Publications by authors named "Patrick R Jones"
Article Synopsis
- * Using a (234)Th scavenging model, researchers estimated PAH fluxes that were generally higher than those based on sediment traps, highlighting differences in measurement techniques.
- * A significant finding is that alkylated PAHs made up 80% of total fluxes, contrasting with other regions where combustion-derived PAHs are more prevalent, indicating unique characteristics in this marine environment.
Article Synopsis
- - The effectiveness of ambient analysis using DART (Direct Analysis in Real Time) ion sources is influenced by fluid dynamics and mass transport in the sample area, which was visualized using the Schlieren technique to study gas flow profiles.
- - Experiments tested different configurations like skimmer or capillary inlets and various sampling methods, revealing how the helium flow pattern behaves under specific conditions and settings.
- - Results indicated that while DART sources generate a smooth helium stream up to 8 cm, flow disturbances vary based on probe size, placement, and gas settings, highlighting the need for optimization to enhance performance.
Article Synopsis
- Floating marine plastic debris acts like a sponge by adsorbing and concentrating pollutants from seawater, particularly in the North Pacific Gyre.
- Analysis of plastic debris revealed high levels of various hazardous substances: over 50% contained PCBs, around 40% had organochlorine pesticides, and nearly 80% included PAHs, with specific types identified.
- Most of the plastic particles were polyethylene, which doesn’t easily degrade; therefore, they remain on the ocean surface, trapping pollutants that are similar to those found in marine sediments.
Article Synopsis
- The study investigates how two compounds, NiCR and NiCR-2H, interact differently with DNA and how this relates to their varying cytotoxic effects on MCF-7 cancer cells.
- Both compounds were found to bind weakly to DNA, but NiCR-2H shows a stronger coordination with a specific part of the DNA molecule compared to NiCR.
- Additionally, NiCR-2H is more efficient in oxidizing guanines in DNA than NiCR, and it can be formed from NiCR through oxidation when exposed to KHSO(5).
Article Synopsis
- - DART mass spectrometry is a new technique enabling quick analysis of complex samples, and researchers are exploring its ability to detect nucleotides and nucleosides using the DART-AccuTOF instrument.
- - Experimentally, intact nucleotides were not detected; instead, they fragmented, producing a common fragment ion, [C(5)H(5)O](+), indicating intricate reactions in the DART ion source.
- - Unlike nucleotides, nucleosides were detected in intact form, and their fragmentation differed, highlighting the significant role of the phosphate group in nucleotide reactions.
Article Synopsis
- A new test has been developed to quickly and reliably check for sulfur materials in drywall using advanced scientific methods.
- The testing combines direct analysis in real time (DART) mass spectrometry and accurate-mass time-of-flight (TOF) mass spectrometry for effective results.
- This method aims to address concerns regarding potential issues caused by sulfur in wallboard.
Spiders produce high performance fibers with diverse mechanical properties and biological functions. Molecular and biochemical studies of spider egg case silk have revealed that the main constituent of the large diameter fiber contains the fibroin TuSp1. Here we demonstrate by SDS-PAGE and protein silver staining the presence of a distinct approximately 300-kDa polypeptide that is found in solubilized egg case sacs.
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- A new method for quickly identifying melamine in pet food using mass spectrometry (MS) is introduced, which eliminates the need for sample processing.
- The technique utilizes soft ionization via direct analysis in real time (DART), allowing for accurate measurements and multiple forms of data confirmation, improving confidence in results.
- By incorporating hydrogen/deuterium (H/D) exchange at the start of analysis, researchers can confirm melamine's identity without lengthy chromatography or sample preparation, enhancing detection limits and validation of the method.
Article Synopsis
- Thermoplastic resin pellets, used in many cheap consumer goods, often end up in the ocean after disposal, posing risks to marine life.
- Research conducted in 2003-2004 studied the contamination levels of persistent organic pollutants (POPs) on plastic debris from various locations, including the North Pacific Gyre and coastal areas in the U.S. and Mexico.
- The findings revealed significant levels of toxins such as PCBs, DDTs, PAHs, and hydrocarbons on plastic fragments, confirming that plastic can accumulate harmful pollutants in marine environments.
Article Synopsis
- * Researchers used proteomic techniques to identify common peptides in silk fibers from the black widow spider and isolated two specific peptides named SCP-1 and SCP-2.
- * The findings suggest that the aggregate gland is responsible for producing these peptides, with SCP-1 displaying metal-binding properties that may improve the strength and performance of the silk threads.
Nickel is considered a weak carcinogen. It is known to interact with DNA and DNA-binding proteins. The ability of certain nickel compounds to cleave DNA has been exploited mainly for research purposes and less for developing new anticancer drugs.
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- Spider silk proteins, known for their impressive strength and toughness, have been studied to isolate a new protein (ECP-2) from the black widow spider's egg case using advanced mass spectrometry and reverse genetics.
- ECP-2 shows about 52% similarity to an already known protein (ECP-1), featuring conserved regions and unique structural elements, making it important for silk composition.
- Analysis revealed that ECP-2 is mainly produced in the tubuliform gland, with higher mRNA levels compared to ECP-1, indicating its significant structural role alongside other proteins in the egg case silk fiber.
Article Synopsis
- - Araneoid spiders produce various silks through specialized glands, but the specific fibroin sequences for egg case fibers had not been identified until this study, which isolated "tubuliform spidroin 1" (TuSp1) from the black widow spider.
- - TuSp1 is selectively expressed in the spider's tubuliform gland and closely matches the amino acid composition of raw egg case silk, indicating it is a major component in the construction of egg cases.
- - The analysis reveals TuSp1 has a unique structure with repeating units of 184 amino acids, featuring polyserine and short polyalanine sequences, but lacks similarities to other known spider silk proteins, highlighting its distinct position in the spider
Spiders produce multiple types of silk that exhibit diverse mechanical properties and biological functions. Most molecular studies of spider silk have focused on fibroins from dragline silk and capture silk, two important silk types involved in the survival of the spider. In our studies we have focused on the characterization of egg case silk, a third silk fiber produced by the black widow spider, Latrodectus hesperus.
View Article and Find Full Text PDFThe glycosylamines of O-acetyl-protected GlcNAc and chitobiose, as well as two partially unprotected 1-C-aminomethyl glucosides, were photochemically coupled with orthogonally protected N-aspartyl-5-bromo-7-nitroindoline derivatives. The reactions proceeded under neutral conditions by irradiation with near-UV light. The glycosyl asparagines with N- or C-glycosyl linkages were afforded in 60-85% yield on a 10-70 mg scale.
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- Methylation of lysine 79 on histone H3 is linked to active chromatin and transcription across various species, but its relationship with other modifications of the H3 tail is still unclear.
- Research using mass spectrometry shows that increased acetylation of H3 correlates with higher levels of methylation at lysines 4 and 79, suggesting a coordinated mechanism connecting these modifications to active chromatin states.
[reaction: see text] Synthesis of glycosyl cyanides was optimized with a new catalyst system. Reduction of tri-O-acetyl-beta-L-fucopyranosyl cyanide with Pd-hydrogen, in the presence of Ac(2)O and Boc(2)O, gave N-protected-mono- and -di-(2,3,4-tri-O-acetyl-beta-L-fucopyranosylmethyl)-amines, which allow for the syntheses of small cluster oligosaccharide mimetics of fucopyranosylomethyl-substituted ureas. From di-(2,3,4-tri-O-acetyl-beta-L-fucopyranosylmethyl) amine was also prepared a carbamoyl chloride as a potentially useful synthon for preparation of more complex C-glycosidic conjugates.
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- A study analyzed the acetylation isoforms of histone H4 from butyrate-treated HeLa cells using various techniques including liquid chromatography and mass spectrometry.
- Only four specific acetylation sites were identified out of the potential 15, with notable modifications at lysines 5, 8, 12, 16 for tetra- and tri-acetylated forms, while the mono-acetylated form was primarily at lysine 16.
- The findings support a "zip" model for acetylation, suggesting that the modification occurs sequentially from Lys-16 to Lys-5, and show that deacetylation occurs in the reverse order, indicating a coordinated and non-random distribution of
Article Synopsis
- A new strategy for identifying covalent modification sites, particularly acetylation and methylation of histone H3 from chicken erythrocytes, has been developed using low enzyme ratios and short digestion times alongside advanced mass spectrometry techniques.
- High-accuracy MALDI-TOF mass measurements have successfully differentiated between methylated and acetylated peptides, pinpointing specific lysines on histone H3 that are modified.
- Notably, the method has revealed a new methylation site at lysine 79, and offers a faster and more efficient alternative to traditional protein analysis techniques like sequencing and Western blotting, promising advancements in chromosome research.