Hydro*

We demonstrated an unconventional polymerization route to synthesize hydrophilic fluorescent organic nanoparticles (FONs) for multicolor cellular bioimaging in this contribution. Actually, it benefits from our unexpected discovery of a rapid polymerization reaction between 1, 6-hexanediol dipropiolate and 2, 4, 6-triazide-1, 3, 5-triazine under the catalysis of N, N, N', N", N"-pentamethyldiethylenetriamine (PMDETA). Interestingly, the 2, 4, 6-triazide-1, 3, 5-triazine and PMDETA system can also induce rapid free radical polymerization at room temperature...

Stable N-heterocyclic carbene analogues of Thiele and Chichibabin hydrocarbons, [(IPr)(C6 H4 )(IPr)] and [(IPr)(C6 H4 )2 (IPr)] (4 and 5, respectively; IPr=C{N(2,6-iPr2 C6 H3 )}2 CHCH), are reported. In a nickel-catalyzed double carbenylation of 1,4-Br2 C6 H4 and 4,4'-Br2 (C6 H4 )2 with IPr (1), [(IPr)(C6 H4 )(IPr)](Br)2 (2) and [(IPr)(C6 H4 )2 (IPr)](Br)2 (3) were generated, which respectively afforded 4 and 5 as crystalline solids upon reduction with KC8 . Experimental and computational studies support the semiquinoidal nature of 5 with a small singlet-triplet energy gap ΔES-T of 10...

Lipocalin-type prostaglandin D synthase (L-PGDS; EC:5.3.99.2) is an enzyme with dual functional roles as a prostaglandin D2 -synthesizing enzyme and as an extracellular transporter for diverse lipophilic compounds in the cerebrospinal fluid (CSF). Transport of hydrophobic endocannabinoids is mediated by serum albumin in the blood and intracellularly by the fatty acid binding proteins, but no analogous transport mechanism has yet been described in CSF. L-PGDS has been reported to promiscuously bind a wide variety of lipophilic ligands and is among the most abundant proteins found in the CSF...

OBJECTIVES/HYPOTHESIS: Reconstruction of craniofacial cartilagenous defects are among the most challenging surgical procedures in facial plastic surgery. Bioengineered craniofacial cartilage holds immense potential to surpass current reconstructive options, but limitations to clinical translation exist. We endeavored to determine the viability of utilizing adipose-derived stem cell-chondrocyte co-culture and three-dimensional (3D) printing to produce 3D bioscaffolds for cartilage tissue engineering...

The "replacement" of noble metals by earth abundant metals is a desirable aim in catalysis and a possible way of conserving rare elements. The "replacement" is especially attractive if novel selectivity patterns are observed permitting the development of novel coupling reactions. Herein, we report on a novel, robust and reusable iron catalyst, which permits the selective hydrogenation of nitroarenes in the presence of hydrogenation-sensitive functional groups. Based on the selectivity pattern observed, the direct iron catalyzed synthesis of imines and benzimidazoles from nitroarenes and aldehydes becomes feasible...

OBJECTIVES/HYPOTHESIS: To describe the presentation, surgical findings, and outcomes in patients with spontaneous temporal bone cerebrospinal fluid (CSF) fistulas and encephaloceles. STUDY DESIGN: Retrospective chart review. METHODS: A retrospective chart review of patients treated for a spontaneous temporal bone CSF fistula and/or encephalocele over a 10-year period was performed. Data recorded included demographic information, presenting signs and symptoms, radiographic and laboratory studies, surgical approach, materials used for repair, surgical complications, and successful closure of the CSF fistula...

Pyrogenic carbon (PyC) derived from charcoal particles (paleo + modern) deposited in the soil column has been little studied in the Amazon, and our understanding of the factors that control the spatial and vertical distribution of these materials in the region's forest soils is still unclear. The objective of this study was to test the effect of forest type and distance from the ignition source on the PyC stocks contained in macroscopic particles of soil charcoal (≥ 2 mm; 1-m depth) dispersed in ecotone forests of the northern Brazilian Amazon...

One-pot reaction between 8-hydroxyquinoline-2-carboxaldehyde (HQC) and tris(hydroxymethyl)aminomethane (TRIS) followed by in situ cyclization yielded an oxazolidine based ligand which produced four mononuclear complexes of MnII(1), CoII(2), NiII(3), ZnII(4), a tetranuclear iron (FeIII4) complex (5) and a trinuclear cobalt (CoIICoIII2) complex (6). Magnetic studies show dominant antiferromagnetic interaction in tetranuclear iron (FeIII4) complex 5 and presence of the slow relaxation of magnetisation in 6. The compounds were also studied for their antibacterial properties...

Loss of ubiquitin C-terminal hydrolase L1 (UCHL1), a deubiquitinating enzyme required for neuronal function, led to hyperphosphatemia accompanied by phosphaturia in mice, while calcium homeostasis remained intact. We therefore investigated the mechanisms underlying the phosphate imbalance in Uchl1-/- mice. Interestingly, phosphaturia was not a result of lower renal brush border membrane sodium-phosphate cotransporter expression as sodium-phosphate cotransporter 2a and 2c expression levels were similar to wild type levels...

Supercritical fluid extraction (SFE) was applied to investigate the removal of petroleum hydrocarbons (PHCs) from contaminated soils. Per an initial set of tests for different extraction modes and time durations, the combination of 10 min static mode followed by 10 min dynamic mode, repeated for 3 cycles for a total time of 60 min resulted in the highest PHCs removal percentages. SFE experiments were performed at 33 MPa pressure and 75 °C temperature to investigate the influence of soil texture and grain size...

Two stable 3D polyoxometalate-based metal-organic frameworks (PMOFs), [CuI 12 (trz)8 (H2 O)2 ][α-SiW12 O40 ]·2H2 O (1) and [CuI 12 (trz)8 Cl][α-PW12 O40 ] (2) (Htrz = 1- H-1,2,4-triazole) based on Keggin-type POMs were successfully obtained and fully characterized. The basic building units of the two PMOFs are [CuI 12 (trz)8 ], but polyoxoanion (POA) template effect leads to different structures and properties: 1 represents an interesting example that [α-SiW12 O40 ]4- locate in the nine-membered Cu-trz rings through Cu···O weak interactions to form a 3D framework, whereas 2 shows a 3D structure constructed from 2D bilayer cationic network [CuI 12 (trz)8 Cl]3+ and [α-PW12 O40 ]3- lying in the adjacent layers via Cu···O weak interactions...

Nanoparticles comprising three or more different metals are challenging to prepare. General methods that tackle this challenge are highly sought after as multicomponent metal nanoparticles display favorable properties in applications such as catalysis, biomedicine, and imaging. Herein, we report a practical and versatile approach for the synthesis of nanoparticles composed of up to four different metals. This method relies on the thermal decomposition of nanostructured composite materials assembled from platinum nanoparticles, a metal-organic framework (ZIF-8), and a tannic acid coordination polymer...

Theoretically, the accomplishment of phase transformation requires sufficient energy to overcome the barriers of structure rearrangements. Transition of an amorphous to crystalline structure is implemented traditionally by heating at high temperatures. However, phase transformation under ambient condition without involving external energy has not been reported. Here, we demonstrate that phase transformation of GeO2 glass to nanocrystals can be triggered at ambient condition when subjected to aqueous environments...

The first chemical synthesis of L-156,373 (1), a potent oxytocin receptor antagonist isolated from Streptomyces silvensis, is reported. Assembly of the unusual d-Piz-l-Piz dipeptide subunit was achieved through a sequential electrophilic amination-acylation-deprotection strategy followed by late-stage Piz ring formation. Synthesis and incorporation of a novel N-hydroxy-l-isoleucine building block is also described. This submonomer approach was further applied to the expedient synthesis of a di-δ-oxopiperazic acid analogue of 1 starting from Fmoc-Glu( tBu)-OH building blocks...

Ruthenium(II)-catalyzed direct ring-opening reaction of 7-azabenzonorbornadienes with anilides via C-H activation to access hydronaphthylamines has been developed. The transformation proceeds with high stereoselectivity to give cis-configuration products under redox-neutral conditions.

Listeria monocytogenes is a bacterial pathogen that controls much of its virulence through the transcriptional regulator PrfA. In this study, we describe structure-guided design and synthesis of a set of PrfA inhibitors based on ring-fused 2-pyridone heterocycles. Our most effective compound decreased virulence factor expression, reduced bacterial uptake into eukaryotic cells, and improved survival of chicken embryos infected with L. monocytogenes compared to previously identified compounds. Crystal structures identified an intra-protein "tunnel" as the main inhibitor binding site (AI), where the compounds participate in an extensive hydrophobic network that restricts the protein's ability to form functional DNA-binding helix-turn-helix (HTH) motifs...

Two new pyrrolinone-containing lipopeptides, ypaoamides B (1) and C (2), were isolated from an Okeania sp. marine cyanobacterium collected in Okinawa. Their structures were determined by spectroscopic analysis and Marfey's analysis of acid hydrolysates. Ypaoamides B (1) and C (2) stimulated glucose uptake in cultured rat L6 myotubes. In particular, ypaoamide B (1) showed potent activity and activated AMP-activated protein kinase.

Engineered D-lactyl-coenzyme A (LA-CoA)-polymerizing polyhydroxyalkanoate synthase (PhaC1PsSTQK) efficiently produces poly(lactate-co-3-hydroxybutyrate) [P(LA-co-3HB]) copolymer in recombinant Escherichia coli, while synthesizing tiny amounts of poly(lactate) (PLA)-like polymers in recombinant Corynebacterium glutamicum. To elucidate the mechanisms underlying the interesting phenomena, in vitro analysis of PhaC1PsSTQK was performed using homo- and co-polymerization conditions of LA-CoA and 3-hydroxybutyryl-CoA...

Physcion (1,8-dihydroxy-3-methoxy-6-methyl-9,10-anthracenedione) is a bioactive component found in Polygoni Multiflori Radix (PMR) which has been widely used as traditional Chinese medicine. Unfortunately, studies showed hepatotoxicity of PMR during its clinical use. The mechanisms of its toxic action remain unknown. The major objectives of this study were to characterize oxidative metabolites of physcion in vitro and in vivo and to determine the electrophilicity of the parent compound and its oxidative metabolites...

Leydig cell transplantation is a better alternative in the treatment of androgen-deficient males. The main purpose of this study was to investigate the effects of induced pluripotent stem cell-derived conditioned medium (iPS-CM) on the anti-apoptosis, proliferation and function of immature Leydig cells (ILCs), and illuminate the underlying mechanisms. ILCs were exposed to 200 μmol/L hydrogen peroxide (H2 O2 ) for 24 hours with or without iPS-CM treatments. Cell apoptosis was detected by flow cytometric analysis...