Climate Change Implications of Bio-Based and Marine-Biodegradable Plastic: Evidence from Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate).

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), PHBH or PHBHHx, is a novel bio-based polymer that is biodegradable in both soil and marine environments. While bio-based and biodegradability are often celebrated features to mitigate environmental problems of plastics, their life cycle environmental impacts contain uncertainties that are yet to be fully understood. To develop effective introduction schemes for PHBH, this study assessed the life cycle climate change implications of PHBH. We computed the life cycle greenhouse gas emissions (GHG) and fossil resource consumption of produce bags and spoons composed of PHBH and their fossil-based alternatives based on industrial-scale data. The products were assessed against 10 end-of-life scenarios for commercial plastics. As a result, the cradle-to-gate GHG of PHBH ranged between 0.32 and 16.5 kgCO2e/kg-PHBH depending on the land-use change assumed for the biomass production. The product-based comparative analysis presented that PHBH spoons have lower cradle-to-grave GHG emissions over their fossil-based alternatives but not with produce bags because PHBH spoons have a smaller GHG per functional unit than that of its fossil counterpart. The end-of-life scenario analysis conveyed that PHBH should be introduced to a region with a plastic waste management system that avoids methane generation and facilitates energy recovery.

Design-oriented regression models for H2O2 decontamination processes in sterile drug product manufacturing considering rapidity and sterility.

We developed regression models for designing rapid and effective H2O2 decontamination processes in the manufacturing of sterile drug products such as injectables. Decontamination, which is typically performed by using H2O2, is a critical changeover process used to establish a sterile environment for filling products. In the process, there is a trade-off relationship between the duration of the process and the level of sterility assurance that needs to be considered in the design. Our model defines these two items as objective functions and the parameters describing the profile of H2O2 injection and the initial humidity as design variables. Our model also considers aeration, i.e., removal of H2O2 from the environment, as a part of the entire process. This design-oriented modeling considering the entire process is the novelty of the work. Experiments were performed using an industrial isolator to develop and validate a set of regression models that describe the relationship between the design variables and the objective functions. In the application of the model, Pareto-optimal conditions could be indicated given the target H2O2 concentration in aeration, which is useful for the makers of drugs and/or isolators for designing decontamination processes.

Evaluating nanotechnology opportunities and risks through integration of life-cycle and risk assessment.

It has been some 15 years since the topics of sustainability and nanotechnologies first appeared together in the scientific literature and became a focus of organizations' research and policy developments. On the one hand, this focus is directed towards approaches and tools for risk assessment and management and on the other hand towards life-cycle thinking and assessment. Comparable to their application for regular chemicals, each tool is seen to serve separate objectives as it relates to evaluating nanotechnologies' safety or resource efficiency, respectively. While nanomaterials may provide resource efficient production and consumption, this must balance any potential hazards they pose across their life-cycles. This Perspective advocates for integrating these two tools at the methodological level for achieving this objective, and it explains what advantages and challenges this offers decision-makers while highlighting what research is needed to further enhance integration.

Accelerated crystallization of colloidal glass by mechanical oscillation.

Crystallization of a hard-sphere colloidal glass by mechanical oscillation is investigated, and accelerated crystallization is found at a specific frequency. The crystallization frequency increases as attractive force between particles increases, indicating that interparticle interaction affects the crystallization frequency. Time scale of the mechanical oscillation is different from that of the slow relaxation, and notable relationship with the low-frequency mode is not observed. The experimental results are not explained by the previously proposed model for crystallization by oscillatory shear. Conversely, we speculate that activations of the fast relaxation and particle motion in crystal-like clusters are possible causes of the observations.

Optimized Ultrasonic Irradiation Finds Out Ultrastable Aß1-40 Oligomers.

Oligomer species of amyloid ß (Aß) peptides are intensively investigated because of their relevance to Alzheimer's disease (AD), and a stable oligomer will be a cause of AD. In this article, we investigate the structural stability of two representative Aß1-40 oligomers, which are with and without the ß-sheet structure, denoted by ß and non-ß oligomers, respectively, using optimized ultrasonic irradiation (OUI). Recent studies reveal that OUI significantly accelerates the fibril formation in Aß1-40 monomers; it is capable of transforming any unstable oligomers into fibrils (the dead-end products) in a short time. First, we find that ß oligomers can be produced under high-speed stirring agitation; their ß-sheet structures are evaluated by the circular-dichroism spectrum measurement, by the immunoassay using the fibril-specific OC antibody, and by the seeding experiment, showing identical characteristics to those formed in previous reports. Second, we form non-ß oligomers in a high-concentration NaCl solution and confirm that they include no ß-sheet structure, and they are recognized by the oligomer-specific A11 antibody. Furthermore, we confirm the neurotoxicity of the two types of oligomers using the neural tissue derived from mouse embryonic stem cells. We apply the OUI agitation to the ß and non-ß oligomers. The non-ß oligomers are transformed into the fibrils, indicating that they are intermediate species in the fibrillation pathway. However, the ß oligomers are surprisingly unaffected by OUI, indicating their high thermodynamic stability. We conclude that the ß oligomers should be the independent dead-end products of another pathway, different from the fibrillation pathway.

Drastic acceleration of fibrillation of insulin by transient cavitation bubble.

Amyloid-fibril formation of proteins can be accelerated by ultrasonic irradiation to the peptide solutions. Although this phenomenon contributes to understanding pathogenic behavior of amyloidosis, its physical mechanism has not been clarified, because several factors (cavitation, temperature increase, stirring effect, and so on) related to ultrasonic irradiation can participate in the fibrillation reaction. Here, we independently study contributions of the possible factors, using insulin, which is extremely stable and then suitable for the mechanism clarification. We find that the optimized ultrasonic irradiation can drastically accelerate the fibrillation reaction; the time for completing the reaction is shortened compared with the high-speed (1200rpm) stirring agitation by a factor of 430. The fibrillation reaction proceeds only when the subharmonic-mode intensity exceeds a threshold, indicating generation of the transient cavitation bubbles. Our results reveal that not the temperature increase but the transient cavitation bubbles work as the dominant accelerator of the fibrillation reaction.

Thermal Mode Spectroscopy for Thermal Diffusivity of Millimeter-Size Solids.

Heat conduction possesses (thermal) modes in analogy with acoustics even without oscillation. Here, we establish thermal mode spectroscopy to measure the thermal diffusivity of small specimens. Local heating with a light pulse excites such modes that show antinodes at the heating point, and photothermal detection at another antinode spot allows measuring relaxation behavior of the desired mode selectively: The relaxation time yields thermal diffusivity. The Ritz method is proposed for arbitrary geometry specimens. This method is applicable even to a diamond crystal with ∼1 mm dimensions.

Nucleus factory on cavitation bubble for amyloid ß fibril.

Structural evolution from monomer to fibril of amyloid ß peptide is related to pathogenic mechanism of Alzheimer disease, and its acceleration is a long-running problem in drug development. This study reveals that ultrasonic cavitation bubbles behave as catalysts for nucleation of the peptide: The nucleation reaction is highly dependent on frequency and pressure of acoustic wave, and we discover an optimum acoustical condition, at which the reaction-rate constant for nucleation is increased by three-orders-of magnitudes. A theoretical model is proposed for explaining highly frequency and pressure dependent nucleation reaction, where monomers are captured on the bubble surface during its growth and highly condensed by subsequent bubble collapse, so that they are transiently exposed to high temperatures. Thus, the dual effects of local condensation and local heating contribute to dramatically enhance the nucleation reaction. Our model consistently reproduces the frequency and pressure dependences, supporting its essential applicability.

Ultrafast propagation of ß-amyloid fibrils in oligomeric cloud.

Interaction between monomer peptides and seeds is essential for clarifying the fibrillation mechanism of amyloid ß (Aß) peptides. We monitored the deposition reaction of Aß(1-40) peptides on immobilized seeds grown from Aß(1-42), which caused formation of oligomers in the early stage. The deposition reaction and fibrillation procedure were monitored throughout by novel total-internal-reflection-fluorescence microscopy with a quartz-crystal microbalance (TIRFM-QCM) system. This system allows simultaneous evaluation of the amount of deposited peptides on the surface seeds by QCM and fibril nucleation and elongation by TIRFM. Most fibrils reached other nuclei, forming the fibril network across the nucleus hubs in a short time. We found a fibril-elongation rate two-orders-of-magnitude higher in an oligomeric cloud than reported values, indicating ultrafast transition of oligomers into fibrils.

Calibration-free portable Young's-modulus tester with isolated langasite oscillator.

A ballpoint-pen-type portable ultrasonic oscillator is developed for quantitative measurement of Young's modulus on a solid. It consists of an electrodeless rod-shaped langasite oscillator with a tungsten-carbide spherical-shaped tip at the end, permanent magnets for making a constant force at the contact interface, and antennas for exciting and detecting the longitudinal vibration contactlessly. The resonance frequency of the oscillator is changed by contact with the specimen, reflecting Young's modulus of the specimen at the contact area. The langasite oscillator is supported at the nodal points so that its acoustical contact occurs only at the specimen, making a calibration-free measurement realistic. Young's moduli of various specimens were evaluated within 15% error just by touching the specimens with the probe. The error becomes smaller than 10% for lower Young-modulus materials (<∼150 GPa).

Observation of higher stiffness in nanopolycrystal diamond than monocrystal diamond.

Diamond is the stiffest known material. Here we report that nanopolycrystal diamond synthesized by direct-conversion method from graphite is stiffer than natural and synthesized monocrystal diamonds. This observation departs from the usual thinking that nanocrystalline materials are softer than their monocrystals because of a large volume fraction of soft grain-boundary region. The direct conversion causes the nondiffusional phase transformation to cubic diamond, producing many twins inside diamond grains. We give an ab initio-calculation twinned model that confirms the stiffening. We find that shorter interplane bonds along [111] are significantly strengthened near the twinned region, from which the superstiff structure originates. Our discovery provides a novel step forward in the search for superstiff materials.

Acceleration of deposition of Aß(1-40) peptide on ultrasonically formed Aß(1-42) nucleus studied by wireless quartz-crystal-microbalance biosensor.

High-frequency (~ 55 MHz) wireless quartz-crystal microbalance biosensor was used for studying heterogeneous deposition behavior of Aß(1-40) peptide on Aß(1-42) nuclei, which were grown under the stirring agitation and 200-kHz ultrasonication at pH 2.2, 4.6, and 7.4. The deposition reaction was monitored over 40 h, and the deposition rate was deduced. Among the agitation nuclei, the maximum deposition rate was observed on the nucleus grown at pH 4.6. However, ultrasonication nucleus grown at pH 7.4 produced much larger deposition rate, despite the same ß-sheet concentration. This result indicates that local structural modulation is caused in the nucleus by ultrasonication, which adsorbs the Aß peptide more actively than other nuclei. The resultant deposits clearly show oligomeric structure.

Resonance acoustic microbalance with naked-embedded quartz (RAMNE-Q) biosensor fabricated by microelectromechanical-system process.

A resonance acoustic microbalance with a naked-embedded quartz (RAMNE-Q) is realized by a microfabrication method, aiming at broader applications of quartz-crystal microbalance (QCM) biosensors. The RAMNE-Q biosensor consists of three layers; a silicon layer with an engraved microchannel and sandwiching glass layers. The naked AT-cut quartz resonator of 9.3 or 28.5 µm thick is located in the microchannel and supported by the silicon micropillars and semicircular walls without fixing, and it is encapsulated by the rigid body. Cupper antennas are used for generating and receiving electromagnetic fields to excite and detect the shear vibration of the quartz oscillator during the solution flow, thereby achieving the noncontact measurement of the resonance frequency. Because of the isolated resonator, the Q factor is high enough (about 1500 at 170-180 MHz) even in the flowing solution. We succeeded in detecting 1 ng/ml human immunoglobulin G in phosphate-buffered-saline solution via Staphylococcus aureus protein A immobilized nonspecifically on the quartz surfaces, demonstrating the high sensitivity and high signal-to-noise ratio of the RAMNE-Q biosensor. It does not require electrodes and is a replacement-free biosensor, and its reusability is confirmed.

Monitoring and analysis of solvent emissions from metal cleaning processes for practical process improvement.

OBJECTIVES: Industrial cleaning processes are a major source of emissions of chlorinated organic solvents in Japan. Solvent emission mechanisms from metal cleaning processes were analysed to support process improvement aimed at emission reductions. METHODS: The amounts of solvents directly emitted from a washing machine and solvents taken out by metal parts to be cleaned were measured in laboratory experiments using an industrial washing machine. Direct emissions to a local ventilation system and to the workplace were analysed, while several process conditions were changed. The drying rate of solvents on surfaces was analysed for seven metal parts to clarify the effects of their materials and shape. RESULTS: The results for direct solvent emissions show that solvents emitted because of the movement of metal parts inside a washing machine can be mainly exhausted through a local ventilation system, while the operation of an ultrasonic device can increase solvent diffusion to the workplace. Lowering the cooling water temperature can be effective in avoiding such solvent diffusion to the workplace. The results also show that the heat capacity and shape complexity of metal parts can affect the drying rate of solvents on their surfaces. CONCLUSIONS: Analysis of the results shows the effectiveness of using a local ventilation system and cooling pipes in controlling solvent emissions for several work tasks. The minimum time required to dry all solvents on the surface of metal parts was also estimated. Analyses of the emission mechanisms in this study clarified the major factors in solvent emissions and the effectiveness of process modifications for emission reductions. The findings are applicable to practical process improvement aimed at emission reductions in cleaning sites.

Analysis of supercritical water oxidation for detoxification of waste organic solvent in university based on life cycle assessment.

Spray incineration and supercritical water oxidation (SCWO) processes have been used for detoxifying waste organic fluids in the University of Tokyo. In this study, we aim to elucidate the environmental aspects of these waste treatment processes by life cycle assessment (LCA). Through the investigation of actual plants, the inventory data and other characteristics of actual plants were collected and analyzed. To confirm the potential of SCWO, three modification types of the process and operation were considered and assessed on the basis of estimated inventory data. The results demonstrate that spray incineration has less environmental impact than SCWO in all scenarios. However, SCWO has various advantages for installation as a treatment process in universities such as negligible risk of creating dioxins and particulate matter. Proper choice of the treatment method for organic waste fluid requires a comprehensive analysis of risks. Spray incineration poses the risk of providing dioxins and particulate matter, while SCWO has such risk at negligible level. This means that waste including concerned materials related to such emission should be treated by SCWO. Using the right technologies for the right tasks in the detoxification of hazardous materials should be implemented for sustainable universities.

Replacement-free mass-amplified sandwich assay with 180-MHz electrodeless quartz-crystal microbalance biosensor.

This study describes a sensitivity-amplified detection method in a replacement-free electrodeless quartz-crystal microbalance (QCM) biosensor. A sandwich assay is proposed for detecting C-reactive proteins (CRP), where the biotinated second anti-CRP antibody is weighted by streptavidin for sensitivity amplification. Because the first CRP antibody was immobilized nonspecifically on naked quartz surfaces, the sandwich assay was repeated using the same sensor chip, making possible the replacement-free assay. The mass-amplified sandwich assay detected a CRP solution of 0.1 ng/ml. A methodology for determining the molecular mass of the injected protein is also proposed.

Seed-dependent deposition behavior of Aß peptides studied with wireless quartz-crystal-microbalance biosensor.

Real-time monitoring of the deposition processes of Aß1-40 and Aß1-42 peptides on various seeds has been performed using a 55 MHz wireless quartz-crystal microbalance (QCM) over long-time periods (~40 h). Dissolved peptide solutions were stirred for nucleation and growth of seeds at pH = 7.4 and 4.6, which were immobilized on the sensor chips. The isolated Aß peptides were then flowed at the neutral pH, focusing on the interaction between the seeds and the monomers (or small multimers), excluding other interactions among seeds and other aggregates. The thioflavin-T fluorescence assay and atomic-force microscopy were used for evaluating structures of the seeds and deposited aggregates. The deposition rate, determined by the frequency decrease, is about 100 monomers/nm(2)/year in the case of fibril formation. The notable deposition behavior was observed in the deposition of Aß1-40 peptide on Aß1-42 seeds grown at the lower pH, which can be an important model for Alzheimer's disease.

Ultrathin-film oscillator biosensors excited by ultrafast light pulses.

Novel thin-film oscillator biosensors are developed using picosecond ultrasound method. 100-nm silicon-nitride thin films and 16-nm Pt thin films are used, and ultrashort light pulses are focused on their surfaces to excite the through-thickness resonance vibrations, which are detected by the delayed probe-light pulses using the optoelastic effect. Their fundamental resonance frequencies are 45 and 132 GHz, corresponding to theoretical mass sensitivities of 5.0×10(-5) and 2.2×10(-5) pg/cm(2)/Hz, respectively. These thin-film biosensors are used for detecting human immunoglobulin G (hIgG) with Staphylococcus aureus protein A nonspecifically immobilized on the film surfaces. Injection of a 5 nM analyte caused 2% decrease in the resonance frequency.

Multichannel wireless-electrodeless quartz-crystal microbalance immunosensor.

We develop the wireless-electrodeless multichannel quartz-crystal microbalance (QCM) biosensor using quartz plates of slightly different thicknesses. Their shear vibrations are simultaneously excited and detected by a pair of antenna wires to perform the noncontacting measurement. Their fundamental resonance frequencies are between 43 and 55 MHz, and vibrations at up to 10 channels are measured in liquids. Owing to high affinity of naked quartz surfaces for proteins, we immobilized various receptor proteins on different quartz plates nonspecifically and detected various antigen-antibody reactions separately. The exponential coefficient of the frequency change, rather than the amount of the frequency decrease, is found to be useful for distinguishing between specific and nonspecific binding reactions.