bluuebunny/crossref_metadata_2025_split huggingface dataset:
Continuous Glucose Monitoring: 40 Years, What We′ve Learned and What’s Next
Authors: Gifford Raeann 
Published: May 2013

AbstractAfter 40 years of research and development, today continuous glucose monitoring (CGM) is demonstrating the benefit it provides for millions with diabetes. To provide in vivo accuracy, new permselective membranes and mediated systems have been developed to prevent enzyme saturation and to minimize interference signals. Early in vivo implanted sensor research clearly showed that the foreign body response was a more difficult issue to overcome. Understanding the biological interface and circumventing the inflammatory response continue to drive development of a CGM sensor with accuracy and reliability performance suitable in a closed‐loop artificial pancreas. Along with biocompatible polymer development, other complimentary algorithm and data analysis techniques have improved the performance of commercial systems significantly. For example, the mean average relative difference of Dexcom’s CGM system improved from 26 to 14 % and its use‐life was extended from 3 to 7 d. Significant gains in usability, including size, flexibility, insertion, calibration, and data interface, have been incorporated into new generations of commercial CGM systems. Besides Medtronic, Dexcom, and Abbott, other major players are also investing in CGM. Becton Dickinson is conducting clinical trials with an optical galactose glucose binding system. Development of fully implanted sensor systems fulfills the desire for a discreet, reliable CGM system. Research continues to find innovative ways to help make living with diabetes easier and more normal, and new segments are being pursued (intensive care unit, surgery, behavior modification) in which CGM is being utilized.
Probing the γ‐Turn in a Short Proline Dipeptide Chain
Authors: Cabezas Carlos , Varela Marcelino , Alonso José L. 
Published: May 2013

AbstractThe small peptide derived from proline, N‐acetyl‐prolinamide (Ac‐Pro‐NH2), has been investigated using a combination of Fourier transform microwave spectroscopy with laser ablation. Spectral signatures belonging to only one conformer have been detected in the supersonic expansion. Rotational constants and nuclear quadrupole coupling constants of the two 14N nuclei have been used in the characterization of a γ‐turn structure in the gas phase, which is stabilized by a CO⋅⋅⋅HN intramolecular hydrogen bond closing a seven‐membered ring. A methyl group internal rotation barrier of 354 cm−1 has been determined from the analysis of the A–E splittings.
Silver‐Containing Ionic Liquids with Alkylamine Ligands
Authors: Depuydt Daphne , Brooks Neil R. , Schaltin Stijn , Van Meervelt Luc , Fransaer Jan , Binnemans Koen 
Published: May 2013

AbstractThe synthesis, structure and electrochemical properties of several silver‐containing liquid metal salts have been investigated. These ionic liquids comprise of a silver‐containing cation with a silver centre coordinated by two or more alkylamine ligands and a bis(trifluoromethylsulfonyl)imide (Tf2N) anion. With the monodentate amines tert‐butylamine (tBuAm), iso‐butylamine (iso‐BuAm), sec‐butylamine (sec‐BuAm), 2‐ethylhexylamine (2‐EtHexAm), di(2‐ethylhexyl)amine and piperidine (pip), compounds with the formula [Ag(L)2][Tf2N] are formed, several of which are room‐temperature ionic liquids and all melt at or below 100 °C. In the case of [Ag(L)2][Tf2N] (L=tBuAm, iso‐BuAm and pip), single‐crystal X‐ray diffraction shows that, in the solid state, the silver centres are two‐fold coordinated by two amine ligands and the anion and cation exist as separated ion pairs. With ethylenediamine (en), two different compounds were formed, depending on the silver‐to‐ligand ratio and their structures were elucidated by X‐ray diffraction. [Ag(en)][Tf2N] has a very high melting point and is polymeric in the solid state, with en ligands coordinated to different silver(I) centres, creating one‐dimensional chains. [Ag(en)2][Tf2N], on the other hand, is a room‐temperature ionic liquid, with four‐coordinate silver(I) centres, but is actually polymeric in the solid state. The electrodeposition behaviour of [Ag(2‐EtHexAm)2][Tf2N] and [Ag(en)2][Tf2N] was investigated both at room temperature and at 90 °C and it was possible to achieve very high current densities in unstirred solutions and to electrodeposit closed, crack‐free, silver coatings. A crystal of [Ag2(en)Cl2] was obtained from a solution of [Ag(en)][Tf2N] in deuterochloroform and its structure is described.
Standard fluorescent imaging of live cells is highly genotoxic
Authors: Ge Jing , Wood David K. , Weingeist David M. , Prasongtanakij Somsak , Navasumrit Panida , Ruchirawat Mathuros , Engelward Bevin P. 
Published: May 2013

AbstractFluorescence microscopy is commonly used for imaging live mammalian cells. Here, we describe studies aimed at revealing the potential genotoxic effects of standard fluorescence microscopy. To assess DNA damage, a high throughput platform for single cell gel electrophoresis is used (e.g., the CometChip). Light emitted by three standard filters was studied: (a) violet light [340–380 nm], used to excite DAPI and other blue fluorophores, (b) blue light [460–500 nm] commonly used to image green fluorescent protein (GFP) and Calcein AM, and (c) green light [528–553 nm], useful for imaging red fluorophores. Results show that exposure of samples to light during imaging is indeed genotoxic even when the selected wavelengths are outside the range known to induce significant damage levels. Shorter excitation wavelengths and longer irradiation times lead to higher levels of DNA damage. We have also measured DNA damage in cells expressing enhanced GFP or stained with Calcein AM, a widely used green fluorophore. Data show that Calcein AM leads to a synergistic increase in the levels of DNA damage and that even cells that are not being directly imaged sustain significant DNA damage from exposure to indirect light. The nature of light‐induced DNA damage during imaging was assessed using the Fpg glycosylase, an enzyme that enables quantification of oxidative DNA damage. Oxidative damage was evident in cells exposed to violet light. Furthermore, the Fpg glycosylase revealed the presence of oxidative DNA damage in blue‐light exposed cells for which DNA damage was not detected using standard analysis conditions. Taken together, the results of these studies call attention to the potential confounding effects of DNA damage induced by standard imaging conditions, and identify wavelength, exposure time, and fluorophore as parameters that can be modulated to reduce light‐induced DNA damage. © 2013 International Society for Advancement of Cytometry
B‐Mercaptocarboranes: A New Synthetic Route
Authors: Kabytaev Kuanysh Z. , Everett Thomas A. , Safronov Alexander V. , Sevryugina Yulia V. , Jalisatgi Satish S. , Hawthorne M. Frederick 
Published: May 2013

AbstractInvited for the cover of this issue is the group of M. Frederick Hawthorne at the University of Missouri. The cover image shows a novel route for synthesis of 3‐SH‐1,2‐dicarba‐closo‐dodecaborane through Pd‐catalyzed iodine exchange with the sulfur nucleophile TIPS?SH in ortho‐carborane. The thiolated borane clusters can be applied in thiol‐based self‐assembled monolayers (SAMs) on surfaces such as gold.
Copper‐Mediated Cyanation of Aryl Halides by Activation of Benzyl Cyanide as the Cyanide Source
Authors: Wen Qiaodong , Jin Jisong , Mei Yuncai , Lu Ping , Wang Yanguang 
Published: May 2013

AbstractAryl nitriles were efficiently synthesized through copper‐mediated cyanation of aryl halides using benzyl cyanide as the cyanide source. Aryl halides with various substituents on the aromatic ring afforded the corresponding aryl nitriles in 32–97 % yields (25 examples). This reaction could also be carried on a gram scale by using commercially available reagents. Additionally, a C–H bond oxidation and a C–CN cleavage are proposed to be involved in this cascade process.
Utilization of Carbon Paste Electrodes for the Voltammetric Determination of Chlortoluron
Authors: Dejmkova Hana , Houskova Lucie , Barek Jiri , Zima Jiri 
Published: May 2013

AbstractConventional (CPE) and miniaturized (m‐CPE) carbon paste electrodes consisting of a carbon paste filled capillary were used for differential pulse voltammetric determination of chlortoluron in samples of river water and soil, in the latter case after the extraction by methanol. Britton‐Robinson buffer pH 3 with low content of methanol was found to be optimal for the determination. The achieved determination limits were 2.8 µmol L−1 and 0.34 µmol L−1 in river water, and 3.1 and 4.3 µg g−1 in soil, using CPE and m‐CPE, respectively.
Direct Electrocatalytic Oxidation and Simultaneous Determination of 5‐Methylcytosine and Cytosine at Electrochemically Reduced Graphene Modified Glassy Carbon Electrode
Authors: Zheng Xiaoxia , Wang Lishi 
Published: May 2013

AbstractDirect electrocatalytic oxidation and simultaneous determination of 5‐methylcytosine (5‐mC) and cytosine(C) were realized in alkaline solutions by differential pulse voltammetry (DPV) based on an electrochemically reduced graphene oxide (er‐GO) modified glassy carbon electrode (er‐GO/GCE). The as‐prepared er‐GO/GCE exhibited good electrocatalytic activity towards the oxidation of 5‐mC and C. Under optimum conditions, the er‐GO/GCE was applied to the simultaneous determination of 5‐mC and C with a significantly improved peak potential resolution (about 150 mV), and a linear relationship can be obtained in the range of 6–200.0 µmol/L and 8–250.0 µmol/L, respectively. In addition, the proposed method was further successfully applied to the analysis of methylation status in short CpG oligonucleotides with satisfactory results.
Structure and physicochemical properties of starches in lotus (Nelumbo nucifera Gaertn.) rhizome
Authors: Yu Huaguang , Cheng Libao , Yin Jingjing , Yan Shunjun , Liu Kejun , Zhang Fengmin , Xu Bin , Li Liangjun 
Published: May 2013

AbstractThe type and content of starch are believed to be the most critical factors in determining the storage and processing quality of lotus rhizome species, and the intention of this study is to survey the structure and properties of starches isolated from rhizomes of two lotus cultivars using X‐ray powder diffraction, solid‐state nuclear magnetic resonance spectroscopy, attenuated total reflectance‐Fourier transform infrared spectroscopy, scanning electron microscope, differential scanning calorimetry, and rapid viscosity analyzer (RVA). Starch in rhizome of cultivar Meirenhong exhibited C‐type X‐ray diffraction pattern, while starch in rhizome of cultivar Wawalian showed A‐type pattern. 13C cross‐polarization magic‐angle spinning nuclear magnetic resonance (13C CP‐MAS NMR) also confirmed the polymorphs. The relative crystallinity of two starches was quantitatively estimated from two methods and compared. Attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) results indicated that the external regions of the starch granules had a great level of ordered structure. Starch granules in Meirenhong showed oval‐shaped granules, while starch granules in Wawalian were elongated and oval in shape with relatively large size. Gelatinization temperatures of starch in Meirenhong and Wawalian were 330.5 and 342.4 K, respectively, and the gelatinization temperature range of Meirenhong was significantly wider than that of Wawalian. Starch in rhizome of cultivar Meirenhong showed lower pasting temperature, lower hot and cool viscosities, lower setback, and higher peak viscosity and breakdown than those of Wawalian in RVA pasting profiles at 6% starch concentration.
Decadal variations in the global atmospheric land temperatures
Authors: Muller Richard A. , Curry Judith , Groom Donald , Jacobsen Robert , Perlmutter Saul , Rohde Robert , Rosenfeld Arthur , Wickham Charlotte , Wurtele Jonathan 
Published: May 2013

AbstractInterannual to decadal variations in Earth global temperature estimates have often been identified with El Niño Southern Oscillation (ENSO) events. However, we show that variability on time scales of 2–15 years in mean annual global land surface temperature anomalies Tavg are more closely correlated with variability in sea surface temperatures in the North Atlantic. In particular, the cross‐correlation of annually averaged values of Tavg with annual values of the Atlantic Multidecadal Oscillation (AMO) index is much stronger than that of Tavg with ENSO. The pattern of fluctuations in Tavg from 1950 to 2010 reflects true climate variability and is not an artifact of station sampling. A world map of temperature correlations shows that the association with AMO is broadly distributed and unidirectional. The effect of El Niño on temperature is locally stronger, but can be of either sign, leading to less impact on the global average. We identify one strong narrow spectral peak in the AMO at period 9.1 ± 0.4 years and p value of 1.7% (confidence level, 98.3%). Variations in the flow of the Atlantic meridional overturning circulation may be responsible for some of the 2–15 year variability observed in global land temperatures.
T1ρ mapping of pediatric epiphyseal and articular cartilage in the knee
Authors: Cobb Jared Guthrie , Kan J. Herman , Gore John C. 
Published: May 2013

PurposeTo evaluate the feasibility of measuring T1ρ values in epiphyseal cartilage in children, we have conducted a novel study of spin locking techniques. Adult articular cartilage has been widely studied with spin locking techniques by magnetic resonance imaging. However, no results are available for in vivo T1ρ imaging of developing cartilage.Materials and MethodsTen volunteers of age 6 ± 3 years were recruited to have T1ρ mapping performed on the knee at the conclusion of their clinical study. T1ρ maps were generated using a spin‐lock cluster followed by a fast spin‐echo imaging sequence. Regions of interest (ROIs) were placed in non–load‐bearing (NLB), load‐bearing (LB), and articular cartilage.ResultsStudent's t‐tests were performed to compare means among the ROIs. Mean T1ρ for epiphyseal and articular cartilage was 49.8 ± 9 and 76.6 ± 7 ms, respectively. LB and NLB T1ρ vales were 47.1 ± 9.5 and 52.5 ± 9 ms, respectively. Significant differences were found in T1ρ values between epiphyseal and articular cartilage layers (P = 0.0001). No difference in T1ρ was observed between NLB and LB layers. A modest trend was also noted for epiphyseal and articular cartilage regions with age.ConclusionIt is feasible to quantify differences in epiphyseal and articular cartilage layers with SL techniques. T1ρ holds promise as a noninvasive method of studying normal and abnormal developmental states of cartilage in children. J. Magn. Reson. Imaging 2013;38:299–305. © 2012 Wiley Periodicals, Inc.
Assessment of exocrine pancreatic function by secretin‐stimulated magnetic resonance cholangiopancreaticography and diffusion‐weighted imaging in healthy controls
Authors: Wathle Gaute K. , Tjora Erling , Ersland Lars , Dimcevski Georg , Salvesen Øyvind O. , Molven Anders , Njølstad Pål R. , Haldorsen Ingfrid S. 
Published: May 2013

PurposeTo characterize and quantify exocrine pancreatic function by secretin‐stimulated magnetic resonance cholangiopancreaticography (s‐MRCP) and diffusion‐weighted imaging (DWI) in healthy subjects and compare these findings to morphological features, ie, pancreatic volume and secretin‐stimulated peak bicarbonate concentration measured in pancreatic juice.Materials and MethodsPancreatic magnetic resonance imaging (MRI) (1.5 T) was performed in 20 healthy volunteers among which 10 underwent gastroscopy with duodenal intubation. MRI included T2‐weighted imaging and DWI acquired before and 1, 5, 9, and 13 minutes after secretin administration. Secreted pancreatic juice volumes were calculated based on the sequential T2‐weighted images and pancreatic volumes and apparent diffusion coefficient (ADC) values were estimated.ResultsThe mean pancreatic secretion rate declined from 9.5 mL/min at 1–5 minutes (postsecretin) to 2.9 mL/min at 9–13 minutes. Pancreatic head ADC values significantly increased from baseline (1.29 × 10−3 mm2/s) to 1 minute postsecretin (1.48 × 10−3 mm2/s) (P = 0.003). Secreted pancreatic juice volume at 1 minute after secretin correlated positively with peak bicarbonate concentration (n = 10, P = 0.05).ConclusionSecretin‐stimulated MRCP and DWI can characterize and quantify exocrine pancreatic function in healthy subjects. These imaging methods may prove relevant for patients with exocrine pancreatic dysfunction. J. Magn. Reson. Imaging 2014;39:448–454. © 2013 Wiley Periodicals, Inc.
Field‐scale potassium and phosphorus fluxes in the bioenergy crop switchgrass: Theoretical energy yields and management implications
Authors: Woodson Patrick , Volenec Jeffrey J. , Brouder Sylvie M. 
Published: May 2013

AbstractOur understanding of how mineral nutrition affects productivity and composition of bioenergy crops grown on marginal lands remains fragmented and incomplete despite world‐wide interest in using herbaceous biomass as an energy feedstock. Our aim was to determine switchgrass (Panicum virgatum L.) biomass production and maize (Zea mays L.) grain yield on marginal soils used previously to evaluate the effect of soil phosphorus (P) and potassium (K) fertility on alfalfa (Medicago sativa L.) forage production. Grain yield of maize was reduced on P‐ and/or K‐limited plots that also impaired alfalfa forage yield, whereas switchgrass biomass yields were high even in plots possessing very low available P (4 mg kg–1) and K (< 70 mg kg–1) levels. Linear‐plateau regression models effectively described the relationship of soil test P and K to tissue P and K concentrations, and tissue P and K concentrations accurately predicted removal of P and K in harvest biomass. However, neither soil‐test P and K, nor tissue P and K concentrations were effective as diagnostics for predicting switchgrass biomass yield nor could soil tests and their change with cropping predict nutrient removal. Concentrations of cellulose, hemicellulose, lignin, and ash were not influenced by P and K nutrition. Predicted bio‐ethanol production was closely associated with biomass yield whereas high biomass K concentrations reduced estimated bio‐oil production per hectare by as much as 50%. Additional research is needed to identify diagnostics and managements to meet the bioenergy production co‐objectives of having high yield of biomass with very low mineral nutrient concentrations (especially K) while sustaining and improving the fertility of marginal soils.
Effects of uvulopalatopharyngoplasty with or without radiofrequency tongue base reduction on voice in patients with obstructive sleep apnea
Authors: Eun Young Gyu , Shin Seung Youp , Kim Sung Wan 
Published: May 2013

Objectives/HypothesisTo investigate voice change as a complication after uvulopalatopharyngoplasty (UPPP) with or without radiofrequency tongue base reduction (RTBR) in patients with obstructive sleep apnea.Study DesignBefore and after study.MethodsTwenty‐two patients with suspected velopharyngeal collapse only underwent uvulopalatopharyngoplasty (UPPP group). Twenty‐five patients with velopharyngeal and retrolingual collapse underwent concurrent UPPP with RTBR (RTBR group). All patients were evaluated before surgery and at 8 weeks after surgery. Acoustic measures included mean fundamental frequency (mF0), maximal phonation time (MPT), jitter, shimmer, noise‐to‐harmonic ratio (NHR), hypernasality test, and the first three formant frequencies (F1, F2, F3) for sustained vowels. Voice handicap index (VHI) was used to determine subjective voice change.ResultsPostoperative values for mF0, MPT, jitter, shimmer, NHR, hypernasality test, and F1 did not significantly change in either group following surgery. There were the significant decreases at the F2 of /u/ and the F3 of /o/ in the UPPP group, and at the F2 of /o/ and the F3 of /a/, /i/, and /o/ in the RTBR group. Postoperative VHI score was increased only in the RTBR group.ConclusionsUPPP and UPPP with RTBR have an impact on formant frequencies of vowels. Despite a relatively small number of patients, it is apparent that UPPP with RTBR influences VHI. Patients, especially professional voice users, should be advised of this before considering the surgery.Level of Evidence4
Potential adverse events of endosseous dental implants penetrating the maxillary sinus: Long‐term clinical evaluation
Authors: Najm Semaan Abi , Malis Didier , Hage Marc El , Rahban Sonia , Carrel Jean‐Pierre , Bernard Jean‐Pierre 
Published: May 2013

Objectives/HypothesisThe aim of this study was to evaluate the nature and incidence of long‐term maxillary sinus adverse events related to endosseous implant placement with protrusion into the maxillary sinus.Study DesignRetrospective cohort study.MethodsAll patients who underwent placement of endosseous dental implants with clinical evidence of implant penetration into the maxillary sinus with membrane perforation were included in this study. Only patients with a minimum follow‐up of 5 years after implant placement were included in this study. Maxillary sinus assessment was both clinical and radiological.ResultsEighty‐three implants with sinus membrane perforation in 70 patients met the study's inclusion criteria. Mean age was 65.96 years ± 14.23. Twelve patients had more than one implant penetrating the maxillary sinus, and seven of them had bilateral sinus perforation. Estimated implant penetration was ≤3 mm in all cases. The average clinical and radiological follow‐up was 9.98 years ± 3.74 (range 60–243 months). At the follow‐up appointments, there were no clinical or radiological signs of sinusitis in any patient.ConclusionThis long‐term study, spreading over a period of up to 20 years, indicates that no sinus complication was observed following implant penetration into the maxillary sinus. Furthermore, absence of occurrence of such complications is related to the maintenance of successful osseointegration. A contrario, and in the presence of an acute or chronic maxillary sinusitis, the differential diagnosis must always consider other potential odontogenic and nonodontogenic etiologies.Level of Evidence2b. Laryngoscope, 123:2958–2961, 2013
Room Temperature Synthesis of Heptazine‐Based Microporous Polymer Networks as Photocatalysts for Hydrogen Evolution
Authors: Kailasam Kamalakannan , Schmidt Johannes , Bildirir Hakan , Zhang Guigang , Blechert Siegfried , Wang Xinchen , Thomas Arne 
Published: May 2013

AbstractTwo emerging material classes are combined in this work, namely polymeric carbon nitrides and microporous polymer networks. The former, polymeric carbon nitrides, are composed of amine‐bridged heptazine moieties and showed interesting performance as a metal‐free photocatalyst. These materials have, however, to be prepared at high temperatures, making control of their chemical structure difficult. The latter, microporous polymer networks have received increasing interest due to their high surface area, giving rise to interesting applications in gas storage or catalysis. Here, the central building block of carbon nitrides, a functionalized heptazine as monomer, and tecton are used to create microporous polymer networks. The resulting heptazine‐based microporous polymers show high porosity, while their chemical structure resembles the ones of carbon nitrides. The polymers show activity for the photocatalytic production of hydrogen from water, even under visible light illumination.magnified image