Marangoni-driven deterministic formation of softer, hollow microstructures for sensitivity-enhanced tactile system.

Microengineering the dielectric layers with three-dimensional microstructures has proven effective in enhancing the sensitivity of flexible pressure sensors. However, the widely employed geometrical designs of solid microstructures exhibit limited sensitivity over a wide range of pressures due to their inherent but undesired structural compressibility. Here, a Marangoni-driven deterministic formation approach is proposed for fabricating hollow microstructures, allowing for greater deformation while retarding structural stiffening during compression.

A Snakeskin-Inspired, Soft-Hinge Kirigami Metamaterial for Self-Adaptive Conformal Electronic Armor.

A majority of soft-body creatures evolve armor or shells to protect themselves. Similar protection demand is for flexible electronics working in complex environments. Existing works mainly focus on improving the sensing capabilities such as electronic skin (E-skin).

The Conformal Design of an Island-Bridge Structure on a Non-Developable Surface for Stretchable Electronics.

Conformal design of the island-bridge structure is the key to construct high-performance inorganic stretchable electronics that can be conformally transferred to non-developable surfaces. Former studies in conformal problems of epidermal electronics are mainly focused on soft surfaces that can adapt to the deformation of the electronics, which are not suitable for applications in hard, non-developable surfaces because of their loose surface constraints. In this paper, the conformal design problem for the island-bridge structure on a hard, non-developable surface was studied, including the critical size for island and stiffness and the demand for stretchability for the bridge.

Determination of site selectivity of different carcinogens for preferential mutational hot spots in oligonucleotide fragments by ion-pair reversed-phase nano liquid chromatography tandem mass spectrometry.

Ion-pair reversed-phase nano liquid chromatography coupled with nanospray ion trap mass spectrometry was used to investigate site selectivity of the known carcinogens N-acetoxy-2-acetylaminofluorene, N-hydroxy-4-aminobiphenyl and (+/-)-anti-benzo[a]pyrene diol epoxide with the synthetic double-strand 14-mer long oligonucleotide fragment of the p53 gene containing two mutational hot-spot codons (5'-P-ACC155 CGC156 GTC157 CGC158 GC/5'-GCG CGG ACG CGG GT). The investigation was performed using a monolithic polystyrene divinylbenzene capillary column and triethylammonium bicarbonate as an ion-pair reagent. The exact location of the carcinogen on the modified oligonucleotide backbone was determined using characteristic collision-induced dissociation fragmentation patterns obtained under negative-ion mode ionization.

The influence of cytosine methylation on the chemoselectivity of benzo[a]pyrene diol epoxide-oligonucleotide adducts determined using nanoLC/MS/MS.

Benzo[a]pyrene is a major carcinogen implicated in human lung cancer. Almost 60% of human lung cancers have a mutation in the p53 tumor suppressor gene at several specific codons. An on-line nanoLC/MS/MS method using a monolithic nanocolumn was applied to investigate the chemoselectivity of the carcinogenic diol epoxide metabolite, (+/-)-(7R,8S,9S,10R)-benzo[a]pyrene 7,8-diol 9,10-epoxide [(+/-)-anti-benzo[a]pyrene diol epoxide (BPDE)], which was reacted in vitro with a synthesized 14-mer double stranded oligonucleotide (5'-ACCCG5CG7TCCG11CG13C-3'/5'-GCGCGGGCGCGGGT-3') derived from the p53 gene.

Separation and sequencing of isomeric oligonucleotide adducts using monolithic columns by ion-pair reversed-phase nano-HPLC coupled to ion trap mass spectrometry.

An ion-pair reversed-phase nano-high-performance liquid chromatography (IP-RP-nano-HPLC) method using a monolithic poly(styrene-divinylbenzene) (PS-DVB) column coupled to nanoelectrospray ionization mass spectrometry (nano-ESI-MS) was evaluated to separate and identify isomeric oligonucleotide adducts derived from the covalent binding of (+/-)-anti-7r,8t-dihydroxy-9t,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene [(+/-)-anti-BPDE] to double-stranded (ds) 5'-PO4--ACCCGCGTCCGCGC-3'/5'-GCGCGGGCGCGGGT-3' oligonucleotide. The influence of three different nanospray emitters on electrospray signal was evaluated in terms of analyte ion sensitivity. The best nanoelectrospray performance for the oligonucleotides was observed with the distal metal-coated emitter.

Characterization of a novel bivalent morphinan possessing kappa agonist and micro agonist/antagonist properties.

Previous research has shown that compounds with mixed kappa and mu activity may have utility for the treatment of cocaine abuse and dependence. The present study characterizes the pharmacological profile of a bivalent morphinan that was shown to be a kappa opioid receptor agonist and a mu opioid receptor agonist/antagonist. MCL-145 [bis(N-cyclobutylmethylmorphinan) fumarate] is related to the morphinan cyclorphan and its N-cyclobutylmethyl derivative MCL-101 [3-hydroxy-N-cyclobutylmethyl morphinan S-(+)-mandelate].

A deoxynucleotide derivatization methodology for improving LC-ESI-MS detection.

We have developed a novel LC-UV-MS derivatization method for the analysis of deoxyguanosine monophosphate adducts that demonstrates enhanced signal intensities relative to underivatized analytes in positive ion mode electrospray ionization MS. Detection of DNA nucleotide adducts is normally conducted in negative ion mode, which requires basic mobile phases that make chromatographic separations difficult and reduce MS sensitivity. Utilizing coupling reagents typically employed in peptide synthesis, several different deoxyguanosine nucleotide phosphoramidates and phosphomonoesters were synthesized in high conversion yield and under mild reaction conditions.

2-aminothiazole-derived opioids. Bioisosteric replacement of phenols.

A series of aminothiazole-derived morphinans, benzomorphans, and morphine were synthesized. Although their affinities were somewhat lower than their phenol prototypes, one compound (9a, ATPM) has been identified possessing high affinity and selectivity at the kappa receptor. Functional assays showed that 9a was a full kappa but partial mu agonist; the efficacy at kappa was significantly greater than at mu receptors.

10-Ketomorphinan and 3-substituted-3-desoxymorphinan analogues as mixed kappa and micro opioid ligands: synthesis and biological evaluation of their binding affinity at opioid receptors.

A series of 10-ketomorphinan analogues were synthesized, and their binding affinity at all three opioid receptors was investigated. In most cases, high affinity at micro and kappa receptors, and lower affinity at delta receptor was observed, resulting in good selectivity for micro and kappa receptors. A wide range of substituents can be accommodated on the nitrogen position.

Design and synthesis of novel dimeric morphinan ligands for kappa and micro opioid receptors.

A novel series of morphinans were synthesized, and their binding affinity at and functional selectivity for micro, delta, and kappa opioid receptors were evaluated. These dimeric ligands can be viewed as dimeric morphinans, which were formed by coupling two identical morphinan pharmacophores (cyclorphan (1) or MCL 101 (2)) with varying connecting spacers. Ligands 6 and 7 with alkyl spacers on the nitrogen position and ligands 8 and 9 in which the two morphinan pharmacophores were coupled by ether moieties at the 3-hydroxyl positions showed significant decrease in affinity at all three opioid receptors.

A convenient stereoselective synthesis of trifluoromethyl-substituted polyfunctionalized cyclopropane: synthesis of (+/-)-trans-trifluoronorcoronamic acid.

Trifluoromethylated polyfunctionalized cyclopropanes were obtained in high stereoselectivity by reacting 2-bromo-3,3,3-trifluoropropene (BrTFP) with active methylenes. This novel method was further applied to the synthesis of (+/-)-trans-trifluoronorcoronamic acid.

Zn(ODf)2: preparation and application in asymmetric alkynylation of aldehydes.

A new Lewis acid, Zn(ODf)2, was first prepared from commercially available 3,3,4,4-tetrafluoro[1,2]oxathietane 2,2-dioxide in four steps with 56% yields and also was applied to catalyze highly enantioselective alkynylation of aldehydes in the presence of ligand (1S,2S)-3-(tert-butyldimethylsilyloxyl)-2-N,N-dimethylamino-1- (p-nitrophenyl)-propane-1-ol or ligand (-)-N-methylephedrine to afford the corresponding propargylic alcohols in high yields with up to 99% ee.

A novel microtubule destabilizing entity from orthogonal synthesis of triazine library and zebrafish embryo screening.

The first orthogonal combinatorial synthesis of a high-purity triazine library was demonstrated. Novel triazine-based microtubule inhibitors were discovered by an efficient zebrafish embryo screening and in vitro microtubule polymerization assay.

Highly enantioselective alkynylation of aldehydes catalyzed by a readily available chiral amino alcohol-based ligand.

A new inexpensive chiral amino alcohol-based ligand, (1S,2S)-2-N,N-dimethylamino-1-(p-nitrophenyl)-3- (t-butyldimethylsilyloxy)propane-1-ol, was developed for the asymmetric alkynylation of aliphatic and aromatic aldehydes, to prepare the corresponding propargylic alcohols in high yields with up to 99% ee.

Structure-based 3-D-QSAR analysis of marine indole alkaloids.

A 3-D-QSAR study has been performed on these indole alkaloid derivatives to correlate their chemical structures with their observed antitumor activity against IGROV1. Due to the absence of information on their active mechanism, comparative molecular field analysis (CoMFA) has been applied. A model able to well correlate the antitumor activity with the chemical structures of mono and bis(indole) alkaloids 1-18 has been developed which is potentially helpful in the design of novel and more potent antitumor agents.