bluuebunny/crossref_metadata_2025 huggingface dataset:
Accelerated remyelination during inflammatory demyelination prevents axonal loss and improves functional recovery
Authors: Mei Feng , Lehmann-Horn Klaus , Shen Yun-An A , Rankin Kelsey A , Stebbins Karin J , Lorrain Daniel S , Pekarek Kara , A Sagan Sharon , Xiao Lan , Teuscher Cory , von Büdingen H-Christian , Wess Jürgen , Lawrence J Josh , Green Ari J , Fancy Stephen PJ , Zamvil Scott S , Chan Jonah R
Published: September 2016

Demyelination in MS disrupts nerve signals and contributes to axon degeneration. While remyelination promises to restore lost function, it remains unclear whether remyelination will prevent axonal loss. Inflammatory demyelination is accompanied by significant neuronal loss in the experimental autoimmune encephalomyelitis (EAE) mouse model and evidence for remyelination in this model is complicated by ongoing inflammation, degeneration and possible remyelination. Demonstrating the functional significance of remyelination necessitates selectively altering the timing of remyelination relative to inflammation and degeneration. We demonstrate accelerated remyelination after EAE induction by direct lineage analysis and hypothesize that newly formed myelin remains stable at the height of inflammation due in part to the absence of MOG expression in immature myelin. Oligodendroglial-specific genetic ablation of the M1 muscarinic receptor, a potent negative regulator of oligodendrocyte differentiation and myelination, results in accelerated remyelination, preventing axonal loss and improving functional recovery. Together our findings demonstrate that accelerated remyelination supports axonal integrity and neuronal function after inflammatory demyelination.
Proteins from the past
Authors: Wallace Adam F , Schiffbauer James D
Published: September 2016

Some fragments of ancient protein are less prone to degradation because they bind strongly to the surfaces of minerals.
Genetic diversity ofPoa pratensisL. depending on geographical origin and compared with genetic markers
Authors: Szenejko Magdalena , Śmietana Przemysław , Stępień Edyta
Published: September 2016

Background

Poa pratensisis one of the most common species of meadow grass in Europe. Most cultivars of the species found in Poland were originally derived from its ecotypes. We compared the effectiveness of the RAPD and ISSR methods in assessing the genetic diversity of the selected populations ofP. pratensis. We examined whether these methods could be useful for detecting a possible link between the geographical origin of a given population and its assessed genetic variation.

Methods

The molecular markers RAPD and ISSR were used and their efficiency compared using, inter alia, statistical multivariate methods (UPGMA and PCA).

Results

The low value of Dice’s coefficient (0.369) along with the significantly high percentage of polymorphic products indicates a substantial degree of genetic diversity among the studied populations. Our results found a correlation between the geographical origin of the studied populations and their genetic variations. For ISSR, which proved to be the more effective method in that respect, we selected primers with the greatest differentiating powers correlating to geographical origin.

Discussion

The populations evaluated in this study were characterized by a high genetic diversity. This seems to confirm the hypothesis that ecotypes ofP. pratensisoriginating from different regions of Central Europe with different terrain structures and habitat conditions can be a source of great genetic variability.
Sex differences in pacing during ‘Ultraman Hawaii’
Authors: Knechtle Beat , Nikolaidis Pantelis T.
Published: September 2016

Background

To date, little is known for pacing in ultra-endurance athletes competing in a non-stop event and in a multi-stage event, and especially, about pacing in a multi-stage event with different disciplines during the stages. Therefore, the aim of the present study was to examine the effect of age, sex and calendar year on triathlon performance and variation of performance by events (i.e., swimming, cycling 1, cycling 2 and running) in ‘Ultraman Hawaii’ held between 1983 and 2015.

Methods

Within each sex, participants were grouped in quartiles (i.e., Q1, Q2, Q3 and Q4) with Q1 being the fastest (i.e., lowest overall time) and Q4 the slowest (i.e., highest overall time). To compare performance among events (i.e., swimming, cycling 1, cycling 2 and running), race time in each event was converted inzscore and this value was used for further analysis.

Results

A between-within subjects ANOVA showed a large sex × event (p= 0.015,η2= 0.014) and a medium performance group × event interaction (p= 0.001,η2= 0.012). No main effect of event on performance was observed (p= 0.174,η2= 0.007). With regard to the sex × event interaction, three female performance groups (i.e., Q2, Q3 and Q4) increased race time from swimming to cycling 1, whereas only one male performance group (Q4) revealed a similar trend. From cycling 1 to cycling 2, the two slower female groups (Q3 and Q4) and the slowest male group (Q4) increased raced time. In women, the fastest group decreased (i.e., improved) race time from swimming to cycling 1 and thereafter, maintained performance, whereas in men, the fastest group decreased race time till cycling 2 and increased it in the running.

Conclusion

In summary, women pace differently than men during ‘Ultraman Hawaii’ where the fastest women decreased performance on day 1 and could then maintain on day 2 and 3, whereas the fastest men worsened performance on day 1 and 2 but improved on day 3.
Carbon monoxide shifts energetic metabolism from glycolysis to oxidative phosphorylation in endothelial cells
Authors: Kaczara Patrycja , Motterlini Roberto , Kus Kamil , Zakrzewska Agnieszka , Abramov Andrey Y. , Chlopicki Stefan
Published: September 2016

Carbon monoxide (CO) modulates mitochondrial respiration, but the mechanisms involved are not completely understood. The aim of the present study was to investigate the acute effects of CO on bioenergetics and metabolism in intact EA.hy926 endothelial cells using live cell imaging techniques. Our findings indicate that CORM‐401, a compound that liberates CO, reduces ATP production from glycolysis, and induces a mild mitochondrial depolarization. In addition, CO from CORM‐401 increases mitochondrial calcium and activates complexes I and II. The subsequent increase in mitochondrial respiration leads to ATP production through oxidative phosphorylation. Thus, our results show that nonactivated endothelial cells rely primarily on glycolysis, but in the presence of CO, mitochondrial Ca2+ increases and activates respiration that shifts the metabolism of endothelial cells from glycolysis‐ to oxidative phosphorylation‐dependent ATP production.
Late Cenozoic tephrostratigraphy offshore the southern Central American Volcanic Arc: 2. Implications for magma production rates and subduction erosion
Authors: Schindlbeck J. C. , Kutterolf S. , Freundt A. , Straub S. M. , Vannucchi P. , Alvarado G. E.
Published: September 2016

Pacific drill sites offshore Central America provide the unique opportunity to study the evolution of large explosive volcanism and the geotectonic evolution of the continental margin back into the Neogene. The temporal distribution of tephra layers established by tephrochonostratigraphy in Part 1 indicates a nearly continuous highly explosive eruption record for the Costa Rican and the Nicaraguan volcanic arc within the last 8 Myr. The widely distributed marine tephra layers comprise the major fraction of the respective erupted tephra volumes and masses thus providing insights into regional and temporal variations of large‐magnitude explosive eruptions along the southern Central American Volcanic Arc (CAVA). We observe three pulses of enhanced explosive volcanism between 0 and 1 Ma at the Cordillera Central, between 1 and 2 Ma at the Guanacaste and at >3 Ma at the Western Nicaragua segments. Averaged over the long‐term the minimum erupted magma flux (per unit arc length) is ∼0.017 g/ms. Tephra ages, constrained by Ar‐Ar dating and by correlation with dated terrestrial tephras, yield time‐variable accumulation rates of the intercalated pelagic sediments with four prominent phases of peak sedimentation rates that relate to tectonic processes of subduction erosion. The peak rate at >2.3 Ma near Osa particularly relates to initial Cocos Ridge subduction which began at 2.91 ± 0.23 Ma as inferred by the 1.5 Myr delayed appearance of the OIB geochemical signal in tephras from Barva volcano at 1.42 Ma. Subsequent tectonic re‐arrangements probably involved crustal extension on the Guanacaste segment that favored the 2–1 Ma period of unusually massive rhyolite production.
High‐resolution carbon cycle and seawater temperature evolution during the Early Jurassic (Sinemurian‐Early Pliensbachian)
Authors: Price Gregory D. , Baker Sarah J. , VanDeVelde Justin , Clémence Marie‐Emilie
Published: September 2016

The Early Jurassic was marked by a progressive recovery from the end‐Triassic mass extinction and punctuated by recurring episodes of anoxia. These changes, associated with fluctuations in carbon isotope composition of marine carbonates, remain incompletely understood. Here we present a high‐resolution carbon and oxygen isotope record for the Early Jurassic based on well‐preserved marine mollusks (belemnites) from Dorset, UK. Our new data show a number of δ13C excursions, starting with a negative excursion at the Sinemurian‐Pliensbachian boundary Event followed by lesser negative excursions showing in the Polymorphous, Jamesoni, and Masseanum‐Valdani Subzones. The recognition of the Sinemurian‐Pliensbachian boundary Event in this study and elsewhere suggests that observed carbon‐isotope trends are likely to represent a supraregional perturbation of the carbon cycle. A prominent positive carbon‐isotope event is also seen within the Pliensbachian Ibex Zone. This event is also clearly evident in the data from belemnites from Spain. This carbon‐isotope excursion is not, however, coincident with inferred peak temperatures. The oxygen isotope and Mg/Ca data allow the determination of a number of pronounced Pliensbachian cool events. From the low point in the Brevispina Subzone, oxygen isotopes become more negative coupled with an increase in Mg/Ca values culminating in an Early Pliensbachian thermal maximum during the Davoei Zone. Taken with existing data, it appears that the Pliensbachian is characterized by two major warmings, first within the Davoei Zone followed by warming beginning in the latest Pliensbachian and peaking in the Early Toarcian.
Scales and dynamics of Submesoscale Coherent Vortices formed by deep convection in the northwestern Mediterranean Sea
Authors: Bosse Anthony , Testor Pierre , Houpert Loïc , Damien Pierre , Prieur Louis , Hayes Daniel , Taillandier Vincent , Durrieu de Madron Xavier , d'Ortenzio Fabrizio , Coppola Laurent , Karstensen Johannes , Mortier Laurent
Published: September 2016

Since 2010, an intense effort in the collection of in situ observations has been carried out in the northwestern Mediterranean Sea thanks to gliders, profiling floats, regular cruises, and mooring lines. This integrated observing system enabled a year‐to‐year monitoring of the deep waters formation that occurred in the Gulf of Lions area during four consecutive winters (2010–2013). Vortical structures remnant of wintertime deep vertical mixing events were regularly sampled by the different observing platforms. These are Submesoscale Coherent Vortices (SCVs) characterized by a small radius (∼5–8 km), strong depth‐intensified orbital velocities (∼10–20 cm s−1) with often a weak surface signature, high Rossby (∼0.5) and Burger numbers O(0.5–1). Anticyclones transport convected waters resulting from intermediate (∼300 m) to deep (∼2000 m) vertical mixing. Cyclones are characterized by a 500–1000 m thick layer of weakly stratified deep waters (or bottom waters that cascaded from the shelf of the Gulf of Lions in 2012) extending down to the bottom of the ocean at ∼2500 m. The formation of cyclonic eddies seems to be favored by bottom‐reaching convection occurring during the study period or cascading events reaching the abyssal plain. We confirm the prominent role of anticyclonic SCVs and shed light on the important role of cyclonic SCVs in the spreading of a significant amount (∼30%) of the newly formed deep waters away from the winter mixing areas. Since they can survive until the following winter, they can potentially have a great impact on the mixed layer deepening through a local preconditioning effect.
On Optical Dipole Moment and Radiative Recombination Lifetime of Excitons in WSe2
Authors: Jin Chenhao , Kim Jonghwan , Wu Kedi , Chen Bin , Barnard Edward S. , Suh Joonki , Shi Zhiwen , Drapcho Steven G. , Wu Junqiao , Schuck Peter James , Tongay Sefaattin , Wang Feng
Published: September 2016

Optical dipole moment is the key parameter of optical transitions, as it directly determines the strength of light–matter interaction such as intrinsic radiative lifetime. However, experimental determination of these fundamental properties of excitons in monolayer WSe2 is largely limited, because the commonly used measurement, such as (time‐resolved) photoluminescence, is inherently difficult to probe the intrinsic properties. For example, dark states below bright exciton can change the photoluminescence emission rate by orders of magnitude and gives an “effective” radiative lifetime distinctive from the intrinsic one. On the other hand, such “effective” radiative lifetime becomes important itself because it describes how dark states affect exciton dynamics. Unfortunately, the “effective” radiative lifetime in monolayer WSe2 is also not determined as it requires photoluminescence measurement with resonant excitation, which is technically difficult. These difficulties are overcome here to obtain both the “intrinsic” and “effective” radiative lifetime experimentally. A framework is developed to determine the dipole moment and “intrinsic” radiative lifetime of delocalized excitons in monolayer WSe2 from the absorption measurements. In addition, the “effective” radiative lifetime in WSe2 is obtained through time‐resolved photoluminescence and absolute quantum‐yield measurement at resonant excitation. These results provide helpful information for fundamental understanding of exciton light–matter interaction in WSe2.
Single‐Layer MoS2 Nanosheets with Amplified Photoacoustic Effect for Highly Sensitive Photoacoustic Imaging of Orthotopic Brain Tumors
Authors: Chen Jingqin , Liu Chengbo , Hu Dehong , Wang Feng , Wu Haiwei , Gong Xiaojing , Liu Xin , Song Liang , Sheng Zonghai , Zheng Hairong
Published: September 2016

Photoacoustic (PA) imaging, as a fast growing technology that combines the high contrast of light and large penetration depth of ultrasound, has demonstrated great potential for molecular imaging of cancer. However, PA molecular imaging of orthotopic brain tumors is still challenging, partially due to the limited options and insufficient sensitivity of available PA molecular probes. Here, the direct formation of single‐layer (S‐MoS2), few‐layer (F‐MoS2), and multi‐layer (M‐MoS2) nanosheets by the albumin‐assisted exfoliation without further surface modifications is reported. It is demonstrated that the PA effect of the MoS2 nanosheets is highly dependent on their layered nanostructures. Decreasing the number of nanosheet layers from M‐MoS2 to S‐MoS2 can both significantly enhance the near‐infrared light absorption and improve the elastic properties of the nanomaterial, resulting in greatly amplified PA effect. The in vitro experiments demonstrate that the prepared S‐MoS2 with excellent biocompatibility can be efficiently internalized into U87 glioma cells, producing strong PA signals for highly sensitive detection of brain tumor cells, with a detection limit of ≈100 cells. Intravenous administration of S‐MoS2 to both U87 subcutaneous and orthotopic tumor‐bearing mice shows highly efficient tumor retention and significantly enhanced PA contrast. Tumor tissue ≈1.5 mm below the skull can still be clearly visualized in vivo. Previous studies suggest that the fabricated S‐MoS2 with amplified PA effect have high potential to serve as an efficient nanoplatform for sensitive PA molecular imaging and hold promising prospect for translational medicine.
Multifunctional WS2@Poly(ethylene imine) Nanoplatforms for Imaging Guided Gene‐Photothermal Synergistic Therapy of Cancer
Authors: Zhang Chunfang , Yong Yuan , Song Li , Dong Xinghua , Zhang Xiao , Liu Xiangfeng , Gu Zhanjun , Zhao Yuliang , Hu Zhongbo
Published: September 2016

The combination of photothermal therapy (PTT) with gene therapy (GT) to improve PTT efficiency and thus eliminate cancer cells under mild hyperthermia is highly needed. Herein, multifunctional WS2@poly(ethylene imine) (WS2@PEI) nanoplatform has been designed and constructed for gene‐photothermal synergistic therapy of tumors at mild condition. After a surface modification of WS2 with a positively charged PEI, the as‐prepared WS2@PEI nanoplatform can not only act as an efficient survivin‐siRNA carrier for GT but also exhibit remarkable near‐infrared (NIR) photothermal effects for PTT. On the one hand, the photothermal effects induced by WS2@PEI upon NIR irradiation can enhance the cellular uptake owing to the increase of the cell membrane permeability, which leads to the remarkable enhancement of silencing efficiency of survivin. On the other hand, the silencing of survivin can increase the apoptosis as well as reduce the heat resistance of cancer cells by downregulating the heat shock protein 70 expressions, which greatly enhance the sensitivity of cancer cells to PTT. As a result, compared to PTT or GT treatment alone, WS2@PEI mediated synergistic GT/PTT therapy remarkably enhances in vitro cancer cell damage and in vivo tumor elimination.
Sequential Regeneration of Self‐Assembled Monolayers for Highly Selective Atomic Layer Deposition
Authors: Hashemi Fatemeh Sadat Minaye , Bent Stacey F.
Published: September 2016

Next generation 3D electronic devices will require novel processing methods. Area selective atomic layer deposition (ALD) of robust films has the opportunity to play an important role in significantly reducing complexities associated with current top‐down fabrication processes of patterned structures. An all‐vapor process is demonstrated for depositing and regenerating thiol self‐assembled monolayers (SAMs) on copper between ALD cycles. It is shown that by redosing SAM precursors, the SAM quality can be restored after it begins to degrade. It is also shown that this approach is effective in improving the blocking properties of the SAMs against ZnO ALD. This process allows selective deposition of dielectric films on dielectric regions of patterned Cu/SiO2 substrates more than three times thicker than approaches that do not regenerate the SAM. In addition, this all‐vapor strategy provides the ability to integrate the selective deposition process into the ALD reactor, reduces artifacts associated with depositing the SAMs on porous or 3D structures, and decreases the required deposition time for the passivation layer, opening up the possibility for new applications in next generation electronic devices.
Vinyl Sulfonates: A Click Function for Coupling‐and‐Decoupling Chemistry and their Applications
Authors: Cruz Carlos M. , Ortega‐Muñoz Mariano , López‐Jaramillo F. Javier , Hernández‐Mateo Fernando , Blanco Victor , Santoyo‐González Francisco
Published: September 2016

The term coupling‐and‐decoupling (CAD) chemistry refers to applications in which efficient bond formation and subsequent cleavage between two moieties is required. Within this context, the scope of the vinyl sulfonate (VSO) group as an efficient tool for CAD chemistry is reported. The coupling step relies on the click features of the Michael‐type addition of diverse nucleophiles to vinyl sulfonates as a valuable methodology. The feasibility of this strategy has been proved by the high yields obtained in mild conditions with model VSO derivatives. Cleavage of the resulting sulfonate adducts either through nucleophilic substitution with different nucleophiles (for alkyl VSO groups) or through hydrolysis (for both alkyl and aryl VSO) are successful strategies for the decoupling step, the former being the most promising, as the reaction proceeds under milder conditions with thiol nucleophiles. Moreover, the click VSO coupling chemistry proves to be orthogonal with the click CuAAC reaction, which enables the VSO‐CAD methodology for the preparation of hetero‐bifunctional clickable and cleavable linkers for double click modular strategies. The potential of the VSO‐CAD chemistry is demonstrated in two biologically relevant examples: the decoupling of sulfonates with glutathione (GSH) under conditions compatible with those of living systems; and the synthesis of homo‐ and heterogeneous multivalent glycosylated systems from 1‐thio and 1‐azido or 1‐azidoethyl sugar derivatives and bis‐vinyl sulfonates (homo systems) or alkynyl‐VSO bifunctional clickable‐cleavable linkers (hetero systems). As proof of concept, the cleavable character of these multivalent systems was demonstrated by using one of them as a reversible linker for the non‐covalent assembling and chemical decoupling of two model lectins.

magnified image
Inter‐Fullerene Electronic Coupling Controls the Efficiency of Photoinduced Charge Generation in Organic Bulk Heterojunctions
Authors: Larson Bryon W. , Reid Obadiah G. , Coffey David C. , Avdoshenko Stanislav M. , Popov Alexey A. , Boltalina Olga V. , Strauss Steven H. , Kopidakis Nikos , Rumbles Garry
Published: September 2016

Photoinduced charge generation (PCG) dynamics are notoriously difficult to correlate with specific molecular properties in device relevant polymer:fullerene organic photovoltaic blend films due to the highly complex nature of the solid state blend morphology. Here, this study uses six judiciously selected trifluoromethylfullerenes blended with the prototypical polymer poly(3‐hexylthiophene) and measure the PCG dynamics in 50 fs–500 ns time scales with time‐resolved microwave conductivity and femtosecond transient absorption spectroscopy. The isomeric purity and thorough chemical characterization of the fullerenes used in this study allow for a detailed correlation between molecular properties, driving force, local intermolecular electronic coupling and, ultimately, the efficiency of PCG yield. The findings show that the molecular design of the fullerene not only determines inter‐fullerene electronic coupling, but also influences the decay dynamics of free holes in the donor phase even when the polymer microstructure remains unchanged.
Performance of combined use of chlorosilanes and AlCl3 in the carboxylation of toluene with CO2
Authors: Zhang Xibao , Cheng Zhenmin
Published: September 2016

Carboxylation of toluene with CO2 for the production of p‐toluic acid was shown to be promoted by the addition of Me2PhSiCl, Ph2SiCl2, Ph3SiH, or Ph3SiCl into the AlCl3 activated system, and the reaction activity was in the increasing order of Ph2SiCl2 < Me2PhSiCl < Ph3SiH < Ph3SiCl. The spectrum of IR indicated that CO2 could be effectively activated by AlCl3 or Ph3SiCl independently. DFT calculation was carried out to estimate the electrophilic potentials of the chlorine bridged AlCl3···chlorosilane complex in the form of the APT atomic charges of Si and Al. The much higher activity of Ph3Si‐Cl···AlCl3 over AlCl3‐AlCl3 was considered due to its higher valences of Si and Al which are +2.107 and +1.833 compared with the +1.814 of Al in the latter. The mechanism of CO2 activation under the action of double Lewis acid sites of Si and Al and the subsequent carboxylation of toluene was consequently proposed. © 2016 American Institute of Chemical Engineers AIChE J, 63: 185–191, 2017
Absorption of picoliter droplets by thin porous substrates
Authors: Tan Hua
Published: September 2016

Absorption of picoliter (pL) droplets into porous substrates is studied experimentally and numerically. In the case of pL droplets, major phenomena involved in the interaction between droplet and porous media develop at different time scales: spreading and wetting at microseconds, absorption and wicking at milliseconds, and evaporation at seconds. Therefore, one can decouple these processes to minimize the complexity of the study. A high‐speed imaging system capable of 1 million frames per second is used to visualize individual droplets impacting, spreading, and imbibing on substrates. To simulate droplet dynamics, the governing equations for flow outside and inside porous media are proposed and solved using an in‐house developed computational fluid dynamics solver. The simulation results are in good agreement with the experimental data. The effect of drop impact velocity and fluid properties on final dot shape in the porous substrates is investigated through a series of parametric numerical studies. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1690–1703, 2017
Thiotepa‐based conditioning for allogeneic stem cell transplantation in acute lymphoblastic leukemia—A survey from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation
Authors: Eder Sandra , Beohou Eric , Labopin Myriam , Sanz Jaime , Finke Jürgen , Arcese William , Or Reuven , Bonifazi Francesca , Aljurf Mahmoud , Socié Gerard , Passweg Jakob , Giebel Sebastian , Mohty Mohamad , Nagler Arnon
Published: September 2016

In this study, we analyzed a thiotepa‐based conditioning regimen for allogeneic stem cell transplantation in adults with acute lymphoblastic leukemia, using the EBMT database. A total of 323 patients were identified. The median age was 43 years. Disease status at transplant was first complete remission (CR1) in 48.9%, CR2 in 21.7%, CR3 in 6.2%, while 23.2% of the patients had an active disease at the time of transplant. This was performed from a HLA‐matched sibling (49.8%) or a matched‐unrelated donor (51.2%). The incidence of acute graft‐vs.‐host disease (GvHD) (grade > II) was 26.6%, while chronic GvHD occurred in 35.9% of the patients at 1 year (24.6% with extensive disease). With a median follow‐up of 16.8 months, the nonrelapse mortality was 12.4 and 25.3% at 100 days and 1 year, respectively. The relapse incidence at 1 year was 33.3% with no difference for patients in CR1 (27%). The one‐year leukemia‐free survival (LFS) and overall survival (OS) were 57 and 66%, respectively for the entire cohort and 50 and 66%, respectively in patients in CR1. Thiotepa/busulfan ± melphalan (n = 213) in comparison to thiotepa/other (n = 110) conditioning regimen resulted in higher relapse incidence at 1 year (34.9 vs. 30.3%, P = 0.016) and lower LFS (38.8 vs. 45.9%, P = 0.0203), while nonrelapse mortality (23.8 vs. 26.3%, n.s.) and OS (59.6 vs. 51.1%, P = 0.109) did not differ. This large study suggests that a thiotepa‐based conditioning for allogeneic transplantation in acute lymphoblastic leukemia is feasible and effective, with the main outcomes being comparable to those achieved with other regimens. Am. J. Hematol. 92:18–22, 2017. © 2016 Wiley Periodicals, Inc.
Migration and nutritional status of Tarahumara schoolchildren from Chihuahua State (México)
Authors: Benítez‐Hernández Zuliana Paola , De la Torre‐Díaz María de Lourdes , Cervantes‐Borunda Mónica , Hernández‐Torres Rosa Patricia , Cabañas María Dolores , López‐Ejeda Noemí , Marrodán María Dolores
Published: September 2016

Objective

The Tarahumara ethnic group is composed of indigenous people from the Sierra Madre Occidental of Mexico. Conditions of isolation and poverty compel them to migrate to the city in search of better opportunities. This work aims to explore the influence of migration on the growth and nutritional status of Tarahumara schoolchildren.

Methods

One hundred Tarahumara students were analyzed (50 rural with a mean age of 9.78 ± 1.25 years; 50 urban aged 10.0 ± 1.04 years), comparing anthropometric indicators and body composition (T‐Student, U‐Mann–Whitney Tests).

Results

Twenty percent of rural girls and 35% of rural boys showed stunted growth compared to only 9% of the urban girls (no stunted growth among urban boys). Migrants showed greater body size, skinfold thickness, and fat percentage. Weight excess, understood as an increase in the prevalence of overweight and obesity, was detected in 17.8% of urban boys and 13.6% of urban girls compared to 10.0% of boys and 3.3% of girls of the rural series.

Conclusion

Migration reduces stunting and increases adiposity.
Ecogeographic variation across morphofunctional units of the human nose
Authors: Maddux Scott D. , Butaric Lauren N. , Yokley Todd R. , Franciscus Robert G.
Published: September 2016

Objectives

Although the internal nose is overwhelmingly responsible for heat and moisture exchange during respiration, external nasal morphology is more commonly cited as evincing climatic adaptation in humans. Here, we assess variation across all four morphofunctional units of the complete nasorespiratory tract (external pyramid, nasal aperture, internal nasal fossa, and nasopharynx) to determine which units provide the strongest evidence of climatic adaptation.

Materials and Methods

We employ 20 linear measurements collected on 837 modern human crania from major geographic (Arctic Circle, Asia, Australia, Europe, Africa) and climatic (polar, temperate, hot‐arid, tropical) zones. In conjunction with associated climatic and geographic data, these morphological data are employed in multivariate analyses to evaluate the associations between each of these functional nasal units and climate.

Results

The external pyramid and nasopharynx exhibit virtually no evidence of climate‐mediated morphology across the regional samples, while apparent associations between climate and nasal aperture morphology appear influenced by the geographic (and likely genetic) proximities of certain populations. Only the internal nasal fossa exhibits an ecogeographic distribution consistent with climatic adaptation, with crania from colder and/or drier environments displaying internal nasal fossae that are longer, taller, and narrower (especially superiorly) compared to those from hotter and more humid environments.

Conclusions

Our study indicates that the internal nasal fossa exhibits a stronger association with climate compared to other aspects of the human nose. Further, our study supports suggestions that regional variation in internal nasal fossa morphology reflects demands for heat and moisture exchange via adjustment of internal nasal airway dimensions. Our study thus provides empirical support for theoretical assertions related to nasorespiratory function, with important implications for understanding human nasal evolution.
DNA‐basierte Nanoporensensorik
Authors: Liu Lei , Wu Hai‐Chen
Published: September 2016

Die Detektion mithilfe von Nanoporen ist ein vielversprechender, markerfreier Ansatz zur Messung einzelner Moleküle. Entsprechende Sensoren wurden zunächst für die schnelle und kostengünstige DNA‐Sequenzierung vorgeschlagen, wurden in der Folge aber auch für den Nachweis vielfältiger Substrate eingesetzt. Erste Erfolge beruhten größtenteils auf zwei Strategien: 1) dem Aufbau von Sensorelementen innerhalb der Nanopore durch Proteinmutation und chemische Modifizierung; 2) der Verwendung molekularer Adapter zur Verstärkung der Analyterkennung. In den letzten fünf Jahren hat man begonnen, DNA‐Moleküle als Sonden für die Detektion anstatt als Substrate für die Sequenzierung anzuwenden. In diesem Kurzaufsatz präsentieren wir aktuelle Forschungsarbeiten im Bereich der Nanoporensensorik auf Basis DNA‐vermittelter, charakteristischer Stromereignisse. Die Nanoporensensorik wird immer wichtiger für biochemische und biophysikalische Studien, und daher könnte die DNA‐basierte Sensorik breitere Anwendung bei der Untersuchung biologischer Prozesse unter Beteiligung von DNA finden.
Low‐Temperature Transformation of Methane to Methanol on Pd1O4 Single Sites Anchored on the Internal Surface of Microporous Silicate
Authors: Huang Weixin , Zhang Shiran , Tang Yu , Li Yuting , Nguyen Luan , Li Yuanyuan , Shan Junjun , Xiao Dequan , Gagne Raphael , Frenkel Anatoly I. , Tao Franklin (Feng)
Published: September 2016

Direct conversion of methane to chemical feedstocks such as methanol under mild conditions is a challenging but ideal solution for utilization of methane. Pd1O4 single‐sites anchored on the internal surface of micropores of a microporous silicate exhibit high selectivity and activity in transforming CH4 to CH3OH at 50–95 °C in aqueous phase through partial oxidation of CH4 with H2O2. The selectivity for methanol production remains at 86.4 %, while the activity for methanol production at 95 °C is about 2.78 molecules per Pd1O4 site per second when 2.0 wt % CuO is used as a co‐catalyst with the Pd1O4@ZSM‐5. Thermodynamic calculations suggest that the reaction toward methanol production is highly favorable compared to formation of a byproduct, methyl peroxide.
Ion‐Exchange‐Induced 2D–3D Conversion of HMA1−xFAxPbI3Cl Perovskite into a High‐Quality MA1−xFAxPbI3 Perovskite
Authors: Li Ge , Zhang Taiyang , Guo Nanjie , Xu Feng , Qian Xufang , Zhao Yixin
Published: September 2016

High‐quality phase‐pure MA1−xFAxPbI3 planar films (MA=methylammonium, FA=formamidinium) with extended absorption and enhanced thermal stability are difficult to deposit by regular simple solution chemistry approaches owing to crystallization competition between the easy‐to‐crystallize but unwanted δ‐FAPbI3/MAPbI3 and FAxMA1−xPbI3 requiring rigid crystallization conditions. Here A 2D–3D conversion to transform compact 2D mixed composition HMA1−xFAxPbI3Cl perovskite precursor films into 3D MA1−xFAxPbI3 (x=0.1–0.9) perovskites is presented. The designed Cl/I and H/FA(MA) ion exchange reaction induced fast transformation of compact 2D perovskite film, helping to form the phase‐pure and high quality MA1−xFAxPbI3 without δ‐FAPbI3 and MAPbI3 impurity. In all, we successfully developed a facile one‐step method to fabricate high quality phase‐pure MA1−xFAxPbI3 (x=0.1–0.9) perovskite films by 2D–3D conversion of HMA1−xFAxPbI3Cl perovskite. This 2D–3D conversion is a promising strategy for lead halide perovskite fabrication.
An Electrophilic Reagent for the Direct Introduction of the SCF2PO(OEt)2 Group to Molecules
Authors: Xiong Heng‐Ying , Bayle Alexandre , Pannecoucke Xavier , Besset Tatiana
Published: September 2016

An unprecedented electrophilic difluoromethylthiolating reagent (MesNHSCF2PO(OEt)2) was designed. Under mild and metal‐free conditions, this new reagent reacted with various nucleophiles, thus offering an efficient and operationally simple tool for the construction of C−SCF2PO(OR)2, N−SCF2PO(OR)2, and S−SCF2PO(OR)2 bonds. Finally, thanks to this new methodology, the synthesis of the non‐stereoidal anti‐inflammatory diflumidone was achieved.
Über 1,3‐Hydridverschiebungen in Sesquiterpen‐Cyclisierungen
Authors: Rinkel Jan , Rabe Patrick , Garbeva Paolina , Dickschat Jeroen S.
Published: September 2016

Stereospezifisch markierte Vorstufen wurden mit sieben bakteriellen Sesquiterpencyclasen konvertiert, um den stereochemischen Verlauf ihrer initialen Kaskaden aus 1,10‐Cyclisierung und 1,3‐Hydridverschiebung zu untersuchen. Enzyme mit Produkten bekannter absoluter Konfiguration zeigten einen kohärenten stereochemischen Kurs, mit Ausnahme der (−)‐α‐Amorphen‐Synthase, für die die erhaltenen Ergebnisse besser durch initiale 1,6‐Cyclisierung erklärbar sind. Der Zusammenhang zwischen der absoluten Konfiguration des Produktes und dem stereochemischen Verlauf der 1,3‐Hydridverschiebung ermöglichte die Zuordnung der absoluten Konfigurationen für drei Enzymprodukte, die unabhängig über die absolute Konfiguration des gemeinsamen Nebenproduktes Germacren‐D‐4‐ol bestimmt wurden.
DNA‐Based Nanopore Sensing
Authors: Liu Lei , Wu Hai‐Chen
Published: September 2016

Nanopore sensing is an attractive, label‐free approach that can measure single molecules. Although initially proposed for rapid and low‐cost DNA sequencing, nanopore sensors have been successfully employed in the detection of a wide variety of substrates. Early successes were mostly achieved based on two main strategies by 1) creating sensing elements inside the nanopore through protein mutation and chemical modification or 2) using molecular adapters to enhance analyte recognition. Over the past five years, DNA molecules started to be used as probes for sensing rather than substrates for sequencing. In this Minireview, we highlight the recent research efforts of nanopore sensing based on DNA‐mediated characteristic current events. As nanopore sensing is becoming increasingly important in biochemical and biophysical studies, DNA‐based sensing may find wider applications in investigating DNA‐involving biological processes.
Selective Palladium‐Catalyzed Aminocarbonylation of Olefins to Branched Amides
Authors: Liu Jie , Li Haoquan , Spannenberg Anke , Franke Robert , Jackstell Ralf , Beller Matthias
Published: September 2016

A general and efficient protocol for iso‐selective aminocarbonylation of olefins with aliphatic amines has been developed for the first time. Key to the success for this process is the use of a specific 2‐phosphino‐substituted pyrrole ligand in the presence of PdX2 (X=halide) as a pre‐catalyst. Bulk industrial and functionalized olefins react with various aliphatic amines, including amino‐acid derivatives, to give the corresponding branched amides generally in good yields (up to 99 %) and regioselectivities (b/l up to 99:1).
Catalytic Asymmetric C−H Functionalization under Photoredox Conditions by Radical Translocation and Stereocontrolled Alkene Addition
Authors: Wang Chuanyong , Harms Klaus , Meggers Eric
Published: September 2016

This work demonstrates how photoredox‐mediated C(sp3)−H activation through radical translocation can be combined with asymmetric catalysis. Upon irradiation with visible light, α,β‐unsaturated N‐acylpyrazoles react with N‐alkoxyphthalimides in the presence of a rhodium‐based chiral Lewis acid catalyst and the photosensitizer fac‐[Ir(ppy)3] to provide a C−C bond‐formation product with high enantioselectivity (up to 97 % ee) and, where applicable, with some diastereoselectivity (3.0:1 d.r.). Mechanistically, the synthetic strategy exploits a radical translocation (1,5‐hydrogen transfer) from an oxygen‐centered to a carbon‐centered radical with a subsequent stereocontrolled radical alkene addition.
Functionalization of multi‐walled carbon nanotubes with pramipexole for immobilization of palladium nanoparticles and investigation of catalytic activity in the Sonogashira coupling reaction
Authors: Abbasi Sahar , Hekmati Malak
Published: September 2016

Pramipexole drug was attached to the surface of multi‐walled carbon nanotubes (MWCNTs) by reaction of acylated carbon nanotubes with pramipexole for the first time. The modified MWCNTs were characterized using Fourier transform infrared spectroscopy, transmission and scanning electron microscopies and CHNS analysis. The prepared pramipexole–MWCNTs were used for immobilization of palladium nanoparticles as a novel nanocatalyst. After characterization of the final nanocomposite, the pramipexole–MWCNTs/Pd was applied as a novel phosphine‐free recyclable heterogeneous catalyst for Sonogashira reactions. Interestingly, the novel catalyst could be recovered and recycled five times without any significant loss in activity.
A new numerical model for the analysis on low‐velocity impact damage evolution of carbon fiber reinforced resin composites
Authors: Qu Peng , Sun Xiaochen , Ping Lu , Zhang Dawei , Jia Yuxi
Published: September 2016

A new numerical simulation method was proposed to predict the mechanical behavior of carbon fiber reinforced resin composites under low‐velocity impact load. The impact damage evolution can be characterized in the form of energy dissipation which can be calculated through the new numerical model. The evolution mechanism of delamination was analyzed through distinguishing between the normal induced delamination and tangential slip induced delamination. The drop weight tests were conducted on composite laminates with five kinds of stacking sequence. Experimental analysis was also presented in this article. The damage area and distribution was investigated through ultrasonic C‐scan. The prediction had a good agreement with the experimental results through the comparison of impact response. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44374.
Thermoresponsive crosslinked isocyanate‐free polyurethanes by Diels‐Alder polymerization
Authors: Dolci Elena , Froidevaux Vincent , Michaud Guillaume , Simon Frédéric , Auvergne Rémi , Fouquay Stéphane , Caillol Sylvain
Published: September 2016

This new study is a continuation of our previous work on thermocleavable nonisocyanate polyurethanes (NIPUs), but it is focused on crosslinked networks. Two systems are studied: the first system involves a dicyclocarbonate adduct with a PPO‐bicyclocarbonate and a triamine as crosslinker. The second system involves a tetracyclocarbonate DA adduct as crosslinker with the same PPO‐bicyclocarbonate and a difunctional amine. Firstly, Diels‐Alder adducts are synthesized and characterized. Then they are copolymerized to yield two types of cleavable polymer networks. The thermal behavior of synthesized polymers is fully characterized. Finally, by SEC, it was demonstrated that the obtained NIPU polymer chains are sliced up by rDA reaction. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44408.
Biologically Inspired C−H and C=C Oxidations with Hydrogen Peroxide Catalyzed by Iron Coordination Complexes
Authors: Olivo Giorgio , Cussó Olaf , Costas Miquel
Published: September 2016

The development of catalysts for the selective oxidation of readily available hydrocarbons or organic precursors into oxygenated products is a long‐standing goal in organic synthesis. In the last decade, some iron coordination complexes have shown the potential to fit this role. These catalysts can mimic the O−O activation mode of far more sophisticated iron oxygenase enzymes, generating powerful yet selective oxidants. In this review, we report state‐of‐the‐art C−H and C=C oxidations catalyzed by non‐heme iron complexes and H2O2 as the oxidant. Finally, we briefly describe some novel oxidative reactivity and the perspectives of this chemistry.
The Evolution of Governance Education
Authors: Mercier Rose
Published: September 2016

Rose Mercier, chair of the International Policy Governance Association (IPGA), provides a brief overview of the evolution of the need for governance education and the programs to fulfill it and introduces a new program from IPGA.
Regression in thin melanoma is associated with nodal recurrence after a negative sentinel node biopsy
Authors: Rubinstein Jill C. , Han Gang , Jackson Laura , Bulloch Kaleigh , Ariyan Stephan , Narayan Deepak , Rothberg Bonnie G. , Han Dale
Published: September 2016

Prognostic markers for nodal metastasis in thin melanoma patients are debated. We present a single institution study looking at factors predictive of nodal disease in thin melanoma patients. Retrospective review from 1997 to 2012 identified 252 patients with thin melanoma (≤1 mm) who underwent a sentinel lymph node biopsy (SLNB). Node‐positive patients included positive SLNB patients and negative SLNB patients who developed a nodal recurrence (false‐negative SLNB). Clinicopathologic characteristics were correlated with nodal status and outcome. Median follow‐up was 45.5 months. Twelve of 252 patients (4.8%) were node‐positive including six positive SLNB (2.4%) and six false‐negative SLNB (2.4%) patients. No clinicopathologic factors were significantly correlated with nodal disease. For the six false‐negative SLNB patients, median time to nodal recurrence was 37.5 months. Regression was seen in only 16% of cases, but the rate increased to 60% for false‐negative SLNB cases. Both age (odds ratio [OR]: 1.09, 95% CI: 1.01–1.17; P = 0.02) and regression (OR: 8.33, 95% CI: 1.34–52.63; P = 0.02) were significantly associated with nodal recurrence after a negative SLNB on univariable analysis. Nodal disease in thin melanoma patients was seen in 4.8% of cases. Although regression was not correlated with nodal metastasis, it was correlated with a false‐negative SLNB. Patients with thin melanoma and regression may need more intensive surveillance after a negative SLNB. Further study is needed to determine if the same immune mechanisms that result in regression in primary tumors also lead to regression in lymph nodes, which may decrease detection of melanoma nodal metastases.
Covalent Tethering and Residues with Bulky Hydrophobic Side Chains Enable Self‐Assembly of Distinct Amyloid Structures
Authors: Ruiz Jérémy , Boehringer Régis , Grogg Marcel , Raya Jésus , Schirer Alicia , Crucifix Corinne , Hellwig Petra , Schultz Patrick , Torbeev Vladimir
Published: September 2016

Polymorphism is a common property of amyloid fibers that complicates their detailed structural and functional studies. Here we report experiments illustrating the chemical principles that enable the formation of amyloid polymorphs with distinct stoichiometric composition. Using appropriate covalent tethering we programmed self‐assembly of a model peptide corresponding to the [20–41] fragment of human β2‐microglobulin into fibers with either trimeric or dimeric amyloid cores. Using a set of biophysical and biochemical methods we demonstrated their distinct structural, morphological, and templating properties. Furthermore, we showed that supramolecular approaches in which the peptide is modified with bulky substituents can also be applied to modulate the formation of different fiber polymorphs. Such strategies, when applied to disease‐related peptides and proteins, will greatly help in the evaluation of the biological properties of structurally distinct amyloids.
Challenging Thermodynamics: Hydrogenation of Benzene to 1,3‐Cyclohexadiene by Ru@Pt Nanoparticles
Authors: Weilhard Andreas , Abarca Gabriel , Viscardi Janine , Prechtl Martin H. G. , Scholten Jackson D. , Bernardi Fabiano , Baptista Daniel L. , Dupont Jairton
Published: September 2016

Since the earliest reports on catalytic benzene hydrogenation, 1,3‐cyclohexadiene and cyclohexene have been proposed as key intermediates. However, the former has never been obtained with remarkable selectivity. Herein, we report the first partial hydrogenation of benzene towards 1,3‐cyclohexadiene under mild conditions in a catalytic biphasic system consisting of Ru@Pt nanoparticles (NPs) in ionic liquid (IL). The tandem reduction of [Ru(COD)(2‐methylallyl)2] (COD=1,5‐cyclooctadiene) followed by decomposition of [Pt2(dba)3] (dba=dibenzylideneacetone) in 1‐n‐butyl‐3‐methylimidazolium hexafluorophosphate (BMI⋅PF6) IL under hydrogen affords core–shell Ru@Pt NPs of 2.9±0.2 nm. The hydrogenation of benzene (60 °C, 6 bar of H2) dissolved in n‐heptane by these bimetallic NPs in BMI⋅PF6 affords 1,3‐cyclohexadiene with an unprecedented 21 % selectivity at 5 % benzene conversion. Conversely, almost no 1,3‐cyclohexadiene was observed when using monometallic Pt0 or Ru0 NPs under the same reaction conditions and benzene conversions. This study reveals that the selectivity is related to synergetic effects of the bimetallic composition of the catalyst material as well as to the performance under biphasic reaction conditions. It is proposed that colloidal metal catalysts in ILs and under multiphase conditions (“dynamic asymmetric mixtures”) can operate far from the thermodynamic equilibrium akin to chemically active membranes.
Carbopalladation Cascades Using Carbon–Carbon Triple Bonds: Recent Advances to Access Complex Scaffolds
Authors: Düfert Alexander , Werz Daniel B.
Published: September 2016

Alkynes are one of the most versatile functional groups as synthetic handles. They allow for a direct access to partially or fully substituted alkenes through difunctionalization reactions. A prominently utilized transformation for these sequences is the carbopalladation of alkynes, which can be followed by various termination steps such as aromatizations, dearomatizations, cross‐coupling reactions, or pericyclic processes, amongst others. This Minireview provides an overview of the recent literature published in the field of carbopalladation chemistry, both with a focus on methodology as well as its application in the syntheses of complex molecular scaffolds, natural products, and functional molecules.