Gas Turbines are among the most important energy systems for aviation and thermal-based power generation.The performance of gas turbine intakes with S-shaped diffusers is vulnerable to flow separation,reversal flow,an...Gas Turbines are among the most important energy systems for aviation and thermal-based power generation.The performance of gas turbine intakes with S-shaped diffusers is vulnerable to flow separation,reversal flow,and pressure distortion,mainly in aggressive S-shaped diffusers.Severalmethods,including vortex generators and energy promoters,have been proposed and investigated both experimentally and numerically.This paper compiles a review of experimental investigations that have been performed and reported to mitigate flow separation and restore system performance.The operational principles,classifications,design geometries,and performance parameters of Sshaped diffusers are presented to facilitate the analysis and understanding of the influence of each mitigation method on flowenhancement in S-shaped diffusers.Theinfluencing design parameters on the performance of the S-shaped diffuser and the findings achieved by various experimental investigations are discussed and compared.The review concludes that reducing the intake length reduces the size and weight of the gas turbine,leading to a higher power-to-weight ratio.However,the main challenge in shortening the S-shaped diffusers is the flow separation in the high-curvature section,which must be prevented to maintain high performance.Prevention can be achieved through flow control methods,which are categorized into passive and aggressive methods.The static pressure recovery coefficient,total pressure loss coefficient,ideal static pressure coefficient,distortion coefficient,and skin friction coefficient are the primary performance evaluation and comparison parameters between the experimentally investigated mitigation methods.The new trend in S-shaped diffuser studies includes the integration of computational and data-driven methods.展开更多
Lifestyle is related to many chronic diseases,such as knee osteoarthritis(KOA).Food intake is important because it can be controlled.However,the causal relationship of food intake and KOA still remain unclear.To ident...Lifestyle is related to many chronic diseases,such as knee osteoarthritis(KOA).Food intake is important because it can be controlled.However,the causal relationship of food intake and KOA still remain unclear.To identify the relationship between food intake and KOA and to screen relevant targets.First,we performed two-sample Mendelian randomization(MR)analysis.A total of 16 kinds of food intake datasets were included,the inverse variance-weighted analysis showed that the KOA was negatively correlated with cereal intake(odds ratio(OR)0.48;95%CI 0.35-0.68;P=1.98×10−5).Second,potential drug targets of KOA in plasma were explored,secreted protein acidic and rich in cysteine(SPARC,or osteonectin),SPARC,Cwcv,and Kazal-like domains proteoglycan 2(SPOCK2)as the causal protein for plasma with KOA,and increased SPOCK2(OR 0.84;95%CI 0.77-0.92;P=5.52×10−5),decreased the risk of KOA.Integrated transcriptomic analysis(P=0.0285)and in vivo(P=0.0395)showed consistent results.Finally,by metabolomics analysis and molecular docking,seven co-expressed small molecules were detected in cereal and were bound to SPOCK2.Our findings indicate the cereal intake was negatively correlated with KOA,and support the SPOCK2 as a novel potential target for cereal intake in KOA.Our study will provide a clinical dietary guidance for KOA patients and a theoretical basis for the development of novel,side-effect-free drugs for KOA.展开更多
Objective This study aimed to reexplore minimum iodine excretion and to build a dietary iodine recommendation for Chinese adults using the obligatory iodine loss hypothesis.Methods Data from 171 Chinese adults(19–21 ...Objective This study aimed to reexplore minimum iodine excretion and to build a dietary iodine recommendation for Chinese adults using the obligatory iodine loss hypothesis.Methods Data from 171 Chinese adults(19–21 years old)were collected and analyzed based on three balance studies in Shenzhen,Yinchuan,and Changzhi.The single exponential equation was accordingly used to simulate the trajectory of 24 h urinary iodine excretion as the low iodine experimental diets offered(iodine intake:11-26μg/day)and to further deduce the dietary reference intakes(DRIs)for iodine,including estimated average requirement(EAR)and recommended nutrient intake(RNI).Results The minimum iodine excretion was estimated as 57,58,and 51μg/day in three balance studies,respectively.Moreover,it was further suggested as 57,58,and 51μg/day for iodine EAR,and 80,81,and 71μg/day for iodine RNI or expressed as 1.42,1.41,and 1.20μg/(day·kg)of body weight.Conclusion The iodine DRIs for Chinese adults were established based on the obligatory iodine loss hypothesis,which provides scientific support for the amendment of nutrient requirements.展开更多
Industry and energy continue to require piston engines(PICE)at a high level worldwide.Therefore,science and technology must urgently work on improving the PICE working cycle.Improving the quality of the intake process...Industry and energy continue to require piston engines(PICE)at a high level worldwide.Therefore,science and technology must urgently work on improving the PICE working cycle.Improving the quality of the intake process of theworking fluid into the cylinder is one of the most effective ways to improve the operational performance of PICE.The purpose of the study was to assess the impact of various cylinder head(CylH)designs on the gas-dynamic and heat-exchange qualities of air flows within an engine model’s intake system.Three different CylH designs were studied:the basic configuration and upgraded cylinder heads with a square valve and a square valve port.These designs are innovative.Laboratory conditions were used to conduct the studies for stationary air flow.The experiments covered the range of Reynolds numbers from 8500 to 96,000.The intake system’s gas dynamics and heat transfer were determined using the thermal anemometry method,which was based on constant-temperature hot-wire anemometers.It has been established that the use of upgraded CylHs causes an increase in the turbulence number of flow by an average of 13.5%.Additionally,itwas found that the increase in the turbulence number of flowin the cylinder is about 19%when installing new CylH designs.It was shown that therewas an increase in the heat transfer coefficient in the intake pipe by 10%–40%when installing modernized CylH designs in the intake system.The article focused on the problems of increasing the turbulence level and intensifying the heat transfer of stationary air flow in the intake system,specifically in PICEs.The study’s findings are novel in the areas of applied gas dynamics and PICEs.展开更多
Purpose Athletes have presented a deficiency in relative energy in recent years,which calls for appropriate nutritional guid-ance based on the estimated energy requirement(EER)-the target amount of daily energy intake...Purpose Athletes have presented a deficiency in relative energy in recent years,which calls for appropriate nutritional guid-ance based on the estimated energy requirement(EER)-the target amount of daily energy intake(EI).The calculation of EER requires longitudinal physical activity level(PAL)data,which has received insufficient attention.Therefore,this study aimed to clarify the changes in PAL by training periodization using the doubly labeled water(DLW)method,combined with the current status of EI by competition characteristics.Methods The participants comprised four male sprint athletes and five male endurance athletes at the national level.The experimental periods were normal training(NT)and tapering training(TT)periods.PAL was measured using the DLW method,and EI was measured by the dietary record method.Results PAL of the sprint athletes in the NT periods was significantly higher than in TT periods.EI had no significant differ-ences between the two periods.PAL and EI of the endurance athletes had no significant differences beteen the two periods.Conclusions These findings indicated that in sprint athletes,different PAL was observed between the two periods,with the TT period suggesting a lower value than the NT period.In endurance athletes,it had similar PAL values between the two periods.This suggests that the degree of influence of the training period on PAL may vary depending on the athletic events.Furthermore,the EI was not adjusted for changes in PAL,and the participants observed the status of energy-deficient regardless of discipline or training period.展开更多
The intake system of a racing engine plays a crucial role in determining its performance,particularly in terms of volumetric efficiency,power output,and throttle response.According to Formula Society of Automotive Eng...The intake system of a racing engine plays a crucial role in determining its performance,particularly in terms of volumetric efficiency,power output,and throttle response.According to Formula Society of Automotive Engineers(FSAE)regulations,the engine intake systemmust incorporate a 20mmdiameter flow-limiting valve within the intake manifold.This restriction significantly reduces the airflow into the engine,leading to a substantial drop in power output.To mitigate this limitation,the intake system requires a redesign.In this study,theoretical calculations and one-dimensional thermodynamic simulations are employed to determine the optimal parameters for the intake system.A numerical simulation of the intake system’s flow field is then conducted to refine its structure and layout.Finally,experiments are performed on an engine equipped with the optimized intake system,and its feasibility is evaluated based on experimental results.Thefindings indicate that the maximumengine torque increases from56.36 to 59.91 N⋅m,while the maximum power output rises from 59.16 to 63.94 kW.To further enhance performance and adaptability across different competitions,a variable-length intakemanifold control system is also designed,improving both power delivery and overall operational stability of the racing car.展开更多
This study addresses the issue of spray icing on the air intake grilles of ship power systems in cold maritime environments.Through numerical simulation methods,the influence of environmental parameters on icing chara...This study addresses the issue of spray icing on the air intake grilles of ship power systems in cold maritime environments.Through numerical simulation methods,the influence of environmental parameters on icing characteristics is revealed,and an energy-efficient zoned electric heating anti-icing strategy is proposed.A threedimensional grille model is constructed to systematically analyze the effects of environmental temperature(from−20℃to−4℃),droplet diameter(from 50μm to 500μm),and liquid water content(from 0.5 g/m³to 8 g/m³)on icing rates and blockage of the flow channel.The results indicate that low temperature and high liquid water content significantly exacerbate icing.Under the condition of an environmental temperature of−20℃,droplet diameter of 500μm,and liquid water content of 8 g/m³,the flow channel blockage ratio reaches 30.95%within 10 min.Additionally,as droplet diameter increases,the droplet impingement and icing regions become more concentrated toward the leading edge of blades.To mitigate grille icing in cold environments,an electric heating film configuration is employed for thermal protection.Optimization of the heating strategy reveals that the zoned heating approach,compared to the initial uniform heating scheme,effectively homogenizes surface temperature distribution while reducing total power consumption by 37.47%.This study validates the engineering applicability of the zoned electric heating anti/de-icing strategy,providing theoretical and technical support for the design of anti-icing systems in ship power systems operating in cold maritime regions.展开更多
BACKGROUND Bariatric surgery is an effective treatment for severe obesity but is associated with an increased risk for development of eating disorders.Indeed,numerous maladaptive eating behaviors and eating disorders ...BACKGROUND Bariatric surgery is an effective treatment for severe obesity but is associated with an increased risk for development of eating disorders.Indeed,numerous maladaptive eating behaviors and eating disorders have been described following bariatric surgery.However,the differentiation of pathologic eating patterns from expected dietary changes following bariatric surgery can sometimes be difficult to discern.CASE SUMMARY A female in her early 40s presented for medical stabilization of severe protein calorie malnutrition after losing 52.3 kg over the last six months after Roux-en-Y gastric bypass,with subsequent development of cyclic nausea and vomiting.Fear of these aversive physical symptoms led to further restriction of nutritional intake and weight loss.The patient was diagnosed with avoidant/restrictive food intake disorder,which has not been previously reported after bariatric surgery.CONCLUSION Improvement in the diagnostic nomenclature for feeding and eating disorders is warranted for patients who have undergone bariatric surgery.展开更多
Iodine is an essential element for the synthesis of thyroid hormones.Iodine deficiency increases the burden on thyroid function and causes harm to health.The identification of convenient and reliable biomarkers for as...Iodine is an essential element for the synthesis of thyroid hormones.Iodine deficiency increases the burden on thyroid function and causes harm to health.The identification of convenient and reliable biomarkers for assessing iodine nutritional status is essential for evaluating iodine intake.Urinary iodine concentration(UIC)is commonly used for population level iodine status assessment but is less reliable for individuals.A 24-h urine sample is more accurate but difficult to collect[1].Thyroid volume(Tvol)and goiter rate are suitable for evaluating the long-term iodine nutritional status in populations[2].Blood indicator collection is an invasive procedure.展开更多
AIM:To investigate the causal relationship between dietary intake and myopia using Mendelian randomization(MR)analysis.METHODS:Genome-wide association study(GWAS)data from the IEU Open GWAS database were utilized to e...AIM:To investigate the causal relationship between dietary intake and myopia using Mendelian randomization(MR)analysis.METHODS:Genome-wide association study(GWAS)data from the IEU Open GWAS database were utilized to examine associations between myopia and various dietary factors.MR analysis,incorporating both univariable and multivariable approaches,assessed the impact of food intake on myopia risk through five analytical methods,with inverse variance weighted(IVW)serving as the primary reference.Sensitivity analyses,including heterogeneity assessment,horizontal pleiotropy evaluation,and leave-oneout analysis,were conducted to validate the MR findings.RESULTS:Univariable MR analysis identified a causal link between food intake and myopia.Consumption of breaded fish,canned soup,sweet biscuits,and certain fruits correlated with a lower risk of myopia,whereas intake of low-calorie hot chocolate and cereal was associated with an increased risk.Multivariable MR analysis further confirmed that breaded fish consumption exerted a direct protective effect against myopia,particularly when consumed alongside other dietary components.These findings highlight the intricate interplay between specific dietary factors and myopia development,offering valuable insights for further research.CONCLUSION:MR analysis provides evidence supporting a potential causal relationship between breaded fish intake and myopia,underscoring its relevance in targeted myopia prevention strategies.展开更多
BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD)is a common and increasingly prevalent condition in the Middle East,but its determinants in the region are underexplored.Diet and lifestyle are...BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD)is a common and increasingly prevalent condition in the Middle East,but its determinants in the region are underexplored.Diet and lifestyle are known to significantly influence MASLD progression.AIM To assess energy and nutrient intake among MASLD patients living in Qatar and evaluate their dietary patterns.METHODS Using a cross-sectional design,94 Arab patients with MASLD,aged≥18 years,living in Qatar were studied.MASLD was diagnosed using ultrasonography,fibro scan,or elastography.Sociodemographic information was collected using a self-administered questionnaire.Dietary intake was assessed through three 24-hour recalls and a qualitative food frequency questionnaire.Energy,macro-,and micronutrient intake were analyzed using Elizabeth Stewart Hands and Associates Food Processor®Nutrition Analysis software.Statistical analyses,including factor loadings were performed using STATA 18.RESULTS Compared to recommended dietary allowance,MASLD patients had high intakes of fat,saturated fat,and cholesterol.They also showed reduced intakes of vitamin K in men,and vitamins E and A(retinol),calcium and magnesium in both genders,while selenium and sodium intakes were higher than recommendations.Three dietary patterns were identified:The‘Traditional Qatari food’pattern,the‘Prudent’pattern,and the‘Fast-food’pattern.However,no significant associations were found between these dietary patterns and body mass index or low-density lipoprotein,using adjusted regression models.CONCLUSION Findings warrant replication in longitudinal studies and call for dietary interventions to reduce energy density and enhance overall diet quality,including micronutrient intake,for MASLD prevention and management in the region.展开更多
The intake swirl in the cylinder was induced by a swirler which was fixed in one of two intake ports. In order to understand the characteristics of the intake swirl, a transparent water analog was designed which simul...The intake swirl in the cylinder was induced by a swirler which was fixed in one of two intake ports. In order to understand the characteristics of the intake swirl, a transparent water analog was designed which simulated 150 type single cylinder engine. At the same time, the particle image velocimetry was used to measure the flow fields induced by various swirlers in the analog. After measurement, a new method was presented to evaluate the intensity of the intake swirl. Then, when the measured sections, the lifts of valve and the swirlers were different, the calculated results of the flow field were compared.展开更多
The flow over a short intake is characterised by a strong interaction with the fan, that can only be captured when the rotor blades are modelled in the numerical simulations. In this paper, we use a coupled methodolog...The flow over a short intake is characterised by a strong interaction with the fan, that can only be captured when the rotor blades are modelled in the numerical simulations. In this paper, we use a coupled methodology to derive indications about relevant geometric variables affecting the high-incidence operation of an ultra-high bypass ratio turbofan intake with a length-to-diameter ratio of 0.35. By reproducing the effect of the fan through a body force model, we carry out a parametric study of the influence of the contraction ratio and the scarf angle at take-off conditions for a grid of 28 different three-dimensional shapes. The analysis of the selected performance metrics distributions at three angles of attack of 16., 24., and 28. reveals that a contraction ratio higher than 1.20 is needed to avoid separation at high incidence. While for an attached inlet the best performance is found with a moderate scarf angle, in presence of a developed separation the distortion level reduces as the scarf decreases up to negative values. We discuss the correspondence between the distortion indexes and the flow field, highlighting the origin of the detachment for the different geometries, according to the operating condition, and analysing the fan operation in the most distorted case. Finally, we assess the influence of modelling the rotor in the simulations, showing that its suppression effect on the separation at a given incidence depends on the intake geometric features.展开更多
Adequate daily water consumption is an important factor of keeping regular homeostasis. However, the best quantity of daily water consumption for a healthy individual is not virtually stated in the literature. Despite...Adequate daily water consumption is an important factor of keeping regular homeostasis. However, the best quantity of daily water consumption for a healthy individual is not virtually stated in the literature. Despite the dearth of evidence-based recommendations, it is commonly thought that ingesting eight glasses of water a day is good for a healthy person. Avicenna had a unique viewpoint. He believed that daily water intake depended on numerous elements together with age, intercourse, body temperament, season, occupation and various internal and external elements. He also cited a few essential and usefu measures regarding proper water consumption, which have additionally been emphasized in Islamic hadiths.展开更多
The objective was to create an Egyptian database on the contributors of fruit and vegetables in the diets of preschool children and to estimate the usual daily intakes of fruits, vegetables and vitamin C. A total of 5...The objective was to create an Egyptian database on the contributors of fruit and vegetables in the diets of preschool children and to estimate the usual daily intakes of fruits, vegetables and vitamin C. A total of 59 healthy boys and girls aged 2.5 - 6 years attending day care centers in urban Giza governorate completed the study by interviewing their mothers on 6x non-consecutive days using the 24 h dietary recall. Participants were classified according to age, gender and socioeconomic class. Prevalence of daily consumptions of fruits and vegetables amounted to 22% and 54%, respectively of the total children. The daily intakes of fruits and vegetables averaged 117.5 and 56.4 g, respectively. The consumption of different types of fruits and vegetables was unevenly distributed by different personal and social variables. Estimated daily vitamin C supply from the diet was 38 mg per child, which satisfied the respective recommended nutrient intake (RNI) of 30 mg for the first six years of life. However, the diet of 15% of the children covered less than 75% of RNI. Top fruits contributing to vitamin C were oranges, guava, watermelon, pears and grapes. Extra foods such as chipsy was consumed by 81% of the children, contributed 18% to daily vitamin C supply and also 58.6 mg sodium. A multilevel intervention strategy is warranted for promoting daily fruit and vegetable intake and healthy eating in early childhood.展开更多
The aim of this study was to assess the ability of Nile tilapia to balance its own diet, when two ingredient mixes were offered, using carbon stable isotopes. In order to accomplish that, 225 Nile tilapia juveniles （...The aim of this study was to assess the ability of Nile tilapia to balance its own diet, when two ingredient mixes were offered, using carbon stable isotopes. In order to accomplish that, 225 Nile tilapia juveniles （average initial weight 5.0 g ± 0.5 g） were distributed in five tanks, each containing a group of 45 fish. One group of fish were fed exclusively with a high protein mix （HPM; δ^13C = -22.62‰）, the second one fed only with a low protein mix （LPM; δ^13C = -14.34‰）. The other groups had free access to both mixes （free choice system）. The fish from all tanks were fed four times a day. Muscle, liver and blood samples were collected at each five days （from 2 fish/tank/collection） for 86 days, except for the fish fed with LPM （fed for a 120 days period）. The samples were analyzed in a mass spectrometer and proportions of the mixes consumed were estimated through its carbon isotope enrichment （δ^13C）. Energy intake slightly decreased after the 50th day and protein consumption increased after the same period. However, consumption did not present a clear pattern in relation to the individual weight, i.e., protein consumption patterns are mainly related to the age of the individuals and it is not clear if it is also correlated to their weight. Additionally, this technique allowed the observation of differences regarding consumption among the individuals from the experimental group.展开更多
When assessing food intake patterns in groups of individuals, a major problem is finding usual intake distribution. This study aimed at searching for a probability distribution to estimate the usual intake of nutrient...When assessing food intake patterns in groups of individuals, a major problem is finding usual intake distribution. This study aimed at searching for a probability distribution to estimate the usual intake of nutrients using data from a cross-sectional investigation on nutrition students from a public university in Sao Paulo state, Brazil. Data on 119 women aged 19 to 30 years old were used. All women answered a questionnaire about their lifestyle, diet and demographics. Food intake was evaluated from a non-consecutive three-day 24-hour food record. Different probability distributions were tested for vitamins C and E, panthotenic acid, folate, zinc, copper and calcium where data normalization was not possible. Empirical comparisons were performed, and inadequacy prevalence was calculated by comparing with the NRC method. It was concluded that if a more realistic distribution for usual intake is found, results can be more accurate as compared to those achieved by other methods.展开更多
This study aimed to evaluate the quality of healthcare services pertaining to the dietary intake and swallowing functions of residents, nutrition management practices, and performance of residents at long-term care fa...This study aimed to evaluate the quality of healthcare services pertaining to the dietary intake and swallowing functions of residents, nutrition management practices, and performance of residents at long-term care facilities. We investigated outcome indicators, such as changes in dietary intake and swallowing function levels of residents, and clarified which structural and process indicators were associated with the outcome indicators. This was a retrospective study, analyzing information on healthcare services from 1067 long-term care facilities during the fiscal year 2012, sampled from among those registered with the Welfare, Health and Medical Care Information Network of the Welfare and Medical Service Agency in Japan. Five outcome indicators were identified. Next, we examined the relationships between the outcome indicators and structural or process indicators using a multivariate linear regression model, adjusting for facility type. The findings showed how the five outcome indicators were used in long-term care facilities over a period of one year and determined the independent predictors of these outcome indicators. The amplification of dietary function 1 was associated with “assessment of oral functions using a feeding and swallowing assessment checklist every three months”, “holding care conferences related to ingestion and swallowing every three months”, and “maintaining a 1:2 ratio for meal-time assistants to residents”. To improve the quality of care, it is necessary to increase the number of staff (e.g., to provide meal assistance to residents) and to understand changes in the residents’ status through accurate assessment and monitoring.展开更多
Thirty-six daily duplicate diet samples were collected from 12 healthy female Japanese vegans and sodium, potassium, calcium, magnesium, phosphorus, iron, zinc, copper, manganese, iodine, selenium, chromium and molybd...Thirty-six daily duplicate diet samples were collected from 12 healthy female Japanese vegans and sodium, potassium, calcium, magnesium, phosphorus, iron, zinc, copper, manganese, iodine, selenium, chromium and molybdenum in the diets were measured to estimate mineral and trace element intake by Japanese vegans. Significantly higher intake of potassium, magnesium, phosphorus, iron, copper, manganese and molybdenum was observed in vegans than in general Japanese women, but no difference was observed in sodium, iodine, selenium and chromium intake. Vegan calcium intake tended to be low compared to that of general women but the difference was not significant. Since high potassium, magnesium and iron intakes cannot be achieved by general Japanese diets and high intake of potassium and magnesium may prevent hyperextension and cardiovascular disease in vegans, there are few problems with Japanese vegan diets regarding mineral and trace element intake, except for calcium intake, which is low as it is in the general Japanese people.展开更多
AIM： To study the association between nitrite and nitrosamine intake and gastric cancer （GC）, between meat and processed meat intake, GC and oesophageal cancer （OC）, and between preserved fish, vegetable and smok...AIM： To study the association between nitrite and nitrosamine intake and gastric cancer （GC）, between meat and processed meat intake, GC and oesophageal cancer （OC）, and between preserved fish, vegetable and smoked food intake and GC. METHODS： In this article we reviewed all the published cohort and case-control studies from 1985-2005, and analyzed the relationship between nitrosamine and nitrite intake and the most important related food intake （meat and processed meat, preserved vegetables and fish, smoked foods and beer drinking） and GC or OC risk. Sixty-one studies, 11 cohorts and 50 case-control studies were included. RESULTS： Evidence from case-control studies supported an association between nitrite and nitrosamine intake with GC but evidence was insufficient in relation to OC. A high proportion of case-control studies found a positive association with meat intake for both tumours （11 of 16 studies on GC and 11 of 18 studies on OC）. A relatively large number of case-control studies showed quite consistent results supporting a positive association between processed meat intake and GC and OC risk （10 of 14 studies on GC and 8 of 9 studies on OC）. Almost all the case-control studies found a positive and significant association between preserved fish, vegetable and smoked food intake and GC. The evidence regarding OC was more limited. Overall the evidence from cohort studies was insufficient or more inconsistent than that from case-control studies.CONCLUSION： The available evidence supports a positive association between nitrite and nitrosamine intake and GC, between meat and processed meat intake and GC and OC, and between preserved fish, vegetable and smoked food intake and GC, but is not conclusive.展开更多
文摘Gas Turbines are among the most important energy systems for aviation and thermal-based power generation.The performance of gas turbine intakes with S-shaped diffusers is vulnerable to flow separation,reversal flow,and pressure distortion,mainly in aggressive S-shaped diffusers.Severalmethods,including vortex generators and energy promoters,have been proposed and investigated both experimentally and numerically.This paper compiles a review of experimental investigations that have been performed and reported to mitigate flow separation and restore system performance.The operational principles,classifications,design geometries,and performance parameters of Sshaped diffusers are presented to facilitate the analysis and understanding of the influence of each mitigation method on flowenhancement in S-shaped diffusers.Theinfluencing design parameters on the performance of the S-shaped diffuser and the findings achieved by various experimental investigations are discussed and compared.The review concludes that reducing the intake length reduces the size and weight of the gas turbine,leading to a higher power-to-weight ratio.However,the main challenge in shortening the S-shaped diffusers is the flow separation in the high-curvature section,which must be prevented to maintain high performance.Prevention can be achieved through flow control methods,which are categorized into passive and aggressive methods.The static pressure recovery coefficient,total pressure loss coefficient,ideal static pressure coefficient,distortion coefficient,and skin friction coefficient are the primary performance evaluation and comparison parameters between the experimentally investigated mitigation methods.The new trend in S-shaped diffuser studies includes the integration of computational and data-driven methods.
基金supported by the National Natural Science Foundation of China(82072432)Scientific Research and Innovation Platform for Intelligent and Precise Treatment of Bone and Joint Diseases in Shaanxi Province(2024PT-13)Key Project of Shaanxi Provincial Natural Science Foundation(2024JC-ZDXM-55).
文摘Lifestyle is related to many chronic diseases,such as knee osteoarthritis(KOA).Food intake is important because it can be controlled.However,the causal relationship of food intake and KOA still remain unclear.To identify the relationship between food intake and KOA and to screen relevant targets.First,we performed two-sample Mendelian randomization(MR)analysis.A total of 16 kinds of food intake datasets were included,the inverse variance-weighted analysis showed that the KOA was negatively correlated with cereal intake(odds ratio(OR)0.48;95%CI 0.35-0.68;P=1.98×10−5).Second,potential drug targets of KOA in plasma were explored,secreted protein acidic and rich in cysteine(SPARC,or osteonectin),SPARC,Cwcv,and Kazal-like domains proteoglycan 2(SPOCK2)as the causal protein for plasma with KOA,and increased SPOCK2(OR 0.84;95%CI 0.77-0.92;P=5.52×10−5),decreased the risk of KOA.Integrated transcriptomic analysis(P=0.0285)and in vivo(P=0.0395)showed consistent results.Finally,by metabolomics analysis and molecular docking,seven co-expressed small molecules were detected in cereal and were bound to SPOCK2.Our findings indicate the cereal intake was negatively correlated with KOA,and support the SPOCK2 as a novel potential target for cereal intake in KOA.Our study will provide a clinical dietary guidance for KOA patients and a theoretical basis for the development of novel,side-effect-free drugs for KOA.
基金supported by the National Natural Science Foundation of China(Grant No.81872624)Fundamental Research Program of Shanxi Province(Grant No.202403021211139).
文摘Objective This study aimed to reexplore minimum iodine excretion and to build a dietary iodine recommendation for Chinese adults using the obligatory iodine loss hypothesis.Methods Data from 171 Chinese adults(19–21 years old)were collected and analyzed based on three balance studies in Shenzhen,Yinchuan,and Changzhi.The single exponential equation was accordingly used to simulate the trajectory of 24 h urinary iodine excretion as the low iodine experimental diets offered(iodine intake:11-26μg/day)and to further deduce the dietary reference intakes(DRIs)for iodine,including estimated average requirement(EAR)and recommended nutrient intake(RNI).Results The minimum iodine excretion was estimated as 57,58,and 51μg/day in three balance studies,respectively.Moreover,it was further suggested as 57,58,and 51μg/day for iodine EAR,and 80,81,and 71μg/day for iodine RNI or expressed as 1.42,1.41,and 1.20μg/(day·kg)of body weight.Conclusion The iodine DRIs for Chinese adults were established based on the obligatory iodine loss hypothesis,which provides scientific support for the amendment of nutrient requirements.
文摘Industry and energy continue to require piston engines(PICE)at a high level worldwide.Therefore,science and technology must urgently work on improving the PICE working cycle.Improving the quality of the intake process of theworking fluid into the cylinder is one of the most effective ways to improve the operational performance of PICE.The purpose of the study was to assess the impact of various cylinder head(CylH)designs on the gas-dynamic and heat-exchange qualities of air flows within an engine model’s intake system.Three different CylH designs were studied:the basic configuration and upgraded cylinder heads with a square valve and a square valve port.These designs are innovative.Laboratory conditions were used to conduct the studies for stationary air flow.The experiments covered the range of Reynolds numbers from 8500 to 96,000.The intake system’s gas dynamics and heat transfer were determined using the thermal anemometry method,which was based on constant-temperature hot-wire anemometers.It has been established that the use of upgraded CylHs causes an increase in the turbulence number of flow by an average of 13.5%.Additionally,itwas found that the increase in the turbulence number of flowin the cylinder is about 19%when installing new CylH designs.It was shown that therewas an increase in the heat transfer coefficient in the intake pipe by 10%–40%when installing modernized CylH designs in the intake system.The article focused on the problems of increasing the turbulence level and intensifying the heat transfer of stationary air flow in the intake system,specifically in PICEs.The study’s findings are novel in the areas of applied gas dynamics and PICEs.
基金supported by the Japan Society for the Promotion of Science,Grant Numbers JP 24700723,JP 17K13209.
文摘Purpose Athletes have presented a deficiency in relative energy in recent years,which calls for appropriate nutritional guid-ance based on the estimated energy requirement(EER)-the target amount of daily energy intake(EI).The calculation of EER requires longitudinal physical activity level(PAL)data,which has received insufficient attention.Therefore,this study aimed to clarify the changes in PAL by training periodization using the doubly labeled water(DLW)method,combined with the current status of EI by competition characteristics.Methods The participants comprised four male sprint athletes and five male endurance athletes at the national level.The experimental periods were normal training(NT)and tapering training(TT)periods.PAL was measured using the DLW method,and EI was measured by the dietary record method.Results PAL of the sprint athletes in the NT periods was significantly higher than in TT periods.EI had no significant differ-ences between the two periods.PAL and EI of the endurance athletes had no significant differences beteen the two periods.Conclusions These findings indicated that in sprint athletes,different PAL was observed between the two periods,with the TT period suggesting a lower value than the NT period.In endurance athletes,it had similar PAL values between the two periods.This suggests that the degree of influence of the training period on PAL may vary depending on the athletic events.Furthermore,the EI was not adjusted for changes in PAL,and the participants observed the status of energy-deficient regardless of discipline or training period.
基金supported by the Key Laboratory of Automotive Power Train and Electronics(Hubei University of Automotive Technology)(ZDK1201505)Auto Parts TechnologyHubei Province Collaborative Innovation Project(2015XTZX04).
文摘The intake system of a racing engine plays a crucial role in determining its performance,particularly in terms of volumetric efficiency,power output,and throttle response.According to Formula Society of Automotive Engineers(FSAE)regulations,the engine intake systemmust incorporate a 20mmdiameter flow-limiting valve within the intake manifold.This restriction significantly reduces the airflow into the engine,leading to a substantial drop in power output.To mitigate this limitation,the intake system requires a redesign.In this study,theoretical calculations and one-dimensional thermodynamic simulations are employed to determine the optimal parameters for the intake system.A numerical simulation of the intake system’s flow field is then conducted to refine its structure and layout.Finally,experiments are performed on an engine equipped with the optimized intake system,and its feasibility is evaluated based on experimental results.Thefindings indicate that the maximumengine torque increases from56.36 to 59.91 N⋅m,while the maximum power output rises from 59.16 to 63.94 kW.To further enhance performance and adaptability across different competitions,a variable-length intakemanifold control system is also designed,improving both power delivery and overall operational stability of the racing car.
基金supported in part by the Ship Preliminary Research Project (No.3020401020102)。
文摘This study addresses the issue of spray icing on the air intake grilles of ship power systems in cold maritime environments.Through numerical simulation methods,the influence of environmental parameters on icing characteristics is revealed,and an energy-efficient zoned electric heating anti-icing strategy is proposed.A threedimensional grille model is constructed to systematically analyze the effects of environmental temperature(from−20℃to−4℃),droplet diameter(from 50μm to 500μm),and liquid water content(from 0.5 g/m³to 8 g/m³)on icing rates and blockage of the flow channel.The results indicate that low temperature and high liquid water content significantly exacerbate icing.Under the condition of an environmental temperature of−20℃,droplet diameter of 500μm,and liquid water content of 8 g/m³,the flow channel blockage ratio reaches 30.95%within 10 min.Additionally,as droplet diameter increases,the droplet impingement and icing regions become more concentrated toward the leading edge of blades.To mitigate grille icing in cold environments,an electric heating film configuration is employed for thermal protection.Optimization of the heating strategy reveals that the zoned heating approach,compared to the initial uniform heating scheme,effectively homogenizes surface temperature distribution while reducing total power consumption by 37.47%.This study validates the engineering applicability of the zoned electric heating anti/de-icing strategy,providing theoretical and technical support for the design of anti-icing systems in ship power systems operating in cold maritime regions.
文摘BACKGROUND Bariatric surgery is an effective treatment for severe obesity but is associated with an increased risk for development of eating disorders.Indeed,numerous maladaptive eating behaviors and eating disorders have been described following bariatric surgery.However,the differentiation of pathologic eating patterns from expected dietary changes following bariatric surgery can sometimes be difficult to discern.CASE SUMMARY A female in her early 40s presented for medical stabilization of severe protein calorie malnutrition after losing 52.3 kg over the last six months after Roux-en-Y gastric bypass,with subsequent development of cyclic nausea and vomiting.Fear of these aversive physical symptoms led to further restriction of nutritional intake and weight loss.The patient was diagnosed with avoidant/restrictive food intake disorder,which has not been previously reported after bariatric surgery.CONCLUSION Improvement in the diagnostic nomenclature for feeding and eating disorders is warranted for patients who have undergone bariatric surgery.
基金supported by the National Natural Science Foundation of China(Grant numbers 82204041)Gansu Provincial Science and Technology Program Funded Projects(Grant numbers 22JR11RA184).
文摘Iodine is an essential element for the synthesis of thyroid hormones.Iodine deficiency increases the burden on thyroid function and causes harm to health.The identification of convenient and reliable biomarkers for assessing iodine nutritional status is essential for evaluating iodine intake.Urinary iodine concentration(UIC)is commonly used for population level iodine status assessment but is less reliable for individuals.A 24-h urine sample is more accurate but difficult to collect[1].Thyroid volume(Tvol)and goiter rate are suitable for evaluating the long-term iodine nutritional status in populations[2].Blood indicator collection is an invasive procedure.
基金Supported by Xi’an Science and Technology Program Project(No.24YXYJ0108)Support Projects of Xi’an Children’s Hospital(No.2024I07).
文摘AIM:To investigate the causal relationship between dietary intake and myopia using Mendelian randomization(MR)analysis.METHODS:Genome-wide association study(GWAS)data from the IEU Open GWAS database were utilized to examine associations between myopia and various dietary factors.MR analysis,incorporating both univariable and multivariable approaches,assessed the impact of food intake on myopia risk through five analytical methods,with inverse variance weighted(IVW)serving as the primary reference.Sensitivity analyses,including heterogeneity assessment,horizontal pleiotropy evaluation,and leave-oneout analysis,were conducted to validate the MR findings.RESULTS:Univariable MR analysis identified a causal link between food intake and myopia.Consumption of breaded fish,canned soup,sweet biscuits,and certain fruits correlated with a lower risk of myopia,whereas intake of low-calorie hot chocolate and cereal was associated with an increased risk.Multivariable MR analysis further confirmed that breaded fish consumption exerted a direct protective effect against myopia,particularly when consumed alongside other dietary components.These findings highlight the intricate interplay between specific dietary factors and myopia development,offering valuable insights for further research.CONCLUSION:MR analysis provides evidence supporting a potential causal relationship between breaded fish intake and myopia,underscoring its relevance in targeted myopia prevention strategies.
文摘BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD)is a common and increasingly prevalent condition in the Middle East,but its determinants in the region are underexplored.Diet and lifestyle are known to significantly influence MASLD progression.AIM To assess energy and nutrient intake among MASLD patients living in Qatar and evaluate their dietary patterns.METHODS Using a cross-sectional design,94 Arab patients with MASLD,aged≥18 years,living in Qatar were studied.MASLD was diagnosed using ultrasonography,fibro scan,or elastography.Sociodemographic information was collected using a self-administered questionnaire.Dietary intake was assessed through three 24-hour recalls and a qualitative food frequency questionnaire.Energy,macro-,and micronutrient intake were analyzed using Elizabeth Stewart Hands and Associates Food Processor®Nutrition Analysis software.Statistical analyses,including factor loadings were performed using STATA 18.RESULTS Compared to recommended dietary allowance,MASLD patients had high intakes of fat,saturated fat,and cholesterol.They also showed reduced intakes of vitamin K in men,and vitamins E and A(retinol),calcium and magnesium in both genders,while selenium and sodium intakes were higher than recommendations.Three dietary patterns were identified:The‘Traditional Qatari food’pattern,the‘Prudent’pattern,and the‘Fast-food’pattern.However,no significant associations were found between these dietary patterns and body mass index or low-density lipoprotein,using adjusted regression models.CONCLUSION Findings warrant replication in longitudinal studies and call for dietary interventions to reduce energy density and enhance overall diet quality,including micronutrient intake,for MASLD prevention and management in the region.
文摘The intake swirl in the cylinder was induced by a swirler which was fixed in one of two intake ports. In order to understand the characteristics of the intake swirl, a transparent water analog was designed which simulated 150 type single cylinder engine. At the same time, the particle image velocimetry was used to measure the flow fields induced by various swirlers in the analog. After measurement, a new method was presented to evaluate the intensity of the intake swirl. Then, when the measured sections, the lifts of valve and the swirlers were different, the calculated results of the flow field were compared.
文摘The flow over a short intake is characterised by a strong interaction with the fan, that can only be captured when the rotor blades are modelled in the numerical simulations. In this paper, we use a coupled methodology to derive indications about relevant geometric variables affecting the high-incidence operation of an ultra-high bypass ratio turbofan intake with a length-to-diameter ratio of 0.35. By reproducing the effect of the fan through a body force model, we carry out a parametric study of the influence of the contraction ratio and the scarf angle at take-off conditions for a grid of 28 different three-dimensional shapes. The analysis of the selected performance metrics distributions at three angles of attack of 16., 24., and 28. reveals that a contraction ratio higher than 1.20 is needed to avoid separation at high incidence. While for an attached inlet the best performance is found with a moderate scarf angle, in presence of a developed separation the distortion level reduces as the scarf decreases up to negative values. We discuss the correspondence between the distortion indexes and the flow field, highlighting the origin of the detachment for the different geometries, according to the operating condition, and analysing the fan operation in the most distorted case. Finally, we assess the influence of modelling the rotor in the simulations, showing that its suppression effect on the separation at a given incidence depends on the intake geometric features.
文摘Adequate daily water consumption is an important factor of keeping regular homeostasis. However, the best quantity of daily water consumption for a healthy individual is not virtually stated in the literature. Despite the dearth of evidence-based recommendations, it is commonly thought that ingesting eight glasses of water a day is good for a healthy person. Avicenna had a unique viewpoint. He believed that daily water intake depended on numerous elements together with age, intercourse, body temperament, season, occupation and various internal and external elements. He also cited a few essential and usefu measures regarding proper water consumption, which have additionally been emphasized in Islamic hadiths.
文摘The objective was to create an Egyptian database on the contributors of fruit and vegetables in the diets of preschool children and to estimate the usual daily intakes of fruits, vegetables and vitamin C. A total of 59 healthy boys and girls aged 2.5 - 6 years attending day care centers in urban Giza governorate completed the study by interviewing their mothers on 6x non-consecutive days using the 24 h dietary recall. Participants were classified according to age, gender and socioeconomic class. Prevalence of daily consumptions of fruits and vegetables amounted to 22% and 54%, respectively of the total children. The daily intakes of fruits and vegetables averaged 117.5 and 56.4 g, respectively. The consumption of different types of fruits and vegetables was unevenly distributed by different personal and social variables. Estimated daily vitamin C supply from the diet was 38 mg per child, which satisfied the respective recommended nutrient intake (RNI) of 30 mg for the first six years of life. However, the diet of 15% of the children covered less than 75% of RNI. Top fruits contributing to vitamin C were oranges, guava, watermelon, pears and grapes. Extra foods such as chipsy was consumed by 81% of the children, contributed 18% to daily vitamin C supply and also 58.6 mg sodium. A multilevel intervention strategy is warranted for promoting daily fruit and vegetable intake and healthy eating in early childhood.
文摘The aim of this study was to assess the ability of Nile tilapia to balance its own diet, when two ingredient mixes were offered, using carbon stable isotopes. In order to accomplish that, 225 Nile tilapia juveniles （average initial weight 5.0 g ± 0.5 g） were distributed in five tanks, each containing a group of 45 fish. One group of fish were fed exclusively with a high protein mix （HPM; δ^13C = -22.62‰）, the second one fed only with a low protein mix （LPM; δ^13C = -14.34‰）. The other groups had free access to both mixes （free choice system）. The fish from all tanks were fed four times a day. Muscle, liver and blood samples were collected at each five days （from 2 fish/tank/collection） for 86 days, except for the fish fed with LPM （fed for a 120 days period）. The samples were analyzed in a mass spectrometer and proportions of the mixes consumed were estimated through its carbon isotope enrichment （δ^13C）. Energy intake slightly decreased after the 50th day and protein consumption increased after the same period. However, consumption did not present a clear pattern in relation to the individual weight, i.e., protein consumption patterns are mainly related to the age of the individuals and it is not clear if it is also correlated to their weight. Additionally, this technique allowed the observation of differences regarding consumption among the individuals from the experimental group.
文摘When assessing food intake patterns in groups of individuals, a major problem is finding usual intake distribution. This study aimed at searching for a probability distribution to estimate the usual intake of nutrients using data from a cross-sectional investigation on nutrition students from a public university in Sao Paulo state, Brazil. Data on 119 women aged 19 to 30 years old were used. All women answered a questionnaire about their lifestyle, diet and demographics. Food intake was evaluated from a non-consecutive three-day 24-hour food record. Different probability distributions were tested for vitamins C and E, panthotenic acid, folate, zinc, copper and calcium where data normalization was not possible. Empirical comparisons were performed, and inadequacy prevalence was calculated by comparing with the NRC method. It was concluded that if a more realistic distribution for usual intake is found, results can be more accurate as compared to those achieved by other methods.
文摘This study aimed to evaluate the quality of healthcare services pertaining to the dietary intake and swallowing functions of residents, nutrition management practices, and performance of residents at long-term care facilities. We investigated outcome indicators, such as changes in dietary intake and swallowing function levels of residents, and clarified which structural and process indicators were associated with the outcome indicators. This was a retrospective study, analyzing information on healthcare services from 1067 long-term care facilities during the fiscal year 2012, sampled from among those registered with the Welfare, Health and Medical Care Information Network of the Welfare and Medical Service Agency in Japan. Five outcome indicators were identified. Next, we examined the relationships between the outcome indicators and structural or process indicators using a multivariate linear regression model, adjusting for facility type. The findings showed how the five outcome indicators were used in long-term care facilities over a period of one year and determined the independent predictors of these outcome indicators. The amplification of dietary function 1 was associated with “assessment of oral functions using a feeding and swallowing assessment checklist every three months”, “holding care conferences related to ingestion and swallowing every three months”, and “maintaining a 1:2 ratio for meal-time assistants to residents”. To improve the quality of care, it is necessary to increase the number of staff (e.g., to provide meal assistance to residents) and to understand changes in the residents’ status through accurate assessment and monitoring.
基金comprehensive research on cardiovascular and lifestyle disease from the Ministry of Health, Labour and Welfare of Japan
文摘Thirty-six daily duplicate diet samples were collected from 12 healthy female Japanese vegans and sodium, potassium, calcium, magnesium, phosphorus, iron, zinc, copper, manganese, iodine, selenium, chromium and molybdenum in the diets were measured to estimate mineral and trace element intake by Japanese vegans. Significantly higher intake of potassium, magnesium, phosphorus, iron, copper, manganese and molybdenum was observed in vegans than in general Japanese women, but no difference was observed in sodium, iodine, selenium and chromium intake. Vegan calcium intake tended to be low compared to that of general women but the difference was not significant. Since high potassium, magnesium and iron intakes cannot be achieved by general Japanese diets and high intake of potassium and magnesium may prevent hyperextension and cardiovascular disease in vegans, there are few problems with Japanese vegan diets regarding mineral and trace element intake, except for calcium intake, which is low as it is in the general Japanese people.
基金Supported by a fellowship of the 'FundacióPrivada Institut D' investigacio Biomédica de Bellvitge (IDIBELL) partially funded by the ISCⅢnetwork (RCESP C03/09) Spain and ECNIS Network from the 6FP of the EC
文摘AIM： To study the association between nitrite and nitrosamine intake and gastric cancer （GC）, between meat and processed meat intake, GC and oesophageal cancer （OC）, and between preserved fish, vegetable and smoked food intake and GC. METHODS： In this article we reviewed all the published cohort and case-control studies from 1985-2005, and analyzed the relationship between nitrosamine and nitrite intake and the most important related food intake （meat and processed meat, preserved vegetables and fish, smoked foods and beer drinking） and GC or OC risk. Sixty-one studies, 11 cohorts and 50 case-control studies were included. RESULTS： Evidence from case-control studies supported an association between nitrite and nitrosamine intake with GC but evidence was insufficient in relation to OC. A high proportion of case-control studies found a positive association with meat intake for both tumours （11 of 16 studies on GC and 11 of 18 studies on OC）. A relatively large number of case-control studies showed quite consistent results supporting a positive association between processed meat intake and GC and OC risk （10 of 14 studies on GC and 8 of 9 studies on OC）. Almost all the case-control studies found a positive and significant association between preserved fish, vegetable and smoked food intake and GC. The evidence regarding OC was more limited. Overall the evidence from cohort studies was insufficient or more inconsistent than that from case-control studies.CONCLUSION： The available evidence supports a positive association between nitrite and nitrosamine intake and GC, between meat and processed meat intake and GC and OC, and between preserved fish, vegetable and smoked food intake and GC, but is not conclusive.
