bluuebunny/crossref_metadata_2025 huggingface dataset:
How Does Sampling Methodology Influence Molecular Detection and Isolation Success in Influenza A Virus Field Studies?
Authors: Latorre-Margalef Neus , Avril Alexis , Tolf Conny , Olsen Björn , Waldenström Jonas
Published: December 2015

Wild waterfowl are important reservoir hosts for influenza A virus (IAV) and a potential source of spillover infections in other hosts, including poultry and swine. The emergence of highly pathogenic avian influenza (HPAI) viruses, such as H5N1 and H5N8, and subsequent spread along migratory flyways prompted the initiation of several programs in Europe, North America, and Africa to monitor circulation of HPAI and low-pathogenicity precursor viruses (low-pathogenicity avian influenza [LPAI] viruses). Given the costs of maintaining such programs, it is essential to establish best practice for field methodologies to provide robust data for epidemiological interpretation. Here, we use long-term surveillance data from a single site to evaluate the influence of a number of parameters on virus detection and isolation of LPAI viruses. A total of 26,586 samples (oropharyngeal, fecal, and cloacal) collected from wild mallards were screened by real-time PCR, and positive samples were subjected to isolation in embryonated chicken eggs. The LPAI virus detection rate was influenced by the sample type: cloacal/fecal samples showed a consistently higher detection rate and lower cycle threshold (

C
t

) value than oropharyngeal samples. Molecular detection was more sensitive than isolation, and virus isolation success was proportional to the number of RNA copies in the sample. Interestingly, for a given

C
t

value, the isolation success was lower in samples from adult birds than in those from juveniles. Comparing the results of specific real-time reverse transcriptase (RRT)-PCRs and of isolation, it was clear that coinfections were common in the investigated birds. The effects of sample type and detection methods warrant some caution in interpretation of the surveillance data.
Diguanylate Cyclases AdrA and STM1987 Regulate Salmonella enterica Exopolysaccharide Production during Plant Colonization in an Environment-Dependent Manner
Authors: Cowles Kimberly N. , Willis David K. , Engel Tyler N. , Jones Jeffrey B. , Barak Jeri D.
Published: December 2015

Increasing evidence indicates that despite exposure to harsh environmental stresses,
Salmonella enterica
successfully persists on plants, utilizing fresh produce as a vector to animal hosts. Among the important
S. enterica
plant colonization factors are those involved in biofilm formation.
S. enterica
biofilm formation is controlled by the signaling molecule cyclic di-GMP and represents a sessile lifestyle on surfaces that protects the bacterium from environmental factors. Thus, the transition from a motile, planktonic lifestyle to a sessile lifestyle may represent a vital step in bacterial success. This study examined the mechanisms of
S. enterica
plant colonization, including the role of diguanylate cyclases (DGCs) and phosphodiesterases (PDEs), the enzymes involved in cyclic di-GMP metabolism. We found that two biofilm components, cellulose and curli, are differentially required at distinct stages in root colonization and that the DGC STM1987 regulates cellulose production in this environment independent of AdrA, the DGC that controls the majority of
in vitro
cellulose production. In addition, we identified a new function for AdrA in the transcriptional regulation of colanic acid and demonstrated that
adrA
and colanic acid biosynthesis are associated with
S. enterica
desiccation tolerance on the leaf surface. Finally, two PDEs with known roles in motility, STM1344 and STM1697, had competitive defects in the phyllosphere, suggesting that regulation of motility is crucial for
S. enterica
survival in this niche. Our results indicate that specific conditions influence the contribution of individual DGCs and PDEs to bacterial success, perhaps reflective of differential responses to environmental stimuli.
Deterministic Assembly of Complex Bacterial Communities in Guts of Germ-Free Cockroaches
Authors: Mikaelyan Aram , Thompson Claire L. , Hofer Markus J. , Brune Andreas
Published: December 2015

The gut microbiota of termites plays important roles in the symbiotic digestion of lignocellulose. However, the factors shaping the microbial community structure remain poorly understood. Because termites cannot be raised under axenic conditions, we established the closely related cockroach
Shelfordella lateralis
as a germ-free model to study microbial community assembly and host-microbe interactions. In this study, we determined the composition of the bacterial assemblages in cockroaches inoculated with the gut microbiota of termites and mice using pyrosequencing analysis of their 16S rRNA genes. Although the composition of the xenobiotic communities was influenced by the lineages present in the foreign inocula, their structure resembled that of conventional cockroaches. Bacterial taxa abundant in conventional cockroaches but rare in the foreign inocula, such as
Dysgonomonas
and
Parabacteroides
spp., were selectively enriched in the xenobiotic communities. Donor-specific taxa, such as endomicrobia or spirochete lineages restricted to the gut microbiota of termites, however, either were unable to colonize germ-free cockroaches or formed only small populations. The exposure of xenobiotic cockroaches to conventional adults restored their normal microbiota, which indicated that autochthonous lineages outcompete foreign ones. Our results provide experimental proof that the assembly of a complex gut microbiota in insects is deterministic.
Neisseria elongatasubspelongatainfective endocarditis following endurance exercise
Authors: Jenkins Joanne May , Fife Amanda , Baghai Max , Dworakowski Rafal
Published: December 2015

A 31-year-old Argentinian woman presented with a 3-week history of fever, night sweats, myalgia and lethargy following a work trip to Uganda where she ran a marathon. Malarial screens were negative but C reactive protein, erythrocyte sedimentation rate and neutrophil count were raised and she was anaemic. A new pansystolic murmur was heard over the mitral valve and the transthoracic echocardiogram showed a large vegetation (>1 cm) with at least moderate mitral regurgitation. Blood cultures grewNeisseria elongata,subspelongatatreated initially with ceftriaxone then oral ciprofloxacin to complete 4 weeks of treatment. CT scan revealed a wedge-shaped area of low attenuation in the spleen in keeping with a splenic infarct. Seven days postadmission, the patient underwent a successful mitral valve repair. Recovery was complicated by a likely embolic infarct in the right frontal lobe, but the patient was discharged 12 days postoperative with no neurological sequelae.
Hyponatraemia in patients with multiple myeloma
Authors: Mirvis Eitan , De-Silva Dunnya , Mehta Atul
Published: December 2015

Hyponatraemia is the most common electrolyte disturbance encountered in clinical practice. Several causes of hyponatraemia are recognised and in many patients the aetiology may be multifactorial. An important cause is water intoxication and this is often iatrogenic. We present three patients, all of whom suffered from multiple myeloma, who illustrate different aspects of hyponatraemia, its causes and management.
The effect of metformin on cardiovascular risk profile in patients without diabetes presenting with acute myocardial infarction: data from the Glycometabolic Intervention as adjunct to Primary Coronary Intervention in ST Elevation Myocardial Infarction (GIPS-III) trial
Authors: Lexis Chris P H , van der Horst-Schrivers Anouk N A , Lipsic Erik , Valente Mattia A E , Muller Kobold Anneke C , de Boer Rudolf A , van Veldhuisen Dirk J , van der Harst Pim , van der Horst Iwan C C
Published: December 2015

Objective

In patients with diabetes mellitus, metformin treatment is associated with reduced mortality and attenuation of cardiovascular risk. As a subanalysis of the Glycometabolic Intervention as adjunct to Primary Coronary Intervention in ST Elevation Myocardial Infarction (GIPS-III) study, we evaluated whether metformin treatment in patients with ST-segment elevation myocardial infarction (STEMI) without diabetes improves the cardiovascular risk profile.

Methods

A total of 379 patients, without known diabetes, presenting with STEMI were randomly allocated to receive metformin 500 mg twice daily or placebo for 4 months.

Results

After 4 months, the cardiovascular risk profile of patients receiving metformin (n=172) was improved compared with placebo (n=174); glycated hemoglobin (5.83% (95% CI 5.79% to 5.87%) vs 5.89% (95% CI 5.85% to 5.92%); 40.2 mmol/mol (95% CI 39.8 to 40.6) vs 40.9 mmol/mol (40.4 to 41.2), p=0.049); total cholesterol (3.85 mmol/L (95% CI 3.73 to 3.97) vs 4.02 mmol/L (95% CI 3.90 to 4.14), p=0.045); low-density lipoprotein cholesterol (2.10 mmol/L (95% CI 1.99 to 2.20) vs 2.3 mmol/L (95% CI 2.20 to 2.40), p=0.007); body weight (83.8 kg (95% CI 83.0 to 84.7) vs 85.2 kg (95% CI 84.4 to 86.1), p=0.024); body mass index (26.8 kg/m2(95% CI 26.5 to 27.0) vs 27.2 kg/m2(95% CI 27.0 to 27.5), p=0.014). Levels of fasting glucose, postchallenge glucose, insulin, high-density lipoprotein cholesterol, and blood pressure were similar in both groups.

Conclusions

Among patients with STEMI without diabetes, treatment with metformin for 4 months resulted in a modest improvement of the cardiovascular risk profile compared with placebo.

Trial register number

NCT01217307.
Moxibustion as an adjuvant for benign prostatic hyperplasia with lower urinary tract symptoms: a protocol for a parallel-group, randomised, controlled pilot trial
Authors: Lee Hye-Yoon , Nam Jong-Kil , Lee Sang-Don , Lee Dong-Hoon , Han Ji-Yeon , Yun Young-Ju , Lee Ji-Hye , Park Hye-lim , Park Seong-Ha , Kwon Jung-Nam
Published: December 2015

Introduction

This study aims to explore the feasibility of using moxibustion as a supplementary intervention and to assess the sample size for verifying the effectiveness and safety of integrative treatment involving moxibustion compared with conventional treatment for patients with benign prostatic hyperplasia accompanying moderate to severe lower urinary tract symptoms.

Methods and analysis

A total of 60 patients diagnosed with benign prostatic hyperplasia by a urologist based on prostate size, prostate-specific antigen and clinical symptoms will participate of their own free will; urologists will monitor the patients and evaluate their symptoms. The patients will be randomised to either a conventional group or an integrative group with a 1:1 allocation according to computer-generated random numbers concealed in opaque, sealed, sequentially numbered envelopes. Watchful waiting or oral medication including α blocker, 5α-reductase inhibitors or antimuscarinic drugs will be offered as conventional treatment. Integrative treatment will include moxibustion therapy in addition to the conventional treatment. The moxibustion therapy will be conducted twice a week for 4 weeks on the bilateral acupoints SP6, LR3 and CV4 by a qualified Korean medical doctor. The primary outcome will be the International Prostate Symptom Score (IPSS) after eight sessions. The secondary outcomes will be the post-void residual urine volume, the maximum urinary flow rate, IPSS, the results of a Short-Form 36-Question Health Survey after 12 weeks, and the patients’ global impression of changes at each visit.

Ethics and dissemination

Written informed consent will be obtained from all participants. This study was approved by the institutional review boards of both Pusan National University Yangsan Hospital and Pusan National University Korean Medicine Hospital. The trial results will be disseminated through open-access journals and conferences.

Trial registration number

NCT02051036.
Association of GDF1 rs4808863 with fetal congenital heart defects: a case–control study
Authors: Zhang Juan , Wu Qingqing , Wang Li , Li Xiaofei , Ma Yuqing , Yao Ling
Published: December 2015

Background

Congenital heart defects (CHDs) are the most common fetal defects and the most important cause of child mortality and morbidity.

Objective

To investigate the association between growth/differentiation factor 1 (GDF1) polymorphisms and fetal CHDs, by evaluating the association of GDF1 rs4808863 with fetal CHDs.

Design

A case–control study.

Setting

Beijing, China.

Participants

We selected 124 fetuses with a CHD and a normal karyotype and normal array-based comparative genomic hybridisation analysis and compared them with 124 normal fetuses matched for gestational age and sex. Fetuses with a CHD, from 20 to 32 weeks of gestation were included. Fetuses with any chromosomal abnormalities, and fetuses from multiple pregnancies and those carried by pregnant women with chronic diseases, were excluded from this research. DNA extraction and genotyping were carried out for all cases to investigate the genotype distributions of GDF1 rs4808863.

Results

A significant difference was noted for the CT phenotype of GDF1 rs4808863 between the controls and the fetuses with CHDs using homozygote and heterozygote comparisons. The minor allele (T allele) of GDF1 rs4808863 was associated with an increased risk of CHD (p<0.05). A statistically significant difference between controls and fetuses with CHDs was noted in a comparison with the mutation genotype CT+TT and wild-type genotype CC (p<0.05) using dominant modal analysis. After stratification analysis, the CT phenotype, the minor allele (T allele) and the mutation genotype CT+TT of the rs4808863 polymorphism were associated with atrioventricular septal defect (AVSD), left ventricular outflow tract obstruction (LVOTO) and left–right laterality defects (p<0.05).

Conclusions

Our results suggest that the GDF1 rs4808863 polymorphism contributes to an increased risk of fetal CHDs, especially the subtypes of AVSD, LVOTO and left–right laterality defects.
To what extent are surgery and invasive procedures effective beyond a placebo response? A systematic review with meta-analysis of randomised, sham controlled trials
Authors: Jonas Wayne B , Crawford Cindy , Colloca Luana , Kaptchuk Ted J , Moseley Bruce , Miller Franklin G , Kriston Levente , Linde Klaus , Meissner Karin
Published: December 2015

Objectives

To assess the quantity and quality of randomised, sham-controlled studies of surgery and invasive procedures and estimate the treatment-specific and non-specific effects of those procedures.

Design

Systematic review and meta-analysis.

Data sources

We searched PubMed, EMBASE, CINAHL, CENTRAL (Cochrane Library), PILOTS, PsycInfo, DoD Biomedical Research, clinicaltrials.gov, NLM catalog and NIH Grantee Publications Database from their inception through January 2015.

Study selection

We included randomised controlled trials of surgery and invasive procedures that penetrated the skin or an orifice and had a parallel sham procedure for comparison.

Data extraction and analysis

Three authors independently extracted data and assessed risk of bias. Studies reporting continuous outcomes were pooled and the standardised mean difference (SMD) with 95% CIs was calculated using a random effects model for difference between true and sham groups.

Results

55 studies (3574 patients) were identified meeting inclusion criteria; 39 provided sufficient data for inclusion in the main analysis (2902 patients). The overall SMD of the continuous primary outcome between treatment/sham-control groups was 0.34 (95% CI 0.20 to 0.49; p<0.00001; I2=67%). The SMD for surgery versus sham surgery was non-significant for pain-related conditions (n=15, SMD=0.13, p=0.08), marginally significant for studies on weight loss (n=10, SMD=0.52, p=0.05) and significant for gastroesophageal reflux disorder (GERD) studies (n=5, SMD=0.65, p<0.001) and for other conditions (n=8, SMD=0.44, p=0.004). Mean improvement in sham groups relative to active treatment was larger in pain-related conditions (78%) and obesity (71%) than in GERD (57%) and other conditions (57%), and was smaller in classical-surgery trials (21%) than in endoscopic trials (73%) and those using percutaneous procedures (64%).

Conclusions

The non-specific effects of surgery and other invasive procedures are generally large. Particularly in the field of pain-related conditions, more evidence from randomised placebo-controlled trials is needed to avoid continuation of ineffective treatments.
Predictors of lower extremity injuries in team sports (PROFITS-study): a study protocol
Authors: Pasanen Kati , Rossi Marko T , Parkkari Jari , Heinonen Ari , Steffen Kathrin , Myklebust Grethe , Krosshaug Tron , Vasankari Tommi , Kannus Pekka , Avela Janne , Kulmala Juha-Pekka , Perttunen Jarmo , Kujala Urho M , Bahr Roald
Published: December 2015

Introduction

Several intrinsic risk factors for lower extremity injuries have been proposed, including lack of proper knee and body control during landings and cutting manoeuvres, low muscular strength, reduced balance and increased ligament laxity, but there are still many unanswered questions. The overall aim of this research project is to investigate anatomical, biomechanical, neuromuscular, genetic and demographic risk factors for traumatic non-contact lower extremity injuries in young team sport athletes. Furthermore, the research project aims to develop clinically oriented screening tools for predicting future injury risk.

Methods

Young female and male players (n=508) from nine basketball teams, nine floorball teams, three ice hockey teams, and one volleyball team accepted the invitation to participate in this four-and-half-year prospective follow-up study. The players entered the study either in 2011, 2012 or 2013, and gave blood samples, performed physical tests and completed the baseline questionnaires. Following the start of screening tests, the players will be followed for sports injuries through December 2015. The primary outcome is a traumatic non-contact lower extremity injury. The secondary outcomes are other sports-related injuries. Injury risk is examined on the basis of anatomical, biomechanical, neuromuscular, genetic and other baseline factors. Univariate and multivariate regression models will be used to investigate association between investigated parameters and injury risk.
Development of a cross-cultural deprivation index in five European countries
Authors: Guillaume Elodie , Pornet Carole , Dejardin Olivier , Launay Ludivine , Lillini Roberto , Vercelli Marina , Marí-Dell'Olmo Marc , Fernández Fontelo Amanda , Borrell Carme , Ribeiro Ana Isabel , Pina Maria Fatima de , Mayer Alexandra , Delpierre Cyrille , Rachet Bernard , Launoy Guy
Published: December 2015

Background

Despite a concerted policy effort in Europe, social inequalities in health are a persistent problem. Developing a standardised measure of socioeconomic level across Europe will improve the understanding of the underlying mechanisms and causes of inequalities. This will facilitate developing, implementing and assessing new and more effective policies, and will improve the comparability and reproducibility of health inequality studies among countries. This paper presents the extension of the European Deprivation Index (EDI), a standardised measure first developed in France, to four other European countries—Italy, Portugal, Spain and England, using available 2001 and 1999 national census data.

Methods and results

The method previously tested and validated to construct the French EDI was used: first, an individual indicator for relative deprivation was constructed, defined by the minimal number of unmet fundamental needs associated with both objective (income) poverty and subjective poverty. Second, variables available at both individual (European survey) and aggregate (census) levels were identified. Third, an ecological deprivation index was constructed by selecting the set of weighted variables from the second step that best correlated with the individual deprivation indicator.

Conclusions

For each country, the EDI is a weighted combination of aggregated variables from the national census that are most highly correlated with a country-specific individual deprivation indicator. This tool will improve both the historical and international comparability of studies, our understanding of the mechanisms underlying social inequalities in health and implementation of intervention to tackle social inequalities in health.
Effect of immunosuppressive therapy on interferon γ release assay for latent tuberculosis screening in patients with autoimmune diseases: a systematic review and meta-analysis
Authors: Wong Sunny H , Gao Qinyan , Tsoi Kelvin K F , Wu William K K , Tam Lai-shan , Lee Nelson , Chan Francis K L , Wu Justin C Y , Sung Joseph J Y , Ng Siew C
Published: December 2015

Objective

Interferon γ release assay (IGRA) is commonly used to diagnose latent TB infection (LTBI). Immunosuppressive therapy may affect its performance but data are conflicting. We aimed to determine the effect of immunosuppressive therapy on the performance of IGRA in patients with autoimmune diseases.

Methods

We searched PubMed, MEDLINE, EMBASE and the Cochrane Library up to December 2014. We included studies that reported the IGRA results in patients with autoimmune disease with or without immunosuppressive therapy. The pooled effect of immunosuppressive therapy on IGRA was estimated using a Peto fixed-effects model.

Results

We included 17 studies with 3197 participants in the meta-analysis. Among the subjects, 71.5% were taking immunosuppressive therapy and 56.7% had received Bacillus Calmette–Guérin vaccination. Compared with patients not on immunosuppressants, patients receiving immunosuppressive therapy were less likely to have a positive IGRA result (OR 0.66, 95% CI 0.53 to 0.83, I2=23%), especially patients receiving anti-tumour necrosis factor (anti-TNF) treatment (OR 0.50, 95% CI 0.29 to 0.88). The use of immunosuppressive therapy was also associated with a lower rate of positive tuberculin skin test result (OR 0.51, 95% CI 0.42 to 0.61).

Conclusions

Our meta-analysis showed that IGRA results are negatively affected by immunosuppressive therapy. IGRA alone may not be sufficiently sensitive to diagnose LTBI in patients on immunosuppressive therapy. Patients should preferably be screened for LTBI before initiation of immunosuppressive therapy, especially before anti-TNF therapy.
Late Quaternary glaciations in the eastern Mediterranean
Authors: Sarıkaya Mehmet Akif , Çiner Attila
Published: December 2015

Fourteen mountains in the eastern Mediterranean, between southern Turkey and Lebanon, are high enough to support Quaternary valley glaciers or ice caps. The timing of the glaciations has been established mainly by cosmogenic dating. We re-evaluated the dated sites and recalculated some of the published cosmogenic ages using up-to-date production rates. The oldest geochronological records reported from the region belong to glaciations before the globally defined Last Glacial Maximum (LGM). These glaciers probably developed during the beginning of the last glaciation (Marine Isotope Stage (MIS) 4; around 71 ka) and stopped advancing at the end of MIS 3 (at 29–35 ka). Later, glaciers expanded and reached their most extensive positions during MIS 2 (after 29 ka). This locally occurred between 21.5 and 18.5 ka, which was synchronous with the global LGM. After the LGM, glaciers started to retreat to less extensive positions and deposited their moraines ∼16 ka during the late-glacial. Younger Dryas (∼12 ka) advances have also been reported from a few mountains. Rare early Holocene glaciations were dated to 8.5 ka in the interior regions. Late Holocene (1–4 ka) and Little Ice Age advances have also been observed on mountains higher than 3500 m.
Deciphering multiple controls on reservoir quality and inhibition of quartz cement in a complex reservoir: Ordovician glacial sandstones, Illizi Basin, Algeria
Authors: Wells Martin , Hirst Philip , Bouch Jon , Whear Emma , Clark Nigel
Published: December 2015

Late Ordovician (
c.
445 Ma) glacial sandstones form important gas reservoirs in the Illizi Basin, SW Algeria. These reservoirs have a high degree of depositional and diagenetic complexity, such that understanding and predicting reservoir quality (RQ) presents a major challenge to their economic development. Porosity is typically 1–10%, but reaches up to 15% and permeability is typically <10
−15
m
2
(<1 mD), but locally reaches >10
−13
m
2
(>100 mD). The key questions addressed herein concern the development and distribution of this RQ variability, specifically why has good RQ been locally preserved?

Primary depositional fabric exerts a strong control on RQ. Muddy sandstones are either highly compacted or pervasively cemented by quartz and microporous illite, and have very poor RQ. Only fine- to medium-grained, moderately well sorted, clean sandstones can contain good RQ, but texturally and mineralogically similar sandstones span a wide range of porosity and permeability. This range is primarily driven by the degree of quartz cementation, with incomplete cementation resulting in the best RQ. Quartz overgrowths in incompletely cemented clean sandstones are patchy and non-luminescent in scanning electron microscopy with cathodoluminescence (SEM-CL), possibly indicating slow growth rates. There is tentative evidence to link incomplete quartz cementation with oil charging of the reservoir. An alternative or additional explanation of RQ preservation may be related to limited silica supply in the centres of the thickest, stacked, clean sandstones, where the better RQ tends to reside.

The results of this study imply that sustained high-energy depositional processes, coupled with an early oil charge, are prerequisites for retaining the best RQ. This has important implications for the exploration and development of Late Ordovician glacial sandstones in the Illizi Basin, and potentially similar plays elsewhere.
Temperature Changes during Pulse Charging of Lead Acid Battery in Oxygen Cycle Regime
Authors: Křivík Petr
Published: December 2015

The paper deals with changes in temperature of lead acid battery cell during discharge and pulse charging in oxygen cycle regime. It is studied the effect of different pulse charging modes on increase of cell temperature and influence of oxygen cycle on temperature changes of the lead acid battery cell.
Investigation of Vanadium Oxidation States in Sulfuric Acid by Voltammetry and Electrochemical Impedance Spectroscopy
Authors: Vanýsek Petr , Novák Vitězslav , Chladil Ladislav
Published: December 2015

Vanadium has several soluble oxidation forms which can be used as the oxidized and reduced side of an electrochemical cell. This is the basis of the so called redox flow battery. A redox flow battery is an applied technological system from which electrical energy is derived using the electrochemical reaction of the higher and lower oxidation state of a pair of solutions. Our aim was to carry out more fundamental studies of the redox processes on graphite electrodes in solutions of vanadium salts. The experimental setup was using a rotated disk electrode and voltammetric, and impedance measurements were performed.
Degradation Mechanisms in the Lead Acid Battery Causing Premature Capacity Loss
Authors: Zimáková Jana , Vaculík Sebastian , Fryda Daniel , Bača Petr
Published: December 2015

There are several types of degradation mechanisms in the lead-acid battery, according to the type and duration. Usually there isn’t only one type but more, depending on how is battery loaded. Influence of degradation mechanisms cannot be eliminated. However, there are methods to minimize undesirable phenomena. Using of these methods is allowed only in specific regime. Another approach to this problem is manufacturing special accumulators for specific applications. But even in this case it is necessary compromise.
Graphene and Graphene Composites in Electrochemical Capacitors and Li-Ion Batteries
Authors: Walkowiak Mariusz , Wasinski Krzysztof , Polrolniczak Paulina , Martyla Agnieszka , Waszak Daniel , Surendran Anu Arunthathy , Lota Grzegorz
Published: December 2015

Graphene and derived materials have recently emerged as a new promising class of materials featuring unique electrical, mechanical, magnetic and thermal properties. Electrochemical energy conversion and storage devices, in particular supercapacitors and Li-ion batteries, are widely regarded as one of main areas where graphene related materials may find application. The present work describes synthesis and structural properties of reduced graphene oxide (rGO) and rGO/Fe3O4. These materials are subsequently tested in symmetrical capacitors and hybrid capacitors with alkaline electrolyte as well as in a conventional Li-ion cell setup. It is demonstrated that certain electrochemical devices can clearly benefit form graphene materials in terms of power capability. On the other hand, particle agglomeration and increased reactivity hinders making full usage of the graphene capability.
Investigation of Influence of Ebonex on the Formation of Lead-Acid Accumulator Positive Electrode
Authors: Fryda Daniel , Zimáková Jana , Vaculík Sebastian , Bača Petr
Published: December 2015

This article is focused on lead-acid batteries used in hybrid electric vehicles and battery-powered vehicles. These cells work in specific conditions, particularly under partial charge referred to as PSOC and DoD. This fact is responsible for the premature loss of capacity cell lead-acid batteries and their short lifetime. The task of this work is to examine the effect of conductive ceramics as possible additives to the negative electrode active materials of lead-acid battery cells operating in a DoD, in order to prolong their life. This article compares the properties of experimental cells with varying amounts of Ebonex added in the positive active mass. For this experiment were selected electrodes in admixture with 0 wt.%, 0,15 wt.%, 0,46 wt.% and 0,78 wt.% of Ebonex.
Effect of Additives in the Electrolyte Added before the Formation of Lead-Acid Battery
Authors: Vaculík Sebastian , Zimáková Jana , Fryda Daniel , Bača Petr
Published: December 2015

Lead-acid battery serves as the primary power source for vehicles. The total lifetime is determined by the parameters identified in the production, but also handling the operation and maintenance. This work deals with the effect of additives in the electrolyte added before the formation of lead-acid battery.
Lithium-Titanate as a Negative Electrode for Lithium-Ion Batteries
Authors: Libich Jiri , Máca Josef , Sedlaříková Marie , Vondrák Jiri
Published: December 2015

The safety issue of lithium-ion batteries is current important research area. In recent years, the trend is to use higher capacity batteries allowing user to store more energy, to extract it at a higher rate, and to extend the application to new fields such as electrical vehicles propulsion, and smart grid. The comprehension to the all safety aspects of these large energy storage batteries lies extensive demands for battery designers and manufacturers. The failure of lithium-ion battery is accompany by thermal runaway and the venting of toxic and highly flammable gases. That can occur due to exposure battery to excessive temperatures, external shorts, high discharge rate, faulty wiring, or due to internal shorts caused by cell defects. These effects depends on the materials from which the batter yis made of. This paper deals with negative electrode materials and electrolytes for lithium-ion batteries with enhanced higher fire safety.
Comparison of Silicon Nanowire Growth on SiO2 and on Carbon Substrates
Authors: Krause Andreas , Grube Matthias , Mikolajick Thomas , Weber Walter M.
Published: December 2015

Silicon nanowires have emerged as a cheap and efficient technology for nanostructured Si necessary for electronic devices as well as anode material in Li battery technology. They are typically grown via the vapor-liquid-solid mechanism and gold nanoparticles used as catalyst. Here we compare the CVD growth of those silicon nanowires on different substrates, namely Si with 130 nm SiO2 as well as on a carbon surface. The presence of carbon does change the typical characteristics of single crystalline growth to more amorphous or polycrystalline growth regardless of different process conditions typically varied to get optimal nanowire growth.
Preparation and Characterization of Gel Polymer Electrolytes based on Electrospun PLA/PHB Membranes for Lithium-Ion Batteries
Authors: Osinska-Broniarz Monika , Gieparda Weronika , Wesolek Dorota , Martyla Agnieszka , Przekop Robert , Sierczynska Agnieszka
Published: December 2015

Electrospun biodegradable polylactide/poly 3-hydroxybutyrate (PLA/PHB) membranes were prepared using the electrospinning method. The conformation of the biodegradable membranes was verified by SEM, attenuated total reflectance-Fourier transformation infrared spectroscopy (ATR-FTIR), XRD technique, and DSC. For all electrospun PLA/PHB biodegradable membranes a nonwovenen, fibers network structure was observed. The high level of absorption of the liquid phase were observed for blended PLA/PHB biodegradable polymer membranes. Gel polymer electrolytes with polymer matrices containing 70% PLA and 30% PHB showed the highest porosity and liquid phase absorption abilities, and, as a consequence, also the highest values of conductivity amongst all tested polymer electrolytes (1,5·10-2 Scm-1 at 25°C).
Application of Fire Retardants in Electrolytes for Lithium Ion Batteries
Authors: Maca Josef , Hlava Kamil , Vondrák Jiří , Sedlarikova Marie
Published: December 2015

The increase of lithium batteries security can be achieved by the use of sulfolane as a solvent for electrolyte preparation, and by addition of phosphorus compounds (dimethyl methyl phosphonate DMMP and/or triphenylphosphate TPP). Both named flame retardants increase flash point in a considerable measure. The conductivity of lithium salt is lowered by TPP on contrary to DMMP, the presence of which increases the electrolyte conductivity.
Study of the Influence of the Scandium Doping to the Properties of High Voltage LiNi0.5Mn1.5O4 Cathode
Authors: Kazda Tomás , Vondrák Jiří , Sedlarikova Marie , Visintin Arnaldo , Tichy Jiri , Humana Rita M , Cudek Pavel
Published: December 2015

One of the problems which were always associated with accumulators in general is their low voltage. For powering a more demanding application, there is always the need to stack more cells together to obtain a higher voltage. Conventional Li-ion accumulators are charged to 4.2 V maximum and their nominal voltage is 3.6-3.7 V. There have been attempts to produce an accumulator with higher voltage lately. Its charging voltage should be around 5 V and voltage during discharging over 4.5 V. From the group of high voltage cathode materials, the LiNi0.5Mn1.5O4 spinel is the most promising material. Solid state reaction method was chosen as the method of synthesis of this material and as the method of stabilizing the structure by doping by other element - in this case by scandium. Doped sample was studied in terms of obtained capacity, cycle life and stability in a high C-rate.
Lithium-Sulphur Accumulator Based on Structure of Conductive Carbon Fibres
Authors: Kazda Tomás , Cudek Pavel , Vondrák Jiří , Sedlarikova Marie , Tichy Jiri , Slavik Marek
Published: December 2015

Lithium-sulphur batteries are one of the most promising areas in the development of batteries based on lithium. If the problems associated with them will be solved they could be a very attractive secondary energy sources mainly for electromobility due to their high gravimetric energy density. One of the main disadvantages of the lithium-sulphur batteries is the deposition of polysulfide on the surface of the lithium anode leading to loss of capacity during cycling. As a solution to this problem, a carbon fibres structure was used in this article, which will absorb these polysulfide and this will consequently slow down the decline of capacity and increase stability and capacity in higher C-rate.
Nonwoven Separators Fabrication and Analysis Methods
Authors: Musil Michal , Pléha David
Published: December 2015

Non woven separator is a clump of fibres connected together with chemical, physical or mechanical methods. Fibres can originate from nature (celulose and chemically modified derivates) or can be synthetic (PA, PI, PTFE, PVDF, PVC) (1) (2). Nano fibred materials ensure high porosity and relative surface area of separators. These parameters are important to improve ionic mobility between electrodes and ensure sufficient electrolyte volume in battery. These advantages make electrospinning very promising method of nanofibrous separators mass production. In this paper are described electrospinning fabrication process and discussed results of separator’s electric and electrochemical properties measurements compared with Celgard 3401.
Surface Structure of the Total Joint Replacement after Hydroxyapatite Application
Authors: Onderka Filip , Dobrocký David
Published: December 2015

Given that CoCr alloys have excellent corrosion resistance and abrasion resistance, they have found their wide use as a material for replacing human joints, especially the knee and hip replacements (1, 2). CoCr alloys offer a wide range of positive mechanical properties such as high strength, hardness and elasticity. However, despite all the advantages in these alloys are occurring the following problems: corrosive processes that increase the level of metal ions in the local tissues, and systems (in blood) (3), adverse micro and nanotopography of surface, low biological activity, non-hydrophilic surface (2). New approaches are currently looking to reduce the amount of wear particles whilst maintaining the required biocompatibility of the material. The work is focused on the evaluation of surface structure CoCrMo alloy, which is used to produce joint replacements, after the deposition of hydroxyapatite by electrochemical method. The carbon nanotubes (CNT) were added to improve the mechanical properties of the deposited coating of hydroxyapatite.
Proving Ultra-Hard Steel Quality by Means of Measuring Ballistic Resistance Influencing the Life Cycle of the Material within a Specific Temperature Range
Authors: Binar Tomas , Sukac Jiri , Vondrák Jirí , Silinger Karel , Krestan Jan
Published: December 2015

The paper is concerned with basic mechanical properties directly affecting ballistic resistance in relation to the ambient temperature changes. Possible decrease in the material ballistic resistance may eventually lead to the increase in logistic processes-related expenditures, e.g. when acquiring property and services upon combat damage to the military vehicle material. In the experiment, a critical ambient temperature was determined, at which degradation processes, considerably decreasing the ballistic resistance of the material tested, are highly probable to occur. The experiment was supplemented with a chemical analysis using EDS and transmission electron microscopy of selected specimens, where modifications in measured material characteristics were detected, which are influencing the live cycle of the material.
Spring Steel Heat Treatment for the Quality Enhancement of Life Cycles of Military Vehicles Components
Authors: Sukac Jiri , Binar Tomas , Kazda Tomás , Silinger Karel
Published: December 2015

Mechanical components in military vehicles, such as shafts, gears, stubs, forming groups and subgroups, are exposed to extreme service load while in operation in consequence of the environment. Within NATO, the Armed Forces of the Czech Republic deploy military vehicles in demanding mountainous terrain (e.g. in Afghanistan), or in the past, in areas with high dustiness and relative humidity (e.g. in Iraq), which results in shortening of the life cycles of these components and the increase in the financial means expended on the recovery of the vehicles operability. This paper is concerned with proposing a heat treatment of the material of military vehicles components that is supposed to extend the material service life and enhance the corrosion resistance. The experiment is complemented with a tensile test and chemical composition, microhardness and microstructure analyses.
The Steel Ballistic Resistance Directly Affecting Logistics-Related Expenditures
Authors: Binar Tomas , Sukac Jiri , Silinger Karel , Zatloukal Miroslav , Rolc Stanislav
Published: December 2015

As far as the projectile/armour interaction is concerned, it can be generally stated that the interaction triggers degradation processes, and subsequently leads to a limit state in the material. The nature of the armour plate damage is directly related to the type of ammunition used and indirectly to the operating conditions (the shooter’s capability, the technical condition of the weapon, etc.). The paper examines limit conditions (critical temperature), under which ballistic resistance, which is measured based on determined mean velocity V50, decreases. Military vehicles deployed in peace missions abroad operate under various climatic conditions characterised by significant temperature variations in the course of day. When superposing the ambient temperature influence and the ammunition effect, the projectile penetration through the material and unexpected expenditures relating to the restoration of the damaged material original properties can be assumed. In addition to the efficient use of public financial means, foreign operation logistic support planning must take possible damage to the military vehicles, resulting from enemy’s combat activities, into consideration. On the basis of the determined mean velocity within the temperature range -80 °C to 100 °C, the correlation of selected material characteristics was studied. In order to determine the share of the test temperature in the material degradation states, the experiment was supplemented with a fractographic analysis and transmission electron microscopy.
Insights into the Effect of Deposition Temperature on YSZ and CGO Thin Films Fabricated by Spray Pyrolysis
Authors: Tsimekas George , Papastergiades Efthimis , Kiratzis Nikolas Euripides
Published: December 2015

The Spray Pyrolysis technique was applied to synthesize thin electrolytic films of yttria stabilized zirconia (8 mol% YSZ) onto porous substrates of perovskite La0.7Sr0.3MnO3and gadolinia stabilized ceria (10 mol%GSC) onto dense substrates of YSZ. For both electrolytes the main process parameter that determines the film morphology is the deposition temperature. Aqueous precursor solutions were used for all experiments. The morphology was characterized by scanning electron microscopy and X-ray diffraction.The results indicate that it is possible to obtain adhesive and coherent films of YSZ by tuning the substrate temperature value. For the CGO electrolyte, adhesive but not coherent films were obtained. The substrate material was found to affect the final morphology of the deposited film.
Determination of the Temperature Coefficient of Volume Expansion Heat - Transfer Fluids by Using Refractometer
Authors: Strachala David , Hylský Josef , Frk Martin
Published: December 2015

The aim of the submitted work is in the comparison of the two methods used for determination of the temperature coefficient of volume expansion (β) of heat transfer fluids. Temperature coefficient of volume expansion is one of the fundamental thermo-physical parameters monitored in the heat transfer fluids for solar collectors. A first method is based on commonly used Archimedes law principle and second deals with the determination via Abbe refractometer. Measurement of β using an Abbe refractometer is not very common, but in a practical way simpler and quicker than the methods based on the Archimedes principle. The identified thermal volume expansion coefficient under two different methods was compared and also has been found the relation between refractive index and β of the heat-transfer fluids measured by Abbe refractometer.
Analysis of Photovoltaic Modules after 20 Years in Service
Authors: Hylský Josef , Strachala David , Vaněk Jiri
Published: December 2015

Presented work deals with the analysis of photovoltaic modules after 20 years of its function in terms of defects caused by degradation through the years of service. Detection of defects was performed by a several diagnostic mechanisms. Firstly, the panels were examined visually for an obvious defects. In a further step were selected modules explored by a thermal camera to identify faults (especially „hot spots“) in the crystal lattice of the solar cells. Then was used on each of the modules certified flash tester (a workplace of PV Lab at Brno University of Technology). Flash tester measured VA characteristics of which were the basic parameters expressed and compared to those provided by the manufacturer. The power decline after 20 years of operation was evaluated in comparison with an expected drop specified by the manufacturer.
Low-Frequency Noise Diagnostic of Silicon Concentrator Photovoltaic Cell with Very High Efficiency
Authors: Vaněk Jiri , Chobola Zdenek , Lunak Miroslav
Published: December 2015

In this paper we present the comparisons of noise spectroscopy, I-V characteristic and microplasma detection of silicon concentrator photovoltaic (CPV) cell with very high efficiency. Efficiency reaches to 38 %. We studied two groups with different technologies (A and B). Each group had 6 samples. The samples were quality screened using noise analysis. From the measurement results it follows that the noise spectral density related to defects is of 1/f or generation-recombination types. G-R noise and burst noise is not fundamental noise and therefore can by use as a quality indicator.
Processing and Optimization of the Perovskite Solar Cell
Authors: Kadlec Michal , Vaněk Jiri , Sionová M , Weiter M
Published: December 2015

The aim of the work is to find an optimal way for the synthesis and preparation of the perovskite solar cell based on CH3NH3PbI3/PC61BM - methylammonium lead iodide (CH3NH3PbI3) and [6,6]-phenyl- C61-butyric acid methyl ester (PC61BM). The purpose of the project is to achieve the highest possible quality, most stable structures of synthesized materials and to build the long-term stable solar cells with high efficiency of photovoltaic conversion. The result of the experiment is 8 samples, which were further analyzed.
Analysis of Temperature Field in Lithium Ion Battery by Discharging
Authors: Vyroubal Petr , Kazda Tomás , Maxa Jiří , Vondrák Jirí
Published: December 2015

This paper deals with a possibility of numerical simulation of temperature profile by discharging of li-ion battery. The numerical model was prepared using SolidWorks and ANSYS Fluent software and it was compared by real measurement using electrical impedance spectroscopy and thermocamera imaging. The simulation was realised as transient real-time.
Graphitic Carbon as a Part of Anode Material for Rechargeable Sodium Ion Batteries
Authors: Gottwald Tomás , Sedlaříková Marie , Vondrák Jiří , Juračka Martin
Published: December 2015

Electrodes have been successfully prepared from two types of carbon (CR5995 and NORIT® GL50). We prepared and described preparation of two equivalent electrolytes.The first electrolyte (1 M LiClO4 1:1 EC:DMC)was prepared for lithium and the second electrolyte (0,5 M NaClO41:1 EC:DMC) for sodium system .Both materials were tested GCPL (Galvanostatic Cycling with Potential Limitation) procedure and CV (Ciclyc Voltametry) procedure in both systems (Figure 1.). Results were compared.
Lithium Sulphur Batteries
Authors: Juračka Martin , Vondrák Jiří , Sedlaříková Marie , Gottwald Tomás
Published: December 2015

S+C cathode material was prepared by simple solid-state reaction in ball mill. Content of sulphur was approximately 80 wt. % in final sample. Cyclic voltammetry and galvanostatic charge/discharge techniques were used for characterization of the samples. Initial discharge capacity observed for S+C sample was 600 mAh/gsulfur. Capacity loss for S+C sample after 30th cycles was 66 %. Cycling loss is due to insoluble polysulfide formation. In this paper I present fundamental characteristics of Li-S batteries. This paper presents a principle of Li-S batteries, fundamental measurement and their evaluation. I present the techniques of measurement and preparation of cathode materials.