bluuebunny/crossref_metadata_2025 huggingface dataset:
Extremely low‐frequency magnetic fields and risk of childhood leukemia: A risk assessment by the ARIMMORA consortium
Authors: Schüz Joachim , Dasenbrock Clemens , Ravazzani Paolo , Röösli Martin , Schär Primo , Bounds Patricia L. , Erdmann Friederike , Borkhardt Arndt , Cobaleda César , Fedrowitz Maren , Hamnerius Yngve , Sanchez‐Garcia Isidro , Seger Rony , Schmiegelow Kjeld , Ziegelberger Gunde , Capstick Myles , Manser Melissa , Müller Meike , Schmid Christoph D. , Schürmann David , Struchen Benjamin , Kuster Niels
Published: March 2016

Exposure to extremely low‐frequency magnetic fields (ELF‐MF) was evaluated in an International Agency for Research on Cancer (IARC) Monographs as “possibly carcinogenic to humans” in 2001, based on increased childhood leukemia risk observed in epidemiological studies. We conducted a hazard assessment using available scientific evidence published before March 2015, with inclusion of new research findings from the Advanced Research on Interaction Mechanisms of electroMagnetic exposures with Organisms for Risk Assessment (ARIMMORA) project. The IARC Monograph evaluation scheme was applied to hazard identification. In ARIMMORA for the first time, a transgenic mouse model was used to mimic the most common childhood leukemia: new pathogenic mechanisms were indicated, but more data are needed to draw definitive conclusions. Although experiments in different animal strains showed exposure‐related decreases of CD8+ T‐cells, a role in carcinogenesis must be further established. No direct damage of DNA by exposure was observed. Overall in the literature, there is limited evidence of carcinogenicity in humans and inadequate evidence of carcinogenicity in experimental animals, with only weak supporting evidence from mechanistic studies. New exposure data from ARIMMORA confirmed that if the association is nevertheless causal, up to 2% of childhood leukemias in Europe, as previously estimated, may be attributable to ELF‐MF. In summary, ARIMMORA concludes that the relationship between ELF‐MF and childhood leukemia remains consistent with possible carcinogenicity in humans. While this scientific uncertainty is dissatisfactory for science and public health, new mechanistic insight from ARIMMORA experiments points to future research that could provide a step‐change in future assessments. Bioelectromagnetics. 37:183–189, 2016. © 2016 Wiley Periodicals, Inc.
Histone chaperones FACT and Spt6 prevent histone variants from turning into histone deviants
Authors: Jeronimo Célia , Robert François
Published: March 2016

Histone variants are specialized histones which replace their canonical counterparts in specific nucleosomes. Together with histone post‐translational modifications and DNA methylation, they contribute to the epigenome. Histone variants are incorporated at specific locations by the concerted action of histone chaperones and ATP‐dependent chromatin remodelers. Recent studies have shown that the histone chaperone FACT plays key roles in preventing pervasive incorporation of two histone variants: H2A.Z and CenH3/CENP‐A. In addition, Spt6, another histone chaperone, was also shown to be important for appropriate H2A.Z localization. FACT and Spt6 are both associated with elongating RNA polymerase II. Based on these two examples, we propose that the establishment and maintenance of histone variant genomic distributions depend on a transcription‐coupled epigenome editing (or surveillance) function of histone chaperones.
Meta-analysis of antibiotics versus appendicectomy for non-perforated acute appendicitis
Authors: Sallinen V , Akl E A , You J J , Agarwal A , Shoucair S , Vandvik P O , Agoritsas T , Heels-Ansdell D , Guyatt G H , Tikkinen K A O
Published: March 2016

Background

For more than a century, appendicectomy has been the treatment of choice for appendicitis. Recent trials have challenged this view. This study assessed the benefits and harms of antibiotic therapy compared with appendicectomy in patients with non-perforated appendicitis.

Methods

A comprehensive search was conducted for randomized trials comparing antibiotic therapy with appendicectomy in patients with non-perforated appendicitis. Key outcomes were analysed using random-effects meta-analysis, and the quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results

Five studies including 1116 patients reported major complications in 25 (4·9 per cent) of 510 patients in the antibiotic and 41 (8·4 per cent) of 489 in the appendicectomy group: risk difference −2·6 (95 per cent c.i. –6·3 to 1·1) per cent (low-quality evidence). Minor complications occurred in 11 (2·2 per cent) of 510 and 61 (12·5 per cent) of 489 patients respectively: risk difference −7·2 (−18·1 to 3·8) per cent (very low-quality evidence). Of 550 patients in the antibiotic group, 47 underwent appendicectomy within 1 month: pooled estimate 8·2 (95 per cent c.i. 5·2 to 11·8) per cent (high-quality evidence). Within 1 year, appendicitis recurred in 114 of 510 patients in the antibiotic group: pooled estimate 22·6 (15·6 to 30·4) per cent (high-quality evidence). For every 100 patients with non-perforated appendicitis, initial antibiotic therapy compared with prompt appendicectomy may result in 92 fewer patients receiving surgery within the first month, and 23 more experiencing recurrent appendicitis within the first year.

Conclusion

The choice of medical versus surgical management in patients with clearly uncomplicated appendicitis is value- and preference-dependent, suggesting a change in practice towards shared decision-making is necessary.
Legal Assessments of Child Victims of Human Trafficking for Sexual Purposes
Authors: Lindholm Johanna , Cederborg Ann‐Christin
Published: March 2016

The present study investigated how Swedish district court judges assessed child victims' credibility and the reliability of their testimony in cases of alleged human trafficking for sexual purposes. Court files from 12 different cases, involving 16 alleged child victims (aged 13–17 years old), all of them girls, were qualitatively analyzed with particular attention paid to how the judges described credibility and reliability. Results indicated that, although the judges' assessments to a large extent were based on the Swedish Supreme Court's criteria for credibility and reliability, they were applied somewhat arbitrarily and subjectively. They were also applied as if obvious and grounded on shared experiences, although their meaning was never explored. The way that credibility was assessed may also reinforce gender and victim stereotypes. Moreover, there seems to exist a confusion surrounding the credibility and reliability concepts, as they were sometimes used interchangeably despite the intention that they are two different assessments. Overall, an apparent need exists to increase judges' awareness that their subjective impressions should decrease when legitimizing judicial decisions. Copyright © 2016 John Wiley & Sons, Ltd.
IMI Python: Upgraded CS Circles web‐based Python course
Authors: Djokic‐Petrovic Marija , Pritchard David , Ivanovic Milos , Cvjetkovic Vladimir
Published: March 2016

The rapid growth of student demand for flexible education and learning alternatives has caused a significant increase in web‐based programming course offerings. In order to ensure easy and enjoyable ways of acquiring knowledge, many web‐based solutions have customized the design and content to student needs. This paper introduces a project of the Institute for Mathematics and Informatics (IMI) called IMI Python, an interactive online course. It is based on the open‐source Computer Science Circles (CS Circles) project. IMI Python aims to assist the target audience, primarily students, learn a spectrum of Python knowledge. The benefits of this enhanced system are multiple, both for students and their teachers. The course content is structured and divided by levels: basic, medium, and advanced. Flexible navigation through the different levels of difficulty and lesson units allows students to easily review any forgotten material and adopt new knowledge. Teachers have the ability to follow the progress of individual students or all students in a level, and communicate with them about their work. Teachers and students can communicate within the system to discuss individual exercises through a simple user interface. The system is enhanced with the possibility of testing students’ knowledge through quizzes. Quizzes are visible at assigned time intervals and are worth a certain number of points. By tracking students’ results, teachers can determine whether the site has enough quality material and what can contribute to its improvement. © 2016 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:464–480, 2016; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21724
A prognostic model for platinum‐doublet as second‐line chemotherapy in advanced non‐small‐cell lung cancer patients
Authors: Mo Hongnan , Hao Xuezhi , Liu Yutao , Wang Lin , Hu Xingsheng , Xu Jianping , Yang Sheng , Xing Puyuan , Shi Youwu , Jia Bo , Wang Yan , Li Junling , Wang Hongyu , Wang Ziping , Sun Yan , Shi Yuankai
Published: March 2016

Poor prognosis of advanced non‐small‐cell lung cancer (NSCLC) patients and the promising therapeutic effect of platinum urge the oncologists to evaluate the role of platinum doublet as second‐line chemotherapy and establish the definition of platinum sensitivity in NSCLC. We retrospectively analyzed 364 advanced NSCLC patients who received platinum‐doublet regimens as second‐line chemotherapy after platinum‐based first‐line treatment. Patients were divided into four groups by their time‐to‐progression (TTP) after first‐line chemotherapy: 0–3, 4–6, 7–12, and >12‐month group, respectively. Treatment efficacy of patients' overall survival (OS), progression‐free survival (PFS), and response rate (RR), as well as treatment‐related toxicity, were compared among the four groups. A prognosis score system and a nomogram were established by Cox proportional hazard model, and validated by concordance index (c‐index). Median OS was 14.0, 16.0, 20.0, 25.0 months for patients in the 0–3, 4–6, 7–12, >12‐month group, respectively. Age ≤60 years (P = 0.002), female (P = 0.019), and TTP>12 months (P = 0.003) were independent prognostic factors. Prognostic score was calculated by adding 1 point each for any of the above three indicators, with a c‐index of 0.590 (95% confidential interval [CI], 0.552–0.627). Median OS were equal to 25.0, 16.0, and 11.0 months for best (2–3 points), intermediate (1 point) and worst (0 point) category, respectively (P < 0.0001). A nomogram that integrated patient's age, gender, and TTP for OS has a c‐index of 0.623 (95% CI, 0.603–0.643). Female, younger than 60 years, and TTP greater than 12 months may indicate prolonged survival after platinum‐doublet second‐line chemotherapy in advanced NSCLCpatients.
The impact of early detection and intervention of breast cancer‐related lymphedema: a systematic review
Authors: Shah Chirag , Arthur Douglas W. , Wazer David , Khan Atif , Ridner Sheila , Vicini Frank
Published: March 2016

Breast cancer‐related lymphedema (BCRL) has become an increasingly important clinical issue as noted by the recent update of the 2015 NCCN breast cancer guidelines which recommends to “educate, monitor, and refer for lymphedema management.” The purpose of this review was to examine the literature regarding early detection and management of BCRL in order to (1) better characterize the benefit of proactive surveillance and intervention, (2) clarify the optimal monitoring techniques, and (3) help better define patient groups most likely to benefit from surveillance programs. A Medline search was conducted for the years 1992–2015 to identify articles addressing early detection and management of BCRL. After an initial search, 127 articles were identified, with 13 of these studies focused on early intervention (three randomized (level of evidence 1), four prospective (level of evidence 2–3), six retrospective trials (level of evidence 4)). Data from two, small (n = 185 cases), randomized trials with limited follow‐up demonstrated a benefit to early intervention (physiotherapy, manual lymphatic drainage) with regard to reducing the rate of chronic BCRL (>50% reduction) with two additional studies underway (n = 1280). These findings were confirmed by larger prospective and retrospective series. Several studies were identified that demonstrate that newer diagnostic modalities (bioimpedance spectroscopy, perometry) have increased sensitivity allowing for the earlier detection of BCRL. Current data support the development of surveillance programs geared toward the early detection and management of BCRL in part due to newer, more sensitive diagnostic modalities.
Blood lipids and prostate cancer: a Mendelian randomization analysis
Authors: Bull Caroline J. , Bonilla Carolina , Holly Jeff M. P. , Perks Claire M. , Davies Neil , Haycock Philip , Yu Oriana Hoi Yun , Richards J. Brent , Eeles Rosalind , Easton Doug , Kote‐Jarai Zsofia , Amin Al Olama Ali , Benlloch Sara , Muir Kenneth , Giles Graham G. , MacInnis Robert J. , Wiklund Fredrik , Gronberg Henrik , Haiman Christopher A. , Schleutker Johanna , Nordestgaard Børge G. , Travis Ruth C. , Neal David , Pashayan Nora , Khaw Kay‐Tee , Stanford Janet L. , Blot William J. , Thibodeau Stephen , Maier Christiane , Kibel Adam S. , Cybulski Cezary , Cannon‐Albright Lisa , Brenner Hermann , Park Jong , Kaneva Radka , Batra Jyotsna , Teixeira Manuel R. , Micheal Agnieszka , Pandha Hardev , Smith George Davey , Lewis Sarah J. , Martin Richard M. ,   The PRACTICAL consortium
Published: March 2016

Genetic risk scores were used as unconfounded instruments for specific lipid traits (Mendelian randomization) to assess whether circulating lipids causally influence prostate cancer risk. Data from 22,249 prostate cancer cases and 22,133 controls from 22 studies within the international PRACTICAL consortium were analyzed. Allele scores based on single nucleotide polymorphisms (SNPs) previously reported to be uniquely associated with each of low‐density lipoprotein (LDL), high‐density lipoprotein (HDL), and triglyceride (TG) levels, were first validated in an independent dataset, and then entered into logistic regression models to estimate the presence (and direction) of any causal effect of each lipid trait on prostate cancer risk. There was weak evidence for an association between the LDL genetic score and cancer grade: the odds ratio (OR) per genetically instrumented standard deviation (SD) in LDL, comparing high‐ (≥7 Gleason score) versus low‐grade (<7 Gleason score) cancers was 1.50 (95% CI: 0.92, 2.46; P = 0.11). A genetically instrumented SD increase in TGs was weakly associated with stage: the OR for advanced versus localized cancer per unit increase in genetic risk score was 1.68 (95% CI: 0.95, 3.00; P = 0.08). The rs12916‐T variant in 3‐hydroxy‐3‐methylglutaryl‐CoA reductase (HMGCR) was inversely associated with prostate cancer (OR: 0.97; 95% CI: 0.94, 1.00; P = 0.03). In conclusion, circulating lipids, instrumented by our genetic risk scores, did not appear to alter prostate cancer risk. We found weak evidence that higher LDL and TG levels increase aggressive prostate cancer risk, and that a variant in HMGCR (that mimics the LDL lowering effect of statin drugs) reduces risk. However, inferences are limited by sample size and evidence of pleiotropy.
Biosynthesis of Metal and Metal Oxide Nanoparticles
Authors: Jeevanandam Jaison , Chan Yen San , Danquah Michael K.
Published: March 2016

Bioresource‐based green synthesis of nanoparticles has gained significant interest as an emerging technology to reduce the toxicity of nanoparticles commonly associated with conventional chemical synthesis approaches. Studies on green synthesis of metal nanoparticles have been carried out with various biological materials including from bacteria, fungi, and plant extracts. Plant extracts in particular have been extensively used for the synthesis of metal and metal oxide nanoparticles, and this is due to the presence of essential phytochemicals in plant extracts especially from the leaves. Leaf extract contains various types of phytochemicals such as terpenoids, flavonoids, ketones, aldehydes, amides, and carboxylic acids, which play a major role in formulating and enhancing the bioactivity of the nanoparticles. This article discusses flavonoids as an essential phytochemical for the formation of metal and metal oxide nanoparticles and enhancement of their bio‐functionality and compatibility. In addition, bioprocess developments for the synthesis of metal as well as metal oxide nanoparticles from various biological materials are discussed.
Bimodal X‐ray and Infrared Imaging of an Organometallic Derivative of Praziquantel in Schistosoma mansoni
Authors: Clède Sylvain , Cowan Noemi , Lambert François , Bertrand Hélène C. , Rubbiani Riccardo , Patra Malay , Hess Jeannine , Sandt Christophe , Trcera Nicolas , Gasser Gilles , Keiser Jennifer , Policar Clotilde
Published: March 2016

An organometallic derivative of praziquantel was studied directly in worms by using inductively coupled plasma‐mass spectrometry (ICP‐MS) for quantification and synchrotron‐based imaging. X‐ray fluorescence (XRF) and IR absorption spectromicroscopy were used for the first time in combination to directly locate this organometallic drug candidate in schistosomes. The detection of both CO (IR) and Cr (XRF) signatures proved that the Cr(CO)3 core remained intact in the worms. Images showed a preferential accumulation at the worm's tegument, consistent with a possible targeting of the calcium channel but not excluding other biological targets inside the worm.
Morphology‐Specific Inhibition of β‐Amyloid Aggregates by 17β‐Hydroxysteroid Dehydrogenase Type 10
Authors: Aitken Laura , Quinn Steven D. , Perez‐Gonzalez Cibran , Samuel Ifor D. W. , Penedo J. Carlos , Gunn‐Moore Frank J.
Published: March 2016

A major hallmark of Alzheimer's disease (AD) is the formation of toxic aggregates of the β‐amyloid peptide (Aβ). Given that Aβ peptides are known to localise within mitochondria and interact with 17β‐HSD10, a mitochondrial protein expressed at high levels in AD brains, we investigated the inhibitory potential of 17β‐HSD10 against Aβ aggregation under a range of physiological conditions. Fluorescence self‐quenching (FSQ) of Aβ(1–42) labelled with HiLyte Fluor 555 was used to evaluate the inhibitory effect under conditions established to grow distinct Aβ morphologies. 17β‐HSD10 preferentially inhibits the formation of globular and fibrillar‐like structures but has no effect on the growth of amorphous plaque‐like aggregates at endosomal pH 6. This work provides insights into the dependence of the Aβ‐17β‐HSD10 interaction with the morphology of Aβ aggregates and how this impacts enzymatic function.
Tunable Di‐ and Mono‐γ‐C−H Arylation of Phenylacetamides by Palladium‐Catalyzed Domino Reactions
Authors: Liu Yunyun , Huang Bin , Cao Xiaoji , Wan Jie‐Ping
Published: March 2016

The Pd‐catalyzed C−H arylation of phenylacetamides in the γ position was realized for the first time by means of a domino process consisting of in situ directing group installation and C−H arylation. Unprecedented tunable selectivity between di‐ and monoactivation of the two identical γ‐C−H bonds was achieved by modifying the reaction conditions; this is a distinct feature of this one‐pot procedure for the C−H‐activation‐based synthesis of diverse amides.
Production of Adipic Acid from Sugar Beet Residue by Combined Biological and Chemical Catalysis
Authors: Zhang Hongfang , Li Xiukai , Su Xiaoyun , Ang Ee Lui , Zhang Yugen , Zhao Huimin
Published: March 2016

Adipic acid is one of the most important industrial dicarboxylic acids and is used mainly as a precursor to nylon‐6,6. Currently, commercial adipic acid is produced primarily from benzene by a chemical route that is associated with environmental, health, and safety concerns. Herein, we report a new process to produce adipic acid from an inexpensive renewable feedstock, sugar beet residue by combining an engineered Escherichia coli strain and Re‐based chemical catalysts. The engineered E. coli converted d‐galacturonic acid to mucic acid, which was precipitated easily with acid, and the mucic acid was further converted to adipic acid by a deoxydehydration reaction catalyzed by an oxorhenium complex followed by a Pt/C‐catalyzed hydrogenation reaction under mild conditions. A high selectivity to the free acid products was achieved by tuning the acidity of the Re‐based catalysts. Finally, adipic acid was produced directly from sugar beet residue that was hydrolyzed enzymatically with engineered E. coli and two chemical catalysts in a yield of 8.4 %, which signifies a new route for the production of adipic acid.
Combined Operando X‐ray Diffraction/Raman Spectroscopy of Catalytic Solids in the Laboratory: The Co/TiO2 Fischer–Tropsch Synthesis Catalyst Showcase
Authors: Cats Korneel H. , Weckhuysen Bert M.
Published: March 2016

A novel laboratory setup for combined operando X‐ray diffraction and Raman spectroscopy of catalytic solids with online product analysis by gas chromatography is presented. The setup can be used with a laboratory‐based X‐ray source, which results in important advantages in terms of time‐on‐stream that can be measured, compared to synchrotron‐based experiments. The data quality was much improved by the use of a relatively high‐energy MoKα radiation instead of the more conventional CuKα radiation. We have applied the instrument to study the long‐term deactivation of Co/TiO2 Fischer–Tropsch synthesis (FTS) catalysts. No sign of Co sintering or bulk oxidation was found during the experiments. However, part of the metallic Co was converted into cobalt carbide (Co2C), at elevated pressure (10 bar). Furthermore, graphitic‐like coke species are clearly formed during FTS at atmospheric pressure, whereas at elevated pressure fluorescence hampered the interpretation of the measured Raman spectra.
Clusters of Phospholipid Vesicles as Platforms for Glucose Oxidase‐Catalyzed Reaction in a Bubble‐Column Bioreactor
Authors: Yoshimoto Makoto , Sakakida Yuki , Tamura Ryota , Natsume Tomotaka , Ikeda Tomoaki
Published: March 2016

Clusters of negatively charged liposomes encapsulated with glucose oxidase were prepared in the presence of Ca2+ and used to catalyze the oxidation of glucose in an external loop airlift bubble column. The clusters exhibited higher catalytic activity compared to nonclustered glucose oxidase‐containing liposomes (GOLs) when the liposome membranes were incorporated with cholesterol. The clusters were structurally altered in shear flow to give sufficient interfacial area accessible to glucose. The reactivity of GOL clusters could be modulated on the basis of lipid composition of the membranes which affected the mode of interaction among liposomes through Ca2+. Part of GOL clusters could be separated from the reaction mixture by centrifugation, which would be advantageous for reusing liposomal catalysts. The liposome clusters can be the platforms to regulate the catalytic performance of glucose oxidase in the airlift.
Hierarchical Ternary MoO2/MoS2/Heteroatom‐Doped Carbon Hybrid Materials for High‐Performance Lithium‐Ion Storage
Authors: Liu Haidong , Hu Huating , Wang Jun , Niehoff Philip , He Xin , Paillard Elie , Eder Dominik , Winter Martin , Li Jie
Published: March 2016

The synthesis and electrochemical lithium‐ion storage behavior of hierarchical MoO2/MoS2/heteroatom‐doped carbon (MoO2/MoS2/HD‐C) ternary hybrid have been studied. This ternary hybrid is composed of ultrafine MoO2 nanowires and single/few‐layer MoS2 encapsulated by heteroatom‐doped carbon, constituting secondary cauliflower‐like microspheres. The synthesis is achieved through the synergistic interplay of a polymer and an ionic liquid as structure‐directing agents and carbon sources, using a solvothermal reaction followed by a simple thermal treatment. In this unique architecture, each component synergistically acts with a specific purpose. The HD‐C matrix with abundant defects and vacancies provides fast electronic conduction as well as interfacial storage, and buffers the volume changes during charging/discharging processes. The ultrasmall dimensions of both MoO2 nanowires and single/few‐layered MoS2 components enable rapid Li+ transport in all directions, which is of great benefit to the reversibility of “conversion” reactions. The hierarchical secondary structures assure the robust stability upon long‐term cycling. The ternary hybrid material exhibits enhanced Li+‐storage performance as well as reversible capacity, rate capability, and cycling stability. A high reversible specific capacity of 1147 mA h g−1 is delivered at 50 mA g−1 together with excellent cycling stability, and 841 mA h g−1 can be retained after 1000 cycles at 500 mA g−1.
Methyl Complexes of the Transition Metals
Authors: Campos Jesús , López‐Serrano Joaquín , Peloso Riccardo , Carmona Ernesto
Published: March 2016

Organometallic chemistry can be considered as a wide area of knowledge that combines concepts of classic organic chemistry, that is, based essentially on carbon, with molecular inorganic chemistry, especially with coordination compounds. Transition‐metal methyl complexes probably represent the simplest and most fundamental way to view how these two major areas of chemistry combine and merge into novel species with intriguing features in terms of reactivity, structure, and bonding. Citing more than 500 bibliographic references, this review aims to offer a concise view of recent advances in the field of transition‐metal complexes containing M−CH3fragments. Taking into account the impressive amount of data that are continuously provided by organometallic chemists in this area, this review is mainly focused on results of the last five years. After a panoramic overview on M−CH3compounds of Groups 3 to 11, which includes the most recent landmark findings in this area, two further sections are dedicated to methyl‐bridged complexes and reactivity.
Greatly Enhanced Fluorescence by Increasing the Structural Rigidity of an Imine: Enantioselective Recognition of 1,2‐Cyclohexanediamine by a Chiral Aldehyde
Authors: Xu Yimang , Yu Shanshan , Chen Qi , Chen Xuemin , Xiao Meng , Chen Liming , Yu Xiaoqi , Xu Yong , Pu Lin
Published: March 2016

An aldehyde that is not fluorescent responsive toward a chiral diamine has been converted to a sensitive fluorescence enhancement sensor through incorporation of an additional hydrogen bonding unit to increase the structural rigidity of the reaction product of the aldehyde with the diamine. This new chiral aldehyde is synthesized in one step from the reaction of (S)‐3‐formylBINOL with salicyl chloride. When treated with trans‐1,2‐cyclohexanediamine in ethanol, it shows greatly enhanced fluorescence at λ=410 nm with good enantioselectivity. NMR and mass spectroscopic methods are used to investigate the reaction of the chiral aldehyde with the diamine. This study has revealed a two‐stage reaction mechanism including a fast imine formation and a slow ester cleavage.
Tailoring of Polarizing Agents in the bTurea Series for Cross‐Effect Dynamic Nuclear Polarization in Aqueous Media
Authors: Sauvée Claire , Casano Gilles , Abel Sébastien , Rockenbauer Antal , Akhmetzyanov Dimitry , Karoui Hakim , Siri Didier , Aussenac Fabien , Maas Werner , Weber Ralph T. , Prisner Thomas , Rosay Mélanie , Tordo Paul , Ouari Olivier
Published: March 2016

A series of 18 nitroxide biradicals derived from bTurea has been prepared, and their enhancement factors ɛ (1H) in cross‐effect dynamic nuclear polarization (CE DNP) NMR experiments at 9.4 and 14.1 T and 100 K in a DNP‐optimized glycerol/water matrix (“DNP juice”) have been studied. We observe that ɛ (1H) is strongly correlated with the substituents on the polarizing agents, and its trend is discussed in terms of different molecular parameters: solubility, average e–e distance, relative orientation of the nitroxide moieties, and electron spin relaxation times. We show that too short an e–e distance or too long a T1e can dramatically limit ɛ (1H). Our study also shows that the molecular structure of AMUPol is not optimal and its ɛ (1H) could be further improved through stronger interaction with the glassy matrix and a better orientation of the TEMPO moieties. A new AMUPol derivative introduced here provides a better ɛ (1H) than AMUPol itself (by a factor of ca. 1.2).
Enolizable Carbonyls and N,O‐Acetals: A Rational Approach for Room‐Temperature Lewis Superacid‐Catalyzed Direct α‐Amidoalkylation of Ketones and Aldehydes
Authors: Touati Bahria , El Bouakher Abderrahman , Taillier Catherine , Othman Raja Ben , Trabelsi‐Ayadi Malika , Antoniotti Sylvain , Duñach Elisabet , Dalla Vincent
Published: March 2016

An efficient catalytic room‐temperature direct α‐amidoalkylation of carbonyl donors, that is, ketones and aldehydes with unbiased N,O‐acetals, is described. Sn(NTf2)4 is an optimal catalyst to promote this challenging transformation at low loading and the reaction shows promising scope. A comprehensive and rational evaluation of this reaction has led to the establishment of an empirical scale of nucleophilic reactivity for a broad set of ketones that should be helpful in the synthetic design and development of carbonyl α‐functionalization methods.
A Bis(methylpiperazinylstyryl)phenanthroline as a Fluorescent Ligand for G‐Quadruplexes
Authors: Wu Shangrong , Wang Linlin , Zhang Nan , Liu Ying , Zheng Wei , Chang Ang , Wang Fuyi , Li Songqin , Shangguan Dihua
Published: March 2016

G‐quadruplex (G4)‐forming sequences are prevalent in the genome and are considered to play important roles in gene regulation, and hence have been viewed as potential therapeutic targets in oncology. However, the structures and functions of most G4s in the genome are poorly understood. Therefore, the development of fluorescent probes and ligands for G4s is important for G4 research and drug discovery. Herein, we report a new G4 ligand, 2,9‐bis[4‐(4‐methylpiperazin‐1‐yl)styryl]‐1,10‐phenanthroline (BMSP), which was synthesized by a simple process. BMSP exhibits almost no fluorescence in aqueous buffer. The interaction of BMSP with G4s greatly enhances its fluorescence with a large Stokes’ shift of 160 nm. Antiparallel human telomeric G4s exhibit the strongest binding affinity (Kd≈0.13 μm) to BMSP and induce a fluorescence enhancement of up to 150‐fold. BMSP binds to G4s through π–π stacking on the terminal G‐quartets. BMSP can enter live cells, and it strongly inhibits the growth of cancer cells rather than causing cell death. Our results suggest that BMSP has the potential to serve both as a fluorescent probe for some G4s and as a chemotherapeutic agent for cancer treatment.
Dual Palladium(II)/Tertiary Amine Catalysis for Asymmetric Regioselective Rearrangements of Allylic Carbamates
Authors: Bauer Johannes Moritz , Frey Wolfgang , Peters René
Published: March 2016

The streamlined catalytic access to enantiopure allylic amines as valuable precursors towards chiral β‐ and γ‐aminoalcohols as well as α‐ and β‐aminoacids is desirable for industrial purposes. In this article an enantioselective method is described that transforms achiral allylic alcohols and N‐tosylisocyanate in a single step into highly enantioenriched N‐tosyl protected allylic amines via an allylic carbamate intermediate. The latter is likely to undergo a cyclisation‐induced [3,3]‐rearrangement catalysed by a planar chiral pentaphenylferrocene palladacycle in cooperation with a tertiary amine base. The otherwise often indispensable activation of palladacycle catalysts by a silver salt is not required in the present case and there is also no need for an inert gas atmosphere. To further improve the synthetic value, the rearrangement was used to form dimethylaminosulfonyl‐protected allylic amines, which can be deprotected under non‐reductive conditions.
Highly Active and Robust Metalloporphyrin Catalysts for the Synthesis of Cyclic Carbonates from a Broad Range of Epoxides and Carbon Dioxide
Authors: Maeda Chihiro , Shimonishi Junta , Miyazaki Ray , Hasegawa Jun‐ya , Ema Tadashi
Published: March 2016

Bifunctional metalloporphyrins with quaternary ammonium bromides (nucleophiles) at the meta, para, or ortho positions of meso‐phenyl groups were synthesized as catalysts for the formation of cyclic carbonates from epoxides and carbon dioxide under solvent‐free conditions. The meta‐substituted catalysts exhibited high catalytic performance, whereas the para‐ and ortho‐substituted catalysts showed moderate and low activity, respectively. DFT calculations revealed the origin of the advantage of the meta‐substituted catalyst, which could use the flexible quaternary ammonium cation at the meta position to stabilize various anionic species generated during catalysis. A zinc(II) porphyrin with eight nucleophiles at the meta positions showed very high catalytic activity (turnover number (TON)=240 000 at 120 °C, turnover frequency (TOF)=31 500 h−1 at 170 °C) at an initial CO2 pressure of 1.7 MPa; catalyzed the reaction even at atmospheric CO2 pressure (balloon) at ambient temperature (20 °C); and was applicable to a broad range of substrates, including terminal and internal epoxides.
Dithioacetal Exchange: A New Reversible Reaction for Dynamic Combinatorial Chemistry
Authors: Orrillo A. Gastón , Escalante Andrea M. , Furlan Ricardo L. E.
Published: March 2016

Reversibility of dithioacetal bond formation is reported under acidic mild conditions. Its utility for dynamic combinatorial chemistry was explored by combining it with orthogonal disulfide exchange. In such a setup, thiols are positioned at the intersection of both chemistries, constituting a connecting node between temporally separated networks.
A General and Selective Rhodium‐Catalyzed Reduction of Amides, N‐Acyl Amino Esters, and Dipeptides Using Phenylsilane
Authors: Das Shoubhik , Li Yuehui , Lu Liang‐Qiu , Junge Kathrin , Beller Matthias
Published: March 2016

This article describes a selective reduction of functionalized amides, including N‐acyl amino esters and dipeptides, to the corresponding amines using simple [Rh(acac)(cod)]. The catalyst shows excellent chemoselectivity in the presence of different sensitive functional moieties.
Development of a syn‐Selective Mannich Reaction of Aldehydes with Propargylic Imines by Dual Catalysis: Asymmetric Synthesis of Functionalized Propargylic Amines
Authors: Lapuerta Irati , Vera Silvia , Oiarbide Mikel , Palomo Claudio
Published: March 2016

Direct coupling of enolizable aldehydes with C‐alkynyl imines is realized affording the corresponding propargylic Mannich adducts of syn configuration, thus complementing previous methods that gave access to the anti‐isomers. The combination of proline and a urea Brønsted base cocatalyst is key for the reactions to proceed under very mild conditions (3–10 mol % catalyst loading, dichloromethane as solvent, −20 °C, 1.2 molar equivalents of aldehyde) and with virtually total stereocontrol (syn/anti ratio up to 99:1; ee up to 99 %). Some possibilities of further chemical elaboration of adducts are also briefly illustrated.
An Immucillin‐Based Transition‐State‐Analogous Inhibitor of tRNA–Guanine Transglycosylase (TGT)
Authors: Hohn Christoph , Härtsch Adrian , Ehrmann Frederik Rainer , Pfaffeneder Toni , Trapp Nils , Dumele Oliver , Klebe Gerhard , Diederich François
Published: March 2016

Shigellosis is one of the most severe diarrheal diseases worldwide without any efficient treatment so far. The enzyme tRNA–guanine transglycosylase (TGT) has been identified as a promising target for small‐molecule drug design. Herein, we report a transition‐state analogue, a small, immucillin‐derived inhibitor, as a new lead structure with a novel mode of action. The complex inhibitor synthesis was accomplished in 18 steps with an overall yield of 3 %. A co‐crystal structure of the inhibitor bound to Z. mobilis TGT confirmed the predicted conformation of the immucillin derivative in the enzyme active site.
Computational SN2‐Type Mechanism for the Difluoromethylation of Lithium Enolate with Fluoroform through Bimetallic C−F Bond Dual Activation
Authors: Honda Kazuya , Harris Travis V. , Hatanaka Miho , Morokuma Keiji , Mikami Koichi
Published: March 2016

The reaction mechanism for difluoromethylation of lithium enolates with fluoroform was analyzed computationally (DFT calculations with the artificial force induced reaction (AFIR) method and solvation model based on density (SMD) solvation model (THF)), showing an SN2‐type carbon–carbon bond formation; the “bimetallic” lithium enolate and lithium trifluoromethyl carbenoid exert the C−F bond “dual” activation, in contrast to the monometallic butterfly‐shaped carbenoid in the Simmons–Smith reaction. Lithium enolates, generated by the reaction of 2 equiv. of lithium hexamethyldisilazide (rather than 1 or 3 equiv.) with the cheap difluoromethylating species fluoroform, are the most useful alkali metal intermediates for the synthesis of pharmaceutically important α‐difluoromethylated carbonyl products.
Cobalt‐Catalyzed Oxidase C−H/N−H Alkyne Annulation: Mechanistic Insights and Access to Anticancer Agents
Authors: Mei Ruhuai , Wang Hui , Warratz Svenja , Macgregor Stuart A. , Ackermann Lutz
Published: March 2016

Cp*‐free cobalt‐catalyzed alkyne annulations by C−H/N−H functionalizations were accomplished with molecular O2 as the sole oxidant. The user‐friendly oxidase strategy proved viable with various internal and terminal alkynes through kinetically relevant C−H cobaltation, providing among others step‐economical access to the anticancer topoisomerase‐I inhibitor 21,22‐dimethoxyrosettacin. DFT calculations suggest that electronic effects control the regioselectivity of the alkyne insertion step.
Carboxylation of Phenols with CO2 at Atmospheric Pressure
Authors: Luo Junfei , Preciado Sara , Xie Pan , Larrosa Igor
Published: March 2016

A convenient and efficient method for the ortho‐carboxylation of phenols under atmospheric CO2 pressure has been developed. This method provides an alternative to the previously reported Kolbe–Schmitt method, which requires very high pressures of CO2. The addition of a trisubstituted phenol has proved essential for the successful carboxylation of phenols with CO2 at standard atmospheric pressure, allowing the efficient preparation of a broad variety of salicylic acids.
Defined Palladium–Phthalimidato Catalysts for Improved Oxidative Amination
Authors: Martínez Claudio , Muñiz Kilian
Published: March 2016

New palladium(II)–phthalimidato complexes have been synthesized, isolated, and structurally characterized. As demonstrated from over 30 examples, they constitute superior catalysts for oxidative amination reactions of alkenes with phthalimide as the nitrogen source. This work streamlines vicinal difunctionalization of alkenes and provides access to significantly improved and experimentally simplified synthetic protocols.
Synthesis of the First Example of the 12‐Vertex‐closo/12‐Vertex‐nido Biscarborane Cluster by a Metal‐Free B−H Activation at a Phosphorus(III) Center
Authors: Wong Yuen Onn , Smith Mark D. , Peryshkov Dmitry V.
Published: March 2016

An unusual 12‐vertex‐closo‐C2B10/12‐vertex‐nido‐C2B10 biscarborane cluster was synthesized through an unprecedented regioselective metal‐free B−H activation by a sterically hindered PIII center under mild conditions accompanied by cage‐opening rearrangement. A combination of the electron‐accepting properties of a carborane cage and steric enforcement of close interatomic contacts represent a new synthetic strategy for the activation of strong B−H bonds in carboranes.
A Photoresponsive Surface Covalent Organic Framework: Surface‐Confined Synthesis, Isomerization, and Controlled Guest Capture and Release
Authors: Liu Chunhua , Zhang Wei , Zeng Qingdao , Lei Shengbin
Published: March 2016

By introducing an azobenzene group to the backbone of diboronic acid, we have obtained a surface‐confined, photoresponsive single‐layer covalent organic framework with long‐range order and almost entire surface coverage. Scanning tunneling microscopic characterization indicates that though the covalent linkage provides a significant locking effect, isomerization can still happen under UV irradiation, which causes destruction of the surface COF. Furthermore, the decomposed surface COF can recover upon annealing. This photoinduced decomposition provides a facile approach for the controlled capture and release of targeted objects using these nanoporous surface COFs as a host, which has been demonstrated in this work using copper phthalocyanine as a model guest.
Catalytic Asymmetric Cycloaddition of In Situ‐Generated ortho‐Quinone Methides and Azlactones by a Triple Brønsted Acid Activation Strategy
Authors: Yu Xiao‐Ye , Chen Jia‐Rong , Wei Qiang , Cheng Hong‐Gang , Liu Zhi‐Cheng , Xiao Wen‐Jing
Published: March 2016

A convergent and highly stereoselective [4+2] cycloaddition of in situ‐generated ortho‐Quinone methides (o‐QMs) and azlactone enols has been successfully developed through a triple Brønsted acid catalysis strategy. This protocol provides an efficient and mild access to various densely functionalized dihydrocoumarins bearing adjacent quaternary and tertiary stereogenic centers in high yields with excellent diastereo‐ and enantioselectivity.
ChemInform Abstract: FLUORIDE ION AFFINITY OF SOME LEWIS ACIDS
Authors: HAARTZ J. C. , MCDANIEL DARL H.
Published: March 2016

Die Fähigkeit der Lewis‐Säuren SO2, HCl, HBr, BCl3, BF3, PF5, SiF4, AsF5, SbF6 und von Kombinationen davon, Addukte mit F‐ zu bilden, wird durch Ionen‐Cyclotronresonanzspektroskopie untersucht.
ChemInform Abstract: BESTIMMUNG DER KINETISCHEN PARAMETER DER OBERFLAECHENREAKTION ELEKTROCHEMISCHER UND ANDERER HETEROGEN‐CHEMISCHER PROZESSE AN DER PHASENGRENZE FEST/FLUESSIG MIT DER METHODE DER ROTIERENDEN SCHEIBE
Authors: MUELLER LOTHAR
Published: March 2016

Es wird zusammenfassend über 2 Verfahren zur Bestimmung der Geschwindigkeit von Reaktionen an der Phasengrenze fest/ flüssig berichtet.
ChemInform Abstract: GLASS‐RANEY NICKEL TABLET CATALYST
Authors: YASUMURA JIRO , NAKABAYASHI ICHIRO , ENDO TADASHI
Published: March 2016

Aus Mischungen eines Glaspulvers mit 30 oder 50% Raney‐Ni wurden Tabletten gepreßt, diese bei 760‐900°C gesintert und danach zur Aktivierung mit wäßriger NaOH‐ Lösung behandelt.
ChemInform Abstract: THE PREPARATION OF CHLORINE MONOFLUORIDE
Authors: SCHACK C. J. , WILSON R. D.
Published: March 2016

Chlortrifluorid (I) bildet mit Chlor in der Wärme Chlormonofluorid (III).
ChemInform Abstract: ENANTIOMEREN‐REINHEIT UND ABSOLUTE KONFIGURATION VON DURCH ASYMMETRISCHE SYNTHESE DARGESTELLTER BETA‐HYDROXY‐BETA‐TRIFLUORMETHYL‐BETA‐PHENYL‐PROPIONSAEURE
Authors: MIOSKOWSKI C. , SOLLADIE G.
Published: March 2016

Von der aus dem Keton (I) mit dem Acetat (II) erhaltenen Säure (III) wird in Gegenwart eines chiralen Europium‐Komplexes die Enantiomeren‐Reinheit bestimmt.
ChemInform Abstract: PHOTOCHEMIE DES 3‐METHYL‐CYCLOPENTANONS, SYNTHESE VON OPTISCH AKTIVEM DIHYDROTAGETON
Authors: LEFEBVRE BERNARD , LE ROUX JEAN‐PIERRE , KOSSANYI JEAN , BASSELIER JEAN‐JACQUES
Published: March 2016

Aus den Produkten der Photoisomerisierung des (+)‐Methylcyclopentanons (I) unter der Einwirkung von UV‐Licht in O2‐freiem Pentan läßt sich dünnschichtchromatogra‐ phisch der (+)‐Aldehyd (II) abtrennen.
ChemInform Abstract: DI‐ AND TRIMETHYL‐2‐CYCLOHEXENONES
Authors: WENKERT E. , GOLOB N. F. , SMITH R. A. J.
Published: March 2016

Das Dimethylcyclohexenon (I) reagiert mit Methylmagnesiumbromid zum Addukt (II) und wird durch Chromsäure zu (IIIa) oxidiert, aus dem mit N‐Bromsuccinimid das Bromderivat (IIIb) ensteht, das leicht zu (IV) dehydrobromiert wird.
ChemInform Abstract: INVESTIGATION OF THE RELATIONSHIP BETWEEN LIPID‐LEVEL DECREASING EFFECT AND STRUKTURE IN THE SERIES OF GLYOXYLIC ACID PHENYLACETALS PART 2
Authors: FISCHER J. , TOTH G. , FODOR T. , RAKOCZI J.
Published: March 2016

Bei UV‐Bestrahlung reagiert das Acetal (I) mit Brom unter Bildung des Äthers (II), der sich mit Alkoholen, Alkoholaten und Phenolaten zu gemischten Acetalen umsetzen läßt, so z.B. mit Methanol in Äther in Gegenwart von Pyridin zu (IIIa) und mit Na‐2‐brom‐4‐chlor‐phenolat zu (IIIb).
ChemInform Abstract: CONFORMATIONAL AND CONFIGURATIONAL STUDIES OF SOME DIETHYL 2,3‐DIARYLSUCCINATES USING NUCLEAR MAGNETIC RESONANCE
Authors: GORTLER L. , BRANDSPIGEL K. , HARMAN E. , HECHT S. , LEAVITT R.
Published: March 2016

Aus den Benzaldehyden (I) und Benzylcyanid (II) entstehen die Diarylacrylnitrile (III), die mit HCN in die Addukte (IV) übergehen und dann zu den Diaryl‐bernsteinsäureestern (V) umgesetzt werden können.
ChemInform Abstract: TRIARYLMETHANES PART 5, BEHAVIOUR OF NAPHTHOQUINONE DIPHENYLMETHIDES TOWARDS AMINES AND DIAZOMETHANE
Authors: ELKASCHEF MOHAMED A.‐F. , ABDEL‐MEGEID FAROUK M. E. , ELZEIN SALAH M. M.
Published: March 2016

Das Diphenylmethid (I) reagiert mit den Aminen (II) bei Raumtemperatur zu den entsprechenden Triarylmethylaminen (III).
ChemInform Abstract: 5‐SUBSTITUIERTE 2‐THIAZOLIN‐4‐CARBONSAEUREAETHYLESTER
Authors: SCHOELLKOPF ULRICH , HOPPE DIETER
Published: March 2016

Durch Reaktion der Isonlitril‐ester (I) mit Schwefelwasserstoff werden die Titelverbindungen (II) dargestellt (Diskussion des Reaktionsmechanismus).
ChemInform Abstract: STUDIES ON AROMATIC BASIC ETHERS WITH ANTISPASMODIC ACTIVITY PART 3, CONFIGURATION OF ALKYL OR ARYL 3‐(2‐METHYLPIPERIDINO)‐1‐PHENYLPROPYL ETHER DERIVATIVES
Authors: YOSHIDA A. , MORITA M. , OGAWA S.
Published: March 2016

Durch Natriumborhydrid‐Reduktion des Ketons (I) erhält man die diastereoisomeren Alkohole (II), die durch Reaktion mit Thionylchlorid, Reaktion mit Phenolaten und Methylierung mit Methyljodid in (III), (IV) und (V‐) umgewandelt werden.
ChemInform Abstract: STEREOSELECTIVITY IN THE BASE‐CATALYZED DECARBOXYLATION OF 5,5‐DICARBOXY‐2‐ISOPROPYL‐1,3‐DIOXANE
Authors: BANKS H. D.
Published: March 2016

5,5‐Dicarboxy‐2‐isopropyl‐1,3‐dioxan (I) wird der Decarboxylierung zu den isomeren Carbonsäuren (II) und (III) unterworfen.
ChemInform Abstract: STEREOCHEMIE IM INNERN CYCLISCHER VERBINDUNGEN, KRONENAETHER, KATAPINATE UND KRYPTATE
Authors: VOEGTLE F. , NEUMANN P.
Published: March 2016

Die Autoren geben einen Überblick über die neueste Entwicklung auf dem Gebiet der Kronenäther‐Komplexe und Kryptate und legen das Schwergewicht auf die sehr interessante Stereochemie solcher "Wirts"‐Moleküle.
ChemInform Abstract: HOMOATOMIC ORGANOARSINE LADDER POLYMERS, SYNTHESIS AND PHYSICAL PROPERTIES
Authors: RHEINGOLD ARNOLD L. , LEWIS JOHN E. , BELLAMA JON M.
Published: March 2016

Leiterpolymere (I) der CH3‐As=‐Gruppe mit hohem Molekulargewicht werden in makrokristalliner Form durch die Reaktion von Methylarsin mit Methyldihalogenoarsin oder durch katalysierte Umlagerung der cyclischen Oligomeren (CH3As)5 dargestellt.
ChemInform Abstract: ARSENORGANO‐VERBINDUNGEN 22. MITT. ZUR SYNTHESE DER 1,3‐BENZAZARSOLINE
Authors: TZSCHACH A. , DROHNE D. , HEINICKE J.
Published: March 2016

Die elektrochemische Reduktion der o‐Nitrophenylarsonsäure (I) liefert in guter Ausbeute o‐Aminophenylarsin (II), das in flüssigem Ammoniak zu (III) metallierbar ist.
ChemInform Abstract: OPTICALLY ACTIVE STIBONIUM IODIDE
Authors: SATO S. , MATSUMURA Y. , OKAWARA R.
Published: March 2016

Das Stiboniumjodid (II) kann entweder aus (I) oder aus (III) dargestellt werden.
ChemInform Abstract: MU(3)‐OXOTRIMETAL ACETATO‐COMPLEXES OF CHROMIUM, MANGANESE, IRON, COBALT, RHODIUM, AND IRIDIUM
Authors: UEMURA SAKAE , SPENCER ALWYN , WILKINSON GEOFFREY
Published: March 2016

Die Komplexe (I) werden durch Umsetzung entsprechender Metall(III)‐Salze mit Na‐acetat und Essigsäure in Äthanol oder Wasser oder Oxidation entsprechender Metall(II)‐acetate zu Aquo‐Analogen der gewünschten Produkte und darauffolgende Reaktion mit den Pyridin‐Liganden in Gegenwart von Na‐perchlorat synthetisiert.
ChemInform Abstract: UEBER DEN CARBENANALOGEN CHARAKTER VON DICYCLOPENTADIENYLZINN(II)
Authors: ALBERT H. J. , SCHROEDER U.
Published: March 2016

Während Dicyclopentadienylzinn(II) (I) mit ungesättigten Kohlenwasserstoffen auch bei 200°C nicht reagiertyerhält es sich bei der spontanen Umsetzung mit Halogenen (II) als Carbenanalogon, wobei (III) entsteht.
ChemInform Abstract: REARRANGEMENTS OF BIMETALLIC COBALTACARBORANES
Authors: EVANS W. J. , JONES C. J. , STIBR B. , HAWTHORNE M. F.
Published: March 2016

Das grüne Carboran (I) gehtdurcheine Kobalt‐Wanderung in das rote (II) über.