RESUMO
Alzheimer's disease (AD) is recognized as the leading cause of dementia, imposing a significant economic toll on society. Despite the emergence of novel therapeutic approaches for AD, their efficacy and safety mandates further validation through rigorous clinical trials. In this context, hypertension (HTN) has garnered considerable attention as an amendable risk factor for AD. Research indicates that hypertension during midlife is associated with an elevated risk of AD in later years, influencing both the onset and progression of the disease. Nevertheless, the relationship between AD and hypertension in the later stages of life remains a subject of debate. Moreover, the consequences of blood pressure reduction on cognitive function, along with the optimal pharmacological interventions and therapeutic thresholds for hypertension, have emerged as pivotal areas of inquiry. This review synthesizes findings on epidemiology, neuroimaging, and biomarkers, and the effects of antihypertensive medications to elucidate the link between hypertension and cognitive performance. We particularly investigate how hypertension and AD are related by plasma sulfide dysregulation, offering possible indicators for future diagnosis and therapy.
Assuntos
Doença de Alzheimer , Hipertensão , Neuroimagem , Humanos , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Hipertensão/fisiopatologia , Hipertensão/complicações , Neuroimagem/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Encéfalo/metabolismoRESUMO
BACKGROUND: Early-onset cancer (diagnosed under age 50) generally manifests as an aggressive disease phenotype. The association between healthy lifestyle and early-onset cancer and whether it varies by common genetic variants remains unclear. METHODS: We analyzed a prospective cohort of 66,308 participants who were under age 50 and free of cancer at baseline in the UK Biobank. Using Cox regression, we estimated Hazard ratios (HRs) and 95% confidence intervals (CIs) for early-onset total and breast cancer based on sex-specific composite total cancer polygenic risk scores (PRSs), a breast cancer-specific PRS, and sex-specific health-associated lifestyle scores (HLSs). RESULTS: In multivariable-adjusted analyses with 2-year latency, higher genetic risk (highest vs lowest tertile of PRS) was associated with significantly increased risks of early-onset total cancer in females (HR, 95% CI: 1.83, 1.49-2.26) and males (2.03, 1.51-2.73) as well as early-onset breast cancer in females (3.06, 2.20-4.26). An unfavorable lifestyle (highest vs lowest category of HLS) was associated with higher risk of total cancer and breast cancer in females across genetic risk categories; the association with total cancer and breast cancer was stronger in the highest genetic risk category than the lowest: HRs (95% CIs) were 1.55 (1.12, 2.14) and 1.69 (1.11, 2.57) in the highest genetic risk category and 1.03 (0.64, 1.67) and 0.81 (0.36, 1.85) in the lowest. CONCLUSIONS: Genetic and lifestyle factors were independently associated with early-onset total and breast cancer risk. Individuals with a high genetic risk may benefit more from adopting a healthy lifestyle in preventing early-onset cancer.
RESUMO
Herpes simplex virus-2 encephalitis (HSV2E) in immunocompetent adults is exceptionally rare, and the subsequent onset of autoimmune encephalitis after HSV2E is even less common. This report presents the inaugural Chinese case of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) induced by HSV2E, confirmed via metagenomic next-generation sequencing (mNGS). The patient demonstrated a favorable response to intravenous immunoglobulin (IVIG) monotherapy. This case emphasizes the importance of considering autoimmune encephalitis in patients exhibiting new or recurrent neurological symptoms after HSV2E recovery. Comprehensive mNGS and neuronal antibody testing are essential for timely diagnosis. Moreover, IVIG monotherapy can serve as an effective treatment for NMDARE induced by HSV2, providing a viable alternative, particularly when steroid therapy is contraindicated.
RESUMO
The difunctionalization of alkenes represents a powerful tool to incorporate two functional groups into the alkene bones for increasing molecular complexity and has been widely utilizations in chemical synthesis. Upon the catalysis of the green, sustainable, mild photo-/electrochemistry technologies, much attentions have been attracted to the development of new tactics for the transformations of the important alkene and alkane feedstocks driven by C-H radical functionalization. Herein, we summarize recent advances in the photo-/electrocatalytic difunctionalization of alkenes enabled by C-H radical functionalization. We detailedly discuss the substrate scope and the mechanisms of the photo-/electrocatalytic alkene difunctionalization reactions by selecting impressive synthetic examples, which are divided into four sections based on the final terminated step, including oxidative radical-polar crossover coupling, reductive radical-polar crossover coupling, radical-radical coupling, and transition-metal-catalyzed coupling.
RESUMO
With the rapid expansion of human activities, there has been a significant increase in the release of volatile organic compounds (VOCs) from factories and interior decoration materials, posing a substantial risk to the surrounding ecosystem and human health. Photocatalysis technology based on semiconductors has emerged as a promising solution for mitigating atmospheric pollution and indoor air quality concerns. However, single semiconductors encounter several challenges when it comes to VOC photodegradation, including issues like the weak adsorption capacity for VOC molecules, insufficient surface-active sites, and limited light utilization. In recent decades, carbon-based materials have gained considerable interest in photodegrading VOCs owing to their strong adsorption capacity, electrical conductivity, broad light absorption range, and tunable surface characteristics. The incorporation of carbon materials can enhance the photodegradation efficiency of VOCs by facilitating the transfer of VOCs from the ambient air to the surface of the photocatalysts, increasing the number of active surface sites, expanding the light absorption region, and promoting the separation of charge carriers. This review provides a comprehensive overview of the applications of carbon materials with different dimensions in enhancing the performance of semiconductors for the photocatalytic degradation of VOCs. Based on the fundamental principles of photocatalytic VOC degradation, this review explores the factors influencing the degradation performance of catalysts and elucidates the degradation mechanisms. Moreover, it summarizes a range of synthesis approaches for carbon-based photocatalysts, discussing the multiple roles played by carbon materials in these processes. In conclusion, the review offers insights into the current state of carbon-based photocatalysts and outlines the existing challenges. It also provides a perspective on the future development of these materials, highlighting the need for continued research and innovation in this field.
Assuntos
Carbono , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/química , Catálise , Carbono/química , Adsorção , FotóliseRESUMO
OBJECTIVE: Osimertinib plays a crucial role in patients with non-small cell lung cancer (NSCLC). However, the haematological toxicities caused by osimertinib in such a population have not been well characterised. This analysis was performed to determine the incidence of osimertinib-related haematological toxicity in patients with NSCLC. METHOD: A literature search was conducted in PubMed, Embase, Cochrane Library and Web of Science. Eligible studies were included to describe the pooled incidences of anaemia, neutropenia and thrombocytopenia secondary to osimertinib in NSCLC patients. RESULTS: 1288 patients from 10 studies were enrolled in this study. The overall incidences of osimertinib-related all-grade anaemia, neutropenia and thrombocytopenia in NSCLC patients were 21.1% (95% CI 10.9% to 33.3%), 14.6% (95% CI 5.9% to 26.1%) and 28.4% (95% CI 12.4% to 47.6%), respectively. In items of high-grade haematological toxicities, there were 0.5% (95% CI 0.1% to 1.1%) for anaemia, 2.0% (95% CI 0.3% to 4.6%) for neutropenia and 0.4% (95% CI 0% to 1.1%) for thrombocytopenia. CONCLUSIONS: There is non-negligible haematological toxicity associated with osimertinib, and it should be taken seriously.
RESUMO
Recent scientific investigations have revealed the intricate mechanisms underlying bone formation, emphasizing the essential role of long non-coding RNAs (lncRNAs) as critical regulators. This process, essential for skeletal strength and functionality, involves the transformation of mesenchymal stem cells into osteoblasts and subsequent deposition of bone matrix. lncRNAs, including HOX transcript antisense RNA (HOTAIR), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), differentiation antagonizing non-coding RNA (DANCR), and maternally expressed gene 3 (MEG3), have emerged as prominent players in this regulatory network. HOTAIR modulates osteoblast differentiation by interacting with chromatin-modifying enzymes, while MALAT1 regulates osteogenic differentiation through microRNA interactions. DANCR collaborates with Runx2 to fine-tune osteoblast differentiation, and MEG3 orchestrates multiple signaling pathways crucial for bone formation. Moreover, other lncRNAs such as H19, lncRNA for enhancing osteogenesis 3, rhabdomyosarcoma 2-associated transcript, urothelial cancer associated 1, taurine up-regulated gene 1, and nuclear enriched abundant transcript 1 contribute to the complex regulatory network governing osteoblast activities. Understanding the precise roles of these lncRNAs offers promising avenues for developing innovative therapeutic strategies targeting bone-related disorders like osteoporosis. Overall, this review summarizes the pivotal role of lncRNAs in bone formation, highlighting their potential as targets for future research endeavors aimed at advancing therapeutic interventions in bone diseases.
RESUMO
BACKGROUND: Gastric cancer (GC) is one of the deadliest malignant tumors with unknown pathogenesis. Due to its treatment resistance, high recurrence rate, and lack of reliable early detection techniques, a majority of patients have a poor prognosis. Therefore, identifying new tumor biomarkers and therapeutic targets is essential. This review aims to provide fresh insights into enhancing the prognosis of patients with GC by summarizing the processes through which microRNAs (miRNAs) regulate the tumor microenvironment (TME) and highlighting their critical role in the TME. MAIN TEXT: A comprehensive literature review was conducted by focusing on the interactions among tumor cells, extracellular matrix, blood vessels, cancer-associated fibroblasts, and immune cells within the GC TME. The role of noncoding RNAs, known as miRNAs, in modulating the TME through various signaling pathways, cytokines, growth factors, and exosomes was specifically examined. Tumor formation, metastasis, and therapy in GC are significantly influenced by interactions within the TME. miRNAs regulate tumor progression by modulating these interactions through multiple signaling pathways, cytokines, growth factors, and exosomes. Dysregulation of miRNAs affects critical cellular processes such as cell proliferation, differentiation, angiogenesis, metastasis, and treatment resistance, contributing to the pathogenesis of GC. CONCLUSIONS: miRNAs play a crucial role in the regulation of the GC TME, influencing tumor progression and patient prognosis. By understanding the mechanisms through which miRNAs control the TME, potential biomarkers and therapeutic targets can be identified to improve the prognosis of patients with GC.
Assuntos
Biomarcadores Tumorais , Regulação Neoplásica da Expressão Gênica , MicroRNAs , Neoplasias Gástricas , Microambiente Tumoral , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Neoplasias Gástricas/metabolismo , Microambiente Tumoral/genética , MicroRNAs/genética , Biomarcadores Tumorais/genética , Animais , Transdução de Sinais , PrognósticoRESUMO
PURPOSE: This study aims to evaluate outcomes in patients with mesenteric artery embolism (MAE) who received primary endovascular therapy (EVT) or laparotomy, and investigate risk factors for 30-day mortality. METHODS: A retrospective analysis of 94 MAE patients who underwent two different treatment strategies was undertaken. An inverse probability of treatment weighting (IPTW) method was used to balance the confounding effects of baseline clinical data. Logistic regression analysis was performed to compare the outcomes according to type of treatment regimens before and after IPTW. Univariate and multivariable analysis were conducted to determine the risk factors for 30-day mortality. RESULTS: Twenty-eight MAE patients received primary EVT, and 66 Open Surgery (OS). Logistic regression analysis showed that there was no significant difference between the EVT and OS group in 30-day mortality rate before (odds ratio [OR] 0.477, 95% confidence interval [CI] 0.170 to 1.340, P = 0.160), and after IPTW (OR 0.647, 95% CI 0.210 to 1.993, P = 0.449). After IPTW, it revealed that the rates of second-look surgery (OR 36.727, 95% CI 5.407 to 249.458, P < 0.001) and hospital stay [> 30 days] (OR 0.006, 95% CI 0.000 to 0.363, P = 0.014) were different in the two groups. D-dimer (> 4 mg/L) and procalcitonin (> 0.5 ng/mL) were the independent risk factors for 30-day mortality in MAE patients postoperatively (P < 0.05). CONCLUSION: In this retrospective study, MAE patients who performed primary EVT had no obvious difference in 30-day mortality rate compared to those who received OS; but it was conducive to reducing prolonged hospital stays. An increase in procalcitonin level and higher D-dimer were associated with short-term poor prognosis in patients with MAE.
RESUMO
Background: With the popularity of the internet, short videos have become an indispensable tool to obtain health information. However, avoiding health disinformation owing to the openness of the Internet is difficult for users. Disinformation may endanger the health and lives of users. Objective: With a focus on the process of identifying short videos' health disinformation and the factors affecting the accuracy of identification, this study aimed to investigate the identification methods, coping strategies, and the impact of short videos' health disinformation on undergraduate nursing students. The findings will provide guidance to users on obtaining high-quality and healthy information, in addition to reducing health risks. Methods: Semi-structured in-depth interviews were conducted with 22 undergraduate nursing students in October 2022, and data were collected for collation and content analyses. Results: The techniques used to identify short videos that include health disinformation as well as how undergraduate nursing students perceived these videos' features are among the study's findings. The failure factors in identification, coping paths, and adverse impacts of short videos on health disinformation were analyzed. The platform, the material itself, and the students' individual characteristics all have an impact on their identifying behavior. Conclusions: Medical students continue to face many obstacles in identifying and responding to health disinformation through short videos. Preventing and stopping health disinformation not only requires individual efforts to improve health literacy and maintain rational thinking, it also requires the joint efforts of short video producers, relevant departments, and platforms.
RESUMO
BACKGROUND: The lower clinical exposure of Pediatric Emergency Medicine (PEM) fellows to critical procedures may impede skill acquisition. We sought to determine the tracheal intubation learning curve of PEM fellows during training and compared PEM fellow success against standards for tracheal intubation success. METHODS: This was a retrospective, video-based study of a cohort of PEM fellows at a single academic pediatric emergency department (PED). All forms of tracheal intubation were included (rapid sequence intubation and crash or no medication). The cohort consisted of 36 PEM fellows from all or part of 5 consecutive fellowship classes. Data were collected by structured review of both existing ceiling-mounted videos and the electronic medical record. The main outcome was PEM fellows' success on the first or second attempt. We used cumulative summation to generate tracheal intubation learning curves. We specifically assessed the proportion of PEM fellows who reached 1 of 4 thresholds for procedural performance: 90% and 80% predicted success on the first and the first or second attempt. RESULTS: From July 2014 to June 2020, there were 610 patient encounters with at least 1 attempt at tracheal intubation. The 36 PEM fellows performed at least 1 attempt at tracheal intubation for 414 ED patient encounters (65%). Median patient age was 2.1 years (interquartile range, 0.4-8.1). The PEM fellows were successful on the first attempt for 276 patients (67%) and on the first or second attempt for 337 (81%). None of the 36 PEM fellows reached the 90% threshold for either first or second attempt success. Four fellows (11%) met the 80% threshold for first attempt success and 11 (31%) met the 80% threshold for first or second attempt success. CONCLUSIONS: Despite performing the majority of attempts, PEM fellows often failed to reach the standard thresholds for performance of tracheal intubation. Clinical exposure alone is too low to ensure acquisition of airway skills.
RESUMO
Previous research has revealed that platelets promote tumor metastasis by binding to circulating tumor cells (CTCs). However, the role of platelets in epithelial-mesenchymal transition (EMT) of cancer cells at the primary tumor site, the crucial initial step of tumor metastasis, remains to be elucidated. Here, we found that platelet releasate enhanced EMT and motility of hepatocellular carcinoma (HCC) cells via AMPK/mTOR-induced autophagy. RNA-seq indicated that platelet releasate altered TGF-ß signaling pathway of cancer cells. Inhibiting TGFBR or deleting platelet TGF-ß1 suppressed AMPK/mTOR pathway activation and autophagy induced by platelet releasate. Compared with Pf4cre-; Tgfb1fl/fl mice, HCC orthotopic models established on Pf4cre+; Tgfb1fl/fl mice showed reduced TGF-ß1 in primary tumors, which corresponded with decreased cancer cell EMT, autophagy, migration ability and tumor metastasis. Inhibition of autophagy via Atg5 knockdown in cancer cells negated EMT and metastasis induced by platelet-released TGF-ß1. Clinically, higher platelet count correlated with increased TGF-ß1, LC3 and N-cad expression in primary tumors of HCC patients, suggesting a link between platelets and HCC progression. Our study indicates that platelets promote cancer cell EMT in the primary tumor and HCC metastasis through TGF-ß1-induced HCC cell autophagy via the AMPK/mTOR pathway. These findings offer novel insights into the role of platelets in HCC metastasis and the potential therapeutic targets for HCC metastasis.
Assuntos
Autofagia , Plaquetas , Carcinoma Hepatocelular , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas , Transdução de Sinais , Fator de Crescimento Transformador beta1 , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/genética , Animais , Plaquetas/metabolismo , Plaquetas/patologia , Humanos , Camundongos , Movimento Celular , Linhagem Celular Tumoral , Serina-Treonina Quinases TOR/metabolismo , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Proteínas Quinases Ativadas por AMP/metabolismo , Metástase Neoplásica , Masculino , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismoRESUMO
Patulin (PAT) is a mycotoxin-produced secondary metabolite that can contaminate foods, causing toxic effects on animal and human health. Therefore, for the first time, we have constructed a "turn-on" dual-mode aptamer sensor for PAT using oleic acid-coated upconversion nanomaterials (OA-UCNPs) and G-Quadruplex-hemin DNAzyme (G4-DNAzyme) as fluorescent and colorimetry probes. The sensor employs aptamers binding to PAT as recognition elements for specific molecule detection. Mxene-Au can be used as a biological inducer to assist OA-UCNPs in controlling fluorescence intensity. In addition, colorimetric signal amplification was performed using the trivalent G4-DNAzyme to increase detection sensitivity and reduce false positives. Under optimal conditions, the dual-mode aptasensor has a detection limit of 5.3 pg mL-1 in fluorescence and 2.4 pg mL-1 in colorimetric methods, respectively, with the wider linear range and limit of detection (LOD) of the colorimetric assay. The combination aptasensor can detect PAT with high sensitivity and high specificity and has broad application prospects in the field of food safety detection.
Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , DNA Catalítico , Quadruplex G , Hemina , Patulina , Patulina/análise , Aptâmeros de Nucleotídeos/química , DNA Catalítico/química , Técnicas Biossensoriais/métodos , Hemina/química , Colorimetria/métodos , Limite de Detecção , Nanoestruturas/químicaRESUMO
Microplastics (MPs) and antibiotic resistance genes (ARGs) are gaining increasing attention as they pose a threat to the ecological environment and human health as emerging contaminants. MPs has been proved to be a hot spot in ARGs, and although it has been extensively studied in water environment, the results of bibliometrics statistical analysis in this paper showed that relevant studies in soil ecological environment are currently in the initial stage. In view of this, the paper provides a systematic review of the sources, interactions, influencing factors, and ecological risks associated with MPs and ARGs in soil environments. Additionally, the mechanism and influencing factors of plastisphere formation and resistance are elaborated in detail. The MPs properties, soil physicochemical properties, soil environmental factors and agricultural activities are the primarily factors affecting the interaction between MPs and ARGs in soil. Challenges and development directions of related research in the future are also prospected. It is hoped that the review could assist in a deeper comprehension and exploration of the interaction mechanism between MPs and ARGs in soil as well as the function of MPs in the transmission process of ARGs among diverse environmental media and organisms, and provide theory basis and reference for the MPs and ARGs pollution control and remediation in soil.
Assuntos
Resistência Microbiana a Medicamentos , Monitoramento Ambiental , Microplásticos , Microbiologia do Solo , Poluentes do Solo , Solo , Microplásticos/toxicidade , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Resistência Microbiana a Medicamentos/genética , Solo/químicaRESUMO
Osteoarthritis (OA) is a worldwide joint disease, leading to the physical pain, stiffness, and even disability. Lactate dehydrogenase A (LDHA) is known as a lactylation mediator that can regulate histone lactylation of its target genes. However, the role of LDHA-mediated histone H3 lysine 18 lactylation (H3K18la) in OA progression is yet to be clarified. Our study aims at revealing the role and mechanism of LDHA-mediated histone lactylation in the glycolysis of chondrocytes. In this study, we determined at first that the H3K18la level was enhanced in OA. Energy metabolism such as glycolysis is often altered in OA progress. Therefore, we further explored the mechanism mediating glycolysis and thus promoting OA progress. Moreover, glycolysis was enhanced in LPS-induced OA cell model, as evidenced by the increased glucose consumption and lactate production. Furthermore, we silenced LDHA for loss-of-function assays. The results showed that knockdown of LDHA suppressed glycolysis of LPS-induced chondrocytes. In vivo animal study demonstrated that knockout of LDHA recovered cartilage injury of OA mice. Mechanistically, we uncovered that LDHA-mediated H3K18la in TPI1 promoter enhanced the transcription activity of TPI1. Mutation of K69 site was found to ameliorate LPS-induced glycolysis in OA cell model. In conclusion, our study reveals the role of LDHA-mediated H3K18la of TPI1 promoter in OA progress.
Assuntos
Condrócitos , Glicólise , Histonas , Osteoartrite , Osteoartrite/metabolismo , Osteoartrite/genética , Osteoartrite/patologia , Animais , Camundongos , Histonas/metabolismo , Humanos , Condrócitos/metabolismo , Modelos Animais de Doenças , Lactato Desidrogenase 5/metabolismo , Masculino , Regulação da Expressão Gênica , Camundongos Knockout , Regiões Promotoras Genéticas , Transcrição GênicaRESUMO
After rotator cuff injuries, uncontrolled inflammation hinders tendon-bone junction regeneration and induces scar formation in situ. Therefore, precisely controlling inflammation could be a solution to accelerate tendon-bone junction regeneration. In this study, we synthesized a peptide-metal ion complex hydrogel with thermosensitive capability that can be used as a hydrogel chemical regulator. By the coordination complex between Mg2+ and BMP-12, the free and coordinated Mg2+ can be programmability released from the hydrogel. The fast release of free Mg2+ can prevent inflammation at the early stage of injuries, according to the results of RT-qPCR and immunofluorescence staining. Then, the coordinated Mg2+ was slowly released from the hydrogel and provided an anti-inflammatory environment for tendon-bone junction regeneration in the long term. Finally, the hydrogel demonstrated enhanced therapeutic effects in a rat rotator cuff tear model. Overall, the Mg2+/BMP-12 peptide-metal ion complex-based hydrogel effectively addresses the regenerative requirements of the tendon-bone junction across various stages by graded modulating inflammation.
RESUMO
OBJECTIVE: To identify risk factors associated with childhood enuresis. METHODS: We conducted a retrospective analysis of 146 children aged 6 to 13 years diagnosed with enuresis at Anhui Province Children's Hospital between June 2020 and June 2023. Children were categorized based on bedwetting frequency: those with less frequent episodes (once a week to twice a month) were placed in the mild group (60 cases), and those with frequent episodes (two or more times per week) were placed in the severe group (86 cases). We compared demographic data, family histories, and personal characteristics between the groups and performed logistic regression to determine significant risk factors. RESULTS: The analysis revealed that a stubborn personality, nocturnal polyuria, sleep-wake disorders, and bladder dysfunction significantly increased the risk of enuresis (P < 0.05). These findings underscore the importance of a holistic approach in evaluating psychological aspects, nocturnal urination patterns, sleep quality, and bladder health in managing enuresis. CONCLUSION: The study identifies stubborn personality, nocturnal polyuria, sleep-wake disorders, and bladder dysfunction as independent risk factors for childhood enuresis. Understanding these factors is crucial for developing targeted interventions that can enhance the management and outcomes of enuresis. Future research should explore the interrelationships among these factors to refine preventive and therapeutic strategies for early childhood enuresis.
RESUMO
Fatigue failure is invariably the most crucial failure mode for metallic structural components. Most microstructural strategies for enhancing fatigue resistance are effective in suppressing either crack initiation or propagation, but often do not work for both synergistically. Here, we demonstrate that this challenge can be overcome by architecting a gradient structure featuring a surface layer of nacre-like nanolaminates followed by multi-variant twinned structure in pure titanium. The polarized accommodation of highly regulated grain boundaries in the nanolaminated layer to cyclic loading enhances the structural stability against lamellar thickening and microstructure softening, thereby delaying surface roughening and thus crack nucleation. The decohesion of the nanolaminated grains along horizonal high-angle grain boundaries gives rise to an extraordinarily high frequency (≈1.7 × 103 times per mm) of fatigue crack deflection, effectively reducing fatigue crack propagation rate (by 2 orders of magnitude lower than the homogeneous coarse-grained counterpart). These intriguing features of the surface nanolaminates, along with the various toughening mechanisms activated in the subsurface twinned structure, result in a fatigue resistance that significantly exceeds those of the homogeneous and gradient structures with equiaxed grains. Our work on architecting the surface nanolaminates in gradient structure provides a scalable and sustainable strategy for designing more fatigue-resistant alloys.
RESUMO
Background: Patients with fractures of the proximal humerus often local complications and failures attributed to osteoporosis. Currently, there is a lack of straight forward screening methods for assessing the extent of local osteoporosis in the proximal humerus. This study utilizes machine learning techniques to establish a diagnostic approach for evaluating local osteoporosis by analyzing the patient's demographic data, bone density, and X-ray ratio of the proximal humerus. Methods: A cohort comprising a total of 102 hospitalized patients admitted during the period spanning from 2021 to 2023 underwent random selection procedures. Resulting in exclusion of 5 patients while enrolling 97 patients for analysis encompassing patient demographics, shoulder joint anteroposterior radiographs, and bone density information. Using the modified Tingart index methodology involving multiple measurements denoted as M1 through M4 obtained from humeral shafts. Within this cohort comprised 76 females (78.4 %) and 21 males (21.6 %), with an average age of 73.0 years (range: 43-98 years). There were 25 cases with normal bone density, 35 with osteopenia, and 37 with osteoporosis. Machine learning techniques were used to randomly divide the 97 cases into training (n = 59) and validation (n = 38) sets with a ratio of 6:4 using stratified random sampling. A decision tree model was built in the training set, and significant diagnostic indicators were selected, with the performance of the decision tree evaluated using the validation set. Multinomial logistic regression methods were used to verify the strength of the relationship between the selected indicators and osteoporosis. Results: The decision tree identified significant diagnostic indicators as the humeral shaft medullary cavity ratio M2/M4, age, and gender. M2/M4 ≥ 1.13 can be used as an important screening criterion; M2/M4 < 1.13 was predicted as local osteoporosis; M2/M4 ≥ 1.13 and age ≥83 years were also predicted as osteoporosis. M2/M4 ≥ 1.13 and age <64 years or males aged between 64 and 83 years were predicted as the normal population; M2/M4 ≥ 1.13 and females aged between 64 and 83 years were predicted as having osteopenia. The decision tree's accuracy in the training set was 0.7627 (95 % CI (0.6341, 0.8638)), and its accuracy in the test set was 0.7895 (95 % CI (0.6268, 0.9045)). Multinomial logistic regression results showed that humeral shaft medullary cavity ratios M2/M4, age, and gender in X-ray images were significantly associated with the occurrence of osteoporosis. Conclusion: Utilizing X-ray data of the proximal humerus in conjunction with demographic information such as gender and age enable the prediction of localized osteoporosis, facilitating physicians' rapid comprehension of osteoporosis in patients and optimization of clinical treatment plans. Level of evidence: Level IV retrospective case study.
RESUMO
The microplastics in aquatic ecosystems pose a serious threat to ecological security and environmental health, which have received widespread attention. To reveal the response of a water-Vallisneria natans-sediment system to microplastics exposure, the V. natans was exposed to polyethylene microplastics ï¼PE-MPsï¼ with different mass fractions ï¼1%-5%, sediment wet mass fractionï¼, and the effects of PE-MPs on the physiochemical indicators of water quality, morphological characteristics of submerged plants, physiological characters, antioxidant system, and microbial community structure in sediments were studied respectively. The results showed that the physiochemical properties of the water body were not significantly changed in the PE-MPs treatment group, whereas the plant height, oxidative stress index, and antioxidant system were significantly inhibited. For the plant height, the 1% PE-MPs treatment group height was only 47.44% of that in the control group. Chlorophyll a content was 81.04% of that in the control group, and the activities of catalase ï¼CATï¼, malondialdehyde ï¼MDAï¼, and peroxidase ï¼PODï¼ increased by 233.70%, 117.82%, and 61.62%, respectively. Different mass fractions of PE-MPs had a certain impact on microbial community structure in sediments. The above results are helpful to improve the evaluation system of PE-MPs ecological risk in the water-submerged plant-sediment system.