Corn starch/polyvinyl alcohol (PVA)/glycerol composite films incorporated with ε-polylysine were prepared, and their properties were investigated. The Fourier-transform infrared (FTIR) spectroscopy ...indicated that the interactions happened between the amino group of ε-polylysine and hydroxyl group starch/PVA composite films. X-ray diffraction (XRD) analysis showed that the addition of ε-polylysine decreased the intensity of all crystal peaks. Thermogravimetric (TGA) analysis suggested that ε-polylysine improved the thermal stability of composite films. Scanning electron microscopic (SEM) analysis showed that the upper surface of composite films incorporated with ε-polylysine presented more compact and flat surface. The antimicrobial activity of the composite film progressively increased with the increasing of ε-polylysine concentration (
< 0.05). The tensile strength, elongation at break and water absorption significantly increased, whereas water solubility decreased with the increasing of ε-polylysine concentration (
< 0.05). Therefore, the corn starch/PVA/glycerol composite films incorporated with ε-polylysine had good mechanical, physical and antimicrobial properties and could have potential application as a novel antimicrobial packaging material.
Data services (i.e., office on wheels and entertainment on wheels) are expected to become a primary driver in the development of future connected cars. However, the sparse spatial distribution of ...roadside stationary units (RSUs) along the road renders the downloading of data via roadside-to-vehicle (R2V) connections intermittent. As a result, data services, particularly for those dealing with large volumes of data, may not achieve a good quality of service. In this paper, we propose a multiple-vehicle protocol for collaborative data downloading by using network coding (NC). When multiple vehicles that are approaching each other have a common interest in certain data, they can collaboratively download the data from an RSU to significantly reduce their download time. We first derive the probability mass functions (PMFs) of the downloading completion time for three downloading methods, i.e., random, feedback, and NC based, to quantify the benefits of the proposed scheme. Our analytical derivations show that, compared with random- and feedback-based methods, the proposed approach can significantly improve the download time and will remove any need for uplink communications from vehicles to the infrastructure. Moreover, we discuss the cooperative group formation issues and vehicle-to-vehicle (V2V) data sharing in detail. Simulation results show that the proposed protocol has a more robust performance compared with random- and feedback-based schemes. In addition, we constitute simulations to show that the proposed scheme can apply to the scenarios with dynamic network topology and imperfect V2V data sharing.
Prophylactic and therapeutic drugs are urgently needed to combat coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Over the past year, ...SARS-CoV-2 neutralizing antibodies have been developed for preventive or therapeutic uses. While neutralizing antibodies target the spike protein, their neutralization potency and breadth vary according to recognition epitopes. Several potent SARS-CoV-2 antibodies have shown degrees of success in preclinical or clinical trials, and the US Food and Drug Administration has issued emergency use authorization for two neutralizing antibody cocktails.Nevertheless, antibody therapy for SARS-CoV-2 still faces potential challenges, including emerging viral variants of concern that have antibody-escape mutations and the potential for antibody-mediated enhancement of infection or inflammation. This review summarizes representative SARS-CoV-2 neutralizing antibodies that have been reported and discusses prospects and challenges for the development of the next generation of COVID-19 preventive or therapeutic antibodies.
Wi-Fi fingerprint-based indoor positioning systems have extensive application prospects. Indoor positioning based on channel state information (CSI) becomes a research hotspot because it can provide ...fine-grained information. This paper proposes the Adaboost positioning system (ABPS) that uses the phase information in CSI and the ensemble learning (EL) method to train the fingerprint map. In this system, the abnormal phase data is eliminated by density-based clustering and the remainder is linearly transformed to build the fingerprint map. Through continuous iteration with the Adaboost algorithm, the sample weights of the training sets are continuously adjusted to prepare for classification. Finally, it can achieve position coordinates regression by means of confidence level. A series of experiments have been conducted to illustrate the effects of EL parameters, such as the number of iterations, the maximum depth of decision tree, the maximum number of features, and the minimum number of samples required for node subdivision. Meanwhile, the influence of input data sets size is investigated in an open environment and a complex laboratory environment. The experimental results of various classification and regression methods are also discussed, which validates the effectiveness of the proposed method.
Graphene quantum dots (GQDs) have generated enormous excitement because of their superiority in chemical inertness, biocompatibility and low toxicity. Due to quantum confinement and edge effects, ...GQDs have excellent properties, attracting extensive attention from scientists in the fields of chemistry, physics, materials science, biology, and other interdisciplinary sciences. In this review, we aim to present a comprehensive view on the synthesis of GQDs for biological applications. We highlight potential methods like acid oxidation, hydrothermal and solvothermal reactions, microwave-assisted methods, electrochemical oxidation, as well as pyrolysis and carbonization for the successful preparation of GQDs. Meanwhile, four representative types of biomedical application based on GQDs, bioimaging, biosensing, drug delivery, and antimicrobial materials, are introduced and discussed in detail. This work will be very useful for quickly gaining knowledge and experience for synthesizing various GQDs, and developing advanced strategies for creating novel functional GQD-based nanomaterials for further applications in biomedicine, materials science, analytical science, and optical nanodevices.
A comprehensive review on the technical synthesis and biomedical applications of graphene quantum dots was presented.
Orbital data indicate that the youngest volcanic units on the Moon are basalt lavas in Oceanus Procellarum, a region with high levels of the heat-producing elements potassium, thorium, and uranium. ...The Chang’e-5 mission collected samples of these young lunar basalts and returned them to Earth for laboratory analysis. We measure an age of 1963 ± 57 million years for these lavas and determine their chemical and mineralogical compositions. This age constrains the lunar impact chronology of the inner Solar System and the thermal evolution of the Moon. There is no evidence for high concentrations of heat-producing elements in the deep mantle of the Moon that generated these lavas, so alternate explanations are required for the longevity of lunar magmatism.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with multiple spike mutations enable increased transmission and antibody resistance. We combined cryo-electron microscopy ...(cryo-EM), binding, and computational analyses to study variant spikes, including one that was involved in transmission between minks and humans, and others that originated and spread in human populations. All variants showed increased angiotensin-converting enzyme 2 (ACE2) receptor binding and increased propensity for receptor binding domain (RBD)-up states. While adaptation to mink resulted in spike destabilization, the B.1.1.7 (UK) spike balanced stabilizing and destabilizing mutations. A local destabilizing effect of the RBD E484K mutation was implicated in resistance of the B.1.1.28/P.1 (Brazil) and B.1.351 (South Africa) variants to neutralizing antibodies. Our studies revealed allosteric effects of mutations and mechanistic differences that drive either interspecies transmission or escape from antibody neutralization.
The coronavirus (CoV) spike (S) protein, involved in viral-host cell fusion, is the primary immunogenic target for virus neutralization and the current focus of many vaccine design efforts. The ...highly flexible S-protein, with its mobile domains, presents a moving target to the immune system. Here, to better understand S-protein mobility, we implemented a structure-based vector analysis of available β-CoV S-protein structures. Despite an overall similarity in domain organization, we found that S-proteins from different β-CoVs display distinct configurations. Based on this analysis, we developed two soluble ectodomain constructs for the SARS-CoV-2 S-protein, in which the highly immunogenic and mobile receptor binding domain (RBD) is either locked in the all-RBDs 'down' position or adopts 'up' state conformations more readily than the wild-type S-protein. These results demonstrate that the conformation of the S-protein can be controlled via rational design and can provide a framework for the development of engineered CoV S-proteins for vaccine applications.
Perfluorooctane sulfonate (PFOS) is one of the most widely used and distributed perfluorinated compounds proven to cause adverse health outcomes. Datasets of ecotoxico-genomics and proteomics have ...given greater insights for PFOS toxicological effect. However, the molecular mechanisms of hepatotoxicity of PFOS on post-translational modifications (PTMs) regulation, which is most relevant for regulating the activity of proteins, are not well elucidated. Protein glycosylation is one of the most ubiquitous PTMs associated with diverse cellular functions, which are critical towards the understanding of the multiple biological processes and toxic mechanisms exposed to PFOS. Here, we exploit the multilayered glycoproteomics to quantify the global protein expression levels, glycosylation sites, and glycoproteins in PFOS exposure and wild-type mouse livers. The identified 2439 proteins, 1292 glycosites, and 799 glycoproteins were displayed complex heterogeneity in PFOS exposure mouse livers. Quantification results reveal that 241 dysregulated proteins (fold change ≥ 2, p < 0.05) in PFOS exposure mouse livers were involved in the lipid and xenobiotic metabolism. While, 16 overexpressed glycoproteins were exclusively related to neutrophil degranulation, cellular responses to stress, protein processing in endoplasmic reticulum (ER). Moreover, the interactome and functional network analysis identified HP and HSP90AA1 as the potential glycoprotein biomarkers. These results provide unique insights into a deep understanding of the mechanisms of PFOS induced hepatotoxicity and liver disease. Our platform of multilayered glycoproteomics can be adapted to diverse ecotoxicological research.
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•Multilayered glycoproteomic techniques were adapted to uncover PFOS induced hepatoxic mechanism.•Dysregulated glycoproteome exclusively involved in ER stress and neutrophil degranulation.•HSP90AA1 and HP were potential glycobiomarkers for PFOS hepatotoxicity.•This platform can be adapted to diverse ecotoxicological research.
•A pilot-scale AnMBR with 5 m3 succeeded in treating municipal wastewater at 25 °C.•Stable biogas yield and organic removel are obtained during long-term operation.•Theoretical net energy potential ...was 0.174 kWh/m3 and bio-energy recovered by 69%.•Practical net energy potential was −0.014 kWh/m3 and bio-energy recovered by −8%.•The AnMBR exhibited promising net energy potential compared with the CAS process.
The potential of bio-energy recovery from real municipal wastewater was investigated using a one-stage pilot-scale submerged anaerobic membrane bioreactor (AnMBR) for a range of HRTs from 24 h to 6 h at ambient temperature around 25 °C. This pilot-scale AnMBR demonstrated a high COD removal efficiency of over 90% during an operation of 217 days for municipal wastewater treatment. The energy balance of the AnMBR was calculated from both theoretical and practical aspects. The theoretical net energy potential was calculated as 0.174 kWh/m3 by applying operational data to empirical equations, obtaining a bio-energy recovery efficiency of 69.4%. The practical net energy potential was estimated as −0.014 kWh/m3 using the powers of engines applied in a full-scale wastewater treatment plant. This is considerably lower than that of the conventional activated sludge process. These results are evidence of the potential of the AnMBR and feasibility in the treatment of municipal wastewater treatment.
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