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OBJECTIVE: To explore the dairy consumption among children and adolescents aged 7-17 in China. METHODS: 10 rounds of follow-up data from the "China Health and Nutrition Survey" from 1991 to 2018 were collected, and individuals aged 7-17 were selected as the study subjects. Dietary data was collected by using 3-day 24-hour dietary review method and household weighing accounting method(edible oils and seasonings). Dairy consumption was calculated by converting various dairy products into liquid milk intake using the China Food Composition. After excluding those with missing demographic information, missing data from the "3 days and 24 hours" dietary survey, and abnormal daily energy intake, 18 529 participants were included in the final analysis. Joinpoint regression model was used to analyze the trend of changes in dairy intake. RESULTS: The dairy consumption rate increased from 2.8% in 1991 to 42.3% in 2018, while it increased from 8.4% to 58.8% in urban and from 0.9% to 32.1% in rural areas. Meanwhile, the proportion of people whose dairy intake reaches the recommended intake(300 g/d) increased from 0.2% to 3.0%, and the proportion in rural area was 2.0%, which was lower than that in urban areas(4.9%). From 1991 to 2018, dairy intake increased at a rate of 12.97%(P=0.02), and the growth rate of urban and rural areas were 9.79%(P=0.03) and 15.67%(P<0.01), respectively. There was a faster growth trend from 1991-2004 compared to 2004-2018. The growth rate in urban and rural areas also showed different growth trends. CONCLUSION: The dairy intake of children and adolescents aged 7-17 in China improved significantly from 1991 to 2018, with higher consumption rate in urban areas than in rural areas, but it still need to be improved for health.
Subject(s)
Dairy Products , Diet , Nutrition Surveys , Rural Population , Humans , China , Adolescent , Child , Female , Male , Diet/trends , Diet/statistics & numerical data , Rural Population/statistics & numerical data , Diet Surveys , Urban Population , Energy Intake , Feeding BehaviorABSTRACT
OBJECTIVE: To analyze food carbon footprint and its socio-demographic disparities among adults in China. METHODS: A total of 12 777 adults aged 18 years and above from the China Health and Nutrition Survey in 2018 who have completed dietary and socio-demographic data were analyzed. The information of food intake were collected by 24 h recalls combined with the weighing of household seasonings. Food consumption was converted into energy intake by the China Food Composition Table. Carbon footprint of 26 food groups were calculated by the food carbon footprint database based on life-cycle assessment(LCA), multinomial logit model was used to analyze the association of socio-demographic factors and food carbon footprint. RESULTS: Average food carbon footprint were decreased with increasing age while increased with increasing income and education levels, and was higher among male than that among female, was higher among urban residents than that among rural residents, was higher in the south than that in the north. Multinomial logit analysis showed that compared with people aged 18-44, the likelihood of occurring high carbon footprint in 60y and above group were 29%(OR=0.71, 95%CI 0.61-0.83) lower than that occurring low carbon footprint. Women were 11%(OR=0.89, 95%CI 0.81-0.99) and 25%(OR=0.75, 95%CI 0.67-0.84) less likely to appear medium and high carbon footprint than low carbon footprint, compared with their male counterparts. In comparison to people living in cities, rural dwellers were 24%(OR=0.76, 95%CI 0.69-0.85) and 38%(OR=0.62, 95%CI 0.55-0.70) less likely to appear medium and high carbon footprint than low carbon footprint. People in the south were 3.89 times(95%CI 3.52-4.30) and 11.35 times(95%CI 10.01-12.88) more likely to occur medium and high carbon footprint than low carbon footprint, compared with people in the north. Participants were more likely to occur medium carbon footprint and high carbon footprint with the increasing income level(OR>1), and were more likely to occur high carbon footprint with the increasing education level(OR>1). CONCLUSION: The food carbon footprint of adults in China in 2018 show different socio-demographic disparities, gender, income and education level are significant factors.
Subject(s)
Carbon Footprint , Nutrition Surveys , Rural Population , Socioeconomic Factors , Humans , China , Male , Adult , Female , Carbon Footprint/statistics & numerical data , Middle Aged , Adolescent , Young Adult , Rural Population/statistics & numerical data , Aged , Diet/statistics & numerical data , Urban Population/statistics & numerical data , Food/statistics & numerical data , Sociodemographic FactorsABSTRACT
OBJECTIVE: To analyze the dietary patterns changes of young people aged 18-35 in 15 provinces(autonomous regions, municipalities) from 1989 to 2018. METHODS: Using the data of China Health and Nutrition Survey, a total of 25 400 young people aged 18-35 with complete dietary and sociodemographic information from 1989 to 2018 in 15 provinces(autonomous regions, municipalities) were selected as the research objects. Nutrition survey was carried out by using 3 consecutive days of 24-hour review method combined with weighing accounting method. Energy and nutrient intake was calculated based on food composition list. The principal component cluster analysis was used to select food groups and K-mean cluster was uesd to extract dietary patterns. Dwass-Steel-Critchlow-Fligner was used to test the difference of food intake in different dietary patterns. Cochran-Armitage trend test was to analyze the change of dietary patterns with the years. Chi-square test was to analyze the difference of people with different dietary patterns in 2018. RESULTS: The dietary patterns of young people aged 18-35 in 15 provinces(autonomous regions, municipalities) were mainly divided into three categories: "traditional rice", "traditional pasta" and "high-quality protein". In 2018, the proportion of "traditional rice" dietary patterns was higher for men than for women, and the proportion of "high-quality protein" dietary patterns was lower than for women. The proportion of "traditional pasta" dietary pattern in people aged 25-35 was higher than that aged 18-24, and the proportion of "high-quality protein" dietary pattern was lower than that aged 18-24. The proportion of people in urban with "traditional rice" dietary pattern was lower than that in rural areas, and the proportion of "high-quality protein" dietary pattern was higher than that in rural areas. The northern region was dominated by "traditional pasta" dietary pattern, while the southern region was dominated by "traditional rice" dietary pattern, and the proportion of people with "high-quality protein" dietary pattern was higher in the northern region than in the southern region. With the increase of education level and income level, the proportion of people with "high-quality protein" dietary pattern showed an increasing trend. From 1989 to 2018, the "traditional rice" dietary pattern had always maintained a high proportion among young people aged 18-35 in 15 provinces(autonomous regions, municipalities) in China, and the "traditional pasta" dietary pattern had been decreasing since 2009, and the "high-quality protein" dietary pattern had significantly increased since 2011. CONCLUSION: From 1989 to 2018, the proportion of young people aged 18-35 with reasonable dietary pattern has increased in 15 provinces(autonomous regions, municipalities), but the traditional dietary pattern still needs to be improved.
Subject(s)
Diet , Feeding Behavior , Nutrition Surveys , Humans , China , Male , Adolescent , Female , Young Adult , Adult , Diet/statistics & numerical data , Diet/trends , Energy Intake , Dietary PatternsABSTRACT
Infectious myonecrosis virus (IMNV) has affected shrimp farming in many countries, such as northeastern Brazil and southeast Asia, and poses a serious threat to the global shrimp industry. Reverse transcription enzymatic recombinant amplification technology (RT-ERA) is a rapid DNA amplification assay with high specificity in isothermal conditions and has been widely applied to the pathogen's detection. In this study, two novel ERA assays of IMNV, real-time RT-ERA and an RT-ERA combined with lateral flow dipsticks assay (RT-ERA-LFD), were developed and evaluated. The real-time RT-ERA assay could be carried out at 38-42 °C and had the highest end-point fluorescence value and the smallest Ct value at 41 °C. The brightness and width of the detection line were at a maximum at 39 °C and 30 min, and these conditions were selected in RT-ERA-LFD. Both real-time RT-ERA and RT-ERA-LFD produced positive results with IMNV standard plasmids only and showed no cross-reaction with Vibrio parahaemolyticus, which causes acute hepatopancreatic necrosis disease (VpAHPND); white spot syndrome virus (WSSV); infectious hypodermal and hematopoietic necrosis virus (IHHNV); or Ecytonucleospora hepatopenaei (EHP). Meanwhile, we compared the sensitivities of nested RT-PCR, real-time RT-PCR, real-time RT-ERA, and RT-ERA-LFD. The sensitivities of real-time RT-ERA and RT-ERA-LFD were both 101 copies/µL. The detection sensitivities of nested RT-PCR and real-time RT-PCR were 100 and 102 copies/µL, respectively. As a result, two ERA assays were determined to be specific, sensitive, and economical methods for the on-site diagnosis of IMNV infection, showing great potential for the control of IMNV infections.
Subject(s)
Nucleic Acid Amplification Techniques , Penaeidae , Animals , Nucleic Acid Amplification Techniques/methods , Penaeidae/virology , Recombinases/metabolism , Sensitivity and SpecificityABSTRACT
OBJECTIVE: To analyze the prevalence of cardio-metabolic(CM) risk in women aged 15-49 years in 4 provinces of China and the influence of socioeconomic factors on them. METHODS: A total of 2851 women aged 15-49 years from Community-based Cohort Study on Nervous System Disease in 2018 were selected. Obesity, central obesity, elevated triglyceride(TG), elevated total cholesterol(TC), decreased high-density lipoprotein cholesterol(HDL-C), elevated low-density lipoprotein cholesterol(LDL-C), elevated blood pressure, elevated blood glucose and risk factor aggregation were analyzed. χ~2 test was used for univariate analysis, multinomial Logit model was used to evaluate the relationship between socioeconomic factors and CM risk factors, and Cochran-Armitage trend test was used for trend analysis. RESULTS: The detection rate of CM risk factors in this study from high to low were central obesity(26.76%), overweight(22.41%), pre central obesity(17.47%), decreased HDL-C(15.36%), elevated TG(11.78%), borderline elevated TC(11.40%), borderline elevated TG(11.12%), elevated blood pressure(9.71%) and hypertension(9.12%). The prevalence rates of CM risk factors were different among different age groups, income groups and education levels(P<0.05). In addition to decreased HDL-C, the prevalence of other metabolic risk factors increased with age(P_(trend)<0.05). With the improvement of educational level, the prevalence rates of overweight, obesity, central obesity, central obesity, elevated TG, decreased HDL-C, elevated blood pressure, hypertension, elevated blood pressure and diabetes showed a downward trend(P_(trend)<0.05). Multinomial Logit model showed that the rick of metabolic risk factors in the age group of 40 to 49 years old was higher than that in the younger age group aged 15-29 years, and was more significant in hypertension, elevated blood pressure and elevated blood glucose, which were 8.51 times(95% CI 5.45-13.27), 3.14 times(95%CI 2.20-4.48)and 2.66(95% CI 1.52-4.66)times of the younger age group, respectively. Women with high-income level have a higher risk of borderline elevated TC, elevated TC and borderline elevated LDL-C(OR=1.85, 95% CI 1.44-2.38;OR=2.01, 95% CI 1.25-3.22;OR=2.16, 95% CI 1.61-2.90), but the lower risk of overweight and elevated blood pressure(OR=0.79, 95% CI 0.64-0.98;OR=0.69, 95% CI 0.50-0.94). The risk of obesity, hypertension and diabetes of people with college degree or above was about 50% lower than those with junior high school education or below(OR=0.52, 95% CI 0.35-0.78;OR=0.43, 95% CI 0.27-0.67; OR=0.52, 95% CI 0.28-0.96). CONCLUSION: Central obesity, overweight, pre central obesity and HDL-C decrease were prominent CM risk factors in women aged 15-49 years in four provinces of China in 2018. The detection rate of CM risk factors is higher in women of high age group or low education level.
Subject(s)
Diabetes Mellitus , Hypertension , Humans , Female , Adult , Middle Aged , Child, Preschool , Obesity, Abdominal , Overweight/epidemiology , Blood Glucose , Cholesterol, LDL , Cohort Studies , Risk Factors , Hypertension/epidemiology , Obesity/epidemiology , China/epidemiologyABSTRACT
Accurate determination of protein localization, levels, or protein-protein interactions is pivotal for the study of their function, and in situ protein labeling via homologous recombination has emerged as a critical tool in many organisms. While this approach has been refined in various model fungi, the study of protein function in most plant pathogens has predominantly relied on ex situ or overexpression manipulations. To dissect the molecular mechanisms of development and infection for Verticillium dahliae, a formidable plant pathogen responsible for vascular wilt diseases, we have established a robust, homologous recombination-based in situ protein labeling strategy in this organism. Utilizing Agrobacterium tumefaciens-mediated transformation (ATMT), this methodology facilitates the precise tagging of specific proteins at their C-termini with epitopes, such as GFP and Flag, within the native context of V. dahliae. We demonstrate the efficacy of our approach through the in situ labeling of VdCf2 and VdDMM2, followed by subsequent confirmation via subcellular localization and protein-level analyses. Our findings confirm the applicability of homologous recombination for in situ protein labeling in V. dahliae and suggest its potential utility across a broad spectrum of filamentous fungi. This labeling method stands to significantly advance the field of functional genomics in plant pathogenic fungi, offering a versatile and powerful tool for the elucidation of protein function.
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The application of traditional pressure sensors in health monitoring is limited by their initial rigidity. Flexible pressure sensors have thus received extensive attention owing to their excellent device flexibility. In this paper, we demonstrate a method of constructing flexible pressure sensors by inverting porous skeleton nickel foam based on multi-wall carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS). MWCNTs and PDMS were mixed to form a composite conductive film, and the mass fraction of MWCNTs was optimized by evaluating the resistance change rate of the composite film. The optimized value of the mass fraction was 5%, which was used to prepare the flexible pressure sensors. The response, hysteresis, and stability of the sensors were further characterized. Pulse signals of humans were detected through flexible sensors, which can be used to evaluate cardiovascular conditions of the human body. These performance characteristics and the application demonstration show that our flexible pressure sensors have good prospects in human health care.
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Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is classified as a reportable crustacean disease by the World Organisation for Animal Health (WOAH), which causes poor growth in Penaeus vannamei. According to genome sequence alignment analysis, enzymatic recombinase amplification (ERA) primers and probe were designed based on the ORF1 region of IHHNV, and a real-time ERA assay for IHHNV detection (IHHNV-ERA) was established. The experimental results show that IHHNV-F2/IHHNV-R2 and IHHNV-Probe can effectively amplify the target gene, and the sensitivity is 1.4 × 101 copies/µL within 14.97 ± 0.19 min, while the qPCR using primers 309F/309R could reach the detection limit of 1.4 × 101 copies/µL within 21.76 ± 0.63 min, and the sensitivity results of one-step PCR could be as low as 1.4 copies/µL with expense of time and false positives. The IHHNV-ERA system can effectively amplify the target gene at 42 â within 20 min, and has no cross-reaction with white spot syndrome virus (WSSV), Ecytonucleospora hepatopenaei (EHP), Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease (VpAHPND), and healthy shrimp genomic DNA. Test results of practical samples showed that the detection rate of IHHNV-ERA (18/20) was better than the industrial standard qPCR assay (17/20). Compared with the existing technology, the useful results of this detection assay are: (1) get rid of the dependence on the thermal cycle instrument in the PCR process; (2) the experimental procedure is simple, time-consuming and fast; (3) the detection sensitivity is high. This study provides an ERA based detection assay for IHHNV, which can be used not only for the rapid detection of IHHNV infection, but also for the field screening of pathogens. This assay can also be applied to clinical inspection, customs detection, enterprise quality inspection and other fields, and has obvious practical application value.
Subject(s)
Densovirinae , Penaeidae , Animals , Densovirinae/genetics , Recombinases , Polymerase Chain Reaction/methods , DNA PrimersABSTRACT
What is already known about this topic?: Consuming refined grains, specifically white rice, elevates the risk of developing type 2 diabetes (T2D). Conversely, incorporating whole grains into the diet is linked to a reduced risk. What is added by this report?: This study employed a novel multi-trajectory modeling technique to account for the intercorrelations among various cereal consumption patterns. Four distinct multi-trajectory groups of cereal intake, identified from 1997 to 2018 within the Chinese population, were associated with varying levels of T2D risk. What are the implications for public health practice?: This research investigates the implications of evolving cereal consumption patterns on T2D in nondiabetic adults. This study delineates unique trajectories linked with cereal intake patterns, thereby providing a robust foundation for policymakers to craft initiatives to prevent T2D among adults in China.
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Limited knowledge currently exists regarding the dynamics of generational shifts in food consumption among adult residents in China. This study aimed to investigate the generational differences in dietary status among different generations of Chinese adult residents aged 20 years and older. Survey participants from four waves (1991, 2000, 2009, and 2018) of the China Health and Nutrition Survey (CHNS) cohort were included in the study (N = 40,704), providing three-day 24 h dietary data. Participants were categorized into six age groups (20-29, 30-39, 40-49, 50-59, 60-69, and ≥70 years old), each corresponding to specific generations (Gen 10, 20, 30, 40, 50, 60, 70, 80, and 90) based on their age at the time of the survey. This study examined generational differences in the intake of cereals, animal-based foods, vegetables, fruits, dairy, energy, and the contribution of macronutrients to energy using chi-square tests and Kruskal-Wallis tests. All analyses were stratified by gender. Our findings revealed that younger generations exhibited lower daily intake of cereals, vegetables, energy, and contribution of carbohydrates to energy, compared to their older counterparts, regardless of gender. Conversely, regardless of male or female, younger generations showed higher daily consumption of animal-based foods, average fruit and dairy intake, fruit and dairy consumption rates, as well as contributions of protein and fat to energy, compared to older generations. The magnitude of generational differences in food consumption varied by age and gender. In addition, cereal and vegetable intake, energy intake, and contribution of carbohydrates to energy declined with age across all generations, while average dairy intake, fruit and dairy consumption rates, and the contribution of fat to energy tended to increase, regardless of gender. In conclusion, generational differences in food consumption were evident among different generations of Chinese adult residents, characterized by an increase in animal-based food intake and the contribution of fat to energy among generations. Attention should be directed towards addressing the eating behavior of younger generations.
Subject(s)
Diet , East Asian People , Adult , Aged , Female , Humans , Male , Carbohydrates , Energy Intake , Feeding Behavior , Fruit , Nutrition Surveys , Vegetables , Age FactorsABSTRACT
Precise manipulation of the coordination environment of single-atom catalysts (SACs), particularly the simultaneous engineering of multiple coordination shells, is crucial to maximize their catalytic performance but remains challenging. Herein, we present a general two-step strategy to fabricate a series of hollow carbon-based SACs featuring asymmetric Zn-N2 O2 moieties simultaneously modulated with S atoms in higher coordination shells of Zn centers (n≥2; designated as Zn-N2 O2 -S). Systematic analyses demonstrate that the synergetic effects between the N2 O2 species in the first coordination shell and the S atoms in higher coordination shells lead to robust discrete Zn sites with the optimal electronic structure for selective O2 reduction to H2 O2 . Remarkably, the Zn-N2 O2 moiety with S atoms in the second coordination shell possesses a nearly ideal Gibbs free energy for the key OOH* intermediate, which favors the formation and desorption of OOH* on Zn sites for H2 O2 generation. Consequently, the Zn-N2 O2 -S SAC exhibits impressive electrochemical H2 O2 production performance with high selectivity of 96 %. Even at a high current density of 80â mA cm-2 in the flow cell, it shows a high H2 O2 production rate of 6.924â mol gcat -1 h-1 with an average Faradaic efficiency of 93.1 %, and excellent durability over 65â h.
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Few articles have investigated the impact of long-term meat intake trends and their changes during follow-up on the risk of type 2 diabetes (T2D). We aimed to explore the long-term trajectories of meat intake and determine its association with T2D risk in Chinese adults. This study used seven rounds of data from the China Health and Nutrition Survey (1997, 2000, 2004, 2006, 2009, 2015, and 2018), and 4464 adults aged 18 years or older were analyzed. The group-based trajectory modeling was used to identify meat intake trajectories over 21 years. Multivariate Cox proportional hazard and restricted cubic spline models were used to analyze the association and dose-response relationship between meat intake and T2D. Four trajectory groups were identified: "low-increase intake group" (Group 1), "moderate-increase intake group" (Group 2), "medium-stable intake group" (Group 3), and "high intake group" (Group 4). Compared with Group 2, Group 4 was associated with a higher risk of developing T2D (hazard ratio 2.37 [95% CI 1.41-3.98]). After adjusting for demographic characteristics, lifestyle, total energy intake, waist circumference, and systolic blood pressure, and using the third quintile as a reference, the risk of T2D was increased by 46% in the lowest quintile with meat intake (hazard ratio 1.46 [95% CI 1.07-2.01]) and by 41% in the highest quintile with meat intake (HR 1.41 [95% CI 1.03-1.94]). A U-shape was observed between meat intake and T2D risk (p for nonlinear < 0.001). When the intake was lower than 75 g/day, the risk of T2D was negatively correlated with meat intake, while the risk of T2D was positively correlated with meat intake when the intake was higher than 165 g/day. We identified four trajectory groups of meat intake from 1997 to 2018, which were associated with different risks of developing T2D. A U-shaped association was observed between meat intake and T2D in Chinese adults.
Subject(s)
Diabetes Mellitus, Type 2 , Adult , Humans , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/etiology , Risk Factors , Meat/adverse effects , Nutrition Surveys , China/epidemiologyABSTRACT
The strong polarization-induced electric field in the multi-quantum well region reduces the radiative recombination rates by separating the electron and hole wave functions, which is one of the most detrimental factors that is to blame for the low luminous efficiency of AlGaN deep-ultraviolet light-emitting diodes (DUV LEDs). In this work, we redesigned the active region by incorporating Si and Mg doping at the vicinity of the quantum wells, forming a series of embedded p-i-n junctions in the multi-quantum well region. The additional electric field induced by the fixed charges from the embedded doping-induced junctions can effectively compensate for the intrinsic polarization-induced electric fields in the quantum well region and give rise to the improved overlap of hole and electron wave function, hence enhancing the radiative recombination rates and the external quantum efficiency and optical power of DUV LEDs. The mechanism behind the alleviated polarization electric field is comprehensively discussed and analyzed. The embedded p-i-n junctions can also alter the band diagram structure of the active region, decrease the effective barrier heights for holes, and diminish the electron leakage into the p-type region. In addition, different thicknesses and doping concentrations of the embedded p- and n- layers were designed, and their influence on the performance of DUV LEDs was numerically analyzed. The proposed structure with embedded p-i-n junctions provides an alternative way to achieve efficient DUV LEDs.
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The monoanionic tetrapyrrolic macrocycle B,C-tetradehydrocorrin (TDC) resides chemically between corroles and corrins. This chemical space remains largely unexplored due to a lack of reliable synthetic strategies. We now report the preparation and characterization of Co(II)- and Ni(II)-metalated TDC derivatives ([Co-TDC]+ and [Ni-TDC]+, respectively) with a combination of crystallographic, electrochemical, computational, and spectroscopic techniques. [Ni-TDC]+ was found to undergo primarily ligand-centered electrochemical reduction, leading to hydrogenation of the macrocycle under cathodic electrolysis in the presence of acid. Transient absorption (TA) spectroscopy reveals that [Ni-TDC]+ and the two-electron-reduced [Ni-TDC]- possess long-lived excited states, whereas the excited state of singly reduced [Ni-TDC] exhibits picosecond dynamics. The Co(I) compound [Co-TDC] is air stable, highlighting the notable property of the TDC ligand to stabilize low-valent metal centers in contradistinction to other tetrapyrroles such as corroles, which typically stabilize metals in higher oxidation states.
ABSTRACT
Beamforming and its applications in steered-response power (SRP) technology, such as steered-response power delay and sum (SRP-DAS) and steered-response power phase transform (SRP-PHAT), are widely used in sound source localization. However, their resolution and accuracy still need improvement. A novel beamforming method combining SRP and multi-channel cross-correlation coefficient (MCCC), SRP-MCCC, is proposed in this paper to improve the accuracy of direction of arrival (DOA). Directional weight (DW) is obtained by calculating the MCCC. Based on DW, suppressed the non-incoming wave direction and gained the incoming wave direction to improve the beamforming capabilities. Then, sound source localizations based on the dual linear array under different conditions were simulated. Compared with SRP-PHAT, SRP-MCCC has the advantages of high positioning accuracy, strong spatial directivity and robustness under the different signal-noise ratios (SNRs). When the SNR is -10 dB, the average positioning error of the single-frequency sound source at different coordinates decreases by 5.69%, and that of the mixed frequency sound sources at the same coordinate decreases by 5.77%. Finally, the experimental verification was carried out. The results show that the average error of SRP-MCCC has been reduced by 8.14% and the positioning accuracy has been significantly improved, which is consistent with the simulation results. This research provides a new idea for further engineering applications of sound source localization based on beamforming.
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SignificanceThe chemical reduction of unsaturated bonds occurs by hydrogenation with H2 as the reductant. Conversely, in biology, the unavailability of H2 engenders the typical reduction of unsaturated bonds with electrons and protons from different cofactors, requiring olefin hydrogenation to occur by proton-coupled electron transfer (PCET). Moreover, the redox noninnocence of tetrapyrrole macrocycles furnishes unusual PCET intermediates, including the phlorin, which is an intermediate in tetrapyrrole ring reductions. Whereas the phlorin of a porphyrin is well established, the phlorin of a chlorin is enigmatic. By controlling the PCET reactivity of a chlorin, including the use of a hangman functionality to manage the proton transfer, the formation of a chlorinphlorin by PCET is realized, and the mechanism for its formation is defined.
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Glycosylphosphatidylinositol (GPI) molecules are complex glycophospholipids and serve as membrane anchors for tethering many proteins to the cell surface. Attaching GPI to the protein in the endoplasmic reticulum (ER) is catalyzed by the transmembrane GPI transamidase (GPIT) complex, which is essential for maturation of the GPI-anchored proteins. The GPIT complex is known to be composed of five subunits: PIGK, PIGU, PIGT, PIGS and GPAA1. Here, we determined the structure of the human GPIT complex at a resolution of 3.1 Å using single-particle cryo-EM, elucidating its overall assembly. The PIGK subunit functions as the catalytic component, in which we identified a C206-H164-N58 triad that is critical for the transamination reaction. Transmembrane helices constitute a widely opened cleft, which is located underneath PIGK, serving as a GPI substrate-binding site. The ubiquitin E3 ligase RNF121 is visualized at the back of the complex and probably serves as a quality control factor for the GPIT complex.
Subject(s)
Acyltransferases , Glycosylphosphatidylinositols , Acyltransferases/chemistry , Endoplasmic Reticulum/metabolism , Humans , Ubiquitin-Protein LigasesABSTRACT
In a complex heterogeneous metal-catalyzed reaction process, unique cooperative effects between metal sites and surface-interface active sites, as well as favorable synergy between surface-interface active sites, can play crucial roles in improving their catalytic performances. In this work, a ZnO-modified Cu-based catalyst over defect-rich Pr2O3 nanosheets for high-efficiency CO2 hydrogenation to produce methanol was successfully constructed. It was demonstrated that an as-fabricated nanosheet-like Cu-based catalyst presented several structural advantages including the formation of highly dispersive Cu0 sites and the coexistence of abundant defective Pr3+-Vo-Pr3+ structures (Vo: oxygen vacancy) and interfacial Cu-O-Pr sites. Combining structural characterization and catalytic reaction results with density functional theory calculations, it was clearly unveiled that the synergy between surface defective structures and Cu-Pr2O3 interfaces over the catalyst remarkably promoted the adsorption of CO2 and CO intermediate, thus boosting the CO2 hydrogenation simultaneously via both the formate intermediate pathway and the intense reverse water-gas shift reaction-derived CO hydrogenation pathway, along with a high space-time yield of methanol of 0.395 gMeOH·gcat-1·h-1 under mild reaction conditions (260 °C and 3.0 MPa). The study provides a new strategy to construct high-performance Cu-based catalysts for high-efficiency CO2 hydrogenation to produce methanol and a deep understanding of the promotional roles of synergy between surface-interface active sites in the CO2 hydrogenation.
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Detecting low-frequency underwater acoustic signals can be a challenge for marine applications. Inspired by the notably strong response of the auditory organs of pectis jellyfish to ultralow frequencies, a kind of otolith-inspired vector hydrophone (OVH) is developed, enabled by hollow buoyant spheres atop cilia. Full parametric analysis is performed to optimize the cilium structure in order to balance the resonance frequency and sensitivity. After the structural parameters of the OVH are determined, the stress distributions of various vector hydrophones are simulated and analyzed. The shock resistance of the OVH is also investigated. Finally, the OVH is fabricated and calibrated. The receiving sensitivity of the OVH is measured to be as high as -202.1 dB@100 Hz (0 dB@1 V/µPa), and the average equivalent pressure sensitivity over the frequency range of interest of the OVH reaches -173.8 dB when the frequency ranges from 20 to 200 Hz. The 3 dB polar width of the directivity pattern for the OVH is measured as 87°. Moreover, the OVH is demonstrated to operate under 10 MPa hydrostatic pressure. These results show that the OVH is promising in low-frequency underwater acoustic detection.
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Real-time non-destructive monitoring of water use efficiency (WUE) is important for screening high-yielding high-efficiency varieties and determining the rational allocation of water resources in winter wheat production. Compared with vertical observation angles, multi-angle remote sensing provides more information on mid to lower parts of the wheat canopy, thereby improving estimates of physical and chemical indicators of the entire canopy. In this study, multi-angle spectral reflectance and the WUE of the wheat canopy were obtained at different growth stages based on field experiments carried out across 4 years using three wheat varieties under different water and nitrogen fertilizer regimes. Using appropriate spectral parameters and sensitive observation angles, the quantitative relationships with wheat WUE were determined. The results revealed that backward observation angles were better than forward angles, while the common spectral parameters Lo and NDDAig were found to be closely related to WUE, although with increasing WUE, both parameters tended to become saturated. Using this data, we constructed a double-ratio vegetation index (NDDAig/FWBI), which we named the water efficiency index (WEI), reducing the impact of different test factors on the WUE monitoring model. As a result, we were able to create a unified monitoring model within an angle range of -20-10°. The equation fitting determination coefficient (R 2) and root mean square error (RMSE) of the model were 0.623 and 0.406, respectively, while an independent experiment carried out to test the monitoring models confirmed that the model based on the new index was optimal, with R 2, RMSE, and relative error (RE) values of 0.685, 0.473, and 11.847%, respectively. These findings suggest that the WEI is more sensitive to WUE changes than common spectral parameters, while also allowing wide-angle adaptation, which has important implications in parameter design and the configuration of satellite remote sensing and UAV sensors.