Polypeptoids have been prepared and researched for more than 20 years. However, the efficient generation of polypeptoids and sequence‐defined polypeptoids faces many challenges and difficulties. The ...Ugi reaction of amino acids has recently been introduced into polypeptoid chemistry as a new and powerful method to furnish polypeptoids. In the following mini review, the recent progress on the application of the Ugi reaction of amino acids in polypeptoid science, including polypeptoid from sustainable furfural, sequence‐defined polypeptoids, and more is summarized. Moreover, the future development of the Ugi reaction of amino acids in polypeptoid science is discussed.
The Ugi reaction of amino acids has recently been introduced into polypeptoid chemistry as a new and powerful method to furnish polypeptoids. In this mini review, the recent progress on the application of the Ugi reaction of amino acids in polypeptoid science, including polypeptoid from sustainable furfural, sequence‐defined polypeptoids, and more, is summarized.
This paper aims to study the asynchronous static output-feedback (S-OF) stabilization problem for discrete-time Markovian jump linear systems (MJLSs) with non-ideal state and mode detection. Since ...the system state and mode cannot always be obtained ideally, an asynchronous S-OF controller is designed whose mode can be estimated from the system mode via a hidden Markovian model (HMM). A system augmentation approach is used to obtain an equivalent augmented system, in which the input and (controller gain)-output matrices are separated to facilitate the parameterization of controller gains. Under the augmented system characterization, several new necessary and sufficient stability conditions are established for the concerned closed-loop systems. An iterative LMI-based algorithm is proposed to design an asynchronous S-OF controller. A D-K optimization approach is used to improve its feasibility by finding more appropriate initial values. Three numerical examples are presented to demonstrate the effectiveness of the proposed design methods.
Altered metabolism is a hallmark of cancer, and the reprogramming of energy metabolism has historically been considered a general phenomenon of tumors. It is well recognized that long noncoding RNAs ...(lncRNAs) regulate energy metabolism in cancer. However, lncRNA‐mediated posttranslational modifications and metabolic reprogramming are unclear at present. In this review, we summarized the current understanding of the interactions between the alterations in cancer‐associated energy metabolism and the lncRNA‐mediated posttranslational modifications of metabolic enzymes, transcription factors, and other proteins involved in metabolic pathways. In addition, we discuss the mechanisms through which these interactions contribute to tumor initiation and progression, and the key roles and clinical significance of functional lncRNAs. We believe that an in‐depth understanding of lncRNA‐mediated cancer metabolic reprogramming can help to identify cellular vulnerabilities that can be exploited for cancer diagnosis and therapy.
Plant-pathogen interactions induce a signal transmission series that stimulates the plant's host defense system against pathogens and this, in turn, leads to disease resistance responses. Plant ...innate immunity mainly includes two lines of the defense system, called pathogen-associated molecular pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). There is extensive signal exchange and recognition in the process of triggering the plant immune signaling network. Plant messenger signaling molecules, such as calcium ions, reactive oxygen species, and nitric oxide, and plant hormone signaling molecules, such as salicylic acid, jasmonic acid, and ethylene, play key roles in inducing plant defense responses. In addition, heterotrimeric G proteins, the mitogen-activated protein kinase cascade, and non-coding RNAs (ncRNAs) play important roles in regulating disease resistance and the defense signal transduction network. This paper summarizes the status and progress in plant disease resistance and disease resistance signal transduction pathway research in recent years; discusses the complexities of, and interactions among, defense signal pathways; and forecasts future research prospects to provide new ideas for the prevention and control of plant diseases.
Polypeptoids are peptidomimetic polymers invented in the early 1990s. Although polypeptoid chemistry is developing rapidly, the simple synthesis of polypeptoids and sequence‐controlled polypeptoids ...still remains a challenge. Fortunately, we have seen a drastic rising trend in the area of Ugi reaction for polypeptoid chemistry. In the following article, recent examples of the Ugi reaction for polypeptoids synthesis will be presented, as will their suitability for sequence‐defined peptide‐peptoid hybrids. The advantages and limitations of the Ugi reaction will be discussed, which is important for the simple and general synthesis of polypeptoids.
Ring-opening polymerization of O-carboxyanhydrides (OCAs) can furnish polyesters with a diversity of functional groups that are traditionally hard to harvest by polymerization of lactones. Typical ...ring-opening catalysts are subject to unavoidable racemization of most OCA monomers, which hampers the synthesis of highly isotactic crystalline polymers. Here, we describe an effective bifunctional single-molecule organocatalysis for selective ring-opening polymerization of OCAs without epimerization. The close vicinity of both activating groups in the same molecule engenders an amplified synergetic effect and thus allows for the use of mild bases, thereby leading to minimal epimerization for polymerization. Ring-opening polymerization of manOCA monomer (OCA from mandelic acid) mediated by the bifunctional single-molecule organocatalyst yields highly isotactic poly(mandelic acid) (PMA) with controlled molecular weights (up to 19.8 kg mol–1). Mixing of the two enantiomers of PMA generates the first example of a crystalline stereocomplex in this area, which displayed distinct T m values around 150 °C. Remarkably, the bifunctional catalysts are moisture-stable, recyclable, and easy to use, allowing sustainable and scalable synthesis of a stereoregular functional polyester.
Designing artificial macromolecules with absolute sequence order is still a long-term challenge in polymer chemistry as opposed to natural biopolymers with perfectly defined sequences like proteins ...and DNA. Herein, we combined amino acid building blocks and iterative Ugi reactions for the
design and synthesis of sequence-defined peptoids. The highly efficient strategy provided excellent yields and enables multigram-scale synthesis of perfectly defined peptoids. This new strategy furnishes the broad structural diversity of side chains, as well as backbones. Importantly, the overall hydrophobicity and lower critical solution temperature (LCST) behaviours of these precisely defined peptoids can be logically altered by variation of the sequence. By following the same Ugi chemistry, these peptoids are also conjugated to DNA in a simple way, facilitating the development of novel therapeutics.
This study is intended to investigate the asynchronous stabilization problem for discrete-time Markov jump linear systems (MJLSs) with complex mode transition probabilities (C-TPs). A practical ...scenario is considered in this study. First, the system mode may not always be precisely detected in practice, therefore a hidden Markov model (HMM) is used to characterize the mismatched mode phenomenon. Second, some mode TPs associated with the Markov process of the original system may be unknown or inaccurate, rendering the C-TPs scenario. This issue could also exist in the conditional TPs associated with the joint process of the HMM. A mode separation strategy is proposed to separate the Markov process and the joint process such that we can deal with the C-TPs associated with them, respectively. Based on the above considerations, a unified controller design framework is established for MJLSs with or without C-TPs. Moreover, the results developed in this study can cover some existing works as special cases without introducing additional conservativeness. A DC motor device is used to demonstrate the effectiveness of the proposed design method.
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•Stroke-related sarcopenia is considered to be a kind of secondary sarcopenia.•The exact mechanism of sarcopenia in stroke patients is still unclear.•Some simple and convenient ...rehabilitation scores and clinical tests can be used for the screening.•It is necessary to pay attention to stroke-related sarcopenia.
Sarcopenia is a syndrome characterized by progressive systemic muscle loss and decreased function. The loss of systemic muscle mass and decreased function after stroke can't be explained by brain injury alone, and it is considered to be a kind of secondary sarcopenia, which is called stroke-related sarcopenia. More and more evidence shows that stroke-related sarcopenia can promote the occurrence and development of sarcopenia through a variety of pathogenesis, such as immobilization, impaired feeding, sympathetic activation, inflammation and denervation. Post-stroke disability brings difficulties to the screening and diagnosis of sarcopenia. Simple and easy rehabilitation scores and clinical tests can be used for the determination of body function under specific conditions of stroke, as well as for the screening stroke-related sarcopenia. At present, there is still no particularly effective way to stop its progress,however, the combination of rehabilitation exercise, nutrition supply and drugs may delay or even prevent the development of stroke-related sarcopenia. This article reviews the latest progress in the pathogenesis, screening, evaluation and treatment of stroke-related sarcopenia to provide reference for clinical treatment and rehabilitation of stroke.
Trichinella spiralis (T. spiralis) is a parasite occurring worldwide that has been proven to have antitumour ability. However, studies on the antitumour effects of cross antigens between the tumour ...and T. spiralis or antibodies against cross antigens between tumours and T. spiralis are rare.
To study the role of cross antigens between osteosarcoma and T. spiralis, we first screened the cDNA expression library of T. spiralis muscle larvae to obtain the cross antigen gene tumour protein D52 (TPD52), and prepared fusion protein TPD52 and its antiserum. The anti-osteosarcoma effect of the anti-TPD52 antiserum was studied using cell proliferation and cytotoxicity assays as well as in vivo animal models; preliminary data on the mechanism were obtained using western blot and immunohistochemistry analyses.
Our results indicated that TPD52 was mainly localized in the cytoplasm of MG-63 cells. Anti-TPD52 antiserum inhibited the proliferation of MG-63 cells and the growth of osteosarcoma in a dose-dependent manner. The tumour inhibition rate in the 100 μg treatment group was 61.95%. Enzyme-linked immunosorbent assay showed that injection of anti-TPD52 antiserum increased the serum levels of IFN-γ, TNF-α, and IL-12 in nude mice. Haematoxylin and eosin staining showed that anti-TPD52 antiserum did not cause significant pathological damage. Apoptosis of osteosarcoma cells was induced by anti-TPD52 antiserum in vivo and in vitro.
Anti-TPD52 antiserum exerts an anti-osteosarcoma effect by inducing apoptosis without causing histopathological damage.
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