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1.
Sci Total Environ ; 917: 170604, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38309362

RESUMO

The pollution due to plastic and other anthropogenic particles has steadily increased over the last few decades, presenting a significant threat to the environment and organisms, including avian species. This research aimed to investigate the occurrence of anthropogenic pollutants in the digestive and respiratory systems of four birds of prey: Common Buzzard (Buteo buteo), Black Kite (Milvus migrans), Eurasian Sparrowhawk (Accipiter nisus), and Northern Goshawk (Accipiter gentilis). The results revealed widespread contamination in all species with microplastics (MPs) and cellulosic anthropogenic fibers (AFs), with an average of 7.9 MPs and 9.2 AFs per specimen. Every digestive system contained at least one MP, while 65 % of specimens exhibited MPs in their respiratory systems. This is the work reporting a high incidence of MPs in the respiratory system of birds, clearly indicating inhalation as a pathway for exposure to plastic pollution. The content of MPs and AFs varied significantly when comparing specimens collected from central Madrid with those recovered from other parts of the region, including rural environments, suburban areas, or less populated cities. This result aligns with the assumption that anthropogenic particles disperse from urban centers to surrounding areas. Additionally, the dominant particle shape consisted of small-sized fibers (> 98 %), primarily composed of polyester, polyethylene, acrylic materials, and cellulose fibers exhibiting indicators of industrial treatment. These findings emphasize the necessity for further research on the impact of plastic and other anthropogenic material contamination in avian species, calling for effective strategies to mitigate plastic pollution.


Assuntos
Águias , Poluentes Químicos da Água , Animais , Microplásticos , Plásticos , Polietilenos , Cidades , Poluentes Químicos da Água/análise , Monitoramento Ambiental
2.
Angew Chem Int Ed Engl ; 62(16): e202218640, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-36806838

RESUMO

We report on the chemical design of chiral molecular junctions with stress-dependent conductance, whose helicity is maintained during the stretching of a single molecule junction due to the stapling of both ends of the inner helix. In the reported compounds, different conductive pathways are observed, with clearly different conductance values and plateau-length distributions, attributed to different conformations of the helical structures. The large chiro-optical responses and the potential use of these molecules as unimolecular spin filters have been theoretically proved using state-of-the-art Density Functional Theory (DFT) calculations, including a fully ab-initio estimation of the CISS-originating spin polarization which is done, for the first time, for a realistic molecular system.

5.
Pediatr. aten. prim ; 24(94)abr. - jun. 2022. ilus
Artigo em Espanhol | IBECS | ID: ibc-212126

RESUMO

La trombosis venosa abdominal es una forma poco común de enfermedad tromboembólica venosa en niños. Si bien las tasas de mortalidad son bajas, una proporción significativa de niños afectados pueden sufrir morbilidad a largo plazo. Entre sus etiologías, se sabe que existe asociación con trastornos protrombóticos, siendo poco frecuente la ausencia del factor XII. El tratamiento incluye anticoagulación y la resección quirúrgica de los órganos isquémicos con potencial trasplante posterior (AU)


Abdominal venous thrombosis is a rare form of venous thromboembolic disease in children. Although the associated mortality is low, a significant proportion of affected children suffer from long-term morbidity. Among its aetiologies, there is evidence of an association with prothrombotic disorders, absence of factor XII being an infrequent one. Treatment includes anticoagulant medication and surgical resection of the ischaemic organs, potentially followed by transplantation. (AU)


Assuntos
Humanos , Masculino , Criança , Trombose Venosa/genética , Veia Porta/diagnóstico por imagem , Fator XII/genética , Mutação/genética , Trombose Venosa/diagnóstico por imagem , Ecocardiografia Doppler
6.
Rev. clín. med. fam ; 15(2): 125-126, Jun. 2022. ilus
Artigo em Espanhol | IBECS | ID: ibc-209838

RESUMO

El dígito pélvico es un tipo de anomalía congénita benigna poco frecuente, que se localiza en la región coxofemoral, en relación con el ilion.A pesar de que suele ser asintomático, es importante conocer su existencia, así como los posibles diagnósticos diferenciales, ya que se puede encontrar como un hallazgo incidental en la radiografía simple.Se presenta el caso de un hombre, de 58 años, que acude a su médico de Atención Primaria (AP) por artralgias generalizadas, quien observa en la radiografía simple de cadera un hallazgo inusual, por lo que interconsulta al servicio de Radiodiagnóstico, donde se realiza el diagnóstico de dígito pélvico.(AU)


The pelvic digit is a rare benign congenital abnormality, located in the hip region, in regard to the ilium.Although usually asymptomatic, it is important to be aware of its existence as well as the possible differential diagnoses since it can be found as an incidental finding on plain x-ray.We report the case of a 58-year-old man who presented to his primary care physician because of generalized arthralgia. He observed an unusual finding on plain x-ray of the hip, whereby he consulted the radiology department, where pelvic digit was diagnosed.(AU)


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Atenção Primária à Saúde , Quadril , Quadril/anormalidades , Quadril/diagnóstico por imagem , Artralgia , Serviço Hospitalar de Radiologia , Radiografia , Resultado do Tratamento , Pacientes Internados , Exame Físico , Avaliação de Sintomas , Medicina de Família e Comunidade
8.
Polymers (Basel) ; 14(5)2022 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-35267732

RESUMO

A series of pressure-sensitive adhesives (PSA) were prepared by emulsion polymerization in order to obtain a PSA that meet with the current label market requirements. For it, the effect of the incorporation of acrylonitrile (ACN) as hard monomer was investigated in a n-butyl acrylate (n-BA) and acrylic acid (AA) system. Great differences were found in the adhesive performance according to the ACN weight ratio. Its increased resulted in a considerable rise in the average sol molecular weight and in the glass transition temperature. This was reflected in a decrease of adhesion forces (peel resistance and tack) and an increase of the cohesion forces (shear resistance). Moreover, the incorporation of the minimum amount of ACN studied showed a great change in the elastic modulus determined by dynamic shear resistance with respect to the based formulation that did not contain ACN. Finally, the ice bucket test was carried out to check the adhesive performance in cold and wet environments.

11.
Nanomaterials (Basel) ; 12(3)2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35159831

RESUMO

On-surface synthesis, complementary to wet chemistry, has been demonstrated to be a valid approach for the synthesis of tailored graphenic nanostructures with atomic precision. Among the different existing strategies used to tune the optoelectronic and magnetic properties of these nanostructures, the introduction of non-hexagonal rings inducing out-of-plane distortions is a promising pathway that has been scarcely explored on surfaces. Here, we demonstrate that non-hexagonal rings, in the form of tropone (cycloheptatrienone) moieties, are thermally transformed into phenyl or cyclopentadienone moieties upon an unprecedented surface-mediated retro-Buchner-type reaction involving a decarbonylation or an intramolecular rearrangement of the CO unit, respectively.

13.
Polymers (Basel) ; 13(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34451167

RESUMO

A series of pressure-sensitive adhesives (PSAs) was prepared using a constant monomeric composition and different preparation processes to investigate the best combination to obtain the best balance between peel resistance, tack, and shear resistance. The monomeric composition was a 1:1 combination of two different water-based acrylic polymers-one with a high shear resistance (A) and the other with a high peel resistance and tack (B). Two different strategies were applied to prepare the adhesives: physical blending of polymers A and B and in situ emulsion polymerization of A + B, either in one or two steps; in this last case, by polymerizing A or B first. To characterize the polymer, the average particle size and viscosity were analyzed. The glass transition temperature (Tg) was determined by differential scanning calorimetry (DSC). The tetrahydrofuran (THF) insoluble polymer fraction was used to calculate the gel content, and the soluble part was used to determine the average sol molecular weight by means of gel permeation chromatography (GPC). The adhesive performance was assessed by measuring tack as well as peel and shear resistance. The mechanical properties were obtained by calculating the shear modulus and determination of maximum stress and the deformation energy. Moreover, an adhesive performance index (API) was designed to determine which samples are closest to the requirements demanded by the self-adhesive label market.

16.
Angew Chem Int Ed Engl ; 60(12): 6609-6616, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33348468

RESUMO

The single-molecule conductance of a series of BN-acene-like derivatives has been measured by using scanning tunneling break-junction techniques. A strategic design of the target molecules has allowed us to include azaborine units in positions that unambiguously ensure electron transport through both heteroatoms, which is relevant for the development of customized BN-doped nanographenes. We show that the conductance of the anthracene azaborine derivative is comparable to that of the pristine all-carbon anthracene compound. Notably, this heteroatom substitution has also allowed us to perform similar measurements on the corresponding pentacene-like compound, which is found to have a similar conductance, thus evidencing that B-N doping could also be used to stabilize and characterize larger acenes for molecular electronics applications. Our conclusions are supported by state-of-the-art transport calculations.

17.
Cir Cir ; 88(Suppl 2): 18-20, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33284265

RESUMO

La perforación esofágica es la más letal de todas las perforaciones del aparato digestivo. Se presenta el caso de un varón de 65 años que acude a urgencias por un cuadro clínico de dolor torácico, vómitos e hipotensión. Se le realizó tomografía computarizada por sospecha de síndrome aórtico agudo, con hallazgos sugerentes de perforación esofágica. El síndrome de Boerhaave consiste en la rotura longitudinal del esófago sobre una pared macroscópicamente sana. Su tratamiento definitivo se realiza con cirugía durante las primeras 24 horas. El síndrome de Boerhaave debe considerarse como complicación posible en los pacientes con dolor epigástrico y vómitos, ya que es una emergencia quirúrgica con alta morbimortalidad.Esophageal perforation is the most lethal of all perforations of the digestive system. 65-year-old male who goes to the emergency department due to clinical symptoms of chest pain, vomiting and hypotension, who underwent CT scan for suspected acute aortic syndrome, with suggestive findings of esophageal perforation. Boerhaave syndrome consists of the longitudinal rupture of the esophagus on a macroscopically healthy wall. Its definitive treatment is performed with surgery during the first 24 hours. Boerhaave syndrome should be considered as a possible complication in patients with epigastric pain and vomiting, as it is a surgical emergency with high morbidity and mortality.


Assuntos
Dor , Tomografia Computadorizada por Raios X , Idoso , Humanos , Masculino
18.
Polymers (Basel) ; 12(12)2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33266313

RESUMO

Currently, pressure-sensitive adhesives (PSA) are used in more than 80% of all labels in the market today. They do not require any heat, solvent, or water to activate: It only takes light pressure to apply them to a product surface. Many products that come in glass bottles need labels that have staying power in harsh conditions. For that reason, it is necessary to have a good balance between all the polymer adhesive properties. In this study is described how adhesive properties of water-based PSA were affected by varying the amount of functional monomer acrylic acid (AA) and chain transfer agent, tert-dodecyl mercaptan (TDM). Four series of PSA were prepared by emulsion polymerization. Within each polymer series, the AA monomer proportion was held constant between 0.5 and 3.0 phm, and the fraction of the chain transfer agent was varied 0.0 to 0.2 phm. The results showed that the gel content decreased with the increase of the chain transfer agent and with the reduction of AA. All adhesives properties (tack, peel, and shear resistance) improved with increasement of the AA monomer. The increase of chain transfer agent caused decrease of the gel content resulting in higher peel resistance and tack values, but lower shear resistance values.

19.
Angew Chem Int Ed Engl ; 59(18): 7139-7145, 2020 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-32159924

RESUMO

A new family of distorted ribbon-shaped nanographenes was designed, synthesized, and their optical and electrochemical properties were evaluated, pointing out an unprecedented correlation between their structural characteristics and the two-photon absorption (TPA) responses and electrochemical band gaps. Three nanographene ribbons have been prepared: a seven-membered-ring-containing nanographene presenting a tropone moiety at the edge, its full-carbon analogue, and a purely hexagonal one. We have found that the TPA cross-sections and the electrochemical band gaps of the seven-membered-ring-containing compounds are higher and lower, respectively, than those of the fully hexagonal polycyclic aromatic hydrocarbon (PAH). Interestingly, the inclusion of additional curvature has a positive effect in terms of non-linear optical properties of those ribbons.

20.
Polymers (Basel) ; 12(2)2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32059370

RESUMO

A series of Pressure-Sensitive Adhesives (PSAs) with different soft monomer compositions were prepared by using emulsion polymerization. The monomers used were acrylic acid (AA), n-butyl acrylate (n-BA) and 2-ethylhexyl acrylate (2-EHA). Maintaining the same acrylic acid fraction in all polymerizations, the n-BA/2-EHA weight ratio varied from 0 to 1. These polymers were characterized by using Fourier Transformed Infrared Spectroscopy (FTIR), and the Glass Transition Temperature (Tg) was determined both theoretically from the Fox equation and experimentally by means of differential scanning calorimetry (DSC). The tetrahydrofuran (THF) insoluble polymer fraction was used to calculate the gel content, and the soluble part was used to determine the average molecular weight by means of Gas Permeation Chromatography (GPC). The adhesive performance was assessed by measuring tack, peel and shear resistance. The results showed that with the 2-EHA rate, the elastic modulus slightly decreased and the shear yield strength slightly increased. Consequently, the loop tack and peel resistances decreased. This behavior was attributed to the increase of the gel content with the ratio of comonomers studied. The adhesives were tested in paper labels on glass bottles immersed in a cold-water bath, the so-called ice bucket test, and all of them showed that they could withstand wet and cold environment conditions.

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