bluuebunny/crossref_metadata_2025 huggingface dataset:
Electromagnetic ion cyclotron waves in the Earth's magnetosphere with a kappa‐Maxwellian particle distribution
Authors: Sugiyama Hajime , Singh Satyavir , Omura Yoshiharu , Shoji Masafumi , Nunn David , Summers Danny
Published: August 2015

A theoretical model to study electromagnetic ion cyclotron (EMIC) waves in kappa‐Maxwellian plasma is developed. The plasma is assumed to have five components, i.e., electrons, cool and hot protons, and singly charged helium and oxygen ions. The kappa‐Maxwellian anisotropic particle distribution function is assumed for the hot protons. We use the Kyoto University Plasma Dispersion Analysis Package, a full dispersion solver developed at Kyoto University, to obtain the numerical results and delineate the oxygen, helium, and proton bands. Higher harmonics of the EMIC waves are also studied, and the effects of the kappa distribution on the growth of these waves are clearly demonstrated. Our results are applied to Cluster spacecraft observations of EMIC waves in the inner magnetosphere.
Prevalence of Severe Fatigue Among Adolescents With Pediatric Rheumatic Diseases
Authors: Nijhof Linde N. , van de Putte Elise M. , Wulffraat Nico M. , Nijhof Sanne L.
Published: August 2015

Objective

To determine the prevalence of severe fatigue and fatigue‐related limitations among adolescents with juvenile idiopathic arthritis (JIA) and other pediatric rheumatic diseases (PRDs). In addition, we assessed the effect of disease activity and pain on the severity of fatigue.

Methods

This cross‐sectional study included 175 patients (ages 10–18 years) who visited the pediatric rheumatology and immunology outpatient clinic at Wilhelmina Children's Hospital from April through July 2013. Patients completed validated questionnaires regarding fatigue, physical functioning, and school attendance. Disease activity in JIA patients was measured using the Juvenile Arthritis Disease Activity Score including 27 joints. The results were compared against a healthy control group.

Results

The prevalence of severe fatigue among patients with PRDs was 25.1%, which was significantly higher than among the healthy control group (P < 0.001). Fatigued patients had significantly lower levels of physical functioning compared to nonfatigued patients (62.1% versus 89.0%, respectively; P < 0.001) and a significantly higher percentage of school absences (21.2% versus 11.6%, respectively; P = 0.005). Among JIA patients, the level of pain was significantly correlated with fatigue. Finally, disease activity was not a predictor for fatigue.

Conclusion

Fatigue is a common problem among teenagers with PRDs, with a higher prevalence among these patients than in the general population. Severe fatigue leads to significant impairments, including increased school absences and decreased physical functioning. Interestingly, fatigue was associated with pain, but not with the disease activity. Therefore, in this patient population, fatigue may be a promising therapeutic target for improving functioning, school attendance, and possibly pain as well.
Alternative Methods for Defining Osteoarthritis and the Impact on Estimating Prevalence in a US Population‐Based Survey
Authors: Cisternas Miriam G. , Murphy Louise , Sacks Jeffrey J. , Solomon Daniel H. , Pasta David J. , Helmick Charles G.
Published: August 2015

Objective

Provide a contemporary estimate of osteoarthritis (OA) by comparing the accuracy and prevalence of alternative definitions of OA.

Methods

The Medical Expenditure Panel Survey (MEPS) household component (HC) records respondent‐reported medical conditions as open‐ended responses; professional coders translate these responses into International Classification of Diseases, Ninth Revision, Clinical Modification (ICD‐9‐CM) codes for the medical conditions files. Using these codes and other data from the MEPS‐HC medical conditions files, we constructed 3 case definitions of OA and assessed them against medical provider diagnoses of ICD‐9‐CM 715 (osteoarthrosis and allied disorders) in a MEPS subsample. The 3 definitions were 1) strict = ICD‐9‐CM 715; 2) expanded = ICD‐9‐CM 715, 716 (other and unspecified arthropathies) OR 719 (other and unspecified disorders of joint); and 3) probable = strict OR expanded + respondent‐reported prior diagnosis of OA or other arthritis excluding rheumatoid arthritis.

Results

Sensitivity and specificity of the 3 definitions, respectively, were 34.6% and 97.5% for strict, 73.8% and 90.5% for expanded, and 62.9% and 93.5% for probable.

Conclusion

The strict definition for OA (ICD‐9‐CM 715) excludes many individuals with OA. The probable definition of OA has the optimal combination of sensitivity and specificity relative to the 2 other MEPS‐based definitions and yields a national annual estimate of 30.8 million adults with OA (13.4% of US adult population) for 2008–2011.
Chemical nature of active sites for defect‐mediated nucleation on silicon dioxide
Authors: McCrate Joseph M. , Ekerdt John G.
Published: August 2015

Germanium nanoparticle growth on SiO2 proceeds via defect‐mediated nucleation and particle density can be enhanced by chemically treating the SiO2 with SiHx. The influence of SiHx fragments on SiO2 surface sites is studied using a fluorescent probe‐based technique to understand the chemical nature of the inherent defect trapping sites and the chemical nature of the additional trapping sites formed by SiHx. Oxygen‐vacancy sites on SiO2 are the inherent sites for defect‐mediated nucleation. SiHx fragments, generated by cracking disilane on a hot tungsten filament, are shown to react with strained siloxane sites, leading to a conversion of these strained siloxane sites into a different low density defect site that is shown to display reactive characteristics similar to the oxygen‐vacancy defect sites. Previous work demonstrating an increased density of Ge nuclei on SiO2 surfaces with increasing SiHx exposure is interpreted in the context of the current experimental results. © 2015 American Institute of Chemical Engineers AIChE J, 62: 367–372, 2016
Effect of channel size on liquid‐liquid plug flow in small channels
Authors: Tsaoulidis Dimitrios , Angeli Panagiota
Published: August 2015

The hydrodynamic properties of plug flow were investigated in small channels with 0.5‐, 1‐, and 2‐mm internal diameter, for an ionic liquid/aqueous two‐phase system with the aqueous phase forming the dispersed plugs. Bright field Particle Image Velocimetry combined with high‐speed imaging were used to obtain plug length, velocity, and film thickness, and to acquire velocity profiles within the plugs. Plug length decreased with mixture velocity, while for constant mixture velocity it increased with channel size. Plug velocity increased with increasing mixture velocity and channel size. The film thickness was predicted reasonably well for Ca > 0.08 by Taylor's (Taylor, J Fluid Mech. 1961;10(2):161–165) model. A fully developed laminar profile was established in the central region of the plugs. Circulation times in the plugs decreased with increasing channel size. Pressure drop was predicted reasonably well by a modified literature model, using a new correlation for the film thickness derived from experimental values. © 2015 American Institute of Chemical Engineers AIChE J, 62: 315–324, 2016
Recent Advances in the Development of Pharmacologically Active Compounds that Contain a Benzoxazole Scaffold
Authors: Singh Sarbjit , Veeraswamy Gajulapati , Bhattarai Deepak , Goo Ja‐Il , Lee Kyeong , Choi Yongseok
Published: August 2015

In recent years, the emergence of biologically active compounds that contain a heterocyclic ring has gained a great deal of attention among medicinal chemists. Among these, benzoxazole‐based compounds are particularly attractive because of their wide range of pharmacological activities. In this focus review, we highlight recent advancements in the development of benzoxazole‐based pharmacologically active compounds since the year 2000.
Hybride Volatolomik und der Nachweis von Krankheiten
Authors: Broza Yoav Y. , Mochalski Pawel , Ruzsanyi Vera , Amann Anton , Haick Hossam
Published: August 2015

Hier stellen wir einige der Hauptkonzepte und Ansätze der Volatolomik, einem sich rasch entwickelnden Gebiet der schnellen, risikofreien und wahrscheinlich preisgünstigen Diagnostik, vor. Wir versuchen, einen Überblick über die Herkunft und die Eigenschaften der Volatolomik anhand von flüchtigen organischen Verbindungen (“volatile organic compounds”, VOCs), die von Zellen und ihrer Mikroumgebung freigesetzt werden, zu geben. Wir beschreiben außerdem das Vorkommen von VOCs in verschiedenen Körperflüssigkeiten, darunter die zelluläre Umgebung, Blut, Atemluft, Haut, Faeces, Urin und Speichel. Schließlich diskutieren wir den Nutzen der Volatolomik für eine Diagnosestellung auf Basis einer einzelnen Körperflüssigkeit ebenso wie die Verbesserung der Diagnosesicherheit durch den “Hybrid”‐Ansatz, bei dem die VOC‐Profile von zwei oder mehr Körperflüssigkeiten erstellt und kombiniert werden. Die Perspektiven dieser Verfahrensweise zur Weiterentwicklung der Diagnostik werden aufgezeigt.
Spontaneous Reconstitution of Functional Transmembrane Proteins During Bioorthogonal Phospholipid Membrane Synthesis
Authors: Cole Christian M. , Brea Roberto J. , Kim Young Hun , Hardy Michael D. , Yang Jerry , Devaraj Neal K.
Published: August 2015

Transmembrane proteins are critical for signaling, transport, and metabolism, yet their reconstitution in synthetic membranes is often challenging. Non‐enzymatic and chemoselective methods to generate phospholipid membranes in situ would be powerful tools for the incorporation of membrane proteins. Herein, the spontaneous reconstitution of functional integral membrane proteins during the de novo synthesis of biomimetic phospholipid bilayers is described. The approach takes advantage of bioorthogonal coupling reactions to generate proteoliposomes from micelle‐solubilized proteins. This method was successfully used to reconstitute three different transmembrane proteins into synthetic membranes. This is the first example of the use of non‐enzymatic chemical synthesis of phospholipids to prepare proteoliposomes.
Ein Chitin‐MOF‐Kompositmaterial mit hierarchischem Porensystem für Anwendungen in der Luftfiltration
Authors: Wisser Dorothea , Wisser Florian M. , Raschke Silvia , Klein Nicole , Leistner Matthias , Grothe Julia , Brunner Eike , Kaskel Stefan
Published: August 2015

Metall‐organische Gerüste (MOFs) sind vielversprechende Materialien für die Gastrennung und Luftfiltration. Für diese Anwendungen müssen die MOF‐Kristalle jedoch in robuste und leicht zu handhabende Trägermaterialien eingebettet werden. Wir haben ein chitinbasiertes Netzwerk aus einem marinen Schwamm als ungiftiges, bioabbaubares und leichtes Trägermaterial für die Abscheidung eines MOF verwendet. Die Struktureigenschaften des Materials begünstigen die Kristallanbindung des MOF hauptsächlich im Inneren der hohlen Fasern. Das Kompositmaterial weist ein hierarchisches Porensystem mit einer inneren Oberfläche von 800 m2 g−1 und einem Porenvolumen von 3.6 cm3 g−1 auf. Dieses Porensystem ermöglicht eine gute Transportkinetik und eine sehr hohe Beladung mit dem aktiven Material. Ammoniak‐Durchbruchskurven zeigen zudem die Zugänglichkeit der MOF‐Kristalle und das Adsorptionspotenzial des Kompositmaterials, das vielversprechend für die Aufreinigung toxischer Industriegase ist.
An Indoxyl‐Based Strategy for the Synthesis of Indolines and Indolenines
Authors: Yu Yuanyuan , Li Guang , Jiang Long , Zu Liansuo
Published: August 2015

An indoxyl‐based strategy for the synthesis of indolines and indolenines via unprecedented aza‐pinacol and aza‐semipinacol rearrangements was developed. This method provides direct access to the core structures of several classes of indole alkaloids. The synthetic utility was demonstrated by the divergent synthesis of an array of functionalized polycyclic structures from a common intermediate and the formal total synthesis of the indoline natural product minfiensine. The reversed reactivity of indoxyl as a building block compared to that of indole offers a conceptually distinct disconnection strategy for indoline‐ and indolenine‐containing heterocycles and natural products.
A 2:1 Receptor/C60 Complex as a Nanosized Universal Joint
Authors: Yanney Michael , Fronczek Frank R. , Sygula Andrzej
Published: August 2015

Buckycatcher II, a C51H24 hydrocarbon with two corannulene pincers on a dibenzonorbornadiene tether, exhibits an affinity toward C60 in organic solvents that is dramatically higher than the original buckycatcher C60H28 and other corannulene‐based molecular receptors for fullerenes. In addition to the formation of an usual 1:1 C60@catcher inclusion complex, a trimeric C60@(catcher)2 assembly is detected in solutions and in the solid state. X‐ray structure determination reveals a remarkable “universal joint” solvent‐free crystal arrangement of the trimer, with a single fullerene cage wrapped by four corannulene subunits of two cooperating catcher receptors.
The Energetics of a Three‐State Protein Folding System Probed by High‐Pressure Relaxation Dispersion NMR Spectroscopy
Authors: Tugarinov Vitali , Libich David S. , Meyer Virginia , Roche Julien , Clore G. Marius
Published: August 2015

The energetic and volumetric properties of a three‐state protein folding system, comprising a metastable triple mutant of the Fyn SH3 domain, have been investigated using pressure‐dependent 15N‐relaxation dispersion NMR from 1 to 2500 bar. Changes in partial molar volumes (ΔV) and isothermal compressibilities (ΔκT) between all the states along the folding pathway have been determined to reasonable accuracy. The partial volume and isothermal compressibility of the folded state are 100 mL mol−1 and 40 μL mol−1 bar−1, respectively, higher than those of the unfolded ensemble. Of particular interest are the findings related to the energetic and volumetric properties of the on‐pathway folding intermediate. While the latter is energetically close to the unfolded state, its volumetric properties are similar to those of the folded protein. The compressibility of the intermediate is larger than that of the folded state reflecting the less rigid nature of the former relative to the latter.
Synthesis of Well‐Defined Bicapped Octahedral Iron Clusters [(trenL)2Fe8(PMe2Ph)2]n (n=0, −1)
Authors: Sánchez Raúl Hernández , Willis Alexander M. , Zheng Shao‐Liang , Betley Theodore A.
Published: August 2015

The synthesis of polynuclear clusters with control over size and cluster geometry remains an unsolved challenge. Herein, we report the synthesis and characterization of open‐shell octairon clusters supported by two heptaamine ligands [o‐H2NC6H4NH(CH2)2]3N (trenLH9). The crystal structure of the all‐ferrous species ([trenL)2Fe8(PMe2Ph)2] (1) displays a bicapped octahedral geometry with FeFe distances ranging from 2.4071(6) to 2.8236(5) Å, where the ligand amine units are formally in amine, amide, and imide oxidation states. Several redox states of the octairon cluster are accessible, as ascertained using cyclic voltammetry. The one‐electron‐reduced clusters [M]+[(trenL)2Fe8(PMe2Ph)2]− (M=Bu4N (2 a); (15‐crown‐5)Na(thf) (2 b)) were isolated and characterized. Variable‐temperature magnetic susceptibility data indicates that the exchange coupling within the [Fe8] core is antiferromagnetic which is attenuated upon reduction to the mixed valent anion.
Synthesis of Silicate Zeolite Analogues Using Organic Sulfonium Compounds as Structure‐Directing Agents
Authors: Jo Changbum , Lee Sungjune , Cho Sung June , Ryoo Ryong
Published: August 2015

A microporous crystalline silica zeolite of the MEL structure type and three other zeolite analogues composed of germanosilicate frameworks were synthesized using tributylsulfonium, triphenylsulfonium, or tri(para‐tolyl)sulfonium as the structure‐directing agent. The germanosilicates thus obtained had ISV, ITT, or a new zeolite structure depending on the synthesis conditions. The structure of the new germanosilicate was solved using X‐ray powder diffraction data with the aid of a charge‐flipping method. The solution indicated a crystal structure belonging to the P63/mmc space group with cell parameters of a=16.2003 Å and c=21.8579 Å. After calcination, the new germanosilicate material exhibited two types of accessible micropores with diameters of 0.61 and 0.78 nm.
Time‐Resolved Crystallography of the Reaction Intermediate of Nitrile Hydratase: Revealing a Role for the Cysteinesulfenic Acid Ligand as a Catalytic Nucleophile
Authors: Yamanaka Yasuaki , Kato Yuki , Hashimoto Koichi , Iida Keisuke , Nagasawa Kazuo , Nakayama Hiroshi , Dohmae Naoshi , Noguchi Keiichi , Noguchi Takumi , Yohda Masafumi , Odaka Masafumi
Published: August 2015

The reaction mechanism of nitrile hydratase (NHase) was investigated using time‐resolved crystallography of the mutant NHase, in which βArg56, strictly conserved and hydrogen bonded to the two post‐translationally oxidized cysteine ligands, was replaced by lysine, and pivalonitrile was the substrate. The crystal structures of the reaction intermediates were determined at high resolution (1.2–1.3 Å). In combination with FTIR analyses of NHase following hydration in H218O, we propose that the metal‐coordinated substrate is nucleophilically attacked by the O(SO−) atom of αCys114‐SO−, followed by nucleophilic attack of the S(SO−) atom by a βArg56‐activated water molecule to release the product amide and regenerate αCys114‐SO−.
An Inexpensive and Recyclable Silver‐Foil Catalyst for the Cyclopropanation of Alkenes with Diazoacetates under Mechanochemical Conditions
Authors: Chen Longrui , Bovee Mark O. , Lemma Betsegaw E. , Keithley Kimberlee S. M. , Pilson Sara L. , Coleman Michael G. , Mack James
Published: August 2015

The diastereoselective cyclopropanation of various alkenes with diazoacetate derivatives can be achieved under mechanochemical conditions using metallic silver foil and a stainless‐steel vial and ball system. This solvent‐free method displays analogous reactivity and selectivity to solution‐phase reactions without the need for slow diazoacetate addition or an inert atmosphere. The heterogeneous silver‐foil catalyst system is easily recyclable without any appreciable loss of activity or selectivity being observed. The cyclopropanation products were obtained with excellent diastereoselectivities (up to 98:2 d.r.) and in high yields (up to 96 %).
Chiral Polymers of Intrinsic Microporosity: Selective Membrane Permeation of Enantiomers
Authors: Weng Xilun , Baez José E. , Khiterer Mariya , Hoe Madelene Y. , Bao Zongbi , Shea Kenneth J.
Published: August 2015

Following its resolution by diastereomeric complexation, 5,5′,6,6′‐tetrahydroxy‐3,3,3′,3′‐tetramethyl‐1,1′‐spirobisindane (TTSBI) was used to synthesize a chiral ladder polymer, (+)‐PIM‐CN. (+)‐PIM‐COOH was also synthesized by the acid hydrolysis of (+)‐PIM‐CN. Following characterization, both (+)‐PIM‐CN and (+)‐PIM‐COOH were solvent cast directly into semipermeable membranes and evaluated for their ability to enable the selective permeation of a range of racemates, including mandelic acid (Man), Fmoc‐phenylalanine, 1,1′‐bi‐2‐naphthol (binol), and TTSBI. High ee values were observed for a number of analytes, and both materials exhibited high permeation rates. A selective diffusion–permeation mechanism was consistent with the results obtained with these materials. Their high permeability, processability, and ease of chemical modification offer considerable potential for liquid‐phase membrane separations and related separation applications.
A Metal‐Free Synthesis of N‐Aryl Carbamates under Ambient Conditions
Authors: Guo Wusheng , Gónzalez‐Fabra Joan , Bandeira Nuno A. G. , Bo Carles , Kleij Arjan W.
Published: August 2015

The first chemo‐ and site‐selective process for the formation of N‐aryl‐carbamates from cyclic organic carbonates and aromatic amines is reported. The reactions proceed smoothly under extremely mild reaction conditions using TBD (triazabicyclodecene) as an effective and cheap organocatalyst, thus providing a sustainable and new methodology for the formation of a wide variety of useful N‐aryl carbamate synthons in good to excellent yields. Computational investigations have been performed and show the underlying reason for the observed unique reactivity as related to an effective proton‐relay mechanism mediated by the bicyclic guanidine base.
Chlorine‐Free Red‐Burning Pyrotechnics
Authors: Sabatini Jesse J. , Koch Ernst‐Christian , Poret Jay C. , Moretti Jared D. , Harbol Seth M.
Published: August 2015

The development of a red, chlorine‐free pyrotechnic illuminant of high luminosity and spectral purity was investigated. Red‐light emission based solely on transient SrOH(g) has been achieved by using either 5‐amino‐1H‐tetrazole or hexamine to deoxidize the combustion flame of a Mg/Sr(NO3)2/Epon‐binder composition and reduce the amount of both condensed and gaseous SrO, which emits undesirable orange‐red light. The new formulations were found to possess high thermal onset temperatures. Avoiding chlorine in these formulations eliminates the risk of the formation of PCBs, PCDDs, and PCDFs. This finding, hence, will have a great impact on both military pyrotechnics and commercial firework sectors.
Promotion of Inflammatory Arthritis by Interferon Regulatory Factor 5 in a Mouse Model
Authors: Duffau Pierre , Menn‐Josephy Hanni , Cuda Carla M. , Dominguez Salina , Aprahamian Tamar R. , Watkins Amanda A. , Yasuda Kei , Monach Paul , Lafyatis Robert , Rice Lisa M. , Kenneth Haines G. , Gravallese Ellen M. , Baum Rebecca , Richez Christophe , Perlman Harris , Bonegio Ramon G. , Rifkin Ian R.
Published: August 2015

Objective

Polymorphisms in the transcription factor interferon regulatory factor 5 (IRF5) are associated with an increased risk of developing rheumatoid arthritis (RA). This study was undertaken to determine the role of IRF5 in a mouse model of arthritis development.

Methods

K/BxN serum–transfer arthritis was induced in mice deficient in IRF5, or lacking IRF5 only in myeloid cells, and arthritis severity was evaluated. K/BxN arthritis was also induced in mice deficient in TRIF, Toll‐like receptor 2 (TLR2), TLR3, TLR4, and TLR7 to determine the pathways through which IRF5 might promote arthritis. In vitro studies were performed to determine the role of IRF5 in interleukin‐1 (IL‐1) receptor and TLR signaling.

Results

Arthritis severity was reduced in IRF5‐deficient, TRIF‐deficient, TLR3‐deficient, and TLR7‐deficient mice. The expression of multiple genes regulating neutrophil recruitment or function and bioactive IL‐1β formation was reduced in the joints during active arthritis in IRF5‐deficient mice. In vitro studies showed that TLR7 and the TRIF‐dependent TLR3 pathway induce proinflammatory cytokine production in disease‐relevant cell types in an IRF5‐dependent manner.

Conclusion

Our findings indicate that IRF5 contributes to disease pathogenesis in inflammatory arthritis. This is likely due at least in part to the role of IRF5 in mediating proinflammatory cytokine production downstream of TLR7 and TLR3. Since TLR7 and TLR3 are both RNA‐sensing TLRs, this suggests that endogenous RNA ligands present in the inflamed joint promote arthritis development. These findings may be relevant to human RA, since RNA capable of activating TLR7 and TLR3 is present in synovial fluid and TLR7 and TLR3 are up‐regulated in the joints of RA patients.
Juvenile Idiopathic Arthritis in Olmsted County, Minnesota, 1960–2013
Authors: Krause Megan L. , Crowson Cynthia S. , Michet C. John , Mason Thomas , Muskardin Theresa Wampler , Matteson Eric L.
Published: August 2015

Objective

To evaluate the incidence and prevalence of juvenile idiopathic arthritis (JIA) in Olmsted County, Minnesota in 1994–2013 and trends in juvenile rheumatoid arthritis (JRA) in 1960–2013.

Methods

Cases of arthritis in 1994–2013 were identified by diagnosis code with medical chart review to confirm diagnosis separately for JIA and JRA. Overall incidence rates with 95% confidence intervals (95% CIs) were age and sex adjusted to the 2010 US white population. Comparisons were made with an earlier (1960–1993) cohort from this same population.

Results

Seventy‐one incident cases of JIA in 1994–2013 were identified, with an overall age‐ and sex‐adjusted incidence rate of 10.3 per 100,000 (95% CI 7.9–12.7). Forty‐two (59%) were female, with an incidence of 12.4 per 100,000 (95% CI 8.6–16.2), as compared to 8.3 per 100,000 (95% CI 5.2–11.3) in males. The most common subtype was oligoarthritis (63%). The mean ± SD age at diagnosis was 8.2 ± 5.3 years. The prevalence of JIA on January 1, 2000 and January 1, 2010 was 51.0 per 100,000 (95% CI 25.2–76.8) and 57.6 per 100,000 (95% CI 31.0–94.5), respectively. When the annual incidence of JRA was compared over time from 1960 to 2013, there was no significant change in incidence overall; however, the incidence decreased among females (P = 0.003). A cyclic pattern of incidence was observed, with peaks approximately every 10 years. Similar to the findings with regard to incidence, prevalence did not change overall, but decreased among females (P = 0.048). There were 4 deaths in the cohort of JRA patients diagnosed in 1960–2013; the standardized mortality ratio was 1.50 (95% CI 0.41–3.83).

Conclusion

Incidence of juvenile arthritis overall in Olmsted County, Minnesota has not changed significantly in the past 53 years. A consistent cyclic pattern was noted.
Association of Polymorphisms of Cytochrome P450 2D6 With Blood Hydroxychloroquine Levels in Patients With Systemic Lupus Erythematosus
Authors: Lee Ji Yeon , Vinayagamoorthy Nadimuthu , Han Kyungdo , Kwok Seung Ki , Ju Ji Hyeon , Park Kyung Su , Jung Seung‐Hyun , Park Sung‐Won , Chung Yeun‐Jun , Park Sung‐Hwan
Published: August 2015

Objective

To evaluate associations of genetic polymorphisms in cytochrome P450 (CYP) isoforms 2D6, 3A5, and 3A4 with blood concentrations of hydroxychloroquine (HCQ) and its metabolite, N‐desethyl HCQ (DHCQ), in patients with systemic lupus erythematosus (SLE).

Methods

SLE patients taking HCQ for >3 months were recruited and were genotyped for 4 single‐nucleotide polymorphisms in CYP2D6*10, CYP3A5*3, and CYP3A4*18B. Blood HCQ and DHCQ concentrations ([HCQ] and [DHCQ]) were measured and their association with corresponding genotypes was investigated.

Results

A total of 194 patients were included in the analysis. CYP2D6*10 polymorphisms (rs1065852 and rs1135840) were significantly associated with the [DHCQ]:[HCQ] ratio after adjustment for age, sex, dose per weight per day, and SLE Disease Activity Index score (P = 0.03 and P < 0.01, respectively). In adjusted models, the [DHCQ]:[HCQ] ratio was highest in patients with the G/G genotype of the CYP2D6*10 (rs1065852) polymorphism and lowest in those with the A/A genotype (P = 0.03). Similarly, the [DHCQ]:[HCQ] ratio was highest in patients with the C/C genotype of the CYP2D6*10 (rs1135840) polymorphism and lowest in those with the G/G genotype (P < 0.01). The CYP2D6*10 (rs1065852) polymorphism was significantly related to the [DHCQ] (P = 0.01). However, the polymorphisms of CYP3A5*3 and CYP3A4*18B did not show any significant association with the [HCQ], [DHCQ], or [DHCQ]:[HCQ] ratio.

Conclusion

Our study showed that the [DHCQ]:[HCQ] ratio was related to CYP2D6 polymorphisms in Korean lupus patients taking oral HCQ. CYP polymorphisms may explain why there is wide variation in blood HCQ concentrations. The role of an individual's CYP polymorphisms should be considered when prescribing oral HCQ.
Synthesis of Uniform, Monodisperse, Sophorolipid Twisted Ribbons
Authors: Cuvier Anne‐Sophie , Babonneau Florence , Berton Jan , Stevens Christian V. , Fadda Giulia C. , Genois Isabelle , Le Griel Patrick , Péhau‐Arnaudet Gérard , Baccile Niki
Published: August 2015

Control over size monodispersity in chiral self‐assembled systems is important for potential applications like templating, tissue engineering or enantioselective chromatography, just to cite a few examples. In this context, it was reported that the saturated form of sophorolipids (SL), a bioderived glycolipid, are able to form self‐assembled twisted ribbons in water at neutral pH. Here, we show the possibility to control their size dispersion, generally between 10 and 40 nm after synthesis to a value of 13.5±1.5 nm, by a simple dialysis step eliminating the excess of NaCl. We use transmission electron microscopy under cryogenic conditions (cryo‐TEM) combined with small angle neutron scattering (SANS) to characterize the ribbon dispersion both visually and statistically. Two negative controls show the importance of salt in the aggregation process of the ribbons.
A Cyclodextrin‐Based Photoresponsive Molecular Gate that Functions Independently of Either Solvent or Potentially Competitive Guests
Authors: Loh Ka‐Heng , Smith Nicole M. , Onagi Hideki , Lincoln Stephen F. , Easton Christopher J.
Published: August 2015

The photoinduced interconversion between cinnamido‐substituted cyclodextrins constitutes a gating switch through which the substituent moves to open or block access to the cyclodextrin cavity. Most unusually for a cyclodextrin‐based device, the operation of this gate is solvent‐independent and unaffected by potentially competitive guests. It occurs in MeOH and DMSO, as well as in water. This contrasts with other cyclodextrin inclusion phenomena that are usually driven by hydrophobic effects and limited to aqueous media.
Quantitative analysis of histone H3 and H4 post‐translational modifications in doxorubicin‐resistant leukemia cells
Authors: Liu Tao , Guo Qingcheng , Guo Huaizu , Hou Sheng , Li Jing , Wang Hao
Published: August 2015

The epigenetic remodeling of chromatin through histone modifications has been widely implicated in drug resistance of cancer cells. However, whether epigenetic mechanisms contribute specifically to doxorubicin resistance in leukemia has not been carefully examined. Using a stable and sensitive workflow based on LC‐MS, we quantitatively compared the extents of methylation and acetylation of histone H3 and H4 in acute leukemia cell line HL60 and its doxorubicin‐resistant derivative, HL60/ADR, as well as the chronic leukemia cell line K562 and its doxorubicin‐resistant derivative, K562/ADR. We found that increased levels of H3K9 methylation, H3K14, H3K18 and H3K23 acetylation, and potentially H4K20 methylation, are associated with drug resistance in both cells. Our results demonstrated that the doxorubicin‐resistant acute and chronic leukemia cell lines may share a common epigenetic mechanism that involves a combination of transcriptional activation and silencing. Copyright © 2015 John Wiley & Sons, Ltd.
Use of random forest in FTIR analysis of LDL cholesterol and tri‐glycerides for hyperlipidemia
Authors: Chen Hua‐Zhou , Tang Guo‐Qiang , Ai Wu , Xu Li‐Li , Cai Ken
Published: August 2015

A quantitative determination method for the diagnosis of hyperlipidemia was developed using Fourier transform infrared (FTIR) spectroscopy. Random forest (RF) was demonstrated as a potential multivariate algorithm for the FTIR analysis of low‐density lipoprotein cholesterol (LDL‐C) and tri‐glycerides (TG) in human serum samples. The informative wavebands for LDL‐C and TG were selected based on the Gini importance. The selected wavebands were mainly within the fingerprint region. The RF modeling results were better than those derived using PLS in validation process, because the chance for over‐fitting was possibly eliminated in RF algorithm. ARF also demonstrated favorable results in the test process. The prospective model exhibited a higher than 90% true prediction in negative/positive properties for male and female samples. These clinical statistical results indicated the optimization of RF algorithm performed accurately in the FTIR determination of LDL‐C and TG. RF is evaluated as a promising tool for diagnosing and controlling hyperlipidemia in populations. The parameter optimization methodology is useful in the improving model accuracy using FTIR spectroscopic technology. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1693–1702, 2015
Protein Synthesis in Sub‐Micrometer Water‐in‐Oil Droplets
Authors: Gallo Valentina , Stano Pasquale , Luisi Pier Luigi
Published: August 2015

Water‐in‐oil (w/o) emulsions are used as a cellular model because of their unique cell‐like architecture. Previous works showed the capability of eukaryotic‐cell‐sized w/o droplets (5–50 μm) to support protein synthesis efficiently; however data about smaller w/o compartments (<1 μm) are lacking. This work focuses on the biosynthesis of the enhanced green fluorescent protein (EGFP) inside sub‐micrometric lecithin‐based w/o droplets (0.8–1 μm) and on its dependence on the compartments’ dynamic properties in terms of solute exchange mechanisms. We demonstrated that protein synthesis is strongly affected by the nature of the lipid interface. These findings could be of value and interest for both basic and applied research.
A Mild and Chemoselective Reduction of Nitro and Azo Compounds Catalyzed by a Well‐Defined Mo3S4 Cluster Bearing Diamine Ligands
Authors: Pedrajas Elena , Sorribes Iván , Junge Kathrin , Beller Matthias , Llusar Rosa
Published: August 2015

Herein, we report a novel well‐defined diamino Mo3S4‐based catalyst system for the reduction of nitroarenes and azo compounds to the corresponding anilines with silanes as reducing agents. This catalytic protocol provides a facile route to access aromatic amines under mild conditions in good to excellent yields. Notably, even anilines functionalized with other potentially reducible moieties are obtained with high selectivity. The new chemoselective catalyst of formula [Mo3S4Cl3(dmen)3](BF4) (dmen: N,N′‐dimethylethylenediamine) is conveniently synthesized through coordination of the diamine ligand to the incomplete Mo3S4 cubane‐type cluster core in a one‐pot two‐step procedure. The crystal structure of the [Mo3S4Cl3(dmen)3]+ cation confirms the formation of a single isomer in which the chlorine atom lies trans to the bridging sulfur atom to afford a C3 symmetry complex with intrinsic backbone chirality. The structure is preserved in solution, as evidenced by multinuclear NMR spectroscopy and electrospray‐ionization mass spectrometric techniques.
Structural Engineering of Electrocatalysts for the Hydrogen Evolution Reaction: Order or Disorder?
Authors: Xie Junfeng , Xie Yi
Published: August 2015

Electrocatalytic hydrogen evolution has been regarded as a promising strategy to realize efficient hydrogen production to face the energy crisis in the future. Hence, the design of hydrogen‐evolving catalysts with high activity and low cost is imperative. In this Minireview article, state‐of‐the‐art electrocatalysts for the hydrogen evolution reaction (HER) are overviewed, and the strategies for constructing ordered and disordered HER electrocatalysts are summarized in detail. By means of facet engineering, nanoscale, polymorph engineering accompanied by interface engineering, HER catalysts with an ordered structure could be optimized. For designing disordered catalysts, defect engineering, amorphization, elemental doping, and surface modification, as well as constructingan alloyed structure, could be effective to realize the beneficial modulation of active sites and electronic structure. This Minireview provides a structural perspective for the design of efficient HER electrocatalysts in the future.
Cascade Coupling of Ene‐Reductases and ω‐Transaminases for the Stereoselective Synthesis of Diastereomerically Enriched Amines
Authors: Monti Daniela , Forchin Maria Chiara , Crotti Michele , Parmeggiani Fabio , Gatti Francesco G. , Brenna Elisabetta , Riva Sergio
Published: August 2015

One‐pot sequential and cascade processes performed by employing ene‐reductases (ERs) together with ω‐transaminases (ω‐TAs) for the obtainment of diastereomerically enriched (R)‐ and (S)‐amine derivatives containing an additional stereocenter were investigated. By using either α‐ or β‐substituted unsaturated ketones as substrates and by coupling purified ERs belonging to the Old Yellow Enzyme (OYE) family with a panel of commercially available ω‐TAs, the desired products were obtained in up to >99 % conversion and >99 % de. The sequential reactions were performed in a one‐pot fashion with no need to adapt the reaction conditions to the reductive amination step or to purify the reaction intermediate. Moreover, high chemoselectivity of the tested ω‐TAs for the saturated ketones was shown in the cascade reactions.
Azido‐Substituted BODIPY Dyes for the Production of Fluorescent Carbon Nanotubes
Authors: Fedeli Stefano , Paoli Paolo , Brandi Alberto , Venturini Lorenzo , Giambastiani Giuliano , Tuci Giulia , Cicchi Stefano
Published: August 2015

A series of azido‐dyes were synthesized through Knoevenagel reactions of an azido‐BODIPY with aromatic aldehydes. The nature of the substituents allowed the fine tuning of their spectroscopic properties. The dyes were used to decorate oxidized multiwalled carbon nanotubes (ox‐MWCNTs), bearing terminal triple bond groups, by CuAAC reactions, affording fluorescent materials. This decoration allowed the efficient determination of the internalization of the ox‐MWCNT derivatives by different model cancer cells, such as MCF7.
Factors Controlling β‐Elimination Reactions in Group 10 Metal Complexes
Authors: Sosa Carrizo E. Daiann , Bickelhaupt F. Matthias , Fernández Israel
Published: August 2015

Trends in reactivity of β‐chloride and β‐hydride elimination reactions involving Group 10 transition‐metal complexes have been computationally explored and analyzed in detail by DFT. These reactions do not require the initial formation of a vacant coordination site; they proceed concertedly without a prior ligand‐dissociation step. Whereas β‐chloride elimination is associated with relatively moderate activation barriers, the high barriers calculated for analogous β‐hydride eliminations suggest that the latter process is unfeasible for this type of compounds. This differential behavior is analyzed within the activation strain model, which provides quantitative insight into the physical factors controlling these β‐elimination reactions. The effects of the nature of the Group 10 transition metal (Ni, Pd, Pt), as well as the substituents attached to the β‐eliminating fragment (R2CCR2X; R, X=H, Cl) on the transformation have also been considered and are rationalized herein.
Multiple Multidentate Halogen Bonding in Solution, in the Solid State, and in the (Calculated) Gas Phase
Authors: Jungbauer Stefan H. , Schindler Severin , Herdtweck Eberhardt , Keller Sandro , Huber Stefan M.
Published: August 2015

The binding properties of neutral halogen‐bond donors (XB donors) bearing two multidentate Lewis acidic motifs toward halides were investigated. Employing polyfluorinated and polyiodinated terphenyl and quaterphenyl derivatives as anion receptors, we obtained X‐ray crystallographic data of the adducts of three structurally related XB donors with tetraalkylammonium chloride, bromide, and iodide. The stability of these XB complexes in solution was determined by isothermal titration calorimetry (ITC), and the results were compared to X‐ray analyses as well as to calculated binding patterns in the gas phase. Density functional theory (DFT) calculations on the gas‐phase complexes indicated that the experimentally observed distortion of the XB donors during multiple multidentate binding can be reproduced in 1:1 complexes with halides, whereas adducts with two halides show a symmetric binding pattern in the gas phase that is markedly different from the solid state structures. Overall, this study demonstrates the limitations in the transferability of binding data between solid state, solution, and gas phase in the study of complex multidentate XB donors.
Intramolecular Acylal Cyclisation (IAC) as an Efficient Synthetic Strategy towards the Total Synthesis of Erythrina Alkaloid Derivatives
Authors: Monaco Alessandra , Aliev Abil E. , Hilton Stephen T.
Published: August 2015

Compounds that comprise the erythrina alkaloid class of natural products are based on a tetracyclic spiroamine framework and exhibit a range of biological activities on the central nervous system. Herein, we report a new and efficient total synthesis of this multiple‐ring system based on an intramolecular acylal cyclisation (IAC) approach. Using this methodology, the tetracyclic core was rapidly assembled over a two‐step domino process catalysed by a Lewis acid. The effect of heteroatoms, substituents and ring size on the IAC has also been investigated, and the broad application of this procedure is demonstrated by the synthesis of a library of derivatives in good yields with excellent regioselectivity.
Spontaneous Dimerization of Allenes in Situ: An Efficient Synthesis of Substituted 1,2‐Dimethylenecyclobutanes with High Regio‐ and Stereoselectivities
Authors: Miao Maozhong , Wang Wenmin , Yang Weijun , Xu Lijun , Ma Jing , Ren Hongjun
Published: August 2015

An intermolecular [2+2] cycloaddition reaction for the synthesis of 1,2‐dimethylenecyclobutane derivatives from the commercially available starting materials aryl acetylenes, nBuLi, formamides, and trimethylsilyl cyanide (TMSCN) has been achieved. This reaction displays high regio‐ and stereoselectivities due to the captodative effect. The mechanism of the reaction has been investigated by the deuterium labeling experiments and DFT calculations.
Palladium‐Catalyzed Oxidative Cycloisomerization of 2‐Cinnamyl‐1,3‐Dicarbonyls: Synthesis of Functionalized 2‐Benzyl Furans
Authors: Nallagonda Rajender , Reddy Reddy Rajasekhar , Ghorai Prasanta
Published: August 2015

A new palladium‐catalyzed intramolecular oxidative cycloisomerization of readily available starting materials, 2‐cinnamyl‐1,3‐dicarbonyls, has been demonstrated for the creation of structurally diverse 2‐benzyl furans. The cycloisomerization occurs by a regioselective 5‐exo‐trig pathway. The reaction shows a broad substrate scope with good to excellent yields. Furthermore, a one‐pot procedure has been executed by using readily available cinnamyl alcohols and 1,3‐diketones.
Thermal‐Enzymatic Hydrolysis of Wheat Straw in a Single High Pressure Fixed Bed
Authors: Reynolds Wienke , Kirsch Christian , Smirnova Irina
Published: August 2015

An integrated flow‐through fixed‐bed reactor concept for lignocellulose separation at 3 L scale is presented. Wheat straw is degraded using sequential liquid hot water treatment and enzymatic hydrolysis in a single‐pot reactor setup. System responses on process parameters are modeled and optimized using response surface methodology. Accurate empiric models and significant factor influences could be identified for both treatment steps. With optimal factor settings, 23.9 and 49.2 wt % hot‐water‐soluble lignin and C5 oligomers could be recovered, respectively. 70.0 wt % cellulose solubilization could be achieved in the fixed‐bed enzymatic hydrolysis after 72 hours.
Partikelform und Porosität von biogenen Pyrolysekoksen
Authors: Nicoleit Thomas , Haßel Arndt , Niebel Andreas , Sauer Jörg
Published: August 2015

Kokspartikel aus pyrolysierter Biomasse variieren stark in Partikelgröße und ‐form. Die durchschnittliche Länglichkeit der Partikel nimmt mit der Größe signifikant zu. In Abhängigkeit der Partikelgröße ist die durchschnittliche Länglichkeit für die untersuchten Proben unabhängig von Ausgangsstoff und Pyrolyseverfahren. Mit klassischen kugelbasierten Größenverteilungen werden die Partikel nur ungenau beschrieben. Unter Berücksichtigung der Partikelform lassen sich die Kokse mittels Partikelgrößenverteilungen beschreiben, die auf einem Ellipsoidmodell basieren. Die hohe Schüttgutporosität ist im Wesentlichen auf die interpartikulären Zwischenräume zurückzuführen.
Synthesis of Hydroxyapatite Nanorods under Mild Conditions and Their Drug Release Properties
Authors: Kong Deyan , Xiao Xinli , Qiu Xueying , Zhang Wenbo , Yang Yulin
Published: August 2015

Hydroxyapatite (HAp) nanorods possess vast potential applications in various fields, and here HAp nanorods with high aspect ratio were synthesized via a convenient two‐stage precipitation‐hydrolysis process at 60°C under atmospheric pressure. The precursor of CaHPO4 at precipitation stage is well crystallized as nubby morphology with CTAB as surfactant, while CaHPO4 was dissolved and CTA+ stabilized the HAp nuclei during the hydrolysis stage. OH− ions were absorbed onto the active crystal surface, where Ca2+ and PO43+ reacted with OH− to make the nuclei grow into larger crystals, and highly crystalline HAp nanorods were obtained by Ostwald ripening. The loaded drug of IBU on the HAp crystals can be 100% released in 24 h. PVP modified HAp nanorods can increase the drug‐loading capacity and release drug faster than pure HAp nanorods. The results indicate that HAp nanorods modified with suitable surfactants are of great use in drug delivery system.
Radon Concentrations in Schools and Kindergartens in Kragujevac City, Central Serbia
Authors: Stajic Jelena M. , Milenkovic Biljana , Nikezic Dragoslav
Published: August 2015

Measurements of radon activity concentrations have been conducted in public kindergartens, primary, and secondary schools in Kragujevac City. This study represents the first step towards radon mapping of Central Serbia. Passive discriminative radon/thoron detectors (so called UFO) were used for monitoring. The radon calibration coefficient of 0.026 (track/cm2)/(Bq m−3 day) was calculated by exposing the UFO detectors in a Rn chamber monitored by a RAD7 device. The Rn concentration was in the range of 27–145 Bq m−3 in kindergartens and 25–86 Bq m−3 in schools. The value of the arithmetic mean was 59.6 Bq m−3 and the standard deviation was 25.6 Bq m−3. The distribution of the results was well fitted by log‐normal function. No significant correlation between measured activity concentrations and periods of building constructions was found.
Dynein‐deficient flagella respond to increased viscosity with contrasting changes in power and recovery strokes
Authors: Wilson Kate S. , Gonzalez Olivia , Dutcher Susan K. , Bayly Philip V.
Published: August 2015

Changes in the flagellar waveform in response to increased viscosity were investigated in uniflagellate mutants of Chlamydomonas reinhardtii. We hypothesized that the waveforms of mutants lacking different dynein arms would change in different ways as viscosity was increased, and that these variations would illuminate the feedback pathways from force to dynein activity. Previous studies have investigated the effects of viscosity on cell body motion, propulsive force, and power in different mutants, but the effect on waveform has not yet been fully characterized. Beat frequency decreases with viscosity in wild‐type uniflagellate (uni1) cells, and outer dynein arm deficient (oda2) mutants. In contrast, the inner dynein arm mutant ida1 (lacking I1/f) maintains beat frequency at high viscosity but alters its flagellar waveform more than either wild‐type or oda2. The ida1 waveform is narrower than wild‐type, primarily due to an abbreviated recovery stroke; this difference is amplified at high viscosity. The oda2 mutant in contrast, maintains a consistent waveform at high and low viscosity with a slightly longer power stroke than wild‐type. Analysis of the delays and shear displacements between bends suggest that direct force feedback in the outer dynein arm system may initiate switching of dynein activity. In contrast, I1/f dynein appears to delay switching, most markedly at the initiation of the power stroke, possibly by controlling inter‐doublet separation. © 2015 Wiley Periodicals, Inc.
Well‐Posed Treatment of Space‐Charge Layers in the Electroneutral Limit of Electrodiffusion
Authors: Stinchcombe Adam R. , Mori Yoichiro , Peskin Charles S.
Published: August 2015

The electroneutral model describes cellular electrical activity, accounting for ionic concentration dynamics without resolution of the fine spatial scales of the space‐charge layer. This is done by asserting that the ionic solution is electrically neutral at each point in space. However, electroneutrality is inconsistent with the original boundary conditions at cell membranes. We consider three separate methods of resolving this inconsistency that result in well‐posed models that are accurate approximations to a detailed model in which the space‐charge layer is fully resolved. A particular electrodiffusion problem is utilized to make the discussion specific.© 2015 Wiley Periodicals, Inc.