RESUMEN

The effects of vegetable planting on soil loss and nutrient loss, runoff, soil erosion, and nitrogen (ammonium nitrogen and nitrate nitrogen) losses under individual rainfalls of fruit- and leaf-vegetable fields between April to October in 2021 were observed using in-situ observation testing. The results showed that: ① the runoff, erosion, and nitrogen loss of the fruit-vegetable pattern (eggplant-chili) were 1.27-2.00 times those under the leaf-vegetable pattern (leaf lettuce-sweet potato leaves), especially under the second season vegetable period. Those losses under the second season vegetable accounted for 50.86%-68.83% of the total losses under different vegetable patterns, which were approximately 1.03-2.04 times those under the first season vegetable. The runoff, erosion, and nutrient loss of vegetable fields under different treatments were both concentrated in June and July, and the nitrogen loss was mainly in the form of nitrate nitrogen with surface runoff. ② The runoff, erosion, and nutrient losses under individual rainfalls of vegetable fields under different treatments fluctuated among the vegetable growing season, and the losses were mainly concentrated in several typical rainfall events. On the whole, the loss and concentration of nitrate and ammonium nitrogen in runoff and erosion sediment of vegetables in the first season were lower than those in the second season. The runoff, erosion, and loss of ammonium nitrogen and nitrate nitrogen of fruit-vegetable were higher than those of leaf-vegetable. ③ Both rainfall amount and maximum 30 min rainfall intensity had significantly positive effects on runoff, soil loss, and nitrogen loss. Runoff, erosion, and nutrient losses under different vegetable patterns were mainly generated by moderate rain, heavy rain, and heavy rainstorms, which accounted for 29.58%-46.68%, 24.54%-36.79%, and 24.01%-39.13% of the total losses, respectively. The results also showed that soil erosion and nutrient losses generated by different rainfall grades were obviously different for the fruit- and leaf-vegetable treatments. The results indicated that the vegetable pattern had significant impacts on soil loss and nutrient loss, and the leaf-vegetable pattern could reduce soil erosion and nutrient loss compared with the fruit-vegetable pattern. Furthermore, for different vegetable patterns and vegetable growing seasons, the effects of rainfall on soil loss and nutrient loss were quite different. The results of this study were helpful in clarifying the soil erosion and nutrient loss characteristics of vegetable fields in South China.

Asunto(s)

Erosión del Suelo , Verduras , Nitrógeno/análisis , Nitratos , Fósforo/análisis , Movimientos del Agua , Suelo , Lluvia , China

RESUMEN

Inner wall temperature of ladle is closely related to the quality of steelmaking and control of steel-making tapping temperature. This article adopts a rotating platform to drive an infrared temperature sensor and a laser sensor to scan the temperature field distribution of the ladle inner wall at the hot repair station, where the scanning laser sensor obtains coordinates of each measured point. Because of measuring errors of infrared thermal radiation caused by emissivity uncertainty of the ladle inner wall surface, this article proposes a method for temperature measurement based on Monte Carlo model for effective emissivity correction of each measured point. In the model, we consider the ladle and fire baffle as a cavity. By calculation of the model, the effect of distance from the fire baffle to the ladle and the material surface emissivity of the ladle inner wall on the effective emissivity of the cavity are obtained. After that, the effective emissivity of each measured point is determined. Then the scanning temperature of each measured point is corrected to real temperature. By field measuring test and verification contrast, the results show that: the maximum absolute error of the method in this article is 4.7 °C, the minimum error is 0.6 °C, and the average error is less than 2.8 °C. The method in this article achieves high measurement accuracy and contributes to the control of metallurgical process based on temperature information.

RESUMEN

The abnormal deposition of the extracellular amyloid-ß peptide is the typical pathological hallmark of Alzheimer's disease. Strategies to reduce the amyloid-ß deposition effectively alleviate the neuronal degeneration and cognitive deficits of Alzheimer's disease. Danggui-Shaoyao-San has been considered a useful therapeutic agent known for the treatment of Alzheimer's disease. However, the mechanism of Danggui-Shaoyao-San for the treatment of Alzheimer's disease remains unclear. We investigated Danggui-Shaoyao-San's effect on amyloidosis and neuronal degeneration in an APP/PS1 mouse model. We found Danggui-Shaoyao-San alleviated the cognitive deficits in APP/PS1 mice. Additionally, Danggui-Shaoyao-San ameliorated the neuronal degeneration in these mice. Danggui-Shaoyao-San reduced the amyloidosis and amyloid-ß1-42 deposition in APP/PS1 mouse brain and down-regulated the receptor for advanced glycation end products, and up-regulated the level of low-density lipoprotein receptor-related protein-1. However, the protein expression of the ß-amyloid precursor protein, ß-Secretase and presenilin-1 (PS1) in the amyloid-ß production pathway, and the expression of neprilysin and insulin-degrading enzyme in the amyloid-ß degradation pathway were not altered. Our findings collectively suggest that Danggui-Shaoyao-San could ameliorate the amyloidosis and neuronal degeneration of Alzheimer's disease, which may be associated with its up-regulation lipoprotein receptor-related protein-1 and down-regulation of the receptor for advanced glycation end products.

Asunto(s)

Enfermedad de Alzheimer/tratamiento farmacológico , Amiloidosis/tratamiento farmacológico , Disfunción Cognitiva/tratamiento farmacológico , Medicamentos Herbarios Chinos/farmacología , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/efectos de los fármacos , Receptor para Productos Finales de Glicación Avanzada/efectos de los fármacos , Animales , Modelos Animales de Enfermedad , Regulación hacia Abajo/efectos de los fármacos , Ratones , Ratones Transgénicos , Regulación hacia Arriba/efectos de los fármacos

RESUMEN

Amino cellulose (AC) is a cellulose derivative with biodegradability, biocompatibility, and excellent film-forming property, but AC film exhibits poor mechanical property and thermal stability. To improve the performance of AC film and further promote application, a novel composite film prepared from AC and bisphenol A-type-benzoxazine (BATB) are reported. In this paper, AC and BATB were firstly synthesized and characterized, then AC-BATB composite films were prepared with different weight ratios (AC/BATB) and temperatures by the synergistic interactions of chemical cross-linking and hydrogen bonds. Based on the results of tensile test and thermal analysis, BATB played a vital role in improving the mechanical and thermal properties of composite films, and the enhancement effect was more remarkable at elevated temperature. The maximum tensile strength and tensile modulus of composite films were 2.86 times and 7.26 times higher than that of AC control film, thus promoting the functional application of composite films.

RESUMEN

This study aimed to estimate the prevalence of chlamydial trachomatis (CT) infection and explore its risk factors among patients attending sexual and reproductive health clinics in Shenzhen, China. We collected demographic and clinical information from attendees (aged 18-49). CT and Neisseria gonorrhoeae (NG) infection was determined by nucleic acid amplification test (NAAT) on self-collected urine specimens. Of 1,938 participants recruited, 10.3% (95% confidence interval [CI]: 9.6%-11.0%) tested positive for CT. Prevalence was similar between men (10.6% [85/804]; 95% CI, 9.5%-11.7%) and women (10.1% [115/1134]; 95% CI: 9.2%-11.0%). Being 18-25 years old (adjusted odds ratio [aOR] = 2.52; 95%CI:1.35-4.71), never tested for CT before (aOR = 2.42; 95%CI: 1.05-5.61) and infected with NG(aOR = 3.87; 95%CI: 2.10-7.10) were independently associated with CT infection. We found that CT infection is prevalent among patients attending sexual and reproductive health clinics in Shenzhen, China. A comprehensive program including CT screening, surveillance and treatment is urgently needed.

Asunto(s)

Infecciones por Chlamydia/diagnóstico , Chlamydia trachomatis/aislamiento & purificación , Adolescente , Adulto , Instituciones de Atención Ambulatoria , China/epidemiología , Infecciones por Chlamydia/epidemiología , Chlamydia trachomatis/genética , Estudios Transversales , ADN Bacteriano/química , ADN Bacteriano/metabolismo , Femenino , Gonorrea/diagnóstico , Gonorrea/epidemiología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico , Oportunidad Relativa , Prevalencia , Salud Reproductiva , Adulto Joven

RESUMEN

Nano-IR technology was firstly employed on bamboo fiber research with purpose to further understand the fine structure of bamboo fiber cell wall. Chemical constituent distribution of bamboo fiber was studied, and the feasibility of the novel technology was discussed by comparing with other traditional methods. The results showed that Nano-IR technology, which has made a breakthrough on diffraction limit of traditional infrared spectroscopy, can acquire nano-scale infrared spectrum of bamboo cell wall in situ condition. The characteristic peak positions of Nano-IR spectrum is basically the same with that of microscopic FTIR spectrum, indicating that Nano-IR spectrum can reveal the chemical information of bamboo cell wall. The results of the present work suggested that nano-IR technology could be an effective research tool in research of nano chemical composition distribution of bamboo cell wall.

Asunto(s)

Pared Celular , Espectrofotometría Infrarroja

RESUMEN

Study on the modified mechanism of wood cell walls, it is very important for improving treatment reagents, optimizing treatment technology, and enhancing wood density, mechanical properties, dimensional stability, and so on. Samples of plantation Chinese fir were treated gradually with synthesized water-soluble low-molecular-weight phenol formaldehyde (PF) resins under vacuum and pressure. The correlated physical and chemical properties of the treated and untreated reference samples were determined by X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), and nuclear magnetic resonance spectrometer(NMR) (Using method of Cross Polarization/Magic Angle Spinning for continuous testing) with high precision and resolution. The results showed that, after treated with water-soluble low-molecular-weight PF resin, the average values of crystallinity from the treated samples were decreased obviously, and the average reduction rate was 12.67%, 11.91% and 6.26%, respectively. Comparing water-soluble, low-molecular-weight PF resin modified Chinese fir with untreated reference samples, no new chemical shifts and characteristic peaks of functional groups from esters, ethers, etc. were present by using FTIR and ¹³C NMR spectrum. It was considered that there was no distinct chemical reaction between the water-soluble low-molecular-weight PF resin and Chinese Fir cell walls. But water-soluble low-molecular-weight PF resin could enter into the structure relatively loose, large size spaces, relatively area large amorphous regions in cell walls of Chinese fir tracheids, and form physical filling, which resulting in the decreasing of relative crystallinity. This study has important reference value for the development of new wood modification reagents and the optimization of wood modification process. The findings also provide important theoretical foundation for further proving the modification mechanisms of wood cell walls and enriching the modified theories of wood cell walls.

Asunto(s)

Pared Celular , Cunninghamia/citología , Formaldehído/química , Fenoles/química , Polímeros/química , Madera , Espectroscopía de Resonancia Magnética , Peso Molecular

RESUMEN

BACKGROUND: Although interleukin-10 (IL-10) is a potent inhibitor of allergic diseases, the association between promoter -1082/-819/-592 polymorphisms and asthma susceptibility remains inconclusive. We sought to determine if IL-10 promoter -1082/-819/-592 polymorphisms contribute to asthma susceptibility and are associated with phenotypes of atopic asthma. METHODS: Systematic computerized searches were performed. Pooled odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated by using random-effect and fixed-effect models, based on between-study heterogeneity. Subgroup analyses were performed according to age, ethnicity, and atopy. Publication bias was detected by funnel plot using Egger's test. RESULTS: A total of 4,716 asthmatic patients and 5,093 controls were included. The asthma susceptibility correlated significantly with IL-10 promoter gene -1082 polymorphism [OR (95 % CI) 1.26 (1.02, 1.55) for AA vs. AG + GG] and -592 polymorphism [OR (95 % CI) 1.12 (1.07, 1.34) for AC + AA vs. CC] (both P < 0.05), but not with -819 polymorphism (P > 0.05). Subgroup analyzes suggested that the AA versus AG + GG genotype of -1082A/G polymorphism and AC + AA versus CC genotype of -592A/C polymorphism contributed significantly to increased asthma susceptibility in adults [OR (95 % CI) 1.39 (1.03, 1.87) for -1082A/G and 1.53 (1.25, 1.87) for -592A/C polymorphism]. The Asian population [OR (95 % CI) 1.35 (1.1, 1.7) for -1082A/G and 1.4 (1.12, 1.64) for -592A/C polymorphism] and subjects with atopic asthma [OR (95 % CI) 1.49 (1.18, 1.88) for -1082A/G and 1.23 (1.01, 1.48) for -592A/C polymorphism] also had an increased susceptibility of asthma. No publication bias was detected. CONCLUSIONS: IL-10 promoter -1028A/G, -592A/C polymorphisms and their haplotypes, but not -819T/C polymorphism, correlate with asthma susceptibility.

Asunto(s)

Pueblo Asiatico/genética , Asma/genética , Interleucina-10/genética , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas , Adulto , Factores de Edad , Asma/etnología , Asma/inmunología , Estudios de Casos y Controles , Niño , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Haplotipos , Humanos , Oportunidad Relativa , Fenotipo , Factores de Riesgo

RESUMEN

In this study, we investigated the effects and the protective mechanism of ginsenoside Rd (GRd) which has been identified as one of the effective compounds from ginseng on relapsing colitis model induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats. After inducing relapsing colitis in experimental rats on two occasions by intracolonic injection of TNBS, GRd (10, 20 and 40 mg/kg) was administered to experimental colitis rats for 7 days. The inflammatory degree was assessed by macroscopic score, histology and myeloperoxidase (MPO) activity. The levels of proinflammatory cytokines, such as TNF-α, IL-1ß, and IL-6 were determined by ELISA. Mitogen-activated protein kinase (MAPK) phosphorylation was analyzed by western blotting method. The results showed that GRd markedly attenuates the inflammatory response to TNBS-induced relapsing colitis, as evidenced by improved signs, increased body weight, decreased colonic weight/length ratio, reduced colonic macroscopic and microscopic damage scores, inhibited the activity of MPO, lowered proinflammatory cytokine levels and suppressed phosphorylation of p38 and JNK. The possible mechanism of protection on experimental colitis after GRd administration was that it could reduce the accumulation of leukocytes and down-regulate multiple proinflammatory cytokines through modulation of JNK and p38 activation.

Asunto(s)

Colitis/tratamiento farmacológico , Ginsenósidos/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Animales , Peso Corporal/efectos de los fármacos , Colitis/inducido químicamente , Colitis/enzimología , Colitis/metabolismo , Colon/efectos de los fármacos , Colon/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Interleucina-1beta/antagonistas & inhibidores , Interleucina-1beta/metabolismo , Interleucina-6/antagonistas & inhibidores , Interleucina-6/metabolismo , Leucocitos/efectos de los fármacos , Leucocitos/metabolismo , MAP Quinasa Quinasa 4/metabolismo , Masculino , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Peroxidasa/antagonistas & inhibidores , Peroxidasa/metabolismo , Fosforilación/efectos de los fármacos , Ratas , Ratas Wistar , Ácido Trinitrobencenosulfónico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo

RESUMEN

X-ray diffraction technique, pit aperture observing technique, polarized light microscope technique and near infrared spectrum technique were used separately to test the wood microfibril angle of Chinese fir, and the results were as follows: For the identical tree of Chinese fir, the average microfibril angle obtained by the polarized light microscope technique was the biggest, followed by those obtained by X-ray diffraction technique, and then by polarized light microscope technique, but the difference in the average microfibril angle was not significant. For the different annual rings, the microfibril angle obtained by X-ray diffraction technique became the biggest after the 20th annual ring, the fluctuation of the microfibril angle got by the pit aperture observing technique were big, but the fluctuation got by the polarized light microscope technique was just the reverse. The measurement value curves got by the three techniques were fitted well, and the difference in the average microfibril angle was not significant between different annual rings. For the microfibril angle of the same annual ring, the difference between the maximum and the minimum value tested by the polarized light microscope technique was less than 4 degrees, but the difference tested by the pit aperture observing technique achieved 21.53 degrees, and the standard deviation achieved 4.75. The near infrared spectrum and the Xray diffraction techniques were all called nondestructive testing techniques. The model set up by the two techniques was very good because of its high prediction and repeatability, and the model was also good for online analysis. The R2 of calibration model and tested model achieved 0.81 and 0.75 respectively,and the standard error of calibration and prediction were 1.79 and 2.02 respectively. In addition, the near infrared spectrum technique could be also used with the other three techniques to predict the wood microfibril angle, showing the superiority of the near infrared spectrum technique. Meanwhile, the advantages and shortcomings were analyzed for the four kinds of measurement techniques.