An investigation of the concentration dependence and response to analyte mixtures of carbon black/insulating organic polymer composite vapor detectors

The responses relative to an air background of carbon black/polymer composite vapor detectors have been determined as a function of the concentration of a homologous series of alcohols (n-CnH2n+1OH, 1 < or = n < or = 8), a homologous series of alkanes (n-CnH2n+2, 5 < or = n < or = 10 and n = 12, 14), and a set of diverse solvent vapors. In all cases, the steady-state relative differential resistance responses, delta R/Rb, of the carbon black/polymer composite vapor detectors were well-described by a linear relationship with respect to the analyte partial pressure, at least over the tested concentration range (P/P degree = 0.005-0.03, where P degree is the vapor pressure of the analyte). When two vapors in air were simultaneously presented to the detectors, the delta R/Rb response, relative to an air background, was the sum of the delta R/Rb values obtained when each analyte was exposed separately to the carbon black/polymer composite detectors under study. Similarly, when an analyte was exposed to the detectors on top of a background level of another analyte, the delta R/Rb values of the array of detectors were very close to those obtained when the test analyte was exposed to the detectors only in the presence of background air. The initial training requirements from the array response output data of such detectors are minimized because the delta R/Rb response pattern produced by the analyte of concern can be associated uniquely with that odor, under the conditions explored in this work.     

Formation of maltosine, a product of the Maillard reaction with a pyridone structure

Summary By heating N^a-acetyllysine with maltose or lactose, the pyridone8 not known up to now is formed, which is transformed into the lysine derivative9 when the acetyl group is split off. We propose the name maltosine for compound9. In contrast to maltosine, the well-known pyridosine, used in the determination of lysine damage, is an artificial product formed during acid protein hydrolysis. From the reaction mixtures of galactosyl isomaltol and an Amadori product of maltose with propylamine, the pyridinium betaines13 and14 can be isolated. They are intermediates in the formation of the pyridone12a.

---

Bildung von Maltosin: Ein Produkt der Maillard-Reaktion mit Pyridonstruktur

Zusammenfassung Beim Erhitzen von N^a-Acetyllysin mit Maltose oder Lactose bildet sich u. a. das bisher nicht bekannte Pyridon8 aus dem nach Abspaltung der Acetylgruppe das Lysinderivat9 erhalten wird. Für die neue Substanz9 schlagen wir die Bezeichnung Maltosin vor. Im Gegensatz zum Maltosin ist das schon früher bekannte und zum Nachweis einer Lysinschädigung herangezogene Pyridosin ein Kunstprodukt der sauren Proteinhydrolyse. Aus den Umsetzungsgemischen von Galaktosylisomaltol und eines Amadoriprodukts der Maltose mit Propylamin lassen sich die Pyridiniumbetaine13 und14 isolieren. Sie sind Zwischenprodukte bei der Bildung des Pyridons12a.

     

Formation of acids, lactones and esters through the Maillard reaction

Summary From a glucose/glycine reaction mixture acids, esters and lactones were isolated and identified. Sugar degradation products could also be determined as benzimidazole derivatives after reaction witho-phenylenediamine. Results derived from model systems suggested possible reaction pathways leading to some of the isolated substances. A lactic acid ester is formed as a product of an unstable-pyranone intermediate. A 3-deoxyhexosone serves as a precursor of two furanolactones.

---

Bildung von Säuren, Lactonen und Estern im Verlauf der Maillard-Reaktion

Zusammenfassung Aus einem Glucose/Glycin-Reaktionsgemisch wurden Säuren, Ester und Lactone isoliert und identifiziert. Zuckerumwandlungsprodukte ließen sich auch nach Umsetzung mito-Phenylendiamin als Benzimidazolderivate nachweisen. Die Ergebnisse verschiedener Modellumsetzungen lassen Rückschlüsse auf den Bildungsmechanismus einiger isolierter Reaktionsprodukte zu. So bildet sich ein Milchsäureester über ein labiles Zuckerumwandlungsprodukt. Ein 3-Desoxyoson dient als Vorstufe für zwei Furanolaktone.

     

Properties of iron-containing nanohydroxyapatite-based composites

The paramagnetic properties of compounds resulting from the synthesis of nanohydroxyapatite in the presence of Fe(III) ions have been studied by electron paramagnetic resonance, Mössbauer spectroscopy, and magnetochemistry. Based on the obtained results on the mechanism of the reaction between an orthophosphoric acid solution and an aqueous calcium hydroxide suspension, we have found conditions for incorporating Fe(III) impurity ions into hydroxyapatite. We have studied samples differing in the sequence in which reagents were mixed and in hydroxyapatite crystallite formation conditions. It has been shown that, in all instances, the composition and properties of the iron-containing phases in the composites depend significantly on both synthesis and heat treatment conditions.     

Microstructure and Elastic Constants of Transition Metal Dichalcogenide Monolayers from Friction and Shear Force Microscopy

Optical and electrical properties of 2D transition metal dichalcogenides (TMDCs) grown by chemical vapor deposition (CVD) are strongly determined by their microstructure. Consequently, the visualization of spatial structural variations is of paramount importance for future applications. This study demonstrates how grain boundaries, crystal orientation, and strain fields can unambiguously be identified with combined lateral force microscopy and transverse shear microscopy (TSM) for CVD‐grown tungsten disulfide (WS₂) monolayers, on length scales that are relevant for optoelectronic applications. Further, angle‐dependent TSM measurements enable the fourth‐order elastic constants of monolayer WS₂ to be acquired experimentally. The results facilitate high‐throughput and nondestructive microstructure visualization of monolayer TMDCs and insights into their elastic properties, thus providing an accessible tool to support the development of advanced optoelectronic devices based on such 2D semiconductors.     

Use of PET Imaging to Assess the Efficacy of Thiethylperazine to Stimulate Cerebral MRP1 Transport Activity in Wild-Type and APP/PS1-21 Mice

Multidrug resistance-associated protein 1 (MRP1, encoded by the ABCC1 gene) may contribute to the clearance of amyloid-beta (Aβ) peptides from the brain into the blood and stimulation of MRP1 transport activity may be a therapeutic approach to enhance brain Aβ clearance. In this study, we assessed the effect of thiethylperazine, an antiemetic drug which was shown to stimulate MRP1 activity in vitro and to decrease Aβ load in a rapid β-amyloidosis mouse model (APP/PS1-21), on MRP1 transport activity by means of positron emission tomography (PET) imaging with the MRP1 tracer 6-bromo-7-[¹¹C]methylpurine. Groups of wild-type, APP/PS1-21 and Abcc1^(−/−) mice underwent PET scans before and after a 5-day oral treatment period with thiethylperazine (15 mg/kg, once daily). The elimination rate constant of radioactivity (k_elim) was calculated from time–activity curves in the brain and the lungs as a measure of tissue MRP1 activity. Treatment with thiethylperazine had no significant effect on MRP1 activity in the brain and the lungs of wild-type and APP/PS1-21 mice. This may either be related to a lack of an MRP1-stimulating effect of thiethylperazine in vivo or to other factors, such as substrate-dependent MRP1 stimulation, insufficient target tissue exposure to thiethylperazine or limited sensitivity of the PET tracer to measure MRP1 stimulation.     

Zone-Dependent Architecture and Biochemical Composition of Decellularized Porcine Nasal Cartilage Modulate the Activity of Adipose Tissue-Derived Stem Cells in Cartilage Regeneration

Previous anatomical studies have shown different functional zones in human nasal septal cartilage (NC). These zones differ in respect to histological architecture and biochemical composition. The aim of this study was to investigate the influence of these zones on the fate of stem cells from a regenerative perspective. Therefore, decellularized porcine septal cartilage was prepared and subjected to histological assessment to demonstrate its equivalence to human cartilage. Decellularized porcine NC (DPNC) exposed distinct surfaces depending on two different histological zones: the outer surface (OS), which is equivalent to the superficial zone, and the inner surface (IS), which is equivalent to the central zone. Human adipose tissue-derived stem cells (ASCs) were isolated from the abdominal fat tissue of five female patients and were seeded on the IS and OS of DPNC, respectively. Cell seeding efficiency (CSE), vitality, proliferation, migration, the production of sulfated glycosaminoglycans (sGAG) and chondrogenic differentiation capacity were evaluated by histological staining (DAPI, Phalloidin, Live-Dead), biochemical assays (alamarBlue^®, PicoGreen^®, DMMB) and the quantification of gene expression (qPCR). Results show that cell vitality and CSE were not influenced by DPNC zones. ASCs, however, showed a significantly higher proliferation and elevated expression of early chondrogenic differentiation, as well as fibrocartilage markers, on the OS. On the contrary, there was a significantly higher upregulation of hypertrophy marker MMP13 (p < 0.0001) and GAG production (p = 0.0105) on the IS, whereas cell invasion into the three-dimensional DPNC was higher in comparison to the OS. We conclude that the zonal-dependent distinct architecture and composition of NC modulates activities of ASCs seeded on DPNC. These findings might be used for engineering of cartilage substitutes needed in facial reconstructive surgery that yield an equivalent histological and functional structure, such as native NC.     

Need for cognition as a predictor and a moderator of outcome in a tailored letters smoking cessation intervention.

Objective: To analyze whether baseline need for cognition (NFC) was a predictor or a moderator of treatment outcome in a tailored letters intervention for smoking cessation. Design: A total of 1,499 daily smokers were recruited from general medical practices in Germany within a quasi-randomized trial testing the efficacies of two brief interventions for smoking cessation: (a) computer-generated tailored letters and (b) physician-delivered brief counseling versus assessment-only. For this study, we used data from 1,097 daily smokers who were assigned to the tailored letters or the assessment-only condition. Main Outcome Measures: self-reported 6-month prolonged abstinence from tobacco smoking assessed at 12-, 18-, and 24-month follow-ups, and smoking cessation self-efficacy assessed at 6- and 24-month follow-ups. Results: Baseline NFC predicted 6-month prolonged smoking abstinence (p = .01) and smoking cessation self-efficacy (p .05) but on smoking cessation self-efficacy (p = .05). Tailored letters resulted in higher smoking cessation self-efficacy only for persons with higher NFC. Conclusion: Higher levels of NFC are required to increase smoking cessation self-efficacy in computer-tailored interventions for smoking cessation. Considering an individual's NFC might improve the efficacy of written interventions for smoking cessation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Treatment-Induced Neuropathy in Diabetes (TIND)—Developing a Disease Model in Type 1 Diabetic Rats

Treatment-induced neuropathy in diabetes (TIND) is defined by the occurrence of an acute neuropathy within 8 weeks of an abrupt decrease in glycated hemoglobin-A1c (HbA1c). The underlying pathogenic mechanisms are still incompletely understood with only one mouse model being explored to date. The aim of this study was to further explore the hypothesis that an abrupt insulin-induced fall in HbA1c may be the prime causal factor of developing TIND. BB/OKL (bio breeding/OKL, Ottawa Karlsburg Leipzig) diabetic rats were randomized in three groups, receiving insulin treatment by implanted subcutaneous osmotic insulin pumps for 3 months, as follows: Group one received 2 units per day; group two 1 unit per day: and group three 1 unit per day in the first month, followed by 2 units per day in the last two months. We serially examined blood glucose and HbA1c levels, motor- and sensory/mixed afferent conduction velocities (mNCV and csNCV) and peripheral nerve morphology, including intraepidermal nerve fiber density and numbers of Iba-1 (ionized calcium binding adaptor molecule 1) positive macrophages in the sciatic nerve. Only in BB/OKL rats of group three, with a rapid decrease in HbA1c of more than 2%, did we find a significant decrease in mNCV in sciatic nerves (81% of initial values) after three months of treatment as compared to those group three rats with a less marked decrease in HbA1c <2% (mNCV 106% of initial values, p ≤ 0.01). A similar trend was observed for sensory/mixed afferent nerve conduction velocities: csNCV were reduced in BB/OKL rats with a rapid decrease in HbA1c >2% (csNCV 90% of initial values), compared to those rats with a mild decrease <2% (csNCV 112% of initial values, p ≤ 0.01). Moreover, BB/OKL rats of group three with a decrease in HbA1c >2% showed significantly greater infiltration of macrophages by about 50% (p ≤ 0.01) and a decreased amount of calcitonin gene related peptide (CGRP) positive nerve fibers as compared to the animals with a milder decrease in HbA1c. We conclude that a mild acute neuropathy with inflammatory components was induced in BB/OKL rats as a consequence of an abrupt decrease in HbA1c caused by high-dose insulin treatment. This experimentally induced neuropathy shares some features with TIND in humans and may be further explored in studies into the pathogenesis and treatment of TIND.     

Potential of green ammonia production in India

The threat of climate change is forcing the world to decarbonize all economic sectors. Ammonia primarily used for fertilizer production and a potential, ‘hydrogen carrier’ currently accounts for ~27% of global hydrogen consumption and ~1% of global greenhouse gas emissions. In this analysis, we assess the techno-economic potential of ammonia production using onshore wind, open-field photovoltaic and batteries for both domestic usage and export scenarios in India, which is currently one of the world's largest producer and importer of ammonia. Our results reveal that India's potential can comfortably satisfy global ammonia demand with lowest ammonia costs of 723 EUR/t_NH3 and 765 EUR/t_NH3 for the domestic and export scenario, respectively. To compete with conventional ammonia production a carbon tax of 224–335 €/t_CO2 would be required. Finally, costs of shipping liquid hydrogen and the ‘hydrogen carrier’ ammonia are similar here giving other economic, environmental and safety factors higher relevance.