Not only is ATP a ubiquitous source of energy but it is also used widely as an intercellular signal. For example, keratinocytes release ATP in response to numerous external stimuli including ...pressure, heat, and chemical insult. The released ATP activates purinergic receptors on nerve fibers to generate nociceptive signals. The importance of an ATP signal in epithelial-to-neuronal signaling is nowhere more evident than in the taste system. The receptor cells of taste buds release ATP in response to appropriate stimulation by tastants and the released ATP then activates P2X2 and P2X3 receptors on the taste nerves. Genetic ablation of the relevant P2X receptors leaves an animal without the ability to taste any primary taste quality. Of interest is that release of ATP by taste receptor cells occurs in a non-vesicular fashion, apparently via gated membrane channels. Further, in keeping with the crucial role of ATP as a neurotransmitter in this system, a subset of taste cells expresses a specific ectoATPase, NTPDase2, necessary to clear extracellular ATP which otherwise will desensitize the P2X receptors on the taste nerves. The unique utilization of ATP as a key neurotransmitter in the taste system may reflect the epithelial rather than neuronal origins of the receptor cells.
The long term dynamics of radiocesium in typical forest ecosystems was studied in the radioactive contaminated areas in Fukushima Prefecture. Six observations sites located in Yamakiya Village ...(Kawamata Town; since 2014), Tsushima Village (Namie Town, since 2015), and Tomioka Town (since 2017) were monitored. The forests consisted of artificial plantations of Japanese cedar (Cryptomeria japonica) at Yamakiya Village, Tsushima Village, and Tomioka Town. Tsushima Village also had a natural mixed forest dominated by Japanese red pine (Pinus densiflora), and Tomioka Town had a young and a mature artificial plantation of Japanese cypress (Chamaecyparis obtuse). Concentrations of 137Cs were monitored in the samples collected from the main aboveground biomass compartments, fresh litterfall, forest litter, and soil. Concentrations of exchangeable forms of 137Cs and stable K were measured in soil samples. During the observation period, the litter radiocesium inventories at all sites decreased significantly to approximately 1% or less of the total ground deposition. Approximately 80% of the total radiocesium inventory is localized in the upper 5-cm layer of soil and there is little downward migration of radiocesium. At the sites with the longest monitoring series (Yamakiya and Tsushima), the radiocesium expectation depths and expectation mass depths were relatively constant at 2–3 cm and 5–6 kg m−2, respectively. Aboveground biomass compartments showed similar decreasing trends in radiocesium aggregated transfer factors, Tag, in the compartments that were exposed to atmospheric fallout in March 2011 (old foliage, small branches, and outer bark). The mean Tag in cedar stand compartments currently are in the range of 10−3-10−2 m2 kg−1 dw. However, the mean Tag and their dynamic trend significantly differed in the wood compartments of the cedar stands, which may indicate root uptake differences of orders of magnitude between observation sites. The difference in radiocesium concentration in wood between the sites becomes less pronounced when normalized by the ratio of exchangeable 137Cs/K in the soils.
•Dynamics of 137Cs in typical Fukushima forests in 2014–2020 have been studied.•Litter inventories of 137Cs dropped significantly by 2020 to ∼1% of ground deposition.•About 80% of 137Cs ground deposition is localized in the upper 5 cm layer of soil.•Decreasing trends of 137Cs concentrations were observed in tree crown compartments.•Dynamic trends of 137Cs in wood of the same species differed between the study sites.
Foreword by Clyde Barker and Thomas E. Starzl
A History of Organ Transplantationis a comprehensive and ambitious exploration of transplant surgery-which, surprisingly, is one of the longest ...continuous medical endeavors in history. Moreover, no other medical enterprise has had so many multiple interactions with other fields, including biology, ethics, law, government, and technology. Exploring the medical, scientific, and surgical events that led to modern transplant techniques, Hamilton argues that progress in successful transplantation required a unique combination of multiple methods, bold surgical empiricism, and major immunological insights in order for surgeons to develop an understanding of the body's most complex and mysterious mechanisms. Surgical progress was nonlinear, sometimes reverting and sometimes significantly advancing through luck, serendipity, or helpful accidents of nature.The first book of its kind,A History of Organ Transplantationexamines the evolution of surgical tissue replacement from classical times to the medieval period to the present day. This well-executed volume will be useful to undergraduates, graduate students, scholars, surgeons, and the general public. Both Western and non-Western experiences as well as folk practices are included.
Abstract Objective The purpose of this investigation was two-fold: first, we examined associations between suicidal ideation, maladaptive sleep patterns and abnormal sleep behaviors in a sleep center ...population, an understudied population in the domain of suicide research; and then, we explored whether significant associations remained after accounting for the possible influence of depressive symptoms. Method Data were analyzed from intake information obtained from 1584 adult patients presenting at a community-based private sleep medical center. The sample was parsed into a Suicidal Ideation (SI) group ( N = 211) and No Suicidal Ideation (NSI) group ( N = 1373). Comparisons of these groups were made on measures of self-reported sleep complaints, habits, and behaviors, suicidal ideation, depressive symptoms, and associated psychopathology. Results Approximately 13% of participants reported suicidal ideation. Clinically significant suicidal ideation was present in 4.5% of the sample. Compared to the NSI group, the SI group showed a pervasive pattern of significantly greater frequency or severity of sleep problems in areas of insomnia, nightmares and other parasomnia behaviors, poor sleep quality, and sleep-related psychophysiologic conditioning as well as worse sleep-related impairment and quality of life. Several relationships were significant after controlling for depressive symptoms. Discussion Suicidal ideation was consistently associated with a broad array of sleep complaints, even when controlling for level of depressive symptoms. As these self-reported sleep disturbances are treatable sleep disorders, future research should examine the efficacy of sleep and behavioral medicine for reducing the risk of suicidal ideation.
Material flow analysis (MFA), a central methodology of industrial ecology, quantifies the ways in which the materials that enable modern society are used, reused, and lost. Sankey diagrams, termed ...the “visible language of industrial ecology”, are often employed to present MFA results. This Perspective assesses the history and current status of MFA, reviews the development of the methodology, presents current examples of metal, polymer, and fiber MFAs, and demonstrates that MFAs have been responsible for creating related industrial ecology specialties and stimulating connections between industrial ecology and a variety of engineering and social science fields. MFA approaches are now being linked with environmental input-output assessment, scenario development, and life cycle assessment, and these increasingly comprehensive assessments promise to be central tools for sustainable development and circular economy studies in the future. Current shortcomings and promising innovations are also presented, as are the implications of MFA results for corporate and national policy.
CO2 conversion covers a wide range of possible application areas from fuels to bulk and commodity chemicals and even to specialty products with biological activity such as pharmaceuticals. In the ...present review, we discuss selected examples in these areas in a combined analysis of the state-of-the-art of synthetic methodologies and processes with their life cycle assessment. Thereby, we attempted to assess the potential to reduce the environmental footprint in these application fields relative to the current petrochemical value chain. This analysis and discussion differs significantly from a viewpoint on CO2 utilization as a measure for global CO2 mitigation. Whereas the latter focuses on reducing the end-of-pipe problem “CO2 emissions” from todays’ industries, the approach taken here tries to identify opportunities by exploiting a novel feedstock that avoids the utilization of fossil resource in transition toward more sustainable future production. Thus, the motivation to develop CO2-based chemistry does not depend primarily on the absolute amount of CO2 emissions that can be remediated by a single technology. Rather, CO2-based chemistry is stimulated by the significance of the relative improvement in carbon balance and other critical factors defining the environmental impact of chemical production in all relevant sectors in accord with the principles of green chemistry.
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