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1.
Nano Lett ; 24(32): 9974-9982, 2024 Aug 14.
Article in English | MEDLINE | ID: mdl-39083237

ABSTRACT

Various applications related to glucose catalysis have led to the development of functional nanozymes with glucose oxidase (GOX)-like activity. However, the unsatisfactory catalytic activity of nanozymes is a major challenge for their practical applications due to their inefficient hydrogen and electron transfer. Herein, we present the synthesis of AuFe/polydopamine (PDA) superparticles that exhibit photothermal-enhanced GOX-like activity. Experimental investigations and theoretical calculations reveal that the glucose oxidation process catalyzed by AuFe/PDA follows an artificial-cofactor-mediated hydrogen atom transfer mechanism, which facilitates the generation of carbon-centered radical intermediates. Rather than depending on charged Au surfaces for thermodynamically unstable hydride transfer, Fe(III)-coordinated PDA with abundant amino and phenolic hydroxyl groups serves as cofactor mimics, facilitating both hydrogen atom and electron transfer in the catalytic process. Finally, leveraging the photothermal-enhanced GOX-like and catalase-like activities of AuFe/PDA, we establish a highly sensitive and accurate point-of-care testing blood glucose determination with exceptional anti-jamming capabilities.


Subject(s)
Glucose Oxidase , Gold , Hydrogen , Indoles , Polymers , Glucose Oxidase/chemistry , Glucose Oxidase/metabolism , Gold/chemistry , Hydrogen/chemistry , Electron Transport , Indoles/chemistry , Polymers/chemistry , Glucose/chemistry , Catalysis , Oxidation-Reduction , Blood Glucose/analysis , Iron/chemistry , Humans
2.
New Phytol ; 244(1): 176-191, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39135382

ABSTRACT

Diurnal floret opening time (DFOT) is a pivotal trait for successful fertilization and hybrid breeding in rice. However, the molecular mechanism underlying this trait is poorly understood in rice. In this study, we combined the cytological, genetic and molecular studies to demonstrate that jasmonic acid (JA) regulates DFOT in rice through modulating the turgor and osmotic pressure of the lodicules. We show that lodicules undergo dramatic morphologic changes, accompanied by changes in water and sugar contents during the process of floret opening. Consistently, a large set of genes associated with cell osmolality and cell wall remodeling exhibits distinct expression profiles at different time points in our time-course transcriptomes of lodicules. Notably, a group of JA biosynthesis and signaling genes is continuously upregulated, accompanied by a gradual increase in JA accumulation as floret opening approaching. Furthermore, we demonstrate that the JA biosynthesis gene OsAOS1 is required for endogenous JA biosynthesis in lodicules and promoting rice DFOT. Moreover, OsMYC2, a master regulator of JA signaling, regulates rice DFOT by directly activating OsAOS1, OsSWEET4, OsPIP2;2 and OsXTH9. Collectively, our findings establish a core regulatory network mediated by JA for modulating rice DFOT and provide effective gene targets for the genetic improvement of DFOT in rice.


Subject(s)
Circadian Rhythm , Cyclopentanes , Gene Expression Regulation, Plant , Gene Regulatory Networks , Oryza , Oxylipins , Plant Proteins , Oryza/genetics , Oryza/physiology , Oryza/metabolism , Cyclopentanes/metabolism , Oxylipins/metabolism , Plant Proteins/metabolism , Plant Proteins/genetics , Circadian Rhythm/genetics , Circadian Rhythm/physiology , Flowers/physiology , Flowers/genetics , Signal Transduction , Genes, Plant , Osmotic Pressure , Time Factors , Water/metabolism , Transcriptome/genetics
3.
Environ Sci Technol ; 2024 Oct 03.
Article in English | MEDLINE | ID: mdl-39363448

ABSTRACT

Nitrous acid (HONO) is crucial in atmospheric chemistry as a precursor to morning peak hydroxyl radicals and significantly affects urban air quality by forming secondary pollutants, yet the mechanisms of its daytime formation is not fully understood. This study investigates the role of formic acid (HCOOH), a prevalent electron and proton donor, in the transformation of nitrogen oxides (NOx) and the formation of HONO on photoactive mineral dust. Exploiting hematite (Fe2O3) as an environmental indicator, we demonstrate that HCOOH significantly promotes the photoreduction of NO2 to HONO, while suppressing nitrate accumulation. This occurs through the formation of a surface ≡Fe-OOCH complex, where sunlight activates the C-H bond to generate and transfer active hydrogen, directly converting NO2 to HONO. Additionally, HCOOH can trigger the photolysis of nitrates as predeposited on Fe2O3, further increasing HONO production. These findings show that HCOOH-mediated photochemical reactions on iron minerals may contribute to elevated atmospheric HONO levels, highlighting a crucial pathway with broad effects on atmospheric chemistry and public health.

4.
Angew Chem Int Ed Engl ; : e202415051, 2024 Sep 30.
Article in English | MEDLINE | ID: mdl-39345005

ABSTRACT

Microscale zero-valent iron (mZVI) is widely used for water pollutant control and environmental remediation, yet its reactivity is still constrained by the inert oxide shell. Herein, we demonstrate that mechanochemical thioglycolate (TG) modification can dramatically enhance heavy metal (NiII, CrVI, CdII, PbII, HgII, and SbIII) removal rates of mZVI by times of 16.7 to 88.0. Compared with conventional impregnation (wet chemical process), this dry mechanochemical process could construct more robust covalent bonding between TG and the inert oxide shell of mZVI through its electron-withdrawing carboxylate group to accelerate the electron release from the iron core, and more effectively strengthen the surface heavy metal adsorption through metal(d)-sulfur(p) orbital hybridization between its thiol group and heavy metal ions. Impressively, this mechanochemically TG-modified mZVI exhibited an unprecedented NiII removal capacity of 580.4 mg Ni g-1 Fe, 17.1 and 9.5 times those of mZVI and wet chemically TG-modified mZVI, respectively. Its application potential was further validated by more than 10 days of stable groundwater NiII removal in a column flow reactor. This study offers a promising strategy to enhance the reactivity of mZVI, and also emphasizes the importance of the modification strategy in optimizing its performance for environmental applications.

5.
Angew Chem Int Ed Engl ; 63(31): e202406046, 2024 Jul 29.
Article in English | MEDLINE | ID: mdl-38771293

ABSTRACT

The electrochemical nitrate reduction reaction (NO3RR) is able to convert nitrate (NO3 -) into reusable ammonia (NH3), offering a green treatment and resource utilization strategy of nitrate wastewater and ammonia synthesis. The conversion of NO3 - to NH3 undergoes water dissociation to generate active hydrogen atoms and nitrogen-containing intermediates hydrogenation tandemly. The two relay processes compete for the same active sites, especially under pH-neutral condition, resulting in the suboptimal efficiency and selectivity in the electrosynthesis of NH3 from NO3 -. Herein, we constructed a Cu1-Fe dual-site catalyst by anchoring Cu single atoms on amorphous iron oxide shell of nanoscale zero-valent iron (nZVI) for the electrochemical NO3RR, achieving an impressive NO3 - removal efficiency of 94.8 % and NH3 selectivity of 99.2 % under neutral pH and nitrate concentration of 50 mg L-1 NO3 --N conditions, greatly surpassing the performance of nZVI counterpart. This superior performance can be attributed to the synergistic effect of enhanced NO3 - adsorption on Fe sites and strengthened water activation on single-atom Cu sites, decreasing the energy barrier for the rate-determining step of *NO-to-*NOH. This work develops a novel strategy of fabricating dual-site catalysts to enhance the electrosynthesis of NH3 from NO3 -, and presents an environmentally sustainable approach for neutral nitrate wastewater treatment.

6.
Environ Sci Technol ; 57(36): 13559-13568, 2023 09 12.
Article in English | MEDLINE | ID: mdl-37647604

ABSTRACT

Mineral dust serves as a significant source of sulfate aerosols by mediating heterogeneous sulfur dioxide (SO2) oxidation in the atmosphere. Given that a considerable proportion of small organic acids are deposited onto mineral dust via long-range transportation, understanding their impact on atmospheric SO2 transformation and sulfate formation is of great importance. This study investigates the effect of oxalate on heterogeneous SO2 uptake and oxidation phenomenon by in situ FTIR, theoretical calculation, and continuous stream experiments, exploiting hematite (Fe2O3) as an environmental indicator. The results highlight the critical role of naturally deposited oxalate in mononuclear monodentate coordinating surface Fe atoms of Fe2O3 that enhances the activation of O2 for oxidizing SO2 into sulfate. Meanwhile, oxalate increases the hygroscopicity of Fe2O3, facilitating H2O dissociation into reactive hydroxyl groups and further augmenting the SO2 uptake capacity of Fe2O3. More importantly, other conventional iron minerals, such as goethite and magnetite, as well as authentic iron-containing mineral dust, exhibit similar oxalate-promoted sulfate accumulation behaviors. Our findings suggest that oxalate-assisted SO2 oxidation on iron minerals is one of the important contributors to secondary sulfate aerosols, especially during the nighttime with high relative humidity.


Subject(s)
Iron , Oxalates , Sulfates , Minerals , Oxidation-Reduction , Sulfur Oxides , Aerosols
7.
Angew Chem Int Ed Engl ; 62(24): e202302286, 2023 Jun 12.
Article in English | MEDLINE | ID: mdl-37067456

ABSTRACT

Seawater is one of the most important CO2 sequestration media for delivering value-added chemicals/fuels and active chlorine; however, this scenario is plagued by sluggish reaction rates and poor product selectivity. Herein, we first report the synthesis of nitrogen-doped BiOCl atomic layers to directly split carbon-sequestrated natural seawater (Yellow Sea, China) into stoichiometric CO (92.8 µmol h-1 ) and HClO (83.2 µmol h-1 ) under visible light with selectivities greater than 90 %. Photoelectrons enriched on the exposed BiOCl{001} facet kinetically facilitate CO2 -to-CO reduction via surface-doped nitrogen bearing Lewis basicity. Photoholes, mainly located on the lateral facets of van der Waals gaps, promote the selective oxidation of Cl- into HClO. Sequestrated CO2 also maintains the pH of seawater at around 4.2 to prevent the alkaline earth cations from precipitating. The produced HClO can effectively kill typical bacteria in the ballast water of ocean-going cargo ships, offering a green and safe way for onsite sterilization.

8.
Environ Sci Technol ; 56(20): 14478-14486, 2022 10 18.
Article in English | MEDLINE | ID: mdl-36173086

ABSTRACT

The photocatalytic O2 activation for pollutant removal highly depends on the controlled generation of desired reactive oxygen species (ROS). Herein, we demonstrate that the robust excitonic effect of BiOBr nanosheets, which is prototypical for singlet oxygen (1O2) production to partially oxidize NO into a more toxic intermediate NO2, can be weakened by surface boronizing via inducing a staggered band alignment from the surface to the bulk and simultaneously generating more surface oxygen vacancy (VO). The staggered band alignment destabilizes excitons and facilitates their dissociation into charge carriers, while surface VO traps electrons and efficiently activates O2 into a superoxide radical (•O2-) via a one-electron-transfer pathway. Different from 1O2, •O2- enables the complete oxidation of NO into nitrate with high selectivity that is more desirable for safe indoor NO remediation under visible light irradiation. This study provides a facile excitonic effect manipulating method for layered two-dimensional photocatalysts and sheds light on the importance of managing ROS production for efficient pollutant removal.


Subject(s)
Environmental Pollutants , Nitrates , Bismuth , Catalysis , Light , Nitrogen Dioxide , Oxygen , Reactive Oxygen Species , Singlet Oxygen , Superoxides
9.
Molecules ; 21(10)2016 Oct 15.
Article in English | MEDLINE | ID: mdl-27754460

ABSTRACT

The reactions of isolable dialkylsilylene 1 with aromatic acyl chlorides afforded aroylsilanes 3a-3c exclusively. Aroylsilanes 3a-3c were characterized by ¹H-, 13C-, and 29Si-NMR spectroscopy, high-resolution mass spectrometry (HRMS), and single-crystal molecular structure analysis. The reaction mechanisms are discussed in comparison with related reaction of 1 with chloroalkanes and chlorosilanes.


Subject(s)
Chlorides/chemistry , Organosilicon Compounds/chemistry , Silanes/chemistry , Crystallography, X-Ray , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Structure
10.
Cell Stem Cell ; 31(9): 1280-1297.e7, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-39084220

ABSTRACT

During pregnancy, placental-fetal nutrient allocation is crucial for fetal and maternal health. However, the regulatory mechanisms for nutrient metabolism and allocation in placental trophoblasts have remained unclear. Here, we used human first-trimester placenta samples and human trophoblast stem cells (hTSCs) to discover that glucose metabolism is highly active in hTSCs and cytotrophoblasts, but during syncytialization, it decreases to basal levels, remaining necessary for fueling acetyl-CoA and differentiation potential. Acetate supplementation could rescue syncytiotrophoblast fusion from glycolysis deficiency by replenishing acetyl-CoA and maintaining histone acetylation, thus rescuing the activation of syncytialization genes. Even brief glycolysis deficiency could permanently inhibit differentiation potential and promote inflammation, which could also be permanently rescued by brief acetate supplementation in vivo. These results suggest that hTSCs retain only basal glycolytic acetyl-CoA metabolism during syncytialization to regulate cell fates via nutrient-responsive histone acetylation, with implications for our understanding of the balance between placental and fetal nutrition.


Subject(s)
Acetyl Coenzyme A , Histones , Stem Cells , Trophoblasts , Humans , Trophoblasts/metabolism , Trophoblasts/cytology , Acetyl Coenzyme A/metabolism , Female , Histones/metabolism , Acetylation , Pregnancy , Stem Cells/metabolism , Stem Cells/cytology , Cell Differentiation , Placenta/metabolism , Glycolysis , Animals , Glucose/metabolism
11.
ACS Nano ; 18(37): 25685-25694, 2024 Sep 17.
Article in English | MEDLINE | ID: mdl-39223090

ABSTRACT

Phosphates within tumors function as key biomolecules, playing a significant role in sustaining the viability of tumors. To disturb the homeostasis of cancer cells, regulating phosphate within the organism proves to be an effective strategy. Herein, we report single-atom Ce-doped Pt hydrides (Ce/Pt-H) with high phosphatase-like activity for phosphate hydrolysis. The resultant Ce/Pt-H exhibits a 26.90- and 6.25-fold increase in phosphatase-like activity in comparison to Ce/Pt and Pt-H, respectively. Mechanism investigations elucidate that the Ce Lewis acid site facilitates the coordination with phosphate groups, while the surface hydrides enhance the electron density of Pt for promoting catalytic ability in H2O cleavage and subsequent nucleophilic attack of hydroxyl groups. Finally, by leveraging its phosphatase-like activity, Ce/Pt-H can effectively regulate intracellular phosphates to disrupt redox homeostasis and amplify oxidative stress within cancer cells, ultimately leading to tumor apoptosis. This work provides fresh insights into noble-metal-based phosphatase mimics for inducing tumor apoptosis.


Subject(s)
Apoptosis , Cerium , Oxidative Stress , Oxidative Stress/drug effects , Cerium/chemistry , Cerium/pharmacology , Apoptosis/drug effects , Humans , Phosphoric Monoester Hydrolases/metabolism , Phosphoric Monoester Hydrolases/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Mice
12.
ACS Nano ; 17(15): 15077-15084, 2023 Aug 08.
Article in English | MEDLINE | ID: mdl-37489696

ABSTRACT

Two-dimensional (2D) layered photocatalysts with highly ordered out-of-plane symmetry usually display robust excitonic effects, thus being ineffective in driving catalytic reactions that necessitate unchained charge carriers. Herein, taking 2D BiOBr as a prototype model, we implement a superficial asymmetric [Br-Bi-O-Bi] stacking in the out-of-plane direction by selectively stripping off the top-layer Br of BiOBr. This local asymmetry disrupts the diagnostic confinement configuration of BiOBr to urge energetic exciton dissociation into charge carriers and further contributes to the emergence of a surface dipole field that powers the subsequent separation of transient electron-hole pairs. Distinct from the symmetric BiOBr, which activates O2 into 1O2 via an exciton-mediated energy transfer, surface asymmetric BiOBr favors selective O2 activation into ·O2- for a broad range of amine-to-imine conversions. Our work here not only presents a paradigm for asymmetric photocatalyst design but also expands the toolkit available for regulating exciton behaviors in semiconductor photocatalytic systems.

13.
Cell Prolif ; 56(5): e13459, 2023 May.
Article in English | MEDLINE | ID: mdl-37177849

ABSTRACT

During ageing, adult stem cells' regenerative properties decline, as they undergo replicative senescence and lose both their proliferative and differentiation capacities. In contrast, embryonic and foetal progenitors typically possess heightened proliferative capacities and manifest a more robust regenerative response upon injury and transplantation, despite undergoing many rounds of mitosis. How embryonic and foetal progenitors delay senescence and maintain their proliferative and differentiation capacities after numerous rounds of mitosis, remains unknown. It is also unclear if defined embryonic factors can rejuvenate adult progenitors to confer extended proliferative and differentiation capacities, without reprogramming their lineage-specific fates or inducing oncogenic transformation. Here, we report that a minimal combination of LIN28A, TERT, and sh-p53 (LTS), all of which are tightly regulated and play important roles during embryonic development, can delay senescence in adult muscle progenitors. LTS muscle progenitors showed an extended proliferative capacity, maintained a normal karyotype, underwent myogenesis normally, and did not manifest tumorigenesis nor aberrations in lineage differentiation, even in late passages. LTS treatment promoted self-renewal and rescued the pro-senescence phenotype of aged cachexia patients' muscle progenitors, and promoted their engraftment for skeletal muscle regeneration in vivo. When we examined the mechanistic basis for LIN28A's role in the LTS minimum combo, let-7 microRNA suppression could not fully explain how LIN28A promoted muscle progenitor self-renewal. Instead, LIN28A was promoting the translation of oxidative phosphorylation mRNAs in adult muscle progenitors to optimize mitochondrial reactive oxygen species (mtROS) and mitohormetic signalling. Optimized mtROS induced a variety of mitohormetic stress responses, including the hypoxic response for metabolic damage, the unfolded protein response for protein damage, and the p53 response for DNA damage. Perturbation of mtROS levels specifically abrogated the LIN28A-driven hypoxic response in Hypoxia Inducible Factor-1α (HIF1α) and glycolysis, and thus LTS progenitor self-renewal, without affecting normal or TS progenitors. Our findings connect embryonically regulated factors to mitohormesis and progenitor rejuvenation, with implications for ageing-related muscle degeneration.


Subject(s)
Adult Stem Cells , Rejuvenation , Tumor Suppressor Protein p53/metabolism , Cell Differentiation , Adult Stem Cells/metabolism
14.
Cell Res ; 33(9): 712-726, 2023 09.
Article in English | MEDLINE | ID: mdl-37188880

ABSTRACT

During homeostasis and after injury, adult muscle stem cells (MuSCs) activate to mediate muscle regeneration. However, much remains unclear regarding the heterogeneous capacity of MuSCs for self-renewal and regeneration. Here, we show that Lin28a is expressed in embryonic limb bud muscle progenitors, and that a rare reserve subset of Lin28a+Pax7- skeletal MuSCs can respond to injury at adult stage by replenishing the Pax7+ MuSC pool to drive muscle regeneration. Compared with adult Pax7+ MuSCs, Lin28a+ MuSCs displayed enhanced myogenic potency in vitro and in vivo upon transplantation. The epigenome of adult Lin28a+ MuSCs showed resemblance to embryonic muscle progenitors. In addition, RNA-sequencing revealed that Lin28a+ MuSCs co-expressed higher levels of certain embryonic limb bud transcription factors, telomerase components and the p53 inhibitor Mdm4, and lower levels of myogenic differentiation markers compared to adult Pax7+ MuSCs, resulting in enhanced self-renewal and stress-response signatures. Functionally, conditional ablation and induction of Lin28a+ MuSCs in adult mice revealed that these cells are necessary and sufficient for efficient muscle regeneration. Together, our findings connect the embryonic factor Lin28a to adult stem cell self-renewal and juvenile regeneration.


Subject(s)
Adult Stem Cells , Satellite Cells, Skeletal Muscle , Animals , Mice , Muscle, Skeletal , Muscle Fibers, Skeletal , Cell Self Renewal
15.
Plant Commun ; 3(6): 100412, 2022 11 14.
Article in English | MEDLINE | ID: mdl-35836378

ABSTRACT

Plant height is an important agronomic trait for lodging resistance and yield. Here, we report a new plant-height-related gene, OsUBR7 in rice (Oryza sativa L.); knockout of OsUBR7 caused fewer cells in internodes, resulting in a semi-dwarf phenotype. OsUBR7 encodes a putative E3 ligase containing a plant homeodomain finger and a ubiquitin protein ligase E3 component N-recognin 7 (UBR7) domain. OsUBR7 interacts with histones and monoubiquitinates H2B (H2Bub1) at lysine148 in coordination with the E2 conjugase OsUBC18. OsUBR7 mediates H2Bub1 at a number of chromatin loci for the normal expression of target genes, including cell-cycle-related and pleiotropic genes, consistent with the observation that cell-cycle progression was suppressed in the osubr7 mutant owing to reductions in H2Bub1 and expression levels at these loci. The genetic divergence of OsUBR7 alleles among japonica and indica cultivars affects their transcriptional activity, and these alleles may have undergone selection during rice domestication. Overall, our results reveal a novel mechanism that mediates H2Bub1 in plants, and UBR7 orthologs could be utilized as an untapped epigenetic resource for crop improvement.


Subject(s)
Histones , Oryza , Histones/genetics , Histones/metabolism , Oryza/genetics , Oryza/metabolism , Ubiquitination , Ubiquitin-Protein Ligases/genetics , Cell Proliferation
16.
Syst Biol Reprod Med ; 65(3): 214-222, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30608887

ABSTRACT

Endometriosis affects 6-10% of healthy women of reproductive age. Therefore, it is important to study the molecular mechanism by which endometriosis develops. This study examined whether aberrant expression of LINC01541 contributes to the pathogenesis of endometriosis. Human endometrial stromal cells (ESCs) were stimulated with 10 nmol/L of 17ß-Estradiol (17ß-E2) to simulate ectopic cells found in endometriosis. Next, the levels of proteins related to the epithelial-mesenchymal transition (EMT), cell invasion, and metastasis were investigated. The effects of LINCO1541 silencing and overexpression were also examined in ESCs. Cell proliferation and apoptosis were detected by cell counting kit-8 and flow cytometry assays, respectively. ESCs stimulated with 17ß-E2 displayed increased levels of N-Cadherin and vimentin expression, but decreased levels of E-Cadherin expression. 17ß-E2 promoted the migration and invasion of ESCs, and those affects were partially reversed by overexpression of LINC01541. Furthermore, silencing of LINC01541 attenuated apoptosis and promoted the EMT of ESCs, while overexpression of LINC01541 stimulated cell apoptosis, increased the levels of caspase 3 protein, and decreased the levels of B cell leukemia/lymphoma 2 protein. Overexpression of LINC01541 also decreased the expression of vascular endothelial growth factor A (VEGFA) by repressing the Wnt/ß-catenin pathway. Our, results suggest that LINC01541 can inhibit the EMT process, metastasis of ESCs, and VEGFA expression by regulating the Wnt/ß-catenin pathway, which may play an important role in the pathogenesis of endometriosis. Abbreviations: ESCs: endometrial stromal cells; 17ß-E2: 17ß-Estradiol; EMT: epithelial-mesenchymal transition; CASP3: caspase 3; BCL2: B cell leukemia/lymphoma 2; VEGFA: vascular endothelial growth factor A; lncRNA: long non-coding RNA; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; RT-qPCR: reverse transcription-quantitative polymerase chain reaction.


Subject(s)
Endometriosis/etiology , RNA, Long Noncoding/metabolism , Cell Movement , Cells, Cultured , Endometriosis/metabolism , Endometrium/cytology , Estradiol , Female , Humans , Stromal Cells/physiology
17.
Chem Asian J ; 12(11): 1204-1207, 2017 Jun 01.
Article in English | MEDLINE | ID: mdl-28195409

ABSTRACT

Isolable dialkylsilylene 5 reacts with dihydrogen in the presence of a small amount of a conventional Lewis acid (BPh3 , BEt3 ) or a base (PPh3 , PEt3 , NPh3 , NEt3 ) at low temperatures in a hydrocarbon solvent, giving the corresponding dihydrosilane 10 in high yields. Both 5/Lewis acid and Lewis base/5 pairs work as a frustrated Lewis pair (FLP) to split dihydrogen, being in accord with the amphoteric nature of silylene 5.

18.
Nat Commun ; 8(1): 1310, 2017 11 03.
Article in English | MEDLINE | ID: mdl-29101356

ABSTRACT

Hybrids between divergent populations commonly show hybrid sterility; this reproductive barrier hinders hybrid breeding of the japonica and indica rice (Oryza sativa L.) subspecies. Here we show that structural changes and copy number variation at the Sc locus confer japonica-indica hybrid male sterility. The japonica allele, Sc-j, contains a pollen-essential gene encoding a DUF1618-domain protein; the indica allele, Sc-i, contains two or three tandem-duplicated ~ 28-kb segments, each carrying an Sc-j-homolog with a distinct promoter. In Sc-j/Sc-i hybrids, the high-expression of Sc-i in sporophytic cells causes suppression of Sc-j expression in pollen and selective abortion of Sc-j-pollen, leading to transmission ratio distortion. Knocking out one or two of the three Sc-i copies by CRISPR/Cas9 rescues Sc-j expression and male fertility. Our results reveal the gene dosage-dependent allelic suppression as a mechanism of hybrid incompatibility, and provide an effective approach to overcome the reproductive barrier for hybrid breeding.


Subject(s)
Oryza/genetics , Plant Infertility/genetics , Alleles , DNA Copy Number Variations , DNA, Plant/genetics , Gene Dosage , Gene Knockout Techniques , Genes, Plant , Genomic Structural Variation , Hybridization, Genetic , Models, Genetic , Oryza/classification , Oryza/physiology , Plant Breeding , Plants, Genetically Modified , Pollen/genetics , Pollen/growth & development , Species Specificity
19.
Mol Neurobiol ; 53(1): 720-727, 2016 Jan.
Article in English | MEDLINE | ID: mdl-25589004

ABSTRACT

In recent years, CD133 has been identified as a cancer stem cell (CSC) marker in gliomas. Nevertheless, the clinical and prognostic value of CD133 in glioma patients remains controversial. Therefore, we conducted a systematic meta-analysis to evaluate the correlation of CD133 with World Health Organization (WHO) grade, age, gender, overall survival (OS), and progression-free survival (PFS) in glioma patients. Eligible studies on this subject were included, and then pooled odd ratios (ORs) and hazard ratios (HRs) with 95 % confidence intervals (95 % CIs) were estimated. Publication bias was assessed by the funnel plots, and heterogeneity and sensitivity were analyzed as well. In the present study, 21 articles with the total number of 1535 patients were included. High expression of CD133 in glioma patients was associated with high WHO grade (III + IV) (n = 11, OR 5.10, 95 % CI 2.99-8.69; p = 0.000), rather than age (n = 4, OR 2.54, 95 % CI 0.68-9.52; p = 0.167) and gender (n = 4, OR 0.71, 95 % CI 0.21-2.45; p = 0.587). In addition, survival analysis demonstrated a significant association between CD133 high expression and poor 2-year OS (n = 11, HR 2.18, 95 % CI 1.29-3.7; p = 0.004), 5-year OS (n = 4, HR 10.39, 95 % CI 2.59-41.63; p = 0.001), as well as PFS (n = 10, HR 2.34, 95 % CI 1.62-3.37; p = 0.000). Taken together, this study suggests that CD133 expression correlates to higher grade of gliomas and worse prognosis in glioma patients. Thus, CD133 could be recommended as a useful pathological and prognostic biomarker in clinical practice.


Subject(s)
Antigens, CD/biosynthesis , Brain Neoplasms/diagnosis , Brain Neoplasms/metabolism , Glioma/diagnosis , Glioma/metabolism , Glycoproteins/biosynthesis , AC133 Antigen , Biomarkers, Tumor/biosynthesis , Humans , Peptides , Prognosis
20.
Chem Commun (Camb) ; 49(84): 9776-8, 2013 Oct 28.
Article in English | MEDLINE | ID: mdl-24022616

ABSTRACT

The 1 : 2 reactions of isolable dialkylsilylene with nitriles having electron-donating aromatic substituents gave 1,4-diaza-2-siloles with a hitherto-unknown type of ring system, in contrast to the previous studies showing exclusive formation of the corresponding 1,3-diaza-2-siloles; the reactions of with aromatic nitriles bearing electron-withdrawing substituents afforded the latter ring system. The remarkable diversity of the reactions is explained by invoking the corresponding nitrile silaylides as key intermediates whose polarity switches depending on the substituents of nitriles.

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