Microfluidic-SANS: flow processing of complex fluids

Understanding and engineering the flow-response of complex and non-Newtonian fluids at a molecular level is a key challenge for their practical utilisation. Here we demonstrate the coupling of microfluidics with small angle neutron scattering (SANS). Microdevices with high neutron transmission (up to 98%), low scattering background ([Image: see text]), broad solvent compatibility and high pressure tolerance (≈3–15 bar) are rapidly prototyped via frontal photo polymerisation. Scattering from single microchannels of widths down to 60 μm, with beam footprint of 500 μm diameter, was successfully obtained in the scattering vector range 0.01–0.3 Å(−1), corresponding to real space dimensions of [Image: see text]. We demonstrate our approach by investigating the molecular re-orientation and alignment underpinning the flow response of two model complex fluids, namely cetyl trimethylammonium chloride/pentanol/D(2)O and sodium lauryl sulfate/octanol/brine lamellar systems. Finally, we assess the applicability and outlook of microfluidic-SANS for high-throughput and flow processing studies, with emphasis of soft matter

Microporous polymer particles via phase inversion in microfluidics: impact of non-solvent quality

We investigate the impact of ternary phase behavior on the microstructure of porous polymer particles produced by solvent extraction of polymer solution droplets by a nonsolvent. Microfluidic devices fabricated by frontal photopolymerization are employed to produce monodisperse polymer (P)/solvent (S) droplets suspended in a carrier (C) phase before inducing solvent extraction by precipitation in a nonsolvent (NS) bath. Model systems of sodium poly(styrenesulfonate) (P), water (S), hexadecane (C), and either methyl ethyl ketone (MEK) or ethyl acetate (EA) as NS are selected. Extraction across the liquid–liquid interface results in a decrease in the droplet radius and also an ingress of nonsolvent, leading to droplet phase demixing and coarsening. As the concentration of the polymer-rich phase increases, droplet shrinkage and solvent exchange slow down and eventually cease, resulting in microporous polymer particles (of radius ≃50–200 μm) with a smooth surface. The internal structure of these capsules, with pore sizes of ≃1–100 μm, is found to be controlled by polymer solution thermodynamics and the extraction pathway. The ternary phase diagrams are measured by turbidimetry, and the kinetics of phase separation is estimated by stopped-flow small-angle neutron scattering. The higher solubility of water in MEK results in faster particle-formation kinetics than in EA. Surprisingly, however, the lower polymer miscibility with EA/water results in a deeper quench inside the phase boundary and small phase sizes, thus yielding particles with small pores (of narrow distribution). The effects of droplet size, polymer content, and nonsolvent quality provide comprehensive insight into porous particle and capsule formation by phase inversion, with a range of practical applications

Caso para diagnóstico

Human scabies is an intensely pruritic skin infestation caused by Sarcoptes scabiei var. hominis. Crusted scabies (previously known as Norwegian scabies) is a rare form, very contagious and transmitted by direct contact with the skin. Despite being readily treatable, a delayed diagnosis often leads to widespread infestation of contacts, and therefore difficult to restrain. This case concerns a patient where dermoscopy (with scabetic burrows and a visible hand-glider structure), together with direct microscopic examination, allowed a prompt diagnosis, thereby reinforcing the increasing importance of this technique in daily practice

Botulismo Infantil em Portugal – Um Lactente com Hipotonia

O Botulismo Infantil (BI) constitui uma síndrome neuroparalítica rara, potencialmente fatal, causada pela neurotoxina do Clostridium botulinum. Descreve-se o primeiro caso reportado desde o início da notificação obrigatória em Portugal (1999). Lactente de dois meses, internado por prostração, dificuldade alimentar e obstipação. Constatou-se envolvimento inicial dos pares cranianos associado a fraqueza muscular progressiva, descendente e simétrica. Constituíam factores de risco o consumo de mel caseiro e o banho com ervas de camomila. A confirmação diagnóstica foi efectuada pela pesquisa de esporos de Clostridium botulinum nas fezes e pela prova de inoculação em ratinhos. O tratamento implicou suporte respiratório e nutricional, e imunoglobulina humana anti-toxina, com evolução favorável. A clínica e o contexto epidemiológico são importantes para o diagnóstico, permitindo a instituição precoce do tratamento

Synergetic enhancement of organic solar cell thermal stability by wire bar coating and light processing

OPV film deposition by wire-bar coating and light soaking result in polymer:fullerene solar cells with synergetically enhanced thermal stability.</p

Triple POCUS: A New Approach to an Old Problem

Pulmonary embolism (PE) is the most serious and life-threatening clinical presentation of venous thromboembolism, and difficult to diagnose. Triple point-of-care-ultrasonography (POCUS) of the lung, heart and leg veins is a multiorgan approach that may help to evaluate patients suspected of having PE, in combination with existing protocols and computed tomographic pulmonary angiography (CTPA). We present the case of a 26-year-old man with sudden onset of dyspnoea and swelling of the leg with a Well's score of 9. With CTPA unavailable at the time of presentation, triple POCUS showed subpleural consolidations and a venous thrombus in a popliteal vein. A diagnosis of deep vein thrombosis with PE was made and the appropriate treatment was started immediately. Although triple POCUS has less sensitivity and specificity than CTPA, it could be very useful in some clinical settings.info:eu-repo/semantics/publishedVersio

N170 Asymmetry as an Index of Inferior Occipital Dysfunction in Patients With Symptomatic Occipital Lobe Epilepsy

Objective: Localizing epileptic foci in posterior brain epilepsy remains a difficult exercise in surgery for epilepsy evaluation. Neither clinical manifestations, neurological, EEG nor neuropsychological evaluations provide strong information about the area of onset, and fast spread of paroxysms often produces mixed features of occipital, temporal and parietal symptoms. We investigated the usefulness of the N170 event-related potential to map epileptic activity in these patients. Methods: A group of seven patients with symptomatic posterior cortex epilepsy were submitted to a high-resolution EEG (78 electrodes), with recordings of interictal spikes and face-evoked N170. Generators of spikes and N170 were localized by source analysis. Range of normal N170 asymmetry was determined in 30 healthy volunteers. Results: In 3 out of 7 patients the N170 inter-hemispheric asymmetry was outside control values. Those were the patients whose spike sources were nearest (within 3 cm) to the fusiform gyrus, while foci further away did not affect the N170 ratio. Conclusions: N170 event-related potential provides useful information about focal cortical dysfunction produced by epileptic foci located in the close neighborhood of the fusiform gyrus, but are unaffected by foci further away. Significance: The N170 evoked by faces can improve the epileptic foci localization in posterior brain epilepsy

The role of the tyrosine kinase Wzc (Sll0923) and the phosphatase Wzb (Slr0328) in the production of extracellular polymeric substances (EPS) by Synechocystis PCC 6803

Many cyanobacteria produce extracellular polymeric substances (EPS) mainly composed of heteropolysaccharides with unique characteristics that make them suitable for biotechnological applications. However, manipulation/optimization of EPS biosynthesis/characteristics is hindered by a poor understanding of the production pathways and the differences between bacterial species. In this work, genes putatively related to different pathways of cyanobacterial EPS polymerization, assembly, and export were targeted for deletion or truncation in the unicellular Synechocystis sp. PCC 6803. No evident phenotypic changes were observed for some mutants in genes occurring in multiple copies in Synechocystis genome, namely ¿wzy (¿sll0737), ¿wzx (¿sll5049), ¿kpsM (¿slr2107), and ¿kpsM¿wzy (¿slr2107¿sll0737), strongly suggesting functional redundancy. In contrast, ¿wzc (¿sll0923) and ¿wzb (¿slr0328) influenced both the amount and composition of the EPS, establishing that Wzc participates in the production of capsular (CPS) and released (RPS) polysaccharides, and Wzb affects RPS production. The structure of Wzb was solved (2.28 Å), revealing structural differences relative to other phosphatases involved in EPS production and suggesting a different substrate recognition mechanism. In addition, Wzc showed the ATPase and autokinase activities typical of bacterial tyrosine kinases. Most importantly, Wzb was able to dephosphorylate Wzc in vitro, suggesting that tyrosine phosphorylation/dephosphorylation plays a role in cyanobacterial EPS production.Norte Portugal Regional Operational Programme (NORTE 2020), Grant/Award Number: NORTE‐01‐0145‐FE?ER‐000008 and NORTE‐01‐0145‐FE?ER‐000012; FCT ‐ Fundação para a Ciência e a Tecnologia/ Ministério da Ciência, Tecnologia e Ensino Superior, Grant/Award Number: PTDC/BIA‐ MIC/28779/2017, SFRH/BD /119920/2016, SFRH/B?/84914/2012 and SFRH/BD/99715/ 2014; FEDER ‐ Fundo Europeu de Desen‐ volvimento Regional funds through the COMPETE 2020 ‐ Operational Programme for Competitiveness and Internationalisation (POCI), Grant/Award Number: POCI‐01‐0145‐ FE?ER‐007274 ACKNOWLEDGMENTS: This work was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020— Operational Programme for Competitiveness and Internationalisation (POCI); projects NORTE‐01‐0145‐FEDER‐000012—Structured Programme on Bioengineering Therapies for Infectious ?iseases and Tissue Regeneration and NORTE‐01‐0145‐FEDER‐000008— Porto Neurosciences and Neurologic Disease Research Initiative at i3S, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement; and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI‐01‐0145‐FEDER‐007274 and PTDC/BIA‐ MIC/28779/2017) and grants SFRH/BD /119920/2016 (MS), SFRH/ BD /99715/2014 (CF), and SFRH/BD /129921/2017 (JPL). The au‐ thors thank F. Chauvat and the Commissariat à l’Energie Atomique (CEA), Direction des Sciences du Vivant, for providing the cas‐ sette for the deletion of the Synechocystis sll0923, the staff of the European Synchrotron Radiation Facility (Grenoble, France) and SOLEIL (Essonne, France) synchrotrons, Filipe Pinto, Frederico Silva, Hugo Osório, and Joana Furtado for their technical assistance