Ternary composites of poly(vinylidene fluoride-co-hexafluoropropylene) with silver nanowires and titanium dioxide nanoparticles as separator membranes for lithium-ion batteries

In the realm of polymer composites, there is growing interest in the use of more than one filler for achieving multifunctional properties. In this work, a composite separator membrane has been developed for lithium-ion battery application, by incorporating conductive silver nanowires (AgNWs) and titanium dioxide (TiO2) nanoparticles into a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymer matrix. The composite membranes were manufactured by solvent casting and thermally induced phase separation, with total filler content varying up to 10 wt%. The ternary composites composites present improved mechanical characteristics, ionic conductivity and lithium transfer number compared to the neat polymer matrix. On the other hand, the filler type and content within the composite has little bearing on the morphology, polymer phase, or thermal stability. Once applied as a separator in lithium-ion batteries, the highest discharge capacity value was obtained for the 5 wt% AgNWs/5 wt% TiO2/PVDF-HFP membrane at different C-rates, benefiting from the synergetic effect from both fillers. This work demonstrates that higher battery performance can be achieved for next-generation lithium-ion batteries by using separator membranes based on ternary composites.

The effect of urbanization on species composition and trophic guilds of bats (Mammalia, Chiroptera) in the Brazilian Savanna

Urban environments present less environmental heterogeneity in relation to the natural ones, affecting the biodiversity of bats and the ecological processes in which they participate. In this way, we will identify how urbanization influences the structure of bat communities in the municipality of Goiânia, Goiás, Brazil. We compared species composition, guilds and bat richness in a gradient that crossed urban, semi-urban and natural areas in the municipality of Goiânia, contained in the Cerrado biome. We captured a total of 775 bats of 16 species distributed in three families. Urban areas had a higher species abundance, while semi-urban areas had a higher species richness. The three types of environments have different compositions, the urban one being more homogeneous, the fauna in these areas is composed of generalist species, which benefit from this process. The diversity present in semi-urban areas is a consequence of the intersection between urban and natural fauna, which is why urban expansion needs to occur in a planned manner to minimize the impacts of this process and ensure the maintenance of biodiversity.

An Anxious Heart: The Relation Between Cardiovascular Disease and Prevalence of Anxiety Symptoms

Introduction

Cardiovascular disease represent the leading cause of death worldwide, and is also responsible for the consumption of many medical resources, work absenteeism and worse Quality of Life. On the other hand, psychiatric diseases have recently gained more relevance worldwide as one of the principal causes of disability.

Objectives

Evaluate a possible relationship between cardiovascular risk factors (CVRF) and anxious or depressive symptoms.

Methods

Observational and cross-sectional study in a non-probabilistic and convenience sample, composed by patients followed on five primary healthcare facilites, who voluntarily accepted to answer the questionnaire through an interview, between July 2020 and January 2021. After an informed consent, a questionnaire was carried out including sociodemographic characterization, presence of cardiovascular disease and/or cardiovascular risk factors and the Portuguese version of HADS. Descriptive and inferential statistics were performed, using Mann-Whitney U test. A value of p<0,05 was considered statistically significant.

Results

Sample of 179 people, 53,1% female, with an average age of 51,05 ± 22,02 years, in which 57,5% had one or more CVRF and 59,8% had CVD and/or CVFR and the most prevalent CVRF were hypertension (48%) and dyslipidemia (43,6%). There was a statistically significant relationship between diabetes and anxiety (p<0,05).

Conclusions

There was a greater prevalence of anxiety symptoms in people with diabetes compared to people without diabetes. This suggests the importance of giving attention to anxiety in patients with diabetes, given the relevance of this comorbidity in their quality of life. The main limitation of the study is related with the sample size.

Disclosure

No significant relationships.

Cutoff Points for Grip Strength in Screening for Sarcopenia in Community-Dwelling Older-Adults: A Systematic Review

BACKGROUND

Currently, different cutoff points for handgrip strength (HGS) have been used to estimate the prevalence of sarcopenia. In addition, the variability of equipment and protocols for this assessment can significantly influence the early detection of this important public health problem. Thus, this review aims to identify the different cutoff points for HGS adopted for older men and women in screening for sarcopenia.

OBJECTIVES

this review aims to identify the different cutoff points for HGS adopted for older men and women in screening for sarcopenia.

METHODS

In accordance with the PRISMA 2020 recommendations, which included published studies from the last 10 years, from 6 databases, in 3 different languages.

RESULTS

19.730 references were identified, of which 62 were included for the review. All references analyzed used algorithms and definitions of sarcopenia already known in the literature. Of the studies found, 16 chose to develop cutoff values for HGS based on their own population. The variation in cutoff points was evident when compared between gender and regions of the world.

CONCLUSION

It has become evident that there is a variability of normative values for HGS in sarcopenia screening. In addition, this systematic review shows the difference in the cutoff points used between the consensuses and those developed for each population.

Clinical findings, neurological manifestations and survival of dogs with insulinoma: 116 cases (2009-2020)

OBJECTIVES

To review the clinical findings and outcome in dogs diagnosed with insulinoma, and to assess which factors are predictors of overall survival. Additionally, to describe the neurological manifestations of this population and their correlation with survival.

MATERIALS AND METHODS

Retrospective multicentric study of canine insulinoma cases (2009 to 2020). Signalment, clinical history, neurological examination, diagnostic findings, treatment and outcome were obtained from clinical records. Univariate and multivariate analyses were used to compare the overall survival.

RESULTS

One hundred and sixteen cases were included. Median duration of clinical signs before presentation was 1.5 months. The most common presenting clinical signs were weakness (59.5%), epileptic seizures (33.6%) and changes in consciousness or behaviour (27.6%). Three dogs were suspected to have paroxysmal dyskinesia. Thirty-two dogs had an abnormal neurological examination, most commonly showing obtundation (28.1%), decreased withdrawal reflexes (21.9%) and absent menace response (18.8%). Overall survival for dogs undergoing surgery (20 months) was significantly longer than in medically treated (8 months; adjusted hazard ratio: 0.33; 95% confidence interval: 0.18, 0.59). Presence of metastases was the only other variable associated with prognosis (adjusted hazard ratio 1.72; 95% confidence interval: 1.02, 2.91).

CLINICAL SIGNIFICANCE

Clinical signs of canine insulinoma are vague and non-specific. Weakness, epileptic seizures and changes in mentation or behaviour were the most commonly reported. Obtunded mentation and forebrain neurolocalisation were the main neurological manifestations. Dogs undergoing surgery had a longer overall survival compared to medically treated cases, and dogs with metastasis had a shorter overall survival regardless of treatment modality. Abnormalities in the neurological examination did not correlate with prognosis.

Crystal morphology control of synthetic giniite for enhanced photo-Fenton activity against the emerging pollutant metronidazole

Metronidazole (MNZ) is a recalcitrant antibiotic with toxic and carcinogenic effects in aquatic environments. In this work, Fe₅(PO₄)₄(OH)₃·2H₂O (giniite) particles were synthesised with three different alkaline cations (Li⁺, Na⁺ and K⁺) and used as Fenton catalysts for MNZ removal. It is shown that the addition of different cations during the hydrothermal synthesis process promote different morphologies from asterisk-like to flower-like and branches-like, maintaining the crystalline structure of pure giniite. The photo-Fenton activity of these particles was then evaluated through the degradation of MNZ under sunlight radiation for 9 h. The results indicate that the alkaline cation has a predominant role in the photo-Fenton efficiency, as demonstrated by the superior degradation efficiencies of Na@giniite particles (91.2% and 72.5% with giniite concentration of 0.2 g L^-1 and 0.07 g L^-1, respectively), related with its high surface area (10.7 m² g^-1). Thus, it is demonstrated the suitability of Na@giniite particles as Fenton catalyst for MNZ removal from water.

Does sequential balloon expulsion test improve the screening of defecation disorders?

Background

A defecation disorder (DD) is a difficulty in evacuation documented by physiological exams. However, this physiological evaluation can be cumbersome, inaccessible and costly. Three “low-cost” tools to evaluate DD—a clinical DD score, the balloon expulsion test (BET) and a digital rectal examination (DRE) score were evaluated as separate or combined tests for DD screening.

Methods

This prospective study occurred between January 2015 and March 2019 in the Gastroenterology Department of a tertiary hospital. Besides the gold standard physiological tests, constipated patients answered the clinical DD score and were evaluated by DRE and BET [standard and variable volume (VV)].

Results

From 98 constipated patients, 35 (38.9%) were diagnosed with DD according to Rome IV criteria, mainly female (n = 30, 86%) with a median age of 60 years old. The clinical DD score revealed an AUC of 0.417 (SE = 0.07, p = 0.191). The DRE score displayed an AUC of 0.56 (SE = 0.063, p = 0.301). The standard BET displayed a sensitivity of 86%, specificity of 58%, positive predictive value (PPV) of 57% and negative predictive value (NPV) of 86%. The sequential VVBET followed by standard BET improved the BET performance regarding the evaluation of DD, with a sensitivity of 86%, specificity of 67%, PPV of 63% and NPV of 87%. The sequential BET had an OR 8.942, p > 0.001, CI 3.18–25.14, revealing to be the most significant predictor for DD screening.

Conclusion

The sequential BET is a low cost, well-performing DD screening tool, appropriate to the Primary Care Setting.

Enhanced ionic conductivity in poly(vinylidene fluoride) electrospun separator membranes blended with different ionic liquids for lithium ion batteries

Electrospun poly(vinylidene fluoride) (PVDF) fiber membranes doped with different ionic liquids (ILs) and sharing the same anion were produced and their potential as separator membranes for battery applications was evaluated. Different types of ILs containing the same anion, bis(trifluoromethylsulfonyl)imide [TFSI]^-, were used with IL concentrations ranging between 0 and 15 wt% The morphology, microstructure, thermal and electrical properties (ionic conductivity and electrochemical window) of the membranes were evaluated. The presence of ILs in the PVDF polymer matrix influences the fiber diameter and the content of the polar β phase within the polymer, as well as the degree of crystallinity. The thermal stability of the membranes decreases with the incorporation of IL. Impedance spectroscopy tests show a maximum ionic conductivity of 2.8 mS.cm^-1 for 15% of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][TFSI]) at room temperature. The electrochemical stability of the samples ranges from 0.0 to 6.0 V. When evaluated as battery separator membranes in C-LiFePO₄ half-cells, a maximum discharge capacity of 119 mAh.g^-1 at C-rate was obtained for the PVDF membrane with 15% [Emim][TFSI], with a coulombic efficiency close to 100%. The results demonstrate that the produced electrospun membranes are suitable for applications as separators for lithium ion batteries (LIBs).

Burnout among Portuguese oncology healthcare providers – Differences between pediatric an adult teams

Introduction

Burnout is characterized by emotional exhaustion, depersonalization and reduced personal accomplishment, resulting from the inability to cope with chronic job stress. The literature suggests that staffs working in adult oncology are at risk of burnout. At the same time, research found that pediatric staff experiences a different set of stressors when compared with colleagues working in adult oncology. However, no studies were identified which directly compared prevalence and sources of Burn-out on pediatric and adult oncology staff.

Objectives

To compare the differences on prevalence and sources of burnout between pediatric and adult oncology multidisciplinary teams.

Methods

Pediatric and adult oncology professionals, including medical and nursing from a Portuguese oncology center completed the Portuguese version of the Copenhagen Burnout Inventory. Data was analyzed using SPSS.

Results

Since the study is currently ongoing the authors will only be able to provide final results and conclusions by the time of submission of our work presentation, in March 2016. However, according to the literature available, we are expecting to found symptoms of Burnout in the superior limit of normality, with differences in the major sources of stress between adult and pediatric professionals.

Conclusion

The differences in the challenges experienced by adult and pediatric teams highlight the importance of adequate prevention strategies to specific needs of each unit. Further investigation of stress across a wider range of professional disciplines is required in order to explore this gap.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Preliminary investigation of serum cardiac troponin I in dogs with acute ischaemic stroke

OBJECTIVES

To describe the incidence of elevated serum cardiac troponin I in dogs with acute ischaemic strokes, to evaluate its prognostic value in these patients and characterise a possible relationship between cardiac troponin I elevation in dogs with ischaemic strokes and underlying cardiac dysfunction.

MATERIALS AND METHODS

Prospective study of 18 dogs with acute ischaemic stroke diagnosed by MRI of the brain. Serum cardiac troponin I concentration, trans-thoracic echocardiography and six-lead electrocardiography were performed and findings were compared between dogs with good and poor outcome.

RESULTS

Serum cardiac troponin I was increased in 17 dogs (median 0.95 ng/mL; range 0.146 to 153). Focal hyperechoic regions of myocardium were visible in two dogs using trans-thoracic echocardiography and presumed to represent acute infarcts. A significant association was found between cardiac troponin I and creatinine concentrations. No difference in cardiac troponin I concentrations was detected between dogs that experienced good and poor outcomes. Clinically important cardiac dysfunction was identified in two dogs.

CLINICAL SIGNIFICANCE

Cardiac troponin I is commonly elevated in patients diagnosed with acute ischaemic stroke but, in this small study population, did not have prognostic value. Larger studies (recruiting a study population of 98 dogs for a power of 0.8 and a 0.05 alpha/critical value) would aid in further investigation of these preliminary results.

Abstract P2-12-11: Does conservative surgery treatment for locally advanced breast cancer safe after neoadjuvant treatment?

BACKGROUND:

The aim of this study was to assess the oncological efficacy of breast conserving surgery (BCS) after neoadjuvant chemotherapy in patients with local advanced breast cancer.

PATIENTS AND METHODS:

A retrospective cohort study was conducted with locally advanced breast cancer invasive (Stage IIb to III) treated at ICESP, an oncologic referral center between 2008 and 2016. Endpoints were disease free survival (DFS), local disease free survival (LDFS) and overall survival (OS). Multivariable analyses were performed using Cox proportional hazards models.

RESULTS:

530 patients were included, 26% (138) were stage IIB, 41.9% (222) IIIA, 29.6% (157) IIIB and 2.5% (13) IIIA. 88.8% (470) were invasive ductal carcinoma. The mean age was 51.5(23-95). 95.5% and 4.5% were submitted Neoadjuvant Chemotherapy and Hormone therapy, respectively. The BCS were performed in 24.5% (130) patients versus 75.5% (400) of mastectomies. The mean follow up was 36.4(0.16-80.2) months. There were no differences in local disease free-survival 59 (95%CI 58-61) versus 60 (95%CI 57-60); p=0.4 and overall survival 56.2 (95%CI 52-60) versus 59.3(95%CI 53-65); p= 0.24 for mastectomy and BCS. The disease free survival was lower at mastectomy group 51.4 (95%CI 49-53) versus 56,8 (95%CI 53-59); p=0.01. Logistic regression models were significant only for cancer stage both patterns, although the results were better for masses, particularly when kinetic assessments were included (LR 12.8; p = 0.005)

CONCLUSION:

In our population, the BCS does not affect the overall and local disease-free survival rates, which seems to be safe to perform in patients who desire to conserve the breast after neoadjuvant treatment.

Citation Format: Boufelli G, Mota BS, Franca FC, Doria MT, Maesaka JY, Ricci MD, Piato JRM, Rocha FBC, Giribela AHG, Gonçalves R, Masili-Oku S, Mano MS, Chala LF, Thompson BM, Baracat EC, Filassi JR. Does conservative surgery treatment for locally advanced breast cancer safe after neoadjuvant treatment? [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-12-11.

The Relation Between Parent Personality Traits and Children Psychopathology: A Pilot Study

Introduction

Personality plays a crucial role in a person's behavior, emotions and cognitive patterns and shows an important relationship with several variables such as marital status, mental disorders or parenting models. However, little is known about the relation between the parental Big Five personality traits (Neuroticism, Extraversion, Openness, Conscientiousness and Agreeableness) and children psychopathology regardless of the diagnostic of their offspring.

Objectives

To analyze the correlation between parents’ Big Five personality traits and their children categorical diagnosis and psychopathology score.

Methods

The authors recruited 105 children in the outpatient unit of the child and adolescent psychiatry department of the pediatric hospital of Coimbra and their 117 parents. Parents were assessed using the Portuguese version of Neo Five-Factor Inventory and children psychopathology scores were rated by child and adolescent psychiatrists using the Brief Psychiatric Rating Scale for Children.

Results

Forty-nine children (46.7%) were male and 56 (53.3%) were female, with a mean age of 12.5 ± 3.2 and 13.6 ± 2.9, respectively. Twenty parents (17.1%) were male and 97 (82.9%) were female, with a mean age of 45.8 ± 4.1 and 41.2 ± 5.4, respectively. After excluding children diagnosed with Schizophrenia, bipolar disorder, autism spectrum disorders and intellectual developmental disorder, Pearson's correlation coefficients were significant between: parents’ neuroticism and children Uncooperativeness (0.211), Manipulativeness (0.238), Hallucinations (0.257), Sleep difficulties (0.296) and Disorientation (0.204); parents’ agreeableness and children hostility (−0.228); and parent's conscientiousness and children disorientation (−0.231), all P < 0.05.

Conclusions

These preliminary results suggest that parental personality traits may influence psychopathological outcomes in their children. Data are still being collected to clarify the nature of this relationship.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Clinical Features, Imaging Characteristics, and Long-term Outcome of Dogs with Cranial Meningocele or Meningoencephalocele

Background

The term meningoencephalocele (MEC) describes a herniation of cerebral tissue and meninges through a defect in the cranium, whereas a meningocele (MC) is a herniation of the meninges alone.

Hypothesis/Objectives

To describe the clinical features, magnetic resonance imaging (MRI) characteristics, and outcomes of dogs with cranial MC and MEC.

Animals

Twenty‐two client‐owned dogs diagnosed with cranial MC or MEC.

Methods

Multicentric retrospective descriptive study. Clinical records of 13 institutions were reviewed. Signalment, clinical history, neurologic findings and MRI characteristics as well as treatment and outcome were recorded and evaluated.

Results

Most affected dogs were presented at a young age (median, 6.5 months; range, 1 month – 8 years). The most common presenting complaints were seizures and behavioral abnormalities. Intranasal MEC was more common than parietal MC. Magnetic resonance imaging identified meningeal enhancement of the protruded tissue in 77% of the cases. Porencephaly was seen in all cases with parietal MC. Cerebrospinal fluid (CSF) analysis identified mild abnormalities in 4 of 11 cases. Surgery was not performed in any affected dog. Seventeen patients were treated medically, and seizures were adequately controlled with anti‐epileptic drugs in 10 dogs. Dogs with intranasal MEC and mild neurologic signs had a fair prognosis with medical treatment.

Conclusion and clinical importance

Although uncommon, MC and MEC should be considered as a differential diagnosis in young dogs presenting with seizures or alterations in behavior. Medical treatment is a valid option with a fair prognosis when the neurologic signs are mild.

Proactive therapeutic drug monitoring of infliximab: a comparative study of a new point-of-care quantitative test with two established ELISA assays

BACKGROUND

Therapeutic drug monitoring is a powerful strategy known to improve the clinical outcomes and to optimise the healthcare resources in the treatment of autoimmune diseases. Currently, most of the methods commercially available for the quantification of infliximab (IFX) are ELISA-based, with a turnaround time of approximately 8 h, and delaying the target dosage adjustment to the following infusion.

AIM

To validate the first point-of-care IFX quantification device available in the market - the Quantum Blue Infliximab assay (Buhlmann, Schonenbuch, Switzerland) - by comparing it with two well-established methods.

METHODS

The three methods were used to assay the IFX concentration of spiked samples and of the serum of 299 inflammatory bowel diseases (IBD) patients undergoing IFX therapy.

RESULTS

The point-of-care assay had an average IFX recovery of 92%, being the most precise among the tested methods. The Intraclass Correlation Coefficients of the point-of-care IFX assay vs. the two ELISA-based established methods were 0.889 and 0.939. Moreover, the accuracy of the point-of-care IFX compared with each of the two reference methods was 77% and 83%, and the kappa statistics revealed a substantial agreement (0.648 and 0.738).

CONCLUSIONS

The Quantum Blue IFX assay can successfully replace the commonly used ELISA-based IFX quantification kits. This point-of-care IFX assay is able to deliver the results within 15 min makes it ideal for an immediate target concentration adjusted dosing. Moreover, it is a user-friendly desktop device that does not require specific laboratory facilities or highly specialised personnel.

Cytomegalic hepatitis in a patient receiving omalizumab

Cytomegalovirus is a double stranded DNA virus that can be present in nearly all organs and body fluids. The primary infection is usually asymptomatic in the immunocompetent host and it is common among adolescents and young adults. The symptomatic form appears, in the majority of cases, as a mononucleosis syndrome with full recovery without specific treatment. We report a case of a 25 years old woman who presented with hepatitis due to CMV infection and history of omalizumab administration one month earlier. This recombinant monoclonal antibody is used to control refractory asthma and chronic spontaneous urticarial as it inhibits human IgE. Despite that, the long course of the disease lead us to initiate treatment with valganciclovir. The improvement after that was rapid and complete.

Unravelling the relationship between protein sequence and low-complexity regions entropies: Interactome implications

Low-complexity regions are sub-sequences of biased composition in a protein sequence. The influence of these regions over protein evolution, specific functions and highly interactive capacities is well known. Although protein sequence entropy has been largely studied, its relationship with low-complexity regions and the subsequent effects on protein function remains unclear. In this work we propose a theoretical and empirical model integrating the sequence entropy with local complexity parameters. Our results indicate that the protein sequence entropy is related with the protein length, the entropies inside and outside the low-complexity regions as well as their number and average size. We found a small but significant increment in the sequence entropy of hubs proteins. In agreement with our theoretical model, this increment is highly dependent of the balance between the increment of protein length and average size of the low-complexity regions. Finally, our models and proteins analysis provide evidence supporting that modifications in the average size is more relevant in hubs proteins than changes in the number of low-complexity regions.

Bioaccumulation of animal adenoviruses in the pink shrimp

Adenoviruses are among the most promising viral markers of fecal contamination. They are frequently found in the water, sediment and soil of regions impacted by human activity. Studies of the bioaccumulation of enteric viruses in shrimp are scarce. The cities located in the northern coast of the lake systems in Southern Brazil have high urbanization and intensive farming rates, and poor sewage collection and treatment. One hundred (n = 100) Farfantepenaeus paulensis pink-shrimp specimens and 48 water samples were collected from coastal lagoons between June 2012 and May 2013. Water samples were concentrated and the shrimp, mashed. After DNA extraction, samples were analyzed by real time polymerase chain reaction (qPCR) in order to detect and quantify viral genomes. Thirty-five percent of shrimp samples were positive for contamination, predominantly by avian adenoviruses. A total of 91.7% of water samples contained adenoviruses DNA, with the human form being the most frequent. Our results provided evidence of significant bioaccumulation of adenoviruses in shrimp, showing the extent of the impact of fecal pollution on aquatic ecosystems.

Novel Anisotropic Magnetoelectric Effect on δ-FeO(OH)/P(VDF-TrFE) Multiferroic Composites

The past decade has witnessed increased research effort on multiphase magnetoelectric (ME) composites. In this scope, this paper presents the application of novel materials for the development of anisotropic magnetoelectric sensors based on δ-FeO(OH)/P(VDF-TrFE) composites. The composite is able to precisely determine the amplitude and direction of the magnetic field. A new ME effect is reported in this study, as it emerges from the magnetic rotation of the δ-FeO(OH) nanosheets inside the piezoelectric P(VDF-TrFE) polymer matrix. δ-FeO(OH)/P(VDF-TrFE) composites with 1, 5, 10, and 20 δ-FeO(OH) filler weight percentage in three δ-FeO(OH) alignment states (random, transversal, and longitudinal) have been developed. Results have shown that the modulus of the piezoelectric response (10-24 pC·N(-1)) is stable at least up to three months, the shape and magnetization maximum value (3 emu·g(-1)) is dependent on δ-FeO(OH) content, and the obtained ME voltage coefficient, with a maximum of ∼0.4 mV·cm(-1)·Oe(-1), is dependent on the incident magnetic field direction and intensity. In this way, the produced materials are suitable for innovative anisotropic sensor and actuator applications.

Magnetoelectric CoFe2O4/polyvinylidene fluoride electrospun nanofibres

Magnetoelectric 0-1 composites comprising CoFe2O4 (CFO) nanoparticles in a polyvinylidene fluoride (PVDF) polymer-fibre matrix have been prepared by electrospinning. The average diameter of the electrospun composite fibres is ∼325 nm, independent of the nanoparticle content, and the amount of the crystalline polar β phase is strongly enhanced when compared to pure PVDF polymer fibres. The piezoelectric response of these electroactive nanofibres is modified by an applied magnetic field, thus evidencing the magnetoelectric character of the CFO/PVDF 0-1 composites.

Magnetic resonance imaging of the lentiform nuclei in dogs with portosystemic shunts

OBJECTIVES

To develop and evaluate a method to quantify the T1-weighted magnetic resonance imaging signal intensity of the lentiform nuclei in dogs, and to determine if there is any significant difference in this signal intensity between dogs with portosystemic shunts and a control group.

MATERIALS AND METHODS

A retrospective blinded study was performed to investigate the reliability and use of a quantitative method for assessing the T1-weighted magnetic resonance imaging signal intensity of the lentiform nuclei in dogs with and without portosystemic shunts. The lentiform nuclei index (mean lentiform nucleus signal intensity/mean white matter signal intensity) was calculated for nine dogs with portosystemic shunts and a control group of 14 dogs.

RESULTS

The intra- and inter-observer intraclass correlation coefficients were considered excellent (>0 · 75), suggesting that the lentiform nuclei index is a reliable method. The dogs with portosystemic shunts had a higher lentiform nuclei index than the control group (P = 0 · 0127).

CLINICAL SIGNIFICANCE

This method of quantifying the T1-weighted magnetic resonance imaging signal intensity of the lentiform nuclei was reliable and showed that dogs with portosystemic shunts tend to have increased signal intensity. Further prospective studies are necessary to investigate the clinical significance and applications of these findings.

Development of magnetoelectric CoFe2O4 /poly(vinylidene fluoride) microspheres

Magnetoelectric microspheres based on piezoelectric poly(vinylidene fluoride) (PVDF) and magnetostrictive CoFe₂O₄ (CFO), a novel morphology for polymer-based ME materials, have been developed by an electrospray process.

Selected anthropometric variables and aerobic fitness as predictors of cardiovascular disease risk in children

The aim of this study was to assess the suitability of body mass index, waist circumference, waist-to-height ratio and aerobic fitness as predictors of cardiovascular risk factor clustering in children. A cross-sectional study was conducted with 290 school boys and girls from 6 to 10 years old, randomly selected. Blood was collected after a 12-hour fasting period. Blood pressure, waist circumference (WC), height and weight were evaluated according to international standards. Aerobic fitness (AF) was assessed by the 20-metre shuttle-run test. Clustering was considered when three of these factors were present: high systolic or diastolic blood pressure, high low-density lipoprotein (LDL) cholesterol, high triglycerides, high plasma glucose, high insulin concentrations and low high-density lipoprotein (HDL) cholesterol. A ROC curve identified the cut-off points of body mass index (BMI), WC, waist-to-height ratio (WHtR) and AF as predictors of risk factor clustering. BMI, WC and WHR resulted in significant areas under the ROC curves, which was not observed for AF. The anthropometric variables were good predictors of cardiovascular risk factor clustering in both sexes, whereas aerobic fitness should not be used to identify cardiovascular risk factor clustering in these children.

Corpus callosal abnormalities in dogs

BACKGROUND

Corpus callosal abnormalities (CCA) in dogs have been only sporadically reported and are poorly characterized.

HYPOTHESIS/OBJECTIVES

To describe the clinical presentation and magnetic resonance imaging (MRI) characteristics of dogs with CCA.

ANIMALS

Fifteen client-owned dogs.

METHODS

Retrospective study. Records of the contributing institutions were reviewed to identify dogs diagnosed with malformations affecting the corpus callosum (CC); cases in which the CCA was thought to be secondary were excluded.

RESULTS

The most represented breeds were Staffordshire Bull Terriers (5/15) and Miniature Schnauzers (3/15; n = 3, 20%) and the mean age at time of presentation of 19 months (range 3-81 months). The clinical signs most commonly reported were adipsia/hypodipsia with associated hypernatremia (12/15), tremors (6/15), and seizures (6/15). Review of the MR images revealed that 10 dogs had absence of the rostral CC and hypoplasia of the caudal portion, 4 dogs had a diffusely hypoplastic and dysplastic CC, and 1 dog had a diffusely hypoplastic CC. In 14 cases, there was abnormal cortical development with fusion of the ventral frontal lobes and part of the diencephalon, indicating lobar holoprosencephaly.

CONCLUSIONS AND CLINICAL IMPORTANCE

Previous literature has mainly associated CCA with adipsia and only 12 of 15 dogs in the current series demonstrated this abnormality. There are different degrees of the malformation but in 10 dogs the rostral portion of the CC is most severely affected. Fourteen dogs have simultaneous fusion of the midline structures rostral to the CC; this region has several structures involved in thirst regulation and might explain this derangement.

Electrosprayed poly(vinylidene fluoride) microparticles for tissue engineering applications

Poly(vinylidene fluoride) microparticles with diameters between 0.80 and 5.50 μm were produced. Cell viability shows their suitability for tissue engineering.

Effect of zeolite content in the electrical, mechanical and thermal degradation response of poly(vinylidene fluoride)/NaY zeolite composites

Polymer based composites of a-PVDF doped with different NaY zeolite (Na53Al53Si139O384) content were investigated. A good dispersion of NaY zeolite within the polymer matrix is achieved. The introduction of NaY nanoparticles enhance the storage modulus and the dielectric constant at room temperature. The dielectric constant at room temperature increases up to the value of 500 for the 32 wt% composite, at 1 kHz. The increase of the dielectric constant is mainly attributed to interfacial polarization effects. For increasing zeolite content, the nanocomposite conductivity shows two conducting regimes separted by the so called breaking voltage, which is associated to an intrazeolite charge transport. Thermogravimetric results show that the introduction of zeolites affects the thermal degradation of the polymer for low zeolite contents and also indicate the presence of water that also plays an important role in the electrical response of the materials.