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1.
Int J Mol Sci ; 24(2)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36674988

RESUMO

Plastic waste is a serious problem in modern society. Every day, mankind produces tons of waste that must be disposed of or recycled. The most common types of plastic waste are disposable tableware, bags, packaging, bottles, and containers, and not all are recycled. Therefore, there is a great interest in producing environmentally friendly disposable materials. In this study, modified gelatin blends using polysaccharides (e.g., agarose, starch) were produced to obtain a stable coating. Various techniques were used to characterize the obtained bioplastics, including FTIR spectroscopy (Fourier-transform infrared spectroscopy), TGA (thermogravimetric analysis)/DSC (differential scanning calorimetry), contact angle measurements, and surface energy characterization. We also investigated the influence of thermal and microbiological degradation on the properties of the biocomposite. The addition of agarose increased the hardness of the blend by 27% compared to the control sample without added polysaccharides. Increases were also observed in the surface energy (24%), softening point (15%), and glass transition temperature (14%) compared to the control sample. The addition of starch to the biopolymer increased the softening point by 15% and the glass transition temperature by 6%. After aging, both blends showed an increase in hardness of 26% and a decrease in tensile strength of 60%.


Assuntos
Gelatina , Amido , Amido/metabolismo , Gelatina/química , Sefarose , Solventes , Polissacarídeos , Plásticos , Espectroscopia de Infravermelho com Transformada de Fourier
2.
Molecules ; 29(1)2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38202776

RESUMO

The subjects of this research are the burial clothes of Polish King Sigismund III Vasa and his wife Constance, which were woven and embroidered with silk and metal threads. Fragments of the textiles underwent spectroscopic, spectrometric, and thermogravimetric analyses. The hydrofluoric acid extraction method was improved to isolate various classes of dyes from the textile samples that had direct contact with human remains. High-performance liquid chromatography, coupled with diode array and tandem mass spectrometry detectors with electrospray ionization (HPLC-DAD-ESI-MS/MS) facilitated the detection and identification of colorants present in the textiles. Cochineal, indigo-, madder-, orchil-, and tannin-producing plants were identified as the sources of dyes used. Scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDS) was employed to identify and characterize the silk fibers and mordants and the metal threads. The presence of iron, aluminum, sodium, and calcium in the silk threads suggests their potential use as mordants. The analysis of the metal threads revealed that most of them were made from flattened gilded silver wire, with only a few being cut from a sheet of metal. Typical degradation mechanisms of metal threads were shown, resulting from both burial environment and earlier manufacturing process, and the use of the textiles in clothing, i.e., a significant loss of the gold layer was observed in most of silver gilt threads, caused by abrasion and delamination. The results of the thermal analysis confirmed the presence of silk and silver threads in the examined textiles.

3.
Molecules ; 24(5)2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30832297

RESUMO

In this study, novel organic⁻inorganic composites were prepared by the complexation of dicarboxylic azo dye (AD) with aluminum⁻magnesium hydroxycarbonate (AlMg⁻LH). This procedure provides an effective method for the stabilization of dicarboxylic organic chromophores on an AlMg-LH host. The structures of the hybrid composites were examined by X-ray diffraction (XRD), secondary ion mass spectrometry (TOF-SIMS), 27-Al solid-state nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis (TGA) and scanning transmission electron microscopy (STEM). The TOF-SIMS method was applied to investigate the metal⁻dye interactions and to monitor the thermal stability of the organic⁻inorganic complexes. Secondary ion mass spectrometry confirmed the presence of a characteristic peak for C18H10O5N2Mg22+, indicating that both carboxylic groups interacted with AlMg-LH by forming complexes with two Mg2+ ions. Modification with hybrid pigments affected the crystal structure of the AlMg-LH mineral, as shown by the appearance of new peaks on the X-ray diffraction patterns. Adsorption of the dicarboxylic chromophore not only led to significantly enhanced solvent resistance but also improved the thermal and photostability of the hybrid pigments. We propose a possible arrangement of the azo dye in the inorganic matrix, as well as the presumed mechanism of stabilization.


Assuntos
Hidróxido de Alumínio/química , Compostos Azo/química , Carbonatos/química , Compostos Inorgânicos/química , Hidróxido de Magnésio/química , Compostos Orgânicos/química , Hidróxido de Alumínio/síntese química , Compostos Azo/síntese química , Carbonatos/síntese química , Compostos Inorgânicos/síntese química , Hidróxido de Magnésio/síntese química , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Compostos Orgânicos/síntese química , Termogravimetria , Difração de Raios X
4.
Molecules ; 24(3)2019 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-30717480

RESUMO

In this study, hybrid pigments based on carminic acid (CA) were synthesized and applied in polymer materials. Modification of aluminum-magnesium hydroxycarbonate (LH) with CA transformed the soluble chromophore into an organic-inorganic hybrid colorant. Secondary ion mass spectroscopy (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and UV-Vis spectroscopy were used to study the structure, composition, and morphology of the insoluble LH/CA colorant. Successful modification of the LH was confirmed by the presence of interactions between the LH matrix and molecules of CA. XPS analysis corroborated the presence of CA complexes with Mg2+ ions in the LH host. The batochromic shift in UV-Vis spectra of the organic-inorganic hybrid colorant was attributed to metal-dye interactions in the organic-inorganic hybrid colorants. Strong metal-dye interactions may also be responsible for the improved solvent resistance and chromostability of the modified LH. In comparison to uncolored ethylene-norbornene copolymer (EN), a modified EN sample containing LH/CA pigment showed lower heat release rate (HRR) and reduced total heat release (THR), providing the material with enhanced flame retardancy.


Assuntos
Hidróxido de Alumínio/química , Carbonatos/química , Carmim/química , Hidróxido de Magnésio/química , Polímeros/química , Estrutura Molecular , Espectroscopia Fotoeletrônica , Pigmentos Biológicos/química , Termogravimetria , Difração de Raios X
5.
Arch Virol ; 161(7): 1969-72, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27068167

RESUMO

Here, we present the first detected cases of bluetongue virus (BTV) in native cattle from Poland. The virus was found in animals located near the Polish-Belarusian and Polish-Lithuanian borders. The positive animals were detected through an official epidemiological surveillance program. A combination of type-specific real-time RT-PCR and phylogenetic tests revealed the presence of BTV serotype 14 (BTV-14). This serotype is highly homologous to the vaccine strain and BTV-14 present in Russia, Lithuania, and Spain (from an animal imported from Lithuania). The most probable route of virus introduction to Poland was transmission through midges. All of the cases were subclinical.


Assuntos
Vírus Bluetongue/isolamento & purificação , Bluetongue/virologia , Doenças dos Bovinos/virologia , Animais , Bluetongue/transmissão , Vírus Bluetongue/classificação , Vírus Bluetongue/genética , Bovinos , Doenças dos Bovinos/transmissão , Ceratopogonidae/virologia , Insetos Vetores/virologia , Filogenia , Polônia , Federação Russa , Espanha
6.
Sci Rep ; 14(1): 8530, 2024 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609489

RESUMO

Functional antibacterial textile materials are in great demand in the medical sector. In this paper, we propose a facile, eco-friendly approach to the design of antibacterial biodegradable cotton fabrics. Cotton fiber fabrics were enhanced with a chitosan coating loaded with plant extracts and essential oils. We employed Fourier-transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), UV-Vis spectrophotometry, optical microscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) to characterize the color, structure, and thermal properties of the modified fabrics. The fabrics were found to effectively induce growth inhibition of Gram-positive and Gram-negative bacteria, especially when a synergic system of aloe vera extract and cinnamon essential oil was applied in the coating formulation. Additionally, we observed significant color and weight changes after 5, 10, and 20 days in soil biodegradability tests. Given the straightforward modification process and the use of non-toxic natural materials, these innovative bio-based and biodegradable cotton fabrics show great promise as protective antimicrobial textiles for healthcare applications.


Assuntos
Quitosana , Extratos Vegetais , Antibacterianos/farmacologia , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Têxteis , Microscopia Eletrônica de Varredura
7.
Int J Biol Macromol ; 259(Pt 1): 129178, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38184044

RESUMO

There is great interest in using eco-friendly functional colorants with antibacterial activity to produce colorful textile and plastic products. In this study, we designed, produced, and analyzed a novel multifunctional hybrid color composite colorant with antimicrobial properties, prepared from plant-based products. The new functional color composite was prepared by stabilizing lawsone dye onto amino-silanized cellulose from bamboo fibers. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy were performed to examine the possible interactions between the lawsone dye and silanized bamboo fibers. The color performance, morphology, chemical stability, and thermal stability of the prepared color composite were evaluated using scanning electron microscopy (SEM), UV-Vis spectrophotometry, and thermogravimetric analysis (TGA). The results were compared to those for pure lawsone dye. Modification of amino-silanized bamboo fibers with lawsone dye led to the formation of a light brown colorant that is more resistant to organic solvents (e.g. acetone, ethanol) and elevated temperatures than raw natural dye. Importantly, the designed bamboo fiber/lawsone system (BF-APTES-L) benefits from the synergistic combination of lawsone and bamboo fibers, showing strong antibacterial activity compared to the control sample of bamboo-as evidenced by noticeably inhibited growth of E. coli, S. aureus, and B. subtilis.


Assuntos
Lawsonia (Planta) , Naftoquinonas , Lawsonia (Planta)/química , Staphylococcus aureus , Escherichia coli , Antibacterianos/farmacologia , Antibacterianos/química
8.
JAC Antimicrob Resist ; 6(2): dlae038, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38476772

RESUMO

Objectives: To determine the percentage of patients across Ireland who are discharged from the Emergency Department (ED) with an antimicrobial prescription, the indication, classification of infections, and guideline compliance. To identify potential areas for antimicrobial stewardship (AMS) interventions in the ED. Patients and methods: A multicentre, prospective cohort analysis study in EDs across eight hospitals in Ireland. At each site, patients aged 1 month and older who presented to the ED and were discharged directly from the ED were included. A random selection of records of patients discharged from the ED were reviewed until a minimum of 30 records with an infection diagnosis resulting in an antibiotic prescription were obtained per hospital. The number of patient discharges with no antibiotic prescriptions were included to calculate the denominator. The indication, infection classification and guideline compliance data were collected on the 30 prescriptions in the participating hospitals. Results: A total of 2619 patient records were reviewed. Of these, 249 (9.5%) patients were discharged with antimicrobial prescriptions from the ED. Most (158; 63%) were classified as probable bacterial infection, 21 (8%) as probable viral, and 18 (7%) had no documented evidence of infection. Three indications accounted for 73% of antimicrobial prescriptions: skin/soft tissue infection; ear, nose and throat infection; and urinary tract infection. Overall guideline compliance was 64%. Conclusions: Several areas for AMS interventions to optimize antimicrobial prescribing in the ED were identified, including targeted local and national guideline reviews, delayed prescribing, improved point-of-care testing and prescriber and patient education.

9.
Int J Biol Macromol ; 237: 124143, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36972831

RESUMO

In this study, eco-friendly cotton fabrics with antimicrobial and flame-retardant properties were produced using newly developed bioactive formulations. The new natural formulations combine the biocidal properties of the biopolymer (chitosan (CS)) and essential oil (thyme oil) (EO) with the flame-retardant properties of mineral fillers (silica (SiO2), zinc oxide (ZnO), titanium dioxide (TiO2), and hydrotalcite (LDH)). The modified cotton eco-fabrics were analyzed in terms of morphology (optical and scanning electron microscopy (SEM)), color (spectrophotometric measurements), thermal stability (thermogravimetric analysis (TGA)), biodegradability, flammability (micro-combustion calorimetry (MCC)), and antimicrobial characteristics. The antimicrobial activity of the designed eco-fabrics was determined against different kinds of microorganism (S. aureus, E. coli, P. fluorescens, B. subtilis, A. niger, C. albicans). The antibacterial effects and flammability of the materials were found to depend strongly on the compositions of the bioactive formulation. The best results were obtained for the samples of fabric coated with the formulations containing LDH and TiO2 filler. These samples showed the highest decreases in flammability, with heat release rate (HRR) values of 168 (W/g) and 139 (W/g), respectively, compared to the reference (233 W/g). The samples also showed very good inhibition of growth against of all the studied bacteria.


Assuntos
Fibra de Algodão , Dióxido de Silício , Escherichia coli , Staphylococcus aureus , Antibacterianos/química
10.
Behav Ecol Sociobiol ; 77(12): 134, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38076722

RESUMO

Abstract: The social and mating systems of orangutans, one of our closest relatives, remain poorly understood. Orangutans (Pongo spp.) are highly sexually dimorphic and females are philopatric and maintain individual, but overlapping home ranges, whereas males disperse, are non-territorial and wide-ranging, and show bimaturism, with many years between reaching sexual maturity and attaining full secondary sexual characteristics (including cheek pads (flanges) and emitting long calls). We report on 21 assigned paternities, among 35 flanged and 15 unflanged, genotyped male Bornean orangutans (Pongo pygmaeus wurmbii), studied from 2003 to 2018 in Tuanan (Central Kalimantan, Indonesia). All 10 infants born since mid-2003 with an already identified sire were sired by flanged males. All adult males ranged well beyond the study area (c. 1000 ha), and their dominance relations fluctuated even within short periods. However, 5 of the 10 identified sires had multiple offspring within the monitored area. Several sired over a period of c. 10 years, which overlapped with siring periods of other males. The long-calling behavior of sires indicated they were not consistently dominant over other males in the area around the time of known conceptions. Instead, when they were seen in the area, the known sires spent most of their time within the home ranges of the females whose offspring they sired. Overall, successful sires were older and more often resident than others. Significance statement: It is difficult to assess reproductive success for individuals of long-lived species, especially for dispersing males, who cannot be monitored throughout their lives. Due to extremely long interbirth intervals, orangutans have highly male-skewed operational sex ratios and thus intensive male-male competition for every conception. Paternity analyses matched 21 immature Bornean orangutans with their most likely sire (only 10 of 50 genotyped males) in a natural population. Half of these identified sires had multiple offspring in the study area spread over periods of at least 10 years, despite frequently ranging outside this area. Dominance was a poor predictor of success, but, consistent with female mating tactics to reduce the risk of infanticide, known "sires" tended to have relatively high local presence, which seems to contribute to the males' siring success. The results highlight the importance of large protected areas to enable a natural pattern of dispersal and ranging. Supplementary Information: The online version contains supplementary material available at 10.1007/s00265-023-03407-6.

11.
Materials (Basel) ; 15(14)2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35888430

RESUMO

The purpose of this research was to evaluate the impact of selected pigments on the performance of waterborne emulsion paint. Each pigment was incorporated into the paint at 5% w/w. Density and viscosity measurements as well as the rub-out test were used to test the wet state properties of the colored paint. Wet-scrub, adhesion-to-substrate, water-uptake, vapor-permeability, UV-aging, and other tests were conducted to evaluate effects of the pigments on the dried paint. Bohemian green earth pigment was found to have the most positive effect, as it improved the water resistance of the paint without changing its rheological properties. Therefore, this pigment was selected for further studies, in which the pigment was included as part of the paint formula rather than as a post-additive. The results were satisfactory, confirming the compatibility of the pigment with the formula. However, a slight change in the rheological profile of the paint was observed during tests on a rotational rheometer. This research shows the need for intensive quality control measures while testing alternative formulations, to both enable early detection of negative effects and identify possible improvements.

12.
Materials (Basel) ; 15(13)2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35806732

RESUMO

Natural dyes were extracted from various plant sources and converted into lake pigments based on aluminum and tin. Three different plants (weld, Persian berries, and Brazilwood) were chosen as representative sources of natural dyes. High-performance liquid chromatography (HPLC) and triple-quadrupole mass spectrometry (QqQ MS) were used to identify dyestuffs in the raw extracts. The natural dyes and lake pigments were further characterized by optical and scanning electron microscopy (SEM), UV-Vis spectrophotometry, and thermogravimetric analysis (TGA). The stabilization of the studied plant extracts onto aluminum and tin salts led to the formation of natural lake pigments characterized by different color shades. The natural lake pigments showed improved thermal and chemical stability, which was confirmed by their higher degradation temperatures and lower solubility in chemical agents compared to natural dyes extracted from plants. This improvement can be attributed to electrostatic attraction due to the process of chelation. Ethylene-norbornene (EN) composites colored with the lake pigments exhibited uniform color and improved resistance to long-term UV exposure aging. After 300 h of UV exposure, the aging factor of the neat EN copolymer reduced to 0.3, indicating an advanced aging process of polymer compared to colored samples. Prolonged UV exposure deteriorated the mechanical properties of EN by approximately 57%, compared to about 43% with the application of BW/Al lake pigment. Natural lake pigments could be used as effective substitutes for commercial colorants in plastics for packaging applications.

13.
Nanomaterials (Basel) ; 13(1)2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36615958

RESUMO

Polypropylene (PP)/acrylonitrile butadiene rubber (NBR) composite plates reinforced with halloysite nanotubes (HNTs) were manufactured in the presence of dual compatibilizers: PP-grafted maleic anhydride (PP-g-MA) and styrene ethylene butylene styrene-grafted maleic anhydride (SEBS-g-MA). The mechanical characteristics and microstructure of the PP/NBR/HNT nanocomposites were investigated as a function of NBR content (10, 20, and 30 wt.%) and HNTs content (3, 5, and 7 wt.%). The results demonstrated that the rubber particles were well dispersed over the PP matrix and that the HNTs were partly agglomerated at contents above 5%. Friction stir welding (FSW) was used to join the nanocomposite plates. A significant reduction in scattered NBR droplet size was seen in the FS-welded specimens containing 80/20 (wt/wt) PP/NBR composites in the presence of a dual compatibilizer. Considerable improvement in particle dispersion was observed in the case of PP/NBR blends filled 80/20 (wt/wt) with HNTs joined using FSW, leading to enhanced mechanical properties in the joints. This was due to the stirring action of the FSW tool. Suitable agreement between anticipated and confirmed values was observed in experiments.

14.
Polymers (Basel) ; 14(7)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35406257

RESUMO

We studied the effects of silicon carbide (SiC) and SiC hybrid systems with different conventional fillers (silica, carbon black, graphene, hydrotalcite, halloysite) on the rheometric measurements, crosslink density, mechanical performance, aging stability, morphology, thermal behaviour, and flammability of ethylene-propylene-diene (EPDM) rubber composites. The hybrid filler systems showed technically promising synergetic effects on the performance of the EPDM composites. A pronounced reinforcing effect in EPDM composites filled with hybrid SiC filler systems was noted. Tensile strength increased in the systems with carbon black, silica, and graphene nanoplatelets, by 21%, 37%, and 68%, respectively, compared to the neat EPDM. Dynamic-mechanical analysis (DMA) revealed a shift of the glass transition temperature (Tg) of EPDM composites towards higher values following the incorporation of hybrid SiC fillers, indicating that the mobility of the macromolecule chains was restricted by the presence of filler particles. Importantly, the application of SiC as a filler in EPDM rubber composites contributed to a considerable reduction in flammability, as demonstrated by microscale combustion calorimetry (MCC). The most promising results were obtained for HAL/SiC and LDH/SiC hybrid systems, which produced final composites with high flame retardancy and good mechanical performance. The study highlights the significant potential of SiC and SiC hybrid systems as effective fillers improving the properties of elastomer composites.

15.
Materials (Basel) ; 14(14)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34300972

RESUMO

Multicolor ethylene-norbornene (EN) composites filled with three different spinel pigments (Cobalt Green-PG50, Zinc Iron Yellow-PY 119, Praseodym Yellow-PY159) were prepared by melt mixing and characterized in terms of their stability under destructive environmental conditions. The EN films were subjected to accelerated aging by ultraviolet (UV) photooxidation for 300 h, 600 h, or 900 h. The mechanical performance of the EN composites was investigated in static and dynamic mechanical tests. The morphologies of the EN samples and their color changes during the aging process were evaluated by scanning electron microscopy (SEM) and spectrophotometric measurements. Fourier transform infrared (FTIR) spectroscopy was applied to determine the amount of carbonyl groups resulting from surface oxidation at different aging times. The effects of the spinel pigments on the thermal stability and combustion properties of the multicolor polymer composites were also assessed, and compared with a sample containing the organic Pigment Yellow 139 (PY139). The results show that the color changes (ΔE) in the spinel pigments were minor in comparison to those in the organic pigment (PY139) and the reference film. The Zinc Yellow (PY119) pigment was the most effective stabilizer of EN copolymer. Moreover, the spinel pigments had a positive effect on the flame retardancy of the EN composites. Microcombustion tests (MCC) showed that the incorporation of both the spinels and the organic pigment PY139 into the EN matrix reduced the heat release rate (HRR) and total heat release (THR) parameters.

16.
Materials (Basel) ; 14(18)2021 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-34576469

RESUMO

Due to growing restrictions on the use of halogenated flame retardant compounds, there is great research interest in the development of fillers that do not emit toxic compounds during thermal decomposition. Polymeric composite materials with reduced flammability are increasingly in demand. Here, we demonstrate that unmodified graphene and carbon nanotubes as well as basalt fibers or flakes can act as effective flame retardants in polymer composites. We also investigate the effects of mixtures of these carbon and mineral fillers on the thermal, mechanical, and rheological properties of EPDM rubber composites. The thermal properties of the EPDM vulcanizates were analyzed using the thermogravimetric method. Flammability was determined by pyrolysis combustion flow calorimetry (PCFC) and cone calorimetry.

17.
Materials (Basel) ; 14(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202830

RESUMO

The textile fragments of the funeral clothes found in the 17th and 18th century crypts were subjected to spectroscopic, spectrometric, and microbial investigation. The next-generation sequencing enabled DNA identification of microorganisms at the genus and in five cases to the species level. The soft hydrofluoric acid extraction method was optimized to isolate different classes of dyes from samples that had direct contact with human remains. High-performance liquid chromatography coupled with diode matrix and tandem mass spectrometry detectors with electrospray ionization (HPLC-DAD-ESI-MS/MS) enabled the detection and identification of 34 colourants that are present in historical textiles. Some of them are thus far unknown and uncommon dyes. Indigo, madder, cochineal, turmeric, tannin-producing plant, and young fustic were identified as sources of dyes in textiles. Scanning electron microscopy with energy-dispersive X-ray detector (SEM-EDS) and Fourier transform infrared spectroscopy (FT-IR) were used to identify and characterize fibres and mordants in funeral gowns. Of the 23 textile samples tested, 19 were silk while the remaining four were recognized as wool. The presence of iron, aluminium, sodium, and calcium suggests that they were used as mordants. Traces of copper, silica, and magnesium might originate from the contaminants. The large amount of silver indicated the presence of metal wire in one of the dyed silk textiles. SEM images showed that textile fibres were highly degraded.

18.
Primates ; 62(1): 41-49, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32623603

RESUMO

In February 2017 and August 2018, respectively, two Bornean orangutans (Pongo pygmaeus wurmbii) reintroduced into the Bukit Batikap Protection Forest in Central Kalimantan were found in weakened physical condition and with deep puncture wounds. The first individual was a sub-adult male, and the second an adult female whose 6- to 8-week-old infant was missing. Both individuals were rescued and transported back to the field base camp for treatment. Experienced veterinarians treating the injuries reported that the type of wounds appeared consistent with those expected from an attack by a large felid. The Sunda clouded leopard (Neofelis diardi) is the largest felid known to inhabit Bukit Batikap Protection Forest, and we suspect that these cases were unsuccessful predatory attacks by this species. Given the severity of his condition when found, the male orangutan would probably have died without medical intervention; however, both orangutans fully recovered following intensive treatment and were successfully returned to the forest. Predation attempts on orangutans are infrequently reported, thus our observations add to the body of knowledge about possible predation by clouded leopards on reintroduced, rehabilitant orangutans.


Assuntos
Felidae , Pongo pygmaeus/lesões , Comportamento Predatório , Animais , Mordeduras e Picadas/veterinária , Conservação dos Recursos Naturais , Feminino , Indonésia , Masculino , Ferimentos e Lesões/veterinária
19.
Materials (Basel) ; 13(16)2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32784574

RESUMO

Two different silane treatment methods were used to improve the reinforcing activity of carbon nanofibers (CNF) in acrylonitrile-butadiene rubber (NBR) composites. The first method was chemical silanization with [3-(2-aminoethylamino)propyl]trimethoxysilane (APTS) in ethanol solution, preceded by oxidation of the CNF with H2SO4/HNO3. The second method was direct incorporation of silanes during preparation of the composites (in-situ silanization). Three different silane coupling agents were used: [3-(2-aminoethylamino)propyl]trimethoxysilane, (3-mercaptopropyl)trimethoxysilane (MPTS), and 3-ureidopropyltrimethoxysilane (UPTS). The NBR composites were prepared in an internal laboratory mixer, with increasing concentrations of pure or modified CNF. The crosslink density and flammability of the NBR-filled composites were analyzed, as well as their rheological and mechanical properties. The electrical conductivity of the composites was measured to assess the formation of CNF networks in the elastomer matrix. The morphology of the CNF was assessed by scanning electron microscopy (SEM). Both the dispersion of the CNF in the NBR matrix and the polymer-filler interactions were improved following silane modification, as shown in SEM images and by the Payne Effect. The composites were also found to have enhanced moduli, tensile strength, hardness, damping, and electrical conductivity. Chemical treatment proved to be more effective at improving the reinforcing effect of CNF in the elastomer matrix than in-situ silanization. The results of this study demonstrate the great potential of both in-situ and chemical silanization for the preparation of reinforced polymer composites filled with CNF.

20.
Materials (Basel) ; 13(19)2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003590

RESUMO

In this paper, we present the design of reinforced silica-filled elastomer composites exhibiting a high transparency, high mechanical performance in static and dynamic conditions, and improved electrical conductivity. Two different imidazolium ionic liquids (ILs) were used with increasing loads: 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIMTFSI) and 1-butyl-3-methylimidazolium tetrachloroaluminate (BMIMAlCl4). The composites were prepared in a two-roll mill. The influence of the ILs on the dispersion of the silica in the nitrile rubber (NBR) matrix was assessed by scanning electron microscopy (SEM). The presence of ILs in the NBR/SiO2 systems improved the crosslink density and ionic conductivity of the composites. Their mechanical properties and aging stability remained almost unchanged, at a very satisfactory level. Greater crosslinking was observed for the NBR/SiO2 composites containing BMIMAlCl4, due to its catalytic effect on the efficiency of interface crosslinking reactions. We found the optimal formulation for obtaining transparent reinforced NBR/SiO2 composites. The application of 2.5 phr of BMIMAlCl4 resulted in a high transparency in the case of NBR composites filled with 30 phr of silica.

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