A large proportion of protein–protein interactions (PPIs) occur between a short peptide and a globular protein domain; the peptides involved in surface interactions play important roles, and there is ...great promise for using peptide motifs to interfere with protein interactions. Peptide inhibitors show more promise in blocking large surface protein interactions compared to small molecule inhibitors. However, peptides have drawbacks including poor stability against circulating proteolytic enzymes and an intrinsic inability to penetrate cell membranes. Stapled helical peptides, by adopting a preformed, stable α-helical conformation, exhibit improved proteolytic stability and membrane permeability compared to linear bioactive peptides. In this review, we summarize the broad aspects of peptide stapling for chemistry, biophysics, and biological applications and specifically highlight the methodology by providing an inventory of different anchoring residues categorized into two natural amino acids, two nonnatural amino acids, or a combination of natural and nonnatural amino acids. Additional advantages of specific peptide stapling techniques, including but not limited to reversibility, bio-orthogonal reactivity, and photoisomerization, are also discussed individually. This review is expected to provide a broad reference for the rational design of druggable stapled peptides targeting therapeutic proteins, particularly those involved in PPIs, by considering the impact of anchoring residues, functional cross-linkers, physical staple length, staple components, and the staple motif on the biophysical properties of the peptides.
In recent years, natural and anthropogenic geohazards have occured frequently all over the world, and field monitoring is becoming an increasingly important task to mitigate these risks. However, ...conventional geotechnical instrumentations for monitoring geohazards have a number of weaknesses, such as low accuracy, poor durability, and high sensitivity to environmental interferences. In this aspect, fiber Bragg grating (FBG), as a popular fiber optic sensing technology, has gained an explosive amount of attention. Based on this technology, quasi-distributed sensing systems have been established to perform real-time monitoring and early warning of landslides, debris flows, land subsidence, earth fissures and so on. In this paper, the recent research and development activities of applying FBG systems to monitor different types of geohazards, especially those triggered by human activities, are critically reviewed. The working principles of newly developed FBG sensors are briefly introduced, and their features are summarized. This is followed by a discussion of recent case studies and lessons learned, and some critical problems associated with field implementation of FBG-based monitoring systems. Finally the challenges and future trends in this research area are presented.
In the article, we present the best possible parameters
,
,
,
∈ ℝ and
,
∈ 1/2, 1 such that the double inequalities
hold for
,
> 0 with
≠
, and provide new bounds for the complete elliptic integral of ...the second kind, where
,
) = (
+
)/2 is the arithmetic mean,
is the quadratic mean,
,
) = (
+
)/(
+
) is the contra-harmonic mean,
;
,
) =
+ (1 –
,
+ (1 –
is the one-parameter contra-harmonic mean and
is the Toader mean of order 3.
•Summarized the over-growth risks of non-pathogenic CRB.•Presented the genus, sources and chlorine resistance of all the isolated CRB strains.•Demonstrated the lack of widely-accepted method to ...evaluate chlorine resistance.•Proposed a recommended evaluating method for chlorine resistance.•Proposed a quantitative definition of chlorine-resistant bacteria.
Chlorine-resistant bacteria (CRB) are commonly defined as bacteria with high resistance to chlorine disinfection or bacteria which can survive or even regrow in the residual chlorine. Chlorine disinfection cannot completely control the risks of CRB, such as risks of pathogenicity, antibiotic resistance and microbial growth. Currently, researchers pay more attention to CRB with pathogenicity or antibiotic resistance. The microbial growth risks of non-pathogenic CRB in water treatment and reclamation systems have been neglected to some extent. In this review, these three kinds of risks are all analyzed, and the last one is also highlighted. In order to study CRB, various methods are used to evaluate chlorine resistance. This review summarizes the evaluating methods for chlorine resistance reported in the literatures, and collects the important information about the typical isolated CRB strains including their genera, sources and levels of chlorine resistance. To our knowledge, few review papers have provided such systematic information about CRB. Among 44 typical CRB strains from 17 genera isolated by researchers, Mycobacterium, Bacillus, Legionella, Pseudomonas and Sphingomonas were the five genera with the highest frequency of occurrence in literatures. They are all pathogenic or opportunistic pathogenic bacteria. In addition, although there are many studies on CRB, information about chlorine resistance level is still limited to specie level or strain level. The difference in chlorine resistance level among different bacterial genera is less well understood. An inconvenient truth is that there is still no widely-accepted method to evaluate chlorine resistance and to identify CRB. Due to the lack of a unified method, it is difficult to compare the results about chlorine resistance level of bacterial strains in different literatures. A recommended evaluating method using logarithmic removal rate as an index and E. coli as a reference strain is proposed in this review based on the summary of the current evaluating methods. This method can provide common range of chlorine resistance of each genus and it is conducive to analyzing the distribution and abundance of CRB in the environment.
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In reverse osmosis (RO) system for wastewater reclamation, biofouling is an inevitable issue. Chlorine disinfection is commonly used in pretreatment to control biofouling. Some chlorine-resistant ...bacteria could survive after chlorine disinfection and the microbial community structure in feed water changes significantly, thus leading to the change of biofouling potential. In this study, the effect of chlorine disinfection on the biofouling of RO membrane was investigated using a laboratory cross-flow RO system. Chlorine disinfection inactivated most bacteria in feed water. However, during the operation of RO system, with the increase of chlorine dosage the flux decline became more severe after a period of operation. The final normalized flux after 21 days was 0.27, 0.26, 0.20, and 0.21 with 0, 1, 5, and 15 mg-Cl2/L chlorine as pretreatment, respectively. After the operation, the numbers of active bacteria in the foulants on the fouled membrane were on the same level regardless of the chlorine dosage, whereas the thickness of the foulants increased with the chlorine dosage significantly. Additionally, the higher total organic carbon concentration indicated more extracellular polymeric substances (EPS) in foulants. Microbial community structure analysis showed that the abundance and the species number of chlorine-resistant bacteria increased significantly with the chlorine dosage. Typical chlorine-resistant bacteria, including Methylobacterium, Pseudomonas, Sphingomonas, and Acinetobacter, were identified as significantly distinctive genera in the foulants after the pretreatment by 15 mg-Cl2/L chlorine. Compared with the bacteria without chlorine disinfection, these remaining bacteria produced more EPS with higher molecular weight, which could be the major contribution to more severe RO membrane fouling after chlorine disinfection.
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•Studied effect of chlorine disinfection on biofouling of reverse osmosis (RO) system.•Applied lab RO systems, multiple microscopy, gene sequencing and organic analysis.•Chlorine disinfection changed the microbial community structure in foulants.•Four dominant chlorine-resistant strains were found in foulants with 15 mg-Cl2/L.•Extracellular polymeric substance produced by these strains caused severe biofouling.
For successful wastewater reclamation, advanced oxidation processes have attracted attention for elimination of emerging contaminants. In this study, the synergistic treatment with UV irradiation and ...chlorine (UV/chlorine) was used to degrade carbamazepine (CBZ). Neither UV irradiation alone nor chlorination alone could efficiently degraded CBZ. UV/chlorine oxidation showed a significant synergistic effect on CBZ degradation through generation of radical species (OH and Cl), and this process could be well depicted by pseudo first order kinetic. The degradation rate constants (kobs,CBZ) of CBZ increased linearly with increasing UV irradiance and chlorine dosage. The degradation of CBZ by UV/chlorine in acidic solutions was more efficient than that in basic solutions mainly due to the effect of pH on the dissociation of HOCl and OCl− and then on the quantum yields and radical species quenching of UV/chlorine. When pH was increased from 5.5 to 9.5, the rate constants of degradation of CBZ by OH decreased from 0.65 to 0.14 min−1 and that by Cl decreased from 0.40 to 0.11 min−1. The rate constant for the reaction between Cl and CBZ was 5.6 ± 1.6 × 1010 M−1 s−1. Anions of HCO3− (1–50 mM) showed moderate inhibition of CBZ degradation by UV/chlorine, while Cl− did not. UV/chlorine could efficiently degrade CBZ in wastewater treatment plant effluent, although the degradation was inhibited by about 30% compared with that in ultrapure water with chlorine dosage of 0.14–0.56 mM. Nine main oxidation products of the CBZ degradation by UV/chlorine were identified using the HPLC-QToF MS/MS. Initial oxidation products arose from hydroxylation, carboxylation and hydrogen atom abstraction of CBZ by OH and Cl, and were then further oxidized to generate acylamino cleavage and decarboxylation products of acridine and acridione.
•UV/chlorine showed synergistic degradation of carbamazepine than UV and chlorination.•Carbamazepine degraded through both OH and Cl ways during UV/chlorine oxidation•Carbamazepine could be efficiently degraded by UV/chlorine in UPW and WWTP effluent.•The second order rate constant between carbamazepine and Cl were examined
The chemo-free concept represents a new direction for managing adult patients with Ph-positive acute lymphoblastic leukemia (Ph + ALL). The tyrosine kinase inhibitors (TKIs), blinatumomab and ...venetoclax serve as the backbone of chemo-free regimens; several prospective studies involving these drugs have demonstrated high remission rates and promising, albeit short, survival outcomes. This review summarizes the latest updates on chemo-free regimens in the treatment of adult patients with Ph + ALL, presented at the 2023 ASH annual meeting.
Rechargeable aqueous zinc ion batteries (AZIBs), as a rising star in aqueous ion batteries, are restricted by the narrow voltage window and the unsatisfactory reversibility, which are dominated by ...the high activity of H2O molecules, side reaction, Zn dendrites, and structural degeneration of the cathode. Electrolyte manipulation has seen a great deal of research recently, particularly various kinds of organic molecules have been shown to achieve outstanding effects on stabilizing the Zn anode, yet the exploration of the mechanism behind the high performance has not been thorough. In an attempt to find such underlying principles, the basic reactions and the corresponding progress on the anode side of AZIBs are first assessed. Then, the roles of organic molecules in recent studies are researched, followed by a deep insight into the role of organic molecules. Finally, several designed strategies are proposed for the further exploration of high performance aqueous rechargeable ZIBs through incorporating appropriate organic molecules in the electrolytes.
Organic molecules as electrolyte regulators, influence the efficiency of Zn electrodes by tuning the interplay among the Zn surface, Zn ions, water molecules, and anions, including manipulating Zn2+‐solvation structure, constructing Zn2+‐organic molecule coordination, decreasing the Zn2+‐water coordination, and impairing the electrostatic coupling between the cations and anions.
In this paper, a reverse group consensus problem is investigated for the dynamic agents with the inputs in the cooperation-competition network which can be divided into two sub-networks. The weights ...between the agents in the same sub-network are positive, while the weights between the agents among different sub-networks are negative. Then, the reverse group consensus is firstly studied without the in-degree balance condition. By defining the mirror graph and establishing the solution of the multi-agent system, it is found that the reverse group consensus problem can be achieved if the mirror graph is strongly connected. The explicit expression of the error level is also derived, which would be vanished for multi-agent systems with some special kinds of inputs. Furthermore, as an extension, the decomposing of the cooperation-competition network is discussed, where the concept of the condensation undirected graph and the path balance condition are defined, and several effective sufficient conditions are obtained. Finally, numerical simulation demonstrates the effectiveness of the theoretical analysis.
Protein misfolding and aggregation are a hallmark of several neurodegenerative diseases (NDs). However, how protein aggregation leads to cytotoxicity and neurodegeneration is still controversial. ...Emerging evidence demonstrates that sequestration of cellular‐interacting partners by protein aggregates contributes to the pathogenesis of these diseases. Here, we review current research on sequestration of cellular proteins by protein aggregates and its relation to proteinopathies. Based on different interaction modes, we classify these protein sequestrations into four types: protein coaggregation, domain/motif‐mediated sequestration, RNA‐assisted sequestration, and sequestration of molecular chaperones. Thus, the cellular essential proteins and/or RNA hijacked by protein aggregates may lose their biological functions, consequently resulting in cytotoxicity and neurodegeneration. We have proposed a hijacking model recapitulating the sequestration process and the loss‐of‐function pathology of ND.
Protein misfolding and aggregation are generally related to the pathogenesis of neurodegenerative diseases. The hijacking model has been proposed for recapitulating a loss‐of‐function pathology. An amyloidogenic protein self‐aggregates and sequesters its cellular interacting proteins and/or RNAs into insolubilities. This snowball‐like sequestration effect may cause the partners to be dysfunctional and cytotoxic, and consequently lead to the degeneration of neuronal cells.
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