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Alkylation reactions are pivotal in organic chemistry, with wide-ranging utilization across various fields of applied synthetic chemistry. However, conventional reagents employed in alkylations often pose substantial health and exposure risks. Quaternary ammonium salts (QAS) present a promising alternative for these transformations offering significantly reduced hazards as they are non-cancerogenic, non-mutagenic, non-flammable, and non-corrosive. Despite their potential, their use in direct organic transformations remains relatively unexplored. This review outlines strategies for utilizing QAS as alternative reagents in alkylation reactions, providing researchers with safer approaches to chemical synthesis.
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The copper-catalyzed azide-alkyne cycloaddition (CuAAC) has heralded a new era of chemical biology and biomedicine. However, caveats of CuAAC include formation of reactive oxygen species (ROS) and other copper-related toxicity. This limits utility in sensitive biological samples and matrices. Towards addressing these caveats, we synthesized and fully characterized two air and water stable trinuclear Cu (I) dimer complexes. The complexes were stable to oxidation in the presence of hydrogen peroxide, acid, base, and other chelators, which was reasoned to be due to the linear benzimidazole-Cu-benzimidazole geometry. Computational investigations of the catalytic cycle implicated two of the three coppers in the trimer complex as the active metal centers. The complexes were shown to catalyze the reaction at far below sub-toxic concentrations for intracellular click reactions to label triple negative breast cancer cells and compared to the current CuSO-4-THPTA standard.
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Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder worldwide, and the therapeutic is focused on several approaches including the inhibition of fibril formation by small compounds, avoiding the formation of cytotoxic oligomers. Thus, we decided to explore the capacity of compounds carrying catechol moieties to inhibit the progression of α-synuclein. Overall, the compounds rosmarinic acid (1), carnosic acid (2), carnosol (3), epiisorosmanol (4), and rosmanol (5) avoid the progression of fibril formation assessed by Thiofavine T (ThT), and atomic force microscopy images showed that morphology is influenced for the actions of compounds over fibrillization. Moreover, ITC experiments showed a Kd varying from 28 to 51 µM, the ΔG showed that the reaction between compounds and α-syn is spontaneous, and ΔH is associated with an exothermic reaction, suggesting the interactions of hydrogen bonds among compounds and α-syn. Docking experiments reinforce this idea showing the intermolecular interactions are mostly hydrogen bonding within the sites 2, 9, and 3/13 of α-synuclein, and compounds 1 and 5. Thus, compound 1, rosmarinic acid, interestingly interacts better with site 9 through catechol and Lysines. In cultured Raw 264. 7 cells, the presence of compounds showed that most of them can promote cell differentiation, especially rosmarinic acid, and rosmanol, both preserving tubulin cytoskeleton. However, once we evaluated whether or not the aggregates pre-treated with compounds could prevent the disruption of microtubules of Raw 264.7 cells, only pre-treated aggregates with rosmarinic acid prevented the disruption of the cytoskeleton. Altogether, we showed that especially rosmarinic acid not only inhibits α-syn but stabilizes the remaining aggregates turning them into not-toxic to Raw 264.7 cells suggesting a main role in cell survival and antigen processing in response to external α-syn aggregates.
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Cinamatos , Depsídeos , Microtúbulos , Ácido Rosmarínico , alfa-Sinucleína , Depsídeos/farmacologia , Depsídeos/química , Depsídeos/isolamento & purificação , Cinamatos/química , Cinamatos/farmacologia , Cinamatos/síntese química , Animais , Camundongos , Células RAW 264.7 , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Estrutura Molecular , alfa-Sinucleína/metabolismo , alfa-Sinucleína/antagonistas & inibidores , Relação Estrutura-Atividade , Relação Dose-Resposta a Droga , Sobrevivência Celular/efeitos dos fármacos , Simulação de Acoplamento MolecularRESUMO
Non-small cell lung cancer (NSCLC) continues to be the leading cause of cancer-related deaths. Although advances have been made in the past decade to treat such tumors, most options induce multiple side effects, and many patients discontinue therapy due to toxicity. Thus, the need remains for non-toxic, effective NSCLC therapies, especially in an elderly patient population. Our lab has previously identified a protein fraction from the nutraceutical Avemar®-dubbed fermented wheat germ protein (FWGP)-with demonstrated efficacy in lymphoma models both in vitro and in vivo. Here, we show that FWGP also has anti-tumor activity in vitro and in vivo against lung cancer. In vitro cytotoxicity against multiple lung cancer cell lines yielded IC50 values comparable to those previously established with the parent product, Avemar. Further, significant A549 xenograft growth inhibition occurred in athymic nu/nu mice receiving FWGP in both pre-radiated and non-radiated models when compared to the untreated control. Encouragingly, mice treated with FWGP experienced no toxicities as detected by weight reduction or blood chemistry analysis. These data support the further study of FWGP as a potential non-toxic therapy for lung cancer and other oncologic indications.
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This document provides the new EANM guideline on radioiodine therapy of benign thyroid disease. Its aim is to guide nuclear medicine physicians, endocrinologists, and practitioners in the selection of patients for radioiodine therapy. Its recommendations on patients' preparation, empiric and dosimetric therapeutic approaches, applied radioiodine activity, radiation protection requirements, and patients follow-up after administration of radioiodine therapy are extensively discussed.
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Doença de Graves , Proteção Radiológica , Doenças da Glândula Tireoide , Humanos , Radioisótopos do Iodo/uso terapêutico , Doença de Graves/tratamento farmacológico , Doenças da Glândula Tireoide/radioterapia , Doenças da Glândula Tireoide/tratamento farmacológico , RadiometriaRESUMO
BACKGROUND: Ovarian cancer is the most lethal cancer in gynaecology. Surgery, chemotherapy, and radiotherapy are the most often used cancer-fighting strategies. Post-surgery infection is fairly prevalent, especially among people with insufficient immunity. Zinc oxide nanoparticles (ZnOnps) have amazing biomedical features as anticancer and antibacterial agents. METHODS: We investigated the behaviour of ZnOnps synthesized by green methods on ovarian cancers using established human ovarian cancer cell lines, besides the antibacterial action toward models of gram + ve and gram -ve bacteria. The cytotoxic effect of ZnOnps was calculated using a Sulforhodamine B (SRB) trial. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were tested as models for gram + ve and gram -ve bacteria. The selected bacteria were subjected to concentrations of 20, 40, 80, and 100 µg/ml. RESULTS: The synthesized ZnOnps induced 50% inhibitory concentration (IC50) at a concentration of 27.45 µg/ml. The diameter of inhibition ranged between 20.16 ± 0.16 and 27 ± 0.57 mm for S. aureus and 25.66 ± 0.33 to 31 ± 0.33 mm for E. coli. ZnOnps antagonistic effect statistically differed with neomycin, cefaclor, and cefadroxil. CONCLUSIONS: Green synthesis of ZnOnps is easily prepared, low cost, non-toxic, and eco-friendly. Their cytotoxic action on SKOV3 cells and their antibacterial characteristics pave the way to be an alternative therapy for ovarian cancer and S. aureus and E. coli infection.
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Antineoplásicos , Nanopartículas Metálicas , Nanopartículas , Neoplasias Ovarianas , Óxido de Zinco , Humanos , Feminino , Staphylococcus aureus , Óxido de Zinco/farmacologia , Escherichia coli , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológicoRESUMO
BACKGROUND: We have performed an updated meta-analysis of randomized controlled trials (RCT) comparing total thyroidectomy (TT) with less than total thyroidectomy (LTT) for benign multinodular non-toxic goiter (BMNG). OBJECTIVES: The objective was to evaluate the effects and outcomes of TT as compared to LTT. METHODS: Eligibility criteria: RCTs comparing TT vs LTT. INFORMATION SOURCES: PubMed, Embase, Cochrane Library and online registers were searched for articles comparing TT with LTT. Risk of bias: Articles were assessed for risk of bias using the Cochrane's revised tool to assess risk of bias in randomized trials (RoB 2 tool). SYNTHESIS OF RESULTS: The main summary measures were risk difference using a random effects model. RESULTS: Five randomized controlled trials were included in the meta-analysis. Recurrence rate was lower for TT compared to LTT. Adverse events like temporary or permanent recurrent laryngeal nerve (RLN) palsy and permanent hypoparathyroidism were similar in both groups except for the rate of temporary hypoparathyroidism which was lower in the LTT group. DISCUSSION: All studies had unclear risk of bias for blinding of the participants and personnel and high risk of bias for certain selective reporting. This meta-analysis did not show any clear benefit or harm of either procedure (TT vs LTT) for goiter recurrence and re-operation rates (for both recurrence and incidental thyroid cancer). However, re-operation for goiter recurrence was significantly higher in the LTT group based on a single RCT. Evidence suggests increased rates of temporary hypoparathyroidism with TT but there was no difference in the rate of RLN palsy and permanent hypoparathyroidism between the two methods. The overall quality of evidence was low to moderate.
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Bócio Nodular , Hipoparatireoidismo , Paralisia das Pregas Vocais , Humanos , Bócio Nodular/cirurgia , Bócio Nodular/etiologia , Tireoidectomia/efeitos adversos , Tireoidectomia/métodos , Recidiva Local de Neoplasia/cirurgia , Hipoparatireoidismo/etiologia , Paralisia das Pregas Vocais/etiologiaRESUMO
In the current study we investigate the antifouling potential of three polyphenolic resveratrol multimers (-)-hopeaphenol, vaticanol B and vatalbinoside A, isolated from two species of Anisoptera found in the Papua New Guinean rainforest. The compounds were evaluated against the growth and settlement of eight marine microfoulers and against the settlement and metamorphosis of Amphibalanus improvisus barnacle cyprids. The two isomeric compounds (-)-hopeaphenol and vaticanol B displayed a high inhibitory potential against the cyprid larvae metamorphosis at 2.8 and 1.1 µM. (-)-Hopeaphenol was also shown to be a strong inhibitor of both microalgal and bacterial adhesion at submicromolar concentrations with low toxicity. Resveratrol displayed a lower antifouling activity compared to the multimers and had higher off target toxicity against MCR-5 fibroblasts. This study illustrates the potential of natural products as a valuable source for the discovery of novel antifouling leads with low toxicity.
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Biofilmes , Thoracica , Animais , Resveratrol/farmacologia , FenóisRESUMO
Globally, many low to medium yielding peanut fields have the potential for further yield improvement. Low phosphorus (P) limitation is one of the significant factors curtailing Arachis hypogaea productivity in many regions. In order to demonstrate the effects of gamma-aminobutyric acid (GABA) on peanuts growing under P deficiency, we used a pot-based experiment to examine the effects of exogenous GABA on alleviating P deficiency-induced physiological changes and growth inhibition in peanuts. The key physiological parameters examined were foliar gas exchange, photochemical efficiency, proton motive force, reactive oxygen species (ROS), and adenosine triphosphate (ATP) synthase activity of peanuts under cultivation with low P (LP, 0.5 mM P) and control conditions. During low P, the cyclic electron flow (CEF) maintained the high proton gradient (∆pH) induced by low ATP synthetic activity. Applying GABA during low P conditions stimulated CEF and reduced the concomitant ROS generation and thereby protecting the foliar photosystem II (PSII) from photoinhibition. Specifically, GABA enhanced the rate of electronic transmission of PSII (ETRII) by pausing the photoprotection mechanisms including non-photochemical quenching (NPQ) and ∆pH regulation. Thus, GABA was shown to be effective in restoring peanut growth when encountering P deficiency. Exogenous GABA alleviated two symptoms (increased root-shoot ratio and photoinhibition) of P-deficient peanuts. This is possibly the first report of using exogenous GABA to restore photosynthesis and growth under low P availability. Therefore, foliar applications of GABA could be a simple, safe and effective approach to overcome low yield imposed by limited P resources (low P in soils or P-fertilizers are unavailable) for sustainable peanut cultivation and especially in low to medium yielding fields.
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Arachis , Fotossíntese , Espécies Reativas de Oxigênio , Trifosfato de Adenosina , Fósforo/farmacologia , Ácido gama-Aminobutírico/farmacologiaRESUMO
Selenium is a main group element and an essential trace element in human health. It was discovered in selenocysteine (SeC) by Stadtman in 1974. SeC is an encoded natural amino acid hailed as the 21st naturally occurring amino acid (U) present in several enzymes and which exquisitely participates in redox biology. As it turns out, selenium bears a U-shaped toxicity curve wherein too little of the nutrient present in biology leads to disorders; concentrations that are too great, on the other hand, pose toxicity to biological systems. In light of many excellent previous reviews and the corpus of literature, we wanted to offer this current review, in which we present aspects of the clinical and biological literature and justify why we should further investigate Se-containing species in biological and medicinal contexts, especially small molecule-containing species in biomedical research and clinical medicine. Of central interest is how selenium participates in biological signaling pathways. Several clinical medical cases are recounted; these reports are mainly pertinent to human cancer and changes in pathology and cases in which the patients are often terminal. Selenium was an option chosen in light of earlier chemotherapeutic treatment courses which lost their effectiveness. We describe apoptosis, and also ferroptosis, and senescence clearly in the context of selenium. Other contemporary issues in research also compelled us to form this review: issues with CoV-2 SARS infection which abound in the literature, and we described findings with human patients in this context. Laboratory scientific studies and clinical studies dealing with two main divisions of selenium, organic (e.g., methyl selenol) or inorganic selenium (e.g., sodium selenite), are discussed. The future seems bright with the research and clinical possibilities of selenium as a trace element, whose recent experimental clinical treatments have so far involved dosing simply and inexpensively over a set of days, amounts, and time intervals.
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COVID-19 , Selênio , Oligoelementos , Humanos , Selênio/farmacologia , Selênio/metabolismo , Oxirredução , Selenocisteína/metabolismo , Estresse Oxidativo , Apoptose , Transdução de SinaisRESUMO
Solution-processed quantum dot (QD) based blue emitters are of paramount importance in the field of optoelectronics. Despite large research efforts, examples of efficient deep blue/near UV-emitting QDs remain rare due to lack of luminescent wide band gap materials and high defect densities in the existing ones. Here, we introduce a novel type of QDs based on heavy metal free gallium sulfide (Ga2 S3 ) and their core/shell heterostructures Ga2 S3 /ZnS as well as Ga2 S3 /ZnS/Al2 O3 . The photoluminescence (PL) properties of core Ga2 S3 QDs exhibit various decay pathways due to intrinsic defects, resulting in a broad overall PL spectrum. We show that the overgrowth of the Ga2 S3 core QDs with a ZnS shell results in the suppression of the intrinsic defect-mediated states leading to efficient deep-blue emission at 400â nm. Passivation of the core/shell structure with amorphous alumina yields a further enhancement of the PL quantum yield approaching 50 % and leads to an excellent optical and colloidal stability. Finally, we develop a strategy for the aqueous phase transfer of the obtained QDs retaining 80 % of the initial fluorescence intensity.
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Turbidity and opaqueness are inherent properties of tissues that limit the capacity to acquire microscopic images through large tissues. Creating a uniform refractive index, known as tissue clearing, overcomes most of these issues. These methods have enabled researchers to image large and complex 3D structures with unprecedented depth and resolution. However, tissue clearing has been adopted to a limited extent due to a combination of cost, time, complexity of existing methods and potential negative impact on fluorescence signal. Here, we describe 2Eci (2nd generation ethyl cinnamate-based clearing), which can be used to clear a wide range of tissues in several species, including human organoids, Drosophila melanogaster, zebrafish, axolotl and Xenopus laevis, in as little as 1-5â days, while preserving a broad range of fluorescent proteins, including GFP, mCherry, Brainbow and Alexa-conjugated fluorophores. Ethyl cinnamate is non-toxic and can easily be used in multi-user microscope facilities. This method opens up tissue clearing to a much broader group of researchers due to its ease of use, the non-toxic nature of ethyl cinnamate and broad applicability.
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Cinamatos/química , Corantes Fluorescentes/química , Imageamento Tridimensional/métodos , Organoides/citologia , Ambystoma mexicanum , Animais , Drosophila melanogaster , Humanos , Microscopia de Fluorescência , Xenopus laevis , Peixe-ZebraRESUMO
This study reports curcumin as an efficient photolarvicide against Aedes aegypti larvae under natural light illumination. Larval mortality and pupal formation were monitored daily for 21 days under simulated field conditions. In a sucrose-containing formulation, a lethal time 50 (LT50) of 3 days was found using curcumin at 4.6 mg L-1. This formulation promoted no larval toxicity in the absence of illumination, and sucrose alone did not induce larval phototoxicity. The photodegradation byproducts (intermediates) of curcumin were determined and the photodegradation mechanisms proposed. Intermediates with m/z 194, 278, and 370 were found and characterized using LC-MS. The ecotoxicity of the byproducts on non-target organisms (Daphnia, fish, and green algae) indicates that the intermediates do not exhibit any destructive potential for aquatic organisms. The results of photodegradation and ecotoxicity suggest that curcumin is environmentally safe for non-target organisms and, therefore, can be considered for population control of Ae. aegypti.
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Aedes , Curcumina , Inseticidas , Animais , Curcumina/farmacologia , Inseticidas/farmacologia , Larva , Fotólise , Sacarose , Luz SolarRESUMO
In the past few years, the research on particle-stabilized emulsion (Pickering emulsion) has mainly focused on the usage of inorganic particles with well-defined shapes, narrow size distributions, and chemical tunability of the surfaces such as silica, alumina, and clay. However, the presence of incompatibility of some inorganic particles that are non-safe to humans and the ecosystem and their poor sustainability has led to a shift towards the development of materials of biological origin. For this reason, nano-dimensional cellulose (nanocellulose) derived from natural plants is suitable for use as a Pickering material for liquid interface stabilization for various non-toxic product formulations (e.g., the food and beverage, cosmetic, personal care, hygiene, pharmaceutical, and biomedical fields). However, the current understanding of nanocellulose-stabilized Pickering emulsion still lacks consistency in terms of the structural, self-assembly, and physio-chemical properties of nanocellulose towards the stabilization between liquid and oil interfaces. Thus, this review aims to provide a comprehensive study of the behavior of nanocellulose-based particles and their ability as a Pickering functionality to stabilize emulsion droplets. Extensive discussion on the characteristics of nanocelluloses, morphology, and preparation methods that can potentially be applied as Pickering emulsifiers in a different range of emulsions is provided. Nanocellulose's surface modification for the purpose of altering its characteristics and provoking multifunctional roles for high-grade non-toxic applications is discussed. Subsequently, the water-oil stabilization mechanism and the criteria for effective emulsion stabilization are summarized in this review. Lastly, we discuss the toxicity profile and risk assessment guidelines for the whole life cycle of nanocellulose from the fresh feedstock to the end-life of the product.
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Ecossistema , Emulsificantes , Humanos , Emulsões/química , Emulsificantes/química , Celulose/química , Água/químicaRESUMO
Nowadays, the discovery of a new non-toxic metal complex with biological activity represents a very active area of research. Two Cu+2 complexes, [Cu(L1)2(H2O)3] (C1) (HL1= N-(5-(4-methylphenyl)-[1,3,4]-thiadiazole-2-yl)-naphtalenesulfonamide) and [Cu(L2)2(py)2(H2O)] (C2) (HL2= N-(5-ethyl-[1,3,4]-thiadiazole-2-yl)-naphtalenesulfonamide), with two new ligands were synthesized. The X-ray crystal structures of the complexes were determined. In both complexes, Cu+2 is five-coordinated, forming a CuN2O3 and CuN4O chromophore, respectively. The ligands act as monodentate, coordinating the metal ion through a single Nthiadiazole atom; for the C2 complex, the molecules from the reaction medium (pyridine and water) are also involved in the coordination of Cu+2. The complexes have a distorted square pyramidal square-planar geometry. The compounds were characterized by FT-IR, electronic EPR spectroscopy, and magnetic methods. The nuclease activity studies confirm the complexes' capacity to cleave the DNA molecule. Using a xanthine-xanthine oxydase system, the SOD mimetic activity of the complexes was demonstrated. Cytotoxicity studies were carried out on two tumor cell lines (HeLa, WM35) and on a normal cell line (HFL1) using the MTT method, with cisplatin used as a positive control. The antibacterial activity of the complexes was investigated against two Gram-positive and two Gram-negative bacteria, and compared with Amoxicillin and Norfloxacin using the disk diffusion method. Both complexes showed in vitro biological activity but the C2 complex was more active. A lack of in vivo toxicity was demonstrated for the C2 complex by performing hepatic, renal, and hematological studies on Swiss mice.
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Antioxidantes , Tiadiazóis , Animais , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Cobre/química , Ligantes , Camundongos , Espectroscopia de Infravermelho com Transformada de Fourier , Sulfanilamida , Sulfonamidas/química , Sulfonamidas/farmacologia , XantinasRESUMO
Type 2 diabetes mellitus (T2DM) patient outcomes, treatment options, and corresponding healthcare expenses are affected by the presence of different comorbidities. AIM: The aim of this work was to develop an algorithm for predicting the risk of diffuse non-toxic goitre development in patients with T2DM according to a mathematical model obtained by regression analysis, for the timely implementation of appropriate preventive measures among T2DM patients. MATERIALS AND METHODS: We analyzed 541 medical records of T2DM patients. RESULTS: It was found the following risk factors influencing the occurrence of diffuse non-toxic goitre in patients with T2DM: age, gender, body mass index (BMI), glycosylated hemoglobin (HbA1c), homeostasis model assessment for insulin resistance (HOMA-IR), thyroid stimulating hormone (TSH), free thyroxine (fT4). Prognostic model of the risk of diffuse non-toxic goitre development in T2DM patients was built using multiple regression analysis. In order to stratify the risk of diffuse nontoxic goitre development in T2DM patients, the following criteria were proposed: no risk at RCG ≤ 5.0; low risk at 5.1≤ RCG ≤12,9; high risk at RCG ≥13.0.; where RCG - risk coefficient for the diffuse non-toxic goiter development in T2DM patients. CONCLUSIONS: Therefore, the developed algorithm and mathematical model for predicting the development of diffuse non-toxic goitre in T2DM patients are highly informative and allow to determine in advance the contingent of patients with a high probability of diffuse non-toxic goitre risk based both on routine laboratory data, such as HbA1c, HOMA-IR, TSH, fT4 levels and such factors as age, gender, and BMI.
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Diabetes Mellitus Tipo 2 , Bócio , Resistência à Insulina , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Hemoglobinas Glicadas/análise , Humanos , Testes de Função Tireóidea , TireotropinaRESUMO
OBJECTIVE: The gold standard for measuring blood-retinal barrier permeability is the Evans blue assay. However, this technique has limitations in vivo, including non-specific tissue binding and toxicity. This study describes a non-toxic, high-throughput, and cost-effective alternative technique that minimizes animal usage. METHODS: Sodium fluorescein fundus angiography was performed in non-diabetic and diabetic Brown Norway rats on days 0, 7, 14, 21, and 28. Sodium fluorescein intensity in the retinal interstitium and a main retinal vessel were measured over time. The intensity gradients were used to quantify retinal vascular permeability. Post-study eyes were fixed, dissected, and stained (isolectin B4) to measure required parameters for permeability quantification including total vessel length per retinal volume, radius, and thickness. RESULTS: In the non-diabetic cohort retinal permeability remained constant over the 28-day study period. However, in the diabetic cohort there was a significant and progressive increase in retinal permeability from days 14-28 (P < .01, P < .001, P < .0001). CONCLUSIONS: This novel imaging methodology in combination with mathematical quantification allows retinal permeability to be non-invasively and accurately measured at multiple time points in the same animal. In addition, this technique is a non-toxic, rapid, sensitive, and cost-effective alternative to the Evans blue assay.
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Barreira Hematorretiniana , Permeabilidade Capilar , Diabetes Mellitus Experimental , Retinopatia Diabética , Animais , Barreira Hematorretiniana/metabolismo , Barreira Hematorretiniana/fisiopatologia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Retinopatia Diabética/metabolismo , Retinopatia Diabética/fisiopatologia , Masculino , RatosRESUMO
The aim of this work was to characterise three non-toxic ammunition (NTA) from the GECO and Fiocchi brands, which are available in the Italian market. Characterisation was carried out by considering both the elemental chemical composition and morphology, using scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDS). Particles were collected from both the cartridge cases and the shooters' hands after shooting tests. Six volunteers fired two shots for each ammunition. Several elements, such as aluminium, potassium, silicon, sulphur, titanium and zinc were found in gunshot residue (GSR) particles from different ammunition. We also studied the persistence of these types of GSR on the hands of the shooters in a range between 1 and 6 h after shooting. The GSR particles from the three NTA tested were found on the hands of shooters until 6 h after the shots. The characterisations undertaken in this work will be useful for specialists in forensic science and legal medicine to evaluate trace evidence from these new NTA in casework, as such formulations are in growth.
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Armas de Fogo , Metaloides/análise , Metais Leves/análise , Pele/química , Zinco/análise , Balística Forense/métodos , Medicina Legal , Mãos , Humanos , Fatores de TempoRESUMO
In this study, sulfur-free expanded graphite (EG) was obtained by using flake graphite as the raw material, and EG/Fe3O4 composites with excellent microwave absorption properties were prepared by a facile one-pot co-precipitation method. The structure and properties of as-prepared EG/Fe3O4 were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Raman, X-ray photoelectron spectrometry (XPS), thermogravimetric (TG), and vibrating sample magnetometry (VSM) characterizations. The Fe3O4 intercalated between the layers of expanded graphite forms a sandwich-like structure which is superparamagnetic and porous. When applied as a microwave absorber, the reflection loss (RL) of EG/Fe3O4 reaches -40.39 dB with a thickness of 3.0 mm (10 wt% loading), and the effective absorption bandwidth (EAB < -10 dB) with RL exceeding -10 dB is 4.76-17.66 GHz with the absorber thickness of 1.5-4.0 mm. Considering its non-toxicity, easy operation, low cost, suitability for large-scale industrial production, and excellent microwave absorbing performance, EG/Fe3O4 is expected to be a promising candidate for industrialized electromagnetic absorbing materials.
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Compostos Férricos/química , Grafite/química , Micro-Ondas , Espectroscopia Fotoeletrônica , Fenômenos Físicos , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios XRESUMO
The global aquaculture has shown an impressive growth in the last decades contributing with a major part of total food fish supply. However, it also helps in the spread of diseases that in turn, causes great economic losses. The White Spot Syndrome Virus (WSSV) is one of the major viral pathogen for the shrimp aquaculture industry. Several attempts to eliminate the virus in the shrimp have been addressed without achieving a long-term effectiveness. In this work, we determine the capacity of the commercial non-toxic PVP-coated silver nanoparticles to promote the response of the immune system of WSSV-infected shrimps with or without an excess of iron ions. Our results showed that a single dose of metallic silver in the nanomolar range (111 nmol/shrimp), which is equivalent to 12â¯ng/mL of silver nanoparticles, produces 20% survival of treated infected shrimps. The same concentration administered in healthy shrimps do not show histological evidence of damage. The observed survival rate could be associated with the increase of almost 2-fold of LGBP expression levels compared with non-treated infected shrimps. LGBP is a key gene of shrimp immunological response and its up-regulation is most probably induced by the recognition of silver nanoparticles coating by specific pathogen-associated molecular pattern recognition proteins (PAMPs) of shrimp. Increased LGBP expression levels was observed even with a 10-fold lower dose of silver nanoparticles (1.2 ng/shrimp, 0.011â¯nmol of metallic silver/shrimp). The increase in LGBP expression levels was also observed even in the presence of iron ion excess, a condition that favors virus proliferation. Those results showed that a single dose of a slight amount of silver nanoparticles were capable to enhance the response of shrimp immune system without toxic effects in healthy shrimps. This response could be enhanced by administration of other doses and might represent an important alternative for the treatment of a disease that has still no cure, white spot syndrome virus.