Several inflammatory conditions of the bile ducts cause strictures that prevent the drainage of bile into the gastrointestinal tract. Non-pharmacological treatments to re-establish bile flow include plastic or self-expanding metal stents (SEMs) that are inserted in the bile ducts during endoscopic retrograde cholangiopancreatography (ERCP) procedures. The focus of this study was to 3D print an anatomically accurate model of the extrahepatic bile ducts (EHBDs) with tissue-like mechanical properties to improve in vitro testing of stent prototypes. Following generation of an EHBD model via computer aided design (CAD), we tested the ability of Formlabs SLA 3D printers to precisely print the model with polymers selected based on the desired mechanical properties. We found the printers were reliable in printing the dimensionally accurate EHBD model with candidate polymers. Next, we evaluated the mechanical properties of Formlabs Elastic (FE), Flexible (FF), and Durable (FD) resins pre- and post-exposure to water, saline, or bile acid solution at 37 °C for up to one week. FE possessed the most bile duct-like mechanical properties based on its elastic moduli, percent elongations at break, and changes in mass under all liquid exposure conditions. EHBD models printed in FE sustained no functional damage during biliary stent deployment or when tube connectors were inserted, and provided a high level of visualization of deployed stents. These results demonstrate that our 3D printed EHBD model facilitates more realistic pre-clinical in vitro testing of biliary stent prototypes. Bile is produced in the liver and drains through the bile ducts into the small intestine where it aids in digestion A. CholesDue to anatomical constraints, biomedical devices like biliary stents cannot be in vivo tested in small animal research models; these devices must be tested in porcine, ovine, or non-human primate models. Efficient and accurate in vitro testing of these devices during pre-clinical studies, in lieu of large animal testing, reduces the number of research animals that undergo procedures and/or are sacrificed to obtain the pre-clinical data required for submission to the FDA ,5,6. To The EHBDs are comprised of the common bile duct (CBD), cystic duct, common hepatic duct (CHD), left hepatic duct (LHD), and right hepatic duct (RHD). The duct walls, lined with cholangiocytes and formed by a thin layer of smooth muscle and connective tissue, serve as the conduit for bile between the liver and the small intestine. Ex vivo studies on porcine and human CBDs demonstrated the tissues are bi-axially elastic and relatively strong ,12. TherWe generated three CAD models of the EHBD with wall thicknesses of 0.5 mm, 0.75 mm, and 1 mm, based on average anatomical EHBD dimensions ,19,20 insing see . In brieA CAD model of an ASTM D-1708 micro-tensile sample was generated with Autocad Fusion360 software. The micro-tensile sample .STL file was imported into PreForm software and prepped for printing in FE as described above. Printed samples were removed from the print bed prior to washing for 30 min in >95% IPA. Following the IPA wash, the print supports were removed and the samples were UV cured in a Formlabs UV Cure Station according to Formlabs guidelines.m/m in MilliQ water, pH 6.7) for 3 days or 7 days at 37 °C , or bile acid solution (BAS) , HIMEDIA, VWR, Radnor, PA, USA 10% at 37 °C . After l6 emitter and utilizing a secondary electron detection.Samples designated for imaging via scanning electron microscope (SEM) were dried for 3 h at 37 °C followed by sputter coating with a gold/palladium alloy. The resulting samples were imaged using a TESCAN VEGA 3 XMU VP-SEM  with a LaBN ≥ 6 per condition). Data were recorded at a rate of 10 samples per second.Tensile tests to failure on the micro-tensile samples were performed within two hours of conclusion of the liquid exposure on a Mark-10 ESM303 at a stretch speed of 5 mm/s . Stress–strain curves were obtained by plotting the averages for m/m in MilliQ water, pH 6.7) in a 37 °C water bath. Bile acid solution was pumped through the stented Elastic EHBD model at flow rates from 0.5 mL/min to 5.0 mL/min [Plastic biliary stents ranging in length from 40 mm to 120 mm  and SEM biliary stents ranging in length from 40 mm to 60 mm  were deployed in the Elastic EHBD model with standard 8–10F catheters (N ≥ 6 per stent type). Once stents were deployed, the EHBD models were connected via barbed 1/8 inch or ¼ inch PVDF connectors  and size 16 tubing  to a peristaltic pump  in line with a pulse dampener  and a reservoir of bile acid solution (BAS) , HIMEDIA, VWR, 10% 0 mL/min .Our CAD EHBD model had a uniform wall thickness throughout at 0.5 mm, 0.75 mm, or 1.0 mm. Designs were generated with three different wall thicknesses to compensate for the variations in achievable printing resolution across the three resins we tested. Formlabs Durable, Flexible, and Elastic resins were selected for this study. Formlabs material datasheets indicated the maximum print resolution possible was 50 Through a combination of following Formlabs PreForm guidelines for print orientation and trial and error, we determined that the EHBD model must be angled ~45° from the print platform . Angles Prints of the EHBD model at all wall thicknesses (WT) were successful in each resin but printing artifacts and difficulties with post-processing determined the wall thickness version evaluated for each resin. All of the 1 mm-walled EHBD models had no major printing or post-processing issues. We did find that the walls of the LHD and RHD in the printed Elastic EHBD would be thicker than in the CAD model as a consequence of the viscosity of the resin and laser scatter during printing. This caused a narrowing of the duct lumens and decreased flexibility of the ducts, neither of which were desirable.To compensate for the resin viscosity and laser scatter (note: the Form2 and Form3 do heat the resins during printing to mitigate this issue), we printed Elastic EHBD models with 0.5 mm walls. However, minor jostling when these Elastic EHBD models with 0.5 mm walls were transferred from the printer to the wash station caused tears along the CBDs and CHDs. Ultimately, we found that 0.75 mm-walled EHBD CAD models printed in Elastic resin could endure handling during post-processing and had duct WT of 1 mm We found our room temperature (RT), untreated Elastic samples to have a Young’s modulus of 1.71 MPa Liquid-exposed sample weights for water, PBS and BAS increased by 0.63% p < 0.0001). After 7 days of liquid exposure at 37 °C we saw the Young’s Moduli return to values over 1.5 MPa . The EHBD connect the liver to the gall bladder and the small intestine. The branching pattern of the intrahepatic bile ducts is unique to each individual, but the orientation and size of the EHBDs are shared anatomical features across the majority of the population ,23,24. IRegarding the duct lumens and lengths in our EHBD model, an inner diameter of 5.0 mm is slightly larger than the population average for the CBD found by Zuleta et al. but on par for the CHD . The lenOur aim was to identify which Formlabs resin could be used to reliably and accurately print our EHBD model. We intended the model to be anatomically accurate and possess similar mechanical properties to the EHBD in vivo; upon qualitative evaluation of EHBD prints in FE, FD, and FF, we concluded that FD and FF EHBD were unsuitable for our application. The FD EHBDs were dimensionally accurate but lacked flexibility. The FF EHBDs were completely opaque which would hinder accurate stent placement during experiments. We sought confirmation that the FE EHBD had similar mechanical properties to the EHBD in vivo and maintained those properties under the conditions required for in vitro testing of biliary stents, e.g., deployment or patency tests. Studies on the mechanical properties of the bile ducts are scarce . In the ectively ,32. We fs moduli ,32, thisBasic requirements for an in vitro stent testing system include that the system (1) holds a stent at body temperature (37 °C), (2) moves bile acid solution through the stent at low volumetric flow and low pressure, and (3) duct material does not rapidly fatigue under those conditions. In turn, we exposed Elastic polymer samples to no liquid, water, PBS, or BAS at 37 °C for three or seven days. After three days, we saw an initial decrease in Young’s modulus for FE and we speculate that this increase in elasticity, bringing the values even closer to those measured in ex vivo bile duct and small intestine specimens, can be attributed to the FE absorbing liquid. After seven days, all of the liquid-exposed samples showed decreases in elasticity. The ongoing exposure to 37 °C likely caused the decrease in elasticity; Formlabs Elastic resin datasheet notes that prolonged exposure to UV and/or high temperatures can affect the mechanical characteristics of prints made with Elastic resin. Fortunately, the change in Young’s moduli and percent elongation, though statistically significant, were not large. In addition, we do not anticipate a small decrease in tensile strength to adversely impact our intended application, so we maintain that the EHBD printed in Formlabs’ Elastic resin is highly suitable for use in an in vitro biliary stent testing system.Previous in vitro biliary stent testing systems, while meeting the basic requirements described above for an in vitro stent testing system, have lacked the combination of features found in our FE EHBD model. Bang et al.  and KwonAn ideal in vitro biliary stent testing system would be a bioreactor that provides an environment that is both anatomically accurate and physiologically accurate. Tissue engineered EHBD could potentially meet those requirements; however, fabrication of tissue engineered BD, thus far, is time and consumable intensive. Many tissue engineering protocols rely on multi-day culture timelines and numerous reagents to evaluate products ,35,36,37Our results demonstrate that our FE EHBD model is anatomically accurate with similar mechanical properties to biliary and intestinal tissues. We also show, from a manufacturing perspective, that we are able to reliably, and precisely fabricate our EHBD model with commercially available equipment and materials. These features make our EHBD model a cost-effective means to generate data on stent mechanics and/or stent patency with an in vitro biliary stent testing system. In the future, we plan to address ways in which we can improve the anatomical and physiological accuracy of our Formlabs Elastic EHBD model. Formlabs does not indicate biocompatibility of FE but it does report that FE is autoclavable with minimal impact to mechanical properties . This wi


Acidovorax, an iron oxidizing microorganisms, in native rock samples of the Iberian Pyrite Belt subsurface. Our results suggest a strong correlation between the presence of Acidovorax genus and pyrite, suggesting that the mineral might greatly influence its subsurface distribution.Despite being considered an extreme environment, several studies have shown that life in the deep subsurface is abundant and diverse. Microorganisms inhabiting these systems live within the rock pores and, therefore, the geochemical and geohydrological characteristics of this matrix may influence the distribution of underground biodiversity. In this study, correlative fluorescence and Raman microscopy (Raman-FISH) was used to analyze the mineralogy associated with the presence of members of the genus  Interest in deep continental subsurface geomicrobiology has grown in the last decades and led to an increase in the amount of information on these environments. Today, we know that life in deep continental subterranean environments is widespread, diverse and active . HoweverOne of the great unknowns that needs to be studied in depth is how mineralogy affects the distribution of the microbial populations, and conversely, how a specific microbial population affects the mineralogy of the system. Some investigations have shown that deep subsurface biodiversity depends directly on the mineralogical composition of the subsurface . MineralIberian Pyrite Belt Subsurface Life Detection (IPBSL) is a drilling project designed to characterize the Iberian Pyrite Belt (IPB) subsurface biosphere , whose aAcidovorax , a circumneutral nitrate-dependent Fe2+ oxidizing bacteria  techniques allow the visualization and identification of microorganisms in their natural environment  decontaminated with Virkon S , ethanol and a 50:50 bleach:water solution before the introduction of each core. Then, central and untouched portions of the core were obtained using hydraulic core splitter and a rotary hammer with sterile bits, controlling the temperature (40°C maximum) with an infrared thermometer. Potential contamination of cores was monitored routinely by Ion Chromatography, used to detect sodium bromide, which was added to the drilling fluid as a contamination tracer. Additional controls carried out by DNA massive sequencing showed that no microbial contamination was introduced during sampling.Drilling of borehole 10 (BH10) and sampling was previously described in detail by 4)2SO4 132 mg/l, KH2PO4 27 mg/l, MgCl2∗6H2O 53 mg/l, CaCl2∗2H2O 147 mg/l, pH 1.8] for 2 h at 4°C. After fixation, rock samples were washed with Mackintosh minimal media to remove the fixation agent, PBS  to neutralize the pH and, finally, stored in ethanol:PBS (1:1) at −20°C until further processing.Rock samples for FISH analyses, consisting of small fragments and rock powder, were obtained from the central portion of the core with a sterile chisel. Rock samples were fixed in the field laboratory with 4% formaldehyde in Mackintosh minimal media [ to detach microorganisms from rock and 100 μl of supernatant was filtered in 0.22 μm black membranes  in aseptic conditions. Filters were washed with PBS and absolute ethanol and then air dried. Catalyzed Reported Deposition-FISH (CARD-FISH) experiments and their respective controls were performed in membrane filters as previously described in 3+ was stained with 2 μM Ferrum 430TM  diluted in ethanol/H2O 90/10 (%Vol/Vol) for 10 min. Samples were washed with ethanol/H2O 90/10 (%Vol/Vol) and let air dry in darkness.Biofilm detection was performed directly on fixed rock samples. Rocks were ground gently in a sterile mortar and pestle under sterile conditions to the size of grains of sand. Double labeling of oligonucleotide probes-FISH (DOPE-FISH) was carried out as described previously in Filters and powdered rock samples were counterstained with Syto9  as manufacturer recommended and covered with a mix of 1:4 Vectashield : Citifluor . Filters were mounted onto glass slides and rock samples were mounted onto μ-slides 8-well glass bottom .Samples were imaged with a confocal laser scanning microscope LSM710 coupled with an inverted microscope AxioObserver  and equipped with diode (405 nm), argon (458/488/514 nm) and helium and neon (543 and 633 nm) lasers. Images were collected with 63×/1.4 oil immersion lens. Fiji software was used to project the stacks to 2D images .CARD-FISH was performed in powdered rocks as described above for biofilm detection. However, samples were not immobilized in agarose or covered with antifade mounting medium to avoid any interference of either agarose and Vectashield:Citifluor mixture with Raman spectroscopy. Samples were mounted onto a glass Micro-Slide Field Finder, on which a rectangular-coordinate grid pattern was drawn .Rock samples were imaged using a confocal laser scanning microscope LSM710 as described above but coupled with a vertical microscope AxioObserver . Images were collected with a 50×/1.4 air lens.2). A total of 23 Raman mappings were carried out in the different samples examined. Collected spectra were analyzed by using Witec Control Plus software . Comparison of Raman band intensities and Raman shifts between different Raman spectra were analyzed using Lorentzian peak curves to fit the Raman bands and the results represented by derived Raman image. In each Raman mapping, spectra were divided in two groups: Acidovorax+, which includes those spectra that present Acidovorax signal; and Acidovorax-, which includes those spectra that do not present Acidovorax signal. From each group, the average of the Ag/Eg values of the pyrite Raman bands as well as the average of the Ag and Eg Raman peaks shift values were calculated. As a result, paired data from each Raman mapping were obtained and represented in box plots. Additionally, Pearson’s correlation coefficient (PCC) was calculated from Raman images by using the ImageJ software plugins JACoP    and EzCo Plugin) . ImageJ Acidovorax genus is present throughout the first 300 meters below surface (mbl) of the IPB column  and spectrum 2 to polysaccharides. All the spectra could be classified into three representative groups, named spectra 1, 2, and 3 . Both sp–1 . Howeverectively ; and DNAer bonds . On the hydrates . Thus, w–1 and a less intense band at 435 cm–1, which are characteristic of the Raman-active modes of pyrite .As shown in Acidovorax and this displacement  was carried out to determine if charides , which echarides , 6D. Thiric iron .Acidovorax genus in the IPB subsurface, a geological formation considered one of the largest massive sulfide deposits in the world , a drilling project devoted to the study of the underground bioreactor responsible for the peculiarities of Río Tinto , downshifting of the pyrite bands up to 12.7 cm–1 due to the laser heating has been reported  they varied from 0.81 to 2.01 due to the differential excitation of the bands of the diverse analyzed pyrite faces. In fact, the mean value of the intensity ratio Eg/Ag band varies from 0.9 to 3.5 in studies in which pyrite of varied sizes and morphologies were analyzed using a range of laser powers , 6B,E contensity . HoweverAcidovorax and pyrite, which may be explained by the microorganism’s metabolic preference for pyrite. In addition, heterogeneity in uncolonized vs. Acidovorax-associated pyrite Raman spectra was observed. One possible explanation for this observation is the modification of the pyrite by Acidovorax. However, the lack of information about a possible biological alteration in pyrite Raman spectrum at the micrometer scale makes the interpretation of these results difficult. Thus additional experiments are needed to analyze any advantages to Acidovorax growing in the presence of pyrite or dissolution of the mineral carried out by the microorganism with the possible fingerprints resulting from their interaction. Nevertheless, correlative fluorescence and confocal Raman microscopy has been shown to be a useful method with which to analyze, in situ, the mineral dependent distribution of the subsurface biodiversity.Since rocks are the matrix in which microorganisms live in subsurface, it is feasible to assume that their composition might influence the microbial distribution in this environment. Our Raman-FISH results suggest a strong relationship between the distribution of The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.in situ hybridizations and fluorescence microscopy observations. AC performed confocal Raman microscopy analyses. CE, AC, CS, JA, and RA interpreted the Raman part of the study. RA, AC, CS, JA, JM, and FG corrected the manuscript. All authors contributed to the article and approved the submitted version.CE wrote the manuscript. CE and RA designed the study and interpreted the results. CE and JM carried out the fluorescence 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.


Acremonium fungal biofilm during the COVID-19 pandemic era with an impressive result in PD patient presenting with fungal peritonitis and ultrafiltration failure. The organism species was disclosed from PD effluent and catheter cultures. Adjuvant treatment with in-situ lyticase may be considered for catheter salvage therapy if the catheter could not promptly removed in time.We reported the first clinical use of lyticase enzyme in salvaging the peritoneal dialysis (PD) catheter obstruction from  Intracatheter obstruction with the fungal biofilm was first described in 1985 [outcomes . The Int68–100%) . In some68–100%) ; however68–100%) . We firs23 with 73% neutrophil and fungal hyphae in a KOH preparation  and 99.64%  similarities. His initial laboratory investigations revealed hemoglobin of 10.8 gm/dL, a leukocyte count of 14,000 cells/mm3, 91% neutrophil, and a platelet count of 146,000/mm3. Blood chemistries demonstrated mild hyponatremia of 129 mmol/L while the others were within normal limits. The follow-up analysis of PDE is depicted in A 46 years old psychotic Thai male with anuric end-stage kidney disease from unknown etiologies, possibly nephrotoxicity and diabetic nephropathy, treated with nighttime intermittent peritoneal dialysis (NIPD) for 5 years, was admitted to the King Chulalongkorn Memorial Hospital (day 0) due to failure in filling and draining PD solution for 2 days. He also complained of generalized abdominal pain, afebrile, and poor appetite. Due to his complaint of mechanical failure in both filling in and draining out the PD solution, the PD catheter was irrigated by the dialysis nurse but failed to unclog the catheter. However, a small amount of the retained fluid in the catheter was obtained. The retained fluid analysis revealed a leukocyte count of 1445 cells/mmparation B. The inAfter discussing the treatment plan with the patient and family, they insisted on staying on PD therapy and refused modality switching to hemodialysis because of a city lockdown and a night curfew. Intraluminal lyticase enzyme at a dosage of 70 mg in a total of 6 mL was overnight locked, and intravenous amphotericin B desoxycholate at a dosage of 40 mg once daily was prescribed for 14 days and subsequently switched to oral voriconazole at a 200 mg dosage twice daily for 7 days. On the following day (day 1), the catheter was successfully unclogged promptly after draining the retained medications. The PD catheter inflow and outflow were completely restored. The drained PDE was plated onto the Sabouraud dextrose agar for fungal culture and smeared on the KOH mounted slide. Fungal colonies that grew on the plate from specimen day 1 were lower than specimen day 0 before the retention therapy. In addition, the mold hyphae demonstrated from the drained PDE on day 1 was disintegrated with broken branches. The PDE cell counts were gradually reduced with negative PDE culture since day 7, and the patient's abdominal symptom was recovered. Using broth dilution antifungal susceptibility testing , the pathogen was susceptible to amphotericin B with minimal inhibitory concentration (MIC) of < 1 μg/mL and resist to itraconazole, fluconazole, and voriconazole with MICs > 16 μg/mL, > 16 μg/mL, and 16 μg/mL, respectively.3Bipolaris hawaiiensis. The patient was successfully treated with the catheter removal and 2-week oral itraconazole at a 200 mg dosage daily [Acremonium obclavatum in the same patient and the first clinical use of lyticase enzyme to salvage the PD catheter from fungal biofilm. Acremonium is classified as hyaline mold, belonging to the phylum Ascomycota, and is saprophytic, generally found in plant material and soil, and considered non–pathogenic in healthy person [The spectrum of fungal species causing fungal peritonitis keeps expanding nowadays; more than 100 fungal species are published in PubMed literature . Howevery person .There is no specific recommendation for treating PD catheter obstruction from fungal biofilm, probably due to a rare incidence. PD catheter obstruction from other causes, including fibrin and blood clots, generally are initially treated by the push-pull maneuver with a syringe. If it is unsuccessful, the catheter may be salvageable by fibrinolytic agent (Urokinase or rTPA) or invasive procedures, including intracatheter brushing, guidewire manipulation, or catheter repositioning surgery . The strCandida and many filamentous fungi, including Aspergillus, Cladosporium, and Acremonium, have been shown to grow and form biofilm [In the present case, the PD catheter patency was effectively restored and maintained by using lyticase retention therapy and daily intravenous amphotericin B. Lyticase is a combination of endoglucanase and alkaline protease with the capability in degrading fungal cell wall at β (1 → 3) and β (1 → 4) bonds between the glucose units . Additio biofilm ,15.Arthrobacter luteus, Gram-positive bacteria containing peptidoglycans, anaphylaxis and toxemia might be speculated if the enzyme is spilled out from the catheter via the peritoneal cavity to the systemic circulation. However, with meticulous securing the catheter with retention therapy, the potential spilled-out would be avoidable.Lyticase proves in novelty in our presented case by an immediate restoration of the PD catheter obstruction. Not only is the catheter unclogged promptly after draining the retention therapy, but the intraluminal colonization of fungal has also disappeared. The microscopic examination of the drained solution revealed largely defected fungal hyphae and mycelium. Besides, the colony count of the fungi at 24-h incubation period revealed a substantial reduction in number compared to the colony count from the untreated PDE. Since the enzyme is the by-products of In conclusion, the first clinical use of lyticase enzyme in salvaging the PD catheter from fungal biofilm obstruction is reported here. However, the mainstay therapy for fungal peritonitis with or without PD catheter obstruction from the fungal biofilm is still immediate PD catheter removal in conjunction with an antifungal agent. Adjuvant treatment with intra-catheter lyticase may be considered for catheter salvage therapy if the catheter could not be promptly removed in time.The authors declare no conflicts of interest. The authors alone are responsible for the content of the study.


Early diagnosis of liver metastasis is of great importance for enhancing the survival of colorectal adenocarcinoma (CAD) patients, and the combined use of a single biomarker in a classier model has shown great improvement in predicting the metastasis of several types of cancers. However, it is little reported for CAD. This study therefore aimed to screen an optimal classier model of CAD with liver metastasis and explore the metastatic mechanisms of genes when applying this classier model.GSE131418. The classification performances of six selected algorithms, namely, LR, RF, SVM, GBDT, NN, and CatBoost, for classification of CAD with liver metastasis samples were compared using the MCC dataset GSE131418 by detecting their classification test accuracy. In addition, the consortium datasets of GSE131418 and GSE81558 were used as internal and external validation sets to screen the optimal method. Subsequently, functional analyses and a drug‐targeted network construction of the feature genes when applying the optimal method were conducted.The differentially expressed genes between primary CAD samples and CAD with metastasis samples were screened from the Moffitt Cancer Center (MCC) dataset The optimal CatBoost model with the highest accuracy of 99%, and an area under the curve of 1, was screened, which consisted of 33 feature genes. A functional analysis showed that the feature genes were closely associated with a “steroid metabolic process” and “lipoprotein particle receptor binding” (eg APOB and APOC3). In addition, the feature genes were significantly enriched in the “complement and coagulation cascade” pathways . In a drug‐target interaction network, F2 and F9 were predicted as targets of menadione.The CatBoost model constructed using 33 feature genes showed the optimal classification performance for identifying CAD with liver metastasis. APOB, APOC3, FGA, F2, F9, and NKX2‐3 were potential biomarkers for classification of CAD with liver metastasis. Menadione might be a promising anti‐metastatic drug of CAD cells through functioning its role at sites of F2 and F9. CatBoost model constructed by 33 feature genes showed the optimal classification performance for identifying CAD liver metastasis. A new method for analyzing the transcriptomic differences between primary CAD and a distant metastasis was developed, and FBN2 and MMP3 were identified as CAD metastasis related genes, which may help predict a high‐level risk of CAD metastasis.et al have found that the random forest (RF) has the highest specificity, the Naive Bayes (NB) has highest sensitivity while the traditional machine learning approaches [logistic regression (LR) and linear discriminant analysis] had the highest total accuracy for metastasis prediction in breast cancer.Machine learning a computer‐based algorithm, has shown high degrees of accuracy and prediction that exceeds the abilities of standard statistical methods to make predictions about outcomes in patients.Although machine learning techniques comparisons are widely studied in cancer metastasis such as breast cancer and nonsmall cell lung cancer,22.1GSE131418 and GSE81558, downloaded from Gene Expression Omnibus (GEO) were used in this study. The Moffitt Cancer Center (MCC) dataset GSE131418 was used as the training set, whereas the consortium datasets GSE131418 and GSE81558 were used as internal and external validation sets for the liver metastasis models respectively. GSE131418 includes 333 CAD and 184 liver metastasis samples from the MCC cohort dataset, and 545 primary CAD and 73 liver metastasis samples from a consortium cohort dataset. The transcriptomic data of GSE131418 were generated from the GPL15048 Rosetta/Merck Human RSTA Custom Affymetrix 2.0 microarray platform [HuRSTA_2a520709.CDF]. In addition, a total of 23 primary CAD and 19 liver metastasis samples were analyzed from GSE81558. The sequencing platform of GSE81558 was the GPL15207 [PrimeView] Affymetrix Human Gene Expression Array.Two datasets, 2.2GSE81558, the expression data of the downloaded Series Matrix File(s) were standardized using the robust multiarray average (RMA) algorithm. Subsequently, a principal component analysis (PCA) was conducted to observe the sample grouping by the FactoMineR package in R.Before data preprocessing, GSE131418_RAW.tar was downloaded from GEO using the GEOquery package.2.3P‐value < 0.05 and |log2 fold change (FC)|> 2. In addition, the ggscatter function of the ggpubr package in R was used to draw a volcano plot of the DEGs, and the gene symbols of the top‐30 DEGs ranked by |log2 FC| were presented. The pheatmap package in R was applied to conduct the hierarchical clustering.A modified t‐test applying an empirical Bayesian method was applied to conduct mRNA transcriptomic differences between the primary CAD and CAD with liver metastasis groups. The DEGs were then identified under 2.4The count data of the DEGs were transformed into log2(x + 1) formatted data, and a binary label value of “1” was used for classifying the liver metastasis samples, and a value of “0” was used for classifying the nonmetastasis samples. For each group, 80% of the samples were divided into a training set using the train_test_split machine learning method in Python (version 0.21.2),Before the model construction, the recursive feature elimination (RFE) algorithm based on the sklearn.feature_selection method was applied to the feature selection. Machine learning models, ie LR, based on the sklearn.linear_model; RF and GBDT, based on sklearn.ensemble; an SVM, based on sklearn.svm; and NN, based on sklearn.neural_network, were constructed Data . Another2.5GSE131418 and GSE81558 were used as the internal and external validation sets for the predicted models above respectively. First, the feature DEGs were input into the six well‐trained or constructed liver metastasis models described above. The expression values of the feature DEGs in the samples were utilized as an eigenvalue to classify and identify CAD samples with or without liver metastasis. The risk of liver metastasis in the samples of the validation sets was predicted by assessing the accuracy and AUC values, which were used to evaluate the prediction and classification capability of the six models.The consortium datasets Following the construction and data validation of the six models, the model with the highest AUC value in both the training and validation sets was screened as the optimal model. The feature genes in the optimal model were chosen for the following analysis.2.6P value < 0.05 and count ≥ 2.Kyoto Encyclopedia of Genes and Genomes (KEGG) is a database offering a biological interpretation of the genome function through KEGG pathway mapping, and links genomic information to more ordered information of biological functions.2.7http://www.string‐db.org/) was used to predict interactions of the feature genes with a PPI score of 0.4 (medium confidence), disable structural previews inside network bubbles, and hide disconnected nodes in the network. The pairs obtained were then visualized in a PPI network using Cytoscape software.The Search Tool for the Retrieval of Interacting Genes (STRING) database provides available sources on protein‐protein associations for 5,090 organisms.2.8www.dgidb.org) was used to predict the small drug molecules that interact with the feature genes. The drug‐target interactions reported in previous papers and by the FDA were then obtained. Finally, the drug‐target interaction network was constructed using Cytoscape.The drug‐gene interaction database is an open resource used to excavate information of a drug‐gene interaction and druggable genome.33.1GSE131418 and GSE81558 are shown in Table GSE131418 and GSE81558 respectively. After annotation, a total of 47 408 probes involved in 24 495 genes were obtained from the GSE131418 dataset, and a set of 46 879 probes related to 18 835 genes were obtained from the GSE81558 dataset.Information regarding the total number of samples, the probes, the annotated probes, and the gene symbols of GSE81558 , CC of “blood microparticle” (GO:0 072 562), and MF of “steroid binding”   to create classifiers for CAD classification with liver metastasis samples. The optimal model with the highest accuracy (99%) and AUC (1) based on the CatBoost algorithm was screened, and consists of 33 feature genes. A functional analysis showed that the feature genes were closely associated with a lipid metabolic process such as the “steroid metabolic process” (eg APOB and APOC3) and “lipoprotein particle receptor binding” (eg APOB and APOC3). In addition, the feature genes were significantly enriched in the “complement and coagulation cascade” pathway , revealing the potential biomarkers and pathogenesis of CAD with liver metastasis.According to the comparisons among six classification algorithms, the optimal model CatBoost was achieved for identifying CAD liver metastases with higher classification performance in training set and best reproducibility in validation set. Although NN classier showed a higher or equal classification performance in training, internal and external validation sets than CatBoost classier, the feature genes in this classier were consisted by all the DEGs (131), while there were 33 feature genes in CatBoost classier, which meant that the classification ability of 33 feature genes in CatBoost was almost equal to 131 feature genes in NN. The number of feature gene is also a critical parameter to evaluate the performance of classier, and a method with minimum number of feature genes for a classification problem with an objective function to maximize the classification accuracy is always needed.Except for the number of feature gene, the parameters of accuracy and AUC were also used to measure the performance of classier in this study. Accuracy may be interpreted as the proportion of instances the classifier always classify correctly for an given dataset or other data.CatBoost is a new developed algorithm based on GBDT algorithm that can successfully handle categorical features with advantage of reducing overfitting on available datasets, and outperforms traditional GBDT algorithm to overcome the gradient bias with ordered boosting.In addition, the underlying biological meaning of 33 feature genes in CatBoost classier was analyzed. In our study, we predicted that APOB and APOC3 were both upregulated in CAD liver metastasis samples, and associated with “steroid metabolic process” and “lipoprotein particle receptor binding”. Serum lipids are risk factors of numerous types of cancers, and has crucial roles in cancer metabolism.Coagulation factor II  or prothrombin has a pivotal role in maintaining the vascular integrity by regulating the thrombin using prothrombinase.NK2 Homeobox 3 (NKX2‐3) encodes a homeodomain‐containing transcription factor and as a member of the Nkx family is applied to determine the tissue differentiation.Although several feature genes for predicting CAD with liver metastasis were screened in this study, and a functional analysis and drug prediction of these genes were conducted, the experimental verifications of these findings remain lacking. Thus, future research is required.In conclusion, the CatBoost model showed the optimal classification performance in identifying CAD with liver metastasis. The feature genes in the CatBoost model, such as APOB, APOC3, FGA, F2, F9, and NKX2‐3 were demonstrated to be potential biomarkers for the classification and prediction of CAD with liver metastasis samples.5The authors declare that no conflicts of interest exist.All authors participated in the conception and design of the study; Conceived the manuscript: Han Shuwen and Yang Xi; Wrote the paper: Han Shuwen, Yang Xi, and Zhuang Jing; Processed the data: Wu Wei and Liu Jin; Drew figures: Zhuang Jing; All authors read and approved the paper.6Not Applicable.7Not applicable.8The datasets generated during the current study are not publicly available but obtained from corresponding authors on reasonable request.Figure S1.Click here for additional data file.Figure S2.Click here for additional data file.Figure S3.Click here for additional data file.Figure S4.Click here for additional data file.Data S1.Click here for additional data file.


Each of these surfaces was also functionalized with tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS). Surfaces were characterized by their ability to support platelet adhesion, topology by atomic force microscopy, contact angle, and peptides absorption. PDMS readily absorbs collagen peptides, depleting them from solution, thus reducing their adsorption to glass and silicon substrates when used for micropatterning. Treatment of PDMS with FOTS, but not bovine serum albumin or poloxamer 407, inhibits collagen peptide absorption and supports adsorption and platelet adhesion at venous and arterial shear rates. Similarly, FOTS treatment of glass or silicon supports collagen peptide adsorption even in the presence of untreated PDMS. In conclusion, PDMS acts as an absorptive sink for collagen peptides, rendering a non-adhesive surface for platelet adhesion and competing for peptides when used for micropatterning. The absorption of collagen peptides can be overcome by functionalization of PDMS with a fluorinated alkyl silane, thus allowing its use as a material for micropatterning or as a surface for platelet adhesion flow assays.Collagen peptides are an alternative to animal derived collagens for platelet function studies under flow. The purpose of this study was to examine the use of collagen peptides in polydimethylsiloxane (PDMS) devices. Three collagen peptides with amino acid sequences and structures that capture von Willebrand factor and bind it with the platelet receptors integrin α Platelet adhesion and aggregation are shear stress dependent phenomena. A repertoire of different receptors promote rolling and adhesion to extracellular matrix proteins within the vascular wall and support homotypic and heterotypic cohesion between platelets and other blood cells . A usefu−1) by supporting rolling mediated by the glycoprotein Ib-V-IX complex , 5(6)-carboxyfluorescein (FAM) labeled CRP-XL, GFOGER [GPC(GPP)5GFOGER(GPP)5GPC-amide], and VWF-III [GPCGPP)5GPRGQOGVMGFO(GPP)5GPC-amide] were obtained from Cambcol Laboratories . Glass slides (2” x 3“) were obtained from Fisher Scientific . Pierce Quantitative Fluorometric Peptide Assay (23290) and Texas Red dye (T20175) were from Thermo Fischer . Phosphate-buffered saline (PBS) was prepared to 137 mM NaCl, 2.7 mM KCl, 10 mM Na2HPO4, 1.8 mM KH2PO4, and pH 7.4.Bovine serum albumin (BSA) (A9418), 3,3’-dihexyloxacarbocyanine iodide (DiOC6) (D273), glutaraldehyde (340855) heparin salt (H3393), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) (H3375), poloxamer 407  were from Sigma–Aldrich . 3.2% sodium citrate vacutainers (369714) and 21-gauge VacutainerBlood was collected from healthy donors by venipuncture into 4.5 mL, 3.2% sodium citrate  vacutainers using a 21-gauge needle. The first vacutainer was discarded. DiOC6 was added to the citrated whole blood to a final concentration of 1 μM and incubated at 37°C for 10 min prior to running flow assays. The study and consent process received institutional review board approval from the Colorado Multiple Institutional Review Board in accordance with the Declaration of Helsinki.Glass slides were immersed in a 50:50 solution of 12 M HCl:methanol for 4 h at room temperature. They were then rinsed with deionized (DI) water, rinsed with isopropyl alcohol, dried with an air brush, and dehydrated in an oven at 60 °C for 4 h. A thin film of PDMS was achieved by pouring a degassed mixture of PDMS base and crosslinker (mixed in 10:1 ratio) into a petri dish. A glass slide was firmly pressed into the petri dish containing PDMS and placed in an oven to cure for 24 h. The slide was removed from the dish and excess PDMS was removed, leaving a thin film of PDMS on one side of the slide. For FOTS functionalization, the PDMS-coated slide was treated with an oxygen plasma for 30 seconds prior to FOTS deposition . FOTS was vapor deposited onto glass slides, silicon wafers, or slides with PDMS films in a desiccator under vacuum for 12 h.A PDMS microfluidic channel (length (l) = 49 mm, width (w) = 100 µm, height (h) = 50 µm) was either left untreated or was blocked with 2% BSA in PBS or 2% Pluronics F-127 for 45 min and then thoroughly rinsed with deionized water, as indicated in the text. To pattern peptides in a strip, the untreated or blocked channel was laid horizontally across glass, PDMS, FOTS-glass, or FOTS-PDMS surfaces. Collagen peptides were mixed together in 10 mM acetic acid to a final concentration of 250 μg/mL each. The microfluidic channel was filled with the peptide solution and incubated for 2 h at room temperature in a petri dish with wet Kim-Wipes® to maintain a humid environment. The channel was then rinsed with 10 mM acetic acid containing 0.1% w/v Texas Red. The Texas Red was used to locate the micropatterned strip of peptides before running the microfluidic assay. The microfluidic device was then gently removed, and the residual liquid was allowed to air dry.To pattern peptides in the absence of a PDMS channel, a 0.5 µL drop of peptides was pipetted in 10 mM acetic acid (250 µg/mL of each peptide) on each of the four surfaces described above and incubated for 2 h at room temperature in a petri dish with wet Kim-Wipes® to maintain a humid environment. The surface was then rinsed with 10 mM acetic acid and dried. −1 and 1500 s−1 on the bottom wall of the channel for 5 min using a syringe pump . Brightfield and epifluorescent images of platelet accumulation were recorded . PBS with 10 U/mL heparin was perfused for 2 min to rinse the channels. Platelet aggregates were then fixed by perfusing 2% glutaraldehyde in PBS through the channels for 5 min. The channels were rinsed once more with PBS followed by brightfield and epifluorescent imaging of the final platelet aggregates.A 32 channel  microfluidic device  was laidCustom Python scripts were used to calculate the mean fluorescence intensity (MFI) of each image. Background MFI was defined as the MFI of the first image of the assay where blood had just begun to perfuse through the microfluidic channel, but before significant platelet adhesion. This value was subtracted from each image to correct for background fluorescence. Maximum fluorescence of the assay was used to quantify overall platelet buildup for a given assay.The morphology of collagen peptides on silicon and PDMS with or without FOTS treatment was measured, as described above, using atomic force microscopy (AFM) . Collagen peptide solutions were incubated on the surfaces using the microspot patterning, as described above, or in 4 mm diameter PDMS wells. A solution containing 250 µg/mL of each peptide  in 10 mM acetic was incubated in these wells for 2 h at room temperature in a humid environment. The wells were rinsed in triplicate using DI water, the PDMS device was removed, and the substrate was dried using an air brush. AFM images of the spots were taken using alternating current (AC) Tapping mode in air. The root mean square roughness (RMS) was calculated for each surface using Gwyddion .The contact angle of water on different substrates was measured using an in-house interfacial tensiometer constructed by Aman et al. . BrieflyA PDMS microfluidic device  was laid on top of a PDMS-coated glass slide and filled with a solution of CRP, GFOGER, and VWF-III at a concentration of 250 µg/mL. Peptides were either patterned together  on PDMS or FOTS-functionalized PDMS, or they were patterned separately  on PDMS. The solution was incubated in the device for 2 h, after which it was recovered from the microfluidic chamber. The concentration of peptides was measured before and after incubation using a peptide-specific fluorometric assay .A PDMS microfluidic device  was laid on top of a glass coverslip. The device and coverslip were either both clean, untreated surfaces or were both treated with FOTS. The microfluidic channel was filled with FAM-labeled CRP-XL at a concentration of 750 µg/mL in 10 mM acetic acid. After 2 h, the channel was rinsed with ten channel volumes of 10 mM acetic acid, removed from the coverslip it was patterned on, and was then moved to a clean coverslip for imaging. Images of the front of the peptides along the wall of the microfluidic channel were taken at z-sections of the channel . Maximum intensity projections, line profiles of fluorescence intensity moving into the PDMS bulk, and mean fluorescence values of the projections were all computed using Fiji image processing software . Mean fl−1 and 1500 s−1 was observed  patterned with an untreated PDMS microfluidic channel or microspotted directly on a surface (no PDMS). When patterning collagen peptides on glass or PDMS using a PDMS microfluidic channel, little to no platelet accumulation at wall shear rates of 300 sobserved . Similarobserved  was obseBecause of the differences we observed in platelet accumulation on the different surfaces, we hypothesized that hydrophobic interactions were driving the differences in peptide adsorption on the surfaces. We measured the contact angle of glass, silicon, and PDMS on the clean surface or when functionalized with FOTS. Glass and silicon displayed low contact angles of 22°–23°, while PDMS or all of the FOTS-functionalized surfaces showed contact angles of greater than 100°. We found no significant difference between the contact angle of PDMS and any of the FOTS surfaces . These oAFM was used to measure topology of collagen peptides on four surfaces following microspot patterning; silicon, FOTS-silicon, PDMS, and FOTS-PDMS . SiliconTo recreate conditions where a PDMS microfluidic channel was used to pattern peptides for the flow assays, a PDMS well was used to pattern peptides on silicon and silicon-FOTS . On untrOne possible explanation for the platelet adhesion and AFM data is that PDMS is depleting collagen peptides by absorption. To test this hypothesis, we measured the change in the bulk concentration of three of the collagen peptides after incubation in a microfluidic channel with four PDMS walls for 2 h. We observed a 32% reduction in peptide concentration A. RepeatTo visualize the degree of absorption of collagen peptides into PDMS, we incubated a microfluidic channel with a solution of FAM-labeled CRP (CRP-FAM) for 2 h. Penetration of the peptides into the PDMS was observed for untreated PDMS, while no penetration was observed for a FOTS-treated channel A. The CRIn this study, we found that previously developed collagen peptides that support VWF capture and platelet adhesion and aggregation do not adsorb to PDMS in a manner that supports platelet adhesion under flow. Rather, our data suggest that PDMS absorbs collagen peptides. Blocking the microfluidic patterning device with Pluronics F-127 or BSA did not show an increase in platelet adhesion in our flow assays, indicating that blocking the surface with common surfactants used in microfluidics does not effectively disrupt the absorption. However, the absorption of collagen peptides to a PDMS patterning device can be blocked by functionalizing with FOTS. Alternatively, FOTS functionalization of the assay surface (glass or PDMS) provides adsorption that is faster than absorption by the PDMS patterning device. This finding has ramifications, both for using PDMS for micropatterning collagen peptides and for using it as a material for microfluidic flow assays.The absorption of collagen peptides by PDMS is supported by several lines of evidence. First, platelets do not adhere to PDMS surfaces incubated at a concentration of collagen peptides that support adhesion to glass. Second, there was no observable adsorption of peptides on PDMS at the resolution provided by AFM. Third, incubation of collagen peptide solutions in a monolithic PDMS channel results in significant depletion. Finally, significant penetration of a fluorescently labeled collage peptide was observed in untreated PDMS.Untreated PDMS absorbs small, hydrophobic molecules, such as some fluorophores and sex hormones ,29. MoleThe absorption of collagen peptides in PDMS was blocked when the PDMS was functionalized with a fluorinated alkyl silane. This conclusion is based on observations that incubation of collagen peptides on FOTS-PDMS supported platelet adhesion under flow, showed significant topological changes suggesting adsorption, demonstrated negligible depletion of collagen peptide solutions, and showed negligible absorption into the channel wall as visualized with a fluorescently labeled peptide. Whether FOTS blocks absorption by steric hindrance, by promoting hydrophobic interactions, or by some other mechanism requires further investigation. Nevertheless, in practice this simple modification allows PDMS to be used for either micropatterning collagen peptides to glass slides or as a substrate for adsorption itself.The rate of adsorption of collagen peptides appears to be different for hydrophilic and hydrophobic surfaces. This inference is based on differences observed between untreated and FOTS-functionalized glass and silicon. These findings are supported by molecular dynamics simulations showing that adsorption of a collagen triple helix was more favorable for a hydrophobic surface compared to a hydrophilic surface due to stabilization of the triple helix structure . For untMicrofluidic flow assays are an important tool for studying platelet function. Incorporating repeatable, homogeneous substrates is a desired feature if these assays are to move from research tools to clinical assays. Collagen peptides are an attractive candidate to simulate the response of platelets to subendothelial collagen. Here, we have shown that collagen peptides absorb into PDMS, the most common material used for microfluidic flow assays, yielding a surface that does not support platelet adhesion at venous and arterial shear rates. Importantly, typical blocking reagents like BSA and Pluronics-F127 did not block collagen peptide absorption. However, collagen peptide adsorption can be promoted by treatment of the assay surface with a fluorinated alkyl silane, after which it can be used for micropatterning or for flow assays.


Due to their direct contact with taste buds, taste sensation is an important factor. Preparing microparticles with taste masking polymers utilizing spray drying is an efficient technique for reducing the bitterness of drugs. Ethylcellulose is a hydrophobic polymer widely used as a taste masking material. Rupatadine fumarate, one of the newest antihistamines, features an intensive bitter taste, hence in designing orodispersible formulations, achieving an acceptable taste is a crucial issue. The main objective of this work was to formulate orodispersible minitablets containing taste masked ethylcellulose-based microparticles with rupatadine fumarate and evaluation of their quality, especially in terms of taste masking efficacy. The accessed data indicated that all obtained minitablets were characterized by beneficial pharmaceutical properties. Three independent methods: in vivo with healthy volunteers, in vitro drug dissolution, and “electronic tongue” confirmed that all designed formulations provided satisfactory taste masking rate and that formulation F15 (prepared with Pearlitol The challenge of modern pharmaceutical technology is designing easy-to-administer drug dosage forms where the dose is sufficiently flexible to enable proper application and dose titration both to paediatric and adult patients. The currently available formulations that might be used in any age population are primarily liquids. However, the barrier of their utilization are difficulties in effective taste masking of bitter active pharmaceutical ingredients (API), the necessity of applying a large volume of medical preparation to adults, as well as low physicochemical and microbiological stability. Therefore, new technological solutions and strategies are being sought, as the appropriate drug formulation should be acceptable for a wide age group, in terms of organoleptic properties  to ensure regular intake of medicine, even while prolonged therapy. In case of solids, a crucial element that decides if they are swallowed, is their size—the smaller the unit, the easier application ,2,3,4.The solid drug dosage form, which connects the advantages of liquids  with the qualities of solids , as well as enables individual dose adjustments for patients of all ages are minitablets (MT). MT are created for those encountering difficulties with application of larger tablets or as a form providing the possibility of dose titration by “multiplication”, which allows the use of one product for the entire age population. The appropriate dose is determined by the number of MT administered . MT are characterized by small sizes of one to three millimeters and mass of 5–25 mg. They are produced like traditional tablets, using existing technologies and production lines, as well as standard tableting blends. A promising type of MT are orodispersible minitablets (ODMT), which are characterized by very short disintegration and dissolution rates. ODMT are particularly recommended for patients with swallowing problems, by eliminating the risk of choking to a minimal ,9,10,11.The major limitation in designing orodispersible formulations is unpleasant taste of API. Insufficient taste masking effect of medicine is the most common reason for refusing of taking the preparation . Taste mThe aim of the following paper was to create ODMT containing microparticles with rupatadine fumarate (RUP) as a model bitter drug. Microparticles were obtained employing the spray-drying, utilizing ethylcellulose as a barrier forming polymer. In our previous work, microparticles prepared using different forms of EC were compared. The microparticles prepared with an aqueous dispersion of EC were found to have better properties in terms of taste masking effectiveness and morphology , therefo® ECD was donated from FMC BioPolymer, Newark, NJ, USA. Surelease® E-7-19040 was given from Colorcon Inc., Harleysville, PA, USA. Parteck® ODT was received from Merck KGaA, Darmstadt, Germany. SmartEx® QD-50 was handed over from Shin-Etsu Chemical Co., Ltd., Tokyo, Japan. F-Melt C was purchased from Fuji Chemical Industry Co., Ltd., Toyama, Japan. Pearlitol® Flash was a gift from Roquette, Lestrem, France. Magnesium stearate and methylene blue were acquired from POCh, Piekary Śląskie, Poland. RUP was procured from Xi’An Kerui Biotechnology Co., Ltd., Xi’An, China.Aquacoat® and Aquacoat® ECD as a barrier coatings were utilized -borate (KTFPB), tridodecylmethylammonium chloride (TDMAC), 1-dodecylpyridinium chloride (DDPC), , and potassium tetrakis(p-chlorophenyl)borate (KTpCPB) ; calix[6]arene-hexaacetic acid hexaethylester (amine ionophore I) , and 3-mercapto-5-/2′-hydroxynaphthyl-azo-triazole (METRIAN) .(1)w/w) PVC, 70% (w/w) of plasticizers, DOS or o-NPOE,weighing inner layer components: 30% ((2)mixing and deaerating of obtained mixture,(3)filling the Teflon holder with mixture to cover the silver-silver chloride electrode,(4)gelating inner layer (1) at 373 K for 30 min, cooling of the gelled layer,(5)w/w) of PVC, 64–68% (w/w) of plasticizers, 1–5% of electroactive components (2)  ,(6)dissolving of obtained mixture in THF,(7)placing drops on the inner layer (1),(8)gelating outer layer (2) in result of evaporation THF at 293 K; repeating the steps several times.Each solid contact electrode consists of a conventional body and an exchange Teflon holder in which the two phases are placed. The interior lamina (1) contains PVC with plasticizer in which the Ag/AgCl electrode is inserted and the exterior lamina (2) contains the ion-sensitive component and inner layer components. The exterior lamina is in contact with the tested solutions. The steps of the membrane phase preparation:−5–10−3 mol L−1 RUP solutions because of the poor solubility of RUP in water. Previously developed measurement protocol for electronic tongue analysis of pharmaceutical samples [EMF electrochemistry interface system  and IBM PC were used for potentiometric measurements. The potentiometric sensor array of the system contains 16 solid contact ion-selective electrodes (two sensors of each type) differing active substances and plasticizers each other. The constructed solid contact electrodes were stored for 24 h in RUP solutions before the first measurement. As a standard, Ag/AgCl electrode  was used. The electrodes calibration curves were performed in 10 samples  was appl® software .Data matrix was composed of data vectors assigned to every investigated formulation . The data matrixes were processed by chemometric procedures: Principal Component Analysis (PCA) or Partial Least Squares (PLS). These calculations as well as data analysis and presentation were performed in SOLO® was 3.2 +/− 1.1 µm and from Aquacoat® ECD was 3.6 +/− 1.5 µmAn attempt was made to design and develop ODMT as an innovative drug dosage form, utilizing RUP enclosed in ethylcellulose microparticles to reduce bitterness. In preparation of ODMT, mainly spherical, homogenous, smooth surfaced microparticles based on EC aqueous dispersions were used . The mea1 receptor permanently and firmly, acting as an inverse agonist, which prolongs duration of its action. It was indicated that RUP is characterized by far greater affinity to H1 receptor than fexofenadine or levocetirizine. Furthermore, by binding to PAF receptors, RUP causes their blockade, what is clinically relevant to PAF allergic inflammatory processes and bronchial hyperreactivity symptoms. RUP has not only been shown to reduce the amount of erythema , but also reduces PAF-induced platelet aggregation. The third component of RUP activity is its additional anti-inflammatory effect consisting in: inhibition of mast cell degranulation and release of histamine and cytokines , inhibition of eosinophil and neutrophil chemotaxis, inhibition of expression of adhesive molecules  and transcription factors [As a model drug with bitter taste, RUP  was utilized. RUP is the histamine receptor selective antagonist and receptor for platelet activating factor (PAF), which highlights it from drugs belonging to this group and clarifies its unique mechanism of action. RUP binds to the H factors ,37,38,39 factors  and due ®) and as aqueous dispersions . Surelease® contains a 25% of solid EC and dibutyl sebacate and oleic acid as plasticizers. In Aquacoat® ECD there is 27% EC, sodium lauryl sulfate, and cetyl alcohol. The dispersions are accepted for pharmaceutical use in the Europe, United States, and Japan [To reduce bitterness of RUP, ethylcellulose (EC), a hydrophobic polymeric material widespread applied in masking the unpleasant aroma and taste was applied. It belongs to the GRAS  and FDA Inactive Ingredients . Moreovend Japan ,49.® ODT, SmartEx® QD-50, FMelt® C, Pearlitol® Flash. The amount of API was set as 0.5 mg per one ODMT. The dose selection was related to the fact that by multiplication, the dose of 2.5 mg required for children weighting from 10 to 25 kg can be easily achieved. No significant technological problems were observed during tableting process. It was connected with low API content in the tablet masses, so it did not affect the flowing properties of powders. The similar composition of all mixtures based mainly on mannitol caused all the obtained formulations to be characterized by similar physical parameters  and the quick disintegration time was captured. The obtained ODMT were hard enough that they did not crush while handling, and simultaneously, the formulations were characterized by the desired rapid disintegration time (below 30 s) . The weiDisintegration time tests, conducted under conditions imitating those prevailing in the oral cavity (2–7 mL) are recommended ,51,52,53An appropriate selection of pharmaceutical excipients is a key issue in creating drug dosage forms, as the excipients might affect physicochemical properties of API. Differential scanning calorimetry (DSC) is one of the analytical techniques frequently applied to determine drug physical properties, as well as to investigate potential incompatibilities with other components. The procedure provides detailed information about the presence of impurities and energetic properties of substances pointing to the differences in the heat flow generated or absorbed by the sample. To evaluate possible interactions, RUP raw material (API), microparticles placebo , microparticles , ODMT placebo , ODMT with pure RUP  and ODMT with RUP enclosed in SUR MP  and AQ MP   were assEvaluation of taste masking effectiveness is a significant issue, as there are no pharmacopoeial and universal methods to assess the taste. To determine taste masking degree, in vivo (human taste panel) and various in vitro methods  can be utilized. Human taste panel is the most frequently used strategy of taste evaluation as it is widely available; however, it presents a certain challenge. There are high variances in human taste receptors expression and differences in taste perception . As well, children’s participation in such a study is considered to be unethical, in turn the results obtained in adults are difficult to extrapolate to the entire population due to the different perception of taste sensations. Nevertheless, the predominant approach of assessing the taste of raw medicines and drug dosage forms is by human volunteers. An alternative approach is electronic tongues utilization. It is an analytical gustatory tool for automatic analysis of drug taste. Its essential element is the sensor array composed of chemical sensors with various selectivity. Potentiometric signals recorded in the tested sample do not provide direct information about the composition of the sample, but create its specific digital chemical image, whose interpretation allows to identify a sample or the content of its individual components, including those responsible for generating the taste. Evaluation of bitter taste can also be correlated to the drug release rate. It seems to be the simplest way to determine taste-masking efficacy based mainly on the quantification of drug concentration ,57,58,59Initially, six selected healthy volunteers assessed ODMT formulations containing microparticles  as non-bitter or slightly bitter in comparison to those with pure RUP , which were determined as moderately or very bitter . It shouTaste masking was also evaluated by RUP release from obtained formulations. Slowing the release of a drug is associated with better efficacy of masking the taste. ODMT made with microparticles  released RUP significantly slower compared to ODMT with pure RUP , where immediate release of RUP occurred . After oTo investigate in detail taste masking efficiency for the studied formulations, human panel responses were processed by means of a multivariate technique—PCA. This data analysis method helps to find the most significant information hidden in the multidimensional data structure. As a result, a score plot in principal components (PC) coordinates is obtained, which shows clusters of samples based on their similarity. The more similar multidimensional characteristics are, the closer are the objects in the PC1-PC2 space. PCA scores plot  presentsThe formulations form various clusters according to the sensed bitterness. The most bitter formulations: F2, F6, F10, F14, that reached mean score higher than 2, are placed close to each other and are characterized by high value of PC1. F6, F10, and F14 were evaluated identically by all volunteers, therefore they are overlapping, having the same coordinates PC1-PC2. Only one volunteer (a) estimated F2 as very bitter in contrast to F6, F10, F14 scored by him/her as moderately bitter, therefore F2 is similar to F6, F10, F14 PC1-PC2 scores, but not the same. ODMT F15 are placed in the highest distance from F2, F6, F10, and F14 cluster, having the lowest value of PC1, because they were estimated as not bitter by 5 out of 6 volunteers . All remaining formulations were scored as very slightly bitter , and accordingly, they exhibit moderate PC1 values. All these observations perfectly match the dissolution tests , where f−1 to about 51 mV decade−1 of 10−5–10−3 mol L−1.Before the measurements of pharmaceutical formulations, an important stage of research was optimization of the sensor array. For this purpose, calibration curves of electrodes towards RUP were determined. As it results from −1 in the 10−5–10−3 mol L−1 linear range, good mean correlation coefficient R2 = 0.9944 (n = 3). The electrodes containing KTpCPB reveal visible differences between each other; the sensor‘s membrane plasticized with DOS (CSC-D) showed lower mean sensitivity 23.1 ± 4.4 mV decade−1 (R2 = 0.9983) than electrode with o-NPOE. This electrode exhibited linear range with slope close to the near Nernstian 51.5 ± 4.0 mV decade−1 and good correlation coefficient R2 = 0.9993. Slightly lower sensitivity exhibited the electrode with amine ionophore, mean response 41.5 ± 4.6 mV decade−1. Moreover, the lowest slope of characteristics was obtained for electrodes prepared with ammonium and pyridinium ion exchangers. The slope coefficient of linear range of characteristic amounts 10 mV decade−1 for PC-N electrode and 6 mV decade−1 for AN-N electrode. The sensor based on metrian (MET-N) showed a similar response to electrodes CSF. All electrodes possessed lower or higher sensitivity to ionic RUP molecules  as a result of the interaction of RUP with the active components of the polymeric membrane. Concluding, the prepared electrodes of electronic tongue sensor array exhibited satisfactory sensitivity towards studied API. According to our previous studies [The electrodes based on KTFPB  displayed very similar calibration curves, with mean sensitivity 29.2 ± 4.3–32.4 ± 0.89 mV decade studies ,60,61, sThe prepared sensor array was applied to check taste masking efficiency of all prepared ODMT. The procedure of measurements are presented in the experimental section. According to it, the responses of every sensor was given as ΔEMF in a function of time. Taste evaluation was performed for signals recorded after two minutes of release and resulting PCA score plot is presented in All placebos formed a distinct cluster; they are grouped together even though their composition is different. On the opposite side of the plot, pure RUP samples are observed. All studied formulations take place between placebos and API, showing moderate taste between the two, which is correct and was expected. The clusters of formulations are partially overlapping, however similarity between electronic tongue study and human panel evaluation can be noticed. There is a cluster formed by F2, F6, and F14 ODMT in the closest distance to pure RUP, therefore their bitterness is most similar to pure API. Moreover, in proximity of this cluster, F10 can be seen. These four formulations showed the highest bitterness according to human panel  and highSignals of electrodes forming sensor array of electronic tongue were recorded during 10 min of formulation release. These outputs are related to RUP release, because the sensors are sensitive towards this API; however, they are also strongly influenced by increasing concentration of excipients, which are also released, due to cross-sensitivity of sensors. Therefore, to extract information of RUP release from sensor responses, a supervised data analysis technique was applied. First, we attempted to construct a Partial Least Squares (PLS) model. PLS regression is a chemometric procedure combining PCA and multiple regression. This approach leads to the possibility of the prediction of dependent variables from independent variables (measurement data). It is performed by transforming the obtained results into so-called latent components enabling the calculation of the dependent variables . We applMinitablets are getting increasingly significant among modern solid oral drug dosage forms, enabling the application of medicinal substances for patients of all ages by dose multiplying. Due to their small size they are easy to administer and swallow. Minitablets in orodispersible form improve patient compliance in relation to rapid disintegration in the oral cavity within seconds in the presence of the saliva without requirement of drinking water. Orodispersible minitablets (ODMT) with rupatadine fumarate were successfully prepared by direct compression of commercially available ready to use blends and ethylcellulose microparticles. Designed ODMT were characterized by beneficial physicochemical parameters. The presented study also indicates that MP made of etyhylcellulose with rupatadine fumarare might be efficiently utilized in preparation of ODMT by direct compression technique. The evaluation of taste masking level undertaken by three alternative approaches  established that designed ODMT are efficient taste–masking carriers of rupatadine fumarate and are supposed to be a promising alternative for traditional tablets.


Previous literature suggests the use of smartphones and tablet devices may result in various postural and musculoskeletal disorders, predominantly of the neck and upper extremities. However, factors that contribute to the symptoms have not been adequately explored.This study aimed to investigate the prevalence and patterns  of musculoskeletal symptoms among adult smartphone and tablet device users. It also investigated device usage in terms of usage time, postures adopted during use, operational methods and purposes of device use in order to explain the symptom occurrences. Participants from eastern states of Australia retrospectively reported device usage and symptoms in the preceding two-week period, via an online survey. Data was analysed using Chi-square [χ2] analysis to determine the relationships between categorical variables; Mann-Whitney U tests to compare two groups (e.g. smartphone-only users versus tablet users) where dependant variables were ordinal; independent samples t-tests if dependent variables were continuous and approximated a normal distribution; and Spearman’s correlation analysis to assess the relationships between pairs of continuous or ordinal variables.N = 207, p = .554). The most prevalent symptom was stiffness. The most prevalent symptom occurred in the neck (18.1% in smartphone-only users and 19.3% in tablet device users). Tablet users who were 18–24 year-old and used their device for more than 30 min in each usage session more often experienced symptoms  than those who used a device for 30 min or less (52.2%) .Of the 207 participants, 59.9% reported musculoskeletal symptoms during or after device use; for 64.5% of these, symptoms began within the first 30 min (mostly between 15 and 30 min) of commencing usage. No statistically significant differences were observed between smartphone-only users and tablet device users in proportions reporting symptoms during device use (χ2 = .350, These findings suggest that user age, duration and frequency of usage, and type of device are important factors to consider in the formation of evidence-based guidelines to reduce experiences of musculoskeletal symptoms among smartphone and tablet device users. If usage was capped at < 15 min, the majority of smartphone and tablet device users would avoid symptoms. Ownership of handheld devices, such as smartphones and tablet devices, is increasing exponentially , 20. SmaYoung et al.  demonstrWithin this context, the current research aimed to: 1) investigate the prevalence and patterns  of musculoskeletal symptoms among smartphone and tablet device users; 2) investigate the usage of smartphones and tablet devices in terms of time, postures adopted during usage, operational methods and purposes of use (e.g. work); and 3) compare smartphone and tablet device users with regard to these variables. The study was designed to gather data on the maximum amount of time a smartphone or tablet device can be safely used prior to the onset of musculoskeletal symptoms, as well as how demographics and usage factors are associated with the symptoms.H18271).A survey design, using an online questionnaire, was employed, in which participants were asked to report on musculoskeletal symptoms and device usage within the preceding two-weeks. The term ‘musculoskeletal symptoms’ in this study included any physical symptoms in muscles, joints, bones and soft tissue, including but not limited to pain, stiffness, aches, discomfort, numbness and paraesthesia. Survey designs are commonly used for conducting research on this topic  and enabhttps://www.surveymonkey.com/mp/sample-size-calculator/).The survey population included Australian adults (over 18 years of age) residing in eastern states of Australia , who usParticipants were recruited through advertisements via radio, email and online. Specifically, advertisements were made through the Charles Sturt University (CSU) Facebook page and a CSU News article which received 967 unique views. Additional Facebook posts were made, sharing the News article to CSU student groups and personal pages of the researchers. Emails were sent to CSU research committees, physiotherapy staff and students at CSU, based on the researchers’ established networks. An interview was broadcast on the ABC radio station (Greater West) which directed people to the CSU News article. Participants in QLD and VIC were recruited only through Facebook.Upon clicking on the survey link, prospective participants were first presented with an information sheet and consent statement to ensure they understood what was involved in participating in the survey and consented on that basis.All data were collected online via an anonymous questionnaire hosted through the online survey platform, SurveyMonkey. A copy of the survey used is available as a Prior to administration, the questionnaire was reviewed by University academics and students to screen for common errors such as double barrelled, confusing or leading questions.p < .05), and strong inter-tester correlations for VAS and for semantic differential scale (p < .05) on a musculoskeletal pain population. A body chart  was used within the questionnaire to rate pain on a scale of 0–10, with 10 indicating the worst pain and 0 indicating no pain. Olaogun et al.  showed sThe following additional variables, which may have contributed to explaining device use or musculoskeletal symptoms, were also recorded in the questionnaire: gender, age, height and weight used to compute body mass index (BMI), previous injuries, postural habits during device use, and reason for device use .Data were exported from SurveyMonkey to SPSS statistical analysis software  for cleaning and analysis. Responses were excluded if they did not originate from eastern states, or if they were incomplete . Data were first analysed descriptively to provide an overview of demographic information, symptom prevalence and symptom patterns. The selection of parametric or non-parametric statistical tests was informed by visual inspection of histograms to ascertain whether distributions of variables approximated a normal distribution. Specific data were analysed as follows: 1) Chi-square [χ2] analysis was used to determine the relationships between categorical variables; 2) Mann-Whitney U tests were used to compare two groups where dependent variables were ordinal , and independent samples t-tests were used if dependent variables were continuous and approximated a normal distribution; and 3) Spearman’s correlation analysis was used to assess the relationships between pairs of two continuous or ordinal variables - this was chosen over Pearson’s correlation because key variables were either ordinal or not normally distributed.Survey response rates were not calculable due to the methods of recruitment, meaning it was impossible to assess the exact number of people the survey adverts had reached. However, numbers of respondents were reported.Data from a total of 207 eligible respondents  were analysed in this study. Typical reasons for exclusion were: non-consent to participation (3), outside geographical range (7), and incomplete responses (47). The majority (75.1%) of participants were between 18 and 34 years of age. The median BMI recorded was 23.9 . Handedness was reported in trend with the general population, with 87.9% reporting a right-handed preference, 9.2% left-handed and 2.9% indicating they were ambidextrous (Table device usage level (between 0 and 36) for each respondent. This reflected the total daily usage of each device type by each respondent (Table Usage for smartphones and tablet devices was recorded in terms of frequency (times per day a device was used), duration (average duration of time spent in one session of device use) Table  and purpAs seen in Table Nearly all participants (206 of 207) reported using their devices for leisure, 66.7% for work and 61.4% for education while 3.9% reported using their devices for ‘other’ purposes, which mainly included descriptions of leisure activities or daily living activities such as banking or obtaining weather updates.p = .083; tablet U = 3666, z = − 1.879, p = .060).Distributions of device usage levels for males and females were similar for smartphone and tablet device use, when assessed by visual inspection. The difference in device usage levels between males  and females  was not statistically significant , or within the 15–30 min time period (38.3%). Together, 64.5% of symptomatic participants began to experience their symptoms within the first 30 min of usage. Furthermore, 73.8% of symptomatic users did not begin to experience symptoms until after 15 min of device usage . However, Fig. Among smartphone-only users, 61.3% 87 of 142) experienced musculoskeletal symptoms, compared to 56.9% (27 of 65) of significant tablet device users, and this difference did not reach significance .Both device-type groups reported their most prevalent type of symptom to be stiffness (29.4% of symptomatic smartphone-only users and 29.6% of symptomatic tablet users), followed by discomfort (27.6 and 26.5%), aches (16 and 22.7%), pain (14.3 and 11.3%), pins and needles (6.8 and 5.5%), and numbness (5.9 and 4.4%). Where pain was the symptom experienced, the mean (±SD) level of pain reported was 2.9 (±1.4) out of 10 on the VAS, and the reported levels of pain ranged between 1 and 6 on the 10-point VAS. The mean pain level for smartphone-only users was 3.01 (±1.5) and for tablet users was 2.77 (±1.4). The difference in mean pain levels between smartphone-only users and tablet device users was not statistically significant . The relationships between symptom occurrence and participants’ BMI levels or ordered age categories  were very weak and did not reach statistical significance in the Spearman’s correlation analyses .Ninety-four (94) of 148 female participants (64%) and 30 of 59 male participants (51%) reported musculoskeletal symptoms associated with device use in the previous two-week period. This gender difference was not statistically significant .Of right-handed participants, 59.9% experienced symptoms, compared to 52.6% of left-handed participants, and notably, 83.3% (5 of 6) of ambidextrous participants experienced symptoms. Disregarding those who were ambidextrous (only 2.9% of participants), there was no significant association of right or left handedness with symptom experience  or over 25 year-olds . However, Table N = 140, p = .043). Further analysis revealed that this association reached significance in the 18–24 year-old group  but not in the over 25 year-old age group , and equal prevalence with lying on back for smartphone users  than other operational methods Table . This opThis study investigated the prevalence and patterns of musculoskeletal symptoms among smartphone and tablet device users using an online questionnaire. It also explored patterns in the usage of smartphone and tablet devices in terms of time, postures, operational methods and purposes. It was found that the majority of mobile device users experienced symptoms during device use. Most symptoms began within the first 30 min of device usage, and particularly between 15 and 30 min of usage. There was a significant positive association between tablet (but not smartphone) usage duration and symptom prevalence. No significant differences between smartphone-only and tablet users in usage and symptom experience were found. Symptoms occurred least frequently in device users who sometimes adopted a standing posture, changed position frequently, did not hold their device when using it, or used both hands equally to operate their device.A majority of participants experienced symptoms over the previous two-week usage period. This finding is consistent with a previous systematic review of the symptoms associated with handheld device use conducted by Xie et al. . This stPrevious literature has reported a lack of clear association between device usage time and symptom prevalence . Our finAs expected from the study inclusion criteria, all participants used a mobile device of some sort; all used a smartphone (96.6% significantly) but only a third of participants also used a tablet device significantly. Smartphone users and tablet users experienced similar rates of musculoskeletal symptoms.Smartphone-only users and significant tablet device users both reported their most prevalent symptom to be stiffness, followed by discomfort, aches, pain, pins and needles, and numbness. The most common location of symptoms for both device-types was the neck, with almost one fifth of all symptoms reported occurring in this region. This is consistent with observations from a high-quality systematic review, which ascertained that neck complaints were the most prevalent symptoms, occurring in 17.3 to 67.8% of mobile device users . In the Symptoms in the significant tablet device user group tended to localise more proximally than in the smartphone-only user group; arms  and shoulders (particularly left shoulder) were more prominent symptom locations among the tablet device users than the smartphone-only users. To the best of our knowledge, this is the first study to distinguish tablet devices from smartphone devices in a study investigating symptom location and type.Aside from the age-specific relationship between duration of tablet use and symptom prevalence discussed in section 4.1, age was not significantly associated with symptom experience.There were also no statistically significant associations between gender, BMI, or handedness and symptom prevalence. The finding regarding gender differences contrasts with findings of previous research, which found female tablet users were 2.1 times more likely to have symptoms than males . This maSymptom prevalence tended not to change much based on position when using devices. However, symptoms occurred least frequently in device users who sometimes adopted a standing posture. Sitting had the highest symptom prevalence in both device-type groups (and was the most commonly adopted posture) and an equivalent prevalence of symptoms was recorded for smartphone users lying on their back. Previous literature reports posture during device use with neck flexion as a prominent risk factor for musculoskeletal symptoms , 6, 9. VThe lowest prevalence of musculoskeletal symptoms occurred in people who changed positions more frequently (every 5 min). The most common timeframe for changing positions was every 30 min for smartphone users and every 30–60 min for tablet device users. Increased time between changing positions tended to increase percentage of people experiencing symptoms up until every 30–60 min for smartphone users and hourly or longer for tablet users. After this point, symptom prevalence reduced and plateaued; this may be due to the small number of participants in those longer time ranges.Participants who did not hold the device at all  were least likely to experience symptoms. Conversely, left hand only holders were most at risk of experiencing symptoms, however, this may have been an artefact of small cell numbers. Operating the device using both hands equally tended to be lower risk for symptoms among smartphone users than other operational methods. This operational method was also low risk for tablet device users, but right hand only was the lowest risk method for tablet device users. This may be due to single-handed usage increasing asymmetry of muscular demands and strain.The research design was carefully considered to ensure the validity of findings. Particular design issues considered included: i) differentiating between smartphones and tablet devices; ii) ensuring a broad population was surveyed (age ranges 18 to over 65); iii) gathering and considering in analyses the characteristics of participants; iv) including a body chart for reporting of symptoms; and (v) ensuring the recall period was short (two-weeks) to minimise recall bias in findings. To the best of the authors’ knowledge, this research is also the first of its type conducted in the eastern states of Australia.The study also has some limitations. It only measured musculoskeletal symptoms and not any other impact of device use, including those affecting a person’s psychological health. Information regarding the specific activities that were being undertaken on devices was not assessed. No intervention occurred in this research project - the study was limited to analysing retrospective self-reported information obtained through the online questionnaire only. This survey did not include some body locations such as the eye, which have been found to be a location of strain and discomfort in previous literature . The samThe subjective nature of self-reported symptoms may result in self-report bias arising for example from perceptions of social desirability or specific responses, the two-week recall period or selective recall. The recall bias associated with this study may have been an issue for some participants who have irregular use patterns. Participants were able to assess their usage using screen time apps which was encouraged, however not enforced. Future studies may benefit from enforcing the use of a screen time app for reporting, a logbook or a laboratory-based study with more objective measures taken and external assessors of device usage.The anonymous nature of the survey may have reduced the impact of social desirability bias on participant responses. The survey was also only available online, which limited access for those without internet accessibility. Although the tools employed to gather data on pain location and intensity were relatively simple and intuitive, it is possible that lack of familiarity of respondents with these tools may have affected the data.The findings of this study can contribute to the formulation of evidence-based guidelines to reduce experiences of musculoskeletal symptoms among smartphone and tablet device users and guide future research into the possible risks associated with smartphone and tablet device use. Specifically, the significance of duration of tablet use and younger age on experience of musculoskeletal symptoms has been identified, along with a range of posture and device-operation factors that affect experiences of musculoskeletal symptoms. Symptom onset most commonly occurred between 15 and 30 min from commencement of device use, in both device-type groups. If participants were to have limited their usage to 15 min per session, over 70% of participants would have avoided symptoms.Based on the findings, it is reasonable to recommend that adult mobile device users cap their usage at less than 15 min per session whenever possible, avoid sustained static postures during device use, use external supports for their device, and use both hands equally to operate the device, in order to minimise their risk of experiencing musculoskeletal symptoms.These findings can also be used to support future studies on the factors impacting musculoskeletal symptoms and further advance knowledge of the ever-evolving issues surrounding mobile device use and human health. Further research is warranted to evaluate the effectiveness of these recommendations and to investigate their relevance for children.Additional file 1.