This paper estimated and evaluated the spatial–temporal evolution of the concentration of healthcare resources (HCRs), in 31 provinces in China between 2004 and 2017, by using the entropy method. The spatial Durbin model (SDM) was used to further analyze the mechanisms behind the spatial driving forces at the national and regional levels. The findings revealed that: (i) The concentration of HCRs differed significantly among eastern, central, and western regions. The eastern, followed by the central region, had the highest concentration. Going east to west, the concentration of HCRs in the first echelon decreased, while it increased in the second and third echelons; (ii) places with higher concentrations clustered, while those with lower concentrations agglomerated; and (iii) economic development, population size, and urbanization promoted concentration. Education facilitated HCR concentration in the eastern and central regions, income stimulated HCR concentration in the eastern and western regions, and fiscal expenditure on healthcare promoted HCR concentration in the eastern region. Economic development inhibited HCR concentration in neighboring regions, population size restrained HCR concentration in neighboring areas in the western region, urbanization and income curbed HCR concentration in neighboring areas in the eastern and western regions, and fiscal expenditure on healthcare hindered HCR concentration in neighboring areas in the eastern region. Policy recommendations were proposed toward optimizing allocation of healthcare resources, increasing support for healthcare and education, and accelerating urbanization. According to the World Health Organization (WHO), everyone has the right to access basic healthcare services, in other words, healthcare accessibility is a universal right. The access of healthcare resources (HCRs) is affected by the government’s supply of people and infrastructure in the HCR field. An imbalance in the spatial distribution of HCRs leads to huge differences in the access of HCRs among residents in different regions. Since the implementation of the new healthcare reforms, China’s healthcare system has significantly improved. However, due to the combined influence of population size, economic conditions, and spatial distance of HCRs , HCR conHCR concentration reflects an area’s ability to attract various healthcare elements from neighboring areas or even the entire state to agglomerate locally, thereby generating added value and spillover effects. HCRs mainly include healthcare-related human, material, and financial resources. The main measurement indicators of HCR concentration are the number of medical and healthcare institutions, hospital beds, and medical practitioners in a given area. Relative to residents’ unlimited needs for healthcare services, the HCRs of a state, province, or even a given area are always limited. Therefore, with the limited total amount of HCRs that are available, it is very important and urgent to know how to allocate HCRs reasonably and efficiently. Therefore, the study of the spatial–temporal evolution and its spatial drivers of HCRs can clarify the interaction path of the HCRs among provinces and cities, and then, it can pertinently refine the policy to improve the utilization efficiency of HCRs in China. The study of HCR concentration in China began later than in foreign countries; however, its development has been relatively swift. In particular, with the deepening of healthcare reforms, exploring HCR concentration and the mechanisms behind its spatial driving forces from a microscopic perspective has become a research interest. In terms of area of study, existing studies in HCR concentration have approached the subject from a national, cross-provincial, or provincial level, performing analysis on national data ,5,6, theI was used to examine spatial autocorrelation of the model; and the spatial Durbin model (SDM) was then applied to analyze mechanisms behind the spatial driving forces of HCR concentration in China.The introduction of spatial factors into the study of HCR concentration is conducive to understanding the subject from a more realistic perspective. In recent years, scholars have introduced spatial analysis methods into healthcare research and achieved a range of results ,20,21; hHCRs include healthcare-related human, material, and financial resources. Referring to relevant literature and expert opinions, a comprehensive evaluation indicator system was constructed to measure the HCR concentration of provinces and cities, and the entropy method was used to determine the weight of each indicator. The entropy method mainly determines the objective weight according to index variability. Generally speaking, the smaller the information entropy of an index, the greater the degree of variation of the value of the index; and the larger the amount of information provided, the greater the role played in the comprehensive evaluation index system and the greater the weight. On the contrary, the bigger the information entropy of an index, the smaller the variation degree of the index value; and the less the amount of information provided, the smaller the role played in the evaluation system of the comprehensive index and the smaller the weight. To avoid the influence of inconsistent units of variables on the weight determination process, min–max normalization was employed to normalize data and convert them into numerical data with values between 0 and 1. The evaluation indicator system of HCR concentration and the corresponding weights are shown in I. In this study, Moran’s I showed the degree of attribute similarity between spatially adjacent areas in terms of HCR concentration. The global spatial autocorrelation of the variable can be expressed as follows:iθ and jθ are the HCR concentrations of provinces i and j, respectively; n represents the total number of provinces and cities; and ijW symbolizes the spatial weight adjacency matrix of attributes of provinces within samples. Generally, the value of ijW is either 0 or 1, “0” means that the attribute values of provinces are not associated, and “1” indicates that attribute values are closely associated and highly similar. The existence of spatial autocorrelation is the premise for conducting a regression analysis using spatial econometric models. Spatial autocorrelation is usually measured by Moran’s Traditional econometric modeling does not consider errors caused by spatial effects on the estimation results. In 1970, Tobler proposed the “first law of geography,” pointing out the existence of geographical dependence and correlation between observations. Spatial econometric models can thus describe the geographical dependence between observations. Some commonly used spatial econometric models for analyzing mechanisms behind spatial drivers include the spatial autoregressive (SAR) model, spatial error model (SEM), and spatial Durbin model (SDM).ρ, W, Y, X, β, Nαl, and ε represent the spatial autoregressive coefficient, interprovincial N×N spatial weight adjacency matrix, HCR concentration, explanatory variables, N×1 constant term, and random disturbances, respectively.(1) Spatial Autoregressive Model (SAR)λ and u symbolize the spatial error coefficient of N×1 HCR concentration and the spatial error (disturbance) term when the independent distribution was respected, respectively; and the meanings of the remaining symbols are consistent with those in the previous formula.(2) Spatial Error Model (SEM)(3) Spatial Durbin Model (SDM)When there are spatial lags in the model, the regression results illustrate more than the effect of explanatory variables on HCR concentration. LeSage and Pace  suggesteEquation (6) can be further converted as follows:Equation (7) can be converted into a matrix as follows:ijSr(W) symbolizes the ith and jth elements in Sr(W), and iV(W) represents the ith row of V(W).iiSr(W); the indirect effect is equal to the mean of the non-diagonal elements, Sr(W)ij; and the overall effect is equal to the mean of the sum of the matrices, Sr(W). The direct effect is equal to the mean of the diagonal elements, In this study, the following factors were considered to be spatial driving forces for HCR concentration: (i) economic development—measured using regional Gros Domestic Product(GDP), (ii) population size—measured using the total population at the end of a given year, (iii) urbanization—measured using the proportion of urban land area to total land area, (iv) education—measured using the number of students in colleges and universities in a given region, (v) annual salary—measured using the average annual salary of employees in the healthcare industry, and (vi) fiscal expenditure on healthcare—measured using fiscal expenditure on the healthcare industry. The names, operational definition, and descriptive statistics of the variables are shown in Data were extracted from the China Public Health Statistical Yearbook, China Health and Family Planning Yearbook, and China City Statistical Yearbook for the period between 2005 and 2018. In order to maintain data continuity and stability, data for earlier years were recompiled and merged based on the most recent administrative divisions. This study used 31 provinces in China as research subjects and employed the entropy method to measure HCR concentration between 2004 and 2017. The average values for HCR concentration at the regional and national levels are presented in Nevertheless, changes in average values for regional HCR concentration were unable to completely reflect the spatial distribution of HCR concentration in China. Hence, sectional data for the corresponding provinces in 2004, 2010, and 2017 were further compared . In 2004I of HCR concentration in China from 2004 to 2017 ; and the values of LM-error and Robust LM-error were 186.0900 (p < 0.01) and 1.3849 (p > 0.01), respectively, indicating that a lagged spatial dependence existed in the panel model of HCR concentration in China. The test results of the spatial econometric models revealed that the p-values of spatial lag and spatial error coefficients of LR and Wald were smaller than 0.01, rejecting the zero hypothesis that SDM degenerates into SAR and SEM; hence, there were sufficient reasons to choose SDM as the model to explore the mechanisms behind the spatial driving forces of HCR concentration in China.Based on panel data from 2004 to 2017 and referring to the method proposed by LeSage and Pace (2009) , the MATFurthermore, results of the Hausman test showed that the fixed effects model should be used. As reported in However, the adopted approach tended to cause a bias in estimation. Moreover, direct, indirect, and overall effects should be considered when applying spatial econometric models ,25. TherThe direct effects of economic development (GDP) on HCR concentration at the regional and national levels were significant and positive, which were consistent with the findings of a scholar  , while iThe coefficients of direct effects, indirect effects, and overall effects of population size (Pop) on HCR concentration were large. Specifically, the indirect effects of population size on the HCR concentration of the eastern and central regions were positive, yet not statistically significant; and those on national HCR concentration and the HCR concentration in the western region were significant and negative. The remaining effects of population size were found to be significant and positive. These findings suggested that population size played a significant role in promoting the overall HCR concentration in China and the HCR concentration of a given place, which were roughly consistent with the findings of a scholar  . This cop > 0.1), indicating that urbanization significantly facilitated the concentration of HCRs in a given region in China, which were consistent with the view that the development of urbanization was beneficial to the improvement of HCR concentration  [The direct effects, indirect effects, and overall effects of urbanization level (Urb) were significant and positive, with the exception of its indirect effects on national HCR concentration and the HCR concentration of the central region  . On one The direct effects of education (Stu) on the overall HCR concentration in China and the HCR concentration of the eastern and central regions were found to be significant and positive. The overall effects were positive at regional and national levels; however, such effects were significant only in the eastern and central regions. The indirect effects were not statistically significant. None of the effects were found to be statistically significant on HCR concentration in provinces of the western region. Students in colleges and universities are the “reserve army” for health and medical personnel and the main pillars for the improvement of HCR concentration. In the eastern and central regions, there are many well-known universities, such as the “985 project” and “211 project” universities, which can directly supply medical and health personnel to various provinces. A majority of the medical students from universities, however, tend to complete their internship at medical and health institutions with strong regional cooperation ties to their schools; hence, the indirect effects of education were small and statistically insignificant. Provinces in the western region have comparatively fewer colleges and students; hence, the effects of education on the improvement of HCR concentration in the region were not prominent. The overall effects of salary (Wag) on national HCR concentration and the HCR concentration of the western region and the indirect effects of salary on national HCR concentration and the HCR concentration in the eastern and western regions were significant and negative. The direct effects of salary on HCR concentration at the regional and national levels were significant and positive. These findings highlighted that the increase of annual salary in the medical and healthcare industry promoted HCR concentration in a given province (city), and inhibited HCR concentration in neighboring provinces and cities. Salary increases in the medical and healthcare industry directly stimulated the engagement of doctors, nurses, workers, and management personnel in the industry, as well as attracted corresponding human resources from neighboring provinces and cities, resulting in a negative spillover effect. The direct effects of fiscal expenditure on healthcare (Exp) on national HCR concentration and the HCR concentration of the eastern region were significant and positive, which were consistent with the view that fiscal expenditure on healthcare promoted the concentration of HCR concentration   and the In order to verify the reliability of the above analysis results, the robustness of results was tested using a transformation of the spatial weights matrix. Referring to the study by Parent et al. , the spaI of HCR concentration in China was positive, indicating that provinces with a higher HCR concentration generally tended to cluster together, while those with a lower HCR concentration tended to agglomerate together in China; and (iii) the mechanisms behind the spatial driving forces of HCR concentration had different degrees of promoting effects on HCR concentration in China depending on the driver variable and region. From a national perspective, economic development, urbanization, education situation, fiscal expenditure on health care, annual salary of the healthcare industry, and population size of a given place were found to share positive relationships with HCR concentration and promote the increase in HCR concentration in that region. However, economic development, population size, annual salary of the healthcare industry, and fiscal expenditure on healthcare were found to curb the increase of HCR concentration in neighboring provinces and cities. In the eastern region, economic development, urbanization, education situation, fiscal expenditure on healthcare, annual salary of the healthcare industry, and population size were found to be the direct driving forces of HCR concentration in provinces within the region. Urbanization in the eastern region was found to have substantial facilitating effects on the ability of neighboring provinces to attract HCRs; however, economic development, annual salary of the healthcare industry, and fiscal expenditure on healthcare were found to have a negative effect on HCR concentration in neighboring provinces and cities. In the central region, economic development, urbanization, education situation, and population size were found to be the direct driving forces of HCR concentration in provinces within the region; however, economic development of a given place tended to hinder HCR concentration in neighboring areas. In the western region, economic development, annual salary of the healthcare industry, and population size promoted HCR concentration in provinces within the region, while significantly inhibiting HCR concentration in neighboring provinces and cities; however, urbanization was found to not only promote HCR concentration of a given area, but also stimulate HCR concentration in neighboring areas. Using the entropy method, this study estimated and evaluated the spatial–temporal evolution of HCR concentration in 31 provinces in China between 2004 and 2017. The SDM was used to further analyze the mechanisms behind the spatial driving forces at the national and regional levels . The conclusions are as follows: (i) HCR concentration differed significantly among the eastern, central, and western regions. The provinces in the eastern region had the highest HCR concentration, followed by the central region and the HCR concentration was the lowest in provinces from the western region. In addition, the number of provinces with HCR concentration belonging to the first echelon gradually decreased from east to west, while the number of provinces with HCR concentration belonging to the second and third echelons gradually increased from east to west; (ii) the global Moran’s In response to the aforementioned conclusions, the following policy recommendations were proposed: (i) Optimize the allocation of healthcare resources. Optimizing limited medical and healthcare resources and improving the overall concentration of such resources in various provinces are global problems. With the growing need for better physical health, the utilization of healthcare resources can only be maximized through rational allocation. At present, the difference of regional HCR concentration in China is very obvious, which is embodied in the eastern region having more HCRs than the central and western regions. In addition, slow economic development and vast unpopulated areas in these regions have led to low coverage and imbalanced distribution of HCRs. Therefore, it is necessary to optimize HCRs between and within regions and provide greater support to the development of the healthcare industry in the western region, so as to achieve the joint establishment and common enjoyment of HCRs; (ii) increase the support for healthcare and education in relevant fields. At present, the average salary of the healthcare industry and fiscal expenditure on the industry have insignificant promoting effects on HCR concentration in the central region. Moreover, the education situation and fiscal expenditure on healthcare also have insignificant promoting effects on HCR concentration in the western region. In addition to acting as the foundation and an important safeguard for the development of the healthcare sector, fiscal expenditure is also an important source of salaries for employees in the medical and healthcare industry. It is only with the support of sufficient funding that a region can be enabled to bring in healthcare personnel, facilities, and equipment to promote the concentration of HCRs in the region. The education situation in the region signifies the potential of reserve forces of the healthcare industry and serves as one of the major components of HCRs. Therefore, in addition to the continued increase of fiscal expenditure on healthcare, the government should also actively support the development of the education industry in the western region, improve the pool of talent, and fundamentally enhance the ability of the region to “create new blood; and (iii) the process of urbanization must be accelerated. Urbanization not only plays a decisive role in the HCR concentration in a given province, but also has significant indirect effects on HCR concentration in neighboring areas. However, urbanization levels in China remain low, and the rural population—which accounts for approximately 40% of the total population—remains a barrier for further improvement in HCR concentration. For this reason, the government should spare no effort in continuing to advance the process of urbanization in order to maximize the vast potential of urbanization in improving HCR concentration.Although this paper examined the spatial drivers of HCR concentration in China by adding the spatial weight matrix, to a certain extent, it made up for the shortcomings of previous studies, which were limited in expressing the spatial distribution of HCR concentration and ignored its spatial interaction; however, the spatial weight matrix does not have the time sequence, and cannot be consistent with the various HCR data. On the other hand, this paper only studied the spatial–temporal evolution and its spatial drivers of HCR concentration from three regions in eastern China, central China, and western China, and ignored the influence of the huge difference of the administrative area and population factors among provinces and cities on HCR concentration, which will be the focus of future technical improvement and research.


Anastomus oscitans, have long been known to migrate from South to Southeast Asia for breeding and nesting. In Thailand, the first outbreak of H5N1 highly pathogenic avian influenza (HPAI) infection in the Openbills coincided with the outbreak in the poultry. Therefore, the flyways of Asian Openbills was determined to study their role in the spread of H5N1 HPAI virus to poultry and wild birds, and also within their flocks.Asian Openbills, 2 per month (95% utility distribution). There was no positive result of the viral infection from oral and cloacal swabs of the Openbills and wild birds living in the vicinity by viral isolation and genome detection during 2007 to 2010 whereas the specific antibody was not detected on both Openbills and wild birds by using microneutralization assay after 2008. The movement of these Openbills did not correlate with H5N1 HPAI outbreaks in domestic poultry but correlated with rice crop rotation and populations of the apple snails which are their preferred food. Viral spread within the flocks of Openbills was not detected.Flyways of 5 Openbills from 3 colonies were monitored using Argos satellite transmitters with positioning by Google Earth Programme between 2007 and 2013. None of the Openbills tagged with satellite telemeters moved outside of Thailand. Their home ranges or movement areas varied from 1.6 to 23,608 kmThis study showed that Openbills played no role in the spread of H5N1 HPAI virus, which was probably due to the very low prevalence of the virus during the monitoring period. This study revealed the ecological factors that control the life cycle of Asian Openbills.The online version of this article (10.1186/s12917-018-1683-x) contains supplementary material, which is available to authorized users. Anastomus oscitans, are large wading birds in the family Ciconiidae [Pomacea canaliculata and P. insularum [Asian Openbills or Asian Open-billed storks, coniidae . The birconiidae . This gaconiidae , 4. Usinconiidae , 3. In Tconiidae . Openbilconiidae , 6. In Tconiidae , 7, inclnsularum .The outbreaks of H5N1 highly pathogenic avian influenza (HPAI), occurred in Thailand in January 2004 and resulted in enormous economic losses of poultry and several human deaths. With restricted control strategy, no human case was found after July 2006 , while nInitially, the Openbills was suspected of bringing in the virus along with their migration from Bangladesh to Thailand. Therefore, depopulation of Openbills was proposed to be an approach for avian influenza (AI) control. However, this opinion was stopped based on the information that there was no occurrence of H5N1 HPAI outbreak in South Asia at that time. According to the Office International des Epizooties (OIE) , the firOur field observation revealed that the flock of Openbills returned to the old nesting places in early November every year, and by the end of February, the flocks disappeared from the nesting areas or markedly decreased in population size. No further information exists on where the birds go after February, and the role of Openbills in H5N1 AI spread has not been elucidated. This study used satellite telemetry in combination with field surveys and virological assays to monitor the flyways of Openbills and investigate the possible spread of H5N1 HPAI virus within the flocks and to other animal species living in the vicinity in Thailand.Biographic data of the 5 Openbills tagged with satellite transmitters are shown in Table movebank.org, study name “Asian Openbill tagging with satellite telemetry in Thailand, 2007-2013”) and are published.The data used in this study are available on Movebank ; and it was 2477 km2/month  for bird 74,800  and 414 km km2/month (range 1.6 to 4481: 95% UD), respectively. The signal of bird ID 74799 lost after three years of follow-up, while the monitoring of bird ID 74794 was terminated by the project after 5.5 years of tracking   of serum samples collected in 2007, 1.7% (2 of 120) in 2008, and none in 2009 and 2010  from Nakhon Sawan province, and one Ashy wood swallow (family Artamidae) from Nakhon Pathom province in 2008  is an alien imported from Taiwan and Japan into Thailand in 1982, for decorating and cleaning the walls of fish tanks. Snails escaped and bred very quickly, becoming overpopulated. They subsequently spread in natural waterways throughout the country. After the big flood in 1995, apple snails were found in at least 60 of 76 (number at that time) provinces of Thailand [Pila snail species in the fields. Apple snails are an enemy that causes considerable economic losses in rice agriculture. The Openbills partially control them as predators. Eventually, the free-grazing ducks also feed on snails besides falling rice grains after harvesting season.The present study determined the potential role of Openbills in the spread of H5N1 HPAI virus by using satellite telemetry to monitor the flyways of birds which overlapped to the locations of AI outbreaks. Using solar power PTT-100 and Argos/GPS PTT-100 transmitters, we monitored the movements of 5 Openbills for periods varying from 1 to more than 5 years between February 2007 and September 2013. During the monitoring period, the flyways or movements of these Openbills did not correlate with the locations of H5N1 HPAI outbreak. We noted that with the strict control measures of the government and private sector actors, the occurrence of AI outbreaks was rapidly declining and became rare events during our study period. Previous investigators have demonstrated an H5N1 virus infection rate of 26.7% in Openbills in 2004; subsequently, the prevalence decreased to 0.9% in 2005, and 0% in 2006 and 2007 . Similar dose 50 . Also, t dose 50 , compare dose 50 , 13. We  dose 50 . An AsiaThailand . In natuThe primary factor that contributes to the over-population of the apple snails in Thailand is the improvement of the irrigation system and rice farming. Several decades ago, Thai farmers grew rice only once or twice a year depending on rainfall and the water supply. Improvements of the irrigation system by construction of dams, large water reservoirs, and canals, together with rice strain selection, allowed Thai farmers to grow rice all year round. Crop rotation takes place two to three times a year and generates abundant young rice stems, a large food surplus for apple snails. During our monitoring period, the movements of Openbills from their nesting places to feeding areas coincided with the beginning of a new rice crop , Nakhon Sawan province, in the northern Central region; and Phitsanulok province in North Thailand; at distances of 58, 244 and 444 km from Bangkok, respectively. All study sites had good irrigation systems and are close to rivers or water reservoirs. The sites were mainly agricultural areas with paddy rice fields. Two to three rice crops are produced per year. Repeated outbreaks of H5N1 HPAI were reported in several poultry farms in these three provinces during 2004 to 2005.The colony in Nakhon Pathom province was located in a mango orchard where the Openbills nested on the mango trees. This study site was surrounded by several poultry farms and various kinds of farm gardens including rice fields. The Nakhon Sawan site was close to Bungborapet where hundreds of species of resident and migratory birds shared the same habitat. The third study site, in Phitsanulok province, was surrounded by agricultural fields. This province is famous for the breeding of fighting cocks.Asian Openbills were trapped from their nests by hand net during the night. Being colonial breeders, the birds built several nests in the same tree Fig. . The birFive healthy adult Openbills negative for influenza viral antigen were selected from colonies in the three study sites for flyway monitoring by satellite telemetry. Each of these Openbills was tagged with a ring band and fitted with a 35-g-solar power PTT-100 or a 40-g solar Argos/GPS PTT-100 satellite transmitter  on its back with a Teflon harness  Fig. . The solMicrosoft Excel 2016  was used for the data analysis. The positions of each Openbill were displayed and analyzed by ArcGIS 9.3.1 and ArcGIS 10 software . More than 10,000 records of the bird positions were cleaned and determined for their habitats and home ranges using a fixed kernel density estimator, and then displayed on Google Earth maps.Oropharyngeal and cloacal swabs from Openbills and other wild birds caught during 2007 to 2010 were used for detection of H5N1 HPAI viral genome by real-time reverse transcription-polymerase chain reaction (RT-PCR), and also for virus isolation in chick embryonated eggs and Madin Darby canine kidney (MDCK) cells; and blood specimens were used for detection of H5N1 antibody by microneutralization (MN) assays.https://www.oie.int/fileadmin/Home/eng/Health_standards/tahm/2.03.04_AI.pdf) and/or those established by the U.S. Centers for Disease Control and Prevention (CDC). Oropharyngeal and cloacal swabs from each bird were investigated in separate reaction tubes.Real-time RT-PCR for detection of H5N1 HPAI viral genome was performed using the protocol as described by OIE  cell monolayers, in duplicate. Amniotic and allantoic fluids and MDCK culture supernatant were screened for the presence of influenza virus by hemagglutination with 0.5% goose red blood cells. Two blind passages were carried out before reporting the result as negative virus isolation.ELISA based-MN assay for detection of neutralizing antibody to H5N1 HPAI virus was employed according to the WHO manual for avian influenza , and modAdditional file 1:Table S1. Serosurveillance in the wild birds along the movement areas of Asian Openbills. Figure S1. The rice farming area nearby the large fresh marsh, the major habitat of the Asian Openbills. (PDF 1994 kb)


The Journal and Chief Editors retract the 25 January 2017 article cited above. Concerns regarding the reliability of the data presented in this manuscript were brought to the attention of the journal in April 2018. Following an investigation by the Editorial Office and Chief Editors of the journal, it was found that appropriate controls had not been used for some of the experiments presented. The article is therefore being retracted from the journal due to concerns with the reliability of the data. The authors do not agree to the retraction, and the notice.


During median follow-up for 5.3 (4.5–6.0) years, 83 (12%) patients developed graft failure. In Cox regression analyses, urinary taurine excretion was inversely associated with graft failure (hazard ratio: 0.74 (0.67–0.82); P < 0.001). This association remained significant independent of potential confounders. High urinary taurine excretion is associated with low risk of late graft failure in RTR. Therefore, increasing taurine intake may potentially support graft survival in RTR. Further studies are warranted to determine the underlying mechanisms and the potential of taurine supplementation.Taurine is a sulfur containing nutrient that has been shown to protect against oxidative stress, which has been implicated in the pathophysiology leading to late graft failure after renal transplantation. We prospectively investigated whether high urinary taurine excretion, reflecting high taurine intake, is associated with low risk for development of late graft failure in renal transplant recipients (RTR). Urinary taurine excretion was measured in a longitudinal cohort of 678 stable RTR. Prospective associations were assessed using Cox regression analyses. Graft failure was defined as the start of dialysis or re-transplantation. In RTR  45 ± 19 mL/min/1.73 m Globally, renal transplantation becomes more prevalent each year , and renTaurine is an amino sulfonic acid found in high concentrations in many cells, where it is implicated in numerous physiological functions. In some species, e.g., cats, taurine is an essential nutrient, but in humans, it is considered a conditionally essential nutrient ,8,9. WhiThis observational prospective study was conducted in a large single center renal transplant recipients (RTR) cohort, as previously described ,21. In sAll measurements were performed during a morning visit to the outpatient clinic after an 8- to 12-h overnight fasting period. Blood pressure was measured (in millimeters of mercury) with a semiautomatic device  according to a strict protocol as previously described . InformaInformation on dietary intake was obtained from a validated semiquantitative food-frequency questionnaire (FFQ), which was linked to the Dutch food composition table (NEVO) to compute the intake of energy, macronutrients and micronutrients . It was 13C6, 15N3-histidine). Data were analyzed using MultiQuant MD 3.0.2 (Sciex). Inter-assay precision was monitored using three urine pool samples. The inter-assay precisions were 8.5% at 270.4 µmol/L, 9.8% at 594.7 µmol/L and 7.9% at 762.0 µmol/L. The upper limit of detection was 1200 µmol/L and values above 1200 µmol/L were reported as 1201 µmol/L. Urinary protein concentration was determined by means of the Biuret reaction . Proteinuria was defined as urinary protein excretion ≥0.5 g/24 h. Upon completion of the 24-h urine collection, fasting venous blood samples anti-coagulated with lithium-heparin, sodium-fluoride and potassium-ethylenediaminetetraacetic acid (EDTA) were obtained the following morning. For routine clinical chemistry assays, heparin plasma was analyzed spectrophotometrically on the same morning using automated and validated routine methods . Fasting glucose was assessed from fluoride plasma on the same morning on the same equipment. EDTA plasma was separated in small aliquots and stored frozen at −80°C for later use. Aliquots of the 24 h urine collection were also stored frozen at −80°C for later use. Free sulfhydryl groups in serum were quantified using Ellman’s reagent. Human leukocyte antigen I (HLA-I) and HLA-II antibodies were quantified using an ELISA . Urinary inorganic sulfate was measured with a validated ion-chromatography method . Urinary thiosulfate was determined using a validated HPLC method  taurine was recovered in urine; about 70% in the form of taurine and 25% in the form of sulfate [After absorption, taurine is widely distributed among tissues, with the high concentrations found in the retina, brain, heart, liver, kidney and muscles . Plasma  sulfate . After c sulfate . In huma sulfate ,72. As t sulfate . TherefoStrengths of this study include the large sample size of this well-defined and specific patient group of RTR, the long follow-up and the presence of appropriate controls. In addition, extensive data collection of many demographical and laboratory parameters enabled adjustment for many potential confounders. However, several limitations of this study need to be addressed. In general, statistical significance in observational studies suggests, but does not confirm, biologic significance. Whether the significant relation between urinary taurine excretion and graft failure in RTR is a causal or an associative relation remains to be determined. Due to the observational design of this study we also were unable to measure oxidative stress in the kidney, which precluded us from determining whether urinary taurine excretion was associated with oxidative stress in the kidney. Similarly, the observational design of this study does not allow for further studies to elucidate the biological mechanisms underlying the association of urinary taurine excretion with graft failure. Furthermore, the observational design of the study precluded us to demonstrate in an experimental way that urinary taurine excretion is not influenced by renal function. In addition, our study population consisted predominantly of Caucasian individuals, which calls prudence to extrapolation of our results to populations of other ethnicities. Lastly, the Dutch Food Composition Table did not include information on taurine content, which prevented us from comparing FFQ-based taurine intake to urinary excretion of taurine.Higher urinary taurine excretion is associated with improved graft survival in renal transplant recipients. As taurine synthesis in humans is very limited, 24 h urinary taurine excretion largely reflects daily taurine intake. Therefore, an increased taurine intake may potentially increase graft survival in renal transplant recipients. However, further research is warranted to determine the mechanisms underlying this association and to investigate the potential of taurine supplementation in renal transplant recipients.


Journal of Educational Evaluation for Health Professions, JEEHP) has been evaluated for inclusion in Scopus by the Content Selection & Advisory Board (CSAB). The review of this title is now complete and the CSAB has advised that the title will be accepted for inclusion in Scopus.”On the morning of January 6, 2019, I received an email from the Scopus Title Evaluation Team stating that “The title mentioned above , adopted in an English-only policy, and became an online-only journal without publication frequency [December 2006: The journal changed its official title to English from Korean  Title of ‘The Korean Journal of ...’ is preferable.(2) Too broad of an area is covered in the journal.(3) The author instructions need to be described more in detail(4) Only one issue is published per year. The number of articles is small.(5) There is no international diversity among authors.(6) Citedness is below expectations. It is weak in the international rankings.(7) The journal covers poor quality of presented research.I and the editorial team have done our best to overcome the above weaknesses. Turning to the above-listed recommendations, it would be difficult to change the title to ‘The Korean Journal of ...’ because JEEHP has already become widely known throughout the world under its present title. Furthermore, authors from Korea accounted for only 21.1% of the articles and reviews published from 2015 to 2018. The top-ranking country of authors is the United States (31.3%). The 147 articles and reviews published during this period were from 48 countries . TherefoEvaluation and the Health Professions, deals with evaluations; however, in addition to educational evaluations, its scope extends to health programs, teaching and training services, and products. However more precise description of the scope was added such as adoption of measurement theory to medical health education.Each journal should have its own specific scope, and the scope of JEEHP is limited to educational evaluations in the field of medical health education. There is no other title in Scopus that has the same scope. One title in Scopus, https://jeehp.org).The author instructions were revised to contain a full description, including general information, research and publication ethics, manuscript preparation, manuscript submission, article processing charge, the peer review and publication process, principles of transparency and best practice of scholarly publishing, copyright information, open access policy, open access license agreement, and contact address, and are available at the journal homepage  XML . Second,I am proud to have been invited to be an editor of this journal, published by a public organization, the Korea Health Professions Licensing Examination Institute, where my senior physician and researcher colleagues have worked and carried out leadership roles with great devotion. I and the editorial team will strive to make the journal more readable and to be well-appreciated by medical and health instructors throughout the world.


There is a high level of interest in international experiences during United States (U.S.) ophthalmology residency training among both program directors and trainees.An electronic invitation to a 26-question survey was sent to all 114 U.S. ophthalmology residency program directors. The invitation requested that the survey be completed by the one faculty member who was most involved in overseeing the international experiences for the residents. The survey consisted of multiple choice and Likert-type scale questions. The Mann-Whitney U test was used for analysis of demographic data and Friedman’s test and Wilcoxon-Signed Rank test were used to analyze ranked responses.Responses were obtained from 70 faculty mentors representing unique programs, yielding a response rate of 61.4%. The majority of programs that responded  either offered international ophthalmology experiences for residents or supported residents finding their own experiences to go abroad. International experience participation rate among residents correlated with the number of years the experiences had been offered by the programs (p = 0.001). More than half of the respondents  felt that the residents benefited more than the hosts during these international experiences. Approximately half of the respondents  believed that additional training beyond what is covered in the standard curriculum to practice ophthalmology in the U.S. is necessary for practicing ophthalmology in an international setting.There is high interest and participation in international experiences within U.S. ophthalmology residency programs. This high participation warrants further investigation into the long-term impact of these international experiences and how U.S. residency programs can structure these experiences to maximize the benefits to both the residents and the international host communities. International health electives offered by United States (U.S.) residency programs are becoming increasingly popular among trainees –5. InterGiven the amount of preventable and treatable blindness worldwide, ophthalmology lends itself to global work –20. Not Given the significant interest and participation in international ophthalmology among U.S. ophthalmology residency programs, it is important to explore the structure of these experiences to assess how to maximize the benefits to the residents and the international communities that host the residents, to better inform not only residency training in ophthalmology but also in other medical specialties. This study aims to analyze the current structure of international experiences in U.S. ophthalmology residency programs and to explore the perspectives of international experiences from the standpoint of the faculty mentors who oversee these experiences.An anonymous, cross-sectional survey of all 114 U.S. ophthalmology residency programs participating in the 2018–2019 San Francisco (SF) Match was conducted from June to July 2018. REDCap electronic data capture tool hosted at Penn State Hershey Medical Center was used to collect and manage the study data . Survey Statistical analysis was performed using SPSS . For the purpose of statistical comparison, ophthalmology programs were divided into two groups based on the number of years international experiences had been offered for the residents. Programs that had offered international ophthalmology experiences for six or more years were designated as “established programs” and programs that had offered international ophthalmology experiences for five or fewer years were designated as “newer programs.” The Mann-Whitney U test was used for analysis of demographic data and to assess the relationship of the ranked responses between independent groups. Friedman’s test and Wilcoxon-Signed Rank test were used to analyze ranked responses. Missing information was handled by a pairwise deletion for each analysis completed. P-values < 0.05 were considered statistically significant for all analyses, except when the Bonferroni correction was applied to multiple simultaneous comparisons. This study was deemed exempt by the Penn State Hershey Institutional Review Board.Responses were received from 70 faculty mentors representing unique residency programs, yielding a response rate of 61.4% (S3). Seven surveys contained missing responses to some of the questions. Of those who answered the question, 89.1% (n = 49) were program directors. Of the residency programs represented, 88.6% (n = 62) either offered international ophthalmology experiences for residents or supported residents finding their own experiences to go abroad. The vast majority of programs that supported international ophthalmology experiences  reported resident participation in international experiences within the past three years. Respondents reported a total of 41 different host countries to which residents have traveled to internationally over the last five years, with India (n = 18) and Haiti (n = 11) being the most commonly reported countries .The demographics of the residency programs supporting international experiences are summarized in . CompareWhen asked about resident responsibilities to the home institution before and after participating in an international experience, 40.3% (n = 25) of respondents reported having no mandatory responsibilities before participating in an international experience and 25.8% (n = 16) of respondents reported no mandatory responsibilities after returning. Of the programs that did have requirements, the most commonly reported requirements before participating in an international experience included a formal meeting with a faculty mentor , creation of personalized learning objectives , and surgical wet lab . Requirements after returning from an international experience included formal presentation , debriefing with faculty mentor , and written reflection on experience .Respondents who reported specific sites where they send residents at least annually (n = 25) were asked who their residents work with most during an international experience. The most common response was local ophthalmologists from the host site , followed by ophthalmologists from the U.S. .Roughly half of the respondents  believed that additional training beyond what is covered in the standard curriculum to practice ophthalmology in the U.S. is necessary to practice ophthalmology in an international setting . The proWhen asked why it was important that international experiences be made available to residents, “Exposure to another ophthalmology/healthcare system,” “To broaden clinical, surgical, or research experience,” and “Exposure to another country/culture/people” outranked “To serve the underserved” .More than half of respondents  felt that the benefit to the residents was greater than the benefit to the international host, and 41.7% (n = 25) felt the benefit was equal . Only 3.Of the respondents who either offered international ophthalmology experiences for residents or supported residents finding their own international experiences, 60.0% (n = 36) hosted international trainees or faculty at their home institutions . EstabliPrevious studies have suggested that interest in international ophthalmology is high among both U.S. residency program directors and applicants ,21. ThisThe majority of respondents felt that residents benefited from the international experience more than the international hosts. Faculty mentors ranked resident exposure and education categories significantly higher than the opportunity to serve the underserved. Within a residency training paradigm where education is a primary goal, it may be expected that the residents would be the primary beneficiaries of an international experience rather than the other parties involved, including the hosts. Interestingly, this majority perspective among faculty mentors differs from the majority perspective of ophthalmology residency applicants in a previous study, where 59.0% of respondents ranked “offer service to the underserved” as the most important goal of an international experience, over learning goals such as “learn from national eye care provider(s) in the country visited” and “learn about another eye care system” . This suAlthough there currently is no literature on the perspectives of international hosts that work with U.S. ophthalmology trainees, the notion that the international hosts may benefit less than the residents should be evaluated in light of recent literature from other specialties that highlight the perspectives of international hosts in other medical fields –32. ImbaAlmost half of the faculty mentors surveyed do not believe any additional training is necessary to practice ophthalmology internationally beyond what is covered in the current residency curriculum. A similar number of the programs (40%) require no mandatory education responsibilities before residents travel internationally. Although not statistically significant, faculty mentors who had traveled to the international host sites were more likely to believe that additional training is necessary as compared to those who had not. These findings are similar to the findings of a previous study in which ophthalmology applicants who had previously participated in a healthcare-related experience in an international setting were more likely to believe that additional training was necessary . The heaAlthough ophthalmology residents can receive credit for time spent internationally, as it stThere were several limitations in this study, one being the partial response rate. This being said, the response rate of 61.4% is comparable to the response rates of previous studies that surveyed residency program directors of ophthalmology and other surgical specialties –26,34,35In conclusion, there is high interest and participation in international experiences in U.S. ophthalmology residency programs. Although this study was performed on ophthalmology residency programs, there are aspects of global health education that are not specialty specific, and some of the findings and implications of this study may be applicable to residency programs in other medical and surgical specialties. There is great opportunity for U.S. residency programs to work with international hosts in determining how to structure these international experiences and to shape pre- and post-experience education, not only to maximize the benefits to the residents, but also to the host communities.S1 AppendixA 26-item questionnaire including multiple choice and Likert-type scale questions.(DOCX)Click here for additional data file.S2 AppendixList displaying all countries respondents listed as countries their residents have visited in the last five years.(DOCX)Click here for additional data file.S3 AppendixComplete collection of data from anonymous questionnaire of 70 faculty mentors.(XLSX)Click here for additional data file.


A lot of shaded zirconia blocks are being introduced into the market. Their effect on the final shade of the restoration is yet uncertain. Twenty-four zirconia crowns were fabricated for 8 patients who needed to restore a single maxillary central incisor, and divided into 3 groups according to the color and type of the zirconia (Zr) used  Zr crowns). Using Easyshade spectrophotometer, delta E color difference was calculated between fabricated crown and adjacent tooth. The ΔEs obtained were assessed based on 1.6 ΔE which represented the color difference that could not be detected by the human eye and considered clinically acceptable. No statistically significant values were found between the 3 groups related to different Zr color and type. Within the limitations of this study, it could be concluded that the shade of the zirconia blank had no significant effect on the final color of the crown. This raises reasonable doubt about the necessity to use colored zirconia blanks or use of dip-in solutions. The clinical implications were that, there was no need to use colored zirconia cores to get more esthetically pleasing restorations with respect to color perception. The use of monolithic high translucent zirconia crowns gained the advantages of high translucency and color reproduction. Key words:Zirconia, easyshade, monolithic, spectrophotometer, delta E. The replication of natural teeth, especially with single-tooth restorations, represents a challenge. Due to the fact of the individuality of each single human tooth, it is a great order to create single anterior restorations that match harmoniously to the existing adjacent teeth . DemandsContemporary high-strength zirconia-based ceramics exhibit very good clinical data and superior esthetics . ZirconiAdditionally, they could eliminate the use of masking liner material over white zirconia frameworks. Nevertheless, these new colored frameworks need adjustment of the veneer-application procedure to achieve the required final color. The bond strength between zirconia framework and ceramic veneer is affected by the coloring of the zirconia . To prevEight patients were recruited with the need to restore a single ceramic crown on one of their maxillary incisors. The patients were fully informed about the purposes and design of the clinical study and consent was obtained prior to treatment. The study design was accepted by the IRB committee at BAU (2014H-003-D-P-0012).Patients were selected based on the following inclusion criteria:• Indicated for single all-ceramic crowns on one of their maxillary central incisors.• At least one of the adjacent teeth was sound to serve as a guideline and control for shade determination.• Small proximal fillings that would not affect the buccal aesthetic appearance were accepted.• Good oral hygiene and awareness.For each patient 3 crowns were fabricated. Crowns were divided to 3 groups according to color and type of zirconia .All teeth were cleansed and polished with plain white dentifrice, using rubber-polishing cup on a low speed. Intraoral spectrophotometer  was used to record preoperative shades instrumentally for the central incisor to be restored and the target adjacent tooth as control shade. Each tooth underwent spectrophotometric analysis at circular areas of 1.5 mm on the middle of its labial surface with the probe tip positioned at 90 degrees to the surface of the tooth . Care waFinal impressions were made in another session to give proper time for marginal periodontium healing and give time for interim restoration to mold the gingiva to prevent bleeding during retraction cord placement  using doFor the 3 Groups, manual finishing after sintering was done to both the inner and outer surfaces of the copings using air particle abrasion with 100μ alumina particles. Each coping and crown were trial fitted to its corresponding tooth. Cleaning was accomplished by aid of a steam cleaner. Easyshade V was used for recording the color coordinates  of each coping/crown. Copings were veneered using feldspathic ceramic (Cercon CeramS) using silicone index for group WC and CC whereas for group MZ, body stains were used as external stains on crowns.Completed crowns were consecutively tried on corresponding patient for proper fit, contacts and occlusal adjustments (if needed) before they were sent for glazing.Each patient was given the opportunity to select one of the 3 crowns to be cemented permanently on the prepared tooth. All patients selected the monolithic ones most probably for their light weight. All intaglio surfaces were air particle abraded using 100μ Al2O3 then zirconia primer was applied. Proper cementation procedures were accomplished by the use of the resin cement .Color MeasurementCIE color coordinates L*, a*and b* were calculated in each of 3 areas of the ceramic crowns. The areas of interest were measured 3x3 mm in the cervical, body, and incisal regions. Triplet measurements were performed, and average readings were used for data calculation. Color data obtained from the adjacent target tooth were considered as control. Color difference ΔE between the control (adjacent tooth) and the color of zirconia crowns was calculated as follows:• ΔL*= L*control – L*experimental• Δa*= a*control – a*experimental• Δb*= b*control – b*experimental• ΔE*= (ΔL*2+Δa*2+Δb*2)1/2• The ΔEs obtained were assessed based on ΔE of 1.6 which represented the color difference that could not be detected by the human eye and considered clinically acceptable .-Statistical AnalysisResults were recorded, tabulated, and statistically analyzed. Numerical data were explored for normality by checking the distribution of data, calculating the mean and median values as well as using tests of normality (Kolmogorov-Smirnov and Shapiro-Wilk tests). Color parameters (L*) and (b*) data showed parametric distribution while (a*) parameter, color change (ΔE) data showed non-parametric distribution. Data were presented as mean, standard deviation (SD), minimum, maximum and 95% confidence interval (95% CI) values.For parametric data (L* and b*); repeated measures ANOVA test was used for comparisons between different groups and control group, to study the effect of core type on color parameters and to study the effect of cement on color parameters. Bonferroni’s post-hoc test was used for pair-wise comparisons when ANOVA test is significant.For non-parametric data (a* and ΔE); Friedman’s test was used for comparisons between different groups and control group, to study the effect of core type and to study the effect of cement shade. Wilcoxon signed-rank test was used for pair-wise comparisons when Friedman’s test was significant. Bonferroni’s correction was applied for the pair-wise comparisons.-Effect of core type on color parametersIn , as rega-Color difference (ΔE) Descriptive statisticsDescriptive statistics of color difference (ΔE) are presented in -3.In the present study, maxillary central incisor was chosen since as regards to esthetics, it poses the greatest restorative challenge for clinicians; not surprisingly, it can also be the most difficult tooth for the dental technician to match . ZirconiSpectrophotometric color measurements in terms of the CIE L*, a*, and b* color coordinates for different Zr cores were reported. The color difference value (ΔE) represented the numerical distance between 2 colors each having the coordinates L*, a*, and b* . The pur“L” coordinate which represents the lightness of an object was (67.7) with the white core, (55.9) with the colored core, and (81.2) with the monolithic crown. The monolithic crown had the privilege being monolayer and the whole crown was milled from the same high translucency zirconia blank, this gave the bulk color more lightness. The white core was milled from the other blank, which was lighter than the colored blanks. In order to get the selected shade, darker colored blanks (than the selected shade) were chosen on purpose by the laboratory technician to achieve the desired shade by the addition of the lighter veneering ceramic. This justified the big difference between the “L” coordinate of the colored core alone (55.9) and that of colored core with veneering ceramic (80.3).et al, in 2010, who studied the influence of colored zirconia frameworks on the overall color match of zirconia-veneered restorations and found that white frameworks were too bright and offered high L values  respectively. For both white core alone or with veneer, the “L” color coordinates were always lighter than that of the colored cores or veneered colored cores. This finding came in accordance with Aboushelib pecimens .The authors compared the effects of various dentin ceramic thicknesses and repeated firings which may affected their results. In the current study the ceramic thickness was the same in all groups which secured the differences in color coordinates to be attributed to the difference in color as it was the only variable; also the number of firings wasn’t a tested variable.The “a” color coordinate represents chromacity in which negative values indicate green and positive values indicate red. The highest mean of the “a” coordinate was found in the colored core (7.3) followed by the white core  and thenet al. in 1989 (1 to 2 ΔE), it may not have a clinical relevance as far as color detection is concerned  ( It should be noted that although the ΔE values in current study fell within the perceivable range reported by Seghi oncerned . That iset al. in 2010 reported that, the application of the required veneer ceramic over the natural zirconia framework resulted in an accurate reproduction of the required color; while for colored zirconia application of liner material or deep chroma dentin In our study, the CAD/CAM system used was the Cercon in which pre-colored zirconia blanks were available. No liner was used with the white zirconia cores before the addition of the veneering ceramic as recommended by the manufacturer’s instructions. This also helped in neglecting the effect of adding a liner on the final color of the white zirconia cores after veneering. Aboushelib was necessary to reproduce the required color .Their results were in accordance with current study, as the authors concluded that using pre-colored zirconia frameworks did not offer any direct advantages over the standard natural zirconia. Moreover, the selection of monolithic crowns and being more conservative in tooth preparation would rise to top by the insignificant color difference between the monolith and the other crowns.Among the limitations of this study was the number of patients due to difficulty of finding patients in need to crown single central incisor.A point worth mentioning was that most of the papers related to color coordinates, the specimens used were discs ,30 whereThe hypothesis was rejected as there was no difference in color among tested groups.


Oh dear, I have lost count of the number of times someone in publishing has complained. Not about me, I should hasten to add, but at how journals are compared. Invariably the complaint is about the impact factor, the IF, that journal metric we love to hate, that metric that simply will not go away.For some reason, we love to be published in journals with an IF that is sky high, as by implication it means that our paper was more than marvellous. That is not the case, of course, as even in truly high impact journals, up to 40% of papers may never be cited. The IF is a measure designed for a journal, not the papers it contains. Even its founder, Garfield , highligThe IF was originally introduced in 1955  as a wayNature as an example. Who would not sacrifice a considerable amount to be published in that? But although journals such as Nature are publishing an increasing number of high-citation papers, they are not keeping up with the market. Between 1997 and 2012, for example, the number of papers submitted to Nature increased by 43%. During the same period, the number of papers published worldwide increased by 86% [Years ago, I applied for an overseas academic post. I did not get it, of course, but my curriculum vitae was returned splattered with pencil scribblings. An assessor had been truly busy and had laboriously gone through each of my more than 200 publications and worked out the impact factor for every journal in which my research had appeared. I was unceremoniously kicked into touch. Yet there are signs that the worm is turning. Take the journal JHPS, to seek an impact factor, as the moment we do so, our journal will be stood alongside so many others. We will be compared to them purely on numerical grounds. To me, and to plenty of others [JHPS is astonishingly impressive. Our Editorial Board, too, is well-known, hard-working, eminent and actively participates in the journal’s decisions and future shape. And my fellow Editors and Editorial Correspondents are, to put it mildly, utterly brilliant.So, I become restless when folk ask me if it is time for this journal, f others , the moset al. [Just look at our last issue, in which I found it almost impossible to select papers to consider. Each was first rate. There was the excellent review article by Michael Wyatt and Martin Beck on the management of the painful borderline dysplastic hip , an areaet al. . True arJHPS is difficult to beat. Each submission seems almost better than the last. Again, being unable to pick a favourite as I simply cannot decide, I was especially interested in the paper by Davies et al., who help identify factors increasing the risk of failure after hip arthroscopy [et al. As the authors state, it is only rational to consider the use of cell-based treatments to potentially regenerate lost or damaged bone [And if our last issue was not enough, try this one, issue 5.3. In recent times we have been receiving a huge number of papers, so thanks to all who have taken the plunge and realised that hroscopy . What anged bone .JHPS. It is published for you, the hip preservation practitioner, and is filled from cover to cover with brilliance. I commend this issue to you in its entirety.So, as ever, please enjoy this issue of My very best wishes to you all.


Snack samples results showed a maximum hardness in MS, with a value of 121 N, and the NS (100%) presented the highest EI value (1.41). The lowest DAP values were obtained for the MS  and AF  samples. P increased to a higher concentration of AF. In the optimum formulation, the SEM image showed that the expanded microwave sample increased the porosity and obtained an RS value of 8.2%. The formulation obtained in the present study presents high characteristics to be used in the development of a healthy snack.This study aimed to obtain a second-generation snack by extrusion from the by-product of rice milling enriched with amaranth. The raw material used was amaranth flour (AF), rice starch (NS) and modified rice starch (MS), which were evaluated by the analysis of substitution degree (SD), differential scanning calorimetry (DSC), viscosity (RVA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The snacks were expanded by extrusion and microwave oven, as a reference method. The samples were evaluated in hardness (D), expansion index (EI), apparent density (DAP), and protein content (P). Afterward, the optimized samples were evaluated by scanning electron microscopy (SEM) and resistant starch (RS). During the thermal characterization, a clear trend in the decrement in gelatinization temperatures was observed (78.35 to 63.90 °C in NS and MS respectively). The curves obtained in RVA analyses showed typical behavior of native (6.35 Pa.s) and extruded starches (2.88 Pa.s), with a significant decrease in viscosity peak. Through the analysis of FT-IR, the introduction of the functional acetyl group (stretching at a wavelength of 1735 cm Obesity and overweight are currently a challenge for public health in the world. This condition is associated with the development of chronic diseases such as diabetes mellitus type 2, hypertension, cerebrovascular diseases, and cancer. Its increase is directly linked to the consumption of foods with high caloric density and nutrient deficit, as well as little or no physical activity ,2. Urban(Oryza sativa), a subproduct of milling rice, was used, as well as puffing amaranth (Amaranthus spp), acquired in the local market .Cracked and broken rice The amaranth and rice flours were obtained through a dry grind in a rotor mill  and subsequently sieved in a 60 mesh (250 μm). The yield was around 90%.w/v), and it was kept stirring for 1 h, then it was neutralized with a solution of hydrochloric acid . The mixture was left to settle for 24 h cooling and after the time the supernatant was removed and the sediment was centrifuged  at 4000 rpm (2750× g) for 10 min, making three consecutive washes with distilled water. The sedimented starch was dried in an oven  at 40 °C for 12 h. Finally, the sample was milled in a rotor mill  to obtain a particle size of 250 μm (60 mesh).Starch isolation was performed based on the methodology described by Santos et al. , where a®, CDMX, Mexico) was used as an esterifying agent, where 500 g of native starch was adjusted to a humidity of 22% and then 5.5 g of acetic anhydride was added. The sample was stored for 12 h. After that time, 50 mL of NaOH solution was added at 10% (w/v) until the pH was adjusted in a range of 8.5 to 9. The acetylated sample was processed in an extrusion machine  of a single screw with a 1:1 compression ratio, screw speed of 50 rpm and a die diameter of 9.5 mm. The temperatures used were 60, 70, 80, and 100 °C in zones 1, 2, 3, and 4 respectively. The extrudate was dried in an oven  with air circulation at 40 °C up to a humidity of 8%. Finally, it was ground in a rotor mill  and sieved at 60 mesh (250 μm).This modification was made based on the methodology described by Mali and Grossmann . Anhydriv/v) was added. The mixture was kept under stirring for 30 min at a temperature of 50 °C. Once the cold mixture was added, 40 mL of potassium hydroxide (0.5 N)  was added and it was kept at rest for 72 h, with occasional agitation. After the time, it was titrated with a standard solution of HCl (0.5 N), using phenolphthalein as an indicator. Simultaneously, a control sample was titrated using native starch. By means of the following Equations (1) and (2), the percentage of acetylation and the degree of substitution (DS) were obtained:It was carried out based on the methodology described by Bello-Pérez et al. . One graThis analysis was performed in triplicate in each of the treatments.®, Selb, Germany). Two milligrams of the sample were weighed directly into 40 μL aluminum trays, and 20 μL of deionized water was added with a micropipette to obtain a solid suspension with a water content of 65–75% (w/w). The trays were sealed through a press (NETZSCH DSC) and allowed to equilibrate for 1 h at room temperature. The analysis was carried out at a heating rate of 10 °C/min, and a temperature range of 30 to 140 °C, with a sensitivity of 0.005 mcal/s. An empty tray was used as a reference for all measurements, the equipment with indium being previously calibrated. The transition temperature  and enthalpy of gelatinization (ΔHg) were determined using NETZSCH Proteus® Analysis software. This analysis was performed in triplicate in each of the treatments.The thermal characterization was carried out according to the methodology described by Paredes-López et al.  using a max), minimum viscosity (μmin), final viscosity (μf), and the retrogradation viscosity (μr) were determined to evaluate the rheological properties of the structure of the flours and starches. For the measurement, 40 mL of distilled water and 8.69 g of starch were weighed. The temperature profile used for the analysis consisted of a heating phase of 25 to 90 °C, at a speed of 2 °C/min, followed by a stability phase in which the sample was maintained at 90 °C for a time of 10 min to finish with a cooling stage of 90 °C to 25 °C at 2 °C/min; the shear rate was kept constant at a value of 210 s−1 throughout the analysis. Rheoplus Software was used for the analysis of the results. This analysis was performed in duplicate in each of the treatments.Pasting properties were determined based on method 61-02.01 . The ana−1 with a resolution of 4 cm−1.The characterization of native and modified starch was carried out according to the methodology reported by Andreuccetti et al. . A PerkiThis analysis was carried out according to the methodology described by Remya et al. . An X-raThis analysis was performed in duplicate in each of the treatmentsThe snack formulation was made according to the experimental design of mixtures using a statistical software Desing Expert v.9  where the concentrations of native starch, modified starch and amaranth flour were established for each treatment in values ranging from 0 to 100%. The extrusion was performed in a single screw extruder  with a 1:1 compression ratio, screw speed of 50 rpm and an exit die with a diameter of 6.5 mm. The temperatures used were 60, 80, 90, and 140 °C in zones 1, 2, 3 and 4 respectively. The extrudate was dried in an oven  with air circulation at 40 °C until a humidity of 8% was reached, and later expanded in a microwave oven  for a time of 2.5 min and power of (900 W) in order to obtain greater expansion and improve the textural properties of the product.The hardness of the snack was carried out based on the methodology reported by Limón-Valenzuela et al. . The texThe EI analysis was determined according to the method reported by Gujska and Khan , where tm) to finally determine the density using Equation (4):The bulk density of the extrudates was determined according to the technique reported by Pérez-Navarrete et al. . Ten extProtein determination was performed by method 923.04 .® CR-400/410, Tokyo, Japan), calibrated with a standard . The sample was previously grounded and placed in a Petri box to the edge for the measurement; this was performed in the dark to avoid interference; this was done five times for each sample.This analysis was performed based on the ASTM D6290 standard . The colw/v), the samples were placed in a scanning electron microscope , to a field of 15 kV to obtain micrographs at 20X, 100X and 500X.The extruded samples were observed in SEM based on the methodology described by Hu et al. . When exg at a temperature of 4 °C. The supernatant was discarded and washed twice with 10 mL of distilled water, centrifuged again and the supernatant discarded. After that, 3 mL of distilled water and 3 mL of KOH (4 M), prepared that same day, were added and left to rest for 30 min at room temperature with constant agitation. Next, 5.5 mL of HCl (2 M) and 3 mL of sodium acetate buffer  were added in the same way. After that, 25 μL of amyloglucosidase were added, and left for 45 min in 60 °C water bath, with constant agitation. The samples were centrifuged for 15 min at 3000× g at 4 °C and the supernatant was collected and taken to a 50 mL graduated flask. The residue was washed two more times with 10 mL of distilled water each time and the supernatant was combined with the one obtained previously. Then, 50 mL was adjusted, and 50 μL of the sample were taken to determine the glucose released by enzymatic digestion, employing the GOD/PAD method (Glucose Oxidase/Peroxidase), reading the optical densities of the samples at 510 nm.For the determination of RS, the methodology described by Goñi et al.  was usedp ≤ 0.05).A mixture design with centroid was used in order to evaluate the effect of the composition of the flours in the mixture. Three factors were analyzed: Native Starch (NS), Modified Starch (MS) and Amaranth Flour (AF), where the levels used  were defined preliminarily by the package Statistical Design Expert v.9.0.3.  Table 1Table 1, During the modification, a percentage of acetylation (% Ac) of 1.43 ± 0.11 was achieved, representing a degree of acetylation of 0.05 ± 0.002, classified as low grade. For the use of modified starches in food, the FDA approves GAc in a range of 0.01–0.2, the value obtained is within the specifications ,25, whic0); gelatinization maximum temperature (Tg); gelatinization final temperature (Tf); and enthalpy of gelatinization (ΔHg) obtained for rice flour (RF), native starch (NS) and modified starch (MS). The starch consists of a mixture of linear (amylose) and branched polymers (amylopectin) which form an ordered granular structure. When the starch is heated in excess of water, the granules undergo an irreversible phase transition known as gelatinization [nization .p < 0.05). For rice flour and native starch, the values were slightly higher than those reported by Singh et al. [For the gelatinization onset temperature, the highest value (81.63 °C) was obtained for the rice flour, followed by the native starch (73.15 °C) and finally the modified starch with a value of 61.15 °C. In the case of gelatinization temperatures, the same tendency was observed; the higher value was obtained for rice flour (82.63 °C); for native starch, the value decreased to 78.35 °C while the modified starch decreased to 63.9 °C. In the final temperature of the gelatinization, the rice flour presented a value of 85.25 °C, while the native starch and the modified starch presented temperatures of 83.50 and 66.95 °C respectively, which turned out to be significantly different  in the values of temperature and enthalpies of gelatinization. The extraction process mainly gives the difference between the rice flour and the native starch by using the sodium hydroxide solution in the starch, where there is a decrease in the content of proteins, lipids and fiber, as well as a destabilization in the structure, thus facilitating the entry of water into the granules; this behavior is closely related to the increase in the solubility index. Similar values for native starch and modified starch were reported by Sodhi and Singh [There was a significant decrease  of enthalpy of gelatinization is observed. This decrease indicates the loss of the order of the double helices, as well as the loss of crystallinity in the starch. The highest value (8.64 J/g) corresponds to the rice flour while the lower value (1.35 J/g) was obtained for the modified starch; this decrement is due to the breakdown of the double helices during the acetylation reaction together with the shear effect in the extrusion. A lower value of enthalpy is a reflection of lower stability during gelatinization. Similar behavior was observed by Liu et al. [On the other hand, a significant decrease , minimum viscosity (μmin), final viscosity (μf), and viscosity of retrogradation (μr) obtained from the viscoamylogram for rice flour, native starch and modified starch.max) is a measure of the degree of swelling of the granules. The drop in viscosity from a value to a minimum value (μmin) is the decomposition value (breakdown); it is an index of the stability of the pasta during cooking, while the final viscosity (μf) indicates the stability of the cooked pasta. The retrogradation viscosity (μr) is indicated as the difference between the maximum viscosity and minimum viscosity [max (15.8 Pa*s) is presented by rice flour, while the lowest value of μmax (2.88 Pa*s) was obtained in the modified starch. For the minimum viscosity values, the same behavior was observed; a higher value (8.78 Pa*s) that corresponds to the rice flour and a lower value (2.34 Pa*s) was found in the modified starch. The values of μr exhibited the same trend, in the same way, the highest value (15.35 Pa*s) was obtained in the rice flour and the lowest value (6.45 Pa*s) was obtained in the modified starch. The rice flour also had a higher value (6.1 Pa*s) of retrogradation viscosity while the native starch and the modified starch presented equal values (3.6 Pa*s), lower than that found in rice flour.The maximum viscosity  were found for the values of μmax and μmin in rice flour and starches. For the values of final viscosity and retrogradation viscosity, the differences between the native starch and the modified starch did not turn out to be significant (p < 0.05), while for these same parameters the differences between the rice flour and the native starch, as well as the rice flour and the modified starch were found to be significant (p < 0.05). The viscosity achieved by a paste depends on the level of gelatinization of the starch granules and the degree of decomposition in the molecular structure. The higher viscosity reached by the rice flour is due to the high content of non-gelatinized starch; likewise, the presence of proteins can increase the water retention capacity. Similar viscoamylograms were obtained by Fitzgerald et al. [For the parameters of μd et al.  in the rd et al.  reportedThe viscosity drop observed in the native starch is due to the degradation during the extraction and milling processes; on the other hand, the decrease in the viscosity of the modified starch is directly related to a depolymerization product of the partial pregelatinization of the starch induced by the extrusion process. Similar behavior was observed by Hagenimana et al.  and MartThe structural changes caused by the introduction of acetyl groups in the structure of the starch were verified and confirmed by Fourier transform infrared spectroscopy (FT-IR). A comparison of the spectrum of the native starch with the acetylated starch indicated the introduction of the acetyl group; the spectra obtained for the native starch and the modified starch is shown in −1, this occurs due to the stretching vibrations of the O–H bond. On the other hand, the bands corresponding to the range 3000–2800 cm−1 coincide with the stretching vibrations of the C–H bond. The band found corresponding to the range 900–1500 cm−1 is known as the footprint region because it yields unique patterns of the samples and coincides with the stretching of the C–O [The IR spectra of the native and modified starch have global stretches and similar functional groups. For both starches, the intense band can be observed in the range of 3600–3200 cm the C–O ,40. Simi the C–O .−1; this is the consequence of the stretching of the carbonyl ester, which indicated that acetylation of the starch was done. On the other hand, the absence of a peak in the area 1850–1760 cm−1 was observed, this means that the starch was free of unreacted acetic anhydride, and the absence of absorption in the area of 1700 cm−1 for the carboxyl group indicated that the product was also free of acetic acid byproduct [For the modified starch, an increase in the absorption band was observed at 1735 cmyproduct .−1 were reported by Colussi et al. [−1, reaching a degree of substitution of 0.144, and Tang et al. [−1 for rice starch hydrolyzed with pullulanase and acetylated.Similar spectra with an absorption peak at 1750 cmi et al.  during ti et al.  demonstri et al.  obtainedi et al.  observedg et al.  found anIn It can also be observed that both patterns turned out to be similar without great changes in the peaks of reflection; the slightly higher intensity found in the native starch is related to a higher crystallinity reaching a value of 14% while the modified starch showed a lower crystallinity observing a value of 10% ,45,46,47In the X-ray pattern of the modified starch, the changes turned out to be imperceptible. The degree of substitution achieved during the chemical modification, as well as the thermal treatments determine the structural changes in the starch. A low degree of acetylation (0.05) caused minimal destabilization in the amylopectin chains. Studies conducted by Sha et al.  for obtaThe response variables  obtained according to the experimental design are shown in 2 = 0.72); however, the model presented a lack of adjustment.The maximum hardness value (121 N) corresponds to a 100% concentration of modified starch (MS), while the lowest value (32 N) was obtained in the formulation composed of 66.7% of native starch (NS) and 16.7% modified starch (MS) and amaranth flour (AF). A strong tendency to decrease is observed when the AF content in the mixture is increased.These values are closely related to those reported by Meza et al.  where haIt is known that extrusion is a process that leads to starch gelatinization, protein denaturation and formation of starch-lipid and protein-lipid complexes. The formation of these complexes results in a reduction of the expansion and therefore, an increase in hardness.The hardness values of the amaranth formulations were higher than those reported by Dokić et al.  in corn The addition of amaranth in the formulations could lead to changes in the structure of the starches, reducing the hardness compared to the modified starch, the presence of fiber limits the interactions between the polysaccharides and the proteins which could lead to the reduction of the hardness, behavior similar to that explained by Diaz et al. , where aThe response surface graphic A corresp2 = 0.83 (83% representativeness of the model) and without lack of adjustment. A significant effect (p < 0.05) of the linear components was observed, as well as of the quadratic components . The linear terms have a positive effect on the response; the quadratic term NS * AF had a negative impact; while the term MS * AF had a positive impact on the expansion index. The maximum value observed for IEE was 1.41 and corresponded to the native starch (100%). The lowest value for this response was 1.08 obtained in the modified starch extrudate (100%). A trend to decrease is evidenced when the modified starch content in the mixture is increased.The IEE response variable was represented with a quadratic model of R2 = 0.73 (73% representativeness of the model) and without lack of adjustment, identifying a saddle behavior. A negative impact of the quadratic components  on the expansion index was observed while the linear components did not exert significant effects on the response. Although the effect of a microwave expansion did not show higher expansion rates in all the formulations, a higher expansion rate (1.57) was obtained in the modified starch (100%), corroborating the efficiency of the modification processes (acetylation and extrusion). The low values of the expansion index found for the modified starch were caused by changes in its structure; the introduction of the acetyl molecule favors the destabilization in the morphology of the starch granules, causes an increase in the absorption of water, and a decrease in the temperature of gelatinization. However, the temperature in zone 4 of the extruder (140 °C) was not sufficient to achieve rapid evaporation of the absorbed water, limiting the production of air cells and giving rise to a rigid structure; this coincides with the high values of hardness obtained for the modified starch. On the other hand, the humidity (18%) could act with a plasticizing effect; high humidity values decrease the viscosity of the mixture in the extruder and favors the transport of the material minimizing the pressure and therefore the expansion at the output of the equipment [For the response variable IEM, a quadratic model was obtained with a Rquipment . On the In the formulations with high levels of amaranth flour, the expansion was limited mainly by the fat content. Percentages of fats exceeding 6% work as lubricants during the extrusion process, cause an irregular flow, decrease the dissipation of mechanical energy (minimizes the action of shear), and exert a protective effect on the dispersion and gelatinization of starch granules, with a high tendency to the formation of amylose-lipid complexes ,54. On tAccording to Souza et al. , for fur3 being observed for the mixtures of the three components. This variable was represented by a special quartic model with a value of R2 = 0.98 (98% representativeness of the model) and without lack of adjustment. All the terms of the model were significant, which implies a marked influence of the three components on the density of the extrudate. The lowest apparent density values were obtained for the modified starch  and the amaranth flour .3. These researchers reported a marked influence of amaranth content on the density; a minimum value was found for 30% of amaranth content; in this same study, a high-density dependence with temperature and humidity during the process of extrusion is also indicated.A tendency to increase the density was observed for the mixtures of the three components, in the same way for the mixtures of native starch and modified starch the density showed an increase. The apparent density of the extrudates is inversely related to the expansion index. The density was higher than that reported by Ilo et al.  where thThe differences can be given by the extension of the gelatinization and the formation of air cells; the use of temperatures in the last zone of the extruder that varied from 150–190 °C and caused a decrease in the viscosity of the mixture which favored the growth of the bubbles, with a subsequent collapse and increase of expansion rates with a consequent decrease in density. Meza et al.  reportedOn the other hand, the moisture content in the feed zone influences the elasticity of the sample inside the equipment. At lower humidity, the shear rates effect and the degree of gelatinization increase, favoring a higher pressure inside the extruder. On the contrary, moisture values higher than (11–16%), used by Ilo et al. , could hAt lower humidity, it increases the shear rates effect and the degree of gelatinization, facilitating an increase in the pressure inside the extruder, a higher moisture value (18%) with respect to that used by Ilo et al.  (11–12) 3. However, they agreed that the introduction of materials rich in proteins and fiber increase the density of the expanded ones, behavior similar to that obtained in the present investigation.The apparent density values also turned out to be superior to those obtained by Nascimento et al.  in the p2 = 0.99 was obtained (99% representativeness of the model) and without lack of adjustment. The highest protein values were represented as expected by the amaranth extrudate (100%); a tendency to increase was observed when increasing its percentage in the formulation. Meza et al. [a et al.  reported2 = 0.74 (74% representativeness of the model) and without lack of adjustment. Greater values of color change were obtained for the formulations with a higher content of modified starch and amaranth flour. This behavior turned out to be different from that reported by Ilo et al. [o et al. , where t2 = 0.99 (99% representativeness of the model) and without lack of adjustment. It was observed that the highest values of crispness were found when only pure components were extruded (100%). A tendency to decrease was evident for the formulations of the three components and for the MS-AF and NS-AF mixtures.Compact structures with a minimum of pores have less crispness. During the extrusion cooking of starch-based formulations, the main interactions that occur among the macromolecules of the network are electrostatic forces and hydrogen bonds formed between the hydroxyl groups present in the molecular chains. The main interactions between the macromolecules of the supramolecular network are electrostatic and hydrogen bonds between the hydroxyl groups of the polymers. An increase of proteins in the mixture results in the formation of a network of greater rigidity, due to the active participation of amaranth proteins . The stiThe optimal formulation was characterized as having a resistant starch content of 8.20 ± 2.30%. The formation of RS during the different processes is linked to the retrogradation of amylose. Factors such as the length of the polymer chain, the presence of sugars and lipids, as well as the incubation time and temperature affect retrogradation of amylose. The extrusion has been used to produce resistant starch, during this process are carried out the transformation of the structure of starch granules, the formation of amylose-lipid complexes, or of unstable crystalline structures (type E) ,61. ArenParchure and Kulkarni  determinThe reduction of the expansion index, the increase in density, and the decrease in crunchiness are directly linked to the porosity of the extrudates; these results were due to presence of amaranth flour in the formulations. The micrographs exhibit the lubricating effect exerted by the oil content in this pseudocereal, limiting the complete gelatinization of the starch and the development of larger pores. Dokić et al.  in theirThe differences between the values of rice starch and amaranth starch are attributed to differences in amylose contents in each sample. The treatments of roasting, drum drying, extrusion, and frying caused a decrease in the content of resistant starch in comparison with the native starches. According to these researchers, the decrease is produced due to solubilization caused by macromolecular degradation and also possible dextrinization. The differences found between these results and those reported in the present study could be given by the moisture content used (18%) and a lower screw speed (50 rpm), influencing the processes of gelatinization, degradation and retrogradation.The differences found between the reported values and the one obtained in the present study can be given by several factors, among them, the methods and the processing variables. According to Eroglu and Buyuktuncer , the sho−1 corresponding to the introduction of the acetyl groups in the starch. A significant decrease in the gelatinization temperature and viscosity peaks of the native starch was also observed, confirming that a chemical and physical-mechanical modification was carried out. The expansion was limited by the content of fats in the amaranth, exerting a strong lubricating effect, due to the fiber content which limited the development of vapor bubbles and subsequent collapse, decreasing the number of air cells, as well as their size. An increase in the expansion index was obtained at higher contents of native starch and amaranth, 1.39 and 1.36, respectively, during the direct expansion, while during the microwave expansion, greater expansion was observed at higher content of modified starch with a value of 1.57. The density values were found to be high compared to those reported by the literature; the lowest values were found in mixtures containing only native starch and amaranth (0.57 g/cm3). Through the optimization technique, the concentrations of native starch (26%), modified starch (14%) and amaranth flour (60%) with high protein content (10.06%) were determined in comparison to commercial snacks, which represents a high potential to be developed as healthy snacks. The scanning electron micrographs of the optimal formulation showed differences in size, amount and distribution of pores. Resistant starch content of 8.20% was determined, which is higher than the expected value.A degree of substitution in the acetylated starch of a value of 0.05 was reached in the range allowed by the FDA: 0.01–0.2 as safe use for food. A band in the FT-IR spectrum was observed at a wavelength of approximately 1740 cm