bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Family of Two‐Dimensional Zeolites Prepared from the Intermediate Layered Precursor IPC‐3P Obtained during the Synthesis of TUN Zeolite
Authors: Kubů Martin , Roth Wieslaw J. , Greer Heather F. , Zhou Wuzong , Morris Russell E. , Přech Jan , Čejka Jiří 
Published: August 2013

AbstractThe crystallization of zeolite TUN with 1,4‐bis(N‐methylpyrrolidinium)butane as template proceeds through an intermediate, designated IPC‐3P, following the Ostwald rule of successive transformations. This apparently layered transient product has been thoroughly investigated and found to consist of MWW monolayers stacked without alignment in register, that is, disordered compared with MCM‐22P. The structure was confirmed based on X‐ray diffraction and high‐resolution (HR)TEM analysis. The layered zeolite precursor IPC‐3P can be swollen and pillared affording a combined micro‐ and mesoporous material with enhanced Brunauer–Emmett–Teller (BET) surface area (685 m2g−1) and greater accessibility of Brønsted acid sites for bulky molecules. This mesoporous material was probed with 2,6‐di‐tert‐butylpyridine (DTBP). IPC‐3P and its modification create a new layered zeolite sub‐family belonging to the MWW family. FTIR data indicate that (Al)MWW materials MCM‐22 and IPC‐3 with Si/Al ratios greater than 20 exhibit a lower relative ratio of Brønsted to Lewis acid sites than MCM‐22 (with Si/Al ratios of around 13), that is, less than 2 versus more than 3, respectively. This is maintained even upon pillaring and warrants further exploration of materials like IPC‐3P with a higher Al content. The unique XRD features of IPC‐3P indicating misaligned stacking of layers and distinct from MCM‐22P, are also seen in other MWW materials such as EMM‐10P, hexamethonium‐templated (HM)‐MCM‐22, ITQ‐30, and UZM‐8 suggesting the need for more detailed study of their identity and properties.
Highly Stable Duplex Formation by Artificial Nucleic Acids Acyclic Threoninol Nucleic Acid (aTNA) and Serinol Nucleic Acid (SNA) with Acyclic Scaffolds
Authors: Murayama Keiji , Tanaka Yoshihiro , Toda Takasuke , Kashida Hiromu , Asanuma Hiroyuki 
Published: August 2013

AbstractThe stabilities of duplexes formed by strands of novel artificial nucleic acids composed of acyclic threoninol nucleic acid (aTNA) and serinol nucleic acid (SNA) building blocks were compared with duplexes formed by the acyclic glycol nucleic acid (GNA), peptide nucleic acid (PNA), and native DNA and RNA. All acyclic nucleic acid homoduplexes examined in this study had significantly higher thermal stability than DNA and RNA duplexes. Melting temperatures of homoduplexes were in the order of aTNA>PNA≈GNA≥SNA≫RNA>DNA. Thermodynamic analyses revealed that high stabilities of duplexes formed by aTNA and SNA were due to large enthalpy changes upon formation of duplexes compared with DNA and RNA duplexes. The higher stability of the aTNA homoduplex than the SNA duplex was attributed to the less flexible backbone due to the methyl group of D‐threoninol on aTNA, which induced clockwise winding. Unlike aTNA, the more flexible SNA was able to cross‐hybridize with RNA and DNA. Similarly, the SNA/PNA heteroduplex was more stable than the aTNA/PNA duplex. A 15‐mer SNA/RNA was more stable than an RNA/DNA duplex of the same sequence.
Formation and Dynamic Behavior of Mono‐ and Bimetallic Cadmium(II) Porphyrin Complexes: Allosteric Control of Coupled Intraligand Metal Migrations
Authors: Le Gac Stéphane , Fusaro Luca , Dorcet Vincent , Boitrel Bernard 
Published: August 2013

AbstractThe complexation behavior of a bis‐strapped porphyrin ligand (1) towards CdII has been investigated by 1H and 113Cd NMR spectroscopy with the help of X‐ray diffraction structures. The presence of an overhanging carboxylic acid group on each side of the macrocycle is responsible for the instantaneous insertion of the metal ion(s) at room temperature, and allows the formation of bimetallic species with unusual coordination modes at the origin of unique dynamic behaviors. In the absence of base, a C2‐symmetric bimetallic complex (1Cd2) is readily formed, in which the porphyrin acts as a bridging ligand. Both CdII ions are bound to the N core and to a COO− group of a strap. In contrast, the presence of a base induces a two‐step binding process with the successive formation of mono and bimetallic species (1Cd and 1Cd⋅CdOAc). Formally, a CdII ion is first inserted into the N core and experiences a strong out‐of‐plane (OOP) displacement due to the binding of an overhanging carbonyl group in an apical position. A second CdII ion then binds exclusively to the strap on the opposite side, in a so‐called hanging‐atop (HAT) coordination mode. These two complexes display a fluxional behavior that relies on intraligand migration processes of the metal ion(s). In 1Cd, the CdII ion exchanges between the two equivalent overhanging apical ligands by funneling through the porphyrin ring. In 1Cd⋅CdOAc, the two CdII ions exchange their coordination mode (HAT↔OOP) in a concerted way while staying on their respective side of the macrocycle, in a so‐called Newton’s cradle‐like motion. The intramolecular pathway was notably evidenced by variable temperature 113Cd heteronuclear NMR experiments. This coupled motion of the CdII cations is under allosteric control; the addition of an acetate anion (the allosteric effector) to the “resting” C2‐symmetric complex 1Cd2 affords the dissymmetric complex 1Cd⋅CdOAc and triggers equilibrium between its two degenerate states. The rate of the swinging motion further depends on the concentration of AcO−, with a higher concentration leading to a slower motion. As compared with the related PbII and BiIII bimetallic complexes, the Newton’s cradle‐like motion proceeds faster with the smaller CdII ion. These results open the way to novel multistable devices and switches.
Effect of Phosphate Modification on the Brønsted Acidity and Methanol‐to‐Olefin Conversion Activity of Zeolite ZSM‐5
Authors: Dyballa Michael , Klemm Elias , Weitkamp Jens , Hunger Michael 
Published: August 2013

AbstractPhosphate‐modified ZSM‐5 zeolites were studied by standard characterization techniques and solid‐state nuclear magnetic resonance spectroscopy, and in the methanol‐to‐olefin (MTO) conversion. Considering the physicochemical properties of the ZSM‐5 zeolites, the most important effects of the phosphate modification are a deposition of polyphosphates in the pore system and a decrease of the acid site density, but not of the acid site strength. The significant increase in the selectivity to C2 – C4 alkenes and the decrease of C5+ formation in the MTO reaction for a phosphate coverage of about 5 wt % are explained by extra‐framework phosphate species near the crossing intersections of the ZSM‐5 pore system, which hinder the formation of large intermediates and reaction products.
Preservation of neurocognitive function and local control of 1 to 3 brain metastases treated with surgery and carmustine wafers
Authors: Brem Steven , Meyers Christina A. , Palmer Gary , Booth‐Jones Margaret , Jain Surbhi , Ewend Matthew G. 
Published: August 2013

BACKGROUNDNeurosurgical resection and whole‐brain radiation therapy (WBRT) are accepted treatments for single and oligometastatic cancer to the brain. To avoid the decline in neurocognitive function (NCF) linked to WBRT, the authors conducted a prospective, multicenter, phase 2 study to determine whether surgery and carmustine wafers (CW), while deferring WBRT, could preserve NCF and achieve local control (LC).METHODSNCF and LC were measured in 59 patients who underwent resection and received CW for a single (83%) or dominant (oligometastatic, 2 to 3 lesions) metastasis and received stereotactic radiosurgery (SRS) for tiny nodules not treated with resection plus CW. Preservation of NCF was defined as an improvement or a decline ≤1 standard deviation from baseline in 3 domains: memory, executive function, and fine motor skills, evaluated at 2‐month intervals.RESULTSSignificant improvements in executive function and memory occurred throughout the 1‐year follow‐up. Preservation or improvement of NCF occurred in all 3 domains for the majority of patients at each of the 2‐month intervals. NCF declined in only 1 patient. The chemowafers were well tolerated, and serious adverse events were reversible. There was local recurrence in 28% of the patients at 1‐year follow‐up.CONCLUSIONSPatients with brain metastases had improvements in their cognitive trajectory, especially memory and executive function, after treatment with resection plus CW. The rate of LC (78%) was comparable to historic rates of surgery with WBRT and superior to reports of WBRT alone. For patients who undergo resection for symptomatic or large‐volume metastasis or for tissue diagnosis, the addition of CW can be considered as an option. Cancer 2013;119:3830–3838. © 2013 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.
Rapid on‐site evaluation for endoscopic ultrasound‐guided fine‐needle biopsy of the pancreas decreases the incidence of repeat biopsy procedures
Authors: Collins Brian T. , Murad Faris M. , Wang Jeff F. , Bernadt Cory T. 
Published: August 2013

BACKGROUNDRapid on‐site evaluation (ROSE) for endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) biopsy of the pancreas provides immediate feedback regarding cellular adequacy to aid in obtaining a definitive diagnosis and has the potential to avoid repeat procedures. The objective of the current study was to measure the impact of ROSE service on the incidence of repeat EUS FNA biopsy procedures.METHODSOver a consecutive 3‐year period, the pathology database at Washington University Medical Center was searched for patients with both an initial and subsequent EUS FNA biopsy demonstrating a solid lesion of the pancreas. These were divided temporally between the time before and after the introduction of ROSE service. Reports were reviewed and results were recorded.RESULTSA total of 379 patients underwent ROSE service and 377 patients did not. The percentage of repeat non‐ROSE EUS FNA cases was 5.8% and the percentage of repeat ROSE EUS FNA cases was 2.9%. The use of the ROSE service was found to decrease the number of repeat procedures by approximately 50% (P = .024). For those patients who underwent a repeat EUS‐FNA procedure, the ROSE service provided a higher rate of definitive diagnosis among patients undergoing repeat procedures (67%) versus the non‐ROSE cohort (27%).CONCLUSIONSThe use of ROSE for EUS‐FNA biopsy of the pancreas was found to result in fewer patients undergoing repeat procedures. Patients who required a repeat procedure with the use of ROSE had a higher percentage of definitive diagnostic categorization on the repeat biopsy. Initial use of ROSE for EUS‐FNA of solid pancreatic lesions was found to decrease the number of patients who required a repeat procedure. Cancer (Cancer Cytopathol) 2013;121:518–24. © 2013 American Cancer Society.
Tanycyte‐like cells form a blood–cerebrospinal fluid barrier in the circumventricular organs of the mouse brain
Authors: Langlet Fanny , Mullier Amandine , Bouret Sebastien G. , Prevot Vincent , Dehouck Benedicte 
Published: August 2013

ABSTRACTTanycytes are highly specialized ependymal cells that form a blood–cerebrospinal fluid (CSF) barrier at the level of the median eminence (ME), a circumventricular organ (CVO) located in the tuberal region of the hypothalamus. This ependymal layer harbors well‐organized tight junctions, a hallmark of central nervous system barriers that is lacking in the fenestrated portal vessels of the ME. The displacement of barrier properties from the vascular to the ventricular side allows the diffusion of blood‐borne molecules into the parenchyma of the ME while tanycyte tight junctions control their diffusion into the CSF, thus maintaining brain homeostasis. In the present work, we combined immunohistochemical and permeability studies to investigate the presence of tanycyte barriers along the ventricular walls of other brain CVOs. Our data indicate that, unlike cuboidal ependymal cells, ependymal cells bordering the CVOs possess long processes that project into the parenchyma of the CVOs to reach the fenestrated capillary network. Remarkably, these tanycyte‐like cells display well‐organized tight junctions around their cell bodies. Consistent with these observations, permeability studies show that this ependymal layer acts as a diffusion barrier. Together, our results suggest that tanycytes are a characteristic feature of all CVOs and yield potential new insights into their involvement in regulating the exchange between the blood, the brain, and the CSF within these “brain windows.” J. Comp. Neurol. 521:3389‐3405, 2013. © 2013 Wiley Periodicals, Inc.
Brain‐derived neurotrophic factor: mRNA expression and protein distribution in the brain of the teleost Nothobranchius furzeri
Authors: D'Angelo Livia , De Girolamo Paolo , Lucini Carla , Terzibasi Eva Tozzini , Baumgart Mario , Castaldo Luciana , Cellerino Alessandro 
Published: August 2013

ABSTRACTBDNF (brain‐derived neurotrophic factor) is a member of the neurotrophin family and it is implicated in regulating brain development and function. The BDNF gene organization and coding sequence are conserved in all vertebrates. The present survey was conducted in a teleost fish, Nothobranchius furzeri, because it is an emerging model of aging studies due to its short lifespan and shows the high rate of adult neurogenesis typical of anamniotes. The present survey reports: 1) the identification and characterization of the cDNA fragment encoding BDNF protein, and 2) the localization of BDNF in the whole brain. BDNF mRNA expression was assessed by in situ hybridization, by employing an antisense RNA probe; BDNF protein was detected by employing a sensitive immunohistochemical technique, along with highly specific affinity‐purified antibodies to BDNF. Both BDNF mRNA and protein were detected in neurons and glial cells of all regions of the brain of N. furzeri. Interestingly, BDNF was localized also in brain areas involved in adult neurogenic activities, suggesting a specific role for this neurotrophic factor in controlling cell proliferation. These results provide baseline information for future studies concerning BDNF involvement in the aging processes of the teleost brain. J. Comp. Neurol. 522:1004–1030, 2014. © 2013 Wiley Periodicals, Inc.
Anatomy of hierarchy: Feedforward and feedback pathways in macaque visual cortex
Authors: Markov Nikola T. , Vezoli Julien , Chameau Pascal , Falchier Arnaud , Quilodran René , Huissoud Cyril , Lamy Camille , Misery Pierre , Giroud Pascale , Ullman Shimon , Barone Pascal , Dehay Colette , Knoblauch Kenneth , Kennedy Henry 
Published: August 2013

ABSTRACTThe laminar location of the cell bodies and terminals of interareal connections determines the hierarchical structural organization of the cortex and has been intensively studied. However, we still have only a rudimentary understanding of the connectional principles of feedforward (FF) and feedback (FB) pathways. Quantitative analysis of retrograde tracers was used to extend the notion that the laminar distribution of neurons interconnecting visual areas provides an index of hierarchical distance (percentage of supragranular labeled neurons [SLN]). We show that: 1) SLN values constrain models of cortical hierarchy, revealing previously unsuspected areal relations; 2) SLN reflects the operation of a combinatorial distance rule acting differentially on sets of connections between areas; 3) Supragranular layers contain highly segregated bottom‐up and top‐down streams, both of which exhibit point‐to‐point connectivity. This contrasts with the infragranular layers, which contain diffuse bottom‐up and top‐down streams; 4) Cell filling of the parent neurons of FF and FB pathways provides further evidence of compartmentalization; 5) FF pathways have higher weights, cross fewer hierarchical levels, and are less numerous than FB pathways. Taken together, the present results suggest that cortical hierarchies are built from supra‐ and infragranular counterstreams. This compartmentalized dual counterstream organization allows point‐to‐point connectivity in both bottom‐up and top‐down directions. J. Comp. Neurol. 522:225–259, 2014. © 2013 Wiley Periodicals, Inc.
Protracted maturation of forebrain afferent connections of the ventral tegmental area in the rat
Authors: Yetnikoff Leora , Reichard Rhett A. , Schwartz Zachary M. , Parsely Kenneth P. , Zahm Daniel S. 
Published: August 2013

ABSTRACTThe mesocorticolimbic dopamine system has long attracted the interest of researchers concerned with the unique gamut of behavioral and mental health vulnerabilities associated with adolescence. Accordingly, the development of the mesocorticolimbic system has been studied extensively, but almost exclusively with regard to dopaminergic output, particularly in the nucleus accumbens and medial prefrontal cortex. To the contrary, the ontogeny of inputs to the ventral tegmental area (VTA), the source of mesocorticolimbic dopamine, has been neglected. This is not a trivial oversight, as the activity of VTA neurons, which reflects their capacity to transmit information about salient events, is sensitively modulated by inputs. Here, we assessed the development of VTA afferent connections using the β subunit of cholera toxin (Ctβ) as a retrograde axonal tracer in adolescent (postnatal day 39) and early adult (8–9‐week‐old) rats. After intra‐VTA injections of Ctβ, adolescent and early adult animals exhibited qualitatively similar distributions of retrogradely labeled neurons in the sense that VTA‐projecting neurons were present at all of the same rostrocaudal levels in all of the same structures in both age groups. However, quantitation of retrogradely labeled neurons revealed that adolescent brains, compared with early adult brains, had significantly fewer VTA‐projecting neurons preferentially within an interconnected network of cortical and striatopallidal forebrain structures. These findings provide a novel perspective on the development of the mesocorticolimbic dopamine system and may have important implications for age‐dependent specificity in the function of this system, particularly with regard to adolescent impulsivity and mental health vulnerabilities. J. Comp. Neurol. 522:1031–1047, 2014. © 2013 Wiley Periodicals, Inc.
Distinctive population of Gfap‐expressing neural progenitors arising around the dentate notch migrate and form the granule cell layer in the developing hippocampus
Authors: Seki Tatsunori , Sato Toru , Toda Keiko , Osumi Noriko , Imura Tetsuya , Shioda Seiji 
Published: August 2013

ABSTRACTIn the adult hippocampus, granule cells continue to be generated from astrocyte‐like progenitors expressing glial fibrillary acidic protein (GFAP) that differ from embryonic neocortical progenitors. However, during the embryonic period, dentate granule neurons and neocortical pyramidal neurons are derived from the ventricular zone (VZ) of the pallium. Our question is when do GFAP+ progenitors of granule neurons appear in the developing hippocampus during the embryonic period, and how do they form the granule cell layer. The present analysis using Gfap‐GFP transgenic mice shows that the GFP+ distinct cell population first appears in the VZ of the medial pallium at the dorsal edge of the fimbria on embryonic day 13.5. During the perinatal period, they form a migratory stream from the VZ to the developing dentate gyrus, and establish the germinal zones in the migratory stream, and the marginal and hilar regions in the developing dentate gyrus. GFP+ cells in these regions were positive for Sox2 and Ki67, but negative for BLBP. GFP+ cells with Neurogenin2 expression were largely distributed in the VZ, whereas GFP+ cells with Tbr2 and NeuroD expressions were seen in the migratory stream and developing dentate gyrus. Prox1‐expressing GFP+ cells were restricted to the developing dentate gyrus. These results suggest that distinctive Gfap‐expressing progenitors arising around the dentate notch form germinal regions in the migratory stream and the developing dentate gyrus where they differentiate into granule neurons, indicating that distinct astrocyte‐like neural progenitors continue to generate granule neurons, from the beginning of dentate development and throughout life. J. Comp. Neurol. 522:261–283, 2014. © 2013 Wiley Periodicals, Inc.
Should diabetic ketosis without acidosis be included in ketosis‐prone type 2 diabetes mellitus?
Authors: Xie Xiao‐Jing , Hu Yun , Cheng Cheng , Feng Tian‐Tian , He Ke , Mao Xiao‐Ming 
Published: August 2013

AbstractBackgroundThe incidence of ketosis‐prone type 2 diabetes is very low except for people of sub‐Saharan African origin and African Americans. However, there also are some type 2 diabetes patients with diabetic ketosis without acidosis (DKWA). We question whether DKWA should be included as a subtype of ketosis‐prone type 2 diabetes mellitus and compared the clinical characteristics of DKWA and diabetic ketoacidosis (DKA) patients.MethodsThe study population consisted of 594 consecutive unrelated Chinese inpatients with newly diagnosed type 2 diabetes. Demographic and clinical characteristics (age, gender, family history of diabetes, body mass index, blood pressure and plasma lipid parameters) were recorded. The patients were divided into ketosis‐resistant diabetes (KRD), DKWA and DKA groups on the basis of urinary ketones, blood pH and bicarbonate levels. The blood glucose and c‐peptide levels of the patients were also evaluated.ResultsThe prevalence of KRD, DKWA and DKA were 78.33%, 19.72% and 1.95%, respectively, in the study population. The clinical characteristics of patients with DKWA group patients were similar to those with DKA, except that DKA patients had higher blood glucose and deteriorated β cell function.ConclusionsDiabetic ketosis without acidosis and DKA patients share similar clinical characteristics; DKWA should be considered ketosis‐prone type 2 diabetes. Therefore, the prevalence of ketosis‐prone type 2 diabetes might be underestimated. Copyright © 2013 John Wiley & Sons, Ltd.
Construction of Enantioenriched Cyclic Compounds by Asymmetric Allylic Alkylation and Ring‐Closing Metathesis
Authors: Giacomina Francesca , Alexakis Alexandre 
Published: August 2013

AbstractA new approach to highly enantioenriched cyclic compounds (up to 98 % ee) has been developed by using ω‐ethylenic allylic substrates in a one‐pot asymmetric allylic alkylation and ring‐closing metathesis sequence. The starting compounds are synthetic equivalents of cyclic allylic substrates. The method is exemplified with both Cu and Ir catalysts, and chiral phosphoramidite ligands.
Fuel‐mix and energy utilization analysis of Port Harcourt Refining Company, Nigeria
Authors: Badmus Ismaila , Fagbenle Richard Olayiwola , Oyewola Olanrewaju Miracle 
Published: August 2013

AbstractThis study analyses the fuel‐mix and energy utilization patterns in Port Harcourt Refining Company from 2000 to 2011. The average fuel mix over the study period is 43% refinery fuel gas, 0% liquefied petroleum gas (LPG), 44% low pour fuel oil (LPFO), 8% Coke, and 5% automotive gas oil (AGO). The present ratio of high‐carbon fuel consumption to low‐carbon fuel consumption adversely influences the specific fuel consumption by increasing it. Our proposal is that the present AGO and LPFO consumption levels are totally replaced with equivalent amounts of natural gas. This would yield the following fuel mix: 46% refinery fuel gas, 46% natural gas, and 8% coke. This, in effect, would result in a proportion of 92% low‐carbon fuels and 8% coke. It would also lead to a specific fuel consumption that is averagely unaffected by high‐carbon/low‐carbon fuel consumption ratios. Natural gas utilization has its main advantage in its flare/waste and consequent environmental degradation reduction. Finally, the proposed fuel mix would generally lead to a reduction in specific fuel consumption, thus saving energy and reducing costs.