Structure of crystalline and amorphous materials in the NASICON system Na1+xAlxGe2-x(PO4)3.

The structure of crystalline and amorphous materials in the sodium (Na) super-ionic conductor system Na1+xAlxGe2-x(PO4)3 with x = 0, 0.4, and 0.8 was investigated by combining (i) neutron and x-ray powder diffraction and pair-distribution function analysis with (ii) 27Al and 31P magic angle spinning (MAS) and 31P/23Na double-resonance nuclear magnetic resonance (NMR) spectroscopy. A Rietveld analysis of the powder diffraction patterns shows that the x = 0 and x = 0.4 compositions crystallize into space group-type R3̄, whereas the x = 0.8 composition crystallizes into space group-type R3̄c. For the as-prepared glass, the pair-distribution functions and 27Al MAS NMR spectra show the formation of sub-octahedral Ge and Al centered units, which leads to the creation of non-bridging oxygen (NBO) atoms. The influence of these atoms on the ion mobility is discussed. When the as-prepared glass is relaxed by thermal annealing, there is an increase in the Ge and Al coordination numbers that leads to a decrease in the fraction of NBO atoms. A model is proposed for the x = 0 glass in which super-structural units containing octahedral Ge(6) and tetrahedral P(3) motifs are embedded in a matrix of tetrahedral Ge(4) units, where superscripts denote the number of bridging oxygen atoms. The super-structural units can grow in size by a reaction in which NBO atoms on the P(3) motifs are used to convert Ge(4) to Ge(6) units. The resultant P(4) motifs thereby provide the nucleation sites for crystal growth via a homogeneous nucleation mechanism.

On the effect of thermodynamic equilibrium on the assembly efficiency of complex multi-layered virus-like particles (VLP): the case of rotavirus VLP.

Previous studies have reported the production of malformed virus-like-particles (VLP) in recombinant host systems. Here we computationally investigate the case of a large triple-layered rotavirus VLP (RLP). In vitro assembly, disassembly and reassembly data provides strong evidence of microscopic reversibility of RLP assembly. Light scattering experimental data also evidences a slow and reversible assembly untypical of kinetic traps, thus further strengthening the fidelity of a thermodynamically controlled assembly. In silico analysis further reveals that under favourable conditions particles distribution is dominated by structural subunits and completely built icosahedra, while other intermediates are present only at residual concentrations. Except for harshly unfavourable conditions, assembly yield is maximised when proteins are provided in the same VLP protein mass composition. The assembly yield decreases abruptly due to thermodynamic equilibrium when the VLP protein mass composition is not obeyed. The latter effect is more pronounced the higher the Gibbs free energy of subunit association is and the more complex the particle is. Overall this study shows that the correct formation of complex multi-layered VLPs is restricted to a narrow range of association energies and protein concentrations, thus the choice of the host system is critical for successful assembly. Likewise, the dynamic control of intracellular protein expression rates becomes very important to minimize wasted proteins.

Biosilicate®-gelatine bone scaffolds by the foam replica technique: development and characterization.

The development of bioactive glass-ceramic materials has been a topic of great interest aiming at enhancing the mechanical strength of traditional bioactive scaffolds. In the present study, we test and demonstrate the use of Biosilicate® glass-ceramic powder to fabricate bone scaffolds by the foam replica method. Scaffolds possessing the main requirements for use in bone tissue engineering (95% porosity, 200-500 µm pore size) were successfully produced. Gelatine coating was investigated as a simple approach to increase the mechanical competence of the scaffolds. The gelatine coating did not affect the interconnectivity of the pores and did not significantly affect the bioactivity of the Biosilicate® scaffold. The gelatine coating significantly improved the compressive strength (i.e. 0.80 ± 0.05 MPa of coated versus 0.06 ± 0.01 MPa of uncoated scaffolds) of the Biosilicate® scaffold. The combination of Biosilicate® glass-ceramic and gelatine is attractive for producing novel scaffolds for bone tissue engineering.

Gender-Related Trends in Publication Authorship: A 10-Year Analysis of a Brazilian Surgical Journal.

There is a gender gap in the representation of women in the authorship of surgical literature worldwide. In Brazil, data on the gender distribution of the authorship of articles are scarce; and hence, there is a lack of awareness about the contemporary situation of women surgeons within the academic surgery in the country. In light of this, we conducted this study with an aim to describe and evaluate the authorship trends in a Brazilian surgical journal over a period of 10 years (2010-2019). We included 4,301 authors from 792 articles extracted from 60 editions of this journal. We analyzed the female representation as authors in general, first and last authors, and the female surgeons' representation as first and last authors for 568 original articles. We found that, in general, women represented 27.8% of all authors. Regarding original articles, women surgeons represented 8.4% and 6.1% of first and last authors, respectively. The linear regression analysis demonstrated that there was an increase over the years in women authorship. However, despite this increase over the years, a gender gap still persists in terms of women's representation as authors in the Brazilian surgical literature.

Impact of physicochemical parameters on in vitro assembly and disassembly kinetics of recombinant triple-layered rotavirus-like particles.

Virus-like particles constitute potentially relevant vaccine candidates. Nevertheless, their behavior in vitro and assembly process needs to be understood in order to improve their yield and quality. In this study we aimed at addressing these issues and for that purpose triple- and double-layered rotavirus-like particles (TLP 2/6/7 and DLP 2/6, respectively) size and zeta potential were measured using dynamic light scattering at different physicochemical conditions, namely pH, ionic strength, and temperature. Both TLP and DLP were stable within a pH range of 3-7 and at 5-25 degrees C. Aggregation occurred at 35-45 degrees C and their disassembly became evident at 65 degrees C. The isoelectric points of TLP and DLP were 3.0 and 3.8, respectively. In vitro kinetics of TLP disassembly was monitored. Ionic strength, temperature, and the chelating agent employed determined disassembly kinetics. Glycerol (10%) stabilized TLP by preventing its disassembly. Disassembled TLP was able to reassemble by dialysis at high calcium conditions. VP7 monomers were added to DLP in the presence of calcium to follow in vitro TLP assembly kinetics; its assembly rate being mostly affected by pH. Finally, DLP and TLP were found to coexist under certain conditions as determined from all reaction products analyzed by capillary electrophoresis. Overall, these results contribute to the design of new strategies for the improvement of TLP yield and quality by reducing the VP7 detachment from TLP.

Blind multicenter study of the efficacy and safety of injections of a commercial preparation of botulinum toxin type A reconstituted up to 15 days before injection.

BACKGROUND: It is recommended that attention be given to the shelf life of botulinum toxin type A (BT-A) after its reconstitution. OBJECTIVE: To assess the efficacy and safety of 500 U of BT-A after reconstitution up to 15 days after injection. MATERIAL AND METHODS: BT-A vials were diluted 15 days, 8 days, and 8 hours before injection. One hundred five volunteers were randomized to one of three treatment groups, according to dilution dates. They were evaluated at baseline and 28, 56, 84, and 112 days after treatment. At each visit, the investigator and the volunteer evaluated the motility of the treated area using a 4-point qualitative scale. Five independent specialists, who scored the motility of the treated area on the same scale, blind analyzed photographs taken at each visit. The reconstituted vials of BT-A were stored and analyzed before and after the study. RESULTS: No significant difference was shown between the groups. No evidence of contamination was found in the BT-A vials. CONCLUSION: The results confirm the possibility of injecting 500 U of BT-A up to 15 days after its reconstitution safely and without loss of efficacy.

Our Timing to Remove Peritoneal Catheter Dialysis After Kidney Transplant.

BACKGROUND: Patients on peritoneal dialysis treatment represent 15% of the global dialysis population. The major complication of peritoneal dialysis is catheter and peritoneal infection. Peritoneal dialysis patients who receive kidney transplants are at increased risk of infection because of immunosuppressive therapy. AIM: The purpose of this study is to show our ideal timing to remove peritoneal catheter after kidney transplant, which gives adequate security on renal function recovery and reduction of septic risk. METHOD OF STUDY: We analyzed the outcomes of 65 patients on peritoneal dialysis who underwent kidney transplant between 2000 and 2016. RESULTS: In 61 cases there was an immediate graft functional recovery. In 4 cases there was a delayed graft function (DGF), and we performed a hemodialysis with temporary placement of a venous catheter. In all patients we removed peritoneal dialysis catheter 30 to 45 days after transplant. There has been 1 case of catheter infection, which was treated with antibiotic therapy. DISCUSSION: Our average time to remove the peritoneal dialysis catheter was shorter than times in previous studies, between the 30th and 45th postoperative day. In the 4 cases in which there has been a DGF, we performed hemodialysis treatment to avoid, in the immediate postoperative period, direct insults to the peritoneum by local dialysis procedures. CONCLUSION: Our experience show that the 30th to 45th postoperative day is a good time frame, better yet a good watershed between the safe removal of peritoneal catheter when patients have a stabilized renal function and the possibility of leaving it in situ, to resume peritoneal dialysis in case of persistent DGF.

Sodium dodecyl sulfate-capillary gel electrophoresis analysis of rotavirus-like particles.

This work describes the application of a sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE) method for the analysis of triple 2/6/7 and double-layered 2/6 rotavirus-like particles (RLPs), candidate vaccines against rotavirus infection. SDS-CGE analysis of RLPs resulted in peaks that could be attributed to the viral proteins (VP2, VP6 and VP7) according to their apparent molecular mass (MWapp). Samples containing the glycoprotein VP7 were analysed after deglycosylation with PNGase F. Upon deglycosylation, VP7 MWapp decreased 4-7kDa consistent with a degree of glycosylation of approximately 12-21%. VP2 was eventually detected in the form of more than one related proteins, despite the small areas due to the relative low mass proportion of this protein in the particle (16%). The effect of analytical parameters such as capillary temperature on method performance was evaluated. MWapp values estimated by SDS-CGE were compared with values obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The method described in this work proved to be fast, consistent and reproducible, representing a feasible alternative to the laborious conventional electrophoresis for the characterization of RLPs.

Purification of recombinant rotavirus VP7 glycoprotein for the study of in vitro rotavirus-like particles assembly.

Rotavirus VP7 is a glycoprotein that forms the viral capsid outerlayer and is essential to the correct assembly of triple-layered rotavirus-like particles (RLPs). In this work, a novel purification strategy was designed to allow obtaining highly pure monomeric VP7 required for the RLPs in vitro assembly. VP7 production kinetics in baculovirus-insect cells at cell concentration at infection (CCI) of 1x10(6)cellsmL(-1) was compared in terms of VP7/glycoprotein 64 (gp64) ratio at different multiplicity of infection (MOI). The best productivity was achieved at MOI of 0.1plaque forming unit (pfu)cell(-1) and time of harvest of 80h post-infection. After preliminary clarification steps, the proteins eluted from Concanavalin A were concentrated and loaded onto size exclusion chromatography. The polishing step was anion exchange chromatography with Mono Q. The high resolution of this column resulted in separation of monomers from dimers of VP7. Overall, the purification protocol yielded high level of purity (>90%). Purified VP7 was characterized by MALDI-TOF mass spectrometry and SDS-capillary gel electrophoresis. The MW and apparent MW were determined as 31.6 and 39kDa, respectively, confirming the efficacy of the proposed purification strategy that now enables RLPs assembly studies.

Genetic and clinical heterogeneity in eIF2B-related disorder.

Eukaryotic initiation factor 2B (eIF2B)-related disorders are heritable white matter disorders with a variable clinical phenotype (including vanishing white matter disease and ovarioleukodystrophy) and an equally heterogeneous genotype. We report 9 novel mutations in the EIF2B genes in our subject population, increasing the number of known mutations to more than 120. Using homology modeling, we have analyzed the impact of novel mutations on the 5 subunits of the eIF2B protein. Although recurrent mutations have been found at CpG dinucleotides in the EIF2B genes, the high incidence of private or low frequency mutations increases the challenge of providing rapid genetic confirmation of this disorder, and limits the application of EIF2B screening in cases of undiagnosed leukodystrophy.

Staphylococcus aureus and Escherichia coli dual-species biofilms on nanohydroxyapatite loaded with CHX or ZnO nanoparticles.

Implant-associated infections are caused by surface-adhering microorganisms persisting as biofilms, resistant to host defense and antimicrobial agents. Given the limited efficacy of traditional antibiotics, novel strategies may rely on the prevention of such infections through the design of new biomaterials. In this work, two antimicrobial agents applied to nanohydroxyapatite materials-namely, chlorhexidine digluconate (CHX) and zinc oxide (ZnO) nanoparticles-were compared concerning their ability to avoid single- or dual-species biofilms of Staphylococcus aureus and Escherichia coli. The resulting biofilms were quantified by the enumeration of colony-forming units and examined by confocal microscopy using both Live/Dead staining and bacterial-specific fluorescent in situ hybridization. The sessile population arrangement was also observed by scanning electron microscopy. Both biomaterials showed to be effective in impairing bacterial adhesion and proliferation for either single- or dual-species biofilms. Furthermore, a competitive interaction was observed for dual-species biofilms wherein E. coli exhibited higher proliferative capacity than S. aureus, an inverse behavior from the one observed in single-species biofilms. Therefore, either nanoHA-CHX or nanoHA-ZnO surfaces appear as promising alternatives to antibiotics for the prevention of devices-related infections avoiding the critical risk of antibiotic-resistant strains emergence. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 491-497, 2017.

Metal complexes of 1-oxa-4,7,10-triazacyclododecane-N,N',N''-triacetic acid.

The macrocyclic complexone 1-oxa-4,7,10-triazacyclododecane-N,N',N''-triacetic acid (cODTA) has been synthesized and its protona constants, stability constants of metal complexes and enthalpy changes for the formation of alkaline-earth complexes have been determined. Although it is not so powerful a complexing agent as the N-acetate derivative of the corresponding tetra-aza macrocycle, cDOTA, this is still one of the strongest complexones known, particularly towards the alkaline-earth metals. The complexes of the transition metals are also very stable and there is an inversion of the Irving-Williams order of stability for the complexes of cobalt and nickel.

Pain assessment and management in the NICU: analysis of an educational intervention for health professionals.

OBJECTIVE: to study the perception of a Neonatal Intensive Care team on pain assessment and management before and after an educational intervention created and implemented in the unit. METHODS: intervention study developed as action research, in three phases. In Phase 1, a quantitative study was performed to identify how professionals perceive pain management in the unit. In Phase 2, an educational intervention was carried out, using the Operational Group (OG), which defined strategies to be adopted to seek improvements in pain assessment and management. In Phase 3, the initial questionnaire was reapplied to assess professionals' perceptions about the subject after the intervention. All professionals directly working in newborn care were included. RESULTS: the perception of professionals about pain management and assessment in the unit showed a statistically significant difference between the two phases of research, highlighting the increase in frequency of reference for evaluation and use of some method of pain relief procedures for most analyzed procedures. Participation in training (one of the strategies defined by the operational group) was reported by 86.4% of the professionals. They reported the use of scales for pain assessment, established by the protocol adopted in the service after the intervention, with a frequency of 94.4%. Changes in pain assessment and management were perceived by 79.6% of the participants. CONCLUSION: the professionals involved in the educational intervention observed changes in pain management in the unit and related them to the strategies defined and implemented by the OG.

Characterization and in vivo biological performance of biosilicate.

After an introduction showing the growing interest in glasses and glass-ceramics as biomaterials used for bone healing, we describe a new biomaterial named Biosilicate. Biosilicate is the designation of a group of fully crystallized glass-ceramics of the Na2O-CaO-SiO2-P2O5 system. Several in vitro tests have shown that Biosilicate is a very active biomaterial and that the HCA layer is formed in less than 24 hours of exposure to "simulated body fluid" (SBF) solution. Also, in vitro studies with osteoblastic cells have shown that Biosilicate disks supported significantly larger areas of calcified matrix compared to 45S5 Bioglass, indicating that this bioactive glass-ceramic may promote enhancement of in vitro bone-like tissue formation in osteogenic cell cultures. Finally, due to its special characteristics, Biosilicate has also been successfully tested in several in vivo studies. These studies revealed that the material is biocompatible, presents excellent bioactive properties, and is effective to stimulate the deposition of newly formed bone in animal models. All these data highlight the huge potential of Biosilicate to be used in bone regeneration applications.

A modular reactor to simulate biofilm development in orthopedic materials.

Surfaces of medical implants are generally designed to encourage soft- and/or hard-tissue adherence, eventually leading to tissue- or osseo-integration. Unfortunately, this feature may also encourage bacterial adhesion and biofilm formation. To understand the mechanisms of bone tissue infection associated with contaminated biomaterials, a detailed understanding of bacterial adhesion and subsequent biofilm formation on biomaterial surfaces is needed. In this study, a continuous-flow modular reactor composed of several modular units placed in parallel was designed to evaluate the activity of circulating bacterial suspensions and thus their predilection for biofilm formation during 72 h of incubation. Hydroxyapatite discs were placed in each modular unit and then removed at fixed times to quantify biofilm accumulation. Biofilm formation on each replicate of material, unchanged in structure, morphology, or cell density, was reproducibly observed. The modular reactor therefore proved to be a useful tool for following mature biofilm formation on different surfaces and under conditions similar to those prevailing near human-bone implants.

Sustained reduction of the dengue vector population resulting from an integrated control strategy applied in two Brazilian cities.

Aedes aegypti has developed evolution-driven adaptations for surviving in the domestic human habitat. Several trap models have been designed considering these strategies and tested for monitoring this efficient vector of Dengue. Here, we report a real-scale evaluation of a system for monitoring and controlling mosquito populations based on egg sampling coupled with geographic information systems technology. The SMCP-Aedes, a system based on open technology and open data standards, was set up from March/2008 to October/2011 as a pilot trial in two sites of Pernambuco -Brazil: Ipojuca (10,000 residents) and Santa Cruz (83,000), in a joint effort of health authorities and staff, and a network of scientists providing scientific support. A widespread infestation by Aedes was found in both sites in 2008-2009, with 96.8%-100% trap positivity. Egg densities were markedly higher in SCC than in Ipojuca. A 90% decrease in egg density was recorded in SCC after two years of sustained control pressure imposed by suppression of >7,500,000 eggs and >3,200 adults, plus larval control by adding fishes to cisterns. In Ipojuca, 1.1 million mosquito eggs were suppressed and a 77% reduction in egg density was achieved. This study aimed at assessing the applicability of a system using GIS and spatial statistic analysis tools for quantitative assessment of mosquito populations. It also provided useful information on the requirements for reducing well-established mosquito populations. Results from two cities led us to conclude that the success in markedly reducing an Aedes population required the appropriate choice of control measures for sustained mass elimination guided by a user-friendly mosquito surveillance system. The system was able to support interventional decisions and to assess the program's success. Additionally, it created a stimulating environment for health staff and residents, which had a positive impact on their commitment to the dengue control program.

Monitoring virus-like particle and viral protein production by intact cell MALDI-TOF mass spectrometry.

A new application of intact cell MALDI-TOF MS (ICM-MS) methodology is described for monitoring the production of viral proteins and viral like particles using the baculovirus/insect cells expression system. Various MALDI matrices, cell preparation methods, cell/matrix volume ratio and MALDI target application procedures were tested in order to obtain the highest intensity and reproducibility of intact insect cell spectra. The web interface, SPECLUST (http://bioinfo.thep.lu.se/speclust.html), was used to construct dendograms based on MALDI-TOF MS data for evaluation of fingerprint changes. We demonstrate that insect cell mass spectrum fingerprints are characteristic of each viral protein/particle production. Their changes along the time for each production experiment correlate with the intracellular viral protein content determined by Western blot. This work shows that this simple, fast and low cost assay, which requires low sample volume, is a powerful analytical tool that complements the most common analytical methods used for monitoring bioprocesses and has potential application in the biotechnological industry namely, in the production of recombinant proteins.

Virus-like particles in vaccine development.

Virus-like particles (VLPs) are multiprotein structures that mimic the organization and conformation of authentic native viruses but lack the viral genome, potentially yielding safer and cheaper vaccine candidates. A handful of prophylactic VLP-based vaccines is currently commercialized worldwide: GlaxoSmithKline's Engerix (hepatitis B virus) and Cervarix (human papillomavirus), and Merck and Co., Inc.'s Recombivax HB (hepatitis B virus) and Gardasil (human papillomavirus) are some examples. Other VLP-based vaccine candidates are in clinical trials or undergoing preclinical evaluation, such as, influenza virus, parvovirus, Norwalk and various chimeric VLPs. Many others are still restricted to small-scale fundamental research, despite their success in preclinical tests. This article focuses on the essential role of VLP technology in new-generation vaccines against prevalent and emergent diseases. The implications of large-scale VLP production are discussed in the context of process control, monitorization and optimization. The main up- and down-stream technical challenges are identified and discussed accordingly. Successful VLP-based vaccine blockbusters are briefly presented concomitantly with the latest results from clinical trials and the recent developments in chimeric VLP-based technology for either therapeutic or prophylactic vaccination.

Pain assessment and management in the NICU: analysis of an educational intervention for health professionals / Avaliação e manejo da dor na UTI neonatal: análise de uma intervenção educativa para os profissionais de saúde

OBJECTIVE: to study the perception of a Neonatal Intensive Care team on pain assessment and management before and after an educational intervention created and implemented in the unit. METHODS: intervention study developed as action research, in three phases. In Phase 1, a quantitative study was performed to identify how professionals perceive pain management in the unit. In Phase 2, an educational intervention was carried out, using the Operational Group (OG), which defined strategies to be adopted to seek improvements in pain assessment and management. In Phase 3, the initial questionnaire was reapplied to assess professionals' perceptions about the subject after the intervention. All professionals directly working in newborn care were included. RESULTS: the perception of professionals about pain management and assessment in the unit showed a statistically significant difference between the two phases of research, highlighting the increase in frequency of reference for evaluation and use of some method of pain relief procedures for most analyzed procedures. Participation in training (one of the strategies defined by the operational group) was reported by 86.4% of the professionals. They reported the use of scales for pain assessment, established by the protocol adopted in the service after the intervention, with a frequency of 94.4%. Changes in pain assessment and management were perceived by 79.6% of the participants. CONCLUSION: the professionals involved in the educational intervention observed changes in pain management in the unit and related them to the strategies defined and implemented by the OG. .

OBJETIVO: conhecer a percepção de uma equipe de terapia intensiva neonatal sobre a avaliação e manejo dor antes e após uma intervenção educativa construída e implementada na unidade. MÉTODOS: estudo de intervenção desenvolvido na modalidade de pesquisa-ação, desenvolvido em três fases. Na 1ª fase, foi realizado um estudo quantitativo, para identificar como os profissionais percebiam o manejo da dor na unidade. Na 2ª fase, foi realizada uma intervenção educativa, utilizando o Grupo Operativo, que definiu estratégias a serem adotadas buscando melhorias na avaliação e manejo da dor. Na 3ª fase foi reaplicado o questionário inicial, para avaliar a percepção dos profissionais acerca do tema, após a intervenção. Foram incluídos todos os profissionais que atuam nos cuidados diretos aos recém-nascidos. RESULTADOS: a percepção dos profissionais acerca do manejo e da avaliação da dor na unidade mostrou diferença estatisticamente significante entre as duas fases da pesquisa, destacando-se o aumento na referência de frequência de avaliação e de utilização de algum método de alívio da dor em procedimentos, para a maioria dos procedimentos pesquisados. A participação na capacitação (uma das estratégias definidas pelo grupo operativo) foi referida por 86,4% dos profissionais. Estes referiram a utilização das escalas para avaliação da dor, estabelecidas no protocolo adotado no serviço após a intervenção, com frequência de 94,4%. Mudanças na avaliação e manejo da dor foram percebidas por 79,6% dos participantes. CONCLUSÃO: os profissionais envolvidos na intervenção educativa perceberam mudanças no manejo da dor na unidade e ...