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1.
Nutr Metab Cardiovasc Dis ; 34(11): 2570-2578, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39098378

RESUMEN

BACKGROUND AND AIM: Cardiometabolic diseases (CMDs) are leading causes of death and disability, but little is known about the additive mortality effects of multiple CMDs. This study aimed to examine the association between single and multiple CMDs and all-cause mortality among older Chinese population. METHODS AND RESULTS: Using the Chinese Longitudinal Healthy Longevity Survey (CLHLS) database, we analyzed data from 2008 to 2018 to assess the relationship between CMDs and mortality. Cox regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for single and multiple CMDs. At baseline, 11,351 participants (56.9% female) aged 60 years or older were included. 11.91% of participants had a single CMD, 1.51% had two CMDs, and 0.22% had three CMDs. Over a decade follow-up, 8992 deaths (79.2%) were recorded. A dose-response relationship was observed, with the mortality risk increasing by 17% for each additional disease. The fully-adjusted HRs for all-cause mortality were 1.16, 1.36, and 2.03 for one, two, and three CMDs, respectively. Larger effects of single and multiple CMDs were observed in the male group (P = 0.015) and the younger senior group (P < 0.001). CONCLUSIONS: This large-scale study found that CMDs multiply mortality risks, especially in younger seniors and males. The risk is highest when heart disease and stroke coexist, and diabetes further increases it. Public health efforts should prioritize evidence-based management and prevention of CMDs.


Asunto(s)
Factores de Riesgo Cardiometabólico , Causas de Muerte , Bases de Datos Factuales , Humanos , Masculino , Femenino , Anciano , China/epidemiología , Estudios Prospectivos , Persona de Mediana Edad , Medición de Riesgo , Factores de Edad , Anciano de 80 o más Años , Factores de Tiempo , Enfermedades Cardiovasculares/mortalidad , Multimorbilidad , Pronóstico , Factores Sexuales , Factores de Riesgo , Pueblos del Este de Asia
2.
Sensors (Basel) ; 24(2)2024 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-38257581

RESUMEN

In this study, a portable spectral analysis instrument based on spontaneous emission spectroscopy (SES) was developed for the in situ, non-intrusive, and quantitative measurement of gaseous Na inside ZD coal-fired boilers, which is mainly applied for predicting slagging in furnaces. This technology is needed urgently because the problem of fouling and slagging caused by high alkali metals in ZD coal restricts the rational utilization of this coal. The relative extended uncertainty for the measurement of gaseous Na concentration is Urel = 10%, k = 2, which indicates that measurement data are reliable under working conditions. It was found that there is a clear linear relationship between the concentration of gaseous Na and fouling in high-alkali coal boilers. Therefore, a fast and efficient method for predicting the slagging and fouling of high-alkali coal boilers can be established by using this in situ online real-time optical measurement.

3.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(5): 456-460, 2024 May 15.
Artículo en Zh | MEDLINE | ID: mdl-38802904

RESUMEN

OBJECTIVES: To explore the value of metagenomic next-generation sequencing (mNGS) technology in the etiological diagnosis of sepsis in preterm infants following antibiotic use. METHODS: A retrospective analysis of medical records for 45 preterm infants with sepsis who were treated at Henan Provincial People's Hospital. All patients received antibiotic treatment for ≥3 days and underwent both blood culture and mNGS testing. The detection rates of pathogens by blood culture and mNGS testing were compared. RESULTS: The positive detection rate of pathogens by blood mNGS was higher than that by blood culture (44% vs 4%; P<0.001). Blood mNGS detected 28 strains of pathogens, including 23 bacteria, 4 fungi, and 1 Ureaplasma parvum. Blood culture identified one case each of Rhodotorula mucilaginosa and Klebsiella pneumoniae. In the group treated with antibiotics for >10 days, the positive rate of blood mNGS testing was higher than that of blood culture (40% vs 3%; P<0.001); similarly, in the group treated with antibiotics for ≤10 days, the positive rate of blood mNGS testing was also higher than that of blood culture (53% vs 7%; P=0.020). Treatment plans were adjusted based on blood mNGS results for 13 patients, with an effectiveness rate of 85% (11/13). CONCLUSIONS: In preterm infants with sepsis following antibiotic use, the positive rate of pathogen detection by blood mNGS is higher than that by blood culture and is unaffected by the duration of antibiotic use. Therefore, mNGS testing can be considered for confirming pathogens when clinical suspicion of infection is high but blood culture fails to detect the pathogen.


Asunto(s)
Antibacterianos , Secuenciación de Nucleótidos de Alto Rendimiento , Recien Nacido Prematuro , Metagenómica , Sepsis , Humanos , Recién Nacido , Antibacterianos/uso terapéutico , Sepsis/microbiología , Sepsis/tratamiento farmacológico , Masculino , Femenino , Estudios Retrospectivos , Metagenómica/métodos
4.
Entropy (Basel) ; 24(7)2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35885145

RESUMEN

In this paper, a theoretical numerical analysis of the thermodynamics second law in ammonia/ethylene counter-flow diffusion flames is carried out. The combustion process, which includes heat and mass transfer, as well as a chemical reaction, is simulated based on a detailed chemical reaction model. Entropy generation and exergy loss due to various reasons in ammonia/ethylene and argon/ethylene flames are calculated. The effects of ammonia addition on the thermodynamics efficiency of combustion are investigated. Based on thermodynamics analysis, a parameter, the lowest emission of pollutant (LEP), is proposed to establish a relationship between the available work and pollutant emissions produced during the combustion process. Chemical reaction paths are also analyzed by combining the chemical entropy generation, and some important chemical reactions and substances are identified. The numerical results reveal that ammonia addition has a significant enhancement on heat transfer and chemical reaction in the flames, and the total exergy loss rate increases slightly at first and then decreases with an increase in ammonia concentration. Considering the factors of thermodynamic efficiency, the emissions of CO2 and NOx reach a maximum when ammonia concentration is near 10% and 30%, respectively. In terms of the chemical reaction path analysis, ammonia pyrolysis and nitrogen production increase significantly, while ethylene pyrolysis and carbon monoxide production decrease when ammonia is added to hydrocarbon diffusion flames.

5.
Entropy (Basel) ; 24(2)2022 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-35205499

RESUMEN

In studies on the combustion process, thermodynamic analysis can be used to evaluate the irreversibility of the combustion process and improve energy utilization efficiency. In this paper, the combustion process of a laminar oxy-fuel diffusion flame was simulated, and the entropy generation due to the irreversibilities of the radiation process, the heat conduction and heat convection process, the mass diffusion process, and the chemical reaction process was calculated. The effect of the oxygen concentration in the oxidizer on the entropy generation was analyzed. The results indicated that, as the oxygen concentration in the oxidizer increases, the radiative entropy generation first increases and then decreases, and the convective and conductive entropy generation, the mass diffusion entropy generation, the chemical entropy generation, and the total entropy generation gradually increase.

6.
BMC Musculoskelet Disord ; 18(1): 107, 2017 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-28288607

RESUMEN

BACKGROUND: The Proximal Femoral Nail Antirotation (PFNA) system for treatment of intertrochanteric fractures is currently widely applied worldwide. However, even though the PFNA has produced good clinical outcomes, a poor introduction technique with an inappropriate entry point can cause surgical complications. Some researchers suggest improving clinical outcomes by modifying the entry point, but no research has focused on this issue. The purpose of the present study is to compare the clinical and radiological outcomes of two different trochanteric entry points for the treatment of intertrochanteric fractures using the PFNA system. METHODS: From May 2010 to October 2015, a total of 212 elderly patients with intertrochanteric fractures who were treated with the PFNA-II system were included into this retrospective cohort study. Group LA (98 patients) was treated using a lateral anterior trochanteric entry point, and group MP (114 patients) was treated using a medial posterior trochanteric entry point. All patients underwent follow-up assessments at 1, 3, 6, and 12 months after surgery. Radiographic evaluation was based on the impingement, tip-apex distance (TAD) and the position of the helical blade within the femoral head. Clinical evaluation was based on the surgical time, fluoroscopy time, blood loss, hospital stay, visual analogue scale (VAS), thigh pain, and Harris hip score. RESULTS: The impingement was significantly reduced (P = 0.011) in group MP. The helical blade positions were significantly lower (P = 0.001) in group MP. The TADs in group LA (22.40 ± 4.43) and group MP (23.39 ± 3.60) were not significantly different (P = 0.075). The fluoroscopy time of group LA (53.26 ± 14.44) was shorter than that of group MP (63.29 ± 11.12, P = 0.000). Five iatrogenic lateral proximal fractures and 3 helical blade cutouts occurred in group LA, but none occurred in group MP. At 1 and 3 months postoperation, the Harris hip scores were significantly higher in group MP (P = 0.001 and P = 0.000, respectively), and the VAS scores were lower (P < 0.05). CONCLUSIONS: The medial posterior trochanteric entry point achieved excellent nail and helical blade position, reduced surgical complications, and enabled early hip function recovery but required longer fluoroscopy time than the lateral anterior trochanteric entry point.


Asunto(s)
Fracturas de Cadera/diagnóstico por imagen , Fracturas de Cadera/cirugía , Complicaciones Posoperatorias/prevención & control , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Fracturas de Cadera/epidemiología , Humanos , Masculino , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Resultado del Tratamiento
7.
Zhongguo Dang Dai Er Ke Za Zhi ; 18(11): 1174-1180, 2016 Nov.
Artículo en Zh | MEDLINE | ID: mdl-27817787

RESUMEN

OBJECTIVE: To study the dynamic changes in the percentage of Th17 cells/CD4+CD25+ regulatory T cells after intervention with montelukast sodium, a leukotriene receptor antagonist, in asthmatic mice and the association between them. METHODS: Balb/c mice were randomly divided into blank group, asthma group, and montelukast sodium group. The asthmatic mouse model of airway remodeling was established by sensitization with intraperitoneal injection of chicken ovalbumin (OVA) and aluminum hydroxide suspension and aerosol inhalation of OVA. The mice in the blank group were given normal saline, and those in the montelukast sodium group were given montelukast sodium by gavage before aerosol inhalation. Eight mice were randomly sacrificed within 24 hours after 2, 4, and 8 weeks of aerosol inhalation. The pathological sections of lung tissue were used to observe the degree of airway remodeling. Flow cytometry was used to measure the percentages of Th17 cells and CD4+CD25+ regulatory T cells in CD4+ T cells. RESULTS: The asthma group and the montelukast sodium group had significantly higher bronchial wall thickness and smooth muscle thickness at all time points compared with the blank group (P<0.05). At 8 weeks of intervention, the montelukast sodium group had significantly greater improvements in the above changes compared with the asthma group (P<0.05). Compared with the blank group, the asthma group and the montelukast sodium group had significant increases in Th17 cells (positively correlated with airway remodeling) and significant reductions in CD4+CD25+ regulatory T cells (negatively correlated to airway remodeling) at all time points (P<0.05). At 8 weeks of intervention, the montelukast sodium group had a significant reduction in the number of Th17 cells and a significant increase in the number of CD4+CD25+ regulatory T cells compared with the asthma group (P<0.05). CONCLUSIONS: Montelukast sodium intervention can alleviate airway remodeling and achieve better improvements over the time of intervention. The possible mechanism may be related to the improvement of immunologic derangement of CD4+CD25+ regulatory T cells and inhibition of airway inflammation.


Asunto(s)
Acetatos/farmacología , Remodelación de las Vías Aéreas (Respiratorias)/efectos de los fármacos , Asma/tratamiento farmacológico , Quinolinas/farmacología , Linfocitos T Reguladores/inmunología , Células Th17/inmunología , Animales , Asma/inmunología , Ciclopropanos , Femenino , Pulmón/patología , Ratones , Ratones Endogámicos BALB C , Sulfuros
8.
Microb Cell Fact ; 14: 71, 2015 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-25981633

RESUMEN

BACKGROUND: The shikimic acid (SA) pathway is a fundamental route to synthesize aromatic building blocks for cell growth and metabolic processes, as well as for fermentative production of various aromatic compounds. Genes encoding enzymes of SA pathway are not continuous on genome and they are differently regulated. RESULTS: In this study, efforts were made to construct continuous genetic modules of SA pathway that are regulated by a same Ptac promoter. Firstly, aro genes [aroG (NCgl2098), aroB (NCgl1559), aroD (NCgl0408) and aroE (NCgl1567)] from Corynebacterium glutamicum and ribosome binding site (RBS) libraries that were tailored for the above genes were obtained, and the strength of each RBS in the 4 libraries was quantified. Secondly, 9 genetic modules were built up from the RBS libraries, a previously characterized ribozyme insulator (RiboJ) and transcriptional promoter (Ptac) and terminator, and aroG, aroB, aroD and aroE. The functionality and efficiency of the constructed genetic modules were evaluated in C. glutamicum by determination of SA synthesis. Results showed that C. glutamicum RES167ΔaroK carrying a genetic module produced 4.3 g/L of SA, which was 54 folds higher compared to that of strain RES167ΔaroK (80 mg/L, without the genetic module) during fermentation in 250-mL flasks. The same strain produced 7.4, and 11.3 g/L of SA during 5-L batch and fed-batch fermentations, respectively, which corresponding to SA molar yields of 0.39 and 0.24 per mole sucrose consumption. CONCLUSION: These results demonstrated that the constructed SA pathway modules are effective in increasing SA synthesis in C. glutamicum, and they might be useful for fermentative production of aromatic compounds derived from SA pathway.


Asunto(s)
Corynebacterium glutamicum/metabolismo , Regiones Promotoras Genéticas/genética , Ribosomas/metabolismo , Ácido Shikímico/síntesis química , Sitios de Unión , Fermentación , Redes Reguladoras de Genes , Ácido Shikímico/metabolismo
9.
Zhongguo Dang Dai Er Ke Za Zhi ; 17(9): 994-1000, 2015 Sep.
Artículo en Zh | MEDLINE | ID: mdl-26412186

RESUMEN

OBJECTIVE: To study the dynamic changes in Th17 cells and CD4⁺ CD25⁺ regulatory T cells (Treg) in the spleen and to analyze their relationship with airway remodeling. METHODS: A total of 48 female specific pathogen-free Balb/c mice were randomly divided into control and asthmatic groups. To establish the asthmatic airway remodeling model, the mice were sensitized to ovalbumin (OVA) through intraperitoneal injection of OVA and aluminum hydroxide suspension and challenged by inhalation of aerosol OVA. The matched control group was treated with normal saline instead. In 24 hours after 2-week, 4-week, and 8-week aerosol inhalation, 8 mice were randomly selected from each group and sacrificed. Then histopathological examination of the left lung was performed to measure the degree of airway remodeling. The percentages of Th17 and CD4⁺ CD25⁺ Treg cells in total CD4(+) cells from the spleen were determined by flow cytometry. RESULTS: In the asthmatic group, the ratios of total bronchial wall area to bronchial basement membrane perimeter (WAt/Pbm) and bronchial smooth muscle area to bronchial basement membrane perimeter (WAm/Pbm) significantly increased as the challenge proceeds (P<0.01). The percentage of Th17 cells derived from the cell suspension of the spleen gradually increased and it was positively correlated with the degree of asthmatic airway remodeling (P<0.01). The percentage of CD4⁺ CD25⁺ Treg cells from the suspension gradually decreased and it was negatively correlated with the degree of asthmatic airway remodeling (P<0.01). CONCLUSIONS: In mice with asthma, as the challenge proceeds, the airway remodeling becomes more severe, the percentage of Th17 cells increases, and the percentage of CD4⁺ CD25⁺ Treg cells decreases. The immunological imbalance is possibly one of the important factors inducing airway remodeling.


Asunto(s)
Remodelación de las Vías Aéreas (Respiratorias) , Asma/inmunología , Linfocitos T Reguladores/inmunología , Células Th17/inmunología , Animales , Asma/patología , Modelos Animales de Enfermedad , Femenino , Pulmón/patología , Ratones , Ratones Endogámicos BALB C
10.
Materials (Basel) ; 16(2)2023 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-36676536

RESUMEN

In this paper, a three-dimensional (3-D) high-temperature furnace filled with a gas-solid medium was investigated, and the radiative transfer equation and the radiative entropy transfer equation in the chamber were applied in order to analyze the effect of coal deposits on thermal radiation. The heat flux on the walls of the furnace and the entropy generation rate were determined due to the irreversibility of the radiative heat transfer process in the furnace. Furthermore, the effect of ash deposits on the wall surface on the irreversibility of the radiation heat transfer process was investigated. The numerical results show that when burning bituminous and sub-bituminous coal, ash deposits in the furnace led to a 48.2% and 63.2% decrease in wall radiative heat flux and a 9.1% and 12.4% decrease in the radiative entropy rate, respectively. The ash deposits also led to an increase in the entropy generation number and a decrease in the thermodynamic efficiency of the radiative heat transfer process in the furnace.

11.
Tumour Biol ; 33(6): 2357-64, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23055189

RESUMEN

ING4 is a novel tumor suppressor which is downregulated in a number of cancers. In this study, we investigated the role of ING4 in tumor angiogenesis in colorectal carcinoma (CRC) patients. Semi-quantitative RT-PCR, western blots, and immunohistochemistry were used to determine ING4 mRNA and protein expression in CRC and normal tissue from 60 CRC specimens and 30 colonic adenoma specimens. The correlation between ING4 expression and clinical stage, histological grade as well as lymph node metastasis was evaluated. Immunohistochemistry was performed to explore the correlation between ING4 expression and microvessel density (MVD) in CRC. CRC tissue had significantly lower levels of ING4 mRNA and protein compared to colonic adenoma and normal intestinal tissue. Immunostaining showed ING4 expression in 38 (63.3 %), 30 (100 %), and 60 (100 %) cases of normal colonic mucosa, adenoma, and normal intestinal mucosal tissue, respectively. Lower ING4 levels correlated with higher clinical stage and histological grade. ING4 mRNA and protein levels were significantly lower in CRC patients with lymph node metastasis compared to patients without lymph node metastasis (0.41 ± 0.30 vs. 0.91 ± 0.29 and 0.60 ± 0.21 vs. 0.87 ± 0.27, respectively; p < 0.001). Importantly, ING4 mRNA and protein levels were negatively correlated with MVD in CRC patients (p < 0.001). Our data suggest that ING4 levels are a potential biomarker of CRC progression and that ING4 may inhibit tumor growth by modulating angiogenesis in CRC.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Neoplasias del Colon/patología , Proteínas de Homeodominio/metabolismo , Mucosa Intestinal/metabolismo , Microvasos/patología , Proteínas Supresoras de Tumor/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Proteínas de Ciclo Celular/genética , Neoplasias del Colon/irrigación sanguínea , Neoplasias del Colon/metabolismo , Femenino , Proteínas de Homeodominio/genética , Humanos , Metástasis Linfática , Masculino , Microvasos/metabolismo , Persona de Mediana Edad , Clasificación del Tumor , Estadificación de Neoplasias , Neovascularización Patológica , Pronóstico , Proteínas Supresoras de Tumor/genética , Adulto Joven
12.
Int J Gynecol Cancer ; 22(1): 54-62, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22193644

RESUMEN

OBJECTIVE: Metastatic ovarian tumors are a series of lethal carcinomas that almost always have bad prognosis. Their prognoses, however, vary depending on the primary tumor malignancies of each. It has been reported that LAPTM4B, a novel tumor-associated gene, might indicate a worse prognosis when it was overexpressed in other carcinomas. Therefore, the authors expected to investigate whether LAPTM4B overexpression is an independent prognostic marker in metastatic ovarian tumors. METHODS: Immunohistochemistry was used to assess LAPTM4B expression in metastatic ovarian tumors from 102 patients. Subsequently, univariate and multivariate survival analyses with Cox regression were performed to determine the association between LAPTM4B expression and prognosis. To identify any differences in prognosis between the 2 groups of patients with differing primary malignancies, the log-rank test was used. RESULTS: The median overall and progression-free survival rates of patients with tumors of gastrointestinal tract origin were 0.97 and 0.51 years, respectively, and both were statistically significantly lower than those of patients with tumors of breast origin (P < 0.0001), which were 2.68 and 1.96 years, accordingly. Of 102 patients, 77 were classified as having a high expression of LAPTM4B, and LAPTM4B expression had a significant association with the prognosis of metastatic ovarian tumors (P < 0.01); no statistically significant interaction between LAPTM4B expression and primary malignancies was detected (P > 0.1). On the other hand, medians of overall survival and progression-free survival of patients with tumors of gastrointestinal tract origin were significantly lower than those of patients with tumors of breast origin (P < 0.0001). CONCLUSIONS: Patients with metastatic ovarian tumors of breast origin had significantly better prognosis than those with the disease from gastrointestinal tract primary malignancies. LAPTM4B overexpression might be an independent prognostic marker of metastatic ovarian tumors.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/patología , Neoplasias Gastrointestinales/patología , Proteínas de la Membrana/metabolismo , Proteínas Oncogénicas/metabolismo , Neoplasias Ováricas/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Terapia Combinada , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Inmunohistoquímica , Estimación de Kaplan-Meier , Persona de Mediana Edad , Neoplasias Ováricas/mortalidad , Neoplasias Ováricas/secundario , Neoplasias Ováricas/terapia , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Tasa de Supervivencia
13.
Appl Opt ; 51(36): 8863-72, 2012 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-23262626

RESUMEN

The film thickness of a hanging soap bubble has been studied along its gravitational orientation after its birth and before its bursting using large lateral shearing displacement interferometry, with a theoretical error of less than 0.325λ. The results show that the spatial distribution of the film thickness could be approximated with an exponential model in all captured frames, especially in the lower half of the soap bubble. Before its bursting, a special zone, where the water layer has drained out while the surfactant solution layer remains, will occur at the top of the soap bubble and gradually expand toward the bottom. Moreover, the simulated fringe patterns based on the computed values match well with the experimentally observed ones.

14.
J Org Chem ; 76(10): 3797-804, 2011 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-21466227

RESUMEN

Organocatalytic conjugate addition of malononitrile to conformationally restricted dienones has been studied. A series of chiral primary and tertiary amine catalysts were screened. A piperidine-based thiourea-tertiary amine was found to be the efficient catalyst. Chiral pyran derivatives were obtained in excellent yields and enantioselectivities via a cascade conjugate addition-intramolecular cyclization pathway. The reaction is remarkably different for the corresponding reaction of conformationally flexible dienones.


Asunto(s)
Alquenos/química , Cetonas/química , Conformación Molecular , Nitrilos/química , Catálisis
15.
ACS Omega ; 6(42): 27702-27710, 2021 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-34722970

RESUMEN

This work established a high-speed camera-assisted visualization system that investigated the effect of volatile matter and fixed carbon content in biomass particles on single-particle combustion phases and their luminous properties. Three types of biomass particles, namely, sawdust (a mixture of pine and willow), corncob, and rice husk, were examined on a Hencken flat-flame burner. The luminous region and intensity of single biomass particles were closely related to the flammability and calorific value of biomass fuel and derived by analyzing a sequence of images captured using a high-speed camera. The combustion temperature was determined through analysis of its radiant energy. The results showed that the ignition mechanisms of volatile matter and fixed carbon corresponded to homogeneous and heterogeneous reactions, respectively. The maximum luminous region values of 1.75 × 106, 2.1 × 106, and 1.0 × 106 µm2 for sawdust (SD), corncob (CC), and rice husk (RH) correlated to the volatile matter content of each biomass sample, which was 69.38, 74.15, and 64.56%, respectively. Because of the high fixed carbon content, the peak temperature of the SD particles could reach 1549 °C. The luminous region and intensity of the combusting particles were significantly affected by the volatile matter and fixed carbon, respectively.

16.
Bioresour Technol ; 320(Pt B): 124375, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33186802

RESUMEN

The combustion behaviours of three components, namely hemicellulose, cellulose, and lignin, and four types of biomass, namely rice straw, bamboo, peanut shell, and chestnut shell, were examined in a drop tube furnace set at 1273 K, in O2/N2 atmospheres containing 21-100% O2. Radiant energy analysis technology was employed to infer the temperatures of the samples. The results show that the ignition mechanisms of cellulose and hemicellulose change at 30% and 70% O2, respectively, and the lignin particle ignites homogeneously at 20-30% O2, heterogeneously at 50% O2, and hetero-homogeneously at 70-100% O2, respectively. The changes in the ignition mechanisms of biomass particles with lignin content > 10% and < 10% under a certain oxygen concentration depend considerably on the lignin and cellulose contents in the biomass particle, respectively. The expansion of biomass particles with lignin content > 10% and < 10% during combustion process are caused by lignin and hemicellulose, respectively.


Asunto(s)
Celulosa , Lignina , Biomasa , Oxígeno , Polisacáridos
17.
J Environ Sci (China) ; 22(5): 738-43, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20608511

RESUMEN

Enantioselectivity of chiral pollutants is receiving growing concern due to the difference in toxicology and environment fate between enantiomers. In this study, enantiomers of insecticide beta-cypermethrin (beta-CP) were separated on selected chiral column by HPLC, and the toxicity of enantiomers was evaluated using the zebrafish embryo-larval assays. The enantiomers of beta-CP were baseline separated on Chiralcel OD and Chiralpak AD columns and detected by circular dichroism (CD) at 236 nm. Better separation could be achieved at lower temperature (e.g., 20 degrees C) and with lower levels of polar modifiers. Pure enantiomers were obtained on Chiralcel OD. The CD spectra of enantiomers were recorded. By comparing the elution order with a previous similar study, the absolute configuration of beta-CP enantiomers was determined. The individual enantiomers were used in zebrafish embryo test, and the results showed that beta-CP enantioselectively induced yolk sac edema, pericardial edema and crooked body. The IR-cis-alphaS and 1R-trans-alphaS enantiomers showed strong developmental toxicities at concentration of 0.1 mg/L, while the 1S-cis-alphaR and 1S-trans-alphaR induced no malformations at higher concentration (e.g., 0.3 mg/L). The results suggest that the enantioselective toxicological effects of beta-CP should be considered when evaluating its ecotoxicological effects.


Asunto(s)
Embrión no Mamífero/efectos de los fármacos , Insecticidas/toxicidad , Piretrinas/química , Piretrinas/toxicidad , Pruebas de Toxicidad/métodos , Pez Cebra/embriología , Pez Cebra/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Dicroismo Circular , Embrión no Mamífero/anomalías , Insecticidas/química , Insecticidas/aislamiento & purificación , Piretrinas/aislamiento & purificación , Estereoisomerismo , Temperatura
18.
Waste Manag ; 102: 486-491, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31756685

RESUMEN

In order to address slagging, fouling and high-temperature corrosion problems caused by alkali metals in Municipal Solid Waste (MSW), in-situ measurement of alkali metal in MSW incinerators is needed. The paper presents experimental measurements of temperatures and alkali metal concentrations in two MSW incinerators based on Flame Emission Spectroscopy (FES). Through the analysis of spontaneous emission spectra and a calibration procedure, the concentration of gas phase sodium (Na) and potassium (K), temperature and thermal radiation in the incinerator were in-situ measured by a portable spectral system simultaneously. Experimental results showed MSW composition has significant effect on the measured gaseous Na and K. Higher volatile content in MSW may enhance the alkali metal emission. Besides that, the released gaseous Na and K in the two incinerators are correlated with temperature in incinerators. The study provided a low cost and effective solution for in-situ measurement of temperature and alkali metal concentration in MSW incinerators.


Asunto(s)
Metales Alcalinos , Residuos Sólidos , Incineración , Análisis Espectral , Temperatura
19.
Bioresour Technol ; 310: 123456, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32388354

RESUMEN

The aim of this work was to investigate the effects of cellulose, hemicellulose and lignin on the ignition behaviors of biomass. The ignition events of three components and five types of single biomass particles were captured by a high-speed camera in a drop tube furnace with a temperature of 1273 K, and the combustion temperatures for the single biomass particles were measured by radiant energy analysis technology. The comparison of the flame images and the temperature evolution of five types of biomass with three components shows that the lignin content in the biomass particle strongly influences the ignition behaviors. The ignition mechanism of the biomass particle depends heavily on the lignin content. After homogeneous ignition, the rate of increase in the flame temperature and the char ignition of biomass are closely related to the lignin content. The ignition temperature of the biomass particle depends mainly on the cellulose component.


Asunto(s)
Celulosa , Lignina , Biomasa , Polisacáridos
20.
Psychiatry Res ; 288: 112953, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32302814

RESUMEN

A series of unexplained pneumonia appeared in Wuhan, Hubei Province, China, which is highly contagious. The virus is prone to nervous and anxious psychological reactions. In the objective environment of complex and densely populated hospitals, it is a high-risk area for virus-transmitted infections and children generally have lower immunity who are more likely to develop infections. The results showed that the mental health problems of parents of hospitalized children during the epidemic were more serious, and the anxiety and depression were more obvious.


Asunto(s)
Niño Hospitalizado , Infecciones por Coronavirus , Pandemias , Padres , Neumonía Viral , Adulto , Ansiedad/epidemiología , Betacoronavirus , COVID-19 , Niño , China/epidemiología , Infecciones por Coronavirus/psicología , Depresión/epidemiología , Femenino , Humanos , Masculino , Relaciones Padres-Hijo , Padres/psicología , Neumonía Viral/psicología , SARS-CoV-2
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