In this paper, a novel concept on the design of a broadband printed Yagi antenna for S-band wireless communication applications is presented. The proposed antenna exhibits a wide bandwidth  operating in the frequency range 2.6 GHz–4.3 GHz. This is achieved by employing an elliptically shaped coupled-directive element, which is wider compared with other elements. Compared with the conventional printed Yagi design, the tightly coupled directive element is placed very close (0.019λ to 0.0299λ) to the microstrip-fed dipole arms. The gain performance is enhanced by placing four additional elliptically shaped directive elements towards the electromagnetic field’s direction of propagation. The overall size of the proposed antenna is 60 mm × 140 mm × 1.6 mm. The proposed antenna is fabricated and its characteristics, such as reflection coefficient, radiation pattern, and gain, are compared with simulation results. Excellent agreement between measured and simulation results is observed. In many wireless communication and radar applications, such as TV, microwave imaging, wireless ad-hoc networks, point-to-point and multipoint links, digital array radars, and high-resolution direction tracking, radio frequency (RF) front-end systems are required to operate over a wide bandwidth ,2,3,4. FCommonly used broadband microstrip antennas include antipodal and slot-coupled Vivaldi antennas; log-periodic arrays; feedline–coupled, multilayer-stacked patch antennas; and quasi-Yagi antennas ,14,15,16Due to their simple structure, easy integration with other microwave circuits and high gain, Yagi antennas are also suitable in wireless applications. However, typical microstrip Yagi antennas offer a narrow bandwidth (<10%) ,18. ReseThe printed Yagi antenna consists of a dipole antenna acting as a feed, which is called driven element. The directive elements are printed toward the end-fire direction to enhance the gain of the antenna by directing the electromagnetic energy toward a specific direction. The front-to-back ratio and gain over a broad bandwidth or multiple bands can be improved by increasing the number of directive elements. However, this technique increases the overall size of the antenna. For example, a printed Yagi antenna comprising two different types of feeding networks  has been proposed in . This anIn this work, a moderate-size modified printed Yagi antenna is presented. This antenna is designed to exhibit high gain and wide bandwidth, simultaneously. The conventional printed Yagi antenna comprises a driven element followed by multiple directive elements of a typical rectangular shape. As the electromagnetic energy is coupled from the driven element to the directive element, the inter-element spacing must be in the range 0.15λ–0.3λ. Moreover, the typical rectangular shape can affect matching over a wide bandwidth due to rapid changes in the input impedance. Therefore, in the proposed printed Yagi antenna design, an elliptical shape for the dipole antenna and directive elements was selected. Additionally, contrary to the typical spacing (0.15λ to 0.3λ) used for the directive elements, the input impedance can be matched over a wider bandwidth by placing the first directive element in a closer proximity . Thus, the proposed antenna exhibits a wide bandwidth  covering the S-band from 2.6 GHz to 4.3 GHz. In the proposed design, the directive elements are printed on both the top and bottom sides of the substrate. The bottom-plane directive elements are placed by some offset with respect to the top-plane directive elements. This enhances the effective length toward the direction of propagation, resulting in enhanced gain without increasing the overall dimensions of the antenna.Antenna design based on elliptical shaped microstrip structures has been emerged as unique and important category among the different shaped because of its dual resonant feature and flexibility in optimization. Design of an elliptical shape microstrip patch antenna has more degree of freedom as the resonant frequency is the function of its major axis and minor axis radii as following :(1)f11e,jor axis . The appussed in . It can In Yagi antennas, induced current exhibits progressive phase shift on the rest of parasitic elements which establishes an array structure suitable for supporting travelling wave. For the circuits printed over a dielectric material, it is essential to present a smooth transitions of induced electric field from the first directive element to the last directive element over the complete band of interest. However, abrupt discontinuity because of sharp edges of a rectangular shape geometry, the electric field lines bends at the edges which results in fringing electric fields. Therefore, to avoid sudden discontinuities along the whole structure, we selected elliptical shape geometry for our design. The results revealed by multiple electromagnetic simulations, we found the antenna’s elements with an elliptical shape geometry improves the overall performance especially the bandwidth thus support the travelling wave phenomenon better than its counterpart structure.The general design principles and analytical investigations related to printed Yagi antenna has been extensively discussed in the literature ,35,36. H.In travelling wave antennas, gain enhancement is the function of longitudinal dimensions thus proportional to the larger dimensions (length) of the antenna. In Yagi antennas gain increases by increasing the number of directive elements. However, practically, there is a limit beyond that additional directive element enhances very little to the gain value because of gradual reduction in induced electric field on the farthest directive elements. For our gain requirements (8 dBi~9 dBi), we found maximum four equally spaced directive elements are suitable resulting in overall antenna length to be 140 mm including the ground plane (reflector). As the guided wavelength is smaller than free space wavelength by a factor of square root of the relative permittivity of the substrate material, the major design parameters such as dipole arm lengths, length and spacing between the directive elements are normalized accordingly. Considering the same number of directive elements, the initial length and width of the antenna without dielectric material was calculated to be 285 mm and 85 mm, respectively. It can be seen that the use of substrate material reduces the length by more than halfIn summary, typical performance characteristics parameters of a printed Yagi antenna are affected by (i) reflector and feeder geometry (ii) spacing between reflector and the feeder and (iii) the total numbers of directive elements. Therefore, to achieve required performance it is essential to optimize the geometrical parameters of these structural variables.g/4 from the active dipoles, towards end-fire direction as shown in g/4 length printed on both metallization planes of the substrate. The truncated ground plane layer acts as a reflector for the Yagi structure. The antenna is fed by a 50 Ω microstrip line printed on the ground plane. The plated-via holes are placed on the two sides (left and right) of the printed circuit board (PCB). These holes are capable of reducing the side-lobe levels (SLL) by concentrating the radiated fields toward the end-fire direction [The location and geometric parameter (length and width) of the directive elements is very important in designing a Yagi antenna element. The input impedance of the antenna element is mainly affected by the first parasitic directive element. We have exploited this fact to design a wideband Yagi antenna. At first, we designed a Yagi antenna using conventional design approach, where first parasitic directive element is placed at λirection . The antirection . The finnf, rnw, d4 and d5 in md and rnw, respectively. At first, by varying major and minor axis diameters of the said directive element, the variation inreflection coefficient and gain values are studied as shown in In a standard travelling-wave printed Yagi antenna, the effect of various geometrical antenna parameters such as (i) driven elements’ width and length (ii) reflector’s spacing, width and length (iii) different or equal length directive elements (iv) number of directive elements and (v) different or equal width directive elements, on critical performance parameter, has been extensively studied in the literature ,35,36. I11) and realised gain are shown in 11) less than −10 dB in the frequency range 2.5–3.2 GHz, which correspond to a 28% fractional bandwidth value. On the other hand, the proposed antenna presents S11 less than −10 dB in the frequency range 2.6–4.3 GHz correspond to a 49.3% fractional bandwidth value. Similarly, the presence of tightly coupled directive element enhances realized gain value by more than 1.5 dB. The maximum realized gain values of the Yagi without and with wide directive element are found 7.1 dBi and 8.6 dBi, respectively. To illustrate the effect on input impedance of planar Yagi antenna because of additional directive element, Z-parameter of both designs are calculated and compared shown in 11  and Z11 (imaginary) are shown in 11  values are close to 50 over a wider bandwidth as compared to the antenna without wide directive element. Similarly, the antenna with wide directive element, Z11 (imaginary) values are close to “zero” over a wider bandwidth as compared to the antenna without wide directive element. It can be concluded that presence of additional parasitic directive element in close proximity of the active dipoles does not increase the overall antenna dimensions of a planar Yagi antenna. However, it significantly improves the bandwidth and gain parameters simultaneously.Finally, the performance of the proposed antenna element having a wide tightly coupled directive element, is studied and compared with the antenna without wide directicetive element. The major performance parameters such as reflection coefficient, realised gain and input impedance of both antenna elements are calculted and plotted. The simulated results of reflection cofficient (S2. A photograph of the fabricated Yagi antenna is shown in 11) are presented in 11) of the proposed antenna are less than −10 dB in the frequency range 2.6–4.3 GHz, which is equivalent to a fractional bandwidth of 49.3%.The designed antenna was fabricated using a conventional chemical-based fabrication process. A moisture and dust green-solder mask was used to protect the metalized layers from oxidation. The spacing used between the plated-through holes of 1-mm in diameter was 1.6 mm. These holes were fabricated using a conventional drilling and plating process. The overall dimensions of the proposed antenna structure are 60 × 140 mmThe simulated and measured E-plane (xy-plane) and H-Plane (yz-plane) radiation patterns at 3 GHz, 3.5 GHz, and 4.0 GHz are presented in 21) was measured using (i) a broadband horn antenna (LB-10180) from the A-info company and (ii) a standard-gain horn (SGH) antenna from the NSI company. Next, the standard-gain horn antenna was replaced by the antenna under test (printed Yagi), and the S21 measurements were recorded. The gain values were calculated by consulting the SGH data-sheet and comparing both readings. A comparison between the simulated and measured gain performance is shown in The 3D-radiation pattern graphs at 2.75 GHz and 3.5 GHz are presented in Both simulated and measured results are in good agreement with a difference not exceeding ± 0.8 dB. Commonly, such difference may occur due to connector’s insertion loss, fabrication tolerances, radiation pattern measurements performed in non-anechoic chamber environment, difference in substrate material definition used in simulation and real fabrication especially the dissipation factor (tanδ) value. From the parametric analysis, it can be discovered that antenna’s performance parameters especially the reflection coefficient and the gain values are significantly affected by the varying structural parameters in the order of few millimeters. The simulated antenna’s directivity and gain at 3.5 GHz are found to be 9.93 dBi and 8.31 dBi, respectively. This difference might be due to the fabrication tolerances of the antenna manufacturing process. Secondly, we considered that the substrate used in fabrication may have exhibited more dissipation loss than that one used in our simulation setup. It is important to calculate the antenna’s total efficiency as following :(2)∈T= ∈ antenna (3)∈T= P antenna ,(4)∈R=P loss is (5)∈lm=1x-oriented Electric Far-field probe, which was placed at 500 cm toward the radiation direction . Using (1), the pulse fidelity factor was calculated to be 0.97. It can be concluded that the proposed printed Yagi antenna is capable of radiating broadband signals with low dispersion.Antenna’s radiation efficiency is very important figure of merit for its characterization. Many measurements methods such as pattern integration, directivity/gain, wheeler cap, sliding wall cavity and Q-factor has been developed to find antenna’s radiation efficiency. A comprehensive discussion on different efficiency measurement methods is found in . Among sollowing :(7)D≈4πθollowing :(8)%∈R=1In this paper, the concept of bandwidth enhancement of a conventional printed Yagi bi-layer antenna operating at the S-band was presented. Both metalized layers at the top and bottom antenna planes comprise ground plane, microstrip feedline, driven elements, and directive elements. The bottom plane directive elements are placed with some offset toward the direction of propagation to enhance the overall effective width. The aim was to simultaneously maximize gain and bandwidth. To achieve broad bandwidth matched to 50 Ω input impedance, elliptically-shaped directive elements were introduced in close proximity of the active dipole elements. Full-wave analysis of the tightly-coupled directive elements was performed by conducting multiple electromagnetic simulations using CST Microwave Studio. The performance of proposed antenna element having wide directive element is compared with the typical design without the wide directive element. Compared to the traditional Yagi antenna, the proposed antenna outperformed by presenting simultaneously, larger bandwidth and higher gain values. The designed antenna exhibited a 49.3% fractional bandwidth operating in the frequency range 2.6−4.3 GHz. Plated via-holes were introduced near the left and right boundaries of the PCB board to concentrate the electromagnetic energy toward the main direction of the electric-field flow. The proposed antenna exhibits excellent radiation performance with an average gain of more than 7 dBi and maximum side-lobe levels of less than −10 dB. Due to the high-fidelity factor value, the proposed antenna can be used in broadband RF applications.


These profiles provide novel insights into angiogenic and inflammatory pathologies that may contribute to VCID.Agglomerative hierarchical clustering analysis (HCA) is a commonly used unsupervised machine learning approach for identifying informative natural clusters of observations. HCA is performed by calculating a pairwise dissimilarity matrix and then clustering similar observations until all observations are grouped within a cluster. Verifying the empirical clusters produced by HCA is complex and not well studied in biomedical applications. Here, we demonstrate the comparability of a novel HCA technique with one that was used in previous biomedical applications while applying both techniques to plasma angiogenic  and inflammatory  protein data to identify informative subsets of individuals. Study subjects were diagnosed with mild cognitive impairment due to cerebrovascular disease (MCI-CVD). Through comparison of the two HCA techniques, we were able to identify subsets of individuals, based on differences in VEGF ( Vascular cognitive impairment and dementia (VCID) is an active area in dementia research  and is dCurrently, magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) biomarkers are used to differentiate VCID from AD and monitor the progression of VCID . Plasma post hoc analysis of the clusters produced by HCA to determine their validity. We propose a unique methodology for validating clusters produced by HCA. This method relies on using two unique HCA models on the same dataset and evaluates congruencies between the two models by comparing a novel HCA model to one that is widely used . Inclusion criteria for the parent study include age older than 55 years, Montreal Cognitive Assessment score < 29, and at least one uncontrolled vascular risk factor. Risk factors included poorly controlled hypertension, poorly controlled cholesterol, cardiomyopathy/CHF, diabetes with a fasting glucose > 110 or HbA1c > 7%, homocysteine > 12, history of transient ischemic attack, tobacco use > 30 pack-years, and BMI > 30. Potential subjects were excluded from this cohort if they had dementia, evidence of a non-CVD cause of cognitive decline, evidence of a non-CVD neurologic disease, or any focal motor, sensory, visual, or auditory deficits. For the current study, participants were also excluded if they had an incomplete panel of markers as measured via MSD assays as described below (n = 7).Plasma samples were collected from a cohort of adult research volunteers enrolled in a randomized behavioral intervention study for MCI-CVD  and Proinflammatory Panel 1 (human)] and Ultra-Sensitive assays (MMP 2-Plex and MMP 3-Plex). Plasma did not undergo any freeze-thaw cycles after the initial thawing of the aliquot. Assays were performed using plate specific protocols as followed with analysis performed in the MSD Discovery Workbench 4.0 software.MMP plates were brought to room temperature for approximately 30 min and then loaded with 25 μL of diluent, covered (protect from light), and incubated at room temperature for 30 min while shaking at 600 r/min. After incubation, plates were removed from the shaker and 25 μL of calibrator was added to the assigned wells in duplicate with 5 μL of undiluted sample and 20 μL of diluent. Plates were covered and incubated at room temperature while shaking at 600 r/min. After incubation, plates were removed from the shaker and washed three times with 300 μL of wash buffer. Plates were turned upside down and tapped against paper towels to ensure the removal of all wash buffer from the wells. 25 μL of the antibody mix was loaded into each well, covered (protect from light), and incubated at room temperature for 2 h shaking at 600 r/min. After incubation, plates were removed from the shaker and the wash steps were repeated from above; 150 μL of read buffer was loaded into each well and read on the MSD Quickplex SQ 120 machine.Proinflammatory plates were brought to room temperature for approximately 30 min and washed three times with 300 μL of wash buffer. Plates were turned upside down and tapped against paper towels to ensure the removal of all wash buffer from the wells; 50 μL of calibrator was added to the assigned wells in duplicate with 50 μL of undiluted sample and covered (protect from light). Plates were incubated at 4°C overnight while shaking at 600 r/min. In the morning, plates were removed from 4°C and incubated at room temperature for 1 h while shaking at 600 r/min. After incubation, plated were removed from the shaker and the wash steps were repeated from above; 25 μL of the antibody mix was added into each well, covered (protect from light), and incubated at room temperature for 2 h shaking at 600 r/min. After incubation, plates were removed from the shaker and wash steps were repeated from above; 150 μL of read buffer was loaded into each well and read on the MSD Quickplex SQ 120 machine.Angiogenesis plates were brought to room temperature for approximately 30 min and then loaded with 150 μL of diluent, covered (protect from light), and incubated at room temperature for 1 h while shaking at 600 r/min. After incubation, plates were removed from the shaker and washed three times with 300 μL of wash buffer. Plates were turned upside down and tapped against paper towels to ensure the removal of all wash buffer from the wells; 50 μL of calibrator was added to the assigned wells in duplicate with 25 μL of undiluted sample and 25 μL of diluent. Plates were covered (protect from light) and incubated at 4°C overnight while shaking at 600 r/min. In the morning, plates were removed from 4°C and incubated at room temperature for one hour while shaking at 600 r/min. After incubation, plates were removed from the shaker and wash steps were repeated from above; 25 μL of the antibody mix was added into each well, covered (protect from light), and incubated at room temperature for 2 h shaking at 600 r/min. After incubation, plates were removed from the shaker and wash steps were repeated from above; 150 μL of read buffer was loaded into each well and read on the MSD Quickplex SQ 120 machine.Samples were run in duplicate and three pooled control samples were run on each plate to measure inter- and intra-plate variability. MSD quantification was performed on a table stabilizer in order to reduce error in MSD plate readings.n = 7) due to their effects on clustering techniques. The final dataset consisted of 66 patient plasma samples, which were quantified for 11 plasma markers .Protein markers measured through MSD assays were subjected to intra- and inter-plate variability tests. Intra-plate variability was assessed through two distinct methods. The first method calculated the percentage of samples for each marker that had a coefficient of variation, as determined by the duplicate runs for each sample, greater than or equal to 0.25. Markers that contained 20% of samples above this threshold were removed from further analysis. The second method ran three pooled control sample twice on the same plate (two samples each run in duplicate) to ensure consistency in final quantifications. The coefficient of variation for each of the three controls measured for each marker was then averaged together. Markers with an average coefficient of variation greater than 0.25 were excluded from the analysis. Markers that passed both criteria were included in the final analysis. Inter-plate variability was accounted for using the three pooled control samples run on each plate. Each plate control value was divided by the control mean and all three of these values for each marker were averaged together to provide a plate-scaling factor. Each value was then divided by this factor to adjust for inter-plate variability. The resulting measures were log-transformed to scale each marker to a common order of magnitude, which is required in clustering algorithms to provide equal weighting of markers. Grubb’s test was lastly applied to the data to remove outliers . Individpdist, linkage, and cluster. Previously described HCA models were comprised of three different algorithms, distance, linkage, and clustering  of sub linkages within each new linkage. Clusters were formed when the inconsistency coefficient for each linkage and all sub linkages were less than a specified cutoff (cut) value. Each linkage algorithm output was run through multiple iterations of the inconsistency clustering algorithm with values for depth (dep) from 2 to 6 in increments of 1, whereas cutoff (cut) values were adjusted from 1.0 to 3.0 in increments of 0.1. All iterations of depth and cutoff were evaluated, and if only one cluster was formed, then that iteration was not used in the consensus clustering model. Once each clustering model was established, distances between samples were calculated based on the percentage of models in which two samples shared a cluster. Samples that shared no clusters were given a distance of 1 and, samples that were paired in the same cluster in each model were given a distance of 0. Plots of each clustering model were created using the dimensionality reduction function, t-distributed stochastic neighbor embedding (t-sne), with a random number generation seed of 10 to maintain reproducibility . A similar result was found in a dataset with two distant variable clusters   . These r= 0.857)  and thre= 0.857) . The estp = 0.486, p = 0.962, We hypothesized that clusters, if any, in our empirical dataset would overlap more and thus be more difficult to differentiate than those used in the previous experiments. To test the accuracy of each model in this distribution, we generated simulated data from predicted distributions based on analysis from our collaborators , Tie-2 (p = 0.013), VEGF (p < 0.001), MMP1 (p < 0.001), MMP3 (p = 0.005), MMP9 (p < 0.001), and IL8 (p < 0.001) , MMP1 , and IL8 , respectively. Cluster 1 was also increased in FGF (p = 0.004), Tie-2 (p = 0.033), and MMP9 (p = 0.003) compared to cluster 3. The elevated level of these proteins in cluster 1 agrees with the characteristics of cluster 1 established previously with both models demonstrating a subset with significant increases in VEGF, MMP1, and IL8 compared to the other subsets (p < 0.001 and p < 0.001) and VEGF (p = 0.032 and p = 0.016), respectively, but different levels of FGF (p < 0.001). These differences lead to the possibility of four disease profiles within the MCI-CVD patient population.We proceeded to analyze the differences that drive cluster differentiation. First, we examined the clusters produced by the novel HCA model , and fou< 0.001) . When th< 0.001) , we foun subsets . HoweverThe results of this study provide evidence supporting the use of the novel combined HCA model in datasets with extensive overlapping distributions. The results of the first set of experiments demonstrate that the Euclidean distance HCA model outperforms the novel combined HCA model in datasets with a moderate amount of overlapping distributions . This diIt is important to note that the capacity of the two HCA models to accurately cluster data into their known distributions decreases as the datasets become more complex. In our experiments involving two distant distributions of data, both models were able to separate each distribution with an ARI approximately equal to 1 . In expeBoth the Euclidean distance HCA model and the novel combined HCA model resulted in similar disease profiles within our cohort of MCI-CVD patients . In thisThe usage of both the novel HCA model and a Euclidean distance HCA model identified a novel subset of patients within the MCI-CVD population. This study provides insight into a potential underlying inflammatory and angiogenic profile of disease in patients with VCID. Defining subsets of patients within this population with different disease profiles continues to be a key research objective. These profiles can provide a more complete understanding of disease progression and allow physicians and researchers to identify patients undergoing different rates of pathologic change in a prospective cohort. In the future, we hope to further clarify these profiles by combining plasma and MRI imaging biomarkers that can also be used in clinical trials as key outcome measures to determine the efficacy of novel therapeutics.The datasets generated for this study are available on request to the corresponding author.The studies involving human participants were reviewed and approved by the University of Kentucky Institutional Review Board. The patients/participants provided their written informed consent to participate in this study.ZW designed and executed the analyses. TS performed the assessment of analytes using MSD. DF and QC consulted on study design. LG consulted on clinical readouts. PN provided samples. FS consulted on neuropsychological assessments. GJ assessed the patients and collected all samples. DW oversaw the studies and assisted in the development of hypotheses and data interpretation.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The idea of creating a video corner has been discussed and approved by the board of our Journal.From the beginning in 2009 Facts, Views and Vision always showed a major interest in images, art contributions, innovative techniques and visionary ideas. Therefore, we believe that this Journal provides the perfect scientific environment and conditions to initiate and support the publication of peer-reviewed scientific video articles.It is our aim to facilitate further learning and understanding, especially when complex matters are involved. High definition audiovideo presentations, accompanied by clear and evidence based articles or case-reports provide, in our opinion, the best way of showing and explaining complicated cases and pathologies that normally require extensive writing to be described and completely understood.This Journal embraces all ObGyn disciplines and within the context of a video corner, educational skills can be improved and learning curves can be shortened.The management of obstetrical complications and its treatment, setting up unusual projects, the management of complications during surgical and medical treatments, new operative techniques and instrumentation, important details of an operation, rare pathologies, anatomical deviations etc. can be demonstrated in a better way and will surely have an added value in the transfer of medical information and knowledge, which would not be possible without a video presentation.From a didactic point of view, video articles will undoubtedly be useful in training youngsters and trainees. Above this,video presentations can be stored to constitute a library dealing with challenging surgical techniques, original situations and extraordinary clinical cases.The guidelines for authors will be very similar to that of written format articles but with restricted word counts, a few images and entries will be accompanied by a video clip. Each video article has to describe the learning objectives in a constructive and clear way and to discuss crucial scientific matters and conclusive remarks.The video articles will be reviewed by a group of experts of each discipline in ObGyn. In the next issue of Facts, Views and Vision we will publish a few examples of a video article. From March 2020 onwards it will be possible to submit your video contributions to the Journal.Willem Ombelet, Editor-in-Chief


Staphylococcus aureus (MRSA) agents using the large health insurance claims database.Ward pharmacists are required for the active implementation of therapeutic drug monitoring (TDM). This epidemiological study verified whether Japanese ward pharmacists contribute to improving the TDM implementation proportions of anti-methicillin-resistant The patients who received intravenous anti-MRSA agents from April 2012 to March 2017 were enrolled. We defined ward pharmacy service as the “drug management and guidance fee” and/or “inpatient pharmaceutical services premium”. In addition, implementation of TDM was identified by “the specific drug treatment management fee”. We compared the proportions of TDM implementation for vancomycin (VCM), teicoplanin (TEIC), and arbekacin (ABK) in the ward and non-ward pharmacy service groups. To avoid confounding, the propensity score method was employed. Moreover, the clinical variables affecting TDM implementation in each anti-MRSA agent were analyzed by using a multiple logistic regression model.n = 2138), TEIC (n = 596), and ABK (n = 142). After propensity score matching, the proportions of TDM implementation for VCM and TEIC were higher in the ward pharmacy service group than in the non-ward pharmacy service group , while no significant difference was observed for ABK (21.2% vs 23.1%). As independent clinical variables affecting TDM implementation for VCM and TEIC, several clinical variables, including ward pharmacy services, were extracted. In contrast, no clinical variables were extracted for ABK.The following number of patients were included in the study: VCM (We found that the ward pharmacy service is associated with the active implementation of TDM for anti-MRSA agents, such as VCM and TEIC. Staphylococcus aureus (MRSA) agents, antiepileptic agents, immunosuppressants, and arrhythmia agents [Therapeutic drug monitoring (TDM) is a useful tool to improve the efficacy and safety of pharmacotherapy –4. TDM ia agents . Among ta agents –9. For ea agents . Masuda a agents . In addia agents . Furthera agents . Thus, tIn Japan, there are two medical fees associated with ward pharmacy services, “drug management and guidance fee” and “inpatient pharmaceutical services premium” . The “drAs described above, the effectiveness of pharmacist interventions in TDM have been reported previously –9. HowevTherefore, this study surveyed whether calculation of “drug management and guidance fee” and “inpatient pharmaceutical services premium” (i.e. implementation of ward pharmacy service) is related to the calculation of “specific drug treatment management fee” (i.e. implementation of TDM) using large health insurance claims database.As described above, the JMDC claims database was employed . This daIn this study, we investigated the proportions of TDM implementation of anti-MRSA agents, such as VCM, TEIC, and arbekacin (ABK). Patients who received intravenous injections of these anti-MRSA agents for more than three days from April 2012 to March 2017 during hospitalization were enrolled. VCM, TEIC, and ABK were identified using the ATC system, with the codes J01XA01, J01XA02, and J01GB12, respectively. The clinical departments and the institutions were identified by the text codes and the institutional IDs, respectively. For each anti-MRSA agent, if a patient received multiple administrations during the study period, only the first administration was included in the analysis.The implementation of TDM was defined as calculating the “specific drug treatment management fee” during the administration period. In addition, implementation of ward pharmacy service was defined as the calculation of “drug management and guidance fee” and/ or “inpatient pharmaceutical services” during or within one week before or after the administration period. The data regarding age, sex , duration of treatment with each anti-MRSA agent, number of hospital beds, and clinical departments that prescribed the anti-MRSA agent were collected. The duration of treatment was evaluated as the total number of prescription days. If there was a lapse of more than seven days in the administration of VCM or TEIC, or three days in the administration of ABK, it was considered the end of administration. For evaluating the clinical departments, the top five departments that prescribed each anti-MRSA agent frequently were extracted. The number of hospital beds was categorized as ≤199 beds, 200–499 beds, and ≥ 500 beds.Eligible patients were divided into ward pharmacy service group and non-ward pharmacy service group. As the primary endpoint, the proportions of TDM implementation were compared for VCM, TEIC, and ABK after propensity score matching between the two groups . In addiAs the secondary endpoint, clinical variables affecting TDM implementation for each anti-MRSA agent were analyzed after propensity score matching. For this analysis, the implementation of ward pharmacy service was evaluated in addition to the above- mentioned patient characteristics.To compare the proportions and to analyze the clinical variables affecting TDM implementation, we employed propensity score matching because the data were not randomized. Considering this, the factors that could potentially affect implementation of ward pharmacy service  in a multivariate logistic model were included. As the reason for extracting these variables, for hospitals not calculating “inpatient pharmaceutical services premium”, age, sex, treatment duration, and clinical departments might potentially affect to perform the “drug management and guidance”. That is, some hospitals may perform the “drug management and guidance” by pharmacists for a limited number of wards and patients. Also, we selected the “number of hospital beds” as potential variables because small hospitals may have difficulty in performing ward pharmacy service.The propensity score was calculated from the selected significant factors. Pairs of ward pharmacy service group and non-ward pharmacy service group were matched by nearest neighbor matching within a caliper (0.2 of the standard deviation of the logit of the propensity score) , 16. AftThe present study analyzed the association between some clinical variables  and TDM implementation including ward pharmacy and non-ward pharmacy services (after propensity score matching) using multiple logistic regression. The justification for selecting these potential variables were: (1) age; blood collection from pediatric patients may present a challenge, (2) sex; prevalence of complications that affect the pharmacokinetics of VCM, TEIC and ABK are often different between men and women , (3) trP value of ≤0.05 was considered to be significantly different. We employed statistical analysis software JMP 14® .In all statistical analyses, n = 2138), TEIC (n = 596), and ABK (n = 142), and were divided into ward pharmacy service group and non-ward pharmacy service group.As shown in Fig. Additional files Figure When pediatric (under 18-years old) and non-pediatric patients (18 years and older) were evaluated after propensity score matching , TEIC (97%), and ABK (93%) . AlthougConsidering these limitations, we could not evaluate an overall “contribution” of ward pharmacy service to the implementation of TDM but were able to find a beneficial “association” in the case of VCM and TEIC. Importantly, this study is the first epidemiological verification of an association between ward pharmacy service and TDM implementation using a claims database. An additional novelty of our study is that it showed the usefulness of a large claims database to verify the efficacy of pharmacist intervention. Thus, our approach can be applied to other pharmacist interventions and can be developed further.We found that the ward pharmacy service is associated with the active implementation of TDM for anti-MRSA agents, such as VCM and TEIC.Additional file 1: Table S1. Comparison of patient characteristics of vancomycin before and after propensity score matching. A standardized difference (Std diff) < 0.1 is generally accepted as an adequate variable balance after propensity matching, a) Mann-Whitney U test, b) Chi-squared test. *P values ≤0.05 were considered statistically significant.Additional file 2: Table S2. Comparison of patient characteristics of teicoplanin before and after propensity score matching. A standardized difference (Std diff) < 0.1 is generally accepted as an adequate variable balance after propensity matching, a) Mann-Whitney U test, b) Chi-squared test, c) Fisher’s exact test. *P values ≤0.05 were considered statistically significant.Additional file 3: Table S3. Comparison of patient characteristics of arbekacin before and after propensity score matching. A standardized difference (Std diff) < 0.1 is generally accepted as an adequate variable balance after propensity matching, a) Mann–Whitney U test, b) Chi-squared test, c) Fisher’s exact test. *P values ≤0.05 were considered statistically significant.


Ultrasound imaging is affected by coherent noise or speckle, which reduces contrast and overall image quality and degrades the diagnostic precision of the collected images. Elevational angular compounding (EAC) is an attractive means of addressing this limitation, since it reduces speckle noise while operating in real-time. However, current EAC implementations rely on mechanically rotating a one-dimensional (1D) transducer array or electronically beam steering of two-dimensional (2D) arrays to provide different elevational imaging angles, which increases the size and cost of the systems. Here we present a novel EAC implementation based on a 1D array, which does not necessitate mechanically rotating the transducer. The proposed refraction-based elevational angular compounding technique (REACT) instead utilizes a translating cylindrical acoustic lens that steers the ultrasound beam along the elevational direction. Applying REACT to investigate phantoms and excised tissue samples demonstrated superior suppression of ultrasound speckle noise compared to previous EAC methods, with up to a two-fold improvement in signal- and contrast-to-noise ratios. The effects of elevational angular width on speckle reduction was further investigated to determine the appropriate conditions for applying EAC. This study introduces acoustic refractive elements as potential low cost solutions to noise reduction, which could be integrated into current medical ultrasound devices. While speckle can be exploited to obtain dynamic information (e.g. on blood flow)5, it can also degrade both the resolution and contrast of static structures and blur the boundaries of layered tissues, which can hinder the interpretation of tissue morphology and fine structure and adversely affect diagnostic procedures10. Image post-processing or compounding methods are commonly used to reduce speckle in US imaging20. Post-processing is based on image filter algorithms that use information extracted from the images13, which limits realistic enhancement of structures obscured by speckle noise. Compounding methods average sequential images from the same field of view (FOV) with varied spatial or frequency content10, enhancing correlated features while removing uncorrelated speckle noise, which can reveal structures obscured by speckle in individual images. Frequency compounding methods either vary the emitted frequency or decompose the spectrum of the echo signal to obtain images with uncorrelated speckle patterns, while spatial compounding methods acquire images at different US beam orientations20. However, both compounding methods typically result in a loss of spatial or temporal resolution, as capturing multiple images reduces acquisition speeds and collecting signals from adjacent fields of view reduces the lateral resolution18.Speckle noise is an inherent property of ultrasound (US) imaging that results from constructive and destructive interference of backscattered acoustic waves caused by heterogeneities in tissue19. EAC obtains partially correlated images by steering the elevational imaging plane with small angular steps20. EAC methods typically employ either one-dimensional (1D) arrays that can only control the US beam in the azimuthal direction  or two-dimensional (2D) arrays that can control the US beam in both the azimuthal and elevational directions (the latter being perpendicular to the imaging plane)23. US systems with 1D arrays are simple and inexpensive. However, implementing EAC in such systems necessitates bulky mechanical stages to physically move or rotate the 1D array in order to steer the beam in the elevational direction19, which is impractical in clinical applications. In contrast, US systems integrating 2D arrays can electronically steer the beam along the elevational direction without changing the detector’s position23.However, EAC has only been preliminarily validated in systems integrating 2D detector arrays on simulated data and, although this implementation was reported in patents25, it has not thus far been experimentally validated. Furthermore, the use of 2D array detectors increases the size and cost of the US system. Thus, there is a need for a means of incorporating EAC into US systems that are both economical and have a small form factor.Elevational angular compounding (EAC) is a type of spatial compounding that can simultaneously offer high speckle noise reduction and good temporal resolution, making it desirable for medical applicationsIn this work, we aimed to develop a method of implementing EAC, which could be integrated into simple and low cost US system without sacrificing the image enhancement capabilities. We hypothesized that an acoustic refractive lens could steer a US beam from a 1D transducer array, imparting it with the elevational steering ability of a stationary 2D array while retaining the advantages in size, cost, and simplicity of a 1D array. Furthermore, linear micro-translation of a refractive element should impart precision control of elevational angular steering in a 1D transducer array while minimizing motion artefacts compared to rotating the entire transducer. We describe herein this refraction-based EAC technique (REACT) and assess its qualitative and quantitative enhancements of US images in experiments on phantoms and tissues ex vivo. Moreover, we examine the effect of experimental parameters that can cause image deformation due to compounding different elevational angular views.The implementation scheme of REACT using an acoustic refractive element is shown in Fig. 27. The lenses were fabricated from 2.5 mm ± 4 µm thick PMMA blocks. Figure 6 kg/m2s) and water 27. The distance between the transducer and ACL was held to < 1 mm (while avoiding contact) to minimize the effect of multiple reflection artefacts on the image due to the impedance mismatch between the PMMA and water. Each ACL can produce a characteristic maximum elevational angular deflection, which is 0° for ACL1, 2.5° for ACL2, and 5° for ACL3. Given the radius of curvature, the usable scanning length (w) is geometrically constrained and the translation step is defined to acquire a fixed number of images (N = 100). ACL1 and ACL2 were scanned with steps of δ1 = δ2 = 150 µm, whereas ACL3 was scanned in steps of δ3 = 100 µm. The total deflection angle was theoretically calculated using Snell’s law as c1sinθ2 = c2sinθ1 29 and confirmed experimentally as follows.Customized ACLs designed to cover the full sensor area were manufactured from Polymethyl methacrylate (PMMA), which has a sound speed of 2750 m/s and low acoustic attenuation of 1.4 dB/cm/MHzi), without ACLs, was first determined by measuring the distance between two opposing needle tips, which were inserted into opposite sides of an agar phantom until they just appeared on each side of the image. By recording their imaging depth, an inherent elevation angular FOV of 29.5° was calculated for the employed linear transducer. Similarly, the extended elevational angular FOVs (θE) when employing ACL2 and ACL3 were calculated as 32° and 34.5°, respectively. The effective compounding angles of 0° , 2.5° (ACL2), and 5° (ACL3) were computed by subtracting the inherent transducer angular elevation FOV from the extended ones obtained for each ACL.The transducer’s inherent elevational angular FOV , frustum (intermediate diameter gradient), and cone (high diameter gradient) and was used to explore the effect of elevational angular width and the target’s cross-sectional variation on EAC image fidelity. An excised chicken heart and swine kidney were utilized as biological phantoms to further explore the importance of the cross-sectional appearance of the sample on image fidelity for a given elevational angular width using REACT. The chicken heart was chosen due to its conical shape to represent a sample with high cross-sectional variation. The swine kidney, which is larger than a chicken heart, was selected because of its low cross-sectional variation. For comparability, US images of the biological phantoms were captured and despeckled under the same imaging condition utilizing ACL3. The phantoms were stabilized during imaging by pinning them to polystyrene foam. No live specimens were used in the experiments.Custom acoustic phantoms (50 mm × 20 mm × 15 mm) comprising 2% agar and 4% TiO30 , i.e. two effective Δ values. A single image and two compounded images using 5° elevational angular deflection are shown in Fig. 1, smaller Δ). The cone with an intermediate diameter gradient  shows image fidelity for both Δ cases, without blurry edges. The impacts of these findings were further explored using a biological phantom of an excised chicken heart , which efficiently de-speckles US images using an acoustic refractive element. This method enables EAC in a US system comprising a low-cost 1D detector array without moving or tilting the entire transducer head, eliminating the need for bulky mechanical stages or costly 2D arrays and easing implementation in current US imaging systems equipped with 1D arrays.14. While the widest angle employed in our study was 5°, the selection of the optimal compounding angle should take into account the trade-off between speckle reduction efficiency and image distortion (discussed below). Our results in Table 14. This superior enhancement could be attributed to a reduction in motion artefacts because of the fixed transducer. Note that imaging through the PMMA refractive lenses caused a 7.5% signal loss due to acoustic attenuation and reflection  and utilizing diffraction lenses with lower effective thicknesses31.In contrast to previous EAC implementations, REACT uses a fixed 1D transducer array with a translating acoustic cylindrical lens. Visual and quantitative inspection of US images depicted in Fig. 14. Our results demonstrate that image deformation can also occur in EAC with narrow elevational angles, particularly from deeper imaging positions, due to the associated increase in elevational angular width (Δ). Image fidelity in EAC, or in other words, accurate representation of structural features from the despeckled plane, is affected by interference from structures in adjacent elevational planes. We explored the trade-off between imaging depth and elevational angular width when employing EAC methods on targets with shapes that have no (cylinder), low (frustum), and high (cone) diameter gradient along the elevational direction (Fig. ex vivo chicken heart and swine kidney with REACT, which demonstrated the importance of accounting for the morphology of the sample for a given elevational angular width in EAC. The spatial resolution along elevational direction is the main limiting factor in all EAC implementation and depends on the total elevational beam width. Hence, out of plane signals can degrade compounding quality, particularly when imaging small organs. This was confirmed in our experiments, where the high variation of the cross-sectional appearance of the chicken heart resulted in distortions in the compounded image (Fig. Although EAC is recognized as an efficient way to suppress speckle noise in US images, it suffers from anatomic structure deformation and edge blurriness in compounded images captured within wide elevational angular viewsion Fig. . We founage Fig. f,g, wherIn summary, we utilized acoustic refraction to introduce elevational angular steering into existing 1D transducer arrays and demonstrated its application in a novel implementation of EAC called REACT. Such a low-cost and simple compounding de-speckling method can be of great benefit in clinics to improve current US visualization and interpretation during disease diagnosis. Further work aims at miniaturising ACL embodiments and allowing real-time despeckling by automating the position of the lens and synchronizing frames to evaluate REACT in a clinical context.


Examining whether any association exists between addiction to video games and cognitive abilities in children could inform ongoing prevention and management of any possible harm. The objective of this study was to investigate the associations between addiction to video games, and memory, attention and learning abilities among a sample of Lebanese school children.This cross-sectional study, conducted between January and May 2019, enrolled 566 school children aged between 9 and 13 years. Three private schools were chosen conveniently for this study. Students were randomly chosen from the list given by the school administration. The students’ parents are those who responded to the questionnaire.The results showed that higher addiction to video gaming salience was significantly associated with worse episodic memory, problem solving, basic reading skills, written expression skills and worse clinical attention. Higher addiction to video gaming tolerance were significantly associated with worse novel problem solving and worse attention. Higher addiction to video gaming withdrawal were significantly associated with worse attention, factual memory, attention, processing speed, visual spatial organization, sustained sequential processing, working memory, novel problem solving and worse written expression skills.The results suggest a correlation between addiction to video games and worse memory, attention, as well as cognitive and academic abilities among school children. Those findings indicate the need for more extensive research, and serve to highlight vital next steps needed in future papers, such as identifying predicting factors that could aid in early detection of video gaming addiction in children. Recent advances in new technologies have made video games the top leisure time occupation for children, who are particularly susceptible for addiction. Currently, video games have become the most famous type played worldwide among children. Nielsen reports that total weekly time spent playing games increased expeditiously from 5.1 to 6.3 h in 2011 and 2013 respectively  was employed for the calculation of the required sample size for our study, with a prevalence of internet gaming disorder of 9.2% among 524 Lebanese high school students from a study done by Hawi et al. , with anThe questionnaire was distributed to each student in the classroom to be taken home. Parents filled it within 25 min approximately. The completed questionnaires were collected back and sent for data entry. During the data collection process, the anonymity of the participants was guaranteed.The self-administered questionnaire used was in Arabic, the native language of Lebanon. The first part assessed the sociodemographic details of the participants . The second part of the questionnaire included the following scales:The 21-item Gaming Addiction Scale (GASC) is an instrument based on DSM criteria to assess gaming addiction. The seven items in the GAS are rated using a five-point Likert scale ranging from 1 (never) to 5 (very often). A higher score on the GAS indicates more problematic use of online gaming. The scale measures 7 criteria of computer addiction: salience, tolerance, mood modification, withdrawal, relapse, conflict and problems . In thisThe CMQ is a 36-item questionnaire designed to assess parents’ perceptions of their children’s memory. The CMQ requires parents to assess their child’s memory based on five possible options: 1 = never or almost never happens; 2 = happens less than once a week; 3 = happens once or twice in a week; 4 = happens about once a day; and 5 = happens more than once a day . Three sThe scale measures the frequency of activity and attention by asking the parent and teacher to respond to a series of 12 statements and their applicability to their child in the morning and afternoon. Response options range from “not true” (0), “somewhat or sometimes true” (1), “very often” or often true (2). The higher the scores, the greater the attention problems exist . In thisThe LEAF is a 55 item self-report questionnaire that assesses executive functions, related neurocognitive functions, and academic skills in children and adults. The LEAF evaluates a broad set of core cognitive abilities as well as related cognitive learning and academic abilities. Cognitive areas assessed by the LEAF include attention, processing speed , and sustained sequential processing to achieve goals , working memory, and novel problem-solving. Also, LEAF includes comprehension and concept formation, declarative/factual memory, and academic functioning. The LEAF contains Academic subscales assessing reading, writing, and math fluency and abilities. LEAF items are grouped by subscale, and all subscales have the same number of items.The subscales of the LEAF are: (1) comprehension and conceptual learning (tracking and understanding information), (2) factual memory (memorization and retention of facts); (3) attention (sustained focus); (4) processing speed ; (5) visual-spatial organization ; (6) sustained sequential processing (planning and sustaining effort in order to follow and complete multistep directions and sequences); (7) working memory (remembering and processing multiple things at the same time); and (8) novel problem solving (initiating effort toward processing new or unfamiliar information). (9) Mathematics skills ; (10) basic reading skills (reading/phonics difficulty); and (11) written expression skills (limited/impoverished or slow/effortful written expression). Individual items are rated on a 0–3 scale, and a raw subscale score for each of the 11 content areas is created by summing the 5 constituent items, such that higher scores indicate more cognitive problems . In thisThe forward translation was done by one translator. An expert committee formed by healthcare professionals and a language professional verified the Arabic translated version. A backward translation was then performed by a second translator, unaware of the initial English version. The back-translated English questionnaire was subsequently compared to the original English one, by the expert committee. Discrepancies related to inadequate expressions and concepts, confusing in meaning and slightly off in meaning during the reconciliation of the back translated questionnaire with the original source were resolved by consensus.SPSS software version 23 was used to conduct data analysis. Cronbach’s alpha values were recorded for reliability analysis for all the scales. A descriptive analysis was done using the counts and percentages for categorical variables and mean and standard deviation for continuous measures. A multivariate analysis of covariance (MANCOVA) was carried out to compare multiple measures  taking the GAS as the major independent variable, controlling for potential confounding variables: age, gender, family monthly income, and mother and father education level. A p-value less than 0.05 was considered significant.Out of 700 distributed questionnaires, 566 (80.86%) questionnaires were completed and collected back. The sociodemographic characteristics of the participants are summarized in Table The description of all the scales used in terms of mean, standard deviation, median, minimum and maximum is summarized in Table The bivariate analysis of the sociodemographic variables associated with the memory and attention scores is summarized in Tables Higher addiction to video gaming salience, tolerance, relapse, withdrawal, conflict and problems scores were significantly correlated with lower/worse episodic memory, working memory, visual memory, clinical attention in the morning and in the afternoon, comprehension and conceptual learning, factual memory, LEAF attention, processing speed, visual spatial organization, sustained sequential processing, LEAF working memory, novel problem solving, mathematics skills, basic reading and written expression skills scores, except for the mood modification that was not associated with the visual memory and mathematics skills scores Table .Table 5BThe MANCOVA analysis was performed taking the scales as the dependent variables and the addiction to video gaming salience as the independent variable, adjusting for the covariates .Higher addiction to video gaming salience was significantly associated with higher episodic memory score (worse episodic memory), higher novel problem solving score (worse problem solving), higher basic reading skills score (worse basic reading skills), higher written expression skills score (worse written expression skills) and higher clinical attention in the morning and afternoon scores (worse episodic memory and attention).Higher addiction to video gaming tolerance were significantly associated with higher novel problem solving score (worse novel problem solving) and higher clinical attention in the morning and afternoon scores (worse attention).Higher addiction to video gaming withdrawal were significantly associated with higher clinical attention in the afternoon score (worse attention), higher factual memory score , higher attention score (worse attention), higher processing speed score (worse processing speed), higher visual spatial organization score , higher sustained sequential processing score , higher working memory score (worse working memory), higher novel problem solving score (worse novel problem solving) and higher written expression skills score (worse written expression skills) Table .Table 6MThus far, this is the first study to be conducted on Lebanese school children to evaluate the association between addiction to video games, memory, attention and learning abilities. Taking into consideration that intensive video gaming has frequently been linked to the development of addictive-like behaviors among children, we found highly important to assess some cognitive factors that could be affected in this delicate population. The results showed that higher addiction to video gaming was significantly associated with higher memory score (worse memory), with higher attention score (worse attention), and higher LEAF scale and subscales scores (worse cognitive and academic abilities). We also found that having a father with university education level was significantly associated with lower attention score (better attention) and lower LEAF scale and subscales scores (better cognitive and academic abilities).Higher addiction to video gaming was significantly associated with higher memory score (worse memory). When the different studies were reviewed, the results were found to be contradictory. Some of the studies argued that video games have negative effects on memory, while other ones did not support this finding . MoreoveMoreover, higher addiction to video gaming was significantly associated with higher attention score (worse attention). Similar to our results, increasing behavioral studies proved that video games addicts showed attention deficits. De facto, Zhou et al.  demonstrLikewise, higher addiction to video gaming was significantly associated with higher LEAF scale and subscales scores (worse cognitive and academic abilities). Correspondingly, Gentile et al.  found thIn addition to the previous findings, having a father with university education level was significantly associated with lower attention score (better attention) and lower LEAF scale and subscales scores (better cognitive and academic abilities). To our knowledge, no study in the literature discussed the education level of the parents, particularly the father, in this particular context. The cause for our result could be that highly educated fathers raise their children in a similar educative way, which enhances their cognitive and academic skills.The current study provides many valuable contributions to the literature. Despite growing numbers of published studies examining cognitive skills in children playing video games, there is a paucity of rigorous ones from which to draw firm conclusions. This study procures firm evidence that addiction to video games is linked to worse memory, attention, as well as cognitive and academic skills in school children. This analysis constitutes a vital first step towards a better understanding of video games addiction in children, supporting its evidence as a plausible entity with detrimental association. By this, the study encourages parents of children addicted to video games to set particular gaming rules (such as limiting gaming time and avoiding exploration of new games), advocates schools to introduce children to other fun activities to do, and highlights the importance of consulting a therapist in extreme cases.There are several limitations that should be noted. First of all, all scales were self-rated, which may only show high risk of addiction to video gaming rather than the diagnosis. Second, residual confounding bias is also possible, since there could be factors related to video gaming such as pre-existing attention problems, ADHD diagnosis that were not measured in this study. Moreover, parents might have over-or underestimated the answers to the questions, possibly predisposing us to information bias. A selection bias is also possible because of the enrollment of the students from three schools only and because of the convenient sample. The group of students chosen in this study were not representative of most of students in their age. Students’ parents filled up the video gaming addiction scale, which could lead to information bias since this scale is not applicable to them. To add on that, since this study is cross-sectional, the findings of this study cannot address the causal relationships among the primary constructs of interest. Finally, the scales used have not been validated in Lebanon. The use of a random sample is an important advantage to the study, thus, the results we obtained can be generalized to the whole population. The results cannot be generalized to the whole population since it only recruited students from private schools, as well as a high percentage of well-educated mothers. A prospective longitudinal study is needed to better follow up the cognitive function of children over time.In conclusion, the results suggest a correlation between addiction to video games and worse memory, attention, as well as cognitive and academic abilities among school children. Those findings indicate the need for more extensive research, and serve to highlight vital next steps needed in future papers, such as identifying predicting factors that could aid in early detection of video gaming addiction in children.


Measurement of post-exertion oxygen saturation has been proposed to assess illness severity in suspected COVID-19 infection. We aimed to determine the accuracy of post-exertional oxygen saturation for predicting adverse outcome in suspected COVID-19.We undertook a substudy of an observational cohort study across 70 emergency departments during the first wave of the COVID-19 pandemic in the UK. We collected data prospectively, using a standardised assessment form, and retrospectively, using hospital records, from patients with suspected COVID-19, and reviewed hospital records at 30 days for adverse outcome (death or receiving organ support). Patients with post-exertion oxygen saturation recorded were selected for this analysis. We constructed receiver-operating characteristic curves, calculated diagnostic parameters, and developed a multivariable model for predicting adverse outcome.We analysed data from 817 patients with post-exertion oxygen saturation recorded after excluding 54 in whom measurement appeared unfeasible. The c-statistic for post-exertion change in oxygen saturation was 0.589 (95% CI 0.465 to 0.713), and the positive and negative likelihood ratios of a 3% or more desaturation were, respectively, 1.78 (1.25 to 2.53) and 0.67 (0.46 to 0.98). Multivariable analysis showed that post-exertion oxygen saturation was not a significant predictor of adverse outcome when baseline clinical assessment was taken into account (p=0.368). Secondary analysis excluding patients in whom post-exertion measurement appeared inappropriate resulted in a c-statistic of 0.699 (0.581 to 0.817), likelihood ratios of 1.98 (1.26 to 3.10) and 0.61 (0.35 to 1.07), and some evidence of additional prognostic value on multivariable analysis (p=0.019).Post-exertion oxygen saturation provides modest prognostic information in the assessment of selected patients attending the emergency department with suspected COVID-19.ISRCTN56149622) http://www.isrctn.com/ISRCTN28342533.ISRCTN Registry ( Post exertional decrease in oxygen saturation can be used to predict prognosis in chronic lung diseases.Post exertional desaturation has been proposed as a way of predicting adverse outcome in people with suspected COVID-19.Post-exertion oxygen saturation provides modest prognostic information in the assessment of selected patients attending the emergency department with suspected COVID-19.Guidelines for assessment of suspected COVID-19 recommend measurement of peripheral oxygen saturation to determine the severity of acute respiratory infection.Pneumocystis carinii pneumonia.Field walking tests are commonly used to evaluate exercise capacity and assess prognosis in chronic respiratory diseases.The Pandemic Respiratory Infection Emergency System Triage (PRIEST) Study is a multicentre observational cohort study designed to develop and evaluate triage methods for patients with suspected COVID-19 infection. We added evaluation of post-exertion oxygen saturation to the aims of the PRIEST Study in response to reports of its use in the assessment of suspected COVID-19. Our specific objective for this post hoc substudy was to determine the accuracy of post-exertional oxygen saturation as a prognostic factor for 30-day adverse outcome.For the PRIEST Study, we collected data from consecutive patients presenting with suspected COVID-19 infection to 70 hospital emergency departments (EDs) from 53 recruiting sites in the UK, where some sites cover more than one hospital. Hospitals used either prospective data collection, through a standardised assessment form for suspected COVID-19, or retrospective data collection, through research staff extracting data from hospital records onto the standardised form.Patients were included in the PRIEST Study if the assessing clinician used the standardised assessment form or recorded that the patient had suspected COVID-19 infection. The clinical diagnostic criteria used for suspected COVID-19 during the study wereThe population for this substudy was patients who had post-exertion oxygen saturation recorded as part of routine care. The assessing clinician made the decision to measure post-exertion oxygen saturation and determined the approach to achieving exertion. The study did not influence clinical care, so we were unable to standardise the selection of patients or the approach to measuring post-exertion oxygen saturation. Measurement could have been undertaken deliberately, by asking the patient to exercise in a specified way, or opportunistically, by recording oxygen saturation after the patient had exerted themselves for another purpose.Research staff reviewed hospital records to identify outcomes up to 30 days after initial presentation. We defined patients who died or required respiratory, cardiovascular or renal support as having an adverse outcome. We defined respiratory support as any intervention to protect the patient’s airway or assist their ventilation, including mechanical ventilation, non-invasive ventilation or continuous positive airway pressure, but not supplemental oxygen alone or nebulised bronchodilators. We defined cardiovascular support as any intervention to maintain organ perfusion, including extracorporeal membrane oxygenation, inotropic drugs or invasive cardiovascular monitoring, but not peripheral intravenous cannulation and/or fluid administration. We defined renal support as any intervention to assist renal function, including haemofiltration, haemodialysis or peritoneal dialysis, but not intravenous fluid administration or urinary catheterisation.We undertook an initial descriptive analysis of the patients with post-exertion oxygen saturation recorded. This identified a number of patients for whom post-exertion oxygen saturation measurement appeared unfeasible, based on age (less than 3 years), performance status bed/chair bound, baseline oxygen saturation below 85%, post-exertion oxygen saturation below 50%, receiving supplemental oxygen or Glasgow Coma Score less than 14. We excluded these patients from the analysis.et al.We examined baseline oxygen saturation, post-exertion oxygen saturation and post-exertion change in oxygen saturation . Analysis focused on the latter, because this indicates the additional value achieved by measuring oxygen saturation after exertion. We estimated the accuracy of each index test in terms of the sensitivity, specificity and likelihood ratios of each test across a range of thresholds for positivity, for predicting adverse outcome up to 30 days. CIs for likelihood ratios were calculated using the methods outlined in Bedrick and Koopman.To determine whether measurement of post-exertion oxygen saturation adds prognostic information to standard respiratory assessment, we fitted a multivariable logistic regression model with age, baseline oxygen saturation, respiratory rate, heart rate, asthma, other chronic respiratory illness and post-exertional oxygen saturation as covariates.We undertook a secondary analysis that excluded patients for whom post-exertion oxygen saturation measurement appeared less appropriate, based on age (less than 16 years), performance status of limited self-care, baseline oxygen saturation less than 94%, or heart rate, respiratory rate or systolic blood pressure scoring 3 points on the National Early Warning Score (NEWS2). The rationale for this analysis was that local guidelinesWe planned for the PRIEST Study to recruit a sample size of 20 000. The analysis presented here is a secondary analysis, so no sample size was prespecified.The Sheffield Emergency Care Forum (SECF) is a public representative group interested in emergency care research.The PRIEST Study recruited 22 484 patients across 70 hospitals between 26 March 2020 and 28 May 2020, of whom 39 requested withdrawal of their data. We identified 874 patients who had post-exertion oxygen saturation recorded and excluded 57 in whom measurement appeared unfeasible, leaving 817 for analysis. Adverse outcome occurred in 30 participants (3.7%), of these 9 died, 22 had respiratory support, 5 had cardiovascular support and 4 renal support.10.1136/emermed-2020-210528.supp1Supplementary dataIn the multivariable model on the primary analysis cohort, post-exertional oxygen saturation did not add prognostic value over other factors in the model . For the secondary analysis, post-exertional oxygen saturation added prognostic value over other factors , indicating that post-exertion desaturation may help to predict adverse outcome even when other clinical features are taken into account.Our findings suggest that measurement of post-exertion oxygen saturation adds modest prognostic information to clinical assessment of suspected COVID-19 in the ED. The likelihood ratios in the primary analysis suggest that a desaturation of 3% or more provides a small amount of prognostic information, the c-statistic of 0.589 for post-exertion change suggests little discriminant value, and multivariate analysis suggests that post-exertion oxygen saturation measurement does not add prognostic value once baseline measurements are taken into account. Secondary analysis limited to more appropriate cases suggested better discriminant value, with a c-statistic of 0.699, and additional prognostic value on multivariable analysis. In appropriate cases, post-exertion oxygen saturation measurement should be safe and relatively easy to incorporate into clinical assessment. It may therefore be worth using in selected patients, such as those with normal baseline observations and oxygen saturation. The low risk of adverse outcome in these selected patients means that absence of desaturation could provide reassurance that discharge home is appropriate.The observation that oxygen saturation increased post-exertion, and that some people with adverse outcome showed an increase, may seem surprising, but is probably explained by random variation. Oxygen saturation varies randomly from one measurement to the next and this variation is likely to be greater in sicker patients with baseline hypoxia. Thus, we might expect greater variation in oxygen saturation to show some association with adverse outcome.et alGreenhalgh Our study consisted of a clinically relevant population and was recruited across a wide range of settings, but evaluation of post-exertion oxygen saturation was a post hoc secondary analysis and the study was not designed specifically for this purpose. We are unable to say how patients were selected for measurement of post-exertion oxygen saturation, and the method for undertaking exertion was not standardised or recorded. We excluded 57 patients from analysis for whom post-exertion oxygen saturation measurement appeared unfeasible, and excluded a further 162 from secondary analysis for whom measurement appeared less appropriate. These cases may reflect opportunistic oxygen saturation measurement after exertion, such as on attempting to mobilise, but we cannot exclude the possibility of data recording errors. Furthermore, our judgements regarding feasibility and appropriateness of measurement were somewhat subjective, so others may consider that measurement in these cases could be feasible or appropriate. Only 874 out of 22 445 patients (3.9%) had post-exertion oxygen saturation recorded. This may reflect limited awareness and use of post-exertion oxygen saturation, but may also reflect severity of illness in the ED population. Measurement of post-exertion oxygen saturation is only likely to be feasible and clinically indicated in those with milder illness. The relatively small number of adverse outcomes (N=30) limited the precision of our estimates of sensitivity and power to undertake multivariable analysis.In summary, measuring post-exertion oxygen saturation provides modest prognostic information in the assessment of selected patients attending the ED with suspected COVID-19. It could be added to clinical assessment for patients with normal baseline oxygen saturation when there is uncertainty around the decision to admit to hospital.10.1136/emermed-2020-210528.supp2Supplementary data10.1136/emermed-2020-210528.supp3Supplementary data10.1136/emermed-2020-210528.supp4Supplementary data10.1136/emermed-2020-210528.supp5Supplementary data


Hemodialysis (HD) majorly represents the global treatment option for patients with chronic kidney disease stage 5, and, despite advances in dialysis technology, these patients face a high risk of morbidity and mortality from malnutrition. We aimed to provide a novel view that malnutrition susceptibility in the global HD community is either or both of iatrogenic and of non-iatrogenic origins. This categorization of malnutrition origin clearly describes the role of each factor in contributing to malnutrition. Low dialysis adequacy resulting in uremia and metabolic acidosis and dialysis membranes and techniques, which incur greater amino-acid losses, are identified modifiable iatrogenic factors of malnutrition. Dietary inadequacy as per suboptimal energy and protein intakes due to poor appetite status, low diet quality, high diet monotony index, and/or psychosocial and financial barriers are modifiable non-iatrogenic factors implicated in malnutrition in these patients. These factors should be included in a comprehensive nutritional assessment for malnutrition risk. Leveraging the point of origin of malnutrition in dialysis patients is crucial for healthcare practitioners to enable personalized patient care, as well as determine country-specific malnutrition treatment strategies. The last three decades witnessed considerable growth in the global burden of chronic kidney disease (CKD), accounted for by 77.5% of end-stage kidney disease (ESKD) patients on kidney replacement therapy (KRT), with 43.1% alone provided by dialysis . The tecMorbidity arising from malnutrition in these patients severely affects quality of life (QoL) , frailtyMalnutrition occurrence in the dialysis population has generated much research. However, different definition terms exist for malnutrition such as protein-energy wasting, protein-energy malnutrition, malnutrition–inflammation complex syndrome, malnutrition–inflammation–atherosclerosis and uremic wasting syndrome depending on involvement of inflammation, hypercatabolism, and increased uremia . MultiplIn essence, factors contributing to the development of malnutrition may be categorized as of iatrogenic and non-iatrogenic origin . IatrogeThis review aims to provide a global view of the iatrogenic and non-iatrogenic causes of malnutrition, irrespective of its form described in current literature, as some aspects with regard to this topic have changed over recent years. Our approach discusses mechanisms elucidating the implication of each factor contributing to malnutrition. The origin of malnutrition contributed by both iatrogenic and non-iatrogenic factors is important to understand the implications for healthcare practitioners in performing the assessment and treatment for malnutrition. Before this categorization, malnutrition must also be delineated according to its development history. This review is, therefore, organized into (i) development of malnutrition in HD, (ii) iatrogenic factors of malnutrition, and (iii) non-iatrogenic factors of malnutrition.The decision to start dialysis for an ESKD patient varies across countries and is influenced by the local nephrology practice, healthcare policies, and cost for dialysis treatment . The Dia2 to reduce uremic symptoms or signs of malnutrition.Earlier opinion on dialysis initiation did consider poor nutritional status as a factor to initiate dialysis. However, this was not based on markers of malnutrition but rather signs and symptoms of malnutrition such as anorexia, nausea, and fatigue . Van de Dialysis treatment is expected to improve nutritional status for patients with a more liberal protein prescription compared to the pre-dialysis stage ,30,31. HESKD patients with pre-existing malnutrition on maintenance dialysis become additionally vulnerable over time to the catabolic effects of the dialysis treatment, which predispose the patient to greater mortality and morbidity in long-term dialysis. The concern is that the presence of poor nutritional status in dialysis patients predicts increased mortality risk.Kwon et al. (2016) prospectively used SGA to monitor patients, observing that those in SGA B and C categories at baseline almost tripled their risk of mortality by 12 months . HD patiIatrogenic malnutrition or “physician-induced malnutrition” is the development of malnutrition arising from medical procedures, pharmacological treatment, prolonged hospitalization, nosocomial infections, or delayed wound healing . SimilarThe dialysis process is instrumental to chronic nutrient losses, particularly protein and amino acids. About 6–12 g of amino acids and 7–8 g of protein losses occurring during each dialysis session ,43,44,45Nutrient losses via dialysis depend on the mechanism of solute removal and the pore size of the dialyzer membrane, which determines solute removal . HoweverDialysis performed during the 1960s used low-flux membranes , which eWith highly permeable membranes or HF and HDF techniques, patients are reported to achieve better intradialytic and hemodynamic stability , alongsiContrarily, two studies reported a significant reduction in serum albumin levels in patients dialyzing with HCO membranes ,65. The In low-to-middle-income countries, the practice of dialyzer reuse is common ,68. HoweMany factors lead to inflammation in HD patients such as biocompatibility of the dialyzer membrane ,74,75, ip = 0.034) and low normalized protein catabolic rate (nPCR) levels (p = 0.029) [Whether dialysis access directly contributes to malnutrition has not been shown. Arteriovenous fistula (AVF) failures were not influenced by markers of poor nutritional status except for high cholesterol (= 0.029) . HD pati= 0.029) . In fact= 0.029) . Instead= 0.029)  mediated= 0.029) . Therefo= 0.029) , whereby= 0.029) .Direct effects of the membrane, the extent of complement stimulation induced by the membrane, and the degree of eosinophilia associated with the clearance of cytokines determine the magnitude of the inflammatory response during dialysis . InflammInflammation also occurs with dialysate contamination by microorganisms, which produce endotoxins that pass through the dialyzer membrane and enter into blood circulation , amplifyOverall, dialysis patients are vulnerable to oxidative stress with a marked increase in reactive oxygen species (ROS) production and antioxidant depletion. ROS induces activation of nuclear factor kappa B (NF-κB), which is translocated to the cell nucleus stimulating cytokine production, in turn causing inflammation . Indeed,Another impact of the HD treatment is the activation of polymorphonuclear white blood cells, which trigger production of ROS and other pro-oxidants . Indeed,p = 0.039) [However, Silva et al. (2019) found no difference in markers of oxidative stress and antioxidant defenses in malnourished HD patients identified using global objective assessment compared to mild or well-nourished patients . In cont= 0.039) .r = 0.65, p = 0.040) of malnourished HD patients categorized by SGA B and C with high C-reactive protein (CRP) levels [When malnutrition coexists with inflammation in dialysis patients, the combination of both conditions is known as malnutrition–inflammation complex syndrome . The inf) levels .A major aim of dialysis therapy is to remove uremic waste products ,102. HowThe removal of uremic solutes depends on dialyzer membrane permeability. As mentioned earlier see , uremic urea of 1.2, which designates the dialyzer urea clearance (K), time on dialysis (t), and total body water (V) [Uremic solute clearance depends on dialysis adequacy, which refers to the frequency and duration of dialysis . Expert ater (V) ,102.p > 0.05) [nPCR), a surrogate marker for DPI with greater decline in the low compared to high dialysis dose group (p = 0.007).However, the hemodialysis (HEMO) study in a 3 year follow-up of 1846 dialyzing patients established that neither high (Kt/V = 1.65) nor low (Kt/V = 1.25) dialysis dose significantly affected markers of nutritional status such as serum albumin, post-dialysis weight, dietary energy and protein intakes, calf and upper arm circumference, and appetite status  . The onlurea is based on urea, a surrogate marker for clearance of small solutes. It does not represent removal of the more detrimental larger uremic solutes [Of note, the calculation of Kt/V solutes ,110. Ine solutes ,112.Increasing the thrice-weekly frequency of dialysis sessions to >4 times may support better management of fluid removal  and loweIn some countries, weekly frequency of dialysis may depend on the patient’s access to financial support. For example, dialysis frequency in low-income countries such as India and Pakistan may be offered as two sessions four-hourly per week ,117 comp2-microglobulin compared to patients on standard dialysis, and this occurs without affecting dialysis adequacy [p = 0.049), despite both patient groups having similar pre-dialysis levels [Increasing the dialysis duration results in greater removal of small and large uremic solutes compared to the standard HD regime ,119. Patadequacy . Lower ps levels .Nutritional marker improvements through higher serum albumin and hemoglobin levels and lower white blood cell count appear to be associated with longer dialysis duration, as indicated from combined data of the three DOPPS . These iMetabolic acidosis develops in the early stages of CKD from the kidney’s inability to excrete nonvolatile acids and synthesize bicarbonate to maintain acid–base balance . HD treaMetabolic acidosis contributes to malnutrition by reducing protein synthesis and increasing muscle degradation . The malAdditionally, the acidic environment affects insulin binding to receptors, thus reducing tissue sensitivity to insulin and affecting glucose uptake . Separatp = 0.046) [nPCR  but positively with serum albumin . Acidosis-led catabolism triggers breakdown of the endogenous proteins, which influence higher nPCR levels. In different malnourished HD populations, serum bicarbonate levels of >23 [The impact of metabolic acidosis on nutritional status of HD patients by assessment of serum bicarbonate levels may present anomalies in interpretation. In one study, patients with serum bicarbonate levels ≤22 mmol/L rather than serum bicarbonate levels >22 mmol/L had lower serum albumin levels (= 0.046) . In thess of >23 ,136 or >s of >23 ,136 haves of >23 .Comorbid non-iatrogenic factors may also contribute to malnutrition development in dialysis patients. These non-iatrogenic factors are elaborated on in the sections below.Suboptimal dietary intake is a primary contributing factor to malnutrition  and is aHowever, achieving DEI and DPI adequacies remains a challenge for HD patients with intakes falling below recommendations as indicated by many studies . This isSuboptimal DEI is of greater concern than DPI inadequacy, as gluconeogenesis is implied. Three studies reported HD patients achieving DPI adequacy >1.2g/kg/BW but failing to meet DEI adequacy ,151,155.p = 0.004) and 0.43 g/kg BW/day (p = 0.006), respectively. Importantly, Sualaheen et al. (2020) investigating habitual dietary patterns of Malaysian HD patients showed that the highest vs. lowest tertiles of a balanced and varied dietary pattern were associated with lower DMI  and lower malnutrition risk identified via malnutrition–inflammation score (MIS) assessment  [The background of dietary inadequacy observed in HD patients may be attributed to monotonous dietary patterns ,154,162,= 0.010) .Suboptimal DEI from reduced food intake also affects patient adequacy for other essential nutrients, as the overall diet quality falls. Kim et al. (2015) reported that an insufficient DEI of 21.90 ± 6.70 kcal/kg BW affected adequacy for micronutrients such as vitamin A and C, thiamin, riboflavin, niacin, folate, calcium, phosphorus, and zinc, as well as dietary fiber .nPCR, and DPI. Reported DEI values for both groups were similarly low  highlighting that energy inadequacy evidently prevailed for all patients. This study also reported a 71% increased risk of mortality (odds ratio (OR) = 1.71, 95% CI: 1.01–1.37) in patients with altered taste perception.Low palatability of diets is underscored by taste alterations experienced by HD patients, and this factor reportedly affects 31–44% of HD populations . Lynch eTaste alterations experienced by HD patients may be explained by food aversion learning . Aversiop = 0.049), DPI  but higher MIS scores  indicative of malnutrition [HD patients reporting poor appetite experience significantly higher frequency of hospital admissions, longer duration of hospitalization, poor QoL, and nutritional outcomes such as lower normalized protein nitrogen appearance levels and high inflammatory marker levels than those reporting good appetite ,165. Theutrition . Of concutrition .The mechanism for poor appetite may be explained by changes in appetite hormones in HD patients. Ghrelin, an orexigenic hormone mainly secreted by the stomach, regulates appetite by stimulating spontaneous food intake ,169. GhrLeptin, an adipokine, has an inhibitory effect on appetite in normal metabolism . HoweverStudies reporting the impact of poor appetite on malnutrition as indicated by various nutritional outcomes in HD patients are summarized in Insulin resistance is implicated in the etiology of malnutrition in HD patients. Insulin at physiological levels bears both catabolic and anabolic effects on skeletal muscle. Insulin’s anabolic role is to promote BCAA transport and regulate protein synthesis in the muscle . AnotherInsulin resistance is associated with peripheral resistance of glucose uptake at the skeletal muscle site and manifests as impaired insulin signaling through the phosphorylation of insulin receptor substrate-1, which inhibits tyrosine kinase activity at the insulin receptor ,183. AnoReduced insulin sensitivity affects BCAA transport, blunting the anabolic effect of insulin for decreasing skeletal muscle breakdown . DepletiIt is, thus, clear that, in ESKD patients, apart from chronic suboptimal food intake, gluconeogenesis may also be driven by insulin resistance associated with inflammation, uremia, and metabolic acidosis. Gluconeogenesis is a normal adaptive catabolic process to produce energy. Protein sparing under conditions of energy sufficiency occurs as the primary protein function for tissue synthesis and repair. With dietary energy insufficiency, amino acids and proteins derived from dietary protein or breakdown of skeletal muscle during starvation become new substrates for energy . As HD pPsychosocial factors may negatively impact physical and emotional status, QoL, and nutritional status in HD patients ,191,192,Depression is reported to be prevalent in 6% to 84% of HD patients  and arisnPCR levels with increased inflammation [nPCR, serum albumin, and pre-dialysis blood urea nitrogen levels, along with a significant decrease in depression score compared to healthy controls [Several studies have reported associations between depression and markers of malnutrition such as poor anthropometry measures, as well as low serum albumin, creatinine, hemoglobin, and ammation ,192,193.ammation . These fcontrols . Thus, aESKD patients exist in a complex matrix of relationships with family, friends, healthcare professionals, and financial support . The quaHD patients lacking social support have higher prevalence of diminished appetite, reduced physical functioning, and poor adherence to HD treatment ,200,201.Financial constraints commonly faced by HD patients may be attributed to physical limitations to perform work tasks imposed by treatment and time commitments to dialysis treatment . With unn = 2637) found that peritoneal dialysis patients compared to HD had a higher employment rate  from greater flexibility in treatment schedule and mobility [Employment status in 231 Chinese working-age HD patients was 51% prior to HD initiation, which fell to 11% once they began treatment . These pmobility .p < 0.01) despite perceiving their income to be insufficient to meet their needs [Lack of income is commonly prevalent in approximately 50% of the HD population ,203. Finir needs .p = 0.002) and requiring assistance in meal preparation  [The influence of financial status on dietary intake is unclear but forms a factor contributive to malnutrition ,213. Fre= 0.001) . Both faComorbidities associated with CKD such as sarcopenia, vascular dysfunction, inflammation, and malnutrition  negativer = −0.125, p = 0.002) [Fatigue is central to the reduced physical capacity to perform activities of daily living by HD patients and contributes to malnutrition ,216,217.= 0.002) . Malnour= 0.002) , suggestWe presented a global view that malnutrition susceptibility in the HD community is either or both of iatrogenic and of non-iatrogenic origins. Keeping in view disparities in dialysis provision between upper- and lower–middle-income countries, leveraging the point of origin of malnutrition in dialysis patients by healthcare practitioners would enable personalized patient care, as well as country-specific malnutrition treatment strategies. Nutrition assessment is a critical first step to identify the factors of iatrogenic and/or non-iatrogenic origin implicated in malnutrition etiology. This is important as the next step of prevention or treatment for malnutrition depends on the identified factors and aligning effective strategies for nutritional intervention.The iatrogenic factors that may be implicated in malnutrition may be (i) low dialysis adequacy resulting in poor uremia and metabolic acidosis correction, and/or (ii) low serum albumin levels for patients if dialyzing on highly permeable membranes or dialysis techniques that incur greater amino-acid losses. The non-iatrogenic approach should identify implications of (i) dietary inadequacy as per suboptimal DEIs and DPIs, (ii) poor appetite status, inflammation markers, low diet quality, and high diet monotony index, which indicate barriers to achieving dietary adequacy, and/or (iii) identification of psychosocial and financial barriers to nutritional optimization. These factors are modifiable and should be incorporated as part of a comprehensive nutritional assessment. Identification of factors causing malnutrition that are patient-specific would be crucial for healthcare practitioners to provide a more personalized patient care to treat malnutrition.