Physiochemical properties and prolonged release behaviours of chitosan-denatured β-lactoglobulin microcapsules for potential food applications

Chitosan (CS) and β-lactoglobulin (βlg) double-wall coating was designed as a shell structure to achieve prolonged release of core material in the gastrointestinal tract (GI) for potential food applications. A model core material, brilliant blue (BB) dye, was incorporated into CS as the primary wall material, and subsequently, denatured βlg, a secondary wall material, was used to coat the outer layer. The strongest interaction occurred between 0.5% (w/v) βlg and 0.5% (w/v) CS at pH 5.5 ± 0.1, where the opposite charges of CS and βlg formed a complex, which is especially favourable in acidic beverage systems. Under simulated stomach conditions, a denatured-βlg coat resisted acid conditions and pepsin hydrolysis for 2 h. While mimicking small intestine conditions, βlg was degraded by pancreatin, causing the release of BB-loaded CS to the intestinal fluid at a constant rate. The sustained release of core material later in the GI tract provided an optimal absorption rate in the small intestine.     

Public health impacts of combustion emissions in the United Kingdom

Combustion emissions are a major contributor to degradation of air quality and pose a risk to human health. We evaluate and apply a multiscale air quality modeling system to assess the impact of combustion emissions on UK air quality. Epidemiological evidence is used to quantitatively relate PM(2.5) exposure to risk of early death. We find that UK combustion emissions cause ～13,000 premature deaths in the UK per year, while an additional ～6000 deaths in the UK are caused by non-UK European Union (EU) combustion emissions. The leading domestic contributor is transport, which causes ～7500 early deaths per year, while power generation and industrial emissions result in ～2500 and ～830 early deaths per year, respectively. We estimate the uncertainty in premature mortality calculations at -80% to +50%, where results have been corrected by a low modeling bias of 28%. The total monetized life loss in the UK is estimated at ￡6-62bn/year or 0.4-3.5% of gross domestic product. In Greater London, where PM concentrations are highest and are currently in exceedance of EU standards, we estimate that non-UK EU emissions account for 30% of the ～3200 air quality-related deaths per year. In the context of the European Commission having launched infringement proceedings against the UK Government over exceedances of EU PM air quality standards in London, these results indicate that further policy measures should be coordinated at an EU-level because of the strength of the transboundary component of PM pollution.     

Characteristics of solderable electrically conductive adhesives (ECAs) for electronic packaging

This study investigated the effect of the viscosity of the ECAs using a low-melting-point alloy (LMPA) filler on its bonding characteristics. The curing behaviors of the ECAs were determined using Differential Scanning Calorimetry (DSC), and ECA temperature-dependant viscosity characteristics were observed using a torsional parallel rheometer. The wetting test was conducted to investigate the reduction capability of ECAs and the flow-coalescence-wetting behavior of the LMPAs in ECAs. Electrical and mechanical properties were determined and compared to those with commercial ECAs and eutectic tin/lead (Sn/Pb) solder. In the metallurgically interconnected Quad Flat Package (QFP) joint, a typical scallop-type Cu–Sn intermetallic compound (IMC) layer formed at the upper SnBi/Cu interface after curing process. On the other hand, a (Cu, Ni)₆Sn₅ IMC layer formed on the SnBi/ENIG interface. In addition, the fracture surface exhibited by cleavage fracture mode and the fracture was propagated along the Cu–Sn IMC/SnBi interface. The extremely low-level viscosity of ECAs had a significant influence on the flow-coalescence-wetting behavior of the LMPAs in ECAs and also on the interconnection properties. Stable interconnected assemblies showed good electrical and mechanical properties.     

Catalytic pyrolysis of oilsand bitumen over nanoporous catalysts

The catalytic cracking of oilsand bitumen was performed over nanoporous materials at atmospheric conditions. The yield of gas increased with application of nanoporous catalysts, with the catalytic conversion to gas highest for Meso-MFI. The cracking activity seemed to correlate with pore size rather than weak acidity or surface area.     

Carrier dynamics and activation energy of CdxZn(1-x)Te/ZnTe quantum dots on GaAs and Si substrates

We have investigated the carrier dynamics and activation energy of CdxZn(1-x)Te/ZnTe quantum dots (QDs) on GaAs and Si substrates. The carrier dynamics of QDs on GaAs and Si substrates is studied using time-resolved photoluminescence (PL) measurements, revealing shorter exciton lifetimes of QDs on Si substrate. In particular, the activation energy of electrons confined in QDs on the GaAs substrate, as obtained from temperature-dependent PL spectra, is higher than that of electrons confined in QDs on the Si substrate. Both results confirm that defects and dislocations in QDs on the Si substrate provide nonradiative channels.     

Removal of formaldehyde over amine functionalized SBA-15

Amine-functionalized SBA-15 materials were synthesized by a post synthesis method. Surface area and pore size decreased by attaching functional groups to the pore surface. Furthermore, pore volume was reduced with functionalization. The carbon and nitrogen content gradually increased with the number of amine groups in the silane precursors. Among the amine-functionalized SBA-15 materials, the SBA-15/TMSPDETA showed the highest removal activity given its high reactivity with formaldehyde.     

Q-factor enhancement in a one-dimensional photonic crystal cavity with embedded planar plasmonic metamaterials

We report Q-factor enhancement in a one-dimensional (1D) photonic crystal (PC) cavity by embedding electromagnetic-induced-transparency (EIT) planar plasmonic metamaterials in the cavity. Microwave experiments show tenfold Q-factor enhancements, confirming the numerical simulations. More importantly, the Q-factor enhancement is mainly due to both the longitudinal and lateral confinements contributed by the 1D PC cavity and the planar EIT metamaterials, respectively. The combined PC-EIT structure with a prominent cavity figure of merit may find new applications in nonlinear optics, cavity quantum electrodynamics, and low-threshold lasers.     

Spacer effects on in vivo properties of DOTA-conjugated dimeric [Tyr3]octreotate peptides synthesized by a "Cu(I)-click" and "sulfo-click" ligation method

We report on the SSTR2-binding properties of a series of four dimeric [Tyr3]octreotate analogues with different spacer lengths (nine, 19, 41, and 57 atoms) between the peptides. Two analogues (9 and 57 atoms) were selected as precursors for the design, synthesis, and biological evaluation of DOTA-conjugated dimeric [Tyr3]octreotate analogues for tumor targeting. These compounds were synthesized by using a two-stage click ligation procedure: a Cu(I) -catalyzed 1,3-dipolar cycloaddition ("copper-click" reaction) and a thio acid/sulfonyl azide amidation ("sulfo-click" reaction). The IC(50) values of these DOTA-conjugated [Tyr3]octreotate analogues were comparable, and internalization studies showed that the nine-atom (111) In-DOTA-labeled [Tyr3]octreotate dimer had rapid and high receptor binding. Biodistribution studies with BALB/c nude mice bearing subcutaneous AR42J tumors showed that the (111) In-labeled [Tyr3]octreotate dimer (nine atoms) had a high tumor uptake at 1 h p.i. (38.8 ± 8.3 % ID g(-1) ), and excellent tumor retention at 4 h p.i. (40.9 ± 2.5 % ID g(-1) ). However, the introduction of the extended hydrophilic 57 atoms spacer led to rapid clearance from the circulation; this limited tumor accumulation of the radiotracer (21.4 ± 4.9 % ID g(-1) at 1 h p.i.). These findings provide important insight on dimerization and spacer effects on the in vivo properties of DOTA-conjugated [Tyr3]octreotate dimers.     

Dye-sensitized solar cells based on electrospun poly(vinylidenefluoride-co-hexafluoropropylene) nanofibers

Poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers were prepared by the electrospinning method and used as polymer electrolytes in dye-sensitized solar cells (DSSCs). The electrolyte uptake and ionic conductivity of electrospun PVDF-HFP nanofibers with different diameters changed significantly, regardless of the nanofiber thickness. The PVDF-HFP nanofibers prepared from a 15 wt% spinning solution showed high ionic conductivity (1.295 S/cm) and electrolyte uptake (947 %). DSSCs based on the 15 wt% PVDF-HFP nanofiber electrolyte showed an electron transit time of 6.34 × 10^?3 s, electronic recombination time of 5.88 × 10^?2 s, and conversion efficiency of 3.13 %. Thus, we concluded that the electrospun PVDF-HFP nanofibers can be used as polymer electrolytes in flexible DSSCs as well.