Ursodeoxycholic acid does not interfere with in vivo Helicobacter pylori colonization

A low frequency of Helicobacter pylori in the gastric mucosa of patients with alkaline gastritis has been reported. At the same time, it can be noted that the growth of bacteria can be inhibited by bile acids. We studied 40 patients with chronic gastritis related to Helicobacter pylori in order to determine the effect of ursodeoxycholic acid on this infection. Diagnoses of the infection and the inflammatory process were obtained by histologic study of gastric biopsies collected during endoscopy. Two groups were studied: group I received ursodeoxycholic acid - 300 mg/day, and group II received the placebo, twice a day, both for 28 days. The colonization by Helicobacter pylori and the intensity of the mononuclear and polymorphonuclear inflammatory infiltrate were determined before (time 1) and after (time 2) treatment. Ursodeoxycholic acid had no effect on the Helicobacter pylori infection. A significant reduction in the intensity of the mononuclear inflammatory infiltrate of the gastric antrum mucosa was observed in patients from group I, when we compared not only times 1 and 2 but also groups I and II. However, this was not the case with the body mucosa. We concluded that ursodeoxycholic acid had no action on the colonization by Helicobacter pylori or on the polymorphonuclear inflammatory infiltrate, but it caused a significant reduction in the intensity of the mononuclear inflammatory infiltrate of the gastric antrum.

The effect of intravenous zoledronic acid on glucocorticoid-induced multiple vertebral fractures in juvenile systemic lupus erythematosus

Glucocorticoids are widely used in the treatment of lupus patients, and adverse effects, which include osteoporosis and associated fractures, are frequent. Treatment of osteoporosis of young patients should be effective and not harmful to bone growth and remodeling. Bisphosphonates are drugs that decrease the incidence of bone fractures, but their use in juvenile patients is still controversial because of their possible side effects on the growing skeleton. However, recently published studies showed that linear growth continued normally after treatment with these drugs, and there was no excessive suppression of bone remodeling or mineralization defects. Zoledronic acid is a new intravenous bisphosphonate that has been approved by the US FDA for use with hypercalcemia of malignancies and might be an effective treatment for postmenopausal osteoporosis. The authors report a case of a young girl with systemic lupus who developed multiple vertebral collapses due to glucocorticoid therapy, and zoledronic acid was used producing significant clinical and densitometric improvement.

Dynamics of serotonergic neurons revealed by fiber photometry

This work was developed in the context of the MIT Portugal Program, area of Bioengineering Systems, in collaboration with the Champalimaud Research Programme, Champalimaud Center for the Unknown, Lisbon, Portugal. The project entitled Dynamics of serotonergic neurons revealed by fiber photometry was carried out at Instituto Gulbenkian de Ciência, Oeiras, Portugal and at the Champalimaud Research Programme, Champalimaud Center for the Unknown, Lisbon, Portugal

High performance fiber reinforced concrete for the shear reinforcement: experimental and numerical research

High performance fiber reinforced concrete (HPFRC) is developing rapidly to a modern structural material with unique rheological and mechanical characteristics. Despite applying several methodologies to achieve self15 compacting requirements, some doubts still remain regarding the most convenient strategy for developing a HPFRC. In the present study, an innovative mix design method is proposed for the development of high17 performance concrete reinforced with a relatively high dosage of steel fibers. The material properties of the developed concrete are assessed, and the concrete structural behavior is characterized under compressive, flexural and shear loading. This study better clarifies the significant contribution of fibers for shear resistance of concrete elements. This paper further discusses a FEM-based simulation, aiming to address the possibility of calibrating the constitutive model parameters related to fracture modes I and II.

Evaluation of antibacterial activity of caffeic acid encapsulated by -cyclodextrins

Context: Caffeic acid is described as antibacterial, but this bioactive molecule has some issues regarding solubility and stability to environmental stress. Thus, encapsulation devices are required. Objective: The aim of this work was to study the effect of the caffeic acid encapsulation by cyclodextrins on its antibacterial activity. Materials and methods: The interactions between the caffeic acid and three cyclodextrins (-cyclodextrin (CD), 2-hydroxypropyl--cyclodextrin (HPCD) and methyl--cyclodextrin were study. Results and discussion: The formation of an aqueous soluble inclusion complex was confirmed for CD and HPCD with a 1:1 stoichiometry. The CD/caffeic acid complex showed higher stability than HPCD/caffeic acid. Caffeic acid antibacterial activity was similar at pH 3 and pH 5 against the three bacteria (K. pneumoniae, S. epidermidis and S. aureus). Conclusions: The antibacterial activity of the inclusion complexes was described here for the first time and it was shown that the caffeic acid activity was remarkably enhanced by the cyclodextrins encapsulation.

Thermal characterization of polyhydroxyalkanoates and poly(lactic acid) blends obtained by injection molding

In this work we present the thermal characterization of the full scope of polyhydroxyalcanoate and poly(lactic acid) blends obtain by injection molding. Blends of polyhydroxyalcanoate and poly(lactic acid) (PHA/PLA) were prepared in different compositions ranging from 0–100% in steps of 10%. The blends were injection molded and then characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and wide angle X-ray diffraction (WAXD). The increment of PHA fraction increased the degree of crystallinity of the blend and the miscibility of the base polymers as verified by the Fox model. The WAXD analysis indicates that the presence of PHA hindered the PLA crystallization. The crystallization evolution trough PHA weight fraction (wf) shows a phase inversion around 50-60%. SEM analyses confirmed that the miscibility of PHA/PLA blends increased with the incorporation of PHA and became total for values of PHA higher that 50%.

Influence of oxygen plasma treatment parameters on poly(vinylidene fluoride) electrospun fiber mats wettability

Electrospun poly(vinylidene fluoride) (PVDF) fiber mats find applications in an increasing number of areas, such as battery separators, filtration and detection membranes, due to their excellent properties. However, there are limitations due to the hydrophobic nature and low surface energy of PVDF. In this work, oxygen plasma treatment has been applied in order to modify the surface wettability of PVDF fiber mats and superhydrophilic PVDF electrospun membranes have been obtained. Further, plasma treatment does not significantly influences fiber average size (~400 ± 200 nm), morphology, electroactive -phase content (~80-85%) or the degree of crystallinity (Xc of 42 ± 2%), allowing to maintain the excellent physical-chemical characteristics of PVDF. Plasma treatment mainly induces surface chemistry modifications, such as the introduction of oxygen and release of fluorine atoms that significantly changes polymer membrane wettability by a reduction of the contact angle of the polymer fibers and an overall decrease of the surface tension of the membranes.

Erratum: Influence of oxygen plasma treatment parameters on poly(vinylidene fluoride) electrospun fiber mats wettability

Electrospun poly(vinylidene fluoride) (PVDF) fiber mats find applications in an increasing number of areas, such as battery separators, filtration and detection membranes, due to their excellent properties. However, there are limitations due to the hydrophobic nature and low surface energy of PVDF. In this work, oxygen plasma treatment has been applied in order to modify the surface wettability of PVDF fiber mats and superhydrophilic PVDF electrospun membranes have been obtained. Further, plasma treatment does not significantly influences fiber average size (~400 ± 200 nm), morphology, electroactive -phase content (~80-85%) or the degree of crystallinity (Xc of 42 ± 2%), allowing to maintain the excellent physical-chemical characteristics of PVDF. Plasma treatment mainly induces surface chemistry modifications, such as the introduction of oxygen and release of fluorine atoms that significantly changes polymer membrane wettability by a reduction of the contact angle of the polymer fibers and an overall decrease of the surface tension of the membranes.

Study of the potential employment of Malvaceae Species in composites materials

The employ of vegetal fibers for textiles and composites represents a great potential in economic and social sustainable development. Some Malvaceae species are considered tropical cosmopolitans, such as from Sida genus. Several species of this genus provide excellent textile bast fibers, which are very similar in qualities to the jute textile fiber. The objective of the present study is present the physicochemical characterization of six Brazilian vegetal fibers: Sida rhombifolia L.; Sida carpinifolia L. f.; Sidastrum paniculatum (L.) Fryxell; Sida cordifolia L.; Malvastrum coromandelianum (L.) Gurck; Wissadula subpeltata (Kuntze) R.E.Fries. Respectively the two first species are from Brazilian Atlantic Forest biome and the four remaining from Brazilian Cerrado biome, despite of present in other regions of the planet. The stems of these species were retted in water at 37oC for 20 days. The fibers were tested in order to determine tensile rupture strength, tenacity, elongation, Young’s modulus, cross microscopic structure, Scanning Electronic Microscopy (SEM), regain, combustion, acid, alkali, organic solvent and cellulase effects, pH of the aqueous extract, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The obtained values were compared with those from fibers of recognized applicability in the textile industry including hemp. The results are promising in terms of their employment in thermoset and thermoplastic medium resistance composites.

Mechanical performance of natural fiber-reinforced composites for the strengthening of masonry

The growing concerns regarding the environmental impact generated by the use of inorganic materials in different fields of application increased the interest towards products based on materials with low environmental impact. In recent years, researchers have turned their attention towards the development of materials obtained from renewable sources, easily recoverable or biodegradable at the end of use. In the field of civil structures, a few attempts have been done to replace the most common composites (e.g. carbon and glass fibers) by materials less harmful to the environment, as natural fibers. This work presents a comprehensive experimental research on the mechanical performance of natural fibers for the strengthening of masonry constructions. Flax, hemp, jute, sisal and coir fibers have been investigated both from physical and mechanical points of view. The fibers with better performance were tested together with three different matrices (two of organic nature) in order to produce composites. These experimental results represent a useful database for understanding the potentialities of natural fibers as strengthening systems.

Effect of chemical and plasma DBD treatments on pseudostem plantain fiber properties

Las fibras del seudotallo de plátano (FSP) fueron modificadas mediante epiclorhidrina (EP), anhídrido acético (AA), y su combinación (AA_EP), y con plasma a tres descargas de barrera dieléctrica (DBD) 1, 3 y 6 kW min m-2. Las FSP tratadas y sin tratar fueron caracterizadas mediante espectroscopia infrarroja por la transformada de Fourier (FT-IR), termogravimetría (TGA), microscopía electrónica de barrido (SEM) y pruebas mecánicas de tensión y de humectabilidad. Los espectros FT-IR, las micrografías SEM, y el análisis TGA indicaron pérdidas de lignina, hemicelulosa, impurezas y ceras. Estos efectos en conjunto con las reacciones de grupos OH y -C-C-, con los tratamientos químicos y de plasma respectivamente, incrementaron la hidrofobicidad de las FSP tratadas. Los tratamientos químicos produjeron reacciones de esterificación, eterificación y entrecruzamiento de los grupos OH libres en las FSP, lo que hizo que mostraran mayor rigidez que las expuestas al plasma. Las micrografías SEM mostraron que las FSP expuestas al plasma quedaron con superficie más irregular y rugosa que la de las FSP tratadas químicamente. La humectabilidad de las fibras, medida mediante pruebas de ángulo de contacto, se redujo como consecuencia de ambos tratamientos, característica importante para un relleno en los materiales compuestos.

Aminobenzocoumarinylmehtyl esters as photoactive precursors for the release of butyric acid

The evaluation of the photorelease of a carboxylic acid drug, using butyric acid as a representative model, was carried out by using 7-amino-4-chloromethyl-2-oxo-2Hnaphtho[1,2-b] pyran, an aminobenzocoumarin, and its mono- and di-methylated or ethylated derivatives. This study was intended to improve the release of butyric acid from benzocoumarins by the addition of an amino group to the heterocycle by applying the knowledge of second-generation coumarinylmethyl-based photoremovable protecting groups. Photolysis studies were performed on the resultant ester cages by irradiation in a photochemical reactor at 254, 300, 350 and 419 nm, using methanol/HEPES buffer 80:20 solutions as solvent. The data obtained showed that these new fluorescent aminobenzocoumarins are superior to all the previously tested benzocoumarins with the same or different ring fusions. As well as the photolysis, the photophysics of the compounds were characterised by both steady state and time-resolved methods.

Microencapsulation of ellagic acid from pomegranate husk and karaya gum by spray drying

Objective: The aim of this study was to obtain and characterize microcapsules with Ellagic Acid (EA) from pomegranate as core material and Karaya Gum (KG) as wall material. Methods: EA was obtained from dry pomegranate peel powder via methanolysis and quantified by HPLC. Microcapsules were obtained preparing a dispersion containing KG and EA in phosphate buffer pH 8. The dispersion was processed in a spray dryer under specific conditions (inlet temperature at 150 °C, feed flow at 30% and aspirator at 100 %) for obtaining of microcapsules. Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used for characterization. Results: Obtained material contains 98.03±2.82 mg EA/g of pomegranate peel. FTIR showed that there were changes in the molecular structure of microcapsules referred to raw materials. SEM confirmed that particles obtained had micron-size (1-5 µm). DSC analysis showed that raw materials had glass transition temperatures of 79.58 and 83.41 °C and for microcapsules the value was67.25 °C. Conclusion: Methanolysis is a viable technique for the obtaining of EA from the peel of pomegranate. KG shows good potential for be used as wall material for EA microencapsulation.

Photoactivation of butyric acid from 6-aminobenzocoumarin cages

A new benzocoumarin bearing an amino group is proposed as a photocleavable protecting group for carboxylic acids. The novel heterocycle, 6-amino-4-chloromethyl-2-oxo-2H-naphtho[1,2-b]pyran was used in the preparation of ester conjugates of butyric acid, and of the corresponding mono- and di-methylated or ethylated derivatives. The photolability of the ester conjugates was studied by irradiation at selected wavelengths in methanol/HEPES buffer (80:20) solutions, and the release of butyric acid was followed with HPLC/UV and 1H NMR monitoring. Release of the carboxylic acid was faster for the monoalkylated derivatives (approximately within 20 min), at the longer wavelengths of irradiation (350 and 419 nm). The photophysics of the heterocyclic conjugates was also evaluated by both steady state and time-resolved methods.

Cheese whey: a cost-effective alternative for hyaluronic acid production by Streptococcus zooepidemicus

This study focuses on the optimization of cheese whey formulated media for the production of hyaluronic acid HA by Streptococcus zooepidemicus. Culture media containing whey (W; 2.1 g/L) or whey hydrolysate (WH; 2.4 g/L) gave the highest HA productions. Both W and WH produced high yields on protein consumed, suggesting cheese whey is a good nitrogen source for S. zooepidemicus production of HA. Polysaccharide concentrations of 4.0 g/L and 3.2 g/L were produced in W and WH in a further scale-up to 5 L bioreactors, confirming the suitability of the low-cost nitrogen source. Cheese whey culture media provided high molecular weight (> 3000 kDa) HA products. This study revealed replacing the commercial peptone by the low-cost alternative could reduce HA production costs by up to a 70%compared to synthetic media.