Deep Eutectic Solvents Synthesis, Characterization and Applications in Pretreatment of Lignocellulosic Biomass

There has been an increased interest in green solvents and biofuels with the growing environmental awareness across the globe. Conventional methods of biofuel production involve the use of large quantities of molecular solvents and ionic liquids (ILs), but they have the drawbacks of high vapor pressure (organic solvents), toxicity, and recyclability in terms of a sustainability point of view. Deep eutectic solvents (DESs) have recently emerged as green alternatives to molecular solvents and ionic liquids (ILs). They are defined as eutectic mixtures formed between quaternary ammonium, phosphonium or sulfonium salts and hydrogen bond donors (HBDs) with the freezing temperature lower than their individual components. Sixteen different novel DESs were synthesized by varying the components (ChCl, AcChCl, U, and G) and their composition, employing various methods such as such as mixing (vortex), heating and mixing (thermal treatment, microwave irradiation, sonication, and shaking incubation), and evaporating the solvent (freeze drying and rotary evaporation). The DESs formation by solvent evaporation took longer time than mixing, and heating and mixing took the least amount of time. The DESs synthesized by different methods varied the amount of water present which affected their freezing point. The freezing temperature of DESs was always found to be much lower than the melting point of their starting materials, which is a characteristic feature of eutectic solvents. The freezing point of DESs depended on the composition and components of QASs and HBDs. The shifts in the representative peaks and broadening of the involved bonds in the FTIR spectra, and the shift in the resonance signal upfield in 1H-NMR spectra confirmed the formation of eutectics and hydrogen bonds in DESs. Comprehensive characterization of the synthesized DESs was carried out. DESs physicochemical and thermal properties including pH, density, refractive index (RI), surface tension, viscosity, octanol-water partition coefficient (Kow), flammability, freezing temperature (Tf), and decomposition temperature (Td) depended on their components and composition. Among the QASs and HBDs studied, the latter had the greater effect on most of the measured properties. A good agreement between the measured various properties of DESs was observed. Most of the measured physicochemical and thermal properties of DESs were comparable to the imidazolium ILs and lower or higher than organic solvents. Miscibility and solvatochromic parameters, including polarity and Kamlet-Taft parameters, of synthesized DESs were determined. The studied DESs were miscible in polar protic solvents and immiscible in nonpolar solvents. Miscibility in polar aprotic solvents depend on the ability to form hydrogen bonds. The DESs studied fall into the category of polar hydrogen bond accepting (HBA) solvents due to their high ET(NR) or ET N and β values. DESs E(NR) and ENT polarities were comparable to short-chain alcohols and imidazolium ILs, but Kamlet-Taft parameters α, β and π* were quite different. DESs ET(NR) and ENT polarities and hydrogen bond donating (HBD) acidity parameter α decreased, and HBA basicity parameter β and dipolarity/polarizability parameter π* remain unchanged with an increase in temperature from 25 to 45 °C. DESs ET(NR) and EN T polarities, HBD acidity parameter α and dipolarity/polarizability parameter π* increased, and HBA basicity parameter β remain unchanged with an increase in water content from zero to 20 wt %. The equation of lines derived from the studies of effect of temperature and added water content to predict the DESs polarity and Kamlet-Taft parameters. Genotoxicity and cytotoxicity of DESs and their individual components were evaluated using the Ames test and LDH, and MTT assays. A synergetic effect was observed because the toxicity of DESs was higher than their individual components. Therefore careful use of the term nontoxic must be considered. The genotoxicity and cytotoxicity of the DESs under study are far less toxic than imidazolium ILs at studied concentration, time and cell lines. The utilization of DESs for the dissolution of biopolymers such as cellulose, hemicellulose, and lignin was evaluated. The DESs selective dissolution of lignin was further explored and an extraction method optimized to selectively extract lignin from lignocellulosic biomass. The DESs extracted up to 80% of the lignin from PCG and SWG biomass was achieved. The extracted lignin was confirmed by FTIR and 1H NMR spectroscopy studies. A new source of DESs-extracted lignin was produced because the extraction was carried out with less harsh solvents at moderate temperature. The DESs were recovered simply by adding water and evaporating, which allowed reuse up to three times without losing significant activity. The selective extraction of lignin and ease of recovery of eutectic solvents demonstrated that DESs pretreatment is a promising green procedure in the biofuel production from lignocellulosic biomass. As DESs research for applications in this regard is still in its infancy, further investigations are still needed to successfully apply DESs as solvents in pretreatment processes at large-scale industrial applications

Capacitação a distância: uma proposta para policiais de postos rodoviários

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção.Esta pesquisa foi realizada com os policiais dos postos do Batalhão da Polícia Rodoviária do Estado do Paraná (BPRv), no período de 2000 a 2002, com o objetivo de levantar o seu perfil e as suas dificuldades no uso de sistemas de informação no seu cotidiano. O Batalhão da Polícia Rodoviária está vinculado ao Departamento de Estradas e Rodagem (DER/PR) o qual orienta e executa as atividades de segurança, policiamento e fiscalização do trânsito nas rodovias sob sua jurisdição. O Diretor do DER, sendo a "autoridade de trânsito" das rodovias estaduais, delega esta autoridade ao policial militar que passa a ser um agente de trânsito então chamado policial militar rodoviário. Fica estabelecida, desta forma, a relação DER-BPRv. Os resultados evidenciaram, claramente, a necessidade de capacitação do policial em recursos computacionais. Entretanto, a carência de efetivo, a distribuição geográfica e o perfil do policial indicaram que a modalidade de ensino a distância é a mais adequada a estas condições associada à infra-estrutura da rede de comunicação e de equipamentos disponível no Batalhão e nos postos rodoviários. Como resultado desta pesquisa foi elaborada uma proposta de treinamento a distância em sistemas de informação direcionados às necessidades do policial rodoviário. Tal proposta prevê a participação de uma Universidade conveniada ao DER/PR que cumpra o papel de provedora e certificadora. São elencados doze tópicos a serem abordados por diferentes ações educativas. O material é disponibilizado em CD-Rom e página específica na web. Estão previstos encontros presenciais do educador/educando para promover a interação neste processo. Acredita-se que a implantação da proposta poderá contribuir na capacitação deste profissional e na melhoria dos serviços por ele prestados aos usuários das rodovias e à população do Estado do Paraná

Treatment of depressive disorders in primary care - protocol of a multiple treatment systematic review of randomized controlled trials

Background: Several systematic reviews have summarized the evidence for specific treatments of primary care patients suffering from depression. However, it is not possible to answer the question how the available treatment options compare with each other as review methods differ. We aim to systematically review and compare the available evidence for the effectiveness of pharmacological, psychological, and combined treatments for patients with depressive disorders in primary care. Methods/Design: To be included, studies have to be randomized trials comparing antidepressant medication (tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), hypericum extracts, other agents) and/or psychological therapies (e.g. interpersonal psychotherapy, cognitive therapy, behavioural therapy, short dynamically-oriented psychotherapy) with another active therapy, placebo or sham intervention, routine care or no treatment in primary care patients in the acute phase of a depressive episode. Main outcome measure is response after completion of acute phase treatment. Eligible studies will be identified from available systematic reviews, from searches in electronic databases (Medline, Embase and Central), trial registers, and citation tracking. Two reviewers will independently extract study data and assess the risk of bias using the Cochrane Collaboration's corresponding tool. Meta-analyses (random effects model, inverse variance weighting) will be performed for direct comparisons of single interventions and for groups of similar interventions (e.g. SSRIs vs. tricyclics) and defined time-windows (up to 3 months and above). If possible, a global analysis of the relative effectiveness of treatments will be estimated from all available direct and indirect evidence that is present in a network of treatments and comparisons. Discussion: Practitioners do not only want to know whether there is evidence that a specific treatment is more effective than placebo, but also how the treatment options compare to each other. Therefore, we believe that a multiple treatment systematic review of primary-care based randomized controlled trials on the most important therapies against depression is timely

Impact of geriatric comorbidity and polypharmacy on cholinesterase inhibitors prescribing in dementia

<p>Abstract</p> <p>Background</p> <p>Although most guidelines recommend the use of cholinesterase inhibitors (ChEIs) for mild to moderate Alzheimer's Disease, only a small proportion of affected patients receive these drugs. We aimed to study if geriatric comorbidity and polypharmacy influence the prescription of ChEIs in patients with dementia in Germany.</p> <p>Methods</p> <p>We used claims data of 1,848 incident patients with dementia aged 65 years and older. Inclusion criteria were first outpatient diagnoses for dementia in at least three of four consecutive quarters (incidence year). Our dependent variable was the prescription of at least one ChEI in the incidence year. Main independent variables were polypharmacy (defined as the number of prescribed medications categorized into quartiles) and measures of geriatric comorbidity (levels of care dependency and 14 symptom complexes characterizing geriatric patients). Data were analyzed by multivariate logistic regression.</p> <p>Results</p> <p>On average, patients were 78.7 years old (47.6% female) and received 9.7 different medications (interquartile range: 6-13). 44.4% were assigned to one of three care levels and virtually all patients (92.0%) had at least one symptom complex characterizing geriatric patients. 13.0% received at least one ChEI within the incidence year. Patients not assigned to the highest care level were more likely to receive a prescription (e.g., no level of care dependency vs. level 3: adjusted Odds Ratio [OR]: 5.35; 95% CI: 1.61-17.81). The chance decreased with increasing numbers of symptoms characterizing geriatric patients (e.g., 0 vs. 5+ geriatric complexes: OR: 4.23; 95% CI: 2.06-8.69). The overall number of prescribed medications had no influence on ChEI prescription and a significant effect of age could only be found in the univariate analysis. Living in a rural compared to an urban environment and contacts to neurologists or psychiatrists were associated with a significant increase in the likelihood of receiving ChEIs in the multivariate analysis.</p> <p>Conclusions</p> <p>It seems that not age as such but the overall clinical condition of a patient including care dependency and geriatric comorbidities influences the process of decision making on prescription of ChEIs.</p

Peripheral blood and neuropsychological markers for the onset of action of antidepressant drugs in patients with Major Depressive Disorder

<p>Abstract</p> <p>Background</p> <p>In Major Depressive Disorder (MDD), treatment outcomes with currently available strategies are often disappointing. Therefore, it is sensible to develop new strategies to increase remission rates in acutely depressed patients. Many studies reported that true drug response can be observed within 14 days (early improvement) of antidepressant treatment. The identical time course of symptom amelioration after early improvement in patients treated with antidepressants of all classes or with placebo strongly suggests a common biological mechanism, which is not specific for a particular antidepressant medication. However, the biology underlying early improvement and final treatment response is not understood and there is no established biological marker as yet, which can predict treatment response for the individual patient before initiation or during the course of antidepressant treatment. Peripheral blood markers and executive functions are particularly promising candidates as markers for the onset of action and thus the prediction of final treatment outcome in MDD.</p> <p>Methods/Design</p> <p>The present paper presents the rationales, objectives and methods of a multi-centre study applying close-meshed repetitive measurements of peripheral blood and neuropsychological parameters in patients with MDD and healthy controls during a study period of eight weeks for the identification of biomarkers for the onset of antidepressants' action in patients with MDD. Peripheral blood parameters and depression severity are assessed in weekly intervals from baseline to week 8, executive performance in bi-weekly intervals. Patients are participating in a randomized controlled multi-level clinical trial, healthy controls are matched according to mean age, sex and general intelligence.</p> <p>Discussion</p> <p>This investigation will help to identify a biomarker or a set of biomarkers with decision-making quality in the treatment of MDD in order to increase the currently disappointing remission rates of antidepressant treatment.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00974155">NCT00974155</a></p