bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enzymatic transesterification monitored by an easy‐to‐use Fourier transform infrared spectroscopy method
Authors: Natalello Antonino , Sasso Francesco , Secundo Francesco 
Published: July 2012

AbstractTransesterification of triglycerides with short chain alcohols is the key reaction in biodiesel production, in addition to other applications in chemical synthesis. However, it is crucial to optimize reaction conditions to make enzymatic transesterification a cost‐effective and competitive process. In this work, a new, easy Fourier transform infrared (FTIR) spectroscopic approach for monitoring the transesterification reaction is reported and compared with a gas‐chromatographic method. The concentration of the total methyl esters in the reaction mixture is determined from the peak intensity at ∼1435 cm–1 in the second derivatives of the FTIR absorption spectra using a linear regression calibration. Interestingly, we found that the use of second derivatives allows an accurate determination of the methyl esters without the interference of free fatty acids. Moreover, information on substrate hydrolysis can be obtained within the same measurement by the infrared absorption at ∼1709 cm–1. We applied this approach to monitor methanolysis and hydrolysis reactions catalyzed by different commercial lipases, which displayed different sensitivities to methanol inhibition. Therefore, the FTIR approach reported in this work represents a rapid, inexpensive, and accurate method to monitor enzymatic transesterification, requiring very limited sample preparation and a simple statistical analysis of the spectroscopic data.
RET expression and detection of KIF5B/RET gene rearrangements in Japanese lung cancer
Authors: Sasaki Hidefumi , Shimizu Shigeki , Tani Yoichi , Maekawa Masahiko , Okuda Katsuhiro , Yokota Keisuke , Shitara Masayuki , Hikosaka Yu , Moriyama Satoru , Yano Motoki , Fujii Yoshitaka 
Published: July 2012

AbstractRET encodes the tyrosine kinase receptor of growth factors belonging to the glial‐derived neurotrophic factor family. Recently, RET gene rearrangements with N‐terminal of KIF5B gene were identified in lung adenocarcinomas from large‐scale sequencing. We investigated RET mRNA expression by real‐time reverse‐transcriptase polymerase chain reaction (RT‐PCR) assay using LightCycler, and KIF5B/RET gene rearrangements using newly established fluorescence in situ hybridization (FISH) analysis in surgically treated nonsmall cell lung cancer (NSCLC) cases. RET protein expression was also investigated by immunohistochemistry (IHC). This study included 157 surgically removed NSCLC cases for mRNA level analyses. The RET/β actin mRNA levels were not significantly different between lung cancer (6.359 ± 15.268) and adjacent normal lung tissues (8.205 ± 28.931, P = 0.6332). Tumor/normal (T/N) ratio of RET/β actin mRNA levels was not different within gender, stage, smoking status, and pathological subtypes. T/N ratio of RET/β actin mRNA levels was significantly higher in KIF5B/RET rearrangement samples (161.763 ± 123.488) than in wild‐type samples (5.9013 ± 17.148, P = 0.044). Although RET IHC positivity was not perfectly correlated with KIF5B/RET arrangement, we have detected the KIF5B/RET rearrangements using FISH analysis. Thus, we have successfully introduced FISH for diagnosing KIF5B/RET positive lung adenocarcinoma. This method facilitates the molecular evaluation for RET fusions and could be applicable in clinical practice to detect lung cancer that may be responsive to RET inhibitors.
Palladium‐Catalyzed Carbonylation of Chloroacetates to Afford Malonates: Controlling the Selectivity of the Product in a Buffer
Authors: Hu Jianglin , Zhang Qi , Guan Zhenhong , Gu Yanlong , Mo Wanling , Li Tao , Li Guangxing 
Published: July 2012

AbstractWe report an efficient process for the synthesis of diethyl malonate (DEM) and other malonates through the palladium‐catalyzed carbonylation of chloroacetates. Excellent selectivity (96 %) and yield (94 %) were obtained without the formation of Pd black. For the first time, a weakly alkaline buffer was used to control the selectivity for DEM in the reaction and we discuss the relationship between the buffer medium and selectivity in the reaction. The combination of anisole as the solvent and a Na2HPO4/NaH2PO4 buffer was beneficial for completely restraining the phase‐transfer‐catalyzed substitution of DEM with ethyl chloroacetate, as well as accommodating the proposed [(PPh3)2PdI]−[Bu4N]+ intermediate, by providing a suitable environment for its stable existence. We achieved the highest efficiency in the catalytic cycle by fine‐tuning the balance between the rates of oxidative addition and reductive elimination; moreover, we synthesized a recoverable heterogeneous polymer‐bound Pd catalyst in 85 % yield that could be reused without an appreciable loss in activity over four cycles.
Structure and Bonding Nature of the Strained Lewis Acid 3‐Methyl‐1‐boraadamantane: A Case Study Employing a New Data‐Analysis Procedure in Gas Electron Diffraction
Authors: Vishnevskiy Yury V. , Abaev Maxim A. , Rykov Anatolii N. , Gurskii Mikhail E. , Belyakov Pavel A. , Erdyakov Sergey Yu. , Bubnov Yuri N. , Mitzel Norbert W. 
Published: July 2012

AbstractBase‐free 3‐methyl‐1‐boraadamantane was synthesized by starting from its known THF adduct, transforming it to a butylate‐complex withn‐butyllithium, cleaving the cage with acetyl chloride to give 3‐n‐butyl‐5‐methyl‐7‐methylene‐3‐borabicyclo[3.3.1]nonane and closing the cage again by reacting the latter with dicyclohexylborane. The identity of 3‐methyl‐1‐boraadamantane was proven by1H,11B and13C NMR spectroscopy and elemental analysis. The experimental equilibrium structure of the free 3‐methyl‐1‐boraadamantane molecules has been determined at 100 °C by using gas‐phase electron diffraction. For this structure determination, an improved method for data analysis has been introduced and tested: the structural refinement versus gas‐phase electron diffraction data (in terms of Cartesian coordinates) with a set of quantum‐chemically derived regularization constraints for the complete structure under optimization of a regularization constant, which maximizes the contribution of experimental data while retaining a stable refinement. The detailed analysis of parameter errors shows that the new approach allows obtaining more reliable results. The most important structural parameters are:re(B‐C)av=1.556(5) Å,${\angle }$e(C‐B‐C)av=116.5(2)°. The configuration of the boron atom is pyramidal with${\sum \angle }$(C‐B‐C)=349.4(4)°. The nature of bonding was analyzed further by applying the natural bond orbital (NBO) and atoms in molecules (AIM) approaches. The experimentally observed shortening of the BC bonds and elongation of the adjacent CC bonds can be explained by the σ(C‐C)→p(B) hyperconjugation model. Both NBO and AIM analyses predict that the BC bonds are significantly bent in the direction out of the cage.
Probing the Motional Behavior of Eumelanin and Pheomelanin with Solid‐State NMR Spectroscopy: New Insights into the Pigment Properties
Authors: Thureau Pierre , Ziarelli Fabio , Thévand André , Martin Rachel W. , Farmer Patrick J. , Viel Stéphane , Mollica Giulia 
Published: July 2012

AbstractMelanin is the most widespread pigment in the animal kingdom. Despite its importance, its detailed structure and overall molecular architecture remain elusive. Both eumelanin (black) and pheomelanin (red) occur in the human body. These two melanin compounds show very different responses to UV‐radiation exposure, which could relate to their microscopic features. Herein, the structural properties and motional behavior of natural eu‐ and pheomelanin extracted from black and red human hair are investigated by means of solid‐state NMR spectroscopy. Several 1D and 2D NMR spectroscopic techniques were combined to highlight the differences between the two forms of the pigment. The quantitative analysis of the 1H NMR wide‐line spectra extracted from 2D 1H–13C LG‐WISE experiments revealed the presence of two dynamically distinguishable components in both forms. Remarkably, the more mobile fraction of the pigment showed a higher mobility with respect to the proteinaceous components that coexist in the melanosome, which is particularly evident for the red pigment. An explanation of the observed effects takes into account the different architecture of the proteinaceous matrix that constitutes the physical substrate onto which melanin polymerizes within the eu‐ and pheomelanosomes. Further insight into the molecular structure of the more mobile fraction of pheomelanin was also obtained by means of the analysis of 2D 1H–13C INEPT experiments. Our view is that not only structural features inherent in the pure pigment, but also the role of the matrix structure in defining the overall melanin supramolecular arrangement and the resulting dynamic behavior of the two melanin compounds should be taken into account to explain their functions. The reported results could pave a new way toward the explanation of the molecular origin of the differences in the photoprotection activity displayed by black and red melanin pigments.
Consequences of the One‐Electron Reduction and Photoexcitation of Unsymmetric Bis‐imidazolium Salts
Authors: Gierz Verena , Melomedov Jascha , Förster Christoph , Deißler Christine , Rominger Frank , Kunz Doris , Heinze Katja 
Published: July 2012

AbstractCoupling of uronium salts with in situ generated N‐heterocyclic carbenes provides straightforward access to symmetrical [4]2+ and unsymmetrical bis‐imidazolium salts [6]2+ and [9]2+. As indicated by cyclic and square‐wave voltammetry, [6]2+ and [9]2+ can be (irreversibly) reduced by one electron. The initially formed radicals [6].+ and [9].+ undergo further reactions, which were probed by EPR spectroscopy and density functional calculations. The final products of the two‐electron reduction are the two carbenes. Upon irradiation with UV light both [6]2+ and [9]2+ emit at room temperature in solution but with dramatically different characteristics. The different fluorescence behavior is analyzed by emission spectroscopy and interpreted by using time‐dependent density functional calculations as largely due to different excited‐state dynamics of [6]2+ and [9]2+. The geometries of both radicals [6].+ and [9].+ and excited states {[6]2+}* and {[9]2+}* are substantially different from those of the parent ground‐state molecules.
Toward Ultralow‐Bandgap Liquid Crystalline Semiconductors: Use of Triply Fused Metalloporphyrin Trimer–Pentamer as Extra‐large π‐Extended Mesogenic Motifs
Authors: Tanaka Seiya , Sakurai Tsuneaki , Honsho Yoshihito , Saeki Akinori , Seki Shu , Kato Kenichi , Takata Masaki , Osuka Atsuhiro , Aida Takuzo 
Published: July 2012

AbstractIn contrast with their dimeric homologue, triply fused zinc porphyrin trimer–pentamer, as extra‐large π‐extended mesogens, assemble into columnar liquid crystals (LCs) when combined with 3,4,5‐tri(dodecyloxy)phenyl side groups (3 PZn–5 PZn, Figure 1). Their LC mesophases develop over a wide temperature range, namely, 41–280 °C (on heating) for 5 PZn, and all adopt an oblique columnar geometry, typically seen in columnar LC materials involving strong mesogenic interactions. These LC materials are characterized by their wide light‐absorption windows from the entire visible region up to a near infrared (NIR) region. Such ultralow‐bandgap LC materials are chemically stable and serve as hole transporters, in which 5 PZn gives the largest charge carrier mobility (2.4×10−2 cm V−1 s−1) among the series. Despite a big dimensional difference, they coassemble without phase separation, in which the resultant LC materials display essentially no deterioration of the intrinsic conducting properties.
Discovery of BAY 94‐8862: A Nonsteroidal Antagonist of the Mineralocorticoid Receptor for the Treatment of Cardiorenal Diseases
Authors: Bärfacker Lars , Kuhl Alexander , Hillisch Alexander , Grosser Rolf , Figueroa‐Pérez Santiago , Heckroth Heike , Nitsche Adam , Ergüden Jens‐Kerim , Gielen‐Haertwig Heike , Schlemmer Karl‐Heinz , Mittendorf Joachim , Paulsen Holger , Platzek Johannes , Kolkhof Peter 
Published: July 2012

AbstractAldosterone is a hormone that exerts manifold deleterious effects on the kidneys, blood vessels, and heart which can lead to pathophysiological consequences. Inhibition of the mineralocorticoid receptor (MR) is a proven therapeutic concept for the management of associated diseases. Use of the currently marketed MR antagonists spironolactone and eplerenone is restricted, however, due to a lack of selectivity in spironolactone and the lower potency and efficacy of eplerenone. Several pharmaceutical companies have implemented programs to identify drugs that overcome the known liabilities of steroidal MR antagonists. Herein we disclose an extended SAR exploration starting from cyano‐1,4‐dihydropyridines that were identified by high‐throughput screening. Our efforts led to the identification of a dihydronaphthyridine, BAY 94‐8862, which is a potent, selective, and orally available nonsteroidal MR antagonist currently under investigation in a clinical phase II trial.
Development of the principal nucleus trigeminal lemniscal projections in the mouse
Authors: Kivrak Beril G. , Erzurumlu Reha S. 
Published: July 2012

AbstractThe principal sensory (PrV) nucleus‐based trigeminal lemniscus conveys whisker‐specific neural patterns to the ventroposteromedial (VPM) nucleus of the thalamus and subsequently to the primary somatosensory cortex. Here we examined the perinatal development of this pathway with carbocyanine dye labeling in embryonic and early postnatal mouse brains. We developed a novel preparation in which the embryonic hindbrain and the diencephalon are flattened out, allowing a birds‐eye view of the PrV lemniscus in its entirety. For postnatal brains we used another novel approach by sectioning the brain along an empirically determined oblique horizontal angle, again preserving the trigeminothalamic pathway. PrV neurons are born along the hindbrain ventricular zone and migrate radially for a short distance to coalesce into a nucleus adjacent to the ascending trigeminal tract. During migration of the spindle‐shaped cell bodies, slender axonal processes grow along the opposite direction towards the floor plate. As early as embryonic day (E) 11, pioneering axons tipped with large growth cones cross the ventral midline and immediately make a right angle turn. By E13 many PrV axons form fascicles crossing the midline and follow a rostral course. PrV axons reach the midbrain by E15 and the thalamus by E17. While the target recognition and invasion occurs prenatally, organization of PrV axon terminals into whisker‐specific rows and patches takes place during the first 4 postnatal (P) days. Initially diffuse and exuberant projections in the VPM at P1 coalesce into row and whisker specific terminal zones by P4. J. Comp. Neurol. 521:299–311, 2013. © 2012 Wiley Periodicals, Inc.
Sex‐specific expression of estrogen receptors α and β and Kiss1 in the postnatal rat amygdala
Authors: Cao Jinyan , Patisaul Heather B. 
Published: July 2012

AbstractThe rodent amygdaloid complex is composed of numerous subnuclei important for the sex‐specific regulation of sociosexual behavior. Although estrogen receptors (ERs) are critical for organizing functional and cytoarchitectural sex differences in these subnuclei, a detailed developmental profile of ER expression in the amygdaloid complex is not available. Moreover, the kisspeptin gene (Kiss1) was recently identified in the adult amygdala, but it remains unknown if it is expressed during development. To fill these data gaps, rat brains (5–7/group) were assessed on postnatal days (PNDs) 0, 2, 4, 7, and 19 for ER alpha (ERα; Esr1), beta (ERβ; Esr2), and Kiss1 expression using in situ hybridization. Expression was quantified in the posterodorsal portion of the medial amygdala posterodorsal (MePD), lateral (PLCo), and medial (PMCo) components of the posterior cortical nucleus, and the amygdalohippocampal area (AHi). ERα expression was high throughout the amygdala at birth, but sexually dimorphic only in the AHi. ERα expression in the MePD and the PLCo showed a U‐shaped expression pattern over time. In the PMCo, ERα expression decreased from PND 2 and remained low through PND 19. Sexually dimorphic expression of ERβ in the MePD was observed on PND 0, with higher levels in females, but reversed by PND 4 due to declining levels in females. No Kiss1 signal was observed in the postnatal amygdala, suggesting that expression arises after puberty. These data reveal that ER expression is region‐specific within the neonatal amygdala. These differences likely contribute to sex differences in sociosexual behavior across the lifespan. J. Comp. Neurol. 521:465–478, 2013. © 2012 Wiley Periodicals, Inc.
Glutamatergic neuronal populations in the brainstem of the sea lamprey, Petromyzon marinus: An in situ hybridization and immunocytochemical study
Authors: Villar‐Cerviño Verona , Barreiro‐Iglesias Antón , Fernández‐lópez Blanca , Mazan Sylvie , Rodicio María Celina , Anadón Ramón 
Published: July 2012

AbstractGlutamate is the major excitatory neurotransmitter in vertebrates, and glutamatergic cells probably represent a majority of neurons in the brain. Physiological studies have demonstrated a wide presence of excitatory (glutamatergic) neurons in lampreys. The present in situ hybridization study with probes for the lamprey vesicular glutamate transporter (VGLUT) provides an anatomical basis for the general distribution and precise localization of glutamatergic neurons in the sea lamprey brainstem. Most glutamatergic neurons were found within the periventricular gray layer throughout the brainstem, with the following regions being of particular interest: the optic tectum, torus semicircularis, isthmus, dorsal and medial nuclei of the octavolateral area, dorsal column nucleus, solitary tract nucleus, motoneurons, and reticular formation. The reticular population revealed a high degree of cellular heterogeneity including small, medium‐sized, large, and giant glutamatergic neurons. We also combined glutamate immunohistochemistry with neuronal tract‐tracing methods or γ‐aminobutyric acid (GABA) immunohistochemistry to better characterize the glutamatergic populations. Injection of Neurobiotin into the spinal cord revealed that retrogradely labeled small and medium‐sized cells of some reticulospinal‐projecting groups were often glutamate‐immunoreactive, mostly in the hindbrain. In contrast, the large and giant glutamatergic reticulospinal perikarya mostly lacked glutamate immunoreactivity. These results indicate that glutamate immunoreactivity did not reveal the entire set of glutamatergic populations. Some spinal‐projecting octaval populations lacked both VGLUT and glutamate. As regards GABA and glutamate, their distribution was largely complementary, but colocalization of glutamate and GABA was observed in some small neurons, suggesting that glutamate immunohistochemistry might also detect non‐glutamatergic cells or neurons that co‐release both GABA and glutamate. J. Comp. Neurol. 521:522–557, 2013. © 2012 Wiley Periodicals, Inc.
Self‐Assembled Monolayers of Single‐Molecule Magnets [Tb{Pc′(SR)8}2] on Gold
Authors: Glebe Ulrich , Weidner Tobias , Baio Joe E. , Schach Denise , Bruhn Clemens , Buchholz Axel , Plass Winfried , Walleck Stephan , Glaser Thorsten , Siemeling Ulrich 
Published: July 2012

AbstractThe magnetic properties of the bis(phthalocyaninato)terbium complexes [Tb{Pc′(SR)8}2] (1) containing eight β‐positioned long‐chain alkylthio substituents SR (a: R=n‐C8H17, b: R=n‐C12H25) were studied by SQUID measurements, which revealed that both compounds are single‐molecule magnets with an effective energy barrier for spin reversal significantly higher than that found for pristine bis(phthalocyaninato)terbium [Tb(Pc)2]. Thin films on gold were fabricated from 1 a and 1 b by chemisorption from solution and were characterised by near‐edge X‐ray absorption fine structure (NEXAFS) and X‐ray photoelectron spectroscopy (XPS). In the case of 1 a, atomic force microscopy (AFM) was used in addition. The results are in accord with the formation of self‐assembled monolayers which contain the macrocyclic rings mainly in an approximately horizontal orientation. The chemisorption is primarily due to the peripheral SR substituents, giving rise to coordinatively bound thioether units, whose alkyl chains are in an almost parallel orientation with respect to the surface. In the case of 1 b, covalently attached thiolate units were also observed, indicating that the chemisorption process can lead to carbon–sulfur bond cleavage. In addition, the crystal structure of 1 a was determined.
Ethylene Production by ODHE in Catalytically Modified Ba0.5Sr0.5Co0.8Fe0.2O3−δ Membrane Reactors
Authors: Lobera M. Pilar , Escolástico Sonia , Garcia‐Fayos Julio , Serra José M. 
Published: July 2012

AbstractProcess intensification by the integration of membranes and high‐temperature reactors offers several advantages with regard to conventional process schemes, that is, energy saving, safe operation, reduced plant/unit size, and higher process performance, for example, higher productivity, catalytic activity, selectivity, or stability. We present the study of oxidative dehydrogenation of ethane at 850 °C on a catalytic membrane reactor based on a mixed ionic–electronic conducting membrane. The surface of the membrane made of Ba0.5Sr0.5Co0.8Fe0.2O3−δ has been activated by using different porous catalytic layers based on perovskites. The layer was deposited by screen printing, and the porosity and thickness was studied for the catalyst composition. The different catalyst formulations are based on partial substitution of A‐ and B‐site atoms of doped strontium ferrite/cobaltites (A0.6Sr0.4Co0.5Fe0.5O3−δ and Ba0.6Sr0.4BO3−δ) and were synthesized by an ethylenediaminetetraacetic acid–citrate complexation route. The use of a disk‐shaped membrane in the reactor enabled the direct contact of gaseous oxygen and hydrocarbons to be avoided, and thus, the ethylene content increased. High ethylene yields (up to ≈81 %) were obtained by using a catalytic coating based on Ba0.5Sr0.5Co0.8Fe0.2O3−δ, which included macropores produced by the addition of graphite platelets into the screen‐printing ink. The promising catalytic results obtained with this catalytically modified membrane reactor are attributed to the combination of 1) the high activity, as a result of the high temperature and oxygen species diffusing through the membrane; 2) the control of oxygen dosing and the low concentration of molecules in the gas phase; and 3) suitable fluid dynamics, which enables appropriate feed contact with the membrane and the rapid removal of products.