Explore the vast range of titles available.

This work investigates the feasibility of using coffee silverskin (CSS) as a reinforcing agent in biobased polyethylene (BioPE) composites, by adding it in bulk and thin film samples. The effect of two different treatments, alkali bleaching (CSS_A) and esterification with palmitoyl chloride (CSS_P), on mechanical, thermal, morphological and water absorption behavior of produced materials at different CSS loading (10, 20 and 30 wt %) was investigated. A reactive graft copolymerization of BioPE with maleic anhydride was considered in the case of alkali treated CSS. It was found that, when introduced in bulk samples, improvement in the elastic modulus and a reduction in strain at maximum stress were observed with the increase in CSS fraction for the untreated and treated CSS composites, while the low aspect ratio of the CSS particles and their poor adhesion with the polymeric matrix were responsible for reduced ductility in films, decreasing crystallinity values and reduction of elastic moduli. When CSS_A and CSS_P are introduced in the matrix, a substantial reduction in the water uptake is also obtained in films, mainly due to presence of maleated PE, that builds up some interactions to eliminate the amounts of OH groups and hydrophobized CSS, due to the weakened absorption capacity of the functionalized CSS.

Diethyl l‐tartrate (DET) is used as a biobased plasticizer for poly(lactide) (PLA) formulations with improved ductile properties without compromising biodegradation. Different weight percentages (wt.%) of DET in the 0–50 wt.% range are added to PLA by melt compounding and subsequently processed by injection molding. The effect of wt.% DET on mechanical, thermal, thermo‐mechanical, morphology, biodegradation, and crystallinity is studied. Addition of 20 wt.% DET leads to a noticeable increase in elongation at break up to values of 567%, which is quite an interesting result considering the extreme brittleness of PLA. These results are verified by field emission scanning electron microscopy (FESEM) images, where filament‐like structures are observed, indicative of an effective plasticization. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) show that the glass transition temperature of PLA is drastically decreased down to values of 23 °C for the sample with the highest amount of DET (50 wt.%), thus increasing its ductility and processability. Fourier‐transformed infrared spectroscopy (FTIR) spectra show that there exists chemical interactions between PLA and DET. Finally, the biodegradability analysis proves that the developed blends are fully biodegradable, achieving complete disintegration after 49 days. It is observed that DET enhanced the disintegration rate of PLA. This work reports on the development of PLA blends with diethyl tartrate (DET) as a plasticizer, which greatly increases the ductility of PLA, an extremely fragile polymer. Achieving values superior to 550% elongation at break for a sample with 20 wt.% DET. Moreover, this plasticizer is naturally‐based and completely biodegradable, which makes the blend totally environmentally friendly.

Entrants and incumbents can create new products and displace the products of competitors. Incumbents can also improve their existing products. How much of aggregate productivity growth occurs through each of these channels? Using data from the U.S. Longitudinal Business Database on all nonfarm private businesses from 1983 to 2013, we arrive at three main conclusions: First, most growth appears to come from incumbents. We infer this from the modest employment share of entering firms (defined as those less than 5 years old). Second, most growth seems to occur through improvements of existing varieties rather than creation of brand new varieties. Third, own-product improvements by incumbents appear to be more important than creative destruction. We infer this because the distribution of job creation and destruction has thinner tails than implied by a model with a dominant role for creative destruction.

During the early months of the COVID-19 pandemic, there was an unusually high submission rate of scholarly articles. Given that most academics were forced to work from home, the competing demands for familial duties may have penalized the scientific productivity of women. To test this hypothesis, we looked at submitted manuscripts and peer review activities for all Elsevier journals between February and May 2018-2020, including data on over 5 million authors and referees. Results showed that during the first wave of the pandemic, women submitted proportionally fewer manuscripts than men. This deficit was especially pronounced among more junior cohorts of women academics. The rate of the peer-review invitation acceptance showed a less pronounced gender pattern with women taking on a greater service responsibility for journals, except for health & medicine, the field where the impact of COVID-19 research has been more prominent. Our findings suggest that the first wave of the pandemic has created potentially cumulative advantages for men.

Proton exchange membrane water electrolysis is a promising technology to produce green hydrogen from renewables, as it can efficiently achieve high current densities. Lowering iridium amount in oxygen evolution reaction electrocatalysts is critical for achieving cost-effective production of green hydrogen. In this work, we develop catalysts from Ir double perovskites. Sr 2 CaIrO 6 achieves 10 mA cm −2 at only 1.48 V. The surface of the perovskite reconstructs when immersed in an acidic electrolyte and during the first catalytic cycles, resulting in a stable surface conformed by short-range order edge-sharing IrO 6 octahedra arranged in an open structure responsible for the high performance. A proton exchange membrane water electrolysis cell is developed with Sr 2 CaIrO 6 as anode and low Ir loading (0.4 mg Ir cm −2 ). The cell achieves 2.40 V at 6 A cm −2 (overload) and no loss in performance at a constant 2 A cm −2 (nominal load). Thus, reducing Ir use without compromising efficiency and lifetime. While water splitting offers a renewable means to produce H 2 fuel, most electrolyzers rely on scarce elements to function. Here, authors study low-content Iridium catalysts derived from mixed oxides for proton exchange membrane water electrolysis anodes without compromising activity and durability.

The modeling of reactive transport through porous media is a challenging numerical problem. Methods of solution have leveraged the stoichiometry of chemical reactions to address the transport of multiple aqueous species by expressing them in terms of an equivalent, linearly independent variable (component). This approach effectively decouples advection‐dispersion transport from the source terms associated with equilibrium reactions. A common assumption found in the literature is that all species disperse with the same transport coefficients. Recent experimental studies have discussed that this is not necessarily the case, particularly for transverse mixing, which is limited by the species‐specific molecular diffusion. This article presents a formulation of multicomponent reactive transport that takes into account the differences in dispersion coefficients. These differences lead to a nonlinear transport equation for the components, from where an expression for evaluating reaction rates is derived. It is demonstrated that this expression simplifies to the well‐known equations assuming the same dispersion for all species. Numerical simulations of a binary chemical system under diffusion‐ and advection‐dominated transport conditions are used to evaluate the influence that differential transport coefficients have upon the output of chemical reactions. Results indicate that differences in transport coefficients are particularly relevant when the chemical signature of the input solutions is not strongly dominated by one of the species in the component. Unexpectedly, this opens the possibility to mineral dissolution coexisting with precipitation during the mixing of two waters in equilibrium. This phenomenon can be explained by nonlinear mixing processes proportional to the differences in transport coefficients. Key Points New formulation of multicomponent reactive transport with species‐specific dispersion properties and nonlinear transport for the components A general expression for evaluating reaction rates is derived considering the transport properties of all species Differences in coefficients can lead to dissolution coexisting with precipitation for a equilibrium binary reaction in dilute systems

Framing the Circular Bioeconomy, the use of reactive compatibilizers was applied in order to increase the interfacial adhesion and, hence, the physical properties and applications of green composites based on biopolymers and food waste derived lignocellulosic fillers. In this study, poly(butylene succinate) grafted with maleic anhydride (PBS-g-MAH) was successfully synthetized by a reactive melt-mixing process using poly(butylene succinate) (PBS) and maleic anhydride (MAH) that was induced with dicumyl peroxide (DCP) as a radical initiator and based on the formation of macroradicals derived from the hydrogen abstraction of the biopolymer backbone. Then, PBS-g-MAH was used as reactive compatibilizer for PBS filled with different contents of pistachio shell flour (PSF) during melt extrusion. As confirmed by Fourier transform infrared (FTIR), PBS-g-MAH acted as a bridge between the two composite phases since it was readily soluble in PBS and could successfully form new esters by reaction of its multiple MAH groups with the hydroxyl (–OH) groups present in cellulose or lignin of PSF and the end ones in PBS. The resultant compatibilized green composites were, thereafter, shaped by injection molding into 4-mm thick pieces with a wood-like color. Results showed significant increases in the mechanical and thermomechanical rigidity and hardness, meanwhile variations on the thermal stability were negligible. The enhancement observed was related to the good dispersion and the improved filler-matrix interfacial interactions achieved by PBS-g-MAH and also to the PSF nucleating effect that increased the PBS’s crystallinity. Furthermore, water uptake of the pieces progressively increased as a function of the filler content, whereas the disintegration in controlled compost soil was limited due to their large thickness.

Biology has been transformed by the rapid development of computing and the concurrent rise of data-rich approaches such as, omics or high-resolution imaging. However, there is a persistent computational skills gap in the biomedical research workforce. Inherent limitations of classroom teaching and institutional core support highlight the need for accessible ways for researchers to explore developments in computational biology. An analysis of the Scripps Research Genomics Core revealed increases in the total number and diversity of experiments: the share of experiments other than bulk RNA- or DNA-sequencing increased from 34% to 60% within 10 years, requiring more tailored computational analyses. These challenges were tackled by forming a volunteer-led affinity group of approximately 300 academic biomedical researchers interested in computational biology, referred to as the Computational Biology and Bioinformatics (CBB) affinity group. This adaptive group has provided continuing education and networking opportunities through seminars, workshops, and coding sessions while evolving along with the needs of its members. A survey of CBB’s impact confirmed the group’s events increased the members’ exposure to computational biology educational and research events (79% respondents) and networking opportunities (61% respondents). Thus, volunteer-led affinity groups may be a viable complement to traditional institutional resources for enhancing the application of computing in biomedical research.

Hydrostatic lung compression in diving marine mammals, with collapsing alveoli blocking gas exchange at depth, has been the main theoretical basis for limiting N2 uptake and avoiding gas emboli (GE) as they ascend. However, studies of beached and bycaught cetaceans and sea turtles imply that air-breathing marine vertebrates may, under unusual circumstances, develop GE that result in decompression sickness (DCS) symptoms. Theoretical modelling of tissue and blood gas dynamics of breath-hold divers suggests that changes in perfusion and blood flow distribution may also play a significant role. The results from the modelling work suggest that our current understanding of diving physiology in many species is poor, as the models predict blood and tissue N2 levels that would result in severe DCS symptoms (chokes, paralysis and death) in a large fraction of natural dive profiles. In this review, we combine published results from marine mammals and turtles to propose alternative mechanisms for how marine vertebrates control gas exchange in the lung, through management of the pulmonary distribution of alveolar ventilation () and cardiac output/lung perfusion (), varying the level of in different regions of the lung. Man-made disturbances, causing stress, could alter the mismatch level in the lung, resulting in an abnormally elevated uptake of N2, increasing the risk for GE. Our hypothesis provides avenues for new areas of research, offers an explanation for how sonar exposure may alter physiology causing GE and provides a new mechanism for how air-breathing marine vertebrates usually avoid the diving-related problems observed in human divers.

Obesity is a chronic disease caused by the accumulation of excessive adipose tissue. This disorder is characterized by chronic low-grade inflammation, which promotes the release of proinflammatory mediators, including cytokines, chemokines and leptin. Simultaneously, chronic inflammation can predispose to cancer development, progression and metastasis. Proinflammatory molecules are involved in the recruitment of specific cell populations in the tumor microenvironment. These cell populations include myeloid-derived suppressor cells (MDSCs), a heterogeneous, immature myeloid population with immunosuppressive abilities. Obesity-associated MDSCs have been linked with tumor dissemination, progression and poor clinical outcomes. A comprehensive literature review was conducted to assess the impact of obesity-associated MDSCs on cancer in both preclinical models and oncological patients with obesity. A secondary objective was to examine the key role that leptin, the most important proinflammatory mediator released by adipocytes, plays in MDSC-driven immunosuppression Finally, an overview is provided of the different therapeutic approaches available to target MDSCs in the context of obesity-related cancer.