Cyclic compounds are generally preferred over linear compounds for functional studies due to their enhanced bioavailability, stability towards metabolic degradation, and selective receptor binding. This has led to a need for effective cyclization strategies for compound synthesis and hence increased interest in macrocyclization mediated by thioesterase (TE) domains, which naturally boost the chemical diversity and bioactivities of cyclic natural products. Many non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) derived natural products are assembled to form cyclodimeric compounds, with these molecules possessing diverse structures and biological activities.
View Article and Find Full Text PDFProtein retention expansion microscopy (ExM) retains fluorescent signals in fixed tissue and isotropically expands the tissue to allow nanoscale (<70 nm) resolution on diffraction-limited confocal microscopes. Despite the numerous advantages of ExM, the protocol is time-consuming. Here, we adapted an ExM protocol to vibratome-sectioned brain tissue of Xenopus laevis tadpoles and implemented a microwave (M/W)-assisted protocol (ExM) to reduce the workflow from days to hours.
View Article and Find Full Text PDFNat Methods
October 2024
It remains to be determined whether there is a geographical distribution pattern and phylogenetic signals for the strains with seed germination of the orchid plant . This study analyzed the community composition and phylogenetics of 72 strains associated with varieties (. f.
View Article and Find Full Text PDFProtein retention expansion microscopy (ExM) retains genetically encoded fluorescent proteins or antibody-conjugated fluorescent probes in fixed tissue and isotropically expands the tissue through a swellable polymer network to allow nanoscale (<70 nm) resolution on diffraction-limited confocal microscopes. Despite numerous advantages ExM brings to biological studies, the full protocol is time-consuming and can take multiple days to complete. Here, we adapted the ExM protocol to the vibratome-sectioned brain tissue of tadpoles and implemented a microwave-assisted protocol to reduce the workflow from days to hours.
View Article and Find Full Text PDFIn developing Xenopus tadpoles, the optic tectum begins to receive patterned visual input while visuomotor circuits are still undergoing neurogenesis and circuit assembly. This visual input regulates neural progenitor cell fate decisions such that maintaining tadpoles in the dark increases proliferation, expanding the progenitor pool, while visual stimulation promotes neuronal differentiation. To identify regulators of activity-dependent neural progenitor cell fate, we profiled the transcriptomes of proliferating neural progenitor cells and newly differentiated neurons using RNA-Seq.
View Article and Find Full Text PDFBacterial azapteridine-containing phytotoxin toxoflavin is a causal agent of rice grain rot. Here, we heterologously reconstitute toxoflavin biosynthesis in and identify key pathway intermediates, including the hitherto unknown ribityl-dedimethyl-toxoflavin. Furthermore, we characterized a cofactorless oxidase that converts ribityl-dedimethyl-toxoflavin to ribose and dedimethyl-toxoflavin, the latter of which then undergoes stepwise methylations to form toxoflavin.
View Article and Find Full Text PDFObjectives: To study the moderating effect of mother-child relationship in the association between maternal parenting stress and emotional and behavioral problems in preschool children, and to provide reference for the prevention and control of emotional and behavioral problems in preschool children.
Methods: Using a stratified cluster sampling method, 2 049 preschool children were surveyed from November to December 2021, who sampled from 12 kindergartens in Wuhu City, Anhui Province. The emotional and behavioral problems of preschool children were assessed with the Strength and Difficulties Questionnaire.
BigNeuron is an open community bench-testing platform with the goal of setting open standards for accurate and fast automatic neuron tracing. We gathered a diverse set of image volumes across several species that is representative of the data obtained in many neuroscience laboratories interested in neuron tracing. Here, we report generated gold standard manual annotations for a subset of the available imaging datasets and quantified tracing quality for 35 automatic tracing algorithms.
View Article and Find Full Text PDFProtein degradation is critical for brain function through processes that remain incompletely understood. Here, we investigated the in vivo function of the 20S neuronal membrane proteasome (NMP) in the brain of tadpoles. With biochemistry, immunohistochemistry, and electron microscopy, we demonstrated that NMPs are conserved in the tadpole brain and preferentially degrade neuronal activity-induced newly synthesized proteins in vivo.
View Article and Find Full Text PDFBackground: New and more severe clinical manifestations associated with the coronavirus disease 2019 (COVID-19) are emerging constantly in the pediatric age group. Patients in this age group are also primary carriers of the influenza virus and are at a higher risk of developing severe infection. However, studies comparing influenza and COVID-19 to show which condition causes a more severe form of disease amongst the pediatric age group are scarce.
View Article and Find Full Text PDFZhongguo Dang Dai Er Ke Za Zhi
October 2022
Objectives: To investigate the sleep patterns and characteristics of infants and young children and the association between sleep patterns and breastfeeding.
Methods: A general information questionnaire, Brief Infant Sleep Questionnaire (BISQ), and a questionnaire on feeding were used to investigate the sleep quality and feeding patterns of 1 148 infants and young children aged 7-35 months. The K-means clustering method was used to identify sleep patterns and characteristics.
The nitrogen-nitrogen bond is a core feature of diverse functional groups like hydrazines, nitrosamines, diazos, and pyrazoles. Such functional groups are found in >300 known natural products. Such N-N bond-containing functional groups are also found in significant percentage of clinical drugs.
View Article and Find Full Text PDFIntercellular transfer of toxic proteins between neurons is thought to contribute to neurodegenerative disease, but whether direct interneuronal protein transfer occurs in the healthy brain is not clear. To assess the prevalence and identity of transferred proteins and the cellular specificity of transfer, we biotinylated retinal ganglion cell proteins in vivo and examined biotinylated proteins transported through the rodent visual circuit using microscopy, biochemistry, and mass spectrometry. Electron microscopy demonstrated preferential transfer of biotinylated proteins from retinogeniculate inputs to excitatory lateral geniculate nucleus (LGN) neurons compared with GABAergic neurons.
View Article and Find Full Text PDFCyberchondria is considered "the anxiety-amplifying effects of online health-related searches." During the COVID-19 pandemic, people are likely to search health-related information online for reassurance because of fear and related physical symptoms, while cyberchondria may be triggered due to the escalation of health anxiety, different online seeking behavior preference, information overload, and insufficient e-health literacy. This study aimed to investigate the status and influencing factors of cyberchondria in residents in China during the epidemic period of COVID-19.
View Article and Find Full Text PDFIndolmycin is an antibiotic from ATCC 12648 with activity against , , and methicillin-resistant . Here we describe the use of the indolmycin biosynthetic genes in to make indolmycenic acid, a chiral intermediate in indolmycin biosynthesis, which can then be converted to indolmycin through a three-step synthesis. To expand indolmycin structural diversity, we introduce a promiscuous tryptophanyl-tRNA synthetase gene () into our production system and feed halogenated indoles to generate the corresponding indolmycenic acids, ultimately allowing us to access indolmycin derivatives through synthesis.
View Article and Find Full Text PDFCold Spring Harb Protoc
January 2022
In vivo time-lapse imaging of complete dendritic arbor structures in tectal neurons of tadpoles has served as a powerful in vivo model to study activity-dependent structural plasticity in the central nervous system during early development. In addition to quantitative analysis of gross arbor structure, dynamic analysis of the four-dimensional data offers particularly valuable insights into the structural changes occurring in subcellular domains over experience/development-driven structural plasticity events. Such analysis allows not only quantifiable characterization of branch additions and retractions with high temporal resolution but also identification of the loci of action.
View Article and Find Full Text PDFNatural products with rare functional groups are likely to be constructed by unique biosynthetic enzymes. One such rare functional group is the O-methyl nitronate, which can undergo [3 + 2] cycloaddition reactions with olefins in mild conditions. O-methyl nitronates are found in some natural products; however, how such O-methyl nitronates are assembled biosynthetically is unknown.
View Article and Find Full Text PDFMost organ donation coordinators suffer varying degrees of anxiety, depression and poor sleep caused by constant work pressure, and their professional identity is only at a medium level. All of this leads to a great risk of job burnout. To identify the influencing factors of and effective countermeasures against job burnout among organ donation coordinators.
View Article and Find Full Text PDFBackground: Angioimmunoblastic T cell lymphoma (AITL) is an infrequent hematological malignancy with variable and often atypical presentations. The presence of dysproteinemia, autoantibodies and systemic involvement in AITL has often led to a delay in diagnosis or even misdiagnosis in practice. We herewith present a case of AITL that primarily presented with acute kidney injury associated with type II Cryoglobulinemia, the underlying cause was only identified 8 months after the emergence of initial symptoms.
View Article and Find Full Text PDFGastrodin (GAS) is the main bioactive component of Tianma, a traditional Chinese medicine widely used to treat neurological disorders as well as cardio- and cerebrovascular diseases. In the present study, the protective effects of GAS on H9c2 cells against ischemia-reperfusion (IR)-like injury were found to be related to decreasing of oxidative stress. Furthermore, GAS could protect H9c2 cells against oxidative injury induced by HO.
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