20 research outputs found
Dietary Exposure Estimates of 14 Trace Elements in Xuanwei and Fuyuan, Two High Lung Cancer Incidence Areas in China
Xuanwei and Fuyuan, located in the Yunnan province in southwest of China, are known to have a strikingly high incidence of lung cancer. Among the many factors that have been explored, the association between lung cancer and trace elements has not received enough attention. In this study, dietary samples were collected from 60 families of the lung cancer and control groups and abundances of 14 trace elements were determined using inductively coupled-plasma mass spectroscopy. Accuracy and sensitivity of the method were demonstrated by analyzing national standard reference materials. The results showed that the dietary intake of the trace elements contributed 96.6% of total intake. Among the 14 elements tested, cadmium and titanium were found to be present at a significantly higher level in the food consumed by the cancer group than by the control group. The intake of selenium by the population living in the areas is much lower than what it should be, with the people in the cancer group experiencing even more severe selenium deficiency. In addition, in both groups, the intakes of several essential elements (iron, copper, and zinc) from food and the drinking water were found to be significantly lower than required according to the Chinese Dietary Reference Intakes. The present study of the relationship between trace element intakes of lung cancer cases and controls provides important information urgently needed for the assessment of lung cancer risk of healthy subjects. The study also gives rational dietary suggestions to local residents which is important to the early diagnosis and pretreatment of lung cancer.Xuanwei and Fuyuan, located in the Yunnan province in southwest of China, are known to have a strikingly high incidence of lung cancer. Among the many factors that have been explored, the association between lung cancer and trace elements has not received enough attention. In this study, dietary samples were collected from 60 families of the lung cancer and control groups and abundances of 14 trace elements were determined using inductively coupled-plasma mass spectroscopy. Accuracy and sensitivity of the method were demonstrated by analyzing national standard reference materials. The results showed that the dietary intake of the trace elements contributed 96.6% of total intake. Among the 14 elements tested, cadmium and titanium were found to be present at a significantly higher level in the food consumed by the cancer group than by the control group. The intake of selenium by the population living in the areas is much lower than what it should be, with the people in the cancer group experiencing even more severe selenium deficiency. In addition, in both groups, the intakes of several essential elements (iron, copper, and zinc) from food and the drinking water were found to be significantly lower than required according to the Chinese Dietary Reference Intakes. The present study of the relationship between trace element intakes of lung cancer cases and controls provides important information urgently needed for the assessment of lung cancer risk of healthy subjects. The study also gives rational dietary suggestions to local residents which is important to the early diagnosis and pretreatment of lung cancer
Non-Contact Monitoring of Human Vital Signs Using FMCW Millimeter Wave Radar in the 120 GHz Band
A non-contact heartbeat/respiratory rate monitoring system was designed using narrow beam millimeter wave radar. Equipped with a special low sidelobe and small-sized antenna lens at the front end of the receiving and transmitting antennas in the 120 GHz band of frequency-modulated continuous-wave (FMCW) system, this sensor system realizes the narrow beam control of radar, reduces the interference caused by the reflection of other objects in the measurement background, improves the signal-to-clutter ratio (SCR) of the intermediate frequency signal (IF), and reduces the complexity of the subsequent signal processing. In order to solve the problem that the accuracy of heart rate is easy to be interfered with by respiratory harmonics, an adaptive notch filter was applied to filter respiratory harmonics. Meanwhile, the heart rate obtained by fast Fourier transform (FFT) was modified by using the ratio of adjacent elements, which helped to improve the accuracy of heart rate detection. The experimental results show that when the monitoring system is 1 m away from the human body, the probability of respiratory rate detection error within ±2 times for eight volunteers can reach 90.48%, and the detection accuracy of the heart rate can reach 90.54%. Finally, short-term heart rate measurement was realized by means of improved empirical mode decomposition and fast independent component analysis algorithm
A Rapid Screening Method for the Determination of Seventy Pesticide Residues in Soil Using Microwave-Assisted Extraction Coupled to Gas Chromatography and Mass Spectrometry
A rapid screening method using microwave-assisted extraction (MAE) in combination with gas chromatography and mass spectrometry for the determination of 70 pesticide residues in soil was established. The pesticides included 27 organophosphorus pesticides (OPPs), 29 organochlorine pesticides (OCPs), nine pyrethroids, and five carbamates. Parameters that could affect the efficiency of extraction, such as temperature, time, and solvent, were investigated. The condition of the extraction, under which recoveries of all 70 pesticides ranged from 70% to 120%, was optimized with a 1: 1 (V/V) mixture of acetone and hexane, a temperature of 100 degrees C, and an extraction time of 10 min. All compounds studied could be recovered in good yields and with relative standard deviations (RSDs) lower than 20%. The linearity of the method for all the pesticides was greater than 0.99 over a concentration range of 0.1-5 mu g/g. The detection limits varied from 0.5 to 211.25 ng/g. Interday and intraday precision analyses yielded RSDs of 1.2%-11.7% and 3.6%-15.1%, respectively. This method, which was as effective as Soxhlet extraction and accelerated solvent extraction (ASE), proved to be accurate and precise. When the proposed method was used to examine environmental samples, the obtained results were in good agreement with those obtained using Soxhlet extraction.A rapid screening method using microwave-assisted extraction (MAE) in combination with gas chromatography and mass spectrometry for the determination of 70 pesticide residues in soil was established. The pesticides included 27 organophosphorus pesticides (OPPs), 29 organochlorine pesticides (OCPs), nine pyrethroids, and five carbamates. Parameters that could affect the efficiency of extraction, such as temperature, time, and solvent, were investigated. The condition of the extraction, under which recoveries of all 70 pesticides ranged from 70% to 120%, was optimized with a 1: 1 (V/V) mixture of acetone and hexane, a temperature of 100 degrees C, and an extraction time of 10 min. All compounds studied could be recovered in good yields and with relative standard deviations (RSDs) lower than 20%. The linearity of the method for all the pesticides was greater than 0.99 over a concentration range of 0.1-5 mu g/g. The detection limits varied from 0.5 to 211.25 ng/g. Interday and intraday precision analyses yielded RSDs of 1.2%-11.7% and 3.6%-15.1%, respectively. This method, which was as effective as Soxhlet extraction and accelerated solvent extraction (ASE), proved to be accurate and precise. When the proposed method was used to examine environmental samples, the obtained results were in good agreement with those obtained using Soxhlet extraction
Discrimination of blue ballpoint pen inks in Chinese market with confocal Raman microscope
DEVELOPMENT AND CALIBRATION OF A K-BAND GROUND-BASED HYPERSPECTRAL MICROWAVE RADIOMETER FOR WATER VAPOR MEASUREMENTS
Abstract—In this paper, a K-band ground-based hyperspectral microwave radiometer for atmospheric sounding is proposed, which improves the profile error and vertical resolution of moisture profiling under the high water vapor condition. The hyperspectral microwave radiometer (80K-band spectral channels) can observe the rapidly changing weather with high sensitivity and accuracy of brightness temperature by using a stable high-speed receiver and an improved tipping calibration method. By combining several advantages of traditional microwave receiver, the MMIC receiver has good ultra-wideband performance, high linearity, and short measuring time. Moreover, through correcting the calibration parameters of traditional tipping calibration, the proposed calibration method can increase calibration accuracy based on the radiative transfer equation in the atmosphere. Measurement results demonstrate that the radiometer achieves a sensitivity of 0.1K for 2 s of integration time and an accuracy of better than 0.77K. For the water vapor profile, the variational retrievals method is used to extract the redundant information under the microwave hyperspectral condition. Preliminary comparisons of measured water vapor profiles with traditional results show good improvement of the profile error and vertical resolution. 1
Occurrence and profiles of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in soils from a typical e-waste recycling area in Southeast China
Surface soils collected from Taizhou, a typical e-waste recycling area in Southeast China, were analyzed for the residues of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) by using microwave-assisted extraction and gas chromatography -mass spectrometry (GC-MS). The total concentrations of 16 PAHs in US EPA's priority list (Sigma PAHs), six indicator PCBs (Sigma PCBs), 15 OCPs widely used in China (Sigma OCPs) in soils ranged from 125 to 4737 ng/g (average: 854 ng/g), from not detected to 55.4 ng/g (3.16 ng/g), and from 47.9 to 820 ng/g (276 ng/g), respectively. Individual PAHs were ubiquitously found in soil samples with detected ratio of 96% and their residual levels were comparable with those of serious polluted sites. Principal component analysis in combination with diagnostic ratios suggested that the combustion of coal, wood, and plastic wastes that are closely associated with illegal and unsafe recycling operations of e-wastes was the main source of PAHs in this area. Compared with other polluted sites, the PCBs residues in soils were generally low except for those in the major recycling site. The residual levels of OCPs in this region were also relatively higher and hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its metabolite forms including dichlorodiphenyldichloroethane (DDD) and dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), and dicofol were dominant species. The composition analysis indicated that the HCHs residues in soils might originate from the application of lindane (pure gamma-HCH) and parts of DDTs possibly from the wide use of dicofol with high impurity of DDT compounds in this region.Surface soils collected from Taizhou, a typical e-waste recycling area in Southeast China, were analyzed for the residues of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) by using microwave-assisted extraction and gas chromatography -mass spectrometry (GC-MS). The total concentrations of 16 PAHs in US EPA's priority list (Sigma PAHs), six indicator PCBs (Sigma PCBs), 15 OCPs widely used in China (Sigma OCPs) in soils ranged from 125 to 4737 ng/g (average: 854 ng/g), from not detected to 55.4 ng/g (3.16 ng/g), and from 47.9 to 820 ng/g (276 ng/g), respectively. Individual PAHs were ubiquitously found in soil samples with detected ratio of 96% and their residual levels were comparable with those of serious polluted sites. Principal component analysis in combination with diagnostic ratios suggested that the combustion of coal, wood, and plastic wastes that are closely associated with illegal and unsafe recycling operations of e-wastes was the main source of PAHs in this area. Compared with other polluted sites, the PCBs residues in soils were generally low except for those in the major recycling site. The residual levels of OCPs in this region were also relatively higher and hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its metabolite forms including dichlorodiphenyldichloroethane (DDD) and dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), and dicofol were dominant species. The composition analysis indicated that the HCHs residues in soils might originate from the application of lindane (pure gamma-HCH) and parts of DDTs possibly from the wide use of dicofol with high impurity of DDT compounds in this region
Exploring the Relationship between Ecosystem Services under Different Socio-Economic Driving Degrees
The large-scale transformation of natural ecosystems to socio-economic development land types under human activities was a primary reason for the decline of regional ecosystem services. It is a key issue for regional ecosystem planning and management to reveal the relationship between ecosystem services of different land use types under different socio-economic driving degrees. However, the current related research was not in-depth. Based on the land use data of Wuhan City in 1980, 1990, 2000, 2010, and 2020, this study classified land use into three categories according to the different degrees of human activities on natural ecosystem development: the land use of a natural ecosystem (LUNE), the land use of a productive ecosystem (LUPE), and the land use of a socio-economic system (LUSE). The InVEST model was used to simulate five ecosystem services (grain yield, water yield, carbon storage, habitat quality, and water purification), and the spatio-temporal distribution and functional transformation of the three land use types were analyzed. Results showed that with the intensified urban expansion in Wuhan, the LUSE types increased to 2.7 times that of the original. However, the natural land types basically maintained a stable area, coupling with the large-scale transformation between the LUPE and LUSE types. Land use change resulted in significant spatial changes of five ecosystem services, especially carbon storage and habitat quality. The correlation analysis indicated that the five kinds of ecosystem services mainly showed a synergistic relationship, meanwhile the LUSE type denoted the most significant correlation with ecosystem services among these three category types. This study indicated that besides the protection of natural ecosystems, the LUSE type would become the key land use type in the planning and management of improving regional ecological function
Current progress on catalytic oxidation of toluene: a review
Toluene is one of the pollutants that are dangerous to the environment and human health and has been sorted into priority pollutants; hence, the control of its emission is necessary. Due to severe problems caused by toluene, different techniques for the abatement of toluene have been developed. Catalytic oxidation is one of the promising methods and effective technologies for toluene degradation as it oxidizes it to CO2 and does not deliver other pollutants to the environment. This paper highlights the recent progressive advancement of the catalysts for toluene oxidation. Five categories of catalysts, including noble metal catalysts, transition metal catalysts, perovskite catalysts, metal-organic frameworks (MOFs)-based catalysts, and spinel catalysts reported in the past half a decade (2015–2020), are reviewed. Various factors that influence their catalytic activities, such as morphology and structure, preparation methods, specific surface area, relative humidity, and coke formation, are discussed. Furthermore, the reaction mechanisms and kinetics for catalytic oxidation of toluene are also discussed