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Neutrophils are specialized innate cells that require constant replenishment from proliferative bone marrow (BM) precursors as a result of their short half-life. Although it is established that neutrophils are derived from the granulocyte-macrophage progenitor (GMP), the differentiation pathways from GMP to functional mature neutrophils are poorly defined. Using mass cytometry (CyTOF) and cell-cycle-based analysis, we identified three neutrophil subsets within the BM: a committed proliferative neutrophil precursor (preNeu) which differentiates into non-proliferating immature neutrophils and mature neutrophils. Transcriptomic profiling and functional analysis revealed that preNeu require the C/EBPε transcription factor for their generation from the GMP, and their proliferative program is substituted by a gain of migratory and effector function as they mature. preNeus expand under microbial and tumoral stress, and immature neutrophils are recruited to the periphery of tumor-bearing mice. In summary, our study identifies specialized BM granulocytic populations that ensure supply under homeostasis and stress responses.
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Células da Medula Óssea/fisiologia , Neutrófilos/fisiologia , Animais , Células da Medula Óssea/imunologia , Proteínas Estimuladoras de Ligação a CCAAT/fisiologia , Linhagem da Célula , Movimento Celular , Proliferação de Células , Células Cultivadas , Perfilação da Expressão Gênica , Humanos , Camundongos , Neoplasias Experimentais/imunologia , Neutrófilos/imunologiaRESUMO
The unbalanced immune state is the dominant feature of myocardial injury. However, the complicated pathology of cardiovascular diseases and the unique structure of cardiac tissue lead to challenges for effective immunoregulation therapy. Here, we exploited oral fullerene nanoscavenger (OFNS) to maintain intestinal redox homeostasis to resolve systemic inflammation for effectively preventing distal myocardial injury through bidirectional communication along the heart-gut immune axis. Observably, OFNS regulated redox microenvironment to repair cellular injury and reduce inflammation in vitro. Subsequently, OFNS prevented myocardial injury by regulating intestinal redox homeostasis and recovering epithelium barrier integrity in vivo. Based on the profiles of transcriptomics and proteomics, we demonstrated that OFNS balanced intestinal and systemic immune homeostasis for remote cardioprotection. Of note, we applied this principle to intervene myocardial infarction in mice and mini-pigs. These findings highlight that locally addressing intestinal redox to inhibit systemic inflammation could be a potent strategy for resolving remote tissue injury.
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Fulerenos , Infarto do Miocárdio , Suínos , Camundongos , Animais , Fulerenos/farmacologia , Porco Miniatura , Inflamação/patologia , Infarto do Miocárdio/prevenção & controle , Homeostase , Mucosa IntestinalRESUMO
OBJECTIVE: Adverse childhood experiences (ACEs) have been associated with a range of adverse health outcomes, with pain being potentially one of them. This population-based cross-sectional study aimed to investigate the associations between Adverse Childhood Experiences (ACEs) and pain in Chinese adults and evaluate whether physical activity and demographic and socioeconomic characteristics modify this associations. METHODS: Cross-sectional data from the China Health and Retirement Longitudinal Study (CHARLS), were utilized in this study. A total of 9923 respondents with information on 12 ACE indicators and 15 self-reported body pains were included. Logistic regression models were used to assess associations of the ACEs and pain. Modification of the associations by physical activity, demographic and socioeconomic characteristics was assessed by stratified analyses and tests for interaction. RESULTS: Among the 9923 individuals included in the primary analyses, 5098 (51.4%) males and the mean (SD) age was 61.18 (10·.44) years. Compared with individuals with 0 ACEs, those who with ≥ 5 ACEs had increased risk of single pains and multiple pain. A dose-response association was found between the number of ACEs and the risk of pain (e.g. neck pain for ≥ 5 ACEs vs. none: OR, 1.107; 95% CI, 0.903-1.356; p < 0.001 for trend). In the associations of each body pain with each ACE indicator, most ACE indicators were associated with an increased risk of pain. In addition, physical activity, sociodemographic and socioeconomic characteristics, such as age, sex, educational level, area of residence, childhood economic hardship, did not demonstrate a significant modify on the associations between ACEs and pain. CONCLUSIONS: These findings indicate that cumulative ACE exposure is associated with increased odds of self-reported pain in Chinese adults, regardless of adult physical activity, sociodemographic and socioeconomic characteristics.
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Experiências Adversas da Infância , Dor , Humanos , Masculino , Feminino , China/epidemiologia , Estudos Longitudinais , Experiências Adversas da Infância/estatística & dados numéricos , Pessoa de Meia-Idade , Estudos Transversais , Idoso , Dor/epidemiologia , Exercício Físico , Fatores Socioeconômicos , Fatores de RiscoRESUMO
The study aims to explore the fluctuating expression of C/EBP Homologous Protein (CHOP) following rat carotid artery injury and its central role in vascular stenosis. Using in vivo rat carotid artery injury models and in vitro ischemia and hypoxia cell models employing human aortic endothelial cells (HAECs) and vascular smooth muscle cells (T/G HA-VSMCs), a comprehensive investigative framework was established. Histological analysis confirmed intimal hyperplasia in rat models. CHOP expression in vascular tissues was assessed using Western blot and immunohistochemical staining, and its presence in HAECs and T/G HA-VSMCs was determined through RT-PCR and Western blot. The study evaluated HAEC apoptosis, inflammatory cytokine secretion, cell proliferation, and T/G HA-VSMCs migration through Western blot, ELISA, CCK8, and Transwell migration assays. The rat carotid artery injury model revealed substantial fibrous plaque formation and vascular stenosis, resulting in an increased intimal area and plaque-to-lumen area ratio. Notably, CHOP is markedly elevated in vessels of the carotid artery injury model compared to normal vessels. Atorvastatin effectively mitigated vascular stenosis and suppresses CHOP protein expression. In HAECs, ischemia and hypoxia-induced CHOP upregulation, along with heightened TNFα, IL-6, caspase3, and caspase8 levels, while reducing cell proliferation. Atorvastatin demonstrated a dose-dependent suppression of CHOP expression in HAECs. Downregulation of CHOP or atorvastatin treatment led to reduced IL-6 and TNFα secretion, coupled with augmented cell proliferation. Similarly, ischemia and hypoxia conditions increased CHOP expression in T/G HA-VSMCs, which was concentration-dependently inhibited by atorvastatin. Furthermore, significantly increased MMP-9 and MMP-2 concentrations in the cell culture supernatant correlated with enhanced T/G HA-VSMCs migration. However, interventions targeting CHOP downregulation and atorvastatin usage curtailed MMP-9 and MMP-2 secretion and suppressed cell migration. In conclusion, CHOP plays a crucial role in endothelial injury, proliferation, and VSMCs migration during carotid artery injury, serving as a pivotal regulator in post-injury fibrous plaque formation and vascular remodeling. Statins emerge as protectors of endothelial cells, restraining VSMCs migration by modulating CHOP expression.
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PURPOSE: This systematic review and meta-analysis aimed to evaluate the safety of outpatient and inpatient Unicompartmental Knee Arthroplasty (UKA) based on the incidence of adverse events. METHOD: A systematic search of the literature was performed in October 2022 on PubMed, Web of Science, Cochrane library, and Embase. The Meta package for R was used to perform the meta-analysis. RESULT: Five studies with a total of 26,301 patients were included. 5813 patients (22.1%) were treated with outpatient UKA, and 20,488 patients (77.9%) were treated with inpatient UKA. There were no statistically significant differences in the incidence of total complications (RR = 1.36, 95% CI = 0.64-2.89, Z = 0.79, P = 0.43), readmission (RR = 1.02, 95% CI = 0.40-2.60, Z = 0.05, P = 0.96), and venous thrombosis (RR = 1.43, 95% CI = 0.96-2.11, Z = 1.78, P = 0.08). Incidence rates were lower in outpatient UKA regarding urinary tract infection (RR = 1.48, 95% CI = 1.07-2.04, Z = 2.40, P = 0.02), pulmonary embolus (RR = 7.48, 95% CI = 1.80-31.17, Z = 2.76, P < 0.01), and transfusion (RR = 2.77, 95% CI = 1.63-4.71, Z = 3.78, P < 0.01). CONCLUSION: In summary, outpatient UKA shows lower incidences of hospital-acquired complications such urinary tract infection, pulmonary embolus, and transfusion. It's worth noting that the incidences of total complications, readmission, and venous thrombosis in outpatient UKA were not higher than the incidences of inpatient UKA, suggestting that outpatient UKA can be considered a safe alternative to inpatient UKA.
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This study aims to predict the possible targets and related signaling pathways of Modified Huoluo Xiaoling Pills against colorectal cancer(CRC) by both network pharmacology and molecular docking and verify the mechanism of action by experiments. TCMSP was used to obtain the active ingredients and targets of Modified Huoluo Xiaoling Pills, and GeneCards, DrugBank, OMIM, and TTD were employed to acquire CRC-related targets. Cytoscape software was utilized to construct the drug-active ingredient-target network, and the STRING database was applied to establish the protein-protein interaction(PPI) network. DAVID platform was adopted to investigate the targets in terms of GO function and KEGG pathway enrichment analysis. Molecular docking was performed in AutoDock Vina. HCT 116 cells were intervened by different concentrations of Modified Huoluo Xiaoling Pills-containing serum, and CCK-8 was used to detect the proliferation inhibition of HCT 116 cells in each group. Transwell was employed to show the invasive abi-lity of HCT 116 cells, and Western blot was taken to reveal the expression levels of ß-catenin, cyclinD1, c-Myc, as well as epithelial-mesenchymal transition(EMT) marker proteins E-cadherin, N-cadherin, vimentin, MMP2, MMP7, MMP9, and TWIST in HCT 116 cells. The network pharmacological analysis yielded 242 active ingredients of Modified Huoluo Xiaoling Pills, 1 844 CRC targets, and 127 overlapping targets of CRC and Modified Huoluo Xiaoling Pills, and the signaling pathways related to CRC involved PI3K-Akt, TNF, HIF-1, IL-17, Wnt, etc. Molecular docking showed that the key active ingredients had a stable binding conformation with the core proteins. CCK-8 indicated that Modified Huoluo Xiaoling Pills significantly inhibited the proliferation of HCT 116 cells. Transwell assay showed that with increasing concentration of Modified Huoluo Xiaoling Pills containing serum, the invasive ability of HCT 116 cells was more obviously inhibited. The expression of ß-catenin, cyclinD1, c-Myc, N-cadherin, vimentin, MMP2, MMP7, MMP9, and TWIST proteins were suppressed, and the expression of E-cadherin was improved by the intervention of drug-containing serum. Thus, it can be seen that Modified Huoluo Xiaoling Pills restrains the proliferation, invasion, and metastasis of CRC cells through multiple components, multiple targets, and multiple pathways, and the mechanism of action may be related to the inhibition of the activation of the Wnt/ß-catenin signaling pathway, thereby affecting the occurrence of EMT.
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Proliferação de Células , Neoplasias Colorretais , Medicamentos de Ervas Chinesas , Simulação de Acoplamento Molecular , Farmacologia em Rede , Humanos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/química , Proliferação de Células/efeitos dos fármacos , Células HCT116 , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Mapas de Interação de Proteínas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacosRESUMO
C(sp3) centers adjacent to (hetero)aryl groups are widely present in physiologically active molecules. Metal-hydride-catalyzed hydroalkylation of alkenes represents an efficient means of forging C(sp3)-C(sp3) bonds, boasting advantages as a wide source of substrates, mild reaction conditions, and facile selectivity manipulation. Nevertheless, the hydroalkylation of vinylarenes encounters constraints in terms of substrate scope, necessitating the employment of activated alkyl halides or alkenes containing chelating groups, remains a challenge. In this context, we report a general nickel-hydride-catalyzed hydroalkylation protocol for vinylarenes. Remarkably, this system enables α-selective hydroalkylation of both aryl and heteroaryl alkenes under an extra ligand-free condition, demonstrating excellent coupling efficiency and selectivity. Furthermore, through the incorporation of chiral bisoxazoline ligands, we have achieved regio- and enantioselective hydroalkylation of vinylpyrroles, thereby facilitating the synthesis of α-branched alkylated pyrrole derivatives.
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Site- and enantio-selective alkyl-alkyl bond formation is privileged in the retrosynthetic analysis due to the universality of sp3-hybridized carbon atoms in organic molecules. Herein, we report a nickel-catalyzed remote asymmetric hydroalkylation of alkenyl ethers via synchronous implementation of alkene isomerization and enantioselective C(sp3)-C(sp3) bond formation. Regression analysis of catalyst structure-activity relationships accelerates the rational ligand modification through modular regulation. This reaction has several advantages for synthesizing chiral dialkyl carbinols and their ether derivatives, including the broad substrate scope, good functional group tolerance, excellent regioselectivity (>20:1 regioisomeric ratio), and high enantioselectivity (up to 95% enantiomeric excess).
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Superstructures made from nanoscale clusters with new collective properties are promising in high-tech applications; however, chiral superstructures remain elusive, and the limited intercluster coupling effect at room temperature hampers the tailoring of collective properties. Here, we show that from chiral monomeric copper clusters to two enantiomeric pairs of supercrystals with distinct phases, the absorption band edge red-shifts by over 1.3 eV, with photoluminescence and circularly polarized phosphorescence from visible (572 nm) to near-infrared (NIR, 858 nm). These supercrystals with high NIR quantum yields of up to 45% at room temperature are prototyped for night-vision imaging. In response to solvent and temperature stimuli, chiral supercrystal-to-supercrystal transformations occurred, concomitant with high-contrast optical/chiroptical switching. In situ single-crystal X-ray diffraction (SCXRD), steady-state and time-resolved optical spectroscopy, and response experiments combined with theoretical calculations demonstrate that distance-sensitive intercluster orbital interactions contribute to the exceptional collective optical responses. Such chiral supercrystals built from subnanoscale metal clusters with novel collective chiroptical responses would be useful in the fields of information storage and NIR optical devices.
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Stable luminescent radicals are open-shell emitters with unique doublet emission characteristics. This feature makes stable luminescent radicals exhibit widespread application prospects in constructing optical, electrical, and magnetic materials. In this work, a stable luminescent radical-based X-ray scintillator of AuPP-1.0 was prepared, which exhibited a high X-ray excited luminescence (XEL) efficiency as well as excellent stability. A mechanism study showed that the heavy atom of Au in AuPP-1.0 endowed it with effective absorption of X-rays, and the doublet emission characteristics of AuPP-1.0 significantly increased its exciton utilization rate in the radioluminescence process. Moreover, AuPP-1.0 has good processability to fabricate a flexible screen for high-quality X-ray imaging, whose resolution can reach 20 LP mm-1. This work demonstrates that the doublet emission is beneficial for improving the exciton utilization rate of radioluminescence, providing a brand-new strategy for the construction of high-performance X-ray scintillators.
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PURPOSE: Endoplasmic reticulum stress (ERS) plays a crucial role in myocardial ischemia-reperfusion injury (MIRI). Cellular FLICE-inhibitory protein (cFLIP) is an essential regulator of apoptosis and plays a major role in regulating ERS. The present study aimed to investigate the effects of long isoform cFLIP (cFLIPL) on endogenous apoptosis and the mechanism of ERS in MIRI. METHODS: The cFLIPL recombinant adenovirus vector was used to infect H9c2 cells and Sprague-Dawley (SD) rats. After infection for 72 h, ischemia was induced for 30 min, and reperfusion was then performed for 2 h to establish the MIRI model in SD rats. H9c2 cells were hypoxic for 4 h and then reoxygenated for 12 h to simulate ischemia/reperfusion (I/R) injury. Model parameters were evaluated by assessing cardiomyocyte viability, cell death (apoptosis), and ERS-related protein expression. In addition, tunicamycin (TM), an ERS agonist, was also added to the medium for pretreatment. Coimmunoprecipitation (Co-IP) of cFLIPL and p38 MAPK protein was performed. RESULTS: cFLIPL expression was decreased in I/R injury and hypoxia/reoxygenation (H/R) injury, and cFLIPL overexpression reduced myocardial infarction in vivo and increased the viability of H9c2 cells in vitro. I/R and H/R upregulated the protein expression of GRP78, IRE-1, and PERK to induce ERS and apoptosis. Interestingly, overexpression of cFLIPL significantly inhibited ERS and subsequent apoptosis, which was reversed by an agonist of ERS. Moreover, Co-IP showed that cFLIPL attenuated ERS and was associated with inhibiting the activation of p38 protein. CONCLUSION: The expression of cFLIPL is significantly downregulated in MIRI, and it is accompanied by excessive ERS and apoptosis. Upregulated cFLIPL suppresses ERS to reduce myocardial apoptosis, which is associated with inhibiting the activity of p38 MAPK. Therefore, cFLIPL may be a potential intervention target for MIRI.
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Traumatismo por Reperfusão Miocárdica , Ratos , Animais , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Traumatismo por Reperfusão Miocárdica/metabolismo , Ratos Sprague-Dawley , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/genética , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/farmacologia , Estresse do Retículo Endoplasmático , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/farmacologiaRESUMO
BACKGROUND: Adult brainstem high-grade glioma (HGG) is a refractory disease, and the treatment strategy of resection is still controversial. OBJECTIVE: To investigate the prognostic value of brainstem HGG resection in adults. METHODS: We collected 126,386 samples from the Surveillance, Epidemiology, and End Results (SEER) database between 1998 and 2016, and screened 973 patients diagnosed with adult brainstem HGG, who were in turn, grouped into 899 cases of non-resections and 74 cases of resections. Competing risk models were used to screen independent prognostic factors. Propensity score matching (PSM) was performed to reduce the influence of confounding factors. Conditional survival (CS) rate was considered to evaluate the changes in overall survival (OS) and disease-specific survival (DSS) of patients with HGG over time. RESULTS: Based on the competing risk model and PSM, univariate analysis showed that age ≥ 45 years and male gender were poor prognostic factors for adult brainstem HGG. No previous history of glioma was a beneficial factor. Multivariate analysis revealed only the absence of a history of glioma to be a favorable prognostic factor. Considering the CS rate of the resection group, after the patient had survived for 3 years, the OS and DSS remained unchanged at 100% during the fourth and fifth years, whereas in the non-resection group, the OS and DSS of the patients were 82% and 74%, respectively. CONCLUSION: Adult brainstem HGG resection has a poor prognosis in the early stage; however, patients have a potentially significant survival benefit after 3 years of survival.
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Neoplasias Encefálicas , Glioma , Humanos , Adulto , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias Encefálicas/diagnóstico , Taxa de Sobrevida , Pontuação de Propensão , Glioma/diagnóstico , Tronco Encefálico/cirurgia , Estudos RetrospectivosRESUMO
BACKGROUND: Previous studies have suggested the potential association between air pollution and tuberculosis incidence, but this association remains inconclusive and evidence to assess causality is particularly lacking. We aimed to draw causal inference between fine particulate matter less than 2.5 µm in diameter (PM2.5) and tuberculosis in China. METHODS: Granger causality (GC) inference was performed within vector autoregressive models at levels and/or first-differences using annual national aggregated data during 1982-2019, annual provincial aggregated data during 1982-2019 and monthly provincial aggregated data during 2004-2018. Convergent cross-mapping (CCM) approach was used to determine the backbone nonlinear causal association based on the monthly provincial aggregated data during 2004-2018. Moreover, distributed lag nonlinear model (DLNM) was applied to quantify the causal effects. RESULTS: GC tests identified PM2.5 driving tuberculosis dynamics at national and provincial levels in Granger sense. Empirical dynamic modeling provided the CCM causal intensity of PM2.5 effect on tuberculosis at provincial level and demonstrated that PM2.5 had a positive effect on tuberculosis incidence. Then, DLNM estimation demonstrated that the PM2.5 exposure driven tuberculosis risk was concentration- and time-dependent in a nonlinear manner. This result still held in the multi-pollutant model. CONCLUSIONS: Causal inference showed that PM2.5 exposure driving tuberculosis, which showing a concentration gradient change. Air pollutant control may have potential public health benefit of decreasing tuberculosis burden.
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Poluentes Atmosféricos , Poluição do Ar , Tuberculose , Humanos , Material Particulado/efeitos adversos , Material Particulado/análise , Poluentes Atmosféricos/efeitos adversos , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Tuberculose/epidemiologia , Causalidade , China/epidemiologia , Exposição Ambiental/efeitos adversosRESUMO
BACKGROUND: Laser interstitial thermal therapy (LITT) has been used to treat brain metastases (BMs) in several countries, and its safety and effectiveness have been confirmed. In most cases, magnetic resonance imaging (MRI) reveals an increase in tumor volume with an enhanced margin after LITT. However, little is known about the relationship between this MRI change and tumor recurrence. OBJECTIVE: We report the first case series of BMs treated by LITT in China to evaluate the clinical characteristics and predictive factors of tumor recurrence. MATERIAL AND METHODS: Patients with less than four brain metastatic lesions and a Karnofsky performance status (KPS) > 70 were eligible for study inclusion. Standard LITT procedures were performed, and a follow-up MRI was performed to analyze the radiographic changes, especially the volume ratio of the enhanced margin and the whole lesion on MRI at 30 days postoperatively. All the volume-related data were delineated and calculated using 3D Slicer software. Related predictors were also collected to evaluate the correlation with local tumor control. RESULTS: Eighteen patients with nineteen lesions were enrolled for treatment and follow-up. Primary tumor histology included pulmonary carcinoma (n = 11) and breast cancer (n = 4). On average, the tumor size measured 3.01 cm3 (range, 0.40-7.40 cm3), the total ablation time was 13.58 min (range, 2.88-37.15 min), and the complete ablation rate was 92.4% (range, 29.2-100%). Comparing 3s0-day follow-up MRI results with preoperative MRI findings, 18 lesions showed a 2.28-fold (range, 1.21-4.88) volume increase; all the lesions displayed an enhanced component with a volume ratio of 42.35% (range, 10.14-100%). Five patients experienced tumor recurrence, and the local tumor control rates at 90 days and 180 days of follow-up were 68.4% and 66.7%, respectively. Univariate analysis indicated that the primary tumor, ablation rate, and enhanced volume ratio (EVR) > 40% in the 30-day MRI were associated with tumor recurrence, whereas multivariate analysis showed that only EVR > 40% was a predictive factor of local control. CONCLUSION: LITT is a minimally invasive method used to ablate brain metastases which can be used as the first-line treatment for BM patients under certain indications. After LITT, most tumors showed volume enlargement on the 30-day MRI scan, and EVR > 40% on the 30-day MRI may indicate late tumor recurrence.
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Neoplasias Encefálicas , Terapia a Laser , Humanos , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/cirurgia , Recidiva Local de Neoplasia/etiologia , Terapia a Laser/métodos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Imageamento por Ressonância Magnética/métodos , Lasers , Resultado do TratamentoRESUMO
In the pursuit of automating the entire underground drilling process in coal mines, the automatic rod feeding technology of drilling robots plays a crucial role. However, the current lack of positional accuracy in automatic rod feeding leads to frequent accidents. To address this issue, this paper presents an algorithm for compensating positioning errors in automatic rod feeding. The algorithm is based on a theoretical mathematical model and manual teaching methods. To enhance the positioning accuracy, we first calibrate the pull rope sensor to correct its measurement precision. Subsequently, we establish a theoretical mathematical model for rod feeding positions by employing spatial coordinate system transformations. We determine the target rod feeding position using a manual teaching-based approach. Furthermore, we analyze the relationship between the theoretical rod delivery position and the target rod delivery position and propose an anisotropic spatial difference compensation technique that considers both distance and direction. Finally, we validate the feasibility of our proposed algorithm through automatic rod feeding tests conducted on a coal mine underground drilling robot. The results demonstrate that our algorithm significantly improves the accuracy of rod feeding positions for coal mine underground drilling robots.
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Structural health monitoring technology can assess the status and integrity of structures in real time by advanced sensors, evaluate the remaining life of structure, and make the maintenance decisions on the structures. Piezoelectric materials, which can yield electrical output in response to mechanical strain/stress, are at the heart of structural health monitoring. Here, we present an overview of the recent progress in piezoelectric materials and sensors for structural health monitoring. The article commences with a brief introduction of the fundamental physical science of piezoelectric effect. Emphases are placed on the piezoelectric materials engineered by various strategies and the applications of piezoelectric sensors for structural health monitoring. Finally, challenges along with opportunities for future research and development of high-performance piezoelectric materials and sensors for structural health monitoring are highlighted.
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Eletricidade , Transdutores , Estresse MecânicoRESUMO
Cyclopropene hydrofunctionalization has been a promising strategy for accessing multi-substituted cyclopropanes; however, cyclopropene hydroalkylation remains underdeveloped. Herein, we report a low-valent CoH-catalyzed facial-selective cyclopropene hydroalkylation to access multi-substituted cyclopropanes. This reaction exhibits a broad substrate scope of alkyl halides and cyclopropenes and tolerates many functional groups. Moderate-to-good facial-selectivity is obtained without any directing groups. Mechanism studies provide evidence that alkyl radicals are generated from alkyl halides and irreversible CoH insertion is responsible for the facial-selectivity. Our preliminary exploration demonstrates that asymmetric cyclopropene hydroalkylation can be realized without conspicuous auxiliary groups.
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X-ray imaging technology has achieved important applications in many fields and has attracted extensive attentions. Dynamic X-ray flexible imaging for the real-time observation of the internal structure of complex materials is the most challenging type of X-ray imaging technology, which requires high-performance X-ray scintillators with high X-ray excited luminescence (XEL) efficiency as well as excellent processibility and stability. Here, a macrocyclic bridging ligand with aggregation-induced emission (AIE) feature was introduced for constructing a copper iodide cluster-based metal-organic framework (MOF) scintillator. This strategy endows the scintillator with high XEL efficiency and excellent chemical stability. Moreover, a regular rod-like microcrystal was prepared through the addition of polyvinyl pyrrolidone during the in situ synthesis process, which further enhanced the XEL and processibility of the scintillator. The microcrystal was used for the preparation of a scintillator screen with excellent flexibility and stability, which can be used for high-performance X-ray imaging in extremely humid environments. Furthermore, dynamic X-ray flexible imaging was realized for the first time. The internal structure of flexible objects was observed in real time with an ultrahigh resolution of 20 LP mm-1 .
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Photonic crystal lasers with a high-Q factor and small mode volume are ideal light sources for on-chip nano-photonic integration. Due to the submicron size of their active region, it is usually difficult to achieve high output power and single-mode lasing at the same time. In this work, we demonstrate well-selected single-mode lasing in a line-defect photonic crystal cavity by coupling it to the high-Q modes of a short double-heterostructure photonic crystal cavity. One of the FP-like modes of the line-defect cavity can be selected to lase by thermo-optically tuning the high-Q mode of the short cavity into resonance. Six FP-like modes are successively tuned into lasing with side mode suppression ratios all exceeding 15 dB. Furthermore, we show a continuous wavelength tunability of about 10 nm from all the selected modes. The coupled cavity system provides a remarkable platform to explore the rich laser physics through the spatial modulation of vacuum electromagnetic field at submicron scale.
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Despite many advances across the surgical sciences, post-surgical peritoneal adhesions still pose a considerable risk in modern-day procedures and are highly undesirable. We have developed a novel mouse peritoneal strip ex vivo adhesion model which may serve to bridge the gap between single cell culture systems and in vivo animal drug testing for the assessment of potential anti-adhesion agents, and study of causality of the process. We investigated the optimal conditions for adhesion formation with mouse peritoneal tissue strips by modifying an existing ex vivo rat model of peritoneal adhesions. We assessed the impact of the following conditions on the formation of adhesions: contact pressure, abrasions, and the presence of clotted blood. Macroscopic adhesions were detected in all mouse peritoneal strips exposed to specific conditions, namely abrasions and clotted blood, where peritoneal surfaces were kept in contact with pressure using cotton gauze in a tissue cassette. Adhesions were confirmed microscopically. Interestingly, connexin 43, a gap junction protein, was found to be upregulated at sites of adhesions. Key features of this model were the use of padding the abraded tissue with gauze and the use of a standardised volume of clotted blood. Using this model, peritoneal strips cultured with clotted blood between abraded surfaces were found to reproducibly develop adhesion bands at 72 h. Our goal is to develop a model that can be used in genetically modified mice in order to dissect out the role of particular genes in adhesion formation and to test drugs to prevent adhesion formation.