-
Nanomaterials (Basel, Switzerland) Jan 2021Bulk inorganic materials play important roles in human society, and their construction is commonly achieved by the coalescence of inorganic nano- or micro-sized... (Review)
Review
Bulk inorganic materials play important roles in human society, and their construction is commonly achieved by the coalescence of inorganic nano- or micro-sized particles. Understanding the coalescence process promotes the elimination of particle interfaces, leading to continuous bulk phases with improved functions. In this review, we mainly focus on the coalescence of ceramic and metal materials for bulk construction. The basic knowledge of coalescent mechanism on inorganic materials is briefly introduced. Then, the properties of the inorganic precursors, which determine the coalescent behaviors of inorganic phases, are discussed from the views of particle interface, size, crystallinity, and orientation. The relationships between fundamental discoveries and industrial applications are emphasized. Based upon the understandings, the applications of inorganic bulk materials produced by the coalescence of their particle precursors are further presented. In conclusion, the challenges of particle coalescence for bulk material construction are presented, and the connection between recent fundamental findings and industrial applications is highlighted, aiming to provide an insightful outlook for the future development of functional inorganic materials.
PubMed: 33477573
DOI: 10.3390/nano11010241 -
Cellulose (London, England) 2021Polyacrylonitrile (PAN)-based carbon precursor is a well-established and researched material for electrodes in energy storage applications due to its good physical... (Review)
Review
Polyacrylonitrile (PAN)-based carbon precursor is a well-established and researched material for electrodes in energy storage applications due to its good physical properties and excellent electrochemical performance. However, in the fight of preserving the environment and pioneering renewable energy sources, environmentally sustainable carbon precursors with superior electrochemical performance are needed. Therefore, bio-based materials are excellent candidates to replace PAN as a carbon precursor. Depending on the design requirement (e.g. carbon morphology, doping level, specific surface area, pore size and volume, and electrochemical performance), the appropriate selection of carbon precursors can be made from a variety of biomass and biowaste materials. This review provides a summary and discussion on the preparation and characterization of the emerging and recent bio-based carbon precursors that can be used as electrodes in energy storage applications. The review is outlined based on the morphology of nanostructures and the precursor's type. Furthermore, the review discusses and summarizes the excellent electrochemical performance of these recent carbon precursors in storage energy applications. Finally, a summary and outlook are also given. All this together portrays the promising role of bio-based carbon electrodes in energy storage applications.
PubMed: 33897123
DOI: 10.1007/s10570-021-03881-z -
European Journal of Immunology Jan 2019Innate lymphoid cells (ILCs) represent a family of innate effector cells including NK cells, lymphoid tissue inducer (LTi) cells, and distinct ILC1, ILC2, and ILC3... (Review)
Review
Innate lymphoid cells (ILCs) represent a family of innate effector cells including NK cells, lymphoid tissue inducer (LTi) cells, and distinct ILC1, ILC2, and ILC3 subsets that produce IFN-γ, IL-5/IL-13, and IL-17A/IL-22, respectively. ILCs accumulate at mucosal sites and can promote the first-line defense against infection. ILCs are also implicated in tissue repair and can either pre-empt, or alternatively, exacerbate inflammation. Studies in mice have identified ILC precursors in fetal liver and adult BM that have diverse lineage potential. As such, these sites have been considered as the 'factories' to generate mature ILC. Here, we summarize knowledge concerning murine and human ILC development and discuss the recent identification of circulating multipotent and unipotent ILC precursors. We propose an alternative model of "ILC-poiesis", whereby blood ILC precursors migrate into tissues to complete their differentiation into mature ILC subsets under the influence of local environmental factors. Within this framework, ILC-poiesis guarantees appropriate ILC generation at the right place and the right time. We further discusss the potential applications of circulating ILC precursors for cell therapy of human disease.
Topics: Animals; Cell Differentiation; Cytokines; Hematopoiesis; Humans; Immunity, Innate; Lymphocytes; Mice
PubMed: 30350853
DOI: 10.1002/eji.201747294 -
Developmental Biology Dec 2018Melanocytes derive from neural crest cells, which are a highly migratory population of cells that play an important role in pigmentation of the skin and epidermal...
Melanocytes derive from neural crest cells, which are a highly migratory population of cells that play an important role in pigmentation of the skin and epidermal appendages. In most vertebrates, melanocyte precursor cells migrate solely along the dorsolateral pathway to populate the skin. However, zebrafish melanocyte precursors also migrate along the ventromedial pathway, in route to the yolk, where they interact with other neural crest derivative populations. Here, we demonstrate the requirement for zebrafish paralogs pcdh10a and pcdh10b in zebrafish melanocyte precursor migration. pcdh10a and pcdh10b are expressed in a subset of melanocyte precursor and somatic cells respectively, and knockdown and TALEN mediated gene disruption of pcdh10a results in aberrant migration of melanocyte precursors resulting in fully melanized melanocytes that differentiate precociously in the ventromedial pathway. Live cell imaging analysis demonstrates that loss of pchd10a results in a reduction of directed cell migration of melanocyte precursors, caused by both increased adhesion and a loss of cell-cell contact with other migratory neural crest cells. Also, we determined that the paralog pcdh10b is upregulated and can compensate for the genetic loss of pcdh10a. Disruption of pcdh10b alone by CRISPR mutagenesis results in somite defects, while the loss of both paralogs results in enhanced migratory melanocyte precursor phenotype and embryonic lethality. These results reveal a novel role for pcdh10a and pcdh10b in zebrafish melanocyte precursor migration and suggest that pcdh10 paralogs potentially interact for proper transient migration along the ventromedial pathway.
Topics: Animals; Cadherins; Cell Differentiation; Cell Movement; Melanocytes; Neural Crest; Pigmentation; Protocadherins; Skin; Zebrafish; Zebrafish Proteins
PubMed: 29604249
DOI: 10.1016/j.ydbio.2018.03.022 -
Frontiers in Plant Science 2017Tocochromanols are organic compounds mostly produced by photosynthetic organisms that exhibit vitamin E activity in animals. They result from the condensation of... (Review)
Review
Tocochromanols are organic compounds mostly produced by photosynthetic organisms that exhibit vitamin E activity in animals. They result from the condensation of homogentisate with four different polyprenyl side chains derived all from geranylgeranyl pyrophosphate. The core tocochromanol biosynthesis has been investigated in several photosynthetic organisms and is now well-characterized. In contrast, our current knowledge of the biosynthesis and transport of tocochromanol biosynthetic precursors is much more limited. While tocochromanol synthesis occurs in plastids, converging genetic data in Arabidopsis and soybean demonstrate that the synthesis of the polar precursor homogentisate is located in the cytoplasm. These data implies that tocochromanol synthesis involves several plastidic membrane transporter(s) that remain to be identified. In addition, the metabolic origin of the lipophilic isoprenoid precursor is not fully elucidated. While some genetic data exclusively attribute the synthesis of the prenyl component of tocochromanols to the plastidic methyl erythritol phosphate pathway, multiple lines of evidence provided by feeding experiments and metabolic engineering studies indicate that it might partially originate from the cytoplasmic mevalonate pathway. Although this question is still open, these data demonstrate the existence of membrane transporter(s) capable of importing cytosolic polyprenyl pyrophosphate such as farnesyl pyrophosphate into plastids. Since the availability of both homogentisate and polyprenyl pyrophosphates are currently accepted as major mechanisms controlling the type and amount of tocochromanols produced in plant tissues, we summarized our current knowledge and research gaps concerning the biosynthesis, metabolic origins and transport of tocochromanol biosynthetic precursors in plant cells.
PubMed: 29184568
DOI: 10.3389/fpls.2017.01959 -
Molecular & Cellular Proteomics : MCP Feb 2023Data-independent acquisition (DIA) methods have become increasingly popular in mass spectrometry-based proteomics because they enable continuous acquisition of fragment...
Data-independent acquisition (DIA) methods have become increasingly popular in mass spectrometry-based proteomics because they enable continuous acquisition of fragment spectra for all precursors simultaneously. However, these advantages come with the challenge of correctly reconstructing the precursor-fragment relationships in these highly convoluted spectra for reliable identification and quantification. Here, we introduce a scan mode for the combination of trapped ion mobility spectrometry with parallel accumulation-serial fragmentation (PASEF) that seamlessly and continuously follows the natural shape of the ion cloud in ion mobility and peptide precursor mass dimensions. Termed synchro-PASEF, it increases the detected fragment ion current several-fold at sub-second cycle times. Consecutive quadrupole selection windows move synchronously through the mass and ion mobility range. In this process, the quadrupole slices through the peptide precursors, which separates fragment ion signals of each precursor into adjacent synchro-PASEF scans. This precisely defines precursor-fragment relationships in ion mobility and mass dimensions and effectively deconvolutes the DIA fragment space. Importantly, the partitioned parts of the fragment ion transitions provide a further dimension of specificity via a lock-and-key mechanism. This is also advantageous for quantification, where signals from interfering precursors in the DIA selection window do not affect all partitions of the fragment ion, allowing to retain only the specific parts for quantification. Overall, we establish the defining features of synchro-PASEF and explore its potential for proteomic analyses.
Topics: Tandem Mass Spectrometry; Proteomics; Proteome; Peptides
PubMed: 36566012
DOI: 10.1016/j.mcpro.2022.100489 -
Frontiers in Plant Science 2022is both a traditional herbal medicine and a plant of high ornamental and medicinal value. Alkaloids, especially terpenoid indole alkaloids (TIAs), with pharmacological...
is both a traditional herbal medicine and a plant of high ornamental and medicinal value. Alkaloids, especially terpenoid indole alkaloids (TIAs), with pharmacological activities are present in the tissues of . A number of genes involved in alkaloid biosynthetic pathways have been identified. However, the regulatory mechanisms underlying the precursor and methyl jasmonate (MeJA)-induced accumulation of alkaloids in are poorly understood. In this study, we collected protocorm-like bodies (PLBs) and treated them with TIA precursors (tryptophan and secologanin) and MeJA for 0 (T0), 4 (T4) and 24 h (T24); we also established control samples (C4 and C24). Then, we measured the total alkaloid content of the PLBs and performed transcriptome sequencing using the Illumina HiSeq 2,500 system. The total alkaloid content increased significantly after 4 h of treatment. Go and KEGG analysis suggested that genes from the TIA, isoquinoline alkaloid, tropane alkaloid and jasmonate (JA) biosynthetic pathways were significantly enriched. Weighted gene coexpression network analysis (WGCNA) uncovered brown module related to alkaloid content. Six and seven genes related to alkaloid and JA bisosynthetic pathways, respectively, might encode the key enzymes involved in alkaloid biosynthesis of . Moreover, 13 transcription factors (TFs), which mostly belong to AP2/ERF, WRKY, and MYB gene families, were predicted to regulate alkaloid biosynthesis. Our data provide insight for studying the regulatory mechanism underlying TIA precursor and MeJA-induced accumulation of three types of alkaloids in .
PubMed: 35937364
DOI: 10.3389/fpls.2022.941231 -
Biological Chemistry Oct 2023The ribosomal RNA precursor (pre-rRNA) comprises three of the four ribosomal RNAs and is synthesized by RNA polymerase (Pol) I. Here, we describe the mechanisms of Pol I... (Review)
Review
The ribosomal RNA precursor (pre-rRNA) comprises three of the four ribosomal RNAs and is synthesized by RNA polymerase (Pol) I. Here, we describe the mechanisms of Pol I transcription in human cells with a focus on recent insights gained from structure-function analyses. The comparison of Pol I-specific structural and functional features with those of other Pols and with the excessively studied yeast system distinguishes organism-specific from general traits. We explain the organization of the genomic rDNA loci in human cells, describe the Pol I transcription cycle regarding structural changes in the enzyme and the roles of human Pol I subunits, and depict human rDNA transcription factors and their function on a mechanistic level. We disentangle information gained by direct investigation from what had apparently been deduced from studies of the yeast enzymes. Finally, we provide information about how Pol I mutations may contribute to developmental diseases, and why Pol I is a target for new cancer treatment strategies, since increased rRNA synthesis was correlated with rapidly expanding cell populations.
Topics: Humans; RNA, Ribosomal; RNA Precursors; Saccharomyces cerevisiae; Transcription, Genetic; RNA Polymerase I; DNA, Ribosomal
PubMed: 37454246
DOI: 10.1515/hsz-2023-0214 -
Journal of Labelled Compounds &... Jan 2022Copper-mediated nucleophilic radiofluorination using boronic precursors is a promising, general method to label aromatic compounds with [ F]fluoride. However, in various...
Copper-mediated nucleophilic radiofluorination using boronic precursors is a promising, general method to label aromatic compounds with [ F]fluoride. However, in various reports, large amounts of precursor (60 μmol) were needed to achieve high radiochemical conversions (RCCs), which is neither ideal nor practical for the preparation of F radiopharmaceuticals. To investigate this matter, we studied alcohol-enhanced Cu-mediated nucleophilic radiofluorination using a variety of model reactions in which we varied the concentration of [ F]fluoride (no carrier added or isotope diluted) and the amount of precursor, base, and Cu(OTF) (Py) . We found that lower amounts of precursors (e.g., 15 μmol) could be used and that the amount of base (e.g., K CO or KHCO ) played a critical and limiting role in the labeling reactions. Greater than one-equivalent of base and sufficient amounts of precursors and Cu(OTf) (Py) were required to achieve good to high RCCs. The RCCs were also dependent on the overall concentration of the labeling reactions, with low reaction volumes and high concentrations of reagents being preferred. Our findings will help to improve the design of radiolabeling protocols using alcohol-enhanced copper-mediated radiofluorination of boronic precursors for the preparation of F labeled radiopharmaceuticals and other radiohalogen-labeled compounds.
Topics: Copper; Fluorides; Fluorine Radioisotopes; Isotope Labeling; Radiochemistry; Radiopharmaceuticals
PubMed: 34617619
DOI: 10.1002/jlcr.3955 -
Current Opinion in Structural Biology Apr 2018The small subunit processome is the first precursor of the small eukaryotic ribosomal subunit. During its assembly in the nucleolus, many ribosome biogenesis factors, an... (Review)
Review
The small subunit processome is the first precursor of the small eukaryotic ribosomal subunit. During its assembly in the nucleolus, many ribosome biogenesis factors, an RNA chaperone, and ribosomal proteins associate with the nascent pre-rRNA. Biochemical studies have elucidated the rRNA-subdomain dependent recruitment of these factors during SSU processome assembly and have been complemented by structural studies of the assembled particle. Ribosome biogenesis factors encapsulate and guide subdomains of pre-ribosomal RNA in distinct compartments. This prevents uncoordinated maturation and enables processing of regions not accessible in the mature subunit. By sequentially reducing conformational freedom, flexible proteins facilitate the incorporation of dynamic subcomplexes into a globular particle. Large rearrangements within the SSU processome are required for compaction into the mature small ribosomal subunit.
Topics: Animals; Humans; Models, Molecular; Nucleic Acid Conformation; Protein Conformation; RNA Precursors; RNA, Ribosomal; Ribosomal Proteins; Ribosome Subunits, Small
PubMed: 29414516
DOI: 10.1016/j.sbi.2018.01.008