Intra-allantoic injection of calcium promotes hatching of chick embryos grown in shell-less culture.

The hatch rate of chick embryos cultured outside of the eggshell with 350 mg calcium l-lactate hydrate (CaL) and 3.5 mL water is fourfold greater in cultures in which the chorioallantoic membrane (CAM) surrounds the egg contents by incubation day 17.5 (E17.5) an event which occurs in ovo by E13. It was first investigated whether decreasing the volume of water added with 350 mg CaL would promote CAM expansion due to the smaller volume to enclose. When 350 mg CaL was present, the CAM did not surround the egg contents by E13. By E17.5, the CAM surrounded the egg contents in 53%-74% of cultures; however, CAM expansion was not significantly different when 0, 1, 2, or 3.5 mL water was present. The hatch rate with 2 or 3.5 mL water was greater than 50% but was not improved with less water. Second, it was investigated whether CaL or water inhibits CAM expansion. In the absence of CaL, the CAM surrounded the egg contents in up to two-thirds of cultures by E13, whether 2 mL water was present or not. Thus CaL, but not water, inhibits expansion of the CAM by E13, even though CaL promotes hatching. Finally, it was investigated whether injection of aqueous CaL into the allantoic fluid, in conjunction with not adding CaL to culture hammocks, would promote CAM expansion. Allantoic injection of CaL starting at E13 did not promote CAM expansion at E17.5 but resulted in hatch rates of approximately 30%. Allantoic injection is a novel route for supplementation of calcium in cultured chick embryos.

Nanofeather ruthenium nitride electrodes for electrochemical capacitors.

Fast charging is a critical concern for the next generation of electrochemical energy storage devices, driving extensive research on new electrode materials for electrochemical capacitors and micro-supercapacitors. Here we introduce a significant advance in producing thick ruthenium nitride pseudocapacitive films fabricated using a sputter deposition method. These films deliver over 0.8 F cm-2 (~500 F cm-3) with a time constant below 6 s. By utilizing an original electrochemical oxidation process, the volumetric capacitance doubles (1,200 F cm-3) without sacrificing cycling stability. This enables an extended operating potential window up to 0.85 V versus Hg/HgO, resulting in a boost to 3.2 F cm-2 (3,200 F cm-3). Operando X-ray absorption spectroscopy and transmission electron microscopy analyses reveal novel insights into the electrochemical oxidation process. The charge storage mechanism takes advantage of the high electrical conductivity and the morphology of cubic ruthenium nitride and Ru phases in the feather-like core, leading to high electrical conductivity in combination with high capacity. Accordingly, we have developed an analysis that relates capacity to time constant as a means of identifying materials capable of retaining high capacity at high charge/discharge rates.

Establishing reaction networks in the 16-electron sulfur reduction reaction.

The sulfur reduction reaction (SRR) plays a central role in high-capacity lithium sulfur (Li-S) batteries. The SRR involves an intricate, 16-electron conversion process featuring multiple lithium polysulfide intermediates and reaction branches1-3. Establishing the complex reaction network is essential for rational tailoring of the SRR for improved Li-S batteries, but represents a daunting challenge4-6. Herein we systematically investigate the electrocatalytic SRR to decipher its network using the nitrogen, sulfur, dual-doped holey graphene framework as a model electrode to understand the role of electrocatalysts in acceleration of conversion kinetics. Combining cyclic voltammetry, in situ Raman spectroscopy and density functional theory calculations, we identify and directly profile the key intermediates (S8, Li2S8, Li2S6, Li2S4 and Li2S) at varying potentials and elucidate their conversion pathways. Li2S4 and Li2S6 were predominantly observed, in which Li2S4 represents the key electrochemical intermediate dictating the overall SRR kinetics. Li2S6, generated (consumed) through a comproportionation (disproportionation) reaction, does not directly participate in electrochemical reactions but significantly contributes to the polysulfide shuttling process. We found that the nitrogen, sulfur dual-doped holey graphene framework catalyst could help accelerate polysulfide conversion kinetics, leading to faster depletion of soluble lithium polysulfides at higher potential and hence mitigating the polysulfide shuttling effect and boosting output potential. These results highlight the electrocatalytic approach as a promising strategy for tackling the fundamental challenges regarding Li-S batteries.

Shell-less culture system for chick embryos from the blastoderm stage to hatching.

Since 2014, methods have been described to hatch chick embryos from shell-less culture after egg contents are first incubated within shells for 55-70 h. The present report describes for the first time a shell-less culture system for chick embryos from the blastoderm stage to hatching. For the first 69-70 h, egg contents suspended in polymethylpentene kitchen wrap (F.O.R. Wrap, Riken Fabro, Tokyo, Japan) supported in 6.35 or 6.67 cm inside diameter tripods and covered with a disc of immobilized Milli-Wrap, were rotated back and forth through 90° at 16 or 22 cycles per minute (CPM). Subsequently, the Milli-Wrap disc was removed and culture tripods were transferred to environmental chambers, which were rocked ±20° through incubation day 8.5 (E8.5). From E9, environmental chambers were maintained in the horizontal position through to hatching with controlled O2 and CO2 . To provide supplemental calcium, an aqueous solution containing 100 mg/mL of calcium l-lactate hydrate was injected through the plastic wrap into the albumen at E9 (2.5 mL) and at E13 (1.0 mL) or E15 (1.0 mL). After incubation for 69-70 h at 16 or 22 CPM, 80%-83% of previously unincubated egg contents yielded apparently normal embryos. Hatch rate of normal embryos resulting from turntable incubation at 16 or 22 CPM was approximately 43%. Of note, egg contents remained in the same culture tripod from blastoderm stage to hatching. This technique may find use as an educational tool and in basic investigations of early embryogenesis, teratogenesis, and gene transfer experiments.

Supplemental calcium increases hatch rate but not hatchling mass of chick embryos in shell-less culture.

A method is described for culturing 64-70 h-old chicken embryos and egg contents outside of the eggshell through to hatching. Cultured egg contents were suspended in polymethylpentene kitchen wrap (F.O.R. wrap; Riken Fabro) supported in polyvinyl chloride tripods. Tripods were incubated in Plexiglas environmental chambers which were rocked automatically through an angle of ±20°. The concentration of CO2 was maintained at 2% throughout incubation, while that of O2 was increased from ambient to 50%, and relative humidity was decreased from 90%-92% to 83%-84% at incubation Day 9. Cultured embryos not supplemented with calcium did not hatch. The Hatch rate increased when supplemental calcium L-lactate hydrate was increased between 250 and 350 mg. A maximal hatch rate of 54.8% was achieved when cultures were supplemented with 350 mg of calcium L-lactate hydrate and 3.5 ml of sterile water. Adding 400 or 450 mg of calcium L-lactate hydrate did not increase the hatch rate further. The mass of cultured hatchlings (including the retracted yolk) and yolk-free carcass wet and dry mass and length of the right third toe were significantly less than the corresponding parameters observed in hatchlings in ovo. No statistically significant differences in hatchling mass, yolk-free carcass wet or dry mass, or length of the right third toe were noted among cultured hatchlings supplemented with 250-450 mg of calcium L-lactate hydrate. Failure to completely absorb albumen was the most common abnormality observed in cultures which failed to hatch. The present technique allows a unique approach to study the physiology of the developing chicken embryo.

Surface-redox sodium-ion storage in anatase titanium oxide.

Sodium-ion storage technologies are promising candidates for large-scale grid systems due to the abundance and low cost of sodium. However, compared to well-understood lithium-ion storage mechanisms, sodium-ion storage remains relatively unexplored. Herein, we systematically determine the sodium-ion storage properties of anatase titanium dioxide (TiO2(A)). During the initial sodiation process, a thin surface layer (~3 to 5 nm) of crystalline TiO2(A) becomes amorphous but still undergoes Ti4+/Ti3+ redox reactions. A model explaining the role of the amorphous layer and the dependence of the specific capacity on the size of TiO2(A) nanoparticles is proposed. Amorphous nanoparticles of ~10 nm seem to be optimum in terms of achieving high specific capacity, on the order of 200 mAh g-1, at high charge/discharge rates. Kinetic studies of TiO2(A) nanoparticles indicate that sodium-ion storage is due to a surface-redox mechanism that is not dependent on nanoparticle size in contrast to the lithiation of TiO2(A) which is a diffusion-limited intercalation process. The surface-redox properties of TiO2(A) result in excellent rate capability, cycling stability and low overpotentials. Moreover, tailoring the surface-redox mechanism enables thick electrodes of TiO2(A) to retain high rate properties, and represents a promising direction for high-power sodium-ion storage.

Bubble-Channeling Electrophoresis of Honeycomb-Like Chitosan Composites.

A chitosan composite with a vertical array of pore channels is fabricated via an electrophoretic deposition (EPD) technique. The composite consists of chitosan and polyethylene glycol, as well as nanoparticles of silver oxide and silver. The formation of hydrogen bubbles during EPD renders a localized increase of hydroxyl ions that engenders the precipitation of chitosan. In addition, chemical interactions among the constituents facilitate the establishment of vertical channels occupied by hydrogen bubbles that leads to the unique honeycomb-like microstructure; a composite with a porosity of 84%, channel diameter of 488 µm, and channel length of 2 mm. The chitosan composite demonstrates an impressive water uptake of 2100% and a two-stage slow release of silver. In mass transport analysis, both Disperse Red 13 and ZnO powders show a much enhanced transport rate over that of commercial gauze. Due to its excellent structural integrity and channel independence, the chitosan composite is evaluated in a passive suction mode for an adhesive force of 9.8 N (0.56 N cm-2 ). The chitosan composite is flexible and is able to maintain sufficient adhesive force toward objects with different surface curvatures.

Understanding the Electrochemical Performance of FeS2 Conversion Cathodes.

Conversion cathodes represent a viable route to improve rechargeable Li+ battery energy densities, but their poor electrochemical stability and power density have impeded their practical implementation. Here, we explore the impact cell fabrication, electrolyte interaction, and current density have on the electrochemical performance of FeS2/Li cells by deconvoluting the contributions of the various conversion and intercalation reactions to the overall capacity. By varying the slurry composition and applied pressure, we determine that the capacity loss is primarily due to the large volume changes during (de)lithiation, leading to a degradation of the conductive matrix. Through the application of an external pressure, the loss is minimized by maintaining the conductive matrix. We further determine that polysulfide loss can be minimized by increasing the current density (>C/10), thus reducing the sulfur formation period. Analysis of the kinetics determines that the conversion reactions are rate-limiting, specifically the formation of metallic iron at rates above C/8. While focused on FeS2, our findings on the influence of pressure, electrolyte interaction, and kinetics are broadly applicable to other conversion cathode systems.

Investigating the Perovskite Ag1-3xLaxNbO3 as a High-Rate Negative Electrode for Li-Ion Batteries.

The broader development of the electric car for tomorrow's mobility requires the emergence of new fast-charging negative electrode materials to replace graphite in Li-ion batteries. In this area, the design of new compounds using innovative approaches could be the key to discovering new negative electrode materials that allow for faster charging and discharging processes. Here, we present a partially substituted AgNbO3 perovskite material by introducing lanthanum in the A-site. By creating two vacancies for every lanthanum introduced in the structure, the resulting general formula becomes Ag1-3xLax□2xNbO3 (with x ≤ 0.20 and where □ is a A-site vacancy), allowing the insertion of lithium ions. The highly substituted Ag0.40La0.20□0.40NbO3 oxide shows a specific capacity of 40 mAh.g-1 at a low sweep rate (0.1 mV s-1). Interestingly, Ag0.70La0.10□0.20NbO3 retains 64% of its capacity at a very high sweep rate (50 mV s-1) and about 95% after 800 cycles. Ex situ 7Li MAS NMR experiments confirmed the insertion of lithium ions in these materials. A kinetic analysis of Ag1-3xLax□2xNbO3 underlines the ability to store charge without solid-state ion-diffusion limitations. Furthermore, in situ XRD indicates no structural modification of the compound when accommodating lithium ions, which can be considered as zero-strain material. This finding explains the interesting capacity retention observed after 800 cycles. This paper thus demonstrates an alternative approach to traditional insertion materials and identifies a different way to explore not-so common electrode materials for fast energy storage application.

Mechanistic Insight and Local Structure Evolution of NiPS3 upon Electrochemical Lithiation.

Transition metal phosphorus trisulfide materials have received considerable research interest since the 1980-1990s as they exhibit promising energy conversion and storage properties. However, the mechanistic insights into Li-ion storage in these materials are poorly understood to date. Here, we explore the lithiation of NiPS3 material by employing in situ pair-distribution function analysis, Monte Carlo molecular dynamics calculations, and a series of ex situ characterizations. Our findings elucidate complex ion insertion and storage dynamics around a layered polyanionic compound, which undergoes intercalation and conversion reactions in a sequential manner. This study of NiPS3 material exemplifies the Li-ion storage mechanism in transition metal phosphorus sulfide materials and provides insights into the challenges associated with achieving reliable, high-energy phosphorus trisulfide systems.

Transparent silica aerogel slabs synthesized from nanoparticle colloidal suspensions at near ambient conditions on omniphobic liquid substrates.

This paper presents a novel sol-gel method to synthesize large and thick silica aerogel monoliths at near ambient conditions using a commercial aqueous solution of colloidal silica nanoparticles as building blocks. To achieve slabs with high visible transmittance and low thermal conductivity, the method combines the strategies of (i) synthesizing gels on an omniphobic perfluorocarbon liquid substrate, (ii) aging at temperatures above room temperature, and (iii) performing solvent exchange with a low-surface-tension organic solvent prior to ambient drying. The omniphobic liquid substrates were used to prevent cracking and ensure an optically-smooth surface, while nanoparticle building blocks were small (<10 nm) to limit volumetric light scattering. Gels were aged at temperatures between 25 and 80 °C for up to 21 days to make them stronger and stiffer and to reduce shrinkage and cracking during ambient drying. Ambient drying was achieved by first exchanging water in the gel pores for octane, followed by drying in an octane-rich atmosphere to decrease capillary forces. The synthesized nanoparticle-based silica aerogel monoliths had thicknesses up to 5 mm, diameters up to 10 cm, porosities exceeding 80%, and thermal conductivities as low as 0.08 W m-1 K-1. Notably, the slabs featured visible transmittance exceeding 75% even for slabs as thick as 5 mm. The as-synthesized aerogel monoliths were exposed to TMCS vapor to induce hydrophobic properties resulting in a water contact angle of 140° that prevented water infiltration into the pores and protected the aerogels from water damage. This simple synthesis route conducted at near ambient conditions produces hydrophobic aerogel monoliths with promising optically transparent and thermally insulating properties that can be adhered to glass panes for window insulation and solar-thermal energy conversion applications.

Photopatternable Porous Separators for Micro-Electrochemical Energy Storage Systems.

The miniaturization of electrochemical energy storage (EES) systems, one of the key challenges facing the rapid expansion of the Internet-of-Things, has been limited by poor performance of the various energy-storage components at the micrometer scale. Here, the development of a unique photopatternable porous separator that overcomes the electrolyte difficulties involving resistive losses at small dimensions is reported. The separator is based on modifying the chemistry of SU-8, an epoxy-derived photoresist, through the addition of a miscible ionic liquid. The ionic liquid serves as a templating agent, which is selectively removed by solution methods, leaving the SU-8 scaffold whose interconnected porosity provides ion transport from the confined liquid electrolyte. The photopatternable separator exhibits good electrochemical, chemical, thermal, and mechanical stability during the operation of electrochemical devices in both 2D and 3D formats. For the latter, the separator demonstrates the ability to form conformal coatings over 3D structures. The development of the photopatternable separator overcomes the electrolyte issues, which have limited progress in the field of micro-EES.

Two-dimensional quantum-sheet films with sub-1.2 nm channels for ultrahigh-rate electrochemical capacitance.

Dense, thick, but fast-ion-conductive electrodes are critical yet challenging components of ultrafast electrochemical capacitors with high volumetric power/energy densities1-4. Here we report an exfoliation-fragmentation-restacking strategy towards thickness-adjustable (1.5‒24.0 µm) dense electrode films of restacked two-dimensional 1T-MoS2 quantum sheets. These films bear the unique architecture of an exceptionally high density of narrow (sub-1.2 nm) and ultrashort (~6.1 nm) hydrophobic nanochannels for confinement ion transport. Among them, 14-µm-thick films tested at 2,000 mV s-1 can deliver not only a high areal capacitance of 0.63 F cm-2 but also a volumetric capacitance of 437 F cm-3 that is one order of magnitude higher than that of other electrodes. Density functional theory and ab initio molecular dynamics simulations suggest that both hydration and nanoscale channels play crucial roles in enabling ultrafast ion transport and enhanced charge storage. This work provides a versatile strategy for generating rapid ion transport channels in thick but dense films for energy storage and filtration applications.

Amorphous VO2 : A Pseudocapacitive Platform for High-Rate Symmetric Batteries.

Among the various VO2 polymorphs, the layered compound, VO2 (B), has been the most widely investigated lithium-ion battery electrode material. For sodium-ion electrodes, however, an amorphous solid may be more advantageous as a result of the open framework to facilitate ion insertion and the ability to tolerate volumetric changes. Herein, it is shown that the Na+ insertion properties of amorphous VO2 (a-VO2 ) are superior to those of crystalline VO2 (B). Amorphous VO2 exhibits a linear voltage characteristic over a 3 V range (4.0 to 1.0 V vs Na/Na+ ) leading to a reversible capacity as high as 400 mAh g-1 and rapid redox kinetics, which is attributed to its pseudocapacitive nature. The linear voltage characteristic over 3 V affords the opportunity of fabricating a symmetric Na-ion battery in which the a-VO2 material serves as both the positive electrode and the negative electrode. Such a symmetric battery offers safer operation in terms of overcharging, overdischarging, polarity reversal, high charge/discharge current abuse, and long-term usage. The results suggest that amorphous transition metal oxides may offer advantageous attributes for rapid, safe, and energy-dense storage.

Acclimatization of photosynthetic apparatus and antioxidant metabolism to excess soil cadmium in Buddleja spp.

Heavy metal (HM) pollutants can cause serious phytotoxicity or oxidative stress in plants. Buddleja L., commonly known as "butterfly bushes", are frequently found growing on HM-contaminated land. However, to date, few studies have focused on the physiological and biochemical responses of Buddleja species to HM stress. In this study, potted seedlings of B. asiatica Lour. and B. macrostachya Wall. ex Benth. were subjected to various cadmium (Cd) concentrations (0, 25, 50, 100, and 200 mg kg-1) for 90 days. Both studied Buddleja species showed restricted Cd translocation capacity. Exposure to Cd, non-significant differences (p > 0.05) were observed, including quantum yield of photosystem II (PSII), effective quantum yield of PSII, photochemical quenching and non-photochemical quenching in both species between all studied Cd concentrations. Moreover, levels of cellular reactive oxygen species (ROS) significantly declined (p < 0.05) with low malondialdehyde concentrations. In B. asiatica, high superoxide dismutase and significantly enhanced (p < 0.05) peroxidase (POD) activity contributed greatly to the detoxification of excess ROS, while markedly enhanced POD activity was observed in B. macrostachya. Additionally, B. macrostachya showed higher membership function values than did B. asiatica. These results suggested that both Buddleja species exhibited high Cd resistance and acclimatization.

Synthesis and Crystallization of Atomic Layer Deposition ß-Eucryptite LiAlSiO4 Thin-Film Solid Electrolytes.

Atomic layer deposition (ALD) was used to control the stoichiometry of thin lithium aluminosilicate films, thereby enabling crystallization into the ion-conducting ß-eucryptite LiAlSiO4 phase. The rapid thermal annealed ALD film developed a well-defined epitaxial relationship to the silicon substrate: ß-LiAlSiO4 (12̅10)||Si (100) and ß-LiAlSiO4 (101̅0)||Si (001). The extrapolated room temperature ionic conductivity was found to be 1.2 × 10-7 S/cm in the [12̅10] direction. Because of the unique 1-D channel along the c axis of ß-LiAlSiO4, the epitaxial thin film has the potential to facilitate ionic transport if oriented with the c axis normal to the electrode surface, making it a promising electrolyte material for three-dimensional lithium-ion microbatteries.

Understanding Stabilization in Nanoporous Intermetallic Alloy Anodes for Li-Ion Batteries Using Operando Transmission X-ray Microscopy.

Tin-based alloying anodes are exciting due to their high energy density. Unfortunately, these materials pulverize after repetitive cycling due to the large volume expansion during lithiation and delithiation; both nanostructuring and intermetallic formation can help alleviate this structural damage. Here, these ideas are combined in nanoporous antimony-tin (NP-SbSn) powders, synthesized by a simple and scalable selective-etching method. The NP-SbSn exhibits bimodal porosity that facilitates electrolyte diffusion; those void spaces, combined with the presence of two metals that alloy with lithium at different potentials, further provide a buffer against volume change. This stabilizes the structure to give NP-SbSn good cycle life (595 mAh/g after 100 cycles with 93% capacity retention). Operando transmission X-ray microscopy (TXM) showed that during cycling NP-SbSn expands by only 60% in area and then contracts back nearly to its original size with no physical disintegration. The pores shrink during lithiation as the pore walls expand into the pore space and then relax back to their initial size during delithiation with almost no degradation. Importantly, the pores remained open even in the fully lithiated state, and structures are in good physical condition after the 36th cycle. The results of this work should thus be useful for designing nanoscale structures in alloying anodes.

Dual redox mediators accelerate the electrochemical kinetics of lithium-sulfur batteries.

The sluggish electrochemical kinetics of sulfur species has impeded the wide adoption of lithium-sulfur battery, which is one of the most promising candidates for next-generation energy storage system. Here, we present the electronic and geometric structures of all possible sulfur species and construct an electronic energy diagram to unveil their reaction pathways in batteries, as well as the molecular origin of their sluggish kinetics. By decoupling the contradictory requirements of accelerating charging and discharging processes, we select two pseudocapacitive oxides as electron-ion source and drain to enable the efficient transport of electron/Li+ to and from sulfur intermediates respectively. After incorporating dual oxides, the electrochemical kinetics of sulfur cathode is significantly accelerated. This strategy, which couples a fast-electrochemical reaction with a spontaneous chemical reaction to bypass a slow-electrochemical reaction pathway, offers a solution to accelerate an electrochemical reaction, providing new perspectives for the development of high-energy battery systems.

NMR Relaxometry and Diffusometry Analysis of Dynamics in Ionic Liquids and Ionogels for Use in Lithium-Ion Batteries.

We have investigated the charge transport dynamics of a novel solid-like electrolyte material based on mixtures of the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM] TFSI) and various concentrations of lithium salt bis(trifluoromethylsulfonyl)imide (LiTFSI) confined within a SiO2 matrix, prepared via a sol-gel method. The translational diffusion coefficients of BMIM+, TFSI-, and Li+ in ILs and confined ILs (ionogels, IGs) with different concentrations of lithium salt have been measured at variable temperatures, covering the 20-100 °C range, using nuclear magnetic resonance (NMR) pulsed field gradient diffusion spectroscopy. The mobility of BMIM+, TFSI-, and Li+ was found to increase with the [BMIM] TFSI/LiTFSI ratio, exhibiting an almost liquid-like mobility in IGs. Additionally, the effect of confinement on IL rotational dynamics has been analyzed by measuring 1H, 19F, and 7Li spin-lattice relaxation rate dispersions of IGs at different temperatures, using fast field-cycling NMR relaxometry. The analysis of the experimental data was performed assuming the existence of two fractions of the liquid: a bulk fraction (at least several ionic radii from the silica particles) and a surface fraction (close to the silica particles) and using two different models based on translational and rotational diffusion and reorientation mediated by translational displacements. The existence and weighting of these two fractions of ions were obtained from the direct diffusion measurements. The results show that the ion dynamics slowed only modestly under confinement, which evidences that IGs preserve IL transport properties, and this behavior is an encouraging indication for using IGs as a solid electrolyte for Li+ batteries.

A general method to synthesize and sinter bulk ceramics in seconds.

Ceramics are an important class of materials with widespread applications because of their high thermal, mechanical, and chemical stability. Computational predictions based on first principles methods can be a valuable tool in accelerating materials discovery to develop improved ceramics. It is essential to experimentally confirm the material properties of such predictions. However, materials screening rates are limited by the long processing times and the poor compositional control from volatile element loss in conventional ceramic sintering techniques. To overcome these limitations, we developed an ultrafast high-temperature sintering (UHS) process for the fabrication of ceramic materials by radiative heating under an inert atmosphere. We provide several examples of the UHS process to demonstrate its potential utility and applications, including advancements in solid-state electrolytes, multicomponent structures, and high-throughput materials screening.