COVID-19, the disease caused by the SARS-CoV-2 virus, has been declared a pandemic by the World Health Organization, which has reported over 18 million confirmed cases as of August 5, 2020. In this ...review, we present an overview of recent studies using Machine Learning and, more broadly, Artificial Intelligence, to tackle many aspects of the COVID19 crisis. We have identified applications that address challenges posed by COVID-19 at different scales, including: molecular, by identifying new or existing drugs for treatment; clinical, by supporting diagnosis and evaluating prognosis based on medical imaging and non-invasive measures; and societal, by tracking both the epidemic and the accompanying infodemic using multiple data sources. We also review datasets, tools, and resources needed to facilitate Artificial Intelligence research, and discuss strategic considerations related to the operational implementation of multidisciplinary partnerships and open science. We highlight the need for international cooperation to maximize the potential of AI in this and future pandemics.
•Nanofibrillated (BNFC) was extracted from bacterial cellulose without using chemicals.•Varying high pressure effects on the diameter and crystallite size of BNFC.•The obtained BNFC shows slightly ...lower thermal stability and crystallinity.
Varying levels of high pressure homogenization (HPH) were applied to disintegrate bacterial nanofibrillated cellulose (BNFC) from bacterial cellulose (BC). HPH was considered as a simple, non-toxic and highly efficient physical method for nanofibrillated cellulose extraction. The blended BC passed through chambers at high pressures of 68, 138 and 207MPa for 30 cycles. The particle size confirmed disintegration of the BC network fibers to bundles of BNFC and the atomic force microscopy images showed the decreased diameter of individual BNFC in the range 36–67nm. Fourier transform infrared spectroscopy measurement indicated there were no change in the chemical functional groups of the BNFC compared with BC. The decreased crystallinity index and crystallite size of BNFC with increased pressure confirmed the effect of HPH on the BNFC. Nevertheless, BNFC at 207MPa had the lowest thermal stability due to having the highest surface area, which resulted in the minimum nanofiber diameter.
•The human skin cells were cultivated on cellulose nanocrystals-based nanocomposites.•The nanocomposites were non-cytotoxic biomaterial with cell viability (82%).•The porous structure of ...nanocomposites was effected due to CNC contents (2–10wt%).
Sugarcane bagasse has been utilized as a source of nanocellulose in nanomaterial science. However, the biocompatibility of cellulose nanocrystals-based nanocomposites on human fibroblast skin cell has rarely been reported. Therefore, in this study, cellulose nanocrystals (CNCs) obtained from sugarcane bagasse were incorporated with polyvinyl alcohol (PVA) in the synthesis of tissue engineering scaffolds to reveal the responses of human skin cells to this scaffold in vitro. Scanning electron microscopy images illustrated that increasing the CNC concentration coincided with pore size enlargement to 164.7μm and 96.2μm for PVA/CNC nanocomposites and neat PVA, respectively. The three-dimensional porous structure of the nanocomposite showed irregular and interconnected pore structures as well as the pore distribution. Moreover, X-ray diffraction indicated that the relative crystallinity of the PVA with 2 and 4wt% of CNCs was lower (44.94±0.97% and 45.8±1.05%, respectively) than that of neat PVA (49.79±0.9%), and the highest relative crystallinity (48.53±1.04%) was recorded at 6wt% of CNCs. Fourier transform infrared spectroscopy was used to confirm the changes of chemical functional groups, and the non-cytotoxicity of PVA/CNC_10 was recorded at 82±4.1% cell viability in an in vitro cytotoxicity test. Additionally, thermal, swelling and mechanical behaviors were significantly improved by increasing the CNC content. The compressive modulus and the major degradation temperature of PVA/CNC_10 reached 6.36MPa and 343±4.14°C, respectively, while the swelling degree of 4 and 6wt% CNCs scaffolds shared a similar maximum level of approximately 853%. Moreover, the biocompatibility of the obtained PVA/CNC_10 with a human fibroblast skin cell line (CRL-2522) illustrated good spreading and adhesion of cells on the material surfaces. These findings indicated that the integration of a PVA/CNC scaffold with fibroblast cells in vitro can be further studied for in vivo and biomedical applications.
Cassava bagasse (CB) is one of the largest yielding agricultural residues in Thailand. Thus, utilization of CB in cellulose extraction with amylase-assisted pretreatment was carried out in this ...research. Amylase pretreatment was used for starch removal, followed by bleaching with sodium chloride. Subsequently, cellulose nanofibrils (CNFs) were prepared using high-pressure homogenization. The chemical composition of the fibers at different stages showed an increase in the α-cellulose content from 19.27 ± 0.36 to 50.45 ± 0.46%. In contrast, the starch content clearly decreased from 61.60 ± 0.38 to 7.20 ± 0.42%. Scanning electron microscopy demonstrated a smooth surface on the bleached fibers due to the removal of non-cellulosic compounds. Atomic force microscopy and transmission electron microscopy confirmed that the diameter of the CNFs was in the range 15–30 nm after high-pressure homogenization at 15,000 psi for 30 passages. Moreover, the crystallinity and thermal stability were evaluated using X-ray diffraction and thermogravimetric analysis, respectively. The crystallinity of the CNFs was 63.40 ± 0.48%; whereas the temperature of maximum decomposition of the CNFs was 325 °C. Therefore, the CNFs prepared from amylase-treated CB using high-pressure homogenization could be applied as a reinforced matrix in material research.
Polyvinyl alcohol/cellulose nanocrystals (CNC) and hydroxyapatite (HA) (PCH) were combined using an in situ method to fabricate porous scaffolds. CNC was extracted from sugarcane bagasse and the ...effect of HA on PVA/CNC composites was varied with 0, 0.5, 1 and 3 wt%. The scanning electron microscopy images of the PCH composites showed interior pores with pore channels, while the energy dispersive spectroscopy (EDS) results confirmed the increased HA content in the nanocomposite with a Ca/P ratio of 1.67. Porosity and the equilibrium swelling ratio were slightly affected by the HA content. The Fourier transform infrared spectra supported the EDS results by identifying significant peaks belonging to the HA curves of the PCH composites. The crystallinity revealed decreased crystal regions at higher HA content, whereas the mechanical behavior showed the improvement at 0.5 wt% of HA. Cytotoxicity with L929 demonstrated the compatibility of the PCH composites, with 85 ± 0.92% cell viability.
Electronically conductive protein-based materials can enable the creation of bioelectronic components and devices from sustainable and nontoxic materials, while also being well-suited to interface ...with biological systems, such as living cells, for biosensor applications. However, as proteins are generally electrical insulators, the ability to render protein assemblies electroactive in a tailorable manner can usher in a plethora of useful materials. Here, an approach to fabricate electronically conductive protein nanowires is presented by aligning heme molecules in proximity along protein filaments, with these nanowires also possessing charge transfer abilities that enable energy harvesting from ambient humidity. The heme-incorporated protein nanowires demonstrate electron transfer over micrometer distances, with conductive atomic force microscopy showing individual nanowires having comparable conductance to other previously characterized heme-based bacterial nanowires. Exposure of multilayer nanowire films to humidity produces an electrical current, presumably through water molecules ionizing carboxyl groups in the filament and creating an unbalanced total charge distribution that is enhanced by the heme. Incorporation of heme and potentially other metal-center porphyrin molecules into protein nanostructures could pave the way for structurally- and electrically-defined protein-based bioelectronic devices.
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Hydroxyapatite (HA), an inorganic compound, plays an essential role in the proliferation and differentiation of bone cells. Using cellulose nanocrystals (CNCs) as green dispersants to ...improve homogenization of HA is promising in the fabrication of nanocomposite scaffolds with biocompatibility for bone tissue engineering. The HA/CNC (HC) nanoparticle suspension was incorporated in polyvinyl alcohol (PVA)-based scaffold to investigate the physical and chemical properties. The PVA/HC composites demonstrated high porous structure and swelling ability for cell attachment and a 3-fold improvement in compressive modulus compared with free HC scaffold. Moreover, the presence of HC nanoparticles has promoted the proliferation and mineralization of pre-osteoblast. Our findings could provide an effective strategy by using bio-dispersants to incorporate mineral elements into synthetic polymers for the fabrication of functional tissue engineering scaffolds.
This research examined the idea that children's inferences about their parents' goals for them is a possible mechanism by which parents' responses to their children's performance contribute to ...children's psychological functioning. American (N = 447; Mage = 13.24 years; 49% girls; 95% European American) and Chinese (N = 439; Mage = 13.36 years; 52% girls) early adolescents reported on parents' responses to their performance, parents' self-worth and self-improvement goals for them, and their psychological functioning (e.g., subjective well-being) twice over a year. The more parents used success-oriented responses, the more their children inferred they held self-worth goals, which predicted enhanced psychological functioning among children over time. The more parents used failure responses, the more their children inferred they held self-improvement goals, but this did not underlie the tendency for parents' failure responses to predict poorer psychological functioning over time. These pathways tended to be stronger in the United States than China.
Shanghai of the early twentieth century represents the blossoming of urban culture in Modern China. With an extensive research on archival materials, this paper examines the amusement industry of the ...city by looking into the two major amusement halls, Great World (da shijie) and New World (xin shijie), and their associated tabloids, known as “amusement hall newspapers.” Specifically, it asks, “How might have women experienced amusement differently?” With the term pleasure seeker, this study surveys female visitors who were seeking fun in these amusement halls, whose existence has yet to be acknowledged. Second, it questions the presumed relationship between women and pleasure, object and subject of the gaze. It discusses in particular the presence of courtesans, actresses and female audience in such pleasurable mechanism.
Introduction: NanoString nCounter technology, a novel molecular assay, is gaining prevalent use in clinical settings as it can overcome some common constraints that are associated with the use of ...polymerase chain reaction (PCR). Compared to PCR, NanoString technology does not involve any amplification steps, which significantly minimizes the chance of contamination. NanoString measures the number of mRNA transcripts directly by 'molecular counting', as up to 800 colored probes can be run simultaneously in a single reaction.
Areas covered: This manuscript reviews the principle of NanoString and covers the main applications of NanoString in companion diagnostics with a focus on cancer immunotherapy and disease prognosis estimation. This review has also taken a step in the direction of personalized medicine, with the application of NanoString on the realm of companion diagnostics.
Expert opinion: NanoString is going to take a vital role in companion diagnostics and personalized medicine, owing to its simple and easy to use characteristics. Yet, the use of NanoString requires normalization of expression level, which is represented by the copy number of respective mRNA, with a reference gene. Furthermore, difficulty in probe design, which demands prior knowledge of known sequence, has also been a limitation of NanoString.
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