bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen incorporation into decomposing litter of Spartina alterniflora
Authors: White David S. , Howes Brian L. 
Published: May 2010

Litter N dynamics were followed duringdecay in aboveground biomass of Spartina alterniflora (Loisel.) in litter bags and a cohort of intact culms. Initial enrichment with 15N allowed partitioning of the total litter N pool into originally incorporated N during plant growth vs. N incorporated from external sources during decay. Both the original 15N and total N pools declined through fall but stabilized in winter. As temperatures increased in spring, the original 15N pool again declined, but the total N pool remained stable due to significant incorporation of N from external sources. By the midpoint in decomposition, 50–65% of the total detrital N pool was from external sources and at least part of the N incorporation was biologically mediated. The apparent incorporation of external N based on 15N techniques in this study is greater than previous estimates based on net N accumulation. We conclude that external N incorporation into decaying S. alterniflora is a potentially much more important mechanism of short‐term N retention in salt‐marsh ecosystems than previously thought.
Chemical identity and ecological implications of a waterborne, larval settlement cue
Authors: Zimme‐Faust Richard K. , Tamburri Mario N. 
Published: May 2010

Planktonic oyster larvae (Crassostrea virginica) respond behaviorally to waterborne chemical cues and rapidly settle on substratum. “Settlement” is defined here as attachment of the larval foot to the substrate. Although a topic of considerable research for the past 50 yr, the identity of these cues remains unresolved. We provide four lines of experimental evidence all pointing to the singular identity of these substances. First, molecular‐weight fractionations of seawater used to bathe adult oysters (with intact biofilms) were bioassayed, indicating the presence of waterborne settlement inducers between 500 and 1,000 Da. The inducers were degraded by proteases but not by carbohydrases or by lipase. Of several proteases we applied, only those cleaving basic amino acids (lysine and arginine) from the C‐terminal and arginase (an enzyme condensing arginine at the C‐terminal to ornithine) eliminated settlement‐inducing activity. Second, trypsin hydrolysates of casein were significantly more effective in causing larval settlement than products of either acid or pronase hydrolysis of this protein. Third, a tri‐peptide having arginine at the C‐terminal, glycyl‐glycyl‐l‐arginine (hereafter referred to as GGR), evoked settlement at a concentration as low as 10−10 M. Dose‐response curves for GGR and for the active fraction (500–1,000 Da) of oyster bath water were essentially identical. Fourth, tests of 21 free amino acids identified only lysine and arginine as settlement cues. Larval settlers were far more sensitive to arginine than lysine but significantly less sensitive to arginine than to peptides with arginine at the C‐terminal.Our combined results are all consistent in identifying low‐molecular‐weight peptides with arginine at the C‐terminal as the natural, water‐soluble cues inducing oyster settlement.
The rare earth element geochemistry of Mono Lake water and the importance of carbonate complexing
Authors: Johannesson Kevin H. , Lyons W. Berry 
Published: May 2010

Rare earth element (REE) concentrations for the alkaline, saline waters of Mono Lake in eastern California are reported. The total REE concentrations of the lake water ranged from 4,681 to 7,979 pmol kg−1 . Shale‐normalized REE profiles for the lake water indicate that the heavy REEs (HREE) are enriched 20–200 times over the light REEs (LREE) compared to shale.The speciation of the REEs in Mono Lake was modeled with a combined specific ion interaction and ion‐pairing model which allowed activity coefficients for the major solutes (γM, γX), the REEs (γM), and the REE ion pairs (γMX) to be determined in the high ionic strength lake waters (I = 1.84 m). The speciation model suggests that essentially all the REEs in solution are complexed with carbonate ions and that >99% of each REE is complexed as Ln(CO3)2− species. The carbonate ion concentration of Mono Lake water is 0.27 m. Stability constants for these complexes increase with atomic number; consequently, these complexes are responsible for the HREE enrichments. Activity product calculations for REE phosphate coprecipitates in the high phosphate waters of Mono Lake (i.e. 800–1,000 µmol kg−1) indicate that the lake water is close to saturation with respect to these precipitates and suggest that the coprecipitates may effectively limit the maximum dissolved REE concentrations in the lake.
Modeling phytoplankton patchiness under the influence of wind‐driven currents inlakes
Authors: Verhagen Jan H. G. 
Published: May 2010

A model has been developed that describes phytoplankton patchiness under the influence of wind‐induced circulation in lakes. It is shown that especially in large lakes the adjustment of the horizontal phytoplankton distribution to a change in windspeed (in the lower windspeed region) can take several weeks, but the vertical patchiness response is much faster, usually within 1 d. In the model presented here, the phytoplankton cells are allowed to disperse in the horizontal direction by introducing a dispersion coefficient in the wind direction that takes into account some of the effects of mixing by large‐scale currents in the horizontal plane. The model shows that horizontal and vertical patchiness increases with the flotation velocity of the phytoplankton, decreases with windspeed, and decreases with the strength of the horizontal wind‐induced circulation currents compared to the circulation strength in the vertical plane. Model results are in agreement with observations reported in the literature.With the help of the model results, simulations of surface chlorophyll patterns in lakes can give important information about the general pattern of horizontal wind‐driven circulation.
Observations of the free‐swimming behavior of Acartia tonsa: Effects of food concentration and turbulent water motion
Authors: Saiz Enric 
Published: May 2010

The free‐swimming behavior of the calanoid copepod Acartia tonsa is described as a function of food concentration and quantified turbulence.In still water, Acartia spent most of its time feeding. Time allocated to feeding bouts did not change much as a function of food concentration (from 98% to 81%). Functional response to food was mainly determined by the duration of feeding bouts and the proportion of time spent in them. Lengthy feeding bouts might be involved with the actual capture and ingestion of food, while brief feeding bouts might be involved in the search for an optimum food density and the discrimination of food quality.Turbulence did not affect the amount of time allocated to feeding bouts but induced a significant shift to bouts of shorter duration at low food concentration. Computed encounter rates were 2.5 times higher in the presence of turbulence and indicated that turbulence intensity might have been enough to increase realized food concentrations to levels comparable to satiation at some of the low food concentrations tested.
CO2 availability, carbonic anhydrase, and the annual dinoflagellate bloom in Lake Kinneret
Authors: Berman-Frank Ilana , Zohary Tamar , Erez Jonathan , Dubinsky Zvy 
Published: May 2010

Changes with time in the concentration of inorganic carbon in Lake Kinneret subsurface water were followed throughout two seasonal dinoflagellate blooms. The response of natural populations of the dominant dinoflagellate, Peridinium gatunense, to these changes was recorded by examining fluctuations over time in the activity of the enzyme carbonic anhydrase (CA) and in photosynthetic parameters. Our results show distinct fluctuations of both external and cytoplasmic CA activity in P. gatunense throughout the annual bloom. Higher levels of activity were triggered by the decline of total dissolved inorganic C below 1.8 mM and more specifically by low concentrations of dissolved CO2 (1–10 µM) during the seasonal bloom decline in May–June. Laboratory studies on cultured P. gatunense confirmed our field observations, suggesting that supplemental mechanisms are activated in P. gatunense that enhance inorganic C uptake when CO2 is limiting for photosynthesis.Eventually, the cellular adaptations of P. gatunense to the declining CO2 concentrations could not prevent decline of photosynthetic rates contributing to the subsequent decrease in P. gatunense biomass in May–June. In Lake Kinneret, P. gatunense is succeeded by Peridiniopsis spp., the photosynthetic rates and external CA activities of which were much higher under environmental conditions typical of the end of the bloom.
Effect of forest and savanna vegetation on the carbon‐isotope composition of sediments from the Sanaga River, Cameroon
Authors: Bird M. I. , Giresse P. , Chivas A. R. 
Published: May 2010

The carbon‐isotope composition (δ13C) of organic matter from modern sediments in the Sanaga River basin, Cameroon, shows a progressive downriver decrease in δ13C values. Sediments in tributaries draining montane grassland regions have consistent δ13C values of ∼−19‰, while rivers draining savanna regions have δ13C values of around −22‰. After the river passes through extensively forested regions, the 13C values of the sediments closest to the mouth of the river decrease to −25‰. Samples collected from rivers with entirely forested catchment had low δ13C values (from −27 to −29‰) consistent with a pure C3 vegetation source. The downriver carbon‐isotope trends are consistent with the hypothesis that observed variations are due to changes in the relative proportions of C3 and C4 carbon in the sediments, which are derived from terrestrial vegetation in the river catchment.Some sediments from the Mbam River, the principal tributary of the Sanaga River, have extremely high δ13C values (up to −16.7‰). These high values may be the result of severe erosion in the densely populated and intensively farmed Bamileke region in the headwaters of the Mbam.An underrepresentation of C4‐derived carbon in the upper reaches of the Sanaga is possibly due to the damming of the Djerem River at Mbakaou. Since the dam was constructed <25 yr ago, this suggests that the δ13C value of river sediments responds rapidly to changes in the basin.
Abnormal dynamic functional connectivity in young nondisabling intracerebral hemorrhage patients
Authors: Yang Dan , Luo Xiangqi , Sun Shengjun , Zhang Xue , Zhang Fengxia , Zhao Xingquan , Zhou Jian 
Published: May 2024

AbstractObjectivePrevious resting‐state functional magnetic resonance imaging studies on intracerebral hemorrhage patients have focused more on the static characteristics of brain activity, while the time‐varying effects during scanning have received less attention. Therefore, the current study aimed to explore the dynamic functional network connectivity changes of intracerebral hemorrhage patients.MethodsUsing independent component analysis, the sliding window approach, and the k‐means clustering analysis method, different dynamic functional network connectivity states were detected from resting‐state functional magnetic resonance imaging data of 37 intracerebral hemorrhage patients and 44 healthy controls. The inter‐group differences in dynamic functional network connectivity patterns and temporal properties were investigated, followed by correlation analyses between clinical scales and abnormal functional indexes.ResultsTen resting‐state networks were identified, and the dynamic functional network connectivity matrices were clustered into four different states. The transition numbers were decreased in the intracerebral hemorrhage patients compared with healthy controls, which was associated with trail making test scores in patients. The cerebellar network and executive control network connectivity in State 1 was reduced in patients, and this abnormal dynamic functional connectivity was positively correlated with the animal fluency test scores of patients.InterpretationThe current study demonstrated the characteristics of dynamic functional network connectivity in intracerebral hemorrhage patients and revealed that abnormal temporal properties and functional connectivity may be related to the performance of different cognitive domains after ictus. These results may provide new insights into exploring the neurocognitive mechanisms of intracerebral hemorrhage.
Topological Exciton Polaritons in Compact Perovskite Junction Metasurfaces
Authors: An Soo‐Chan , Lim Yeonsoo , Lee Ki Young , Choi Daegwang , Kim Seongheon , Gong Su‐Hyun , Yoon Jae Woong , Jun Young Chul 
Published: May 2024

AbstractExciton polaritons are hybrid light‐matter quasi‐particles that hold exceptional opportunities for future optoelectronic devices. Taking the synergic advantages of room‐temperature perovskite excitons and topological photonic structures, topological exciton‐polaritons are experimentally demonstrated in organic–inorganic hybrid perovskite thin films. Topological junction structures based on perovskite gratings are realized using a momentum‐space analog of the 1D Dirac system. Desired enhancement phenomena are observed including narrow‐beam polariton emission from a tightly localized junction region, polaritonic nonlinearity boost, and enhanced luminescence. These remarkable features are obtained from highly compact devices with footprint widths on the order of a few micrometers and are efficiently tailorable with simple unit‐cell geometry control. Therefore, the proposed approach can be a powerful platform for room‐temperature topological exciton‐polaritons and concomitant device applications.
Manipulating Spin‐Lattice Coupling in Layered Magnetic Topological Insulator Heterostructure via Interface Engineering
Authors: Maity Sujan , Dey Dibyendu , Ghosh Anudeepa , Masanta Suvadip , De Binoy Krishna , Kunwar Hemant Singh , Das Bikash , Kundu Tanima , Palit Mainak , Bera Satyabrata , Dolui Kapildeb , Watanabe Kenji , Taniguchi Takashi , Yu Liping , Taraphder A , Datta Subhadeep 
Published: May 2024

AbstractInduced magnetic order in a topological insulator (TI) can be realized either by depositing magnetic adatoms on the surface of a TI or engineering the interface with epitaxial thin film or stacked assembly of 2D van der Waals (vdW) materials. Herein, the observation of spin‐phonon coupling in the otherwise non‐magnetic TI Bi2Te3 is reported, due to the proximity of FePS3 (an antiferromagnet (AFM), TN ≈ 120 K), in a vdW heterostructure framework. Temperature‐dependent Raman spectroscopic studies reveal deviation from the usual phonon anharmonicity originated from spin‐lattice coupling at the Bi2Te3/FePS3 interface at/below 60 K in the peak position (self‐energy) and linewidth (lifetime) of the characteristic phonon modes of Bi2Te3 (106 and 138 cm−1) in the stacked heterostructure. The Ginzburg‐Landau (GL) formalism, where the respective phonon frequencies of Bi2Te3 couple to phonons of similar frequencies of FePS3 in the AFM phase, is adopted to understand the origin of the hybrid magneto‐elastic modes. At the same time, the reduction of characteristic TN of FePS3 from 120 K in isolated flakes to 65 K in the heterostructure, possibly due to the interfacial strain, which leads to smaller Fe‐S‐Fe bond angles as corroborated by computational studies using density functional theory (DFT). Besides, inserting hexagonal boron nitride within Bi2Te3/FePS3 stacking regains the anharmonicity in Bi2Te3. Controlling interfacial spin‐phonon coupling in stacked heterostructure can have potential application in surface code spin logic devices.
Tailored Phototherapy Agent by Infection Site In Situ Activated Against Methicillin‐Resistant S. aureus
Authors: Guo Lixia , Tian Yafei , Zhou Liang , Kang Shiyue , Zhang Chengwu , Liu Wen , Diao Haipeng , Feng Liheng 
Published: May 2024

AbstractPhototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), is a promising treatment approach for multidrug resistant infections. PDT/PTT combination therapy can more efficiently eliminate pathogens without drug resistance. The key to improve the efficacy of photochemotherapy is the utilization efficiency of non‐radiation energy of phototherapy agents. Herein, a facile phototherapy molecule (SCy‐Le) with the enhancement of non‐radiative energy transfer is designed by an acid stimulation under a single laser. Introduction of the protonated receptor into SCy‐Le results in a distorted intramolecular charge in the infected acidic microenvironment, pH ≈ 5.5, which in turn, enhances light capture, reduces the singlet–triplet transition energies (ΔES1–T1), promotes electron system crossing, enhances capacity of reactive oxygen species generation, and causes a significant increase in temperature by improving vibrational relaxation. SCy‐Le shows more than 99% bacterial killing rate against both methicillin‐resistant Staphylococcus aureus and its biofilms in vitro and causes bacteria‐induced wound healing in mice. This work will provide a new perspective for the design of phototherapy agents, and the emerging photochemotherapy will be a promising approach to combat the problem of antibiotic resistance.
Enhanced Mechanical Strength and Sustained Drug Release in Carrier‐Free Silver‐Coordinated Anthraquinone Natural Antibacterial Anti‐Inflammatory Hydrogel for Infectious Wound Healing
Authors: Liang Xiaoliu , Ding Linyu , Ma Jiaxin , Li Jiwei , Cao Lei , Liu Hui , Teng Minglei , Li Zhenjie , Peng Yisheng , Chen Hu , Zheng Yali , Cheng Hongwei , Liu Gang 
Published: May 2024

AbstractThe persistent challenge of healing infectious wounds and the rise of bacterial resistance represent significant hurdles in contemporary medicine. In this study, based on the natural small molecule drug Rhein self‐assembly to form hydrogels and coordinate assembly with silver ions (Ag+), a sustained‐release carrier‐free hydrogel with compact structure is constructed to promote the repair of bacterial‐infected wounds. As a broad‐spectrum antimicrobial agent, Ag+ can avoid the problem of bacterial resistance caused by the abuse of traditional antibiotics. In addition, due to the slow‐release properties of Rhein hydrogel, continuous effective concentration of Ag+ at the wound site can be ensured. The assembly of Ag+ and Rhein makes the hydrogel system with enhanced mechanical stability. More importantly, it is found that Rhein effectively promotes skin tissue regeneration and wound healing by reprogramming M1 macrophages into M2 macrophages. Further mechanism studies show that Rhein realizes its powerful anti‐inflammatory activity through NRF2/HO‐1 activation and NF‐κB inhibition. Thus, the hydrogel system combines the excellent antibacterial properties of Ag+ with the excellent anti‐inflammatory and tissue regeneration ability of Rhein, providing a new strategy for wound management with dual roles.
Synchronous Switching Strategy to Enhance the Real‐Time Powering and Charging Performance of Triboelectric Nanogenerator
Authors: Xia Yuxuan , Zhi Jinyan , Zhang Ruichao , Zhou Feng , Liu Shuhai , Xu Qi , Qin Yong 
Published: May 2024

AbstractTriboelectric nanogenerators (TENGs) are of great significance as sustainable power sources that harvest energy from the human body and environment. Nevertheless, due to TENG's impedance‐dependent output voltage characteristics, in traditional strategy (TS), real‐timely powering a sensor with TENG has a poor sensing on/off ratio (or response), and directly charging a capacitor with TENG shows a low charging efficiency. This degraded real‐time powering and charging performance of TENG compared to a commercial constant voltage source is a huge challenge of the TENG field for a long time. This work proposes a synchronous switching strategy (SSS) for TENG to real‐timely power sensors or charge capacitors without degrading its performance. Compared with TS, this new strategy enables sensors to have 5–7 times sensing on/off ratio enhancement when using TENG as a power source, reaching the powering ability of a commercial constant voltage source, it makes the powering performance of TENG stable under different driving frequency, improving the powering robustness of TENG. In addition, compared with TS, SSS can also enhance the charging efficiency of TENG in every charging cycle by up to 2.4 times when charging capacitors. This work contributes to real‐timely powering or charging the distributed, mobile and wireless electronics using TENG.
Deep‐Blue and Fast Delayed Fluorescence from Carbene–Metal–Amides for Highly Efficient and Stable Organic Light‐Emitting Diodes
Authors: Brannan Alexander C. , Cho Hwan‐Hee , Reponen Antti‐Pekka M. , Gorgon Sebastian , Phuoc Nguyen Le , Linnolahti Mikko , Greenham Neil C. , Romanov Alexander S. 
Published: May 2024

AbstractLinear gold complexes of the “carbene–metal–amide” (CMA) type are prepared with a rigid benzoguanidine amide donor and various carbene ligands. These complexes emit in the deep‐blue range at 424 and 466 nm with 100% quantum yields in all media. The deep‐blue thermally activates delayed fluorescence originates from a charge transfer state with an excited state lifetime as low as 213 ns, resulting in fast radiative rates of 4.7 × 106 s−1. The high thermal and photo‐stability of these carbene–metal–amide (CMA) materials enabled the authors to fabricate highly energy‐efficient organic light‐emitting diodes (OLED) in host–guest architectures. Deep‐blue OLED devices with electroluminescence at 416 and 457 nm with practical external quantum efficiencies of up to 23% at 100 cd m−2 with excellent color coordinates CIE (x; y) = 0.16; 0.07 and 0.17; 0.18 are reported. The operating stability of these OLEDs is the longest reported to date (LT50 = 1 h) for deep‐blue CMA emitters, indicating a high promise for further development of blue OLED devices. These findings inform the molecular design strategy and correlation between delayed luminescence with high radiative rates and CMA OLED device operating stability.
Ultrafast UV Luminescence of ZnO Films: Sub‐30 ps Decay Time with Suppressed Visible Component
Authors: Cadatal‐Raduban Marilou , Olejníček Jiří , Hibino Kota , Maruyama Yuki , Písaříková Aneta , Shinohara Keito , Asaka Toru , Lebedová Volfová Lenka , Kohout Michal , Jiaqi Zhang , Akabe Yugo , Nakajima Makoto , Harrison John A. , Hippler Rainer , Sarukura Nobuhiko , Ono Shingo , Hubička Zdeněk , Yamanoi Kohei 
Published: May 2024

AbstractUltrafast sub‐100 picosecond luminescence is vital in many applications involving ultrafast events and time‐of‐flight systems. Materials exhibiting fast luminescence, such as barium fluoride (BaF2) and zinc oxide (ZnO), also suffer from an intrinsically slow nanosecond (ns) to microsecond (µs) luminescence. Here, 2.2 micrometer (µm)‐ to 5.7 µm‐thick undoped ZnO films on soda‐lime glass (SLG) substrates without a buffer layer by a hybrid pulsed reactive magnetron sputtering operating in the medium‐frequency range (MF magnetron) assisted by an electron cyclotron wave resonance (ECWR) plasma is deposited. The undoped ZnO films exhibited superior optical properties characterized by intense ultraviolet (UV) luminescence, unprecedented ultrafast decay times, and for the case of MF+ECWR‐deposited films, suppressed defect‐related visible luminescence. The 2.2 µm‐thick MF‐deposited film exhibited the fastest 9‐ps decay time at room temperature. The impressive properties of the films are attributed to the use of advanced deposition technology with properly tuned plasma parameters, especially a high degree of dissociation of molecular oxygen together with an increased proportion of activated zinc particles, leading to a higher deposition rate, better crystallinity, fewer defects, and a lower proportion of oxygen vacancies. These films will pave the way toward the development of time‐of‐flight detectors, high‐resolution nuclear imaging cameras, and high‐rate ultrafast timing devices.