1,595 research outputs found
Introducing the concept of breast cancer stem cells
Breast tumours are well known to be composed of phenotypically diverse groups of cells. Which of these cell types contribute to tumour development, however, is not well understood. Two hypotheses exist: either all the cell population
Determination of acrylamide levels in selected commercial and traditional foods in Syria
Purpose: To determine acrylamide (AA) levels in different brands of commercial and traditional foodstuffs available in Syria by ultra-performance liquid chromatography-mass spectrometery (UPLCMS).Methods: A total of 63 samples were analyzed. Food samples were defatted by hexane and then extracted with methanol 98 % in a vortex mixer. Thereafter, Carrez I and Carrez II were added to precipitate proteins from the co-extractives and then centrifuged to obtain a clear aqueous extract that was evaporated to dryness. The extract was dissolved in 1 mL of water, eluted through a preconditioned Oasis HLB cartridge and then filtered. The filtrate was analyzed by UPLC-MS/MS to determine AA content.Results: Among the commercial foods tested, the highest acrylamide quantity was found in potato products (396 ± 3.59 – 1844 ± 5.29 μg kg−1) and the lowest in corn products (183 ± 2.64 – 366 ± 4.58 μg kg−1). This was followed by biscuits (57 ± 2.64 – 1433 ± 2.51 μg kg−1), breakfast cereals (121 ± 8.73 – 245 ± 3.60 μg kg−1), bread (119 ± 1.73 – 263 ± 3.60 μg kg−1) and then coffee (113 ± 2.64 - 64 ± 3.05 μg kg−1). Regarding traditional foods, the highest level of AA was found in AL- Mshabak (481 ± 2.08 μg kg−1) and AL-Awamat (421 ± 2.64 μg kg−1) followed by AL-Namora (282 ± 4.35 μg kg−1) and AL-Kenafa (242 ± 2.64 μg kg−1). It was also observed that the lowest amount of AA was in fried bread (230 μg kg−1), AL-Fatayer (192 ± 3.51 μg kg−1) and AL-Baqlawa (172 ± 4.35 μg kg−1) while Eid Aqras (130 ± 4.58 μg kg−1) and AL-Brazeq (167 ± 3.78 μg kg−1) contained the least amount of AA.Conclusion: The results indicate that the highest levels of AA are found in the most commonly consumed foods. There was significant difference (p < 0.05) in AA levels among different food items and within different brands of the same product.Keywords: Acrylamide, Commercial foods, Traditional foods, Syrian food, Contaminants, UPLCMS/M
Breast cancer stem cell markers – the rocky road to clinical applications
Lately, understanding the role of cancer stem cells in tumor initiation and progression became a major focus in stem cell biology and in cancer research. Considerable efforts, such as the recent studies by Honeth and colleagues, published in the June issue of Breast Cancer Research, are directed towards developing clinical applications of the cancer stem cell concepts. This work shows that the previously described CD44+CD24- stem cell phenotype is associated with basal-type breast cancers in human patients, in particular BRCA1 inherited cancers, but does not correlate with clinical outcome. These very interesting findings caution that the success of our efforts in translating cancer stem cell research into clinical practice depends on how thorough and rigorous we are at characterizing these cells
Robust and Skew-resistant Parallel Joins in Shared-Nothing Systems
The performance of joins in parallel database management systems is critical for data intensive operations such as querying. Since data skew is common in many applications, poorly engineered join operations result in load imbalance and performance bottlenecks. State-of-the-art methods designed to handle this problem offer significant improvements over naive implementations. However, performance could be further improved by removing the dependency on global skew knowledge and broadcasting. In this paper, we propose PRPQ (partial redistribution & partial query), an efficient and robust join algorithm for processing large-scale joins over distributed systems. We present the detailed implementation and a quantitative evaluation of our method. The experimental results demonstrate that the proposed PRPQ algorithm is indeed robust and scalable under a wide range of skew conditions. Specifically, compared to the state-of-art PRPD method, we achieve 16% - 167% performance improvement and 24% - 54% less network communication under different join workloads
An integrated life cycle costing database: a conceptual framework
Life cycle costing (LCC) is a management technique that has been available to the
industry for some time, but despite this it continues to languish in obscurity. Some
clients, most apparently from the public sector, are fostering the technique by
commissioning studies based on the LCC appraisal techniques. However, the
majority of building designs are still currently produced unsullied by thoughts of
maintenance implications, life expectancy or energy consumption.
Recent technological developments, particularly in Web, Virtual Reality (VR), and
Object Oriented technologies and mathematical and computational modelling
techniques will undoubtedly help in resolving some of the problems associated with
life cycle costing techniques. This paper outlines a conceptual framework for an
innovative system that facilitates the implementation of LCC in various design and
occupancy stages. This system is being developed within an EPSRC-funded research
project, undertaken through a joint collaboration between the Robert Gordon
University and the University of Salford
Improving generalization of machine learning-identified biomarkers with causal modeling: an investigation into immune receptor diagnostics
Machine learning is increasingly used to discover diagnostic and prognostic
biomarkers from high-dimensional molecular data. However, a variety of factors
related to experimental design may affect the ability to learn generalizable
and clinically applicable diagnostics. Here, we argue that a causal perspective
improves the identification of these challenges, and formalizes their relation
to the robustness and generalization of machine learning-based diagnostics. To
make for a concrete discussion, we focus on a specific, recently established
high-dimensional biomarker - adaptive immune receptor repertoires (AIRRs). We
discuss how the main biological and experimental factors of the AIRR domain may
influence the learned biomarkers and provide easily adjustable simulations of
such effects. In conclusion, we find that causal modeling improves machine
learning-based biomarker robustness by identifying stable relations between
variables and by guiding the adjustment of the relations and variables that
vary between populations
Identifying Barriers to Umbilical Cord Blood Banking in Jordan: A Cross-Sectional Survey of Obstetricians
Background: The expansion of umbilical cord blood (UCB) banking necessitates a greater understanding among obstetricians in order to responsibly inform parents about UCB collection and storage. Gaps in knowledge can compromise public UCB banking efforts and result in missed opportunities and public misguidance about UCB banking.
Materials and Methods: A cross-sectional survey was disseminated among obstetricians in Amman, Jordan. The questionnaire aimed to evaluate obstetricians’ knowledge of and attitude toward UCB storage and applications, as well as current practice patterns.
Results: Ninety-six obstetricians responded (55% response rate), most of whom were Jordanian (71%), female (83%), resident physicians (59%), and working in either private (43%) or public (42%) hospitals, with an average of 6.5 years in practice. Only 26% had personal experience in UCB collection, and 20% had received education on UCB collection. Nearly 75% said their hospitals lacked standard operating procedures, guidelines, or infectious disease screening for UCB units. Overall knowledge about UCB was moderate, and the internet was the most common information source (54%). Overall attitudes were positive, especially in desire to expand personal knowledge about UCB, integrate information into medical residency curricula, and establish a public UCB bank in Jordan. However, many believed that ethical (61%) and religious (56%) controversies surround UCB donation.
Conclusion: This study identifies deficiencies in quality control and experience in UCB collection in Jordan, as well as areas of inadequate knowledge and ethical controversies among obstetricians. These issues contribute to public misinformation and limit public UCB donation programs, and requires improved medical education on this topi
Compact Circularly Polarized Multiband Antennas for RFID Applications
This paper presents multiband circularly polarized (CP) antennas for
radio frequency identification (RFID). A coax-fed and a microstrip-line-fed antennas having optimized cross-slots in their patches are first
designed for dual-band CP operation. The microstrip-line-fed design is then modified, by incorporating a U-shaped slot in its partial ground
plane, to achieve additional operation band with a CP characteristic. Simulation and measured results of the presented designs are reported.
The measured results are in accordance with the computed ones. The compact size and CP property make these designs suitable for RFID
applications
Stilbene derivatives promote Ago2-dependent tumour-suppressive microRNA activity
It is well known that natural products are a rich source of compounds for applications in medicine, pharmacy, and biology. However, the exact molecular mechanisms of natural agents in human health have not been clearly defined. Here, we demonstrate for the first time that the polyphenolic phytoalexin resveratrol promotes expression and activity of Argonaute2 (Ago2), a central RNA interference (RNAi) component, which thereby inhibits breast cancer stem-like cell characteristics by increasing the expression of a number of tumour-suppressive miRNAs, including miR-16, -141, -143, and -200c. Most importantly, resveratrol-induced Ago2 resulted in a long-term gene silencing response. We also found that pterostilbene, which is a natural dimethylated resveratrol analogue, is capable of mediating Ago2-dependent anti-cancer activity in a manner mechanistically similar to that of resveratrol. These findings suggest that the dietary intake of natural products contributes to the prevention and treatment of diseases by regulating the RNAi pathway
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