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•Biomass pyrolysis has been classified based on recent advancements.•The merits and demerits of each approach are highlighted.•Suitability of each approach for green hydrogen ...production is discussed.•Biomass pyrolysis is a sustainable and effective approach for H2 production.
Biomass pyrolysis has recently gained increasing attention as a thermochemical conversion process for obtaining value-added products, thanks to the development of cutting-edge, innovative and cost-effective pyrolysis processes. Over time, new and novel pyrolysis techniques have emerged, and these processes can be tuned to maximize the production of high-quality hydrogen. This review examines recent advancements in biomass pyrolysis by classifying them into conventional, advanced and emerging approaches. A comprehensive overview on the recent advancements in biomass pyrolysis, highlighting the current status for industrial applications is presented. Further, the impact of each technique under different approaches on conversion of biomass for hydrogen production is evaluated. Techniques, such as inline catalytic pyrolysis, microwave pyrolysis, etc., can be employed for the sustainable production of hydrogen. Finally, the techno-economic analysis is presented to understand the viability of pyrolysis at large scale. The outlook highlights discernments into future directions, aimed to overcome the current shortcomings.
Aging coincides with the progressive loss of muscle mass and strength, increased adiposity, and diminished physical function. Accordingly, interventions aimed at improving muscle, metabolic, and/or ...physical health are of interest to mitigate the adverse effects of aging. In this study, we tested a stem cell secretome product, which contains extracellular vesicles and growth, cytoskeletal remodeling, and immunomodulatory factors. We examined the effects of 4 weeks of 2×/week unilateral intramuscular secretome injections (quadriceps) in ambulatory aged male C57BL/6 mice (22–24 months) compared to saline‐injected aged‐matched controls. Secretome delivery substantially increased whole‐body lean mass and decreased fat mass, corresponding to higher myofiber cross‐sectional area and smaller adipocyte size, respectively. Secretome‐treated mice also had greater whole‐body physical function (grip strength and rotarod performance) and had higher energy expenditure and physical activity levels compared to control mice. Furthermore, secretome‐treated mice had greater skeletal muscle Pax7+ cell abundance, capillary density, collagen IV turnover, reduced intramuscular lipids, and greater Akt and hormone sensitive lipase phosphorylation in adipose tissue. Finally, secretome treatment in vitro directly enhanced muscle cell growth and IL‐6 production, and in adipocytes, it reduced lipid content and improved insulin sensitivity. Moreover, indirect treatment with secretome‐treated myotube culture media also enhanced muscle cell growth and adipocyte size reduction. Together, these data suggest that intramuscular treatment with a stem cell secretome improves whole‐body metabolism, physical function, and remodels skeletal muscle and adipose tissue in aged mice.
In this study, we show that the 4‐week administration of a stem cell secretome, made up of exosomes, growth, immune, and extracellular matrix factors, robustly ameliorated several hallmarks of aging in male mice resulting in improvements in physical function, metabolism, adiposity, and skeletal muscle remodeling.
On the basis of a carbon isotopic record of both marine carbonates and organic matter from the Triassic-Jurassic boundary to the present, we modeled oxygen concentrations over the past 205 million ...years. Our analysis indicates that atmospheric oxygen approximately doubled over this period, with relatively rapid increases in the early Jurassic and the Eocene. We suggest that the overall increase in oxygen, mediated by the formation of passive continental margins along the Atlantic Ocean during the opening phase of the current Wilson cycle, was a critical factor in the evolution, radiation, and subsequent increase in average size of placental mammals.
•Spring bloom onset cannot be explained as a purely bottom-up or top-down process.•Conceptual bases of critical depth and dilution-recoupling hypotheses are true under realistic conditions.•Mixed ...layer fluctuations can shift bloom timing by modifying nutrient and light availability.•Changes in zooplankton concentrations produce only negligible shifts in bloom timing.
The spring bloom – a massive growth of phytoplankton that occurs annually during the spring season in mid and high latitudes – plays an important role in carbon export to the deep ocean. The onset of this event has been explained from bottom-up and top-down perspectives, exemplified by the “critical-depth” and the “dilution-recoupling” hypotheses, respectively. Both approaches differ in their key expectations about how seasonal fluctuations of the mixed layer affect the plankton community. Here we assess whether the assumptions inherent to these hypotheses are met inside a typical onedimensional Nutrient–Phytoplankton–Zooplankton–Detritus (NPZD) model, optimized to best represent climatological annual cycles of satellite-based phytoplankton biomass in the Subpolar North Atlantic. The optimized model is used in idealized experiments that isolate the effects of mixed layer fluctuations and zooplankton grazing, in order to elucidate their significance. We analyzed the model sensitivity qualitatively and using a second-order Taylor series decomposition of the model equations. Our results show that the conceptual bases of both bottom-up and top-down approaches are required to explain the process of blooming; however, neither of their bloom initiation mechanisms fully applies in the experiments. We find that a spring bloom can develop in the absence of mixed layer fluctuations, and both its magnitude and timing seem to strongly depend on nutrient and light availability. Furthermore, although zooplankton populations modulate the phytoplankton concentrations throughout the year, directly prescribed and physically driven changes in zooplankton grazing do not produce significant time shifts in bloom initiation, as hypothesized. While recognizing its limitations, our study emphasizes the processes that require further testing in order to discern among competing hypotheses.
We use a statistical emulator technique, the polynomial chaos expansion, to estimate time-dependent values for two parameters of a 3-dimensional biological ocean model. We obtain values for the ...phytoplankton carbon-to-chlorophyll ratio and the zooplankton grazing rate by minimizing the misfit between simulated and satellite-based surface chlorophyll. The misfit is measured by a spatially averaged, time-dependent distance function. A cross-validation experiment demonstrates that the influence of outlying satellite data can be diminished by smoothing the distance function in time. The optimal values of the two parameters based on the smoothed distance function exhibit a strong time-dependence with distinct seasonal differences, without overfitting observations. Using these time-dependent parameters, we derive (hindcast) state estimates in two distinct ways: (1) by using the emulator-based interpolation and (2) by performing model runs with time-dependent parameters. Both approaches yield chlorophyll state estimates that agree better with the observations than model estimates with globally optimal, constant parameters. Moreover, the emulator approach provides us with estimates of parameter-induced model state uncertainty, which help determine at what time improvement in the model simulation is possible. The time-dependence of the analyzed parameters can be motivated biologically by naturally occurring seasonal changes in the composition of the plankton community. Our results suggest that the parameter values of typical biological ocean models should be treated as time-dependent and will result in a better representation of plankton dynamics in these models. We further demonstrate that emulator techniques are valuable tools for data assimilation and for analyzing and improving biological ocean models.
► Use of emulators for data assimilation and parameter estimation in biological model. ► Clear spatial and temporal dependence of plankton model parameters. ► Improved representation of plankton in ocean models through time-dependent parameters. ► Improved state estimates of emulator in comparison to optimized fixed parameter model.
Muscle mass is balanced between hypertrophy and atrophy by cellular processes, including activation of the protein kinase B-mechanistic target of rapamycin (Akt-mTOR) signaling cascade. Stressors ...apart from exercise and nutrition, such as heat stress, can stimulate the heat shock protein A (HSPA) and C (HSPC) families alongside hypertrophic signaling factors and muscle growth. The effects of heat stress on HSP expression and Akt-mTOR activation in human skeletal muscle and their magnitude of activation compared with known hypertrophic stimuli are unclear. Here, we show a single session of whole body heat stress following resistance exercise increases the expression of HSPA and activation of the Akt-mTOR cascade in skeletal muscle compared with resistance exercise in a healthy, resistance-trained population. Heat stress alone may also exert similar effects, though the responses are notably variable and require further investigation. In addition, acute heat stress in C2C12 muscle cells enhanced myotube growth and myogenic fusion, albeit to a lesser degree than growth factor-mediated hypertrophy. Though the mechanisms by which heat stress stimulates hypertrophy-related signaling and the potential mechanistic role of HSPs remain unclear, these findings provide additional evidence implicating heat stress as a novel growth stimulus when combined with resistance exercise in human skeletal muscle and alone in isolated murine muscle cells. We believe these findings will help drive further applied and mechanistic investigation into how heat stress influences muscular hypertrophy and atrophy.
We show that acute resistance exercise followed by whole body heat stress increases the expression of HSPA and increases activation of the Akt-mTOR cascade in a physically active and resistance-trained population.
Using two emulator‐based procedures, we estimate time‐dependent values for two key plankton parameters in a three‐dimensional biogeochemical (BGC) ocean model. The estimation is based on a 4 year ...time series of daily surface satellite chlorophyll observations. The estimated parameters display an annual periodicity that can be explained by the succession of plankton groups in the study region. Model simulations using these parameters show improved fit to observations and better forecasting abilities compared to simulations with constant optimal parameters; the newly introduced sequential parameter estimation procedure creates the strongest improvement. The inclusion of time‐dependent parameters represents a simple way to improve the predictive skill of BGC models and their representation of plankton dynamics.
Key Points
Two techniques for estimating time‐dependent parameters are introduced and comparedTime‐dependent parameters improve plankton representation in 3‐D ocean modelsAnnual periodicity in parameters improves forecast over constant parameters
Abstract
Whilst the peripheral immune response to COVID-19 infection is well characterised, less is known about the tissue response in the lungs of affected patients. We conducted a multi-omic ...investigation in post-mortem lung tissue from fatal COVID-19 infection comprising bulk Quantseq RNA sequencing, spatial transcriptomic profiling on the Nanostring GeoMX, multiplex immunohistochemistry on the Lunaphore COMET and in-situ transcriptomcics with RNAscope. We found the SARS-CoV-2 virus was progressively cleared in more temporally advanced disease. Furthermore, collagen VI was found to be transcriptionally up-regulated by bulk sequencing and within the interstitium on spatial transcriptomics. These findings were supported by multiplex immunohistochemistry at a proteomic level which showed fibrillar deposition of collagen VI in the interstitum. To validate these findings clinically, we looked at blood markers for collagen VI synthesis and degradation by ELISA in a cohort of severe and mildly infected COVID-19 patients. Blood markers of collagen VI synthesis (PRO-C6) was significantly predictive for mortality in hospitalised (p = 0.0065) and intensive care (p = 0.028) COVID-19 patients. Overall, blood PRO-C6 levels, based on increase interstitial lung deposition, could help identify high-risk of patients enabling better treatment stratification. The study also demonstrates the power of post-mortem investigation and spatial profiling in elucidating clinically relevant insights into complex disease phenomena.
Single‐shot coherent diffraction imaging (CDI) is a powerful approach to characterize the structure and dynamics of isolated nanoscale objects such as single viruses, aerosols, nanocrystals and ...droplets. Using X‐ray wavelengths, the diffraction images in CDI experiments usually cover only small scattering angles of a few degrees. These small‐angle patterns represent the magnitude of the Fourier transform of the 2D projection of the sample's electron density, which can be reconstructed efficiently but lacks any depth information. In cases where the diffracted signal can be measured up to scattering angles exceeding ∼10°, i.e. in the wide‐angle regime, some 3D morphological information of the target is contained in a single‐shot diffraction pattern. However, the extraction of the 3D structural information is no longer straightforward and defines the key challenge in wide‐angle CDI. So far, the most convenient approach relies on iterative forward fitting of the scattering pattern using scattering simulations. Here the Scatman is presented, an approximate and fast numerical tool for the simulation and iterative fitting of wide‐angle scattering images of isolated samples. Furthermore, the open‐source software implementation of the Scatman algorithm, PyScatman, is published and described in detail. The Scatman approach, which has already been applied in previous work for forward‐fitting‐based shape retrieval, adopts the multi‐slice Fourier transform method. The effects of optical properties are partially included, yielding quantitative results for small, isolated and weakly interacting samples. PyScatman is capable of computing wide‐angle scattering patterns in a few milliseconds even on consumer‐level computing hardware, potentially enabling new data analysis schemes for wide‐angle coherent diffraction experiments.
A fast method for wide‐angle coherent scattering simulations of weakly absorbing isolated samples, called the Scatman, is presented. Its quantitative agreement with exact solutions and the low simulation time of its software implementation PyScatman open new perspectives for single‐shot 3D coherent diffraction imaging.
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