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1.
Nature ; 600(7887): 54-58, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34666338

RESUMO

The Moon has a magmatic and thermal history that is distinct from that of the terrestrial planets1. Radioisotope dating of lunar samples suggests that most lunar basaltic magmatism ceased by around 2.9-2.8 billion years ago (Ga)2,3, although younger basalts between 3 Ga and 1 Ga have been suggested by crater-counting chronology, which has large uncertainties owing to the lack of returned samples for calibration4,5. Here we report a precise lead-lead age of 2,030 ± 4 million years ago for basalt clasts returned by the Chang'e-5 mission, and a 238U/204Pb ratio (µ value)6 of about 680 for a source that evolved through two stages of differentiation. This is the youngest crystallization age reported so far for lunar basalts by radiometric dating, extending the duration of lunar volcanism by approximately 800-900 million years. The µ value of the Chang'e-5 basalt mantle source is within the range of low-titanium and high-titanium basalts from Apollo sites (µ value of about 300-1,000), but notably lower than those of potassium, rare-earth elements and phosphorus (KREEP) and high-aluminium basalts7 (µ value of about 2,600-3,700), indicating that the Chang'e-5 basalts were produced by melting of a KREEP-poor source. This age provides a pivotal calibration point for crater-counting chronology in the inner Solar System and provides insight on the volcanic and thermal history of the Moon.

2.
Proc Natl Acad Sci U S A ; 121(30): e2404164121, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39012823

RESUMO

The development of advanced neural modulation techniques is crucial to neuroscience research and neuroengineering applications. Recently, optical-based, nongenetic modulation approaches have been actively investigated to remotely interrogate the nervous system with high precision. Here, we show that a thin-film, silicon (Si)-based diode device is capable to bidirectionally regulate in vitro and in vivo neural activities upon adjusted illumination. When exposed to high-power and short-pulsed light, the Si diode generates photothermal effects, evoking neuron depolarization and enhancing intracellular calcium dynamics. Conversely, low-power and long-pulsed light on the Si diode hyperpolarizes neurons and reduces calcium activities. Furthermore, the Si diode film mounted on the brain of living mice can activate or suppress cortical activities under varied irradiation conditions. The presented material and device strategies reveal an innovated optoelectronic interface for precise neural modulations.


Assuntos
Neurônios , Optogenética , Silício , Animais , Silício/química , Neurônios/fisiologia , Camundongos , Optogenética/métodos , Cálcio/metabolismo , Luz , Encéfalo/fisiologia
3.
Mol Cell ; 70(4): 695-706.e5, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29775583

RESUMO

We provide a comprehensive analysis of transcription in real time by T7 RNA Polymerase (RNAP) using single-molecule fluorescence resonance energy transfer by monitoring the entire life history of transcription initiation, including stepwise RNA synthesis with near base-pair resolution, abortive cycling, and transition into elongation. Kinetically branching pathways were observed for abortive initiation with an RNAP either recycling on the same promoter or exchanging with another RNAP from solution. We detected fast and slow populations of RNAP in their transition into elongation, consistent with the efficient and delayed promoter release, respectively, observed in ensemble studies. Real-time monitoring of abortive cycling using three-probe analysis showed that the initiation events are stochastically branched into productive and failed transcription. The abortive products are generated primarily from initiation events that fail to progress to elongation, and a majority of the productive events transit to elongation without making abortive products.


Assuntos
RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/metabolismo , Regiões Promotoras Genéticas , RNA/química , Sítio de Iniciação de Transcrição , Transcrição Gênica , Proteínas Virais/química , Proteínas Virais/metabolismo , RNA Polimerases Dirigidas por DNA/genética , Humanos , Ligação Proteica , Subunidades Proteicas , RNA/genética , RNA/metabolismo , Proteínas Virais/genética
4.
Nucleic Acids Res ; 52(12): 7096-7111, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38783009

RESUMO

Aminoacyl-tRNA synthetases (AARS) and tRNAs translate the genetic code in all living cells. Little is known about how their molecular ancestors began to enforce the coding rules for the expression of their own genes. Schimmel et al. proposed in 1993 that AARS catalytic domains began by reading an 'operational' code in the acceptor stems of tRNA minihelices. We show here that the enzymology of an AARS urzyme•TΨC-minihelix cognate pair is a rich in vitro realization of that idea. The TΨC-minihelixLeu is a very poor substrate for full-length Leucyl-tRNA synthetase. It is a superior RNA substrate for the corresponding urzyme, LeuAC. LeuAC active-site mutations shift the choice of both amino acid and RNA substrates. AARS urzyme•minihelix cognate pairs are thus small, pliant models for the ancestral decoding hardware. They are thus an ideal platform for detailed experimental study of the operational RNA code.


Assuntos
Aminoacil-tRNA Sintetases , Conformação de Ácido Nucleico , RNA de Transferência , RNA de Transferência/metabolismo , RNA de Transferência/química , RNA de Transferência/genética , Aminoacil-tRNA Sintetases/metabolismo , Aminoacil-tRNA Sintetases/química , Aminoacil-tRNA Sintetases/genética , Domínio Catalítico , Código Genético , RNA Catalítico/química , RNA Catalítico/metabolismo , Especificidade por Substrato , Leucina-tRNA Ligase/metabolismo , Leucina-tRNA Ligase/química , Leucina-tRNA Ligase/genética
5.
Nucleic Acids Res ; 51(15): 8070-8084, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37470821

RESUMO

Leucyl-tRNA synthetase (LeuRS) is a Class I aminoacyl-tRNA synthetase (aaRS) that synthesizes leucyl-tRNAleu for codon-directed protein synthesis. Two signature sequences, HxGH and KMSKS help stabilize transition-states for amino acid activation and tRNA aminoacylation by all Class I aaRS. Separate alanine mutants of each signature, together with the double mutant, behave in opposite ways in Pyrococcus horikoshii LeuRS and the 129-residue urzyme ancestral model generated from it (LeuAC). Free energy coupling terms, Δ(ΔG‡), for both reactions are large and favourable for LeuRS, but unfavourable for LeuAC. Single turnover assays with 32Pα-ATP show correspondingly different internal products. These results implicate domain motion in catalysis by full-length LeuRS. The distributed thermodynamic cycle of mutational changes authenticates LeuAC urzyme catalysis far more convincingly than do single point mutations. Most importantly, the evolutionary gain of function induced by acquiring the anticodon-binding (ABD) and multiple insertion modules in the catalytic domain appears to be to coordinate the catalytic function of the HxGH and KMSKS signature sequences. The implication that backbone elements of secondary structures achieve a major portion of the overall transition-state stabilization by LeuAC is also consistent with coevolution of the genetic code and metabolic pathways necessary to produce histidine and lysine sidechains.


Assuntos
Aminoacil-tRNA Sintetases , Leucina-tRNA Ligase , Aminoacil-tRNA Sintetases/metabolismo , Anticódon , Aminoacilação de RNA de Transferência , Código Genético , Leucina-tRNA Ligase/metabolismo , Catálise
6.
Nano Lett ; 24(5): 1635-1641, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38277778

RESUMO

We present an on-chip filter with a broad tailorable working wavelength and a single-mode operation. This is realized through the application of topological photonic crystal nanobeam filters employing synthesis parameter dimensions. By introducing the translation of air holes as a new synthetic parameter dimension, we obtained nanobeams with tunable Zak phases. Leveraging the bulk-edge correspondence, we identify the existence of topological cavity modes and establish a correlation between the cavity's interface morphology and working wavelength. Through experiments, we demonstrate filters with adjustable filtering wavelengths ranging from 1301 to 1570 nm. Our work illustrates the use of the synthetic translation dimension in the design of on-chip filters, and it holds potential for applications in other devices such as microcavities.

7.
Nitric Oxide ; 149: 67-74, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38897561

RESUMO

Sodium thiosulfate has been used for decades in the treatment of calciphylaxis and cyanide detoxification, and has recently shown initial therapeutic promise in critical diseases such as neuronal ischemia, diabetes mellitus, heart failure and acute lung injury. However, the precise mechanism of sodium thiosulfate remains incompletely defined and sometimes contradictory. Although sodium thiosulfate has been widely accepted as a donor of hydrogen sulfide (H2S), emerging findings suggest that it is the executive signaling molecule for H2S and that its effects may not be dependent on H2S. This article presents an overview of the current understanding of sodium thiosulfate, including its synthesis, biological characteristics, and clinical applications of sodium thiosulfate, as well as the underlying mechanisms in vivo. We also discussed the interplay of sodium thiosulfate and H2S. Our review highlights sodium thiosulfate as a key player in sulfide signaling with the broad clinical potential for the future.


Assuntos
Sulfeto de Hidrogênio , Transdução de Sinais , Tiossulfatos , Tiossulfatos/química , Sulfeto de Hidrogênio/metabolismo , Sulfeto de Hidrogênio/química , Humanos , Animais , Transdução de Sinais/efeitos dos fármacos
8.
BMC Ophthalmol ; 24(1): 259, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38880899

RESUMO

BACKGROUND: The anatomic structure of the anterior chamber (AC) helps to explain differences in refractive status in school-aged children and is closely associated with primary angle closure (PAC). The aim of this study was to quantify and analyze the anterior chamber and angle (ACA) characteristics in Chinese children with different refractive status by swept-source optical coherence tomography (SS-OCT). METHODS: In a cross-sectional observational study, 383 children from two primary schools in Shandong Province, China, underwent a complete ophthalmic examination. First, the anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA) were evaluated automatically using a CASIA2 imaging device. AOD and TISA were measured at 500, 750 µm nasal (N1 and N2, respectively), and temporal (T1 and T2, respectively) to the scleral spur (SS). Cycloplegic refraction and axial length (AL) were then measured. According to spherical equivalent refraction (SER), the children were assigned to hyperopic (SER > 0.50D), emmetropic (-0.50D < SER ≤ 0.50D), and myopic groups (SER ≤ -0.50D). RESULTS: Out of the 383 children, 349 healthy children (160 girls) with a mean age of 8.23 ± 1.06 years (range: 6-11 years) were included. The mean SER and AL were - 0.10 ± 1.57D and 23.44 ± 0.95 mm, respectively. The mean ACD and ACW were 3.17 ± 0.24 mm and 11.69 ± 0.43 mm. The mean AOD were 0.72 ± 0.25, 0.63 ± 0.22 mm at N1, T1, and 0.98 ± 0.30, 0.84 ± 0.27 mm at N2, T2. The mean TISA were 0.24 ± 0.09, 0.22 ± 0.09mm2 at N1, T1, and 0.46 ± 0.16, 0.40 ± 0.14mm2 at N2, T2. The myopic group had the deepest AC and the widest angle. Compared with boys, girls had shorter AL, shallower ACD, narrower ACW, and ACA (all p < 0.05). By Pearson's correlation analysis, SER was negatively associated with ACD, AOD, and TISA. AL was positively associated with ACD, ACW, AOD, and TISA. In the multiple regression analysis, AOD and TISA were associated with deeper ACD, narrower ACW, and longer AL. CONCLUSION: In primary school students, the myopic eyes have deeper AC and wider angle. ACD, ACW, AOD, and TISA all increase with axial elongation. ACA is highly correlated with deeper ACD.


Assuntos
Câmara Anterior , Refração Ocular , Tomografia de Coerência Óptica , Humanos , Tomografia de Coerência Óptica/métodos , Estudos Transversais , Criança , Feminino , Masculino , Câmara Anterior/diagnóstico por imagem , Câmara Anterior/patologia , China/epidemiologia , Refração Ocular/fisiologia , Glaucoma de Ângulo Fechado/fisiopatologia , Glaucoma de Ângulo Fechado/diagnóstico , Glaucoma de Ângulo Fechado/etnologia , Erros de Refração/fisiopatologia , População do Leste Asiático
9.
Nucleic Acids Res ; 50(2): 717-730, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-34935970

RESUMO

Immobile four-way junctions (4WJs) are core structural motifs employed in the design of programmed DNA assemblies. Understanding the impact of sequence on their equilibrium structure and flexibility is important to informing the design of complex DNA architectures. While core junction sequence is known to impact the preferences for the two possible isomeric states that junctions reside in, previous investigations have not quantified these preferences based on molecular-level interactions. Here, we use all-atom molecular dynamics simulations to investigate base-pair level structure and dynamics of four-way junctions, using the canonical Seeman J1 junction as a reference. Comparison of J1 with equivalent single-crossover topologies and isolated nicked duplexes reveal conformational impact of the double-crossover motif. We additionally contrast J1 with a second junction core sequence termed J24, with equal thermodynamic preference for each isomeric configuration. Analyses of the base-pair degrees of freedom for each system, free energy calculations, and reduced-coordinate sampling of the 4WJ isomers reveal the significant impact base sequence has on local structure, isomer bias, and global junction dynamics.


Assuntos
Sequência de Bases , DNA/química , Simulação de Dinâmica Molecular , Conformação de Ácido Nucleico , Algoritmos
10.
Proc Natl Acad Sci U S A ; 118(18)2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33903240

RESUMO

Inorganic semiconductor-based microscale light-emitting diodes (micro-LEDs) have been widely considered the key solution to next-generation, ubiquitous lighting and display systems, with their efficiency, brightness, contrast, stability, and dynamic response superior to liquid crystal or organic-based counterparts. However, the reduction of micro-LED sizes leads to the deteriorated device performance and increased difficulties in manufacturing. Here, we report a tandem device scheme based on stacked red, green, and blue (RGB) micro-LEDs, for the realization of full-color lighting and displays. Thin-film micro-LEDs (size ∼100 µm, thickness ∼5 µm) based on III-V compound semiconductors are vertically assembled via epitaxial liftoff and transfer printing. A thin-film dielectric-based optical filter serves as a wavelength-selective interface for performance enhancement. Furthermore, we prototype arrays of tandem RGB micro-LEDs and demonstrate display capabilities. These materials and device strategies provide a viable path to advanced lighting and display systems.

11.
Crit Rev Food Sci Nutr ; 63(19): 3716-3733, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34704503

RESUMO

Obesity has become a global health concern. It increases the risk of several diseases, such as type 2 diabetes mellitus, nonalcoholic fatty liver disease, and certain cancers, which threatens human health and increases social economic burden. As one of the most consumed beverages, tea contains various phytochemicals with potent bioactive properties and health-promoting effects, such as antioxidant, immune-regulation, cardiovascular protection and anticancer. Tea and its components are also considered as potential candidates for anti-obesity. Epidemiological studies indicate that regular consumption of tea is beneficial for reducing body fat. In addition, the experimental studies demonstrate that the potential anti-obesity mechanisms of tea are mainly involved in increasing energy expenditure and lipid catabolism, decreasing nutrient digestion and absorption as well as lipid synthesis, and regulating adipocytes, neuroendocrine system and gut microbiota. Moreover, most of clinical studies illustrate that the intake of green tea could reduce body weight and alleviate the obesity. In this review, we focus on the effect of tea and its components on obesity from epidemiological, experimental, and clinical studies, and discuss their potential mechanisms.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/prevenção & controle , Obesidade/prevenção & controle , Obesidade/metabolismo , Chá/química , Bebidas , Lipídeos
12.
Eur Radiol ; 33(3): 2160-2170, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36222864

RESUMO

OBJECTIVES: To construct and validate a contrast-enhanced computed tomography (CECT)-based radiomics nomogram to predict Ki-67 expression level in head and neck squamous cell carcinoma (HNSCC). METHODS: A total of 217 patients with HNSCC who underwent CECT scans and immunohistochemical examination of their Ki-67 index were enrolled in this study. The patients were divided into a training set (n = 140; Ki-67: ≥ 50% [n = 72] and < 50% [n = 68]) and an external test set (n = 77; Ki-67: ≥ 50% [n = 38] and < 50% [n = 39]). The least absolute shrinkage and selection operator method was used to select key features for a CECT-image-based radiomics signature and a radiomics score (Rad-score) was calculated. A clinical model was established using clinical data and CT findings. The independent clinical factors and Rad-score were then combined to construct a radiomics nomogram. The performance characteristics of the Rad-score, clinical model, and nomogram were assessed using ROCs and decision curve analysis. RESULTS: Twenty features were finally selected to construct the Rad-score. The radiomics nomogram incorporating the Rad-score, low histological grade, and lymphatic spread showed higher predictive value for the Ki-67 index (≥ 50% vs. < 50%) than the clinical model on both the training (AUC, 0.919 vs. 0.648, p < 0.001) and test (AUC, 0.832 vs. 0.685, p = 0.030) sets. Decision curve analysis demonstrated that the radiomics nomogram was more clinically useful than the clinical model. CONCLUSIONS: A CECT-based radiomics nomogram was constructed to predict the expression of Ki-67 in HNSCC. This model showed favorable predictive efficacy and might be useful for prognostic evaluation and clinical decision-making in patients with HNSCC. KEY POINTS: • Accurate pre-treatment prediction of Ki-67 index in HNSCC is crucial. • A CECT-based radiomics nomogram showed favorable predictive efficacy in estimation of Ki-67 expression status in HNSCC patients.


Assuntos
Neoplasias de Cabeça e Pescoço , Nomogramas , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Antígeno Ki-67 , Tomografia Computadorizada por Raios X/métodos , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem
13.
Macromol Rapid Commun ; 44(2): e2200618, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35973086

RESUMO

Controlling the internal structures of single-chain nanoparticles (SCNPs) is an important factor for their targeted chemical design and synthesis, especially in view of nanosized compartments presenting different local environments as a main feature to control functionality. We here design SCNPs bearing near-infrared fluorescent dyes embedded in hydrophobic compartments for use as contrast agents in pump-probe photoacoustic (PA) imaging, displaying improved properties by the location of the dye in the hydrophobic particle core. Compartment formation is controlled via single-chain collapse and subsequent crosslinking of an amphiphilic polymer using external crosslinkers in reaction media of adjustable polarity. Different SCNPs with hydrodynamic diameters of 6-12 nm bearing adjustable label densities are synthesized. It is found that the specific conditions for single-chain collapse have a major impact on the formation of the desired core-shell structure, in turn adjusting the internal nanocompartments together with the formation of excitonic dye couples, which in turn increase their fluorescence lifetime and PA signal generation. SCNPs with the dye molecules accumulate at the core also show a nonlinear PA response as a function of pulse energy-a property that can be exploited as a contrast mechanism in molecular PA tomography.


Assuntos
Corantes Fluorescentes , Nanopartículas , Corantes Fluorescentes/química , Meios de Contraste , Nanopartículas/química , Diagnóstico por Imagem , Polímeros/química
14.
Nutr Metab Cardiovasc Dis ; 33(11): 2076-2088, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37573217

RESUMO

AIMS: The epidemiological evidence regarding the impact of ultra-processed foods (UPFs) on the risk of cardio-cerebrovascular diseases (CCVDs) is controversial. The aim of this systematic review and meta-analysis is to examine the association between UPF consumption and the risk of CCVDs within cohort studies. DATA SYNTHESIS: A systematic literature search was conducted across multiple databases, including PubMed/Medline, Embase, Web of Science, Scopus, and the Cochrane Library databases, covering the inception of these databases up until January 1st, 2023. A total of 39 cohort studies involving 63,573,312 human participants were deemed eligible according to the inclusion criteria. Utilizing random-effects models, risk ratios (RRs) were estimated to determine the pooled results. Our findings indicate a significant association between a higher consumption of UPF and an increased likelihood of CCVDs (RR: 1.08, 95% CI: 1.01-1.16, I2 = 89%; p < 0.01) compared to individuals who either abstain from or consume lesser amounts of UPF. Nonlinear dose-response meta-analyses showed that a consistent high intake of UPFs was associated with an elevated risk of developing CCVDs (p non-linearity <0.001). Notably, the risk of CCVDs escalated by approximately 7% with an UPF intake of up to 1 serving per day. Subgroup analysis further revealed a significant augmentation in the risk of total CVD and hypertension with increased UPF consumption. CONCLUSIONS: A higher intake of UPF significantly increases the risk of developing CCVDs. Prospective studies controlling for confounding factors are needed to validate the relationship between UPF intake and the development of CCVDs.

15.
Oral Dis ; 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38135895

RESUMO

OBJECTIVE: Midpalatal expansion (MPE) is routinely employed to treat transverse maxillary arch deficiency. Neutrophils are indispensable for recruiting bone marrow stromal cells (BMSCs) at the initial stage of bone regeneration. This study aimed to explore whether neutrophils participate in MPE and how they function during bone formation under mechanical stretching. MATERIALS AND METHODS: The presence and phenotype of neutrophils in the midpalatal suture during expansion were detected by flow cytometry and immunofluorescence staining. The possible mechanism of neutrophil recruitment and polarization was explored in vitro by exposing vascular endothelial cells (VECs) to cyclic tensile strain. RESULTS: The number of neutrophils in the distracted suture peaked on Day 3, and N2-type neutrophils significantly increased on Day 5 after force application. The depletion of circulatory neutrophils reduced bone volume by 43.6% after 7-day expansion. The stretched VECs recruited neutrophils via a CXCR2 mechanism in vitro, which then promoted BMSC osteogenic differentiation through the VEGFA/VEGFR2 axis. Consistently, these neutrophils showed higher expression of canonical N2 phenotype genes, including CD206 and Arg1. CONCLUSIONS: These results suggested that neutrophils participated in early bone formation during MPE. Based on these findings, we propose that stretched VECs recruited and polarized neutrophils, which, in turn, induced BMSC osteogenic differentiation.

16.
Neurosurg Rev ; 46(1): 169, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37432487

RESUMO

Neurogenic pulmonary edema (NPE) is a life-threatening and severe complication in patients with spontaneous subarachnoid hemorrhage (SAH). The prevalence of NPE varies significantly across studies due to differences in case definitions, study populations, and methodologies. Therefore, a precise estimation of the prevalence and risk factors related to NPE in patients with spontaneous SAH is important for clinical decision-makers, policy providers, and researchers. We conducted a systematic search of the PubMed/Medline, Embase, Web of Science, Scopus, and Cochrane Library databases from their inception to January 2023. Thirteen studies were included in the meta-analysis, with a total of 3,429 SAH patients. The pooled global prevalence of NPE was estimated to be 13%. Out of the eight studies (n = 1095, 56%) that reported the number of in-hospital mortalities of NPE among patients with SAH, the pooled proportion of in-hospital deaths was 47%. Risk factors associated with NPE after spontaneous SAH included female gender, WFNS class, APACHE II score ≥ 20, IL-6 > 40 pg/mL, Hunt and Hess grade ≥ 3, elevated troponin I, elevated white blood cell count, and electrocardiographic abnormalities. Multiple studies showed a strong positive correlation between the WFNS class and NPE. In conclusion, NPE has a moderate prevalence but a high in-hospital mortality rate in patients with SAH. We identified multiple risk factors that can help identify high-risk groups of NPE in individuals with SAH. Early prediction of the onset of NPE is crucial for timely prevention and early intervention.


Assuntos
Edema Pulmonar , Hemorragia Subaracnóidea , Humanos , Feminino , Edema Pulmonar/epidemiologia , Edema Pulmonar/etiologia , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/epidemiologia , Mortalidade Hospitalar , Prevalência , Bases de Dados Factuais
17.
Yi Chuan ; 45(10): 922-932, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37872114

RESUMO

This study aimed to assess and compare the performance of different machine learning models in predicting selected pig growth traits and genomic estimated breeding values (GEBV) using automated machine learning, with the goal of optimizing whole-genome evaluation methods in pig breeding. The research employed genomic information, pedigree matrices, fixed effects, and phenotype data from 9968 pigs across multiple companies to derive four optimal machine learning models: deep learning (DL), random forest (RF), gradient boosting machine (GBM), and extreme gradient boosting (XGB). Through 10-fold cross-validation, predictions were made for GEBV and phenotypes of pigs reaching weight milestones (100 kg and 115 kg) with adjustments for backfat and days to weight. The findings indicated that machine learning models exhibited higher accuracy in predicting GEBV compared to phenotypic traits. Notably, GBM demonstrated superior GEBV prediction accuracy, with values of 0.683, 0.710, 0.866, and 0.871 for B100, B115, D100, and D115, respectively, slightly outperforming other methods. In phenotype prediction, GBM emerged as the best-performing model for pigs with B100, B115, D100, and D115 traits, achieving prediction accuracies of 0.547, followed by DL at 0.547, and then XGB with accuracies of 0.672 and 0.670. In terms of model training time, RF required the most time, while GBM and DL fell in between, and XGB demonstrated the shortest training time. In summary, machine learning models obtained through automated techniques exhibited higher GEBV prediction accuracy compared to phenotypic traits. GBM emerged as the overall top performer in terms of prediction accuracy and training time efficiency, while XGB demonstrated the ability to train accurate prediction models within a short timeframe. RF, on the other hand, had longer training times and insufficient accuracy, rendering it unsuitable for predicting pig growth traits and GEBV.


Assuntos
Genoma , Modelos Genéticos , Suínos/genética , Animais , Fenótipo , Genômica/métodos , Genótipo , Polimorfismo de Nucleotídeo Único
18.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(5): 497-501, 2023 May 15.
Artigo em Zh | MEDLINE | ID: mdl-37272176

RESUMO

OBJECTIVES: To study the clinical and genetic features of Joubert syndrome (JS) in children. METHODS: A retrospective analysis was performed on the clinical data, genetic data, and follow-up data of 20 children who were diagnosed with JS in the Department of Children's Rehabilitation, the Third Affiliated Hospital of Zhengzhou University, from January 2017 to July 2022. RESULTS: Among the 20 children with JS, there were 11 boys and 9 girls. The common clinical manifestations were developmental delay (20 children, 100%), abnormal eye movement (19 children, 95%), and hypotonia (16 children, 80%), followed by abnormal respiratory rhythm in 5 children (25%) and unusual facies (including prominent forehead, low-set ears, and triangular mouth) in 3 children (15%), and no limb deformity was observed. All 20 children (100%) had the typical "molar tooth sign" and "midline cleft syndrome" on head images, and 6 children (30%) had abnormal eye examination results. Genetic testing was performed on 7 children and revealed 6 pathogenic genes, i.e., the CPLANE1, RPGRIP1L, MKS1, CC2D2A, CEP120, and AHI1 genes. CONCLUSIONS: For children with developmental delay, especially those with abnormal eye movement and hypotonia, it is recommended to perform a head imaging examination to determine the presence or absence of "molar tooth sign" and "midline cleft syndrome", so as to screen for JS to avoid missed diagnosis and misdiagnosis. There are many pathogenic genes for JS, and whole-exome sequencing can assist in the diagnosis of JS.


Assuntos
Anormalidades Múltiplas , Anormalidades do Olho , Doenças Renais Císticas , Masculino , Feminino , Humanos , Criança , Cerebelo , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Doenças Renais Císticas/diagnóstico , Doenças Renais Císticas/genética , Anormalidades do Olho/diagnóstico , Anormalidades do Olho/genética , Retina , Estudos Retrospectivos , Hipotonia Muscular/diagnóstico , Hipotonia Muscular/genética
19.
Anal Chem ; 94(22): 7944-7951, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35616317

RESUMO

High-quality oxygen isotope analysis of composition-variable minerals (e.g., ubiquitous carbonates) using secondary ion mass spectrometry (SIMS) is extremely challenging. The classical off-line procedure, which requires additional electron probe microanalyzer (EPMA) chemical compositions for calibrating instrumental mass fractionation (IMF), is inherently inaccurate and analytically inefficient. In this study, the first accurate and paired SIMS analysis of δ18O and Fe# [molar Fe/(Mg + Fe)] in dolomite is reported. Based on five newly developed dolomite O-isotopic standards with an Fe# range of 0.01-0.35 obtained by SIMS, a novel accurate and rapid online matrix effect calibration method for dolomite O-isotope analysis was developed using concurrent SIMS 18O-16O-56Fe16O-24Mg16O measurements without additional chemical electron probe microanalysis. A logistic equation was proposed as the best-fit curve to represent the δ18O matrix effect based on the 56Fe16O/24Mg16O ratios. For CTD-4 carbonatitic dolomite with variable Fe# but homogeneous oxygen isotopes, the off-line method exhibited highly variable apparent δ18O values in the range of 5.74-10.11‰. The online method yielded a homogeneous δ18O value of 7.94 ± 0.34‰ (2SD, n = 40), which is comparable with that of bulk analysis (7.94 ± 0.20‰; 2SD). Comprehensive analyses validated the online method as the best strategy for performing accurate δ18O analysis of samples with highly heterogeneous compositions. Based on its accuracy, simplicity, and economic feasibility, this method has potential applications in the analysis of composition-complex dolomites, detrital dolomites, and other precious terrestrial and extraterrestrial materials.


Assuntos
Carbonato de Cálcio , Minerais , Carbonato de Cálcio/química , Calibragem , Magnésio , Isótopos de Oxigênio/química
20.
Small ; 18(10): e2106144, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35038220

RESUMO

Solid phase conversion sulfur cathode is an effective strategy for eliminating soluble polysulfide intermediates (LiPSs) and improving cyclability of Li-S batteries. However, realizing such a sulfur cathode with high sulfur loading and high capacity utilization is very challenging due to the insulating nature of sulfur. In this work, a strategy is proposed for fabricating solid phase conversion sulfur cathode by encapsulating sulfur in the mesoporous channels of CMK-3 carbon to form a coaxially assembled sulfur/carbon (CA-S/C) composite. Vinyl carbonate (VC) is simultaneously utilized as the electrolyte cosolvent to in-situ form a dense solid electrolyte interface (SEI) on the CA-S/C composite surface through its nucleophilic reaction with the freshly generated polysulfides at the beginning of initial discharge, thus separating the direct contact of interior sulfur with the outer electrolyte. As expected, such a CA-S/C cathode can operate in a solid phase conversion manner in the VC-ether cosolvent electrolyte to exhibit a full capacity utilization (1667 mA h g-1 , ≈100%), a high rate capability of 2.0 A g-1 and excellent long-term cyclability over 500 cycles even at a high sulfur loading (75%, based on the weight of CA-S/C composite), demonstrating great promise for constructing high-energy-density and cycle-stable Li-S batteries.

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