Dynamic adsorption of diclofenac onto a magnetic nanocomposite in a continuous stirred-tank reactor.

In this study, a waste-based magnetic activated carbon (MAC) was used for the first time in a continuous-flow stirred tank reactor (CSTR). The aim was to evaluate the dynamic removal of diclofenac (DCF) from water and wastewater. Firstly, the breakthrough curves corresponding to DCF adsorption from distilled water at different feed flow rates and doses of MAC were determined. After selecting the most favourable conditions, namely 0.18 h L-1 flow rate and 400 mg L-1 of MAC, the effect of different aqueous matrices was studied, with the breakthrough curves evidencing a performance decline in wastewater in comparison with distilled water. Finally, the exhausted MAC was magnetically recovered, regenerated by microwave-assisted heating and applied in two subsequent adsorption cycles. The regeneration studies pointed to a decrease of the specific surface area and an improvement of the magnetic retrievability of MAC. After the first regeneration step, just mild effects were observed in the dynamic adsorptive performance of MAC. However, after a second regeneration step, the performance declined ca. 50%. Overall, the results highlight the feasibility of producing waste-based magnetic composites that simultaneously combine high adsorption efficiency under dynamic operation in a CSTR, with easy retrievability and successful one-stage regeneration for further reutilization.

Angina bullosa haemorrhagica: A 14-year multi-institutional retrospective study from Brazil and literature review.

BACKGROUND: Angina bullosa haemorrhagica (ABH) is characterized by the recurrent appearance of blood blisters on the oral mucosa, mainly in adults' soft palate. In general, the blisters rupture spontaneously, lacking the necessity for biopsy. We report the clinical features of 23 ABH cases, emphasizing the clinical behavior and the management of these conditions. MATERIAL AND METHODS: A retrospective descriptive cross-sectional study was performed. A total of 12,727 clinical records of oral and maxillofacial lesions from four dental services in Brazil were analyzed. Clinical data were collected from the clinical records and evaluated. RESULTS: The series comprised 12 males (52.2%) and 11 females (47.8%), with a mean age of 56.8 ± 14.6 years (ranging: 24-82 years) and a 1.1:1 male-to-female ratio. Most of the lesions affected the soft palate (n = 15, 65.2%). Clinically, the lesions presented mainly as an asymptomatic (n = 17, 73.9%) blood-filled blister that ruptured after a few minutes or hours, leaving an erosion. The masticatory trauma was the most frequent triggering event. No patient had coagulation disorders. A biopsy was performed in only four cases (17.4%). Treatment was symptomatic with a favorable outcome. CONCLUSIONS: ABH is still poorly documented in the literature, and its etiology remains uncertain. ABH mainly affects the soft palate of elderly adults and has a favorable evolution in a few days. The therapeutic approach is often focused only on the relief of symptoms. However, it can share some clinical features with more serious diseases. Therefore, clinicians must recognize these lesions to avoid misdiagnosis.

Revisiting the metallothionein genes polymorphisms and the risk of oral squamous cell carcinoma in a Brazilian population.

BACKGROUND: Metallothioneins (MTs) gene polymorphisms have been associated with the ability of free radical scavenging and detoxification of heavy metals leading to cancer development. Our aim was to revisit, in a Brazilian population, single-nucleotide polymorphisms (SNPs) of the MT gene family previously associated with oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: A case-control investigation with 28 OSCC patients and 45 controls was conducted, using conventional risk factors (tobacco use and alcohol consumption) as covariates. SNPs genotyping for rs8052334 (MT1B), rs964372 (MT1B), and rs1610216 (MT2A) was performed by PCR-RFLP, and SNPs for rs11076161 (MT1A) were analyzed by TaqMan assay. RESULTS: The only SNP associated with increased risk for OSCC was the MT-1A AA genotype (OR = 4.7; p = 0.01). We have also evidenced for the first time a significant linkage disequilibrium between the SNPs of MT-2A and MT-1A in this population with the highest frequency (30%) of the unfavorable haplotype G/A/C/T (rs1610216 / rs11076161 / rs964372 / rs8052334) of MT gene polymorphisms (OR = 6.2; p = 0.04). Interestingly, after removing the effects of conventional risk factors, we have uncovered the significance of the AA genotype of the rs11076161 with increased odds of 19-fold higher towards OSCC development. CONCLUSIONS: This is the first demonstration that a significant linkage disequilibrium among gene polymorphisms of the MT family may affect susceptibility to oral cancer, which is conditioned by the G/A/C/T haplotype (rs1610216/rs11076161/rs964372/ rs8052334) and the MT-1A gene polymorphism has a potential clinical utility for the OSCC risk assessment.

Uso da somatotropina recombinante bovina em búfalas leiteiras II: metabolismos energético e mineral / Use of recombinant bovine somatotropin (rbST) in dairy buffaloes II: energy and mineral metabolism

Avaliou-se a influência da somatotropina recombinante bovina (rbST) sobre os metabolismos energético e mineral de búfalas entre 63e 154 dias em lactação. Foram utilizadas 22 búfalas, distribuídas em dois grupos experimentais: grupo rbST - aplicação de 500mg de rbST a cada 14 dias; grupo Controle - sem aplicação de rbST. A cada sete dias, foram coletadas amostras de sangue para a determinação do perfil bioquímico e mensuraram-se a produção de leite e o escore de condição corporal dos animais. As médias dos parâmetros estudados para os grupos rbST e Controle foram, respectivamente: produção de leite (PL): 6,44kg vs. 6,68kg; escore de condição corporal-ECC (1-5): 3,51 vs. 3,57; glicose: 70,58 vs. 64,81mg/dL (P = 0,0003); colesterol: 132,38 vs. 133,40mg/dL; triglicérides: 29,18 vs. 28,32mg/dL; proteína total: 8,57 vs. 8,75g/dL; albumina: 3,47 vs. 3,60g/dL; ureia: 32,46 vs. 33,86mg/dL; creatinina: 1,27 vs. 1,39mg/dL; cálcio:10,25 vs. 10,73mg/dL; fósforo:5,76 vs. 5,62mg/dL; e magnésio:3,70 vs. 3,70mg/dL. O uso de 500mg de rbSTinfluenciou o metabolismo da glicose, porém não modificou a PL, o ECC e os níveis dos demais parâmetros metabólicos estudados.(AU)

The aim was to evaluate the influence of recombinant bovine somatotropin (rbST) on the energy and mineral metabolism of buffaloes between 63 - 154 days in milk. Twenty-two buffaloes distributed in two experimental groups were used: Group rbST (n= 11) - application of 500mg of rbST every 14 days; Control Group (n= 11) - no rbST. Every seven days, blood samples were taken to determine the biochemical profile, and milk production and body condition score were measured. The averages of the variables for rbST and Control groups were, respectively: milk yield (MY) - 6.44kg vs. 6.68kg; body condition score (BCS) - 3.51 vs 3.57 (1-5); glucose - 70.58 vs. 64.81mg/dL (P = 0.0003); cholesterol - 132.38 vs. 133.40mg/dL; triglycerides -29.18 vs. 28.32mg/dL; total protein - 8.57 vs. 8.75g/dL; albumin - 3.47 vs 3.60g/dL; urea - 32.46 vs 33.86mg/dL; creatinine - 1.27 vs 1.39mg/dL; calcium - 10.25 vs. 10.73mg/dL; phosphorus - 5.76 vs 5.62mg/dL; and magnesium - 3.70 vs 3.70mg/dL. Use of 500mg rbST influenced glucose metabolism, but did not modify the MY, BCS and the levels of the other metabolic parameters studied.(AU)

BNNT/Fe3O4 System as an Efficient Tool for Magnetohyperthermia Therapy.

Nanostructured materials have been widely studied aiming to biomedical applications, primarily for the purpose of carrying drugs or molecules of interest in a selected tissue or organ. In this context, boron nitride nanotubes (BNNTs), when functionalized with specific moieties, could be useful as nanovectors for delivery of proteins, drugs, and also RNAi molecules, due to their capacity to be uptaked by cells. The introduction of magnetic nanoparticles allows the use of such system as a hyperthermia agent. Thus, once it has been targeted to tumor areas, it could kill cancer cells by magnetohyperthermia therapy. In order to study this effect, magnetite nanoparticles were incorporated into hydroxilated BNNT. The system was characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). The results obtained show that magnetite nanoparticles are linked to the nanotubes. Magnetic measurements show that coercivity and magnetization were not disturbed after incorporation to the BNNT. Based on this, a new methodology for in vitro magnetohyperthermia experiments was developed, aiming to treat each cell group individually preserving its sterility. The biological assays of the system demonstrate its good cell viability and the great potential of this nanomaterial as a magnetohyperthermia agent for cancer treatment.

Multifunctional catalysts based on carbon nanotubes and titanate nanotubes for oxidation of organic compounds in biphasic systems.

Amphiphilic catalysts composed of carbon nanotubes (CNTs) and titanate nanotubes (TiNTs) have been successfully synthesized by refluxing anatase TiO2 and functionalised CNTs in concentrated NaOH solution. The prepared materials were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis (TGA), and N2 physisorption isotherms. The catalytic activity of the synthesized composites was first evaluated in the oxidation of methyl yellow (MY) using H2O2 as oxidant in a single liquid phase system and in a biphasic water/oil mixture. The results of these experiments indicated that the catalytic activities of nanocomposites were very similar in the single liquid-phase oxidation. However, the modification of TiNTs with CNTs led to a substantially enhanced MY oxidation in the biphasic system. The nanocomposites show excellent interaction with both hydrophilic and hydrophobic compounds and thus stabilise emulsions. Under biphasic conditions, the catalysts can be easily separated and recycled, retaining catalytic activity even after eight runs. Additionally, the hybrid materials show superior catalytic activity and selectivity in the biphasic oxidation of benzyl alcohol with H2O2, as compared to pure TiNTs.

Boron nitride nanotubes chemically functionalized with glycol chitosan for gene transfection in eukaryotic cell lines.

Nanostructured materials have been widely studied concerning their potential biomedical applications, primarily to selectively carry specific drugs or molecules within a tissue or organ. In this context, boron nitride nanotubes (BNNTs) have generated considerable interest in the scientific community because of their unique properties, presenting good chemical inertness and high thermal stability. Among the many applications proposed for BNNTs in the biomedical field in recent years, the most important include their use as biosensors, nanovectors for the delivery of proteins, drugs, and genes. In the present study, BNNTs were synthesized, purified, and functionalized with glycol chitosan through a chemical process, yielding the BNNT-GC. The size of BNNT-GC was reduced using an ultrasound probe. Two samples with different sizes were selected for in vitro assays. The nanostructures were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA), and dynamic light scattering (DLS). The in vitro assays MTT and neutral red (NR) were performed with NIH-3T3 and A549 cell lines and demonstrated that this material is not cytotoxic. Furthermore, the BNNT-GC was applied in gene transfection of plasmid pIRES containing a gene region that express a green fluorescent protein (GFP) in NIH-3T3 and A549 cell lines. The gene transfection was characterized by fluorescent protein produced in the cells and pictured by fluorescent microscopy. Our results suggest that BNNT-GC has moderate stability and presents great potential as a gene carrier agent in nonviral-based therapy, with low cytotoxicity and good transfection efficiency.

Properties of nanoparticles prepared from NdFeB-based compound for magnetic hyperthermia application.

Nanoparticles were prepared from a NdFeB-based alloy using the hydrogen decrepitation process together with high-energy ball milling and tested as heating agent for magnetic hyperthermia. In the milling time range evaluated (up to 10 h), the magnetic moment per mass at H = 1.59 MA m(-1) is superior than 70 A m(2) kg(-1); however, the intrinsic coercivity might be inferior than 20 kA m(-1). The material presents both ferromagnetic and superparamagnetic particles constituted by a mixture of phases due to the incomplete disproportionation reaction of Nd(2)Fe(14)BH(x) during milling. Solutions prepared with deionized water and magnetic particles exposed to an AC magnetic field (H(max) ~ 3.7 kA m(-1) and f = 228 kHz) exhibited 26 K ≤ ΔT(max) ≤ 44 K with a maximum estimated specific absorption rate (SAR) of 225 W kg(-1). For the pure magnetic material milled for the longest period of time (10 h), the SAR was estimated as ~2500 W kg(-1). In vitro tests indicated that the powders have acceptable cytotoxicity over a wide range of concentration (0.1-100 µg ml(-1)) due to the coating applied during milling.

Study of mesoporous silica/magnetite systems in drug controlled release.

Ordered mesoporous materials like SBA-15 have a network of channels and pores with well-defined size in the nanoscale range. This particular silica matrix pore architecture makes them suitable for hosting a broad variety of compounds in very promising materials in a range of applications, including drug release magnetic carriers. In this work, magnetic nanoparticles embedded into mesoporous silica were prepared in two steps: first, magnetite was synthesized by oxidation-precipitation method, and next, the magnetic nanoparticles were coated with mesoporous silica by using nonionic block copolymer surfactants as structure-directing agents. The materials were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), N(2) adsorption, and scanning electron microscopy (SEM). The influence of magnetic nanoparticles on drug release kinetics was studied with cisplatin, carboplatin, and atenolol under in vitro conditions in the absence and in the presence of an external magnetic field (0.25 T) by using NdFeB permanent magnet. The constant external magnetic field did not affect drug release significantly. The low-frequency alternating magnetic field had a large influence on the cisplatin release profile.

Mesoporous silica/apatite nanocomposite: special synthesis route to control local drug delivery.

Synthetic hydroxyapatite is widely used in medicine and dentistry due its notable biocompatibility and bioactivity properties. The hydroxyapatite incorporation into silica has demonstrated excellent bioactivity or biodegradability, according to the content of calcium ions. Procedures to obtain ordered mesoporous silicates rely on the micelle-forming properties of a surfactant, whose chemical composition, size and concentration control the structural dimensions of the final material. This paper reports the synthesis of two types mesoporous materials: pure MCM-41 and a nanocomposite of apatite and mesoporous silica, MCM-41-HA. The samples were charged with atenolol as a model drug and in vitro release essays were carried out. The bioactivity behavior was investigated as a function of soaking time in simulated body fluid. The materials were characterized by X-ray diffraction, N2 adsorption, FTIR spectroscopy, scanning electron microscopy, dispersive energies spectroscopy, and transmission electron microscopy. The influence of the release rate of atenolol molecules from pure MCM-41 mesoporous and containing hydroxyapatite was demonstrated, since it results in a very slowly drug delivery from the nanocomposite system.

Mesoporous silica-magnetite nanocomposite synthesized by using a neutral surfactant.

Magnetite nanoparticles coated by mesoporous silica were synthesized by an alternative chemical route using a neutral surfactant and without the application of any functionalization method. The magnetite (Fe(3)O(4)) nanoparticles were prepared by precipitation from aqueous media, and then coated with mesoporous silica by using nonionic block copolymer surfactants as the structure-directing agents. The mesoporous SiO(2)-coated Fe(3)O(4) samples were characterized by x-ray diffraction, Fourier-transform infrared spectroscopy, N(2) adsorption-desorption isotherms, transmission electron microscopy, (57)Fe Mössbauer spectroscopy, and vibrating sample magnetometry. Our results revealed that the magnetite nanoparticles are completely coated by well-ordered mesoporous silica with free pores and stable (∼8 nm thick) pore walls, and that the structural and magnetic properties of the Fe(3)O(4) nanoparticles are preserved in the applied synthesis route.

Mesoporous SBA-15 HPLC evaluation for controlled gentamicin drug delivery.

Mesoporous silica SBA-15 was prepared to evaluate its application as gentamicin drug delivery system. Two procedures were used to evaluate the delivery: calcined powder and disk conformed. The samples were charged with gentamicin sulphate and the experiments were carried out in vitro. No significant difference between powder and disk was observed in the tests. The release profiles exhibited a pronounced initial burst release effect of 60%, followed by a very slow release pattern. A new HPLC method was employed for calculated gentamicin amount in the delivery test. This method requires a small amount of sample, very advisable in these kinds of assays.

Determination of age from cemental incremental lines for forensic dentistry.

Determination of age from cemental incremental lines was evaluated in intact teeth obtained from 17 individuals aged 23-77 years. Mineralized 100 microm cross sections were subjected to one of three treatments: unstained, stained with Villanueva's blood stain, and stained with acridine orange. Ideal areas were selected by light microscopy and photographed. Countability of incremental lines from photographic enlargements were evaluated. The average number of years required for the eruption of a particular tooth was added to the incremental lines count to determine the estimated age for that individual. Results obtained from unstained mineralized 100 microm thick cross sections using differential interference microscopy (Nomarsky) provided the most countable lines. The accuracy and repeatability of the method is not dependent on tooth type or location, but on the average obtained from making as many counts as possible. This method can be applied to general populations regardless of systemic or periodontal health.