Synthetic rubber produced from nonrenewable fossil fuel requires high energy costs and is dependent on the presumed unstable petroleum price. Natural rubber latex (NRL) is one of the major alternative sustainable rubber sources since it is derived from the plant ‘Hevea brasiliensis’. Our study focuses on integrating sustainably processed carboxycellulose nanofibers from untreated jute biomass into NRL to enhance the mechanical strength of the material for various applications. The carboxycellulose nanofibers (NOCNF) having carboxyl content of 0.94 mmol/g was prepared and integrated into its nonionic form (–COONa) for its higher dispersion in water to increase the interfacial interaction between NRL and NOCNF. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) analyses of NOCNF showed the average dimensions of nanofibers were length (L) = 524 ± 203 nm, diameter (D) 7 ± 2 nm and thickness 2.9 nm. Furthermore, fourier transform infra-red spectrometry (FTIR) analysis of NOCNF depicted the presence of carboxyl group. However, the dynamic light scattering (DLS) measurement of NRL demonstrated an effective diameter in the range of 643 nm with polydispersity of 0.005. Tensile mechanical strengths were tested to observe the enhancement effects at various concentrations of NOCNF in the NRL. Mechanical properties of NRL/NOCNF films were determined by tensile testing, where the results showed an increasing trend of enhancement. With the increasing NOCNF concentration, the film modulus was found to increase quite substantially, but the elongation-to-break ratio decreased drastically. The presence of NOCNF changed the NRL film from elastic to brittle. However, at the NOCNF overlap concentration (0.2 wt. %), the film modulus seemed to be the highest.

RESUMO: Objetivo: investigar a prevalência de mortalidade materna decorrentes da DHEG em mulheres internadas em uma maternidade do Estado do Pará, no período de 2009 a 2012. Método: pesquisa do tipo documental, descritiva e retrospectiva, com abordagem quantitativa cuja análise estatística foi feita por meio do programa Bioestat 5.0. Resultados: Dos 122 óbitos maternos, 27% foram por DHEG, o maior percentual das gestantes que evoluíram a óbito por DHEG tinham entre 20 a 29 anos (48,5%), possuíam união estável (48,5%), eram pardas (60,6%), do lar (39,4%), o óbito ocorreu no puerpério (81,8%). Conclusão: Recomenda-se mais atenção às gestantes com DHEG ou potencial para desenvolvê-la, a partir de acompanhamento sistemático e o adequado compartilhamento na Rede de Atenção. Assim como, aponta-se a necessidade da melhoria dos determinantes socioeconômicos, revelando, assim, a importância de intervenções amplas, sociais e clínico-assistenciais, para melhorar estes indicadores que fazem parte dos Objetivos de Desenvolvimento do Milênio. Descritores: Mortalidade materna; Eclampsia; Fatores de risco.ABSTRACT: Objective: to investigate the prevalence of maternal mortality resulted by PIH in women hospitalized in a maternity ward of the state of Pará, in the period 2009-2012. Method: documentary, descriptive and retrospective research, with a quantitative approach in which the statistical analysis was done using the software BioeStat 5.0. Results: Out of 122 maternal deaths, 27% were by PIH, most women (48.5%) were between 20 to 29 years old, had incomplete primary education (39.4%), were in a stable union (48.5%), brown-skinned (60.6%), housewives (39.4%), and the death occurred in the puerperium (81.8%). Conclusion: It is recommended more attention to pregnant women

Carboxycellulose nanofibers (CNFs) promise to be a sustainable and inexpensive alternative material for polymer electrolyte membranes compared to the expensive commercial Nafion membrane. However, its practical applications have been limited by its relatively low performance and reduced mechanical properties under typical operating conditions. In this study, carboxycellulose nanofibers were derived from wood pulp by TEMPO oxidation of the hydroxyl group present on the C6 position of the cellulose chain. Then, citric acid cross-linked CNF membranes were prepared by a solvent casting method to enhance performance. Results from FT-IR spectroscopy, 13C NMR spectroscopy, and XRD reveal a chemical cross-link between the citric acid and CNF, and the optimal fuel cell performance was obtained by cross-linking 70 mL of 0.20 wt % CNF suspension with 300 µL of 1.0 M citric acid solution. The membrane electrode assemblies (MEAs), operated in an oxygen atmosphere, exhibited the maximum power density of 27.7 mW cm−2 and the maximum current density of 111.8 mA cm−2 at 80 °C and 100% relative humidity (RH) for the citric acid cross-linked CNF membrane with 0.1 mg cm−2 Pt loading on the anode and cathode, which is approximately 30 times and 22 times better, respectively, than the uncross-linked CNF film. A minimum activation energy of 0.27 eV is achieved with the best-performing citric acid cross-linked CNF membrane, and a proton conductivity of 9.4 mS cm−1 is obtained at 80 °C. The surface morphology of carboxycellulose nanofibers and corresponding membranes were characterized by FIB/SEM, SEM/EDX, TEM, and AFM techniques. The effect of citric acid on the mechanical properties of the membrane was assessed by tensile strength DMA.

The fuel cell is the best alternative to compensate for today’s energy demand, but the high cost of fabrication of membrane (e.g., Nafion) hampers the prevalent commercialization. Plant-derived nanocellulose is...

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