Shell Coat Research Articles

Understanding the Size‐Dependent Photostability and Photoluminescence Intermittency of Blue‐Emitting Core/Graded Alloy/Shell “giant”‐Quantum Dots

AbstractRecently, giant quantum dots (g‐QDs) with a core/interface graded alloy shell/shell structure have shown promise in reducing photoluminescence (PL) intermittency and improving photostability. However, this approach has been mainly demonstrated with red and green emitting g‐QDs but the blue‐emitting graded alloy QDs has remained less explored. To tackle this challenge, a composition gradient method is employed to create three blue‐emitting CdZnS/CdxZn1–xS/ZnS core/interface graded alloy shell/shell (C/A/S) quantum dots (QDs) with different diameters. The sample with the largest diameter (gQD‐3) exhibits superior optical characteristics, with a photoluminescence quantum yield (PLQY) of approximately 62% and around 80% ON/radiative events at the single‐particle level. Conversely, the smallest diameter (gQD‐1) sample shows lower PLQY and only 30% radiative events with longer OFF/nonradiative events. Probability distribution analysis of PL trajectories, fitted with a truncated power law, reveals a significantly higher carrier de‐trapping rate in gQD‐3 compared to gQD‐1, attributed to its proximity to band edge trap states. Additionally, the largest diameter sample retains remarkable optical performance during 48 h of continuous UV irradiation in colloidal suspension and single‐particle levels. These findings show optimized core/shell structures, gradual alloy interfaces, and outer shell coatings can stabilize blue‐emitting quantum dots, advancing next‐gen optoelectronics.

Observations on the reproductive morphology of the female short-beaked echidna, Tachyglossus aculeatus.

Although monotremes diverged from the therian mammal lineage approximately 187 million years ago, they retain various plesiomorphic and/or reptilian-like anatomical and physiological characteristics. This study examined the morphology of juvenile and adult female reproductive tracts across various stages of the presumptive oestrous cycle, collected opportunistically from cadaver specimens submitted to wildlife hospitals during the breeding season. In adult females, ovaries had a convoluted cortex with follicles protruding from the ovarian surface. While protruding antral follicles were absent from the ovaries of juvenile echidnas, histological analysis identified early developing primordial and primary follicles embedded into the ovarian cortex. The infundibulum epithelial cells of the oviducts were secretory during the follicular phase but not at other stages, the ampulla region was secretory at all stages and is likely responsible for the mucoid layer deposited around the zona pellucida, and the isthmus region of the oviduct appeared to be responsible for initial deposition of the shell coat, as in marsupials. Female echidnas have two separate uteri, which never merge and enter separately into the urogenital sinus (UGS). This study confirmed that both uteri are functional and increase in glandular activity during the luteal phase. In the juvenile uteri, the endometrium was immature with minimal, small uterine glands. A muscular cervical region at the caudal extremity of each uterus, just before the cranial region of the UGS was defined by the absence of glandular tissue in all female echidnas, including the juveniles. There was no evidence of a definitive vaginal region. A clitoris was also detected that possessed a less developed but similar structural (homologous) anatomy to the male penis; urethral ducts while present did not appear to be patent.

Inert Shell Coating for Enhanced Laser Refrigeration of Nanoparticles: Application in Levitated Optomechanics

Inert Shell Coating for Enhanced Laser Refrigeration of Nanoparticles: Application in Levitated Optomechanics

Fe-carbide/Fe-oxide-based nanocomposites synthesized as magnetic nanomaterials via laser ablation synthesis in solution (LASiS)

Magnetic nanostructured materials (MNMs) have gained prominence in materials technology developments owing to their potential biomedical applications for hyperthermia cancer treatment, and transplant organ cryopreservation. Herein, we report the facile and cost-effective synthesis of Fe-based composite MNMs, comprising both Fe@Fe2O3 and Fe3C@C core-shell nanoparticles (NPs), via Laser Ablation Synthesis in Solution (LASiS) using Fe targets ablated under acetone and toluene. Detailed materials characterizations using electron microscopy-based imaging, diffraction studies, and spectroscopic analyses - including Raman and Mössbauer spectroscopy - relate the structure-composition properties for different Fe-oxide/carbide phases in the aforesaid MNMs to their respective magnetic responses. Specifically, we confirm the presence of ultra-small (2–10 nm) amorphous Fe-oxide NPs, as well as Fe@Fe2O3 core-shell NPs (20–40 nm) in the samples synthesized by ablating Fe under acetone. In contrast, samples synthesized under toluene indicate a higher concentration of Fe3C@C core-shell NPs (20–40 nm) with a relatively low concentration of Fe2O3 NPs (2–10 nm). Furthermore, the crystallinity of the metallic phases and carbonaceous shell coatings are systematically increased by carrying out LASiS under heated toluene (up to ∼95 °C). Mössbauer spectroscopy results indicate that the elevation in toluene temperature leads to an increase in the concentrations of Fe3C@C NPs from ∼40 % to ∼53 % (at.).

Influence of protein nativity on the stability of bovine serum albumin coated microbubbles

Protein-coated microbubbles have become one of the emerging platforms in biomedical research as theranostic agents. In recent years, microbubbles have been extensively used as ultrasound contrast agents and carriers of molecular cargoes, pertaining to which several studies have focused on tuning the properties of these bubbles to achieve a higher degree of biocompatibility and extended stability. Synthesis of microbubbles has so far been traditionally carried out with pre-heated proteins like bovine serum albumin (BSA) as shell coatings, owing to the ease in making BSA crosslinked structures through disulfide bridge formation. We, however, have performed experiments to demonstrate that air core microbubbles formed with native BSA are more stable compared with those formed using denatured BSA. The experimental observations have been supported with analytical modeling and computational studies, which offer insights into the effect of BSA conformation in stabilizing the microbubbles shells and prolonging their lifetimes.

Cation Exchange Synthesis of Aliovalent Doped InP QDs and Their ZnSexS1-x Shell Coating for Enhanced Fluorescence Properties.

III-V quantum dots (QDs), in particular InP QDs, have emerged as high-performance and environmentally friendly candidates to replace cadmium based QDs. InP QDs exhibit properties of direct band gap structure, low toxicity, and high mobility, which make them suitable for high-performance optoelectronic applications. However, it is still challenging to precisely regulate the components and crystal structure of InP QDs, especially in the engineered stable aliovalent doping. In this work, we developed our original reverse cation exchange strategy to achieve Cu+ doped InP (InP:Cu) QDs at lower temperature. A ZnSexS1-x shell was then homogeneously grown on the InP:Cu QDs as the passivation shell. The as-prepared InP:Cu@ZnSexS1-x core-shell QDs exhibited better fluorescence properties with a photoluminescence quantum yield (PLQY) of 56.47%. Due to the existence of multiple luminous centers in the QDs, variable temperature-dependent fluorescence characteristics have been studied. The high photoluminescence characteristics in the near-infrared region indicate their potential applications in optoelectronic devices and biological fields.

Gap-enhanced gold nanodumbbells with single-particle surface-enhanced Raman scattering sensitivity.

Gap-enhanced Raman tags (GERTs) have been widely used for surface-enhanced Raman scattering (SERS) imaging due to their excellent SERS performances. Here, we reported a synthetic strategy for novel gap-enhanced dumbbell-like nanoparticles with anisotropic shell coatings. Controlled shell growth at the tips of gold nanorods was achieved by using cetyltrimethylammonium bromide (CTAB) as a capping agent. A mechanism related to the shape-directing effects of CTAB was proposed to explain the findings. Optimized gap-enhanced gold dumbbells exhibited highly enhanced SERS responses compared to rod cores, with an enhancement ratio of 101.5. We further demonstrated that gap-enhanced AuNDs exhibited single-particle SERS sensitivity with an acquisition time as fast as 0.1 s per spectrum, showing great potential for high-speed SERS imaging.

Mechanical tuning of virus-like particles

HypothesisVirus-like particles (VLPs) are promising scaffolds for developing mucosal vaccines. For their optimal performance, in addition to design parameters from an immunological perspective, biophysical properties may need to be considered. ExperimentsWe investigated the mechanical properties of VLPs scaffolded on the coat protein of Acinetobacter phage AP205 using atomic force microscopy and small angle X-ray scattering. FindingsInvestigations showed that AP205 VLP is a tough nanoshell of stiffness 93 ± 23 pN/nm and elastic modulus 0.11 GPa. However, its mechanical properties are modulated by attaching muco-inert polyethylene glycol to 46 ± 10 pN/nm and 0.05 GPa. Addition of antigenic peptides derived from SARS-CoV2 spike protein by genetic fusion increased the stiffness to 146 ± 54 pN/nm although the elastic modulus remained unchanged. These results, which are interpreted in terms of shell thickness and coat protein net charge variations, demonstrate that surface conjugation can induce appreciable changes in the biophysical properties of VLP-scaffolded vaccines.

Silica Shell Thickness-Dependent Fluorescence Properties of SiO2@Ag@SiO2@QDs Nanocomposites.

Silica shell coatings, which constitute important technology for nanoparticle (NP) developments, are utilized in many applications. The silica shell’s thickness greatly affects distance-dependent optical properties, such as metal-enhanced fluorescence (MEF) and fluorescence quenching in plasmonic nanocomposites. However, the precise control of silica-shell thicknesses has been mainly conducted on single metal NPs, and rarely on complex nanocomposites. In this study, silica shell-coated Ag nanoparticle-assembled silica nanoparticles (SiO2@Ag@SiO2), with finely controlled silica shell thicknesses (4 nm to 38 nm), were prepared, and quantum dots (QDs) were introduced onto SiO2@Ag@SiO2. The dominant effect between plasmonic quenching and MEF was defined depending on the thickness of the silica shell between Ag and QDs. When the distance between Ag NPs to QDs was less than ~10 nm, SiO2@Ag@SiO2@QDs showed weaker fluorescence intensities than SiO2@QD (without metal) due to the quenching effect. On the other hand, when the distance between Ag NPs to QDs was from 10 nm to 14 nm, the fluorescence intensity of SiO2@Ag@SiO2@QD was stronger than SiO2@QDs due to MEF. The results provide background knowledge for controlling the thickness of silica shells in metal-containing nanocomposites and facilitate the development of potential applications utilizing the optimal plasmonic phenomenon.

Characterization of pinto and cranberry bean (Phaseolus vulgaris L.) landraces from western Himalayan Kashmir for yield and quality

The present study aimed to characterize pinto and cranberry bean landraces of Kashmir valley. A set of 30 genotypes including 16 pinto and 12 cranberry type bean landraces and two checks viz., Shalimar Rajmash-1 (SR-1) and Shalimar French Bean-1 (SFB-1) were evaluated for seven qualitative and 10 quantitative traits.  There was a substantial variation among 30 accessions (28 landraces and 2 checks) evaluated for all the traits.  Out of 28 landrace accessions, 13 were bushy type and 15 were pole type.  Pods were predominantly green and seed colour was predominantly brown with characteristic mottling of varying colour shades.  Out of 30 accessions, 16 were medium sized with oval seeds. There was substantial variability as depicted by a wide range for both morphological and seed quality traits pertaining to water absorption as well as protein content and phytic acid. The heat map revealed that seed yield had a significant correlation with the number of pods per plant (0.505), followed by seed length (0.455) and seeds per pod (0.414). Similarly, water absorption percentage was significantly correlated with hydration coefficient followed by seed wet weight and hydration capacity but was negatively correlated with hard shell percentage and coat proportion. Principal component analysis based on the seed yield and related traits concentrated the variability in the first three components for morphological traits and four components for seed quality traits explaining 67.23 % and 78.60 % variation, respectively.  A number of desirable genotypes could be identified based on consistent performance for various maturity, yield and seed quality traits including high protein and low phytic acid content. Keywords: Common bean, Western Himalayas, Pinto beans, Cranberry beans, Cooking quality, Seed protein, Phytic acid  

Quantifying the Influence of Inert Shell Coating on Luminescence Brightness of Lanthanide Upconversion Nanoparticles

Quantifying the Influence of Inert Shell Coating on Luminescence Brightness of Lanthanide Upconversion Nanoparticles

Tailoring the Metallic and Oxide Sites of Pd/C and Ni/C Catalysts for Optimum Hydrogen Oxidation Reaction (HOR) and Durability in Alkaline Media

In recent years, Pd- and Ni-based, or Pd-Ni alloys catalysts for HOR in alkaline electrolytes obtained increasing attention due to their higher durability than Pt-based catalysts. [1-3] However, to prevent passivation in high pH media and maintain active metal/oxide sites, it is necessary to protect the surface of Pd and Ni. It is well documented that different types of carbon cover layers surrounding Ni particles, such as graphite or carbon nanotube, can be beneficial for several applications, e.g. hydrogenation, dehydrogenation, methanol oxidation [4-6], and HOR. Gao et al. reported different degree of graphite coverage-Ni particles of controlled metal/oxide ratio that can enhance the HOR activity of Ni in alkaline electrolytes [7]. In this work, we explore different carbon layer properties, morphology and thickness that cover Pd and Ni particles. Thicker cover layers lead to low HOR activity initially because of the un-balanced metal/oxide sites (the amount of metal sites is higher originally), but can be improved (activated) by voltage pulsing (0.1 - 1.23 V vs. RHE, 3 s each potential, 300 cycles) in 0.1 M KOH, 25°C, Ar gas, without agglomerating the particles (as shown in Figure 1). After full activation, protected Pd and protected Ni were compared with bare Pd and bare Ni (no protecting layers) before and after accelerated stress test (AST) in the potential range of [0.1, 1.23] V vs. RHE. IL-TEM, XRD and XPS techniques show that for protected Pd and Ni, the passivation and degradation happen much slower than for bare Pd and bare Ni (which are immediately deactivated upon AST); also, the proportion of metal or oxide sites can be tailored by different activation procedure, which renders these protected catalysts suitable for long-term alkaline HOR. Figure 1 IL-TEM of Pd C1 (Pd-capped 1) at its initial state vs. post-activation (300 cycles-Ar). Top: 200 k magnified micrographs. Bottom: 500 k magnified micrographs.[1] Lafforgue, C.; Zadick, A.; Dubau, L.; Maillard, F.; Chatenet, M. Selected Review of the Degradation of Pt and Pd-Based Carbon-Supported Electrocatalysts for Alkaline Fuel Cells: Towards Mechanisms of Degradation. Fuel Cells 2018, No. 0, 1–10.[2] Sankar, S.; Anilkumar, G. M.; Tamaki, T.; Yamaguchi, T. Binary Pd−Ni Nanoalloy Particles over Carbon Support with Superior Alkaline Formate Fuel Electrooxidation Performance. ChemCatChem 2019, 11 (19), 4731–4737.[3] Zhao, Y.; Wang, G.; Xiao, L.; Lu, J.; Zhuang, L. Hydrogen Oxidation Reaction on Pd-Ni(OH)2 Composite Electrocatalysts in an Alkaline Electrolyte. ChemistrySelect 2020, 5 (26), 7803–7807. )[4] Ortega-Domínguez, R. A.; Vargas-Villagrán, H.; Peñaloza-Orta, C.; Saavedra-Rubio, K.; Bokhimi, X.; Klimova, T. E. A Facile Method to Increase Metal Dispersion and Hydrogenation Activity of Ni/SBA-15 Catalysts. Fuel 2017, 198, 110–122.[5] Jiao, C.; Sun, L.; Xu, F.; Liu, S. S.; Zhang, J.; Jiang, X.; Yang, L. NiCo Nanoalloy Encapsulated in Graphene Layers for Improving Hydrogen Storage Properties of LiAlH4. Sci. Rep. 2016, 6 (January), 4–11.[6] Tong, X.; Qin, Y.; Guo, X.; Moutanabbir, O.; Ao, X.; Pippel, E.; Zhang, L.; Knez, M. Enhanced Catalytic Activity for Methanol Electro-Oxidation of Uniformly Dispersed Nickel Oxide Nanoparticles-Carbon Nanotube Hybrid Materials. Small 2012, 8 (22), 3390–3395.[7] Yang, Y.; Sun, X.; Han, G.; Liu, X.; Zhang, X.; Sun, Y.; Zhang, M.; Cao, Z.; Sun, Y. Enhanced Electrocatalytic Hydrogen Oxidation on Ni/NiO/C Derived from a Nickel-Based Metal–Organic Framework. Angew. Chemie - Int. Ed. 2019, 58 (31), 10644–10649.[8] Gao, Y.; Peng, H.; Wang, Y.; Wang, G.; Xiao, L.; Lu, J.; Zhuang, L. Improving the Antioxidation Capability of the Ni Catalyst by Carbon Shell Coating for Alkaline Hydrogen Oxidation Reaction. ACS Appl. Mater. Interfaces 2020, 12 (28), 31575–31581. Figure 1

Comparing Different Nanoparticles Protecting Layers That Can Slow Down the Degradation of Pd-Ni Based Catalyst during Hydrogen Oxidation Reaction (HOR) in Alkaline Media

Alkaline fuel cell (AFC) technology has several advantages over the mature Proton exchange membrane fuel cell (PEMFC), notably its low cost, coming from the use of non-Pt catalysts. [1] Gencell Energy is one of the very few companies that invest in AFC, with a specialty on membraneless AFC that can be used at extreme weather condition without compromising their lifetime and efficiency, where it is impossible to use PEMFC. The 6.6 M KOH electrolyte of membraneless AFC drive is a key to its robustness [2,3], but it is a highly corrosive environment, in which the HOR catalyst on the anode side can deactivate. Based on previously reports, Pd-Ni is a good candidate for HOR in high pH compared to Pt-based catalysts [4,5]. Yet, after long-term operation, Pd-Ni still suffer severe particle detachment and passivation. To increase the durability of such catalyst, forming a protecting layer that covers the nanoparticle is necessary, without hindering the HOR activity. [6,7] This work presents a variety of protecting layers that cover the Pd-Ni particles to slow down the degradation. An example of HOR activity for one of the Pd-Ni capped is presented in Figure 1. The Pd-Ni capped generation 1 (G1)/ Vulcan XC72 needs an activation using prolonged potential cycling in Ar (typically 300 CVs from 0.1-1.23 V vs. RHE, 100 mV/s). Once the catalyst is fully activated, accelerated stress tests (AST) are performed up to 3300 cycles to track the durability of the catalyst. As shown, after 21 AST runs (which corresponds to 3150 CVs), the catalyst still maintains its HOR activity. It will be shown that different cover layers (varying in type and thickness of the cover) enable to modulate the materials’ activation and durability. In any case, the HOR activity and rate of degradation of Pd-Ni with different protecting layers is tracked using IL-TEM, XRD and XPS pre and post AST.(1) Simon, C.; Hanzlik, M.; Gasteiger, H. A.; Schuler, T.; Durst, J.; Siebel, A.; Hasche, F.; Herranz, J.; Rheinlander, P. J. Hydrogen Oxidation and Evolution Reaction (HOR/HER) on Pt Electrodes in Acid vs. Alkaline Electrolytes: Mechanism, Activity and Particle Size Effects. ECS Trans. 2014, 64 (3), 1069–1080.(2) Gülzow, E. Alkaline Fuel Cells. Fuel Cells 2004, 4 (4), 251–255.(3) Gouérec, P.; Poletto, L.; Denizot, J.; Sanchez-Cortezon, E.; Miners, J. H. The Evolution of the Performance of Alkaline Fuel Cells with Circulating Electrolyte. J. Power Sources 2004, 129 (2), 193–204.(4) Sankar, S.; Anilkumar, G. M.; Tamaki, T.; Yamaguchi, T. Binary Pd−Ni Nanoalloy Particles over Carbon Support with Superior Alkaline Formate Fuel Electrooxidation Performance. ChemCatChem 2019, 11 (19), 4731–4737.(5) Zhao, Y.; Wang, G.; Xiao, L.; Lu, J.; Zhuang, L. Hydrogen Oxidation Reaction on Pd-Ni(OH)2 Composite Electrocatalysts in an Alkaline Electrolyte. ChemistrySelect 2020, 5 (26), 7803–7807.(6) Yang, Y.; Sun, X.; Han, G.; Liu, X.; Zhang, X.; Sun, Y.; Zhang, M.; Cao, Z.; Sun, Y. Enhanced Electrocatalytic Hydrogen Oxidation on Ni/NiO/C Derived from a Nickel-Based Metal–Organic Framework. Angew. Chemie - Int. Ed. 2019, 58 (31), 10644–10649.(7) Gao, Y.; Peng, H.; Wang, Y.; Wang, G.; Xiao, L.; Lu, J.; Zhuang, L. Improving the Antioxidation Capability of the Ni Catalyst by Carbon Shell Coating for Alkaline Hydrogen Oxidation Reaction. ACS Appl. Mater. Interfaces 2020, 12 (28), 31575–31581. Figure 1

Hollow Gold-Silver Nanoshells Coated with Ultrathin SiO2 Shells for Plasmon-Enhanced Photocatalytic Applications.

This article details the preparation of hollow gold-silver nanoshells (GS-NSs) coated with tunably thin silica shells for use in plasmon-enhanced photocatalytic applications. Hollow GS-NSs were synthesized via the galvanic replacement of silver nanoparticles. The localized surface plasmon resonance (LSPR) peaks of the GS-NSs were tuned over the range of visible light to near-infrared (NIR) wavelengths by adjusting the ratio of silver nanoparticles to gold salt solution to obtain three distinct types of GS-NSs with LSPR peaks centered near 500, 700, and 900 nm. Varying concentrations of (3-aminopropyl)trimethoxysilane and sodium silicate solution afforded silica shell coatings of controllable thicknesses on the GS-NS cores. For each type of GS-NS, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images verified our ability to grow thin silica shells having three different thicknesses of silica shell (~2, ~10, and ~15 nm) on the GS-NS cores. Additionally, energy-dispersive X-ray (EDX) spectra confirmed the successful coating of the GS-NSs with SiO2 shells having controlled thicknesses. Extinction spectra of the as-prepared nanoparticles indicated that the silica shell has a minimal effect on the LSPR peak of the gold-silver nanoshells.

Conformality of PVD shell layers on GLAD-nanorods investigated by Monte Carlo simulations

The quality of the shell coating around nanorods is critical in device applications. Conventional physical vapor deposition (PVD) techniques can be utilized for highly conformal shell coating formation in core-shell structure devices. To identify scalable fabrication techniques for conformal shell coatings, Monte Carlo (MC) simulations of PVD growth were performed under different atomic flux distributions and angles on arrays of glancing angle deposition (GLAD) nanorods, which were also generated by MC simulations. We investigated the conformality of PVD films (shell) around GLAD rod arrays (core) and analyzed the thickness uniformity of the shell layer across the sidewalls of rods. Our results show that Angular Flux-Normal Angle (A-NAD), which might correspond to high-pressure sputter deposition at normal incidence (HIPS at θ = 0o) can generate better conformal shell coating compared to others. In Uniform Flux-Normal Angle technique (U-NAD), which corresponds to a thermal evaporation deposition, the growth suffers from poor sidewall coverage. In addition, introducing a small angle to the flux also improves the shell conformality. Therefore, high-pressure sputter deposition technique is expected to provide superior conformality for a catalyst or semiconductor coating around base nanorods, for example for fuel cell and solar cell applications, with the help of obliquely incident atoms of the HIPS flux.

Improving the Antioxidation Capability of the Ni Catalyst by Carbon Shell Coating for Alkaline Hydrogen Oxidation Reaction.

Increasing the antioxidation capability of Ni for the hydrogen oxidation reaction (HOR) is considered important and challenging for alkaline polymer electrolyte fuel cells (APEFCs). Herein, we report a series of Ni-core carbon-shell (Ni@C) catalysts obtained by a vacuum pyrolysis method treated at different temperatures. According to the cyclic voltammetry tests and the HOR tests, Ni@C treated at 500 °C exhibits a much higher Ni core utilization and better catalytic activity toward HOR than the commonly used Ni/C catalyst. Furthermore, X-ray photoelectron spectroscopy characterization shows that a higher percentage of Ni0 appears at the surface of the Ni core of Ni@C than the Ni/C catalyst. The accelerated durability tests, as well as the chronoamperometry tests, suggest that the antioxidation capability of Ni has been obviously improved by the carbon shells. The Raman spectra show that the graphitization degree of the carbon shells might be the key factor affecting the Ni utilization and the HOR catalytic activity of the Ni@C catalysts. The APEFC achieves a peak power density of 160 mW/cm2 using Ni@C-500 °C as the anode, which could also stably discharge for 120 h at 0.7 V.

Effects of heat treatments and edible shell coatings on egg quality after storage at room temperature

Abstract The objective of this study was to evaluate the effect of thermal treatments using different water temperatures and immersion times, as well as the application of eggshell coatings using edible materials on eggshell quality after storage for 4 weeks at room temperature (22.8 ± 4.4 °C). A total of 180 brown fresh eggs were distributed in a completely randomized design with six treatments and five replicates of six eggs each. The treatments consisted of a control group without any treatment (T1), three groups treated thermally: 56 °C/32 minutes (T2); 56 °C/20 minutes (T3); 56 °C/10 minutes (T4); and two groups with gelatin 2% (T5) and 5% NaCl solution (T6). After storage, it was found that the heat treatments at 56 °C for 10, 20 and 32 minutes provided maintenance of the albumen height, which reflected the values ​​of the Haugh units but negatively influenced the albumen foam stability. The treatment with 5% NaCl solution showed the lowest lipid oxidation rate and the best albumen foam stability. The proposed treatments (thermal or coatings), individually, caused significant improvements on some eggs quality markers evaluated after 30 days of storage.

The role of mammalian foetal membranes in early embryogenesis: Lessons from marsupials.

Across mammals, early embryonic development is supported by uterine secretions taken up through the yolk sac and other foetal membranes (histotrophic nutrition). The marsupial conceptus is enclosed in a shell coat for the first two-thirds of gestation and nutrients pass to the embryo through the shell and the avascular bilaminar yolk sac. At around the time of shell rupture, part of the yolk sac is trilaminar and supplied with blood vessels. It attaches to the uterus and forms a choriovitelline placenta. Rapid growth of the embryo ensues, still supported by histotrophe as well as exchange of oxygen and nutrients between maternal and foetal blood vessels (haemotrophic nutrition). Few marsupials have a chorioallantoic placenta and the highly altricial newborn is delivered after a short gestation. Eutherian embryos pass through a similar sequence before there is a fully functional chorioallantoic placenta. In most orders, there is transient yolk sac placentation, but even before this, nutrients are transferred through an avascular yolk sac. Yolk sac placentation does not occur in rodents or catarrhine primates. Early embryonic development in the mouse is nonetheless dependent on histotrophic nutrition. In the first trimester of human pregnancy, uterine glands open to the intervillous space and secretion products are taken up by the trophoblast. Transfer of nutrients to the early human embryo also involves the yolk sac, which floats free in the exocoelom. Marsupials can therefore inform us about the role of foetal membranes and histotrophic nutrition in early embryogenesis, knowledge that can translate to eutherians.

Rapid Intestinal Uptake and Targeted Delivery to the Liver Endothelium Using Orally Administered Silver Sulfide Quantum Dots.

Quantum dots (QDs) are used for imaging and transport of therapeutics. Here we demonstrate rapid absorption across the small intestine and targeted delivery of QDs with bound materials to the liver sinusoidal endothelial cells (LSECs) or hepatocytes in vitro and in vivo following oral administration. QDs were radiolabeled with 3H-oleic acid, with a fluorescent tag or 14C-metformin placed within a drug binding site. Three different biopolymer shell coatings were compared (formaldehyde-treated serum albumin (FSA), gelatin, heparin). Passage across the small intestine into mesenteric veins is mediated by clathrin endocytosis and micropinocytosis. 60% of an oral dose of QDs was rapidly distributed to the liver within 30 min, and this increased to 85% with FSA biopolymer coating. Uptake into LSECs also increased 3-fold with FSA coating, while uptake into hepatocytes was increased from 40% to 85% with gelatin biopolymer coating. Localization of QDs to LSECs was confirmed with immunofluorescence and transmission electron microscopy. 85% of QDs were cleared within 24 h of administration. The bioavailability of 14C-metformin 2 h post-ingestion was increased 5-fold by conjugation with QD-FSA, while uptake of metformin into LSECs was improved 50-fold by using these QDs. Endocytosis of QDs by SK-Hep1 cells (an LSEC immortal cell line) was via clathrin- and caveolae-mediated pathways with QDs taken up into lysosomes. In conclusion, we have shown high specificity targeting of the LSEC or hepatocytes after oral administration of QDs coated with a biopolymer layer of FSA or gelatin, which improved the bioavailability and delivery of metformin to LSECs.

A Nanosilver Embedded Graphite-C Shell Coating on Large Size Micro Silicon Formed by Low Temperature Carbonizing with Ag+ Increased the Cross-Linking of Alginate as an Anode for LIBs

Silicon (Si) is an aussichtsreich anode candidate for a new generation lithium-ion batteries on account of its enormous theoretical capacity. However, its progress is tremendously hindered due to the tremendous volumetric change causes structure instability and poor cycling stability during the charge/discharge cycle. To overcome these issues associated with Si anodes, fabricated Si/C composites have been extensively studied. Here, this paper exploits a method for preparing a Si/C composite at low temperature and under atmospheric conditions, which has a graphite-C layer embedded with nanosilver particles. Carboxyl-rich alginate as a carbon source which silicon-carbon was tightly bound due to forms strong bonds (hydrogen bond) on the silicon surface. Tiny silver ions (0.01 M) were added to improve carbon stability by enhancing the cross-linking of alginate coated on the surface of large size micro silicon powder. The Si/Ag@C ternary composites were obtained, which combined simultaneous synthesis of nanosilver and crack-free graphite-C by subsequent low-temperature carbonization at 480 °C. Si/Ag@C exhibits high conductivity and long period recycle stability due to inducing high conductivity of nanosilver and crack-free graphite-C as anodes for LIBs. Si/Ag@C shows a well reversible capacity (724 mAh/g) over 100 cycles at 200 mA/g, which is more than thirty times that of Si (21 mAh/g). Si/Ag@C shows low electrochemical impedance and satisfactory rate capability due to its special structure.