bluuebunny/crossref_metadata_2025 huggingface dataset:
Geochemical Evaluation of the Silurian, Devonian, and Carboniferous Source Rocks at the Erawin Field, Murzuq Basin, SW Libya
Authors: Albaghday Alsharef A. , Aboglila S. , Abdullah Moustafa A. , Abousif Alsedik M. A. , Farifr E. , Targhi Mohamed H.
Published: October 2024

Eighty-five rock samples corresponding to the Palaeozoic formations were taken from two wells in the NC 200 Block of the Murzuq Basin. The study aimed to find out geochemical characteristics of Silurian Bir Tlacsin/Tanezzuft Formations, the Devonian Awaynat Wanin/BDS II Formations, and the Carboniferous Marar/Lower Marar Formations. Rock-Eval analysis, Total organic carbon (TOC) parameters and specific Gas Chromatography-Mass Spectrometry (GC-MS) biomarkers were applied to determine the potential hydrocarbon generation. Per se, Rocks are good sources and hold fair content of organic matter, crossing in the range of good accumulation, in which the very good source rocks have an organic carbon richness (TOC) reached of 3.7 wt%. The studied rocks are ranged from immature to late mature organic matter (OM) with total organic carbon richness (TOC) range between 0.4 – 3.7 wt%.  Rock-Eval parameters S1, S2, S3, Tmax, S2/S3, OI, PI and HI of the source rock samples have values ranged from 0.02 – 0.3, 0.22 – 6, 0.36 – 4, 423 – 443, 24= 350, 0 – 0.27 and 42 – 384 respectively. The range of hydrogen index (HI) related to oxygen index (OI) displays that all kerogen types from Type II to Type III are exist and increase with depth. The Tmax parameter is wide-ranging among studied formations, indicating different levels of organic matter maturity, from immature oil window and to late mature for the Devonian-Carboniferous and Silurian source rocks, associated with more depth. Molecular composition analysis of n-alkanes and other biomarkers supported the findings of Rock-Eval pyrolysis data, revealing varied hydrocarbon signatures across the formations. The Carbon isotope analysis (δ13C) suggested multiple sources contributing to the generated oil, including Type I to Type III kerogens.
TKM 15 -A High Yielding, Short Duration Rice Variety Suitable for Direct Sown Water Limited Areas of Tamil Nadu, India
Authors: Sheeba A. , Banumathy S. , Yogameenakshi P. , Muthuramu S. , Selvi C. Tamil , Bhaskaran M.
Published: October 2024

Drought is one of the major abiotic stresses that affect rice production in rainfed areas of Tamil Nadu. Tamil Nadu experienced recurrent droughts during the years 2012, 2013, 2014, 2016 and 2018 and rice production is worst affected. Rice Research Station, Tirur established in 1942 in Tiruvallur District of Tamil Nadu (TNAU) to evolve varieties suitable for semidry areas, took up research programme to  develop a short duration, high yielding drought tolerant rice variety suitable for rainfed and semidry cultivation and came up with the drought tolerant, short duration rice variety TKM 15 during 2022 for direct sown rainfed and semidry areas of Tamil Nadu viz., Kancheepuram, Chengalpattu, Tiruvallur, Pudukottai, Ramanathapuram, Virudhunagar, Sivagangai and Thoothukudi districts. TKM 15 matures in 118 days and has the ability to withstand early-stage water stress, good germination percentage under direct sowing, early vigour and high drought recovery. This variety has manifested the grain yield of 3995 kg/ha and 4217 kg/ha under rainfed and semidry conditions respectively which was 10.42% and 17.89% increase over the check variety Anna (R) 4 in rainfed and semidry conditions. TKM 15 has erect, high tillering and non-lodging plant habit, with dense droopy compact panicle (25 cm) having more number of grains per panicle (253 no.). It is moderately resistant to major diseases such as blast, sheath rot, sheath blight, brown spot and RTD and field tolerant to major pests like leaf folder, stem borer and gall midge which are its added advantage. It has good hulling (80%) percentage, milling (68%) percentage and Head Rice Recovery (62.9 %). Rice is white, medium slender with 1000 grain weight of 15.0 g with non-sticky property and has good taste upon cooking. It has higher proline content (2.15 mg/g), Chlorophyll Stability Index (80.23 %) and total chlorophyll content (1.51 mg/g) under water stress. The feedback from the farmers was that, TKM 15 tolerates water stress and recovers quickly with the receipt of rainfall, has more tillers, densely packed panicle with medium slender grains, gives higher yield under rainfed and semidry environments and also free from pests and diseases under field condition.
Mutations in the tetramer interface of human glucose‐6‐phosphate dehydrogenase reveals kinetic differences between oligomeric states
Authors: Ranzani Americo Tavares , Cordeiro Artur Torres
Published: March 2017

Glucose‐6‐phosphate dehydrogenase (G6PDH) catalyzes the oxidation of glucose‐6‐phoshate to 6‐phospho‐gluconolactone with the concomitant reduction of NADP+ to NADPH. In solution, the recombinant human G6PDH is known to be active as dimers and tetramers. To distinguish between the kinetic properties of dimers and tetramers of the G6PDH is not trivial. Steady‐state kinetic experiments are often performed at low enzyme concentrations, which favor the dimeric state. The present work describes two novel human G6PDH mutants, one that creates four disulfide bonds among apposing dimers, resulting in a ‘cross‐linked’ tetramer, and another that prevents the dimer to dimer association. The functional and structural characterizations of such mutants indicate the tetramer as the most active form of human G6PDH.
Rapid sedimentation and overpressure in shallow sediments of the Bering Trough, offshore southern Alaska
Authors: Daigle Hugh , Worthington Lindsay L. , Gulick Sean P. S. , Van Avendonk Harm J. A.
Published: March 2017

Pore pressures in sediments at convergent margins play an important role in driving chemical fluxes and controlling deformation styles and localization. In the Bering Trough offshore Southern Alaska, extreme sedimentation rates over the last 140 kyr as a result of glacial advance/retreats on the continental shelf have resulted in elevated pore fluid pressures in slope sediments overlying the Pamplona Zone fold and thrust belt, the accretionary wedge resulting from subduction of the Yakutat microplate beneath the North American Plate. Based on laboratory experiments and downhole logs acquired at Integrated Ocean Drilling Program Site U1421, we predict that the overpressure in the slope sediments may be as high as 92% of the lithostatic stress. Results of one‐dimensional numerical modeling accounting for changes in sedimentation rate over the last 130 kyr predicted overpressures that are consistent with our estimates, suggesting that the overpressure is a direct result of the rapid sedimentation experienced on the Bering shelf and slope. Comparisons with other convergent margins indicate that such rapid sedimentation and high overpressure are anomalous in sediments overlying accretionary wedges. We hypothesize that the shallow overpressure on the Bering shelf/slope has fundamentally altered the deformation style within the Pamplona Zone by suppressing development of faults and may inhibit seismicity by focusing faulting elsewhere or causing deformation on existing faults to be aseismic. These consequences are probably long‐lived as it may take several million years for the excess pressure to dissipate.
Effect of a fast‐moving tropical storm Washi on phytoplankton in the northwestern South China Sea
Authors: Zhao Hui , Pan Jiayi , Han Guoqi , Devlin Adam T. , Zhang Shuwen , Hou Yijun
Published: March 2017

Tropical cyclones may augment nutrients in the ocean surface layer through mixing, entrainment, and upwelling, triggering phytoplankton blooms in oligotrophic waters such as the South China Sea (SCS). Previous studies focused mainly on responses of marine environments to strong or slow‐moving typhoons in the SCS. In this study, we analyze variations of chlorophyll a (Chl a) and oceanic conditions in the continental shelf region east of Hainan Island during the fast‐moving tropical storm Washi and investigate its influences on phytoplankton bloom and related dynamic mechanisms. Results indicate that there was significant variation of Chl a concentration in the continental shelf region, with low values (about 0.1 mg m−3) before the storm and a 30% increase after the storm. This increase was spatially variable, much larger nearshore than offshore. Power spectral analysis of Acoustic Doppler Current Profiler (ADCP) data at a shelf site near the study region reveals strong near‐inertial oscillations (NIOs) in the upper layer, with a period of about 36 h, close to the local inertial period. The NIOs intensified mixing and modified the stratification of the upper layer, inducing uplift of nutrients and Chl a into the mixed layer from below, and leading to surface Chl a increase. The relatively shallow nutricline and thermocline in the continental shelf region before the storm were favorable for upwelling of nutrients and generation of NIOs. Advection of nutrients from enhanced runoff during and after the storm may be responsible for the larger increase of the Chl a nearshore.
Observation‐based parameterization of air‐sea fluxes in terms of wind speed and atmospheric stability under low‐to‐moderate wind conditions
Authors: Zou Zhongshui , Zhao Dongliang , Liu Bin , Zhang Jun A , Huang Jian
Published: March 2017

This study explores the behavior of the exchange coefficients for wind stress (CD), sensible heat flux (CH), and water vapor flux (CE) as functions of surface wind speed (U10) and atmospheric stability using direct turbulent flux measurements obtained from a platform equipped with fast‐response turbulence sensors in a low‐to‐moderate wind region. Turbulent fluxes are calculated using the eddy‐correlation method with extensive observations. The total numbers of quality‐controlled 30 min flux runs are 12,240, 5813, and 5637 for estimation of CD, CH, and CE, respectively. When adjusted to neutral stability using the Monin‐Obukhov similarity theory (MOST), we found that CDN, CHN, and CEN decrease with neutral‐adjusted wind speed when wind speed is less than 5 m/s. CDN is constant over the range 5 m/s < U10N < 12 m/s, then increases with U10N when U10N > 12 m/s. In contrast, CHN and CEN exhibit no clear dependence on wind speed and are generally constant, with mean values of 0.96 × 10−3 and 1.2 × 10−3, respectively. This behavior of neutral exchange coefficients is consistent with the findings of previous studies. We also found that CDN under offshore winds is generally greater than that under onshore wind conditions, which is ascribed to the younger wind waves present due to the shorter fetch in the former case. However, this behavior is not exhibited by CHN or CEN. The original CD, CH, and CE values without MOST adjustment are also investigated to develop a new parameterization based on wind speed and stability. Three stability parameters are tested, including the bulk Richardson number, stability as defined in COARE 3.0, and a simplified Richardson number using the Charnock parameter. This new parameterization is free of MOST and the associated self‐correlation. Compared with previous studies and COARE 3.0 results, the new parameterization using the simplified Richardson number performs well, with an increased correlation coefficient and reduction of root‐mean‐square error and bias.
Wind‐driven ocean dynamics impact on the contrasting sea‐ice trends around West Antarctica
Authors: Lee Sang‐Ki , Volkov Denis L. , Lopez Hosmay , Cheon Woo Geun , Gordon Arnold L. , Liu Yanyun , Wanninkhof Rik
Published: March 2017

Since late 1978, Antarctic sea‐ice extent in the East Pacific has retreated persistently over the Amundsen and Bellingshausen Seas in warm seasons, but expanded over the Ross and Amundsen Seas in cold seasons, while almost opposite seasonal trends have occurred in the Atlantic over the Weddell Sea. By using a surface‐forced ocean and sea‐ice coupled model, we show that regional wind‐driven ocean dynamics played a key role in driving these trends. In the East Pacific, the strengthening Southern Hemisphere (SH) westerlies in the region enhanced the Ekman upwelling of warm upper Circumpolar Deep Water and increased the northward Ekman transport of cold Antarctic surface water. The associated surface ocean warming south of 68°S and the cooling north of 68°S directly contributed to the retreat of sea‐ice in warm seasons and the expansion in cold seasons, respectively. In the Atlantic, the poleward shifting SH westerlies in the region strengthened the northern branch of the Weddell Gyre, which in turn increased the meridional thermal gradient across it as constrained by the thermal wind balance. Ocean heat budget analysis further suggests that the strengthened northern branch of the Weddell Gyre acted as a barrier against the poleward ocean heat transport, and thus produced anomalous heat divergence within the Weddell Gyre and anomalous heat convergence north of the gyre. The associated cooling within the Weddell Gyre and the warming north of the gyre contributed to the expansion of sea‐ice in warm seasons and the retreat in cold seasons, respectively.
A statistical study on the subthermocline submesoscale eddies in the northwestern Pacific Ocean based on Argo data
Authors: Li Cheng , Zhang Zhiwei , Zhao Wei , Tian Jiwei
Published: March 2017

In this study, statistical characteristics and spatiotemporal variability of the cold‐core subthermocline eddies (STEs) discovered by Zhang et al. (2015) in the northwestern Pacific are investigated with 14 years of Argo temperature/salinity (T/S) data between 2002 and 2015. By applying an objective identification procedure to Argo T/S profiles, a total of 337 lens‐like STEs that trap cold and fresh homogeneous water are obtained. The STEs' cores are primarily located between 26.5 and 26.9
(300–800 m) and their shapes share a uniform Gaussian structure in vertical. Vertical and horizontal scale of the STEs is generally between 100 and 200 m and 5 and 15 km, respectively, suggesting that they are in the category of submesoscale processes. According to their different densities and seasonalities, the STEs are classified into upper and lower types with density interface of 26.7
. The number of upper‐type STEs is much larger in spring and summer than in autumn and winter while that of lower‐type ones show relatively uniform seasonal distributions. Spatially, the STEs are primarily distributed within the region between the Kuroshio Extension (KE) and subarctic front (SAF) in meridional and 140°E–155°E in zonal direction. Based on STEs' spatial distributions and vertical locations, we propose to name these STEs as KE intermediate‐layer eddies (Kiddies). Water property analysis suggests that the Kiddies most likely originated from the SAF region. For the upper‐type Kiddies, they are probably generated through subduction associated with mixed‐layer frontogenesis, which at least contribute to 0.25 Sv annual subduction rate for the layers 26.2–26.7
.
Equatorial Stokes drift and Rossby rip currents
Authors: Weber Jan Erik H.
Published: March 2017

The Stokes drift in long baroclinic equatorial Rossby waves is investigated theoretically by using eigenfunction expansions in the vertical. These waves are nondispersive and propagate westward along the equator. Particular attention is paid to the first baroclinic, first meridional Rossby wave mode which has been observed in the equatorial Pacific. It is demonstrated that the Stokes drift depends very much on the depth‐variation of the Brunt‐Väisälä frequency. Even more importantly, it is found that, for arbitrary stable stratification, the total zonal Stokes volume transport induced by the Rossby wave mode (1,1) is identically zero. The eastward drift due reflected wave energy in the form of internal equatorial Kelvin waves is also addressed. Due to the very long period of the incident Rossby wave mode (1,1), the reflected equatorial Kelvin wave must at least be a 2. mode component in the vertical. The corresponding Stokes drift only induces a minor change near the surface of the total westward drift velocity at the equator. The implication for the existence of compensating Rossby rip currents along the equator is discussed.
Periodicities of polar mesospheric clouds inferred from a meteorological analysis and forecast system
Authors: Stevens M. H. , Lieberman R. S. , Siskind D. E. , McCormack J. P. , Hervig M. E. , Englert C. R.
Published: March 2017

There is currently an ambiguity in what controls polar mesospheric cloud (PMC) periodicities near 83 km altitude. This is primarily because satellite and ground‐based data sets cannot resolve global mesospheric temperature variability over the diurnal cycle. To address this limitation, we employ a global meteorological analysis and forecast system that assimilates mesospheric satellite data with two significant advances. The first is that we use output at a more rapid one hourly cadence, allowing for a quantitative description of diurnal (24 h), semidiurnal (12 h), and terdiurnal oscillations. The second is that the output drives a simple PMC parameterization which depends only on the local temperature, pressure, and water vapor concentrations. Our study focuses on results from July 2009 in the Northern Hemisphere and January 2008 in the Southern Hemisphere. We find that the 24 h migrating temperature tide as well as the 12 h and 24 h nonmigrating tides dominate northern PMC oscillations whereas the 12 h and 24 h nonmigrating tides dominate southern oscillations. Monthly averaged amplitudes for each of these components are generally 2–6 K with the larger amplitudes at lower PMC latitudes (50°). The 2 day and 5 day planetary waves also contribute in both hemispheres, with monthly averaged amplitudes from 1 to 3 K although these amplitudes can be as high as 4–6 K on some days. Over length scales of ~1000 km and timescales of ~1 week, we find that local temperature oscillations adequately describe midlatitude PMC observations.
Continental‐scale variation in controls of summer CO2 in United States lakes
Authors: Lapierre Jean‐Francois , Seekell David A. , Filstrup Christopher T. , Collins Sarah M. , Emi Fergus C. , Soranno Patricia A. , Cheruvelil Kendra S.
Published: March 2017

Understanding the broad‐scale response of lake CO2 dynamics to global change is challenging because the relative importance of different controls of surface water CO2 is not known across broad geographic extents. Using geostatistical analyses of 1080 lakes in the conterminous United States, we found that lake partial pressure of CO2 (pCO2) was controlled by different chemical and biological factors related to inputs and losses of CO2 along climate, topography, geomorphology, and land use gradients. Despite weak spatial patterns in pCO2 across the study extent, there were strong regional patterns in the pCO2 driver‐response relationships, i.e., in pCO2 “regulation.” Because relationships between lake CO2 and its predictors varied spatially, global models performed poorly in explaining the variability in CO2 for U.S. lakes. The geographically varying driver‐response relationships of lake pCO2 reflected major landscape gradients across the study extent and pointed to the importance of regional‐scale variation in pCO2 regulation. These results indicate a higher level of organization for these physically disconnected systems than previously thought and suggest that changes in climate and land use could induce shifts in the main pathways that determine the role of lakes as sources and sinks of atmospheric CO2.
Global satellite data highlights the diurnal asymmetry of the surface temperature response to deforestation
Authors: Schultz Natalie M. , Lawrence Peter J. , Lee Xuhui
Published: March 2017

Uncertainties remain about the spatial pattern and magnitude of the biophysical effects of deforestation. In particular, a diurnal asymmetry in the magnitude and sign of the surface temperature response to deforestation (ΔTS) has been observed, but the biophysical processes that contribute to day and nighttime ΔTS are not fully understood. In this study, we use a space‐for‐time approach with satellite and reanalysis data to investigate the biophysical processes that control the day and nighttime ΔTS. Additionally, we incorporate flux‐tower data to examine two hypotheses for nighttime forest warming relative to open lands: (1) that forests generate turbulence in the stable nocturnal boundary layer, which brings heat aloft down to the surface, and (2) that forests store more heat during the day and release it at night. Our results confirm a diurnal asymmetry in ΔTS. Over most regions of the world, deforestation results in daytime warming and nighttime cooling. The strongest daytime warming is in the tropics, where the average ΔTS is 4.4 ± 0.07 K. The strongest nighttime cooling is observed in the boreal zone, where open lands are cooler than forests by an average of 1.4 ± 0.04 K. Daytime patterns of ΔTS are explained by differences in the latent heat flux (ΔLE) and absorbed solar radiation (ΔKa). We find that nighttime ΔTS is related to the strength of the nocturnal temperature inversion, with stronger temperature inversions at high latitudes and weak inversions in the tropics. Forest turbulence at night combined with stored heat release drives nighttime ΔTS patterns.
Preferential sequestration of terrestrial organic matter in boreal lake sediments
Authors: Guillemette François , von Wachenfeldt Eddie , Kothawala Dolly N. , Bastviken David , Tranvik Lars J.
Published: March 2017

The molecular composition and origin has recently been demonstrated to play a critical role in the persistence of organic matter in lake water, but it is unclear to what degree chemical attributes and sources may also control settling and burial of organic matter in lake sediments. Here we compared the annual contribution of allochthonous and autochthonous sources to the organic matter settling in the water column and present in the sediments of 12 boreal lakes. We used the fluorescence properties and elemental composition of the organic matter to trace its origin and found a consistent pattern of increasing contribution of terrestrial compounds in the sediments as compared to the settling matter, with an annual average allochthony of ~87% and ~57%, respectively. Seasonal data revealed a predominance of in‐lake‐produced compounds sinking in the water column in summer. Yet only a slight concurrent decrease in the contribution of terrestrial C to lake sediments was observed during the same period, and sediment allochthony increased again to high levels in autumn. Our results reveal a preferential preservation of allochthonous matter in the sediments and highlight the role of lakes as sequesters of organic carbon primarily originating from the surrounding landscape.
Decadal‐scale changes in forest soil carbon and nitrogen storage are influenced by organic matter removal during timber harvest
Authors: Mushinski Ryan M. , Boutton Thomas W. , Scott D. Andrew
Published: March 2017

This study investigates whether different intensities of organic matter removal associated with timber harvest influence decadal‐scale storage of soil organic carbon (SOC) and total nitrogen (TN) in the top 1 m of mineral soil 18 years postharvest in a Pinus taeda L. forest in the Gulf Coastal Plain. We quantified forest harvest‐related changes in SOC, TN, microbial biomass carbon (MBC), and nitrogen (MBN) pools (0–100 cm) in unharvested control stands and in two organic matter removal treatment stands subjected to either (i) merchantable bole/stem‐only harvest or (ii) whole‐tree harvest + forest floor removal. In addition, δ13C of SOC and δ15N of TN were measured in mineral soil to provide insights regarding mechanisms that might explain changes in SOC and TN pool sizes. Soils were sampled seasonally for 1 year. Increasing organic matter removal intensity reduced SOC, TN, MBC, and MBN relative to the unharvested control. Furthermore, soils from whole‐tree harvest + forest floor removal stands had lower δ13C and higher δ15N values, suggesting that increasing organic matter removal may decrease heterotrophic activity as well as increase rates of N loss. Seasonal variabilities in SOC and TN were correlated to changes in forest biological properties such as root biomass and forest floor mass. These results indicate that more intensive harvest methods may lead to decade‐scale decreases in SOC and TN storage in surface and subsurface soils which could influence rates of biogeochemical processes, the availability of soil nutrients, and potential forest productivity.
Mechanism of seasonal eddy kinetic energy variability in the eastern equatorial Pacific Ocean
Authors: Wang Minyang , Du Yan , Qiu Bo , Cheng Xuhua , Luo Yiyong , Chen Xiao , Feng Ming
Published: March 2017

Enhanced mesoscale eddy activities or tropical instability waves (TIWs) exist along the northern front of the cold tongue in the eastern equatorial Pacific Ocean. In this study, we investigate seasonal variability of eddy kinetic energy (EKE) over this region and its associated dynamic mechanism using a global, eddy‐resolving ocean general circulation model (OGCM) simulation, the equatorial mooring data, and satellite altimeter observations. The seasonal‐varying enhanced EKE signals are found to expand westward from 100°W in June to 180°W in December between 0°N and 6°N. This westward expansion in EKE is closely connected to the barotropically‐baroclinically unstable zonal flows that are in thermal‐wind balance with the seasonal‐varying thermocline trough along 4°N. By adopting an 1½‐layer reduced‐gravity model, we confirm that the seasonal perturbation of the thermocline trough is dominated by the anticyclonic wind stress curl forcing, which develops due to southerly winds along 4°N from June to December.
Respondent Burden, Reduction of
Authors: Tortora Robert
Published: March 2017

Respondent burden is the effort, in terms of time and cost, required by respondents to provide answers to a survey or census. Burden is a multidimensional concept that includes length of an interview, frequency of being interviewed, the effort to retrieve the data asked for, and the stress encountered in providing the data. Thus, respondent burden has actual and perceived components and has the potential to introduce nonresponse and measurement error. This article presents a section on reducing respondent burden using good web questionnaire design practices and concludes with a discussion of the Consumer Expenditure Survey (CES), which has introduced several modes of data collection to reduce respondent burden as well as nonresponse and measurement error.
Robust Testing Procedures
Authors: Wilcox Rand R.
Published: March 2017

Robust testing procedures are hypothesis testing techniques that are relatively insensitive to violations of assumptions such as normality and homoscedasticity. Major advances on how to study and develop robust testing techniques have appeared during the past 50 years. The result has been a much better understanding of why conventional ANOVA and regression methods can be highly unsatisfactory in terms of both power and control over the type I error probability. There is now a vast collection of new methods that can provide a deeper, more accurate, and more nuanced understanding of data.
Label‐Free, Quantitative Imaging of MoS2‐Nanosheets in Live Cells with Simultaneous Stimulated Raman Scattering and Transient Absorption Microscopy
Authors: Zhang Lili , Shen Sida , Liu Zhuang , Ji Minbiao
Published: March 2017

Probing nanoparticle–cell interactions in vivo plays a key role in the research and development of nanomedicine and nano‐biophotonics. However, simultaneously imaging nanoparticles and intracellular biomolecules in a label‐free manner has been a challenge, especially for the majority of nanoparticles that do not emit one‐ or two‐photon excited fluorescence. In this work, a strong optical transient absorption (TA) signal is observed for synthesized MoS2 nanosheets that could be used for sensitive and quantitative imaging of their intracellular distributions. Furthermore, a dual‐modal microscopy technique is developed to simultaneously image MoS2 with TA microscopy and cellular lipids/proteins with stimulated Raman scattering (SRS) microscopy. This technique is based on precise pulse engineering and dual‐phase lock‐in detection. Its capability to quantify the uptake dynamics of MoS2 into live HeLa cells is demonstrated and the colocalization of MoS2 nanosheets with intracellular lipid rich organelles is observed. Different sized MoS2 nanosheets are found to have distinct uptake dynamics as well as transient photocarrier dynamics. These results indicate that dual‐modal SRS/TA microscopy may provide a general solution for investigating a large variety of nanomaterials that absorb light but do not fluoresce.
Delivery Systems for Low Molecular Weight Payloads: Core/Shell Capsules with Composite Coacervate/Polyurea Membranes
Authors: Dardelle Gregory , Jacquemond Marlène , Erni Philipp
Published: March 2017

Composite polyurea/coacervate core/shell capsules are formed by coupling associative biopolymer phase separation with interfacial polymerization. They combine the excellent chemical stability of synthetic polymer barriers with the strong adhesive properties of protein‐based complex coacervates, inspired by biological underwater glues. To encapsulate volatile oil droplets, a primary coacervate hydrogel capsule is formed by a protein and weak polyanion and is reinforced with a polyurea membrane synthesized in situ at the interface between the coacervate and the oil core. The polyurea layer provides an excellent permeability barrier against diffusion of small volatile molecules while the coacervate portion of the shell enhances adhesion on the targeted substrate.
Designed Synthesis of Size‐Controlled PtCu Alloy Nanoparticles Encapsulated in Carbon Nanofibers and Their High Efficient Electrocatalytic Activity Toward Hydrogen Evolution Reaction
Authors: Wang Juan , Chen Jia Wei , Chen Jia Dong , Zhu Han , Zhang Ming , Du Ming Liang
Published: March 2017

Well‐dispersed PtCu alloy nanoparticles (NPs) with a diameter of only ≈2 nm encapsulated in carbon nanofibers (CNFs) are synthesized using electrospinning technology followed by a graphitization process in a chemical vapor deposition furnace. Distinctly, even with a small amount of Pt, the PtCu/CNFs‐1:2 catalyst possesses outstanding hydrogen evolution reaction (HER) activity, including small overpotential, long‐term stability, and a high exchange current density as well as large double layer capacitance (Cdl). The excellent HER performance of the PtCu/CNFs‐1:2 catalyst is attributed to the synergistic interaction between Pt and Cu, the uniform distribution of the alloy NPs and the use of CNFs with 3D architectures. This development may provide a simple, efficient, and green synthesis method to design bi‐ or multimetal alloys for use as the cathode electrocatalysts for the HER or other electrocatalytic devices.
Synthetic Approach Towards the Synthesis of Antimalarial Gomphostenin
Authors: Swapnil Nipunge , Kumar Alleni Suman , Babu Nanubolu Jagadeesh , Yadav Jhillu Singh
Published: March 2017

An efficient and concise stereoselective synthesis towards the antimalarial (−)‐Gomphostenin, starting with the enantiomerically pure Wieland–Miescher ketone, is reported. The key transformations of the convergent synthesis involved a stereoselective reductive allylation, Palladium‐catalyzed Saegusa–Ito oxidation, Babler–Dauben oxidative rearrangement, and Wittig olefination reactions. The structure and absolute stereochemistry were determined by X‐ray analysis.
Ein achtkerniger metallosupramolekularer Würfel mit Spin‐Crossover‐Eigenschaften
Authors: Struch Niklas , Bannwarth Christoph , Ronson Tanya K. , Lorenz Yvonne , Mienert Bernd , Wagner Norbert , Engeser Marianne , Bill Eckhard , Puttreddy Rakesh , Rissanen Kari , Beck Johannes , Grimme Stefan , Nitschke Jonathan R. , Lützen Arne
Published: March 2017

Nach dem Ansatz der Subkomponenten‐Selbstorganisation lassen sich aus 5,10,15,20‐Tetrakis(4‐aminophenyl)porphyrin oder dessen Zink(II)‐Komplex, 1H‐4‐Imidazol‐carbaldehyd und Zink(II)‐ oder Eisen(II)‐Salzen O‐symmetrische Käfige mit einem abgeschlossenen Hohlraum von 1300 Å3 darstellen. Eisen(II)‐Salze lieferten Käfigverbindungen, die bei Raumtemperatur im High‐spin‐Zustand vorliegen und beim Abkühlen in den Low‐spin‐Zustand übergehen, während die Verwendung von Zink(II)‐Salzen die diamagnetischen Analoga liefert. Die Verbindungen wurden mit Synchrotron‐Einkristallröntgenbeugung, hochauflösender Massenspektrometrie, NMR‐, Mößbauer‐, IR‐ und UV‐Vis‐Spektroskopie charakterisiert. Die Struktur der Käfigverbindungen und ihre UV‐Vis‐Spektren wurden unabhängig durch DFT‐Rechnungen bestätigt. Ein besonderer Effekt ist die Stabilisierung des High‐spin‐Zustands durch Einschluss von C70 in den Käfigen. Im Fall des Wirt‐Gast‐Komplexes liegt die Übergangstemperatur T1/2 um 20 K tiefer als die des freien Wirts.
An Octanuclear Metallosupramolecular Cage Designed To Exhibit Spin‐Crossover Behavior
Authors: Struch Niklas , Bannwarth Christoph , Ronson Tanya K. , Lorenz Yvonne , Mienert Bernd , Wagner Norbert , Engeser Marianne , Bill Eckhard , Puttreddy Rakesh , Rissanen Kari , Beck Johannes , Grimme Stefan , Nitschke Jonathan R. , Lützen Arne
Published: March 2017

By employing the subcomponent self‐assembly approach utilizing 5,10,15,20‐tetrakis(4‐aminophenyl)porphyrin or its zinc(II) complex, 1H‐4‐imidazolecarbaldehyde, and either zinc(II) or iron(II) salts, we were able to prepare O‐symmetric cages having a confined volume of ca. 1300 Å3. The use of iron(II) salts yielded coordination cages in the high‐spin state at room temperature, manifesting spin‐crossover in solution at low temperatures, whereas corresponding zinc(II) salts led to the corresponding diamagnetic analogues. The new cages were characterized by synchrotron X‐ray crystallography, high‐resolution mass spectrometry, and NMR, Mössbauer, IR, and UV/Vis spectroscopy. The cage structures and UV/Vis spectra were independently confirmed by state‐of‐the‐art DFT calculations. A remarkably high‐spin‐stabilizing effect through encapsulation of C70 was observed. The spin‐transition temperature T1/2 is lowered by 20 K in the host–guest complex.
Citalopram Induces Reproductive Toxicity in Male Rats
Authors: Ilgin Sinem , Kilic Gozde , Baysal Merve , Kilic Volkan , Korkut Busra , Ucarcan Seyda , Atli Ozlem
Published: March 2017

Background

Citalopram hydrobromide (CTL) has been shown to cause sexual dysfunction; however, its reproductive toxicity potential has not been sufficiently elucidated in men. Therefore, we aimed to clarify the toxic effects of CTL on the reproductive system of male rats.

Methods

For this purpose, CTL was administered at 5, 10, and 20 mg/kg/day to rats orally for 28 days. Sperm concentration, motility, and morphology were investigated using a computer‐assisted sperm analysis system, and sperm DNA damage was detected using a Comet assay. The testes were histopathologically examined. Serum follicle‐stimulating hormone, luteinizing hormone, and testosterone levels were measured and the oxidative status of testes was investigated.

Results

Our results showed that sperm concentration was reduced, and abnormal sperm morphology and sperm DNA damage were increased in CTL‐administered groups. Additionally, histopathological changes were observed in the testes of CTL‐administered rats. Luteinizing hormone levels were increased in CTL‐administered groups, while testosterone levels were increased in the 5 and 10 mg/kg CTL‐administered groups. Decreased glutathione signaled enhanced oxidative stress in the 10 and 20 mg/kg CTL‐administered groups.

Conclusion

Thus, we concluded that CT induced testicular damage in male rats; this testicular damage was accompanied by oxidative stress and hormonal changes, which are considered as the important causes of reproductive disorders. Birth Defects Research 109:475–485, 2017. © 2017 Wiley Periodicals, Inc.
Foresight beats hindsight: The neural correlates underlying motor preparation in the pro‐/anti‐cue paradigm
Authors: Emmerling Franziska , Duecker Felix , de Graaf Tom A. , Schuhmann Teresa , Adam Jos J. , Sack Alexander T.
Published: March 2017

Background

Human motor behaviors are characterized by both, reactive and proactive mechanisms. Yet, studies investigating the neural correlates of motor behavior almost exclusively focused on reactive motor processes. Here, we employed the pro‐/anti‐cue motor preparation paradigm to systematically study proactive motor control in an imaging environment. In this paradigm, either pro‐ or anti‐cues are presented in a blocked design. Four fingers (two from each hand) are mapped onto four visual target locations. Visual targets require a speeded response by one corresponding finger, but, most importantly, they are preceded by visual cues that are congruent (“pro‐cue”), incongruent (“anti‐cue”), or neutral with respect to the responding hand. With short cue‐target intervals, congruence effects are based on automatic motor priming of the correct hand (in case of pro‐cues) or incorrect hand (in case of anti‐cues), generating, respectively, reaction time benefits or reaction time costs relative to the neutral‐cue. With longer cue‐target intervals, slower top‐down processes become effective, transforming early anti‐cue interference into late anti‐cue facilitation.

Methods

We adapted this paradigm to be compatible with neuroimaging, tested and validated it behaviorally—both inside and outside the imaging environment—and implemented it in a whole‐brain functional magnetic resonance imaging study.

Results and Conclusion

Our imaging results indicate that pro‐cues elicited much less neural activation than did anti‐cues, the latter recruiting well‐known cognitive top‐down networks related to attention, response inhibition, and error monitoring/signaling, thereby revealing high‐level influences on proactive motor processes.
Perioperative intravenous immunoglobulin treatment in a patient with severe acquired von Willebrand syndrome: case report and review of the literature
Authors: Jennes Eva , Guggenberger Dorothee , Zotz Rainer , Thompson Lora , Brümmendorf Tim H. , Koschmieder Steffen , Jost Edgar
Published: March 2017

Key Clinical Message

Acquired von Willebrand syndrome may be related to plasma cell dyscrasia and can cause severe bleeding complications. Treatment, for example, with intravenous immunoglobulins may be indicated in selected cases. Physicians treating plasma cell dyscrasia have to be aware of bleeding complications in these patients, and clarification is necessary.
Palladium‐Catalyzed Ligand‐Controlled Selective Synthesis of Aldehydes and Acids from Aryl Halides and Formic Acid
Authors: Wu Fu‐Peng , Peng Jin‐Bao , Meng Ling‐Shen , Qi Xinxin , Wu Xiao‐Feng
Published: March 2017

Selective synthesis is in the core of modern organic chemistry. In this communication, a novel ligand‐dependent palladium‐catalyzed carbonylation procedure for the divergent synthesis of aldehydes and carboxylic acids from easily available aryl halides was established. Under the same reaction conditions, the reaction pathway could be controlled by the ligands applied to give formylated and carboxylated products selectively. Sterically hindered monodentate ligands facilitated the reductive carbonylation and provided aldehydes, whereas bidentate ligands preferred the carboxylation reaction and produced carboxylic acids. A wide range of functional groups were tolerated, and the products were, in general, obtained in moderate to excellent yields.
Molecular Hybridization Tools in the Development of Furoxan‐Based NO‐Donor Prodrugs
Authors: Fershtat Leonid L. , Makhova Nina N.
Published: March 2017

The molecular hybridization of different compounds with known pharmacological activity is a particularly prominent approach for the design of potential drugs with improved pharmacokinetic profiles. Much attention over the last decade has been focused on the synthesis of hybrid structures with a nitric oxide (NO)‐donor framework, as NO is a ubiquitous and crucial regulator of cellular metabolism, affecting various physiological and pathophysiological processes. 1,2,5‐Oxadiazole 2‐oxides (furoxans), which are capable of exogenous NO release in the presence of thiol cofactors, are an important class of prospective NO donors. As such, a wide range of hybrid compounds that combine a furoxan ring with various pharmacologically active structures have been created. This review focuses on recent results in the synthesis and pharmacological activity of furoxan‐based hybrids. Special attention is given to chemo‐ and regioselective methods used in the preparation of these hybrid structures, and the role of synergistic effects on their pharmacological activity, associated with the furoxan fragment.
Empirical and Computational Insights into N‐Arylation Reactions Catalyzed by Palladium meta‐Terarylphosphine Catalyst
Authors: Yong Fui Fong , Mak Adrian M. , Wu Wenqin , Sullivan Michael B. , Robins Edward G. , Johannes Charles W. , Jong Howard , Lim Yee Hwee
Published: March 2017

An in situ generated Pd–Cy*Phine catalyst has been successfully applied to the N‐arylation of primary and secondary amines, and it exhibited high performance across multiple substrate classes. The performance induced by the meta‐terarylphosphine motif of the Cy*Phine ligand for C−N cross‐coupling displayed only subtle differences to that of its biarylphosphine congener XPhos. DFT studies demonstrated comparable reaction energetics in the catalytic cycle steps for both Pd–Cy*Phine and Pd–XPhos, which was consistent with previous findings. The computational investigation also indicated that a putative rate‐determining step occurred after amine binding, which was likely to have annulled the expected benefits of having a meta‐terarylphosphine ligand architecture.
Lack of adjunctive effect of 0.1% sodium hypochlorite mouthwash combined to full‐mouth ultrasonic debridement on supragingival plaque, gingival inflammation, and subgingival microbiota: A randomized placebo‐controlled 6‐month trial
Authors: Espíndola Laís Christina Pontes , Colombo Ana Paula Vieira
Published: March 2017

To test the adjunctive effect of 0.1% sodium hypochlorite (NaOCl) mouthwash combined to full‐mouth ultrasonic debridement (FMUD) on reducing supragingival plaque, gingival inflammation, and microbial pathogens. In this 6‐month double‐blinded randomized clinical trial, individuals with gingivitis were assigned to test (n = 16) or placebo group (n = 16) and received FMUD followed by rinsing with 0.1% NaOCl (test) or distilled water (placebo), respectively, twice a day for 1 month. Full‐mouth periodontal examination was performed at baseline, 1, 3, and 6 months posttherapy, and subgingival plaque samples were obtained at the same time points and analysed for their composition by checkerboard. Differences between groups over time were examined by Student t test, Mann–Whitney, generalized linear model, and Friedman and chi‐square tests. Both therapeutic protocols resulted in significant clinical improvement in periodontal parameters over time, except for probing depth and attachment level, which had a slight mean increase of 0.2 mm (p < .01). No significant differences between groups were observed for any clinical parameter (p > .05). Most species (>65%) decreased similarly in levels in both groups over time. Significant reductions in the microbial complexes were seen mainly at 1 and 3 months, but they returned to baseline levels in both groups, except for the red and yellow complexes, and other oral species, which were kept in low levels at 6 months (p < .05). A 0.1% NaOCl mouthwash did not provide additional benefits to FMUD in reducing supragingival plaque, gingivitis, and/or microbial pathogens.
Applications of label‐free, quantitative phase holographic imaging cytometry to the development of multi‐specific nanoscale pharmaceutical formulations
Authors: Luther Ed , Mendes Livia P. , Pan Jiyai , Costa Daniel F. , Torchilin Vladimir P.
Published: March 2017

A label‐free, high content, time‐lapse holographic imaging system was applied to studies in pharmaceutical compound development. Multiple fields of cellular images are obtained over typically several day evaluations within standard CO2 incubators. Events are segmented to obtain population data of cellular features, which are displayed in scattergrams and histograms. Cell tracking is accomplished, accompanied by Cartesian plots of cell movement, as well as plots of cell features vs. time in novel 4‐D displays of X position, Y position, time, and cell thickness. Our review of the instrument validation data includes 1) tracking of Giant HeLa cells, which may be undergoing neosis, a process of tumor stem cell generation; 2) tracking the effects of cell cycle related toxic agents on cell lines; 3) using MicroRNAs to reverse the polarization state in macrophages to induce tumor cell killing; 4) development of liposomal nanoformulations to overcome Multi‐Drug Resistance (MDR) in ovarian cancer cells; and 5) development of dual sensitive micelles to specifically target matrix metalloproteinase 2 (MMP2) over‐expressing cell lines. © 2017 International Society for Advancement of Cytometry
Designing better frog call recognition models
Authors: Crump Paul S. , Houlahan Jeff
Published: March 2017

Advances in bioacoustic technology, such as the use of automatic recording devices, allow wildlife monitoring at large spatial scales. However, such technology can produce enormous amounts of audio data that must be processed and analyzed. One potential solution to this problem is the use of automated sound recognition tools, but we lack a general framework for developing and validating these tools. Recognizers are computer models of an animal sound assembled from “training data” (i.e., actual samples of vocalizations). The settings of variables used to create recognizers can impact performance, and the use of different settings can result in large differences in error rates that can be exploited for different monitoring objectives. We used Song Scope (Wildlife Acoustics Inc.) to build recognizers and vocalizations of the wood frog (Lithobates sylvaticus) to test how different settings and amounts of training data influence recognizer performance. Performance was evaluated using precision (the probability of a recognizer match being a true match) and sensitivity (the proportion of vocalizations detected) based on a receiver operating characteristic (ROC) curve‐determined score threshold. Evaluations were conducted using recordings not used to build the recognizer. Wood frog recognizer performance was sensitive to setting changes in four out of nine variables, and small improvements were achieved by using additional training data from different sites and from the same recording, but not from different recordings from the same site. Overall, the effect of changes to variable settings was much greater than the effect of increasing training data. Additionally, by testing the performance of the recognizer on vocalizations not used to build the recognizer, we discovered that Type I error rates appear idiosyncratic and do not recommend extrapolation from training to new data, whereas Type II errors showed more consistency and extrapolation can be justified. Optimizing variable settings on independent recordings led to a better match between recognizer performance and monitoring objectives. We provide general recommendations for application of this methodology with other species and make some suggestions for improvements.