412 research outputs found
Numerical simulation and experimental study of PbWO4/EPDM and Bi2WO6/EPDM for the shielding of {\gamma}rays
The MCNP5 code was employed to simulate the {\gamma}ray shielding capacity of
tungstate composites. The experimental results were applied to verify the
applicability of the Monte Carlo program. PbWO4 and Bi2WO6 were prepared and
added into ethylene propylene diene monomer (EPDM) to obtain the composites,
which were tested in the {\gamma}ray shielding. Both the theoretical simulation
and experiments were carefully chosen and well designed. The results of the two
methods were found to be highly consistent. In addition, the conditions during
the numerical simulation were optimized and double-layer {\gamma}ray shielding
systems were studied. It was found that the {\gamma}-ray shielding performance
can be influenced not only by the material thickness ratio but also by the
arrangement of the composites.Comment: 8 pages,7 figures,Submitted to Chin.Phy.
Fibroblast Growth Factor-10 (FGF-10) Mobilizes Lung-resident Mesenchymal Stem Cells and Protects Against Acute Lung Injury.
FGF-10 can prevent or reduce lung specific inflammation due to traumatic or infectious lung injury. However, the exact mechanisms are poorly characterized. Additionally, the effect of FGF-10 on lung-resident mesenchymal stem cells (LR-MSCs) has not been studied. To better characterize the effect of FGF-10 on LR-MSCs, FGF-10 was intratracheally delivered into the lungs of rats. Three days after instillation, bronchoalveolar lavage was performed and plastic-adherent cells were cultured, characterized and then delivered therapeutically to rats after LPS intratracheal instillation. Immunophenotyping analysis of FGF-10 mobilized and cultured cells revealed expression of the MSC markers CD29, CD73, CD90, and CD105, and the absence of the hematopoietic lineage markers CD34 and CD45. Multipotency of these cells was demonstrated by their capacity to differentiate into osteocytes, adipocytes, and chondrocytes. Delivery of LR-MSCs into the lungs after LPS injury reduced the inflammatory response as evidenced by decreased wet-to-dry ratio, reduced neutrophil and leukocyte recruitment and decreased inflammatory cytokines compared to control rats. Lastly, direct delivery of FGF-10 in the lungs of rats led to an increase of LR-MSCs in the treated lungs, suggesting that the protective effect of FGF-10 might be mediated, in part, by the mobilization of LR-MSCs in lungs
Implement Learner-Centred Pedagogy in China: What Kind of Inequality Issues Make the Pedagogy Hard to Work?
This study explores the challenges of implementing Learner-Centred Education (LCE) in China, focusing on the inequality issues that hinder its effectiveness. The research reviews existing literature on LCE and its counterpart, Teacher-Centred Education (TCE), and examines the obstacles to LCE adoption through Pierre Bourdieu's theory of capital forms (cultural, social, linguistic, and economic). The findings reveal that students from families with higher capital levels adapt more easily to LCE, while those from disadvantaged backgrounds often struggle, leading to unequal educational outcomes. The study concludes that while LCE has potential to improve education quality, its implementation must be context-sensitive, considering the diverse socio-economic and cultural backgrounds of students. Recommendations include fostering inclusive classroom environments, gradually introducing LCE, and addressing resource disparities to ensure equitable educational opportunities
Co-delivery of gemcitabine and Triapine by calcium carbonate nanoparticles against chemoresistant pancreatic cancer
Pancreatic cancer is a malignant disease with high mortality, and its systemic treatment strategy mainly focuses on chemotherapy. Yet, the overall prognosis of pancreatic cancer patients is still extremely poor with a low survival rate. Gemcitabine (GEM) is a widely used chemotherapeutic agent for the treatment of pancreatic cancer. However, GEM chemoresistance remains the major challenge. In this study, we prepared calcium carbonate nanoparticles (CaCO3 NPs) loaded with a nucleotide reductase inhibitor (Triapine) and GEM to suppress the GEM resistance of pancreatic cancer cells (PANC-1/GEM) and solve the problem of poor solubility of Triapine. CaCO3-GEM-Triapine NPs nano-formulations enhanced the therapeutic effect of GEM-based chemotherapy by inhibiting cancer cell proliferation, migration, and resistance to GEM using both 2D PANC-1/GEM cells and 3D tumor spheroids. The study indicated that CaCO3 NPs loaded with GEM and Triapine could provide an effective treatment option to overcome drug resistance in pancreatic cancer
Resistance to immune checkpoint inhibitors in advanced lung cancer: Clinical characteristics, potential prognostic factors and next strategy
BackgroundImmune checkpoint inhibitors (ICIs) have shown unprecedented clinical benefit in cancer immunotherapy and are rapidly transforming the practice of advanced lung cancer. However, resistance routinely develops in patients treated with ICIs. We conducted this retrospective study to provide an overview on clinical characteristics of ICI resistance, optimal treatment beyond disease progression after prior exposure to immunotherapy, as well as potential prognostic factors of such resistance.Methods190 patients diagnosed with unresectable lung cancer who received at least one administration of an anti-programmed cell death 1 (PD-1)/anti-programmed cell death-ligand 1(PD-L1) at any treatment line at Zhongshan Hospital Fudan University between Sep 2017 and December 2019 were enrolled in our study. Overall survival (OS) and progression-free survival (PFS) were analyzed. Levels of plasma cytokines were evaluated for the prognostic value of ICI resistance.ResultsWe found that EGFR/ALK/ROS1 mutation and receiving ICI treatment as second-line therapy were risk factors associated with ICI resistance. Patients with bone metastasis at baseline had a significantly shorter PFS1 time when receiving initial ICI treatment. Whether or not patients with oligo-progression received local treatment seemed to have no significant effect on PFS2 time. Systemic therapies including chemotherapy and anti-angiogenic therapy rather than continued immunotherapy beyond ICI resistance had significant effect on PFS2 time. TNF, IL-6 and IL-8 were significantly elevated when ICI resistance. Lower plasma TNF level and higher plasma IL-8 level seemed to be significantly associated with ICI resistance. A nomogram was established to prognosis the clinical outcome of patients treated with ICIs.ConclusionPatients with EGFR/ALK/ROS1 mutation, or those receiving ICI treatment as second-line therapy had higher risk of ICI resistance. Patients with bone metastasis had poor prognosis during immunotherapy. For those patients with oligo-progression after ICI resistance, combination with local treatment did not lead to a significantly longer PFS2 time. Chemotherapy and anti-angiogenic therapy rather than continued immunotherapy beyond ICI resistance had significant effect on PFS2 time. Levels of plasma cytokines including TNF, IL-6 and IL-8 were associated with ICI resistance
A comprehensive preimplantation genetic testing approach for SEA-type α-thalassemia by fluorescent gap-polymerase chain reaction combined with haplotype analysis
Introduction: This study aimed to evaluate the feasibility and necessity of using fluorescence Gap-polymerase chain reaction combined with haplotype analysis in preimplantation genetic testing for SEA-type α-thalassemia.Methods: A total of 26 preimplantation genetic testing biopsy cycles were performed in 25 families from June 2021 to February 2022. All couples were carriers of SEA-type α-thalassemia. Fluorescent Gap-polymerase chain reaction was used for detecting fragment deletion. Subsequently, according to the results of polymerase chain reaction, reference embryos were identified to establish haplotype using single nucleotide polymorphism array, and aneuploidy was screened simultaneously. In cases wherein the polymerase chain reaction results were inconsistent with the haplotype results, the reasons were investigated, either by retest of the biopsied samples or rebiopsy of the embryo.Results: Among the 172 embryos, 162 had consistent results when tested using both methods, resulting in a consistency rate of 94.2%. Conversely, 10 embryos had inconsistent results, mainly due to chromosome 16 aneuploidy (n = 7), allele dropout in Gap-polymerase chain reaction (n = 2), or incorrect haplotype due to poor sample amplification quality (n = 1). The clinical pregnancy rate of each frozen-thawed embryo transfer was 57.7% (15/26). Six families underwent prenatal diagnosis, which confirmed the results of preimplantation genetic testing.Conclusion: Fluorescent Gap-polymerase chain reaction combined with haplotype analysis is feasible and necessary for SEA-type α-thalassemia preimplantation genetic testing
Case Report: Charcot-marie-tooth disease caused by a de novo MORC2 gene mutation - novel insights into pathogenicity and treatment
Charcot-Marie-Tooth disease (CMT) is a hereditary peripheral neuropathy involving approximately 80 pathogenic genes. Whole-exome sequencing (WES) and confirmatory Sanger sequencing analysis was applied to identify the disease-causing mutations in a Chinese patient with lower limb weakness. We present an 18-year-old male with a 2.5-year history of progressive lower limb weakness and an unsteady gait. Upon admission, a physical examination revealed hands tremulousness, bilateral calf muscle wasting and weakness, pes cavus, and elevated serum creatine kinase (CK) levels. Electromyography demonstrated axonal neuropathy affecting both upper and lower limbs. A de novo heterozygous missense mutation was identified in the MORC2 gene, NM_001303256.3: c.1199A>G, NP_001290186.1: p.Gln400Arg. Consequently, these clinical and genetic findings suggested a diagnosis of hereditary peripheral neuropathy, CMT type 2Z. Oral mecobalamin and coenzyme Q10 was initiated as subsequent treatment. Our study firstly reports the MORC2 c.1199A>G mutation occurring de novo, highlighting its causal association with CMT2Z, and prompting its reclassification as likely pathogenic. Oral mecobalamin and coenzyme Q10 might be a potential treatment approach for early-stage CMT2Z. We recommend genetic testing for CMT patients to identify the genetic etiology, thereby improving clinical management and facilitating genetic counseling
Efficacy of repeated peripheral magnetic stimulation on upper limb motor function after stroke: a systematic review and meta-analysis of randomized controlled trials
BackgroundPost-stroke patients with upper motor neuron lesions have limited motor function in the upper limbs, and spasticity occurs in the limbs, thus affecting functional recovery and activities of daily living. Repetitive peripheral magnetic stimulation (rPMS) is a non-invasive treatment often used in clinical rehabilitation. Recent studies have shown that it can reduce spasticity and improve motor function in patients.ObjectiveThis study aimed to evaluate the effectiveness of rPMS on upper limb motor function and spasticity in stroke patients by meta-analysis.Materials and methodsRandomized controlled trials (RCTs) of rPMS in post-stroke patients were searched in PubMed, Embase, Cochrane Library, Web of Science, and Clinical Trials. Databases from the date of creation to 25 August 2024 were evaluated using the Cochrane Collaboration tool. Methodological quality was assessed using the Cochrane Collaboration tools, and meta-analyses were performed using RevMan (version 5.4) and Stata (version 14.0).ResultsA total of 8 studies were included. RPMS improved patients’ FMA-UE scores compared with controls (MD = 3.34, 95% CI = [0.53, 6.15], p = 0.02 < 0.05). RPMS also reduced spasticity (MD = −0.66, 95% CI = [−1.16, −0.15], p = 0.01 < 0.05) and increased patients’ ability to live independently (MD = 0.85, 95% CI = [0.19, 1.51], p = 0.01 < 0.05). Subgroup analyses showed that the efficacy of treatment frequency ≤ 20 Hz was better than that of frequency > 20 Hz; the treatment time using 15–20 min was more effective than using 30 min; and the application of round coil treatment was more effective than other types of coils.ConclusionThe results suggest that if rPMS is used in post-stroke patients, their upper limb motor function and spasticity may improve. However, the number of studies is small, and further research is needed to extend the current analysis results.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, CRD42024584040
Inhibition of differentiation of monocyte-derived macrophages toward an M2-Like phenotype May Be a neglected mechanism of β-AR receptor blocker therapy for atherosclerosis
The clinical efficacy of adrenergic β-receptor (β-AR) blockers in significantly stabilizing atherosclerotic plaques has been extensively supported by evidence-based medical research; however, the underlying mechanism remains unclear. Recent findings have highlighted the impact of lipid-induced aberrant polarization of macrophages during normal inflammatory-repair and regenerative processes on atherosclerosis formation and progression. In this review, we explore the relationship between macrophage polarization and atherosclerosis, as well as the influence of β-AR blockers on macrophage polarization. Based on the robust evidence supporting the use of β-AR blockers for treating atherosclerosis, we propose that their main mechanism involves inhibiting monocyte-derived macrophage differentiation towards an M2-like phenotype
Synthesis of polyacrylamide-based aerosol fixative and its fixation effect on tellurium aerosol
The removal control of radioactive aerosols in a nuclear emergency is an important issue, and capture fixation is a parameter for studying the purification effect of aerosol fixatives on aerosols. Herein, PAM-g-PAA, PAM-g-PHEA, and PAM-g-PAA/PHEA were obtained by chemical grafting with polyacrylamide as the substrate, acrylic acid and 2-hydroxyethyl acrylate as grafting monomers. The grafting product was confirmed by infrared spectroscopy and the grafting rate was calculated. The microstructure of different products were compared and discussed by scanning electron microscope images of freeze-drying and film formation. The capture and sedimentation effects of tellurium (simulated polonium) aerosol were studied by surface tension and fixed sedimentation experiments (PAM, PAM-g-PAA, PAM-g-PHEA, PAM-g-PAA/PHEA aqueous solution), and the mechanism of aerosol fixation was discussed. The results showed that the surface tension of the grafted product was significantly lower than that of the substrate PAM. Among them, the aerosol fixing agent PAM-g-PHEA grafted with HEA modified polyacrylamide can more effectively capture and fix tellurium aerosol particles, and its fixed sedimentation efficiency is 94.34%, which provides a research idea for the purification of polonium radioactive aerosol by atomization fixation method
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