Natural carbohydrate-based thermosensitive chitosan/pectin adsorbent for removal of Pb(II) from aqueous solutions.

Biodegradable and eco-friendly adsorbents composed of natural carbohydrates have been used to replace carbon-based materials. This study presents a natural carbohydrate-based chitosan/pectin (CS/Pec) hydrogel adsorbent to remove Pb(II) from aqueous solutions. The physical CS/Pec hydrogel was prepared by blending aqueous CS and Pec solutions at 65 °C, preventing the use of toxic chemistries (crosslinking agents). The thermosensitive CS/Pec hydrogel was quickly created by cooling CS/Pec blend at room temperature. The used strategy created stable CS/Pec hydrogel against disintegration and water dissolution. The as-prepared hydrogel was characterized by infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The adsorbent had 1.688 mmol -COO- for each gram. These ionized sites bind Pb(II) ions, promoting their adsorption. The adsorption kinetic and equilibrium studies indicated that the Elovich and pseudo-second-order models adjusted well to the experimental data, respectively. The maximum removal capacities (qm) predicted by the Langmuir and Sips isotherms achieved 108.2 and 97.55 mg/g at 0.83 g/L adsorbent dosage (pH 4.0). The hydrogel/Pb(II) pair was characterized by scanning electron microscopy (SEM), X-ray dispersive energy (EDS), and differential scanning calorimetry (DSC). The chemisorption seems to play an essential role in the Pb(II) adsorption. Therefore, the adsorbent was not recovered, showing low potential for reusability.

Production of starch-polyester bio-support for lipases immobilization: synergistic action of itaconic acid and nanoclay.

The objective of the present work was to develop biodegradable polymeric films (starch-PBAT) as support for the immobilization of lipases using sodium montmorillonite (MMT) as a reinforcing agent (2% w/w) and itaconic acid (IA - 0.5-1.5% w/w) as a compatibilizing agent. The films were produced through a two steps blow-extrusion. The addition of MMT increased the tensile strength and Tg of the films, while the presence of IA made the films more flexible, reducing their Tg. Lipases from Burkholderia cepacia LTEB11 were immobilized in the films by the adsorption method. The ester yield (% of ethyl oleate synthesis) has shown best results (96%, 6 h) for immobilized enzyme in the MMT film and six cycles of reuse were carried out until a reduction of 50% in the catalytic activity of the enzyme.

Fibromatose desmoide extra-abdominal: a importância da cirurgia micrográfica de Mohs em um tumor raro e recidivante / Extra-abdominal desmoid fibromatosis: the importance of Mohs micrographic surgery in a rare and recurrent tumor

Apresenta-se caso de paciente do gênero feminino, 13 anos, com diagnóstico de fibromatose desmoide extra-abdominal, neoplasia dos tecidos moles, de origem benigna, porém incomum. Nosso objetivo é expor este relato pela raridade do tumor bem como por sua desafiadora abordagem terapêutica e pelas altas taxas de recidiva local frequentes nesses tumores. Para o tratame

We report the case of a 13-year-old girl with a diagnosis of extra-abdominal desmoid fibromatosis, a neoplasm of benign origin but uncommon in the soft tissues. This study aims to expose the rarity of the tumor and its challenging therapeutic approach due to its high frequent local recurrence rates. For the treatment, Mohs micrographic surgery was performed in two stages to obtain a free margin.

Pectin-capped gold nanoparticles synthesis in-situ for producing durable, cytocompatible, and superabsorbent hydrogel composites with chitosan.

Studies report the production of gold nanoparticles (AuNPs) and polysaccharides-based composites. However, there are few reports about AuNPs synthesis in-situ followed by the formation of hydrogel composites. Here, we show AuNPs synthesis in-situ into the pectin solutions to yield cytocompatible pectin-capped AuNPs/chitosan hydrogel composites. Visible spectroscopy and dynamic light scattering measurements confirm the AuNPs synthesis. The hydrodynamic radius of the pectin-capped AuNPs ranges from approximately 510 to 721 nm, while the Zeta potential is around -43 mV. Scanning electron microscopy shows that the composites present compact structures. Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy characterize the composites as well. Hydrogels (with or without AuNPs) containing the highest pectin content (at 4.12 pectin/chitosan weight ratio) have low stability (disintegrates approximately 60% after 14 days in phosphate buffer). Composites obtained at 3.75 pectin/chitosan weight ratio disintegrate between 25 and 30% after 14 days in phosphate buffer (physiological condition = pH 7.4). The AuNPs reinforce the hydrogel structures, increasing the elastic modulus (from 3.5 to 7.6 Pa) and decreasing the water uptake from 4465 to 2976%. 3.75 PT/CS weight ratio and 3.0 × 10-4 M Au(III) content provide a durable, cytocompatible, and superabsorbent hydrogel composite. These properties can support materials for drug delivery purposes.

From frustration to coping with caring for death by nurse technicians.

OBJECTIVE: to understand nurse technicians' experience with caring for the death of terminal patients in ICUs and to configure a theoretical model. METHOD: qualitative study with theoretical saturation when analyzing the 10th non-directive interview, having as reference Grounded Theory, Symbolic Interactionism and Bioethics. RESULTS: the core category - from frustration to coping with dignified nursing care for finitude: the acceptance of death as a therapeutic and intervenient component - emerged from the comparison of the sub-processes: when the nurse does not feel prepared for caring for death, accepting death as a therapeutic phenomenon and developing coping strategies. CONCLUSION: according to Symbolic Interactionism, a novice professional's frustration in caring for an individual for death is related to his/her interaction and interpretation of the situation as he/she feels prepared only to care for individuals for life.

Plasma myeloperoxidase levels correlate with hepatocellular carcinoma in chronic hepatitis C.

Myeloperoxidase (MPO) is an enzyme responsible for generating hypochlorous acid and reactive oxidants that may lead to liver injury and cancer in hepatitis C (HCV) infection. MPO expression level is regulated by a polymorphism in the promoter region -463 of MPO gene. In the current study, MPO plasma levels and the G-463A MPO polymorphism were determined in 158 chronically HCV infected patients with and without hepatocellular carcinoma (HCC). MPO plasma levels were determined using a commercially ELISA kit. The G-463A MPO polymorphism was accessed by real time PCR using TaqMan probes. The MPO plasma levels of patients with HCV-HCC were higher in comparison to patients with chronic hepatitis or with those patients with severe fibrosis (p=0.01 and p=0.04, respectively). The MPO G-463A polymorphism was not associated with HCV outcome. These findings suggest MPO levels monitoring may be a potential biological marker to HCC screening in patients with HCV.

Metabolism of the microregions of human breast cancer.

Glucose and glutamine metabolism of two microregions of human infiltrating ductile breast cancer, the center and the periphery, was studied and the results were compared with those of healthy mammary glands. In general, the activities of glycolytic enzymes and of phosphate-dependent glutaminase were as follows: center>periphery>mammary gland. Insulin caused a marked increase of glucose consumption and lactate production by incubated slices of mammary gland but had no effect on both microregions of the tumor. Therefore, human breast cancer presents metabolic microregions.

Ciglitizone and 15d PGJ2 induce apoptosis in Jurkat and Raji cells.

Several studies have shown that PPARgamma agonists play a role in the regulation of lymphocytes function and apoptosis. However, the molecular mechanism(s) underlying the immunomodulatory effects of PPARgamma agonists are not defined yet. In this study, the effects of PPARgamma (15d PGJ2 and ciglitizone) ligands on proliferation, cytokine production and apoptosis of Jurkat and Raji cells (human T and B lymphocytes, respectively) were examined. Ciglitizone and 15d PGJ2 presented antiproliferative and cytotoxic effects on Jurkat and Raji cells as shown by [14C]-thymidine incorporation and cell viability assay. In addition, 15d PGJ2 inhibited cytokine production (IL-2 in Jurkat cells and IL-10 in Raji cells). The mechanism whereby PPARgamma agonists induced cytotoxicity is via apoptosis as shown by DNA fragmentation, nuclear condensation and phosphatidylserine externalization. The induction of apoptosis by ciglitizone and 15d PGJ2 on Jurkat and Raji cells may explain the suppression of cytokine production and the decrease in proliferation observed in both cell types. The apoptotic process was associated with a decrease in mitochondrial membrane potential and a marked down-regulation of the c-myc expression. These findings might play a key role in the apoptosis of T and B lymphocytes induced by PPARgamma agonists.