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1.
Medicine (Baltimore) ; 102(41): e35121, 2023 Oct 13.
Article in English | MEDLINE | ID: mdl-37832057

ABSTRACT

BACKGROUND: It is rare for newly diagnosed (de novo) or newly treated acute myeloid leukemia (AML) complicated with thrombotic complications, especially combined arterial and venous thrombosis. METHODS: We reported a 13-year-old boy diagnosed with AML and leukocytosis, who developed right femoral vein and right dorsal artery thrombosis during chemotherapy. After treatment with low molecular weight heparin, diosmin, and alprostadil, symptoms were relieved. Unfortunately, the child suffered from coagulopathy afterward, which was unexpectedly caused by vitamin K deficiency. RESULTS: After supplementation with vitamin K and prothrombin complex concentrate, coagulation function recovered. CONCLUSION: For childhood AML patients with high thrombotic risks, close monitoring during anticoagulant treatment was necessary. Concomitantly, we should be alert to past medication history and combined medication use, especially those that may lead to vitamin K deficiency, secondary bleeding, and coagulation disorders. Rational use of antibiotics, anticoagulants, and antitumor drugs must be guaranteed.


Subject(s)
Blood Coagulation Disorders , Leukemia, Myeloid, Acute , Thrombosis , Vitamin K Deficiency , Male , Humans , Child , Adolescent , Femoral Vein/pathology , Anticoagulants , Thrombosis/etiology , Blood Coagulation Disorders/chemically induced , Leukemia, Myeloid, Acute/complications , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/pathology , Vitamin K Deficiency/complications , Arteries
2.
Front Pharmacol ; 14: 1283596, 2023.
Article in English | MEDLINE | ID: mdl-37808184

ABSTRACT

[This corrects the article DOI: 10.3389/fphar.2023.1239395.].

3.
BMC Pharmacol Toxicol ; 24(1): 41, 2023 08 04.
Article in English | MEDLINE | ID: mdl-37542326

ABSTRACT

BACKGROUND: drug overdose is a common type of medication error, which caused significant patient injuries and economic losses. To determine which drugs are reported most frequently in association with drug overdose, a comprehensive search was conducted in the FDA Adverse Event Reporting System (FAERS) database. The study also sought to determine the top 10 drugs reported with drug overdose. METHODS: FAERS database was searched for drug overdose records submitted from the first quarter of 2017 to the fourth quarter of 2021. Descriptive analyses were conducted based on the total counts and percentages of reports associated with the drug. Subgroup analyses were performed on drugs of different pharmacological classifications. RESULTS: A total of 170,424 drug overdose reports were retrieved. The results revealed that antipyretics and analgesics took the highest risk for overdose, with 63,143 (37.05%) cases reported. Among them, opioids were associated with the most drug overdose events. The top 10 drug classes relating to drug overdose in FAERS were opioid analgesic, anilide antipyretic analgesic, 5-HT reuptake inhibitors, bronchodilators, monoclonal antibodies and antibody-drug conjugates, benzodiazepines, antipsychotics, GABA derivatives, antimanic agents, and propionic acid derivatives. CONCLUSION: to reduce the occurrence of drug overdose events, some methods could be considered including applying a pre-prescription review system, drug safety education, developing warning lists, etc.


Subject(s)
Drug Overdose , Drug-Related Side Effects and Adverse Reactions , United States/epidemiology , Humans , Adverse Drug Reaction Reporting Systems , United States Food and Drug Administration , Medication Errors , Drug-Related Side Effects and Adverse Reactions/epidemiology , Drug Overdose/epidemiology , Analgesics , Analgesics, Opioid/adverse effects
4.
Front Pharmacol ; 14: 1239395, 2023.
Article in English | MEDLINE | ID: mdl-37601069

ABSTRACT

Acetaminophen (APAP) overdose is a significant cause of drug-induced liver injury and acute liver failure. The diagnosis, screening, and management of APAP-induced liver injury (AILI) is challenging because of the complex mechanisms involved. Starting from the current studies on the mechanisms of AILI, this review focuses on novel findings in the field of diagnosis, screening, and management of AILI. It highlights the current issues that need to be addressed. This review is supposed to summarize the recent research progress and make recommendations for future research.

5.
J Colloid Interface Sci ; 648: 558-566, 2023 Oct 15.
Article in English | MEDLINE | ID: mdl-37307612

ABSTRACT

Highly efficient electrocatalyst for carbon dioxide reduction (CO2RR) is desirable for converting CO2 into carbon-based chemicals and reducing anthropogenic carbon emission. Regulating catalyst surface to improve the affinity for CO2 and the capability of CO2 activation is the key to high-efficiency CO2RR. In this work, we develop an iron carbide catalyst encapsulated in nitrogenated carbon (SeN-Fe3C) with an aerophilic and electron-rich surface by inducing preferential formation of pyridinic-N species and engineering more negatively charged Fe sites. The SeN-Fe3C exhibits an excellent CO selectivity with a CO Faradaic efficiency (FE) of 92 % at -0.5 V (vs. RHE) and remarkably enhanced CO partial current density as compared to the N-Fe3C catalyst. Our results demonstrate that Se doping reduces the Fe3C particle size and improves the dispersion of Fe3C on nitrogenated carbon. More importantly, the preferential formation of pyridinic-N species induced by Se doping endows the SeN-Fe3C with an aerophilic surface and improves the affinity of the SeN-Fe3C for CO2. Density functional theory (DFT) calculations reveal that the electron-rich surface, which is caused by pyridinic N species and much more negatively charged Fe sites, leads to a high degree of polarization and activation of CO2 molecule, thus conferring a remarkably improved CO2RR activity on the SeN-Fe3C catalyst.

6.
Am J Clin Nutr ; 118(2): 360-368, 2023 08.
Article in English | MEDLINE | ID: mdl-37269908

ABSTRACT

BACKGROUND: Tree nuts and peanuts (henceforth, nuts) are nutrient-dense foods rich in neuroprotective components; thus, their consumption could benefit cognitive health. However, evidence to date is limited and inconsistent regarding the potential benefits of nuts for cognitive function. OBJECTIVE: To prospectively evaluate the association between nut consumption and 2-y changes in cognitive performance in older adults at cognitive decline risk. METHODS: A total of 6,630 participants aged 55 to 75 y (mean age 65.0±4.9 y, 48.4% women) with overweight/obesity and metabolic syndrome completed a validated semi-quantitative food frequency questionnaire and a comprehensive battery of neuropsychological tests at baseline and a 2-y follow-up. Composite cognitive scores were used to assess global, general, attention, and executive function domains. Nut consumption was categorized as <1, ≥1 to <3, ≥3 to <7, and ≥7 servings/wk (1 serving=30 g). Multivariable-adjusted linear regression models were fitted to assess associations between baseline nut consumption and 2-y cognitive changes. RESULTS: Nut consumption was positively associated with 2-y changes in general cognitive function (P-trend <0.001). Compared with participants consuming <1 serving/wk of nuts, those categorized as consuming ≥3 to <7 and ≥7 servings/wk showed more favorable changes in general cognitive performance (ß z-score [95% CI] = 0.06 [0.00,0.12] and 0.13 [0.06,0.20], respectively). No significant changes were observed in the multivariable-adjusted models for other cognitive domains assessed. CONCLUSION: Frequent nut consumption was associated with a smaller decline in general cognitive performance over 2 y in older adults at risk of cognitive decline. Randomized clinical trials to verify our findings are warranted.


Subject(s)
Cognitive Dysfunction , Nuts , Humans , Female , Aged , Middle Aged , Male , Cohort Studies , Prospective Studies , Cognitive Dysfunction/prevention & control , Cognition , Risk Factors
7.
BMC Health Serv Res ; 23(1): 652, 2023 Jun 19.
Article in English | MEDLINE | ID: mdl-37331932

ABSTRACT

BACKGROUND: Tyrosine kinase inhibitors combined with conventional chemotherapy (CC) in treating Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) has achieved promising efficacy and safety outcomes. The study was conducted to compare the cost-effectiveness between imatinib (HANSOH Pharma, Jiangsu, China) and dasatinib (CHIATAI TIANQING Pharma, Jiangsu, China) in treating pediatric Ph-positive ALL when combined with CC from the perspective of the health system in China. METHODS: A Markov model was established to simulate a hypothetical cohort of pediatric Ph-positive ALL patients receiving imatinib or dasatinib, combined with CC. The model was designed using a 10-year horizon, a 3- month cycle, and a 5% discount rate. Three health states were included: alive with progression-free survival, progressed disease, and death. Patient characteristics and transition probabilities were estimated based on clinical trials. Other relevant data, such as direct treatment costs and health utility data were extracted from published literature and Sichuan Province's centralized procurement and supervision platform. One-way sensitivity analysis and probabilistic sensitivity analysis were performed to assess the robustness of the results. The willingness-to-pay (WTP) was set as three times China's GDP per capita in 2021. RESULTS: In the base-case analysis, the total medical costs were $89,701 and $101,182, and the quality-adjusted life years (QALYs) gained were 1.99 and 2.70, for imatinib and dasatinib regimens, respectively. The incremental cost-effectiveness ratio for dasatinib versus imatinib was $16,170/QALY. The probabilistic sensitivity analysis indicated that treatment with dasatinib combined with CC achieved a 96.4% probability of cost-effectiveness at a WTP threshold of $37,765/QALY. CONCLUSIONS: Dasatinib combined with CC is likely to be a cost-effective strategy compared to imatinib combination therapy for pediatric Ph-positive ALL in China at a WTP threshold of $37,765/QALY.


Subject(s)
Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Humans , Child , Imatinib Mesylate/therapeutic use , Dasatinib/therapeutic use , Cost-Effectiveness Analysis , Philadelphia Chromosome , Pyrimidines/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Cost-Benefit Analysis , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy
8.
Front Public Health ; 11: 990181, 2023.
Article in English | MEDLINE | ID: mdl-37033079

ABSTRACT

Objective: To analyze the inpatient cost of hematopoietic stem cell transplantation (HSCT) in children, so as to support clinical decision-making. Methods: Study population were children who received HSCT in a tertiary children's hospital (Sichuan, China) between 1st January 2020 and 31st December 2021. The median and interquartile range (IQR) of total cost at 100 days post transplantation were calculated. Subgroup analyses were conducted based on age, gender, transplantation types, and post-transplant complications. The cost differences between subgroups were analyzed to determine whether it had an impact on the total costs. Results: A total of 142 pediatric patients were included in the study with a total cost of 250721.78 yuan (197019.16-315740.52, 1 yuan equals to around 0.15 US dollars). Drug costs accounted for 51.85% of the total cost, followed by medical service costs (12.57%) and treatment expenses (12.24%). In terms of transplantation types, the cost of autologous transplantation was lower than that of allogeneic transplantation (115722.98 yuan vs. 256043.99 yuan, p < 0.05), and the cost of human leukocyte antigen (HLA) complete matched was lower compared with that of partial matched (213760.88 yuan vs. 294044.84 yuan, p < 0.05). As for post-transplant complications, cases with <3 types of complications cost less than those with ≥3 types (212893.25 yuan vs. 286064.60 yuan, p < 0.05), and those with severity ≤ grade 2 cost less than those > grade 2 (235569.37 yuan vs. 280061.58 yuan, p < 0.05). Age and gender of patients did not lead to statistical differences in the total cost, while the transplantation types and post-transplant complications influenced the total cost. Conclusion: The total cost at 100 days post transplantation associated with HSCT treatment were substantial for pediatric patients. The HLA compatibility between donors and recipients, and post-transplant complications were important factors affecting the total cost.


Subject(s)
Hematopoietic Stem Cell Transplantation , Humans , Child , Costs and Cost Analysis , Transplantation, Homologous/adverse effects , Transplantation, Autologous/adverse effects , Hematopoietic Stem Cell Transplantation/adverse effects , China/epidemiology
9.
Chemistry ; 28(66): e202201747, 2022 Nov 25.
Article in English | MEDLINE | ID: mdl-36058891

ABSTRACT

Bismuth-oxygen moieties are beneficial for high-efficiency electrochemical CO2 reduction (CO2 RR) to produce formate; however, preserving bismuth-oxygen moieties while applying a cathodic potential is challenging. This work reports the preparation of ultrathin Bi2 O2 O/Bi2 O2 (OH)(NO3 ) nanosheets (BiON-uts) by in-situ tailoring of hydrogen bonds in a Bi2 O2 (OH)(NO3 ) precursor. The BiON-uts exhibits a formate faradaic efficiency of 98 % with higher partial current density than that of most reported bismuth-based catalysts. Mechanistic studies demonstrate that the ultrathin nanosheet morphology facilitates ion-exchange between BiON-uts and the electrolyte to produce Bi2 O2 CO3 as intermediate, and adsorption of CO2 with surface Bi2 O2 O. DFT calculations reveal that the rate-limiting first electron transfer is effectively improved by the high electron affinity of Bi2 O2 CO3 . More importantly, high-efficiency CO2 RR in turn protects the bismuth-oxygen moieties from being reduced and thus helps to maintain the excellent CO2 RR activity. This work offers an interactive mechanism of CO2 RR promotion and bismuth-oxygen moiety preservation, opening up new opportunities for developing high-performance catalysts.

10.
Paediatr Drugs ; 24(5): 447-464, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35771411

ABSTRACT

BACKGROUND: The results of animal experiments show that quinolone antibacterial drugs may permanently damage the soft tissues of the weight-bearing joints of young animals. Out of safety concerns, using quinolones in children has always been controversial. OBJECTIVE: The aim of this study was to assess the risk of using quinolones in children and provide evidence for clinicians to support decision making. DATA SOURCES: The MEDLINE (Ovid), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), International Pharmaceutical Abstracts (Ovid), CINAHL, CNKI, VIP, and WanFang Data databases were searched from inception to 8 September 2021. STUDY SELECTION: All types of studies that reported the safety data of quinolones in children, including clinical trials and observational studies. DATA EXTRACTION: Data extraction and cross-checking were completed by two independent reviewers using a pilot-tested standardized data extraction form. RESULTS: The overall incidence rate of adverse drug events (ADEs) in children using systemic quinolones was 5.39% and the most common ADEs were gastrointestinal reactions (incidence rate, 2.02%). Quinolone-induced musculoskeletal ADEs in children were uncommon (0.76%). Meta-analysis results showed that the risk of musculoskeletal ADEs in children using quinolones was higher than children in the control group (51 studies; rate ratio [RR] 2.03, 95% confidence interval [CI] 1.82-2.26; p < 0.001; I2 = 18.6%; moderate-quality evidence). However, the subgroup analysis results showed that differences might only be observed in children who were followed up for 2 months to 1 year (2-6 months: RR 2.56, 95% CI 2.26-2.89; 7 months to 1 year: RR 1.35, 95% CI 0.98-1.86). Moreover, children (adolescents) aged between 13 and 18 years might be sensitive to the musculoskeletal toxicity of quinolones (RR 2.69, 95% CI 2.37-3.05; moderate-quality evidence) and the risk of levofloxacin-induced musculoskeletal ADEs might be higher (RR 1.33, 95% CI 1.00-1.77; low-quality evidence). CONCLUSIONS: Although the existing evidence shows that quinolone-induced musculoskeletal ADEs seem to be only short-term and reversible, and no serious skeletal and muscular system damage cases have been reported in children, quinolones should be avoided unless necessary in children because the incidence rate of quinolone-related ADEs is not low and they are broad-spectrum antibiotics that will induce the emergence of resistant strains if used frequently.


Subject(s)
Quinolones , Anti-Bacterial Agents/adverse effects , Humans , Quinolones/adverse effects
11.
Front Pediatr ; 10: 923297, 2022.
Article in English | MEDLINE | ID: mdl-35757138

ABSTRACT

Acute lymphoblastic leukemia (ALL) presenting with hypercalcemia and osteolytic lesions is rare and unusual in childhood. We report a case of a 13-year-old boy with ALL who presented with intermittent fever, nausea, vomiting, and increasing lower limb pain. Skeletal X-rays and CT scan showed severe osteolytic lesions of the skull and extremities. Physical examination revealed multiple inguinal lymph nodes. Laboratory tests demonstrated severe hypercalcemia (Ca > 3.49 mmol/L), decreased parathyroid hormone (PTH), and vitamin D level. Despite a normal complete blood count and the absence of circulating blasts, bone marrow biopsy revealed B-precursor ALL. Hypercalcemia was initially treated with intravenous isotonic sodium chloride and furosemide but the serum calcium level was not normalized. It was successfully managed with calcitonin and pamidronate afterward. Later, the child responded well to chemotherapy and continued with consolidation treatment. The clinical condition was stable, and the bone marrow revealed complete remission. This case indicated that hypercalcemia alone or combined with osteolytic lesions can be the only presenting symptom of ALL in children. Diagnostic errors may occur especially when combined with the absence of circulating blasts in the peripheral blood smear. Bone marrow aspiration should be considered to confirm the diagnosis.

12.
J Clin Med ; 11(12)2022 Jun 16.
Article in English | MEDLINE | ID: mdl-35743546

ABSTRACT

Impulsivity has been associated with type 2 diabetes (T2D) and may negatively impact its management. This study aimed to investigate impulsive personality traits in an older adult population with T2D and their predicting role in long-term weight control and glycemic management, through glycated hemoglobin (HbA1c), following 3 years of intervention with a Mediterranean diet. The Impulsive Behavior Scale (UPPS-P) was administered as a measure of impulsive traits at baseline. Results showed higher total baseline scores of UPPS-P, and higher positive urgency in individuals with T2D, compared with those without T2D. The regression analysis in patients with T2D showed that sensation seeking and lack of perseverance predicted weight loss at follow-up. By contrast, impulsive traits did not predict follow-up levels of HbA1c. In conclusion, the present findings suggest that higher impulsive traits in individuals with T2D seem to affect long-term weight control, but not glycemic control.

13.
Mol Nutr Food Res ; 66(14): e2101058, 2022 07.
Article in English | MEDLINE | ID: mdl-35524484

ABSTRACT

SCOPE: Dairy consumption has been suggested to impact cognition; however, evidence is limited and inconsistent. This study aims to longitudinally assess the association between dairy consumption with cognitive changes in an older Spanish population at high cardiovascular disease risk. METHODS AND RESULTS: Four thousand six hundred sixty eight participants aged 55-75 years, completed a validated food frequency questionnaire at baseline and a neuropsychological battery of tests at baseline and 2-year follow-up. Multivariable linear regression models are used, scaled by 100 (i.e., the units of ß correspond to 1 SD/100), to assess associations between baseline tertile daily consumption and 2-year changes in cognitive performance. Participants in the highest tertile of total milk and whole-fat milk consumption have a greater decline in global cognitive function (ß: -4.71, 95% CI: -8.74 to -0.69, p-trend = 0.020 and ß: -6.64, 95% CI: -10.81 to -2.47, p-trend = 0.002, respectively) compared to those in the lowest tertile. No associations are observed between low fat milk, yogurt, cheese or fermented dairy consumption, and changes in cognitive performance. CONCLUSION: Results suggest there are no clear prospective associations between consumption of most commonly consumed dairy products and cognition, although there may be an association with a greater rate of cognitive decline over a 2-year period in older adults at high cardiovascular disease risk for whole-fat milk.


Subject(s)
Cardiovascular Diseases , Cognition , Dairy Products , Aged , Animals , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/etiology , Cohort Studies , Female , Humans , Male , Middle Aged , Milk , Risk Factors , Yogurt
14.
Front Public Health ; 10: 879289, 2022.
Article in English | MEDLINE | ID: mdl-35493378

ABSTRACT

Background: A study of the current situation and characteristics of hepatitis B virus (HBV) infection among Chinese pregnant women is meaningful to provide baseline information for future research and policy making, with an aim to eliminate HBV in China. Objectives: To provide the epidemiological status of HBV infection among pregnant women in China. Methods: PubMed, EMbase, The Cochrane Library, and three Chinese databases were searched. Cohort studies and cross-sectional studies on HBV prevalence in Chinese pregnant women, published after 2016, were retrieved. In addition, combined HBV prevalence and 95% confidence interval (CI) were calculated. This research was registered in PROSPERO (CRD42021289123). Main Results: A total of 42 studies were included in the study, with a sample size of 4,007,518 cases, and 20 provinces in China. The prevalence of HBV in Chinese pregnant women was 6.64% (95% CI: 5.72-7.57%) during the period between 2016 and 2021. Among HBsAg positive pregnant women, the HBeAg positive rate was 25.80% (95% CI: 22.26-29.69%). Moreover, geographic regions with HBV prevalence ranking from high to low were in western China, eastern China, and central China, successively. Conclusion: The prevalence of HBV in Chinese pregnant women is intermediate endemic, although disparities exist between different regions. Among pregnant women with HBV infection, a high proportion of the patients have strong infectivity. Factors affecting HBV prevalence remain controversial, which demands further studies. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021289123.


Subject(s)
Hepatitis B , Pregnancy Complications, Infectious , China/epidemiology , Cross-Sectional Studies , Female , Hepatitis B/epidemiology , Hepatitis B Surface Antigens , Hepatitis B virus , Humans , Pregnancy , Pregnancy Complications, Infectious/epidemiology , Pregnant Women
15.
Front Aging Neurosci ; 13: 782067, 2021.
Article in English | MEDLINE | ID: mdl-34966270

ABSTRACT

Background and Aims: Plant-forward dietary patterns have been associated with cardiometabolic health benefits, which, in turn, have been related to cognitive performance with inconsistent findings. The objective of this study was to examine the relationship between baseline adherence to three a priori dietary patterns (Mediterranean, DASH, and MIND diets) with 2-year changes in cognitive performance in older adults with overweight or obesity and high cardiovascular disease risk. Methods: A prospective cohort analysis was conducted within the PREDIMED-Plus trial, involving 6,647 men and women aged 55-75 years with overweight or obesity and metabolic syndrome. Using a validated, semiquantitative 143-item food frequency questionnaire completed at baseline, the dietary pattern adherence scores were calculated. An extensive neuropsychological test battery was administered at baseline and 2-year follow-up. Multivariable-adjusted linear regression models were used to assess associations between 2-year changes in cognitive function z-scores across tertiles of baseline adherence to the a priori dietary patterns. Results: Adherence to the Mediterranean diet at baseline was associated with 2-year changes in the general cognitive screening Mini-Mental State Examination (MMSE, ß: 0.070; 95% CI: 0.014, 0.175, P-trend = 0.011), and two executive function-related assessments: the Trail Making Tests Part A (TMT-A, ß: -0.054; 95% CI: -0.110, - 0.002, P-trend = 0.047) and Part B (TMT-B, ß: -0.079; 95% CI: -0.134, -0.024, P-trend = 0.004). Adherence to the MIND diet was associated with the backward recall Digit Span Test assessment of working memory (DST-B, ß: 0.058; 95% CI: 0.002, 0.114, P-trend = 0.045). However, higher adherence to the DASH dietary pattern was not associated with better cognitive function over a period of 2 years. Conclusion: In older Spanish individuals with overweight or obesity and at high cardiovascular disease risk, higher baseline adherence to the Mediterranean dietary pattern may be associated with better cognitive performance than lower adherence over a period of 2 years.

16.
Appl Opt ; 60(22): 6400-6408, 2021 Aug 01.
Article in English | MEDLINE | ID: mdl-34612874

ABSTRACT

Terahertz (THz) testing, by the frequency modulated continuous wave (FMCW) system, is often hampered by the limited range resolution. Thus, in this paper, a software method is proposed to reconstruct the range profile, yielding significant improvements in range resolution and in signal parameter extraction. Specifically, the multiple signal characterization algorithm is first introduced to indicate a higher-resolution range profile qualitatively and to acquire the echoes' initial values. Then, multiple Gaussian functions are applied to fit those echoes in the whole original range profile and to accurately extract the parameters, including the amplitude, range, and width, of each echo. Finally, with these parameters, the range profile can be more precisely and flexibly reconstructed, facilitating the following detection procedure to a great extent. Both the simulated and the real THz data, acquired by a 150-220 GHz FMCW imager, have been used to demonstrate the superiority and effectiveness of our method, qualitatively and quantitatively.

17.
Opt Express ; 28(15): 22200-22217, 2020 Jul 20.
Article in English | MEDLINE | ID: mdl-32752486

ABSTRACT

During the real-aperture-scanning imaging process, terahertz (THz) images are often plagued with the problem of low spatial resolution. Therefore, an accommodative super-resolution framework for THz images is proposed. Specifically, the 3D degradation model for the imaging system is firstly proposed by incorporating the focused THz beam distribution, which determines the relationship between the imaging range and the corresponding image restoration level. Secondly, an adjustable CNN is introduced to cope with this range dependent super-resolution problem. By simply tuning an interpolation parameter, the network can be adjusted to produce arbitrary restoration levels between the trained fixed levels without extra training. Finally, by selecting the appropriate interpolation coefficient according to the measured imaging range, each THz image can be coped with its matched network and reach the outstanding super-resolution effect. Both the simulated and real tested data, acquired by a 160 ∼ 220 GHz imager, have been used to demonstrate the superiority of our method.

18.
Materials (Basel) ; 12(8)2019 Apr 24.
Article in English | MEDLINE | ID: mdl-31022986

ABSTRACT

Understanding the mechanism of hydrogen embrittlement (HE) of austenitic steels and developing an effective strategy to improve resistance to HE are of great concern but challenging. In this work, first-principles studies were performed to investigate the HE mechanism and the improved resistance of Al-containing austenite to HE. Our results demonstrate that interstitial hydrogen atoms have different site preferences in Al-free and Al-containing austenites. The calculated binding energies and diffusion barriers of interstitial hydrogen atoms in Al-containing austenite are remarkably higher than those in Al-free austenite, indicating that the presence of Al is more favorable for reducing hydrogen mobility. In Al-free austenite, interstitial hydrogen atoms caused a remarkable increase in lattice compressive stress and a distinct decrease in bulk, shear, and Young's moduli. Whereas in Al-containing austenite, the lattice compressive stress and the mechanical deterioration induced by interstitial hydrogen atoms were effectively suppressed.

19.
Molecules ; 24(3)2019 Jan 29.
Article in English | MEDLINE | ID: mdl-30700034

ABSTRACT

Developing antioxidants with high efficiency is fundamentally important for the protection of living cells and engineering materials against oxidative damage. In this present study, two azocalix[4]arene derivatives were synthesized via a diazo coupling reaction between calix[4]arene and diazonium salts. Their antiradical and antioxidative performances were evaluated by hydroxyl radical scavenging and pyrogallol autoxidation inhibition experiments. Combined with theoretical studies, the antiradical and antioxidative mechanisms have been explored. The results demonstrated that these two azocalix[4]arene derivatives both exhibited remarkable antiradical and antioxidative activity. The macrocyclic framework of the calix[4]arene and para-azo substituent group at the upper rim of calix[4]arene contributed synergistically and importantly to its excellent antiradical and antioxidant activity.


Subject(s)
Antioxidants/chemistry , Antioxidants/pharmacology , Calixarenes/pharmacology , Models, Molecular , Oxidation-Reduction/drug effects
20.
Materials (Basel) ; 11(5)2018 May 16.
Article in English | MEDLINE | ID: mdl-29772669

ABSTRACT

Hypereutectic Al⁻Si (20 wt.%) alloy parts were fabricated by employing a powder injection moulding (PIM) technique with a developed multi-component binder system composed of high-density polyethylene (35 wt.%), carnauba wax (62 wt.%) and stearic acid (3 wt.%). The feedstocks contained 83 wt.% metal powders. The debinding process was carried out by a combination of solvent extraction and thermal decomposition. The effects of solvent debinding variables such as kind of solvents, debinding temperatures and time, and the bulk surface area to volume ratios on the debinding process were investigated. Thermal debinding and the subsequent sintering process were carried out in a heating sequence under a nitrogen atmosphere. The influences of sintering temperature and sintering time on the mechanical properties and structure were considered. Under the optimal sintering condition, sintering at 550 °C for 3 h, the final sintering parts were free of distortion and exhibited good mechanical properties. Relative sintered density, Brinell hardness, and tensile strength were ~95.5%, 58 HBW and ~154, respectively.

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