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Shima N N S Hashim, Lachlan J Schwarz, Basil Danylec, Mahesh K Potdar, Reinhard I Boysen, Milton T W Hearn
This investigation describes a general procedure for the selectivity mapping of molecularly imprinted polymers, using (E)-resveratrol-imprinted polymers as the exemplar, and polyphenolic compounds present in Pinot noir grape skin extracts as the test compounds. The procedure is based on the analysis of samples generated before and after solid-phase extraction of (E)-resveratrol and other polyphenols contained within the Pinot noir grape skins using (E)-resveratrol-imprinted polymers. Capillary reversed-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionisation tandem mass spectrometry (ESI MS/MS) was then employed for compound analysis and identification...
December 1, 2016: Talanta
Richard A Manderville, Stacey D Wetmore
The formation of DNA adducts by the attack of intermediates derived from toxic substances at the C8 position of 2-deoxyguanosine (dG) is a common damaging event. Although the majority of studies on C8-dG adducts have focused on lesions containing a C8-N-C tether between the bulky moiety and the nucleobase, the formation of O-linked lesions with a similar tether topology and C-linked adducts involving direct C8-C connectivity have also been uncovered. Several studies have been done to try to better understand the structural impact and mutagenicity of O-linked and C-linked aryl C8-dG adducts, including lesions arising from unsubstituted and chloro substituted phenols, and the food mutagen ochratoxin A (OTA)...
October 21, 2016: Chemical Research in Toxicology
Arnab Rit, Jesús Campos, Haoyu Niu, Simon Aldridge
Vinylidene (H2C=C) is a member of the family of compounds of composition CH (and isomeric with ethyne, HC≡CH), but it has been observed only transiently-with a lifetime in the region of 0.1 ns. Indeed, no simple (non-base-stabilized) compounds of the type R2E=E have been characterized structurally for any of the group 14 elements. Here we show that by employing the bulky and strongly electron-donating boryl ligand (HCDippN)2B (Dipp, 2,6-(i)Pr2C6H3), a simple monomeric digermavinylidene compound, (boryl)2GeGe, can be synthesized and is stable at room temperature...
November 2016: Nature Chemistry
Ioannis V Pavlidis, Martin S Weiß, Maika Genz, Paul Spurr, Steven P Hanlon, Beat Wirz, Hans Iding, Uwe T Bornscheuer
The use of transaminases to access pharmaceutically relevant chiral amines is an attractive alternative to transition-metal-catalysed asymmetric chemical synthesis. However, one major challenge is their limited substrate scope. Here we report the creation of highly active and stereoselective transaminases starting from fold class I. The transaminases were developed by extensive protein engineering followed by optimization of the identified motif. The resulting enzymes exhibited up to 8,900-fold higher activity than the starting scaffold and are highly stereoselective (up to >99...
November 2016: Nature Chemistry
Sagar Satpathi, Mandar Kulkarni, Arnab Mukherjee, Partha Hazra
Among different polymorphs of DNA, G-quadruplex (GQ) formation in guanine rich sequences has received special attention due to its direct relevance to cellular aging and abnormal cell growths. To date, smaller ions like Na(+), K(+), Li(+), and NH4(+) are the best possible selective GQ stabilizing materials. Herein, we report that an ionic liquid (IL), i.e. guanidinium tris(pentafluoroethyl)trifluorophosphate, can not only instigate the GQ formation in the absence of conventional GQ forming ions (like Na(+), K(+), NH4(+), etc...
October 21, 2016: Physical Chemistry Chemical Physics: PCCP
Takaki Yoshikawa, Tsutomu Sato, Takanobu Yamada, Toru Aoyama, Takashi Ogata, Haruhiko Cho
Adjuvant chemotherapy aims to eradicate residual micro-metastatic tumor cells existing at distant sites outside the surgical field. The current standard adjuvant chemotherapy is S-1 for 1 year or capecitabine plus oxaliplatin for 6 months after D2 gastrectomy. However, there are some rooms in the overall survival of Stage III. Neoadjuvant chemotherapy(NAC)is a promising approach that combines intensive chemotherapy with high compliance; however, it is under development in Japan. Two JCOG phase II trials suggested that NAC was effective for bulky nodal disease...
October 2016: Gan to Kagaku Ryoho. Cancer & Chemotherapy
Sergio Eduardo Alonso Araujo, Lucas de Araujo Horcel, Victor Edmond Seid, Alexandre Bruno Bertoncini, Sidney Klajner
Background: Stapled hemorrhoidopexy is associated with less postoperative pain and faster recovery. However, it may be associated with a greater risk of symptomatic recurrence. We hypothesized that undertaking a limited surgical excision of hemorrhoid disease after stapling may be a valid approach for selected patients. Aim: To compare long-term results after stapled hemorrhoidopexy with and without complementation with closed excisional technique. Method: In a retrospective uni-institutional cohort study, sixty-five (29 men) patients underwent stapled hemorrhoidopexy and 21 (13 men) underwent stapled hemorrhoidopexy with excision...
July 2016: Arquivos Brasileiros de Cirurgia Digestiva: ABCD, Brazilian Archives of Digestive Surgery
Shogo Okumura, Shu-Wei Tang, Teruhiko Saito, Kazuhiko Semba, Shigeyoshi Sakaki, Yoshiaki Nakao
We report a method that ensures the selective alkylation of benzamides and aromatic ketones at the para-position via cooperative nickel/aluminum catalysis. Using a bulky catalyst/co-catalyst system allows reactions between benzamides with alkenes to afford the corresponding para-alkylated products. The origin of the high para-selectivity has also been investigated by density functional theory calculations.
October 19, 2016: Journal of the American Chemical Society
S F Lax, K F Tamussino, P F Lang
Malignancies of the uterus metastasize by direct invasion of neighboring structures, lymphatically or hematogenously. Endometrial and cervical cancers lymphatically spread to the pelvic and para-aortic lymph nodes. For endometrial cancer the depth of myometrial invasion, lymphosvascular space involvement (LVSI) and a microcystic, elongated and fragmented (MELF) glandular invasion pattern are predictors for lymph node metastases. Metastases to the pelvic lymph nodes occur in approximately 10 % of endometrial cancer patients and in 30 % of these cases the para-aortic lymph nodes are also involved...
October 18, 2016: Der Pathologe
Lorenzo Calisti, Irene Benni, Matilde Cardoso Trabuco, Paola Baiocco, Barbara Ruzicka, Alberto Boffi, Elisabetta Falvo, Francesco Malatesta, Alessandra Bonamore
BACKGROUND: A set of engineered ferritin mutants from Archaeoglobus fulgidus (Af-Ft) and Pyrococcus furiosus (Pf-Ft) bearing cysteine thiols in selected topological positions inside or outside the ferritin shell have been obtained. The two apo-proteins were taken as model systems for ferritin internal cavity accessibility in that Af-Ft is characterized by the presence of a 45Å wide aperture on the protein surface whereas Pf-Ft displays canonical (threefold) channels. METHODS: Thiol reactivity has been probed in kinetic experiments in order to assess the protein matrix permeation properties towards the bulky thiol reactive DTNB (5,5'-dithiobis-2-nitrobenzoic acid) molecule...
October 15, 2016: Biochimica et Biophysica Acta
Sameer Bakhshi, Sainath Bhethanabhotla, Rakesh Kumar, Krishankant Agarwal, Punit Sharma, Sanjay Thulkar, Arun Malhotra, Deepa Dhawan, Sreenivas Vishnubhatla
BACKGROUND: Data about significance of (18)F-FDG positron emission tomography (PET) at interim assessment and end of treatment in pediatric Hodgkin lymphoma (HL) are limited. METHODS: Patients (≤18 years) with HL were prospectively evaluated with contrast-enhanced computed tomography (CECT) and PET combined with low-dose CT(PET-CT) at baseline, post 2 cycles of chemotherapy and post completion of treatment. Revised international working group criteria (RIW) and Deauville (DA) five point-scale for response assessment by PET-CT were used...
October 6, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Amir Rabani
The market for process instruments generally requires low cost devices that are robust, small in size, portable, and usable in-plant. Ultrasonic torsional guided wave sensors have received much attention by researchers for measurement of viscosity and/or density of fluids in recent years. The supporting electronic systems for these sensors providing many different settings of sine-wave signals are bulky and expensive. In contrast, a system based on bursts of square waves instead of sine waves would have a considerable advantage in that respect and could be built using simple integrated circuits at a cost that is orders of magnitude lower than for a windowed sine wave device...
October 12, 2016: Sensors
Alexei Smolyaninov, Mu-Han Yang, Lin Pang, Yeshaiahu Fainman
A high-density array of plasmonic coaxial nanoantennas is used to enhance the two-photon absorption (TPA) process in a conventional silicon photodetector from a mode-locked 76 MHz Ti:sapphire laser over a spectral range from 1340 to 1550 nm. This enhanced TPA was used to generate an interferometric autocorrelation trace of a 150 fs laser pulse. Unlike second-harmonic generation, this technique does not require phase matching or a bulky crystal and can be used on a low-cost integrated silicon platform over a wide range of near-IR wavelengths compatible with modern commercial tunable femtosecond sources...
October 1, 2016: Optics Letters
Vincent Rampazzi, Julien Roger, Régine Amardeil, Marie-José Penouilh, Philippe Richard, Paul Fleurat-Lessard, Jean-Cyrille Hierso
A smart steric control of the metallocene backbone in bis- and poly(phosphino)ferrocene ligands favors intramolecular aurophilic interactions between [AuCl] fragments in polynuclear gold(I) complexes. We synthesized and characterized by multinuclear NMR and X-ray diffraction analysis mono-, di-, and polynuclear gold complexes of constrained ferrocenyl diphosphines, which bear either bulky tert-butyl groups or more flexible siloxane substituents at the cyclopentadienyl rings. The complexes meso-1,1'-bis(diphenylphosphino)-3,3'-di-tert-butylferrocene (4-m), rac-1,1'-bis[bis(5-methyl-2-furyl)phosphino]-3,3'-di-tert-butylferrocene (5-r), and rac-1,1'-bis(diphenylphosphino)-3,3'-bis[(tri-iso-propylsilyl)oxy]ferrocene (6-r) were used to form dinuclear gold complexes...
October 17, 2016: Inorganic Chemistry
Baoping Guo, Hong Cen, Xiaohong Tan, Qing Ke
BACKGROUND: The prognostic significance of tumor-associated macrophages (TAM) in adult classical Hodgkin lymphoma (cHL) remains controversial. Here, we report a meta-analysis of the association of CD68 and CD163 infiltration on the clinical outcome of adult cHL. METHODS: A comprehensive search to identify relevant articles was performed in PubMed, Embase, and Google Scholar on January 31, 2016. Using the fixed effect or random effects model of DerSimonian and Laird, hazard ratios (HR) or odds ratios (OR) with 95 % confidence intervals (CIs) were used as the effect size estimate...
October 17, 2016: BMC Medicine
Pierre R Bourque, Gabrielle Bourque, William Miller, John Woulfe, Jodi Warman Chardon
Perineural invasion is a targeted cellular proliferation guided by neurotrophins, rather than a simple diffusion of tumor in a path of least resistance. Invasion of cranial nerves by squamous cell carcinoma can represent an important diagnostic dilemma. It commonly presents as a distinct clinical neurological syndrome of combined isolated trigeminal and facial neuropathies. The focal cancer source may have been overlooked or remain occult. This case series illustrates diverse clinical presentations and neuroimaging challenges in four patients with squamous cell carcinoma of the cranial nerves...
October 11, 2016: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
Guoyin Yin, Xin Mu, Guosheng Liu
Difunctionalization of alkenes to incorporate two functional groups across a double bond has emerged as a powerful transformation to greatly increase molecular complexity in organic synthesis with improved efficiency. Historically, palladium-catalyzed difunctionalization of alkenes has suffered from difficulties with introducing a second functional group through reductive elimination of a Pd(II) intermediate and competing β-hydride elimination reactions. To overcome these challenges, one strategy involves utilizing a steric bulky ligand to promote the reductive elimination steps from the Pd(II) center and impeding the β-hydride elimination reactions, which are beyond the scope of this Account...
October 14, 2016: Accounts of Chemical Research
Matthew J Gilkey, Alexander V Mironenko, Leerang Yang, Dionisios G Vlachos, Bingjun Xu
The selective ring-opening of cellulose-derived furanic molecules is a promising pathway for the production of industrially relevant linear oxygenates, such as 1,6-hexanediol. 2,5-Dimethylfuran (DMF) is employed as a model compound in a combined experimental and computational investigation to provide insights into the metal-catalyzed ring-opening. Ring-opening to 2-hexanol and 2-hexanone and ring-saturation to 2,5-dimethyltetrahydrofuran (DMTHF) are identified as two main parallel pathways. DFT calculations and microkinetic modeling indicate that DMF adsorbs on Ru in an open-ring configuration, which is potentially a common surface intermediate that leads to both ring-opening and ring-saturation products...
October 14, 2016: ChemSusChem
Kyu Won Lee, Jae Woo Chung, Seung-Yeop Kwak
A highly self-plasticized poly(vinyl chloride) (PVC) is demonstrated for the first time via click grafting of hyperbranched polyglycerol (HPG). The plasticizing effect of the grafted HPG on PVC is systematically investigated by various analytical methods. The amorphous and bulky dendritic structure of HPG efficiently increases the free volume of the grafted PVC, which leads to a remarkably lower glass transition temperature comparable to that of the conventional plasticized PVC. Viscoelastic analysis reveals that HPG considerably improves the softness of the grafted PVC at room temperature and promotes the segmental motion in the system...
October 14, 2016: Macromolecular Rapid Communications
Martin S Weiß, Ioannis V Pavlidis, Paul Spurr, Steven P Hanlon, Beat Wirz, Hans Iding, Uwe T Bornscheuer
Application of amine transaminases (ATAs) for stereoselective amination of prochiral ketones represents an environmentally benign and economically attractive alternative to transition metal catalyzed asymmetric synthesis. However, the restrictive substrate scope has limited the conversion typically to non-sterically demanding scaffolds. Recently, we reported on the identification and design of fold class I ATAs that effect a highly selective asymmetric synthesis of a set of chiral aromatic bulky amines from the corresponding ketone precursors in high yield...
October 14, 2016: Organic & Biomolecular Chemistry
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