Introducing of an Unexplored Aza-BODIPY Diradicaloids with 4-(2,6-Di-butyl)phenoxyl Radicals Located in 1,7-Positions of the Aza-BODIPY Core.

We have prepared and characterized two diradicaloid systems and that originated from the oxidation of a 1,7-(4-(2,6-di--butyl)phenol)-substituted aza-BODIPY core. The aza-BODIPY diradicaloids were characterized by a large array of experimental and computational methods. The diamagnetic closed-shell state was postulated as the ground state in solution and a solid-state with the substantial thermal population originating from both open-shell diradical and open-shell triplet states observed at room temperature.

Imprecision of high-sensitivity cardiac troponin assays at the female 99th-percentile.

Background: An analytical benchmark for high-sensitivity cardiac troponin (hs-cTn) assays is to achieve a coefficient of variation (CV) of ≤ 10.0 % at the 99th percentile upper reference limit (URL) used for the diagnosis of myocardial infarction. Few prospective multicenter studies have evaluated assay imprecision and none have determined precision at the female URL which is lower than the male URL for all cardiac troponin assays.

Outsourcing Intersystem Crossing without Heavy Atoms: Energy Transfer Dynamics in PyridoneBODIPY-C Complexes.

The excited state dynamics in two fully characterized pyridoneBODIPY-fullerene complexes were investigated using time-resolved spectroscopy. Photoexcitation was initially localized on the pyridoneBODIPY chromophore. The energy was rapidly transferred to the fullerene, which subsequently underwent ISC to form a triplet state and returned the energy to the pyridoneBODIPY via triplet-triplet energy transfer.

Light-Driven Hydrodefluorination of Electron-Rich Aryl Fluorides by an Anionic Rhodium-Gallium Photoredox Catalyst.

An anionic Rh-Ga complex catalyzed the hydrodefluorination of challenging C-F bonds in electron-rich aryl fluorides and trifluoromethylarenes when irradiated with violet light in the presence of H , a stoichiometric alkoxide base, and a crown-ether additive. Based on theoretical calculations, the lowest unoccupied molecular orbital (LUMO), which is delocalized across both the Rh and Ga atoms, becomes singly occupied upon excitation, thereby poising the Rh-Ga complex for photoinduced single-electron transfer (SET). Stoichiometric and control reactions support that the C-F activation is mediated by the excited anionic Rh-Ga complex.

Goitered Gazelle Responded to Human Disturbance by Increasing Vigilance Rather than Changing the Group Size.

Nonlethal human disturbances have been confirmed to have a negative effect on wildlife in a variety of ways, including on behaviors. In many studies, the impact of human disturbances on gregarious species of wildlife is assessed through changes in their social organization and vigilance. In our study in the Kalamaili Nature Reserve, China, we wanted to estimate the impacts of differing levels of human disturbances on two different group types (mixed-sex and all-male) of goitered gazelle, , living in three functional zones (experimental, buffer, and core zones), which represent high, medium, and low human disturbance levels, respectively.

Different environmental requirements of female and male Siberian ibex, Capra sibirica.

In sexually dimorphic species, males and females may select different habitat for greater fitness. However, the key factors that play a leading role between sexes in habitat selection are still poorly understood. In this paper, we investigated the possible causes of the differences in habitat preference between male and female Siberian ibex (Capra sibirica) living in the Tianshan Mountains (China).

Fully Conjugated Pyrene-BODIPY and Pyrene-BODIPY-Ferrocene Dyads and Triads: Synthesis, Characterization, and Selective Noncovalent Interactions with Nanocarbon Materials.

Several pyrene-boron-dipyrromethene (BODIPY) and pyrene-BODIPY-ferrocene derivatives with a fully conjugated pyrene fragment appended to the α-position(s) of the BODIPY core have been prepared by Knoevenagel condensation reaction and characterized by one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR), UV-vis, fluorescence spectroscopy, high-resolution mass spectrometry as well as X-ray crystallography. The redox properties of new donor-acceptor BODIPY dyads and triads were studied by electrochemical (cyclic voltammetry (CV) and differential pulse voltammetry (DPV)) and spectroelectrochemical approaches. Formation of weakly bonded noncovalent complexes between the new pyrene-BODIPYs and nanocarbon materials (C, C, single-walled carbon nanotube (SWCNT), and graphene) was studied by UV-vis, steady-state fluorescent, and time-resolved transient absorption spectroscopy.

Two-photon uncaging of bioactive thiols in live cells at wavelengths above 800 nm.

Photoactivatable protecting groups (PPGs) are useful for a broad range of applications ranging from biology to materials science. In chemical biology, induction of biological processes via photoactivation is a powerful strategy for achieving spatiotemporal control. The importance of cysteine, glutathione, and other bioactive thiols in regulating protein structure/activity and cell redox homeostasis makes modulation of thiol activity particularly useful.

Probing Electronic Communication and Excited-State Dynamics in the Unprecedented Ferrocene-Containing Zinc MB-DIPY.

The electronic communication between two ferrocene groups in the electron-deficient expanded aza-BODIPY analogue of zinc manitoba-dipyrromethene (MB-DIPY) was probed by spectroscopic, electrochemical, spectroelectrochemical, and theoretical methods. The excited-state dynamics involved sub-ps formation of the charge-separated state in the organometallic zinc MB-DIPYs, followed by recovery of the ground state via charge recombination in 12 ps. The excited-state behavior was contrasted with that observed in the parent complex that lacked the ferrocene electron donors and has a much longer excited-state lifetime (670 ps for the singlet state).

Photodetachment and Electron Dynamics in 1-Butyl-1-methyl-pyrrolidinium Dicyanamide.

The ultrafast transient absorption spectrum of 1-butyl-1-methyl-pyrrolidinium dicyanamide, [Pyr][DCA], was measured in the visible and near-infrared (IR) spectral regions. Excitation of the liquid at 4.6 eV created initially delocalized and highly reactive electrons that either geminately recombined (69%) or localized onto a cavity with a time constant of ∼300 fs.

A simplified diagnosis algorithm for dysbetalipoproteinemia.

Background: Dysbetalipoproteinemia (DBL) is a disease of remnant lipoprotein accumulation caused by a defective apolipoprotein (apo) E and is associated with a considerable atherogenic burden. However, there exists confusion concerning the diagnosis of this disorder, and as a consequence, misdiagnosis is frequent.

Objective: The objective of the present study is to propose an algorithm for the diagnosis of DBL using simple clinical variables.

Methoxy-Substituted Nitrodibenzofuran-Based Protecting Group with an Improved Two-Photon Action Cross-Section for Thiol Protection in Solid Phase Peptide Synthesis.

Photoremovable caging groups are useful for biological applications because the deprotection process can be initiated by illumination with light without the necessity of adding additional reagents such as acids or bases that can perturb biological activity. In solid phase peptide synthesis (SPPS), the most common photoremovable group used for thiol protection is the -nitrobenzyl group and related analogues. In earlier work, we explored the use of the nitrodibenzofuran (NDBF) group for thiol protection and found it to exhibit a faster rate toward UV photolysis relative to simple nitroveratryl-based protecting groups and a useful two-photon cross-section.

Vigilance behaviour in Siberian ibex (Capra sibirica): Effect of group size, group type, sex and age.

Gregarious prey species modify their behaviours in response to predation risk in two ways: by increasing vigilance level or enlarging herd size. However, individuals of various sex and age have different responses to the same danger, and even the same individuals react differently depending on their status during biological events or within group types. But how these factors influence the interactions between vigilance level and group size is still poorly understood.

Evaluating Large-Scale STEM Outreach Efficacy with a Consistent Theme: Thermodynamics for Elementary School Students.

A biannual chemistry demonstration-based show named "Energy and U" was created to extend the general outreach themes of science, technology, engineering, and mathematics (STEM) fields and a college education with a specific goal: to teach the first law of thermodynamics to elementary school students. The effectiveness of the program was analyzed using a clicker survey system for over 12 000 visiting students. The fraction of the students that correctly answered the question "Is it possible to create energy?" increased from 14% immediately before the show to 89% immediately after the show.

Preparation of Viscosity-Sensitive Isoxazoline/Isoxazolyl-Based Molecular Rotors and Directly Linked BODIPY-Fulleroisoxazoline from the Stable -(Nitrile Oxide)-Substituted BODIPY.

We developed a simple methodology for the preparation of stable -(nitrile oxide)-substituted BODIPYs, which were characterized by spectroscopic methods and X-ray crystallography. These compounds were used for the preparation of isoxazoline- or isoxazolyl-BODIPYs by 1,3-dipolar cycloaddition reaction with dipolarophiles. Several BODIPYs possess molecular rotor behavior, including viscosity-dependent fluorescence.

Synthesis, Characterization, and Electron-Transfer Properties of Ferrocene-BODIPY-Fullerene Near-Infrared-Absorbing Triads: Are Catecholopyrrolidine-Linked Fullerenes a Good Architecture to Facilitate Electron-Transfer?

A series of covalent ferrocene-BODIPY-fullerene triads with the ferrocene groups conjugated to the BODIPY π-system and the fullerene acceptor linked at the boron hub by a common catecholpyrrolidine bridge were prepared and characterized by 1D and 2D NMR, UV/Vis, steady-state fluorescence spectroscopy, high-resolution mass spectrometry, and, for one of the derivatives, X-ray crystallography. Redox processes of the new compounds were investigated by electrochemical (CV and DPV) methods and spectroelectrochemistry. DFT calculations indicate that the HOMO in all triads was delocalized between ferrocene and BODIPY π-system, the LUMO was always fullerene-centered, and the catechol-centered occupied orbital was close in energy to the HOMO.

Rapid Excited-State Deactivation of BODIPY Derivatives by a Boron-Bound Catechol.

The excited-state dynamics and energetics of a series of BODIPY-derived chromophores bound to a catechol at the boron position were investigated with a combination of static and time-resolved spectroscopy, electrochemistry, and density functional theory calculations. Compared with the difluoro-BODIPY-derived parent compounds, the addition of the catechol at the boron reduced the excited-state lifetime by three orders of magnitude. Deactivation of the excited state proceeded through an intermediate charge-transfer state accessed from the initial optically excited π* state in <1 ps.

Effect of extending conjugation via thiophene-based oligomers on the excited state electron transfer rates to ZnO nanocrystals.

Oligothiophene dyes with two to five thiophene units were anchored to oleate-capped, quantum-confined zinc oxide nanocrystals (ZnO NCs) through a cyanoacrylate functional group. While the fluorescence of the bithiophene derivative was too weak for meaningful quenching studies, the fluorescence of the dyes with three, four and five thiophene rings was quenched upon binding to the NCs. Ultrafast pump-probe spectroscopy was used to observe the singlet excited states of the free dyes dissolved in dichloromethane as well as attached to a ZnO NC dispersed in the same solvent.

Diabetes is associated with an increased risk of cardiovascular disease in patients with familial hypercholesterolemia.

Background: Familial hypercholesterolemia (FH) is the most common genetic disorder of lipoprotein metabolism, affecting 1:250 individuals worldwide. This monogenic disease is associated with lifelong elevation in circulating low-density lipoprotein cholesterol and premature cardiovascular disease (CVD). In 2016, the estimated prevalence of diabetes in Canada was 9%.

Evaluation of the Intramolecular Charge-Transfer Properties in Solvatochromic and Electrochromic Zinc Octa(carbazolyl)phthalocyanines.

2,3,9,10,16,17,23·24-Octakis-(9H-carbazol-9-yl) phthalocyaninato zinc(II) (3) and 2,3,9,10,16,17,23·24-octakis-(3,6-di-tert-butyl-9H-carbazole) phthalocyaninato zinc(II) (4) complexes were prepared and characterized by NMR and UV-vis spectroscopies, magnetic circular dichroism (MCD), matrix-assisted laser desorption ionization mass spectrometry, and X-ray crystallography. UV-vis and MCD data are indicative of the interligand charge-transfer nature of the broad band observed in 450-500 nm range for 3 and 4. The redox properties of 3 and 4 were probed by electrochemical and spectro-electrochemical methods, which are suggestive of phthalocyanine-centered first oxidation and reduction processes.

Effects of a phosphonate anchoring group on the excited state electron transfer rates from a terthiophene chromophore to a ZnO nanocrystal.

Terthiophene dyes were synthesized having a carboxylate or a phosphonate moiety at the 2-position which serves as an anchoring group to zinc oxide nanocrystals (ZnO NCs). Electronic absorption and fluorescence measurements, combined with reduction potentials, provided estimates of -1.81 and -1.

Antipredator tactics are largely maternally controlled in goitered gazelle, a hider ungulate.

Predation is usually the primary cause of infant death among ungulate species, with the annual variation in the survival of neonates over their first summer a major factor in the population dynamics of many ungulates. Consequently, the maternal rearing strategy of a species is crucial for its reproductive success. Since the roles mothers and fawns play in the implementation of antipredator strategies in hider species have been poorly understood until now, this paper considers this behavior in the goitered gazelle, which is a typical hider species.

6-Bromo-7-hydroxy-3-methylcoumarin (mBhc) is an efficient multi-photon labile protecting group for thiol caging and three-dimensional chemical patterning.

The photochemical release of chemical reagents and bioactive molecules provides a useful tool for spatio-temporal control of biological processes. However, achieving this goal requires the development of highly efficient one- and two-photon sensitive photo-cleavable protecting groups. Thiol-containing compounds play critical roles in biological systems and bioengineering applications.