The effect of gestational period on the association between maternal prenatal salivary cortisol and birth weight: A systematic review and meta-analysis.

Background: Studies exploring the relations between maternal stress and fetal development show an association between increased maternal stress and adverse birth outcomes. A frequently proposed mechanism linking maternal prenatal stress and adverse birth outcomes is heightened concentrations of maternal cortisol. To date, studies exploring this association have reported conflicting results because of the diverse approaches taken to measuring cortisol and the wide variety of possible birth outcomes explored.

Detection of triacetone triperoxide by thermal decomposition peroxy radical chemical amplification coupled to cavity ring-down spectroscopy.

Triacetone triperoxide (TATP) is frequently used in improvised explosive devices because of its ease of manufacture and tremendous explosive force. In this paper, we describe a new method for detection of TATP, thermal decomposition peroxy radical chemical amplification cavity ring-down spectroscopy (TD-PERCA-CRDS). In this method, air is sampled through a heated inlet to which ~ 1 ppmv nitric oxide (NO) is added.

Habitat availability and ontogenetic shifts alter bottlenecks in size-structured fish populations.

For species that utilize different habitats throughout their life cycle, the habitat limitation at a given stage can act as a bottleneck on population abundance, impacting density-dependent processes such as individual growth and survival. We explore the influence of habitat limitation on population dynamics by developing a multi-stage population model based on lake-dwelling rainbow trout (Oncorhynchus mykiss) populations where adults occupy the lake habitat but use tributaries for spawning and juvenile rearing. The model details density-dependent ecological processes and ontogenetic habitat shifts, harvest mortality, and the impact of climate on growth.

Direct (Hetero)Arylation Polymerization of a Spirobifluorene and a Dithienyl-Diketopyrrolopyrrole Derivative: New Donor Polymers for Organic Solar Cells.

The synthesis and preliminary evaluation as donor material for organic photovoltaics of the poly(diketopyrrolopyrrole-spirobifluorene) () is reported herein. Prepared via homogeneous and heterogeneous direct (hetero)arylation polymerization (DHAP), through the use of different catalytic systems, conjugated polymers with comparable molecular weights were obtained. The polymers exhibited strong optical absorption out to 700 nm as thin-films and had appropriate electronic energy levels for use as a donor with .

Direct (Hetero)Arylation for the Synthesis of Molecular Materials: Coupling Thieno[3,4-c]pyrrole-4,6-dione with Perylene Diimide to Yield Novel Non-Fullerene Acceptors for Organic Solar Cells.

Herein we report on the synthesis of an -annulated perylene diimide (PDI) disubstituted thieno[3,4-c]pyrrole-4,6-dione (TPD) molecular acceptor (PDI-TPD-PDI) by direct heteroarylation (DHA) methods. Three sets of DHA conditions that explore the effects of solvent, temperature, and catalyst were employed to find the optimal conditions for the synthesis of two PDI-TPD-PDI derivatives. We then selected one PDI-TPD-PDI for use as a non-fullerene acceptor in organic solar cell devices with the donor polymer PBDB-T.

Expanding the roles for 2-oxoglutarate-dependent oxygenases in plant metabolism.

Covering: up to 2018 2-Oxoglutarate-dependent oxygenases (2ODOs) comprise a large enzyme superfamily in plant genomes, second in size only to the cytochromes P450 monooxygenase (CYP) superfamily. 2ODOs participate in both primary and specialized plant pathways, and their occurrence across all life kingdoms points to an ancient origin. Phylogenetic evidence supports substantial expansion and diversification of 2ODOs following the split from the common ancestor of land plants.

Benzylic Fluorination of Aza-Heterocycles Induced by Single-Electron Transfer to Selectfluor.

A selective and mild method for the benzylic fluorination of aromatic azaheterocycles with Selectfluor is described. These reactions take place by a previously unreported mechanism, in which electron transfer from the heterocyclic substrate to the electrophilic fluorinating agent Selectfluor eventually yields a benzylic radical, thus leading to the desired C-F bond formation. This mechanism enables high intra- and intermolecular selectivity for aza-heterocycles over other benzylic components with similar C-H bond-dissociation energies.

Nonlinear mixed-modelling discriminates the effect of chemicals and their mixtures on zebrafish behavior.

Zebrafish (Danio rerio) early-life stage behavior has the potential for high-throughput screening of neurotoxic environmental contaminants. However, zebrafish embryo and larval behavioral assessments typically utilize linear analyses of mean activity that may not capture the complexity of the behavioral response. Here we tested the hypothesis that nonlinear mixed-modelling of zebrafish embryo and larval behavior provides a better assessment of the impact of chemicals and their mixtures.

Oxygen Atom Transfer to Cationic PCPNi(II) Complexes Using Amine-N-Oxides.

Three PCP pincer ligands differing in the aryl group linking the phosphine arms with the anchoring carbon donor were used to support square planar Ni(II) bromide complexes 1-3. Exchange of the coordinating bromide anion for the more weakly coordinating triflate (OTf) or hexafluoroantimonate (SbF) anions was accomplished by treatment with AgX or TlX salts to give compounds 1-3; compounds 1, 1, 2, 2, 3, and 3 were all characterized by X-ray crystallography. The reactions of these Ni(II) compounds with the amine-N-oxide oxygen atom transfer agents ONMe and ONMePh were explored.

Spectroscopic Engineering toward Near-Infrared Absorption of Materials Containing Perylene Diimide.

The ability to tune the dye structure synthetically has been crucial in the development of materials with tailored properties for given applications. In this contribution, a series of discrete molecules are reported, which are constructed from the perylene diimide (PDI) chromophore and three dyes, namely thienyl diketopyrrolopyrrole (DPP ), pyridyl diketopyrrolopyrrole (DPP ), and thienoisoindigo (TII). Through the choice of dye molecule and linking of the dye and PDI through conjugated acetylene bridges, the light-harvesting characteristics can be engineered to exhibit optical absorption in the range 300-900 nm.

Effect of mechanical strain on the pluripotency of murine embryonic stem cells seeded in a collagen-I scaffold.

The use of embryonic stem cells (ESC) in regenerative medicine is restricted due to the possibility of tumorigenicity after inefficient or incomplete differentiation. Studies from our group, and others, suggest that mechanical stimuli may have a suppressive effect on the pluripotency/tumorigenesis of murine ESC (mESC). Furthermore, we have demonstrated that mESC seeded in a type I collagen scaffold, and transplanted into a murine bone fracture model, demonstrated repair without tumor formation.

Controlling Differentiation of Stem Cells for Developing Personalized Organ-on-Chip Platforms.

Organ-on-chip (OOC) platforms have attracted attentions of pharmaceutical companies as powerful tools for screening of existing drugs and development of new drug candidates. OOCs have primarily used human cell lines or primary cells to develop biomimetic tissue models. However, the ability of human stem cells in unlimited self-renewal and differentiation into multiple lineages has made them attractive for OOCs.

Biocomposite nanofiber matrices to support ECM remodeling by human dermal progenitors and enhanced wound closure.

Cell-based therapies have recently been the focus of much research to enhance skin wound healing. An important challenge will be to develop vehicles for cell delivery that promote survival and uniform distribution of cells across the wound bed. These systems should be stiff enough to facilitate handling, whilst soft enough to limit damage to newly synthesized wound tissue and minimize patient discomfort.

An unsymmetrical non-fullerene acceptor: synthesis via direct heteroarylation, self-assembly, and utility as a low energy absorber in organic photovoltaic cells.

This study reports on the design and synthesis of an unsymmetrical π-conjugated organic molecule composed of perylene diimide, thienyl diketopyrrolopyrrole, and indoloquinoxaline pieced together using direct heteroarylation. This material demonstrates unprecedented response in the thin-film upon post-deposition solvent vapor annealing, resulting in dramatic red-shifts in optical absorption. Such changes were utilized to enhance photocurrent generation in P3HT based organic solar cells.

Stabilization of Structured Populations via Vector Target-Oriented Control.

In contrast with unstructured models, structured discrete population models have been able to fit and predict chaotic experimental data. However, most of the chaos control techniques in the literature have been designed and analyzed in a one-dimensional setting. Here, by introducing target-oriented control for discrete dynamical systems, we prove the possibility to stabilize a chosen state for a wide range of structured population models.

Optimized synthesis of π-extended squaraine dyes relevant to organic electronics by direct (hetero)arylation and Sonogashira coupling reactions.

This study reports on the synthesis and characterization of four molecular π-extended squaraine compounds relevant to the field of organic electronics. The compounds each consist of a bis-indole squaraine core end-capped with indoloquinoxaline units employing three different bridging units, namely thiophene, thiazole, and acetylene. Compound 10 bears a thiophene bridge, 11 consists of a thiophene bridge and fluorinated indoloquinoxaline terminal units, and compounds 12 and 13 are bridged by thiazole and acetylene, respectively.

Comparison of free-radical inhibiting antioxidant properties of carvedilol and its phenolic metabolites.

Carvedilol is a widely prescribed drug for the treatment of heart failure and the prevention of associated ventricular arrhythmias. It has also been reported to function as a biological antioxidant hydrogen atom transfer from its carbazole N-H moiety to chain-propagating radicals. Metabolites of the drug include phenolic derivatives, such as 3-hydroxy-, 4'-hydroxy- and 5'-hydroxycarvedilol, which are also potential antioxidants.

Fullerene-free polymer solar cells processed from non-halogenated solvents in air with PCE of 4.8.

Progress towards practical organic solar cells amenable to large scale production is reported. Fullerene-free organic solar cells with a PCE of ∼4.8% are achieved based upon an active layer composed of the standard donor polymer PTB7-Th and a highly soluble twisted PDI acceptor tPDI-Hex.

Computer-aided diagnosis of retinopathy in retinal fundus images of preterm infants via quantification of vascular tortuosity.

Retinopathy of prematurity (ROP), a disorder of the retina occurring in preterm infants, is the leading cause of preventable childhood blindness. An active phase of ROP that requires treatment is associated with the presence of plus disease, which is diagnosed clinically in a qualitative manner by visual assessment of the existence of a certain level of increase in the thickness and tortuosity of retinal vessels. The present study performs computer-aided diagnosis (CAD) of plus disease via quantitative measurement of tortuosity in retinal fundus images of preterm infants.

Analysis of Multi-Antenna GNSS Receiver Performance under Jamming Attacks.

Although antenna array-based Global Navigation Satellite System (GNSS) receivers can be used to mitigate both narrowband and wideband electronic interference sources, measurement distortions induced by array processing methods are not suitable for high precision applications. The measurement distortions have an adverse effect on the carrier phase ambiguity resolution, affecting the navigation solution. Depending on the array attitude information availability and calibration parameters, different spatial processing methods can be implemented although they distort carrier phase measurements in some cases.

Cost-effective scat-detection dogs: unleashing a powerful new tool for international mammalian conservation biology.

Recently, detection dogs have been utilized to collect fecal samples from cryptic and rare mammals. Despite the great promise of this technique for conservation biology, its broader application has been limited by the high cost (tens to hundreds of thousands of dollars) and logistical challenges of employing a scat-detection dog team while conducting international, collaborative research. Through an international collaboration of primatologists and the Chinese Ministry of Public Security, we trained and used a detection dog to find scat from three species of unhabituated, free-ranging primates, for less than $3,000.

Metagenomic Analyses Reveal That Energy Transfer Gene Abundances Can Predict the Syntrophic Potential of Environmental Microbial Communities.

Hydrocarbon compounds can be biodegraded by anaerobic microorganisms to form methane through an energetically interdependent metabolic process known as syntrophy. The microorganisms that perform this process as well as the energy transfer mechanisms involved are difficult to study and thus are still poorly understood, especially on an environmental scale. Here, metagenomic data was analyzed for specific clusters of orthologous groups (COGs) related to key energy transfer genes thus far identified in syntrophic bacteria, and principal component analysis was used in order to determine whether potentially syntrophic environments could be distinguished using these syntroph related COGs as opposed to universally present COGs.