bluuebunny/crossref_metadata_2025 huggingface dataset:
Palladium‐Catalyzed Regio‐ and Stereoselective Cross‐Addition of Terminal Alkynes to Ynol Ethers and Synthesis of 1,4‐Enyn‐3‐ones
Authors: Hari Babu Madala , Dwivedi Vikas , Kant Ruchir , Sridhar Reddy Maddi
Published: January 2015

Conjugated enynes, enol ethers, and enynones are versatile building blocks that can be elaborated by a wide variety of synthetic transformations. The selective synthesis of such units is a prerequisite for their effective utilization. The synthesis of conjugated 2‐phenoxyenynes through a palladium‐catalyzed cross‐addition of terminal alkynes to phenylethynyl ethers (hydroalkynylation) is now presented. The reaction is highly regio‐, stereo‐, and chemoselective, and shows excellent tolerance toward functional groups. The addition further features very mild reaction conditions (room temperature) and an inexpensive catalytic system (without a ligand and with a cheaply available Pd catalyst). The thus synthesized enynyl ethers with allylic hydroxy tethers, which survived the reaction, were shown to be ready precursors for valuable 1‐en‐4‐yn‐3‐ones.
Hydrogen‐Bonding Interactions Trigger a Spin‐Flip in Iron(III) Porphyrin Complexes
Authors: Sahoo Dipankar , Quesne Matthew G. , de Visser Sam P. , Rath Sankar Prasad
Published: January 2015

A key step in cytochrome P450 catalysis includes the spin‐state crossing from low spin to high spin upon substrate binding and subsequent reduction of the heme. Clearly, a weak perturbation in P450 enzymes triggers a spin‐state crossing. However, the origin of the process whereby enzymes reorganize their active site through external perturbations, such as hydrogen bonding, is still poorly understood. We have thus studied the impact of hydrogen‐bonding interactions on the electronic structure of a five‐coordinate iron(III) octaethyltetraarylporphyrin chloride. The spin state of the metal was found to switch reversibly between high (S=5/2) and intermediate spin (S=3/2) with hydrogen bonding. Our study highlights the possible effects and importance of hydrogen‐bonding interactions in heme proteins. This is the first example of a synthetic iron(III) complex that can reversibly change its spin state between a high and an intermediate state through weak external perturbations.
Enantioselective Enzymes by Computational Design and In Silico Screening
Authors: Wijma Hein J. , Floor Robert J. , Bjelic Sinisa , Marrink Siewert J. , Baker David , Janssen Dick B.
Published: January 2015

Computational enzyme design holds great promise for providing new biocatalysts for synthetic chemistry. A strategy to design small mutant libraries of complementary enantioselective epoxide hydrolase variants for the production of highly enantioenriched (S,S)‐diols and (R,R)‐diols is developed. Key features of this strategy (CASCO, catalytic selectivity by computational design) are the design of mutations that favor binding of the substrate in a predefined orientation, the introduction of steric hindrance to prevent unwanted substrate binding modes, and ranking of designs by high‐throughput molecular dynamics simulations. Using this strategy we obtained highly stereoselective mutants of limonene epoxide hydrolase after experimental screening of only 37 variants. The results indicate that computational methods can replace a substantial amount of laboratory work when developing enantioselective enzymes.
Enhancing the antifouling properties of polysulfone ultrafiltration membranes by the grafting of poly(ethylene glycol) derivatives via surface amidation reactions
Authors: Yu Haijun , Cao Yiming , Kang Guodong , Liu Zhongnan , Kuang Wu , Liu Jianhui , Zhou Meiqing
Published: January 2015

A carboxylic acid group was introduced on the polysulfone (PSF) membrane surface through a Friedel–Crafts reaction. Then, three kinds of poly(ethylene glycol) (PEG) derivatives were chosen to be immobilized on the PSF membrane surface via amide bonds. The membrane surface morphology, chemical composition, and hydrophilicity were investigated with scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and water contact angle. The results indicate that PEG derivative immobilization effectively improved the antifouling properties of the PSF membranes. We found that prolonging the Friedel–Crafts reaction time or choosing the proper PEG derivative [methoxy poly(ethylene glycol) 550] could increase the surface hydrophilicity effectively and thus render the modified membranes better antifouling properties. The long‐term ultrafiltration experiment demonstrated the improvement of recycling properties and the reliability of the surface modification process. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41870.
Low dielectric and high thermal conductivity epoxy nanocomposites filled with NH2‐POSS/n‐BN hybrid fillers
Authors: Wu Yalan , Li Fang , Huyan Juanni , Zou Xiaorong , Li Ying
Published: January 2015

Hybrid fillers of mono‐amine polyhedral oligomeric silsesquioxane/nanosized boron nitride (NH2‐POSS/n‐BN) were performed to fabricate NH2‐POSS/n‐BN/epoxy nanocomposites. Results revealed that the dielectric constant and dielectric loss values were decreased with the increasing addition of NH2‐POSS obviously, but increased with the increasing addition of BN fillers. For a given loading of NH2‐POSS (5 wt %), the thermal conductivities of NH2‐POSS/n‐BN/epoxy nanocomposites were improved with the increasing addition of n‐BN fillers, and the thermal conductivity of the nanocomposites was 1.28 W/mK with 20 wt % n‐BN fillers. Meantime, the thermal stability of the NH2‐POSS/n‐BN/epoxy nanocomposites was also increased with the increasing addition of n‐BN fillers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41951.
Polypropylene membranes modified with interpenetrating polymer networks for the removal of chromium ions
Authors: Tapiero Yesid , Rivas Bernabé L. , Sánchez Julio , Bryjak Marek , Kabay Nalan
Published: January 2015

Polypropylene (PP) membranes incorporating poly[(ar‐vinylbenzyl) trimethylammonium chloride] P(ClVBTA), and poly[sodium (styrene sulfonate)] P(SSNa) were modified via an “in situ” radical polymerization synthesis. Two methods were used for impregnation of the reactive solution: pressure injection and plasma superficial activation with argon gas. The following conditions were varied: the monomer concentrations, number of injections, and cross‐linked concentration. The modified polypropylene membranes were then characterized using scanning electron microscopy/energy dispersive X‐ray spectroscopy, Fourier transform‐infrared spectroscopy, electrokinetic potential, and Donnan dialysis for the chromium ions transport. The modified membranes exhibited a hydrophilic character with a water uptake capacity between 15% and 20% and a percent modification between 2.5% and 4.0%. This was compared with the results of an unmodified polypropylene membrane as the blank and the mentioned polypropylene membrane has not the capacity to uptake water because this kind of material is highly hydrophobic. Hexavalent chromium ions were efficiently transported by the modified membranes containing P(ClVBTA) via a plasma method and it achieved 59.2% extraction at pH 9.0 using a 1‐mol L−1 NaCl extraction agent. Therefore, unmodified polypropylene membrane shows an extraction percentage close to 10% from the hexavalent chromium ions at pH 9.0. In the same way, the trivalent chromium transport using membranes modified with P(SSNa) achieved 49.0% extraction at pH 2.0 using 1 × 10−1 mol L−1 HNO3 and 1 mol L−1 NaCl as the extraction agents. Moreover, the unmodified polypropylene membrane reached a value close to 10% from the trivalent chromium ions using 1 × 10−1 mol L−1 HNO3 and 1 mol L−1 NaCl. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41953.
Measuring compliance with a Spanish Government open access mandate
Authors: Borrego Ángel
Published: January 2015

Open access (OA) mandates are policies that require researchers to provide free, unrestricted access to their published research by including it in OA journals (gold OA) or depositing it in freely available disciplinary or institutional repositories (green OA). This study measures the degree of compliance with a Spanish government OA mandate 2.5 years after its implementation. A total of 58.4% of articles resulting from publicly funded research had at least one OA copy available 1 year after publication. Among these, 23.8% were in gold OA, 21.8% in green OA and 12.8% in gray OA, i.e., posted on websites and social networks. Most of the green OA articles were in 2 disciplinary repositories: arXiv and PubMed Central. Just 14.4% of the articles resulting from publicly funded research were available in institutional repositories, although more than 90% of the articles in the data set were the result of projects carried out at institutions that have such an archive. There is great potential for growth in green OA, because over two thirds of the articles that were not available as OA were published in journals whose publishers allow a preprint or a postprint copy to be deposited.
Research data and metadata curation as institutional issues
Authors: Mayernik Matthew S.
Published: January 2015

Research data curation initiatives must support heterogeneous kinds of projects, data, and metadata. This article examines variability in data and metadata practices using “institutions” as the key theoretical concept. Institutions, in the sense used here, are stable patterns of human behavior that structure, legitimize, or delegitimize actions, relationships, and understandings within particular situations. Based on prior conceptualizations of institutions, a theoretical framework is presented that outlines 5 categories of “institutional carriers” for data practices: (a) norms and symbols, (b) intermediaries, (c) routines, (d) standards, and (e) material objects. These institutional carriers are central to understanding how scientific data and metadata practices originate, stabilize, evolve, and transfer. This institutional framework is applied to 3 case studies: theCenter forEmbeddedNetworkedSensing (CENS), theLongTermEcologicalResearch (LTER) network, and theUniversityCorporation forAtmosphericResearch (UCAR). These cases are used to illustrate how institutional support for data and metadata management are not uniform within a single organization or academic discipline. Instead, broad spectra of institutional configurations for managing data and metadata exist within and across disciplines and organizations.
Indexing biomedical documents with a possibilistic network
Authors: Chebil Wiem , Soualmia Lina Fatima , Omri Mohamed Nazih , Darmoni Stéfan Jacques
Published: January 2015

In this article, we propose a new approach for indexing biomedical documents based on a possibilistic network that carries out partial matching between documents and biomedical vocabulary. The main contribution of our approach is to deal with the imprecision and uncertainty of the indexing task using possibility theory. We enhance estimation of the similarity between a document and a given concept using the two measures of possibility and necessity. Possibility estimates the extent to which a document is not similar to the concept. The second measure can provide confirmation that the document is similar to the concept. Our contribution also reduces the limitation of partial matching. Although the latter allows extracting from the document other variants of terms than those in dictionaries, it also generates irrelevant information. Our objective is to filter the index using the knowledge provided by the Unified Medical Language System®. Experiments were carried out on different corpora, showing encouraging results (the improvement rate is +26.37% in terms of main average precision when compared with the baseline).
A variant of the h‐index to measure recent performance
Authors: Schreiber Michael
Published: January 2015

The predictive power of the h‐index has been shown to depend on citations to rather old publications. This has raised doubts about its usefulness for predicting future scientific achievements. Here, I investigate a variant that considers only recent publications and is therefore more useful in academic hiring processes and for the allocation of research resources. It is simply defined in analogy to the usual h‐index, but takes into account only publications from recent years, and it can easily be determined from the ISI Web of Knowledge.
Assembly of Large Purely Inorganic Ce‐Stabilized/Bridged Selenotungstates: From Nanoclusters to Layers
Authors: Chen Wei‐Chao , Qin Chao , Li Yang‐Guang , Zang Hong‐Ying , Shao Kui‐Zhan , Su Zhong‐Min , Wang En‐Bo
Published: January 2015

A versatile one‐pot strategy was used to synthesize two large, purely inorganic selenotungstates, nanocluster K6Na16[Ce6Se6W67O230(OH)6(H2O)17]⋅47 H2O (1) and layer K9Na5Ce(H2O)4[Ce6Se10W51O187(OH)7(H2O)18]⋅45 H2O (2), by combining cerium centers and SeO32− heteroanion templates. Compound 1 displays a Ce‐stabilized hexameric nanocluster with one rhombus‐like {W4O15(OH)3} unit in the center, whereas compound 2 is the first example of a Ce‐bridged layer selenotungstate network based on linkage of the unusual {Ce6Se10W51O187(OH)7(H2O)18} clusters and additional Ce(H2O)4 fragments via Ce‐O‐Se bridges. The compounds were characterized by elemental analyses, IR spectroscopy, thermogravimetric analyses, powder and single‐crystal X‐ray diffraction, and electrospray ionization mass spectrometry. Moreover, the electrochemical property of compound 1 was also investigated.
A Novel Boundary Control Solution for Unstable Heat Conduction Systems Based on Active Disturbance Rejection Control
Authors: Zhao Dong , Li Donghai , Wang Youqing
Published: February 2015

In this study, a new boundary control scheme is proposed for a class of unstable heat conduction systems based on active disturbance rejection control and frequency domain analysis methods. The unstable heat conduction systems studied here corresponds to a thin rod with surface heat loss and internal heat generation. An active disturbance rejection boundary controller is designed to stabilize the unstable heat conduction systems. Using the frequency domain analysis method, the Nyquist stability criterion for distributed parameter systems, the relative stability indices (gain margin, phase margin, and exponential stability speed) can be obtained for performance evaluation, and a constructive parameter‐tuning method for controller is proposed. Finally, it is proved that an active disturbance rejection boundary controller can stabilize the unstable heat conduction systems with one unstable pole, and the simulation results demonstrate that the temperature profile of the whole rod has good convergence properties under both Dirichlet and Neumann boundary control.
Application of the planar‐scanning technique to the near‐field dosimetry of millimeter‐wave radiators
Authors: Zhao Jianxun , Lu Hongmin , Deng Jun
Published: January 2015

The planar‐scanning technique was applied to the experimental measurement of the electric field and power flux density (PFD) in the exposure area close to the millimeter‐wave (MMW) radiator. In the near‐field region, the field and PFD were calculated from the plane‐wave spectrum of the field sampled on a scan plane far from the radiator. The measurement resolution was improved by reducing the spatial interval between the field samples to a fraction of half the wavelength and implementing multiple iterations of the fast Fourier transform. With the reference to the results from the numerical calculation, an experimental evaluation of the planar‐scanning measurement was made for a 50 GHz radiator. Placing the probe 1 to 3 wavelengths from the aperture of the radiator, the direct measurement gave the near‐field data with significant differences from the numerical results. The planar‐scanning measurement placed the probe 9 wavelengths away from the aperture and effectively reduced the maximum and averaged differences in the near‐field data by 70.6% and 65.5%, respectively. Applied to the dosimetry of an open‐ended waveguide and a choke ring antenna for 60 GHz exposure, the technique proved useful to the measurement of the PFD in the near‐field exposure area of MMW radiators. Bioelectromagnetics. 36:108–117, 2015. © 2015 Wiley Periodicals, Inc.
Human carotid atherosclerotic lesion protein components decrease cholesterol biosynthesis rate in macrophages through 3‐hydroxy‐3‐methylglutaryl‐CoA reductase regulation
Authors: Cohen Elad , Aviram Michael , Khatib Soliman , Rosenblat Mira , Vaya Jacob
Published: January 2015

Atherosclerosis is characterized by the formation of cholesterol‐loaded macrophages, which are turned into foam cells, the hallmark of early atherogenesis. As part of ongoing research on the interactions among human carotid lesion components and blood elements, the effect of plaque homogenate on macrophage cholesterol biosynthesis rate was examined. Human carotid plaques were ground, extracted with phosphate‐buffered saline (homogenate), and then added to the macrophage medium. This extract decreased macrophage cholesterol biosynthesis rate up to 50% in a dose‐dependent manner. Cholesterol or lipoproteins were separated from the homogenate and added to the MQ medium. Unlike the homogenate, neither free cholesterol nor the lipoproteins were able to inhibit cholesterol biosynthesis rate under the above experimental concentration, suggesting that the homogenate‐induced cholesterol biosynthesis inhibition in our experimental system was not owing to the feedback inhibition of cholesterol. Furthermore, the homogenate remaining after lipoprotein removal (lipoprotein‐deficient homogenate) also decreased cholesterol biosynthesis rate, whereas boiled homogenate or phospholipids extracted from the homogenate decreased macrophage cholesterol biosynthesis rate only partially. Finally, cholesterol biosynthesis inhibition was achieved only upon using the precursor [3H]acetate, but not [14C]mevalonate, suggesting that 3‐hydroxy‐3‐methylglutaryl‐CoA reductase (HMGCoA Reductase), the rate‐limiting enzyme in the cholesterol biosynthesis pathway, is involved in the above antiatherogenic effect of the homogenate, whereas the treatment with homogenate decreased HMGCoA Reductase mRNA. Proteins and phospholipids from human carotid lesion homogenate decrease cholesterol biosynthesis rate in macrophages secondary to HMGCoA Reductase feedback regulation. Such an effect may delay foam cell formation and atherosclerosis progression. © 2015 BioFactors, 41(1):28–34, 2015
Meta-analysis of peak wall stress in ruptured, symptomatic and intact abdominal aortic aneurysms
Authors: Khosla S , Morris D R , Moxon J V , Walker P J , Gasser T C , Golledge J
Published: January 2015

Background

Abdominal aortic aneurysm (AAA) is an important cause of sudden death; however, there are currently incomplete means to predict the risk of AAA rupture. AAA peak wall stress (PWS) can be estimated using finite element analysis (FEA) methods from computed tomography (CT) scans. The question is whether AAA PWS can predict AAA rupture. The aim of this systematic review was to compare PWS in patients with ruptured and intact AAA.

Methods

The MEDLINE database was searched on 25 May 2013. Case–control studies assessing PWS in asymptomatic intact, and acutely symptomatic or ruptured AAA from CT scans using FEA were included. Data were extracted independently. A random-effects model was used to calculate standard mean differences (SMDs) for PWS measurements.

Results

Nine studies assessing 348 individuals were identified and used in the meta-analysis. Results from 204 asymptomatic intact and 144 symptomatic or ruptured AAAs showed that PWS was significantly greater in the symptomatic/ ruptured AAAs compared with the asymptomatic intact AAAs (SMD 0·95, 95 per cent confidence interval 0·71 to 1·18; P < 0·001). The findings remained significant after adjustment for mean systolic blood pressure, standardized at 120 mmHg (SMD 0·68, 0·39 to 0·96; P < 0·001). Minimal heterogeneity between studies was noted (I2 = 0 per cent).

Conclusion

This study suggests that PWS is greater in symptomatic or ruptured AAA than in asymptomatic intact AAA.
Long-term outcomes of sacral nerve stimulation for faecal incontinence
Authors: Altomare D F , Giuratrabocchetta S , Knowles C H , Muñoz Duyos A , Robert-Yap J , Matzel K E , De Miguel Velasco M , Rosen H , Ganio E , Ratto C , Devesa M J , Cui Z
Published: February 2015

Background

Sacral nerve stimulation (SNS) has proven short- to medium-term effectiveness for the treatment of faecal incontinence (FI); fewer long-term outcomes have been presented and usually in small series. Here, the long-term effectiveness of SNS was evaluated in a large European cohort of patients with a minimum of 5 years' follow-up.

Methods

Prospectively registered data from patients with FI who had received SNS for at least 5 years from ten European centres were collated by survey. Daily stool diaries, and Cleveland Clinic and St Mark's incontinence scores were evaluated at baseline, after implantation and at the last follow-up. SNS was considered successful when at least 50 per cent symptom improvement was maintained at last follow-up.

Results

A total of 407 patients underwent temporary stimulation, of whom 272 (66·8 per cent) had an impulse generator implanted; 228 (56·0 per cent) were available for long-term follow-up at a median of 84 (i.q.r. 70–113) months. Significant reductions in the number of FI episodes per week (from median 7 to 0·25) and summative symptom scores (median Cleveland Clinic score from 16 to 7, St Mark's score from 19 to 6) were recorded after implantation (all P < 0·001) and maintained in long-term follow-up. In per-protocol analysis, long-term success was maintained in 71·3 per cent of patients and full continence was achieved in 50·0 per cent; respective values based on intention-to-treat analysis were 47·7 and 33·4 per cent. Predictive analyses determined no significant association between pretreatment variables and successful outcomes. Risk of long-term failure correlated with minor symptom score improvement during the temporary test phase.

Conclusion

SNS remains an effective treatment for FI in the long term for approximately half of the patients starting therapy.
A novel approach for concurrent quantitation of glutathione, glutathione disulfide, and 2‐hydroxyethylated glutathione in lungs of mice exposed to ethylene oxide, using liquid chromatography–positive electrospray tandem mass spectrometry
Authors: Zhang Fagen , Bartels Michael J. , LeBaron Matthew J. , Schisler Melissa R. , Gollapudi B. Bhaskar , Moore Nigel P.
Published: February 2015

Glutathione (GSH), glutathione disulfide (GSSG) and 2‐hydroxyethylated glutathione (HESG) are important biomarkers for exploring the genotoxicity mechanism of ethylene oxide (EO) or ethylene in vivo. A liquid chromatography–tandem mass spectrometry method was developed for simultaneous determination of GSH, GSSG and HESG in mouse lung tissues after inhalation exposure to EO. The lower limit of quantitation for all these biomarkers was 0.002 µg/mL. The linearity of the calibration curves for all analytes was >0.998. The intra‐day assay precision relative standard deviation (RSD) values for quality control samples for all analytes were ≤12.8% with accuracy values ranging from 87.2 to 113%. The inter‐day assay precision (RSD) values for all analytes were ≤13.1% with accuracy values ranging from 86.9 to 103%. This method was applied to concurrently determine the levels of GSH, GSSG and HESG in lung samples isolated from mouse after 4‐week inhalation exposure to EO at 0, 10, 50, 100 and 200 ppm. Copyright © 2015 John Wiley & Sons, Ltd.
Sequential occurrence of dyspnea at the end of life in palliative care, according to the underlying cancer
Authors: Guirimand Frédéric , Sahut d'izarn Marine , Laporte Lucy , Francillard Marie , Richard Jean‐François , Aegerter Philippe
Published: January 2015

Dyspnea is a symptom that severely affects the quality of life of terminally ill patients. Its frequency differs considerably between studies. We aimed to characterize the frequency of dyspnea in a palliative care hospital (PCH) and to identify factors predisposing to dyspnea, particularly during the very last days of life, as a function of the underlying disease. Episodes of dyspnea were identified by the computerized extraction of prospectively collected data from the reports of care assistants or from medical observations recorded in the medical files for all stays at our PCH during the last 6 years. There were 6455 hospital stays, 88% ending in the death of the patient; 13,282 episodes of dyspnea were recorded during 2608 hospital stays (40%). Dyspnea was more frequently observed in cases of cancer than in other conditions (RR = 1.30; 95% CI: 1.14–1.48). Pulmonary metastasis increased the risk of dyspnea from 37% to 51% (RR = 1.37; 95% CI: 1.29–1.46). Dyspnea frequency varied with the primary cancer site, from 24% (brain cancer) to 60% (esophageal cancer). The data for cancer patients staying for more than 6 days who subsequently died indicated that 8% of patients experienced dyspnea exclusively during the last 4 days of the life, independently of the site of the primary cancer. Dyspnea during the last few days of life requires systematic assessment. Exclusively terminal dyspnea should be distinguished from more precocious dyspnea, as the pathophysiological mechanisms and treatments of these two forms are probably different.
Percutaneous removal of unraveled HELEX® septal occluder 4 months post deployment
Authors: Suntharos Patcharapong , Komarlu Rukmini , Prieto Lourdes R.
Published: January 2015

The GORE® HELEX® Septal Occluder (HSO: W.L. Gore & Associates; Flagstaff, AZ) is preferentially used at our institution for percutaneous closure of the patent foramen ovale (PFO). Adequate deployment of the device requires capture of three sequential eyelets by the locking loop. At times, the right atrial eyelet is not caught, particularly when a long tunnel PFO causes too much separation between the discs. Although rarely, unlocked devices have been left in the atrial septum with no untoward events provided they appear stable in the catheterization laboratory and the shunt has been eliminated. We report a patient in whom an unlocked, but otherwise well positioned, HSO subsequently unraveled with the right atrial disc migrating through the tricuspid valve while the left atrial disc remained well apposed to the left side of the atrial septum. The PFO was closed prior to liver transplantation to prevent an embolic event during the transplant. The patient required placement of several internal jugular central lines prior to transplant, and this instrumentation in the right atrium may have caused unraveling of the device. The HSO was removed percutaneously 15 weeks after implantation despite a well‐seated and likely partially endothelialized left atrial disc. © 2015 Wiley Periodicals, Inc.
Polyclonal hyperviscosity syndrome in IgG4‐related disease and associated conditions
Authors: Chen Luke Y.C. , Wong Patrick C.W. , Noda Shinji , Collins David R. , Sreenivasan Gayatri M. , Coupland Robert C.
Published: February 2015

Key Clinical Message

Polyclonal hyperviscosity syndrome (HVS) is rare and has been reported in various disorders of immune dysregulation and lymphoid hyperplasia. IgG4‐Related Disease (IgG4‐RD) is an emerging disorder often associated with exuberant hypergammaglobulinemia, and this review of seven cases establishes IgG4‐RD as an important cause of polyclonal HVS.
Catalytic Properties of Unsupported Palladium Nanoparticle Surfaces Capped with Small Organic Ligands
Authors: Gavia Diego J. , Shon Young‐Seok
Published: January 2015

This Minireview summarizes a variety of intriguing catalytic studies accomplished by employing unsupported, either solubilized or freely mobilized, and small organic ligand‐capped palladium nanoparticles as catalysts. Small organic ligands are gaining more attention as nanoparticle stabilizers and alternates to larger organic supports, such as polymers and dendrimers, owing to their tremendous potential for a well‐defined system with spatial control in surrounding environments of reactive surfaces. The nanoparticle catalysts are grouped depending on the type of surface stabilizers with reactive head groups, which include thiolate, phosphine, amine, and alkyl azide. Applications for the reactions such as hydrogenation, alkene isomerization, oxidation, and carbon‐carbon cross coupling reactions are extensively discussed. The systems defined as “ligandless” Pd nanoparticle catalysts and solvent (e.g. ionic liquid)‐stabilized Pd nanoparticle catalysts are not discussed in this review.
Supramolecular Nanoassemblies of an Amphiphilic Porphyrin–Cyclodextrin Conjugate and Their Morphological Transition from Vesicle to Network
Authors: Zhao Jin , Zhang Heng‐Yi , Sun He‐Lue , Liu Yu
Published: January 2015

An amphiphilic compound, 5‐(4′‐dodecyloxyphenyl)‐10,15,20‐tri(permethyl‐β‐CD)‐modified ZnII–porphyrin (1; β‐CD=β‐cyclodextrin), was synthesized by means of the click reaction of an alkylated Zn–porphyrin derivative with 6‐deoxy‐6‐azidopermethyl‐β‐CD. The complexation between 1 and tetrasodium tetraphenylporphyrintetrasulfonate (5) with different molar ratios led to the formation of two distinctly different nanoarchitectures, which were proven to be vesicle and network aggregates, respectively, by using dynamic light scattering, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. On the basis of the results of the time‐dependent TEM studies, fluorescence, and NMR spectroscopic measurements, we have determined that the mechanism of the morphology transition from vesicles to networks is controlled by the stepwise complexation of 1 with 5. Furthermore, these supramolecular nanoarchitectures show the controlled‐ release property of doxorubicin as potential candidates for drug delivery.
Electrospun Highly Ordered Mesoporous Silica–Carbon Composite Nanofibers for Rapid Extraction and Prefractionation of Endogenous Peptides
Authors: Zhu Gang‐Tian , Chen Xi , He Xiao‐Mei , Wang Han , Zhang Zheng , Feng Yu‐Qi
Published: January 2015

A simple method was developed for the preparation of ordered mesoporous silica–carbon composite nanofibers (OMSCFs). The OMSCFs exhibited high carbon content, continuously long fibrous properties, uniform accessible mesopores, and a large surface area. The OMSCFs were also found to have ion‐exchange capacity. On the basis of the size‐exclusion effect of the mesopores and mixed‐mode hydrophobic/ion‐exchange interactions, the OMSCFs were applied for rapid enrichment of endogenous peptides by using a miniaturized solid‐phase extraction format. The adsorption mechanism was studied, and the eluting solution was optimized with standard peptide/protein solutions and protein digests. Employing a successive three‐step elution strategy, followed by LC‐MS/MS analysis, led to excellent performance with this approach in the extraction and prefractionation of peptides from human serum.
Synthetic Efforts toward the Lycopodium Alkaloids Inspires a Hydrogen Iodide Mediated Method for the Hydroamination and Hydroetherification of Olefins
Authors: Leger Paul R. , Murphy Rebecca A. , Pushkarskaya Eugenia , Sarpong Richmond
Published: January 2015

Progress toward the total syntheses of a diverse set of fawcettimine‐type Lycopodium alkaloids via a “Heathcock‐type” 6–5–9 tricycle is disclosed. This route features an intermolecular Diels–Alder cycloaddition to rapidly furnish the 6–5‐fused bicycle and a highly chemoselective directed hydrogenation to build the azonane fragment. While conducting these synthetic studies, trimethylsilyl iodide was found to effect a hydroamination reaction to furnish the tetracyclic core of serratine and related natural products. This observation has been expanded into a general method for the room temperature hydroamination of unactivated olefins with tosylamides utilizing catalytic “anhydrous” HI (generated in situ from trimethylsilyl iodide and water). The presence of the iodide anion is critical to the success of this Brønsted acid catalyzed protocol, possibly due to its function as a weakly coordinating anion. These conditions also effect the analogous hydroetherification reaction of alcohols with unactivated olefins.
Vibrational Circular Dichroism (VCD), VCD Exciton Coupling, and X‐ray Determination of the Absolute Configuration of an α,β‐Unsaturated Germacranolide
Authors: Sánchez‐Castellanos Mariano , Bucio María A. , Hernández‐Barragán Angelina , Joseph‐Nathan Pedro , Cuevas Gabriel , Quijano Leovigildo
Published: January 2015

The absolute configuration of 1 was deduced by vibrational circular dichroism together with the evaluation of the Flack and Hooft X‐ray parameters. Vibrational circular dichroism exciton coupling, using the carbonyl group signals, confirmed the absolute configuration of 2. In addition, sodium borohydride reduction of the 11,13‐double bond of 6‐epi‐desacetyllaurenobiolide (1) yields an almost equimolecular mixture of C11 epimers, while reduction of the same double bond of 6‐epi‐laurenobiolide (2) provided almost exclusively the (11S) diastereoisomer 4. Chirality 27:247–252, 2015. © 2015 Wiley Periodicals, Inc.
Integration externer Energie in geothermische Kraft‐ bzw. Heizkraftwerke – Möglichkeiten und Grenzen
Authors: Janczik Sebastian , Schmidt Lisa Marie , Kaltschmitt Martin
Published: January 2015

Unter den geologischen Bedingungen in Deutschland sind geothermische Kraft‐ bzw. Heizkraftwerke durch relativ geringe Stromwirkungsgrade und hohe Energiegestehungskosten gekennzeichnet. Hier sollen Möglichkeiten aufgezeigt werden, wie geothermische Anlagen durch Integration von externer nicht genutzter Energie aus fossilen Energieträgern und/oder regenerativen Energien effizienter konzipiert werden können. Die Bewertung der Konzepte erfolgt anhand von Stromwirkungsgraden und Energie‐ bzw. Stromgestehungskosten.
Hypertension and vascular disease in the 1990s
Authors: Gorlin Richard
Published: January 2015

Many pharmacologic agents are effective in normalizing blood pressure in the hypertensive patient. The major issues in antihypertensive therapy today transcend control of blood pressure and focus, instead, on safety considerations, patient acceptance, and additional benefits to target organs. With the drugs currently available, 10–15% of patients withdraw from therapy because of undesirable clinical side effects. Nonclinical side effects such as hyperlipidemia, hypokalemia, and hyperglycemia can limit the clinician's choice of drugs, especially for elderly patients. Antihypertensive agents should also limit target organ damage. The prevalence of stroke can be reduced solely by controlling blood pressure, but inhibition of cardiac ischemic events requires use of specific classes of agents. Beta blockers reduce mortality and reinfarction postmyocardial infarction, whereas angiotensin‐converting enzyme (ACE) inhibitors affect several factors leading to heart failure, including cardiac and vascular hypertrophy, remodeling and dilatation postmyocardial infarction, and arrhythmias. Specific actions on intrarenal and other vascular dynamics may make these drugs appropriate for use in patients with diabetes and perhaps hypertensive kidney disease and systemic arterial disease. The range of options available in antihypertensive therapy in the 1990s affords the physician the opportunity to meet additional goals of therapy, specific for each patient.
ACE inhibitors in renal disease
Authors: Bauer John H. , Reams Garry P.
Published: January 2015

Recent experimental studies suggest that the resistance state of the preglomerular and postglomerular capillary arterioles may determine if a particular class of antihypertensive agents will protect the kidney from hemodynamically mediated glomerular injury. This review discusses (1) the effects of angiotensin II on the renal microcirculation, (2) the pathophysiology of essential hypertensive renal disease, (3) the renal pharmacology of angiotensin‐converting enzyme (ACE) inhibitors, and (4) the hypothesis that renal protection is dependent on control of systemic and glomerular hypertension.
Global Solutions of Two‐Dimensional Incompressible Viscoelastic Flows with Discontinuous Initial Data
Authors: Hu Xianpeng , Lin Fanghua
Published: January 2015

The global existence of weak solutions of the incompressible viscoelastic flows in two spatial dimensions has been a longstanding open problem, and it is studied in this paper. We show global existence if the initial deformation gradient is close to the identity matrix in L2 ∩ L∞ and the initial velocity is small in L2 and bounded in Lp for some p > 2. While the assumption on the initial deformation gradient is automatically satisfied for the classical Oldroyd‐B model, the additional assumption on the initial velocity being bounded in Lp for some p > 2 may due to techniques we employed. The smallness assumption on the L2 norm of the initial velocity is, however, natural for global well‐posedness. One of the key observations in the paper is that the velocity and the “ effective viscous flux” are sufficiently regular for positive time. The regularity of leads to a new approach for the pointwise estimate for the deformation gradient without using L∞ bounds on the velocity gradients in spatial variables. © 2015 Wiley Periodicals, Inc.
Across the Board: Regina Palkovits
Authors: Palkovits Regina
Published: January 2015

In this series of articles, the board members of ChemSusChem discuss recent research that they consider of exceptional quality and importance for sustainability. In this contribution, Prof. Regina Palkovits describes some recent advances in heterogeneous catalytic transformations of lignocellulosic feedstocks into biofuels. While the recent works she highlights are of great significance, challenges with regard to catalyst stability, the associated deactivation mechanisms, and designs for aqueous‐phase reactions remain.
Capacity of SSTS for downlink‐distributed antenna systems in multicell environment
Authors: Liu Yuxi , Lv Sitong , Chen Peng
Published: February 2015

We put forward a novel single selection transmission scheme based on maximum desired signal criterion and investigate the capacity of distributed antenna systems in multicell environment. However, for most of the recent literatures, the interference plus noise is treated as Gaussian random variable with fixed variance by the central limit theorem, which ignores the effect of the short‐term fading on interference. To avoid it, non‐central limit theorem is adopted in which the variance of interference plus noise is considered as a random variable with changeable variance influenced by the short‐term fading. Moreover, channels are assumed to suffer from independent identical Rayleigh fading together with propagation path loss, and the closed‐form expression of capacity for distributed antenna systems is derived. Finally, extensive simulations are carried out to validate the theoretical analysis. Copyright © 2015 John Wiley & Sons, Ltd.
Multifunctional Molecular Conductors
Authors: Saito Gunzi
Published: January 2015

This essay for EurJIC's cluster issue on molecular conductors introduces multifunctional conducting molecular materials. This field involves the design, synthesis, and fabrication of molecular conductors from molecular, crystal, and nanohybrid structures in real space and electronic band structure and periodicity in k space. This multidisciplinary field fuses organic, inorganic, and physical chemistry, and solid‐state and theoretical physics. Understanding multifunctional molecular conductors based on molecular and crystal structures and electronic band structure should lead to the development of new and unconventional molecular conductors.
Chromophores, Fluorophores and Robust Ancillary Ligands for Molecular Catalysts: 1,3‐Bis(2‐pyridylimino)isoindolines
Authors: Sauer Désirée C. , Melen Rebecca L. , Kruck Matthias , Gade Lutz H.
Published: January 2015

Invited for the cover of this issue is the group of Professor L. H. Gade at the University of Heidelberg, Germany. The cover image shows the representation of a 1,3‐bis(2‐pyridylimino)isoindoline (BPI) compound along with its C2‐symmetric derivatives. These ligands were first reported in the early 1950s and have found widespread application in organic, inorganic and materials chemistry.
Ionic Ferrocene‐Based Burning‐Rate Catalysts with Polycyano Anions: Synthesis, Structural Characterization, Migration, and Catalytic Effects during Combustion
Authors: Liu Xuelin , Li Jizhen , Bi Fuqiang , Zhang Weiqiang , Zhang Guofang , Gao Ziwei
Published: January 2015

Alkylferrocene‐based burning‐rate (BR) catalysts, have a high tendency to migrate during curing and storage due to their neutral and nonpolar nature. To overcome these drawbacks, fifteen novel ionic compounds, 1‐(ferrocenylmethyl)imidazolium paired with polycyano anions, were synthesized and characterized. The structures of eleven of the compounds were confirmed by single‐crystal X‐ray diffraction. Compound 1 crystallizes in the tetragonal space group I4(1)/a; 2, 12 and 15 crystallize in the monoclinic space group P21/c, and 3 in the monoclinic space group P21/n; 4, 6–8, 13 and 14 crystallize in the triclinic space group P$\bar {1}$. Cyclic voltammetry investigations suggested that most of the compounds exhibit quasireversible redox systems. Compounds 1–10 have high thermal stability (> 190 °C). Migration studies revealed that these compounds are low‐migratory materials. The thermal degradation of ammonium perchlorate (AP), hexogen (RDX), and octogen (HMX) catalyzed by these compounds was evaluated by differential scanning calorimetry (DSC) and by thermogravimetric (TG) techniques. The results show that the decomposition peak temperature of AP shifts downwards dramatically and that the released heat of AP increases significantly with the new compounds as additives (5 wt.‐%). Moreover, the ionic compounds exhibit significant effects on the thermal decomposition of RDX. The catalytic activities of the new compounds are higher than those of their nitrate and picrate analogues, which supports the conclusion that high nitrogen content in a ferrocene‐based BR catalyst is favorable for its combustion catalytic activity.
Small‐Volume pH Sensing with a Capillary Optode Utilizing Dye‐Loaded Porous Nanocapsules in a Hydrogel Matrix
Authors: Maclin Alex Q. , Kim Mariya D. , Dergunov Sergey A. , Pinkhassik Eugene , Lindner Erno
Published: January 2015

To develop simple optical pH sensors with adequate sensitivity, short response time, and extended life time for the analysis of very small sample volumes, high concentrations of pH sensitive indicator dyes were encapsulated into ∼200 nm diameter nanocapsules (NCs) with ∼1 nm thick porous walls. The capsules were immobilized into high‐porosity polyvinyl alcohol (PVA) gels for robust and versatile sensor platform design (double immobilization). The NCs‐loaded gels were molded into sensing cylinders and secured in glass capillaries, which served as sampling devices and flow‐through optical detector cells (capillary optodes). The color of the sensing cylinder was measured as a function of the sample pH using an optical fiber‐based UV‐VIS spectrophotometer. To optimize the optical properties of the sensing gel the influence of the size of the NCs, the dye concentration in the NCs and the NCs concentration within the PVA gel were studied. The NCs‐based optodes allowed the measurement of the pH within 2 minutes in as little as ∼30 µL volume of sample, with ∼±0.03 pH unit uncertainty and less than 0.001 pH/hour drift.
Integrated Biomass Assessment and Optimized Power Generation
Authors: Dimitrova Elena , Vinklers Janis , Chokani Ndaona , Abhari Reza S.
Published: January 2015

Although power generation from wood biomass is among the fastest growing sectors of renewable power production, applied research that links biomass stock availability and the optimization of the location of the power plants is lacking. In this work, an integrated approach to determine the most economically viable locations for wood‐fired biomass power plants is presented. Forest vegetation maps are generated from recently available multiband satellite images. Field measurements in coniferous and broadleaved forests are used to derive tree‐stocking densities to determine, from the vegetation maps, the quantity of available wood biomass. A multimodal transportation and transmission grid network model is then used to identify the optimum locations for the top ten portfolios of 5, 15, and 20 MW power plants. It is shown that 15 MW power plants have the lowest levelized cost of energy and are the least susceptible to volatility in the wood price.
Discussion on ‘a framework for the evaluation of ground motion selection and modification procedures’ by N. Simon Kwong, Anil K. Chopra, and Robin K. McGuire
Authors: Bradley Brendon A.
Published: January 2015

The paper under discussion proposes a framework to evaluate ground motion selection and modification procedures and illustrates its application for two different procedures as applied to a non‐degrading bilinear inelastic single‐degree‐of‐freedom system. This discussion focuses on providing additional context that this writer feels is needed in relation to both the proposed framework and also its specific application in the paper, which are important for the conclusions made by the authors. Copyright © 2015 John Wiley & Sons, Ltd.
Astrocytes restrict discharge duration and neuronal sodium loads during recurrent network activity
Authors: Karus Claudia , Mondragão Miguel A. , Ziemens Daniel , Rose Christine R.
Published: January 2015

Influx of sodium ions into active neurons is a highly energy‐expensive process which must be strictly limited. Astrocytes could play an important role herein because they take up glutamate and potassium from the extracellular space, thereby dampening neuronal excitation. Here, we performed sodium imaging in mouse hippocampal slices combined with field potential and whole‐cell patch‐clamp recordings and measurement of extracellular potassium ([K+]o). Network activity was induced by Mg2+‐free, bicuculline‐containing saline, during which neurons showed recurring epileptiform bursting, accompanied by transient increases in [K+]o and astrocyte depolarizations. During bursts, neurons displayed sodium increases by up to 22 mM. Astrocyte sodium concentration increased by up to 8.5 mM, which could be followed by an undershoot below baseline. Network sodium oscillations were dependent on action potentials and activation of ionotropic glutamate receptors. Inhibition of glutamate uptake caused acceleration, followed by cessation of electrical activity, irreversible sodium increases, and swelling of neurons. The gliotoxin NaFAc (sodium‐fluoroacetate) resulted in elevation of astrocyte sodium concentration and reduced glial uptake of glutamate and potassium uptake through Na+/K+‐ATPase. Moreover, NaFAc extended epileptiform bursts, caused elevation of neuronal sodium, and dramatically prolonged accompanying sodium signals, most likely because of the decreased clearance of glutamate and potassium by astrocytes. Our experiments establish that recurrent neuronal bursting evokes sodium transients in neurons and astrocytes and confirm the essential role of glutamate transporters for network activity. They suggest that astrocytes restrict discharge duration and show that an intact astrocyte metabolism is critical for the neurons' capacity to recover from sodium loads during synchronized activity. GLIA 2015;63:936–957