Porous Layered Double Hydroxides Synthesized using Oxygen Generated by Decomposition of Hydrogen Peroxide.

Porous magnesium-aluminium layered double hydroxides (LDH) were prepared through intercalation and decomposition of hydrogen peroxide (H2O2). This process generates oxygen gas nano-bubbles that pierce holes in the layered structure of the material by local pressure build-up. The decomposition of the peroxide can be triggered by microwave radiation or chemically by reaction with iodide (I-) ions. The carbonate LDH version [Mg0.80Al0.20(OH)2](CO3)0.1∙mH2O was synthesized by microwave-assisted urea coprecipitation and further modified by iodide or H2O2 intercalation. High resolution Scanning Electron Microscopy (HR-SEM) and Brunauer-Emmet-Teller (BET) analysis were used to assess the morphology and surface area of the new porous materials. The presence of H2O2 in the interlayer region and later decomposition triggered by microwave radiation generated more pores on the surface of the LDH platelets, increasing their specific surface area from initially 9 m2/g to a maximum of 67 m2/g. X-Ray Diffraction showed that the formation of the pores did not affect the remaining crystal structure, allowing possible further functionalization of the material.

Hepatic cyst penetration of cefazolin in patients receiving aspiration sclerotherapy.

BACKGROUND: Hepatic cyst infection is a potentially severe complication in cystic disease. Treatment demands effective antibiotic concentrations within the infected cyst. OBJECTIVES: The aim of this study was to use elective hepatic cyst drainage as a unique pharmacokinetic model to investigate whether cefazolin, a first-generation cephalosporin, is able to penetrate hepatic cysts. PATIENTS AND METHODS: Patients scheduled to undergo percutaneous aspiration sclerotherapy of a symptomatic non-infected, non-neoplastic hepatic cyst were eligible for this study. All participants received a single perioperative prophylactic dose of cefazolin (1000 mg, intravenously). We collected blood and cyst fluid samples to determine total and unbound cefazolin concentrations using HPLC. The primary outcome was hepatic cyst penetration, expressed as the ratio (%) of unbound concentration of cefazolin in cyst fluid to plasma (both in mg/L). RESULTS: We included eight patients [male = 25%, median age = 60 years (IQR 54-75), median estimated glomerular filtration rate = 97 mL/min/1.73 m(2) (IQR 67-102) and median serum albumin = 40 g/L (IQR 37-40)]. We detected low concentrations of unbound cefazolin in cyst fluid (≤1.0 mg/L). The median plasma unbound cefazolin peak level (immediately after cefazolin administration) was 36.6 mg/L (IQR 23.7-54.1) and the level at the time of cyst fluid aspiration was 16.1 mg/L (IQR 13.0-20.1). In total, the hepatic cyst penetration of free cefazolin was only 2.2% (IQR 0.7-5.2). CONCLUSIONS: We developed a study model to investigate the penetration of antibiotics into hepatic cysts. Cefazolin did not reach adequate intracystic concentrations. Future studies should explore alternatives.

Extreme mobility enhancement of two-dimensional electron gases at oxide interfaces by charge-transfer-induced modulation doping.

Two-dimensional electron gases (2DEGs) formed at the interface of insulating complex oxides promise the development of all-oxide electronic devices. These 2DEGs involve many-body interactions that give rise to a variety of physical phenomena such as superconductivity, magnetism, tunable metal-insulator transitions and phase separation. Increasing the mobility of the 2DEG, however, remains a major challenge. Here, we show that the electron mobility is enhanced by more than two orders of magnitude by inserting a single-unit-cell insulating layer of polar La(1-x)Sr(x)MnO3 (x = 0, 1/8, and 1/3) at the interface between disordered LaAlO3 and crystalline SrTiO3 produced at room temperature. Resonant X-ray spectroscopy and transmission electron microscopy show that the manganite layer undergoes unambiguous electronic reconstruction, leading to modulation doping of such atomically engineered complex oxide heterointerfaces. At low temperatures, the modulation-doped 2DEG exhibits Shubnikov-de Haas oscillations and fingerprints of the quantum Hall effect, demonstrating unprecedented high mobility and low electron density.

Estimate of radiation damage to low-level electronics of the RF system in the LHC cavities arising from beam gas collisions.

Monte Carlo simulations have been performed to estimate the radiation damage induced by high-energy hadrons in the digital electronics of the RF low-level systems in the LHC cavities. High-energy hadrons are generated when the proton beams interact with the residual gas. The contributions from various elements-vacuum chambers, cryogenic cavities, wideband pickups and cryomodule beam tubes-have been considered individually, with each contribution depending on the gas composition and density. The probability of displacement damage and single event effects (mainly single event upsets) is derived for the LHC start-up conditions.