Poly(methyl methacrylate)‐grafted cellulose nanocrystals: One‐step synthesis,nanocomposite preparation,and characterization

Cellulose nanocrystals (CNCs) are ideal reinforcing agents for polymer nanocomposites because they are lightweight and nano‐sized with a large aspect ratio and high elastic modulus. To overcome the poor compatibility of hydrophilic CNCs in non‐polar composite matrices, we grafted poly(methyl methacrylate) (PMMA) from the surface of CNCs using an aqueous, one‐pot, free radical polymerization method with ceric ammonium nitrate as the initiator. The hybrid nanoparticles were characterized by CP/MAS NMR, X‐ray photoelectron spectroscopy, infrared spectroscopy, contact angle, thermogravimetric analysis, X‐ray diffraction, and atomic force microscopy. Spectroscopy demonstrates that 0.11 g/g (11 wt %) PMMA is grafted from the CNC surface, giving PMMA‐g‐CNCs, which are similar in size and crystallinity to unmodified CNCs but have an onset of thermal degradation 45 °C lower. Nanocomposites were prepared by compounding unmodified CNCs and PMMA‐g‐CNCs (0.0025–0.02 g/g (0.25–2 wt %) loading) with PMMA using melt mixing and wet ball milling. CNCs improved the performance of melt‐mixed nanocomposites at 0.02 g/g (2 wt %) loading compared to the PMMA control, while lower loadings of CNCs and all loadings of PMMA‐g‐CNCs did not. The difference in Young's modulus between unmodified CNC and polymer‐grafted CNC composites was generally insignificant. Overall, ball‐milled composites had inferior mechanical and rheological properties compared to melt‐mixed composites. Scanning electron microscopy showed aggregation in the samples with CNCs, but more pronounced aggregation with PMMA‐g‐CNCs. Despite improving interfacial compatibility between the nanoparticles and the matrix, the effect of PMMA‐g‐CNC aggregation and decreased thermal stability dominated the composite performance.     

Production of aromatics by catalytic fast pyrolysis of cellulose in a bubbling fluidized bed reactor

Catalytic fast pyrolysis of cellulose was studied at 500°C using a ZSM‐5 catalyst in a bubbling fluidized bed reactor constructed from a 4.92‐cm ID pipe. Inert gas was fed from below through the distributor plate and from above through a vertical feed tube along with cellulose. Flowing 34% of the total fluidization gas through the feed tube led to the optimal mixing of the pyrolysis vapors into the catalyst bed, which experimentally corresponded to 29.5% carbon aromatic yield. Aromatic yield reached a maximum of 31.6% carbon with increasing gas residence time by changing the catalyst bed height. Increasing the hole‐spacing in the distributor plate was shown to have negligible effect on average bubble diameter and hence did not change the product distribution. Aromatic yields of up to 39.5% carbon were obtained when all studied parameters were optimized. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1320–1335, 2014     

Polyphenol conjugated poly(beta-amino ester) polymers with hydrogen peroxide triggered degradation and active antioxidant release

Oxidative stress has been implicated as a primary or secondary player to numerous diseases. A potential approach to control oxidative stress induced diseases is to deliver small antioxidant compounds to compromised sites at equivalent rates of reactive oxygen species (ROS) generation. This becomes a complicated task as antioxidant molecules typically have poor bioavailability and stability. Antioxidants synthesized into poly(beta-amino ester) (PBAE) crosslinked polymers have shown improved delivery by enhancing stability while allowing controlled release through hydrolysis. The tunable crosslinked networks show significant response to specific oxidizing environments, where free radicals can be present. Curcumin conjugated PBAE bulk films have proportional rates of accelerated degradation, thus faster release of curcumin, in a range of low concentrations of hydrogen peroxide (H₂O₂)_, where 2′2-azobis(2-amidinopropane) dihydrochloride has no substantial impact. This effect suggests the possibility to create a system that releases its therapeutic agent in direct relationship to the need through ROS signaling. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48647.     

Salmonella in uncooked retail meats in New Zealand

A national quantitative survey of Salmonella in five types of uncooked retail meats in New Zealand was undertaken from August 2003 to May 2005 to establish baseline proportionality data. The overall prevalence of Salmonella in 1,108 meat samples was 1.1% (95% confidence interval, 0.6 to 1.9). Low prevalences of Salmonella in each meat type were observed, with 3% (1.2 to 6.1) in chicken, 1.3% (0.3 to 3.8) in lamb and mutton, 0.5% (0 to 3.0) in unweaned veal, 0.4% (0 to 2.4) in beef, and 0% (0 to 1.6) in pork. The Salmonella serotypes isolated were Salmonella Infantis from beef; Salmonella Typhimurium PT1 from unweaned veal and chicken; Salmonella sp. 6,7:k:-, Salmonella Enteritidis PT9a, Salmonella sp. 4,5,12:-:-, Salmonella sp. 4,12:-:-, and Salmonella Typhimurium PT160 from chicken; and Salmonella sp. 4:-:2 and Salmonella Brandenburg from lamb. Four of the isolates from chicken, Salmonella sp. 4,5,12:-:- (two isolates), Salmonella sp. 4,12:-:-, and Salmonella Typhimurium PT1, were very similar phenotypically and serologically to the attenuated Salmonella vaccine strain used in MeganVacl for poultry. One lamb sample yielded a count of Salmonella Brandenburg of 4.24 most probable number (MPN)/g, while all other positive samples were <1.0 MPN/g. The results provide baseline proportionality data for Salmonella in retail uncooked meats that will contribute invaluably toward future risk assessment in light of other information, such as consumption data that can be used for risk characterization.     

Authenticity Assessment of Extra Virgin Olive Oil: Evaluation of Desmethylsterols and Triterpene Dialcohols

Extra virgin olive oil (EVOO) has a long history of economic adulteration, the detection of which presents significant challenges due to the diverse composition of cultivars grown around the world and the limitations of existing methods for detecting adulteration. In this study, using Method COI/T.20/Doc. No. 30/Rev. 1 of the International Olive Council, the authenticity of 88 market samples of EVOO was evaluated by comparing total sterol contents, desmethylsterol composition, and contents of triterpene dialcohols (erythrodiol and uvaol) with purity criteria specified in the United States Standards for grades of olive oil and olive‐pomace oil. Three of the 88 samples labeled as EVOO failed to meet purity criteria, indicating possible adulteration with commodity oil and/or solvent‐extracted olive oil. Detection of adulteration was also evaluated by spiking an EVOO sample with commodity oil at the 10 % level. As expected, eight of the spiked samples (canola, corn, hazelnut, peanut, safflower, soybean, and sunflower oils, and palm olein) failed to meet purity criteria. Two of the three samples spiked with 10 % hazelnut oil went undetected for adulteration. Overall, a low occurrence rate of adulteration (<5 %), based on purity criteria for desmethylsterols and triterpene dialcohols, was detected for the 88 products labeled as EVOO.     

Olfactory responses ofIps plastographus maritimus lanier (coleoptera: Scolytidae) to insect and host-associated volatiles in the laboratory

Attraction of both sexes ofIps plastographus maritimus Lanier to bark-phloem-xylem discs of Monterey pine,Pinus radiata D. Don, was demonstrated in the laboratory. Increasing concentrations of male and female volatiles trapped separately and released in a one-to-one ratio decreased attraction for both sexes combined. Attraction of both sexes to volatiles derived from males and females tunneling together in a one-to-one ratio increased with increasing concentration of extract. Attraction of males and females to male-infested discs and to trapped male volatiles increased with increasing dose of males or male extract. Attraction of males and females to female-infested discs and to trapped female volatiles was also demonstrated. The presence of females in male galleries reduced the attractiveness of infested disks to both sexes combined. Increasing numbers of females, tunneling separately from males in the same disc, reduced attraction of males, but not females. When a constant attractive dose of male volatiles was released with increasing doses of female volatiles, there was no difference in response of either sex when female volatiles were present compared with the response to male volatiles alone. When a constant attractive dose of male volatiles was released with increasing concentrations of volatiles derived from males and females tunneling together in a one-to-one ratio, attraction ofI. p. maritimus decreased. Response of females was frequently higher than that of males to the same attractant source. Hence, both sexes produce an attractant, and both sexes tunneling together in the same gallery reduce attraction of males and females to an attractive dose of male attractant.     

Global optimality properties of total annualized and operating cost problems for compressor sequences

The minimum total annualized cost problem for a series of nonisentropic compressors and coolers that brings a gas with constant compressibility factor from a specified initial pressure and temperature to a specified final pressure and the same temperature is studied in this work. It is established analytically that at the global optimum, the cooler outlet temperatures are equal to the minimum allowable temperature. For constant heat capacity, constant compressibility factor gases, additional properties of the globally optimal compressor sequence are analytically established for the minimum operating cost case. The aforementioned properties permit development of a solution strategy that identifies the globally minimum operating cost. Several case studies are presented to illustrate the developed theorems and solution strategies. © 2014 American Institute of Chemical Engineers AIChE J 60: 4134–4149, 2014     

Prevalence and sequelae of betrayal trauma in a Japanese student sample.

The aims of this study were to test predictions of betrayal trauma theory (Freyd, 1996) in a non-Western culture and to contribute to the limited empirical literature on child abuse in Japan. Per betrayal trauma theory, high betrayal trauma is abuse perpetrated by someone close to the victim, medium betrayal trauma is abuse perpetrated by someone not close, low betrayal trauma involves no identifiable perpetrator, and as level of betrayal increases so does posttraumatic distress and trauma-related memory disruption. Seventy-nine Japanese university students completed an anonymous online survey of trauma experiences, psychological health and cultural values. It was hypothesized that high betrayal childhood abuse (physical, sexual, and emotional maltreatment and/or neglect) would predict greater psychological distress and trauma-related memory disruption than would medium betrayal trauma and these hypotheses were partially supported. Endorsement of traditional Asian cultural values (e.g., interpersonal harmony) was not a significant moderator on the betrayal effects found. The findings partially support predictions of betrayal trauma theory in a non-Western culture and have intervention and prevention implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

“优化之道”洞悉IT服务质量

“优化之道”的每个阶段都规定了在成本和技术可逐步实现的步骤，从而使得企业逐渐实现IT服务优化和完全实现业务服务管理。     

Intact and impaired mechanisms of action understanding in autism.

Typically developing children understand and predict others' behavior by extracting and processing relevant information such as the logic of their actions within the situational constraints and the intentions conveyed by their gaze direction and emotional expressions. Children with autism have difficulties understanding and predicting others' actions. With the use of eye tracking and behavioral measures, we investigated action understanding mechanisms used by 18 children with autism and a well-matched group of 18 typically developing children. Results showed that children with autism (a) consider situational constraints in order to understand the logic of an agent's action and (b) show typical usage of the agent's emotional expressions to infer his or her intentions. We found (c) subtle atypicalities in the way children with autism respond to an agent's direct gaze and (d) marked impairments in their ability to attend to and interpret referential cues such as a head turn for understanding an agent's intentions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)