bluuebunny/crossref_metadata_2025_split huggingface dataset:
Verschiedene Reaktivitäten von Iminoboranen gegenüber Carbenen: BN‐Isostere von Carben‐Alkin‐Addukten
Authors: Braunschweig Holger , Ewing William C. , Geetharani K. , Schäfer Marius 
Published: December 2014

AbstractDie ersten Addukte von Iminoboranen mit cyclischen Alkyl(amino)carbenen (CAACs) oder N‐heterocyclischen Carbenen (NHCs) wurden bei tiefer Temperatur (−45 °C) synthetisiert und isoliert. Mit kurzen BN‐Bindungen und planaren Boratomen gleicht die Struktur dieser Addukte derjenigen isoelektronischer Imine. Bei der Reaktion von Di‐tert‐butyliminoboran mit 1,3‐Bis(isopropyl)imidazol‐2‐yliden (IPr) lagerte sich das anfänglich kurz gebildete Lewis‐Säure‐Base‐Addukt schnell zu einem Carben mit einem Aminoboransubstituenten in 4‐Position um. Erwärmen des Iminoboran‐CAAC‐Adduktes auf Raumtemperatur ergab unter intramolekularem Ringschluss ein bicyclisches 1,2‐Azaborolidin.
Preparation and characterization of braided tube reinforced polyacrylonitrile hollow fiber membranes
Authors: Quan Quan , Xiao Changfa , Liu Hailiang , Huang Qinglin , Zhao Wei , Hu Xiaoyu , Huan Guolan 
Published: December 2014

ABSTRACTPolyacrylonitrile (PAN) and polyester (PET) braided hollow tube that used as a special reinforcement are braided from their filaments via two‐dimensional weaving techniques. PAN braided tube reinforced homogeneous PAN hollow fiber membranes and PET braided tube reinforced heterogeneous PAN hollow fiber membranes are prepared by concentric circles squeezed‐coated spinning method. As for PAN hollow fiber membrane, the effects of PAN concentration on the performance of the prepared hollow fiber membranes are investigated in terms of pure water flux, protein rejection, mechanical strength, and morphology observations by a scanning electron microscope (SEM). The interfacial bonding state of the braided tube reinforced PAN hollow fiber membranes is studied by constant speed stretching method. Results show that the breaking strength of two‐dimensional braided tube reinforced PAN hollow fiber membranes is higher than 80 MPa. The structure of separation surface is similar to the structure of an asymmetric membrane. With the increase of polymer concentration, the membrane flux decreases while the retention rate of BSA increase. The membrane porosity and maximum pore size have the same decreasing tendency as the increase of PAN concentration. The results also show that the interfacial bonding state of the PAN two‐dimensional braided tube reinforced homogeneous PAN hollow fiber membranes is better than that of the PET two‐dimensional braided tube reinforced heterogeneous PAN hollow fiber membranes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41795.
Open and continuous fermentation: Products, conditions and bioprocess economy
Authors: Li Teng , Chen Xiang‐bin , Chen Jin‐chun , Wu Qiong , Chen Guo‐Qiang 
Published: December 2014

AbstractMicrobial fermentation is the key to industrial biotechnology. Most fermentation processes are sensitive to microbial contamination and require an energy intensive sterilization process. The majority of microbial fermentations can only be conducted over a short period of time in a batch or fed‐batch culture, further increasing energy consumption and process complexity, and these factors contribute to the high costs of bio‐products. In an effort to make bio‐products more economically competitive, increased attention has been paid to developing open (unsterile) and continuous processes. If well conducted, continuous fermentation processes will lead to the reduced cost of industrial bio‐products. To achieve cost‐efficient open and continuous fermentations, the feeding of raw materials and the removal of products must be conducted in a continuous manner without the risk of contamination, even under ‘open’ conditions. Factors such as the stability of the biological system as a whole during long cultivations, as well as the yield and productivity of the process, are also important. Microorganisms that grow under extreme conditions such as high or low pH, high osmotic pressure, and high or low temperature, as well as under conditions of mixed culturing, cell immobilization, and solid state cultivation, are of interest for developing open and continuous fermentation processes.
Experimental and Theoretical Studies on the Rearrangement of 2‐Oxoazepane α,α‐Amino Acids into 2′‐Oxopiperidine β2,3,3‐Amino Acids: An Example of Intramolecular Catalysis
Authors: Núñez‐Villanueva Diego , Bonache M. Ángeles , Lozano Laura , Infantes Lourdes , Elguero José , Alkorta Ibon , García‐López M. Teresa , González‐Muñiz Rosario , Martín‐Martínez Mercedes 
Published: December 2014

AbstractEnantiopure β‐amino acids represent interesting scaffolds for peptidomimetics, foldamers and bioactive compounds. However, the synthesis of highly substituted analogues is still a major challenge. Herein, we describe the spontaneous rearrangement of 4‐carboxy‐2‐oxoazepane α,α‐amino acids to lead to 2′‐oxopiperidine‐containing β2,3,3‐amino acids, upon basic or acid hydrolysis of the 2‐oxoazepane α,α‐amino acid ester. Under acidic conditions, a totally stereoselective synthetic route has been developed. The reordering process involved the spontaneous breakdown of an amide bond, which typically requires strong conditions, and the formation of a new bond leading to the six‐membered heterocycle. A quantum mechanical study was carried out to obtain insight into the remarkable ease of this rearrangement, which occurs at room temperature, either in solution or upon storage of the 4‐carboxylic acid substituted 2‐oxoazepane derivatives. This theoretical study suggests that the rearrangement process occurs through a concerted mechanism, in which the energy of the transition states can be lowered by the participation of a catalytic water molecule. Interestingly, it also suggested a role for the carboxylic acid at position 4 of the 2‐oxoazepane ring, which facilitates this rearrangement, participating directly in the intramolecular catalysis.
Limitation of using silver ion solid‐phase extraction for animal lipids with a low trans content
Authors: Belaunzaran Xabier , Bravo‐Lamas Leire , Kramer John K. G. , Aldai Noelia 
Published: December 2014

AbstractSilver ion solid‐phase extraction (Ag+‐SPE) was reported to provide effective separations compared to other Ag+ techniques but at a fraction of cost and time. Ag+‐SPE cartridges resolved fatty acid methyl esters (FAMEs) with different number and/or geometric configuration of double bonds. Here we attempted to determine the trans fatty acids (FA) contained in a low total trans FA sample, horse lipids; lamb was used as a control having a markedly higher total trans content. Gas chromatographic assessment of the fractions showed a good separation of the cis and trans monounsaturated FA (MUFA) fractions, but the relative high content of contaminants that coeluted with these FA impaired the identification of the latter in horse lipids. In lamb trans MUFA isomers could be identified since their abundance relative to impurities was greater. Several attempts were made to remove the contaminants from the SPE cartridges including an extensive prewash with acetone and hexane, a prewash with solvents that would elute the cis MUFA fraction, and a complete prewash of all solvents used in the fractionation, hexane, acetone, and acetonitrile. The prewash using all elution solvents removed most contaminants but subsequently impaired the separation of trans and cis MUFA fractions. The same samples were subjected to Ag+‐HPLC fractionation that showed no impurities demonstrating that they were derived from the Ag+‐SPE separation. The trans MUFA fraction collected from Ag+‐HPLC allowed for the identification of the trans 16:1 and 18:1 FA in horse lipids and is recommended for samples with low trans levels.Practical applications: The commercially available silver ion solid‐phase extraction (Ag+‐SPE) cartridges contain appreciable amounts of contaminants that can interfere with the subsequent GC‐FID elution of low levels of trans fatty acid methyl esters (FAMEs), especially when contaminants are leaked by the SPE tube in quantities comparable to the trans MUFA content. The contaminants could not be quantitatively removed by prewashing the cartridges with acetone and hexane. Acetonitrile removed most contaminants but altered the Ag+‐SPE tube ability to resolve the trans and cis MUFA fractions. Ag+‐HPLC fractionation is recommended for isolation of low levels of trans MUFA, since the washing and conditioning of the chromatographic column can be extended as needed.Ag+‐SPE cartridges are used to separate FAMEs based on number and geometric configuration of double bonds to aid in the identification of complex GC separations.
Empirical Bayesian Density Forecasting in Iowa and Shrinkage for the Monte Carlo Era
Authors: Lewis Kurt F. , Whiteman Charles H. 
Published: December 2014

ABSTRACTThe track record of a 20‐year history of density forecasts of state tax revenue in Iowa is studied, and potential improvements sought through a search for better‐performing ‘priors’ similar to that conducted three decades ago for point forecasts by Doan, Litterman and Sims (Econometric Reviews, 1984). Comparisons of the point and density forecasts produced under the flat prior are made to those produced by the traditional (mixed estimation) ‘Bayesian VAR’ methods of Doan, Litterman and Sims, as well as to fully Bayesian ‘Minnesota Prior’ forecasts. The actual record and, to a somewhat lesser extent, the record of the alternative procedures studied in pseudo‐real‐time forecasting experiments, share a characteristic: subsequently realized revenues are in the lower tails of the predicted distributions ‘too often’. An alternative empirically based prior is found by working directly on the probability distribution for the vector autoregression parameters—the goal being to discover a better‐performing entropically tilted prior that minimizes out‐of‐sample mean squared error subject to a Kullback–Leibler divergence constraint that the new prior not differ ‘too much’ from the original. We also study the closely related topic of robust prediction appropriate for situations of ambiguity. Robust ‘priors’ are competitive in out‐of‐sample forecasting; despite the freedom afforded the entropically tilted prior, it does not perform better than the simple alternatives. Copyright © 2014 John Wiley & Sons, Ltd.
Safety and efficacy of multiuse botulinum toxin vials for intralaryngeal injection
Authors: Barrow Emily M. , Rosen Clark A. , Hapner Edie R. , Smith Sarah , Hatcher Jeanne L. , Simpson Blake , Johns Michael M. 
Published: December 2014

Objectives/HypothesisCenters for Disease Control and Prevention guidelines maintain that single‐use vials cannot be used for multiple patients. Botox product labeling states that the reconstituted toxin should be used within 4 hours on a single patient based on concerns of reduced potency, contamination, and consequent infections. The purpose of this study was to determine the safety and efficacy of using single‐use vials in a multidose fashion.Study DesignProspective study and cohort chart review.MethodsA multi‐institutional three‐part study was performed between May 2013 and October 2013: 1) a summation of subjects' recall of their past experiences (symptoms/response) with previous multidose Botox injections, 2) a prospective study of intralaryngeal injections, and 3) a chart review of injection responses in a subset of the cohort.ResultsSeven hundred forty‐three subjects receiving 6,216 injections demonstrated zero infection‐related complications on retrospective chart review. One hundred seventy‐nine subjects recalled 24.0% overall adverse events, 10.6% redness, 7.3% pain and swelling at the injection site, and 0% fever. One hundred seventy‐four subjects prospectively reported 12.6% overall adverse events. The self‐reported efficacy rate of Botox injection was 96.6%.ConclusionsThe low rates of adverse events following the use of Botox in a multipatient fashion are consistent with other percutaneous injections. No evidence of infection was found with multidose Botox use. Given the low incidence of side effects and high success rate, Botox can be used both safely and effectively in a multipatient fashion.Level of Evidence4 Laryngoscope, 125:1149–1154, 2015
Radiation‐associated malignancies of the ear canal and temporal bone
Authors: Lambert Elton M. , Garden Adam S. , DeMonte Franco , Roberts Dianna B. , Gidley Paul W. 
Published: December 2014

Objectives/HypothesisTo examine our experience with surgically treated radiation‐associated malignancy (RAM) of the temporal bone.Study DesignRetrospective chart review.MethodsThirteen patients treated surgically for temporal‐bone RAM during 1999 to 2012 were identified. Demographics, symptoms at presentation with RAM, interval between initial radiotherapy and diagnosis of RAM, pathologic features of RAM, treatment, and recurrence and survival were obtained from medical records.ResultsTen patients had squamous cell carcinoma; three had sarcoma. The mean period between completion of radiotherapy and diagnosis of RAM was 13.38 years (range, 4.5–33.3 years). Three‐year overall and disease‐free survival rates were 59.8% and 42.3%, respectively. Seven patients (54%) had RAM limited to the external auditory canal (LEAC); six had RAM extending beyond it (EEAC). The mean age was 66.5 years for LEAC patients versus 41.1 years for EEAC patients (P = .0161). Compared to patients with EEAC disease, patients with LEAC disease were more likely to have negative margins (100% vs. 33%; P = .021) and less likely to have postoperative adjuvant therapy (0% vs. 67%; P = .0209). The 3‐year disease‐specific survival was significantly better for patients with LEAC disease versus EEAC (log rank P = .023).ConclusionsTo our knowledge, this is the largest reported series of surgically treated RAM of the ear canal or temporal bone. This study highlights the need for vigilance for RAM in patients treated with head and neck radiation.Level of Evidence4. Laryngoscope, 125:1198–1204, 2015
Assessment of ototoxicity of intratympanic administration of Auralgan in a chinchilla animal model
Authors: Mujica‐Mota Mario A. , Bezdjian Aren , Salehi Pezhman , Schermbrucker Jonah , Daniel Sam J. 
Published: December 2014

Objectives/HypothesisAuralgan (benzocaine and antipyrine) is an over‐the‐counter otic drug commonly used for otalgia. Nevertheless, there is limited evidence about the effects of the drug on hearing function and cochlear morphology in the presence of a tympanic membrane perforation. The aim of the present study was to assess the cytotoxicity of Auralgan using cultured auditory cells (HEI‐OC1) and to examine its effects on hearing function and cochlear morphology after intratympanic administration in a chinchilla model.Study DesignAnimal experiment.MethodsCell viability and DNA labeling assays were conducted to investigate the cytotoxic effect of the drug on cultured auditory cells (HEI‐OC1). To examine the possible drug ototoxic effect in vivo, chinchillas received intratympanic injection of Auralgan in one ear, whereas the contralateral control ear received saline. Outcome measures included auditory brainstem response and postmortem cochlear morphology.ResultsA dose‐dependent toxic effect of Auralgan was noted on cultured cells. Animal experiments showed an inflammatory reaction in the experimental ears and facial paralysis in 80% of the animals on the side receiving transtympanic injection of Auralgan (P < .05). Auditory brainstem response testing demonstrated a 30‐ to 50‐dB hearing threshold shift across all frequencies tested (P < .05). Control ears showed no inflammation or significant threshold shift. Microscopy showed damage to the hair cells and stria vascularis with bleeding in the perilymphatic space in the experimental ears and damage to the hair cells.ConclusionsAuralgan was cytotoxic to cultured auditory cells. It promoted an inflammatory reaction and seemed to be ototoxic when given via transtympanic injection in an animal model.Level of EvidenceNA Laryngoscope, 125:1444–1448, 2015
Fast Synthesis of High‐Molecular‐Weight Polyglycolide Using Diphenyl Bismuth Bromide as Catalyst
Authors: Lu Yiyang , Schmidt Christian , Beuermann Sabine 
Published: December 2014

Biodegradable polymers are frequently obtained from ring‐opening polymerizations (ROPs). Applications in the biomedical sector require medical‐grade materials free of any toxic residues, as well as polymers with well‐defined properties. Thus, the selection of nontoxic catalysts for ROP, which allow for well‐controlled molecular weights, is very important. In this contribution, ROPs of diglycolide are reported by using diphenyl bismuth bromide as catalyst. The reactions are carried out in bulk at temperatures ranging from 130 to 150 °C. The number‐average molecular weights are in the range of 20–250 kg mol−1 depending on the reaction temperature and time, as well as the catalyst concentration. The reaction times required to yield diglycolide conversions exceeding 95% are in the range of minutes. The thermal properties such as melting and crystallization temperatures are independent of polymer molecular weight.
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Shape‐Memory Hydrogels with Crystallizable Oligotetrahydrofuran Side Chains
Authors: Balk Maria , Behl Marc , Nöchel Ulrich , Lendlein Andreas 
Published: December 2014

SummaryStimuli‐sensitive materials, such as shape‐memory polymers (SMP) have attracted tremendous interest in the field of biomedical applications and Regenerative Therapies. In case of implants intended for soft tissue, adequate elastic properties can be mimicked by water swollen hydrophilic polymer networks (i.e. hydrogels) and can be equipped with a shape‐memory capability. Shape‐memory hydrogels (SMHs) having body compatible transition temperatures (Ttrans) have not been reported so far. Here we explored, whether SMHs with Ttrans ≤ 37 °C could be created consisting of the hydrophilic poly(N‐vinyl pyrrolidone) segment, the crosslinker oligo(ethylene glycol) dimethacrylate (OEGDMA, Mn = 370 g · mol−1), and grafted crystallizable oligotetrahydrofuran (OTHF, Mn = 7.100 g · mol−1, Tm = 31 °C) segments as switching domains. As function of the OTHF content (30–75 wt%), the hydrogels had a degree of swelling between 450 and 3200%, a Ttrans about 26 °C, and soft mechanical properties in the kPa range. Therefore, these SMHs might be interesting biomaterial candidates e.g. as smart implants.
Varenicline enhances dopamine release facilitation more than nicotine after long‐term nicotine treatment and withdrawal
Authors: Perez Xiomara A. , Khroyan Taline V. , McIntosh J. Michael , Quik Maryka 
Published: December 2014

AbstractAn important factor contributing to the high relapse rates among smokers is nicotine withdrawal symptoms. Multiple studies suggest that decreased dopamine release in nucleus accumbens plays a key role in withdrawal. However, recent reports showed that long‐term nicotine exposure itself also decreases accumbal dopamine release, suggesting that additional mechanisms are involved in withdrawal. Here, we used real‐time cyclic voltammetry in brain slices containing the nucleus accumbens to further elucidate the changes in dopamine release linked to nicotine withdrawal. Rats received vehicle or nicotine via the drinking water for 2–3 months. Studies assessing the expression of somatic signs in vehicle‐treated, nicotine‐treated, and 24‐h nicotine withdrawn rats showed that nicotine withdrawal led to a significant increase in somatic signs. Subsequent voltammetry studies showed that long‐term nicotine decreased single‐pulse‐stimulated dopamine release via an interaction at α6β2* receptors. Nicotine withdrawal led to a partial recovery in α6β2* receptor‐mediated release. In addition, long‐term nicotine treatment alone increased dopamine release paired‐pulse ratios and this was partially reversed with nicotine removal. We then evaluated the effect of bath‐applied nicotine and varenicline on dopamine release. Nicotine and varenicline both decreased single‐pulse‐stimulated release in vehicle‐treated, nicotine‐treated, and nicotine withdrawn rats. However, bath‐applied varenicline increased paired‐pulse ratios to a greater extent than nicotine during long‐term nicotine treatment and after its withdrawal. Altogether these data suggest that nicotine withdrawal is associated with a partial restoration of dopamine release measures to control levels and that varenicline's differential modulation of dopamine release may contribute to its mechanism of action.
Active surveillance of visual impairment due to adverse drug reactions: findings from a national study in the United Kingdom
Authors: Cumberland Phillippa M. , Russell‐Eggitt Isabelle , Rahi Jugnoo S. 
Published: December 2014

AbstractAs visual impairment (VI) due to adverse drug reactions (ADR) is rare in adults and children, there is an incomplete evidence base to inform guidance for screening and for counseling patients on the potential risks of medications. We report on suspected drugs and the eye conditions found in a national study of incidence of diagnosis of visual impairment due to suspected ADR. Case ascertainment was via the British Ophthalmological Surveillance Unit (BOSU), between March 2010 and February 2012, with follow‐up after 6 months. Case definition: any child or adult with bilateral or unilateral visual impairment due to a suspected ADR, using distance acuity worse than Snellen 6/18 (logMAR 0.48) in the better eye (bilateral) or affected eye (unilateral). Anonymized patient information on potential cases was provided by managing ophthalmologists, comprising visual status before and after suspected ADR, ophthalmic condition attributable to the ADR, preexisting eye disease and prescribed medications at the time of the ADR. Permanency and causality of the visual impairment were confirmed by the managing clinician, after 6 months, using the WHO Uppsala Monitoring Committee criteria. Over 2 years, 36 eligible cases were reported of whom 23 had permanent VI. While most cases were due to drugs known to have adverse side‐effects, some were unanticipated sporadic cases. Visual impairment due to ADRs is rare. However, with for example, increasing polypharmacy in the elderly, monitoring of ocular ADRs, although challenging, is necessary.