bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methyl‐tert‐butylether – Bestimmung von Methyl‐tert‐butylether in Blut und Urin mittels Headspace‐Gaschromatographie‐Massenspektrometrie [Biomonitoring Methods in German language, 2018]
Authors: Hoppe H.‐W. , Zarniko M. , Müller J. , Göen T. , Hartwig A. ,   MAK Commission
Published: January 2018

AbstractThe working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area verified the present biomonitoring method.The described analytical method allows the specific and sensitive determination of methyl tert‐butyl ether (MTBE) in blood and urine of persons occupationally exposed to this substance. The volatile MTBE is determined using static headspace GC‐MS. Before analysing an aliquot of the headspace, the urine and blood samples are diluted 1:10 with water, spiked with internal standard and incubated for 45 min at 60 °C. The isotope‐labelled d3‐MTBE serves as internal standard. Aqueous standard solutions are used for calibration.The method was extensively validated and the reliability data were confirmed by an independent laboratory, which has established and cross‐checked the whole procedure.
Furan [MAK Value Documentation, 2006]
Authors: Hartwig A. ,   MAK Commission
Published: January 2018

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated all toxicological endpoints of furan [
110‐00‐9
].

Data indicate a genotoxic potential of furan especially due to the mutagenic metabolite
cis
‐2‐butene‐1,4‐dial. In carcinogenicity studies hepatocellular carcinomas were observed in rats and mice and cholangiocarcinomas in rats starting at the lowest tested dose of 2 mg/kg body weight and day with an incidence of at least 86%. A no observed adverse effect level (NOAEL) was not obtained. Therefore, furan is classified into Category 2 for carcinogens.

Furan is not classified into a Category for Germ Cell Mutagens as effects in testes and ovaries are only observed at doses that induce severe liver toxicity.
Calculations show that dermal absorption can contribute substantially to the systemic toxicity. Therefore, furan is designated with an “H”.
There are no studies investigating the developmental toxicity and sensitizing potential of furan.
2‐Butoxyethanol [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: January 2018

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the carcinogenicity classification of 2‐butoxyethanol [
111‐76‐2
]. In long‐term studies, 2‐butoxyethanol resulted in hepatocellular carcinomas, haemangiosarcomas and forestomach tumours in mice and phaeochromocytomas in rats and was classified in Carcinogen Category 4.

New studies indicate that the hepatic tumours and the phaeochromocytomas are consequences of the haemolysis which is caused by the metabolite butoxyacetic acid. The forestomach tumours in mice are judged to be irrelevant for humans. There are differences between rats and humans concerning the formation and the haemolytic potency of butoxyacetic acid, which renders humans much less susceptible for haemolysis than rats, although humans can develop signs of haemolysis after severe oral intoxication. However, the CNS‐depression and the irritation caused by 2‐butoxyethanol precludes that humans are exposed regularly to 2‐butoxyethanol concentrations at the workplace which might result in significant haemolysis. Therefore, the Commission has removed 2‐butoxyethanol from the Carcinogen Category 4.
Effective and Selective Anti‐Cancer Protein Delivery via All‐Functions‐in‐One Nanocarriers Coupled with Visible Light‐Responsive, Reversible Protein Engineering
Authors: He Hua , Chen Yongbing , Li Yongjuan , Song Ziyuan , Zhong Yinan , Zhu Rongying , Cheng Jianjun , Yin Lichen 
Published: January 2018

AbstractEfficient intracellular delivery of protein drugs and tumor‐specific activation of protein functions are critical toward anti‐cancer protein therapy. However, an omnipotent protein delivery system that can harmonize the complicated systemic barriers as well as spatiotemporally manipulate protein function is lacking. Herein, an “all‐functions‐in‐one” nanocarrier doped with photosensitizer (PS) is developed and coupled with reactive oxygen species (ROS)‐responsive, reversible protein engineering to realize cancer‐targeted protein delivery, and spatiotemporal manipulation of protein activities using long‐wavelength visible light (635 nm) at low power density (5 mW cm−2). Particularly, RNase A is caged with H2O2‐cleavable phenylboronic acid to form 4‐nitrophenyl 4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)benzyl carbonate (NBC)‐modified RNase (RNBC), which is encapsulated in acid‐degradable, ketal‐crosslinked PEI (KPEI)‐based nanocomplexes (NCs) coated with PS‐modified hyaluronic acid (HA). Such NCs harmonize the critical processes for protein delivery, wherein HA coating renders NCs with long blood circulation and cancer cell targeting, and KPEI enables endosomal escape as well as acid‐triggered intracellular RNBC release. Tumor‐specific light irradiation generates H2O2 to kill cancer cells and restore the protein activity, thus achieving synergistic anti‐cancer efficacy. It is the first time to photomanipulate protein functions by coupling ROS‐cleavable protein caging with PS‐mediated ROS generation, and the “all‐functions‐in‐one” nanocarrier represents a promising example for the programmed anti‐cancer protein delivery.
Nasal variation in relation to high‐altitude adaptations among Tibetans and Andeans
Authors: Butaric Lauren N. , Klocke Ross P. 
Published: January 2018

AbstractObjectivesHigh‐altitude (>2500 m) populations face several pressures, including hypoxia and cold‐dry air, resulting in greater respiratory demand to obtain more oxygen and condition inspired air. While cardiovascular and pulmonary adaptations to high‐altitude hypoxia have been extensively studied, adaptations of upper‐respiratory structures, e.g., nasal cavity, remain untested. This study investigates whether nasal morphology presents adaptations to hypoxic (larger noses) and/or cold‐dry (tall/narrow noses) conditions among high‐altitude samples.MethodsCT scans of two high‐ and four low‐altitude samples from diverse climates were collected (n = 130): high‐altitude Tibetans and Peruvians; low‐altitude Peruvians, Southern Chinese (temperate), Mongolian‐Buriats (cold‐dry), and Southeast Asians (hot‐wet). Facial and nasal distances were calculated from 3D landmarks placed on digitally‐modeled crania. Temperature, precipitation, and barometric pressure data were also obtained.ResultsPrincipal components analysis and analyses of variance primarily indicate size‐related differences among the cold‐dry (Mongolian‐Buriats) and hot‐wet (Southeast Asians) adapted groups. Two‐block partial least squares (PLS) analysis show weak relationships between size‐standardized nasal dimensions and environmental variables. However, among PLS1 (85.90% of covariance), Tibetans display relatively larger nasal cavities related to lower temperatures and barometric pressure; regression analyses also indicate high‐altitude Tibetans possess relatively larger internal nasal breadths and heights for their facial size.ConclusionsOverall, nasal differences relate to climate among the cold‐dry and hot‐wet groups. Specific nasal adaptations were not identified among either Peruvian group, perhaps due to their relatively recent migration history and population structure. However, high‐altitude Tibetans seem to exhibit a compromise in nasal morphology, serving in increased oxygen uptake, and air‐conditioning processes.
Interrupted Baeyer–Villiger Rearrangement: Building A Stereoelectronic Trap for the Criegee Intermediate
Authors: Vil' Vera A. , dos Passos Gomes Gabriel , Bityukov Oleg V. , Lyssenko Konstantin A. , Nikishin Gennady I. , Alabugin Igor V. , Terent'ev Alexander O. 
Published: January 2018

AbstractThe instability of hydroxy peroxyesters, the elusive Criegee intermediates of the Baeyer–Villiger rearrangement, can be alleviated by selective deactivation of the stereoelectronic effects that promote the 1,2‐alkyl shift. Stable cyclic Criegee intermediates constrained within a five‐membered ring can be prepared by mild reduction of the respective hydroperoxy peroxyesters (β‐hydroperoxy‐β‐peroxylactones) which were formed in high yields in reaction of β‐ketoesters with BF3⋅Et2O/H2O2.
Cytochrome‐P450‐Induced Ordering of Microsomal Membranes Modulates Affinity for Drugs
Authors: Barnaba Carlo , Sahoo Bikash Ranjan , Ravula Thirupathi , Medina‐Meza Ilce G. , Im Sang‐Choul , Anantharamaiah G. M. , Waskell Lucy , Ramamoorthy Ayyalusamy 
Published: January 2018

AbstractAlthough membrane environment is known to boost drug metabolism by mammalian cytochrome P450s, the factors that stabilize the structural folding and enhance protein function are unclear. In this study, we use peptide‐based lipid nanodiscs to “trap” the lipid boundaries of microsomal cytochrome P450 2B4. We report the first evidence that CYP2B4 is able to induce the formation of raft domains in a biomimetic compound of the endoplasmic reticulum. NMR experiments were used to identify and quantitatively determine the lipids present in nanodiscs. A combination of biophysical experiments and molecular dynamics simulations revealed a sphingomyelin binding region in CYP2B4. The protein‐induced lipid raft formation increased the thermal stability of P450 and dramatically altered ligand binding kinetics of the hydrophilic ligand BHT. These results unveil membrane/protein dynamics that contribute to the delicate mechanism of redox catalysis in lipid membrane.
Palladium‐Catalyzed C−H Silylation through Palladacycles Generated from Aryl Halides
Authors: Lu Ailan , Ji Xiaoming , Zhou Bo , Wu Zhuo , Zhang Yanghui 
Published: January 2018

AbstractA highly efficient palladium‐catalyzed disilylation reaction of aryl halides through C−H activation has been developed for the first time. The reaction has broad substrate scope. A variety of aryl halides can be disilylated by three types of C−H activation, including C(sp2)−H, C(sp3)−H, and remote C−H activation. In particular, the reactions are also unusually efficient. The yields are essentially quantitative in many cases, even in the presence of less than 1 mol % catalyst and 1 equivalent of the silylating reagent under relatively mild conditions. The disilylated biphenyls can be converted into disiloxane‐bridged biphenyls.
Designed Long‐Lived Emission from CdSe Quantum Dots through Reversible Electronic Energy Transfer with a Surface‐Bound Chromophore
Authors: La Rosa Marcello , Denisov Sergey A. , Jonusauskas Gediminas , McClenaghan Nathan D. , Credi Alberto 
Published: January 2018

AbstractThe size‐tunable emission of luminescent quantum dots (QDs) makes them highly interesting for applications that range from bioimaging to optoelectronics. For the same applications, engineering their luminescence lifetime, in particular, making it longer, would be as important; however, no rational approach to reach this goal is available to date. We describe a strategy to prolong the emission lifetime of QDs through electronic energy shuttling to the triplet excited state of a surface‐bound molecular chromophore. To implement this idea, we made CdSe QDs of different sizes and carried out self‐assembly with a pyrene derivative. We observed that the conjugates exhibit delayed luminescence, with emission decays that are prolonged by more than 3 orders of magnitude (lifetimes up to 330 μs) compared to the parent CdSe QDs. The mechanism invokes unprecedented reversible quantum dot to organic chromophore electronic energy transfer.
Isolation of a Cationic Platinum(II) σ‐Silane Complex
Authors: Ríos Pablo , Fouilloux Hugo , Vidossich Pietro , Díez Josefina , Lledós Agustí , Conejero Salvador 
Published: January 2018

AbstractThe platinum complex [Pt(ItBuiPr′)(ItBuiPr)][BArF] interacts with tertiary silanes to form stable (<0 °C) mononuclear PtII σ‐SiH complexes [Pt(ItBuiPr′)(ItBuiPr)(η1‐HSiR3)][BArF]. These compounds have been fully characterized, including X‐ray diffraction methods, as the first examples for platinum. DFT calculations (including electronic topological analysis) support the interpretation of the coordination as an unusual η1‐SiH. However, the energies required for achieving a η2‐SiH mode are rather low, and is consistent with the propensity of these derivatives to undergo Si−H cleavage leading to the more stable silyl species [Pt(SiR3)(ItBuiPr)2][BArF] at room temperature.
Novel soluble carbazole‐based poly(aryl ethers): Preparation, properties, and application for dispersing multiwalled carbon nanotubes
Authors: Lin Li , Wu Xian , Han Yuntao , Zhang Haibo , Jiang Zhenhua , Chen Zheng 
Published: January 2018

ABSTRACTEffectively dispersing of carbon nanotubes (CNTs) is the key to producing high performance CNTs/poly(aryl ethers) (PAEs) composite materials. Here, a series of novel soluble carbazole‐based PAEs with different alkyl side‐chains were synthesized corresponding polymers P1, P2, P3, and P4, and characterized clearly by 1H NMR and IR. All the polymers exhibited good mechanical properties and thermostabilities (Tg ∼ 128–212 °C, Td5% ∼ 450–499 °C) as PAEs. Due to containing lots of large π‐conjugated carbazole derivative units and possess suitable solubility, these non‐conjugated polymers can wrap and disperse MWNTs well (238–416 mg/L) in CHCl3, and the similar work has been reported rarely. This excellent property makes these polymers become a promising and ideal type solubilizer for CNTs/PAEs composite. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46250.
Educational interactive LabVIEW programming of a 3D canal surface design
Authors: Allawi Faridoun A.M. 
Published: January 2018

AbstractEducational computer programming in geometrical modeling is an interactive dynamic educational method which helps to visualize; interactively and graphically; 3D geometrical models under different design conditions. Students using geometrical modeling in hydraulics can get large amount of geometrical data describing the x, y, and z coordinates of any circular cross‐section of the designed 3D canal transition, a step which is very important in the modeling of field and laboratory 3D canal sections. They can visually and interactively perform mathematical analysis of very complicated models very easily. Educational programming of geometrical modeling is very similar to experimental modeling in which the students gets feedback from the computer program and adjust—if necessary—the model specifications and properties to get the best engineering design. In this paper, the LabVIEW Platform and the 3D Bezier surface design method will be used by the students, as an educational interactive computer programming, for the design of a 3D open circular canal cross‐section having a hydraulic constriction and, a bottom slope of certain dimensions.
The effect of relational benefits in loyalty programmes: Evidence from Chinese milk formula customer clubs
Authors: Yang Song , Yu Siu Lung (Kevin) , Bruwer Johan 
Published: January 2018

AbstractAlthough the value of relational benefits has been recognised in customer relationship management, the impact of these benefits on loyalty behaviours is yet to be investigated in the context of loyalty clubs. Little is known why some loyalty programmes outperform others. By using both qualitative and quantitative research approaches, this research developed and estimated a conceptual model that describes the interaction of key relational benefits and their contributions to customer loyalty in a set of milk formula customer clubs in China. Data were collected from 300 Chinese infant milk formula buyers, including both customer club members and nonmembers. This study confirms that the customer‐confidence benefits and identity‐related benefits precede other loyalty rewards and strengthen other loyalty incentives in a loyalty programme. The economic benefits and information‐sharing benefits play a mediating role and contribute directly to customer loyalty. The findings of this research help better understand the mechanism behind loyalty behaviours in customer clubs.
Design and Synthesis of a BODIPY‐Tetrazole Based “Off‐On” in‐Cell Fluorescence Reporter of Hydrogen Peroxide
Authors: An Peng , Lewandowski Tracey M. , Lin Qing 
Published: January 2018

AbstractBODIPY‐linked bithiophene‐tetrazoles were designed and synthesized for bioorthogonal photoclick reactions in vitro and in vivo. The reactivity of these tetrazoles toward dimethyl fumarate was found to depend on the BODIPY attachment site, with the meta‐linked BODIPY–tetrazole being the most reactive. The resulting pyrazoline cycloadduct showed drastically reduced BODIPY fluorescence. However, BODIPY fluorescence recovered after treatment with hydrogen peroxide. This turn‐on effect was attributed to conversion from the pyrazoline to a pyrazole. Finally, we showed that this unique BODIPY–tetrazole off–on fluorescence probe can be used to detect hydrogen peroxide inside HeLa cells.
Application of SAR methods toward inhibition of bacterial peptidoglycan metabolizing enzymes
Authors: Tibaut Tjaša , Drgan Viktor , Novič Marjana 
Published: January 2018

AbstractStructure activity relationship (SAR) methods are applied for a study of inhibition of peptidoglycan metabolizing enzymes, which could represent new antibacterial targets. In this study, we exploit experimental data of inhibition of Mur A and Mur B enzymes for classification of large set of chemicals. Based on inhibitory potency of compounds and their structures from the literature, we developed classification models for new, potential inhibitors of Mur A and Mur B enzymes. The best model for Mur A has the following performance measures for the validation set: 0.85, 0.75, and 0.80, for sensitivity, specificity, and normalized Matthews correlation coefficient, respectively. The same measures of the best Mur B model are 0.94, 0.75, and 0.86. Such models could represent valuable computational tools for theoretic predictions of compounds' activities against specific targets. Additionally, application of such models, like any other computational tools, significantly reduces time and costs in the early phase of drug design.
Modulator‐Controlled Synthesis of Microporous STA‐26, an Interpenetrated 8,3‐Connected Zirconium MOF with thethe‐iTopology, and its Reversible Lattice Shift
Authors: Bumstead Alice M. , Cordes David B. , Dawson Daniel M. , Chakarova Kristina K. , Mihaylov Mihail Y. , Hobday Claire L. , Düren Tina , Hadjiivanov Konstantin I. , Slawin Alexandra M. Z. , Ashbrook Sharon E. , Prasad Ram R. R. , Wright Paul A. 
Published: January 2018

AbstractA fully interpenetrated 8,3‐connected zirconium MOF with thethe‐itopology type, STA‐26 (St Andrews porous material‐26), has been prepared using the 4,4′,4“‐(2,4,6‐trimethylbenzene‐1,3,5‐triyl)tribenzoate (TMTB) tritopic linker with formic acid as a modulating agent. In the as‐prepared form STA‐26 possessesImmsymmetry compared with thePmmsymmetry of the non‐interpenetrated analogue, NU‐1200, prepared using benzoic acid as a modulator. Upon removal of residual solvent there is a shift between the interpenetrating lattices and a resultant symmetry change toCmcmwhich is fully reversible. This is observed by X‐ray diffraction and13C MAS NMR is also found to be remarkably sensitive to the structural transition. Furthermore, heating STA‐26(Zr) in vacuum dehydroxylates the Zr6nodes leaving coordinatively unsaturated Zr4+sites, as shown by IR spectroscopy using CO and CD3CN as probe molecules. Nitrogen adsorption at 77 K together with grand canonical Monte Carlo simulations confirms a microporous, fully interpenetrated, structure with pore volume 0.53 cm3 g−1while CO2adsorption at 196 K reaches 300 cm3STP g−1at 1 bar. While the pore volume is smaller than that of its non‐interpenetrated mesoporous analogue, interpenetration makes the structure more stable to moisture adsorption and introduces shape selectivity in adsorption.
Anion Sensing by Fluorescent Expanded Calixpyrroles
Authors: Pushina Mariia , Koutnik Petr , Nishiyabu Ryuhei , Minami Tsuyoshi , Savechenkov Pavel , Anzenbacher Pavel 
Published: January 2018

AbstractExpanded calixpyrrole‐type macrocycles, calix[2]benzo[4]pyrroles, bearing fluorescent moieties attached via conjugated vinyl spacers, have been synthesized from the corresponding formyl derivatives through Knoevenagel condensation. The anion‐binding properties of the resulting fluorescent macrocycles have been studied by means of NMR, UV/Vis, and fluorescence spectroscopies. Our main focus has been on dicarboxylates matching the size of the binding cavity of the calix[2]benzo[4]pyrrole skeleton. The observed anion‐binding properties were compared with those of the regular calix[4]pyrroles bearing identical fluorophores. Surprisingly, the parent calix[4]pyrroles appear to be equally efficient, if not more so, for sensing anions such as dicarboxylates. Affinity constants determined for various anions and dianions show the sensors S1–S5 to be highly cross‐reactive. The cross‐reactivity of the sensors was utilized in a microchip‐based array, which showed perfect (100 %) classification of 18 analytes utilizing only five sensors. Finally, the same array was used to quantitatively analyze dicarboxylates such as oxalate and malonate. The data from the array were subjected to linear regression, allowing the determination of various concentrations of dianions with low error (<2 %).
Nanoconfined Oxidation Synthesis of N‐Doped Carbon Hollow Spheres and MnO2 Encapsulated Sulfur Cathode for Superior Li‐S Batteries
Authors: Shen Jiadong , Liu Jun , Liu Zhengbo , Hu Renzong , Liu Jiangwen , Zhu Min 
Published: January 2018

AbstractInvited for the cover of this issue is the group of Jun Liu at the South China University of Technology. The image depicts the complete synthetic route of S‐MnO2@C product and the excellent confined effect of rationally introduced carbon and MnO2 for the polysulfide. Read the full text of the article at 10.1002/chem.201704590.
Preparation of nano‐ZIF‐8 in methanol with high yield
Authors: Ta Don N. , Nguyen Hong K. D. , Trinh Bai X. , Le Quynh T. N. , Ta Hung N. , Nguyen Ha T. 
Published: January 2018

AbstractThis article systematically presented analysis results of factors affecting the preparation of nano‐ZIF‐8 in methanol for high yield. Samples were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Brunauer‐Emmett‐Teller (BET) adsorption, and thermogravimetry‐differential thermal analysis (TG/DTA). Synthesized nano‐ZIF‐8 had advantages over commercial ZIF‐8 (Basolite® Z1200 from Sigma‐Aldrich) such as a higher surface area, consisting of not only micropores like Basolite® Z1200 but also subordinate mesopores, formed by an assembly of nano‐ZIF‐8 crystals, which was 30 nm. Specifically, for the first time, nano‐ZIF‐8 was prepared in methanol with the yield of 61.2 %.