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1.
J Microbiol ; 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37129765

RESUMO

The Fusarium graminearum species complex (FGSC) can produce various mycotoxins and is a major concern for food quantity and quality worldwide. In this study, we determined the effects of water activity (aw), temperature, incubation time and their interactions on mycotoxin accumulation and the expression levels of biosynthetic genes in FGSC strains from maize samples in China. The highest deoxynivalenol (DON), 3-acetyldeoxynivalenol(3ADON) and 15-acetyldeoxynivalenol (15ADON) levels of the F. boothii and F. graminearum strains were observed at 0.98 aw/30 °C or 0.99 aw/25 °C. F. asiaticum and F. meridionale reached maximum nivalenol (NIV) and 4-acetylnivalenol (4ANIV) contents at 0.99 aw and 30 °C. With the extension of the incubation time, the concentrations of DON and NIV gradually increased, while those of their derivatives decreased. F. boothii, F. meridionale and one F. asiaticum strain had the highest zearalenone (ZEN) values at 0.95 aw and 25 °C, while the optimum conditions for the other F. asiaticum strain and F. graminearum were 0.99 aw and 30 °C. Four genes associated with trichothecene and zearalenone synthesis were significantly induced under higher water stress in the early stage of production. The results indicated independence of mycotoxin production and gene expression, as maximum amounts of these toxic metabolites were observed at higher aw in most cases. This study provides useful information for the monitoring and prevention of such toxins entering the maize production chain.

2.
J Biomech Eng ; : 1-47, 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37144887

RESUMO

Porous cages with lower global stiffness induce more bone ingrowth and enhance bone-implant anchorage. However, for spinal fusion cages, which usually act as stabilizers, it's dangerous to sacrifice global stiffness for bone ingrowth. Intentional design on internal mechanical environment might be a promising approach to promote osseointegration without undermining global stiffness excessively. In this study, three porous cages with different architectures were designed to provide distinct internal mechanical environments for bone remodeling during spinal fusion process. A design space optimization-topology optimization based algorithm was utilized to numerically reproduce the mechano-driven bone ingrowth process under three daily load cases, and the fusion outcomes were analyzed in terms of bone morphological parameters and bone-cage stability. Simulation results show that the uniform cage with higher compliance induces deeper bone ingrowth than the optimized graded cage. Whereas, the optimized graded cage with the lowest compliance exhibits the lowest stress at the bone-cage interface and better mechanical stability. Combining the advantages of both, the strain-enhanced cage offers extra mechanical stimulus while keeping relatively low compliance, leading to more bone formation and the best mechanical stability. Thus, the internal mechanical environment can be well-designed via tailoring architectures to promote bone ingrowth and achieve a long-term bone-scaffold stability.

3.
Surg Endosc ; 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37145172

RESUMO

OBJECTIVE: To evaluate the effectiveness and safety of endoscopic resection and various suturing methods to treat non-ampullary duodenal submucosal tumors (NAD-SMTs). DESIGN: We performed a retrospective observational study of patients with NAD-SMTs who underwent endoscopic resection at Zhongshan Hospital, Fudan University, China, between June 2017 and December 2020. Data on patient characteristics, treatments and follow-up results were collected. The association between clinicopathologic characteristics and different suturing methods or adverse events were analyzed. RESULTS: Of 128 patients analyzed, 26 underwent endoscopic mucosal resection (EMR), 64 underwent endoscopic submucosal excavation (ESE), and 38 underwent endoscopic full-thickness resection (EFTR). EMR and ESR are both appropriate for non-full-thickness lesions, whereas ESE is more appropriate for tumors located in the bulb or descending duodenum. Gastric tube drainage is more strongly recommended after ESE. Satisfactory suturing is also vital endoscopic resection of NAD-SMTs. Metallic clips are often used in EMR or ESE of non-full-thickness lesions. The pathological findings revealed that the full-thickness lesions were predominantly gastrointestinal stromal tumors (GIST), Brunner's tumor or lipoma, and the surgeons usually used purse-string sutures to close the wounds. The operation time was longer for purse-string suture closure than metallic clip closure. Eleven patients had complications. Risk factors for adverse events included large-diameter tumor (≥ 2 cm), location in the descending part of the duodenum, involvement of the fourth layer of the duodenal wall, EFTR, and GIST. CONCLUSIONS: Endoscopic resection of NAD-SMTs is effective but is associated with a high incidence of complications due to their anatomical peculiarities. Preoperative diagnosis is quite important. Careful selection of treatment and suturing methods are necessary to reduce the risk of adverse effects. Given the increased frequency of severe complications during or following duodenal endoscopic resection, this procedure should be performed by experienced endoscopists.

5.
Med Image Anal ; 87: 102832, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37148864

RESUMO

Colorectal cancer is one of the malignant tumors with the highest mortality due to the lack of obvious early symptoms. It is usually in the advanced stage when it is discovered. Thus the automatic and accurate classification of early colon lesions is of great significance for clinically estimating the status of colon lesions and formulating appropriate diagnostic programs. However, it is challenging to classify full-stage colon lesions due to the large inter-class similarities and intra-class differences of the images. In this work, we propose a novel dual-branch lesion-aware neural network (DLGNet) to classify intestinal lesions by exploring the intrinsic relationship between diseases, composed of four modules: lesion location module, dual-branch classification module, attention guidance module, and inter-class Gaussian loss function. Specifically, the elaborate dual-branch module integrates the original image and the lesion patch obtained by the lesion localization module to explore and interact with lesion-specific features from a global and local perspective. Also, the feature-guided module guides the model to pay attention to the disease-specific features by learning remote dependencies through spatial and channel attention after network feature learning. Finally, the inter-class Gaussian loss function is proposed, which assumes that each feature extracted by the network is an independent Gaussian distribution, and the inter-class clustering is more compact, thereby improving the discriminative ability of the network. The extensive experiments on the collected 2568 colonoscopy images have an average accuracy of 91.50%, and the proposed method surpasses the state-of-the-art methods. This study is the first time that colon lesions are classified at each stage and achieves promising colon disease classification performance. To motivate the community, we have made our code publicly available via https://github.com/soleilssss/DLGNet.

6.
Gastrointest Endosc ; 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37150417

RESUMO

BACKGROUND AND AIMS: Reintervention modalities following myotomy failure in achalasia patients have yet to be established. The efficacy and safety of salvage peroral endoscopic myotomy (POEM) for treatment of achalasia following a myotomy failure were evaluated in the study. METHOD: Between August 2011 to August 2021, at the Endoscopy Center of Zhongshan Hospital, 219 achalasia patients who had previously undergone a myotomy underwent a salvage POEM and were thus retrospectively enrolled in this study. After propensity score matching (PSM), operation-related parameters were compared between the salvage POEM group and the naïve POEM group. Subgroup analysis was performed between patients with previous heller myotomy (HM) and patients with previous POEM. RESULT: With similar baseline characteristics between both groups after PSM, the salvage POEM group presented with shorter tunnel length (11.8±2.2 vs. 12.8±0.9, p<0.0001) and myotomy length (9.8±2.0 vs. 10.4±1.0, p<0.0001) than the naïve POEM group. There were no significant differences in procedure-related adverse events (AEs) between patients of salvage POEM and naïve POEM. The primary outcome of treatment success occurred in 175 of 193 patients (90.7%) in salvage POEM group vs. 362 of 374 patients (96.8%) in naïve POEM group (p = 0.0046). Significantly higher rate of clinical failures were observed at the 2-year and 5-year follow-ups in the previous HM subgroup than the previous POEM subgroup (p = 0.0433, p = 0.0230, respectively). CONCLUSION: Salvage POEM following a previous myotomy failure, especially after POEM failure, is a promising treatment option as it has a durable clinical relief rate.

7.
Cancer Med ; 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37212447

RESUMO

BACKGROUND: To assess the prognostic effect of plasma Epstein-Barr virus (EBV) DNA load after induction chemotherapy (postIC -EBV DNA) on survival outcomes in locoregionally advanced nasopharyngeal carcinoma (LA-NPC). METHODS: Patients who were diagnosed with LA-NPC between August 2017 and October 2021 were included. The chi-squared test, receiver operating characteristic, Kaplan-Meier survival analysis, and Cox proportional hazard model were used for statistical analysis. RESULTS: We included 172 patients with EBV DNA-positive LA-NPC in this study. There were 35.5% (n = 61) of patients had plasma residual EBV DNA after induction chemotherapy (IC). Patients with higher EBV DNA before IC (p < 0.001) and advanced nodal stage (p = 0.031) were significantly related to a higher rate of residual postIC -EBV DNA. Patients with detectable postIC -EBV DNA had inferior 3-year locoregional relapse-free survival (LRFS) (86.7% vs. 96.9%, p = 0.020), distant metastasis-free survival (DMFS) (76.8% vs. 94.2%, p < 0.001), disease-free survival (DFS) (68.2% vs. 91.1%, p < 0.001), and overall survival (OS) (87.8% vs. 97.9%, p = 0.044) compared to those with undetectable postIC -EBV DNA. The multivariate prognostic analyses showed that detectable postIC -EBV DNA was the independent prognostic factor related to LRFS (p = 0.032), DMFS (p = 0.010), and DFS (p = 0.004) than those with undetectable postIC -EBV DNA. Pretreatment EBV DNA load had no prognostic effect in the multivariate analyses. CONCLUSIONS: The monitoring of plasma postIC -EBV DNA has improved prognostication in LA-NPC. Our findings suggest that postIC -EBV DNA may be a robust indicator to identify the optimal candidate for intensive treatment.

8.
Res Sq ; 2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37162996

RESUMO

Background: Cerebral amyloid angiopathy (CAA) is a devastating condition common in patients with Alzheimer's disease but also observed in the general population. Vascular oxidative stress and neurovascular dysfunction have been implicated in CAA but the cellular source of reactive oxygen species (ROS) and related signaling mechanisms remain unclear. We tested the hypothesis that brain border-associated macrophages (BAM), yolk sac-derived myeloid cells closely apposed to parenchymal and leptomeningeal blood vessels, are the source of radicals through the Aß-binding innate immunity receptor CD36, leading to neurovascular dysfunction, CAA, and cognitive impairment. Methods: Tg2576 mice and WT littermates were transplanted with CD36 -/- or CD36 +/+ bone marrow at 12-month of age and tested at 15 months. This approach enables the repopulation of perivascular and leptomeningeal compartments with CD36 -/- BAM. Neurovascular function was tested in anesthetized mice equipped with a cranial window in which cerebral blood flow was monitored by laser-Doppler flowmetry. Amyloid pathology and cognitive function were also examined. Results: The increase in blood flow evoked by whisker stimulation (functional hyperemia) or by endothelial and smooth muscle vasoactivity was markedly attenuated in WT®Tg2576 chimeras but was fully restored in CD36 -/- ®Tg2576 chimeras, in which BAM ROS production was suppressed. CAA-associated Aß 1-40 , but not Aß 1-42 , was reduced in CD36 -/- ®Tg2576 chimeras. Similarly, CAA, but not parenchymal plaques, was reduced in CD36 -/- ®Tg2576 chimeras. These beneficial vascular effects were associated with cognitive improvement. Finally, CD36 -/- mice were able to more efficiently clear exogenous Aß 1-40 injected into the neocortex or the striatum. Conclusions: CD36 deletion in BAM suppresses ROS production and rescues the neurovascular dysfunction and damage induced by Aß. CD36 deletion in BAM also reduced brain Aß 1-40 and ameliorated CAA without affecting parenchyma plaques. Lack of CD36 enhanced the vascular clearance of exogenous Aß. Restoration of neurovascular function and attenuation of CAA resulted in a near complete rescue of cognitive function. Collectively, these data implicate CNS BAM in the pathogenesis of CAA and raise the possibility that targeting BAM CD36 is beneficial in CAA and other conditions associated with vascular Aß deposition and damage.

9.
Front Neurol ; 14: 1135564, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37181551

RESUMO

Weakness is a common symptom after a stroke. This study aims to depict weakness distribution among forearm muscles given that joints in the upper limb are usually driven by a group of muscles. Multi-channel electromyography (EMG) was applied to assess the muscle group, and an EMG-based index was proposed to quantify the weakness of individual muscles. By using this method, four weakness distribution patterns were observed in extensor muscles from five out of eight subjects after stroke. Complex weakness distribution patterns were observed in flexor muscles from seven out of the eight subjects when they performed grasp, tripod pinch, and hook grip. The findings can help determine the weak muscles in a clinic and facilitate the development of appropriate interventions in stroke rehabilitation targeting specific muscle weakness.

10.
J Pediatr Nurs ; 2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37164784

RESUMO

BACKGROUND: Anxiety and depression are common debilitating mental health issues in families of children with chronic health conditions. It is essential to consider the mediating role of caregivers between children and healthcare workers. Previous research has evaluated the effectiveness of caregiver engagement interventions in reducing anxiety and depression in chronically ill children and their caregivers, but their overall impact awaits a synthesis of the available evidence. METHODS: We performed a comprehensive search using PubMed, Embase, Web of Science, Cochrane Library, Ovid, PsycINFO, APA PsycArticles, and Cumulative Index of Nursing and Allied Health Literature (CINAHL). RESULTS: Twenty-nine studies were included. The results demonstrated that caregiver engagement interventions significantly decreased anxiety (standardized mean difference [SMD] = -0.49; 95% confidence interval [CI], -0.77 to -0.22; P < 0.001) and depression (SMD = -0.37; 95% CI, -0.55 to -0.18; P < 0.001) among caregivers, particularly in developing countries. However, no improvements in the anxiety (SMD = 0.00; 95% CI, -0.46 to 0.46; P = 0.99) and depression (SMD = -0.14; 95% CI, -0.32 to 0.04; P = 0.14) of children were observed. CONCLUSIONS: Significant evidence exists regarding the positive effects of caregiver engagement interventions on caregivers' anxiety and depression. Further recommendations for future research should focus on engagement interventions that reduce the anxiety and depression for children with chronic conditions. IMPLICATIONS: Clinicians should concentrate on the mental health of chronically ill children and their caregivers and extend caregiver engagement therapies to improve anxiety and depression resulting from managing the disease.

11.
Entropy (Basel) ; 25(4)2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37190481

RESUMO

An optimized Schwarz domain decomposition method (DDM) for solving the local optical response model (LORM) is proposed in this paper. We introduce a hybridizable discontinuous Galerkin (HDG) scheme for the discretization of such a model problem based on a triangular mesh of the computational domain. The discretized linear system of the HDG method on each subdomain is solved by a sparse direct solver. The solution of the interface linear system in the domain decomposition framework is accelerated by a Krylov subspace method. We study the spectral radius of the iteration matrix of the Schwarz method for the LORM problems, and thus propose an optimized parameter for the transmission condition, which is different from that for the classical electromagnetic problems. The numerical results show that the proposed method is effective.

12.
ACS Omega ; 8(19): 17304-17316, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37214729

RESUMO

Type 2 diabetes (T2D) results from both insulin resistance and pancreatic ß-cell dysfunction. A natural proteoglycan extracted from Ganoderma lucidum, namely, FYGL, has been demonstrated to be capable of ameliorating insulin resistance in previous work. In this work, a T2D rat model induced by streptozocin (STZ) and a high-fat diet was used to investigate the effects of FYGL on pancreatic functions, and the transcriptomics of the rat pancreas was used to investigate the biological processes (BP) and signal pathways influenced by FYGL on the gene basis. Furthermore, the results of transcriptomics were verified both by histopathological analyses and protein expression. The studies showed that FYGL positively regulated T2D-related BP and signaling pathways and recovered the pancreatic function, therefore ameliorating hyperglycemia and hyperlipidemia in vivo. Importantly, the recovery of the pancreatic function suggested a crucial strategy to radically treat T2D.

13.
Gastrointest Endosc ; 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37207844

RESUMO

BACKGROUND AND AIMS: Stenosis after esophageal Endoscopic Submucosal Dissection (ESD) has a high incidence, and muscular injury is an important risk factor for esophageal stenosis. Hence, this study aimed to classify muscular injury degrees and investigate their association with postoperative stenosis. METHODS: This retrospective study included 1,033 patients with esophageal mucosal lesions treated with ESD between August 2015 and March 2021. Demographic and clinical parameters were analyzed, and stenosis risk factors were identified using multivariate logistic regression. A novel muscular injury classification system was proposed and used to investigate the association between different muscular injury degrees and postoperative stenosis. Finally, a scoring system was established to predict muscular injury. RESULTS: Of 1,033 patients, 118 (11.4%) had esophageal stenosis. The multivariate analysis demonstrated that the history of endoscopic esophageal treatment, circumferential range, and muscular injury were significant risk factors for esophageal stenosis. Patients with Type II muscular injuries tended to develop complex stenosis (n = 13, 36.1%, p < 0.05), and Type II muscular injuries were more likely to predispose patients to severe stenosis than Type I (73.3 and 92.3%, respectively). The scoring system showed that patients with high scores (3-6) were more likely to suffer muscular injury. The score model presented good discriminatory power in the internal validation [area under the receiver operating characteristic (ROC) curve (AUC): 0.706; 95% confidence interval (CI): 0.645-0.767] and goodness-of-fit in the Hosmer-Lemeshow test (p = 0.865). CONCLUSIONS: Muscular injury was an independent risk factor for esophageal stenosis. The scoring system demonstrated good performance in predicting muscular injury during ESD.

14.
Clin Cardiol ; 2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37226870

RESUMO

BACKGROUND: Thyroid dysfunction might have a negative impact on the prognosis of patients with heart failure (HF) and affect the lipid metabolism. The aim of our study was to investigate the prognostic role of thyroid dysfunction and its relationship with lipid profile in hospitalized HF patients. HYPOTHESIS: Thyroid dysfunction strongly correlates with prognosis of HF patients and combination with lipid profile improves the prognostic value. METHODS: We performed a single-center retrospective cohort study including hospitalized HF patients between March 2009 and June 2018. RESULTS: Among enrolled 3733 patients, low fT3 (hazard ratio [HR] 1.33; 95% CI: 1.15-1.54; p < .001), elevated TSH (HR 1.37; 95% CI 1.15-1.64; p < .001), LT3S (HR 1.39; 95% CI: 1.15-1.68; p < .001), overt hyperthyroidism (HR 1.73; 95%CI: 1.00-2.98; p = .048), subclinical hypothyroidism (HR 1.43; 95%CI: 1.13-1.82; p = .003) and overt hypothyroidism (HR 1.76; 95%CI: 1.33-2.34; p < .001) independently increased the risk of composite endpoint defined as the combination of all-cause mortality, heart transplantation, or left ventricular assist device requirement. Higher total cholesterol (HR 0.64; 95%CI: 0.49-0.83; p < .001) was still a protective factor in HF patients. When divided into four groups by fT3 and median lipid profiles, comparison of Kaplan-Meier survival curves for various groups showed good risk stratification (p < .001). CONCLUSION: LT3S, overt hyperthyroidism, subclinical and overt hypothyroidism were independently associated with poor outcomes in HF. The combination of fT3 and lipid profile improved the prognostic value.

15.
Ying Yong Sheng Tai Xue Bao ; 34(5): 1375-1383, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37236956

RESUMO

Discovering the underlying mechanisms between carbon metabolism and carbon balance of human-natural system is of important theoretical and practical significance for reducing regional carbon emissions and promoting low-carbon development. Taking Xiamen-Zhangzhou-Quanzhou region from 2000 to 2020 as an example, we constructed the framework of spatial network model of land carbon metabolism based on carbon flow, and inquired into the spatial and temporal heterogeneity in the carbon metabolic structure, function and ecological relationships by using the ecological network analysis. The results showed that the dominant negative carbon transitions related with land use changes came from the conversion of cultivated land to industrial and transportation land, and that the high value areas of negative carbon flow were mainly distributed in the areas with relatively developed industries in the middle and east parts of Xiamen-Zhangzhou-Quanzhou region. Competition relationships were the dominant type and the spatial expansion was obvious, which led to the decreases of the integral ecological utility index and affected the regional carbon metabolic balance. The ecological network hierarchy of driving weight changed from a pyramid structure to a relatively more regular structure, with the producer contributing the most. The ecological network hie-rarchy of pull weight changed from a pyramid structure to an inverted pyramid structure, mainly due to the excessive increase of industrial and transportation land weights. Low-carbon development should focus on the sources of negative carbon transitions caused by land use conversion and its comprehensive impacts on carbon metabolic balance, to formulate differentiated low-carbon land use patterns and carbon emission reduction policies.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Humanos , Conservação dos Recursos Naturais/métodos , Carbono , Indústrias , Homeostase , China , Cidades
16.
Biomolecules ; 13(5)2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37238692

RESUMO

Cell death includes programmed and nonprogrammed cell death. The former mainly includes ferroptosis, necroptosis, pyroptosis, autophagy, and apoptosis, while the latter refers to necrosis. Accumulating evidence shows that ferroptosis, necroptosis, and pyroptosis play essential regulatory roles in the development of intestinal diseases. In recent years, the incidence of inflammatory bowel disease (IBD), colorectal cancer (CRC), and intestinal injury induced by intestinal ischemia-reperfusion (I/R), sepsis, and radiation have gradually increased, posing a significant threat to human health. The advancement in targeted therapies for intestinal diseases based on ferroptosis, necroptosis, and pyroptosis provides new strategies for treating intestinal diseases. Herein, we review ferroptosis, necroptosis, and pyroptosis with respect to intestinal disease regulation and highlight the underlying molecular mechanisms for potential therapeutic applications.


Assuntos
Neoplasias Colorretais , Ferroptose , Doenças Inflamatórias Intestinais , Humanos , Piroptose , Necroptose , Apoptose , Doenças Inflamatórias Intestinais/genética , Neoplasias Colorretais/genética
17.
Diagnostics (Basel) ; 13(10)2023 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-37238217

RESUMO

Papillary thyroid carcinoma (PTC) is the most common pathological type of thyroid cancer. PTC patients with extrathyroidal extension (ETE) are associated with poor prognoses. The preoperative accurate prediction of ETE is crucial for helping the surgeon decide on the surgical plan. This study aimed to establish a novel clinical-radiomics nomogram based on B-mode ultrasound (BMUS) and contrast-enhanced ultrasound (CEUS) for the prediction of ETE in PTC. A total of 216 patients with PTC between January 2018 and June 2020 were collected and divided into the training set (n = 152) and the validation set (n = 64). The least absolute shrinkage and selection operator (LASSO) algorithm was applied for radiomics feature selection. Univariate analysis was performed to find clinical risk factors for predicting ETE. The BMUS Radscore, CEUS Radscore, clinical model, and clinical-radiomics model were established using multivariate backward stepwise logistic regression (LR) based on BMUS radiomics features, CEUS radiomics features, clinical risk factors, and the combination of those features, respectively. The diagnostic efficacy of the models was assessed using receiver operating characteristic (ROC) curves and the DeLong test. The model with the best performance was then selected to develop a nomogram. The results show that the clinical-radiomics model, which is constructed by age, CEUS-reported ETE, BMUS Radscore, and CEUS Radscore, showed the best diagnostic efficiency in both the training set (AUC = 0.843) and validation set (AUC = 0.792). Moreover, a clinical-radiomics nomogram was established for easier clinical practices. The Hosmer-Lemeshow test and the calibration curves demonstrated satisfactory calibration. The decision curve analysis (DCA) showed that the clinical-radiomics nomogram had substantial clinical benefits. The clinical-radiomics nomogram constructed from the dual-modal ultrasound can be exploited as a promising tool for the pre-operative prediction of ETE in PTC.

19.
Opt Express ; 31(6): 10038-10051, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-37157555

RESUMO

Surface hydroxylation is the basis for material removal in chemical mechanical polishing (CMP) of monocrystalline silicon, diamond, and YAG crystals. Existing studies use experimental observations to investigate surface hydroxylation, but lack in-depth understanding of the hydroxylation process. In this paper, for the first time to the best of our knowledge, we analyze the surface hydroxylation process of YAG crystals in an aqueous solution using first-principle calculations. The presence of surface hydroxylation was verified by X-ray photoelectron spectroscopy (XPS) and thermogravimetric mass spectrometry (TGA-MS) detections. This study complements the existing research on the material removal mechanism of the CMP process of YAG crystals and provides theoretical support for the future improvement of the CMP technology.

20.
BMC Plant Biol ; 23(1): 284, 2023 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-37246219

RESUMO

BACKGROUND: The Sinodielsia clade of the subfamily Apioideae (Apiacieae) was established in 2008, and it is composed of 37 species from 17 genera. Its circumscription is still poorly delimited and unstable, and interspecific relationships in the clade lack comprehensive analysis. Chloroplast (cp.) genomes provide valuable and informative data sources for evolutionary biology and have been widely used in studies on plant phylogeny. To infer the phylogenetic history of the Sinodielsia clade, we assembled complete cp. genomes of 39 species and then performed phylogenetic analysis based on these cp. genome sequence data combined with 66 published cp. genomes from 16 genera relative to the Sinodielsia clade. RESULTS: These 39 newly assembled genomes had a typical quadripartite structure with two inverted repeat regions (IRs: 17,599-31,486 bp) separated by a large single-copy region (LSC: 82,048-94,046 bp) and a small single-copy region (SSC: 16,343-17,917 bp). The phylogenetic analysis showed that 19 species were clustered into the Sinodielsia clade, and they were divided into two subclades. Six mutation hotspot regions were detected from the whole cp. genomes among the Sinodielsia clade, namely, rbcL-accD, ycf4-cemA, petA-psbJ, ycf1-ndhF, ndhF-rpl32 and ycf1, and it was found that ndhF-rpl32 and ycf1 were highly variable in the 105 sampled cp. genomes. CONCLUSION: The Sinodielsia clade was subdivided into two subclades relevant to geographical distributions, except for cultivated and introduced species. Six mutation hotspot regions, especially ndhF-rpl32 and ycf1, could be used as potential DNA markers in the identification and phylogenetic analyses of the Sinodielsia clade and Apioideae. Our study provided new insights into the phylogeny of the Sinodielsia clade and valuable information on cp. genome evolution in Apioideae.

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