Effect Of High Temperature Processing Research Articles

Hydroxypropyl methyl cellulose derivatives stabilize fragment antibody against aggregation in spray dried formulations at elevated temperature and resist pH changes

The ability to deliver stable and active dried protein therapeutics from biopharmaceutical drug delivery systems is critical for solid dosage formulation development. Spray dried formulations with carefully selected excipients provide a unique opportunity in amorphous phase stabilization of the therapeutic proteins. Herein, we discuss the role of hydroxypropyl methylcellulose acetate succinate (HPMCAS) derivatives as polymeric excipients for stabilizing a model fragment antibody (Fab2) during high temperature processing and in possible low pH environments of a drug delivery platform. The effects of high temperature processing and microenvironmental pH sensitivity are of particular interest to us due to their adverse impact on stability of molecules that demonstrate temperature and pH dependent inactivation within drug delivery devices. It appears in solid state at 90 °C and 37 °C and within low pH micro-environment HPMCAS protects protein against aggregation. The high temperature performance of HPMCAS is comparable to that of a disaccharide excipient like trehalose in spray dried protein powder. Simultaneously, inside a poly(lactic-co-glycolic acid) (PLGA) based delivery system HPMCAS provides protection to a pH sensitive protein against acidic degradation products from aqueous hydrolysis of PLGA.

Evaluation of confirmatory data following the Article 12 MRL review for chlorothalonil, including assessments for import tolerances for banana, papaya and peanuts

The applicants Syngenta Crop Protection, UPL Europe Ltd. and Oxon Italia S.p.A. submitted requests to the competent national authority in the Netherlands to evaluate the confirmatory data for chlorothalonil that were identified in the framework of the MRL review under Article 12 of Regulation (EC) No 396/2005 as not available; in addition, Syngenta and UPL submitted requests for modifications of existing MRLs. Considering the recent decision on the non‐approval of chlorothalonil, the requests for amending existing MRLs to reflect intended EU uses for chlorothalonil and confirmatory data for EU uses became obsolete. EFSA focused therefore its assessment on the import tolerances and on general information on the analytical method required to enforce legal limits for chlorothalonil and its metabolite SDS‐3701 (R182281). Analytical methods for enforcement are available to control the residues of chlorothalonil and SDS‐3701 in plant matrices at the validated LOQ of 0.01 mg/kg; data on the extraction efficiency for high oil content matrices as requested in the MRL review were not provided. This data gap is relevant for the import tolerance for peanuts. The data submitted in support of import tolerances were found to be sufficient to derive MRL proposals for chlorothalonil and SDS‐3701 for bagged bananas, papayas and peanuts. Studies investigating the effect of high temperature processing on the magnitude of SDS‐3701 in processed products are not available. Based on exposure calculations for chlorothalonil, EFSA concluded that the long‐term intake of residues resulting from the use of chlorothalonil according to the reported agricultural practices is unlikely to present a risk to consumers. For papaya, an acute intake concern was noted for chlorothalonil, while for banana and peanuts, the expected short‐term intake of chlorothalonil residues was below the toxicological reference value. For the metabolite SDS‐3701, the toxicological profile is not fully elucidated, and therefore, toxicological reference values could not be derived. Hence, for this metabolite, the consumer risk assessment cannot be finalised.

Effect of high temperature processing under different environments on physical and surface properties of rubberwood (Hevea brasiliensis)

Plantation grown Hevea brasiliensis (rubberwood) was thermally processed in a vacuum-pressure oven in the temperature range of 150–240 °C under two inert environments (vacuum and nitrogen gas) and normal atmospheric pressure (air). Effect of heat treatments on various physical properties of rubberwood such as equilibrium moisture content (EMC), specific gravity, water uptake, shrinkage, colour and surface roughness profiles was evaluated and compared with untreated wood. The EMC of rubberwood was found to be reduced by almost half while specific gravity was reduced slightly after heat treatment. The intensity of darker brown colour was increased with increasing heat treatment temperatures and colour change was observed to be uniform throughout the wood blocks. Dimensional stability, water resistance, colour and surface quality were observed to be improved after thermal processing of rubberwood at moderately high temperatures under inert environments without affecting other properties deleteriously. Based on improved properties, heat treated rubberwood was found to be suitable for nonstructural applications such as flooring, siding, paneling etc.

The effects of high temperature processing on the structural and optical properties of oxygenated CdS window layers in CdTe solar cells

High efficiency CdTe solar cells typically use oxygenated CdS (CdS:O) window layers. We synthesize CdS:O window layers at room temperature (RT) and 270 °C using reactive sputtering. The band gaps of CdS:O layers deposited at RT increase when O2/(O2 + Ar) ratios in the deposition chamber increase. On the other hand, the band gaps of CdS:O layers deposited at 270 °C decrease as the O2/(O2 + Ar) ratios increase. Interestingly, however, our high temperature closed-space sublimation (CSS) processed CdTe solar cells using CdS:O window layers deposited at RT and 270 °C exhibit very similar cell performance, including similar short-circuit current densities. To understand the underlying reasons, CdS:O thin films deposited at RT and 270 °C are annealed at temperatures that simulate the CSS process of CdTe deposition. X-ray diffraction, atomic force microscopy, and UV-visible light absorption spectroscopy characterization of the annealed films reveals that the CdS:O films deposited at RT undergo grain regrowth and/or crystallization and exhibit reduced band gaps after the annealing. Our results suggest that CdS:O thin films deposited at RT and 270 °C should exhibit similar optical properties after the deposition of CdTe layers, explaining the similar cell performance.

Control Effect of High Temperature Processing and Insecticide Application against Thrips tabaci on Chinese Chive Plants

Control Effect of High Temperature Processing and Insecticide Application against <i>Thrips tabaci</i> on Chinese Chive Plants

Effect of high-temperature processing on the creation of boron-related deep levels in 4H-SiC

High-temperature processing was applied to SiC boron-doped epitaxial layers, epitaxial layers grown on boron-rich substrates, and boron-implanted samples in order to establish conditions favorable for the formation of boron-related centers (D-centers) that introduce a deep level in SiC bandgap. Photoluminescence (PL) was used to detect and compare the formation of the D-center after different processing steps. It was confirmed that the presence of lattice defects was required for achieving significant boron diffusion and D-center formation. In addition, epitaxial growth on the top of a boron-implanted sample yielded efficient boron in-diffusion in the growing layer, which resulted in a material compensated with D-centers. The temperature dependence of the D-center formation efficiency was investigated.

Annealing effect on spin-valve sensor transfer curves

Unshielded spin-valve sensors were fabricated and annealed to study the effect of high temperature processing on the transfer curves. A micromagnetic simulation program was developed to analyze the changes observed on the transfer curves upon annealing. Analysis of experimental data versus the micromagnetic simulations indicates two causes responsible for the progressive loss of the MR signal upon annealing above the blocking temperature: a rotation of the pinned layer magnetization from the transverse to the longitudinal direction (along the sensor trackwidth) and an increase of the free layer anisotropy. Rotation of the free layer easy axis can also be observed. Cool down in a magnetic field can prevent this MR loss by pinning the magnetization direction during the high temperature stage.

Effects of Process Temperature on Polysilicon Thin Film Transistors with Liquid‐Phase Deposited Oxides as Gate Insulators

Liquid‐phase deposited (LPD) oxide has previously been successfully applied to low temperature processed polysilicon thin film transistors (poly‐Si TFTs) as a gate insulator. This paper shows the feasibility of applying room temperature deposited LPD oxide to high temperature processed devices. The thermal effects of high temperature processing on poly‐Si TFTs including postoxide annealing and dopant activation have been investigated. These high temperature treatments show excellent improvement in device characteristics. In addition, the novel devices also show considerably more efficient hydrogenation during ‐plasma treatment, and their reliability under dc electrical stress appears similar to that of conventional poly‐Si TFTs.

Evidence of negative charge trapping in high temperature annealed thermal oxide

The effect of high temperature processing of Si/SiO/sub 2//Si sandwich structures has been studied on a thermal dry oxide, by considering charge trapping after irradiation. The radiation-induced charge trapping is shown to be very different in annealed and unannealed structures. The latter reveal interfacial trapping behavior, whereas annealed structures exhibit a large trapping of both holes and electrons in the bulk of the oxide, similar to SIMOX oxide behavior.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Effect of high temperature processing of Si/SiO2/Si structures on their response to x-ray irradiation

The radiation response of Si/SiO2/ Si structures subjected to x-ray irradiation in the presence and absence of applied electric field has been studied as a function of accumulated dose. High temperature annealing of sandwiches involving thermally grown oxide results in a softening of the radiation response, evidence for both hole and electron trapping is found. Similar behavior is found in buried oxide layers produced by O+ implantation, then subjected to high temperature annealing. Evidence for majority hole trapping is found in unannealed, thermal oxide. It is suggested that high temperature annealing results in a reduction of the oxide which is driven by the Si/SiO2 interface, resulting in electron and hole trap generation.

Effect of High-Temperature Processing on the Aging Behavior of Precision 5-MHz Quartz Crystal Units

The influence of contamination level on the aging behavior of quartz crystal resonators has been studied. Resonators were made using high-temperature bonding techniques and were baked prior to sealing in both dry hydrogen and under high vacuum in order to minimize the level of contamination within the enclosure. The initial stabilization period for the frequency drift rate to reach 3 parts per 1010/month and the period to restabilize after power interruption to oven and oscillator is usually less than a week for these units. The time periods to reach the same drift rate for units made using the current state-of-the-art fabrication tecnhiques range from one to six months. The difference in aging behavior is discussed in terms of a possible aging mechanism.

The effect of high-temperatu re processing on the surface strength of glass

The effect of high-temperatu re processing on the surface strength of glass