bluuebunny/crossref_metadata_2025 huggingface dataset:
The genome and transcriptome of common milkweed (Asclepias syriaca): resources for evolutionary, ecological, and molecular studies in milkweeds and Apocynaceae
Authors: Weitemier Kevin , Straub Shannon CK , Fishbein Mark , Bailey C Donovan , Cronn Richard C , Liston Aaron
Published: February 2018

Milkweeds (Asclepias) are used in wide-ranging studies including floral development, pollination biology, plant-insect interactions and co-evolution, secondary metabolite chemistry, and rapid diversification. We present the first nuclear genome and transcriptome assemblies of the common milkweed, Asclepias syriaca. This is the first species in Apocynaceae subfamily Asclepiadoideae with reconstructions of the nuclear, chloroplast, and mitochondrial genomes, and the first in the Apocynaceae to have linkage group information incorporated into the nuclear assembly. The genome was sequenced to 80.4× depth and the draft assembly contains 54,266 scaffolds ≥1 kbp, with N50 = 3415 bp, representing 37% (156.6 Mbp) of the estimated 420 Mbp genome. A total of 14,474 protein-coding genes were identified based on transcript evidence, closely related proteins, and ab initio models, and 95% of genes were annotated. A large proportion of gene space is represented in the assembly, with 96.7% of Asclepias transcripts, 88.4% of transcripts from the related genus Calotropis, and 90.6% of proteins from Coffea mapping to the assembly. The progesterone 5β-reductase gene family, a key component of cardenolide production, is likely reduced in Asclepias relative to other Apocynaceae. Scaffolds covering 75 Mbp of the Asclepias assembly formed eleven linkage groups. Comparisons of these groups with pseudochromosomes in Coffea found that six chromosomes show consistent stability in gene content, while one may have a long history of fragmentation and rearrangement. The genome and transcriptome of common milkweed provide a rich resource for future studies of the ecology and evolution of a charismatic plant family.
Oxygen Isotope Composition of Arctica islandica Aragonite in the Context of Shell Architectural Organization: Implications for Paleoclimate Reconstructions
Authors: Trofimova Tamara , Milano Stefania , Andersson Carin , Bonitz Fabian G. W. , Schöne Bernd R.
Published: February 2018

The analysis of the stable isotopic composition of bivalve shells provides the data needed to construct climate records at high temporal resolution. Yet, the reproducibility of the results and the effect of microstructural organization on the isotopic signature and measurements have not been extensively studied. Here, we examine the architectural changes within Arctica islandica shells, specifically if samples from microstructurally different shell layers differ in respect to stable oxygen isotope values. The oxygen isotope profiles of two microstructurally different shell layers, each sampled at different temporal resolution, were compared to each other. Our results show that aragonite, collected from the layer that is dominated by cross‐acicular/lamellar structures, tends to be enriched in heavier oxygen isotopes compared to samples from portions of the outer shell layer dominated by homogeneous microstructure. In some cases, this difference exceeded 0.3 ‰, which can significantly affect the interpretation of a recorded environmental signal. Observed differences in stable oxygen isotope data may be associated with the physiology of the mollusk and the physical and chemical composition of studied shell layers.
Satellite Observations of Stratospheric Gravity Waves Associated With the Intensification of Tropical Cyclones
Authors: Hoffmann Lars , Wu Xue , Alexander M. Joan
Published: February 2018

Forecasting the intensity of tropical cyclones is a challenging problem. Rapid intensification is often preceded by the formation of “hot towers” near the eyewall. Driven by strong release of latent heat, hot towers are high‐reaching tropical cumulonimbus clouds that penetrate the tropopause. Hot towers are a potentially important source of stratospheric gravity waves. Using 13.5 years (2002–2016) of Atmospheric Infrared Sounder observations of stratospheric gravity waves and tropical cyclone data from the International Best Track Archive for Climate Stewardship, we found empirical evidence that stratospheric gravity wave activity is associated with the intensification of tropical cyclones. The Atmospheric Infrared Sounder and International Best Track Archive for Climate Stewardship data showed that strong gravity wave events occurred about twice as often for tropical cyclone intensification compared to storm weakening. Observations of stratospheric gravity waves, which are not affected by obscuring tropospheric clouds, may become an important future indicator of storm intensification.
Fat Plumes May Reflect the Complex Rheology of the Lower Mantle
Authors: Davaille A. , Carrez Ph. , Cordier P.
Published: February 2018

Recent tomographic imaging of the mantle below major hot spots shows slow seismic velocities extending down to the core‐mantle boundary, confirming the existence of mantle plumes. However, these plumes are much thicker than previously thought. Using new laboratory experiments and scaling laws, we show that thermal plumes developing in a visco‐plastic fluid present much larger diameters than plumes developing in a Newtonian fluid. Such a rheology requiring a yield stress is consistent with a lower mantle predominantly deforming by pure dislocation climb. Yield stress values between 1 and 10 MPa, implying dislocation densities between 108 and 1010 m−2, would be sufficient to reproduce the plumes morphology observed in tomographic images.
Ionospheric Variability Due to Tides and Quasi‐Two Day Wave Interactions
Authors: Gu Sheng‐Yang , Liu Han‐Li , Dou Xiankang , Jia Mingjiao
Published: February 2018

The ionospheric variabilities due to planetary waves (PWs) are complicated due to their nonlinear interaction with tides (migrating diurnal and semidiurnal tides [DW1 and SW2]) in the mesosphere and lower thermosphere region. The quasi‐two day wave (QTDW) is the most dominant oscillation during austral summer period except tides. This paper quantitatively studies the contribution of W3 QTDW, secondary PWs generated by the QTDW‐tide interaction, and the change of tides to the ionospheric vertical drift variabilities. It is found that the secondary PWs generated by the QTDW‐DW1 interaction (16 hr W4 and 48 hr E2) contribute more to the ionospheric variability than those generated by the QTDW‐SW2 interaction (9.6 hr W5 and 16 hr E1). The latitudinal distribution of the vertical drift induced by tides and PWs varies due to their different wind structures. The vertical drift induced by DW1 is weakened at all latitudes due to the existence of W3 QTDW, whereas the SW2‐induced vertical drift is enhanced at low latitudes and decreased at middle latitudes. The W3 QTDW induces weaker vertical drift in the equatorial region than that induced by 16 hr W4, 48 hr E2, and the change of tides. At middle latitudes, the vertical drift induced by W3 QTDW is slightly stronger than that induced by 48 hr E2 and the change of DW1 but is comparable to that induced by 16 hr W4 and the change of SW2. Our simulations show that the changes of tidal amplitudes and secondary PWs are as important as the QTDW itself to the day‐to‐day ionospheric variabilities.
Three‐Dimensional Dynamics of Baroclinic Tides Over a Seamount
Authors: Vlasenko Vasiliy , Stashchuk Nataliya , Nimmo‐Smith W. Alex M.
Published: February 2018

The Massachusetts Institute of Technology general circulation model is used for the analysis of baroclinic tides over Anton Dohrn Seamount (ADS), in the North Atlantic. The model output is validated against in situ data collected during the 136th cruise of the RRS “James Cook” in May–June 2016. The observational data set includes velocity time series recorded at two moorings as well as temperature, salinity, and velocity profiles collected at 22 hydrological stations. Synthesis of observational and model data enabled the reconstruction of the details of baroclinic tidal dynamics over ADS. It was found that the baroclinic tidal waves are generated in the form of tidal beams radiating from the ADS periphery to its center, focusing tidal energy in a surface layer over the seamount's summit. This energy focusing enhances subsurface water mixing and the local generation of internal waves. The tidal beams interacting with the seasonal pycnocline generate short‐scale internal waves radiating from the ADS center. An important ecological outcome from this study concerns the pattern of residual currents generated by tides. The rectified flows over ADS have the form of a pair of dipoles, cyclonic and anticyclonic eddies located at the seamount's periphery. These eddies are potentially an important factor in local larvae dispersion and their escape from ADS.
Extreme Marine Warming Across Tropical Australia During Austral Summer 2015–2016
Authors: Benthuysen Jessica A. , Oliver Eric C. J. , Feng Ming , Marshall Andrew G.
Published: February 2018

During austral summer 2015–2016, prolonged extreme ocean warming events, known as marine heatwaves (MHWs), occurred in the waters around tropical Australia. MHWs arose first in the southeast tropical Indian Ocean in November 2015, emerging progressively east until March 2016, when all waters from the North West Shelf to the Coral Sea were affected. The MHW maximum intensity tended to occur in March, coinciding with the timing of the maximum sea surface temperature (SST). Large areas were in a MHW state for 3–4 months continuously with maximum intensities over 2°C. In 2016, the Indonesian‐Australian Basin and areas including the Timor Sea and Kimberley shelf experienced the longest and most intense MHW from remotely sensed SST dating back to 1982. In situ temperature data from temperature loggers at coastal sites revealed a consistent picture, with MHWs appearing from west to east and peaking in March 2016. Temperature data from moorings, an Argo float, and Slocum gliders showed the extent of warming with depth. The events occurred during a strong El Niño and weakened monsoon activity, enhanced by the extended suppressed phase of the Madden‐Julian Oscillation. Reduced cloud cover in January and February 2016 led to positive air‐sea heat flux anomalies into the ocean, predominantly due to the shortwave radiation contribution with a smaller additional contribution from the latent heat flux anomalies. A data‐assimilating ocean model showed regional changes in the upper ocean circulation and a change in summer surface mixed layer depths and barrier layer thicknesses consistent with past El Niño events.
New Parametrization for Heat Transport Through Diffusive Convection Interface
Authors: Guo Shuang‐Xi , Cen Xian‐Rong , Zhou Sheng‐Qi
Published: February 2018

A laboratory experiment of two‐layer diffusive convection (DC) within a rectangular cell is reported. The run‐down evolution of two mixed layers and their interface is exhibited by the temperature and salinity structures, where the interface thicknesses of temperature and salinity increase with time as
and
. Heat flux across the interface is respectively evaluated in terms of the heat energy conservation and the assumption of conductive interface. Both of them give the consistent heat flux values. When the 4/3 scaling between heat flux
and temperature difference across the interface
holds (
, where
is function of density ratio
), previous heat flux parameterizations are found to have low coefficient of determination (
) with our heat flux data within
. Heat flux is proposed to be a power law function of
, and the best fitting is
, resulting in r2 as high as 0.74. By using all available heat flux data over a wide
range (1.2–27.6), including those collected in previous literatures,
is revised as
accompanied by
and a reduced chi‐square
. Alternatively,
can be derived from previous DC layer thickness parameterization, which is expressed as
. This formula is also superior to previous parameterizations in the evaluation of heat flux, indicated by high r2 and low
.
Mechanisms of the 40–70 Day Variability in the Yucatan Channel Volume Transport
Authors: van Westen René M. , Dijkstra Henk A. , Klees Roland , Riva Riccardo E. M. , Slobbe D. Cornelis , van der Boog Carine G. , Katsman Caroline A. , Candy Adam S. , Pietrzak Julie D. , Zijlema Marcel , James Rebecca K. , Bouma Tjeerd J.
Published: February 2018

The Yucatan Channel connects the Caribbean Sea with the Gulf of Mexico and is the main outflow region of the Caribbean Sea. Moorings in the Yucatan Channel show high‐frequent variability in kinetic energy (50–100 days) and transport (20–40 days), but the physical mechanisms controlling this variability are poorly understood. In this study, we show that the short‐term variability in the Yucatan Channel transport has an upstream origin and arises from processes in the North Brazil Current. To establish this connection, we use data from altimetry and model output from several high resolution global models. A significant 40–70 day variability is found in the sea surface height in the North Brazil Current retroflection region with a propagation toward the Lesser Antilles. The frequency of variability is generated by intrinsic processes associated with the shedding of eddies, rather than by atmospheric forcing. This sea surface height variability is able to pass the Lesser Antilles, it propagates westward with the background ocean flow in the Caribbean Sea and finally affects the variability in the Yucatan Channel volume transport.
June 2017: The Earliest European Summer Mega‐heatwave of Reanalysis Period
Authors: Sánchez‐Benítez A. , García‐Herrera R. , Barriopedro D. , Sousa P. M. , Trigo R. M.
Published: February 2018

This paper examines the characteristics of the heatwave that affected western and central Europe in June 2017. Using a novel algorithm, we show that its extension, intensity, and persistence were comparable to those of other European mega‐heatwaves, but it occurred earlier in the summer. The most affected area was Iberia, which experienced devastating forest fires with human casualties and the warmest temperatures of the reanalysis period from daily to seasonal scales. The peak of the mega‐heatwave displayed an unprecedented warm air intrusion due to a record‐breaking subtropical ridge with signatures closer to those of July and August. The atmospheric circulation was the main triggering factor of the event. However, thermodynamical changes of the last decades made a substantial contribution to the event, by increasing the likelihood of surpassing high‐temperature thresholds. This episode could be a good example of a coming future, with high‐summer mega‐heatwaves occurring earlier.
SoftX‐Ray Fluorescence Spectroscopy
Authors: Muramatsu Yasuji
Published: February 2018

Soft X‐ray fluorescence (SXF) spectroscopy is X‐ray fluorescence (XRF) spectroscopy for low‐ and middle‐atomic‐number elements whose X‐ray absorption edges are in the soft X‐ray (SX) region. Electron beams have been used as excitation probes for (nonresonantornormal) SXF spectroscopy in laboratories. In addition, synchrotron radiation (SR) beams have been utilized as excitation probes, enabling selective excitation near the X‐ray absorption threshold. Selectively excited SXF involves soft X‐ray scattering, which can be regarded as aresonantsoft X‐ray emission (SXE) spectroscopy. SXF and SXE spectroscopies provide element‐, orbital‐, and symmetry‐specific information. Thus, they are powerful tools for chemical analysis and materials characterization.

In this article, the principles of SXF/SXE spectroscopies and instrumentation focused on gratings are described. Examples ofnonresonant(normal) SXF andresonantSXE spectroscopies are shown, and details of the spectral profiles are explained.ResonantSXE spectroscopy of liquid water andoperandoobservations of the electrode reactions are also demonstrated as advanced chemical analyses.
Washable Multilayer Triboelectric Air Filter for Efficient Particulate Matter PM2.5 Removal
Authors: Bai Yu , Han Chang Bao , He Chuan , Gu Guang Qin , Nie Jin Hui , Shao Jia Jia , Xiao Tian Xiao , Deng Chao Ran , Wang Zhong Lin
Published: February 2018

Efficient removal of particulate matter (PM) is the major goal for various air cleaning technologies due to its huge impact on human health. Here, a washable high‐efficiency triboelectric air filter (TAF) that can be used multiple times is presented. The TAF consists of five layers of the polytetrafluoroethylene (PTFE) and nylon fabrics. Compared with traditional electrostatic precipitator, which requires a high‐voltage power supply, the TAF can be charged by simply rubbing the PTFE and nylon fabrics against each other. The electrical properties of the TAF are evaluated through the periodic contacting–separating of the PTFE and nylon fabrics using a linear motor, and an open‐circuit voltage of 190 V is achieved. After charging, the TAF has a removal efficiency of 84.7% for PM0.5, 96.0% for PM2.5, which are 3.22 and 1.39 times as large as the uncharged one. Most importantly, after washing several times, the removal efficiency of the TAF maintains almost the same, while the commercial face mask drops to 70% of its original efficiency. Furthermore, the removal efficiency of the PM2.5 is very stable under high relative humidity. Therefore, the TAF is promising for fabricating a reusable and high‐efficiency face mask.
2D Ultrathin MXene‐Based Drug‐Delivery Nanoplatform for Synergistic Photothermal Ablation and Chemotherapy of Cancer
Authors: Han Xiaoxia , Huang Ju , Lin Han , Wang Zhigang , Li Pan , Chen Yu
Published: February 2018

Two‐dimensional (2D) MXenes, as a new 2D functional material nanosystem, have been extensively explored for broad applications. However, their specific performance and applications in theranostic nanomedicine have still rarely been explored. This work reports on the drug‐delivery performance and synergistic therapeutic efficiency of Ti3C2 MXenes for highly efficient tumor eradication. These Ti3C2 MXenes not only possess high drug‐loading capability of as high as 211.8%, but also exhibit both pH‐responsive and near infrared laser‐triggered on‐demand drug release. Especially, based on the high photothermal‐conversion capability of Ti3C2 MXenes, they have been further explored for efficient tumor eradication by synergistic photothermal ablation and chemotherapy, which has been systematically demonstrated both in vitro and in vivo. These Ti3C2 MXenes have also been demonstrated as the desirable contrast agents for photoacoustic imaging, showing the potential for diagnostic‐imaging guidance and monitoring during therapy. The high in vivo histocompatibility of Ti3C2 and their easy excretion out of the body have been evaluated and demonstrated, showing the potential high biosafety for further clinical translation. This work paves a new way for broadening biomedical applications of MXenes in nanomedicine where they can exert the high performance and functionality for synergistic therapy, especially on combating cancer.
Soft Ultrathin Electronics Innervated Adaptive Fully Soft Robots
Authors: Wang Chengjun , Sim Kyoseung , Chen Jin , Kim Hojin , Rao Zhoulyu , Li Yuhang , Chen Weiqiu , Song Jizhou , Verduzco Rafael , Yu Cunjiang
Published: February 2018

Soft robots outperform the conventional hard robots on significantly enhanced safety, adaptability, and complex motions. The development of fully soft robots, especially fully from smart soft materials to mimic soft animals, is still nascent. In addition, to date, existing soft robots cannot adapt themselves to the surrounding environment, i.e., sensing and adaptive motion or response, like animals. Here, compliant ultrathin sensing and actuating electronics innervated fully soft robots that can sense the environment and perform soft bodied crawling adaptively, mimicking an inchworm, are reported. The soft robots are constructed with actuators of open‐mesh shaped ultrathin deformable heaters, sensors of single‐crystal Si optoelectronic photodetectors, and thermally responsive artificial muscle of carbon‐black‐doped liquid‐crystal elastomer (LCE‐CB) nanocomposite. The results demonstrate that adaptive crawling locomotion can be realized through the conjugation of sensing and actuation, where the sensors sense the environment and actuators respond correspondingly to control the locomotion autonomously through regulating the deformation of LCE‐CB bimorphs and the locomotion of the robots. The strategy of innervating soft sensing and actuating electronics with artificial muscles paves the way for the development of smart autonomous soft robots.
Robust and Highly Active FeNi@NCNT Nanowire Arrays as Integrated Air Electrode for Flexible Solid‐State Rechargeable Zn‐Air Batteries
Authors: Zhao Xiaotao , Abbas Syed Comail , Huang Yiyin , Lv Jiangquan , Wu Maoxiang , Wang Yaobing
Published: February 2018

The most challenging issue in flexible/portable energy storage devices, such as metal‐air batteries, is the insufficient electrocatalytic performance of the air‐electrode for oxygen reduction/evolution reactions due to low activity and decomposition of the electrocatalyst from the electrode's surface. In an effort to overcome these barriers, robust and highly active FeNi@NCNTs nanowire arrays are rationally synthesized on carbon cloth which directly serves as an integrated air‐electrode for zinc‐air batteries. FeNi@NCNTs/CC shows excellent bifunctional electrochemical performances toward oxygen reduction reaction (onset potential = 0.95 V, half‐wave potential = 0.77 V vs RHE) and oxygen evolution reaction (η = 252 mV@10 mA cm−2), and exhibits excellent stability after being tested for more than 720 hours. More importantly, flexible solid‐state rechargeable Zn‐air batteries directly equipped with the FeNi@NCNTs/CC air‐cathode are demonstrated to exhibit a high discharge voltage (≈1.0 V@2 mA cm−2) and a low charge voltage (≈1.65 V@2 mA cm−2), along with an excellent mechanical and cycling stability (voltage gap increased ≈0.03 V after 200 cycles). The novel designed air‐cathode and simple methodology for flexible solid‐state rechargeable Zn‐air batteries contribute valuable enlightenment toward the development of emerging portable electronics in practice.
Coordination Geometry‐Dependent Multi‐Band Emission and Atypically Deep‐Trap‐Dominated NIR Persistent Luminescence from Chromium‐Doped Aluminates
Authors: Lin Xiaohui , Zhang Ruili , Tian Xiumei , Li Yang , Du Bingsheng , Nie Jianmin , Li Zhenzhang , Chen Li , Ren Jinjun , Qiu Jianrong , Hu Yihua
Published: February 2018

An abnormal trap distribution and coordination geometry‐dependent multi‐band emission are discovered in chromium‐doped aluminates. The multi‐band and broadband persistent luminescence from 650–1100 nm peaking at 688 and 793 nm from Cr3+‐doped SrAl12O19 is systematically studied via structural and spectroscopic analysis. Solid state nuclear magnetic resonance allows the visualization of various coordination configurations in SrAl12O19, thus offering the possibility of tailoring the local geometry of the emission center to trigger the control of the spectral parameter. Deep tissue ex vivo and in vivo imaging in mice both demonstrate that multi‐band‐emissive SrAl12O19:Cr3+ shows superior, high‐quality near‐infrared (NIR) bio‐imaging in the biological transparency window compared to single band‐emissive (with emission only at 688 nm) SrAl2O4:Cr3+, although SrAl2O4:Cr3+ has a higher luminescent intensity and longer duration at 688 nm. Moreover, by measuring the thermoluminescence spectra the driving force of carrier release is discovered to be only from the deep trap (the depth is > 1 eV), which is different from the generally accepted shallow‐dependent afterglow‐emitting process. These findings pave the way for opening a vista of possible avenues for the enhancement of signal‐to‐noise ratio, the improvement of imaging quality, as well as the understanding of the trapping and de‐trapping process in long‐persistent phosphors.
Lactic Acid Production from Renewable Feedstock: Fractionation, Hydrolysis, and Fermentation
Authors: Gavilà Llorenç , Constantí Magda , Medina Francisco , Pezoa‐Conte Ricardo , Anugwom Ikenna , Mikkola Jyri‐Pekka
Published: February 2018

In this paper, an integrated fractionation with a switchable ionic liquid (SIL), pulp hydrolysis, and lactic acid fermentation is carried out. For this, SO2‐swithced SIL is used for fractionation of sugar cane (Saccharum officinarum) bagasse and giant cane (Arundo donax, AD). SIL is able to extract ≈2/3 of lignin when relatively large wood chips (≈4 mm) are used without any mechanical agitation and just 1 h of treatment time for AD. Furthermore, SIL reuse is successfully demonstrated for four runs. Subsequently, the produced pulps are hydrolyzed within 15 min in a microwave reactor, producing a glucose rich hydrolysates. Finally, these hydrolysates are used as a carbohydrate source for Lactobacillus delbrueckii fermentation, which selectively transform all glucose present into optically pure d‐lactic acid. Hence, the whole chain for lactic acid production from biomass is successfully demonstrated.
Bilevel and parallel programing‐based operability approaches for process intensification and modularity
Authors: Carrasco Juan C. , Lima Fernando V.
Published: February 2018

Process operability emerged in the last decades as a powerful tool for the design and control of chemical processes. Recent efforts in operability have been focused on the calculation of the desired input set for process design and intensification of natural gas utilization applications described by nonlinear models. However, there is still a gap in terms of problem dimensionality that nonlinear operability methods can handle. To fill this gap, in this article, the incorporation of bilevel and parallel programing approaches into classical process operability concepts is discussed. Results on the implementation of the proposed method show a reduction in computational time up to two orders of magnitude, when compared to the original results without parallelization. These results could be extrapolated for use in a supercomputer as presented in the computational time analysis performed. In terms of intensification, the proposed approach can produce a natural gas combined cycle plant modular design with a dramatic reduction in size, from the original 400 to 0.11 MW, while still keeping the high net plant efficiency. This approach thus provides a computationally efficient framework for process intensification of high‐dimensional nonlinear energy systems toward modularity. The proposed approach also enables the verification of a modular design and conditions that can be obtained according to economic and physical constraints associated with a specific natural gas well production. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3042–3054, 2018
Hydrothermal pretreatment for deconstruction of plant cell wall: Part I. Effect on lignin‐carbohydrate complex
Authors: Yao Kun , Wu Qinfeng , An Ran , Meng Wei , Ding Mingzhu , Li Bingzhi , Yuan Yingjin
Published: February 2018

Hydrothermal pretreatment with characteristic of green chemistry is considered as promising technology in the biorefineries. Using material balance and multiscale characterization techniques, the effects of process severity factor and pH on chemical behaviors of lignin‐carbohydrate complex (LCC) were systematically studied. During pretreatment, spatial relocation of lignin with covalently linked xylan facilitated local cell wall collapse. A kinetic model was established to describe the behaviors of LCC components changing with severity factor. It was found that cleavage of LCC linkage was strongly pH‐dependent. Low pH dominated cleavage of coumarate/ferulate esters which cross‐linking lignin with xylan and repolymerization of aromatics either from furfural or lignin into polymers such as pseudo lignin, while high pH which allowed the existence of soluble LCC dominated the aldol condensations from xylose to aromatics and depolymerizaton of lignin to phenols. Detailed reaction pathways concerned with LCC were finally established to elucidate the underlying mechanism. © 2018 American Institute of Chemical Engineers AIChE J, 64: 1938–1953, 2018
How Economic Disadvantage Affects the Availability and Nature of Mentoring Relationships During the Transition to Adulthood
Authors: Raposa Elizabeth B. , Erickson Lance D. , Hagler Matthew , Rhodes Jean E.
Published: February 2018

Supportive nonparental adults, particularly nonfamilial adults, provide critical support during the transition to adulthood, opening doors to educational and career paths. This study examined whether economic disadvantage shapes access to these relationships. Results showed that low‐income adolescents had reduced access to naturally occurring mentors, and the relationships they did form tended to be close bonds with family and friends, rather than nonfamilial adults. Their mentors were more likely to focus on practical support, and less likely to serve as role models or provide career advice. These effects of socioeconomic status on natural mentoring relationships remained evident, even when accounting for youth race/ethnicity. Findings suggest that networks of support differ depending on a youth's socioeconomic context in ways that could perpetuate social and economic inequalities.
Early labor force exit subsequent to permanently impairing occupational injury or illness among workers 50‐64 years of age
Authors: Scott Kenneth A. , Liao Qing , Fisher Gwenith G. , Stallones Lorann , DiGuiseppi Carolyn , Tompa Emile
Published: February 2018

Background

Severity of workplace injury tends to increase with age. Whether older workers who experience a workplace injury or illness exit the labor force sooner than comparable peers is not established.

Methods

A case‐cohort study design and complementary log‐log model were used to identify factors associated with average time to early substantial labor force exit among workers’ compensation claimants 50‐64 years of age with permanent impairment from an occupational injury or illness. Analysis was based on Ontario's workers’ compensation claimant data from 1998 to 2006 linked with Canadian tax files.

Results

Workers with permanent impairment left the labor force earlier, on average, than peers without claims. Early retirement was associated with older age in the injury/illness year, greater impairment, lower pre‐claim income, physically demanding jobs, and soft‐tissue injuries.

Conclusions

Policies aiming to extend older adults’ working lives should account for the potentially disparate impacts on older workers of occupational injury and illness.
History and highlights of the teratological collection in the Museum Anatomicum of Leiden University, The Netherlands
Authors: Boer Lucas L. , Boek Peter L. J. , van Dam Andries J. , Oostra Roelof‐Jan
Published: February 2018

The anatomical collection of the Anatomical Museum of Leiden University Medical Center (historically referred to as Museum Anatomicum Academiae Lugduno‐Batavae) houses and maintains more than 13,000 unique anatomical, pathological and zoological specimens, and include the oldest teratological specimens of The Netherlands. Throughout four centuries hundreds of teratological specimens were acquired by more than a dozen collectors. Due to the rich history of this vast collection, teratological specimens can be investigated in a unique retrospective sight going back almost four centuries. The entire 19th century collection was described in full detail by Eduard Sandifort (1742–1814) and his son Gerard Sandifort (1779–1848). Efforts were made to re‐describe, re‐diagnose and re‐categorize all present human teratological specimens, and to match them with historical descriptions. In the extant collection a total of 642 human teratological specimens were identified, including exceptional conditions such as faciocranioschisis and conjoined twins discordant for cyclopia, and sirenomelia. Both father and son Sandifort differed in their opinion regarding the causative explanation of congenital anomalies. Whereas, their contemporaries Wouter Van Doeveren (1730–1783) and Andreas Bonn (1738–1817) both presented an interesting view on how congenital anomalies were perceived and explained during the 18th and 19th centuries; the golden age of descriptive teratology. Although this enormous collection is almost 400 years old, it still impresses scientists, (bio)medical students, and laymen visiting and exploring the collections of the Museum Anatomicum in Leiden, The Netherlands.
Catalytic Asymmetric Synthesis of α‐Trifluoromethylated Carbinols: A Case Study of Tertiary Propargylic Alcohols
Authors: Noda Hidetoshi , Kumagai Naoya , Shibasaki Masakatsu
Published: February 2018

Enantioenriched CF3‐substituted tertiary alcohols have been applied in a broad range of chemical disciplines, including medicinal chemistry and agrochemistry. The widely prescribed anti‐HIV pharmaceutical efavirenz is one particular example of the application of these chiral building blocks. Because the typical synthetic route to this small drug molecule involves the stoichiometric use of a chiral promoter, significant effort has been devoted to the development of catalytic alternatives for accessing this building block. In this Focus Review, we summarize the catalytic asymmetric synthesis of CF3‐substituted tertiary propargylic alcohols based on three retrosynthetic approaches, namely one trifluoromethylation approach and two building‐block strategies. The general challenges that are involved in the construction of a CF3‐substituted tetrasubstituted stereogenic carbon species are highlighted and possible future directions in the field are discussed.
Brief communication: Dental microwear and diet of Homo naledi
Authors: Ungar Peter S. , Berger Lee R.
Published: February 2018

Objectives

A recent study of dental chipping suggested that Homo naledi teeth were exposed to “acute trauma” on a regular basis during life, presumably from the consumption of grit‐laden foods. This follows debate concerning the etiology of dental chips in South African hominin teeth that dates back more than half a century. Some have argued that antemortem chips result from consumption of hard foods, such as nuts and seeds or bone, whereas others have claimed that exogenous grit on roots and tubers are responsible. Here we examine the dental microwear textures of H. naledi, both to reconstruct aspects of diet of these hominins and to assess the possibility that hard foods (gritty or otherwise) are the culprits for the unusually high antemortem chip incidence reported.

Methods

We made high‐resolution replicas of original molars and found that ten individuals preserve antemortem wear. These were scanned by white‐light scanning confocal profilometry and analyzed using scale‐sensitive fractal analysis. Resulting data were compared with those published for other fossil hominins and extant non‐human primates.

Results

Our results indicate that H. naledi had complex microwear textures dominated by large, deep pits. The only known fossil hominin with higher average texture complexity is Paranthropus robustus, and the closest extant primates in a comparative baseline series appear to be the hard‐object feeder, Cercocebus atys, and the eurytopic generalist, Papio ursinus.

Conclusions

This study suggests that H. naledi likely consumed hard and abrasive foods, such as nuts or tubers, at least on occasion, and that these might well be responsible for the pattern of chipping observed on their teeth.
A repeatable geometric morphometric approach to the analysis of hand entheseal three‐dimensional form
Authors: Karakostis Fotios Alexandros , Hotz Gerhard , Scherf Heike , Wahl Joachim , Harvati Katerina
Published: February 2018

Objectives

The purpose of this study was to put forth a precise landmark‐based technique for reconstructing the three‐dimensional shape of human entheseal surfaces, to investigate whether the shape of human entheses is related to their size. The effects of age‐at‐death and bone length on entheseal shapes were also assessed.

Materials and methods

The sample comprised high‐definition three‐dimensional models of three right hand entheseal surfaces, which correspond to 45 male adult individuals of known age. For each enthesis, a particular landmark configuration was introduced, whose precision was tested both within and between observers. The effect of three‐dimensional size, age‐at‐death, and bone length on shape was investigated through shape regression.

Results

The method presented high intra‐observer and inter‐observer repeatability. All entheses showed significant allometry, with the area ofopponens pollicisdemonstrating the most substantial relationship. This was particularly due to variation related to its proximal elongated ridge. The effect of age‐at‐death and bone length on entheses was limited.

Discussion

The introduced methodology can set a reliable basis for further research on the factors affecting entheseal shape. Using both size and shape, variables can provide further information on entheseal variation and its biomechanical implications. The low entheseal variation by age verifies that specimens under 50 years of age are not substantially affected by age‐related changes. The lack of correlation between entheseal shape and bone length or age implies that other factors may regulate entheseal surfaces. Future research should focus on multivariate shape patterns among entheses and their association with occupation.
Orthostatic heart rate changes in patients with autonomic failure caused by neurodegenerative synucleinopathies
Authors: Norcliffe‐Kaufmann Lucy , Kaufmann Horacio , Palma Jose‐Alberto , Shibao Cyndya A. , Biaggioni Italo , Peltier Amanda C. , Singer Wolfgang , Low Phillip A. , Goldstein David S. , Gibbons Christopher H. , Freeman Roy , Robertson David ,   Autonomic Disorders Consortium
Published: February 2018

Objective

Blunted tachycardia during hypotension is a characteristic feature of patients with autonomic failure, but the range has not been defined. This study reports the range of orthostatic heart rate (HR) changes in patients with autonomic failure caused by neurodegenerative synucleinopathies.

Methods

Patients evaluated at sites of the U.S. Autonomic Consortium (NCT01799915) underwent standardized autonomic function tests and full neurological evaluation.

Results

We identified 402 patients with orthostatic hypotension (OH) who had normal sinus rhythm. Of these, 378 had impaired sympathetic activation (ie, neurogenic OH) and based on their neurological examination were diagnosed with Parkinson disease, dementia with Lewy bodies, pure autonomic failure, or multiple system atrophy. The remaining 24 patients had preserved sympathetic activation and their OH was classified as nonneurogenic, due to volume depletion, anemia, or polypharmacy. Patients with neurogenic OH had twice the fall in systolic blood pressure (SBP; −44 ± 25 vs −21 ± 14 mmHg [mean ± standard deviation], p < 0.0001) but only one‐third of the increase in HR of those with nonneurogenic OH (8 ± 8 vs 25 ± 11 beats per minute [bpm], p < 0.0001). A ΔHR/ΔSBP ratio of 0.492 bpm/mmHg had excellent sensitivity (91.3%) and specificity (88.4%) to distinguish between patients with neurogenic from nonneurogenic OH (area under the curve = 0.96, p < 0.0001). Within patients with neurogenic OH, HR increased more in those with multiple system atrophy (p = 0.0003), but there was considerable overlap with patients with Lewy body disorders.

Interpretation

A blunted HR increase during hypotension suggests a neurogenic cause. A ΔHR/ΔSBP ratio < 0.5 bpm/mmHg is diagnostic of neurogenic OH. Ann Neurol 2018;83:522–531
From Symmetry Breaking to Unraveling the Origin of the Chirality of Ligated Au13Cu2 Nanoclusters
Authors: Deng Guocheng , Malola Sami , Yan Juanzhu , Han Yingzi , Yuan Peng , Zhao Chaowei , Yuan Xiting , Lin Shuichao , Tang Zichao , Teo Boon K. , Häkkinen Hannu , Zheng Nanfeng
Published: February 2018

A general method, using mixed ligands (here diphosphines and thiolates) is devised to turn an achiral metal cluster, Au13Cu2, into an enantiomeric pair by breaking (lowering) the overall molecular symmetry with the ligands. Using an achiral diphosphine, a racemic [Au13Cu2(DPPP)3(SPy)6]+ was prepared which crystallizes in centrosymmetric space groups. Using chiral diphosphines, enantioselective synthesis of an optically pure, enantiomeric pair of [Au13Cu2((2r,4r)/(2s,4s)‐BDPP)3(SPy)6]+ was achieved in one pot. Their circular dichroism (CD) spectra give perfect mirror images in the range of 250–500 nm with maximum anisotropy factors of 1.2×10−3. DFT calculations provided good correlations with the observed CD spectra of the enantiomers and, more importantly, revealed the origin of the chirality. Racemization studies show high stability (no racemization at 70 °C) of these chiral nanoclusters, which hold great promise in applications such as asymmetry catalysis.
Highly Enantioselective [3+2] Annulation of Indoles with Quinones to Access Structurally Diverse Benzofuroindolines
Authors: Liu Qiong‐Jie , Zhu Jun , Song Xiang‐Yang , Wang Lijia , Wang Sunewang R. , Tang Yong
Published: February 2018

A facile and efficient method to produce optically pure benzofuroindolines, especially those without 3‐substituents that are susceptible to rearomatization, through [3+2] annulation of indoles with quinones is described. The suitable combination of a BOX ligand CuII hydrate complex and freshly activated molecular sieves functions to give controllably dynamic release of water, which enables the success of this reaction. This reaction can be performed on a gram scale with only 0.5 mol % catalyst loading.
High‐Flux Membranes Based on the Covalent Organic Framework COF‐LZU1 for Selective Dye Separation by Nanofiltration
Authors: Fan Hongwei , Gu Jiahui , Meng Hong , Knebel Alexander , Caro Jürgen
Published: February 2018

Covalent organic frameworks (COFs) are attractive candidates for advanced water‐treatment membranes owing to their high porosity and well‐organized channel structures. Herein, the continuous two‐dimensional imine‐linked COF‐LZU1 membrane with a thickness of only 400 nm was prepared on alumina tubes by in situ solvothermal synthesis. The membrane shows excellent water permeance (ca. 760 L m−2 h−1 MPa−1) and favorable rejection rates exceeding 90 % for water‐soluble dyes larger than 1.2 nm. The water permeance through the COF‐LZU1 membrane is much higher than that of most membranes with similar rejection rates. Long‐time operation demonstrates the outstanding stability of the COF‐LZU1 membrane. As the membrane has no selectivity for hydrated salt ions (selectivity <12 %), it is also suitable for the purification of dye products from saline solutions. The excellent performance and the outstanding water stability render the COF‐LZU1 membrane an interesting system for water purification.
Directing Aluminum Atoms into Energetically Favorable Tetrahedral Sites in a Zeolite Framework by Using Organic Structure‐Directing Agents
Authors: Muraoka Koki , Chaikittisilp Watcharop , Yanaba Yutaka , Yoshikawa Takeshi , Okubo Tatsuya
Published: February 2018

The Al location in zeolites can have massive influences on the zeolite properties because it directly correlates with the cationic active sites. Herein, the synthesis of IFR zeolites with controlled Al distribution at different tetrahedral sites (T sites) is reported. The computational calculations suggest that organic structure‐directing agents (OSDAs) used for zeolite synthesis can alter the energetically favorable T sites for Al. Zeolite products synthesized under identical conditions but with different OSDAs are found to have altered fractions of Al at different T sites in accordance with the energies derived from the zeolite–OSDA complexes. Our finding thus provides evidence for the ability of OSDAs to direct Al into more energetically favorable T sites, thereby offering rational synthetic guidelines for the selective placement of Al into specific crystallographic sites.
Solvent‐Induced Crystal Polymorphism as Studied by Pyroelectric Measurements and Impedance Spectroscopy: Alcohols as Tailor‐Made Inhibitors of α‐Glycine
Authors: Meirzadeh Elena , Dishon Shiri , Weissbuch Isabelle , Ehre David , Lahav Meir , Lubomirsky Igor
Published: February 2018

Metastable polymorphs commonly emerge when the formation of the stable analogues is inhibited by using different solvents or auxiliaries. Herein, we report that when glycine is grown in aqueous solutions in the presence of low concentrations of different co‐solvents, only alcohols and acetone, unlike water and acetic acid, are selectively incorporated in minute amounts within the bulk of the α‐polymorph. These findings demonstrate that although water binds more strongly to the growing face of the crystal, alcohols and acetone are exclusively incorporated, and thus serve as efficient inhibitors of this polymorph, leading to the precipitation of the β‐form. These solvents then create polar domains detectable by pyroelectric measurements and impedance spectroscopy. These results suggest that in the control of crystal polymorphism with co‐solvents, one should consider also the different desolvation rates in addition to the energy of binding to the growing faces of the crystal.
Ferrocene conjugated copper(II) complexes of terpyridine and traditional Chinese medicine (TCM) anticancer ligands showing selective toxicity towards cancer cells
Authors: Deka Banashree , Bhattacharyya Arnab , Mukherjee Sanjoy , Sarkar Tukki , Soni Kiran , Banerjee Samya , Saikia Kandarpa K. , Deka Sasanka , Hussain Akhtar
Published: February 2018

Six novel mixed‐ligand copper(II) complexes, namely, [Cu(R‐tpy)(L)]NO3(1–6), where R‐tpy is 4′‐phenyl‐2,2′:6′,2′′‐terpyridine (Ph‐tpy;1–3) and 4′‐ferrocenyl‐2,2′:6′,2′′‐terpyridine (Fc‐tpy;4–6), L is the bidentateO,Odonor monoanion of plumbagin (5‐hydroxy‐2‐methyl‐1,4‐naphthoquinone; plum in1,4), chrysin (5,7‐dihydroxyflavone; chry in2,5) and curcumin (bis(4‐hydroxy‐3‐methoxyphenyl)‐1,6‐diene‐3,5‐dione; curc in3,6) have been synthesized and characterized and theirin vitrocytotoxicity against cancer cells is evaluated. The energy optimized structures and the frontier orbitals of the complexes have been obtained from the DFT calculations. Complexes4–6with a conjugated ferrocenyl moiety and TCM anticancer ligands, namely, plum (in4), chry (in5) and curc (in6) showed potent cytotoxicity giving respective IC50values of 1.2 μM, 0.62 μM and 0.21 μM in HeLa and 2.0 μM and 1.0 μM and 0.34 μM in MCF‐7 cancer cells while being much less toxic to MCF‐10A normal cells (IC50: 8.3‐17.1 μM). In contrast, complexes1–3with a conjugated phenyl moiety were appreciably less toxic to HeLa cells with respective IC50values of 10.4 μM, 8.1 μM and 5.5 μM when compared with their ferrocenyl analogues4–6. Mechanistic studies using Hoechst staining and Annexin‐V‐FITC assays on cancer cells revealed an apoptotic pathway of cell death induced by the complexes. Fluorescence imaging study showed that complex6having curcumin as ligand localized primarily in the mitochondria of HeLa cells. Thus, we demonstrate in this study that ferrocene conjugation to copper(II) complexes of TCM anticancer ligands significantly increases the selectivity and cytotoxicity of the resulting complexes towards cancer cells over normal cells.