Inteins are protein segments that are capable of enabling the ligation of flanking extein into a new protein, a process known as protein splicing. Since its discovery, inteins have become powerful biotechnological tools for applications such as protein engineering. In the last 10 years, the development in synthetic biology has further endowed inteins with enhanced functions and diverse utilizations. Here we review these efforts and discuss the future directions. The split intein fragments subsequently associate to recover its activity and catalyze the ligation of N-extein and C-extein  into a new protein, a process known as protein splicing . They ar in 1988 . NaturalC-extein   under the control of a single gene by the precise excision of an internal protein segment and concomitantly ligation of the flanking regions . Oftentiet al. identified seven motifs (motif A-G) composed of a series of conserved amino acid residues. For example, motif A is pointed to as the first amino acid residue on the N-terminus of the intein for protein splicing, consisting of a hydroxyl- or thiol-containing residue , while motif G is often found to be an Asn residue at the other junction site on the C-terminus with a His residue at the penultimate site beside Asn(Sce VMA (Vacuolar Membrane ATPase in Saccharomyces cerevisiae) intein initiates a gene recombination process to disperse the intein genes to other strains , and these conservative motifs are tightly related with the splicing reaction and splicing efficacy  Chong a. Shaoroneside Asn. Motif Ceside Asn. These d strains .The protein splicing of class 1 intein is achieved through structural conformational change and chemical bonds shifting on junction sites between intein and exteins, which can be summarized in four main steps  Gorbale. First, et al. reported the discovery of GyrA inteins retrieved from 7 mycobacterial species and subspecies. Especially, the Mycobacterium xenopi GyrA intein (Mxe GyrA) consisted of only 198 amino acid residues (AAs), as compared with the inteins with 420 AAs as analyzed from the rest six species. Sequence analysis confirmed the missing of the endonuclease region in Mxe GyrA  and exhibit protein trans-splicing activity  lack the endonuclease region and only conduct the protein splicing function . TelentiMxe GyrA . Split iA  could facilitate the Ssp DnaB intein C-terminal cleavage activity (cis-splicing)  benefitted the Mxe GyrA intein cleavage reactions (cis-splicing)  plus the minimal concentration of DTT (4 mM) promoted the splicing of the split inteins (trans-splicing)  . Wang etplicing) . Recentlplicing) .In the last 20 years, synthetic biology has been bridging multiple disciplines to design and build novel biomolecular components, networks and pathways, and using these elements and knowledge to rewire and reprogram organisms . As natuet al. conducted random mutagenesis on a mini-intein and coupled the intein activity to a selectable growth phenotype for screening. Specifically, they used E. coli deficient in cellular thymidylate synthase (TS) thus the resultant strain was unable to grow without thymine. They generated a pool of mini-inteins (containing the first 110 and the last 58 amino acids of the 441–amino acid Mtu RecA intein) by mutagenic PCR. To couple the splicing efficiency to the TS reporter system, intein–TS fusions were constructed in such a way that the active TS would be produced by intein-mediated splicing to rescue the host cells , which already showed negligible sensitivity to the N-extein residues. However, Npu DnaE split intein has sequence preference to the catalytic cysteine (+1 position) and large hydrophobic residues (+2 position) of the C-extein. A previous study showed that these large hydrophobic residues were essential in maintaining the splicing rate due to a stabilizing effect between Phe+2 and His125   could potentially adjust the His125 conformational dynamics and therefore restrain the effect of the +2 residue on splicing kinetics. To implement this loop engineering, they conducted saturation mutagenesis on the His125 loop (residues 122–124) of Npu DnaE intein and coupled the splicing activity to antibiotic resistance in E. coli by reconstituting a split version of the aminoglycoside phosphotransferase (resistance to kanamycin) protein. Especially, this splicing was done in the presence of the unfavorable Gly+2. By this strategy, they selected mutants that showed remarkable kanamycin resistance with unfavorable C-extein +2 residue, indicating that the evolved intein could splice with minimal extein residues dependency  . Less bupendency .Besides evolving specific inteins for better performance, people also built intein bank to further explore the potential useful inteins. As mentioned previously, the splicing efficiency of inteins is largely dictated by the junction sequence between the inteins and exteins, and the deviation from the preferred junction sequence may lead to reduced splicing activity . Therefoet al. assessed 34 split inteins libraries and established a library of mutually orthogonal split inteins for both in vivo and in vitro applications. This study offered fully characterized and versatile toolboxes for scientists to choose based on the desired applications. They first chose 11 pairs of thoroughly characterized split inteins with high splicing reaction rates and efficiencies, and 3 inteins that were reported previously but not fully characterized  method) to reveal the split sites for a given protein. They first inserted a transposon randomly into a staging vector, which hosted a coding DNA sequence (CDS) of interest by an in vitro transposition reaction. The CDS with successful insertion was isolated by size selection and further ligated into a vector  has been used in proteins modification, such as introducing the site-specific modification including phosphorylation, biotinylation, ubiquitination, glycosylation, and segmental isotopic labeling both in vitro and in cells  to identify the split sites for given proteins, they continued to demonstrate the universality of the method in engineering protein-based logic gates. They discovered multiple split sites within a repressor  and an activator . TetR or ECF20 were reconstituted only when both the N-lobes and the C-lobes were present under the induction  respectively). The full protein either repressed or activated the expression of mScarlet (output), and effectively generated a NAND (TetR) or AND (ECF 20) logic  logic .et al. have further coupled the orthogonal split inteins with orthogonal split extracytoplasmic function (ECF) sigma factors to build modular logic AND gates that can be wired to build complex logic circuits. ECF sigma factors are the smallest and simplest alternative sigma factors. They split three orthogonal ECFs and fused each one with a pair of split intein . The ECF proteins were reconstituted by the intein mediated trans-splicing. The fluorescence was detected only when both ECF halves were expressed, confirming the behavior of logic AND gates  (Cfa DnaE intein and Ssp DnaB). The protein N- and C-fragments were expressed by HEK cells, while the peptide X containing the ncAAs was generated by chemical synthesis and injected into the cells  . They dig (tPTS) . These the cells . Their ahe cells .et al. engineered E. coli carrying the split toxins constructs. The split toxins constructs were delivered through conjugation between the E. coli and the pathogen. The toxin–intein antimicrobial reagent was only activated in the pathogen that harbors specific transcription factors  was sufficient to kill the E. coli host. Consequently, they split the toxin gene by an intein (DnaE). The expression of the split toxin gene and reconstitution of the toxin could only be activated by ToxR, the essential transcription activator controlling the expression of cholera toxin, colonization factor and outer membrane protein of V. cholerae. By design, the intein-assisted method enabled targeted killing of pathogenic bacteria without harming beneficial members of host-microbiota  in the delivering host and activating to generate the therapeutics through the splicing at the target environment. In 2019, López-Igua  factors . In thei factors . Howevercrobiota .et al. reported the use of a split intein mediated Cas9 system in a dual-vector recombinant adeno-associated virus (rAAV) system, in which rAAV invaded cells, delivered the split-Cas9 elements and reconstituted Cas9 via protein splicing of the Npu DnaE split intein  impedes its efficient delivery. Truong t intein .et al. proved that this problem in retinal gene therapy could be ameliorated by a split intein assisted assembly strategy. In their experiments, they successfully delivered multiple AAV vectors, each encoding one of the fragments of target proteins flanked by the split intein, and reconstituted the large ATP binding cassette subfamily A member 4 (ABCA4) as well as centrosomal protein 290 (CEP290) in the retina of mice, pigs and in human retinal organoids to cure the inherited retinal diseases  vector-based gene therapy biologics can cure an inherited form of blindness . Again, diseases .et al. showed that the problem could be addressed through in vivo protein polymerization catalyzed by split inteins. They designed the monomer construct that contained the 10 repeats of a Nephila clavipes MaSp1 dragline spidroin consensus sequence and flanked by a pair of complementary, fast reacting split inteins in the form of IntC-monomer-IntN, where IntC and IntN represent the C- and N-half of the split inteins, respectively. Expression of this monomer alone, however, caused the protein cyclization instead of polymerization, probably due to the structural flexibility of the monomer permitted the joint of the N- and C-termini. To prevent intramolecular cyclization, they have devised a seed chain polymerization (SCP) method by first inducing a “seed protein”, which contained only one reactive IntN domain fused at the C-terminus of the seed. After a certain time, the IntC-monomer-IntN cassette was subsequently expressed. Considering both the ligation kinetics and the protein synthesis rate, the IntC domain at the N-terminus of the monomer should react with a seed or linear chain before its C-terminal IntN domain can be translated, resulting in linear intermolecular ligation instead of cyclization. Using this method, they have successfully synthesized a spider silk protein with a molecular weight of 300 kDa in E. coli  are still deficient. These problems could be possibly improved with protein design by deep learning and large-scale screening by robotic-driven automation. With the advancement and enrichment in the inteins, new genetic parts and networks, we are expecting to see more exciting and creative roles played by inteins in versatile applications.


Their shortening velocity and their developed tension are dramatically low compared to those of muscles. Like sarcomeric and smooth muscles, they obey Frank-Starling’s law and exhibit the Hill hyperbolic tension-velocity relationship. The molecular motor of the myofibroblast is the non-muscle myosin type IIA (NMIIA). Its essential characteristic is the extreme slowness of its molecular kinetics. In contrast, NMIIA develops a unitary force similar to that of muscle myosins. From a thermodynamic point of view, non-muscle contractile tissues containing NMIIA operate extremely close to equilibrium in a linear stationary mode.Myofibroblasts are contractile cells found in multiple tissues. They are physiological cells as in the human placenta and can be obtained from bone marrow mesenchymal stem cells after differentiation by transforming growth factor-β (TGF-β). They are also found in the stroma of cancerous tissues and can be located in non-muscle contractile tissues. When stimulated by an electric current or after exposure to KCl, these tissues contract. They relax either by lowering the intracellular Ca Up until now, when talking about contractile tissues, we have been referring to muscle tissues that include both sarcomeric skeletal and cardiac striated muscles and non sarcomeric smooth muscles. Their mechanical properties have been widely studied over the past century. More recently, the concept of non-muscle contractile tissues has emerged, referring to tissues that are clearly not muscles but which surprisingly exhibit contractile properties that share strong analogies with those of muscles themselves. What primarily distinguishes muscles from non-muscle tissues is their respective types of cells and molecular motors that generate specific contractile properties. In striated and smooth muscles, the basic contractile cell is the myocyte, and the molecular motors are the muscle myosin types I and II (MI and MII) . In non-A. Huxley’s formalism  providesThe myofibroblast is the basic cell of several non-muscle contractile tissues. Myofibroblasts have been discovered by Gabbiani et al. during research on the presence of modified fibroblasts in the wound granulation tissue of healing skin . Wound cUnder physiological conditions, myofibroblasts are non-muscle contractile cells that are present in organs such as the stem villi of human placenta during normal pregnancies ,17,18,19In non-muscle contractile cells, the molecular motor is the non-muscle myosin type II (NMII) . There a2+-non-myosin ATPase and the actin-binding region. They are followed by neck regions, each of which binds two functionally different light chains, i.e., the ELCs and the RLCs that bind to the heavy chains at the level of the lever arms. The lever arms link the motor domains and rod domains. The neck domain acts as a lever arm to amplify the head rotation and is followed by a long α-helical coiled-coil that forms an extended rod-shaped domain and terminates in a short non-helical tail. In the absence of RLC phosphorylation, NMII forms a compact molecule through a head-to-tail interaction. This results in an assembly-incompetent form (10S). When RLC is phosphorylated, the 10S structure unfolds and leads to an assembly-competent form (6S). The heavy meromyosin (HMM) fragment contains the motor domain, the neck, and a part of the rod. This allows the dimerization of NMII molecular motors, which assemble into bipolar filaments via interactions between their rod domains. These filaments bind to actin through their head domains. The Mg2+-ATPase activity of the motor domain induces a conformational change that moves actin filaments in an anti-parallel manner. Bipolar myosin filaments link actin filaments together in thick bundles. This leads to cellular structures such as stress fibers. The ELCs are important stabilizers of the NMHC structure.Like muscle myosin, NMII contains three pairs of chains, i.e., two non-muscle heavy chains (NMHCs) of 230 kDa, two 20 kDa regulatory light chains (RLCs), and two 17 kDa essential light chains (ELCs). The structure of non-muscle myosin II (NMII) forms a dimer. Two globular motor domains (S-1) of the NMII contain binding sites for both the MgThe NMII activity is regulated by two processes: firstly, by the calcium-calmodulin-myosin light chain kinase (MLCK); secondly, by the Rho/ROCK/myosin light chain phosphatase ,35. NMIIThe ATP molecule binds the NMII-ATPase site located on the motor domain. This allows the dissociation of actin from the NMII head. ATP is then hydrolyzed and subsequently, NMII binds with actin. Then, the power stroke occurs with a tilt of the NMII head, which generates a CB single force  and a diNumerous techniques have been used to measure force generated by fibroblasts and myofibroblasts on cell population or single cells embedded in a collagen lattice ,36. Conto2-5% CO2 to maintain at the pH at 7.4. Contractile samples were stimulated either electrically or chemically by KCl (0.05M). Maximum unloaded shortening velocity  was measured by the zero-load clamp technique i in response to either ISDN or SIL. Huxley’s equations show the low value of maximum ATPase activity [Human PSV kinetics of contraction and relaxation are ultraslow, considerably slower than those observed in muscles ,63 Tabl. Importaactivity ,62 (TablMSCs that reside in bone marrow (BM) can be amplified in vitro. BM-derived MSCs cultured in collagen scaffolds in the presence of TGF-β spontaneously differentiate into myofibroblasts exhibiting contractile properties. MSCs cultured in 2D form an adherent stroma of cells expressing well-organized microfilaments containing α-SMA and non-muscle myosin NMIIA. MSCs can be grown in 3D collagen scaffolds, generating a structure that develops contractile properties following exposure to KCl or stimulation by means of an electrical field . Basic mLike human placenta, collagen scaffolds seeded with MSCs operate near-equilibrium in a stationary linear state. NMIIA molecular kinetics are dramatically low in non-muscle myofibroblasts compared with values reported in cardiomyocytes . HoweverNon-muscle contractile tissues share major mechanical properties with muscles, but quantitatively, they differ considerably when compared to those observed in the heart .2) which is very low compared to that of the heart ).Their maximum shortening velocity (Vmax) is very slow due to their rate constant of detachment  is very long due to their dramatically low CB attachment and detachment rate constants.The elementary force developed by a single CB and the thermodynamic force are approximately of the same order of magnitude in all three contractile systems described in this study.is) are dramatically low compared to those of the heart; dis is the entropy change due to irreversible processes within the contractile system and is much lower in non-muscle contractile tissues than in the heart.The thermodynamic flow and consequently the rate of entropy production  behave in a manner that is nearer to equilibrium than that observed for the heart.The NMIIA molecule is physiologically present in the human placenta and in bioengineered tissues in sufficient number to generate significant contractile properties. These non-muscle contractile tissues exhibit basic mechanical and thermodynamic properties similar to those observed in striated or smooth muscles. However, the values of their mechanical parameters are extremely low compared with those of muscles, as are their molecular myosin kinetics and most of their thermodynamic quantities. Moreover, the unitary force generated by a single NMIIA molecule is comparable to that generated by muscle myosins. It would be interesting to study the mechanics and thermodynamics of certain tissues that contain NMII, such as in the stroma of cancerous tissues.


Objectives: To develop and validate radiomics nomograms for the pretreatment predictions of overall survival (OS) and time to progression (TTP) in the patients with advanced hepatocellular carcinoma (HCC) treated with apatinib plus transarterial chemoembolization (TACE), and to assess the incremental value of the clinical-radiomics nomograms for estimating individual OS and TTP.Methods: A total of 60 patients with advanced HCC (BCLC stage C) treated with apatinib plus TACE were divided into a training set (n=48) and a validation set (n=12). The predictors identified from the clinical variables and the radiomics signature constructed from the computed tomography images, such as ɑ-fetoprotein level (AFP), formfactor, the grey level co-occurrence matrix, the gray level size zone matrix, and the gray level run-length matrix, were used to build the clinical-radiomics nomograms and the radiomics nomograms for the prediction of OS and TTP.Results: Apatinib plus TACE benefited the patients with advanced HCC, with a 579-day median OS and a 270-day median TTP. The nomograms were built with the radiomics signature and AFP, and achieved favorable prediction efficacy with acceptable calibration curves. Decision curve analyses demonstrated that the clinical-radiomics nomograms outperformed the radiomics nomograms for the predictions of OS and TTP.Conclusions: Apatinib plus TACE may improve OS and prolonged TTP in the patients with advanced HCC. The clinical-radiomics nomograms, a noninvasive pretreatment prediction tool that incorporate radiomics signature and AFP, demonstrated good prediction accuracy for OS and TTP in these patients. These results indicate that the clinical-radiomics nomograms may provide novel insight for precise personalized medicine approaches in the patients with advanced HCC. Hepatocellular carcinoma (HCC) is a complex disease most commonly related to chronic liver disease. Epidemiological studies of HCC have revealed that it is the fifth most common cancer and the second most frequent cause of cancer-related death Targeted drug therapy is the most common treatment for advanced HCC. Sorafenib, which inhibits vascular endothelial growth factor receptors, is regarded as the standard first-line systemic therapy for advanced HCC in vitro and in vivo. These findings provide preclinical evidence supporting the potential application of apatinib to the treatment of HCC. What's more, apatinib has potential survival benefits for patients with advance HCC, as demonstrated by a phase II randomized, open-label trial In addition to its association with adverse events, the high cost of sorafenib also limits its long-term use in the treatment of advanced HCC patients. For these reasons, new targeted drugs for advanced HCC are currently being developed and tested. For instance, apatinib is a novel and highly selective inhibitor of VEGFR2 tyrosine kinase, with a binding affinity 10 times greater than that of sorafenib In recent years, the combined use of transarterial chemoembolization (TACE) with anti-angiogenic agents in advanced HCC patients has attracted much interest Radiomics is an emerging field in which high-dimensional features are mathematically extracted from medical images. This extraction results in the conversion of images into mineable data and the subsequent analysis of these data for support of medical decision-making The aim of present study was to develop and validate radiomics nomograms for the pretreatment predictions of OS and TTP in patients with advanced HCC who were treated with apatinib plus TACE, and to assess the incremental value of such clinical-radiomics nomograms in individual OS and TTP estimation.Ethical approval by the institutional review board was obtained for this retrospective analysis and the requirement for informed consent was waived. This study was conducted in accordance with the Declaration of Helsinki.Between January 2014 and June 2018, a total of 60 consecutive patients with advanced HCC (BCLC stage C) who received apatinib plus TACE were enrolled in the present study. Patient recruitment  and inclEnd points were chosen according to the guidelines of the American Association for the Study of Liver Diseases Median OS and median TTP of the full cohort  were calculated using Kaplan-Meier analyses.The radiomics workflow used in the present study is depicted in Figure Intra- and inter-reader agreement for the texture parameters were assessed using intraclass correlation coefficients (ICCs) for each pair of variables in the whole sample. To assess intra-observer reproducibility, reader 1 then repeated the same manual procedure one week later. An ICC greater than 0.7 was considered good feature extraction agreement The least absolute shrinkage and selection operator (LASSO) Cox regression algorithm was used to analyze all high-dimensional data. A LASSO Cox regression was applied to select OS- and TTP-related features with nonzero coefficients from a subset of features out of the 792 texture parameters in the training set after performing the spearman correlation analysis. Penalty parameter tuning was conducted with 10-fold cross-validation. Additional details on feature processing and selection can be found in our prior work The radiomics signature and clinical predictors were tested via a multivariate Cox proportional hazards regression model to predict OS and TTP in the training set. To provide the clinician with a quantitative tool to predict individual probability of OS and TTP, we built the clinical-radiomics nomograms and radiomics nomograms on the basis of multivariate Cox proportional hazards regression analysis with the training set.Nomogram calibration was assessed with a calibration curve. Harrell's C-index was calculated, which was applied to quantify the discrimination performance of the radiomics nomogram. The clinical-radiomics nomograms and radiomics nomograms were subjected to bootstrapping validation  to calculate a relatively corrected C-index The performance of the internally-validated radiomics nomogram was assessed with the validation set. Using the formula constructed in the training set, a Rad-score was calculated for each patient in the validation set. Harrell's C-index and the relatively corrected C-index were calculated, and the resultant calibration curves were obtained.Decision curve analysis (DCA) was conducted to determine the clinical usefulness of the clinical-radiomics nomograms by calculating the net benefits for a range of threshold probabilities on the full cohort with 5-fold cross-validation http://www.Rproject.org) and Python3.7. Package details are available in the Data Supplement. A two-sided P <0.05 was considered significant.Statistical analyses were conducted with R software  and intra-observer  ratings were high, indicating favorable intra- and inter-observer feature extraction reproducibility. Given this, all outcomes were based on the measurements obtained by the first radiologist. All features with spearman correlation coefficients greater than 0.9 were removed. A total of 57 radiomics features for each patient were reserved from the late arterial (29 features) and portal venous phases (28 features).The 57 radiomics features of advanced HCC from the late arterial and venous phases of pretreatment contrast-enhanced CT images were reduced to 8 potential predictors of OS on the basis of 48 patients in the training set (Supplementary A multivariate Cox proportional hazards regression analysis identified the radiomics signature and AFP as independent predictors Table B. The moThe calibration curves of the radiomics nomograms and the clinical-radiomics nomograms for OS and TTP demonstrated good agreement between prediction and observation in the training set Figure C-D. The A decision curve analysis revealed that the clinical-radiomics nomograms developed here had higher overall net benefit than the radiomics nomograms across most of the range of reasonable threshold probabilities for both OS and TPP Figure .This study presents a retrospective analysis to develop and validate radiomics nomograms for the pretreatment predictions of OS and TTP in patients with advanced HCC who were treated with apatinib plus TACE, and to assess the incremental value of such clinical-radiomics nomograms in individual OS and TTP estimation, which is an important complement to these previous studies A multi-feature-based radiomics signature was identified in present study to be an independent biomarker for OS and TTP in patients with advanced HCC treated with apatinib plus TACE. The combined use of a radiomics signature and AFP in the clinical-radiomics nomograms performed better than the radiomics nomograms alone. Prior studies The radiomics features were derived from CT images both in the late arterial and portal venous phases of the patients. The radiomics signature identified from these features included those both in the late arterial and portal venous phases when building clinical-radiomics and radiomics nomograms for OS, as well as the radiomics nomogram for TTP. However, the radiomics signature only included radiomic features in the late arterial phase for building clinical-radiomics nomogram for TTP. Tumor heterogeneity is closely related to tumor prognosis, most notably in HCC lesions As demonstrated in present study, the radiomics signature may predict survival outcomes, supporting the conclusion that radiomics signature can obtain intratumoural heterogeneity in a noninvasive way that is relevant to patient prognosis. Furthermore, the radiomics signature and clinical-radiomics nomogram used here was demonstrated to accurately estimate OS and TTP. When compared with long-term OS outcomes, TTP was defined as a secondary end point associated with less extended follow-up and thus more effective therapeutic adjustment The radiomics nomogram, as a statistical model, accounts for multiple risk factors by assigning a total number of points to each patient. A series of studies Limitations of present study include its retrospective design, a limited sample size, lack of a control group, and lack of an external model validation. A large-scale independent prospective multicenter validation cohort is thus needed to acquire high-level evidence for broader clinical application. In addition, no gene-expression signature has been incorporated into the nomogram used here. Tumor gene expression patterns can provide insights into patient prognosis Apatinib plus TACE may improve OS and prolong TTP in the patients with advanced HCC. The clinical-radiomics nomograms, a noninvasive pretreatment prediction tool that incorporate radiomics signature and AFP, demonstrated good prediction accuracy for OS and TTP in these patients. These results indicate that the clinical-radiomics nomograms may provide novel insight for precise personalized medicine approaches in the patients with advanced HCC.Supplementary figures and tables.Click here for additional data file.


Polyunsaturated fatty acids are metabolized into regulatory lipids important for initiating inflammatory responses in the event of disease or injury and for signaling the resolution of inflammation and return to homeostasis. The epoxides of linoleic acid (leukotoxins) regulate skin barrier function, perivascular and alveolar permeability and have been associated with poor outcomes in burn patients and in sepsis. It was later reported that blocking metabolism of leukotoxins into the vicinal diols ameliorated the deleterious effects of leukotoxins, suggesting that the leukotoxin diols are contributing to the toxicity. During quantitative profiling of fatty acid chemical mediators (eicosanoids) in COVID-19 patients, we found increases in the regioisomeric leukotoxin diols in plasma samples of hospitalized patients suffering from severe pulmonary involvement. In rodents these leukotoxin diols cause dramatic vascular permeability and are associated with acute adult respiratory like symptoms. Thus, pathways involved in the biosynthesis and degradation of these regulatory lipids should be investigated in larger biomarker studies to determine their significance in COVID-19 disease. In addition, incorporating diols in plasma multi-omics of patients could illuminate the COVID-19 pathological signature along with other lipid mediators and blood chemistry. The pandemic coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), initiates an aberrant immunological response resulting in a wide range of disease severities ranging from asymptomatic cases to severe cases with rapid progression to acute respiratory distress syndrome (ARDS) and death . PatientOne of the key pathways regulating the immune response to infections is the release of regulatory lipid mediators that have dual functions of driving inflammation  or promoting resolution of inflammation and return to homeostasis  . Recent Linoleic acid  is the primary source of essential long chain n-6 PUFAs. CYP450 enzymes act on linoleate directly to generate linoleic epoxides , which are further metabolized by soluble epoxide hydrolase (sEH) to their corresponding leukotoxin diols  prior to the COVID-19 pandemic. The methods used for blood collection, plasma processing, use of anti-coagulants/antioxidant/preservatives, and flash-freeze protocol were well-matched between case and control groups. The UC Davis and UC San Diego Institutional Review Boards have approved the use of anonymized biospecimens for this study.Plasma (200 μL) samples were aliquoted to a cocktail solution including 600 μL of methanol with 10 μL of 500 nM of surrogate solution including 9 isotope-labeled oxylipins . Before the extraction, the samples were vortexed and centrifuged at 3,000 rpm in a biosafety hood. The supernatants were then loaded on prewashed SPE cartridges and washed with two column volumes of 5% MeOH solution before elution by 0.5 mL of MeOH and 1.5 mL of ethyl acetate. The eluents were dried under vacuum using the Nutec MaxiVac vacuum concentrator  before reconstitution with 50 μL of 100 nM CUDA solution in methanol. Then, the extracted samples were analyzed using the UPLC/MS/MS system [Waters Acquity UPLC ] hyphenated to AB Sciex 6,500 + QTrap system . The detailed parameters for the UPLC/MS/MS method were described previously , 2019.Plasma cytokines were measured using a multiplex magnetic bead-based cytokine detection kit purchased from Bio-Rad (12007283). Cytokines were measured according to manufacturer’s instructions. Data are provided in the 10 transformed to fit a normal distribution and analyzed in Graphpad Prism (version 8.4.3) using the Wilcoxon rank-sum test with COVID positive and negative status as the main effect.To test for differences between the COVID-19 and the control group cytokine levels, cytokine levels were log1 and scaled using autoscaling before analysis. Multiple data sets described below were integrated to prioritize the oxylipins as possible biomarkers contributing to the severity of COVID. Oxylipins were analyzed by multiple independent t-tests using patient vs. control as the variable and the two-stage step-up method of Benjamini, Krieger and Yekutieli to determine a false discovery rate . The analytes with the largest effect sizes were further evaluated by random effect ANOVA models. We minimized type 1 errors by testing for between-group differences among the analytes with the largest effect sizes and to improve the likelihood of identifying analytes that showed best potential to seve as biomarkers of disease severity. Each analyte with an effect size above 8  was used as a response variable. Random effect ANOVAs were run with “patient” as a random effect to account for the multiple measurements from the same patient, and the fixed effect was “group” . The loghttps://datadryad.org/stash/share/jYEfmOzrIkShoUT1fmMsT-lEl_dIbI7952I5EQ2kMk4). Levels of multiple key pro-inflammatory cytokines and chemokines were significantly higher in patients with COVID-19 than in healthy controls  with more than four-fold change between groups.A volcano plot analysis was performed to evaluate the differences in lipidomic profile between COVID-19 patients and healthy controls . The anaOxylipins were ranked according to effect size  between It is clear that the two regioisomeric linoleic acid diols (DiHOMES) had highly elevated concentrations in these COVID-19 positive patients, as did their precursor epoxides EpOMEs; . PreviouS, EEQs and EDPs, and increasing linoleate epoxides or leukotoxins as shown by our data. Although AA and longer chain omega-3 fatty acid epoxides are better substrates for the sEH, the leukotoxins are still excellent substrates  pro-inflammatory COX and lipoxygenase (LOX) pathways are countered by the more recently discovered and largely anti-inflammatory pathway termed the cytochrome CYP450 pathway . During The high abundance of linoleate as a substrate, coupled with the increased biosynthesis of anti-inflammatory EpFA during severe coronavirus infections and the induction of sEH in an inflammatory state  may explin vivo sEH can also block the toxicity of linoleate epoxides . The names of the repository/repositories and accession number(s) can be found in the article/The datasets presented in this study can be found in online repositories (The studies involving human participants were reviewed and approved by University of California Institutional Review Board. The patients/participants provided their written informed consent to participate in this study.JY, CM, and RR implement the experiments. CM, IC-P, PS, BDH, and JY wrote and revised the manuscript. BGH analyzed data. IK, PS, BGH, and JY designed the study. All authors contributed to the article and approved the submitted version.BDH, CM, IC-P, and JY are partly employed by EicOsis, which is developing a potent soluble epoxide hydrolase inhibitor for pain relief. The remaining 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.


Population-level mathematical models of outbreaks typically assume that disease transmission is not impacted by population density (‘frequency-dependent’) or that it increases linearly with density (‘density-dependent’).We sought evidence for the role of population density in SARS-CoV-2 transmission.Using COVID-19-associated mortality data from England, we fitted multiple functional forms linking density with transmission. We projected forwards beyond lockdown to ascertain the consequences of different functional forms on infection resurgence.COVID-19-associated mortality data from England show evidence of increasing with population density until a saturating level, after adjusting for local age distribution, deprivation, proportion of ethnic minority population and proportion of key workers among the working population. Projections from a mathematical model that accounts for this observation deviate markedly from the current status quo for SARS-CoV-2 models which either assume linearity between density and transmission (30% of models) or no relationship at all (70%). Respectively, these classical model structures over- and underestimate the delay in infection resurgence following the release of lockdown.Identifying saturation points for given populations and including transmission terms that account for this feature will improve model accuracy and utility for the current and future pandemics. Like many pathogens that cause respiratory diseases -3, severStandard transmission models that either do or do not account for this density dependence have been used interchangeably because their projections are generally equivalent when population density remains unperturbed or is homogeneous, e.g. at a national level. While the ca 1% infection fatality rate for COVID-19  is insufAs lockdowns were gradually released over the latter part of 2020, global populations were expected to re-equilibrate to a ‘new normal’ whereby densities of mobile people were increased but in which contact patterns were expected to remain reduced through physical distancing interventions . Using aReported COVID-19-related deaths between 1 March and 31 July 2020 were obtained in anonymised linelist form from Public Health England and were filtered to include all deaths which occurred within 28 days of positive COVID-19 test . We aggregated individual records to lower-tier local authority (LTLA), and nationally by 10-year age bands in order to calculate age-standardised expected counts.Local authority shapefiles and single-age population estimates were obtained from the Office for National Statistics . Four sun) per LTLA, adjusting initially for the three covariates  and subsequently adding a fourth covariate, namely the lag in weeks behind the first death nationally. We adjusted for age distribution within the LTLA via inclusion of age-adjusted expected deaths (E) as an offset; these were calculated according to national age-specific rates  applied to local population estimates in 10-year age bands. We accounted for population density in one of four functional forms: (i) constant/independent of population density, (ii) linear, (iii) log-linear and (iv) saturating.Negative binomial regression models were fitted to the number of deaths (D), age-adjusted expected deaths (E) and defining iIMDx, imino, xiKW, xilagxandidens x, respectively, as the deprivation score, % minority population, % key workers, lag in weeks behind first death nationally and population density of LTLA this yields the following model specification:For observed number of deaths  of the negative binomial distribution and jβ the regression coefficients. The functional form of population density is defined aswhere whererstanarm package [loo package [ϴ for the saturating function was determined by manual optimisation of the generalised linear model with respect to LOOIC on a hold-out set of 40% of LTLA, over a range from 0.001 to 1.Models were fitted using the  package  with def package . InterprFor the saturating model, the impact of an 84% reduction in effective population density as a result of lockdown on predicted mortality rates among the freely moving population was calculated as a percentage change between mean model-predicted deaths under the original and reduced densities.Supplementary Figure S1 shows limited impact of doubling the rate of this connectivity). We compared frequency-dependent and linearly density-dependent transmission  code is freely available from github (https://github.com/lwyakob/COVIDsaturates).We use a discrete-time, deterministic compartmental model  with daint model ) among tNo ethical clearance was needed for this publication because all data which were freely available from the Office for National Statistics were anonymised.Supplementary Figure S2 shows deaths were higher for urban settings [COVID-19-associated deaths appeared to be strongly correlated with population density, aligning with the rural/urban disparities demonstrated in Office for National Statistics bulletins (settings ). AdjustOwing to the heightened risk of earlier outbreak seeding for higher density areas, we repeated the analysis, additionally adjusting for the lag of the local epidemic behind the national. The saturating model was retained as the best fit  and suggSupplementary Figure S3).Under the saturating density-dependent model, the impact of lockdown on reducing transmission among mobile individuals, and consequently on deaths, is heterogeneous, having greatest benefit in regions with low population density  but reduced benefit in high-density regions  . These rSupplement for details of the models). Of the remaining 30% of models, all assumed a linear relationship between population density and transmission.A full-text review of 100 epidemiological models of SARS-CoV-2 published until 19 June 2020 showed that 70% explicitly assumed that contact rate between people (and hence transmission) is unaffected by population density  as well as linearly and saturating density-dependent assumptions. While all functional forms performed equivalently in fitting mortality data leading up to lockdown, dynamics under alternate assumptions may diverge markedly during and following the phase when lockdown is released . We noteAlthough final epidemic size and total deaths were equivalent for the alternative classical assumptions (fd and linearly dd), transmission was delayed by almost a year under a density- vs frequency-dependent model . This deAssuming a maximum national capacity of 5,000 intensive care unit (ICU) beds, we assessed the difference between these temporal limits in the projected duration between the release of lockdown and a second wave of infection exceeding ICU capacity . ThreshoProjections of COVID-19 infection dynamics following the release of a huge proportion of the population from lockdown comprise an urgent and critical component of public health decision-making . The claThe delay is a function of a fundamental aspect of density-dependent transmission: lower host densities reduce the force of infection, and there is a threshold host density below which an infection cannot spread. Despite its origins in human infectious disease modelling , the exiAnalysing COVID-19-associated deaths across different regions in England, and accounting for known major confounders [Less populated areas were shown to have fewer deaths per capita  and slower resurgences following the release of lockdown. This provides more achievable targets and considerably more lead time for health services to prepare than would otherwise be anticipated. It also highlights a hazard. During and after releases from lockdown, in order to fit a prolonged lag in cases, transmission rates derived from most current (frequency-dependent) models will underestimate the effective reproduction number. This could exaggerate the perceived effectiveness of ongoing interventions, such as physical distancing or face masks, with potentially serious consequences.Our study is limited by the fact that we do not have comprehensive data on how contact rates were affected before and over the lockdown period for individuals inhabiting regions of differing population density. We also do not know where people were infected, only where they were when they died. Instead we had to resort to mortality rates and locations as a proxy. It is possible, for example, that contact rates are not affected by dramatic shifts in population density regardless of baseline levels , and that the increased per capita fatality seen in more densely populated regions has an alternative, thus far unidentified, explanation. Mobile phone applications developed to notify participants of urgent health information have already gained millions of users in the current coronavirus context . Piggy-bOwing to the highly complex interactions between population characteristics, behaviours and mortality risk, the association discovered between saturating density and mortality rates may remain confounded by factors not considered here. Moreover, the criterion used for model comparison depends on an independence assumption which may not hold between neighbouring LTLA. Work is ongoing to characterise the patterns of spatial correlation in mortality at the LTLA level.Infectious diseases are emerging at an unprecedented rate and the upwards trend in global travel and urbanisation increases the likelihood of pandemics. Their success in controlling SARS-CoV-2 means that widescale lockdowns will not only continue to be enforced as this pandemic progresses, but they are likely to be more readily applied in future emergencies. It is crucial that we use the current opportunity to collect data to inform more precise forms of how contact rates are altered at varying stages of lockdown. Future work should also address whether the feature of saturating density dependence we have identified from England’s data are generalisable to other countries. Incorporating realistic contact-density relationships into the transmission term of population-level mathematical models will improve precision of their projections and their utility in public health decision-making.


Viruses are obligate parasites that depend on the host cell machinery for their replication and dissemination. Cellular lipids play a central role in multiple stages of the viral life cycle such as entry, replication, morphogenesis, and egress. Most viruses reorganize the host cell membranes for the establishment of viral replication complex. These specialized structures allow the segregation of replicating viral RNA from ribosomes and protect it from host nucleases. They also facilitate localized enrichment of cellular components required for viral replication and assembly. The specific composition of the lipid membrane governs its ability to form negative or positive curvature and possess a rigid or flexible form, which is crucial for membrane rearrangement and establishment of viral replication complexes. In this review, we highlight how different viruses manipulate host lipid transfer proteins and harness their functions to enrich different membrane compartments with specific lipids in order to facilitate multiple aspects of the viral life cycle. Biomolecules are the basic building block of life. Lipids are non-polar biomolecules that can be classified functionally into structural components of the cell (ex: phospholipids), energy storage molecules (ex: triglycerides), and signaling molecules (ex: steroid hormones). Lipid bilayers serve as limiting membranes of different cellular compartments that define their spatial limits and allows regulated exchanges between them. The specific lipid composition of the membranes dictates their functions, and intracellular lipid trafficking machinery helps in tailoring the unique composition of lipid membrane.Viruses being obligate parasites are dependent on the host cell machinery for their replication and dissemination. Apart from being an integral part of the virus particle, cellular lipids play a central role in multiple stages of the viral life cycle. This includes: (i) binding and entry of the virus particle into the host cells by fusion of viral envelopes with cellular membranes, (ii) reorganization of host cell membranes for the establishment of viral replication compartments, and (iii) utilization of host lipid membranes and platforms for envelopment and egress of nascent virions . Thus matrans bilayer flip–flop. Lipid transfer proteins (LTPs) mediate monomeric lipid exchange by transferring a lipid to the acceptor membrane in exchange with a lipid of the acceptor membrane  LTPs that have been implicated to play a vital role in the life cycle of animal viruses, (ii) Functional role of LTPs in the life cycle of these viruses and how viruses exploit them for their production and dissemination, and (iii) Targeting LTPs for therapeutic purpose and development of potential antiviral agents.Oxysterol-binding protein (OSBP) is a major representative member of the ORP family. All the ORPs contain a core OSBP-related domain (ORD). ORPs can bind sterols, however, some ORPs may preferentially bind to other lipids . Many ORThe steroidogenic acute regulatory protein (StAR)-related lipid transfer (START) domain is a protein domain spanning ∼210 residues that binds to lipids such as sterols . FifteenNiemann Pick C (NPC) disease is an autosomal recessive disorder that exhibits impaired neuronal and visceral cell trafficking of cholesterol and other lipids, including glycolipids. Due to defect in the transport of cholesterol from the endosomal/lysosomal compartments the mutant cells exhibit accumulation of lipids in the late endosomes and lysosomes. NPC1 and NPC2 co-ordinate to export cholesterol from endosomal/lysosomal compartments. NPC1 is a membrane glycoprotein that resides primarily in the late endosomes and transiently localizes to lysosomes and TGN . NPC1 co2+/phospholipid binding and protein–protein interactions. E-Syts activities are controlled by Ca2+ and facilitates Ca2+dependent regulation of lipid transport and intracellular membrane transport (2+ mediates the enrichment of E-Syt1 from ER to ER–PM junctions (The extended synaptotagmins (E-Syts) is a family of ER-resident LTPs having an N-terminal membrane anchoring domain and cytosolic exposed C2 domains that transfer glycerophospholipids between ER and plasma membrane . The N- ransport . An incrunctions . E-Syt1 unctions . Currenttrans-Golgi network and facilitates the transportation of proteins from the Golgi complex to the cell surface. It is also involved in GSL metabolism at the Golgi complex (trans-Golgi network whereas the globular domain binds to glucosylceramide (GlcCer) primarily synthesized on the cytosolic leaflet of cis-Golgi. FAPP2 facilitates transfer of GlcCer from the cis-Golgi to the trans-Golgi regions or from the cis-Golgi to the ER (The four-phosphate adaptor protein 2 (FAPP2) is a member of glycolipid-transfer domain family (GLTD) . FAPP2 l complex . FAPP2 h complex   is a member of phosphoinositide transfer protein (PITP) . There aViruses promote membrane rearrangement to establish highly specialized replication compartments. These structures allow spatial segregation of replicating viral RNA from ribosomes and protect from host nucleases and pattern recognition receptors. In addition, by reducing the overall diffusion space these structures promote the enrichment of components required for viral replication and provide a conducive environment for virion assembly. Specific lipid composition of the membranes is required to facilitate the formation of negative or positive curvature and attributes membrane rigidity or flexibility to aid in membrane rearrangement. For instance, cholesterol a lipid of intrinsic negative curvature due to its small head group, and the large hydrophobic tail is enriched in membranes of the vesicles. Many viruses harness the ability of LTPs to promote the transfer of lipids from one membrane compartment to the other to enrich specific lipids that induce curvature and flexibility in membranes that make up the viral replication compartments.Flaviviridae, genus Hepacivirus. About 71 million people worldwide are affected by HCV as per the World Health Organization (Hepatitis C virus (HCV) is a positive-sense ssRNA virus of the family nization . HCV assnization . It has nization .Hepatitis C virus replication factory comprises of a highly convoluted membranous structure known as the ‘membranous web’ derived from the ER membranes. The membranous web is majorly composed of double-membrane vesicles (DMVs) and multi-membrane vesicles (MMVs), which serve as a platform for HCV genome replication. HCV exploits several host factors to promote the enrichment of cholesterol in the replication compartment or membranous web HCV triggers fatty liver by upregulating lipogenesis and downregulating lipid secretion and β-oxidation . HCV nontrans-Golgi to the plasma membrane by mediating the phosphorylation-dependent inhibition of OSBP and CERT. PKD depletion or chemical inhibition enhanced HCV secretion suggesting that the transfer of lipids from ER to Golgi mediated by OSBP and CERT is required for maintenance of Golgi function and HCV egress  is a positive-sense ssRNA arbovirus of the family  to DENV . Annuall to DENV . Infecti to DENV . Like ma to DENV . Dengue  to DENV . DENV in of VRCs . Earlier of VRCs . PI4KIII of VRCs . High-th of VRCs . Treatme of VRCs . In cont of VRCs . Unlike  of VRCs . To date of VRCs . ORP2, u of VRCs . The pre of VRCs . KnockdoEbola virus (EBOV), Marburg virus (MARV) belong to the Filoviridae family. These are filamentous, enveloped and negative-sense ssRNA viruses. Infection with EBOV causes Ebola virus disease (EVD) a fatal illness associated with coagulation disorders, hemorrhagic fever, lymphopenia, leading to septic shock and multi organ failure in affected humans and primates. MARV infection also leads to similar clinical sequelae as that of EBOV. Infected individuals experience severe watery diarrhea, abdominal pain, vomiting, and lethargy which progresses into severe hemorrhagic manifestation and shock. The average fatality rate of EVD is around 50% and about 90% in MARV infection  and facilitates its formation  also requires OSBP-mediated transfer of cholesterol in exchange of PI4P at MCSs  through Phosphatidylinositol transfer protein β (PITPβ), which enhances the complexity of lipids build up in the membranes and facilitates the formation of replication organelles. Similar to Poliovirus, Coxsackievirus has also been shown to reorganize the secretory pathway to promote the formation of PI4P lipid-enriched microenvironment in a PI4KIIIβ-dependent manner  protein to recruit PI4KIIIβ to the viral ROs to produce PI4P and promote OSBP-mediated cholesterol flux (trans-Golgi network (TGN) and stimulates its enzymatic activity to produce PI4P (Enteroviruses A71 (EV-A71), D68 (EV-D68), Rhinovirus, and Poliovirus various groups have demonstrated that 3A protein binds with GOLD domain of ACBD3 and knockdown of either ACBD3 or PI4KIIIβ perturbs replication of these viruses signifying the role of PI4P and OSBP in enterovirus replication  is a positive-sense single-stranded RNA virus of the obuvirus . It is tobuvirus . AiV hijobuvirus . Similarobuvirus . OSBP, Vobuvirus . AiV proobuvirus . AiV repAsfarviridae family and causes hemorrhagic fever in pigs with a high mortality rate. Initially, it was endemic in Africa but has slowly spread to Europe, China, and Southeast Asia causing huge socioeconomic losses (African swine fever virus (ASF), is a large dsDNA virus of the c losses . The virc losses . ASFV rec losses . The choc losses . ASFV utc losses .Adenovirus is a non-enveloped, dsDNA virus of the family Adenoviridae, genus Mastadenovirus. Adenoviruses commonly cause lower respiratory tract infection which is infrequent and sporadic in nature  of group C primarily target epithelial cell lining of the upper respiratory tract through binding to Coxsackievirus B adenovirus receptor (CAR) and αv integrin co-receptors  is a linear dsDNA enveloped virus of the family Herpesviridae, subfamily Alphaherpesvirinae, genus Simplex virus. The pathogenesis of HSV-1 infection follows a cycle of infection which involves infection of epithelial cells followed by latency in neurons, and finally reactivation with symptoms such as primary and recurrent vesicular eruptions generally in the orolabial and genital mucosa  expression . HCV NS5t of ITZ . TTP-830t of ITZ . Posacont of ITZ . OSW-1, for OSBP . OSW-1 efor OSBP . U18666Aoprotein . The U18us entry . NPC1 inus entry . The OSBus entry . The resus entry . A schemThere are still some lacunae in our understanding of how the LTPs function and how they co-ordinate with other LTPs and other modes of lipid transport to maintain intracellular lipid trafficking. Detailed studies of these aspects will provide clear insight into intracellular lipid trafficking and homeostasis. The establishment of specific replication structures is central to the life cycles of many RNA viruses and a clear understanding of the virus-host interactions that govern membrane rearrangement and assembly of these complex structures will enable the development of therapeutic strategies with pan-viral potential. Paradoxically many viruses exploit these common host factors to build structures that are very unique to individual viruses and drastically differ in shape and size. It is still an enigma how the viruses build such atypical structures and how the LTPs contribute in terms of recruiting other essential factors and lipids to the replication sites. Many studies suggest upregulation of autophagy during viral infection and the cross-talk between the LTPs and autophagy would be an interesting area to explore.KA, BS, and PVK drafted the manuscript. KA, BS, and GHS improved the manuscript significantly by extensive discussion, addition and revision. GHS had edited the manuscript. All authors approved the submitted version.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.


When e-textile EMG electrodes are integrated into clothing, the fit of the clothing on the body, and therefore its pattern and cut become important factors affecting the EMG signal quality in relation to the seamless contact between the skin and the e-textile electrode. The research so far on these effects was conducted on commercially available clothing or in tubular sleeve forms for arms. There is no study that investigated different clothing pattern and fit conditions and their effect on e-textile EMG electrode performance. This study investigates the effect of clothing pattern and fit in EMG applications using e-textile electrodes integrated onto the sleeves of custom drafted t-shirts in set-in and raglan sleeve pattern variations. E-textile electrode resistance, signal-to-noise ratio (SNRdB), power spectral density and electrode–skin impedance are measured and evaluated in set-in sleeve and raglan sleeve conditions with participants during a standardized arm movement protocol in comparison to the conventional hydrogel Ag/AgCl electrodes. The raglan sleeve pattern, widely used in athletic wear to provide extra ease for the movement of the shoulder joint, showed superior performance and therefore indicated the pattern and cut of a garment could have significant effect on EMG signal quality in designing smart clothing. Electromyography (EMG) is a diagnostic recording system routinely used in clinical applications to measure electrical activity of striated muscles as voltage and get information about the health condition of neuron groups that stimulate these muscles. Surface EMG (sEMG), which can be applied wirelessly, is widely used to study the dynamic muscle activity where the signals from muscles are registered noninvasively from the skin surface by electrodes to evaluate muscle activity without interfering with movements. In sEMG applications, electronic textile (e-textile) electrodes present multiple advantages including the possibility of being integrated into clothing for continuous muscle activity tracking when compared with the conventional, single use, hydrogel Ag/AgCl electrodes that require skin preparation. E-textile electrodes also offer the advantages of softness, flexibility, air permeability, multi-use and self-administration without medical assistance. In a comprehensive review by Guo et al.  embroideThe major drawback in embedding e-textile electrodes into clothing is the loss of contact between skin and the electrode surface due to movements of the body and clothing in dynamic conditions where clothing may not behave and change in shape corresponding exactly to the body movement. Martin et al. discussed the effect of body size and motion in sensor and electrode placement on clothing .Studies exploring e-textile sEMG electrodes embedded in different clothing forms report on the importance of the interaction between the electrode and body during movement. According to Finni et al. good fit of shorts provided good contact between e-textile electrodes and the skin, and prevented electrode displacement during joint movement . HoweverOther studies attempted to improve e-textile electrode and skin contact through different mechanisms. The first strategy was to add thickness between the electrode and the base fabric through embossed embroidery patterns or filling inserts such as foams, which may end up with uneven surfaces and altered the silhouette in tight-fitting clothing . Liu, ZhComert et al. compared knitted e-textile electrode paddings of different thicknesses and softness in retrieving ECG signals and reported that regardless of the clothing pressure exerted on electrodes, using paddings considerably improves signal quality and lowers motion artefacts . Cho et The second strategy to improve e-textile electrode and skin contact was adjusting clothing tightness or, in other words, clothing fit, which is directly related to clothing pattern and cut . Kim, LeWhen e-textile EMG electrodes are integrated into clothing, the fit of the clothing on the body becomes an important factor directly affecting the EMG signal quality . Fit of The custom-fitted t-shirts with different sleeve variations were prototyped using a one-way stretch, polyester single-jersey knit fabric. For sportswear, knitted fabrics are widely preferred based on their unique characteristics such as elasticity, wrinkle resistance and ease of care , superioIn manufacturing the e-textile EMG electrodes, 100% polyamide core, silver-plated, 2-ply Madeira HC 12 (<100 Ω/m) conductive embroidery thread was used. This particular thread was preferred since it is specifically developed for embroidery applications transforming Statex’ silver plated Shieldex thread. A prior study also proved superior compatibility of Statex Shieldex thread in embroidery applications of e-textiles .Physical and mechanical properties of the knit fabric were measured. The fabric thickness was measured according to the ASTM D1777-96 (2015) standard; mass per unit are (weight) of the fabric was measured according to the ASTM D3776 standard; linear density of the fabric was determined. Bursting strength properties and elasticity of the knit fabric were determined using a Titan Universal Test device with 50 N load cell, consequently according to TS 393 EN ISO13938-1 and EN 14704-2005 standards.The mechanical characteristics of the conductive thread such as thickness (dtex) and twist direction were determined. Electrical characterization of the conductive thread was performed in three repeats and then statistically analyzed. Electrical resistance of the thread was determined with the four-point probe method, while the signal-to-noise ratio (SNRdB) was measured using a function generator and oscilloscope.The t-shirts were prototyped in two different sleeve pattern variations of set-in and raglan sleeve styles . Set-in Two t-shirt patterns with set-in sleeves and raglan sleeves were custom drafted for one male and two female participants whose body measurements were retrieved using a Size Stream 3D body scanner . Waist, E-textile EMG electrodes were embroidered on the right sleeve pattern of each t-shirt prototype using the polyamide silver-plated Madeira HC 12 (<100 Ω/m) thread and a ZSK Sprint CAD embroidery machine. EMG electrodes were digitally modelled using Tajima DG15 by Pulse embroidery software with the satin stitch type which is a series of flat stitches that completely cover a section of the fabric. During the embroidery process under-stitching with non-conductive thread was used to create a stabilized fabric surface, then the electrode surface was embroidered on top with the Madeira HC12 conductive thread. The under-stitching also helped to add extra raised surface for the electrodes which was critical for better electrode–skin contact. Two embroidered EMG electrodes (anode and cathode) with a 20-mm diameter were located 40 mm apart from each other on the sleeve pattern to correspond to the location of the Biceps Brachii muscle of the arm; one embroidered EMG electrode (ground) was located to correspond to the Humerus elbow bone; two additional electrodes were embroidered for use to stimulate muscles . The eleExperiments were conducted based on the procedure approved by Istanbul Technical University IRB with a total of five participants. Body Mass Indexes (BMIs) of all participants, demographic information, major body measurements and clothing sizes are listed in the below Out of these five participants, one male and two female participants were body-scanned and their body measurements were used to custom draft the two t-shirt patterns with set-in and raglan sleeves. In addition to the three body-scanned participants, one female and one male participant with matching sizes to the initial three body-scanned participants were recruited to analyze the conditions where the t-shirt was slightly snug and slightly loose within the same size limits compared to the custom-fit conditions. In EMG measurements were taken from the participants under three conditions: 1. Bare skin with conventional hydrogel Ag Ag/Cl electrode; 2. Raglan sleeve t-shirt with embroidered e-textile electrode, 3. Set-in sleeve t-shirt with embroidered e-textile electrode in a random order. EMG measurements were retrieved using a wireless Delsys snap EMG sensor which was connected to the embroidered electrodes on the sleeves for t-shirt conditions and to the conventional Ag/AgCl hydrogel electrode for the bare skin condition via metal snaps. For each condition, participants engaged in a 2.5 kg dumbbell biceps curl movement which they repeated for 10 times synchronizing their bicep curl movements to a standardized metronome beat/second rhythm. In each condition, EMG data was retrieved in three repetitions of the same movement protocol to ensure a repeated measure experiment design.In addition to the EMG measurements, electrode skin impedance data under three conditions for each participant were measured using a desktop LCR meter device (Instek LCR 6100) while the participants were in a still arm position. The measurements were performed by using a standard two-electrode configuration  and AC sCollected EMG signals under three different conditions were analyzed using MATLAB according to the EMG signal forms, frequencies and SNRdB values to evaluate the effect of sleeve pattern on embroidered EMG electrode performance in comparison to conventional hydrogel electrodes applied to the bare skin.SNRdB was calculated using the Equation (1). 8 contractions among 10 measurements of each participant, excluding the first and last trials, were used to calculate the signal Root Mean Square (RMS). RMS of the noise was calculated from the 10 s of silent muscle activity recording before the beginning of the biceps curl movement.p < 0.05 corresponded to significant difference between conditions.Power spectral density (PSD), a tool for analysing EMG data in frequency domain characteristics, was used to compare the EMG signal further using MatLab. PSD was calculated by squaring the absolute value of Fourier Transform of EMG signal divided by the signal length. Dominant frequency, the frequency of the maximum amplitude of PSD were calculated for each trial of each participant under three conditions. One-way ANOVA and LSD post-hoc analysis were used to analyze all the data where t-test in comparison to conventional hydrogel Ag/AgCl electrodes. In addition, one-way ANOVA and LSD post hoc analysis were used to analyze all the data where p < 0.05 corresponded to significant difference between conditions.Electrode skin impedance results for each participant under three conditions were calculated as mean ± standard deviation (SD). Since the data displayed normal distribution, both electrode–skin impedance and SNRdb measurements for embroidered electrodes on the t-shirts were analyzed using the Student’s 2) and bursting strength was 12.34 kPa. The knit fabric displayed 102.8% elasticity in wale direction and 138.3% in course direction. The residual elasticity rate measurement revealed rates of 10% in wale and 14% in course directions. Residual elasticity rate refers to recovery of the fabric or the bounce back to the original size after it has been stretched. Elasticity percentage and residual elasticity rate in course direction were used to calculate the negative ease during pattern drafting of the t-shirts with set-in and raglan sleeve variations. Negative ease refers to reducing the garment pattern dimensions so that the garment measurements are smaller than the body measurements but the elasticity of the knit fabric provides the ease and room for movement while creating a body tight fit.The wale density of the knit fabric used to prototype the t-shirts was measured as 21 wale/cm while the course density was 41.8 course/cm. As displayed in Madeira HC12 conductive embroidery thread used to embroider EMG electrodes on t-shirt prototypes had 610 ± 15 dtex value and was a z-twist. The mean electrical resistivity of the thread was measured as 6.0 ± 0.0 Ω per 10 cm length. p < 0.05) and results are given as Mean ± SD. Custom fit conditions were used in analyzing these results to achieve a clear comparison between hydrogel and e-textile electrodes and the two set-in and raglan sleeve garment pattern conditions. The EMG measurements retrieved with the raglan sleeve t-shirt showed similar SNRdB to the conventional hydrogel electrode. On the other hand, the set-in sleeve t-shirt with e-textile electrode had statistically significantly lower SNRdb compared to the other two conditions. The overall results for the SNDdb measurements was consistent with the literature . When weThe electrode–skin impedance spectrum as displayed in In addition, the phase angle of the impedance was negative for all conditions. The average phase angle value for the conventional electrode was higher than the e- textile electrode conditions  Set-in aIn addition to analyzing the effect of different sleeve pattern cuts of set-in and raglan sleeve on EMG signal performance, the fit of t-shirts on different body types where the fit for each t-shirt pattern was either slightly snug or loose was studied . Table 7In addition, comparing raglan and set-in sleeve t-shirts from the perspective of fit and its effects on EMG performance, the data showed that set-in sleeve pattern t-shirt performed better with higher SNRdb values in snug fit condition and the SNRdb value dropped drastically in the loose condition. On the other hand, the raglan sleeve pattern t-shirt did not display any drastic changes in EMG signal quality in loose and snug conditions but performed best in the custom-fit condition. Based on this comparison, it is possible to discuss that raglan-sleeve pattern could be less affected by slight fit variations within the same size range and set-in sleeve pattern should be developed with extra negative-ease for better performance.This study investigated the effect clothing pattern and fit in EMG applications using e-textile electrodes integrated onto the sleeves of custom drafted t-shirts with set-in and raglan sleeves. The raglan sleeve pattern, widely used in athletic wear to provide extra ease for the movement of shoulder joint, showed superior performance and therefore indicated the pattern of a garment could have significant effect on EMG signal quality in the design of smart clothing. The findings of the study can be specifically summarized in four points.Embroidered e-textile EMG electrode performance is directly related to clothing pattern and cut. The raglan sleeve pattern, which does not have a seam directly on the shoulder joint, shows significantly higher signal-to-noise ratio and gets less affected from the arm movement.The frequency distribution of the PSD analysis indicated that the e-textile electrodes might detect muscle fatigue more sensitively; however, this finding requires further research.The electrode–skin impedance spectrum analysis of e-textile electrodes in raglan sleeve condition shows a more consistent impedance spectrum across different frequencies and therefore relates to considerably higher signal-to-noise ratio of the measured EMG signal.Embroidered e-textile EMG electrode performance is directly related to how clothing fits on the body. Analysis done in comparison to custom-fit set-in and raglan sleeve pattern conditions revealed that slightly snug or slightly loose fit conditions within the same clothing size range results in decline in the EMG signal quality for the raglan-sleeve pattern style. On the other hand, the set-in sleeve pattern style performs better when the fit is more snig and the EMG signal quality significantly declines in loose conditions.In addition to these findings, there are some limitations of the study that can pave way into future research. Increasing the number of participants can provide a comparison across genders. In this study, even though the data does not show any tendency to be different across genders according to the SNRdb data, it was not possible to draw a generalizable conclusion. In addition, investigation of fabric displacement during movement as well as applied pressure by clothing across different pattern and fit conditions can provide a more in-depth understanding on the role of clothing pattern and cut in smart clothing development for EMG applications.This pioneering preliminary study proves the direct relationship between e-textile electrode performance and clothing pattern and cut and therefore the clothing fit. E-textile EMG electrodes have superior signal quality when t-shirt patterns and sizing are carefully designed, consider the movements of the body and alignment of the seamlines, as well as the elasticity and recovery of the fabric to create the optimum fit in dynamic conditions.


Hospital acquired infections are common, costly, and potentially preventable adverse events. This study aimed to determine the effect of the COVID-19 pandemic-related escalation in infection prevention and control measures on the incidence of hospital acquired infection in surgical patients in a low COVID-19 environment in Australia.This was a retrospective cohort study in a tertiary institution. All patients undergoing a surgical procedure from 1 April 2020 to 30 June 2020 (COVID-19 pandemic period) were compared to patients pre-pandemic (1 April 2019–30 June 2019). The primary outcome investigated was odds of overall hospital acquired infection. The secondary outcome was patterns of involved microorganisms. Univariable and multivariable logistic regression analysis was performed to assess odds of hospital acquired infection.P = 0.434). The multivariable regression analysis adjusting for potentially confounding co-variables also demonstrated no evidence of change in odds of hospital acquired infection .There were 5945 admission episodes included in this study, 224 (6.6%) episodes had hospital acquired infections in 2019 and 179 (7.1%) in 2020. Univariable logistic regression analysis demonstrated no evidence of change in odds of having a hospital acquired infection between cohorts (OR 1.08, 95% CI 0.88–1.33, Increased infection prevention and control measures did not affect the incidence of hospital acquired infection in surgical patients in our institution, suggesting that there may be a plateau effect with these measures in a system with a pre-existing high baseline of practice.The online version contains supplementary material available at 10.1007/s00268-022-06539-4. Hospital acquired infections (HAI) are common adverse events in the developed world and remain challenging to address . The repIn response to the COVID-19 pandemic, increased infection prevention and control (IPC) measures were implemented in hospitals to prevent transmission of COVID-19 to patients and staff. Among these measures was an emphasis on hand hygiene awareness. Hands are vectors for microorganism transmission; proper hand hygiene is the simplest intervention to reduce pathogen transmission and potential infection –6. The eDuring the first half of 2020, Australia was in the unique position of being able to prepare for the COVID-19 pandemic without having suffered any significant COVID-19 impact on the hospital system, as there were small numbers of COVID-19 inpatient admissions and relatively low community transmission rates. This afforded us the opportunity to investigate the impact of the escalation in IPC behaviours on HAI in a low COVID-19 environment. We investigated outcomes in a single tertiary institution where changes in IPC strategies could be measured and substantiated.The aim of this study was to determine the effect of COVID-19 pandemic-related escalation in IPC measures and hygiene behaviours on the incidence of HAI in surgical patients. We chose to study surgical patients surmising that they had a higher likelihood of requiring further minor invasive interventions where increased IPC measures might have effect. A secondary objective of this study was to investigate patterns of microorganisms involved in HAI pre- and during pandemic.This was a retrospective cohort study performed at The Royal Melbourne Hospital (RMH), Melbourne, Victoria, Australia. Ethics approval was granted by the institution (Study ID QA2021042). This study was reported in accordance with the STROBE statement [The exposure group was all admission episodes at RMH city campus with patients undergoing surgical interventions for the period 1 April 2020–30 June 2020. The comparison group was admission episodes with the same inclusion criteria pre-pandemic (1 April 2019–30 June 2019).The time period for the exposure group corresponded with the first wave of COVID-19 in Victoria, Australia. There were 35 COVID-19 admission episodes relating to 32 patients within our institution in the study period. Daily case numbers within the state (population 6.6 million) were fewer than 100 per day .th Revision, Australian modification (ICD-10-AM) codes.Data were collected from several sources of administrative data, including patient administration system data, Australian Classification of Healthcare Interventions (ACHI) procedural codes and International Classification of Diseases, 10The exposure of interest was the 2020 time period, during which there were hospital-wide changes in IPC measures and increased hygiene behaviours in response to the COVID-19 pandemic. These changes were substantiated from several sources. National Hand Hygiene Initiative (NHHI) audit data monitoring hand hygiene compliance were collected, audits were performed using intermittent sampling of ward staff by accredited nurses based on compliance with the WHO five moments of hand hygiene model . The amoDetails on patient demographics and comorbidities (using the Charlson Comorbidity Index (CCI) and the American Society of Anaesthesiologists (ASA) physical status classification system) were collected and categorised. Missing ASA score data were assigned a category of “Not recorded” to avoid data restriction in the final multivariable regression analysis. CCI was categorised into 0, 1 and ≥ 2, as any score ≥ 2 is associated with increased mortality. CCI has been validated for use in ICD-10-AM .Admission data including elective or emergency admission, length of stay (LOS), and intensive care unit (ICU) or coronary care unit (CCU) admission were recorded. Procedural information of surgical unit subspecialty, anaesthetic type, duration of index operation, number of separate visits to the operating suite and ACHI codes for index procedure were recorded. Although LOS can be used as an outcome variable, in this study we have used it as an exposure variable. LOS was categorised as day case, overnight stay and > 2 days to discriminate between short and long stay patients and to act as an indirect measure of the extent of their procedure.The outcome variable “Hospital acquired infection” (HAI) was determined from a standardised list of hospital acquired complication (HAC) infection ICD-10-AM codes used by the Australian Commission on Safety and Quality in Health Care, with the indicator variable of not being present on admission . ReadmisHAI includes the diagnosis of urinary tract infections, surgical site infections (SSI), pneumonia, bloodstream infections, central line and peripheral line-associated bloodstream infection, multi-resistant organism, infection associated with prosthetic or implantable devices, gastrointestinal infection and other high impact infection (such as sepsis). Patients admitted with a pre-existing infection as their principal diagnosis on their index admission were excluded.Clinical surveillance of HAI had been temporarily suspended during the pandemic study period. Clinical surveillance usually involved infection prevention and surveillance staff measuring and reporting on specific performance indicators such as central-line associated blood stream infections in the ICU, and SSI on specific patient cohorts.The secondary outcome investigated was the pattern of microorganisms involved in HAI across both time periods. A file review was conducted of patients who had a HAI and microbiology results were correlated with their clinical notes and type of infection. The type and date of sample, organism cultured and antibiotic sensitivities were recorded.Statistical analysis was performed using STATA version 16.0  statistical software. Baseline data were presented as counts, percentages, median values and inter-quartile range. Univariable logistic regression was used to analyse the odds of overall HAI for the principal exposure of interest (COVID-19 time period compared with pre-COVID-19) and for the other co-variables. The principal exposure of interest, and any co-variables with a greater than 10% effect on odds of HAI from the univariable regression were included in the multi-variable logistic regression analysis.There was a total of 6208 admission episodes across the two time periods. After 263 admission episodes were excluded , 5945 admission episodes were included in the study. There were 3415 admission episodes in the 2019 cohort and 2530 admission episodes in the 2020 cohort. Baseline patient demographics were similar across the two cohorts  in 2019 to 86.7% (CI 85.6%–87.7%) in 2020 (Table P = 0.434) (Table P = 0.530), having adjusted for multiple potential confounding factors (Table There were 224 (6.6%) admission episodes associated with one or more HAI pre-pandemic and 179 (7.1%) during the 2020 pandemic period Table . UnivariStaphylococcus aureus (MRSA) and Extended Spectrum Beta Lactamase (ESBL) Escherichia coli were similar across both time periods, and again too small for meaningful statistical analysis , no change in incidence was found for MRSA [There are studies reporting the effect of enhanced IPC measures on HAI in hospital populations overall, rather than just surgical patients, with variable impact on HAI and MDRO. A Taiwanese study conducted in a low COVID-19 environment found no overall change in incidence density (incidence per 1000 patient days) of HAI. Although there was a reduction in incidence of Vancomycin-resistant enterococcus (VRE) and Carbapenem-resistant for MRSA . A studyfor MRSA .The impact of COVID-19 on HAI will vary based on the local burden of COVID-19 infections and the subsequent effect of that disease burden on the healthcare system. The ratio of COVID-19 to non-COVID-19 hospital admissions and other changes in the hospital system could potentially confound HAI outcomes. The suspension of mandatory reporting for HAI in many parts of the world during the height of the COVID-19 pandemic has made it difficult to accurately report on HAI outcomes during this period . The lacThis was a rare opportunity to investigate the impact of increased IPC measures, including increased hand hygiene compliance, in a low COVID-19 environment. Hand hygiene compliance measurements based on the WHO 5 moments of hand hygiene are a standardised and observable process measure for quality improvement , 21. HowThis study is based on a retrospective review of administrative data to investigate HAI outcomes. The use of administrative data could under or over-ascertain HAI compared to traditional clinical surveillance methods, however, any inherent coding biases are likely to be non-differential over the two observed time periods. Coding practices for conversion of clinical data to administrative data in Australia are standardised and reliable .The changes in IPC measures are described at a hospital-wide level and cannot be measured at an individual level. These results are from a single tertiary institution and may not be generalisable to other hospitals, however, this hospital is representative of Australian metropolitan tertiary hospitals.Australia was in a unique position amongst Western countries during the early phase of the COVID-19 pandemic to study the effects of increased IPC measures in a low COVID-19 environment. This study has found no evidence that increased hand hygiene compliance and other IPC measures altered the incidence of HAI in surgical patients despite adjusting for multiple confounding variables. Numbers of MDRO and overall types of microorganisms were similar throughout the two time periods. In a hospital environment with high levels of pre-existing infection prevention strategies including hand hygiene compliance, there may be a plateau in what further reduction in HAI can be achieved with the existing suite of IPC measures. Further reductions in HAI may require multiple sustained interventions. Given the morbidity and mortality associated with HAI, the need to find additional beneficial interventions is critical.Supplementary file1 (PDF 53 KB)Supplementary file2 (PDF 63 KB)Below is the link to the electronic supplementary material.