Dense Bed Research Articles

Submicron Nonporous Silica Particles for Enhanced Separation Performance in pCEC.

Applications of submicron-scale particles are of rising interest in separation science due to their favorable surface-to-volume ratio and their fabrication of highly ordered structures. The uniformly dense packing beds in columns assembled from nanoparticles combined with an electroosmotic flow-driven system has great potential in a highly efficient separation system. Here, we packed capillary columns using a gravity method with synthesized nanoscale C18-SiO2 particles having diameters of 300-900 nm. The separation of small molecules and proteins was evaluated in the packed columns on a pressurized capillary electrochromatography platform. The run-to-run reproducibility regarding retention time and peak area for the PAHs using a column packed with 300 nm C18-SiO2 particles were less than 1.61% and 3.17%, respectively. Our study exhibited a systematic separation analysis of small molecules and proteins based on the columns packed with submicron particles combined with the pressurized capillary electrochromatography (pCEC) platform. This study may provide a promising analytical approach with extraordinary column efficiency, resolution, and speed for the separation of complex samples.

Fischer-Tropsch wax catalytic cracking for the production of low olefin and high octane number gasoline: Process optimization and heat effect calculation

To produce low olefin gasoline with high octane number by Fischer-Tropsch (F-T) wax fluid catalytic cracking (FCC) process, operating conditions optimization were carried out in the pilot-scale riser and turbulent fluidized bed (TFB) FCC unit. The experimental results in the riser indicated that under the condition of low reaction temperature and regenerated catalyst temperature, large catalyst-to-oil weight ratio (C/O) and long reaction time, the gasoline olefin content could be reduced to 20.28 wt%, but there is large octane number loss owing to a great loss in high octane number olefin. Therefore, a novel FCC process using the TFB reactor was proposed to strengthen the aromatization reaction. The reaction performance of TFB reactor were investigated. The result demonstrated that the TFB reactor has more significant effect in reducing olefins and improving aromatics. At the expense of certain gasoline yield, the gasoline olefin content reduced to 23.70 wt%, aromatics content could increase to 26.79 wt% and the RON was up to 91.0. The comparison of reactor structure and fluidization demonstrated that the TFB reactor has higher catalyst bed density. The reaction heat and coke combustion heat was calculated indicating the feasibility of its industrial application of the TFB process.

Gully erosion model of the archaeological site of Eridu Ziggurat in the southern plateau of Iraq using RS-GIS technology

The metamorphic processes represented by the process of erosion of the grooves by rainwater is one of the most important processes that affect the structure of the archaeological hills, including the site of Zaqra Eridu. This worked on the activity of rain erosion operations during the rainy season of the year. The problem of the research is whether rain erosion leaves grooves that distort the facades or remnants of the Eridu ziggurat area, and can the severity and degree of erosion erosion be measured within the site of the study area using GIS technology, and is it possible to provide means of protection and maintenance of the archaeological site from the processes of gully erosion. The spatial analytical approach will be adopted and the mathematical quantitative approach based on the extrapolation and analysis of geographical data will be adopted, as well as the use of the descriptive approach. In order to achieve this goal, a field survey will be postponed to discover the site of the Eridu Ziggurat by observing and observing the grooves that the region was exposed to, preparing a digital spatial database for the region and building The digital elevation model, as well as building a gully erosion model, its degree and intensity for the location of the study area. GIS technology, in addition to providing a practical study and a spatial database, the results of which benefit from the General Authority for Antiquities of Dhi Qar Governorate. The study shows that the ziggurat of Arduwa is located within a range of a complex drainage network that reaches the sixth rank, and it is also guaranteed that it penetrates with a network of high density (340-580 m / km 2) according to the classification of the density of the river beds, and therefore it suffered from being cut by grooves that showed its buried features under the surface of the earth on one side Its outer walls were smashed on the other hand, that is, it is within the range of high erosion within the category (1501-2700) according to the degrees of erosion of Berkisma. This study seeks to preserve archaeological sites by following planning standards for their maintenance and restoration and exploitation of the attractions of archaeological tourism.

Models of the bed structure dynamics of mass marine bivalves of the White Sea

The present paper is a synthesis of all the results of long-term (for almost 35 years) observations of beds of nine widespread bivalve species, carried out at the Marine Biological Station of St. Petersburg State University in the White Sea (Chupa Inlet mouth, Kandalaksha Bay). The purpose of the investigations is to identify the patterns of the spatial-temporal organization of bivalve beds. As a result, a generalized analysis of the reasons for the spatial and temporal heterogeneity of the bed structure of widespread long-lived bivalve species in an undisturbed environment is presented, and attempts are made to develop models of the dynamics of the age structure of bivalve beds in the White Sea. An integrated approach to identifying the patterns in the organization of bivalve beds: the study of changes in the size-age structure of beds as a reflection of the recruitment, growth and mortality features, made it possible to identify intraspecific relationships as determining long-term trends in the structure changes of mollusk beds in the White Sea. Studies have shown that long-term stability of size-age structure is not a typical feature of the bivalve beds in the White Sea, and substantial fluctuations in their structure take place even under relatively undisturbed environmental conditions. The main reasons for the fluctuations of the bed structure appear to be connected to inter-annual variation in recruitment rates. These variations are mainly caused by the intensity of mollusks intraspecific interactions, and by the conditions of mollusk survival in the early stages of the life cycle. As a result of interannual fluctuations in the bed bivalve recruitment rates, specimens of only 1 or 2 generations dominated for several years. A periodic change of the dominant generations could be considered as a recurrence in the bed development. However, the recurrence of the bed structure dynamics can be easily disrupted under unfavorable conditions for the mollusk survival in the early stages of the life cycle. The bivalve stationary beds in the White Sea are likely the exception from the general rule. They can be formed in case of a relatively stable level of annual recruitment with a decrease in intensity of intraspecific competition. The latter in the White Sea beds of Bivalvia was observed either when the ecological needs of individuals of different ages were differentiated, or in the case of a relatively poor bed density.

Effect of louver baffle on the stability and separation performance of the gas-solid separation fluidized bed

Bed density stability is often the dominant factor restricting the efficiency of coal beneficiation in gas-solid separation fluidized beds (GSSFB). Here, in order to improve the fluidization quality, a louver baffle was introduced into a conventional GSSFB, converting it into a so-called louver baffle separation fluidized bed (LBSFB). The influence of the louver baffle on the fluidization characteristics and coal separation efficiency of the GSSFB were investigated using a combination of experiments and numerical simulations. The minimum fluidized gas velocity, pressure drop, and cross section density of the bed were measured when baffle was placed at two different positions (H=40 mm and H=80 mm). Meanwhile, the evolution of bubble generation and particle flow were simulated when the baffle was placed at H= 40 mm and the operating gas velocity was 7.52 cm/s. The results showed that the use of a single guide baffle could effectively break up the bubbles in the bed, inhibit bubble growth and particle backmixing, and restore the uniform distribution of the updraft. When the louver baffle was installed at a height of H = 40 mm and the superficial gas velocity was 7.52 cm/s, the standard deviation of radial density fluctuation in the bed was reduced to 0.028 g/cm3, which is more than 35% lower than that of the conventional GSSFB, and that of the axial density fluctuation was reduced to 0.146 g/cm3. Under these conditions, the separation of 6–13 mm raw coal in a LBSFB resulted in a clean coal yield of 69.97% and a probable error, E, value of 0.082 g/cm3

Numerical investigation of fiber orientations and homogeneity in powder bed fusion of fiber/polymer composites

ABSTRACT The packing characteristics of fiber/polymer powder in powder bed fusion additive manufacturing exhibit a high correlation with the mechanical behaviours of printed composite parts such as homogeneity and anisotropy. A discrete element model has been developed to investigate the packing characteristics of glass fiber/polyamide 12 (PA12) powder, which include fiber orientations, fiber homogeneity, and packing density. The predicted probability distributions of fiber orientations in the powder bed are comparable with those measured in glass fiber–reinforced PA12 composites printed via multi jet fusion. Three types of fibers with different length distributions are adopted to study the effects of the fiber length distribution on their packing characteristics. The simulation results reveal that a large average fiber length is beneficial to fiber alignment in the powder spreading direction but lowers the fiber homogeneity and packing density of the powder bed. Furthermore, varying the fiber length can provide an effective way to regulate fiber orientations in the powder packing process, which would help achieve satisfactory anisotropic mechanical properties for composite parts.

Acoustical methods for remote sensing in seagrass meadows

Seagrasses provide a multitude of ecosystem services and act as important carbon sinks. However, seagrass habitats are declining globally, and they are among the most threatened ecosystems on earth. For these reasons, long-term and continuous measurements of seagrass parameters are of primary importance for ecosystem health assessment and sustainable management. After a brief historical overview, this talk will present results from both active and passive acoustical methods for ecosystem monitoring in seagrass meadows. From a propagation perspective, gas bodies contained within the seagrass tissue as well as photosynthetic-driven bubble production results in attenuation and scattering of sound that produces increased transmission loss. For the passive approach, the detachment of gas bubbles from the plants is an important component of the ambient soundscape. Examples of both techniques will be presented based on data collected as part of an 18-month continuous deployment of an acoustical measurement system operating in a moderately dense seagrass bed dominated by Thalassia testudinum (turtle grass) in Corpus Christi Bay, Texas. The data show annual trends related to the seasonal growth pattern of Thalassia as well as diurnal trends correlated with photosynthetically active radiation. [Work supported by NSF.]

Experimental approach for development of a powder spreading metric in additive manufacturing

The powder spreading is a vital step of powder-based additive manufacturing (AM) processes. The quality of spread powder can considerably influence the properties of fabricated parts. Poorly packed powder beds with high surface roughness result in printed part layers with large porosity and low dimensional accuracy, leading to poor mechanical properties. Therefore, the powder spreadability and its dependence on process parameters and powder characteristics should be quantified to improve the efficiency of powder-based AM methods. This study proposes a novel dimensionless powder spreadability metric that can be commonly used in different powder-based AM processes. The quality of spread powder in terms of powder bed density and surface roughness was evaluated by adjusting the process parameters including recoating velocity and layer thickness, and powder characteristics including particle size distribution. In addition, the dynamic repose angle was proposed and examined as another powder spreadability metric. The results showed that these two proposed metrics were strongly correlated and lower recoating velocity and larger layer thickness led to higher spreadability and lower dynamic repose angle.

U.S. Adult Critical Care Beds Per Capita: A 2021 County-Level Cross-Sectional Study.

Describe the per capita distribution of staffed adult critical care beds across the United States. Cross-sectional epidemiologic assessment of November 2021 hospital data from the Department of Health and Human Services' Protect Public Data Hub. Staffed adult critical care beds per adult population. The percent of hospitals reporting was high and varied by state/territory (median, 98.6% of states' hospitals reporting; interquartile range [IQR], 97.8-100%). There was a total of 4,846 adult hospitals accounting for 79,876 adult critical care beds in the United States and its territories. Crudely aggregated at the national-level, this calculated to 0.31 adult critical care beds per 1,000 adults. The median crude per capita density of adult critical care beds per 1,000 adults across U.S. counties was 0.00 per 1,000 adults (county, IQR 0.00-0.25; range, 0.00-8.65). Spatially smoothed county-level estimates were obtained using Empirical Bayes and Spatial Empirical Bayes approaches, resulting in an estimated 0.18 adult critical care beds per 1,000 adults (range from both methodological estimates, 0.00-8.20). When compared to counties in the lower quartile of adult critical care bed density, counties in the upper quartile had higher average adult population counts (mean 159,000 vs 32,000 adults per county) and a choropleth map demonstrated high densities of beds in urban centers with low density across rural areas. Among U.S. counties, the density of critical care beds per capita was not uniformly distributed, with high densities concentrated in highly populated urban centers and relative scarcity in rural areas. As it is unknown what defines deficiency and surplus in terms of outcomes and costs, this descriptive report serves as an additional methodological benchmark for hypothesis-driven research in this area.

Dimensioning Air Reactor and Fuel Reactor of a Pressurized Chemical Looping Combustor to Be Coupled to a Gas Turbine: Part 1, the Air Reactor

This paper provides a simple methodology for the design of the air reactor of a chemical looping combustor to optimize its characteristics when it is employed connected to a turbo expander to produce power. The design process, given a certain objective (e.g., electric power) defines the reactor specifics, namely height and diameter, taking into account the following aspects: solids inventory of the air reactor; gas velocity; air reactor transport disengaging height (TDH); solids concentration profile along the reactor height, dense bed height; freeboard height; pressure drop depending on air reactor injectors design and configuration. The total air reactor height was about 9.5 m, while the diameter was about 1.8 m. The total inventory was about 10,880 kg; while the circulation rate in the air reactor was about 110 kg/s. The operating pressure and temperature were, respectively, 12 bar and 1200 °C. The average velocity of the gases inside the reactor was about 4 m/s. The fluidization regime resulted to be comprised between turbulent and fast fluidization. Further work must be directed into the estimate of the pressure drop of the reactor, which will affect the plant efficiency in a considerable way.

Hydrodynamics and mass transfer around active particles in dense gas-fluidized beds

The hydrodynamics of bubbling fluidized beds of Geldart B granular solids operated at ambient temperature and at 500 °C are investigated by uncooled capacitance probes at different gas superficial velocities. Statistical analysis of the time-series of the local bed voidage generates Probability Density Functions (PDF) that display multimodal patterns. A remarkable bimodal character is apparent in the part of the PDF that refers to the emulsion phase when the gas superficial velocity is increased. It is inferred that two phases with different porosity co-exist in the emulsion phase: a lower voidage LV-phase and a higher voidage HV-phase. The link between the LV- and HV-phases as assessed from PDF of capacitance signals and the actual flow patterns induced in the emulsion phase by the bubbles is open to scrutiny.Along a different path, the influence of the bed hydrodynamics and expansion patterns of the emulsion phase on the gas mass transfer around a freely moving coarse active particle is investigated. To this end, mass transfer-limited reaction experiments are performed, consisting in catalytic oxidation of carbon monoxide at 450 °C over Pt-loaded γ-alumina spheres immersed in the fluidized bed. The mass transfer coefficient around the freely moving active particles is measured and worked out to calculate the particle Sherwood (Sh) number. Results obtained from reaction experiments confirm the close relationship between mass transfer and expansion patterns of the emulsion phase, and the need for proper hydrodynamic characterization of the bed. A Frӧssling-type equation, Sh=2·∊e+K·(Ree/∊e)1/2·Sc1/3, well correlates the results. Sh increases with fluidization gas velocity and a best fitting is obtained using the bed voidage of the HV-region of the emulsion phase in the correlation.

Modeling of radiation heat transfer in dense-bed flows of solids in indirectly heated rotary kilns

• modification and implementation of a DOM-radiation model which combines all required physical submodels to simulate heat radiation to dense beds of particles. • Full time and space resolved simulation of thermal conversion of wet moving bulk in a large-scale rotary kiln reactor. • Analytical validation of model and justification with laboratory-scale experiments. • Efficiency optimization of the numerical solver for industrial-scale and long-time simulations on parallel supercomputers. • Parameter studies for large-scale reactors to investigate conversion rate and product quality. This work presents further development and validation of the Discrete Ordinates Model for thermal radiation implemented in OpenFOAM® for application to packed beds of particles. The radiation model is an important part of a more comprehensive model for simulating the thermochemical conversion of the discrete phase (here for instance wet biomass particles). The comprehensive Eulerian-Lagrangian model is part of a three-dimensional, time-resolved simulation of the essential chemical and physical processes occurring within and in-between particles in a moving bed. For the thermal treatment of solid particles, convective and radiative heat transfer couple the energy exchange between the reactor wall, gas- and disperse phase. The original implementation of the finite volume Discrete Ordinate Model (fvDOM) present in OpenFOAM® is valid for a dilute particulate phase and neglects the effect of local opacity due to the existence of individual particles. In the present application, a dense-packed bed of the particulate phase exists in the reactor and, therefore, this direction-based radiation model is adjusted for a computational cell with arbitrary particle volume fractions. To validate the results with the present thermal radiation model, a simple test case is first presented, where a bed of particles is heated from the top of the computational domain. A second test case relates to an experimentally investigated laboratory-scale reactor. The results of the improved fvDOM are compared to the original implementation in OpenFOAM® and the more simple and computationally cheap P-1 radiation model. In the presence of a packed bed, the P-1 model largely overpredicts the radiative heat transfer while the original fvDOM underpredicts the heat flux by about 15 % for the first test case. The new improved model delivers results within 1% deviation at the expense of maximum of 10 % increase in the computational time. Large-scale parallel simulations of real setups are crucial tools to predict the efficiency of a process and improve the operational parameters. To achieve the pre-defined product quality at minimum cost, an example of the implemented radiation model in thermochemical conversion of wet biomass in a rotary drum is been given and the importance of the radiation heat transport to the bulk is highlighted.

Диагностические возможности оптической когерентной томографии при глаукоме

The detection of glaucoma at an early stage remains one of the most urgent problems of modern ophthalmology due to its leading position among the causes of irreversible blindness not only in Russia but also in the world. Despite the currently available capabilities of modern diagnostic equipment, the issue of detecting glaucoma at an early preperimetric stage remains open. Therefore, it seems relevant to search and study the most informative methods for diagnosing this ophthalmopathology. This review of domestic and foreign literature provides data on the diagnostic capabilities of the method for glaucoma, which allows recording objective structural and vascular changes in the retina and optic nerve. We are talking about optical coherence tomography (OCT), including with the function of angiography, which has become widespread both in Russia and abroad. Spectral optical coherence tomography, especially with the function of angiography, has a high sensitivity, not only in terms of diagnosis, but also in the monitoring of glaucoma. Morphometric parameters that are highly informative are the characteristics of the complex of retinal ganglion cells and the peripapillary layer of retinal nerve fibers. The study of the density of the peripapillary vascular bed, the optic disc and the macular area opens up prospects for the early diagnosis of glaucoma and can be used as predictors of the development and progression of glaucoma. Keywords: glaucoma, optical coherence tomography, optical coherence tomography with angiography function, retinal ganglion cell complex, peripapillary layer of retinal nerve fibers

Effect of 3–0 mm fine coal migration characteristics on high sulfur lignite separation in compound dry cleaning apparatus

Coal is the significant basic energy to promote the national economic development. Promoting the energy development is of great significant to realizing the energy strategic goals of Carbon Peak and Carbon Neutrality. In this paper, the influence of the migration behavior of 3–0 mm pulverized coal in the bed space on the separation of high-sulfur lignite using compound dry separation bed was mainly investigated. The migration characteristics of differentiated density and size particles in the bed space was emphatically analyzed and the optimum leading density and particle size composition to form autogenous medium bed were determined. The influence of vibration intensity and airflow velocity on the spatial stability of bed density was systematically investigated. The distribution law of low-grade high-sulfur lignite in compound dry separation bed was analyzed and the distribution area of bed products was determined. The experimental results show that when ρ = 1.8–2.0 g/cm3, d = 0.5–0.25 mm, the pulverized coal particles are distributed uniformly along bed height direction and the fluidization quality of bed reaches the optimum and they are the optimum leading particle size and density composition for forming autogenous medium bed. As the vibration amplitude and frequency increase, the density standard deviation decreases firstly and then increases. When A = 2.4 mm, f = 21 Hz, the density stability of bed space reaches the best and the influence of vibration frequency on the spatial stability of bed density is more sensitive compared with the influence of vibration amplitude. Under the condition (A = 2.4 mm, f = 21 Hz), when the airflow velocity range is Uv = 0.112–0.203 m/s, the bed density could keep being distributed uniformly and stably. Under the optimum operating conditions, the compound dry separation tests for low-grade high-sulfur lignite was conducted. The distribution law of sulfur content in the bed was analyzed and the distribution area of bed products was determined. Area Ⅰ is the low density material separation area; Area Ⅱ is the middle and high density product transition and separation area; Area III is the high density product migration area. The yield of clean coal is 73.06 % and the sulfur content, ash content and caloric value are 0.96 %、9.37 % and 12.38 MJ/Kg, respectively. The probable value (Ep) is 0.08 g/cm3 and the high-precision separation of low-grade high-sulfur lignite using compound dry separation bed has been realized.

Evaluation of common reed (Phragmites australis) bed changes in the context of management using earth observation and automatic threshold

ABSTRACT There is no easy in situ way to monitor large waterbodies for their aquatic vegetation change, especially during mowing works. The objective of this study is to choose the best automatic workflow that would estimate a change in the reed bed area and density over time. This workflow will assess the mowing effect on reeds over 3 years in the Plateliai Lake (Lithuania). Sentinel-2/MSI images were used to derive reed beds using water adjusted vegetation index (WAVI) and normalised difference water index (NDWI). The indices were classified using seven different binary thresholding algorithms. Results were validated with orthophotos gathered from unmanned aerial vehicle surveys in mowed regions and one reference area. Analysis demonstrated that using the NDWI together with the Yen thresholding algorithm generated the best accuracy results, with the highest accuracy resulting with high vegetation areas where the area under the curve values were 0.85 ± 0.17. The changes in estimated density did not show a significant correlation between mowed and reference areas and years. The results indicate that Sentinel-2/MSI is a feasible tool for the evaluation of reed bed change. On this basis, it is recommended to implement it as an additional monitoring tool that covers larger areas than in situ monitoring.

EFFECTIVENESS OF USING THE BED FUND AND HUMAN RESOURCES FOR PROVIDING MEDICAL CARE TO CHILDREN WITH RESPIRATORY DISEASES.

The aim: Retrospectively evaluate the effectiveness of the use of beds and human resources for the treatment of children with respiratory diseases in hospitals in the period 2008-2021. Materials and methods: We calculated indicators that characterize the efficiency of the use of bed and personnel resources: the density of beds per 10,000, the rate of hospitalized children per 10,000 (RH per 10,000), the bed occupancy rate per year (BOR), average length of stay (ALOS), full-time positions (FTP) per 100,000, number of beds per 1 FTP of doctors. Results: During 2008-2021, there was a significant decrease in the density of all types of beds. The percentage of hospitalized children for inpatient treatment decreased, BOR decreased, and ALOS decreased. The density of full-time positions of allergists increased by +23.78%, pediatricians by +4.86%, pulmonologists decreased by -13.15%. In 2021, there were 10.31 beds for 1 FTP of an allergist, 12.8 beds for 1 FTP of a pulmonologist, and 5.83 beds for 1 FTP of a pediatrician. According to the correlation matrix, it was established that the more beds there are for 1 full-time position of a pediatrician and 1 full-time position of an allergist, the longer the ALOS and the bed occupancy rate are. Conclusions: When planning staffing of health care institutions, it is necessary to mind the level of urbanization of the region, and ensure status of the general practitioner as a leading medical specialist responsible for medical care during the first meeting with the patient and his subsequent follow-up.

First mesophotic Ecklonia radiata (Laminariales) records within the iSimangaliso Wetland Park marine-protected area, east coast, South Africa

Abstract A dense Ecklonia radiata (Laminariales) kelp forest extending at least 35 km has been found between 45 and 60 m depth range within the mesophotic zone inside the iSimangaliso marine-protected area (MPA) at the iSimangaliso Wetland park World Heritage Site on the east coast of South Africa. This is the first visual confirmation of the occurrence of E. radiata beds in subtropical South Africa, in an area situated between the tropical and subtropical bioregions, in an area that spans the Natal and Delagoa bioregions of the south-western Indian Ocean, more than 350 km north of its previously documented South African range. The kelp was found to be present across the length of the MPA, but dense beds were present only in the southern Natal bioregion, with sparse occurrences observed elsewhere on soft-coral and sponge-dominated reefs in the upper mesophotic zone. The footage was collected in November 2020, May 2021 and November 2022 during remotely operated vehicle and drop camera surveys of the mesophotic zone inside the MPA. This discovery adds to the body of knowledge on the global distribution of Laminariales populations in deep tropical and subtropical settings and the diversity of habitats within South Africa's largest coastal MPA.

Spatial, temporal and demographic patterns in asthma mortality in China: A systematic analysis from 2014 to 2020

BackgroundAsthma is an important contributor to the burden of non-communicable diseases in China. Understanding spatial, temporal, and demographic patterns in asthma mortality is relevant to the design and implementation of targeted interventions. MethodsThis study collected information on asthma deaths occurring across 605 disease surveillance points (DSPs) as recorded in the population-based national mortality surveillance system (NMSS) of China. Asthma was defined according to the International Classification of Diseases, 10th Revision code J45-J46. Estimates of age-standardized mortality rates and total national asthma deaths were calculated based on yearly population data. Statistical analysis was performed to investigate the influence of various factors on asthma mortality. ResultsBetween 2014 and 2020, a total of 40 116 asthma deaths occurred in DSPs. Standardized asthma mortality per 100 000 people decreased from 1.79 (95% CI: 1.74–1.83) in 2014 to 1.07 (95% CI: 1.03–1.10) in 2020 in China. In 2020, the overall asthma mortality rate was higher for male patients than for female patients, and asthma mortality rates increased substantially with age. Age-standardized asthma mortality per 100,000 people exhibited significant geographic variation, ranging from 0.93 (95% CI: 0.89–0.98) in Eastern China to 1.04 (95% CI: 0.98–1.10) in Central China and 1.37 (95% CI: 1.29–1.45) in Western China in 2020. Asthma mortality in urban areas appeared to be higher than in rural areas. Socioeconomic factors, including gross domestic product per capita and density of hospital beds per 10,000 population, may be related to asthma mortality. Male asthma patients who lived in rural areas and were aged 65 years and above were generally at high risk of asthma-related mortality. ConclusionsThis study found a spatial and temporal trend for a reduction in asthma deaths over seven years in China; however, there remain important sociodemographic groups that have not secured the same decrease in mortality rates. Trial registrationThis was a purely observational study and thus registration was not required.

Regional variation of medical expenditures attributable to hypertension in China's middle-aged and elderly population.

Hypertension is a prevalent and costly health condition in China. Little is known about variation of the inpatient and outpatient expenditures attributable to hypertension between prefecture-level administrative regions (PARs) and the drivers of such variation among China's middle-aged and elderly population. We obtain data from China Health and Retirement Longitudinal Survey between 2011 and 2015, panel tobit models were used in our study to estimate differences across 122 PARs. Expenditure variation was explained by the characteristics of individuals and regions, including measures of healthcare supply. The cost of treatment for patients with hypertension varies greatly geographically, with the highest outpatient and inpatient costs being 77 and 102 times the lowest, respectively. After adjustment for the individual and PAR character, there are associations between expenditure and region bed density. There were significant regional differences in the outpatient and inpatient costs of middle-aged and elderly patients with hypertension in China, the difference between individuals may be an important reason, which has little to do with regional economic development differences, but is related to regional bed density.

Finding flaws in the spatial distribution of health workforce and its influential factors: An empirical analysis based on Chinese provincial panel data, 2010-2019.

The maldistributions of the health workforce showed great inconsistency when singly measured by population quantity or geographic area in China. Meanwhile, earlier studies mainly employed traditional econometric approaches to investigate determinants for the health workforce, which ignored spillover effects of influential factors on neighboring regions. Therefore, we aimed to analyze health workforce allocation in China from demographic and geographic perspectives simultaneously and then explore the spatial pattern and determinants for health workforce allocation taking account of the spillover effect. The health resource density index (HRDI) equals the geometric mean of health resources per 1,000 persons and per square kilometer. First, the HRDI of licensed physicians (HRDI_P) and registered nurses (HRDI_N) was calculated for descriptive analysis. Then, global and local Moran's I indices were employed to explore the spatial features and aggregation clusters of the health workforce. Finally, four types of independent variables were selected: supportive resources (bed density and government health expenditure), healthcare need (proportion of the elderly population), socioeconomic factors (urbanization rate and GDP per capita), and sociocultural factors (education expenditure per pupil and park green area per capita), and then the spatial panel econometric model was used to assess direct associations and intra-region spillover effects between independent variables and HRDI_P and HRDI_N. Global Moran's I index of HRDI_P and HRDI_N increased from 0.2136 (P = 0.0070) to 0.2316 (P = 0.0050), and from 0.1645 (P = 0.0120) to 0.2022 (P = 0.0080), respectively. Local Moran's I suggested spatial aggregation clusters of HRDI_P and HRDI_N. For HRDI_P, bed density, government health expenditure, and GDP had significantly positive associations with local HRDI_P, while the proportion of the elderly population and education expenditure showed opposite spillover effects. More precisely, a 1% increase in the proportion of the elderly population would lead to a 0.4098% increase in HRDI_P of neighboring provinces, while a 1% increase in education expenditure leads to a 0.2688% decline in neighboring HRDI_P. For HRDI_N, the urbanization rate, bed density, and government health expenditure exerted significantly positive impacted local HRDI_N. In addition, the spillover effect was more evident in the urbanization rate, with a 1% increase in the urbanization rate relating to 0.9080% growth of HRDI_N of surrounding provinces. Negative spillover effects of education expenditure, government health expenditure, and elderly proportion were observed in neighboring HRDI_N. There were substantial spatial disparities in health workforce distribution in China; moreover, the health workforce showed positive spatial agglomeration with a strengthening tendency in the last decade. In addition, supportive resources, healthcare needs, and socioeconomic and sociocultural factors would affect the health labor configuration not only in a given province but also in its nearby provinces.