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1.
Chem Sci ; 15(26): 10135-10145, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38966363

RESUMO

The dual catalysis strategy is an efficient and powerful tool to fulfill the stereodivergent synthesis of stereoisomeric products from the same set of starting materials. Great attention has been given to the construction of chiral compounds with two contiguous stereocenters. However, the synthesis of two remote noncontiguous stereocenters is more challenging and is less developed, despite the high demand for synthetic tactics. We herein developed an unprecedented example of the stereodivergent preparation of synthetically useful and biologically important chiral ζ-hydroxy amino ester derivatives containing remote 1,6-noncontiguous stereocenters and a unique ß,γ-unsaturation moiety. This cascade dehydrogenation/1,6-Michael addition/hydrogenation protocol between readily-available ketoimine esters and racemic branched dienyl carbinols was rationally realized with bimetallic copper/ruthenium relay catalysis. The key features of the process were atom economy, step economy, and redox-neutrality. All four stereoisomers of chiral ζ-hydroxy amino ester derivatives were easily achieved by the orthogonal permutations of a chiral copper catalyst and chiral ruthenium catalyst. Importantly, a much more challenging stereodivergent synthesis of all eight stereoisomers of chiral peptide products containing three remote stereocenters was accomplished with excellent results through the cooperation of two chiral catalyst pairs and substrate enantiomers.

2.
Acad Radiol ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39003227

RESUMO

RATIONALE AND OBJECTIVES: Prior to clinical presentations of Alzheimer's Disease (AD), neuropathological changes, such as amyloid-ß and brain atrophy, have accumulated at the earlier stages of the disease. The combination of such biomarkers assessed by multiple modalities commonly improves the likelihood of AD etiology. We aimed to explore the discriminative ability of Aß PET features and whether combining Aß PET and structural MRI features can improve the classification performance of the machine learning model in older healthy control (OHC) and mild cognitive impairment (MCI) from AD. MATERIAL AND METHODS: We collected 94 AD patients, 82 MCI patients, and 85 OHC from three different cohorts. 17 global/regional Aß features in Centiloid, 122 regional volume, and 68 regional cortical thickness were extracted as imaging features. Single or combined modality features were used to train the random forest model on the testing set. The top 10 features were sorted based on the Gini index in each binary classification. RESULTS: The results showed that AUC scores were 0.81/0.86 and 0.69/0.68 using sMRI/Aß PET features on the testing set in differentiating OHC and MCI from AD. The performance was improved while combining two-modality features with an AUC of 0.89 and an AUC of 0.71 in two classifications. Compared to sMRI features, particular Aß PET features contributed more to differentiating AD from others. CONCLUSION: Our study demonstrated the discriminative ability of Aß PET features in differentiating AD from OHC and MCI. A combination of Aß PET and structural MRI features can improve the RF model performance.

3.
Gene ; 928: 148767, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39013483

RESUMO

BACKGROUND: Zellweger Syndrome (ZS), or cerebrohepatorenal syndrome, is a rare disorder due to PEX gene mutations affecting peroxisome function. While PEX6 coding mutations are known to cause ZS, the impact of noncoding mutations is less clear. METHODS: A Chinese neonate and his family were subjected to whole exome sequencing (WES) and bioinformatics to assess variant pathogenicity. A minigene assay was also performed for detailed splicing variant analysis. RESULTS: WES identified compound heterozygous PEX6 variants: c.315G>A (p. Trp105Ter) and c.2095-3 T>G. Minigene assays indicated that the latter variant led to abnormal mRNA splicing and the loss of exon 11 in PEX6 expression, potentially causing nonsense-mediated mRNA decay (NMD) or truncated protein structure. CONCLUSION: The study suggests that PEX6: c.2095-3 T>G might be a genetic contributor to the patient's condition, broadening the known mutation spectrum of PEX6. These insights lay groundwork for potential gene therapy for such variants.

4.
Front Med (Lausanne) ; 11: 1406108, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38933116

RESUMO

Background and objective: Bleeding following endoscopic variceal ligation (EVL) may occur as a result of numerous factors, including a diameter of esophageal varices (EV) that is too large to be completely ligated. The present study aimed to develop an artificial intelligence-based endoscopic virtual ruler (EVR) to measure the diameter of EV with a view to finding more suitable cases for EVL. Methods: The present study was a multicenter retrospective study that included a total of 1,062 EVLs in 727 patients with liver cirrhosis with EV, who underwent EVL from April 2016 to March 2023. Patients were divided into early rebleeding (n = 80) and non-rebleeding groups (n = 982) according to whether postoperative bleeding occurred at 6 weeks. The characteristics of patient baseline data, the status of rebleeding at 6 weeks after surgery and the survival status at 6 weeks after rebleeding were analyzed. Results: The early rebleeding rate following 1,062 EVL procedures was 7.5%, and the mortality rate at 6 weeks after bleeding was 16.5%. Results of the one-way binary logistic regression analysis demonstrated that the risk factors for early rebleeding following EVL included: high TB (P = 0.009), low Alb (P = 0.001), high PT (P = 0.004), PVT (P = 0.026), HCC (P = 0.018), high Child-Pugh score (P < 0.001), Child-Pugh grade C(P < 0.001), high MELD score(P = 0.004), Japanese variceal grade F3 (P < 0.001), diameter of EV (P < 0.001), and number of ligature rings (P = 0.029). Results of the multifactorial binary logistic regression analysis demonstrated that Child-Pugh grade C (P = 0.007), Japanese variceal grade F3 (P = 0.009), and diameter of EV (P < 0.001) may exhibit potential in predicting early rebleeding following EVL. ROC analysis demonstrated that the area under curve (AUC) for EV diameter was 0.848, and the AUC for Japanese variceal grade was 0.635, which was statistically significant (P < 0.001). Thus, results of the present study demonstrated that EV diameter was more optimal in predicting early rebleeding following EVL than Japanese variceal grade criteria. The cut-off value of EV diameter was calculated to be 1.35 cm (sensitivity, 70.0%; specificity, 89.2%). Conclusion: If the diameter of EV is ≥1.4 cm, there may be a high risk of early rebleeding following EVL surgery; thus, we recommend caution with EVL.

5.
Front Med (Lausanne) ; 11: 1385358, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38873213

RESUMO

Objective: To explore the relationship between plasma lactoferrin (Lf) and glaucoma, assessing the clinical utility of Lf in glaucoma. Methods: A cross-sectional study involved 161 glaucoma patients and 115 healthy controls, with a follow-up of 14 subjects after approximately 2 years. Plasma Lf markers were quantified using ELISA, comparing levels between glaucoma patients and healthy controls, and analyzing plasma Lf across different glaucoma severity grades. Results: Glaucoma patients had significantly elevated plasma Lf levels compared to healthy controls (p < 0.001). Higher plasma Lf levels correlated with more severe disease stages (HPA grades showed ρ = 0.435, p < 0.001; AGIS grades showed ρ = 0.436, p < 0.001) and reduced retinal nerve fiber layer (RNFL) thickness (RNFL thickness showed ρ = -0.204, p = 0.024). ROC curve analysis demonstrated the efficacy of glaucoma markers in differentiating early-stage from advanced glaucoma. Conclusion: Plasma Lf levels are significantly associated with glaucoma severity and may be involved in the pathogenic progression of the disease.

7.
ACS Omega ; 9(19): 21307-21321, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38764687

RESUMO

Gas explosion is one of the main accident risks during underground coal gasification (UCG). There are significant differences in the gas composition and explosive environment between UCG syngas and other gases. Previous research on the explosion characteristics of UCG syngas is not comprehensive enough, especially without considering the influence of the initial temperature on various characteristic parameters. A set of calculation methods for explosion characteristic parameters of UCG syngas based on existing research was proposed, which was applied to analyze explosion characteristics of syngas produced by different gasifying processes in the Huating UCG industrial test. The results showed that with the initial temperature improving, the maximum temperature and upper explosion limit of different gases increased, while the maximum pressure, lower explosion limit, and oxygen content safety limit decreased. However, the explosion thermal effect, pressure rise rate, and explosion characteristic values showed small changes. When the initial temperature increased from 298 to 1473 K, the explosion temperature of different gas explosions increased from 1645-2286 to 2652-3238 K, the maximum pressure dropped from 0.59-0.81 MPa (absolute pressure) to 0.19-0.23 MPa, the lower explosion limit dropped from 12.34-29.79% to 0.58-1.77%, the upper explosion limit increased from 55.68-83.35% to 70.89-93.73%, and the safety limit of oxygen content dropped from 4.86-6.37% to 0.26-0.34%. In addition, the gas calorific value also affected the values of various explosion characteristic parameters, among which the explosive thermal effect, maximum temperature, maximum pressure, pressure rise rate, explosion characteristic value, and safety limit of oxygen content in the syngas were all proportional to the calorific value of gas, while the lower and upper limits of explosion were inversely proportional to it. Based on the above research, syngas explosion-prone stages and causes of each potential risk area in the Huating UCG project were analyzed, the explosion characteristic parameters were determined, and targeted prevention and control measures were proposed accordingly. This study can lay a theoretical foundation for the study of syngas explosion characteristics and risk control for the UCG project.

8.
Neuroradiology ; 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38676749

RESUMO

PURPOSE: The Centiloid project helps calibrate the quantitative amyloid-ß (Aß) load into a unified Centiloid (CL) scale that allows data comparison across multi-site. How the smaller regional amyloid converted into CL has not been attempted. We first aimed to express regional Aß deposition in CL using [18F]Flutemetamol and evaluate regional Aß deposition in CL with that in standardized uptake value ratio (SUVr). Second, we aimed to determine the presence or absence of focal Aß deposition by measuring regional CL in equivocal cases showing negative global CL. METHODS: Following the Centiloid project pipeline, Level-1 replication, Level-2 calibration, and quality control were completed to generate corresponding Centiloid conversion equations to convert SUVr into Centiloid at regional levels. In equivocal cases, the regional CL was compared with visual inspection to evaluate regional Aß positivity. RESULTS: 14 out of 16 regional conversions from [18F]Flutemetamol SUVr to Centiloid successfully passed the quality control, showing good reliability and relative variance, especially precuneus/posterior cingulate and prefrontal regions with good stability for Centiloid scaling. The absence of focal Aß deposition could be detected by measuring regional CL, showing a high agreement rate with visual inspection. The regional Aß positivity in the bilateral anterior cingulate cortex was most prevalent in equivocal cases. CONCLUSION: The expression of regional brain Aß deposition in CL with [18F]Flutemetamol has been attempted in this study. Equivocal cases had focal Aß deposition that can be detected by measuring regional CL.

9.
Int J Mol Med ; 53(5)2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38577932

RESUMO

Pyroptosis, a programmed cell death marked by lytic and inflammatory characteristics, plays a crucial role in non­infectious inflammation­related diseases but can lead to detrimental outcomes when dysregulated. Stem cells have emerged as key players in modulating pyroptosis through paracrine signaling, offering a novel avenue for tissue repair and regeneration. The present review delved into previous studies elucidating the intricate interplay between stem cells and pyroptosis, emphasizing the potential of stem cell­based therapies in regulating pyroptotic pathways. The exploration of this dynamic interaction holds promise for developing strategies to harness stem cells for effective tissue repair and regeneration in the context of inflammation­related diseases.


Assuntos
Apoptose , Piroptose , Humanos , Células-Tronco , Inflamação
10.
Chem Commun (Camb) ; 60(38): 5086-5089, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38639097

RESUMO

Iridium-catalyzed dearomative allylation/acyl transfer rearrangement has been developed using easily available 2-pyridinyl benzoates and vinyl ethylene carbonate. This protocol enabled the expedient synthesis of a variety of chiral N-substituted 2-pyridones in good to high yields with excellent enantioselectivity. It has the advantages of high atom economy, wide substrate scope, gram-scale synthesis, and versatile synthetic transformations.

11.
Alzheimers Res Ther ; 16(1): 65, 2024 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-38532501

RESUMO

BACKGROUND: It has been reported that the risk of Alzheimer's disease (AD) could be predicted by the Australian National University Alzheimer Disease Risk Index (ANU-ADRI) scores. However, among non-demented Chinese adults, the correlations of ANU-ADRI scores with cerebrospinal fluid (CSF) core biomarkers and cognition remain unclear. METHODS: Individuals from the Chinese Alzheimer's Biomarker and LifestyLE (CABLE) study were grouped into three groups (low/intermediate/high risk groups) based on their ANU-ADRI scores. The multiple linear regression models were conducted to investigate the correlations of ANU-ADRI scores with several biomarkers of AD pathology. Mediation model and structural equation model (SEM) were conducted to investigate the mediators of the correlation between ANU-ADRI scores and cognition. RESULTS: A total of 1078 non-demented elders were included in our study, with a mean age of 62.58 (standard deviation [SD] 10.06) years as well as a female proportion of 44.16% (n = 476). ANU-ADRI scores were found to be significantly related with MMSE (ß = -0.264, P < 0.001) and MoCA (ß = -0.393, P < 0.001), as well as CSF t-tau (ß = 0.236, P < 0.001), p-tau (ß = 0.183, P < 0.001), and t-tau/Aß42 (ß = 0.094, P = 0.005). Mediation analyses indicated that the relationships of ANU-ADRI scores with cognitive scores were mediated by CSF t-tau or p-tau (mediating proportions ranging from 4.45% to 10.50%). SEM did not reveal that ANU-ADRI scores affected cognition by tau-related pathology and level of CSF soluble triggering receptor expressed on myeloid cells 2 (sTREM2). CONCLUSION: ANU-ADRI scores were associated with cognition and tau pathology. We also revealed a potential pathological mechanism underlying the impact of ANU-ADRI scores on cognition.


Assuntos
Doença de Alzheimer , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Doença de Alzheimer/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Austrália , Biomarcadores/líquido cefalorraquidiano , Cognição , Estilo de Vida , Fragmentos de Peptídeos/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Masculino
12.
J Neurochem ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38533619

RESUMO

Though previous studies revealed the potential associations of elevated levels of plasma fibrinogen with dementia, there is still limited understanding regarding the influence of Alzheimer's disease (AD) biomarkers on these associations. We sought to investigate the interrelationships among fibrinogen, cerebrospinal fluid (CSF) AD biomarkers, and cognition in non-demented adults. We included 1996 non-demented adults from the Chinese Alzheimer's Biomarker and LifestylE (CABLE) study and 337 from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. The associations of fibrinogen with AD biomarkers and cognition were explored using multiple linear regression models. The mediation analyses with 10 000 bootstrapped iterations were conducted to explore the mediating effects of AD biomarkers on cognition. In addition, interaction analyses and subgroup analyses were conducted to assess the influence of covariates on the relationships between fibrinogen and AD biomarkers. Participants exhibiting low Aß42 were designated as A+, while those demonstrating high phosphorylated tau (P-tau) and total tau (Tau) were labeled as T+ and N+, respectively. Individuals with normal measures of Aß42 and P-tau were categorized as the A-T- group, and those with abnormal levels of both Aß42 and P-tau were grouped under A+T+. Fibrinogen was higher in the A+ subgroup compared to that in the A- subgroup (p = 0.026). Fibrinogen was higher in the A+T+ subgroup compared to that in the A-T- subgroup (p = 0.011). Higher fibrinogen was associated with worse cognition and Aß pathology (all p < 0.05). Additionally, the associations between fibrinogen and cognition were partially mediated by Aß pathology (mediation proportion range 8%-28%). Interaction analyses and subgroup analyses showed that age and ApoE ε4 affect the relationships between fibrinogen and Aß pathology. Fibrinogen was associated with both cognition and Aß pathology. Aß pathology may be a critical mediator for impacts of fibrinogen on cognition.

13.
Inorg Chem ; 63(13): 5945-5951, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38502918

RESUMO

Alkali-metal rare-earth carbonates (ARECs) find great potential in nonlinear optical applications. As the most common method, the hydrothermal reaction is widely used in synthesizing ARECs. The black-box nature of the hydrothermal reaction makes it difficult for understanding the formation processes and therefore may slow down the pace of structural discovery. Here, by simply soaking the rare-earth carbonates in Na2CO3 solutions, we successfully obtain a series of noncentrosymmetric Na3RE(CO3)3·6H2O (RE = Tb 1, Sm 2, Eu 3, Gd 4, Dy 5, Ho 6, and Er 7) compounds without using the high-temperature hydrothermal method. The transformation process, investigated by powder X-ray diffraction and scanning electron microscopy, is governed by the concentration of the soaking solutions. Na3Tb(CO3)3·6H2O, as an example, is studied structurally, and its physical properties are characterized. It exhibits a second harmonic generation effect of 0.5 × KDP and a short UV cutoff edge of 222 nm (5.8 eV). Our study provides insights for exploring new AREC structures, which may further advance the development of carbonate nonlinear optical crystals.

14.
Emotion ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38512195

RESUMO

Previous research has shown mixed results regarding the relationship between social class and children's prosocial behavior. The current study aims to further our understanding of these findings by exploring the relationship between social class and children's prosocial behavior in a moral context. Study 1 (N = 833) found that when a target child pursued a morally negative goal and subsequently experienced misfortune, children from higher social class, compared to those from lower social class, experienced greater schadenfreude and exhibited less prosocial behavior. The relation between social class and prosocial behavior was mediated by schadenfreude. Study 2 (N = 389) investigated whether the greater schadenfreude experienced by children from higher social class was due to a weaker empathic response to misfortune or a stronger sense of deservingness. The results revealed a sequential mediation effect of social class on prosocial behavior through deservingness and schadenfreude. These findings provide insight into the impact of social class on the development of children's moral judgment, emotions, and behavior. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

15.
J Neuroinflammation ; 21(1): 43, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38317227

RESUMO

Glaucoma is a complex neurodegenerative disorder characterized by the progressive loss of retinal ganglion cells (RGC) and optic nerve axons, leading to irreversible visual impairment. Despite its clinical significance, the underlying mechanisms of glaucoma pathogenesis remain poorly understood. In this study, we aimed to unravel the multifaceted nature of glaucoma by investigating the interaction between T cells and retinas. By utilizing clinical samples, murine glaucoma models, and T cell transfer models, we made several key findings. Firstly, we observed that CD4+ T cells from glaucoma patients displayed enhanced activation and a bias towards T helper (Th) 1 responses, which correlated with visual impairment. Secondly, we identified the infiltration of Th1 cells into the retina, where they targeted RGC and integrated into the pro-inflammatory glial network, contributing to progressive RGC loss. Thirdly, we discovered that circulating Th1 cells upregulated vascular cell adhesion protein 1 (VCAM-1) on retinal microvessels, facilitating their entry into the neural retina. Lastly, we found that Th1 cells underwent functional reprogramming before reaching the retina, acquiring a phenotype associated with lymphocyte migration and neurodegenerative diseases. Our study provides novel insights into the role of peripheral CD4+ T cells in glaucoma pathogenesis, shedding light on the mechanisms underlying their infiltration into the retina and offering potential avenues for innovative therapeutic interventions in this sight-threatening disease.


Assuntos
Glaucoma , Células Ganglionares da Retina , Humanos , Camundongos , Animais , Células Ganglionares da Retina/patologia , Molécula 1 de Adesão de Célula Vascular/metabolismo , Células Th1/patologia , Glaucoma/metabolismo , Retina/patologia , Transtornos da Visão/patologia , Modelos Animais de Doenças
16.
BMC Plant Biol ; 24(1): 101, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38331759

RESUMO

BACKGROUND: The cultivation of bananas encounters substantial obstacles, particularly due to the detrimental effects of cold stress on their growth and productivity. A potential remedy that has gained attention is the utilization of ethyl mesylate (EMS)-induced mutagenesis technology, which enables the creation of a genetically varied group of banana mutants. This complex procedure entails subjecting the mutants to further stress screening utilizing L-Hyp in order to identify those exhibiting improved resistance to cold. This study conducted a comprehensive optimization of the screening conditions for EMS mutagenesis and L-Hyp, resulting in the identification of the mutant cm784, which exhibited remarkable cold resistance. Subsequent investigations further elucidated the physiological and transcriptomic responses of cm784 to low-temperature stress. RESULTS: EMS mutagenesis had a substantial effect on banana seedlings, resulting in modifications in shoot and root traits, wherein a majority of seedlings exhibited delayed differentiation and limited elongation. Notably, mutant leaves displayed altered biomass composition, with starch content exhibiting the most pronounced variation. The application of L-Hyp pressure selection aided in the identification of cold-resistant mutants among seedling-lethal phenotypes. The mutant cm784 demonstrated enhanced cold resistance, as evidenced by improved survival rates and reduced symptoms of chilling injury. Physiological analyses demonstrated heightened activities of antioxidant enzymes and increased proline production in cm784 when subjected to cold stress. Transcriptome analysis unveiled 946 genes that were differentially expressed in cm784, with a notable enrichment in categories related to 'Carbohydrate transport and metabolism' and 'Secondary metabolites biosynthesis, transport, and catabolism'. CONCLUSION: The present findings provide insights into the molecular mechanisms that contribute to the heightened cold resistance observed in banana mutants. These mechanisms encompass enhanced carbohydrate metabolism and secondary metabolite biosynthesis, thereby emphasizing the adaptive strategies employed to mitigate the detrimental effects induced by cold stress.


Assuntos
Musa , Musa/metabolismo , Metanossulfonato de Etila/metabolismo , Metanossulfonato de Etila/farmacologia , Biomassa , Perfilação da Expressão Gênica , Mutagênese , Fenótipo , Temperatura Baixa , Regulação da Expressão Gênica de Plantas
17.
Front Microbiol ; 15: 1348729, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38380091

RESUMO

Introduction: Excessive intake of lactate caused by improper use of silage in animal husbandry has adverse effects on rumen fermentation, such as rumen acidosis. The speed of absorption and metabolism of D-lactate in rumen epithelial cells was slower than that of L-lactate, making D-lactate more prone to accumulate and induce rumen acidosis. Therefore, this study was conducted to explore the effects of dietary D-lactate levels on rumen fermentation of beef cattle and its mechanism in an in vitro system. Methods: This experiment was adopted in single-factor random trial design, with 5 days for adaptation and 3 days for sample collection. Three treatments (n = 8/treatment) were used: (1) D-LA (0.3%), basal fermentation substrate with 0.3% (dry matter, DM basis) D-lactate; (2) D-LA (0.75%), basal fermentation substrate with 0.75% (DM basis) D-lactate; and (3) D-LA (1.2%), basal fermentation substrate with 1.2% (DM basis) D-lactate. Results: With the dietary D-lactate levels increased, the daily production of total gas, hydrogen and methane, as well as the ruminal concentrations of acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, total volatile fatty acid and D-lactate increased (p < 0.05), but the ruminal pH and acetate/propionate ratios decreased (p < 0.05). Principle coordinate analysis based on Bray-Curtis distance showed that increasing dietary D-lactate levels could significantly affect the structure of rumen bacterial community (p < 0.05), but had no significant effect on the structure of rumen eukaryotic community (p > 0.05). NK4A214_group, Ruminococcus_gauvreauii_group, Eubacterium_oxidoreducens_group, Escherichia-Shigella, Marvinbryantia and Entodinium were enriched in D-LA (1.2%) group (p < 0.05), as well as WCHB1-41, vadinBE97, Clostridium_sensu_stricto_1, Anaeroplasma and Ruminococcus were enriched in D-LA (0.3%) group (p < 0.05). Changes in the composition of ruminal microorganisms affected rumen metabolism, mainly focus on the biosynthesis of glycosaminoglycans (p < 0.05). Discussion: Overall, feeding whole-plant corn silage with high D-lactate content could not induce rumen acidosis, and the metabolization of dietary D-lactate into volatile fatty acids increased the energy supply of beef cattle. However, it also increased the ruminal CH4 emissions and the relative abundance of opportunistic pathogen Escherichia-Shigella in beef cattle. The relative abundance of Verrucomicrobiota and Escherichia-Shigella may be influenced by glycosaminoglycans, reflecting the interaction between rumen microorganisms and metabolites.

18.
Small ; 20(26): e2308527, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38221686

RESUMO

Flexible hydroelectric generators (HEGs) are promising self-powered devices that spontaneously derive electrical power from moisture. However, achieving the desired compatibility between a continuous operating voltage and superior current density remains a significant challenge. Herein, a textile-based van der Waals heterostructure is rationally designed between conductive 1T phase tungsten disulfide@carbonized silk (1T-WS2@CSilk) and carbon black@cotton (CB@Cotton) fabrics with an asymmetric distribution of oxygen-containing functional groups, which enhances the proton concentration gradients toward high-performance wearable HEGs. The vertically staggered 1T-WS2 nanosheet arrays on the CSilk fabric provide abundant hydrophilic nanochannels for rapid carrier transport. Furthermore, the moisture-induced primary battery formed between the active aluminum (Al) electrode and the conductive textiles introduces the desired electric field to facilitate charge separation and compensate for the decreased streaming potential. These devices exhibit a power density of 21.6 µW cm-2, an open-circuit voltage (Voc) of 0.65 V sustained for over 10 000 s, and a current density of 0.17 mA cm-2. This performance makes them capable of supplying power to commercial electronics and human respiratory monitoring. This study presents a promising strategy for the refined design of wearable electronics.

19.
J Prosthodont Res ; 68(2): 193-205, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-37302842

RESUMO

PURPOSE: The surge in digitalization and artificial intelligence has led to the wide application of robots in various fields, but their application in dentistry started relatively late. This scoping review aimed to comprehensively explore and map the current status of the clinical application of robots in dentistry. STUDY SELECTION: An iterative approach was used to gather as much evidence as possible from four online databases, including PubMed, the China National Knowledge Infrastructure, the Japan Science and Technology Information Aggregator, Electronic, and the Institute of Electrical and Electronics Engineers, from January 1980 to December 2022. RESULTS: A total of 113 eligible articles were selected from the search results, and it was found that most of the robots were developed and applied in the United States (n = 56; 50%). Robots were clinically applied in oral and maxillofacial surgery, oral implantology, prosthodontics, orthodontics, endodontics, and oral medicine. The development of robots in oral and maxillofacial surgery and oral implantology is relatively fast and comprehensive. About 51% (n = 58) of the systems had reached clinical application, while 49% (n = 55) were at the pre-clinical stage. Most of these are hard robots (90%; n = 103), and their invention and development were mainly focused on university research groups with long research periods and diverse components. CONCLUSIONS: There are still limitations and gaps between research and application in dental robots. While robotics is threatening to replace clinical decision-making, combining it with dentistry to gain maximum benefit remains a challenge for the future.


Assuntos
Medicina Bucal , Robótica , Cirurgia Bucal , Humanos , Inteligência Artificial , Prostodontia
20.
Angew Chem Int Ed Engl ; 63(7): e202315325, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38155608

RESUMO

An atom- and step-economical and redox-neutral cascade reaction enabled by asymmetric bimetallic relay catalysis by merging a ruthenium-catalyzed asymmetric borrowing-hydrogen reaction with copper-catalyzed asymmetric Michael addition has been realized. A variety of highly functionalized 2-amino-5-hydroxyvaleric acid esters or peptides bearing 1,4-non-adjacent stereogenic centers have been prepared in high yields with excellent enantio- and diastereoselectivity. Judicious selection and rational modification of the Ru catalysts with careful tuning of the reaction conditions played a pivotal role in stereoselectivity control as well as attenuating undesired α-epimerization, thus enabling a full complement of all four stereoisomers that were otherwise inaccessible in previous work. Concise asymmetric stereodivergent synthesis of the key intermediates for biologically important chiral molecules further showcases the synthetic utility of this methodology.


Assuntos
Cobre , Rutênio , Aminoácidos/química , Catálise , Cobre/química , Peptídeos , Estereoisomerismo
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