The first total synthesis of (+)-mucosin

The first total synthesis of (+)-mucosin has been completed allowing assignment of the absolute stereochemistry of the natural product. A zirconium induced co-cyclisation was utilised to install the correct stereochemistry of the four contiguous stereocentres around the unusual bicyclo[4.3.0]nonene core

Oxidation of tertiary amine-derivatized surfaces to control protein adhesion

Selective oxidation of omega-tertiary amine self-assembled thiol monolayers to tertiary amine N-oxides is shown to transform the adhesion of model proteins lysozyme and fibrinogen upon them. Efficient preparation of both secondary and tertiary linker amides as judged by X-ray photoelectron spectroscopy (XPS) and water droplet contact angle was achieved with an improved amide bond formation on gold quartz crystal microbalance (QCM) sensors using 2-(1H-7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyl hexafluorophosphate methanaminium uronium (HATU). Oxidation with hydrogen peroxide was similarly assessed, and adhesion of lysozyme and fibrinogen from phosphate buffered saline was then assayed by QCM and imaged by AFM. Tertiary amine-functionalized sensors adsorbed multilayers of aggregated lysozyme, whereas tertiary amine N-oxides and triethylene glycol-terminated monolayers are consistent with small protein aggregates. The surface containing a dimethylamine N-oxide headgroup and ethyl secondary amide linker showed the largest difference in adsorption of both proteins. Oxidation of tertiary amine decorated surfaces therefore holds the potential for selective deposition of proteins and cells through masking and other patterning techniques

Reactive Oxygen Species (ROS) and Antioxidants as Immunomodulators in Exercise: Implications for Heme Oxygenase and Bilirubin

Exercise is commonly prescribed as a lifestyle treatment for chronic metabolic diseases as it functions as an insulin sensitizer, cardio-protectant, and essential lifestyle tool for effective weight maintenance. Exercise boosts the production of reactive oxygen species (ROS) and subsequent transient oxidative damage, which also upregulates counterbalancing endogenous antioxidants to protect from ROS-induced damage and inflammation. Exercise elevates heme oxygenase-1 (HO-1) and biliverdin reductase A (BVRA) expression as built-in protective mechanisms, which produce the most potent antioxidant, bilirubin. Together, these mitigate inflammation and adiposity. Moderately raising plasma bilirubin protects in two ways: (1) via its antioxidant capacity to reduce ROS and inflammation, and (2) its newly defined function as a hormone that activates the nuclear receptor transcription factor PPARα. It is now understood that increasing plasma bilirubin can also drive metabolic adaptions, which improve deleterious outcomes of weight gain and obesity, such as inflammation, type II diabetes, and cardiovascular diseases. The main objective of this review is to describe the function of bilirubin as an antioxidant and metabolic hormone and how the HO-1–BVRA–bilirubin–PPARα axis influences inflammation, metabolic function and interacts with exercise to improve outcomes of weight management

Double In Situ Approach for the Preparation of Polymer Nanocomposite with Multi-functionality

A novel one-step synthetic route, the double in situ approach, is used to produce both TiO2nanoparticles and polymer (PET), and simultaneously forming a nanocomposite with multi-functionality. The method uses the release of water during esterification to hydrolyze titanium (IV) butoxide (Ti(OBu)4) forming nano-TiO2in the polymerization vessel. This new approach is of general significance in the preparation of polymer nanocomposites, and will lead to a new route in the synthesis of multi-functional polymer nanocomposites

Trade-off between sex and growth in diatoms: Molecular mechanisms and demographic implications

Diatoms are fast-growing and winning competitors in aquatic environments, possibly due to optimized growth performance. However, their life cycles are complex, heteromorphic, and not fully understood. Here, we report on the fine control of cell growth and physiology during the sexual phase of the marine diatom Pseudo-nitzschia multistriata. We found that mating, under nutrient replete conditions, induces a prolonged growth arrest in parental cells. Transcriptomic analyses revealed down-regulation of genes related to major metabolic functions from the early phases of mating. Single-cell photophysiology also pinpointed an inhibition of photosynthesis and storage lipids accumulated in the arrested population, especially in gametes and zygotes. Numerical simulations revealed that growth arrest affects the balance between parental cells and their siblings, possibly favoring the new generation. Thus, in addition to resources availability, life cycle traits contribute to shaping the species ecological niches and must be considered to describe and understand the structure of plankton communities

Unos L-alanil-L-glutamina tijekom kratkotrajne visokointenzivne vježbe u uvjetima blagoga hidracijskoga stresa

The effect of acute L-alanyl-L-glutamine (AG) ingestion on selected hormonal and electrolyte measures was examined during repetitive, short duration, high intensity exercise with mild hypohydration. Subjects (20.3±1.1 yrs; 180.3±10.4 cm; 83.1±14.0 kg; 11.6±3.6% body fat) reported to the Human Performance Laboratory on four occasions. During each trial subjects were hypohydrated to -2.5% of their baseline body mass. During one trial (DHY) subjects rested in a recumbent position for 45 minutes before commencing the exercise session. During the other three trials subjects were rehydrated to 1.5% of their baseline body mass, before exercise, by drinking water only (W), or with two different doses of AG – a low dose (LDAG: 0.05 g�kg-1) and a high dose (HDAG: 0.2 g�kg-1). The exercise protocol consisted of ten 10-second sprints on a cycle ergometer with a 1-min rest between each sprint. Blood draws were collected once the subject achieved the desired level of hypohydration, immediately pre-exercise, immediately post-exercise, and 24 hrs postexercise. Blood samples were analyzed for glutamine, potassium, sodium, aldosterone, arginine vasopressin, C-reactive protein, interleukin-6, malondialdehyde, testosterone, cortisol, ACTH, and growth hormone. The area under the curve (AUC) analysis demonstrated significantly greater sodium concentrations for DHY compared to all other trials. The AUC analysis for aldosterone showed significantly lower concentrations at LDAG compared to DHY. No other differences between trials were observed in any other hormonal or biochemical responses. AG ingestion during a short duration, anaerobic exercise and mild hypohydration stress had a limited effect on selected hormonal and biochemical measures.Učinci akutnoga, trenutačnoga uzimanja L-alanil-L-glutamina (AG) na odabrane hormonske i elektrolitne pokazatelje ispitani su tijekom ponavljajuće kratkotrajne visokointenzivne aktivnosti u uvjetima blage hipohidracije ispitanika. Ispitanici (20,3±1,1 godina; 180,3±10,4 cm; 83,1±14,0 kg; 11,6±3,6% tjelesne masti) bili su testirani u Human Performance Laboratory u četiri navrata. Tijekom svakoga pojedinačnoga mjerenja ispitanici su bili hipohidrirani do -2,5% svoje početne, osnovne tjelesne mase. Tijekom prvoga testiranja (DHY) ispitanici su se odmarali ležeći 45 minuta prije no što su počeli provoditi protokol vježbanja. Tijekom sljedeća tri mjerenja ispitanici su rehidrirani do 1,5% njihove početne tjelesne mase prije vježbanja, i to: pijenjem samo vode (W) te unosom dviju različitih doza AG - male doze (LDAG: 0,05 g∙kg-1) i velike doze (HDAG: 0,2 g∙kg-1). Protokol vježbanja sastojao se od po deset sprintova na bicikl-ergometru u trajanju od 10 sekunda s jednominutnim odmorom između svakoga sprinta. Uzorci krvi vađeni su odmah nakon što je ispitanik dosegao željenu razinu hipohidracije, neposredno prije početka vježbanja, neposredno nakon završetka vježbanja i 24 sata nakon vježbanja. U uzorcima krvi analizirana je koncentracija glutamina, kalija, natrija, aldosterona, arginin vazopresina, C-reaktivnoga proteina, interleukina-6, malondialdehida, testosterona, kortizola, ACTH-a i hormona rasta. Analiza površine ispod krivulje pokazala je statistički značajno veću razinu koncentracije natrija u ispitanika u prvom testu (DHY) u odnosu na sva ostala mjerenja. Analiza površine ispod krivulje za aldosteron je pokazala značajno nižu koncentraciju u testu LDAG u odnosu na test DHY. Nisu zapažene značajne razlike između pojedinih mjerenja ni u jednoj drugoj hormonskoj i biokemijskoj reakciji na protokol vježbanja. Uzimanje AG tijekom kratkotrajne anaerobne aktivnosti i u stanju blagoga hipohidracijskoga stresa pokazalo je ograničene učinke na odabrane hormonske i biokemijske pokazatelje

Development of mPing-based activation tags for crop insertional mutagenesis

Modern plant breeding increasingly relies on genomic information to guide crop improvement. Although some genes are characterized, additional tools are needed to effectively identify and characterize genes associated with crop traits. To address this need, the mPing element from rice was modified to serve as an activation tag to induce expression of nearby genes. Embedding promoter sequences in mPing resulted in a decrease in overall transposition rate; however, this effect was negated by using a hyperactive version of mPing called mmPing20. Transgenic soybean events carrying mPing-based activation tags and the appropriate transposase expression cassettes showed evidence of transposition. Expression analysis of a line that contained a heritable insertion of the mmPing20F activation tag indicated that the activation tag induced overexpression of the nearby soybean genes. This represents a significant advance in gene discovery technology as activation tags have the potential to induce more phenotypes than the original mPing element, improving the overall effectiveness of the mutagenesis system

Optimization of a high work function solution processed vanadium oxide hole-extracting layer for small molecule and polymer organic photovoltaic cells

We report a method of fabricating a high work function, solution processable vanadium oxide (V2Ox(sol)) hole-extracting layer. The atmospheric processing conditions of film preparation have a critical influence on the electronic structure and stoichiometry of the V2Ox(sol), with a direct impact on organic photovoltaic (OPV) cell performance. Combined Kelvin probe (KP) and ultraviolet photoemission spectroscopy (UPS) measurements reveal a high work function, n-type character for the thin films, analogous to previously reported thermally evaporated transition metal oxides. Additional states within the band gap of V2Ox(sol) are observed in the UPS spectra and are demonstrated using X-ray photoelectron spectroscopy (XPS) to be due to the substoichiometric nature of V2Ox(sol). The optimized V2Ox(sol) layer performance is compared directly to bare indium–tin oxide (ITO), poly(ethyleneoxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and thermally evaporated molybdenum oxide (MoOx) interfaces in both small molecule/fullerene and polymer/fullerene structures. OPV cells incorporating V2Ox(sol) are reported to achieve favorable initial cell performance and cell stability attributes