Estudio de copolimerización injerto del acrilato de butilo sobre almidón empleando sistema iniciador redox

The mixture of synthetic and natural materials yields a material with improved physical-chemical properties. One way of obtaining this kind of material is through graft copolymerization. Some natural materials have been used in graft copolymerization with synthetic monomers. In this work, graft copolymerization of butyl acrylate (BA) onto starch using a redox initiator system was carried out. The graft yield was evaluated for different reaction conditions. The graft copolymer was characterized by infrared spectroscopy, thermal analysis and scanning electron microscopy (SEM).

AVALIAÇÃO DE PROPRIEDADES FÍSICAS E QUÍMICAS DE ELETRODEPÓSITOS DE Ni-W-P OBTIDOS EM CÉLULA DE HULL

Ni–W–P electrodeposits were synthesized in a Hull cell in order to simulate the obtainment under industrial conditions. Complete coverage of panels was accomplished by applying total currents of 1.0 and 2.0 A. Panels obtained with a current of 1.0 A appeared brighter. The best compositional uniformities, as determined by Energy Dispersive Spectrometer (EDS) occurred in the current density ranges of 0.6 to 3.0 A dm−2 and 1.6 to 6.0 A dm−2 obtained with 1.0 and 2.0 A, respectively. However, the best morphological characteristics, as determined by Scanning Electro Microscope (SEM), were observed in those obtained with a total current of 1.0 A. Analysis of corrosion resistance by Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Linear Polarization (PLP) in NaCl have shown significant variations in the amount of corrosion potential, polarization resistance, and even total impedance. The alloys exhibited amorphous character (XRD) and crystallized above 400 °C to Ni and Ni3P phases, and possibly Ni–W, with a subsequent increase in hardness. The results suggest that under industrial conditions, current density variations due to the large and complex geometric shapes of substrates lead to formation of distinct alloys. Furthermore, these materials are potential substitutes for chromium deposits in many applications.

Detection and partial characterization of a carlavirus causing stem necrosis of soybean in Brazil

Stunting and stem necrosis were noticed in soybeans (Glycine max) grown in 2000/2001 in West Central Brazil the same condition was also observed in the following year in plantations as far as 2,000 km from the initial area. Based on transmission (mechanical, graft, insect vector), purification and serology, electron microscopy and molecular studies the causal agent was determined to be a whitefly-borne carlavirus which is possibly related to Cowpea mild mottle virus (CpMMV).

Perheyrityksen strategiamalli muuttuvassa toimintaympäristössä

Tutkimuksen tavoitteena on tutkia teollisuudelle aineita maahantuovan perheyrityksen toimintaympäristössä tapahtuvaa muutosta. Tutkimuksessa lähestytään yrityksen muuttuvaa toimintaympäristöä strategian näkökulmasta ja otetaan huomioon muuttuvana seikkana lainsäädäntö eli REACH -kemikaaliasetus. Tutkimuksen tutkimusongelmaa käsitellään konstruktiivisen tutkimuksen tapaan. Tutkimuksen aineisto on kerätty kvalitatiivisen tutkimuksen tapaan keräämällä tutkimustietoa valmiista aineistosta kuten arkistoista, dokumenteista ja kirjallisuudesta. Tutkimukseen on myös käytetty havaintoja, haastatteluja ja arkikokemuksia tutkimuksen kohteesta. Tutkimuksen viitekehyksessä käytiin läpi strategian teoriaa ulkoisesta toimintaympäristöstä yrityksen sisäiseen toimintaympäristöön. Yritykselle laadittiin strategiakeskeinen malli ottaen huomioon uuden lain tuomat vaikutukset yrityksen sisäiseen ja ulkoiseen toimintaympäristöön. Lakimuutoksen vaikutuspintoja löytyi kaksi: yrityksen toimialan toimintaympäristö ja sisäinen toimintaympäristö. Toimialan toimintaympäristössä eriteltiin lakimuutoksen rajapinnat viiden kilpailuvoiman avulla. Tulokseksi saatiin, että REACH vaikuttaa vahvasti läpi koko toimitusketjun. Vaikutustavat ovat korvaavat tuotteet, ostajien vaikutusvalta ja toimittajien vaikutusvalta. Lisäksi yhtenä vaikuttajana voidaan pitää uusia tulijoita sekä kilpailua nykyisten yritysten kanssa. Yrityksen sisäisestä toimintaympäristöstä löydettiin arvoketjun avulla lisää vaikutuskohtia. Ne olivat raaka-aineiden hankinnat, dokumentointi, näytteiden lähetys, varastointi ja varastokirjanpito. Lisäksi huomioitiin tukitoiminnoista lakiasiat ja henkilöstön koulutus.

Therapeutic Properties of Superoxide Dismutase 3 and Mesenchymal Stromal Cells in Peripheral Ischemia

The aim of this study was to characterize the cellular mechanisms leading to the beneficial effect of anti-oxidative gene therapy and pro-angiogenic stem cell therapy in acute peripheral ischemia. Post-ischemic events aim to re-establish tissue blood perfusion, to clear cellular debris, and to regenerate lost tissue by differentiation of satellite cells into myoblasts. Although leukocytes have an essential role in clearing cellular debris and promoting angiogenesis, they also contribute to tissue injury through excessive ROS production. First, we investigated the therapeutic properties of extracellular superoxide dismutase (SOD3) gene transfer. SOD3 was shown to reduce oxidative stress, to normalize glucose metabolism, and to enhance cell proliferation in the ischemic muscle. Analysis of the mitogenic Ras-Erk1/2 pathway showed SOD3 mediated induction offering a plausible explanation for enhanced cell proliferation. In addition, SOD3 reduced NF-κB activity by enhancing IκBα expression thus leading to reduced expression of inflammatory cytokines and adhesion molecules with consequent reduction in macrophage infiltration. Secondly, we sought to determine the fate and the effect of locally transplanted mesenchymal stem/stromal cells (MSCs) in acute ischemia. We showed that a vast majority of the transplanted cells are cleared from the injury site within 24 hours after local transplantation. Despite rapid clearance, transplantation was able to temporarily promote angiogenesis and cell proliferation in the muscle. Lack of graft-derived growth factor expression suggests other than secretory function to mediate this observed effect. In conclusion, both SOD3 and MSCs could be utilized to alleviate peripheral ischemia induced tissue injury. We have described a previously unidentified growth regulatory role for SOD3, and suggest a novel mechanism whereby transplanted MSCs enhance the reparative potential of the recipient tissue through physical contacts.