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1.
Front Plant Sci ; 14: 1271325, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37929166

RESUMEN

High loss and low nitrogen (N) efficiency in agricultural production is severe. Also, ammonia volatilization and N leaching aggravated environmental pollution. The eutrophication of surface water and the emissions of N2O increased, hence green fertilization management urgently needs to be rationalized. Coordinating N supply from different sources has been shown to reduce environmental pollution. Therefore, this study was dedicated to clarifying the transport of N sources in the rice-wheat rotation system. The stable isotope tracer technology was used to label fertilizer (F), soil (T), and straw (J) with 15N, respectively. The utilization of N by crops (the N ratio in organs), as well as the residual N in soil and loss status, were measured. According to the potential of response to N, all the wheat cultivars were divided into groups with high (HNV) and low efficiency (LNV). The N contribution ratio showed that 43.28%~45.70% of total N accumulation was from T, while 30.11%~41.73% and 13.82%~24.19% came from F and J. The trend in soil N residue (T > F > J) was consistent with the above, while it was the opposite in N loss (T< F< J). The seasonal effectiveness showed that T achieved the highest N utilization efficiency (31.83%~44.69%), followed by F (21.05%~39.18%) and J (11.02%~16.91%). The post-season sustainability showed that T decreased the most in soil N residue (2.08%~12.53%), and F decreased the most in N accumulation (9.64%~18.13%). However, J showed an increase in N recovery rate (2.87%~5.89%). N translocation and distribution showed that N from different sources in grains was significantly higher than that in stems, glumes, and leaves. The ratio of HNV (75.14%~79.62%) was higher than that of LNV (71.90%~74.59%) in grain, while it was the opposite in other organs. Plant N accumulation, soil N supply, and straw N transformation were determined jointly by the three N sources, thus reducing N loss and N2O production. Therefore, the results will highlight the insights for constructing local N and emission reduction models.

2.
J Colloid Interface Sci ; 639: 355-368, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36812852

RESUMEN

Adsorption and wettability are crucial components of catalytic oxidation. To increase the reactive oxygen species (ROS) generation/utilization efficiency of peroxymonosulfate (PMS) activators, defect engineering and 2D nanosheet characteristics were used to regulate electronic structures and expose more active sites. Two-dimensional (2D) super-hydrophilic heterostructure by connecting cobalt species modified nitrogen vacancy-rich g-C3N4 (Vn-CN) and LDH (Vn-CN/Co/LDH) with high-density active sites and multi-vacancies, as well as high conductivity and adsorbability, to expedite ROS generation. The degradation rate constant of ofloxacin (OFX) was 0.441 min-1 via the Vn-CN/Co/LDH/PMS system, which was 1-2 orders greater than in the previous studies. Confirmation of the contribution ratios of various reactive oxygen species (ROS), SO4·- and 1O2 in bulk solution, O2·- on the catalyst surface was the most abundant ROS. The catalytic membrane was constructed utilizing Vn-CN/Co/LDH as the assembly element. The 2D membrane achieved the continuous effective discharge of OFX in the simulated water after 80 h/4 cycles of continuous flowing-through filtration-catalysis. This study provides fresh insights into designing a PMS activator for environmental remediation activated on demand.

3.
Water Environ Res ; 94(8): e10773, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35946784

RESUMEN

Multi-isotope method was used to analyze the migration and transformation characteristics of nitrogen in groundwater in the center of a typical confined water basin, and a simplified isotope mixing model was established to quantify the contribution of potential nitrate sources in the center of the basin. Based on the water quality monitoring results, the contour map of nitrate concentration in groundwater in the center of the basin was drawn. The results showed that the nitrate concentration in groundwater in the center of the basin increased gradually from upstream to downstream. The high value area of nitrate concentration in phreatic water is mainly affected by agricultural activities and infiltration of sewage discharge from upstream urban areas. The high value area of nitrate concentration in confined water is mainly due to the water level depression funnel caused by large exploitation of confined water. The quantitative results of N-O isotope mixing model for potential nitrate sources show that the main recharge sources of groundwater in the center of the basin are atmospheric precipitation, agricultural irrigation water, and the lateral inflow of upstream groundwater. Agricultural irrigation water has the highest contribution rate of 67.01%. The main recharge sources of confined aquifer in the center of the basin are phreatic water leakage and lateral inflow of upstream confined water. The contribution rate of upstream confined water is between 45.55% and 56.35%, which is basically maintained at about 50%. Compared with the calculation results of D-O isotope mixing model, the accuracy of the established N-O isotope mixing model meets the basic requirements. The results of this study can provide technical reference and theoretical support for the identification and quantitative research of potential nitrate sources in groundwater under the same type of hydrogeological conditions. PRACTITIONER POINTS: Multiple isotope fingerprint comparison to identify nitrate source contribution ratio. Migration and transformation of nitrogen in the center of a typical confined water basin Simplified the traditional isotope mixing model to quickly quantify the source of contamination.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente/métodos , Nitratos , Nitrógeno , Isótopos de Nitrógeno/análisis , Contaminantes Químicos del Agua/análisis
4.
Materials (Basel) ; 15(10)2022 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-35629593

RESUMEN

Robotic milling has broad application prospects in many processing fields. However, the milling performance of a robot in a certain posture, such as in face milling or grooving tasks, is extremely sensitive to process parameters due to the influence of the serial structure of the robot system. Improper process parameters are prone to produce machining defects such as low surface quality. These deficiencies substantially decrease the further application development of robotic milling. Therefore, this paper selected a certain posture and carried out the robotic flat-end milling experiments on a 7075-T651 high-strength aeronautical aluminum alloy under dry conditions. Milling load, surface quality and vibration were selected to assess the influence of process parameters like milling depth, spindle speed and feed rate on the milling performance. Most notably, the contribution ratio based on the analysis of variance (ANOVA) was introduced to statistically investigate the relation between parameters and milling performance. The obtained results show that milling depth is highly significant in milling load, which had a contribution ratio of 69.25%. Milling depth is also highly significant in vibration, which had a contribution ratio of 51.41% in the X direction, 41.42% in the Y direction and 75.97% in the Z direction. Moreover, the spindle speed is highly significant in surface roughness, which had a contribution ratio of 48.02%. This present study aims to quantitatively evaluate the influence of key process parameters on robotic milling performance, which helps to select reasonable milling parameters and improve the milling performance of the robot system. It is beneficial to give full play to the advantages of robots and present more possibilities of robot applications in machining and manufacturing.

5.
Sci Total Environ ; 829: 154693, 2022 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-35318059

RESUMEN

E1 and E2 are considered as the parent natural estrogens (NEs) in human metabolism pathways of NEs, while the enantiomer of E2, αE2 was not included and ignored. In this study, αE2 along with the other eleven NEs with estrogenic activities were found in six healthy human urines with the total concentration levels of 62.9-99.3 µg/L. The concentration contributed ratios (CCRs) of αE2 to the total twelve NEs ranged from 4.7% to 11.0% with an average CCR of 7.0%. On the basis of the average CCR, αE2 was 1.5 times that of E2, which suggested that αE2 was one important NE in humans. As the main source of NEs in municipal wastewater was derived from human urine, αE2 should also be an important NE in municipal wastewater that can be proven by previous limited studies, in which the municipal effluent concentrations of αE2 ranged from not detection to 144.2 ng/L with an average concentration of 11.9 ng/L, indicating αE2 in municipal effluent was an important source to the natural environment. Although αE2 is a NE with weak estrogenic potency, the estrogenic effect of αE2 via municipal effluent to its receiving water body cannot be ignored because it can be bio-transformed into E2 under aerobic environment. This work is the first to indicate that αE2 is an ignored NE in human and its environmental risk via municipal effluent discharging cannot be ignored, which should be paid with attention.


Asunto(s)
Estradiol , Contaminantes Químicos del Agua , Estradiol/análisis , Estrógenos/análisis , Estrona/análisis , Humanos , Medición de Riesgo , Eliminación de Residuos Líquidos , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
6.
Sci Total Environ ; 803: 150042, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34525709

RESUMEN

Although four major natural estrogens (i.e., estrone (E1), 17ß-estradiol (E2), estriol (E3) and 17α-estradiol (αE2)) have been commonly found in livestock urine, this study reports the occurrence of eight other less-studied natural estrogens in urine of swine and cattle, i.e. 2-hydroxyestone (2OHE1), 4-hydroxyestrone (4OHE1), 2-hydroxyestradiol (2OHE2), 4-hydroxyestradiol (4OHE2), 16-epiestriol (16epiE3), 16α-hydroxyestrone (16αE1), 16-ketoestradiol (16ketoE2), and 17epiestriol (17epiE3). Results showed that each estrogen was found in at least one urine sample, and 6 of 8 the less-studied estrogens were present at frequencies of ≥90% in boars, ≥70% in sows, and ≥50% in dairy cattle. Five of eight the less-studied estrogens were present at frequencies of ≥33.3% in four beef cattle and one bull. On a concentration basis, the 8 less-studied natural estrogens represented 73.2%, 85.2%, 39.9%, 47.7%, 26.9%, 56.0% and 44.1% of total concentrations of the twelve natural estrogens when combining data from all animals. Similar results were observed based on estrogen equivalence, which indicated these newly detected eight less-studied natural estrogens were not negligible. This work is the first to figure out the importance of these less-studied natural estrogens in livestock urine, and their potential environmental risks associated with discharge of livestock wastewater should be urgently assessed in a holistic manner.


Asunto(s)
Estrógenos , Estrona , Animales , Bovinos , Estradiol , Femenino , Ganado , Masculino , Porcinos , Aguas Residuales
7.
Huan Jing Ke Xue ; 42(4): 1839-1846, 2021 Apr 08.
Artículo en Chino | MEDLINE | ID: mdl-33742819

RESUMEN

The Three Gorges Reservoir area (TGRA) is a critical water source protection area in China and one of the regions with rapid economic development in the Yangtze River basin. Non-point source pollution is the leading cause of the deterioration of the water environment in the TGRA; therefore, studying the non-point source pollution status in the TGRA is of great significance to the regional ecological security and sustainable development. The improved export coefficient model was used to estimate the total non-point source nitrogen and phosphorus pollution loads in the TGRA from 1990 to 2015, the spatial and temporal characteristics of the non-point source nitrogen and phosphorus pollution were analyzed, and the primary sources of pollution were determined by calculating the contribution rate of each pollution source. The results concluded that the nitrogen and phosphorus pollution loads were highest in the hinterland of the reservoir, followed by the end of the reservoir, with the lowest in the head of the reservoir, showing significant spatial heterogeneity in the TGRA. The total loads of nitrogen and phosphorus pollution increased firstly and then decreased, which reached the highest value in 2000 and the lowest value in 2015. The contribution rate of each pollution source to the nitrogen and phosphorus pollution loads, from highest to lowest, were land use, rural life, livestock, and poultry farming. Among them, the land use type of dry land was the predominant source of non-point source nitrogen and phosphorus pollution.

8.
J Hazard Mater ; 407: 124865, 2021 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-33359977

RESUMEN

Biochar has been extensively studied as a promising carrier material for fertilizers and an ideal adsorbent for the removal of pesticides. Yet, the application of biochar for simultaneously eliminating the pollution from the agricultural use of fertilizers and pesticides remains unexplored. Herein, we develop P-loaded biochar-based fertilizers (PBC) by the co-pyrolysis of cotton straw and H3PO4. The slow-release performance of PBC and their adsorption properties toward pesticides are investigated. The results indicate that the PBC leads to the improvement of adsorption performance, with the maximum adsorption capacities of lambda-cyhalothrin (LAC) for PBC and pristine biochar are 55.90 mg/g and 42.71 mg/g, respectively. Additionally, the adsorption of LAC is beneficial for the improvement of slow-release performance of PBC. The release ratios of P from PBC within 30 days reach 100.0% and 83.5% in water and LAC solution, respectively, demonstrating the existence of synergistic effects between the adsorption of pesticides and the slow release of nutrients. The mechanistic investigation reveals that the pretreatment of H3PO4 facilitates to activate more surface functional groups of PBC, contributing greatly to the improved adsorption of LAC. The adsorption of LAC reduces the BET of PBC with pore filling, enabling slower release rate of nutrients from PBC.


Asunto(s)
Plaguicidas , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Fertilizantes , Contaminantes Químicos del Agua/análisis
9.
Environ Sci Pollut Res Int ; 26(36): 36710-36719, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31741275

RESUMEN

Due to rapid growth of industrialization and human activities, such as mining and smelting, lead (Pb) has become a major environmental contaminant. As Pb can pose risks to human health, preventing Pb pollution in wheat is important for food safety, requiring accurate verification of pollution sources. Pb concentrations and isotope ratio levels in soil, in the atmosphere, and wheat tissue (root, stem, leaf, grain) in an area of high-Pb deposition (in the vicinity of a Pb smelter in Jiyuan city) and an area of low deposition (the northwest suburb of Zhengzhou city) were examined. The Pb isotope ratio and the binary mixed model were used to quantify the contribution of soil and atmospheric deposition to Pb content in wheat tissues. Results show that Pb content in soil, atmospheric deposition, and wheat in the high deposition area were significantly higher than those in the low deposition area. Pb content in soil, atmospheric deposition, wheat roots, stems, leaves, and grains in the high-deposition area were 355.32 ± 14.78, 5477.90 ± 187.85, 158.72 ± 9.56, 21.36 ± 1.72, 26.49 ± 1.96, and 0.94 ± 0.02 mg kg-1, respectively. Pb content in the low-deposition area were 6.10 ± 0.75, 78.50 ± 4.35, 2.47 ± 0.23, 1.03 ± 0.07, 2.11 ± 0.13, and 0.08 ± 0.01 mg kg-1, respectively. The Pb isotope ratio recorded obvious differences between soil and atmospheric deposition in the two areas. Combined with the significant correlation between Pb isotopes in various tissues of wheat and environmental media, and analysis of the isotopic composition characteristics of wheat and environmental media, in the high-deposition area, the contribution rate of atmospheric deposition in wheat roots, stems, leaves, and grains was 14%, 66%, 84%, and 77%, respectively. And the soil contribution rate was 86%, 34%, 16%, 23%, respectively. In the low-deposition area, the contribution rate of atmospheric deposition in wheat roots, stems, leaves, and grains was 49%, 73%, 93%, and 83%, respectively. And the soil contribution rates were 51%, 27%, 7%, and 17%, respectively. In the low-Pb deposition area, the contribution rate of atmospheric deposition in wheat was higher than that in the high-deposition area. Atmospheric deposition was the main source of Pb in grains, leaves, and stems of wheat in different depositional areas. Pb in wheat roots mainly derives from soil, and the Pb contribution rate of soil to wheat roots in the high-deposition area was significantly higher than that in the low-deposition area.


Asunto(s)
Monitoreo del Ambiente , Plomo/análisis , Contaminantes del Suelo/análisis , Triticum/química , Atmósfera , Grano Comestible/química , Contaminación Ambiental/análisis , Humanos , Isótopos/análisis , Minería , Suelo , Triticum/crecimiento & desarrollo
10.
Front Psychiatry ; 10: 241, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31105601

RESUMEN

College students' mobile phone addiction is negatively associated with physical and mental health and academic performance. Many self-made questionnaires are currently being administered to Chinese college students to evaluate the mobile phone addiction tendency. Using the univariate generalizability theory and multivariate generalizability theory, this study investigated the psychometric properties and the internal structure of the Mobile Phone Addiction Tendency Scale (MPATS), the most widely used survey questionnaire assessing the status of Chinese college students' mobile addiction. Data were a sample of 1,253 college students from the southwest of China. Primary analytic approaches included the generalizability design of univariate random measurement mode p × (i:h) and multivariate random measurement mode p˙ × i°. Results showed that the variance component of the participants and the variation related to the participants explained most of the variation of the scale, while the variance component of the items was small, and the generalizability coefficient and dependability index of the scale were 0.88 and 0.85. In the multivariate generalizability analysis, the variance component of the participants and the variation related to the participants accounted for most of the variation of the scale and the variance component of the items was small. The generalizability coefficients of withdrawal symptoms, salience, social comfort, and mood changes were 0.64-0.80, and the dependability indexes were 0.63-0.77. However, the generalizability coefficient and reliability index of universe score were 0.91 and 0.90. In addition, the contribution ratio of the four dimensions to the universe score variance was different from the assignment intention of the initial scale. Recommendations were discussed on the improvement of the test reliability for each dimension.

11.
Huan Jing Ke Xue ; 39(2): 765-773, 2018 Feb 08.
Artículo en Chino | MEDLINE | ID: mdl-29964840

RESUMEN

The process of phytoplankton succession and change in primary productivity are directly determined by the seasonal variations in nutrients in tributary bays of channel reservoirs. This study aimed at analyzing the effects of the main nutrient sources on seasonal distribution of nutrients in Xiangxi Bay based on the field data collected in 2010 and 2011. The tracing inorganic ions were Cl- and Na+ that showed significant differences (P<0.01) between the mainstream and the tributary. The nutrient contribution rates of different sources were calculated by the binary linear model. The results showed that the nutrient contribution rate of the mainstream was more than 75% during the dry season and the impoundment period. The intrusion of the mainstream was the main source of nutrients in Xiangxi Bay. The difference in the contribution rates between the mainstream and the upstream decreased during the pre-flood drawdown period and the flood season. The concentration of total phosphorus was higher in the upstream, while the concentration of total nitrogen was higher in the mainstream. The patterns of density currents were different and the nutrient contribution rates of different sources changed accordingly. Therefore, the nutrients of Xiangxi Bay changed regularly in different operation periods of the Three Gorges Reservoir.


Asunto(s)
Bahías , Nitrógeno/análisis , Fósforo/análisis , Fitoplancton/crecimiento & desarrollo , Estaciones del Año , China , Monitoreo del Ambiente
12.
Artículo en Coreano | WPRIM (Pacífico Occidental) | ID: wpr-740920

RESUMEN

OBJECTIVES: With the increasing number of single households and so-called Honbab-jok, those who eat alone, people tend to enjoy convenient and simple meals, such as single dish meals. This study was performed to provide data on the energy and nutrient content, and nutritional adequacy of single-dish meal. METHODS: From the literature reviews, 61 types of single-dish meals were selected, and divided into 4 groups (steamed rice, noodle, porridge, and sandwich·burger), and a further 11 sub-groups (bibimbab, fried rice, topped rice, rolled rice/warm noodle, cold noodle, seasoned noodle, dukgook/porridge/, and sandwich, burger). In addition, 382 junior high school students from Gyeonggi, Sejong, Jeonbuk, and Chungnam areas were recruited for the survey. The survey questionnaires were composed of the characteristics, preference, and intake frequency of single-dish meals. The representative energy content (arithmetic mean) of single-dish meals were calculated, and compared with the energy contents of preference and intake frequency-weighted values adjusted. The representative nutrient contents, energy contribution ratio, and INQ (index of nutritional quality) of a single-dish meal were calculated for a nutritional adequacy evaluation. RESULTS: The study subjects considered a single-dish meal as tasty, simple and fast to prepare, inexpensive, nutritious, and no low calorie food. The preference scores of all but 1 sub-group of single-dish meals were ≥ 5.00 (5.00~5.97), and 1 sub-group (porridge) was 4.67 on a 7-point scale. The intake frequency of 11 sub-groups were 0.31~1.71/week, porridge was the lowest at 0.31 and warm noodles was the highest at 1.71. Fried rice, rolled rice, and warm noodle' intake frequency were ≥ 1/week. The representative energy of steamed rice, noodle, sandwich·burger were 443, 429, and 428 kcal, respectively, and that of porridge was 264 kcal. Less than 5% differences in the representative energy of 4 groups were observed when adjusted for the preference or intake frequency-weighted values. The energy contribution ratio of macro-nutrients calculations showed that porridge was a high carbohydrate and low fat food, whereas sandwich·burger were high fat and low carbohydrate foods. The INQ of calcium and vitamin C were less than 1.0 in all 4 food groups, but the INQ of protein and thiamin were > 1.0 in all 4 single-dish food groups. CONCLUSIONS: The representative energy in the 4 groups of single-dish meal was 264~450 kcal, which is a rather low calorie meal, and the energy contribution ratio of macro-nutrients were inadequate. The protein and thiamin levels were sufficient but the calcium and vitamin C levels were insufficient in all 4 groups of a single-dish meal judged by the INQ. The additional intake of fruits and milk·dairy products between meals with a single-dish meal, supply of calcium and vitamin C may increase, which will result in an improved nutritional balance.


Asunto(s)
Humanos , Ácido Ascórbico , Calcio , Composición Familiar , Frutas , Comidas , Estaciones del Año , Vapor
13.
Artículo en Coreano | WPRIM (Pacífico Occidental) | ID: wpr-741010

RESUMEN

OBJECTIVES: With the increasing number of single households and so-called Honbab-jok, those who eat alone, people tend to enjoy convenient and simple meals, such as single dish meals. This study was performed to provide data on the energy and nutrient content, and nutritional adequacy of single-dish meal. METHODS: From the literature reviews, 61 types of single-dish meals were selected, and divided into 4 groups (steamed rice, noodle, porridge, and sandwich·burger), and a further 11 sub-groups (bibimbab, fried rice, topped rice, rolled rice/warm noodle, cold noodle, seasoned noodle, dukgook/porridge/, and sandwich, burger). In addition, 382 junior high school students from Gyeonggi, Sejong, Jeonbuk, and Chungnam areas were recruited for the survey. The survey questionnaires were composed of the characteristics, preference, and intake frequency of single-dish meals. The representative energy content (arithmetic mean) of single-dish meals were calculated, and compared with the energy contents of preference and intake frequency-weighted values adjusted. The representative nutrient contents, energy contribution ratio, and INQ (index of nutritional quality) of a single-dish meal were calculated for a nutritional adequacy evaluation. RESULTS: The study subjects considered a single-dish meal as tasty, simple and fast to prepare, inexpensive, nutritious, and no low calorie food. The preference scores of all but 1 sub-group of single-dish meals were ≥ 5.00 (5.00~5.97), and 1 sub-group (porridge) was 4.67 on a 7-point scale. The intake frequency of 11 sub-groups were 0.31~1.71/week, porridge was the lowest at 0.31 and warm noodles was the highest at 1.71. Fried rice, rolled rice, and warm noodle' intake frequency were ≥ 1/week. The representative energy of steamed rice, noodle, sandwich·burger were 443, 429, and 428 kcal, respectively, and that of porridge was 264 kcal. Less than 5% differences in the representative energy of 4 groups were observed when adjusted for the preference or intake frequency-weighted values. The energy contribution ratio of macro-nutrients calculations showed that porridge was a high carbohydrate and low fat food, whereas sandwich·burger were high fat and low carbohydrate foods. The INQ of calcium and vitamin C were less than 1.0 in all 4 food groups, but the INQ of protein and thiamin were > 1.0 in all 4 single-dish food groups. CONCLUSIONS: The representative energy in the 4 groups of single-dish meal was 264~450 kcal, which is a rather low calorie meal, and the energy contribution ratio of macro-nutrients were inadequate. The protein and thiamin levels were sufficient but the calcium and vitamin C levels were insufficient in all 4 groups of a single-dish meal judged by the INQ. The additional intake of fruits and milk·dairy products between meals with a single-dish meal, supply of calcium and vitamin C may increase, which will result in an improved nutritional balance.


Asunto(s)
Humanos , Ácido Ascórbico , Calcio , Composición Familiar , Frutas , Comidas , Estaciones del Año , Vapor
14.
Biomed Eng Lett ; 7(3): 221-227, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30603169

RESUMEN

We propose a noise reduction method for magnetocardiograms (MCGs) based on independent component analysis (ICA). ICA is useful to separate the noise and signal components, but ICA-based automatic noise reduction faces two main difficulties: the dimensional contraction process applied after the principal component analysis (PCA) used for preprocessing, and the component selection applied after ICA. The results of noise reduction vary among people, because these two processes typically depend on personal qualitative evaluations of the obtained components. Therefore, automatic quantitative ICA-based noise reduction is highly desirable. We will focus on the first difficulty, by improving the index used in the dimensional contraction process. The index used for component ordering after PCA affects the accuracy of separation obtained with ICA. The contribution ratio is often used as an index. However, its efficacy is highly dependent on the signal-to-noise ratio (SNR) it unsuitable for automation. We propose a kurtosis-based index, whose efficacy does not depend on SNR. We compare the two decision indexes through simulation. First, we evaluate their preservation rate of the MCG information after dimensional contraction. In addition, we evaluate their effect on the accuracy of the ICA-based noise reduction method. The obtained results show that the kurtosis-based index does preserve the MCG signal information through dimensional contraction, and has a more consistent behavior when the number of components increases. The proposed index performs better than the traditional index, especially in low SNRs. As such, it paves the way for the desired noise reduction process automation.

15.
Int J Environ Res Public Health ; 13(4): 396, 2016 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-27043605

RESUMEN

Reinforcing the insulation and airtightness of buildings and the use of building materials containing new chemical substances have caused indoor air quality problems. Use of sorptive building materials along with removal of pollutants, constant ventilation, bake-out, etc. are gaining attention in Korea and Japan as methods for improving such indoor air quality problems. On the other hand, sorptive building materials are considered a passive method of reducing the concentration of pollutants, and their application should be reviewed in the early stages. Thus, in this research, activated carbon was prepared as a sorptive building material. Then, computational fluid dynamics (CFD) was conducted, and a method for optimal installation of sorptive building materials was derived according to the indoor environment using the contribution ratio of pollution source (CRP) index. The results show that a method for optimal installation of sorptive building materials can be derived by predicting the contribution ratio of pollutant sources according to the CRP index.


Asunto(s)
Contaminación del Aire Interior/prevención & control , Materiales de Construcción , Adsorción , Contaminantes Atmosféricos/química , Carbono/química , Hidrodinámica , Japón , República de Corea , Ventilación
16.
Int J Occup Saf Ergon ; 22(2): 228-40, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26652099

RESUMEN

Procedures in the development process of crane cabins are arbitrary and subjective. Since approximately 42% of incidents in the construction industry are linked to them, there is a need to collect fresh anthropometric data and provide additional recommendations for design. In this paper, dimensioning of the crane cabin interior space was carried out using a sample of 64 crane operators' anthropometric measurements, in the Republic of Serbia, by measuring workspace with 10 parameters using nine measured anthropometric data from each crane operator. This paper applies experiments run via full factorial designs using a combined traditional and Taguchi approach. The experiments indicated which design parameters are influenced by which anthropometric measurements and to what degree. The results are expected to be of use for crane cabin designers and should assist them to design a cabin that may lead to less strenuous sitting postures and fatigue for operators, thus improving safety and accident prevention.


Asunto(s)
Fenómenos Biomecánicos , Pesos y Medidas Corporales , Espacios Confinados , Industria de la Construcción , Diseño de Equipo/métodos , Índice de Masa Corporal , Humanos , Salud Laboral , Postura , Serbia
17.
Xenobiotica ; 45(2): 107-23, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25180976

RESUMEN

1. 4-[2((1R,2R)-2-Hydroxycyclohexylamino)-benzothiazol-6-yloxyl]-pyridine-2-carboxylic acid methylamide (BLZ945) is a small molecule inhibitor of CSF-1R kinase activity within osteoclasts designed to prevent skeletal related events in metastatic disease. Key metabolites were enzymatically and structurally characterized to understand the metabolic fate of BLZ945 and pharmacological implications. The relative intrinsic clearances for metabolites were derived from in vitro studies using human hepatocytes, microsomes and phenotyped with recombinant P450 enzymes. 2. Formation of a pharmacologically active metabolite (M9) was observed in human hepatocytes. The M9 metabolite is a structural isomer (diastereomer) of BLZ945 and is about 4-fold less potent. This isomer was enzymatically formed via P450 oxidation of the BLZ945 hydroxyl group, followed by aldo-keto reduction to the alcohol (M9). 3. Two reaction phenotyping approaches based on fractional clearances were applied to BLZ945 using hepatocytes and liver microsomes. The fraction metabolized (fm) or contribution ratio was determined for each metabolic reaction type (oxidation, glucuronidation or isomerization) as well as for each metabolite. The results quantitatively illustrate contribution ratios of the involved enzymes and pathways, e.g. the isomerization to metabolite M9 accounted for 24% intrinsic clearance in human hepatocytes. In summary, contribution ratios for the Phase I and Phase II pathways can be determined in hepatocytes.


Asunto(s)
Benzotiazoles/metabolismo , Hepatocitos/enzimología , Microsomas Hepáticos/enzimología , Ácidos Picolínicos/metabolismo , Inhibidores de Proteínas Quinasas/metabolismo , Receptor de Factor Estimulante de Colonias de Macrófagos/antagonistas & inhibidores , Benzotiazoles/química , Benzotiazoles/farmacología , Línea Celular , Proliferación Celular/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/metabolismo , Humanos , Redes y Vías Metabólicas , Ácidos Picolínicos/química , Ácidos Picolínicos/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Receptor de Factor Estimulante de Colonias de Macrófagos/química , Receptor de Factor Estimulante de Colonias de Macrófagos/metabolismo , Transducción de Señal/efectos de los fármacos
18.
Mass Spectrom (Tokyo) ; 3(1): A0032, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-26819874

RESUMEN

Endophytic nitrogen-fixing organisms have been isolated from the aerial parts of field-grown sweet potato (Ipomoea batatas). The (15)N dilution method, which is based on the differences in stable nitrogen isotope ratios, is useful for measuring nitrogen fixation in the field. In this study, seedlings of two sweet potato cultivars, 'Beniazuma' and 'Benikomachi,' were transplanted into an alluvial soil that had been treated with organic improving material in advance. Whole plants were sampled every 2 or 3 weeks. After separating plants into tuberous roots and leaves, the fresh weights of the samples were measured, and the nitrogen content and natural (15)N content of leaves were determined with an elemental analyzer and an isotope ratio mass spectrometer linked to an elemental analyzer, respectively. The contribution of nitrogen fixation derived from atmospheric N2 in sweet potato was calculated by assuming that leaves at 2 weeks after transplanting were in a non-nitrogen-fixing state. The contribution ratios of nitrogen fixation by nitrogen-fixing endophytes in leaves of both sweet potato cultivars increased rapidly from 35 to 61 days after transplanting and then increased gradually to 55-57% at 90 days after transplanting. Over the course of the sweet potato growing season, the activity of nitrogen-fixing endophytes in leaves began to increase at about 47 days after transplanting, the weight of leaves increased rapidly, and then growth of tuberous roots began a few weeks later. Our findings indicate that nitrogen-fixing endophytes will be activated under inorganic nitrogen-free sweet potato cultivation, allowing for growth of the tuberous roots.

19.
Yonsei Medical Journal ; : 415-422, 2006.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-102207

RESUMEN

The medial sural cutaneous nerve (MSCN) and peroneal communicating nerve (PCN) conjoin in the calf area to form the sural nerve (SN). In previous anatomic studies, there was unresolved debate as to the main contributor to the sural nerve, and the relative contributions of MSCN and PCN had not been studied. The purpose of this study is to determine their relative neurophysiologic contributions to the SN by nerve conduction study (NCS). A total of 47 healthy subjects (25 males and 22 females, mean age 29.6+/-10.4 yrs, range 20-59 yrs) participated in the study. This study employed the orthodromic nerve conduction technique: stimulation at the ankle and recording at the mid calf (SN); specifically, we preformed stimulation at the mid calf (MSCN, PCN) and recording at 14cm proximal to the middle of the popliteal fossa (MSCN) and fibular head (PCN). The onset and peak latencies (ms) were SN 2.3+/-0.2 and 3.0+/-0.2; MSCN 2.1+/-0.2 and 2.8+/-0.2; and PCN 2.1+/-0.2 and 2.8+/-0.2. The peak-to-peak amplitudes (micro) and areas (nVsec) of the SN, MSCN, and PCN were 9.7+/-3.9, 7.0+/-4.7, and 5.0+/-3.2; and 7.2+/-2.9, 5.7+/-3.4, and 4.0+/-2.4, respectively. The side-to-side difference was not statistically significant. The main contributor to the SN was found to be the MSCN. The relative contribution ratio of the MSCN to the PCN was 1.37:1 by amplitude and 1.42:1 by area. However, in 32.9% of the subjects, the contribution of the PCN was greater than that of the MSCN.


Asunto(s)
Persona de Mediana Edad , Masculino , Humanos , Femenino , Adulto , Nervio Sural/anatomía & histología , Nervio Peroneo/anatomía & histología , Conducción Nerviosa/fisiología
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