•Overview of nanomaterial immobilized enzyme.•Binding force for enzyme immobilization.•Performance of nanomaterial immobilized enzyme.•Application of immobilized enzyme.•Outlook of nanomaterial in ...enzyme immobilization.
Enzymes have been widely used because of their catalytic properties, and immobilization is a promising technique to improve their catalytic activity and stability. Due to their large specific surface areas, exceptional chemical, mechanical, thermal and cost effective characteristics, nanomaterials should be ideal carriers for the immobilization of enzymes. Enzymes immobilized on nano-carriers are more robust and stable, and can be recycled and reused. This review focuses on the nanomaterial immobilized enzymes and their applications. The introduction addresses the advantages of immobilized enzymes and the features of enzyme immobilization nanocarriers. The next section covers carbonaceous nanomaterials used in enzymes immobilization, with subsections on carbon nanotube, graphene, graphene oxide and reduced graphene oxide. The third section treats metallic nanomaterials for enzymes immobilization, with subsections on metal (gold), metal oxide (titanium dioxide, zinc oxide) and metal hydroxide (layered double hydroxide) nanomaterials. Then, the next section summarizes the applications of nanomaterial immobilized enzymes. A concluding section discusses the challenges and prospects of nanomaterial immobilized enzymes.
Multidrug resistance (MDR) occurs frequently after long-term chemotherapy, resulting in refractory cancer and tumor recurrence. Therefore, combatting MDR is an important issue. Autophagy, a ...self-degradative system, universally arises during the treatment of sensitive and MDR cancer. Autophagy can be a double-edged sword for MDR tumors: it participates in the development of MDR and protects cancer cells from chemotherapeutics but can also kill MDR cancer cells in which apoptosis pathways are inactive. Autophagy induced by anticancer drugs could also activate apoptosis signaling pathways in MDR cells, facilitating MDR reversal. Therefore, research on the regulation of autophagy to combat MDR is expanding and is becoming increasingly important. We summarize advanced studies of autophagy in MDR tumors, including the variable role of autophagy in MDR cancer cells.
Alzheimer's disease (AD) is a neurodegenerative disorder with cognitive impairment and abnormal mental behaviour. There is currently no effective cure. The development of early diagnostic markers and ...the mining of potential therapeutic targets are one of the important strategies. This study aimed to explore potential biomarkers or therapeutic targets related to AD in the hippocampus and prefrontal cortex, two brain regions highly related to AD. Differentially expressed genes and miRNAs between AD patients and healthy controls were obtained from the Gene Expression Omnibus database. The mRNA‐miRNA network was constructed and key genes involved in AD were screened out by protein–protein interaction analysis, and were subsequently verified by independent datasets and qPCR in an AD mouse model. Our findings showed that six hub genes including CALN1, TRPM7, ATR, SOCS3, MOB3A and OGDH were believed to be involved in the pathogenesis of AD. Western blot analysis further determined that CALN1, ATR and OGDH were the possible biomarkers and therapeutic targets for AD. In addition, 6 possible miRNAs biomarkers have also been verified by qPCR on AD animal models. Our findings may benefit clinical diagnosis and early prevention of AD.
Acetylcholinesterase (AChE) is popularly used in biological and chemical sensors since it can be inhibited or reactivated. As the inhibitor of AChE is meaningful for many neurodegenerative diseases ...caused by the lack of AChE substrate acetylcholine (ACh), and the reactivator of inhibited AChE is helpful to treat the blocked neurotransmission resulted from the excessive ACh. Therefore, it is significant to screen AChE inhibitors and reactivators for pharmaceutical application. In addition, the detection of pesticides and heavy metals is of great importance to food safety and environment. So, based on the inhibition of AChE by pesticides and heavy metals, AChE can also be used in food safety and environmental analysis. Colorimetric method is a popular strategy for AChE assay due to its low cost, practicality and simplicity. In this review, we focus on the colorimetric method for AChE assay and the corresponding applications. The basic principles, advantages and disadvantages of Ellman's method, pH indicator-, 3,3′,5,5′-tetramethylbenzidine- (TMB-), noble metal nanomaterial-, and substrate-based colorimetric method are evaluated. In addition, the applications of colorimetric AChE assays in inhibitors and reactivators screening, pesticides and heavy metals detection are reviewed. Finally, the conclusions and future perspectives are provided.
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•Different chromogenic reagent-based colorimetric method for AChE are reviewed.•The mechanism, advantage and disadvantage of colorimetric AChE assay are discussed.•The applications of colorimetric AChE assays in analysis are reviewed.•A perspective for the colorimetric AChE assay is proposed.
Neutral eosin Y‐derived photoexcited states have been found to serve as photoacids and direct hydrogen atom transfer (HAT) catalysts in the activation of glycals and C−H bonds, respectively. These ...studies pave the way for further use of eosin Y in photochemical synthesis.
New sides of eosin Y: Neutral eosin Y‐derived photoexcited states have been found to serve as photoacids and direct hydrogen atom transfer (HAT) catalysts in the activation of glycals and C−H bonds, respectively. These studies pave the way for further use of eosin Y in photochemical synthesis.
Compared with free enzymes, immobilized enzymes are more robust and resistant to environmental changes. In addition, with enhanced stability, immobilized enzymes can be separated from the reaction ...mixture and used for repeated cycles. These advantages prompt their applications in various fields. This review outlines the existing methods and easy separated support materials for enzymes immobilization. After a brief introduction on the immobilized enzyme, the immobilization methods of adsorption, entrapment, covalent attachment and cross-linking are discussed. The emphasis is given on the easy separated support materials of magnetic nanoparticles (MNPs), membranes and capillary columns. An outlook on the immobilized enzyme is given at last.
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•Detailed methods for enzymes immobilization are discussed.•MNPs, membranes and capillary columns are presented to solve the separation problems of immobilized enzymes.•Applications of easy separated support matrices in enzymes immobilization are summarized.•Future perspectives of immobilized enzymes are presented.
This article is concerned with the output feedback exponential stabilization for a flexible beam with tip mass. When there is no disturbance, it is shown that only one noncollocated measurement is ...enough to exponentially stabilize the original system by constructing an infinite-dimensional Luenberger state observer to track the state and designing an estimated state-based output feedback control law. This essentially improves the existing result in (Conrad et al. 1998) where two collocated measurements, including high-order feedback were adopted. In the case that boundary internal uncertainty and external disturbance are considered, an infinite-dimensional disturbance estimator is constructed to estimate the state and total disturbance in real time. By virtue of the estimated state and estimated total disturbance, an output feedback control law is designed to exponentially stabilize the original system while guaranteeing the boundedness of the closed-loop system. Some illustration simulations are presented.
Abnormal N6-methyladenosine (m6A) modification is closely associated with the occurrence, development, progression and prognosis of cancer, and aberrant m6A regulators have been identified as novel ...anticancer drug targets. Both traditional medicine-related approaches and modern drug discovery platforms have been used in an attempt to develop m6A-targeted drugs. Here, we provide an update of the latest findings on m6A modification and the critical roles of m6A modification in cancer progression, and we summarize rational sources for the discovery of m6A-targeted anticancer agents from traditional medicines and computer-based chemosynthetic compounds. This review highlights the potential agents targeting m6A modification for cancer treatment and proposes the advantage of artificial intelligence (AI) in the discovery of m6A-targeting anticancer drugs. Three stages of m6A-targeting anticancer drug discovery: traditional medicine-based natural products, modern chemical modification or synthesis, and artificial intelligence (AI)-assisted approaches for the future.
The local measurement of H
0 is in tension with the prediction of Λ cold dark matter model based on the Planck data. This tension may imply that dark energy is strengthened in the late-time Universe. ...We employ the latest cosmological observations on cosmic microwave background, the baryon acoustic oscillation, large-scale structure, supernovae, H(z) and H
0 to constrain several interacting dark energy models. Our results show no significant indications for the interaction between dark energy and dark matter. The H
0 tension can be moderately alleviated, but not totally released.
Abstract
Background
The duration of humoral and T and B cell response after the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains unclear.
Methods
We performed a ...cross-sectional study to assess the virus-specific antibody and memory T and B cell responses in coronavirus disease 2019 (COVID-19) patients up to 343 days after infection. Neutralizing antibodies and antibodies against the receptor-binding domain, spike, and nucleoprotein of SARS-CoV-2 were measured. Virus-specific memory T and B cell responses were analyzed.
Results
We enrolled 59 patients with COVID-19, including 38 moderate, 16 mild, and 5 asymptomatic patients; 31 (52.5%) were men and 28 (47.5%) were women. The median age was 41 years (interquartile range, 30–55). The median day from symptom onset to enrollment was 317 days (range 257 to 343 days). We found that approximately 90% of patients still have detectable immunoglobulin (Ig)G antibodies against spike and nucleocapsid proteins and neutralizing antibodies against pseudovirus, whereas ~60% of patients had detectable IgG antibodies against receptor-binding domain and surrogate virus-neutralizing antibodies. The SARS-CoV-2-specific IgG+ memory B cell and interferon-γ-secreting T cell responses were detectable in more than 70% of patients.
Conclusions
Severe acute respiratory syndrome coronavirus 2-specific immune memory response persists in most patients approximately 1 year after infection, which provides a promising sign for prevention from reinfection and vaccination strategy.
SARS-CoV-2-specific antibody and memory T and B cell responses were detectable in most patients approximately 1 year after infection, indicating that durable immunity against secondary COVID-19 disease is possible in most individuals.
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