Crystallization kinetics of poly(1,4‐butylene‐co‐ethylene terephthalate)

The crystallization kinetics of poly(butylene terephthalate) (PBT), poly(ethylene terephthalate) (PET), and their copolymers poly(1,4‐butylene‐co‐ethylene terephthalate) (PBET) containing 70/30, 65/35 and 60/40 molar ratios of 1,4‐butanediol/ethylene glycol were investigated using differential scanning calorimetry (DSC) at crystallization temperatures (T_c) which were 35–90 °C below equilibrium melting temperature . Although these copolymers contain both monomers in high proportion, DSC data revealed for copolymer crystallization behaviour. The reason for such copolymers being able to crystallize could be due to the similar chemical structures of 1,4‐butanediol and ethylene glycol. DSC results for isothermal crystallization revealed that random copolymers had a lower degree of crystallinity and lower crystallite growth rate than those of homopolymers. DSC heating scans, after completion of isothermal crystallization, showed triple melting endotherms for all these polyesters, similar to those of other polymers as reported in the literature. The crystallization isotherms followed the Avrami equation with an exponent n of 2–2.5 for PET and 2.5–3.0 for PBT and PBETs. Analyses of the Lauritzen–Hoffman equation for DSC isothermal crystallization data revealed that PBT and PET had higher growth rate constant G_o, and nucleation constant K_g than those of PBET copolymers. © 2001 Society of Chemical Industry     

B6 Mouse Strain: The Best Fit for LPS-Induced Interstitial Cystitis Model

Interstitial cystitis (IC) is a chronic inflammatory disease characterized by bladder pain and increased urinary frequency. Although the C57BL/6J (B6) and FVB/NJ (FVB) mouse strains are commonly used as animal models for studies involving the urinary system, few reports have compared their lower urinary tract anatomy, despite the importance of such data. Our study aimed to characterize bladder function changes in FVB and B6 mouse strains with lipopolysaccharide (LPS)-induced IC, to understand mouse model-based bladder research. The bladder function parameters were measured by cystometrogram. Histological assay was examined by hematoxylin and eosin stain, Masson’s trichrome stain, and immunofluorescence staining. Results indicated that the two strains in the control group exhibited different bladder structures and functions, with significant anatomical differences, including a larger bladder size in the FVB than in the B6 strain. Furthermore, cystometry tests revealed differences in bladder function pressure. LPS-treated B6 mice presented significant changes in peak pressure, with decreased intercontraction intervals; these results were similar to symptoms of IC in humans. Each strain displayed distinct characteristics, emphasizing the care required in choosing the appropriate strain for bladder-model studies. The results suggested that the B6 mouse strain is more suitable for IC models.     

Chemical stability and electrical and mechanical properties of BaZrxCe0.8-xY0.2O3 with CeO2 protection method

This study investigated the decline in the conductivity and mechanical strength after CO₂ poisoning and found a new protective method for BaZr_xCe_0.8-xY_0.2O₃ proton-conducting electrolyte. The high temperature solid state reaction (SSR) was used in synthesizing electrolyte to naturally generate CeO₂ on the surface. A comparison of the oxides in the conductivity decline test revealed that the sample with CeO₂ on the surface substantially improved the stability of conductivity, reducing the decline ratio from 56% to 7% for BCY electrolyte and 50% to 7% for BCZY sample. Raman mapping results indicate the naturally generated CeO₂ on electrolyte surface can considerably reduce impurity formation and maintain the microstructure of electrolyte. This work demonstrates that samples with CeO₂ on the surface effectively protect the BaCeO₃-based proton-conducting electrolyte from CO₂ poisoning. This method may be applied to similar BaCeO₃-based perovskite materials as a new protective method.     

Solar cell efficiency tables (version 16)

Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since January 2000 are reviewed. Copyright © 2000 John Wiley & Sons, Ltd.     

Influence of edge-distance ratio and hole-size ratio on bearing strength of poly(ether ether ketone) and its composites

The influence of edge-distance ratio (E/D) and hole-size ratio (S/D) on the bearing strength and failure modes of three kinds of poly(ether ether ketone) were investigated using the pin-type test method (ASTM E238). The results showed that bearing strength increased with increasing E/D and with increasing S/D. In addition, the bearing strength and failure mode depended on the polymer molecular weight and carbon fiber content. The study also showed that there is a transition region for S/D or E/D between 2 and 3 where the tension and a combination failure mode are mutually changed. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1847–1853, 1997     

Differential Retinal Protein Expression in Primary and Secondary Retinal Ganglion Cell Degeneration Identified by Integrated SWATH and Target-Based Proteomics

To investigate the retinal proteins associated with primary and secondary retinal ganglion cell (RGC) degeneration and explore their molecular pathways, SWATH label-free and target-based mass spectrometry was employed to identify the proteomes in various retinal locations in response to localized optic nerve injury. Unilateral partial optic nerve transection (pONT) was performed on adult Wistar rats and their retinas were harvested 2 weeks later. To confirm the separation of primary and secondary RGC degeneration, immunohistochemistry of RNA binding protein with multiple splicing (RBPMS) and glial fibrillary acidic protein (GFAP) was performed on retinal whole-mounts. Retinal proteomes in the temporal and nasal quadrants were evaluated with high resolution hybrid quadrupole time-of-flight mass spectrometry (QTOF-MS), and SWATH-based acquisition, and their expression was compared to the corresponding retinal quadrant in contralateral control eyes and further validated by multiple reaction monitoring mass spectrometry (MRM-MS). A total of 3641 proteins (FDR < 1%) were identified using QTOF-MS. The raw data are available via ProteomeXchange with the identifier PXD026783. Bioinformatics data analysis showed that there were 37 upregulated and 25 downregulated proteins in the temporal quadrant, whereas 20 and five proteins were upregulated and downregulated, respectively, in the nasal quadrant, respectively (n = 4, p < 0.05; fold change ≥ 1.4-fold or ≤0.7). Six proteins were regulated in both the temporal and the nasal quadrants, including CLU, GFAP, GNG5, IRF2BPL, L1CAM, and CPLX1. Linear regression analysis indicated a strong association between the data obtained by means of SWATH-MS and MRM-MS (temporal, R² = 0.97; nasal, R² = 0.96). Gene ontology analysis revealed statistically significant changes in the biological processes and cellular components of primary RGC degeneration. The majority of the significant changes in structural, signaling, and cell death proteins were associated with the loss of RGCs in the area of primary RGC degeneration. The combined use of SWATH-MS and MRM-MS methods detects and quantifies regional changes of retinal protein expressions after localized injury. Future investigation with this integrated approach will significantly increase the understanding of diverse processes of progressive RGC degeneration from a proteomic prospective.     

Analysis of flow field around a ribbed helix lip seal

In this study, a direct numerical simulation model has been developed to elucidate the pumping mechanism of a radial lip seal with helical ribs. The flow field around the contact region between the seal lip and the shaft surface in the environment of a pumping-rate test rig, where both air and oil sides are filled with oil initially, was simulated. The streamline pattern and pressure field around the seal lip were examined. Complicate three-dimensional streamline topology was depicted. On the air side, high pressures built up on the windward faces of ribbed helices next to the lip helping to pump oil back to the sump. The vortex generated next to the lip on the oil side rotates such to create an inward pumping effect too. The pumping rates were calculated at shaft speeds, ranging from 2000 to 6000 rpm, and compared to the measured values from the test rig. Good agreement was observed. Both calculated and measured pumping rates increase as the shaft speed increases. The current results demonstrate the promising application of CFD in the design of radial lip seals.     

Response surface methodology optimisation of immobilised Lactobacillus acidophilus banana puree fermentation

Fermentation temperature (34–40 °C), total inoculum level (1%–3%, v/v) and peeled-fruit-to-water ratio (12.5%–37.5%, w/v) were combined to study their effects on the fermentation of banana media by free and Ca-alginate or κ-carrageenan-immobilised Lactobacillus acidophilus. A three-variable and three-level design method, analysed by response surface methodology (RSM), was used. These factors, except peeled-fruit-to-water ratio, were found to be significantly effective on viable cell numbers and 1-kestose (GF₂) concentrations. Contour plots were generated using a graphing software package (Surfer Mapping System, Version 5.0; Golden Software Inc., Golden, CO, USA, 1994) based on fitted quadratic regression equations. Optimum conditions for the highest viable cell number and higher GF₂ concentration were found to be around 35 °C fermentation temperature, 1.2% inoculum level and 25.0% peeled-fruit-to-water ratio for Ca-alginate immobilised cell fermentation, and around 39 °C fermentation temperature, 1.8% inoculum level and 25.0% peeled-fruit-to-water ratio for κ-carrageenan immobilised cell fermentation. For free cell fermentation, conditions for the highest viable cell number and higher GF₂ concentration could not be obtained. The predicted optimum conditions of immobilised cell fermentation and the experimental values were consistent. This verified the adequacy of these predicted models. It was concluded that RSM was appropriate for the optimisation of banana puree fermentation using cell immobilised L. acidophilus , and products with better synbiotic effects could be obtained. The consumer palatability of the immobilised cell-fermented banana puree was found to be acceptable.     

Influence of transportation stress and animal temperament on fecal shedding of Escherichia coli O157:H7 in feedlot cattle

To test the influence of transportation stress and temperament on shedding of Escherichia coli O157:H7, cattle (n=150) were classified at various stages of production as Excitable, Intermediate or Calm based on a variety of disposition scores. Presence of E. coli O157:H7 was determined by rectal swabs from live animals and from colons collected postmortem. Percentage of cattle shedding E. coli O157:H7 at arrival at the feedlot was approximately equal among temperament groups. Before shipment to the processing facility, a higher (P=0.03) proportion of cattle from the Calm group shed E. coli O157:H7 compared to the other temperament groups. When pooled across all sampling periods, cattle from the Calm group had a greater percentage test positive for E. coli O157:H7. Neither the acute stressor of transportation nor a more excitable temperament led to increased shedding of E. coli O157:H7 in cattle.