522 research outputs found
Promoter methylation of cancer-related genes in gastric carcinoma
Genetic changes associated with gastric cancer are not completely known, but epigenetic mechanisms involved in this disease seem to play an important role in its pathophysiology. One of these mechanisms, an aberrant methylation in the promoter regions of genes involved in cancer induction and promotion, may be of particular importance in gastric cancer. Aim: To analyze the methylation status of eight genes: Apaf-1, Casp8, CDH1, MDR1, GSTP1, BRCA1, hMLH1, Fas in gastric cancer patients. Methods: The methylation pattern of the genes was assessed by methylation specific restriction enzyme PCR (MSRE-PCR) in gastric tumors taken during surgery of 27 patients and compared with the methylation pattern in material obtained from biopsy in 25 individuals without cancer and pre-cancerous lesions. Results: We observed a promoter hypermethylation in the Casp8, hMLH1, CDH1 and MDR1 in gastric cancer patients as compared with the controls. Additionally, we investigated the relationship between promoter hypermethylation and age, gender, smoking and gastric cancer family history. The hypermethylation of the hMLH1 gene occurred more frequently in female than in men, and the hypermethylation of the CDH1 gene was observed preferentially in smoking than in non-smoking individuals. Conclusion: The data obtained indicate that changes in DNA methylation may contribute to gastric carcinogenesis.Генетические изменения, ассоциированные с опухолью желудка, изучены не в полной мере. В то же время эпигенетические
механизмы скорее всего играют ключевую роль и лежат в основе возникновения этого заболевания. Один из таких механизмов–
нарушенияметилирования промоторов генов, которые регулируют злокачественнуютрансформациюи прогрессирование
опухолевого процесса, может быть особенно важным в развитии рака желудка. Цель: проанализировать статус метилирования
промоторов восьми генов: Apaf-1, Casp8, CDH1, MDR1, GSTP1, BRCA1, hMLH1, Fas у больных раком желудка. Методы: метилирование
промоторов генов изучали с помощьюспецифической к сайтамметилирования рестрикцией с ПЦР (MSRE-PCR)
на хирургическомматериале (опухоли желудка) 27 пациентов. Вкачестве контроля использовали иопсийныйматериал, полученный
от 25 больных, у которых не было выявлено рака или предраковых состояний. Результаты: отмечали гиперметилирование
промоторов генов Casp8, hMLH1, CDH1 и MDR1 в опухолевой ткани желудка по сравнению с контрольными образцами.
Кроме того, нами была прослежена взаимосвязь между гиперметилированием промоторов генов и возрастом, полом пациентов,
курением и семейной историей заболевания раком желудка. Гиперметилирование гена hMLH1 выявляли чаще у женщин, чем у
мужчин, а гиперметилирование гена CDH1 — в основном у курильщиков. Выводы: полученные данные свидетельствуют о том,
что метилирование ДНК может играть важную роль при развитии рака желудка
Electroglottography in Medical Diagnostics of Vocal Tract Pathologies: A Systematic Review.
Electroglottography (EGG) is a technology developed for measuring the vocal fold contact area
during human voice production. Although considered subjective and unreliable as a sole diagnostic method,
with the correct application of relevant computational methods, it can constitute a most promising non-invasive
voice disorder diagnostic tools in a form of a digital vocal tract pathology classifier. The aim of the following
study is to gather and evaluate currently existing digital voice quality assessment systems and vocal tract abnormality classification systems that rely on the use of electroglottographic bio-impedance signals. To fully
comprehend the findings of this review, first the subject of EGG is introduced. For that, we summarise most
relevant existing research on EGG with a particular focus on its application in diagnostics. Then, we move on to
the focal point of this work, which is describing and comparing the existing EGG-based digital voice pathology
classification systems. With the application of PRISMA model, 13 articles were chosen and analysed in detail.
Direct comparison between chosen studies brought us to pivotal conclusions, which have been described in
Section 5 of this report. Meanwhile, certain limitations arising from the literature were identified, such as
questionable understanding of the nature of EGG bio-impedance signals. The appropriate recommendations
for future work were made, including the application of different methods for EGG feature extraction, as well
as the need for continuous EGG datasets development containing signals gathered in various conditions and
with different equipments
Sound-Based Cough Detection System using Convolutional Neural Network.
Sound recording and processing techniques can be used
in designing diagnostic solutions for a variety of medical
conditions related to the respiratory system. In this spectrum,
cough monitoring for chronic or seasonal conditions is a
significant medical practice. In this paper, a precise cough
identification and monitoring system is presented. The system is
utilising a convolutional neural network as a feature extraction
algorithm and classification system. Including several functions of
loading the audio data into the system and converting it into a set
of spectrograms, as well as the pre-segmentation stage function,
the model retains its relatively low-complexity, which allows
accelerating the learning process, also enhanced using dropout.
Due to limited audio data available, the dataset dimension was
established at 600 samples, split into two equal-numbered groups
– 300 samples of “cough” samples, and 300 of “non-cough”
samples. The validation accuracy (thus the percentage of samples
labelled correctly by the system during the validation process)
yielded over 84%, suggesting that this can be a successful cough
detection method for future medical applications and devices, such
as potential respiratory system condition diagnostic tool
COST 733 - WG4: Applications of weather type classification
The main objective of the COST Action 733 is to achieve a general numerical method for
assessing, comparing and classifying typical weather situations in the European regions. To
accomplish this goal, different workgroups are established, each with their specific aims:
WG1: Existing methods and applications (finished); WG2: Implementation and development of
weather types classification methods; WG3: Comparison of selected weather types
classifications; WG4: Testing methods for various applications.
The main task of Workgroup 4 (WG4) in COST 733 implies the testing of the selected weather
type methods for various classifications. In more detail, WG4 focuses on the following topics:•
Selection of dedicated applications (using results from WG1),
• Performance of the selected applications using available weather types provided by WG2,
• Intercomparison of the application results as a results of different methods
• Final assessment of the results and uncertainties,
• Presentation and release of results to the other WGs and external interested
• Recommend specifications for a new (common) method WG2
Introduction
In order to address these specific aims, various applications are selected and WG4 is divided in
subgroups accordingly:
1.Air quality
2. Hydrology (& Climatological mapping)
3. Forest fires
4. Climate change and variability
5. Risks and hazards
Simultaneously, the special attention is paid to the several wide topics concerning some other
COST Actions such as: phenology (COST725), biometeorology (COST730), agriculture (COST 734)
and mesoscale modelling and air pollution (COST728).
Sub-groups are established to find advantages and disadvantages of different classification
methods for different applications. Focus is given to data requirements, spatial and temporal
scale, domain area, specifi
Automatic Heart Rate Detection during Sleep Using Tracheal Audio Recordings from Wireless Acoustic Sensor
Background: Heart rate is an essential diagnostic parameter indicating a patient’s condition.
The assessment of heart rate is also a crucial parameter in the diagnostics of various sleep disorders,
including sleep apnoea, as well as sleep/wake pattern analysis. It is usually measured using an electrocardiograph (ECG)—a device monitoring the electrical activity of the heart using several electrodes
attached to a patient’s upper body—or photoplethysmography (PPG). Methods: The following paper
investigates an alternative method for heart rate detection and monitoring that operates on tracheal
audio recordings. Datasets for this research were obtained from six participants along with ECG
Holter (for validation), as well as from fifty participants undergoing a full night polysomnography
testing, during which both heart rate measurements and audio recordings were acquired. Results:
The presented method implements a digital filtering and peak detection algorithm applied to audio
recordings obtained with a wireless sensor using a contact microphone attached in the suprasternal
notch. The system was validated using ECG Holter data, achieving over 92% accuracy. Furthermore,
the proposed algorithm was evaluated against whole-night polysomnography-derived HR using
Bland-Altman’s plots and Pearson’s Correlation Coefficient, reaching the average of 0.82 (0.93 maximum) with 0 BPM error tolerance and 0.89 (0.97 maximum) at ±3 BPM. Conclusions: The results
prove that the proposed system serves the purpose of a precise heart rate monitoring tool that can
conveniently assess HR during sleep as a part of a home-based sleep disorder diagnostics process
Complex polyploid and hybrid species in an apomictic and sexual tropical forage grass group: genomic composition and evolution in Urochloa (Brachiaria) species
Background and Aims
Diploid and polyploid Urochloa (including Brachiaria, Panicum and Megathyrsus species) C-4 tropical forage grasses originating from Africa are important for food security and the environment, often being planted in marginal lands worldwide. We aimed to characterize the nature of their genomes, the repetitive DNA and the genome composition of polyploids, leading to a model of the evolutionary pathways within the group including many apomictic species.
Methods
Some 362 forage grass accessions from international germplasm collections were studied, and ploidy was determined using an optimized flow cytometry method. Whole-genome survey sequencing and molecular cytogenetic analysis were used to identify chromosomes and genomes in Urochloa accessions belonging to the 'brizantha' and 'humidicola' agamic complexes and U. maxima.
Key Results
Genome structures are complex and variable, with multiple ploidies and genome compositions within the species, and no clear geographical patterns. Sequence analysis of nine diploid and polyploid accessions enabled identification of abundant genome-specific repetitive DNA motifs. In situ hybridization with a combination of repetitive DNA and genomic DNA probes identified evolutionary divergence and allowed us to discriminate the different genomes present in polyploids.
Conclusions
We suggest a new coherent nomenclature for the genomes present. We develop a model of evolution at the whole-genome level in diploid and polyploid accessions showing processes of grass evolution. We support the retention of narrow species concepts for Urochloa brizantha, U. decumbens and U. ruziziensis, and do not consider diploids and polyploids of single species as cytotypes. The results and model will be valuable in making rational choices of parents for new hybrids, assist in use of the germplasm for breeding and selection of Urochloa with improved sustainability and agronomic potential, and assist in measuring and conserving biodiversity in grasslands
Lithium-ion battery fast charging: A review
In the recent years, lithium-ion batteries have become the battery technology of choice for portable devices, electric vehicles and grid storage. While increasing numbers of car manufacturers are introducing electrified models into their offering, range anxiety and the length of time required to recharge the batteries are still a common concern. The high currents needed to accelerate the charging process have been known to reduce energy efficiency and cause accelerated capacity and power fade. Fast charging is a multiscale problem, therefore insights from atomic to system level are required to understand and improve fast charging performance. The present paper reviews the literature on the physical phenomena that limit battery charging speeds, the degradation mechanisms that commonly result from charging at high currents, and the approaches that have been proposed to address these issues. Special attention is paid to low temperature charging. Alternative fast charging protocols are presented and critically assessed. Safety implications are explored, including the potential influence of fast charging on thermal runaway characteristics. Finally, knowledge gaps are identified and recommendations are made for the direction of future research. The need to develop reliable in operando methods to detect lithium plating and mechanical degradation is highlighted. Robust model-based charging optimisation strategies are identified as key to enabling fast charging in all conditions. Thermal management strategies to both cool batteries during charging and preheat them in cold weather are acknowledged as critical, with a particular focus on techniques capable of achieving high speeds and good temperature homogeneities
COST 733 – WG4: Applications of weather type classifications
Presentación realizada para: European Geosciences Union General Assembly celebrado del 19-24 de abril de 2009 en Viena
Limits on the effective quark radius from inclusive scattering at HERA
The high-precision HERA data allows searches up to TeV scales for Beyond the
Standard Model contributions to electron-quark scattering. Combined
measurements of the inclusive deep inelastic cross sections in neutral and
charged current scattering corresponding to a luminosity of around 1
fb have been used in this analysis. A new approach to the beyond the
Standard Model analysis of the inclusive data is presented; simultaneous
fits of parton distribution functions together with contributions of "new
physics" processes were performed. Results are presented considering a finite
radius of quarks within the quark form-factor model. The resulting 95% C.L.
upper limit on the effective quark radius is cm.Comment: 10 pages, 4 figures, accepted by Phys. Lett.
Search for a narrow baryonic state decaying to and in deep inelastic scattering at HERA
A search for a narrow baryonic state in the and
system has been performed in collisions at HERA with the ZEUS detector
using an integrated luminosity of 358 pb taken in 2003-2007. The search
was performed with deep inelastic scattering events at an centre-of-mass
energy of 318 GeV for exchanged photon virtuality, , between 20 and 100
. Contrary to evidence presented for such a state around 1.52
GeV in a previous ZEUS analysis using a sample of 121 pb taken in
1996-2000, no resonance peak was found in the invariant-mass
distribution in the range 1.45-1.7 GeV. Upper limits on the production cross
section are set.Comment: 16 pages, 4 figures, accepted by Phys. Lett. B. Minor changes from
journal reviewing process, including a small correction to figure
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