4,401 research outputs found
Optical Tweezers as an Effective Tool for Spermatozoa Isolation from Mixed Forensic Samples
A single focus optical tweezer is formed when a laser beam is launched through a high numerical aperture immersion objective. This objective focuses the beam down to a diffraction-limited spot, which creates an optical trap where cells suspended in aqueous solutions can be held fixed. Spermatozoa, an often probative cell type in forensic investigations, can be captured inside this optical trap and dragged one by one across millimeter-length distances in order to create a cluster of cells which can be subsequently drawn up into a capillary for collection. Sperm cells are then ejected onto a sterile cover slip, counted, and transferred to a tube for DNA analysis workflow. The objective of this research was to optimize sperm cell collection for maximum DNA yield, and to determine the number of trapped sperm cells necessary to produce a full STR profile. A varying number of sperm cells from both a single-source semen sample and a mock sexual assault sample were isolated utilizing optical tweezers and processed using conventional STR analysis methods. Results demonstrated that approximately 50 trapped spermatozoa were required to obtain a consistently full DNA profile. A complete, single-source DNA profile was also achieved by isolating sperm cells via optical trapping from a mixture of sperm and vaginal epithelial cells. Based on these results, optical tweezers are a viable option for forensic applications such as separation of mixed populations of cells in forensic evidence
Mini Review
Gestational diabetes mellitus (GDM) is a rising global health problem that affects approximately 6% of
pregnant women. Lifestyle interventions, particularly diet, and exercise are the first-line treatment, followed
by pharmacotherapy, but with associated side effects to both mother and offspring. Modulation of gut
microbiota may help prevent or manage GDM. Some gut bacterial groups associated with GDM are also
associated with inflammatory biomarkers and gut dysbiosis. Available literature reports that low-glycaemic
index diet reduces maternal fasting and 2-hour postprandial glucose and maintains a beneficial gut bacterial
composition. Pre- and probiotics can aid GDM therapy by modulating gut microbiota to eubiotic status and
improving glucose metabolism. Probiotics as adjuvant GDM therapy should consider bacterial strains,
dosage, and treatment duration. Limitations in their use require further studies to develop specific probioticbased GDM supplement therapy that impacts glycaemic control and inflammatory status by reducing
fasting plasma glucose, insulin resistance, and improving lipid profiles of pregnant women.info:eu-repo/semantics/publishedVersio
Conformational Change in Molecular Crystals: Impact of Solvate Formation and Importance of Conformational Free Energies
The ribosome assembly gene network is controlled by the feedback regulation of transcription elongation
Ribosome assembly requires the concerted expression of hundreds of genes, which are transcribed by all three nuclear RNA polymerases. Transcription elongation involves dynamic interactions between RNA polymerases and chromatin. We performed a synthetic lethal screening in Saccharomyces cerevisiae with a conditional allele of SPT6, which encodes one of the factors that facilitates this process. Some of these synthetic mutants corresponded to factors that facilitate pre-rRNA processing and ribosome biogenesis. We found that the in vivo depletion of one of these factors, Arb1, activated transcription elongation in the set of genes involved directly in ribosome assembly. Under these depletion conditions, Spt6 was physically targeted to the upregulated genes, where it helped maintain their chromatin integrity and the synthesis of properly stable mRNAs. The mRNA profiles of a large set of ribosome biogenesismutants confirmed the existence of a feedback regulatory network among ribosome assembly genes. The transcriptional response in this network depended on both the specific malfunction and the role of the regulated gene. In accordance with our screening, Spt6 positively contributed to the optimal operation of this global network. On the whole, this work uncovers a feedback control of ribosome biogenesis by fine-tuning transcription elongation in ribosome assembly factor-coding genes.Ministerio de EconomĂa y Competitividad BFU2013-48643-C3-1-P, BFU2016-77728-C3-1-P, BFU2013-48643-C3- 3-P, BFU2013-42958-PJunta de AndalucĂa P12-BIO1938MO, P08-CVI-03508Comunidad Valenciana 2015/00
Magnetism in the Brown Dwarf Regime
A suite of discoveries in the last two decades demonstrate that we are now at
a point where incorporating magnetic behavior is key for advancing our ability
to characterize substellar and planetary systems. The next decade heralds the
exciting maturation of the now-burgeoning field of brown dwarf magnetism, and
investing now in brown dwarf magnetism will provide a key platform for
exploring exoplanetary magnetism and habitability beyond the solar system. We
anticipate significant discoveries including: the nature of substellar and
planetary magnetic dynamos, the characterization of exo-aurora physics and
brown dwarf magnetospheric environments, and the role of satellites in
manifestations of substellar magnetic activity. These efforts will require
significant new observational capabilities at radio and near infrared
wavelengths, dedicated long-term monitoring programs, and committed support for
the theoretical modeling efforts underpinning the physical processes of the
magnetic phenomenaComment: Decadal 2020 science white pape
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