrylates has led to a higher frequency of sensitization in both nail technicians and users. OBJECTIVES: The study aimed to assess cases of allergic contact dermatitis (ACD) caused by acrylates in individuals with occupational or non-occupational exposure to nail techniques. METHODS: A preliminary study was conducted on 30 patients with ACD caused by acrylates in nail techniques, who were patch tested from September 2022 to March 2023 at the First Department of Dermatology and Venereology of Andreas Syggros Hospital, Athens, Greece. RESULTS: Thirty female patients with ACD to acrylates were documented (15 users and 15 nail technicians and users). The most common allergens were: 2-hydroxyethyl methacrylate (HEMA), 2-hydroxypropyl methacrylate (HPMA) and ethyleneglycol dimethacrylate (EGDMA), which tested positive in all 30 patients (100.0%). Twenty patients (66.7%) had been exposed to dental procedures involving acrylates, before the onset of ACD. Nail technicians exhibited extensive skin lesions, 40.0% experienced ACD within the first year of work and 13.3% during their professional practice. Three of them (20.0%) had to discontinue their work. CONCLUSION: Acrylates have been identified as potent allergens, necessitating the implementation of safety measures for the use of these chemicals in nail techniques.


Assuntos
Cosméticos , Dermatite Alérgica de Contato , Dermatite Ocupacional , Humanos , Feminino , Dermatite Alérgica de Contato/etiologia , Acrilatos/efeitos adversos , Projetos Piloto , Grécia , Testes do Emplastro/métodos , Estudos Retrospectivos , Metacrilatos/efeitos adversos , Alérgenos , Cosméticos/efeitos adversos , Dermatite Ocupacional/complicações
2.
Contact Dermatitis ; 90(5): 507-513, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38351475

RESUMO

BACKGROUND: A global epidemic of allergic contact dermatitis to (meth)acrylates has been described in relation to the widespread use of manicure products. OBJECTIVES: To evaluate the frequency of sensitization to 2-hydroxyethyl methacrylate (2-HEMA) among consecutively patch tested patients with eczema in Spain; the percentage of current relevance; the MOAHLFA index; and, the potential sources of exposure to (meth)acrylates. METHODS: From January 2019 to December 2022, 2-HEMA 2% pet. was prospectively patch tested in 24 REIDAC (Spanish Allergic Contact Dermatitis Registry) centres. RESULTS: Six thousand one hundred thirty-four patients were consecutively patch tested with 2-HEMA 2% pet. 265/6134 (4.3%) were positive. Positive reactions of current relevance were identified to involve 184/265 (69%). The efficiency (number of patch tests needed to detect relevant positive patch test reactions) was 34 (6134/184). The variable 'occupational' was found to be significantly associated with a higher risk for relevant positive reactions to 2-HEMA (OR: 10.9; 95% CI: 8.1-14.9). CONCLUSION: (Meth)acrylate sensitization is a prevalent health issue in Spain. 2-HEMA 2% pet. has been identified to be a highly effective (meth)acrylate allergy marker in the GEIDAC baseline series. The responsible authorities should implement policies guaranteeing accurate labelling of industrial, medical, and consumer materials while ensuring the enforcement of said labelling through appropriate legal means.


Assuntos
Dermatite Alérgica de Contato , Dermatite Ocupacional , Humanos , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/epidemiologia , Dermatite Alérgica de Contato/etiologia , Espanha/epidemiologia , Metacrilatos/efeitos adversos , Acrilatos , Testes do Emplastro
3.
Contact Dermatitis ; 91(1): 38-44, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38561321

RESUMO

BACKGROUND: Artificial nail modelling systems (ANMS) pose a significant risk for nail stylists and their clients regarding acrylate sensitization, which might jeopardize the use of acrylate-containing medical devices. OBJECTIVES: To evaluate the frequency of artificial nail practices among female healthcare workers (HCWs) compared with controls and assess ANMS-related side effects. METHODS: In this comparative, cross-sectional, single-centre study, a face-to-face interview with 200 female HCWs and 200 age-matched female dermatology patients (controls) was conducted regarding the use of ANMS between March and November 2023. RESULTS: Among 400 participants (median age: 25), 85 (21.3%) have applied ANMS at least once. The prevalence of ANMS application was significantly higher in HCWs (n = 54/200, 27%) compared with controls (n = 31/200, 15.5%) (p < 0.05). Long-lasting nail polish was the most commonly preferred technique (n = 82/85, 96.5%). ANMS were mainly performed in nail studios by nail stylists (n = 79/85, 92.9%), while three participants were using home kits. Nail brittleness was the most frequently reported side effect (n = 19/85, 22.4%). No case of allergic contact dermatitis (ACD) was detected. CONCLUSIONS: The popularity of ANMS among young female HCWs is growing. This striking trend might further put these individuals not only at risk of medical device-related adverse events but also occupational ACD.


Assuntos
Acrilatos , Dermatite Alérgica de Contato , Dermatite Ocupacional , Pessoal de Saúde , Unhas , Humanos , Feminino , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/epidemiologia , Adulto , Estudos Transversais , Pessoal de Saúde/estatística & dados numéricos , Acrilatos/efeitos adversos , Dermatite Ocupacional/etiologia , Dermatite Ocupacional/epidemiologia , Alérgenos/efeitos adversos , Adulto Jovem , Estudos de Casos e Controles , Pessoa de Meia-Idade
4.
Contact Dermatitis ; 90(1): 1-16, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37778325

RESUMO

This is the second part of a literature review of the clinical aspects of contact allergy to and allergic contact dermatitis from 2-hydroxyethyl methacrylate (HEMA). Topics include cross- and co-sensitization, atypical manifestations of contact allergy, frequency of positive patch tests to HEMA compared with other (meth)acrylates, sensitivity of HEMA as a screening agent, the presence of HEMA in commercial products, and practical information on patch testing procedures. Primary sensitization to methacrylates including HEMA may result in methacrylate and acrylate cross-sensitization. There is a strong cross-allergy between HEMA, ethylene glycol dimethacrylate (EGDMA), and hydroxypropyl methacrylate; many reactions to EGDMA are cross-reactions to primary HEMA sensitization. Rare atypical manifestations of HEMA-allergy include lichen planus, lymphomatoid papulosis, systemic contact dermatitis, leukoderma after positive patch tests, and systemic side effects such as nausea, diarrhoea, malaise, and palpitations. The occurrence of respiratory disease caused by methacrylates such as asthma is not infrequent. HEMA is the most frequently patch test-positive methacrylate. It is a good screening agent for allergy to other (meth)acrylates. Patch test sensitization to HEMA 2% pet. is extremely rare. There are (some) indications that HEMA is frequently used in dental products and nail cosmetics.


Assuntos
Dermatite Alérgica de Contato , Dermatite Ocupacional , Humanos , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/epidemiologia , Testes do Emplastro/métodos , Dermatite Ocupacional/etiologia , Metacrilatos/efeitos adversos , Acrilatos/efeitos adversos
5.
Contact Dermatitis ; 90(3): 262-265, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38093676

RESUMO

BACKGROUND: Over the last 10 years, allergic contact dermatitis (ACD) from acrylate-containing nail cosmetics (acrylic nails, gel nails, gel nail polish) has been reported repeatedly. OBJECTIVES: To investigate the frequency and clinical features of ACD in nail cosmetics in a university hospital in Amsterdam, The Netherlands. PATIENTS AND METHODS: A retrospective study in patients diagnosed with ACD from acrylate-containing nail cosmetics at the Amsterdam University Medical Centers between January 2015 and August 2023. RESULTS: Sixty-seven patients, all women, were diagnosed with ACD from nail cosmetics, representing 1.6% of all individuals and 2.3% of all women patch tested in this period. Sixty-five of sixty-seven (97%) subjects had a positive patch test to 2-hydroxyethyl methacrylate (HEMA). Forty-nine patients (73%) were consumers and 18 (27%) were professional nail stylists. The sites most frequently affected with dermatitis were the fingers (79%), hands (40%) and the head and/or neck. Avoidance of contact with acrylate-containing products resulted in complete clearing of dermatitis in 80% of patients. CONCLUSIONS: ACD from acrylate-containing nail cosmetics is frequent in women patch tested in Amsterdam. Nearly all were identified by a positive patch test to 2-hydroxyethyl methacrylate in the (meth)acrylate series or the European baseline series.


Assuntos
Cosméticos , Dermatite Alérgica de Contato , Humanos , Feminino , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/epidemiologia , Dermatite Alérgica de Contato/etiologia , Estudos Retrospectivos , Unhas , Metacrilatos/efeitos adversos , Acrilatos/efeitos adversos , Cosméticos/efeitos adversos , Testes do Emplastro/métodos
6.
Contact Dermatitis ; 90(1): 66-73, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37828279

RESUMO

BACKGROUND: While many studies have reported on occupational allergic contact dermatitis amongst dental personnel, studies on the relevance of patch testing in dental patients are scarce. OBJECTIVES: To determine the frequency and clinical relevance of contact allergy in patients with intra- and perioral complaints. METHODS: A total of 360 patients with intra- and perioral complaints suspected of having a contact allergy were patch-tested with the dental allergen series, European Baseline Series, and extended Amsterdam Baseline Series at Amsterdam University Medical Centers between January 2015 and November 2021. RESULTS: A total of 285 patients (79.2%) had a positive patch test reaction for either one (18.6%) or multiple allergens (60.6%). Sodium tetrachloropalladate was the most sensitising allergen with 98 patients (27.2%) testing positive, followed by nickel sulphate (23.3%), methylisothiazolinone (15.6%), and fragrance mix I (14.2%). Clinical relevance was found in 68 of 208 patients (32.7%), with patients having one (15.4%) or multiple (17.3%) patch test reactions clinically relevant to their (peri)oral complaints. CONCLUSIONS: Clinically relevant patch test reactions were frequently seen in dental patients. Although this study provides us with a better understanding on the frequency and clinical relevance of contact allergy in dental patients, further studies are needed to confirm our results.


Assuntos
Dermatite Alérgica de Contato , Dermatite Ocupacional , Humanos , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/epidemiologia , Dermatite Alérgica de Contato/etiologia , Relevância Clínica , Alérgenos/efeitos adversos , Dermatite Ocupacional/diagnóstico , Dermatite Ocupacional/epidemiologia , Dermatite Ocupacional/etiologia , Testes do Emplastro/métodos , Estudos Retrospectivos
7.
Int J Mol Sci ; 25(10)2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38791532

RESUMO

The development of photocurable compositions is in high demand for the manufacture of functional materials for electronics, optics, medicine, energy, etc. The properties of the final photo-cured material are primarily determined by the initial mixture, which needs to be tuned for each application. In this study we propose to use simple systems based on di(meth)acrylate, polyimide and photoinitiator for the preparation of new photo-curable compositions. It was established that a fluorinated cardo copolyimide (FCPI) based on 2,2-bis-(3,4-dicarboxydiphenyl)hexafluoropropane dianhydride, 9,9-bis-(4-aminophenyl)fluorene and 2,2-bis-(4-aminophenyl)hexafluoropropane (1.00:0.75:0.25 mol) has excellent solubility in di(met)acrylates. This made it possible to prepare solutions of FCPI in such monomers, to study the effect of FCPI on the kinetics of their photopolymerization in situ and the properties of the resulting polymers. According to the obtained data, the solutions of FCPI (23 wt.%) in 1,4-butanediol diacrylate (BDDA) and FCPI (15 wt.%) in tetraethylene glycol diacrylate were tested for the formation of the primary protective coatings of the silica optical fibers. It was found that the new coating of poly(BDDA-FCPI23%) can withstand prolonged annealing at 200 °C (72 h), which is comparable or superior to the known most thermally stable photo-curable coatings. The proposed approach can be applied to obtain other functional materials.


Assuntos
Fibras Ópticas , Polimerização , Dióxido de Silício , Dióxido de Silício/química , Solubilidade , Imidas/química , Temperatura , Acrilatos/química , Polímeros/química , Halogenação , Processos Fotoquímicos
8.
Molecules ; 29(4)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38398668

RESUMO

This article presents a thorough investigation into the synthesis of trimethylolpropane triacrylate (TMPTA) via the esterification reaction of trimethylolpropane (TMP) with acrylic acid using Amberlite™ 120 IR (H+), Amberlyst® 15, and Dowex™ 50WX8 resins as heterogeneous catalysts. Preliminary comparative tests explored the impact of air flow on water removal during the reaction and different acid-to-alcohol molar ratios (3:1, 6:1, or 9:1 mol:mol). The findings revealed that introducing air significantly enhances TMPTA yield and -OH group conversion, particularly at a 6:1 acid-to-alcohol molar ratio. Based on cost considerations, Amberlite™ 120 IR (H+) was selected as the preferred catalyst for further optimization. This included evaluating the effect of catalyst loading (10%, 5.0%, and 2.5% w/wtot) and assessing the impact of a pre-drying process on resin efficiency. The study concluded that optimal conditions did not necessitate drying, requiring 120 °C, a catalyst loading of 10% w/wtot, a 4 h reaction time, an acid:alcohol ratio of 6:1 mol:mol, the presence of MEHQ (0.1% mol/molAA), and air bubbling at 6 ± 1 Nl/h. Catalyst recycling was effectively implemented with a slight reduction in catalytic activity over consecutive runs. Furthermore, the study explored a scaled-up system with a mechanical stirrer, demonstrating the potential for multi-hundred grams scale-up. Considerations for optimizing the air flow stripping system are also highlighted. In summary, this study provides valuable insights into designing and optimizing the esterification process for TMPTA synthesis, laying the foundation for potential industrial applications.

9.
Actas Dermosifiliogr ; 115(6): 533-538, 2024 Jun.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-38309528

RESUMO

BACKGROUND: Controversy has recently broken out over the potential carcinogenic risk associated with exposure to UV lamps for permanent nail polish. The new LED-based polymerization devices, and their potential biological effect has not been analyzed to this date. OBJECTIVE: To evaluate the emission power and its potential biological effects on the skin of 2 types of UV LED and fluorescent curing lamps under normal use conditions compared to doses of sunlight exposure. MATERIAL AND METHODS: The emission spectrum (290nm to 450nm) of curing lamps and the Sun at noon on an average summer day in mid-latitude Spain was analyzed. The effective biological irradiance potential for erythema, non-melanoma skin cancer, DNA damage, photoimmunosuppression and permanent pigmentation was also characterized. RESULTS: The high-energy UVA-visible irradiance emitted by these devices was similar to the one coming from the Sun in that spectral range while the effective biological doses were lower or similar to those also coming from the Sun. The total UV and high-energy visible dose per manicure session corresponded to that obtained from 3.5min to 6min exposures to the Sun at noon in the summer days at our latitudes. CONCLUSIONS: The exposure times and doses received with the common use of artificial lamp nail drying correspond to sunlight exposures of 3min to 5min in the central hours of the day. This represents a very low carcinogenic potential compared to sunlight exposure, although similar regarding immunosuppressive potential. Photoprotective measures would further minimize the risks.


Assuntos
Unhas , Neoplasias Induzidas por Radiação , Neoplasias Cutâneas , Raios Ultravioleta , Raios Ultravioleta/efeitos adversos , Humanos , Unhas/efeitos da radiação , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/epidemiologia , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Induzidas por Radiação/epidemiologia , Luz Solar/efeitos adversos , Dano ao DNA , Espanha , Eritema/etiologia
10.
Actas Dermosifiliogr ; 115(6): T533-T538, 2024 Jun.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-38648931

RESUMO

BACKGROUND: Controversy has recently broken out over the potential carcinogenic risk associated with exposure to UV lamps for permanent nail polish. The new LED-based polymerization devices, and their potential biological effect has not been analyzed to this date. OBJECTIVE: To evaluate the emission power and its potential biological effects on the skin of 2 types of UV LED and fluorescent curing lamps under normal use conditions compared to doses of sunlight exposure. MATERIAL AND METHODS: The emission spectrum (290nm to 450nm) of curing lamps and the Sun at noon on an average summer day in mid-latitude Spain was analyzed. The effective biological irradiance potential for erythema, non-melanoma skin cancer, DNA damage, photoimmunosuppression and permanent pigmentation was also characterized. RESULTS: The high-energy UVA-visible irradiance emitted by these devices was similar to the one coming from the Sun in that spectral range while the effective biological doses were lower or similar to those also coming from the Sun. The total UV and high-energy visible dose per manicure session corresponded to that obtained from 3.5min to 6min exposures to the Sun at noon in the summer days at our latitudes. CONCLUSIONS: The exposure times and doses received with the common use of artificial lamp nail drying correspond to sunlight exposures of 3min to 5min in the central hours of the day. This represents a very low carcinogenic potential compared to sunlight exposure, although similar regarding immunosuppressive potential. Photoprotective measures would further minimize the risks.


Assuntos
Unhas , Neoplasias Induzidas por Radiação , Neoplasias Cutâneas , Raios Ultravioleta , Raios Ultravioleta/efeitos adversos , Humanos , Unhas/efeitos da radiação , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/epidemiologia , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Induzidas por Radiação/epidemiologia , Luz Solar/efeitos adversos , Dano ao DNA , Espanha , Eritema/etiologia
11.
Chemistry ; 29(19): e202203625, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-36571402

RESUMO

Sulfones and carboxylic acids are prominent motifs widely present in the chemical structure of agrochemicals, pharmaceuticals and many other highly valuable compounds. Herein, we describe a conjunctive strategy for the precise installation of these functionalities onto styrenes using sodium sulfinates and CO2 as coupling partners. The protocol allowed the preparation of carboxy-sulfonylated compounds in good yields and broad functional group tolerance. Additionally, taking advantage of the leaving group ability of the sulfone moiety, a one-pot photocatalytic carboxy-sulfonylation-elimination strategy was developed for the synthesis of α-aryl-acrylates.

12.
Contact Dermatitis ; 89(6): 471-479, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37667591

RESUMO

BACKGROUND: Allergic contact dermatitis from (meth)acrylic monomers (ACDMA) in manicure products is increasing. OBJECTIVE: To evaluate the prognosis, work performance impairment and sequelae of a cohort of beauticians and manicure consumers with ACDMA sensitized from the exposure to manicure products. METHODS: We conducted a telephone survey with patients diagnosed with ACDMA. RESULTS: One hundred and six patients were evaluated, including 75 (70.8%) beauticians and 31 (29.2%) consumers. All were women with a mean age of 39 (19-62). Thirty-seven of 75 beauticians (49.3%) continued to work. Twenty-seven of 106 (25.5%) patients continued to use manicure products with (meth)acrylates regularly. Seventeen of 51 (33.3%) patients who discontinued the exposure described ongoing nail/periungual changes. Nine of 58 (15.5%) patients who required dental restoration, orthodontic or occlusal splint materials recalled reactions from them; and, 25 of 96 (26%) who used sanitary napkins recalled intolerance to them starting after the diagnosis of ACDMA. Fifteen of 25 (60%) discontinued the use of sanitary napkins. CONCLUSION: 49.3% beauticians continued to work; most patients stopped wearing acrylic manicure materials; reactions from dental materials were not uncommon, however, removal of dental materials was never required; and, reactions to sanitary napkins developing after the diagnosis of ACDMA were common most leading to discontinuation of use.


Assuntos
Dermatite Alérgica de Contato , Dermatite Ocupacional , Humanos , Feminino , Adulto , Masculino , Dermatite Alérgica de Contato/diagnóstico , Acrilatos/efeitos adversos , Testes do Emplastro , Prognóstico , Materiais Dentários , Metacrilatos/efeitos adversos
13.
Contact Dermatitis ; 89(6): 401-433, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37752620

RESUMO

2-Hydroxyethyl methacrylate (HEMA) has been increasingly recognised as a contact allergen and was added to the European baseline series in 2019. In this article (2 parts), the results of an extensive literature review of the clinical aspects of contact allergy/allergic contact dermatitis to HEMA are presented. In part 1, the epidemiology of HEMA contact allergy is discussed and detailed information on published case series and case reports presented. HEMA is an important cause of contact allergy/allergic contact dermatitis in North America and Europe with recent prevalences of >3% in the USA + Canada and 1.5%-3.7% in Europe. Currently, most cases are caused by nail cosmetics, both in consumers and professional nail stylists. In our literature review, we have found 24 studies presenting case series of patients with allergic contact dermatitis attributed to HEMA and 168 case reports. However, the presence of HEMA in the products causing ACD was established in only a minority. Part 2 will discuss cross- and co-sensitisation, and other skin reactions to HEMA, will assess whether HEMA is the most frequent (meth)acrylate allergen and how sensitive HEMA as a screening agent is, investigate the presence of HEMA in commercial products and provide practical information on patch testing procedures.


Assuntos
Dermatite Alérgica de Contato , Dermatite Ocupacional , Humanos , Dermatite Alérgica de Contato/etiologia , Dermatite Ocupacional/etiologia , Estudos Retrospectivos , Metacrilatos , Acrilatos , Alérgenos , Testes do Emplastro/métodos
14.
Int J Toxicol ; 42(3_suppl): 144S-161S, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37978581

RESUMO

The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the safety of 12 polyfluorinated polymers in cosmetic products; most of these ingredients have the reported function of film former in common. However, PTFE, the only ingredient that is reported as currently used in cosmetics, functions as a bulking agent and slip modifier, but not as a film former. The Panel reviewed data relevant to the safety of these ingredients under the intended conditions of use in cosmetic formulations, and concluded that PTFE and Hexafluoropropylene/Tetrafluoroethylene Copolymer are safe in cosmetics in the present practices of use and concentration described in the safety assessment; the data are insufficient to determine the safety of the 4 fluorinated-side-chain polymers and 6 fluorinated polyethers.


Assuntos
Cosméticos , Polímeros , Polímeros/toxicidade , Qualidade de Produtos para o Consumidor , Cosméticos/toxicidade , Politetrafluoretileno , Medição de Risco
15.
Int J Mol Sci ; 24(12)2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37373114

RESUMO

The biologically active compound 3-aminopropylsilatrane (a compound with a pentacoordinated silicon atom) underwent an aza-Michael reaction with various acrylates and other Michael acceptors. Depending on the molar ratio, the reaction yielded Michael mono- or diadducts (11 examples) containing functional groups (silatranyl, carbonyl, nitrile, amino, etc.). These compounds were characterized via IR and NMR spectroscopy, mass spectrometry, X-ray diffraction, and elemental analysis. Calculations (using in silico, PASS, and SwissADMET online software) revealed that the functionalized (hybrid) silatranes were bioavailable, druglike compounds that exhibited pronounced antineoplastic and macrophage-colony-stimulating activity. The in vitro effect of silatranes on the growth of pathogenic bacteria (Listeria, Staphylococcus, and Yersinia) was studied. It was found that the synthesized compounds exerted inhibitory and stimulating effects in high and low concentrations, respectively.


Assuntos
Antineoplásicos , Compostos de Organossilício , Antineoplásicos/farmacologia , Antineoplásicos/química , Difração de Raios X , Espectrometria de Massas , Estrutura Molecular
16.
Int J Mol Sci ; 24(18)2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37762120

RESUMO

The aza-Michael reaction of 3-aminopropyltriethoxysilane (1) and -silatrane (2) with acrylates affords functionalized silyl-(3-8) and silatranyl-(9-14) mono- and diadducts with up to a 99% yield. Their structure has been proved with IR and NMR spectroscopies, mass spectrometry and XRD analysis. The hydrolytic homo-condensation of triethoxysilanes 3-5 gives siloxanes 3a-5a, which form complexes with Ag, Cu, and Ni salts. They are also able to adsorb these metals from solutions. The hetero-condensation reaction of silanes 4-8 with OH groups of zeolite (Z), silica gel (S) and glass (G) delivers the modified materials (Z4, S7, G4, G5, G7, G8, etc.), which can adsorb ions of noble metal (Au, Rh, Pd: G4 + Au, G5 + Pd, G7 + Rh). Thus, the synthesized Si-organic polymers and materials turned out to be promising sorbents (enterosorbents) of noble, heavy, toxic metal ions and can be applied in industry, environment, and medicine.

17.
Molecules ; 28(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36771065

RESUMO

Catalyst-free multicomponent reactions of mixed alkylzinc reagents with Michael acceptors and aldehydes, ketones or activated imines are described. Primary, secondary and tertiary alkylzinc reagents, pre-generated in acetonitrile from the corresponding iodoalkanes, were used in the process, leading to the very efficient formation of a variety of ß-hydroxycarbonyl compounds. The imines showed more contrasting results, due to the direct addition of the organozinc compound to the C=N bond. Mechanistic assays involving TEMPO account for a polar instead of a radical character of the reaction.

18.
Contact Dermatitis ; 87(1): 53-61, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35184294

RESUMO

BACKGROUND: Sensitization to acrylates is a concern in the occupational/environmental dermatology field. OBJECTIVE: To describe an occupational allergic contact dermatitis (ACD) outbreak from a smartphone screen protector glue. METHODS: Thirteen affected workers of a chain store selling phone screen protectors were investigated in five Spanish dermatology departments. The glue datasheet and label were assessed. A chemical analysis of the glue was performed. Based on this, some patients underwent additional testing. RESULTS: All patients (all female, mean age: 25) had severe fingertip dermatitis. The datasheet/label indicated that the glue contained isobornyl acrylate (IBOA), a "photoinitiator" and polyurethane oligomer. The company informed us that the ingredients were polyurethane acrylate, "methacrylate" (unspecified), acrylic acid, hydroxyethyl methacrylate, propylmethoxy siloxane, and photoinitiator 184. Isobornyl acrylate (or IBOA) and N,N-dimethylacrylamide (DMAA) were patch tested in eight and two cases, respectively, with negative results. A chemical analysis revealed 4-acryloylmorpholine (ACMO); isobornyl methacrylate (IBMA), and lauryl acrylate in one glue sample. Seven patients were patch tested with dilutions of the identified substances and six of seven were positive for ACMO 0.5% pet. CONCLUSION: An outbreak of occupational ACD, likely from ACMO in a glue is described. Further investigations are needed to corroborate the role played by each compound identified in the chemical analyses.


Assuntos
Dermatite Alérgica de Contato , Dermatite Ocupacional , Acrilatos/efeitos adversos , Adulto , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/epidemiologia , Dermatite Alérgica de Contato/etiologia , Dermatite Ocupacional/diagnóstico , Dermatite Ocupacional/epidemiologia , Dermatite Ocupacional/etiologia , Surtos de Doenças , Feminino , Humanos , Testes do Emplastro , Poliuretanos , Smartphone
19.
Molecules ; 27(22)2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36432000

RESUMO

This study focuses on the experimental and molecular-level investigation of epoxy acrylate formation. Epoxy acrylate vinyl ester resin was prepared by a reaction of diglycidyl ether of bisphenol-A-based epoxy resin and acrylic acid, using benzimidazole as a catalyst. It was confirmed that benzimidazole can effectively catalyze this reaction. FTIR analysis of the product revealed a simple addition esterification reaction between the epoxide group and carboxylic group of acrylic acid excluding the side reactions (e.g., etherification). DFT computational studies were performed to theoretically explore the insights of reaction mechanisms. The calculations revealed that the benzimidazole-catalyzed reaction dominates the uncatalyzed reaction. A comparison of calculated activation energies showed that concerted mechanisms are less significant in such reactions owing to their high activation barriers.


Assuntos
Acrilatos , Resinas Epóxi , Benzimidazóis , Catálise , Ésteres
20.
Angew Chem Int Ed Engl ; 61(4): e202113089, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-34779113

RESUMO

α-Oxygenated Z-olefins are ubiquitous in biologically active molecules and serve as versatile handles for organic synthesis, but their syntheses are often tedious and less selective. Here we report the efficient Z-selective metathesis of various terminal acrylates and allyl alcohols, which enables facile and selective construction of high value-added α-oxygenated Z-olefins from readily available feedstock chemicals. These challenging metathesis transformations are enabled by novel cyclometalated Ru-carbene-nitrate complexes bearing bulky-yet-flexible side arms, whose assembly was unlocked by new organometallic syntheses.

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