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1.
Nature ; 629(8014): 1091-1099, 2024 May.
Article in English | MEDLINE | ID: mdl-38750363

ABSTRACT

The baobab trees (genus Adansonia) have attracted tremendous attention because of their striking shape and distinctive relationships with fauna1. These spectacular trees have also influenced human culture, inspiring innumerable arts, folklore and traditions. Here we sequenced genomes of all eight extant baobab species and argue that Madagascar should be considered the centre of origin for the extant lineages, a key issue in their evolutionary history2,3. Integrated genomic and ecological analyses revealed the reticulate evolution of baobabs, which eventually led to the species diversity seen today. Past population dynamics of Malagasy baobabs may have been influenced by both interspecific competition and the geological history of the island, especially changes in local sea levels. We propose that further attention should be paid to the conservation status of Malagasy baobabs, especially of Adansonia suarezensis and Adansonia grandidieri, and that intensive monitoring of populations of Adansonia za is required, given its propensity for negatively impacting the critically endangered Adansonia perrieri.


Subject(s)
Adansonia , Phylogeny , Madagascar , Adansonia/genetics , Conservation of Natural Resources , Genome, Plant , Biodiversity , Endangered Species , Population Dynamics
2.
Diabetes Metab Syndr ; 18(3): 102992, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38560956

ABSTRACT

AIMS: Type 2 diabetes (T2D), a prevalent cardiovascular disease, is linked with cardiac arrhythmias such as atrial fibrillation (AF) and ventricular arrhythmia. This study evaluated T2D's impact on these arrhythmias in patients with obstructive hypertrophic cardiomyopathy (OHCM). METHODS AND MATERIALS: We retrospectively analyzed the data of 75 patients with OHCM and T2D from two medical centers in China from 2011 to 2020. A propensity score-matched cohort of 150 patients without T2D was also analyzed. RESULTS: Altogether, 225 patients were included. The prevalence of supraventricular tachycardia (SVT), AF, and non-sustained ventricular tachycardia (NSVT) was higher in patients with HCM and T2D than in those without T2D. Multivariate logistic regression showed T2D as an independent risk factor for SVT (odds ratio [OR] = 1.90, 95% confidence interval [CI] = 1.01-3.58, P = 0.04), AF (OR = 2.68, 95% CI = 1.27-5.67, P = 0.01), and NSVT (OR = 2.18, 95% CI = 1.04-4.57, P = 0.04). Further analysis identified fasting glucose and glycosylated hemoglobin levels as independent risk factors for AF and NSVT in patients with T2D. CONCLUSIONS: T2D independently increases the risk of cardiac arrhythmias (SVT, AF, NSVT) in OHCM patients. Furthermore, fasting glucose and glycosylated hemoglobin levels independently heighten AF and NSVT risk in OHCM patients with T2D.


Subject(s)
Arrhythmias, Cardiac , Cardiomyopathy, Hypertrophic , Diabetes Mellitus, Type 2 , Humans , Diabetes Mellitus, Type 2/complications , Male , Female , Cardiomyopathy, Hypertrophic/complications , Cardiomyopathy, Hypertrophic/epidemiology , Middle Aged , Retrospective Studies , Arrhythmias, Cardiac/etiology , Arrhythmias, Cardiac/epidemiology , Follow-Up Studies , Risk Factors , Prognosis , China/epidemiology , Aged , Adult
3.
Bioorg Chem ; 147: 107369, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38640721

ABSTRACT

Non-alcoholic fatty liver disease (NAFLD) is a complex pathogenic metabolic syndrome characterized by increased inflammation and endoplasmic reticulum stress. In recent years, natural polysaccharides derived from traditional Chinese medicine have shown significant anti-inflammatory effects, making them an attractive therapeutic option. However, little research has been conducted on the therapeutic potential of dried tangerine peel polysaccharide (DTPP) - one of the most important medicinal resources in China. The results of the present study showed that DTPP substantially reduced macrophage infiltration in vivo and suppressed the expression of pro-inflammatory factors and endoplasmic reticulum stress-related genes. Additionally, surface plasmon resonance analysis revealed that DTPP had a specific affinity to myeloid differentiation factor 2, which consequently suppressed lipopolysaccharide-induced inflammation via interaction with the toll-like receptor 4 signaling pathway. This study provides a potential molecular mechanism underlying the anti-inflammatory effects of DTPP on NAFLD and suggests DTPP as a promising therapeutic strategy for NAFLD treatment.


Subject(s)
Endoplasmic Reticulum Stress , Inflammation , Polysaccharides , Toll-Like Receptor 4 , Toll-Like Receptor 4/metabolism , Toll-Like Receptor 4/antagonists & inhibitors , Polysaccharides/pharmacology , Polysaccharides/chemistry , Animals , Endoplasmic Reticulum Stress/drug effects , Mice , Inflammation/drug therapy , Inflammation/metabolism , Lymphocyte Antigen 96/antagonists & inhibitors , Lymphocyte Antigen 96/metabolism , Carthamus tinctorius/chemistry , Mice, Inbred C57BL , Molecular Structure , Dose-Response Relationship, Drug , Structure-Activity Relationship , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/pathology , Non-alcoholic Fatty Liver Disease/metabolism , Humans , Lipopolysaccharides/antagonists & inhibitors , Lipopolysaccharides/pharmacology , Male , RAW 264.7 Cells , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/chemistry
4.
BMC Med ; 22(1): 86, 2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38413945

ABSTRACT

BACKGROUND: Myocardial bridging (MB) is common in patients with hypertrophic cardiomyopathy (HCM). There are sparse data on the impact of MB on myocardial fibrosis in HCM. This study was designed to evaluate the relationship between MB and myocardial fibrosis in patients with obstructive HCM. METHODS: In this cohort study, retrospective data were collected from a high-volume HCM center. Patients with obstructive HCM who underwent septal myectomy and preoperative cardiac magnetic resonance (CMR) were screened from 2011 to 2018. RESULTS: Finally, 492 patients were included in this study, with an average age of 45.7 years. Of these patients, 76 patients had MB. MB occurred mostly in the left anterior descending artery (73/76). The global extent of late gadolinium enhancement (LGE) was correlated with the degree of systolic compression (r = 0.33, p = 0.003). Multivariable linear regression analysis revealed that the degree of systolic compression was an independent risk factor for LGE (ß = 0.292, p = 0.007). The LGE fraction of basal and mid anteroseptal segments in patients with severe MB (compression ratio ≥ 80%) was significantly greater than that in patients with mild to moderate MB (compression ratio < 80%). During a median follow-up of 28 (IQR: 15-52) months, 15 patients died. Kaplan-Meier analysis did not identify differences in all-cause death (log-rank p = 0.63) or cardiovascular death (log-rank p = 0.72) between patients undergoing MB-related surgery and those without MB. CONCLUSIONS: MB with severe systolic compression was significantly associated with a high extent of fibrosis in patients with obstructive HCM. Concomitant myotomy or coronary artery bypass grafting might provide excellent survival similar to that of patients without MB. Identification of patients with severe MB and providing comprehensive management might help improve the prognosis of patients with HCM.


Subject(s)
Cardiomyopathy, Hypertrophic , Myocardial Bridging , Humans , Middle Aged , Myocardium/pathology , Contrast Media , Retrospective Studies , Cohort Studies , Myocardial Bridging/complications , Myocardial Bridging/diagnostic imaging , Myocardial Bridging/pathology , Gadolinium , Cardiomyopathy, Hypertrophic/complications , Cardiomyopathy, Hypertrophic/diagnostic imaging , Cardiomyopathy, Hypertrophic/surgery , Fibrosis , Risk Factors
5.
Micromachines (Basel) ; 14(12)2023 Dec 05.
Article in English | MEDLINE | ID: mdl-38138375

ABSTRACT

We investigate the plasmon coupling of gold nanoparticle (AuNP) dimers dispersed in a nematic liquid crystal matrix using the polarization z-scan technique. Our experimental setup includes the precise control of incident light polarization through polarization angles of 0°, 45°, and 90°. Two distinct cell orientations are examined: parallel and twisted nematic cells. In parallel-oriented cells, where liquid crystal molecules and AuNPs align with the rubbing direction, we observe a remarkable 2-3-fold increase in the nonlinear absorption coefficient when the polarization of the incident light is parallel to the rubbing direction. Additionally, a linear decrease in the third-order nonlinear absorption coefficient is noted as the polarization angle varies from 0° to 90°. In the case of twisted nematic cells, the NPs do not have any preferred orientation, and the enhancement remains consistent across all polarization angles. These findings conclusively establish that the observed enhancement in the nonlinear absorption coefficient is a direct consequence of plasmon coupling, shedding light on the intricate interplay between plasmonic nanostructures and liquid crystal matrices.

6.
Nano Lett ; 23(20): 9555-9562, 2023 Oct 25.
Article in English | MEDLINE | ID: mdl-37787483

ABSTRACT

The effective design and construction of high-performance methanol oxidation reaction (MOR) electrocatalysts are significant for the development of direct methanol fuel cells. But the active sites of the MOR electrocatalysts are susceptible to being poisoned by CO, resulting in poor durability. Herein, we report an atomically dispersed CrOX species anchored on Pd metallene through bridging O atoms. This catalyst shows an outstanding MOR performance with 7 times higher mass activity and 100 mV lower CO electrooxidation potential than commercial Pd/C. The results of operando electrochemical Fourier transform infrared spectroscopy demonstrate the rapid removal of CO* on CrOX-Pd metallene. Theoretical calculations reveal that atomically dispersed CrOX can lower the adsorption energy of CO* on Pd sites and enhance that of OH* through the formation of a hydrogen bond, decreasing the formation energy of COOH*. This work provides a new strategy for improving MOR performance via atomically engineering oxide/metal interfaces.

7.
Mech Ageing Dev ; 216: 111879, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37832833

ABSTRACT

Hutchinson-Gilford progeria syndrome (HGPS), also known as hereditary progeria syndrome, is caused by mutations in the LMNA gene and the expression of progerin, which causes accelerated aging and premature death, with most patients dying of heart failure or other cardiovascular complications in their teens. HGPS patients are able to exhibit cardiovascular phenotypes similar to physiological aging, such as extensive atherosclerosis, smooth muscle cell loss, vascular lesions, and electrical and functional abnormalities of the heart. It also excludes the traditional risk causative factors of cardiovascular disease, making HGPS a new model for studying aging-related cardiovascular disease. Here, we analyzed the pathogenesis and pathophysiological characteristics of HGPS and the relationship between HGPS and cardiovascular disease, provided insight into the molecular mechanisms of cardiovascular disease pathogenesis in HGPS patients and treatment strategies for this disease. Moreover, we summarize the disease models used in HGPS studies to improve our understanding of the pathological mechanisms of cardiovascular aging in HGPS patients.


Subject(s)
Atherosclerosis , Cardiovascular Diseases , Cardiovascular System , Progeria , Humans , Adolescent , Progeria/genetics , Progeria/therapy , Progeria/metabolism , Cardiovascular Diseases/genetics , Cardiovascular Diseases/therapy , Aging/metabolism , Atherosclerosis/pathology , Cardiovascular System/metabolism
8.
Cardiol Rev ; 2023 Oct 09.
Article in English | MEDLINE | ID: mdl-37812010

ABSTRACT

Sudden cardiac death is the most unpredictable and devastating consequence of hypertrophic cardiomyopathy, most often caused by persistent ventricular tachycardia or ventricular fibrillation. Although myocardial hypertrophy, fibrosis, and microvascular disorders are the main mechanisms of persistent reentrant ventricular arrhythmias in patients with advanced hypertrophic cardiomyopathy, the cardiomyocyte mechanism based on ion channel abnormalities may play an important role in the early stages of the disease.

9.
Materials (Basel) ; 16(18)2023 Sep 07.
Article in English | MEDLINE | ID: mdl-37763380

ABSTRACT

Quenching and partitioning (Q&P) steel has garnered attention as a promising third-generation automotive steel. While the conventional production (CP) method for Q&P steel involves a significant cumulative cold rolling reduction rate (CRRR) of 60-70%, the thin slab casting and rolling (TSCR) process has emerged as a potential alternative to reduce or eliminate the need for cold rolling, characterized with a streamline production chain, high-energy efficiency, mitigated CO2 emission and economical cost. However, the effect of the CRRR on the microstructure and properties of Q&P steel with an initial ferrite-pearlite microstructure has been overlooked, preventing the extensive application of TSCR in producing Q&P steel. In this work, investigations involving different degrees of CRRRs reveal a direct relationship between increased reduction and decreased yield strength and plasticity. Notably, changes in the microstructure were observed, including reduced size and proportion of martensite blocks, increased ferrite proportion and decreased retained austenite content. The decrease in yield strength was primarily attributed to the increased proportion of the softer ferrite phase, while the reduction in plasticity was primarily linked to the decrease in retained austenite content. This study provides valuable insights for optimizing the TSCR process of Q&P steel, facilitating its wider adoption in the automotive sector.

10.
Arch Esp Urol ; 76(6): 467-474, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37681339

ABSTRACT

OBJECTIVE: The expression of vascular endothelial growth factor-A (VEGF-A) in snakebite patients, its value in patient prognosis and the correlation of VEGF-A with renal function were analysed. METHODS: A total of 124 snakebite patients admitted from January 2019 to January 2021 were retrospectively analysed and included in the observation group, and 40 healthy individuals who underwent physical examination in the same hospital within the same period were included in the control group. The t-test was used in analysing differences between the serum VEGF-A levels of the observation and control groups and changes in VEGF-A and renal function indices before and after treatment in the observation group. The effects of treatment on each patient in the observation group were evaluated, and the patients were divided into improved and unimproved groups according to the post-treatment condition. The predictive value of VEGF-A and renal function indices in patients in the improved and unimproved groups and their efficacy for snakebite patients were analysed through receiver operating characteristic (ROC) analysis. Finally, correlation analysis was used in evaluating the correlation between VEGF-A and renal function indices. RESULTS: VEGF-A was significantly higher in patients in the observation group (339.66 ± 97.72 pg/mL) than in patients in the control group (52.41 ± 8.93 pg/mL; p < 0.001). VEGF-A and renal function indices in the serum of patients were significantly lower after treatment than those before treatment (p < 0.0001). According to efficacy, the patients were divided into improved group (n = 102) and unimproved group (n = 22). The pre-treatment VEGF-A levels were significantly lower in patients in the improved group (318.47 ± 90.80 pg/mL) than in patients in the unimproved group (437.88 ± 63.16 pg/mL; p < 0.001). ROC curve analysis revealed that the area under the curve for VEGF-A in predicting patient treatment efficacy was 0.886, and VEGF-A was positively correlated with blood urea nitrogen, creatinine and cystin C but negatively correlated with glomerular filtration rate (p < 0.001). CONCLUSIONS: VEGF-A was highly expressed in snakebite patients and can be used as an observational indicator for predicting the prognosis of snakebite patients.


Subject(s)
Snake Bites , Humans , Snake Bites/therapy , Vascular Endothelial Growth Factor A , Retrospective Studies , Biomarkers , Hospitalization
11.
Biomed Pharmacother ; 165: 115262, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37542853

ABSTRACT

Neointimal hyperplasia persists as a barrier following vascular interventions. Forkhead Box O1 (FoxO1) is a transcription factor that possesses a distinctive fork head domain and indirectly contributes to various physiological processes. FoxO1 expression and signaling also impact the energy metabolism of vascular smooth muscle cells, potentially influencing neointimal hyperplasia. Our hypothesis is that FoxO1 inhibits neointimal hyperplasia in a rat patch angioplasty model. Four groups were compared in a rat aorta patch angioplasty model: the control group without treatment, patches coated with AS184286 (a FoxO1 inhibitor) in a PLGA matrix, patches coated with FoxO1 in a PLGA matrix, and patches coated with MLN0905 (a PLK1 inhibitor) in a PLGA matrix. The patches were harvested on Day 14 and subjected to analysis. FoxO1-positive and p-FoxO1 cells were observed after patch angioplasty. The addition of FoxO1 through patches coated with exogenous FoxO1 protein in a PLGA matrix significantly inhibited neointimal thickness (p = 0.0012). The treated groups exhibited significantly lower numbers of CD3 (p = 0.0003), CD45 (p < 0.0001), and PCNA (p < 0.0001)-positive cells. PLK1 is an upstream transcriptional regulator of FoxO1, governing the expression and function of FoxO1. MLN0905 PLGA-coated patches exhibited comparable reductions in neointimal thickness and inflammatory cell accumulation. FoxO1 represents a promising therapeutic strategy for inhibiting neointimal hyperplasia.


Subject(s)
Angioplasty , Forkhead Box Protein O1 , Neointima , Animals , Rats , Hyperplasia , Forkhead Box Protein O1/metabolism
12.
Respir Res ; 24(1): 204, 2023 Aug 19.
Article in English | MEDLINE | ID: mdl-37598171

ABSTRACT

BACKGROUND: Pulmonary hypertension (PH) is a lethal vascular disease with limited therapeutic options. The mechanistic connections between alveolar hypoxia and PH are not well understood. The aim of this study was to investigate the role of mitotic regulator Polo-like kinase 1 (PLK1) in PH development. METHODS: Mouse lungs along with human pulmonary arterial smooth muscle cells and endothelial cells were used to investigate the effects of hypoxia on PLK1. Hypoxia- or Sugen5416/hypoxia was applied to induce PH in mice. Plk1 heterozygous knockout mice and PLK1 inhibitors (BI 2536 and BI 6727)-treated mice were checked for the significance of PLK1 in the development of PH. RESULTS: Hypoxia stimulated PLK1 expression through induction of HIF1α and RELA. Mice with heterozygous deletion of Plk1 were partially resistant to hypoxia-induced PH. PLK1 inhibitors ameliorated PH in mice. CONCLUSIONS: Augmented PLK1 is essential for the development of PH and is a druggable target for PH.


Subject(s)
Hypertension, Pulmonary , Humans , Animals , Mice , Hypertension, Pulmonary/genetics , Endothelial Cells , Cell Cycle Proteins/genetics , Hypoxia , Mice, Knockout , Polo-Like Kinase 1
13.
J Clin Med ; 12(15)2023 Jul 30.
Article in English | MEDLINE | ID: mdl-37568419

ABSTRACT

BACKGROUND: The importance of early diagnosis of pediatric malocclusion and early intervention has been emphasized. Without use of radiation, 3D imaging holds the potential to be an alternative for evaluating facial features in school-aged populations. METHODS: Students aged 9 and 10 years were recruited. We performed annual 3D stereophotogrammetry of the participants' heads. A total of 37 recognizable anatomical landmarks were identified for linear, angular, and asymmetric analyses using the MATLAB program. RESULTS: This study included 139 healthy Taiwanese children with a mean age of 9.13, of whom 74 had class I occlusion, 50 had class II malocclusion, and 15 had class III malocclusion. The class III group had lower soft-tissue convexity (p = 0.01) than the class II group. The boys with class II malocclusion had greater dimensions in the anteroposterior position of the mid-face (p = 0.024) at age 10. Overall asymmetry showed no significance (p > 0.05). Heat maps of the 3D models exhibited asymmetry in the mid-face of the class II group and in the lower face of the class III group. CONCLUSION: Various types of malocclusion exhibited distinct facial traits in preadolescents. Those with class II malocclusion had a protruded maxilla and convex facial profile, whereas those with class III malocclusion had a less convex facial profile. Asymmetry was noted in facial areas with relatively prominent soft-tissue features among different malocclusion types.

14.
Arch. esp. urol. (Ed. impr.) ; 76(6): 467-474, 28 aug. 2023. tab, graf
Article in English | IBECS | ID: ibc-224900

ABSTRACT

Objective: The expression of vascular endothelial growth factor-A (VEGF-A) in snakebite patients, its value in patient prognosis and the correlation of VEGF-A with renal function were analysed. Methods: A total of 124 snakebite patients admitted from January 2019 to January 2021 were retrospectively analysed and included in the observation group, and 40 healthy individuals who underwent physical examination in the same hospital within the same period were included in the control group. The t-test was used in analysing differences between the serum VEGF-A levels of the observation and control groups and changes in VEGF-A and renal function indices before and after treatment in the observation group. The effects of treatment on each patient in the observation group were evaluated, and the patients were divided into improved and unimproved groups according to the post-treatment condition. The predictive value of VEGF-A and renal function indices in patients in the improved and unimproved groups and their efficacy for snakebite patients were analysed through receiver operating characteristic (ROC) analysis. Finally, correlation analysis was used in evaluating the correlation between VEGF-A and renal function indices. Results: VEGF-A was significantly higher in patients in the observation group (339.66 ± 97.72 pg/mL) than in patients in the control group (52.41 ± 8.93 pg/mL; p < 0.001). VEGF-A and renal function indices in the serum of patients were significantly lower after treatment than those before treatment (p < 0.0001). According to efficacy, the patients were divided into improved group (n = 102) and unimproved group (n = 22). The pre-treatment VEGF-A levels were significantly lower in patients in the improved group (318.47 ± 90.80 pg/mL) than in patients in the unimproved group (437.88 ± 63.16 pg/mL; p < 0.001) (AU)


Subject(s)
Humans , Male , Female , Adult , Elapid Venoms/adverse effects , Snake Bites/complications , Acute Kidney Injury/etiology , Biomarkers , Acute Kidney Injury/diagnosis , Acute Kidney Injury/therapy , Retrospective Studies
15.
Foods ; 12(14)2023 Jul 16.
Article in English | MEDLINE | ID: mdl-37509810

ABSTRACT

Rice bean (Vigna umbellata) is a medicinal and dietary legume rich in polyphenols. In this study, the free and bound phenolics in rice bean were extracted by water, 80% methanol, and acid, base, and composite enzymatic hydrolysis, respectively. The polyphenol profiles of the extracted fractions were analyzed. The outcome demonstrated that base hydrolysis was the most effective way to liberate bound phenolics from rice bean (14.18 mg GAE/g DW), which was 16.68 and 56.72 folds higher than those extracted by acid and enzymatic hydrolysis, respectively. The bound polyphenols released by base hydrolysis contributed to 71.15% of the total phenolic content. A total of 35 individual phenolics was identified, of which isoquercitrin, procyanidin B1, rutin, taxifolin, and catechin were the main monomeric phenolics in the free fraction, while gallic acid, protocatechuic acid, p-hydroxybenzoic acid, catechin, and phloroglucinol were the main monomeric phenolics in the bound fraction. In comparison to the free phenolics extracted by water and 80% methanol and the bound phenolics extracted using acid and composite enzymatic hydrolysis, the bound phenolics from base hydrolysis had a superior antioxidant capacity. The antioxidant activity of rice bean is primarily attributed to individual phenolics such as catechin, abundant both in free and bound fractions, and also p-hydroxybenzoic acid, gallic acid, and protocatechuic acid in bound fractions. The bound phenolics of rice bean were first reported and showed large differences with the composition of free phenolics. This work suggests that the bound fraction of rice bean must be taken into account in assessing its potential benefits to health.

16.
Sci Total Environ ; 901: 165909, 2023 Nov 25.
Article in English | MEDLINE | ID: mdl-37524182

ABSTRACT

Composting is one of main technologies for treating and thus utilizing livestock manure and sludge. However, heavy metals are major concerns in compost utilization due to their potential environmental hazards and health risks. This study aimed to investigate the effects of electric field-assisted composting on the variations of heavy metals and the affecting factors. The results showed that electric field significantly reduced the contents of bioavailable heavy metals including Mn, Zn, Cu, Ni, and Cd, with their bioavailable concentrations decreasing by 61.7, 63.8, 64.9, 83.7, and 63.8 %, respectively. The heavy metals being transformed into stable states were increased, indicating that the electric field also passivated these heavy metals and reduced their biological toxicity and stabilized their forms. Spearman's correlation analysis revealed that the changes in substances, temperature, and organic matter were the dominant environmental factors affecting the forms of heavy metals. Microbial community analysis indicated an increase in the abundance of metal-resistant bacteria such as Pseudomonas and Bacillus during electric field-assisted composting, with their relative abundances being increased to 2.66 % and 15.63 % in the pile of electric field-assisted composting, respectively, compared to the values of 1.88 % and 4.36 % respectively in the conventional composting. The current study suggests that electric field-assisted composting can significantly reduce the availability of heavy metals in the compost, and thus mitigate the health risks associated with its application.

17.
Nanotechnology ; 34(36)2023 Jun 27.
Article in English | MEDLINE | ID: mdl-37285825

ABSTRACT

We report structural and nonlinear optical properties of 20 nm gold (Au) nanoparticles (NPs) that are dispersed in planar degenerate (non-oriented) and planar oriented nematic liquid crystals (LCs) (4'-Pentyl-4-biphenylcarbonitrile-5CB). Taking advantage of elastic forces in the planar oriented nematic LC, we aligned AuNPs parallel to the 5CB director axis. In the case of planar degenerate, 5CB is not aligned and has no preferred orientation, forcing the AuNPs to disperse randomly. Results show that the linear optical absorption coefficient for the planar oriented 5CB/AuNPs mixture is larger than the corresponding planar degenerate sample. The nonlinear absorption coefficients are greatly enhanced in planar oriented samples at relatively high concentrations which can be attributed to plasmon coupling between the aligned AuNPs. This study demonstrates the utility of LCs for developing the assembly of NPs with enhanced optical properties which may offer important insight and technological advancement for novel applications, including photonic nanomaterials and optoelectronic devices.

18.
Sci Total Environ ; 886: 163954, 2023 Aug 15.
Article in English | MEDLINE | ID: mdl-37160182

ABSTRACT

The working surface of landfills is an important source of volatile organic compounds (VOCs), which have received increasing attention because of their role in potentially forming ozone and secondary organic aerosols (SOAs). In this study, 99 monitoring datasets on VOC emissions from a landfill working surface were obtained in 9 months and used to evaluate their ozone formation potential (OFP) and SOA formation potential (SOAFP) from a statistical perspective and compared using various methods. December was found to have the highest total OFP and SOAFP caused by VOC emissions from the landfill working surface. Both the propylene equivalent concentration (PEC) and maximum incremental reactivity (MIR) methods indicated that oxygenated compounds, especially ethanol, contributed the most to the OFP, accounting for 16.1 %-95.4 % and 44.9 %-98.6 % of the total OFP during the entire observation period, respectively. The fraction aerosol coefficient (FAC) method highlighted the effect of aromatic hydrocarbons which contributed to over 97 % of the total SOAFP. In contrast, the SOA potential (SOAP) method indicated that both aromatic hydrocarbons and oxygenated compounds play important roles, contributing 26.6 %-93.9 % and 21.6 %-73.4 % of the total SOAFP, respectively. Based on their mechanisms and comprehensiveness, PEC and SOAP methods are considered more appropriate for evaluating the OFP and SOAFP of VOCs released from landfill working surfaces. The annual total OFP and SOAFP of VOCs from landfill working surfaces of China in 2020 were thus estimated as 1.5 × 104 t and 135 t, respectively, with high variations among different regions along with the population, waste management system, and the amount of landfilled waste. This study provides a comprehensive understanding of the potential impacts and evaluation methods of local waste landfills in the atmospheric environment from a statistical perspective.


Subject(s)
Air Pollutants , Ozone , Volatile Organic Compounds , Air Pollutants/analysis , Volatile Organic Compounds/analysis , Ozone/analysis , Environmental Monitoring , China , Waste Disposal Facilities , Aerosols/analysis
19.
Int J Biol Macromol ; 238: 124114, 2023 May 31.
Article in English | MEDLINE | ID: mdl-36963540

ABSTRACT

An active polysaccharide (LP) from longan was purified and characterized. LP consisted of galactose and glucose in a molar ratio of 1.5: 98.5, with a molecular weight of 4.67 × 107 g/mol. The main backbone of LP was T-α-D-Glcp-[(1 â†’ 6)-α-D-Glcp-(1 â†’ 6)-α-D-Glcp]n. After simulated gastrointestinal digestion, the molecular weight distribution, monosaccharide composition, and major glycosidic bonds of LP were not significantly changed. LP and digested LP (DLP) reduced phagocytosis and promoted IL-10 and IL-12 secretion of dendritic cells. In addition, the effects of LP and DLP on activating dendritic cells showed no significant difference. This study helps to illuminate the potential mode of immunomodulatory action of longan polysaccharides in vivo.


Subject(s)
Digestion , Polysaccharides , Molecular Weight , Polysaccharides/pharmacology , Polysaccharides/chemistry , Dendritic Cells
20.
Plants (Basel) ; 12(6)2023 Mar 16.
Article in English | MEDLINE | ID: mdl-36987024

ABSTRACT

Tropical East Africa (TEA) is one of the most important biodiversity hotspots on the planet. Its rich flora diversity and inventory have been clearly recognized after the publication of the last volume of the Flora of Tropical East Africa (FTEA) in 2012. However, many new and newly recorded taxa have been named and documented since the publication of the first volume of FTEA in 1952. In this study, we comprehensively compiled new taxa and new records by reviewing the literature on the taxonomic contributions of vascular plants in TEA from 1952 to 2022. Our list includes 444 new and newly recorded species belonging to 81 families and 218 genera. Among these taxa, 94.59% of the plants are endemic to TEA and 48.42% are herbs. Additionally, members of Rubiaceae and Aloe are the most numerous family and genus respectively. These new taxa are unevenly distributed in TEA, but are found mainly in areas of high species richness, such as coastal, central and western areas of Kenya, central and southeastern Tanzania. This study offers summative assessment of the newly recorded flora inventory in TEA and provides recommendations for future research on plant diversity survey and conservation.

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