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Graphene has attracted significant attention in both scientific and industrial fields. The scalable and high-yield chemical functionalization methods have been widely used to produce ...graphene, such as reduced graphene oxide (RGO). However, previously reported conductivity (<1500Scm−1) and mobility (<5cm2V−1s−1) values for RGO film are relatively low, which limits its application in many fields. In this work, we report a RGO film with a record-high conductivity of 6300Scm−1 and a record-high mobility of 320 cm2 V−1 s−1, which was reduced by Joule heating at an extremely high temperature of 3000 K. Thermal reduction process challenges of Joule heating were overcome by employing a two-step reduction and a curved RGO film. An investigation into how charge transport properties of RGO film are influenced by the reduction temperature was pursued. As the reduction temperature increases, the oxygen-containing functional groups, acting as dopant sources and scattering centers, are gradually removed, such that the carrier density gradually decreases, and the mobility and conductivity gradually increases. The localization length, corresponding to the size of graphitic sp2 domains, is 8.7 nm for the 3000-K-reduced RGO film, which exceeds previously reported values. The unique features of the reported 3000-K-reduced RGO film, such as less defects/impurities and large graphitic sp2 domains within a dense structure, enable both record-high conductivity and mobility.
Nanoparticles hosted in conductive matrices are ubiquitous in electrochemical energy storage, catalysis and energetic devices. However, agglomeration and surface oxidation remain as two major ...challenges towards their ultimate utility, especially for highly reactive materials. Here we report uniformly distributed nanoparticles with diameters around 10 nm can be self-assembled within a reduced graphene oxide matrix in 10 ms. Microsized particles in reduced graphene oxide are Joule heated to high temperature (∼1,700 K) and rapidly quenched to preserve the resultant nano-architecture. A possible formation mechanism is that microsized particles melt under high temperature, are separated by defects in reduced graphene oxide and self-assemble into nanoparticles on cooling. The ultra-fast manufacturing approach can be applied to a wide range of materials, including aluminium, silicon, tin and so on. One unique application of this technique is the stabilization of aluminium nanoparticles in reduced graphene oxide film, which we demonstrate to have excellent performance as a switchable energetic material.
The use of next-generation sequencing technologies has enabled the rapid identification of non-synonymous somatic mutations in cancer cells. Neoantigens are mutated peptides derived from somatic ...mutations not present in normal tissues that may result in the presentation of tumour-specific peptides capable of eliciting antitumour T-cell responses. Personalised neoantigen-based cancer vaccines and adoptive T-cell therapies have been shown to prime host immunity against tumour cells and are under clinical trial development. However, the optimisation and standardisation of neoantigen identification, as well as its delivery as immunotherapy are needed to increase tumour-specific T-cell responses and, thus, the clinical efficacy of current cancer immunotherapies.
In this recommendation article, launched by the European Society for Medical Oncology (ESMO), we outline and discuss the available framework for neoantigen prediction and present a systematic review of the current scientific evidence.
A number of computational pipelines for neoantigen prediction are available. Most of them provide peptide major histocompatibility complex (MHC) binding affinity predictions, but more recent approaches incorporate additional features like variant allele fraction, gene expression, and clonality of mutations. Neoantigens can be predicted in all cancer types with high and low tumour mutation burden, in part by exploiting tumour-specific aberrations derived from mutational frameshifts, splice variants, gene fusions, endogenous retroelements and other tumour-specific processes that could yield more potently immunogenic tumour neoantigens. Ongoing clinical trials will highlight those cancer types and combinations of immune therapies that would derive the most benefit from neoantigen-based immunotherapies.
Improved identification, selection and prioritisation of tumour-specific neoantigens are needed to increase the scope of benefit from cancer vaccines and adoptive T-cell therapies. Novel pipelines are being developed to resolve the challenges posed by high-throughput sequencing and to predict immunogenic neoantigens.
•Next-generation sequencing technologies have provided the means to directly identify somatic gene mutations in tumours.•Neoantigens are tumour-specific mutated peptides capable of inducing antitumour immune responses.•The discovery of immunogenic neoantigens is instrumental for the pursuit of cancer vaccines and adoptive T-cell therapy.•Refining computational workflows towards the optimal identification of immunogenic neoepitopes is needed.
U‐Th‐Pb geochronology by laser ablation–multicollector–inductively coupled plasma–mass spectrometry initiated during the mid to late 1990s as a reconnaissance tool, capable of generating ages of only ...moderate precision from relatively large volumes of zircon. New developments in instrumentation and experimental methodology, as described herein and by other researchers, now make it possible it to correct for common Pb accurately (using measured 204Pb), to acquire geochronologic information rapidly (30–40 unknowns/h), to generate U‐Pb ages with an accuracy of better than 1% for most zircon standards, and to conduct analyses on much smaller (e.g., 10 μm by 6 μm) volumes of material. These capabilities are driving important advances in many aspects of Earth science research.
Separation of PEGylated protein mixtures into individual species is a challenging procedure, and many efforts have been focused on creating novel chromatographic supports for this purpose. In this ...study, a new monolithic stationary phase with hyperbranched nanostructures was chemically synthesized. For this, monoliths with a support matrix of poly (glycidyl methacrylate‐co‐ethylene dimethacrylate) and ethylenediamine chemistry were modified with third‐generation dendrons with butyl‐end groups. The new monolith was analyzed by infrared spectroscopy, confirming the dendron with butyl ligands and exhibited low mass transfer resistance as observed by breakthrough frontal analysis. This support was able to separate mono‐PEG ribonuclease A from the PEGylation mixture, indicated by a single band (∼30 kDa) in the electrophoretic analysis. Moreover, the separation of mono‐PEGylated positional isomers was probably observed, as the protein with ∼30 kDa was found in two separate peaks. Interestingly, the dendronized monolith allowed the separation of the reaction mixture into individual PEGylated species when using high ammonium sulfate concentrations (2 M). A correlation between the PEGylation degree and the strength of the hydrophobic interactions on the monolith was observed. This chromatographic approach combines the natural branched architecture of dendrons and the higher capabilities of the monoliths enhancing the hydrophobic surface area, and therefore the interaction between the PEGylated proteins and ligands. Thus, the novel support represents a novel platform for the purification of PEGylated from non‐PEGylated proteins with biotechnological applications.
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We present a two-step method to prepare a hydrophobic cellulosic membrane involving a SiO2 sol-gel process, to increase surface roughness, followed by grafting of ...hexadecyltrimethoxysilane groups to chemically enhance the membrane’s water repellency. The modification processes induced morphological and chemical changes as observed by scanning electron microscopy and infrared spectroscopy, respectively. The hydrophobic membrane was used to separate immiscible oil/water mixtures with efficiencies over 99%. In addition, we tested the material for breaking an asphaltene–stabilized water in oil emulsion and registered separation efficiencies from 75% to 95%. The demulsification process depends on membrane surface hydrophobicity, emulsion viscosity and dispersed droplet size. The hydrophobic/oleophilic cellulose membrane was efficiently reused over 18 times to break a water/oil (50% water) emulsion. This facile solution for breaking low viscosity w/o emulsions and immiscible water/oil mixtures could be easily scalable and used to develop efficient separation methods driven solely by gravity.
Global change is expected to drive short-term evolution of natural populations. However, it remains unclear whether different populations are changing in unison. Here, we study contemporary evolution ...of growth-related and reproductive traits of three populations of Cyanus segetum facing warming and pollinator decline across a latitudinal gradient in France. We resurrected stored seeds sampled up to 24 years apart from northern, central-western, and southern populations and conducted an in situ commongarden experiment. To disentangle neutral from selection-driven differentiation, we calculated neutral genetic differentiation (FST) and quantitative trait differentiation (Q ST) between temporal samples. We found that phenotypic evolution was divergent across populations exhibiting different trends for rosette size, date of flowering, and capitula size. By measuring seed set as a proxy of fitness, we showed that samples with larger mean capitula size outperformed samples with smaller mean capitula size in the western and southern populations. Regression of traits on seed set showed that flowering date and capitula size are the primary determinants of fitness, and QST-FST comparisons indicated that natural selection has likely contributed to the shifts in flowering phenology and rosette size. These findings outline the potential for rescue of natural populations through contemporary evolution and emphasize the complex interplay between spatial and temporal variation in species’ responses to global change.
Chitosan is a naturally occurring compound that can be obtained from deacetylated chitin, which is obtained from various sources such as fungi, crustaceans, and insects. Commercially, chitosan is ...produced from crustaceans. Based on the range of its molecular weight, chitosan can be classified into three different types, namely, high molecular weight chitosan (HMWC, >700 kDa), medium molecular weight chitosan (MMWC, 150-700 kDa), and low molecular weight chitosan (LMWC, less than 150 kDa). Chitosan shows several properties that can be applied in horticultural crops, such as plant root growth enhancer, antimicrobial, antifungal, and antiviral activities. Nevertheless, these properties depend on its molecular weight (MW) and acetylation degree (DD). Therefore, this article seeks to extensively review the properties of chitosan applied in the agricultural sector, classifying them in relation to chitosan's MW, and its use as a material for sustainable agriculture.
In this work, a monolithic polymer based on poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EDMA) was prepared inside 200 μL pipette tips for the extraction of drug of abuse from ...oral fluid samples. After an appropriate surface tip modification, several polymerization mixtures with different monomer/cross-linker ratios, and percentage of porogen were studied. The most appropriate monolith to easily flow organic solvents and oral fluid samples was prepared with a MAA/EDMA ratio of 8:92 wt/wt and dodecanol containing 10 wt% toluene, as porogenic solvent. Parameters affecting the extraction procedure were evaluated and the monolith was characterized in terms of binding capacity, reusability, and precision, using α-pyrrolidinovalerophenone as model compound. Cocaine, diazepam, methamphetamine and 20 new psychoactive substances were determined in oral fluids, using the synthesized poly(MAA-co-EDMA) monolith in-tip on an eight-channel micropipette extraction and ultra-high performance liquid chromatography tandem mass spectrometry. Appropriate recoveries were obtained, ranging from 64 to 115%, with limit of detection values from 0.03 to 0.6 μg L−1, and a high precision with relative standard deviation values lower than 10% for all the evaluated drugs.
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•A MAA-co-EDMA-based monolithic polymer has been synthetized for pipette tip extraction.•Illicit substances were extracted from oral fluid samples using monolith pipette tip extraction.•Several polymerization mixtures and conditions were studied to obtain a porous monolith.•The proposed monolith pipette tip extraction provides a LOD from 0.03 to 0.6 μg L−1.
Heat stress (HS) in dairy cows causes considerable losses in the dairy industry worldwide due to reduced animal performance, increased cases of metabolic disorders, altered rumen microbiome, and ...other health problems. Cows subjected to HS showed decreased ruminal pH and acetate concentration and an increased concentration of ruminal lactate. Heat-stressed cows have an increased abundance of lactate-producing bacteria such as
and unclassified Enterobacteriaceae, and soluble carbohydrate utilizers such as
,
, and unclassified Bacteroidaceae. Cellulolytic bacteria, especially Fibrobacteres, increase during HS due to a high heat resistance. Actinobacteria and
, both acetate-producing bacteria, decreased under HS conditions. Rumen fermentation functions, blood parameters, and metabolites are also affected by the physiological responses of the animal during HS. Isoleucine, methionine, myo-inositol, lactate, tryptophan, tyrosine, 1,5-anhydro-D-sorbitol, 3-phenylpropionic acid, urea, and valine decreased under these conditions. These responses affect feed consumption and production efficiency in milk yield, growth rate, and reproduction. At the cellular level, activation of heat shock transcription factor (HSF) (located throughout the nucleus and the cytoplasm) and increased expression of heat shock proteins (HSPs) are the usual responses to cope with homeostasis. HSP70 is the most abundant HSP family responsible for the environmental stress response, while HSF1 is essential for increasing cell temperature. The expression of bovine lymphocyte antigen and histocompatibility complex class II (DRB3) is downregulated during HS, while HSP90 beta I and HSP70 1A are upregulated. HS increases the expression of the cytosolic arginine sensor for mTORC1 subunits 1 and 2, phosphorylation of mammalian target of rapamycin and decreases the phosphorylation of Janus kinase-2 (a signal transducer and activator of transcription factor-5). These changes in physiology, metabolism, and microbiomes in heat-stressed dairy cows require urgent alleviation strategies. Establishing control measures to combat HS can be facilitated by elucidating mechanisms, including proper HS assessment, access to cooling facilities, special feeding and care, efficient water systems, and supplementation with vitamins, minerals, plant extracts, and probiotics. Understanding the relationship between HS and the rumen microbiome could contribute to the development of manipulation strategies to alleviate the influence of HS. This review comprehensively elaborates on the impact of HS in dairy cows and introduces different alleviation strategies to minimize HS.
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