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INTRODUCTION: Marsupialization is a dependable choice for mandibular unicystic ameloblastoma (UA) management. However, investigations regarding its speed of shrinkage (SS) and reduction rate (RR) are lacking. This case report highlights the treatment of a huge mandibular UA with high SS and RR using marsupialization before secondary surgery. PRESENTATION OF CASE: A 45-year-old male patient presented with severe swelling of the right side of the mandible, resulting in prominent facial asymmetry. Panoramic radiograph revealed a unilocular, radiolucent lesion extending from the mandibular midline to the right ramus. Computed tomography (CT) revealed a large radiolucent lesion that expanded in the buccolingual direction. Incisional biopsy showed that the lesion was UA. After 1.5 years of marsupialization, an SS of 0.183 % per day was reached, leading to an impressive RR of 98.7 %. Treatment was followed by enucleation and peripheral osteotomy. No recurrence was observed at 1 year post-surgery. DISCUSSION: The treatment of mandibular UA remains controversial, ranging from conservative approaches to aggressive interventions. In the current case, marsupialization was highly effective in reducing the volume of the lesion, thereby facilitating a minimally invasive secondary surgery to preserve function. The intact periosteum, which has the potential to differentiate into various cell types, may be associated with the regeneration of new bone after marsupialization. CONCLUSION: Marsupialization remains a successful strategy for managing mandibular UA. Even the huge lesions causing facial deformity can be treated with marsupialization combined with secondary surgery, avoiding the aesthetic and functional disruptions associated with radical treatment.
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Innovative intraoral ultrasound devices with smart artificial intelligence-based identification for dento-anatomy could provide crucial information for oral health diagnosis and treatment and shed light on real-time detection of developmental dentistry. However, the grand challenge is that the current ultrasound technologies are meant for external use due to their bulkiness and low frequency. We report a compact versatile ultrasound intraoral device that consists of a rotational probe head robustly pivoted around a hand-held and portable handle for real-time imaging of intraoral anatomy using high-frequency ultrasonography (up to 25 MHz). The intraoral ultrasound device that could be adjusted for various orientations of the imaging planes by rotating the head provides real-time, high-resolution ultrasonograms of intraoral structures, including dento-periodontium of most tooth types and maxillary palate. Machine learning-based algorithms are integrated to automate the identification of important structures, including alveolar bone and cementum-enamel junction. The intraoral ultrasound device smartened with artificial intelligence could innovate oral health diagnosis and treatment plans toward precision health and patient care.
Subject(s)
Machine Learning , Ultrasonography , Humans , Ultrasonography/methods , Transducers , Periodontium/diagnostic imagingABSTRACT
BACKGROUND: Ticks, as critical vectors of a variety of pathogens, pose a significant public health challenge globally. In Southeast Asia (SEA), ticks are responsible for transmitting a diverse array of pathogens affecting humans and animals. The geographical and ecological diversity of SEA provides a unique environment that supports a wide range of tick species, which complicates the management and study of tick-borne diseases (TBDs). METHODOLOGY/PRINCIPAL FINDINGS: This article synthesizes findings from the first international symposium on ticks and TBDs in Southeast Asia, held in Phnom Penh on June 22 and 23, 2023. It highlights regional efforts to understand tick ecology and pathogen transmission. This paper proposes to present a summary of the various presentations given during the symposium following 3 main parts. The first one is devoted to the state of knowledge regarding ticks and TBDs in SEA countries, with presentations from 6 different countries, namely Cambodia, Indonesia, Laos, Malaysia, Thailand, and Vietnam. The second part focuses on the development of new research approaches on tick-borne pathogens (TBPs) and TBDs. The last part is a summary of the round table discussion held on the final day, with the aim of defining the most important challenges and recommendations for researches on TBP and TBD in the SEA region. CONCLUSIONS/SIGNIFICANCE: Key topics discussed include advancements in diagnostic tools, such as MALDI-TOF MS and proteomics, and the development of sustainable strategies for tick management and disease prevention. The symposium facilitated the exchange of knowledge and collaborative networks among experts from various disciplines, promoting a unified approach to tackling TBDs in the region. The symposium underscored the need for enhanced surveillance, diagnostics, and inter-regional cooperation to manage the threat of TBDs effectively. Recommendations include the establishment of a regional database for tick identification and the expansion of vector competence studies. These initiatives are crucial for developing targeted interventions and understanding the broader implications of climate change and urbanization on the prevalence of TBDs.
Subject(s)
Tick-Borne Diseases , Ticks , Animals , Tick-Borne Diseases/epidemiology , Tick-Borne Diseases/transmission , Humans , Ticks/physiology , Asia, Southeastern/epidemiology , Cambodia/epidemiologyABSTRACT
In mammalian cells, DNA double-strand breaks are predominantly repaired by non-homologous end joining (NHEJ). During repair, the Ku70-Ku80 heterodimer (Ku), X-ray repair cross complementing 4 (XRCC4) in complex with DNA ligase 4 (X4L4) and XRCC4-like factor (XLF) form a flexible scaffold that holds the broken DNA ends together. Insights into the architectural organization of the NHEJ scaffold and its regulation by the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) were recently obtained by single-particle cryo-electron microscopy analysis. However, several regions, especially the C-terminal regions (CTRs) of the XRCC4 and XLF scaffolding proteins, have largely remained unresolved in experimental structures, which hampers the understanding of their functions. Here we used magnetic resonance techniques and biochemical assays to comprehensively characterize the interactions and dynamics of the XRCC4 and XLF CTRs at residue resolution. We show that the CTRs of XRCC4 and XLF are intrinsically disordered and form a network of multivalent heterotypic and homotypic interactions that promotes robust cellular NHEJ activity. Importantly, we demonstrate that the multivalent interactions of these CTRs lead to the formation of XLF and X4L4 condensates in vitro, which can recruit relevant effectors and critically stimulate DNA end ligation. Our work highlights the role of disordered regions in the mechanism and dynamics of NHEJ and lays the groundwork for the investigation of NHEJ protein disorder and its associated condensates inside cells with implications in cancer biology, immunology and the development of genome-editing strategies.
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BACKGROUND: This study aimed to measure the preferences for mental health support among health professionals, their willingness to support the mental health of colleagues and associated factors. METHOD: A descriptive cross-sectional study was performed from August to October 2022 within five hospitals located in Hanoi, Vietnam. A total of 244 health professionals participated in the study. Data on socio-economic status, health and COVID-19-related characteristics, Depression Anxiety Stress Scale (DASS-21); and preferences for mental health support services were collected by using a structured self-reported questionnaire. Multivariate logistic regression models were utilized to identify associated factors with the demand for mental support services. RESULTS: 13.9%, 17.1% and 8.6% reported having at least mild depression, anxiety and stress, respectively. There 13.9% did not seek any mental health support during the COVID-19 pandemic. The most common support included talking with friends (52.9%), family (50.8%), colleagues (47.6%) and using social networks/Internet (43.5%). There 31.1% had been aware of mental health services, but only 18.0% used this service at least once. Regarding preferences, 47.3% had a demand for mental support services, and the most preferred service was providing coping skills (25.9%), followed by skills to support others against mental problems (22.2%). Major sources of support included psychiatrists (34.4%), colleagues (29.1%) and family (27.9%). The main preferred channels for support included telephone/mobile phone (35.7%) and Internet (20.9%). Only 12.3% were willing to provide mental support for colleagues during the pandemic. Age, education, perceived mental health status, ever seeking any mental service, and DASS-21 depression score were associated with demand for mental support services. CONCLUSION: This study found a lack of awareness of mental health services for health professionals, as well as moderate levels of demand for this service in this population. Raising awareness and developing tailored mental health support services are important to enhancing the mental well-being of health professionals in Vietnam to prepare for the next pandemic.
Subject(s)
COVID-19 , Depression , Health Personnel , Mental Health Services , Mental Health , Humans , COVID-19/epidemiology , COVID-19/psychology , Vietnam/epidemiology , Male , Female , Adult , Cross-Sectional Studies , Health Personnel/psychology , Middle Aged , Depression/epidemiology , Anxiety/epidemiology , Pandemics , Surveys and Questionnaires , SARS-CoV-2 , Stress, Psychological/epidemiology , Social SupportABSTRACT
The yeast glucose-induced degradation-deficient (GID) E3 ubiquitin ligase forms a suite of complexes with interchangeable receptors that selectively recruit N-terminal degron motifs of metabolic enzyme substrates. The orthologous higher eukaryotic C-terminal to LisH (CTLH) E3 complex has been proposed to also recognize substrates through an alternative subunit, WDR26, which promotes the formation of supramolecular CTLH E3 assemblies. Here, we discover that human WDR26 binds the metabolic enzyme nicotinamide/nicotinic-acid-mononucleotide-adenylyltransferase 1 (NMNAT1) and mediates its CTLH E3-dependent ubiquitylation independently of canonical GID/CTLH E3-family substrate receptors. The CTLH subunit YPEL5 inhibits NMNAT1 ubiquitylation and cellular turnover by WDR26-CTLH E3, thereby affecting NMNAT1-mediated metabolic activation and cytotoxicity of the prodrug tiazofurin. Cryoelectron microscopy (cryo-EM) structures of NMNAT1- and YPEL5-bound WDR26-CTLH E3 complexes reveal an internal basic degron motif of NMNAT1 essential for targeting by WDR26-CTLH E3 and degron mimicry by YPEL5's N terminus antagonizing substrate binding. Thus, our data provide a mechanistic understanding of how YPEL5-WDR26-CTLH E3 acts as a modulator of NMNAT1-dependent metabolism.
Subject(s)
Nicotinamide-Nucleotide Adenylyltransferase , Prodrugs , Ubiquitin-Protein Ligases , Ubiquitination , Humans , Cryoelectron Microscopy , HEK293 Cells , Nicotinamide-Nucleotide Adenylyltransferase/metabolism , Nicotinamide-Nucleotide Adenylyltransferase/genetics , Prodrugs/metabolism , Protein Binding , Substrate Specificity , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/genetics , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolismABSTRACT
We introduce an approach to particle breakage, wherein the particle is modeled as an aggregate of polyhedral cells with their common surfaces governed by the Griffith criterion of fracture. This model is implemented within a discrete element code to simulate and analyze the breakage behavior of a single particle impacting a rigid plane. We find that fracture dynamics involves three distinct regimes as a function of the normalized impact energy ω. At low values of ω, the particle undergoes elastic rebound and no cracks occur inside the particle. In the intermediate range, the particle is damaged by nucleation and propagation of cracks, and the effective restitution coefficient declines without breakup of the particle. Finally, for values of ω beyond a well-defined threshold, the particle breaks into fragments and the restitution coefficient increases with ω due to kinetic energy carried away by the fragments. We show that particle damage, restitution coefficient, and fracture efficiency (the amount of energy input consumed for particle fracture) collapse well as a function of dimensionless scaling parameters. Our data are also sufficiently accurate to scale fragment size and shape distributions. It is found that fragment masses (volumes) follow a power-law distribution with an exponent decreasing with fracture energy. Interestingly, the average elongation and flatness of fragments are very close to those observed in experiments and lunar samples at the optimal fracture efficiency.
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Non-Hodgkin lymphoma (NHL) is a lymphoproliferative disorder derived from either B or T lymphocytes. Among NHL, activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL) and T cell non-Hodgkin lymphomas (T-NHL) are poor prognosis and aggressive subtypes. Macrophages are professional phagocytic cells and dendritic cells (DCs) are professional antigen-presenting cells in immune system. Doxorubicin (Dox) and Etoposide (ET) are the most effective anti-cancer drugs. A20 and CYLD are negative regulators of NF-κB-dependent functions in many cell types. Little is known about the roles of A20 and CYLD in regulating functions of DCs and macrophages from NHL. The present study, therefore, explored whether A20/CYLD expression contributes to functions of DCs and macrophages from NHL. To this end, blood samples of seventy-nine patients with ABC DLBCL and T-NHL were examined. Gene expression profile was determined by quantitative RT-PCR and immunophenotype, cell apoptosis and phagocytosis by flow cytometry. As a result, immunophenotypic analysis showed that the numbers of CD13+CD117-, CD56+CD40+ and CD23+CD40+ expressing cells were significantly elevated in ABC DLBCL cases compared to healthy individuals and T-NHL patients. Interestingly, upon treatment of Dox and ET, the phagocytosis of lymphoma cells was significantly reduced by CD11c+CD123- DCs and the percentage of CD56+ mature DCs was significantly enhanced in ABC DLBCL patients only in the presence of A20 siRNA, but not CYLD siRNA. In conclusion, ABC DLBCL patients with low A20 expression were defective in elimination of lymphoma cells by DCs and linked to killer DC expansion in circulation.
Subject(s)
Dendritic Cells , Lymphoma, Large B-Cell, Diffuse , Phagocytosis , Tumor Necrosis Factor alpha-Induced Protein 3 , Humans , Dendritic Cells/immunology , Dendritic Cells/metabolism , Phagocytosis/drug effects , Tumor Necrosis Factor alpha-Induced Protein 3/metabolism , Tumor Necrosis Factor alpha-Induced Protein 3/genetics , Female , Lymphoma, Large B-Cell, Diffuse/pathology , Lymphoma, Large B-Cell, Diffuse/immunology , Middle Aged , Male , Lymphoma, Non-Hodgkin/pathology , Lymphoma, Non-Hodgkin/immunology , Apoptosis/drug effects , Aged , Adult , Macrophages/metabolism , Macrophages/immunology , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , ImmunophenotypingABSTRACT
BACKGROUND: Lumbosacral radicular syndrome (LRS) is probably the most frequent neuropathic pain syndrome, exaggerating medical and economy burden on developing countries, such as Vietnam. As a result, the urgence to find an approach which is both affordable and effective always puts great demand on medical researchers. OBJECTIVES: Evaluate the effectiveness of transforaminal pulsed radiofrequency (PRF) stimulation on the dorsal root ganglion (DRG) and epidural steroid injection (ESI) in management of chronic lumbosacral radiculopathy. METHODS: Seventy-six patients with chronic radicular pain were performed transforaminal PRF + ESI by neurosurgeons. Demographic characteristics and surgical outcomes were recorded on admission, pre-procedural and post-procedural for 1-month, 3-month, 6-month and 12-month follow-up. Primary outcome was measured by using Visual Analogue Scale (VAS), Oswestry disability index (ODI) and Straight Leg Raising Test (SLRT). Secondary outcome was subjectively collected based on short assessment of patients' satisfaction (SAPS). RESULTS: Patients who received transforaminal PRF and ESI showed significant improvements on all three evaluation tools (VAS, ODI, SLRT), compared to that before treatment (p<0.001). Pain relief was achievable and long-lasting, which met patients' expectation. No significant complications were observed for 12 months follow-up. CONCLUSION: Transforaminal PRF combined with ESI in management of lumbosacral radiculopathy should be a good method of choice for its effectiveness and safety in management of pain.
Subject(s)
Chronic Pain , Pulsed Radiofrequency Treatment , Radiculopathy , Humans , Radiculopathy/drug therapy , Pulsed Radiofrequency Treatment/methods , Vietnam , Tertiary Care Centers , Treatment Outcome , Chronic Pain/therapy , Chronic Pain/complications , Steroids/therapeutic useABSTRACT
Micropollutants, such as caffeine (M-CF), pose a significant threat to ecosystems and human health through water and food sources. The utilization of metal oxide-based photocatalysts has proven to be an effective treatment method for the removal of organic pollutants. This study explores the efficacy of Ag-doped ZnO (Ag/ZnO) for removing M-CF from wastewater. The characterization of Ag/ZnO underscores the crucial role of band gap energy in the photocatalytic degradation process. This parameter influences the separation of electrons and holes (e-/h+) and the generation of reactive radicals. Under solar light, Ag/ZnO demonstrated markedly superior photocatalytic activity, achieving an impressive degradation efficiency of approximately 93.4%, in stark contrast to the 53.2% occurred by ZnO. Moreover, Ag/ZnO exhibited a remarkable degradation efficiency of M-CF in wastewater, reaching 83.5%. A key advantage of Ag/ZnO lies in its potential for recovery and reuse in subsequent treatments, contributing to a reduction in operational costs for industrial wastewater treatment. Impressively, even after five cycles, Ag/ZnO maintained a noteworthy photodegradation rate of M-CF at 78.6%. These results strongly suggest that Ag/ZnO presents a promising solution for the removal of micropollutants in wastewater, with potential scalability for industrial and large-scale applications.
Subject(s)
Environmental Pollutants , Zinc Oxide , Humans , Ecosystem , Wastewater , CaffeineABSTRACT
BACKGROUND: In Vietnam, a lack of evidence about the unexpected antibodies hinders the capabilities to prepare the necessary resources and personnel for treating patients with blood disorders. This study aimed to measure the rates of different unexpected antibodies in patients having blood orders in Vietnam. STUDY DESIGN AND METHODS: A cross-sectional study was conducted at the National Institute of Hematology - Blood Transfusion, Vietnam on 5608 patients with blood disorders. Information was obtained from the medical records, blood transfusion forms, screening test forms. RESULTS: The prevalence rate of unexpected antibodies in patients with haematological disorders was 9.3%. The most prevalent occurrence was the presence of an atypical antibody type, accounting for 61% of patients. The co-occurrence of this atypical antibody type and other types of antibodies was also observed, with the respective occurrence rates of 23.9%, 10.1%, 3.8%, and 1.2% for the combination of two, three, four, and five unexpected antibody types. The presence of one type of unexpected antibody was predominant, namely anti-E, accounting for the highest proportion (32.9%), followed by anti-Mia (18.4%). Among the 125 patients, the most frequently observed combination of abnormal antibodies was anti-E with anti-c (14.3%) and anti-E with anti-Mia (3.4%). Among the cohort of 53 patients exhibiting three types of unexpected antibodies, the most prevalent combination observed was anti-c, anti-E, and anti-Mia (5.7%). CONCLUSION: This study revealed a prevalence rate of 9.3% in the presence of unexpected antibodies in patients with blood disorders. The occurrence of individual unexpected antibodies surpasses that of coordinated antibodies.
Subject(s)
Blood Group Antigens , Hematologic Diseases , Humans , Vietnam/epidemiology , Cross-Sectional Studies , Antibodies , Blood Transfusion , IsoantibodiesABSTRACT
BACKGROUND: The ephemeral flora of northern Xinjiang, China, plays an important role in the desert ecosystems. However, the evolutionary history of this flora remains unclear. To gain new insights into its origin and evolutionary dynamics, we comprehensively sampled ephemeral plants of Brassicaceae, one of the essential plant groups of the ephemeral flora. RESULTS: We reconstructed a phylogenetic tree using plastid genomes and estimated their divergence times. Our results indicate that ephemeral species began to colonize the arid areas in north Xinjiang during the Early Miocene and there was a greater dispersal of ephemeral species from the surrounding areas into the ephemeral community of north Xinjiang during the Middle and Late Miocene, in contrast to the Early Miocene or Pliocene periods. CONCLUSIONS: Our findings, together with previous studies, suggest that the ephemeral flora originated in the Early Miocene, and species assembly became rapid from the Middle Miocene onwards, possibly attributable to global climate changes and regional geological events.
Subject(s)
Brassicaceae , Ecosystem , Phylogeny , Brassicaceae/genetics , China , Plastids/geneticsABSTRACT
Introduction and importance: Several authors have also made reference to a less prevalent condition known in elbow as ulnar nerve subluxation. However, this particular condition tends to manifest primarily in young individuals who engage in professional sports or activities involving extensive use of the forearm. A more severe form of ulnar nerve subluxation, which is ulnar nerve dislocation, gives rise to a characteristic dislocation and relocation of the nerve at the elbow during flexion and extension of the forearm. Due to the rarity of this condition in clinical settings and its predominant occurrence as subluxation in younger patients, there are instances where traumatic ulnar nerve dislocation can be overlooked and misdiagnosed with two commonly encountered pathological conditions as ulnar nerve entrapment or medial epicondylitis. Case presentation: The authors present a 51-year-old male with chronic pain when moving his right forearm following a fall that caused a direct force injury to his elbow. The patient was misdiagnosed and treated as medial epicondylitis and early-stage ulnar nerve entrapment. However, the symptoms did not improve for a long time. The authors performed the ulnar nerve anterior transposition surgery using the subcutaneous transposition technique and the result is very good without any pain. Clinical discussion: The ulnar nerve can naturally be subluxed or dislocated if Osborne's ligament is loose or when there are anatomical variations in the medial epicondyle. In some case, this ligament can be ruptured by trauma. The symptoms of ulnar instability are caused by friction neuritis. Dynamic ultrasound of the ulnar nerve in two positions show clearly this condition. Conclusion: Post-traumatic ulnar nerve dislocation is a rare condition, and the recurrent characteristic of it leads to neuritis or neuropathy. The condition can be overlooked or misdiagnosed as medial epicondylitis or early-stage ulnar nerve entrapment. The nerve transposition surgery will give good result.
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BACKGROUND: Most skin-related traits have been studied in Caucasian genetic backgrounds. A comprehensive study on skin-associated genetic effects on underrepresented populations such as Vietnam is needed to fill the gaps in the field. OBJECTIVES: We aimed to develop a computational pipeline to predict the effect of genetic factors on skin traits using public data (GWAS catalogs and whole-genome sequencing (WGS) data from the 1000 Genomes Project-1KGP) and in-house Vietnamese data (WGS and genotyping by SNP array). Also, we compared the genetic predispositions of 25 skin-related traits of Vietnamese population to others to acquire population-specific insights regarding skin health. METHODS: Vietnamese cohorts of whole-genome sequencing (WGS) of 1008 healthy individuals for the reference and 96 genotyping samples (which do not have any skin cutaneous issues) by Infinium Asian Screening Array-24 v1.0 BeadChip were employed to predict skin-associated genetic variants of 25 skin-related and micronutrient requirement traits in population analysis and correlation analysis. Simultaneously, we compared the landscape of cutaneous issues of Vietnamese people with other populations by assessing their genetic profiles. RESULTS: The skin-related genetic profile of Vietnamese cohorts was similar at most to East Asian cohorts (JPT: Fst = 0.036, CHB: Fst = 0.031, CHS: Fst = 0.027, CDX: Fst = 0.025) in the population study. In addition, we identified pairs of skin traits at high risk of frequent co-occurrence (such as skin aging and wrinkles (r = 0.45, p = 1.50e-5) or collagen degradation and moisturizing (r = 0.35, p = 1.1e-3)). CONCLUSION: This is the first investigation in Vietnam to explore genetic variants of facial skin. These findings could improve inadequate skin-related genetic diversity in the currently published database.
Subject(s)
Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Skin , Southeast Asian People , Humans , Genome-Wide Association Study , Phenotype , VietnamABSTRACT
The precise spatio-temporal expression of the hematopoietic ETS transcription factor PU.1 that determines the hematopoietic cell fates is tightly regulated at the chromatin level. However, it remains elusive as to how chromatin signatures are linked to this dynamic expression pattern of PU.1 across blood cell lineages. Here we performed an unbiased and in-depth analysis of the relationship between human PU.1 expression, the presence of trans-acting factors, and 3D architecture at various cis-regulatory elements (CRE) proximal to the PU.1 locus. We identified multiple novel CREs at the upstream region of the gene following an integrative inspection for conserved DNA elements at the chromatin-accessible regions in primary human blood lineages. We showed that a subset of CREs localize within a 10 kb-wide cluster that exhibits that exhibit molecular features of a myeloid-specific super-enhancer involved in mediating PU.1 autoregulation, including open chromatin, unmethylated DNA, histone enhancer marks, transcription of enhancer RNAs, and occupancy of the PU.1 protein itself. Importantly, we revealed the presence of common 35-kb-wide CTCF-bound insulated neighborhood that contains the CRE cluster, forming the chromatin territory for lineage-specific and CRE-mediated chromatin interactions. These include functional CRE-promoter interactions in myeloid and B cells but not in erythroid and T cells. Our findings also provide mechanistic insights into the interplay between dynamic chromatin structure and 3D architecture in defining certain CREs as enhancers or silencers in chromatin regulation of PU.1 expression. The study lays the groundwork for further examination of PU.1 CREs as well as epigenetic regulation in malignant hematopoiesis.
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Monolayered transition-metal dichalcogenides (TMDs) are easily exposed to air, and their crystal quality can often be degraded via oxidation, leading to poor electronic and optical device performance. The degradation becomes more severe in the presence of defects, grain boundaries, and residues. Here, we report crack propagation in pristine TMD monolayers grown by chemical vapor deposition under ambient conditions and light illumination. Under a high relative humidity (RH) of â¼60% and white light illumination, the cracks appear randomly. Photo-oxidative cracks gradually propagated along the grain boundaries of the TMD monolayers. In contrast, under low RH conditions of â¼2%, cracks were scarcely observed. Crack propagation is predominantly attributed to the accumulation of water underneath the TMD monolayers, which is preferentially absorbed by hygroscopic alkali metal-based precursor residues. Crack propagation is further accelerated by the cyclic process of photo-oxidation in a basic medium, leading to localized tensile strain. We also found that such crack propagation is prevented after the removal of alkali metals via the transfer of the sample to other substrates.
ABSTRACT
Polycyclic aromatic hydrocarbons (PAHs) associated with indoor PM pose a high risk to human health because of their toxicity. A total of 160 daily samples of indoor PM2.5 and PM0.1 were collected in Hanoi and analysed for 15 PAHs. In general, the concentrations of carcinogenic PAHs (car-PAHs) accounted for 21% ± 2%, 19.1% ± 2%, and 26% ± 3% of the concentrations of 15 PAHs in PM2.5, PM0.1-2.5, and PM0.1, respectively. Higher percentages of car-PAHs were found in smaller fractions (PM0.1), which can be easily deposited deep in the pulmonary regions of the human respiratory tract. The concentrations of 15 PAHs were higher in winter than in summer. The most abundant PAH species were naphthalene and phenanthrene, accounting for 11%-21% and 19%-23%, respectively. The PAH content in PM0.1 was almost twice as high as those in PM2.5 and PM0.1-2.5. Principal component analysis found that vehicle emissions and the combustion of biomass and coal were the main outdoor sources of PAHs, whereas indoor sources included cooking activities, the combustion of incense, scented candles, and domestic uses in houses. According to the results, 60%-90% of the PM0.1-bound BaP(eq) was deposited in the alveoli region, whereas 63%-75% of the PM2.5-bound BaP(eq) was deposited in head airways (HA), implying that most of the particles deposited in the HA region were PM0.1-2.5. The contributions of dibenz[a,h]anthracene and benzo[a]pyrene were dominant and contributed from 36% to 51% and 31%-50%, respectively, to the carcinogenic potential, whereas benzo[a]pyrene contributed from 30% to 49% to the mutagenic potential for both size fractions. The incremental lifetime cancer risk, simulated by Monte Carlo simulation, was within the limits set by the US EPA, indicating an acceptable risk for the occupants. These results provide an additional scientific basis for protecting human health from exposure to indoor PAHs.
Subject(s)
Air Pollutants , Polycyclic Aromatic Hydrocarbons , Humans , Particulate Matter/analysis , Air Pollutants/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Environmental Monitoring , Benzo(a)pyrene/analysis , Risk Assessment , ChinaABSTRACT
Sporadic Parkinson's Disease (sPD) is a progressive neurodegenerative disorder caused by multiple genetic and environmental factors. Mitochondrial dysfunction is one contributing factor, but its role at different stages of disease progression is not fully understood. Here, we showed that neural precursor cells and dopaminergic neurons derived from induced pluripotent stem cells (hiPSCs) from sPD patients exhibited a hypometabolism. Further analysis based on transcriptomics, proteomics, and metabolomics identified the citric acid cycle, specifically the α-ketoglutarate dehydrogenase complex (OGDHC), as bottleneck in sPD metabolism. A follow-up study of the patients approximately 10 years after initial biopsy demonstrated a correlation between OGDHC activity in our cellular model and the disease progression. In addition, the alterations in cellular metabolism observed in our cellular model were restored by interfering with the enhanced SHH signal transduction in sPD. Thus, inhibiting overactive SHH signaling may have potential as neuroprotective therapy during early stages of sPD.