Electrolytes for Zn Batteries: Deep Eutectic Solvents in Polymer Gels.

Gel polymer electrolytes composed of deep eutectic solvent acetamide4 :Zn(TFSI)2 and poly(ethylene oxide) (PEO) are prepared by using a fast, solvent-free procedure. The effect of the PEO molecular weight and its concentration on the physicochemical and electrochemical properties of the electrolytes are studied. Gels prepared with ultrahigh molecular-weight PEO present pseudo-solid behavior and ionic conductivity even higher than that of the original liquid electrolyte. A decrease in the dendritic growth in soft gels with PEO contents up to 1 wt % is demonstrated. The changes in the chemical structure of the electrolyte produced by the strong interactions between ethylene oxide units and Zn2+ have also been studied. The addition of PEO takes the electrolyte out of its original eutectic composition, producing blend crystallization. However, it is possible to retain the eutectic point of the electrolyte in a gel form if the addition of PEO is accompanied by the reduction of acetamide.

Ionic Conductivity Enhancement in UHMW PEO Gel Electrolytes Based on Room-Temperature Ionic Liquids and Deep Eutectic Solvents.

Physical gels made of poly(ethylene oxide) (PEO) and deep eutectic solvents urea-Li bis(trifluoromethanesulfonyl)imide (TFSI) and ethylene glycol/LiTFSI, or pyrrolidinium ionic liquid solutions PYR13TFSI-LiTFSI and PYR14TFSI-LiTFSI, are prepared by a fast, single-step process, which involves no auxiliary solvents or intermediates and is reproducible and scalable. The properties of these gels are studied as a function of the PEO content and its molecular weight and the nature of the liquid electrolyte. The gels prepared with a low concentration (1-5 wt %) of ultrahigh molecular weight (UHMW) PEO are tough, stretchable materials which resemble soft elastomers and are also self-healing and transparent. Their rheology shows the conventional behavior of physical polymer gels, so that the higher the molecular weight of PEO, the lower the polymer concentration needed to produce the gel. However, the ion conductivities and diffusivities of the gels are striking, in many cases being equal to or significantly higher than those of pure liquid electrolytes. This ion conductivity enhancement is the highest for the lowest PEO concentration with the highest molecular weight. This unprecedented molecular weight dependence of conductivity and diffusivity is the result of two combined effects: the liquid electrolyte chemical structure modification as a consequence of the addition of PEO and the development of elastic networks, where ion mobility and rheology are uncoupled when the PEO added is of UHMW.

Addressing Manufacturability and Processability in Polymer Gel Electrolytes for Li/Na Batteries.

Gel electrolytes are prepared with Ultra High Molecular Weight (UHMW) polyethylene oxide (PEO) in a concentration ranging from 5 to 30 wt.% and Li- and Na-doped 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (PYR14-TFSI) by a simple procedure consisting of dissolving PEO by melting it directly in the liquid electrolyte while stirring the blend. This procedure is fast, reproducible and needs no auxiliary solvents, which makes it sustainable and potentially easy to scale up for mass production. The viability of the up-scaling by extrusion has been studied. Extrusion has been chosen because it is a processing method commonly employed in the plastics industry. The structure and morphology of the gel electrolytes prepared by both methods have been studied by DSC and FTIR, showing small differences among the two methods. Composite gels incorporation high concentrations of surface modified sepiolite fibers have been successfully prepared by extrusion. The rheological behavior and ionic conductivity of the gels have been characterized, and very similar performance of the extruded and manually mixed gels is detected. Ionic conductivity of all the gels, including the composites, are at or over 0.4 mS cm-1 at 25 °C, being at the same time thermoreversible and self-healing gels, tough, sticky, transparent and stretchable. This combination of properties, together with the viability of their industrial up-scaling, makes these gel electrolyte families very attractive for their application in energy storage devices.

Tough Polymer Gel Electrolytes for Aluminum Secondary Batteries Based on Urea: AlCl3, Prepared by a New Solvent-Free and Scalable Procedure.

Polymer gel electrolytes have been prepared with polyethylene oxide (PEO) and the deep eutectic mixture of AlCl3: urea (uralumina), a liquid electrolyte which has proved to be an excellent medium for the electrodeposition of aluminum. The polymer gel electrolytes are prepared by mixing PEO in the liquid electrolyte at T > 65 °C, which is the melting point of PEO. This procedure takes a few minutes and requires no subsequent evaporation steps, being a solvent-free, and hence more sustainable procedure as compared to solvent-mediated ones. The absence of auxiliary solvents and evaporation steps makes their preparation highly reproducible and easy to scale up. PEO of increasing molecular weight (Mw = 1 × 105, 9 × 105, 50 × 105 and 80 × 105 g mol-1), including an ultra-high molecular weight (UHMW) polymer, has been used. Because of the strong interactions between the UHMW PEO and uralumina, self-standing gels can be produced with as little as 2.5 wt% PEO. These self-standing polymer gels maintain the ability to electrodeposit and strip aluminum, and are seen to retain a significant fraction of the current provided by the liquid electrolyte. Their gels' rheology and electrochemistry are stable for months, if kept under inert atmosphere, and their sensitivity to humidity is significantly lower than that of liquid uralumina, improving their stability in the event of accidental exposure to air, and hence, their safety. These polymer gels are tough and thermoplastic, which enable their processing and molding into different shapes, and their recyclability and reprocessability. Their thermoplasticity also allows the preparation of concentrated batches (masterbatch) for a posteriori dilution or additive addition. They are elastomeric (rubbery) and very sticky, which make them very robust, easy to manipulate and self-healing.

Solvent-Free Procedure for the Preparation under Controlled Atmosphere Conditions of Phase-Segregated Thermoplastic Polymer Electrolytes.

A solvent-free method that allows thermoplastic solid electrolytes based on poly(ethylene oxide) PEO to be obtained under controlled atmosphere conditions is presented. This method comprises two steps, the first one being the melt compounding of PEO with a filler, able to physically crosslink the polymer and its pelletizing, and the second the pellets' swelling with an electroactive liquid phase. This method is an adaptation of the step described in previous publications of the preparation of thermoplastic electrolytes by a single melt compounding. In comparison to the single step extrusion methodology, this new method permits employing electroactive species that are very sensitive to atmospheric conditions. The two-step method can also be designed to produce controlled phase-segregated morphologies in the electrolyte, namely polymer-poor and polymer-rich phases, with the aim of increasing ionic conductivity over that of homogeneous electrolytes. An evaluation of the characteristics of the electrolytes prepared by single and two-step procedures is done by comparing membranes prepared by both methods using PEO as a polymeric scaffold and a solution of the room-temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide (EMI TFSI) and the bis(trifluoromethanesulfonyl) imide lithium salt (Li TFSI) as liquid phase. The electrolytes prepared by both methods have been characterized by Fourier transform infrared spectroscopy and optic microscopy profilometry, differential scanning calorimetry, self-creep experiments, and dielectric spectroscopy. In this way, the phase separation, rheology, and ionic conductivity are studied and compared. It is striking how the electrolytes prepared with this new method maintain their solid-like behavior even at 90 °C. Compared to the single step method, the two-step method produces electrolytes with a phase-separated morphology, which results in higher ionic conductivity.

Solvent-Free and Scalable Procedure to Prepare PYR13TFSI/LiTFSI/PVDF⁻HFP Thermoplastic Electrolytes with Controlled Phase Separation and Enhanced Li Ion Diffusion.

Solid electrolytes for Li transport have been prepared by melt-compounding in one single step. Electrolytes are composed of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) with PYR13TFSI on its own or with varying concentration of LiTFSI. While the extrusion of PVDF-HFP with PYR13TFSI is possible up to relatively high liquid fractions, the compatibility of PVDF-HFP with LiTFSI/PYR13TFSI solutions is much lower. An organo-modified sepiolite with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS-S) can be used to enhance the compatibility of these blends and allows to prepare homogeneous PYR13TFSI/LiTFSI/PVDF-HFP electrolytes with controlled microphase separations by melt-compounding. The structure and morphology of the electrolytes has been studied by FTIR, differential scanning calorimetry (DSC), SEM, and AFM. Their mechanical properties have been studied by classical strain-stress experiments. Finally, ionic conductivity has been studied in the -50 to 90 °C temperature range and in diffusivity at 25 °C by PFG-NMR. These electrolytes prove to have a microphase-separated morphology and ionic conductivity which depends mainly on their composition, and a mechanical behavior typical of common thermoplastic polymers, which makes them very easy to handle. Then, in this solvent-free and scalable fashion, it is possible to prepare electrolytes like those prepared by solvent casting, but in few minutes instead of several hours or days, without solvent evaporation steps, and with ionic conductivities, which are very similar for the same compositions, above 0.1 mS·cm-1 at 25 °C. In addition, some of the electrolytes have been prepared with high concentration of Li ion, what has allowed the anion exchange Li transport mechanism to contribute significantly to the overall Li diffusivity, making DLi become similar and even clearly greater than DTFSI.

Características Clínicolaboratoriais da Criptococose em Pacientes Admitidos em Pronto Socorro Hospital das Clínicas, Universidade Federal de Minas Gerais, Referência Terciária do Sistema Único de Saúde: Análise Retrospectiva desde 2000 a 2013 / Clinical Laboratory Characteristics of Cryptococcosis in Patients Admitted to the Emergency Room Hospital das Clínicas, Federal University of Minas Gerais, Tertiary Reference of the Unified Health System: Retrospective Analysis from 2000 to 2013

A criptococose é uma micose sistêmica, de ocorrência relativamente rara, potencialmente grave, geralmente oportunista e de elevada frequência em pacientes imunossuprimidos, com amplo espectro de acometimento de órgãos, tropismo especial para o sistema nervoso central (SNC), evolução subaguda ou crônica, e manifestações clínicas variadas. Este estudo descritivo, retrospectivo, observacional, transversal, objetivou descrever os dados demográficos, clínicos, comorbidades, sintomas ou sinais, e o prognóstico de pacientes com neurocriptococose, atendidos e internados no Hospital das Clínicas (HC) da Universidade Federal de Minas Gerais desde 2000 até 2013. O HC é unidade universitária, pública e geral, de nível terciário e quaternário, com 450 leitos de internação, integrado ao Sistema Único de Saúde (SUS), com clientela universalizada, cerca de 40% do total proveniente do interior do estado de Minas Gerais, predominando da região Metropolitana de Belo Horizonte, aberto à transferência de pacientes de todo o território mineiro, com área de abrangência de população de mais de cinco milhões de pessoas, de todas as faixas etárias e todas as especialidades médicas, encaminhados pela intensidade de sua expressão clínica, especialmente em situação crítica, o que torna sua casuísticade máxima gravidade. Os pacientes foram internados a partir do Pronto Socorro do HC que admite, em média, 80 pacientes com urgência clínicas por dia, incluindo obstétricas, e excluídas aquelas devido à acidente ou violência de qualquer natureza. Foram analisados 40 pacientes com neurocriptococose o que significou 0,13% de toda demanda de admissão de urgência para o período estudado, cerca de 603.000 pessoas, isto é 12% da população referida, e associou-se à letalidade de 25%; com frequência da distribuição de acordo com o gênero em 2:1, entre homens e mulheres, respectivamente; e nas faixas etárias entre 20-40, 40-60 e mais de 60 anos de idade, de 36%, 42%, e 22%, respectivamente, sendo a proporção entre 20 a 60 e mais de 60 de aproximadamente, 2:1. A neurocriptococose associou-se em mais de 50% dos pacientes com a: SIDA (57,5%); internação prévia (52,5%) relacionada à quimio e corticoterapia, transplante, cirurgias para ressecção de neoplasias; e, em menos de 20% com doença cardiovascular hipertensiva sistêmica (17,5%), cirurgia prévia (15%) e tuberculose (5%). A sintomatologia isolada presente em pelo menos 40% dos pacientes foi: cefaleia (70%), astenia (50%), febre (45%), vômitos (40%); entretanto, em até um terço deles constituiu-se de: emagrecimento (30%), tontura (30%), dor abdominal (27,5%), convulsão (22,5%). As anormalidades mais e menos especificamente indicadoras de acometimento do SNC foram cefaleia; e, vômito, tontura e convulsão,respectivamente. As alterações do exame neurológico foram relacionadas aos distúrbios da consciência (35%), lesão focal (30%), alteração da marcha (25%) e distúrbio do comportamento (15%). A concomitância de cefaléia, convulsão e vômitos foi anotada em 5% dos pacientes; enquanto de cefaléia e convulsão em 22,5%. Foi observada, à admissão hospitalar, em 40%, dos pacientes a associação de cefaléia e vômito; mas todos os pacientes com vômito e também os com lesão focal apresentavam cefaleia. A presença de cefaleia não foi descrita em 35% dos pacientes com alteração da consciência à admissão hospitalar. O diagnóstico presuntivo de neurocriptococose deve ser realizado, independentemente da sintomatologia clínica neurológica, o que realça a percepção geral do paciente, incluindo epidemiologia, história familiar, história prévia, manifestações clínicas, presença de imunossupressão, para surpreender a criptococose, e iniciar a terapêutica o mais apidamente possível para que possa ser reduzida sua letalidade. A limitação deste estudo relaciona-se ao fato de ter sido retrospectivo, em que o controle dos dados registrados é muito limitada, sendo impossível corrigir a ausência de dados registrados. (AU)

Cryptococcosis is a systemic, relatively rare, potentially severe, often opportunistic and systemic mycosis in immunosuppressed patients with a broad spectrum of organ involvement, a special central nervous system (CNS) tropism, subacute or chronic clinical manifestations. This descriptive, retrospective, observational, cross-sectional study aimed to describe the demographic, clinical, comorbidities, symptoms or signs, and the prognosis of patients with neurocryptococcosis, attended and hospitalized at the Hospital das Clínicas (HC) of the Universidade Federal de Minas Gerais since 2000 until 2013. The HC is a university unit, public and general, tertiary and quaternary level, with 450 beds of hospitalization, integrated into the Unified Health System (SUS), with a universalized clientele, about 40% of the total coming from the interior of the state of Minas Gerais, predominating in the metropolitan region of Belo Horizonte, which is open to the transfer of patients from all over Minas Gerais, with an area of population of more than five million people, of all age groups and all medical specialties. intensity of its clinical expression, especially in a critical situation, which makes its series of age.The patients were hospitalized from the HC Emergency Room, which admitted, on average, 80 urgently needed clinics per day, including obstetrics, and excluded due to accidents or violence of any kind. We analyzed 40 patients with neurocryptococcosis, which represented 0.13% of all urgent admission demands for the period studied, about 603,000 people, ie 12% of the referred population, and was associated with a 25% lethality; with frequency of distribution according to gender in 2: 1, between men and women, respectively; and in the age groups between 20-40, 40-60 and over 60 years of age, of 36%, 42%, and 22% respectively, the ratio being between 20 to 60 and more than 60 of approximately 2: 1. Neurocryptococcosis was associated in more than 50% of patients with: AIDS (57.5%); previous hospitalization (52.5%) related to chemo and corticoid therapy, transplantation, surgeries for resection of neoplasias; and in less than 20% with systemic hypertensive cardiovascular disease (17.5%), previous surgery (15%) and tuberculosis (5%). The isolated symptoms present in at least 40% of the patients were: headache (70%), asthenia (50%), fever (45%), vomiting (40%); (30%), dizziness (30%), abdominal pain (27.5%), and seizure (22.5%). The most and least specific abnormalities of CNS involvement were headache; and, vomiting, dizziness and convulsion, respectively. Changes in neurological examination were related to disturbances of consciousness (35%), focal lesion (30%), gait alteration (25%) and behavior disorder (15%). The concomitance of headache, convulsion and vomiting was noted in 5% of the patients; while headache and seizure in 22.5%. The association of headache and vomiting was observed in 40% of patients; but all patients with vomiting and those with focal lesion also had headache. The presence of headache was not described in 35% of patients with altered consciousness at hospital admission. The presumptive diagnosis of neurocryptococcosis should be performed independently of the clinical neurological symptomatology, which highlights the general perception of the patient, including epidemiology, family history, previous history, clinical manifestations, presence of immunosuppression, to start cryptococcosis, and initiate therapy. as soon as possible so that their lethality can be reduced. The limitation of this study is the fact that it was retrospective, in which the control of the recorded data is very limited, and it is impossible to correct the absence of recorded data. (AU)

Ionic Liquid-Based Thermoplastic Solid Electrolytes Processed by Solvent-Free Procedures.

A series of thermoplastic polymer electrolytes have been prepared employing poly(ethylene oxide) (PEO) as a polymer matrix, bis(trifluoromethane sulfonimide) (LiTFSI), and different room-temperature ionic liquids (RTIL) with bis(fluorosulfonyl)imide (FSI) or TFSI anions. This formulation makes them safe and non-flammable. The electrolytes have been processed in the absence of solvents by melt compounding at 120 °C, using sepiolite modified with d-α-tocoferol-polyethyleneglycol 1000 succinate (TPGS-S) as a physical cross-linker of PEO. Several concentrations of RTILs, lithium salt, and TPGS-S have been tested in order to obtain the highest ionic conductivity (σ) without losing electrolytes' mechanical stability. The materials' rheology and ionic conductivity have been extensively characterized. The excellent crosslinking ability of TPGS-S makes the electrolytes behave as thermoplastic materials, even those with the highest liquid concentration. The electrolytes with the highest concentrations of FSI anion present a σ over 10-3 S·cm-1 at 25 °C and close to 10-2 S·cm-1 at 70 °C, and notably behave as solids at temperatures up to 90 °C despite over 65 wt % of their formulation being liquid. The electrolytes thus obtained are safe solid thermoplastics prepared by industrially scalable procedures and are suitable for energy storage devices, proving the adequacy of polymer-based materials as solid electrolytes for batteries or supercapacitors.

Paracoccidioidomicose (doença de Lutz-Splendore-Almeida): manifestações clínicas / Paracoccidioidomycosis disease (Lutz-Splendore-Almeida): clinical manifestations

A paracoccidioidomicose possui clínica polimórfica, com manifestações localizadas em pele e mucosas até comprometimento de vários órgãos e sistemas, potencialmente capaz de provocar sequelas graves e morte. Deve ser incluída no diagnóstico diferencial das doenças granulomatosas, em áreas endêmicas, como ocorre no Brasil, para que seja reconhecida com precocidade, tratada convenientemente e evitada sua evolução para sequelas e morte prematura.

Paracoccidioidomycosis has polymorphic clinical features with lesions located in the skin and mucous membranes, as well as involvement of various organs and systems, as is potentially capable of causing death and serious sequelae. It should be included in the differential diagnosis of granulomatous diseases in endemic areas, including Brazil, so that it is recognized early, for more convenient treatment as to prevent progression with sequelae or premature death.

Paracoccidioidomicose (doença de Lutz-Splendore-Almeida): propedêutica complementar, diagnóstico diferencial, controle de cura / Paracoccidioidomycosis disease (Lutz-Splendore-Almeida disease): Additional workup, differential diagnosis, cure control

O diagnóstico da paracoccidioidomicose requer a presença de dados epidemiológicos e de algumas manifestações clínicas mais típicas, entretanto, depende da propedêutica complementar que ainda requer métodos intervencionistas, o diagnóstico diferencial com patologias de grande relevância como tuberculose e linfomas, e o controle de cura.Nesta atualização são discutidos os avanços nessas várias áreas que inclui a propedêutica complementar, o diagnóstico diferencial e o controle de cura, apontando para as perspectivas de desenvolvimento que poderão ajudar a definir melhor a sua abordagem.

The diagnosis of paracoccidioidomycosis requires epidemiological data to be available and for the presence of some more typical clinical manifestations.It requires complementary investigation with interventional methods, differential diagnosis of pathologies of great importance such as tuberculosis and lymphomas, and cure control. This update discussesthe advances in these various areas, which include complementary investigation, differential diagnosis and cure control, pointing to development prospects that may help better define the best approach to this disease.

Study of an ethylene oxide-terminated bent-core compound: synthesis and Langmuir-Blodgett film structure.

Bent-core compounds have attracted interest due to their unusual supramolecular structures, uncommon physical properties such as ferro- and antiferroelectricity and potential applications in fields such as nonlinear optics. Their incorporation into nanostructured materials, however, needs to be improved in terms of accurate control of the packing and orientation of the molecules in practical structures. Here, we have synthesized a novel bent-core compound bearing a tetraethylene glycol (TEG) chain as the hydrophilic head group and studied its capacity to obtain monomolecular films by means of the Langmuir-Blodgett technique. We developed a synthetic route to the material and studied its behavior in Langmuir and Langmuir-Blodgett films by means of a variety of characterization techniques, including a new model for the interpretation of UV-Vis reflection spectra of bent-core compounds. We found that the new head group, while destroying the formation of bulk mesophases, stabilizes the formation of the monolayer at the air-water interface and allows core-core interactions to dominate film dynamics, thus providing a promising alternative to carboxylic acid head groups.

Influence of the liquid crystal behaviour on the Langmuir and Langmuir-Blodgett film supramolecular architecture of an ionic liquid crystal.

A new luminescent ionic liquid crystal, called Ipz-2, has been synthesised and its mesophase behaviour and also at the air-liquid interface has been studied and compared with Ipz, another ionic pyrazole derivative, with a similar molecular structure, previously studied. The X-ray diffraction pattern shows that Ipz-2 exhibits hexagonal columnar mesomorphism, while Ipz adopts lamellar mesophases. Langmuir films of both compounds are flat and homogeneous at large areas per molecule, but create different supramolecular structures under further compression. Ipz-2 Langmuir films have been transferred onto solid substrates, and Atomic Force Microscopy (AFM) images of the Langmuir-Blodgett films have shown that large columnar structures hundreds of nm in diameter are formed on top of the initial monolayer, in contrast with well-defined trilayer LB films obtained for Ipz. Our results show that Ipz-2 has a tendency to stack in columnar arrangements both in liquid crystalline bulk and in Langmuir and Langmuir-Blodgett films.