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In eukaryotes, gene expression is performed by three RNA polymerases that are targeted to promoters by molecular complexes. A unique common factor, the TATA-box binding protein (TBP), is thought to serve as a platform to assemble pre-initiation complexes competent for transcription. Here, we describe a novel molecular mechanism of nutrient regulation of gene transcription by dynamic O-GlcNAcylation of TBP. We show that O-GlcNAcylation at T114 of TBP blocks its interaction with BTAF1, hence the formation of the B-TFIID complex, and its dynamic cycling on and off of DNA. Transcriptomic and metabolomic analyses of TBPT114A CRISPR/Cas9-edited cells showed that loss of O-GlcNAcylation at T114 increases TBP binding to BTAF1 and directly impacts expression of 408 genes. Lack of O-GlcNAcylation at T114 is associated with a striking reprogramming of cellular metabolism induced by a profound modification of the transcriptome, leading to gross alterations in lipid storage.
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Glucose/metabolismo , Gotículas Lipídicas/metabolismo , Metabolismo dos Lipídeos , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Proteína de Ligação a TATA-Box/metabolismo , Fator de Transcrição TFIID/metabolismo , Animais , Cromatina/genética , Cromatina/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Regulação da Expressão Gênica , Glicosilação , Células HEK293 , Células HeLa , Humanos , Metabolismo dos Lipídeos/genética , Masculino , Complexos Multiproteicos , Ratos Sprague-Dawley , Transdução de Sinais , Fatores Associados à Proteína de Ligação a TATA/genética , Proteína de Ligação a TATA-Box/genética , Fatores de Tempo , Fator de Transcrição TFIID/genética , Transcrição Gênica , TranscriptomaRESUMO
Large language models (LLMs) are generating interest in medical settings. For example, LLMs can respond coherently to medical queries by providing plausible differential diagnoses based on clinical notes. However, there are many questions to explore, such as evaluating differences between open- and closed-source LLMs as well as LLM performance on queries from both medical and non-medical users. In this study, we assessed multiple LLMs, including Llama-2-chat, Vicuna, Medllama2, Bard/Gemini, Claude, ChatGPT3.5, and ChatGPT-4, as well as non-LLM approaches (Google search and Phenomizer) regarding their ability to identify genetic conditions from textbook-like clinician questions and their corresponding layperson translations related to 63 genetic conditions. For open-source LLMs, larger models were more accurate than smaller LLMs: 7b, 13b, and larger than 33b parameter models obtained accuracy ranges from 21%-49%, 41%-51%, and 54%-68%, respectively. Closed-source LLMs outperformed open-source LLMs, with ChatGPT-4 performing best (89%-90%). Three of 11 LLMs and Google search had significant performance gaps between clinician and layperson prompts. We also evaluated how in-context prompting and keyword removal affected open-source LLM performance. Models were provided with 2 types of in-context prompts: list-type prompts, which improved LLM performance, and definition-type prompts, which did not. We further analyzed removal of rare terms from descriptions, which decreased accuracy for 5 of 7 evaluated LLMs. Finally, we observed much lower performance with real individuals' descriptions; LLMs answered these questions with a maximum 21% accuracy.
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Leucine-rich glioma-inactivated protein 1 (LGI1), a secretory protein in the brain, plays a critical role in myelination; dysfunction of this protein leads to hypomyelination and white matter abnormalities (WMAs). Here, we hypothesized that LGI1 may regulate myelination through binding to an unidentified receptor on the membrane of oligodendrocytes (OLs). To search for this hypothetic receptor, we analyzed LGI1 binding proteins through LGI1-3 × FLAG affinity chromatography with mouse brain lysates followed by mass spectrometry. An OL-specific membrane protein, the oligodendrocytic myelin paranodal and inner loop protein (OPALIN), was identified. Conditional knockout (cKO) of OPALIN in the OL lineage caused hypomyelination and WMAs, phenocopying LGI1 deficiency in mice. Biochemical analysis revealed the downregulation of Sox10 and Olig2, transcription factors critical for OL differentiation, further confirming the impaired OL maturation in Opalin cKO mice. Moreover, virus-mediated re-expression of OPALIN successfully restored myelination in Opalin cKO mice. In contrast, re-expression of LGI1-unbound OPALIN_K23A/D26A failed to reverse the hypomyelination phenotype. In conclusion, our study demonstrated that OPALIN on the OL membrane serves as an LGI1 receptor, highlighting the importance of the LGI1/OPALIN complex in orchestrating OL differentiation and myelination.
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Diferenciação Celular , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos Knockout , Oligodendroglia , Animais , Oligodendroglia/metabolismo , Oligodendroglia/citologia , Camundongos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Bainha de Mielina/metabolismo , Proteínas da Mielina/metabolismo , Proteínas da Mielina/genéticaRESUMO
Artificial intelligence (AI) for facial diagnostics is increasingly used in the genetics clinic to evaluate patients with potential genetic conditions. Current approaches focus on one type of AI called Deep Learning (DL). While DL- based facial diagnostic platforms have a high accuracy rate for many conditions, less is understood about how this technology assesses and classifies (categorizes) images, and how this compares to humans. To compare human and computer attention, we performed eye-tracking analyses of geneticist clinicians (n = 22) and non-clinicians (n = 22) who viewed images of people with 10 different genetic conditions, as well as images of unaffected individuals. We calculated the Intersection-over-Union (IoU) and Kullback-Leibler divergence (KL) to compare the visual attentions of the two participant groups, and then the clinician group against the saliency maps of our deep learning classifier. We found that human visual attention differs greatly from DL model's saliency results. Averaging over all the test images, IoU and KL metric for the successful (accurate) clinician visual attentions versus the saliency maps were 0.15 and 11.15, respectively. Individuals also tend to have a specific pattern of image inspection, and clinicians demonstrate different visual attention patterns than non-clinicians (IoU and KL of clinicians versus non-clinicians were 0.47 and 2.73, respectively). This study shows that humans (at different levels of expertise) and a computer vision model examine images differently. Understanding these differences can improve the design and use of AI tools, and lead to more meaningful interactions between clinicians and AI technologies.
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Inteligência Artificial , Computadores , Humanos , Simulação por ComputadorRESUMO
Artificial intelligence (AI) is increasingly used in genomics research and practice, and generative AI has garnered significant recent attention. In clinical applications of generative AI, aspects of the underlying datasets can impact results, and confounders should be studied and mitigated. One example involves the facial expressions of people with genetic conditions. Stereotypically, Williams (WS) and Angelman (AS) syndromes are associated with a "happy" demeanor, including a smiling expression. Clinical geneticists may be more likely to identify these conditions in images of smiling individuals. To study the impact of facial expression, we analyzed publicly available facial images of approximately 3500 individuals with genetic conditions. Using a deep learning (DL) image classifier, we found that WS and AS images with non-smiling expressions had significantly lower prediction probabilities for the correct syndrome labels than those with smiling expressions. This was not seen for 22q11.2 deletion and Noonan syndromes, which are not associated with a smiling expression. To further explore the effect of facial expressions, we computationally altered the facial expressions for these images. We trained HyperStyle, a GAN-inversion technique compatible with StyleGAN2, to determine the vector representations of our images. Then, following the concept of InterfaceGAN, we edited these vectors to recreate the original images in a phenotypically accurate way but with a different facial expression. Through online surveys and an eye-tracking experiment, we examined how altered facial expressions affect the performance of human experts. We overall found that facial expression is associated with diagnostic accuracy variably in different genetic conditions.
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Expressão Facial , Humanos , Aprendizado Profundo , Inteligência Artificial , Genética Médica/métodos , Síndrome de Williams/genéticaRESUMO
Vanadium oxides with multioxidation states and various crystalline structures offer unique electrical, optical, optoelectronic and magnetic properties, which could be manipulated for various applications. For the past 30 years, significant efforts have been made to study the fundamental science and explore the potential for vanadium oxide materials in ion batteries, water splitting, smart windows, supercapacitors, sensors, and so on. This review focuses on the most recent progress in synthesis methods and applications of some thermodynamically stable and metastable vanadium oxides, including but not limited to V2O3, V3O5, VO2, V3O7, V2O5, V2O2, V6O13, and V4O9. We begin with a tutorial on the phase diagram of the V-O system. The second part is a detailed review covering the crystal structure, the synthesis protocols, and the applications of each vanadium oxide, especially in batteries, catalysts, smart windows, and supercapacitors. We conclude with a brief perspective on how material and device improvements can address current deficiencies. This comprehensive review could accelerate the development of novel vanadium oxide structures in related applications.
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Although immunotherapy is relatively effective in treating hematological malignancies, their efficacy against solid tumors is still suboptimal or even noneffective presently. Compared to hematological cancers, solid tumors exhibit strikingly different immunosuppressive microenvironment, severely deteriorating the efficacy of immunotherapy: (1) chemical features such as hypoxia and mild acidity suppress the activity of immune cells, (2) the pro-tumorigenic domestication of immune cells in the microenvironment within the solid tumors further undermines the effectiveness of immunotherapy, and (3) the dense physical barrier of solid tumor tissues prevents the effective intratumoral infiltration and contact killing of active immune cells. Therefore, we believe that reversing the immunosuppressive microenvironment are of critical priority for the immunotherapy against solid tumors. Due to their unique morphologies, structures, and compositions, nanomedicines have become powerful tools for achieving this goal. In this Perspective, we will first briefly introduce the immunosuppressive microenvironment of solid tumors and then summarize the most recent progresses in nanomedicine-based immunotherapy for solid tumors by remodeling tumor immune-microenvironment in a comprehensive manner. It is highly expected that this Perspective will aid in advancing immunotherapy against solid tumors, and we are highly optimistic on the future development in this burgeoning field.
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Nanomedicina , Neoplasias , Humanos , Microambiente Tumoral , Neoplasias/terapia , Imunoterapia , Carcinogênese , Imunossupressores/farmacologiaRESUMO
The present polyolefin hydrogenolysis recycling cases acknowledge that zerovalent Ru exhibits high catalytic activity. A pivotal rationale behind this assertion lies in the propensity of the majority of Ru species to undergo reduction to zerovalent Ru within the hydrogenolysis milieu. Nonetheless, the suitability of zerovalent Ru as an optimal structural configuration for accommodating multiple elementary reactions remains ambiguous. Here, we have constructed stable Ru0-Ruδ+ complex species, even under reaction conditions, through surface ligand engineering of commercially available Ru/C catalysts. Our findings unequivocally demonstrate that surface-ligated Ru species can be stabilized in the form of a Ruδ+ state, which, in turn, engenders a perturbation of the σ bond electron distribution within the polyolefin carbon chain, ultimately boosting the rate-determining step of C-C scission. The optimized catalysts reach a solid conversion rate of 609 g·gRu-1·h-1 for polyethylene. This achievement represents a 4.18-fold enhancement relative to the pristine Ru/C catalyst while concurrently preserving a remarkable 94% selectivity toward valued liquid alkanes. Of utmost significance, this surface ligand engineering can be extended to the gentle mixing of catalysts in ligand solution at room temperature, thus rendering it amenable for swift integration into industrial processes involving polyolefin degradation.
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Sodium-ion batteries (SIBs) are potential candidates for large energy storage usage because of the natural abundance and cheap sodium. Nevertheless, improving the energy density and cycling steadiness of SIB cathodes remains a challenge. In this work, F-doping Na3Al2/3V4/3(PO4)3(NAVP) microspheres (Na3Al2/3V4/3(PO4)2.9F0.3(NAVPF)) are synthesized via spray drying and investigated as SIB cathodes. XRD and Rietveld refinement reveal expanded lattice parameters for NAVPF compared to the undoped sample, and the successful cation doping into the Na superionic conductor (NASICON) framework improves Na+ diffusion channels. The NAVPF delivers an ultrahigh capacity of 148 mAh g-1 at 100 mA g-1 with 90.8% retention after 200 cycles, enabled by the activation of V2+/V5+ multielectron reaction. Notably, NAVPF delivers an ultrahigh rate performance, with a discharge capacity of 83.6 mAh g-1 at 5000 mA g-1. In situ XRD demonstrates solid-solution reactions occurred during charge-discharge of NAVPF without two-phase reactions, indicating enhanced structural stability after F-doped. The full cell with NAVPF cathode and Na+ preintercalated hard carbon anode shows a large discharge capacity of 100 mAh g-1 at 100 mA g-1 with 80.2% retention after 100 cycles. This anion doping strategy creates a promising SIB cathode candidate for future high-energy-density energy storage applications.
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Vanadium-based compounds have attracted significant attention as cathodes for aqueous zinc metal batteries (AZMBs) because of their remarkable advantages in specific capacities. However, their low diffusion coefficient for zinc ions and structural collapse problems lead to poor rate capability and cycle stability. In this work, bilayered Sr0.25V2O5·0.8H2O (SVOH) nanowires are first reported as a highly stable cathode material for rechargeable AZMBs. The synergistic pillaring effect of strontium ions and water molecules improves the structural stability and ion transport dynamics of vanadium-based compounds. Consequently, the SVOH cathode exhibits a high capacity of 325.6 mAh g-1 at 50 mA g-1, with a capacity retention rate of 72.6% relative to the maximum specific capacity at 3.0 A g-1 after 3000 cycles. Significantly, a unique single-nanowire device is utilized to demonstrate the excellent conductivity of the SVOH cathode directly. Additionally, the energy storage mechanism of zinc insertion and extraction is investigated using a variety of advanced in situ and ex situ analysis techniques. This method of ion intercalation to improve electrochemical performance will further promote the development of AZMBs in large-scale applications.
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BACKGROUND: Sequencing the mitochondrial genome has been increasingly important for the investigation of primary mitochondrial diseases (PMD) and mitochondrial genetics. To overcome the limitations originating from PCR-based mtDNA enrichment, we set out to develop and evaluate a PCR-independent approach in this study, named Pime-Seq (PCR-independent mtDNA enrichment and next generation Sequencing). RESULTS: By using the optimized mtDNA enrichment procedure, the mtDNA reads ratio reached 88.0 ± 7.9% in the sequencing library when applied on human PBMC samples. We found the variants called by Pime-Seq were highly consistent among technical repeats. To evaluate the accuracy and reliability of this method, we compared Pime-Seq with lrPCR based NGS by performing both methods simultaneously on 45 samples, yielding 1677 concordant variants, as well as 146 discordant variants with low-level heteroplasmic fraction, in which Pime-Seq showed higher reliability. Furthermore, we applied Pime-Seq on 4 samples of PMD patients retrospectively, and successfully detected all the pathogenic mtDNA variants. In addition, we performed a prospective study on 192 apparently healthy pregnant women during prenatal screening, in which Pime-Seq identified pathogenic mtDNA variants in 4 samples, providing extra information for better health monitoring in these cases. CONCLUSIONS: Pime-Seq can obtain highly enriched mtDNA in a PCR-independent manner for high quality and reliable mtDNA deep-sequencing, which provides us an effective and promising tool for detecting mtDNA variants for both clinical and research purposes.
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DNA Mitocondrial , Sequenciamento de Nucleotídeos em Larga Escala , Doenças Mitocondriais , Reação em Cadeia da Polimerase , Humanos , DNA Mitocondrial/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Feminino , Reação em Cadeia da Polimerase/métodos , Doenças Mitocondriais/genética , Doenças Mitocondriais/diagnóstico , Gravidez , Reprodutibilidade dos Testes , Masculino , AdultoRESUMO
BACKGROUND: Facioscapulohumeral muscular dystrophy (FSHD) is a high-prevalence autosomal dominant neuromuscular disease characterized by significant clinical and genetic heterogeneity. Genetic diagnosis of FSHD remains a challenge because it cannot be detected by standard sequencing methods and requires a complex diagnosis workflow. METHODS: We developed a comprehensive genetic FSHD detection method based on Oxford Nanopore Technologies (ONT) whole-genome sequencing. Using a case-control design, we applied this procedure to 29 samples and compared the results with those from optical genome mapping (OGM), bisulfite sequencing (BSS), and whole-exome sequencing (WES). RESULTS: Using our ONT-based method, we identified 59 haplotypes (35 4qA and 24 4qB) among the 29 samples (including a mosaic sample), as well as the number of D4Z4 repeat units (RUs). The pathogenetic D4Z4 RU contraction identified by our ONT-based method showed 100% concordance with OGM results. The methylation levels of the most distal D4Z4 RU and the double homeobox 4 gene (DUX4) detected by ONT sequencing are highly consistent with the BSS results and showed excellent diagnostic efficiency. Additionally, our ONT-based method provided an independent methylation profile analysis of two permissive 4qA alleles, reflecting a more accurate scenario than traditional BSS. The ONT-based method detected 17 variations in three FSHD2-related genes from nine samples, showing 100% concordance with WES. CONCLUSIONS: Our ONT-based FSHD detection method is a comprehensive method for identifying pathogenetic D4Z4 RU contractions, methylation level alterations, allele-specific methylation of two 4qA haplotypes, and variations in FSHD2-related genes, which will all greatly improve genetic testing for FSHD.
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Metilação de DNA , Distrofia Muscular Facioescapuloumeral , Sequenciamento Completo do Genoma , Distrofia Muscular Facioescapuloumeral/genética , Distrofia Muscular Facioescapuloumeral/diagnóstico , Humanos , Metilação de DNA/genética , Haplótipos/genética , Masculino , Estudos de Casos e Controles , Proteínas de Homeodomínio/genética , Feminino , Sequenciamento por Nanoporos/métodos , AdultoRESUMO
This study investigated retinal changes in a Western diet (WD)-induced nonhuman primate model of type 2 diabetes. Rhesus nonhuman primates, aged 15 to 17 years, were fed a high-fat diet (n = 7) for >5 years reflective of the traditional WD. Age-matched controls (n = 6) were fed a standard laboratory primate diet. Retinal fundus photography, optical coherence tomography, autofluorescence imaging, and fluorescein angiography were performed before euthanasia. To assess diabetic retinopathy (DR), eyes were examined using trypsin digests, lipofuscin autofluorescence, and multimarker immunofluorescence on cross-sections and whole mounts. Retinal imaging showed venous engorgement and tortuosity, aneurysms, macular exudates, dot and blot hemorrhages, and a marked increase in fundus autofluorescence. Post-mortem changes included the following: decreased CD31 blood vessel density (P < 0.05); increased acellular capillaries (P < 0.05); increased density of ionized calcium-binding adaptor molecule expressing amoeboid microglia/macrophage; loss of regular distribution in stratum and spacing typical of ramified microglia; and increased immunoreactivity of aquaporin 4 and glial fibrillary acidic protein (P < 0.05). However, rhodopsin immunoreactivity (P < 0.05) in rods and neuronal nuclei antibody-positive neuronal density of 50% (P < 0.05) were decreased. This is the first report of a primate model of DR solely induced by a WD that replicates key features of human DR.
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Diabetes Mellitus Tipo 2 , Retinopatia Diabética , Animais , Humanos , Retinopatia Diabética/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Diabetes Mellitus Tipo 2/complicações , Dieta Ocidental , Vasos Retinianos/metabolismo , Primatas , Tomografia de Coerência Óptica/métodosRESUMO
BACKGROUND: Gastric cancer is one of the global health concerns. A series of studies on the stomach have confirmed the role of the microbiome in shaping gastrointestinal diseases. Delineation of microbiome signatures to distinguish chronic gastritis from gastric cancer will provide a non-invasive preventative and treatment strategy. In this study, we performed whole metagenome shotgun sequencing of fecal samples to enhance the detection of rare bacterial species and increase genome sequence coverage. Additionally, we employed multiple bioinformatics approaches to investigate the potential targets of the microbiome as an indicator of differentiating gastric cancer from chronic gastritis. RESULTS: A total of 65 patients were enrolled, comprising 33 individuals with chronic gastritis and 32 with gastric cancer. Within each group, the chronic gastritis group was sub-grouped into intestinal metaplasia (n = 15) and non-intestinal metaplasia (n = 18); the gastric cancer group, early stage (stages 1 and 2, n = 13) and late stage (stages 3 and 4, n = 19) cancer. No significant differences in alpha and beta diversities were detected among the patient groups. However, in a two-group univariate comparison, higher Fusobacteria abundance was identified in phylum; Fusobacteria presented higher abundance in gastric cancer (LDA scored 4.27, q = 0.041 in LEfSe). Age and sex-adjusted MaAsLin and Random Forest variable of importance (VIMP) analysis in species provided meaningful features; Bacteria_caccae was the most contributing species toward gastric cancer and late-stage cancer (beta:2.43, se:0.891, p:0.008, VIMP score:2.543). In contrast, Bifidobacterium_longum significantly contributed to chronic gastritis (beta:-1.8, se:0.699, p:0.009, VIMP score:1.988). Age, sex, and BMI-adjusted MasAsLin on metabolic pathway analysis showed that GLCMANNANAUT-PWY degradation was higher in gastric cancer and one of the contributing species was Fusobacterium_varium. CONCLUSION: Microbiomes belonging to the pathogenic phylum Fusobacteria and species Bacteroides_caccae and Streptococcus_anginosus can be significant targets for monitoring the progression of gastric cancer. Whereas Bifidobacterium_longum and Lachnospiraceae_bacterium_5_1_63FAA might be protection biomarkers against gastric cancer.
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Bactérias , Fezes , Gastrite , Metagenoma , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/microbiologia , Masculino , Feminino , Pessoa de Meia-Idade , Gastrite/microbiologia , Fezes/microbiologia , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , Idoso , Microbioma Gastrointestinal/genética , AdultoRESUMO
Bainong sterility (BNS) is a thermo-sensitive genic male sterile wheat line, characterised by anther fertility transformation in response to low temperature (LT) stress during meiosis, the failure of vacuole decomposition and the absence of starch accumulation in sterile bicellular pollen. Our study demonstrates that the late microspore (LM) stage marks the transition from the anther growth to anther maturation phase, characterised by the changes in anther structure, carbohydrate metabolism and the main transport pathway of sucrose (Suc). Fructan is a main storage polysaccharide in wheat anther, and its synthesis and remobilisation are crucial for anther development. Moreover, the process of pollen amylogenesis and the fate of the large vacuole in pollen are closely intertwined with fructan synthesis and remobilisation. LT disrupts the normal physiological metabolism of BNS anthers during meiosis, particularly affecting carbohydrate metabolism, thus determining the fate of male gametophytes and pollen abortion. Disruption of fructan synthesis and remobilisation regulation serves as a decisive event that results in anther abortion. Sterile pollen exhibits common traits of pollen starvation and impaired starch accumulation due to the inhibition of apoplastic transport starting from the LM stage, which is regulated by cell wall invertase TaIVR1 and Suc transporter TaSUT1.
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Metabolismo dos Carboidratos , Flores , Infertilidade das Plantas , Pólen , Triticum , Triticum/genética , Triticum/crescimento & desenvolvimento , Triticum/metabolismo , Triticum/fisiologia , Infertilidade das Plantas/genética , Pólen/crescimento & desenvolvimento , Pólen/genética , Pólen/metabolismo , Flores/crescimento & desenvolvimento , Flores/genética , Flores/fisiologia , Flores/metabolismo , Amido/metabolismo , Sacarose/metabolismo , Frutanos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genéticaRESUMO
Efficient diode-pumped continuous-wave (CW) and wavelength tunable Tm:YAP lasers based on the vibronic and electronic transitions are investigated. A total maximum output power of 4.1 W is achieved with multi-wavelength output around 2162 nm and 2274 nm, corresponding to a slope efficiency of 29.8% for a 3 at. % Tm:YAP crystal. A maximum output power of 2.48 W with a slope efficiency of 25.4% is obtained at 2146 nm for a 4 at. % Tm:YAP crystal. Using a birefringent filter (BF), the emission wavelengths of the Tm:YAP laser are tuned over spectral ranges of 59 nm from 2115 nm to 2174 nm and 127 nm from 2267 nm to 2394 nm, respectively, which is the first demonstration of wavelength tunable Tm:YAP laser based on the electronic transition 3H4â3H5 and vibronic transition 3F4â3H6, to the best of our knowledge. The results show great potentials of the Tm:YAP crystal for realizing efficient lasers in the spectral range of 2.1-2.4 µm.
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The Ni-catalyzed enantioselective addition reaction of aryl halides to aldehydes was studied with cyanobis(oxazoline) as chiral ligands and Mn as reductant. Aryl and heteroaryl bromides reacted with phenyl aldehyde at room temperature to produce dibenzyl alcohols in 16-99 % yields with 53-92 % ees. Moreover, the coupling of phenyl chloride with a variety of aryl, heteroaryl and alkyl aldehydes was demonstrated in the presence of cyanobis(oxazoline)/Ni(II) at 60 °C in generally high yields with moderate enantioselectivities.
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BACKGROUND: IgA nephropathy (IgAN) is a major cause of primary glomerulonephritis characterized by mesangial deposits of galactose-deficient IgA1 (Gd-IgA1). Toll-like receptors (TLRs), particularly TLR4 are involved in the pathogenesis of IgAN. The role of gut microbiota on IgAN patients was recently investigated. However, whether gut microbial modifications of Gd-IgA1 through TLR4 play a role in IgAN remains unclear. METHODS: We recruited subjects into four groups, including 48 patients with untreated IgAN, 22 treated IgAN patients (IgANIT), 22 primary membranous nephropathy (MN), and 31 healthy controls (HCs). Fecal samples were collected to analyze changes in gut microbiome. Gd-IgA1 levels, expression of TLR4, B-cell stimulators, and intestinal barrier function were evaluated in all subjects. C57BL/6 mice were treated with a broad-spectrum antibiotic cocktail to deplete the gut microbiota and then gavaged with fecal microbiota transplanted fromclinical subjects of every group. Gd-IgA1 and TLR4 pathway were detected in peripheral blood mononuclear cells (PBMCs) from IgAN and HCs co-incubated with Lipopolysaccharide (LPS) and TLR4 inhibitor. RESULTS: Compared with other three groups, different compositions and decreased diversity demonstrated gut dysbiosis in un-treated IgAN, especially the enrichment of Escherichia -Shigella. Elevated Gd-IgA1 levels were found in un-treated IgAN patients and correlated with gut dysbiosis, TLR4, B-cell stimulators, indexes of intestinal barrier damage, and proinflammatory cytokines. In vivo, mice colonized with gut microbiota from IgAN and IgANIT patients, copied the IgAN phenotype with the activation of TLR4/MyD88/NF-κB pathway, B-cell stimulators in the intestine, and complied with enhanced proinflammatory cytokines. In vitro, LPS activated TLR4/MyD88/NF-κB pathway, B-cell stimulators and proinflammatory cytokines in the PBMCs from IgAN patients, which resulted in overproduction of Gd-IgA1 and inhibited by TLR4 inhibitor. CONCLUSIONS: Our results illustrated that gut-kidney axis was involved in the pathogenesis of IgAN. Gut dysbiosis could stimulate the overproduction of Gd-IgA1 by TLR4 signaling pathway production and B-cell stimulators.
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Being generally regarded as safe, Kluyveromyces lactis has been widely taken for food, feed, and pharmaceutical applications, owing to its ability to achieve high levels of protein secretion and hence being suitable for industrial production of heterologous proteins. Production platform strains can be created through genetic engineering; while prototrophic cells without chromosomally accumulated antibiotics resistance genes have been generally preferred, arising the need for dominant counterselection. We report here the establishment of a convenient counterselection system based on a Frs2 variant, Frs2v, which is a mutant of the alpha-subunit of phenylalanyl-tRNA synthase capable of preferentially incorporating a toxic analog of phenylalanine, r-chloro-phenylalanine (4-CP), into proteins to bring about cell growth inhibition. We demonstrated that expression of Frs2v from an episomal plasmid in K. lactis could make the host cells sensitive to 2 mM 4-CP, and a Frs2v-expressing plasmid could be efficiently removed from the cells immediately after a single round of cell culturing in a 4-CP-contianing YPD medium. This Frs2v-based counterselection helped us attain scarless gene replacement in K. lactis without any prior engineering of the host cells. More importantly, counterselection with this system was proven to be functionally efficient also in Saccharomyces cerevisiae and Komagataella phaffii, suggestive of a broader application scope of the system in various yeast hosts. Collectively, this work has developed a strategy to enable rapid, convenient, and high-efficiency construction of prototrophic strains of K. lactis and possibly many other yeast species, and provided an important reference for establishing similar methods in other industrially important eukaryotic microbes.
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Kluyveromyces , Plasmídeos , Kluyveromyces/genética , Kluyveromyces/metabolismo , Plasmídeos/genética , Fenilalanina-tRNA Ligase/genética , Fenilalanina-tRNA Ligase/metabolismo , Engenharia Genética/métodos , Fenilalanina/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismoRESUMO
BACKGROUND: Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital coronary anomaly with the potential to cause adverse cardiac events. However, there is limited data on the association between AAOCA and coronary artery disease (CAD). Therefore, the aim of this study is to determine the prevalence and symptoms of patients with AAOCA, as well as investigate the correlation between AAOCA and CAD in a population referred for coronary computed tomographic angiography (CTA). METHODS AND RESULTS: All consecutive patients who underwent CTA from 2010 to 2021 were included. Characteristics, symptoms, coronary related adverse events and CTA information were reviewed by medical records. Separate multivariable cumulative logistic regressions were performed, using the stenosis severity in each of the four coronaries as individual responses and as a combined patient clustered response. Finally, we identified 207 adult patients with AAOCA, the prevalence of AAOCA is 0.23% (207/90,501). Moreover, this study found no significant association between AAOCA and CAD. AAOCA did not contribute to higher rates of hospitalization or adverse cardiac events, including calcification. CONCLUSION: AAOCA is a rare congenital disease that is not associated with increased presence of obstructive CAD in adults.