Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 49
Filter
1.
J Ultrasound Med ; 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38873702

ABSTRACT

OBJECTIVES: To develop a robust algorithm for estimating ultrasonic axial transmission velocity from neonatal tibial bone, and to investigate the relationships between ultrasound velocity and neonatal anthropometric measurements as well as clinical biochemical markers of skeletal health. METHODS: This study presents an unsupervised learning approach for the automatic detection of first arrival time and estimation of ultrasonic velocity from axial transmission waveforms, which potentially indicates bone quality. The proposed method combines the ReliefF algorithm and fuzzy C-means clustering. It was first validated using an in vitro dataset measured from a Sawbones phantom. It was subsequently applied on in vivo signals collected from 40 infants, comprising 21 males and 19 females. The extracted neonatal ultrasonic velocity was subjected to statistical analysis to explore correlations with the infants' anthropometric features and biochemical indicators. RESULTS: The results of in vivo data analysis revealed significant correlations between the extracted ultrasonic velocity and the neonatal anthropometric measurements and biochemical markers. The velocity of first arrival signals showed good associations with body weight (ρ = 0.583, P value <.001), body length (ρ = 0.583, P value <.001), and gestational age (ρ = 0.557, P value <.001). CONCLUSION: These findings suggest that fuzzy C-means clustering is highly effective in extracting ultrasonic propagating velocity in bone and reliably applicable in in vivo measurement. This work is a preliminary study that holds promise in advancing the development of a standardized ultrasonic tool for assessing neonatal bone health. Such advancements are crucial in the accurate diagnosis of bone growth disorders.

2.
J Hazard Mater ; 476: 134990, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38908179

ABSTRACT

Arsenic (As) is a widespread environmental contaminant that poses a significant threat to ecosystems and human health. Although previous studies have qualitatively revealed the effects of individual soil properties on the transport and fate of As in the vadose zone, their integrated impacts remain obscure. Moreover, studies investigating the retardation factor therein, which is a key parameter for comprehending As transport in the vadose zone, are extremely limited. In this study, we investigated the interplay of soil properties with As transport and retention within the vadose zone, while focusing on the retardation factor of As. We employed steady-state unsaturated water-flow soil column experiments coupled with a mobile-immobile model and multiple linear regression analysis to elucidate the dependence of As retardation factors on the soil properties. In the mobile water zone, iron and organic matter contents emerged as the two most influential properties that impedes As mobility. Whereas, in the immobile water zone, the coefficient of uniformity and bulk density were the most influential factors that enhanced As retention. Finally, we derived an empirical equation for calculating the As retardation factors in each zone, offering a valuable tool for describing and predicting As behavior to protect the groundwater resources underneath.

3.
Front Public Health ; 11: 1231326, 2023.
Article in English | MEDLINE | ID: mdl-37794894

ABSTRACT

Introduction: The outbreak of coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) had significant effects on the mental well-being in general, particularly for healthcare professionals. This study examined the prevalence of depression, anxiety, and stress, and identified the associated risk factors amongst healthcare workers during the COVID-19 outbreak in a tertiary hospital located in Vietnam. Methods: We conducted a cross-sectional study at a tertiary-level hospital, where the Depression Anxiety and Stress Scale 21 (DASS-21) web-based questionnaire was employed. We analyzed the determinant factors by employing multivariate logistic models. Results: The prevalence of depression, anxiety, and stress symptoms were 19.2%, 24.7%, and 13.9%, respectively. Factors such as engaging in shift work during the pandemic, taking care of patients with COVID-19, and staff's health status were associated with mental health issues among health professionals. In addition, having alternate rest periods was likely to reduce the risk of stress. Conclusion: The prevalence of mental health problems in healthcare workers during the COVID-19 pandemic was relatively high. Having resting periods could potentially mitigate the development of stress among health professionals. Our findings could be taken into account for improving mental health of the health professional population.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Pandemics , Cross-Sectional Studies , SARS-CoV-2 , Depression/epidemiology , RNA, Viral , Tertiary Care Centers , Vietnam/epidemiology , Anxiety/epidemiology , Health Personnel/psychology
4.
N Engl J Med ; 389(18): 1672-1684, 2023 Nov 02.
Article in English | MEDLINE | ID: mdl-37870974

ABSTRACT

BACKGROUND: Neoadjuvant or adjuvant immunotherapy can improve outcomes in patients with resectable non-small-cell lung cancer (NSCLC). Perioperative regimens may combine benefits of both to improve long-term outcomes. METHODS: We randomly assigned patients with resectable NSCLC (stage II to IIIB [N2 node stage] according to the eighth edition of the AJCC Cancer Staging Manual) to receive platinum-based chemotherapy plus durvalumab or placebo administered intravenously every 3 weeks for 4 cycles before surgery, followed by adjuvant durvalumab or placebo intravenously every 4 weeks for 12 cycles. Randomization was stratified according to disease stage (II or III) and programmed death ligand 1 (PD-L1) expression (≥1% or <1%). Primary end points were event-free survival (defined as the time to the earliest occurrence of progressive disease that precluded surgery or prevented completion of surgery, disease recurrence [assessed in a blinded fashion by independent central review], or death from any cause) and pathological complete response (evaluated centrally). RESULTS: A total of 802 patients were randomly assigned to receive durvalumab (400 patients) or placebo (402 patients). The duration of event-free survival was significantly longer with durvalumab than with placebo; the stratified hazard ratio for disease progression, recurrence, or death was 0.68 (95% confidence interval [CI], 0.53 to 0.88; P = 0.004) at the first interim analysis. At the 12-month landmark analysis, event-free survival was observed in 73.4% of the patients who received durvalumab (95% CI, 67.9 to 78.1), as compared with 64.5% of the patients who received placebo (95% CI, 58.8 to 69.6). The incidence of pathological complete response was significantly greater with durvalumab than with placebo (17.2% vs. 4.3% at the final analysis; difference, 13.0 percentage points; 95% CI, 8.7 to 17.6; P<0.001 at interim analysis of data from 402 patients). Event-free survival and pathological complete response benefit were observed regardless of stage and PD-L1 expression. Adverse events of maximum grade 3 or 4 occurred in 42.4% of patients with durvalumab and in 43.2% with placebo. Data from 62 patients with documented EGFR or ALK alterations were excluded from the efficacy analyses in the modified intention-to-treat population. CONCLUSIONS: In patients with resectable NSCLC, perioperative durvalumab plus neoadjuvant chemotherapy was associated with significantly greater event-free survival and pathological complete response than neoadjuvant chemotherapy alone, with a safety profile that was consistent with the individual agents. (Funded by AstraZeneca; AEGEAN ClinicalTrials.gov number, NCT03800134.).


Subject(s)
Antineoplastic Agents, Immunological , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Adjuvants, Immunologic/therapeutic use , Administration, Intravenous , Antineoplastic Agents, Immunological/administration & dosage , Antineoplastic Agents, Immunological/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , B7-H1 Antigen/administration & dosage , B7-H1 Antigen/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/surgery , Combined Modality Therapy , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Lung Neoplasms/surgery , Neoplasm Recurrence, Local/drug therapy
5.
Int J Lab Hematol ; 45(4): 442-448, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37345257

ABSTRACT

The proliferation of new molecular technologies in recent years has greatly advanced our knowledge of the genetics that underlie hematologic cancers. Particularly, with the advent and wide-implementation of next-generation sequencing (NGS), a host of somatic (and some germline) gene mutations have been identified as significant in the classification, prognostication, and treatment of the spectrum of myeloid neoplasms. These driver and disease modifier mutations now play a prominent role in the updated international diagnostic guidelines of acute myeloid leukemia (AML), myelodysplastic syndromes/neoplasms (MDS), and myeloproliferative neoplasms (MPN). As high-throughput technologies such as NGS increasingly become standard in the genetic evaluation of myeloid disorders, it is critical that clinicians understand the clinical relevance of these mutations in order to further personalize patient care. In this review we discuss some of the most essential somatic and cytogenetic findings.


Subject(s)
Hematologic Neoplasms , Leukemia, Myeloid, Acute , Myelodysplastic Syndromes , Myeloproliferative Disorders , Humans , Myeloproliferative Disorders/diagnosis , Myeloproliferative Disorders/genetics , Myelodysplastic Syndromes/diagnosis , Myelodysplastic Syndromes/genetics , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Mutation , Hematologic Neoplasms/diagnosis , Hematologic Neoplasms/genetics
6.
Environ Sci Pollut Res Int ; 30(30): 74952-74965, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37209351

ABSTRACT

The knowledge economy system shifts focus on the significance of intellectual capital. Moreover, the concept itself has gained generous amount of recognition at global level due to the increasing pressure from competitors, stakeholders, and environmental forces. Indeed, its antecedents and consequences have been assessed by scholars. However, the assessment appears to be inexhaustive with respect to meaningful frameworks. With the help of preceding literature, the present paper designed a model which involves green intellectual capital, green innovation, environmental knowledge, green social behavior, and learning outcomes. The model stipulates that green intellectual capital makes green innovation possible which further results in competitive advantage in the presence of environmental knowledge as a mediator as green social behavior and learning outcomes as a moderator. Interestingly the model acknowledges the proposed relationship through the empirical evidence collected from 382 Vietnamese textile and garment enterprises. The findings provide deeper insights regarding the issue that how firms could extract maximum benefits from their green assets and capabilities in the form of intellectual capital and green innovation.


Subject(s)
Learning , Textile Industry , Humans , Clothing , Social Behavior , Textiles , Sustainable Growth
7.
J Hazard Mater ; 447: 130826, 2023 Apr 05.
Article in English | MEDLINE | ID: mdl-36682247

ABSTRACT

The nonstationary nature of water and oxygen content in the vadose zone determines various biogeochemical reactions regarding arsenic (As) therein, which affects the groundwater vulnerability to As contamination at a site. In the present study, we evaluated the effect of soil organic matter (OM) on the behavior of As using specifically designed soil columns that simulated the vadose zone. Three wet-dry cycles were applied to each of the four columns with different OM contents and bulk densities. OM was found to exhibit variable effects, either inhibiting or accelerating the mobilization of As, depending on bulk density. At a moderate bulk density (< 1.27 g/cm3), OM slightly lowered the pH of pore water, which enhanced the sorption of As onto the iron (Fe) oxides, promoting the retention of As in soil. In the soil column with a relatively higher bulk density (1.36 g/cm3), however, the dissimilatory reduction of iron oxides was triggered by rich OM under oxygen-limited conditions. X-ray absorption spectroscopy analysis revealed that alternate wetting and drying transformed the Fe oxides in the soil by reductive dissolution and subsequent re-precipitation. Consequently, As was not stably retained in the soil, and its mobilization downwards was further accelerated.

8.
Heliyon ; 8(10): e10701, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36203906

ABSTRACT

Background: Vietnam is one of the countries most impacted by disasters in Asia- Pacific. Floods, droughts and storms are the most common catastrophes. These risks endanger millions of lives and create massive financial and production losses. Objective: This study aims at reviewing the disaster risk management (DRM) system in Vietnam, identifying progress and challenges of this system, hence making recommendations for improving the system for better responding with natural hazards. Method: The study uses PSR model (Pressure- State- Response) in combination with DRM management framework by United Nations Development Program (UNDP) to evaluate DRM system in Vietnam with 5 aspects: (i) DRM regulatory framework (ii) DRM organization (iii) DRM financial resources (iv) DRM integration in to plans at central and local levels (v) Disaster warning and education. The data collection consists of reviewing existing literature and interviewing key informants in DRM. Results: Disasters is a serious threat to Vietnam's socio economic development. To respond, Vietnam has made many efforts including develop a comprehensive legal framework for DRM which Law on Disaster Prevention and Control takes the key role. Vietnam has also established a fairly well organized DRM system from the central to local levels. The financial sources for DRM are arranged from State budget and sources outside State budget. Vietnam has developed major policies for integrating DRM into development plans centrally and locally. The disaster information and warning system is being modernized with the integration of disaster education in training programs. Challenges in DRM are identified, including institutional, financial and information issues. In addition, Vietnam is facing the increase of disasters and extreme climate events due to climate change. Covid 19 and its socio-economic consequences also lead to a lack of resources for DRM. Economic development moreover results in the decline of ecosystem-based disaster mitigation works and put more pressures on DRM. Recommendations: In the future, Vietnam should develop an information-sharing network between ministries, sectors, localities and NGOs to support the policy formulation process and enhance the coordination of multi-stakeholders. The country should also establish more proper funding allocation mechanisms to fulfill DRM's demands, especially for disaster preparedness and reconstruction phases.

9.
Article in English | MEDLINE | ID: mdl-35930519

ABSTRACT

The use of guided wave ultrasonography as a means to assess cortical bone quality has been a significant practice in bone quantitative ultrasound for more than 20 years. In this article, the key developments within the technology of ultrasonic guided waves (UGW) in long bones during the past decade are documented. The covered topics include data acquisition configurations available for measuring bone guided waveforms, signal processing techniques applied to bone UGW, numerical modeling of ultrasonic wave propagation in cortical long bones, formulation of inverse approaches to extract bone properties from observed ultrasonic signals, and clinical studies to establish the technology's application and efficacy. The review concludes by highlighting specific challenging problems and future research directions. In general, the primary purpose of this work is to provide a comprehensive overview of bone guided-wave ultrasound, especially for newcomers to this scientific field.


Subject(s)
Bone and Bones , Ultrasonics , Bone and Bones/diagnostic imaging , Cortical Bone/diagnostic imaging , Ultrasonic Waves , Ultrasonography/methods
10.
Adv Exp Med Biol ; 1364: 95-117, 2022.
Article in English | MEDLINE | ID: mdl-35508872

ABSTRACT

A new application of ultrasonography has been emerging in the bone quantitative ultrasound arena in the last twenty years: cortical bone characterization using axial transmission ultrasound (ATU). Although challenged by the complicated cortical tissue-ultrasonic wave interaction, ATU has proved to have promising potential to be a valuable diagnostic tool in the assessment of cortical bones. This chapter reviews the main landmarks of axial transmission signal processing in the past decade to provide a guide to the diversity of available techniques. In order to increase the readability of the chapter, the signal processing methods are categorized based on the experimental settings: single and multiple transmitter-receiver configuration. The review considers the key stages required for the analysis of bone guided-wave ultrasound data namely dispersion energy imaging, modal filtering, dispersion curve inversion, and measurement automation with integrated artificial intelligence concepts. Besides discussing the recent signal processing advances in the field of bone assessment by axial transmission, this communication offers developments that might be anticipated in the near future.


Subject(s)
Artificial Intelligence , Signal Processing, Computer-Assisted , Bone and Bones/diagnostic imaging , Cortical Bone/diagnostic imaging , Ultrasonography
11.
BMC Infect Dis ; 22(1): 460, 2022 May 13.
Article in English | MEDLINE | ID: mdl-35562690

ABSTRACT

BACKGROUND: With the decline in local malaria transmission in Vietnam as a result of the National Malaria Control Program (NMCP) elimination activities, a greater focus on the importation and potential reintroduction of transmission are essential to support malaria elimination objectives. METHODS: We conducted a multi-method assessment of the demographics, epidemiology, and clinical characteristics of imported malaria among international laborers returning from African or Southeast Asian countries to Vietnam. Firstly, we conducted a retrospective review of hospital records of patients from January 2014 to December 2016. Secondly, we conducted a mixed-methods prospective study for malaria patients admitted to the study sites from January 2017 to May 2018 using a structured survey with blood sample collection for PCR analysis and in-depth interviews. Data triangulation of the qualitative and quantitative data was used during analysis. RESULTS: International laborers were young (median age 33.0 years IQR 28.0-39.5 years), predominantly male (92%) adults returning mostly from the African continent (84%) who stayed abroad for prolonged periods (median time 13.5 months; IQR 6.0-331.5 months) and were involved in occupations that exposed them to a higher risk of malaria infection. Epidemiological trends were also similar amongst study strands and included the importation of Plasmodium falciparum primarily from African countries and P. vivax from Southeast Asian countries. Of 11 P. malariae and P. ovale infections across two study strands, 10 were imported from the African continent. Participants in the qualitative arm demonstrated limited knowledge about malaria prior to travelling abroad, but reported knowledge transformation through personal or co-worker's experience while abroad. Interestingly, those who had a greater understanding of the severity of malaria presented to the hospital for treatment sooner than those who did not; median of 3 days (IQR 2.0-7.0 days) versus 5 days (IQR 4.0-9.5 days) respectively. CONCLUSION: To address the challenges to malaria elimination raised by a growing Vietnamese international labor force, consideration should be given to appropriately targeted interventions and malaria prevention strategies that cover key stages of migration including pre-departure education and awareness, in-country prevention and prophylaxis, and malaria screening upon return.


Subject(s)
Malaria, Vivax , Malaria , Adult , Female , Humans , Malaria/drug therapy , Malaria/epidemiology , Malaria/prevention & control , Malaria, Vivax/epidemiology , Male , Plasmodium falciparum , Prospective Studies , Vietnam/epidemiology
12.
Article in English | MEDLINE | ID: mdl-35271439

ABSTRACT

Due to its sensitivity to geometrical and mechanical properties of waveguides, ultrasonic guided waves (UGWs) propagating in cortical bones play an important role in the early diagnosis of osteoporosis. However, as impacts of overlaid soft tissues are complex, it remains challenging to retrieve bone properties accurately. Meta-learning, i.e., learning to learn, is capable of extracting transferable features from a few data and, thus, suitable to capture potential characteristics, leading to accurate bone assessment. In this study, we investigate the feasibility to apply the multichannel identification neural network (MCINN) to estimate the thickness and bulk velocities of coated cortical bone. It minimizes the effects of soft tissue by extracting specific features of UGW, which shares the same cortical properties, while the overlaid soft tissue varies. Distinguished from most reported methods, this work moves from the hand-design inversion scheme to data-driven assessment by automatically mapping features of UGW to the space of bone properties. The MCINN was trained and validated using simulated datasets produced by the finite-difference time-domain (FDTD) method and then applied to experimental data obtained from cortical bovine bone plates overlaid with soft tissue mimics. A good match was found between experimental trajectories and theoretical dispersion curves. The results demonstrated that the proposed method was feasible to assess the thickness of coated cortical bone plates.


Subject(s)
Osteoporosis , Ultrasonics , Animals , Bone and Bones/diagnostic imaging , Cattle , Cortical Bone/diagnostic imaging , Ultrasonic Waves , Ultrasonography
13.
Med Educ Online ; 27(1): 2007577, 2022 Dec.
Article in English | MEDLINE | ID: mdl-34821211

ABSTRACT

Medical students experience extensive pressure during their undergraduate courses. Given the complex associations between psychological factors in association with academic pressure. We investigated the study with objectives: To examine psychological factors related to academic pressure by analysing interactions between 'study motivation', 'study environment', 'study conditions', 'teacher quality', 'training programme', 'management system', 'evaluation', and 'extracurricular activities' using a network analysis approach. A total of 878 medical students majoring in general medicine from the first, third, and fifth years of a six-year course at the largest medical university in central and highland regions of Vietnam were involved in this cross-sectional study. The approach used was convenient cluster sampling with a self-administered questionnaire by the participants. Network analysis for pairwise correlations between psychological factors was estimated . Important factors in the network analysis were calculated using centrality indices including node strength (S), closeness (C), and betweenness (B). The higher score of S, C, and B indicate the more importance of the node. The results obtained from the network analysis of eight psychological factors showed that 'teaching quality' was mostly connected with other factors overall, while the 'training programme' was seen in both genders and freshman students. 'Study conditions' and 'training programme' were mostly connected with other factors in junior and senior students, respectively. The strong pairwise correlation was confirmed: management system and evaluation activity, followed by study environment and study conditions, and teaching quality and training programme. Additionally, nodes with high centrality were shown to be 'management system' (S = 0.97, C = 0.019, B = 1), and 'training programme' (S = 0.96, C = 0.021, B = 4). Our study findings indicate that satisfaction with the training programme amongst eight psychological factors is the most important factor affecting academic pressure among medical students. The training programme is linked with teaching quality, whereas the management system is correlated with evaluation activity.


Subject(s)
Students, Medical , Cross-Sectional Studies , Female , Humans , Male , Motivation , Surveys and Questionnaires , Vietnam
14.
Ultrasonics ; 120: 106665, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34968990

ABSTRACT

Due to its multimode and dispersive nature, ultrasonic guided waves (UGWs) usually consist of overlapped wave packets, which challenge accurate bone characterization. To overcome this obstacle, a classic idea is to separate individual modes and to extract the corresponding dispersion curves. Reported single-channel mode separation algorithms mainly focused on offering a time-frequency representation (TFR) where the energy distributions of individual modes were apart from each other. However, such approaches are still limited to identifying the modes without significant overlapping in time-frequency domain. In this study, a spectrogram decomposition technique was developed based on a combination strategy of generalized separable nonnegative matrix factorization (GS-NMF) and adaptive basis learning, towards the automatic mode extraction under severe overlapping and low signal-to-noise ratio (SNR). The extracted modes were further used for cortical thickness estimation. The method was verified using broadband simulated and experimental datasets. Experiments were conducted on a bone-mimicking plate and bovine cortical bone plates. For simulated data, the relative errors between extracted and theoretical dispersion curves are 1.33% (SNR = ∞), 1.43% (SNR = 10 dB) and 0.88% (SNR = 5 dB). The root-mean-square errors of the estimated thickness for 3.10 mm-thick bone-mimicking plate, 3.83 mm- and 4.00 mm-thick bovine cortical bone plates are 0.039 mm, 0.049 mm, and 0.052 mm, respectively. It is demonstrated that the proposed method is capable of separating multimodal UGWs even under significantly overlapping and low SNR conditions, further facilitating the UGW-based cortical thickness assessment.


Subject(s)
Cortical Bone/diagnostic imaging , Ultrasonic Waves , Algorithms , Animals , Cattle , Phantoms, Imaging , Signal-To-Noise Ratio , Spectrum Analysis
15.
J Hazard Mater ; 422: 126957, 2022 01 15.
Article in English | MEDLINE | ID: mdl-34449352

ABSTRACT

The water and oxygen contents of the vadose zone change cyclically depending upon the meteorological condition (e.g., intermittent rainfall), which can affect the biogeochemical reactions that govern the fate of arsenic (As). To simulate and evaluate the transient behavior of As in this zone when subjected to repeated wet and dry conditions, soil column experiments with different soil properties were conducted. Three wetting-drying cycles resulted in the fluctuation of water and dissolved oxygen contents, and consequently, the reduction-oxidation potential in the soil columns. Under these circumstances, the biotic reduction of As(V) to As(III) was observed, especially in the column filled with soils enriched in organic matter. Most of the As was found to be associated with soil particles rather than to be dissolved in the pore water in all of the columns tested. Retention of As was more preferable in the soil column with a higher Fe content and bulk density, which provided more sorption sites and reaction time, respectively. However, a considerable amount of soil-bound As could be remobilized and released back to the pore water with the repetition of wetting and drying due to the transformation of As(V) to As(III).


Subject(s)
Arsenic , Soil Pollutants , Arsenic/analysis , Soil , Soil Microbiology , Soil Pollutants/analysis , Water
16.
Article in English | MEDLINE | ID: mdl-34520355

ABSTRACT

Noninvasive characterization of cortical long bones using axial transmission ultrasound is a promising diagnostic technology for osteoporotic cortical thinning assessment. However, the soft tissue-bone coupling effect remains to be a challenge and an ambiguity especially in vivo. The influence of the overlying soft tissue layer with a varying thickness on the propagation of ultrasonic guided waves in cortical bone is studied experimentally and theoretically in this article. The wave propagation is characterized based on waveform comparison, spectral density and decomposition, dispersion energy imaging, and particle displacement analysis. Good agreement between experimental observations with theoretical predictions by semi-analytical finite element simulations is observed. The sensitivity of propagation characteristics in response to the coupled tissue thickness is elucidated. As the thickness of the loading soft tissue grows, the guided wave signals exhibit greater attenuated amplitude and delayed arrival time; more complex dispersive wave patterns emerge; and the modal number and density increase. The research findings advance the fundamental comprehension of ultrasonic-guided-wave excitation and interaction in long bones and facilitate further technical development and clinical utility of quantitative guided-wave ultrasonography in routine healthcare services as a nondestructive imaging modality for cortical bone examination.


Subject(s)
Cortical Bone , Ultrasonics , Bone and Bones/diagnostic imaging , Cortical Bone/diagnostic imaging , Ultrasonic Waves , Ultrasonography
17.
Ultrason Imaging ; 43(3): 157-163, 2021 05.
Article in English | MEDLINE | ID: mdl-33840327

ABSTRACT

Ultrasonic guided wave techniques have been applied to characterize cortical bone for osteoporosis assessment. Compared with the current gold-standard X-ray-based diagnostic methods, ultrasound-based techniques pose some advantages such as compactness, low cost, lack of ionizing radiation, and their ability to detect the mechanical properties of the cortex. Axial transmission technique with a source-receiver offset is employed to acquire the ultrasound data. The dispersion characteristics of the guided waves in bones are normally analyzed in the transformed domains using the dispersion curves. The transformed domain can be time-frequency map using a single channel or wavenumber-frequency (or phase velocity-frequency) map with multi-channels. In terms of acquisition effort, the first method is more cost- and time-effective than the latter. However, it remains unclear whether single-channel dispersion analysis can provide as much quantitative guided-wave information as the multi-channel analysis. The objective of this study is to compare the two methods using numerically simulated and ex vivo data of a simple bovine bone plate and explore their advantages and disadvantages. Both single- and multi-channel signal processing approaches are implemented using sparsity-constrained optimization algorithms to reinforce the focusing power. While the single-channel data acquisition and processing are much faster than those of the multi-channel, modal identification and analysis of the multi-channel data are straightforward and more convincing.


Subject(s)
Cortical Bone , Ultrasonics , Algorithms , Animals , Cattle , Cortical Bone/diagnostic imaging , Signal Processing, Computer-Assisted , Ultrasonic Waves , Ultrasonography
18.
Sci Immunol ; 6(56)2021 02 19.
Article in English | MEDLINE | ID: mdl-33891558

ABSTRACT

Opportunities to interrogate the immune responses in the injured tissue of living patients suffering from acute sterile injuries such as stroke and heart attack are limited. We leveraged a clinical trial of minimally invasive neurosurgery for patients with intracerebral hemorrhage (ICH), a severely disabling subtype of stroke, to investigate the dynamics of inflammation at the site of brain injury over time. Longitudinal transcriptional profiling of CD14+ monocytes/macrophages and neutrophils from hematomas of patients with ICH revealed that the myeloid response to ICH within the hematoma is distinct from that in the blood and occurs in stages conserved across the patient cohort. Initially, hematoma myeloid cells expressed a robust anabolic proinflammatory profile characterized by activation of hypoxia-inducible factors (HIFs) and expression of genes encoding immune factors and glycolysis. Subsequently, inflammatory gene expression decreased over time, whereas anti-inflammatory circuits were maintained and phagocytic and antioxidative pathways up-regulated. During this transition to immune resolution, glycolysis gene expression and levels of the potent proresolution lipid mediator prostaglandin E2 remained elevated in the hematoma, and unexpectedly, these elevations correlated with positive patient outcomes. Ex vivo activation of human macrophages by ICH-associated stimuli highlighted an important role for HIFs in production of both inflammatory and anti-inflammatory factors, including PGE2, which, in turn, augmented VEGF production. Our findings define the time course of myeloid activation in the human brain after ICH, revealing a conserved progression of immune responses from proinflammatory to proresolution states in humans after brain injury and identifying transcriptional programs associated with neurological recovery.


Subject(s)
Brain/pathology , Cerebral Hemorrhage/complications , Neuroinflammatory Diseases/immunology , Adult , Aged , Brain/immunology , Cells, Cultured , Cerebral Hemorrhage/immunology , Cerebral Hemorrhage/pathology , Female , Healthy Volunteers , Hematoma , Humans , Longitudinal Studies , Macrophages/immunology , Male , Middle Aged , Neuroinflammatory Diseases/pathology , Neutrophils/immunology , Primary Cell Culture , RNA-Seq , Transcriptome/immunology
19.
Cancer Res Treat ; 53(3): 650-656, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33421977

ABSTRACT

PURPOSE: Coronavirus disease 2019 (COVID-19) pandemic has spread worldwide rapidly and patients with cancer have been considered as a vulnerable group for this infection. This study aimed to examine the expressions of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) in tumor tissues of six common cancer types. MATERIALS AND METHODS: The expression levels of ACE2 and TMPRSS2 in tumors and control samples were obtained from online databases. Survival prognosis and biological functions of these genes were investigated for each tumor type. RESULTS: There was the overexpression of ACE2 in colon and stomach adenocarcinomas compared to controls, meanwhile colon and prostate adenocarcinomas showed a significantly higher expression of TMPRSS2. Additionally, survival prognosis analysis has demonstrated that upregulation of ACE2 in liver hepatocellular carcinoma was associated with higher overall survival (hazard ratio, 0.65; p=0.016) and disease-free survival (hazard ratio, 0.66; p=0.007), while overexpression of TMPRSS2 was associated with a 26% reduced risk of death in lung adenocarcinoma (p=0.047) but 50% increased risk of death in breast invasive carcinoma (p=0.015). CONCLUSION: There is a need to take extra precautions for COVID-19 in patients with colorectal cancer, stomach cancer, and lung cancer. Further information on other types of cancer at different stages should be investigated.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19/diagnosis , Neoplasms/diagnosis , Neoplasms/genetics , Serine Endopeptidases/genetics , Adenocarcinoma/complications , Adenocarcinoma/diagnosis , Adenocarcinoma/epidemiology , Adenocarcinoma/genetics , Breast Neoplasms/complications , Breast Neoplasms/diagnosis , Breast Neoplasms/epidemiology , Breast Neoplasms/genetics , COVID-19/complications , COVID-19/epidemiology , COVID-19/genetics , Case-Control Studies , Databases as Topic , Female , Gastrointestinal Neoplasms/complications , Gastrointestinal Neoplasms/diagnosis , Gastrointestinal Neoplasms/epidemiology , Gastrointestinal Neoplasms/genetics , Gene Expression Regulation, Neoplastic , Genetic Predisposition to Disease , Humans , Liver Neoplasms/complications , Liver Neoplasms/diagnosis , Liver Neoplasms/epidemiology , Liver Neoplasms/genetics , Lung Neoplasms/complications , Lung Neoplasms/diagnosis , Lung Neoplasms/epidemiology , Lung Neoplasms/genetics , Male , Mutation , Neoplasms/complications , Neoplasms/epidemiology , Pandemics , Prognosis , Prostatic Neoplasms/complications , Prostatic Neoplasms/diagnosis , Prostatic Neoplasms/epidemiology , Prostatic Neoplasms/genetics , Retrospective Studies , SARS-CoV-2/physiology , Survival Analysis
20.
J Med Virol ; 93(2): 878-885, 2021 02.
Article in English | MEDLINE | ID: mdl-32691877

ABSTRACT

The outbreak of novel pneumonia coronavirus disease has become a public health concern worldwide. Here, for the first time, the association between Korean meteorological factors and air pollutants and the COVID-19 infection was investigated. Data of air pollutants, meteorological factors, and daily COVID-19 confirmed cases of seven metropolitan cities and nine provinces were obtained from 3 February 2020 to 5 May 2020 during the first wave of pandemic across Korea. We applied the generalized additive model to investigate the temporal relationship. There was a significantly nonlinear association between daily temperature and COVID-19 confirmed cases. Each 1°C increase in temperature was associated with 9% (lag 0-14; OR = 1.09; 95% CI = 1.03-1.15) increase of COVID-19 confirmed cases when the temperature was below 8°C. A 0.01 ppm increase in NO2 (lag 0-7, lag 0.14, and lag 0-21) was significantly associated with increases of COVID-19 confirmed cases, with ORs (95% CIs) of 1.13 (1.02-1.25), 1.19 (1.09-1.30), and 1.30 (1.19-1.41), respectively. A 0.1 ppm increase in CO (lag 0-21) was associated with the increase in COVID-19 confirmed cases (OR = 1.10, 95% CI = 1.04-1.16). There was a positive association between per 0.001 ppm of SO2 concentration (lag 0, lag 0-7, and lag 0-14) and COVID-19 confirmed cases, with ORs (95% CIs) of 1.13 (1.04-1.22), 1.20 (1.11-1.31), and 1.15 (1.07-1.25), respectively. There were significantly temporal associations between temperature, NO2 , CO, and SO2 concentrations and daily COVID-19 confirmed cases in Korea.


Subject(s)
Air Pollutants/analysis , Air Pollution/analysis , COVID-19/epidemiology , Pandemics , Particulate Matter/analysis , SARS-CoV-2/pathogenicity , COVID-19/diagnosis , Carbon Monoxide/analysis , Cities/epidemiology , Humans , Meteorology/methods , Nitrogen Dioxide/analysis , Republic of Korea/epidemiology , Sulfur Dioxide/analysis , Temperature
SELECTION OF CITATIONS
SEARCH DETAIL
...