388 research outputs found
Synthesis of Medicinally Relevant Thiazolyl Aryl Ketones Under Mild Conditions
Purpose: The growing amount of clinical resistance observed in current antifungal drugs and in anti-HIV pharmaceuticals is a concern in the medical community. The purpose of this study is to develop a mild synthetic process for biomedically relevant thiazolyl aryl ketones that can be used to develop antifungal and anti-HIV drugs. We hypothesized that the proposed synthetic technique would be more efficient, produce fewer unwanted byproducts, and be more tolerant of functional groups than existing methods.
Methods: Prior to each of the ketone reactions, the necessary salt was synthesized by mixing thiazole and 9-bromofluorene neat in a reaction tube heated to 85 °C. The reaction was monitored for the disappearance of 9-bromofluorene, at which point the heating was stopped and the solid product was triturated to remove impurities and characterized using 1H NMR analysis. For each of the various ketone reactions, the aldehyde and base were added to a reaction tube and heated to 60 °C. Once heated, a solution of the salt (3-fluorenylthiazole) was mixed with the solvent, either methanol or THF, and was added dropwise via syringe. Conversion of the aldehyde to the ketone product was monitored by thin layer chromatography (TLC). The product ketone was purified using column chromatography and analyzed for purity by 1H NMR spectroscopy. This study was the repeated for each of the chosen aldehydes. The preparation of thiazolyl salicyl ketone was further analyzed for solvent effects by the introduction of 5% and 10% water, respectively, using otherwise identical reaction conditions. In these reactions, the ketone was isolated using preparative TLC and gravity filtration to separate the silica gel from the desired product. If the ketone was produced after the addition of water, then the reaction may be able to be conducted without the use of anhydrous methanol solvent. Instead, methanol bought in bulk could be substituted and the cost of production would be substantially reduced.
Results: The 3-fluorenylthiazol salt was produced in 91% yield. The yields for the thiazolyl phenyl ketone, thiazolyl 4-fluorophenyl ketone, and the thiazolyl salicyl ketone were 11%, 50%, and 55% yield respectively. Production of thiazolyl salicyl ketone with the addition of 5% water into the solvent produced the ketone with 11% yield. Production of thiazolyl salicyl ketone with the addition of 10% water into the solvent produced a ketone with 13% yield in trial 1 and 56% yield in trial 2.
Discussion: The study found that the two-step synthesis method was successful in producing the desired ketones. These findings suggest that this reaction mechanism could be further optimized to increase reaction yield in order to produce medicinally relevant ketones under mild conditions. Also, upon the addition of water to the solvent, the thiazolyl salicyl ketone was able to be produced in moderate yields in one trial. In this particular trial, salt and salicylaldehyde were added before the solvent and the base suggesting the order that reagents were added affected the percent yield of the ketone. The success of the trial provides promising results that suggest the synthetic method could be conducted without the use of anhydrous methanol thereby decreasing the cost of synthesis by utilizing water in replacement for methanol. Also, substituting water for methanol would provide a safety advantage if enough methanol is replaced so that the solvent is no longer flammable. Overall, the results provide the conclusion that the synthetic technique could be used to produce thiazolyl aryl ketones under mild conditions
Lipid-laden partially-activated plasmacytoid and CD4-CD8a+ dendritic cells accumulate in tissues in elderly mice
Background - Aging is associated with a decline in lymphocyte function however, little is known about dendritic cell (DC) subsets and aging. Aging is also associated with increasing circulating lipid levels and intracellular lipid accumulation modulates DC function. Whether age-associated increases in lipid levels influence DC biology is unknown. Thus, the effects of aging on DC subsets were assessed in vivo using young adult and elderly C57BL/6 J mice. Results - Major age-related changes included increased CD11c+ DC numbers in lymph nodes, spleens and livers, but not lungs, and significantly increased proportions of plasmacytoid (pDC) and CD4-CD8α+ DCs in lymph nodes and livers. Other changes included altered pDC activation status (decreased CD40, increased MHC class-I and MHC class-II), increased lipid content in pDCs and CD4-CD8α+ DCs, and increased expression of key mediators of lipid uptake including lipoprotein lipase, scavenger receptors (CD36, CD68 and LRP-1) in most tissues. Conclusions - Aging is associated with organ-specific numerical changes in DC subsets, and DC activation status, and increased lipid content in pDCs and CD4-CD8α+ DCs. Up-regulation of lipoprotein lipase and scavenger receptors by lipid-rich pDCs and CD4-CD8α+ DCs suggests these molecules contribute to DC lipid accumulation in the elderly. Lipid accumulation and modulated activation in pDCs and CD4-CD8α+ DCs may contribute to the declining responses to vaccination and infection with age
Oral History Conversation with Lydell Aaron (Beartha)
Oral History Interview conducted with Lydell Aaron. He founded Beartha Systems which builds scalable and smart systems that harness energy and resources for small communities
Wednesday Convocation
Program listing performers and works performe
Dispersal of Adult Culex Mosquitoes in an Urban West Nile Virus Hotspot: A Mark-Capture Study Incorporating Stable Isotope Enrichment of Natural Larval Habitats
Dispersal is a critical life history behavior for mosquitoes and is important for the spread of mosquito-borne disease. We implemented the first stable isotope mark-capture study to measure mosquito dispersal, focusing on Culex pipiens in southwest suburban Chicago, Illinois, a hotspot of West Nile virus (WNV) transmission. We enriched nine catch basins in 2010 and 2011 with 15N-potassium nitrate and detected dispersal of enriched adult females emerging from these catch basins using CDC light and gravid traps to distances as far as 3 km. We detected 12 isotopically enriched pools of mosquitoes out of 2,442 tested during the two years and calculated a mean dispersal distance of 1.15 km and maximum flight range of 2.48 km. According to a logistic distribution function, 90% of the female Culex mosquitoes stayed within 3 km of their larval habitat, which corresponds with the distance-limited genetic variation of WNV observed in this study region. This study provides new insights on the dispersal of the most important vector of WNV in the eastern United States and demonstrates the utility of stable isotope enrichment for studying the biology of mosquitoes in other disease systems.The open access fee for this work was funded through the Texas A&M University Open Access to Knowledge (OAK) Fund
Ketamine effects on memory reconsolidation favor a learning model of delusions.
Delusions are the persistent and often bizarre beliefs that characterise psychosis. Previous studies have suggested that their emergence may be explained by disturbances in prediction error-dependent learning. Here we set up complementary studies in order to examine whether such a disturbance also modulates memory reconsolidation and hence explains their remarkable persistence. First, we quantified individual brain responses to prediction error in a causal learning task in 18 human subjects (8 female). Next, a placebo-controlled within-subjects study of the impact of ketamine was set up on the same individuals. We determined the influence of this NMDA receptor antagonist (previously shown to induce aberrant prediction error signal and lead to transient alterations in perception and belief) on the evolution of a fear memory over a 72 hour period: they initially underwent Pavlovian fear conditioning; 24 hours later, during ketamine or placebo administration, the conditioned stimulus (CS) was presented once, without reinforcement; memory strength was then tested again 24 hours later. Re-presentation of the CS under ketamine led to a stronger subsequent memory than under placebo. Moreover, the degree of strengthening correlated with individual vulnerability to ketamine's psychotogenic effects and with prediction error brain signal. This finding was partially replicated in an independent sample with an appetitive learning procedure (in 8 human subjects, 4 female). These results suggest a link between altered prediction error, memory strength and psychosis. They point to a core disruption that may explain not only the emergence of delusional beliefs but also their persistence
Awareness of vaccination status and its predictors among working people in Switzerland
BACKGROUND: Adult vaccination status may be difficult to obtain, often requiring providers to rely on individual patient recall. To determine vaccination status awareness and the sociodemographic predictors of awareness for tetanus, hepatitis A and B, tick born encephalitis (TBE) and influenza vaccination. METHODS: Multivariate analyses were used to evaluate a questionnaire survey of 10 321 employees (4070 women and 6251 men aged 15–72 years) of two companies in Switzerland. RESULTS: Among 10 321 respondents, 75.5% reported knowing their tetanus vaccination status, 64.1% hepatitis A, 61.1% hepatitis B, 64.3% TBE and 71.9% influenza. Between 1 in 4 and 1 in 3 employees were not aware of their vaccination status. Differences in awareness for the five vaccinations considered correlated with gender and language. These differences persisted in multivariate analyses. CONCLUSION: Women employees, German-speaking employees and employees who paid more attention to their diet were more often aware of their vaccination status. A more reliable and readily accessible data source for vaccination status is needed in order to capitalize on opportunities to update vaccinations among Swiss employees
The Physical Conditions of Emission-Line Galaxies at Cosmic Dawn from JWST/NIRSpec Spectroscopy in the SMACS 0723 Early Release Observations
We present rest-frame optical emission-line flux ratio measurements for five
galaxies observed by the JWST Near-Infared Spectrograph (NIRSpec) in the
SMACS 0723 Early Release Observations. We add several quality-control and
post-processing steps to the NIRSpec pipeline reduction products in order to
ensure reliable relative flux calibration of emission lines that are closely
separated in wavelength, despite the uncertain \textit{absolute}
spectrophotometry of the current version of the reductions. Compared to
galaxies in the literature, the galaxies have similar
[OIII]5008/H ratios, similar [OIII]4364/H
ratios, and higher (0.5 dex) [NeIII]3870/[OII]3728
ratios. We compare the observations to MAPPINGS V photoionization models and
find that the measured [NeIII]3870/[OII]3728,
[OIII]4364/H, and [OIII]5008/H emission-line
ratios are consistent with an interstellar medium that has very high ionization
(, units of cm~s), low metallicity (), and very high pressure (, units of
cm). The combination of [OIII]4364/H and
[OIII](4960+5008)/H line ratios indicate very high electron
temperatures of , further implying metallicities of
with the application of low-redshift calibrations for
``-based'' metallicities. These observations represent a tantalizing new
view of the physical conditions of the interstellar medium in galaxies at
cosmic dawn.Comment: Accepted for publication in AAS Journals. 14 pages, 6 figures, 3
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