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2.
Sci Rep ; 12(1): 6592, 2022 04 21.
Article in English | MEDLINE | ID: mdl-35449183

ABSTRACT

Decompression sickness (DCS) is a clinical syndrome caused by the formation of systemic intravascular and extravascular gas bubbles. The presence of these bubbles in blood vessels is known as gas embolism. DCS has been described in humans and animals such as sea turtles and cetaceans. To delve deeper into DCS, experimental models in terrestrial mammals subjected to compression/decompression in a hyperbaric chamber have been used. Fish can suffer from gas bubble disease (GBD), characterized by the formation of intravascular and extravascular systemic gas bubbles, similarly to that observed in DCS. Given these similarities and the fact that fish develop this disease naturally in supersaturated water, they could be used as an alternative experimental model for the study of the pathophysiological aspect of gas bubbles. The objective of this study was to obtain a reproducible model for GBD in fish by an engineering system and a complete pathological study, validating this model for the study of the physiopathology of gas related lesions in DCS. A massive and severe GBD was achieved by exposing the fish for 18 h to TDG values of 162-163%, characterized by the presence of severe hemorrhages and the visualization of massive quantities of macroscopic and microscopic gas bubbles, systemically distributed, circulating through different large vessels of experimental fish. These pathological findings were the same as those described in small mammals for the study of explosive DCS by hyperbaric chamber, validating the translational usefulness of this first fish model to study the gas-bubbles lesions associated to DCS from a pathological standpoint.


Subject(s)
Decompression Sickness , Diving , Embolism, Air , Turtles , Animals , Fishes , Mammals , Pressure
3.
RSC Adv ; 10(33): 19443-19453, 2020 May 20.
Article in English | MEDLINE | ID: mdl-35515433

ABSTRACT

Nanocrystalline titania was synthesized by a simple, innovative and eco-friendly gelation method by using biopolymers (polysaccharides). The effect of the gelling agent, such as carboxymethylcellulose (CMC) or alginate (Alg), and the drying routes (conventional drying at room temperature, or freeze-drying) on the properties and photocatalytic performances of nanostructured TiO2 was examined. The crystallographic structures, and textural and morphological characteristics were investigated by thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy dispersive spectrometry (ESEM-FEG-EDS), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS) and N2 adsorption/desorption isotherms. The as-synthesized samples were fully crystallized and appeared to be highly phase-pure anatase or mixed titania polymorphs, and have a quasi-spherical shape with a particle size ranging from 10.34 to 18.07 nm. Phase-pure anatase was obtained by using alginate as the gelling agent, whereas CMC's gelation promotes mixed structures. The presence of rutile phase results in a lower bandgap value of 3.04 eV corresponding to 408 nm. Thus, the material absorption wavelength shifts slightly from the UV (190-380 nm) to visible region (380-750 nm). The drying process also affects TiO2 properties. The lyophilization route improves the oxide's specific surface area, and also its photocatalytic properties verified during Orange G dye photodegradation study.

4.
Environ Sci Pollut Res Int ; 25(28): 27724-27736, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29557041

ABSTRACT

Magnetite (Fe3O4), a core-shell material (SiO2@Fe3O4), and reduced graphene oxide-Fe3O4 (referred as rGO-MN) were used as supports of a specific highly active TiO2 photocatalyst. Thermal treatments at 200 or 450 °C, different atmospheres (air or N2), and TiO2:support weight ratios (1.0, 1.5, or 2.0) were investigated. X-ray diffractograms revealed that magnetite is not oxidized to hematite when the core-shell SiO2@Fe3O4 material-or a N2 atmosphere (instead of air) in the thermal treatment-was employed to prepare the TiO2-based catalysts (the magnetic properties being preserved). The materials treated with N2 were first tested for degradation of imazalil (a well-known fungicide) in deionized water. The best compromise between the photocatalytic activity, magnetic separation, and Fe leached (1.61 mg L-1, i.e., below the threshold for water reuse in irrigation) was found for the magnetic catalyst prepared with SiO2@Fe3O4, an intermediate TiO2:support ratio (1.5), and treated at 200 °C under N2 atmosphere (i.e., SiO2@Fe3O4-EST-1.5-200-N2). This material was then tested for the treatment of imazalil in a synthetic wastewater, SW (with a chemical composition simulating an effluent resulting from fruit postharvest activity). This SW has a pH of 4.2 and the experiments were carried out at this natural pH0 and at neutral conditions (keeping pH at 7 along the reaction). The magnetic catalyst was more active than bare TiO2 for the treatment of imazalil in SW at natural pH. Since Fe leaching was observed (3.53 mg L-1), added H2O2 enhanced both imazalil degradation and mineralization. Conveniently, these catalysts can be readily recovered by using a conventional magnetic field, as demonstrated over three consecutive recycling runs. Graphical abstract % Imazalil conversion using different magnetic catalysts and comparison with bare TiO2.


Subject(s)
Graphite/chemistry , Imidazoles/analysis , Magnetite Nanoparticles/chemistry , Silicon Dioxide/chemistry , Titanium/chemistry , Water Pollutants, Chemical/analysis , Water Purification/methods , Adsorption , Catalysis , Hydrogen Peroxide/chemistry , Models, Theoretical , Photochemical Processes , Wastewater/chemistry
5.
Front Physiol ; 7: 310, 2016.
Article in English | MEDLINE | ID: mdl-27493634

ABSTRACT

The pathophysiological mechanism of decompression sickness is not fully understood but there is evidence that it can be caused by intravascular and autochthonous bubbles. Doppler ultrasound at a given circulatory location is used to detect and quantify the presence of intravascular gas bubbles as an indicator of decompression stress. In this manuscript we studied the relationship between presence and quantity of gas bubbles by echosonography of the pulmonary artery of anesthetized, air-breathing New Zealand White rabbits that were compressed and decompressed. Mortality rate, presence, quantity, and distribution of gas bubbles elsewhere in the body was examined postmortem. We found a strong positive relationship between high ultrasound bubble grades in the pulmonary artery, sudden death, and high amount of intra and extra vascular gas bubbles widespread throughout the entire organism. In contrast, animals with lower bubble grades survived for 1 h after decompression until sacrificed, and showed no gas bubbles during dissection.

6.
Res Vet Sci ; 106: 48-55, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27234535

ABSTRACT

Gas bubble lesions consistent with decompression sickness in marine mammals were described for the first time in beaked whales stranded in temporal and spatial association with military exercises. Putrefaction gas is a post-mortem artifact, which hinders the interpretation of gas found at necropsy. Gas analyses have been proven to help differentiating putrefaction gases from gases formed after hyperbaric exposures. Unfortunately, chemical analysis cannot always be performed. Post-mortem computed tomography is used to study gas collections, but many different logistical obstacles and obvious challenges, like the size of the animal or the transport of the animal from the stranding location to the scanner, limit its use in stranded marine mammals. In this study, we tested the diagnostic value of an index-based method for characterizing the amount and topography of gas found grossly during necropsies. For this purpose, putrefaction gases, intravenously infused atmospheric air, and gases produced by decompression were evaluated at necropsy with increased post-mortem time in New Zealand White Rabbits using a gas score index. Statistical differences (P<0.001) were found between the three experimental models immediately after death. Differences in gas score between in vivo gas embolism and putrefaction gases were found significant (P<0.05) throughout the 67h post-mortem. The gas score-index is a new and simple method that can be used by all stranding networks, which has been shown through this study to be a valid diagnostic tool to distinguish between fatal decompression, iatrogenic air embolism and putrefaction gases at autopsies.


Subject(s)
Autopsy/methods , Cetacea , Postmortem Changes , Animals , Gases , Models, Animal , Rabbits
7.
Int J Legal Med ; 127(2): 437-45, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23090361

ABSTRACT

Gas embolism can arise from different causes (iatrogenic accidents, criminal interventions, or diving related accidents). Gas analyses have been shown to be a valid technique to differentiate between putrefaction gases and gas embolism. In this study, we performed systematic necropsies at different postmortem times in three experimental New Zealand White Rabbits models: control or putrefaction, infused air embolism, and compression/decompression. The purpose of this study was to look for qualitative and quantitative differences among groups and to observe how putrefaction gases mask in vivo gas embolism. We found that the infused air embolism and compression/decompression models had a similar gas composition prior to 27-h postmortem, being typically composed of around 70-80 % of N(2) and 20-30 % of CO(2), although unexpected higher CO(2) concentrations were found in some decompressed animals, putting in question the role of CO(2) in decompression. All these samples were statistically and significantly different from more decomposed samples. Gas composition of samples from more decomposed animals and from the putrefaction model presented hydrogen, which was therefore considered as a putrefaction marker.


Subject(s)
Embolism, Air/pathology , Postmortem Changes , Animals , Carbon Dioxide/analysis , Emphysema/pathology , Forensic Pathology , Hydrogen/analysis , Models, Animal , Nitrogen/analysis , ROC Curve , Rabbits
8.
Front Physiol ; 3: 177, 2012.
Article in English | MEDLINE | ID: mdl-22675306

ABSTRACT

Gas embolic lesions linked to military sonar have been described in stranded cetaceans including beaked whales. These descriptions suggest that gas bubbles in marine mammal tissues may be more common than previously thought. In this study we have analyzed gas amount (by gas score) and gas composition within different decomposition codes using a standardized methodology. This broad study has allowed us to explore species-specific variability in bubble prevalence, amount, distribution, and composition, as well as masking of bubble content by putrefaction gases. Bubbles detected within the cardiovascular system and other tissues related to both pre- and port-mortem processes are a common finding on necropsy of stranded cetaceans. To minimize masking by putrefaction gases, necropsy, and gas sampling must be performed as soon as possible. Before 24 h post mortem is recommended but preferably within 12 h post mortem. At necropsy, amount of bubbles (gas score) in decomposition code 2 in stranded cetaceans was found to be more important than merely presence vs. absence of bubbles from a pathological point of view. Deep divers presented higher abundance of gas bubbles, mainly composed of 70% nitrogen and 30% CO(2), suggesting a higher predisposition of these species to suffer from decompression-related gas embolism.

9.
Contact Dermatitis ; 66(1): 33-7, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21972791

ABSTRACT

BACKGROUND: Very few studies are available in which the components of henna products used by tattoo artists have been analysed. OBJECTIVE: The aim of this study was to quantify the amounts of lawsone (2-hydroxy-1,4-naphthoquinone, the active ingredient in henna) and p-phenylenediamine (PPD) in products used by tattoo artists and in commercial henna preparations used as hair dyes or to create temporary tattoos. METHODS: We used high-performance liquid chromatography to detect and quantify lawsone and PPD concentrations in three products used by henna tattoo artists, 11 commercially available henna preparations, and a batch of henna leaves (Lawsonia inermis). RESULTS: The henna leaves contained 1.85-1.87% lawsone. Only one of the three preparations used by tattoo artists contained lawsone (0.21-0.35%), and all three were adulterated with PPD (1-64%). Of the 11 commercial henna preparations analysed, nine contained lawsone (1-2%) and two contained PPD (2% and 12%). CONCLUSIONS: Products purporting to be henna, but that in fact contain no henna, are being offered. Moreover, these products may contain PPD, which is associated with health risks, especially severe allergic reactions.


Subject(s)
Coloring Agents/chemistry , Dermatitis, Allergic Contact/etiology , Lawsonia Plant/chemistry , Naphthoquinones/analysis , Phenylenediamines/analysis , Tattooing/adverse effects , Chromatography, High Pressure Liquid , Consumer Product Safety , Hair Dyes/chemistry , Humans , Plant Leaves/chemistry , Spain , Thorax
10.
Ginecol Obstet Mex ; 80(5): 327-31, 2012 May.
Article in Spanish | MEDLINE | ID: mdl-23301424

ABSTRACT

BACKGROUND: The laparoscopic total hysterectomy is an increasingly applied alternative in the surgical management of uterine pathology. OBJECTIVE: To describe the results obtained in patients that underwent total laparoscopic hysterectomy for the management of benign uterine pathology. MATERIAL AND METHOD: We performed a descriptive, longitudinal and retrospective study in which results on 151 patients who underwent total laparoscopic hysterectomy between October 2008 and July 2011 are reported. RESULTS: The average age of the population was 42.5 years (30-56 years); body mass index averaged 25.8 kg/m2 (18-37 kg/m2). The most common surgical indication was uterine fibroids in 121 cases (80.1%). Among the surgical outcomes, the average operative time was 140.3 minutes (70-275 minutes); average total bleeding, 131 mL (50-400 mL); 3 cases (1.98%) of bladder injury were reported. The immediate postoperative evolution was hospitalization of 1.4 days (1-7 days). Late postoperative complications were fistulas of the urinary tract in 7 cases (4.63%), and in 1 case (0.66%) infection of the vaginal vault. The average weight of surgical specimens was 210 g (50-650 g). CONCLUSIONS: Total laparoscopic hysterectomy is an appropriate therapeutic option We believe that careful selection of patients is critical to providing the best results.


Subject(s)
Hysterectomy/methods , Laparoscopy/methods , Uterine Diseases/surgery , Adult , Female , Humans , Longitudinal Studies , Middle Aged , Retrospective Studies , Tertiary Care Centers
11.
J Phys Chem Lett ; 3(16): 2269-74, 2012 Aug 16.
Article in English | MEDLINE | ID: mdl-26295782

ABSTRACT

We investigate the effect of fluorine doping on the optical spectra of stoichiometric and reduced TiO2 anatase, brookite, and rutile using density functional methods. The present approach is able to reproduce the main features of experiments and high-level quasiparticle calculations for undoped titania but at a much lower computational cost, thus allowing the study of doped titania, which requires large supercells. Whereas the simulated spectra of F-substituted brookite and rutile do not show any significant new feature, a relatively intense new band near the visible region is predicted for F-substituted anatase. This allows one to suggest assigning the spectral features near the visible region, observed on multiphase F-doped titania samples, to the presence of anatase. The physical origin of the new absorption band in F-doped anatase is unambiguously attributed to the presence of Ti(3+) centers.

12.
Sci Rep ; 1: 193, 2011.
Article in English | MEDLINE | ID: mdl-22355708

ABSTRACT

Gas-bubble lesions were described in cetaceans stranded in spatio-temporal concordance with naval exercises using high-powered sonars. A behaviourally induced decompression sickness-like disease was proposed as a plausible causal mechanism, although these findings remain scientifically controversial. Investigations into the constituents of the gas bubbles in suspected gas embolism cases are highly desirable. We have found that vacuum tubes, insulin syringes and an aspirometer are reliable tools for in situ gas sampling, storage and transportation without appreciable loss of gas and without compromising the accuracy of the analysis. Gas analysis is conducted by gas chromatography in the laboratory. This methodology was successfully applied to a mass stranding of sperm whales, to a beaked whale stranded in spatial and temporal association with military exercises and to a cetacean chronic gas embolism case. Results from the freshest animals confirmed that bubbles were relatively free of gases associated with putrefaction and consisted predominantly of nitrogen.


Subject(s)
Blood Gas Analysis/instrumentation , Blood Gas Analysis/methods , Chromatography, Gas/methods , Embolism, Air/diagnosis , Whales/physiology , Animals , Embolism, Air/pathology , Equipment Design , Gases , Nitrogen/analysis , Oxygen/analysis , Syringes , Temperature
13.
Ginecol. obstet. Méx ; 59: 299-301, oct. 1991. tab
Article in Spanish | LILACS | ID: lil-111079

ABSTRACT

De marzo de 1987 a julio de 1990, se realizaron 1,568 procedimientos quirúrgicos en el Departamento de Ginecología Oncológica, de los cuales 206 (13.1%) se consideraron procedimientos quirúrgicos "no ginecológicos", 182 (88.3%) fueron secundarios a un diagnóstico de malignidad, siendo el más frecuente el carcinoma de ovario en 54.4%. Dentro de la patología benigna, 11.7% originó cirugía no ginecológica, siendo la más frecuente los procesos pélvicos adherenciales severos en 41.6% y la endometriosis severa en 25%. El procedimiento quirúrgico no ginecológico más frecuente fue linfadenectomía pélvica. Se obtuvo 3.8% de morbilidad y una mortalidad de 0l48% secundaria a un infarto agudo del miocardio. La aceptación del ginecólogo oncólogo es justificada en esta serie en base a supervivencia y morbilidad, permitiendo formar parte de un equipo multidisciplinario.(au)


Subject(s)
Humans , Female , Digestive System/surgery , Genital Neoplasms, Female/surgery , Lymph Node Excision/rehabilitation , Urogenital System/surgery , Genital Neoplasms, Female/therapy , Morbidity , Medical Oncology/education
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