289 research outputs found
Unusual signatures of the ferromagnetic transition in the heavy Fermion compound UMnAl
Magnetic susceptibility results for single crystals of the new cubic
compounds UTAl (T=Mn, V, and Mo) are reported. Magnetization,
specific heat, resistivity, and neutron diffraction results for a single
crystal and neutron diffraction and inelastic spectra for a powder sample are
reported for UMnAl. For T = V and Mo, temperature independent Pauli
paramagnetism is observed. For UMnAl, a ferromagnetic transition is
observed in the magnetic susceptibility at = 20 K. The specific heat
anomaly at is very weak while no anomaly in the resistivity is seen at
. We discuss two possible origins for this behavior of UMnAl:
moderately small moment itinerant ferromagnetism, or induced local moment
ferromagnetism.Comment: 5 pages, 5 figures, to be published in Phys. rev.
Cytokine secretion in breast cancer cells β MILLIPLEX assay data
Β© 2019 The Author(s) Metastatic breast cancer is the most advanced stage of breast cancer and the leading cause of breast cancer mortality. Although understanding of the cancer progression and metastasis process has improved, the bi-directional communication between the tumor cell and the tumor microenvironment is still not well understood. Breast cancer cells are highly secretory, and their secretory activity is modulated by a variety of inflammatory stimuli present in the tumor microenvironment. Here, we characterized the cytokine expression in human breast cancer cells (MDA-MB-231, MCF-7, T-47D, and BT-474) in vitro using 41 cytokine MILLIPLEX assay. Further, we compared cytokine expression in breast cancer cells to those in non-tumorigenic human breast epithelial MCF-10A cells
Structural, electronic, magnetic, and thermal properties of single-crystalline UNi0.5Sb2
We studied the properties of the antiferromagnetic (AFM) UNi0.5Sb2 (TN
\approx 161 K) compound in Sb-flux grown single crystals by means of
measurements of neutron diffraction, magnetic susceptibility ({\chi}), specific
heat (Cp), thermopower (S), thermal conductivity ({\kappa}), linear thermal
expansion ({\Delta}L/L), and electrical resistivity ({\rho}) under hydrostatic
pressures (P) up to 22 kbar. The neutron diffraction measurements revealed that
the compound crystallizes in the tetragonal P42/nmc structure, and the value of
the U-moments yielded by the histograms at 25 K is \approx 1.85 \pm 0.12
{\mu}B/U-ion. In addition to the features in the bulk properties observed at
TN, two other hysteretic features centered near 40 and 85 K were observed in
the measurements of {\chi}, S, {\rho}, and {\Delta}L/L. Hydrostatic pressure
was found to raise TN at the rate of \approx 0.76 K/kbar, while suppressing the
two low temperature features. These features are discussed in the context of
Fermi surface and hybridization effects.Comment: 17 pages, 8 figure
Classical Mus musculus IgΞΊ Enhancers Support Transcription but not High Level Somatic Hypermutation from a V-Lambda Promoter in Chicken DT40 Cells
Somatic hypermutation (SHM) of immunoglobulin genes is initiated by activation-induced cytidine deaminase (AID) in activated B cells. This process is strictly dependent on transcription. Hence, cis-acting transcriptional control elements have been proposed to target SHM to immunoglobulin loci. The Mus musculus IgΞΊ locus is regulated by the intronic enhancer (iE/MAR) and the 3β² enhancer (3β²E), and multiple studies using transgenic and knock-out approaches in mice and cell lines have reported somewhat contradictory results about the function of these enhancers in AID-mediated sequence diversification. Here we show that the M. musculus iE/MAR and 3β²E elements are active solely as transcriptional enhancer when placed in the context of the IGL locus in Gallus gallus DT40 cells, but they are very inefficient in targeting AID-mediated mutation events to this locus. This suggests that either key components of the cis-regulatory targeting elements reside outside the murine IgΞΊ transcriptional enhancer sequences, or that the targeting of AID activity to Ig loci occurs by largely species-specific mechanisms
A regulatory insertion-deletion polymorphism in the FADS gene cluster influences PUFA and lipid profiles among Chinese adults: a population-based study
Background
Arachidonic acid (AA) is the major polyunsaturated fatty acid (PUFA) substrate for potent eicosanoid signaling to modulate inflammation and thrombosis and is controlled in part by tissue abundance. Fatty acid desaturase 1 (FADS1) catalyzes synthesis of omega-6 (nβ3) AA and nβ3 eicosapentaenoic acid (EPA). The rs66698963 polymorphism, a 22-base pair (bp) insertion-deletion 137 bp downstream of a sterol regulatory element in FADS2 intron 1, mediates expression of FADS1 in vitro, as well as exerting positive selection in several human populations. The associations between the polymorphism rs66698963 and plasma PUFAs as well as disease phenotypes are unclear.
Objective
This study aimed to evaluate the relation between rs66698963 genotypes and plasma PUFA concentrations and blood lipid profiles.
Design
Plasma fatty acids were measured from a single sample obtained at baseline in 1504 healthy Chinese adults aged between 35 and 59 y with the use of gas chromatography. Blood lipids were measured at baseline and a second time at the 18-mo follow-up. The rs66698963 genotype was determined by using agarose gel electrophoresis. Linear regression and logistic regression analyses were performed to assess the association between genotype and plasma PUFAs and blood lipids.
Results
A shift from the precursors linoleic acid and Ξ±-linolenic acid to produce AA and EPA, respectively, was observed, consistent with FADS1 activity increasing in the order of genotypes D/D to I/D to I/I. For I/I compared with D/D carriers, plasma concentrations of nβ6 AA and the ratio of AA to nβ3 EPA plus docosahexaenoic acid (DHA) were 57% and 32% higher, respectively. Carriers of the deletion (D) allele of rs66698963 tended to have higher triglycerides (Ξ² = 0.018; SE: 0.009; P = 0.05) and lower HDL cholesterol (Ξ² = β0.008; SE: 0.004; P = 0.02) than carriers of the insertion (I) allele.
Conclusions
The rs66698963 genotype is significantly associated with AA concentrations and AA to EPA+DHA ratio, reflecting basal risk of inflammatory and related chronic disease phenotypes, and is correlated with the risk of dyslipidemia
FADS2 Function Loss at the Cancer Hotspot 11q13 Locus Diverts Lipid Signaling Precursor Synthesis to Unusual Eicosanoid Fatty Acids
Background: Genes coding for the fatty acid desaturases (FADS1, 2, 3) localized at the cancer genomic hotspot 11q13 locus are required for the biosynthesis of 20 carbon polyunsaturated fatty acids (PUFA) that are direct eicosanoid precursors. In several cancer cell lines, FADS2 encoded D6 and D8 desaturation is not functional. Methodology/Principal Findings: Analyzing MCF7 cell fatty acids with detailed structural mass spectrometry, we show that in the absence of FADS2 activity, the FADS1 product D5-desaturase operates to produce 5,11,14β20:3 and 5,11,14,17β20:4. These PUFA are missing the 8β9 double bond of the eicosanoid signaling precursors arachidonic acid (5,8,11,14β20:4) and eicosapentaenoic acid (5,8,11,14,17β20:5). Heterologous expression of FADS2 restores D6 and D8-desaturase activity and normal eicosanoid precursor synthesis. Conclusions/Significance: The loss of FADS2-encoded activities in cancer cells shuts down normal PUFA biosynthesis, deleting the endogenous supply of eicosanoid and downstream docosanoid precursors, and replacing them with unusual butylene-interrupted fatty acids. If recapitulated in vivo, the normal eicosanoid and docosanoid cell signaling milieu would be depleted and altered due to reduction and substitution of normal substrates with unusual substrates, with unpredictable consequences for cellular communication
Distinct C4 sub-types and C3 bundle sheath isolation in the Paniceae grasses.
Funder: U.S. Department of Agriculture; Id: http://dx.doi.org/10.13039/100000199Funder: University of Missouri; Id: http://dx.doi.org/10.13039/100007165In C4 plants, the enzymatic machinery underpinning photosynthesis can vary, with, for example, three distinct C4 acid decarboxylases being used to release CO2 in the vicinity of RuBisCO. For decades, these decarboxylases have been used to classify C4 species into three biochemical sub-types. However, more recently, the notion that C4 species mix and match C4 acid decarboxylases has increased in popularity, and as a consequence, the validity of specific biochemical sub-types has been questioned. Using five species from the grass tribe Paniceae, we show that, although in some species transcripts and enzymes involved in multiple C4 acid decarboxylases accumulate, in others, transcript abundance and enzyme activity is almost entirely from one decarboxylase. In addition, the development of a bundle sheath isolation procedure for a close C3 species in the Paniceae enables the preliminary exploration of C4 sub-type evolution
Understanding the need for digital twinsβ data in patient advocacy and forecasting oncology
Digital twins are made of a real-world component where data is measured and a virtual component where those measurements are used to parameterize computational models. There is growing interest in applying digital twins-based approaches to optimize personalized treatment plans and improve health outcomes. The integration of artificial intelligence is critical in this process, as it enables the development of sophisticated disease models that can accurately predict patient response to therapeutic interventions. There is a unique and equally important application of AI to the real-world component of a digital twin when it is applied to medical interventions. The patient can only be treated once, and therefore, we must turn to the experience and outcomes of previously treated patients for validation and optimization of the computational predictions. The physical component of a digital twins instead must utilize a compilation of available data from previously treated cancer patients whose characteristics (genetics, tumor type, lifestyle, etc.) closely parallel those of a newly diagnosed cancer patient for the purpose of predicting outcomes, stratifying treatment options, predicting responses to treatment and/or adverse events. These tasks include the development of robust data collection methods, ensuring data availability, creating precise and dependable models, and establishing ethical guidelines for the use and sharing of data. To successfully implement digital twin technology in clinical care, it is crucial to gather data that accurately reflects the variety of diseases and the diversity of the population
- β¦