bluuebunny/crossref_metadata_2025 huggingface dataset:
SLC6A14, an amino acid transporter, modifies the primary CF defect in fluid secretion
Authors: Ahmadi Saumel , Xia Sunny , Wu Yu-Sheng , Di Paola Michelle , Kissoon Randolph , Luk Catherine , Lin Fan , Du Kai , Rommens Johanna , Bear Christine E
Published: July 2018

The severity of intestinal disease associated with Cystic Fibrosis (CF) is variable in the patient population and this variability is partially conferred by the influence of modifier genes. Genome-wide association studies have identifiedSLC6A14,an electrogenic amino acid transporter, as a genetic modifier of CF-associated meconium ileus. The purpose of the current work was to determine the biological role ofSlc6a14,by disrupting its expression in CF mice bearing the major mutation, F508del. We found that disruption ofSlc6a14worsened the intestinal fluid secretion defect, characteristic of these mice. In vitro studies of mouse intestinal organoids revealed that exacerbation of the primary defect was associated with reduced arginine uptake across the apical membrane, with aberrant nitric oxide and cyclic GMP-mediated regulation of the major CF-causing mutant protein. Together, these studies highlight the role of this apical transporter in modifying cellular nitric oxide levels, residual function of the major CF mutant and potentially, its promise as a therapeutic target.
Reproducible research and GIScience: an evaluation using AGILE conference papers
Authors: Nüst Daniel , Granell Carlos , Hofer Barbara , Konkol Markus , Ostermann Frank O. , Sileryte Rusne , Cerutti Valentina
Published: July 2018

The demand for reproducible research is on the rise in disciplines concerned with data analysis and computational methods. Therefore, we reviewed current recommendations for reproducible research and translated them into criteria for assessing the reproducibility of articles in the field of geographic information science (GIScience). Using this criteria, we assessed a sample of GIScience studies from the Association of Geographic Information Laboratories in Europe (AGILE) conference series, and we collected feedback about the assessment from the study authors. Results from the author feedback indicate that although authors support the concept of performing reproducible research, the incentives for doing this in practice are too small. Therefore, we propose concrete actions for individual researchers and the GIScience conference series to improve transparency and reproducibility. For example, to support researchers in producing reproducible work, the GIScience conference series could offer awards and paper badges, provide author guidelines for computational research, and publish articles in Open Access formats.
Evaluation of antioxidant and neuroprotective activities of Cassia fistula (L.) using the Caenorhabditis elegans model
Authors: Thabit Sara , Handoussa Heba , Roxo Mariana , El Sayed Nesrine S. , Cestari de Azevedo Bruna , Wink Michael
Published: July 2018

Background

Cassia fistula (L.) (Fabaceae) is a medicinal plant from tropical Asia. It is known for its marked antioxidant activity, which is attributed to its high phenolic content. The present study aims at testing both the antioxidant and neuroprotective effects of a hydroalcoholic extract from the aerial parts of Cassia fistula using the Caenorhabditis elegans model, which is widely used in this context.

Methods

Chemical profiling of secondary metabolites that seem to be responsible for both antioxidant and neuroprotective capacities was carried out by HPLC/PDA/ESI-MSn. Antioxidant activity was tested in vitro by CUPRAC and DPPH assays. In vivo antioxidant and neuroprotective activities were investigated using the C. elegans model.

Results

The Cassia extract improved the survival rate of the nematodes and protected them against oxidative stress. In addition, a decrease in the accumulation of reactive oxygen species (ROS) was observed. The important role of DAF-16/FOXO pathway was confirmed through an increased nuclear localization of the DAF-16 transcription factor, increased expression of SOD-3 stress response gene and decreased expression of HSP-16.2. Furthermore, the putative involvement of SKN-1/NRF2 pathway was demonstrated by a decrease in GST-4 levels. A neuroprotective activity of the Cassia extract was shown by a decline in polyglutamine (polyQ40) aggregate formation and a delay in paralysis caused by amyloid beta (Aβ1–42) accumulation.

Discussion

The Cassia extract exhibits substantial antioxidant and neuroprotective activities in vivo, which might provide a rich and novel source of natural antioxidants and neuroprotective compounds to be further studied for the use in various food and cosmetic industrial fields.
Differences in electromyographic activity of biceps brachii and brachioradialis while performing three variants of curl
Authors: Marcolin Giuseppe , Panizzolo Fausto Antonio , Petrone Nicola , Moro Tatiana , Grigoletto Davide , Piccolo Davide , Paoli Antonio
Published: July 2018

Background

Dumbbell curl (DC) and barbell curl in its two variants, straight (BC) or undulated bar (EZ) are typical exercises to train the elbow flexors. The aim of the study was to verify if the execution of these three variants could induce a selective electromyographic (EMG) activity of the biceps brachii (BB) and brachioradialis (BR).

Methods

Twelve participants performed one set of ten repetitions at 65% of their 1-RM for each variant of curl. Pre-gelled electrodes were applied with an inter-electrode distance of 24 mm on BB and BR. An electrical goniometer was synchronously recorded with EMG signals to determine the concentric and eccentric phases of each variant of curl.

Results

We detected higher activation profile of both BB (P < 0.05) and BR (P < 0.01) during the EZ compared to the DC. Higher levels of activation was found during the concentric phase for only the BR performed with an EZ compared to DC (P < 0.001) and performing BC compared to DC (P < 0.05). The eccentric phase showed a higher activation of the BB muscle in EZ compared to DC (P < 0.01) and in BC compared to DC (P < 0.05). The BR muscle showed a higher activation performing EZ compared to DC (P < 0.01).

Discussion

The EZ variant may be preferred over the DC variant as it enhances BB and BR EMG activity during the whole range of motion and only in the eccentric phase. The small difference between BC and EZ variants of the BB and BR EMG activity makes the choice between these two exercises a matter of subjective comfort.
Kinematic characteristics of barefoot sprinting in habitually shod children
Authors: Mizushima Jun , Seki Keitaro , Keogh Justin W.L. , Maeda Kei , Shibata Atsushi , Koyama Hiroyuki , Ohyama-Byun Keigo
Published: July 2018

Background

Anecdotally, a wide variety of benefits of barefoot running have been advocated by numerous individuals. The influence of the alterations in the properties of the shoe on the running movement has been demonstrated in adults at submaximal jogging speeds. However, the biomechanical differences between shod and barefoot running in children at sprinting speeds and the potential developmental implications of these differences are still less examined. The purpose was to determine the potential differences in habitually shod children’s sprint kinematics between shod and barefoot conditions.

Methods

Ninety-four children (51 boys and 43 girls; 6–12 years-old; height, 135.0 ± 0.12 m; body mass, 29.0 ± 6.9 kg) performed 30 m maximal sprints from standing position for each of two conditions (shod and barefoot). To analyze sprint kinematics within sagittal plane sprint kinematics, a high-speed camera (300 fps) was set perpendicular to the runway. In addition, sagittal foot landing and take-off images were recorded for multiple angles by using five high-speed cameras (300 fps). Spatio-temporal variables, the kinematics of the right leg (support leg) and the left leg (recovery leg), and foot strike patterns: rear-foot strike (RFS), mid-foot strike (MFS), and fore-foot strike (FFS) were investigated. The paired t-test was used to test difference between shod and barefoot condition.

Results

Barefoot sprinting in habitually shod children was mainly characterized by significantly lower sprint speed, higher step frequency, shorter step length and stance time. In shod running, 82% of children showed RFS, whereas it decreased to 29% in barefoot condition. The touch down state and the subsequent joint movements of both support and recovery legs during stance phase were significantly altered when running in condition with barefoot.

Discussion

The acute effects of barefoot sprinting was demonstrated by significantly slower sprinting speeds that appear to reflect changes in a variety of spatiotemporal parameters as well as lower limb kinematics. It is currently unknown whether such differences would be observed in children who typically run in bare feet and what developmental benefits and risks may emerge from increasing the proportion of barefoot running and sprinting in children. Future research should therefore investigate potential benefits that barefoot sprinting may have on the development of key physical fitness such as nerve conduction velocity, muscular speed, power, and sprinting technique and on ways to minimize the risk of any acute or chronic injuries associated with this activity.
Effects of two-week e-learning on eHealth literacy: a randomized controlled trial of Japanese Internet users
Authors: Mitsuhashi Toshiharu
Published: July 2018

Background

The Internet is widely used as a source of information by people searching for medical or healthcare information. However, information found on the Internet has several drawbacks, and the ability to consume accurate health information on the Internet (eHealth literacy) is increasingly important. This study’s goal was to clarify the extent to which eHealth literacy is improved after e-learning in a randomized controlled trial.

Methods

Data were collected on 301 Japanese adults through an online survey. Participants were assigned to the intervention (e-learning about eHealth literacy) group or the control group in a 1:1 ratio. The intervention group included 148 participants, and 153 participants were in the control group. The participants provided information at baseline on demographic characteristics, self-rated health, and frequency of Internet searching. The eHealth Literacy Scale (eHEALS), which was the main measure of eHealth literacy, and data on secondary outcomes (the Healthy Eating Literacy Scale and skill for evaluating retrieved search results) were obtained at baseline and at follow-up. The score difference was calculated by subtracting the score at baseline from the score at follow-up. Linear regression analysis and multinomial regression analysis were performed using the differences in score as the dependent variables and the intervention as the explanatory variable. Intention-to-treat analysis was employed.

Results

The results from participants who responded to all of the questions both times were analyzed (134 in the intervention group and 148 in the control group). eHEALS increased 1.57 points due to the intervention effect (Δ score change = 1.57; 95% CI [0.09–3.05]; p = 0.037). Skills for evaluating retrieved search results improved more in the intervention group than in the control group (relative risk ratio = 2.47; 95% Confidence Interval: 1.33, 4.59; p = 0.004). There were no large differences at baseline between the intervention and control groups in the eHEALS, Healthy Eating Literacy scale, or skill for evaluating retrieved search results. However, at follow-up, the intervention group had improved more than the control group on both the eHEALS and skill for evaluating retrieved search results.

Discussion

eHealth literacy improved after the e-learning, as evidenced by the change to the eHEALS scores and increased skill for evaluating retrieved search results. There was no significant effect of e-learning, which did not include content on healthy eating, on the Healthy Eating Literacy Scale scores. This indicates that scores did not increase much due to effects other than e-learning, as is sometimes seen with the Hawthorne effect. Although it was statistically significant, the effect size was small. Therefore, future research is necessary to verify the clinical implications. In sum, this study suggests that e-learning is an effective way to improve eHealth literacy.
Genetic diversity and population structure of the endangered basal angiospermBrasenia schreberi(Cabombaceae) in China
Authors: Li Zhi-Zhong , Gichira Andrew W. , Wang Qing-Feng , Chen Jin-Ming
Published: July 2018

Brasenia schreberiJ.F. Gmelin (Cabombaceae), an aquatic herb that occurs in fragmented locations in China, is rare and endangered. Understanding its genetic diversity and structure is crucial for its conservation and management. In this study, 12 microsatellite markers were used to estimate the genetic diversity and variation in 21 populations ofB. schreberiin China. A total of 61 alleles were found; assessment of allelic richness (Ar = 1.92) and observed and expected heterozygosity (HO= 0.200,HE= 0.256) suggest lower genetic diversity compared to some endangered species, and higher variation was observed within populations (58.68%) rather than among populations (41.32%). No significant correlation between geographical and genetic distance among populations was detected (Mantel test,r= 0.0694;P= 0.7985), which may have likely resulted from barriers to gene flow (Nm = 0.361) that were produced by habitat fragmentation. However, Bayesian and neighbor-joining cluster analyses suggest a population genetic structure consisting of two clusters (I and II) or four subclusters (I-1, 2 and II-1, 2). The genetic structure and distribution ofB. schreberiin China may have involved glacial refugia that underwent range expansions, introgression, and habitat fragmentation. The findings of the present study emphasize the importance for both in situ and ex situ conservation efforts.
Adaptive switching control of uncertain fractional systems: Application to Chua's circuit
Authors: Aghababa Mohammad Pourmahmood
Published: July 2018

Since the introduction of fractional‐order differential equations, there has been much research interest in synthesis and control of oscillatory, periodic, and chaotic fractional‐order dynamical systems. Therefore, in this article, the problem of stabilization and control of nonlinear three‐dimensional perturbed fractional nonlinear systems is considered. The major novelty of this article is handling partially unknown dynamics of nonlinear fractional‐order systems, as well as coping with input saturation along the existence of model variations and high‐frequency sensor noises via just one control input. The method supposes no known knowledge on the upper bounds of the uncertainties and perturbations. It is assumed that the working region of the input saturation function is also unknown. After the introduction of a simple finite‐time stable nonlinear sliding manifold, an adaptive control technique is used to reach the system variables to the sliding surface. Rigorous stability discussions are adopted to prove the convergence of the developed sliding mode controller. The findings of this research are illustrated using providing computer simulations for the control problem of the chaotic unified system and the fractional Chua's circuit model.
Engineering the Electrochemical Temperature Coefficient for Efficient Low‐Grade Heat Harvesting
Authors: Gao Caitian , Yin Yuling , Zheng Lu , Liu Yezhou , Sim Soojin , He Yongmin , Zhu Chao , Liu Zheng , Lee Hyun‐Wook , Yuan Qinghong , Lee Seok Woo
Published: July 2018

Low‐grade heat to electricity conversion has shown a large potential for sustainable energy supply. Recently, the low‐grade heat harvesting in the thermally regenerative electrochemical cycle (TREC) is a promising candidate with high energy conversion efficiency. In this system, the electrochemical temperature coefficient (α) plays a dominant role in efficient heat harvesting. However, the internal factors that affect α are still not clear and significant improvements are needed. Here, α of various Prussian Blue analogues (PBAs) is investigated and their lattice change during cation intercalation is monitored using the ex situ X‐ray diffraction (XRD) method. For the first time, it is found that α is highly related to the lattice parameter change. Large lattice shrinkage exhibits a large negative α, while lattice expansion is corresponding to a positive α. These are mainly attributed to the different phonon vibration entropy changes upon cation intercalation in various PBAs. Especially, purple cobalt hexacynoferrate delivers the largest α of −0.89 mV K−1 and enables highly efficient heat conversion efficiency up to 2.65% (21% of relative efficiency). The results of this study provide a fundamental understanding of temperature coefficient in electrochemical reactions and pave the way for designing high‐performance material for low‐grade heat harvesting.
Tunable Enzymatically Cross‐Linked Silk Fibroin Tubular Conduits for Guided Tissue Regeneration
Authors: Carvalho Cristiana R. , Costa João B. , da Silva Morais Alain , López‐Cebral Rita , Silva‐Correia Joana , Reis Rui L. , Oliveira J. Miguel
Published: July 2018

Hollow tubular conduits (TCs) with tunable architecture and biological properties are in great need for modulating cell functions and drug delivery in guided tissue regeneration. Here, a new methodology to produce enzymatically cross‐linked silk fibroin TCs is described, which takes advantage of the tyrosine groups present in silk structure that are known to allow the formation of a covalently cross‐linked hydrogel. Three different processing methods are used as a final step to modulate the properties of the silk‐based TCs. This approach allows to virtually adjust any characteristic of the final TCs. The final microstructure ranges from a nonporous to a highly porous network, allowing the TCs to be selectively porous to 4 kDa molecules, but not to human skin fibroblasts. Mechanical properties are dependent both on the processing method and thickness of the TCs. Bioactivity is observed after 30 days of immersion in simulated body fluid only for the TCs submitted to a drying processing method (50 °C). The in vivo study performed in mice demonstrates the good biocompatibility of the TCs. The enzymatically cross‐linked silk fibroin TCs are versatile and have adjustable characteristics that can be exploited in a variety of biomedical applications, particularly in guidance of peripheral nerve regeneration.
“Smart” Nanoprobes for Visualization of Tumor Microenvironments
Authors: Ma Tiancong , Zhang Peisen , Hou Yi , Ning Haoran , Wang Zihua , Huang Jiayi , Gao Mingyuan
Published: July 2018

Physiological parameters in tumor microenvironments, including hypoxia, low extracellular pH, enzymes, reducing conditions, and so on, are closely associated with the proliferation, angiogenesis, invasion, and metastasis of cancer, and impact the therapeutic administrations. Therefore, monitoring the tumor microenvironment is significant for diagnosing tumors, predicting the invasion potential, evaluating therapeutic efficacy, planning the treatment, and cancer prognostics. Noninvasive molecular imaging technologies combined with novel “smart” nanoparticle‐based activatable probes provide a feasible approach to visualize tumor‐associated microenvironment factors. This review summarizes recent achievements in the designs of “smart” molecular imaging nanoprobes responding to the tumor microenvironment–related features, and highlights the state of the art in tumor heterogeneity imaging.
Selective Synthesis of Benzo[a]Carbazoles and Indolo[2,1‐a]‐Isoquinolines via Rh(III)‐Catalyzed C−H Functionalizations of 2‐Arylindoles with Sulfoxonium Ylides
Authors: Chen Guang , Zhang Xinying , Jia Ruixue , Li Bin , Fan Xuesen
Published: July 2018

A highly chem‐ and regioselective synthesis of diversely substituted benzo[a]carbazoles and indolo[2,1‐a]‐isoquinolines through Rh(III)‐catalyzed cascade reactions of 2‐arylindoles with sulfoxonium ylides is presented. To be specific, treatment of 2‐arylindoles, 2‐arylindole‐3‐carbaldehydes, 2‐arylindole‐3‐carbonitriles or 2‐aryl‐3‐methylindoles with sulfoxonium ylides under the catalysis of Rh(III) led to the selective formation of 6‐aryl/alkyl benzo[a]carbazoles, 5‐acylbenzo[a]carbazoles, 6‐amino‐5‐acylbenzo[a]carbazoles or 12‐methylindolo[2,1‐a]isoquinolines, respectively. Mechanistically, the formation of the title compounds involves a cascade process including metalation of the inert C(sp2)−H bond, migratory insertion of ylide into the carbon‐metal bond via an in situ carbenoid formation, protodemetalation, and condensation. To our knowledge, this is the first example in which β‐carbonyl sulfoxonium ylides were used as stable carbene precursors and bifunctional C2 synthons to afford benzo[a]carbazoles and indolo[2,1‐a]isoquinolines.

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Does information about organic status affect consumer sensory liking and willingness to pay for beer?
Authors: Waldrop Megan E. , McCluskey Jill J.
Published: July 2018

The organic beer market is in its infancy, but the product category is growing at a high rate. This study evaluates how information about organic status affects consumers’ willingness to pay and sensory liking for beer. Consumer sensory panels were conducted for the purpose of this study with information treatments and valuation questions. In our sample, informing consumers that beer is organic or certified organic does not significantly affect sensory liking scores, and certified organic has a negative marginal effect on willingness to pay, providing evidence that organic is not a vertical quality attribute for beer. However, panelists who regularly purchase craft beer, care about the environment, and/or have an openness to new foods have a higher willingness to pay for organic beer. Our findings suggest that organic beer appeals to a niche market of consumers. [EconLit citations: L15, L66, Q13]
Bioclimatic factors at an intrabiome scale are more limiting than cyanobiont availability for the lichen‐forming genus Peltigera
Authors: Lu Jade , Magain Nicolas , Miadlikowska Jolanta , Coyle Jessica R. , Truong Camille , Lutzoni François
Published: July 2018

Premise of the Study

Factors shaping spatiotemporal patterns of associations in mutualistic systems are poorly understood. We used the lichen‐forming fungi Peltigera and their cyanobacterial partners Nostoc to investigate the spatial structure of this symbiosis at an intrabiome scale and to identify potential factors shaping these associations.

Methods

Ninety‐three thalli were sampled in Québec, Canada, along a south–north and an east–west transect of ~1300 km each. We identified the two main partners (Peltigera species and Nostoc phylogroups) using molecular markers and modeled the effects of environmental variables and partner occurrence on Peltigera–Nostoc distributions.

Key Results

Peltigera species showed a high degree of specialization toward cyanobionts, whereas two Nostoc phylogroups dominated both transects by associating with several Peltigera species. Peltigera species had narrower ranges than these two main cyanobionts. Distributions of three Peltigera species were highly associated with precipitation and temperature variables, which was not detected for Nostoc phylogroups at this spatial scale.

Conclusions

For these cyanolichens, factors driving patterns of symbiotic associations are scale dependent. Contrary to global‐scale findings, generalist Peltigera species were not more widespread within the boreal biome than specialists. Nostoc availability was not the only driver of Peltigera species’ geographic ranges; environmental factors also contributed to their intrabiome distributions. Climatic conditions (especially precipitation) limited the range of some Peltigera species more than the range of their cyanobacterial partners at an intrabiome (boreal) scale.
Quality indicators for the diagnosis and management of chronic rhinosinusitis
Authors: Cottrell Justin , Yip Jonathan , Chan Yvonne , Chin Christopher J. , Damji Ali , de Almeida John R. , Desrosiers Martin , Janjua Arif , Kilty Shaun , Lee John M. , Macdonald Kristian I. , Meen Eric K. , Rudmik Luke , Sommer Doron D. , Sowerby Leigh , Tewfik Marc A. , Vescan Allan D. , Witterick Ian J. , Wright Erin , Monteiro Eric
Published: July 2018

Background

Chronic rhinosinusitis (CRS) has been identified as a high‐priority disease category for quality improvement. To this end, this study aimed to develop CRS‐specific quality indicators (QIs) to evaluate diagnosis and management that relieves patient discomfort, improves quality of life, and prevents complications.

Methods

A guideline‐based approach, proposed in 2012 by Kötter et al. was used to develop QIs for CRS. Candidate indicators (CIs) were extracted from 3 practice guidelines and 1 international consensus statement on the diagnosis and management of CRS. Guidelines were evaluated using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool. Each CI and its supporting evidence was summarized and reviewed by an expert panel based on validity, reliability, and feasibility of measurement. Final QIs were selected from CIs utilizing the modified RAND Corporation–University of California, Los Angeles (RAND/UCLA) appropriateness methodology.

Results

Thirty‐nine CIs were identified after literature review and evaluated by our panel. Of these, 9 CIs reached consensus as being appropriate QIs, with 4 requiring additional discussion. After a second round of evaluations, the panel selected 9 QIs as appropriate measures of high‐quality care.

Conclusion

This study proposes 9 QIs for the diagnosis and management of patients with CRS. These QIs can serve multiple purposes, including documenting the quality of care; comparing institutions and providers; prioritizing quality improvement initiatives; supporting accountability, regulation, and accreditation; and determining pay‐for‐performance initiatives.
Hochdurchsatz‐Metabolomik mit 1D‐NMR
Authors: Vignoli Alessia , Ghini Veronica , Meoni Gaia , Licari Cristina , Takis Panteleimon G. , Tenori Leonardo , Turano Paola , Luchinat Claudio
Published: July 2018

Metabolomik befasst sich mit der Gesamtheit aller Metabolite, dem Metabolom. Als eine der “Omics”‐Wissenschaften hat sie Querbeziehungen zur Biologie, Physiologie, Pathologie und Medizin; andererseits sind Metabolite chemische Verbindungen, kleine organische Moleküle oder anorganische Ionen. Ihre korrekte Identifizierung und Quantifizierung in komplexen biologischen Matrizen erfordert daher eine solide chemische Grundlage. Im Vergleich beispielsweise zu DNA unterliegen Metabolite sehr viel stärker der Oxidation oder dem enzymatischen Abbau: Wir können große Teile eines Mammut‐Genoms aus einer kleinen Probe rekonstruieren, sind aber nicht in der Lage, dasselbe mit seinem Metabolom zu tun, das innerhalb weniger Stunden nach dem Tod des Tieres wahrscheinlich weitgehend abgebaut war. Erforderlich sind daher Standardverfahren, gute chemische Fertigkeiten der Probenvorbereitung für die Lagerung und anschließende Analyse, genaue analytische Protokolle, eine umfangreiche Kenntnis der Chemometrie, erweiterte statistische Verfahren und fundiertes Wissen über mindestens eine der beiden Metabolomik‐typischen Verfahren, MS oder NMR. All diese Fertigkeiten besitzen traditionell die Chemiker. Entsprechend betrachten wir die Metabolomik aus chemischer Perspektive und beschränken uns auf NMR. Der Analytiker findet Argumente für und gegen NMR, jedoch bietet das Verfahren eine besondere ganzheitliche Perspektive, die für künftige Anwendungen als eine bevölkerungsweite Screeningtechnik für Reihenuntersuchungen sprechen.
Probing Interfacial Electronic and Catalytic Properties on Well‐Defined Surfaces by Using In Situ Raman Spectroscopy
Authors: Wang Ya‐Hao , Liang Miao‐Miao , Zhang Yue‐Jiao , Chen Shu , Radjenovic Petar , Zhang Hua , Yang Zhi‐Lin , Zhou Xiao‐Shun , Tian Zhong‐Qun , Li Jian‐Feng
Published: July 2018

Heterogeneous metal interfaces play a key role in determining the mechanism and performance of catalysts. However, in situ characterization of such interfaces at the molecular level is challenging. Herein, two model interfaces, Pd and Pt overlayers on Au single crystals, were constructed. The electronic structures of these interfaces as well as effects of crystallographic orientation on them were analyzed by shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS) using phenyl isocyanide (PIC) as a probe molecule. A clear red shift in the frequency of the C≡N stretch (νNC) was observed, which is consistent with X‐ray photoelectron spectroscopy (XPS) data and indicates that the ultrathin Pt and Pd layers donate their free electrons to the Au substrates. Furthermore, in situ electrochemical SHINERS studies showed that the electronic effects weaken Pt−C/Pd−C bonds, leading to improved surface activity towards CO electrooxidation.
Porous Ionic Liquids or Liquid Metal–Organic Frameworks?
Authors: Costa Gomes Margarida , Pison Laure , Červinka Ctirad , Padua Agilio
Published: July 2018

Porous liquids can be prepared from the dispersion metal–organic frameworks (MOFs) in ionic liquids (ILs). Porous liquids prepared from 5 % of ZIF‐8 in a phosphonium‐based ionic liquid are capable of absorbing reversibly up to 150 % more nitrogen and 100 % more methane than the pure ionic liquid.
Elastically Flexible Crystals have Disparate Mechanisms of Molecular Movement Induced by Strain and Heat
Authors: Brock Aidan J. , Whittaker Jacob J. , Powell Joshua A. , Pfrunder Michael C. , Grosjean Arnaud , Parsons Simon , McMurtrie John C. , Clegg Jack K.
Published: July 2018

Elastically flexible crystals form an emerging class of materials that exhibit a range of notable properties. The mechanism of thermal expansion in flexible crystals of bis(acetylacetonato)copper(II) is compared with the mechanism of molecular motion induced by bending and it is demonstrated that the two mechanisms are distinct. Upon bending, individual molecules within the crystal structure reversibly rotate, while thermal expansion results predominantly in an increase in intermolecular separations with only minor changes to molecular orientation through rotation.
Highly Emissive Self‐Trapped Excitons in Fully Inorganic Zero‐Dimensional Tin Halides
Authors: Benin Bogdan M. , Dirin Dmitry N. , Morad Viktoriia , Wörle Michael , Yakunin Sergii , Rainò Gabriele , Nazarenko Olga , Fischer Markus , Infante Ivan , Kovalenko Maksym V.
Published: July 2018

The spatial localization of charge carriers to promote the formation of bound excitons and concomitantly enhance radiative recombination has long been a goal for luminescent semiconductors. Zero‐dimensional materials structurally impose carrier localization and result in the formation of localized Frenkel excitons. Now the fully inorganic, perovskite‐derived zero‐dimensional SnII material Cs4SnBr6 is presented that exhibits room‐temperature broad‐band photoluminescence centered at 540 nm with a quantum yield (QY) of 15±5 %. A series of analogous compositions following the general formula Cs4−xAxSn(Br1−yIy)6 (A=Rb, K; x≤1, y≤1) can be prepared. The emission of these materials ranges from 500 nm to 620 nm with the possibility to compositionally tune the Stokes shift and the self‐trapped exciton emission bands.
Materialien und Strukturen für schluckbare elektromechanische medizinische Funktionseinheiten
Authors: Bettinger Christopher J.
Published: July 2018

Schluckbare Biomedizinprodukte diagnostizieren, verhindern und behandeln ein breites Spektrum von Krankheiten und waren über Jahrzehnte der Traum von Ingenieuren und Klinikern. Der steigende Stellenwert der Darmgesundheit für das allgemeine Wohlbefinden sowie die Prävalenz vieler gastrointestinaler Erkrankungen haben die Aufmerksamkeit auf diese aufstrebende Klasse medizinischer Hilfsmittel neu geweckt. Es gibt mehrere prominente Beispiele von kommerziell erfolgreichen, schluckbaren Medizinprodukten. Dennoch bleiben viele technische Herausforderungen zu lösen, bevor schluckbare Medizinprodukte ihr volles klinisches Potenzial ausschöpfen können. Dieser Kurzaufsatz fasst neuste Entdeckungen in diesem interdisziplinären Gebiet zusammen, einschließlich neuartiger Materialien, moderner Verarbeitungstechniken für Materialien und ausgewählter Beispiele integrierter schluckbarer elektromechanischer Systeme. Nach einer kurzen historischen Betrachtung werden diese Themen mit einem speziellen Fokus auf modernen Funktionsmaterialien und Herstellungsstrategien im Kontext der klinischen Translation und potenzieller regulatorischer Überlegungen diskutiert. Zukünftige Perspektiven, Herausforderungen und Chancen des Gebiets werden ebenfalls zusammengefasst.
A Mechanism‐Based Approach to Screening Metagenomic Libraries for Discovery of Unconventional Glycosidases
Authors: Nasseri Seyed Amirhossein , Betschart Leo , Opaleva Daria , Rahfeld Peter , Withers Stephen G.
Published: July 2018

Functional metagenomics has opened new opportunities for enzyme discovery. To exploit the full potential of this new tool, the design of selective screens is essential, especially when searching for rare enzymes. To identify novel glycosidases that employ cleavage strategies other than the conventional Koshland mechanisms, a suitable screen was needed. Focusing on the unsaturated glucuronidases (UGLs), it was found that use of simple aryl glycoside substrates did not allow sufficient discrimination against β‐glucuronidases, which are widespread in bacteria. While conventional glycosidases cannot generally hydrolyze thioglycosides efficiently, UGLs follow a distinct mechanism that allows them to do so. Thus, fluorogenic thioglycoside substrates featuring thiol‐based self‐immolative linkers were synthesized and assessed as selective substrates. The generality of the approach was validated with another family of unconventional glycosidases, the GH4 enzymes. Finally, the utility of these substrates was tested by screening a small metagenomic library.
Synthesis and Reactivity of Multiple Phosphine‐Functionalized Nonagermanide Clusters
Authors: Geitner Felix S. , Klein Wilhelm , Fässler Thomas F.
Published: July 2018

Herein we report on the synthesis of the first multiple phosphine‐substituted nonagermanide clusters in a one‐step reaction from K4Ge9. Their reactions towards various transition metal complexes show a large variety of reactive sites. The novel threefold phosphine‐functionalized [Ge9] clusters [Ge9{PRRI}3]− {R: NiPr2; RI: NiPr2 (1 a) or tBu (2 a)} are obtained by reaction of pristine [Ge9]4− clusters with the respective chlorophosphines. Subsequent reactions with NHCDippCuCl yield neutral compounds (NHCDippCu)[Ge9{P(NiPr2)2}3] (3) and (NHCDippCu)[Ge9{P(NiPr2)tBu}3] (4), respectively. The reaction of neutral compound 3 with Cr(CO)5(thf) yields the first uncharged fivefold substituted [Ge9] cluster (NHCDippCu)2[Ge9{P(NiPr2)2}2Cr(CO)5] (5) via a ligand exchange reaction at the [Ge9] cluster core. Compounds 3 and 5 are characterized by single crystal structure determination.
Adsorbed Intermediates in Oxygen Reduction on Platinum Nanoparticles Observed by In Situ IR Spectroscopy
Authors: Nayak Simantini , McPherson Ian J. , Vincent Kylie A.
Published: July 2018

The sluggish kinetics of oxygen reduction to water remains a significant limitation in the viability of proton‐exchange‐membrane fuel cells, yet details of the four‐electron oxygen reduction reaction remain elusive. Herein, we apply in situ infrared spectroscopy to probe the surface chemistry of a commercial carbon‐supported Pt nanoparticle catalyst during oxygen reduction. The IR spectra show potential‐dependent appearance of adsorbed superoxide and hydroperoxide intermediates on Pt. This strongly supports an associative pathway for oxygen reduction. Analysis of the adsorbates alongside the catalytic current suggests that another pathway must also be in operation, consistent with a parallel dissociative pathway.
Metal‐Free Synthesis of Pharmaceutically Important Biaryls by Photosplicing
Authors: Kloss Florian , Neuwirth Toni , Haensch Veit G. , Hertweck Christian
Published: July 2018

Many pharmaceuticals feature biaryl motifs that are crucial for their binding to the target. Yet, benchmark methods for selective cross‐couplings rely on highly toxic heavy metal catalysts, which are unfavorable in the synthesis of pharmaceuticals. Metal‐free coupling reactions, on the other hand, may require harsh conditions and lack selectivity. We report a novel, metal‐free cross‐coupling reaction that involves the tethering of two phenyl groups by a temporary, traceless sulfonamide linker that directs a photochemical aryl fusion into a single coupling product. The perfect regio‐ and chemoselectivity of the reaction could be rationalized by a cyclic intermediate, which fragments into the biaryl and volatile side products. Using a flow reactor, we synthesized numerous substituted biaryl building blocks for important therapeutics in high yields, such as antibiotics, antitumor, neuroprotective and cholesterol‐lowering agents as well as antiarthritic non‐steroidal antiinflammatory drugs (NSAIDs). The new method was successfully employed in a total synthesis of cannabinol, an important analgesic and antiemetic therapeutic. We also report a metal‐free synthesis of key building blocks used for the preparation of sartans, antihypertensive agents that rank among the top blockbuster drugs worldwide. This safe and convenient protocol is a valuable alternative for the widely used metal‐dependent aryl cross‐coupling methods.
Known Unknowns of Mammalian Mitochondrial DNA Maintenance
Authors: Pohjoismäki Jaakko L. O. , Forslund Josefin M. E. , Goffart Steffi , Torregrosa‐Muñumer Rubén , Wanrooij Sjoerd
Published: July 2018

Mammalian mitochondrial DNA (mtDNA) replication and repair have been studied intensively for the last 50 years. Although recently advances in elucidating the molecular mechanisms of mtDNA maintenance and the proteins involved in these have been made, there are disturbing gaps between the existing theoretical models and experimental observations. Conflicting data and hypotheses exist about the role of RNA and ribonucleotides in mtDNA replication, but also about the priming of replication and the formation of pathological rearrangements. In the presented review, we have attempted to match these loose ends and draft consensus where it can be found, while identifying outstanding issues for future research.
Determination of vortioxetine and its degradation product in bulk and tablets, by LC‐DAD and MS/MS methods
Authors: de Diego Marta , Correa Diana , Mennickent Sigrid , Godoy Ricardo , Vergara Carola
Published: July 2018

Vortioxetine hydrobromide (VOR), is a novel antidepressant used for the treatment of major depressive disorder. It has a chemical structure susceptible to degradation, therefore it is important to have suitable analytical methods to determine VOR in presence of its main degradation products (DP), because if the compound degrades, this could result in diminution of the therapeutic activity and safety. A simple HPLC method with photodiode array detection was developed and validated for determination of VOR in bulk and tablets, in the presence of its major DP. The drug was subjected to oxidative, hydrolytic, and photolytic stress conditions, showing significant degradation under oxidation with the formation of one DP, which was identified by ESI‐MS/MS. A C18 column was used, with mobile phase consisting of acetonitrile and water with acetic acid and triethylamine in isocratic elution mode, with detection at 228 nm and 1.0 mL/min flow rate. The assay was linear in the 25–125 μg/mL concentration range. For precision, the RSD was <1.8%, the recovery was 100.0–101.6%, and the method demonstrated adequate selectivity. The method was successfully applied to quantify VOR in tablets. The results showed that the method is useful for routine analysis and for quality control purposes.
Study reveals how mobile apps can evaluate individual student‐athletes' risk of injuries
Authors: McCarthy Claudine
Published: July 2018

Student‐athlete safety easily ranks as one of the top concerns for college athletics administrators — and with good reason.
The Photosensitising Clinical Agent Verteporfin Is an Inhibitor of SPAK and OSR1 Kinases
Authors: AlAmri Mubarak A. , Kadri Hachemi , Alderwick Luke J. , Jeeves Mark , Mehellou Youcef
Published: July 2018

STE20/SPS1‐related proline/alanine‐rich kinase (SPAK) and oxidative‐stress‐responsive kinase 1 (OSR1) are two serine/threonine protein kinases that play key roles in regulating ion homeostasis. Various SPAK and OSR1 mouse models exhibited reduced blood pressure. Herein, the discovery of verteporfin, a photosensitising agent used in photodynamic therapy, as a potent inhibitor of SPAK and OSR1 kinases is reported. It is shown that verteporfin binds the kinase domains of SPAK and OSR1 and inhibits their catalytic activity in an adenosine triphosphate (ATP)‐independent manner. In cells, verteporfin was able to suppress the phosphorylation of the ion co‐transporter NKCC1; a downstream physiological substrate of SPAK and OSR1 kinases. Kinase panel screening indicated that verteporfin inhibited a further eight protein kinases more potently than that of SPAK and OSR1. Although verteporfin has largely been studied as a modifier of the Hippo signalling pathway, this work indicates that the WNK‐SPAK/OSR1 signalling cascade is also a target of this clinical agent. This finding could explain the fluctuation in blood pressure noted in patients and animals treated with this drug.
Tuning Zeolite Properties for a Highly Efficient Synthesis of Propylene from Methanol
Authors: Palčić Ana , Ordomsky Vitaly V. , Qin Zhengxing , Georgieva Veselina , Valtchev Valentin
Published: July 2018

A series of nanosized ZSM‐5 samples was synthesized at 170, 150, 120, and 100 °C. Experimental data show that the decrease of crystallization temperature leads to significant changes in zeolite properties. Crystals synthesized at 100 °C exhibit many framework defects with lower acid‐site density, strength, and a larger external surface area. The selectivity to light olefins and the propylene‐to‐ethylene ratio increases as the crystallization temperature decreases. A propylene‐to‐ethylene ratio of above 6 with the highest selectivity to propylene of 53 % was obtained over ZSM‐5 catalyst prepared at 100 °C. The stability of the nanosized zeolite in methanol to olefins (MTO) was also improved compared to the industrial sample with a similar Si/Al ratio. This catalytic performance is a result of the decrease in the acid‐site density, strength, and the crystals’ size, providing a shorter diffusion path and larger external surface area. The presence of structural defects and a different external surface in the crystals has been shown to play an important role in the MTO catalyst performance.
You won't believe this old test … that does cheap single‐cell mutation detection
Authors: Köbel Martin , Anglesio Michael S. , Brenton James D.
Published: July 2018

Detecting mutations in single cells from cancer specimens is now a major area of translational research. In a recent article in this journal, Khalique et al validated an immunohistochemistry assay for ARID1A that reliably identifies loss of function mutations in single cells in tissue sections. This work exemplifies best practice for developing and orthogonally validating immunohistochemical assays to provide clearly interpretable mutational results with spatial context.
In Situ Tracking of Organic Reactions at the Vapor/Liquid Interfaces of Ionic Liquids
Authors: Song Yuting , Huo Feng , Jiang Yi , Zhang Suojiang , Chen Shimou
Published: July 2018

The molecular structures of ionic liquids at interfaces play a crucial role in determining their chemical activities in applications. In situ X‐ray photoelectron spectroscopy (XPS) was used to track the evolution of X‐ray irradiation‐induced chemical reactions in a series of ionic liquids ([Cnmim][AuCl4]; n=4, 6, 8, 10) on the Si (111) single‐crystal surface. Analyses of microstructure and chemical bonding based on the XPS results indicated that reactions occurred at the vapor/liquid interfaces of the ionic liquids. The time‐resolved XPS spectra revealed that with increasing irradiation time, the intensity of the peak corresponding to trivalent Au anion decreased for the four ionic liquids as Au was continually reduced to a lower chemical state and finally converted to gold nanoparticles. The rate and conversion of the reaction were associated with the length of the alkyl chain of the ionic liquids cation. Molecular dynamics simulations further revealed that the alkyl chain of the cation in the ionic liquids was oriented towards the vacuum environment at the vapor/liquid interface. Our results provide a real‐time atomic‐scale experimental evidence of organic reactions at the vapor/liquid interfaces of ionic liquids. The findings are important for understanding the roles of ionic liquids in catalysis, separation, electrochemistry, functional materials, and so on.
Energy‐efficient power control for uplink spectrum‐sharing heterogeneous networks
Authors: Pham Quoc‐Viet , Hwang Won‐Joo
Published: July 2018

This article considers energy‐efficient power control schemes for interference management in uplink spectrum‐sharing heterogeneous networks that maximize the energy efficiency of users, protect the macro base station, and support users with QoS consideration. In the first scenario, we define the objective function as the weighted sum of the energy efficiencies and develop an efficient global optimization algorithm with global linear and local quadratic rate of convergence to solve the considered problem. To ensure fairness among individual user equipments (UEs) in terms of energy efficiency, we consider the max‐min problem, where the objective is defined as the weighted minimum of the energy efficiencies, and a fractional programming theory and the dual decomposition method are jointly used to solve the problem and investigate an iterative algorithm. As by‐products, we further discuss the global energy efficiency problem and consider near‐optimal schemes. Numerical examples are provided to demonstrate significant improvements of the proposed algorithms over existing interference management schemes.
Experimental field tests of Batesian mimicry in the swallowtail butterfly Papilio polytes
Authors: Palmer Daniela H. , Tan Yue Qian , Finkbeiner Susan D. , Briscoe Adriana D. , Monteiro Antónia , Kronforst Marcus R.
Published: July 2018

The swallowtail butterfly Papilio polytes is known for its striking resemblance in wing pattern to the toxic butterfly Pachliopta aristolochiae and is a focal system for the study of mimicry evolution. Papilio polytes females are polymorphic in wing pattern, with mimetic and nonmimetic forms, while males are monomorphic and nonmimetic. Past work invokes selection for mimicry as the driving force behind wing pattern evolution in P. polytes. However, the mimetic relationship between P. polytes and P. aristolochiae is not well understood. In order to test the mimicry hypothesis, we constructed paper replicas of mimetic and nonmimetic P. polytes and P. aristolochiae, placed them in their natural habitat, and measured bird predation on replicas. In initial trials with stationary replicas and plasticine bodies, overall predation was low and we found no differences in predation between replica types. In later trials with replicas mounted on springs and with live mealworms standing in for the butterfly's body, we found less predation on mimetic P. polytes replicas compared to nonmimetic P. polytes replicas, consistent with the predator avoidance benefits of mimicry. While our results are mixed, they generally lend support to the mimicry hypothesis as well as the idea that behavioral differences between the sexes contributed to the evolution of sexually dimorphic mimicry.