Synergistic Formation of Radicals by Irradiation with Both Vacuum Ultraviolet and Atomic Hydrogen: A Real-Time In Situ Electron Spin Resonance Study

We report on the surface modification of polytetrafluoroethylene (PTFE) as an example of soft- and bio-materials that occur under plasma discharge by kinetics analysis of radical formation using in situ real-time electron spin resonance (ESR) measurements. During irradiation with hydrogen plasma, simultaneous measurements of the gas-phase ESR signals of atomic hydrogen and the carbon dangling bond (C-DB) on PTFE were performed. Dynamic changes of the C-DB density were observed in real time, where the rate of density change was accelerated during initial irradiation and then became constant over time. It is noteworthy that C-DBs were formed synergistically by irradiation with both vacuum ultraviolet (VUV) and atomic hydrogen. The in situ real-time ESR technique is useful to elucidate synergistic roles during plasma surface modification.Comment: 14 pages, 4 figure

Cleavage of pyrene-stabilized RNA bulge loops by trans-(±)-cyclohexane-1,2-diamine

Chemical agents that cleave HIV genome can be potentially used for anti-HIV therapy. In this report, the cleavage of the upper stem-loop region of HIV-1 TAR RNA was studied in a variety of buffers containing organic catalysts. trans-(±)-Cyclohexane-1,2-diamine was found to cleave the RNA with the highest activity (31%, 37°C, 18 h). Cleavage of the RNA in trans-(±)-cyclohexane-1,2-diamine buffer was also studied when the RNA was hybridized with complementary DNAs. A pyrene-modified C3 spacer was incorporated to the DNA strand to facilitate the formation of a RNA bulge loop in the RNA/DNA duplex. In contrast, unmodified DNAs cannot efficiently generate RNA bulge loops, regardless of the DNA sequences. The results showed that the pyrene-stablized RNA bulge loops were efficiently and site-specifically cleaved by trans-(±)-cyclohexane-1,2-diamine

A DNA aptamer recognising a malaria protein biomarker can function as part of a DNA origami assembly

DNA aptamers have potential for disease diagnosis and as therapeutics, particularly when interfaced with programmable molecular technology. Here we have combined DNA aptamers specific for the malaria biomarker Plasmodium falciparum lactate dehydrogenase (PfLDH) with a DNA origami scaffold. Twelve aptamers that recognise PfLDH were integrated into a rectangular DNA origami and atomic force microscopy demonstrated that the incorporated aptamers preserve their ability to specifically bind target protein. Captured PfLDH retained enzymatic activity and protein-aptamer binding was observed dynamically using high-speed AFM. This work demonstrates the ability of DNA aptamers to recognise a malaria biomarker whilst being integrated within a supramolecular DNA scaffold, opening new possibilities for malaria diagnostic approaches based on DNA nanotechnology

Is a Priming Dose of Insulin Necessary in a Low-Dose Insulin Protocol for the Treatment of Diabetic Ketoacidosis?

OBJECTIVE—The purpose of this study was to assess the efficacy of an insulin priming dose with a continuous insulin infusion versus two continuous infusions without a priming dose

Diquat Derivatives: Highly Active, Two-Dimensional Nonlinear Optical Chromophores with Potential Redox Switchability

In this article, we present a detailed study of structure−activity relationships in diquaternized 2,2′-bipyridyl (diquat) derivatives. Sixteen new chromophores have been synthesized, with variations in the amino electron donor substituents, π-conjugated bridge, and alkyl diquaternizing unit. Our aim is to combine very large, two-dimensional (2D) quadratic nonlinear optical (NLO) responses with reversible redox chemistry. The chromophores have been characterized as their PF_6^− salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Their visible absorption spectra are dominated by intense π → π^* intramolecular charge-transfer (ICT) bands, and all show two reversible diquat-based reductions. First hyperpolarizabilities β have been measured by using hyper-Rayleigh scattering with an 800 nm laser, and Stark spectroscopy of the ICT bands affords estimated static first hyperpolarizabilities β_0. The directly and indirectly derived β values are large and increase with the extent of π-conjugation and electron donor strength. Extending the quaternizing alkyl linkage always increases the ICT energy and decreases the E_(1/2) values for diquat reduction, but a compensating increase in the ICT intensity prevents significant decreases in Stark-based β_0 responses. Nine single-crystal X-ray structures have also been obtained. Time-dependent density functional theory clarifies the molecular electronic/optical properties, and finite field calculations agree with polarized HRS data in that the NLO responses of the disubstituted species are dominated by ‘off-diagonal’ β_(zyy) components. The most significant findings of these studies are: (i) β_0 values as much as 6 times that of the chromophore in the technologically important material (E)-4′-(dimethylamino)-N-methyl-4-stilbazolium tosylate; (ii) reversible electrochemistry that offers potential for redox-switching of optical properties over multiple states; (iii) strongly 2D NLO responses that may be exploited for novel practical applications; (iv) a new polar material, suitable for bulk NLO behavior

Advanced papillary serous carcinoma of the uterine cervix: a case with a remarkable response to paclitaxel and carboplatin combination chemotherapy

Papillary serous carcinoma of the uterine cervix (PSCC) is a very rare, recently described variant of cervical adenocarcinoma. This review, describes a case of stage IV PSCC whose main tumor existed in the uterine cervix and invaded one third of the inferior part of the anterior and posterior vaginal walls. Furthermore, it had metastasized from the para-aortic lymph nodes to bilateral neck lymph nodes. Immnoreactivity for CA125 was positive, whereas the staining for p53 and WT-1 were negative in both the original tumor and the metastatic lymph nodes. Six cycles of paclitaxel and carboplatin combination chemotherapy were administered and the PSCC dramatically decreased in size. The main tumor of the uterine cervix showed a complete response by magnetic resonance imaging (MRI), and on rebiopsy, more than 95% of the tumor cells in the cervix had microscopically disapperared. This is the first report of PSCC in which combination chemotherapy was used and showed a remarkable response

Hepatic Stearoyl-CoA Desaturase (SCD)-1 Activity and Diacylglycerol but Not Ceramide Concentrations Are Increased in the Nonalcoholic Human Fatty Liver

OBJECTIVE—To determine whether 1) hepatic ceramide and diacylglycerol concentrations, 2) SCD1 activity, and 3) hepatic lipogenic index are increased in the human nonalcoholic fatty liver

Long-term effects of high-fat or high-carbohydrate diets on glucose tolerance in mice with heterozygous carnitine palmitoyltransferase-1a deficiency

Background: Abnormal fatty acid metabolism is an important feature in the mechanisms of insulin resistance and β-cell dysfunction. Carnitine palmitoyltransferase-1a (CPT-1a, liver isoform) has a pivotal role in the regulation of mitochondrial fatty acid oxidation. We investigated the role of CPT-1a in the development of impaired glucose tolerance using a mouse model for CPT-1a deficiency when challenged by either a high-carbohydrate (HCD) or a high-fat diet (HFD) for a total duration of up to 46 weeks