Association of Type 2 Diabetes with Submicron Titanium Dioxide Crystals in the Pancreas

Pigment-grade titanium dioxide (TiO₂) of 200–300 nm particle diameter is the most widely used submicron-sized particle material. Inhaled and ingested TiO₂ particles enter the bloodstream, are phagocytized by macrophages and neutrophils, are inflammatory, and activate the NLRP3 inflammasome. In this pilot study of 11 pancreatic specimens, 8 of the type 2 diabetic pancreas and 3 of the nondiabetic pancreas, we show that particles comprising 110 ± 70 nm average diameter TiO₂ monocrystals abound in the type 2 diabetic pancreas, but not in the nondiabetic pancreas. In the type 2 diabetic pancreas, the count of the crystals is as high as 10⁸–10⁹ per gram

Mixed-Valence Metal Oxide Nanoparticles as Electrochemical Half-Cells: Substituting the Ag/AgCl of Reference Electrodes by CeO_2–<i>x</i> Nanoparticles

Cations of mixed valence at surfaces of metal oxide nanoparticles constitute electrochemical half-cells, with potentials intermediate between those of the dissolved cations and those in the solid. When only cations at surfaces of the particles are electrochemically active, the ratio of electrochemically active/all cations is ∼0.1 for 15 nm diameter CeO_2–<i>x</i> particles. CeO_2–<i>x</i> nanoparticle-loaded hydrogel films on printed carbon and on sputtered gold constitute reference electrodes having a redox potential similar to that of Ag/AgCl in physiological (0.14 M) saline solutions. <i>In vitro</i> the characteristics of potentially subcutaneously implantable glucose monitoring sensors made with CeO_2–<i>x</i> nanoparticle reference electrodes are undistinguishable from those of sensors made with Ag/AgCl reference electrodes. Cerium is 900 times more abundant than silver, and commercially produced CeO_2–<i>x</i> nanoparticle solutions are available at prices well below those of the Ag/AgCl pastes used in the annual manufacture of ∼10⁹ reference electrodes of glucose monitoring strips for diabetes management

Simple Synthesis of Nanostructured Sn/Nitrogen-Doped Carbon Composite Using Nitrilotriacetic Acid as Lithium Ion Battery Anode

A composite of 3.5 nm Sn nanoparticles dispersed in nitrogen-doped carbon was prepared from low cost precursors, using simple equipment, by the simple process of hydrolyzing at 300 °C SnCl₄ mixed with nitrilotriacetic acid and then pyrolyzing the complexed SnO₂ at 650 °C. The affordable anode made with the composite retained at 0.2 A g^–1 specific current a specific capacity of 660 mAh·g^–1 at the 200th cycle and a 630 mAh·g^–1 capacity at 400th cycle. At 1 A g^–1 specific current the capacity was as 435 mAh·g^–1

α-Fe₂O₃ Nanorods as Anode Material for Lithium Ion Batteries

Hydrothermally synthesized single-crystalline hematite (α<i>-</i>Fe₂O₃) nanorods were investigated as an anode material for Li-ion batteries. Electrodes prepared with this material exhibited initial reversible capacities of 908 mAh g^–1 at 0.2 C rate and 837 mAh g^–1 at 0.5 C rate, and these capacities were completely retained after numerous cycles. The α<i>-</i>Fe₂O₃ nanorods average ∼40 nm in diameter and ∼400 nm in length providing a short path for lithium-ion diffusion and effective accommodation of the strain generated from volume expansion during the lithiation/delithiation process

Tin–Germanium Alloys as Anode Materials for Sodium-Ion Batteries

The sodium electrochemistry of evaporatively deposited tin, germanium, and alloys of the two elements is reported. Limiting the sodium stripping voltage window to 0.75 V versus Na/Na+ improves the stability of the tin and tin-rich compositions on repeated sodiation/desodiation cycles, whereas the germanium and germanium-rich alloys were stable up to 1.5 V. The stability of the electrodes could be correlated to the surface mobility of the alloy species during deposition suggesting that tin must be effectively immobilized in order to be successfully utilized as a stable electrode. While the stability of the alloys is greatly increased by the presence of germanium, the specific Coulombic capacity of the alloy decreases with increasing germanium content due to the lower Coulombic capacity of germanium. Additionally, the presence of germanium in the alloy suppresses the formation of intermediate phases present in the electrochemical sodiation of tin. Four-point probe resistivity measurements of the different compositions show that electrical resistivity increases with germanium content. Pure germanium is the most resistive yet exhibited the best electrochemical performance at high current densities which indicates that electrical resistivity is not rate limiting for any of the tested compositions

Thin Nanocolumnar Ge_0.9Se_0.1 Films Are Rapidly Lithiated/Delithiated

Thin films of amorphous nanocolumnar germanium subselenide Ge_0.9Se_0.1, with a lithiation/delithiation capacity of 1.2 Ahr g^–1, retain a capacity of 0.8 Ahr g^–1 when lithiated in 1.2 min and 0.5 Ahr g^–1 when lithiated in 36 s. After 1000 cycles of 72 s lithiation/72 s delithiation, the films retain a capacity of 0.8 Ahr g^–1. For delithiation in 3.3 s, the capacity is 0.9 Ahr g^–1, and the specific delithiation current is 1.34 kA g^–1 (kiloampere per gram)

Storage of Lithium in Hydrothermally Synthesized GeO₂ Nanoparticles

Amorphous GeO₂ nanoparticles were prepared via a surfactant-assisted hydrothermal process. The effect of the reaction temperature and the surfactant concentration on the morphology of GeO₂ particles were investigated. Particles of less than 300 nm were obtained when using 1,2-diaminopropane surfactant in a synthesis carried out at 180^◦C. The synthesized germanium oxide nanoparticles were evaluated for their utility as the active anode material in Li-ion batteries. The electrode prepared with this material exhibited a stable capacity ∼600 mAh g^–1 at 0.2 C rate for up to 150 cycles in a conventional electrolyte containing ethylene carbonate (EC). The cyclability of the GeO₂ nanoparticle electrode was further improved by using a fluorinated ethylene carbonate (FEC) based electrolyte, which showed capacities greater than 600 mAh g^–1 and retained more than 96% of their capacity after 500 cycles at 0.2 C rate. The effect of different electrolyte systems was studied by using electrochemical impedance spectroscopy and electron microscopy

Facile Synthesis of Ge/N-Doped Carbon Spheres with Varying Nitrogen Content for Lithium Ion Battery Anodes

The simple fabrication of composites of germanium nanoparticles dispersed on nitrogen-doped carbon nanospheres (Ge/NC) of varying nitrogen content and their performance in lithium ion battery anodes are reported. A heavily nitrogen-doped carbon gel was formed by condensing <i>m</i>-phenylenediamine with formaldehyde (PF-gel); a less heavily N-doped gel was formed by condensing resorcinol and <i>m</i>-phenylenediamine with formaldehyde (RPF-gel); and an undoped gel was formed by condensing resorcinol with formaldehyde (RF-gel). Pyrolises of the gels with GeCl₄ at 750 °C produced nanocrystalline Ge composites with 7.5 atom % N-doped carbon, termed Ge/NC (PF), with 3.9% N-doped carbon, termed Ge/NC (RPF) and undoped carbon, termed Ge/C (RF). The heavily N-doped Ge/NC (PF) anode retained a reversible capacity of 684 mAhg^–1 at a specific current of 0.2 Ag^–1 after 200 cycles, versus 337 mAhg^–1 retained by anode made with Ge/NC (RPF) and 278 mAhg^–1 retained by anode made with undoped Ge/C (RF). At a specific current 2.0 Ag^–1, the capacity of the Ge/NC (PF) anode was 472 mAhg^–1, versus the 210 mAhg^–1 of the Ge/NC (RPF) anode and 83 mAhg^–1 of the Ge/C (RF) anode. The enhanced performance of the Ge/NC (PF) anode is attributed to the better electrical conductivity of Ge/NC (PF) and to the higher density of Li⁺ binding defects in its N-doped carbon

Improving the Stability of Nanostructured Silicon Thin Film Lithium-Ion Battery Anodes through Their Controlled Oxidation

Silicon and partially oxidized silicon thin films with nanocolumnar morphology were synthesized by evaporative deposition at a glancing angle, and their performance as lithium-ion battery anodes was evaluated. The incorporated oxygen concentration was controlled by varying the partial pressure of water during the deposition and monitored by quartz crystal microbalance, X-ray photoelectron spectroscopy. In addition to bulk oxygen content, surface oxidation and annealing at low temperature affected the cycling stability and lithium-storage capacity of the films. By simultaneously optimizing all three, films of ∼2200 mAh/g capacity were synthesized. Coin cells made with the optimized films were reversibly cycled for ∼120 cycles with virtually no capacity fade. After 300 cycles, 80% of the initial reversible capacity was retained

Sn–Cu Nanocomposite Anodes for Rechargeable Sodium-Ion Batteries

Sn_0.9Cu_0.1 nanoparticles were synthesized via a surfactant-assisted wet chemistry method, which were then investigated as an anode material for ambient temperature rechargeable sodium ion batteries. The Sn_0.9Cu_0.1 nanoparticle-based electrodes exhibited a stable capacity of greater than 420 mA h g^–1 at 0.2 <i>C</i> rate, retaining 97% of their maximum observed capacity after 100 cycles of sodium insertion/deinsertion. Their performance is considerably superior to electrodes made with either Sn nanoparticles or Sn microparticles