2,455 research outputs found
Toxic Cyanobacteria Aerosols: Tests of Filters for Cells
Aerosolization of toxic cyanobacteria released from the surface of lakes is a new area of study that could uncover a previously unknown route of exposure to toxic cyanobacteria. Since toxic cyanobacteria may be responsible for adverse human health effects, methods and equipment need to be tested and established for monitoring these airborne bacteria. The primary focus of this study was to create controlled laboratory experiments that simulate natural lake aerosol production. I set out to test for the best type of filter to collect and analyze the aerosolized cells as small as 0.2-2.0 µm, known as picoplankton. To collect these aerosols, air was vacuumed from just above a sample of lake water passing through either glass fiber filters (GFF) or 0.22 µm MF-Millipore™ membrane filters (0.22 Millipore™). Filter collections were analyzed through epiflourescence microscopy for determining cell counts. Data analysis revealed that 0.22 Millipore™ filters were the best option for cell enumeration providing better epiflourescence optical quality and higher cell counts
Methods for the synthesis of polyhydroxylated piperidines by diastereoselective dihydroxylation: Exploitation in the two-directional synthesis of aza-C-linked disaccharide derivatives
Background: Many polyhydroxylated piperidines are inhibitors of the oligosaccharide processing
enzymes, glycosidases and glycosyltransferases. Aza-C-linked disaccharide mimetics are compounds
in which saturated polyhydroxylated nitrogen and oxygen heterocycles are linked by an all-carbon
tether. The saturated oxygen heterocycle has the potential to mimic the departing sugar in a
glycosidase-catalysed reaction and aza-C-linked disaccharide mimetics may, therefore, be more
potent inhibitors of these enzymes.
Results: The scope, limitations and diastereoselectivity of the dihydroxylation of stereoisomeric
2-butyl-1-(toluene-4-sulfonyl)-1,2,3,6-tetrahydro-pyridin-3-ols is discussed. In the absence of a 6-
substituent on the piperidine ring, the Upjohn (cat. OsO4, NMO, acetone-water) and Donohoe
(OsO4, TMEDA, CH2Cl2) conditions allow complementary diastereoselective functionalisation of
the alkene of the (2R*,3R*) diastereoisomer. However, in the presence of a 6-substituent, the
reaction is largely controlled by steric effects with both reagents. The most synthetically useful
protocols were exploited in the two-directional synthesis of aza-C-linked disaccharide analogues.
A two-directional oxidative ring expansion was used to prepare bis-enones such as (2R,6S,2'S)-6-
methoxy-2-(6-methoxy-3-oxo-3,6-dihydro-2H-pyran-2-ylmethyl)-1-(toluene-4-sulfonyl)-1,6-
dihydro-2H-pyridin-3-one from the corresponding difuran. Selective substitution of its N,O acetal
was possible. The stereochemical outcome of a two-directional Luche reduction step was different
in the two heterocyclic rings, and depended on the conformation of the ring. Finally, twodirectional
diastereoselective dihydroxylation yielded seven different aza-C-linked disaccharide
analogues.
Conclusion: A two-directional approach may be exploited in the synthesis of aza-C-linked
disaccharide mimetics. Unlike previous approaches to similar molecules, neither of the heterocyclic
rings is directly derived from a sugar, allowing mimetics with unusual configurations to be prepared.
The work demonstrates that highly unsymmetrical molecules may be prepared using a two
directional approach. The deprotected compounds may have potential as inhibitors of
oligosaccharide-processing enzymes and as tools in chemical genetic investigations
Extending genome-wide association study (GWAS) results to test classic anthropological hypotheses: Human third molar agenesis and the ‘probable mutation effect’
A genome-wide association study (GWAS) identifies regions of the genome that likely affect the variable state of a phenotype of interest. These regions can then be studied with population genetic methods to make inferences about the evolutionary history of the trait. There are increasing opportunities to use GWAS results – even from clinically-motivated studies – for tests of classic anthropological hypotheses. One such example, presented here as a case study for this approach, involves tooth development variation related to dental crowding. Specifically, more than 10% of humans fail to develop one or more permanent third molars (M3 agenesis). M3 presence/absence variation within human populations has a significant genetic component (heritability estimate h2 = 0.47). The evolutionary significance of M3 agenesis has a long history of anthropological speculation. First, the modern frequency of M3 agenesis could reflect a relaxation of selection pressure to retain larger and more teeth following the origins of cooking and other food-softening behaviors (i.e., the genetic drift hypothesis, or classically, the “probable mutation effect”). Alternatively, commensurate with increasing hominin brain size and facial shortening, M3 agenesis may have conferred an adaptive fitness advantage if the risk of M3 impaction and potential health complications was reduced (i.e., the positive selection hypothesis). A recent GWAS identified 70 genetic loci that may play a role in human M3 presence/absence variation. To begin evaluating the contrasting evolutionary scenarios for M3 agenesis, we used the integrated haplotype score (iHS) statistic to test whether those 70 genetic regions are enriched for genomic signatures of recent positive selection. None of our findings are inconsistent with the null hypothesis of genetic drift to explain the high prevalence of human M3 agenesis. This result might suggest that M3 impaction rates for modern humans don’t accurately retrodict those of the pre-agricultural past. Alternatively, the absence of support for the positive selection hypothesis could reflect a lack of power; this analysis should be repeated following the completion of more comprehensive GWAS analyses for human M3 agenesis
The Obesity Epidemic: Survey of Current Physical Therapy Trends in North Dakota
Background and Purpose. Many different health professionals are involved in the prevention and treatment of obesity. The APTA believes that physical therapists should be in a leadership role among other health care providers in providing patient education and instruction regarding physical activity. The purpose of this study was to determine current practice trends among physical therapists in the state of North Dakota relating to patients who are overweight or obese.
Subjects and Methods. Three hundred surveys were mailed to randomly selected physical therapists licensed in the State of North Dakota. The survey consisted of23 questions concerning level of training, referral rates, comfort level in treating patients who are overweight or obese, and interventions provided to these patients.
Results. Of the 300 surveys sent out, 136 (45.3%) were completed and returned for inclusion in this study. Those physical therapists who indicated they had advanced training did not have significantly higher comfort level in treating patients who are overweight or obese. Similarly there was no significant difference between advanced training and discussion or recording of weight status. Seventy-five percent of therapists surveyed had not received any referrals for weight management in the past year. Appearance, weight/height measurements, body mass index (BMI), and patient opinion were the most commonly used methods to assess weight status. The most frequently used interventions included patient education, aerobic exercise, and strength training.
Discussion and Conclusion. Physical therapists have appropriate education to identify at-risk patients and provide intervention to improve weight status, but are not currently active in promoting themselves as members of the weight management team. Additional training may be necessary in the areas of objective methods of assessing weight status and weight management programs for patients with other co-morbidities
A pyrene-appended spiropyran for selective photo-switchable binding of Zn(II): UV-visible and fluorescence spectroscopy studies of binding and non-covalent attachment to graphene, graphene oxide and carbon nanotubes
PublishedArticleSynthesis of photo-switchable, Zn2+ sensitive hybrid materials was achieved by facile non-covalent functionalization of graphene, graphene oxide and carbon nanotubes with a pyrene-appended spiropyran. Solution phase binding studies, using UV–visible and fluorescence spectroscopy, indicated that the pyrene-spiropyran dyad was highly selective for Zn2+ over a range of potentially competitive cations and that binding occurred with 1:1 stoichiometry and a binding constant of K=1.4×104 mol−1 dm3 at 295 K. Zn2+ binding was promoted by UV irradiation or in darkness and reversed upon irradiation with visible light.Engineering & Physical Sciences Research Council (EPSRC
Regulation of adipose tissue inflammation by interleukin 6
Obesity is associated with a chronic state of low-grade inflammation and progressive tissue infiltration by immune cells and increased expression of inflammatory cytokines. It is established that interleukin 6 (IL6) regulates multiple aspects of metabolism, including glucose disposal, lipolysis, oxidative metabolism, and energy expenditure. IL6 is secreted by many tissues, but the role of individual cell types is unclear. We tested the role of specific cells using a mouse model with conditional expression of the Il6 gene. We found that IL6 derived from adipocytes increased, while IL6 derived from myeloid cells and muscle suppressed, macrophage infiltration of adipose tissue. These opposite actions were associated with a switch of IL6 signaling from a canonical mode (myeloid cells) to a noncanonical trans-signaling mode (adipocytes and muscle) with increased expression of the ADAM10/17 metalloprotease that promotes trans-signaling by the soluble IL6 receptor alpha. Collectively, these data demonstrate that the source of IL6 production plays a major role in the physiological regulation of metabolism
Concert recording 2018-03-09a
[Track 1]. Sonata in E major, BWV 1035. I. Adagio ma non tanto [Track 2]. II. Allegro [Track 3]. III. Siciliano / J.S. Bach -- [Track 4]. Madrigal / Philippe Gaubert -- [Track 5]. Sonata no. 3 in G major. I. Adagio II. Allegro / G.F. Handel -- [Track 6]. Sonata for flute and piano. I. Allegro scherzando / Otar Taktakishvili -- [Track 7]. Sonata in A minor, WQ 132 for solo flute. I. Poco adagio / C.P.E. Bach -- [Track 8]. Duo no. 1, op. 80. I. Allegro con gusto / Friedrich Kahlau -- [Track 9]. Suite modale. I. Adagio / Ernest Bloch -- [Track 10]. Maya / Ian Clarke -- [Track 11]. Ballade, op. 288 / Carl Reinecke -- [Track 12]. Fantasie, op. 79 / Gabriel Fauré -- [Track 13]. Duettino for two flutes and piano, op. 36 / Francis Doppler
Complete Genome Sequences of Chop, DelRio, and GrandSlam, Three Gordonia Phages Isolated from Soil in Central Arkansas
Chop, DelRio, and GrandSlam are phage with a Siphoviridae morphotype isolated from soil in Arkansas using the host Gordonia terrae 3612. All three are temperate, and their genomes share at least 96% nucleotide identity. These phage are assigned to cluster DI based on gene content similarity to other sequenced actinobacteriophage
The novel mitochondria-targeted hydrogen sulfide (H2S) donors AP123 and AP39 protect against hyperglycemic injury in microvascular endothelial cells in vitro.
The development of diabetic vascular complications is initiated, at least in part, by mitochondrial reactive oxygen species (ROS) production in endothelial cells. Hyperglycemia induces superoxide production in the mitochondria and initiates changes in the mitochondrial membrane potential that leads to mitochondrial dysfunction. Hydrogen sulfide (H2S) supplementation has been shown to reduce the mitochondrial oxidant production and shows efficacy against diabetic vascular damage in vivo. However, the half-life of H2S is very short and it is not specific for the mitochondria. We have therefore evaluated two novel mitochondria-targeted anethole dithiolethione and hydroxythiobenzamide H2S donors (AP39 and AP123 respectively) at preventing hyperglycemia-induced oxidative stress and metabolic changes in microvascular endothelial cells in vitro. Hyperglycemia (HG) induced significant increase in the activity of the citric acid cycle and led to elevated mitochondrial membrane potential. Mitochondrial oxidant production was increased and the mitochondrial electron transport decreased in hyperglycemic cells. AP39 and AP123 (30-300nM) decreased HG-induced hyperpolarisation of the mitochondrial membrane and inhibited the mitochondrial oxidant production. Both H2S donors (30-300nM) increased the electron transport at respiratory complex III and improved the cellular metabolism. Targeting H2S to mitochondria retained the cytoprotective effect of H2S against glucose-induced damage in endothelial cells suggesting that the molecular target of H2S action is within the mitochondria. Mitochondrial targeting of H2S also induced >1000-fold increase in the potency of H2S against hyperglycemia-induced injury. The high potency and long-lasting effect elicited by these H2S donors strongly suggests that these compounds could be useful against diabetic vascular complications
- …