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PURPOSE: The aim of this study was to develop and validate radiomics signatures based on MRI for preoperative prediction of Ki-67 proliferative index (PI) expression in primary central nervous system lymphoma (PCNSL). METHODS: A total of 341 patients with PCNSL were retrospectively analyzed, including 286 patients in one center as the training set and 55 patients in another two centers as the external validation set. Radiomics features were extracted and selected from preoperative contrast-enhanced T1-weighted images, fluid attenuation inversion recovery to build radiomics signatures according to the Ki-67 PI. The predictive performances of the radiomics model were evaluated using four classifiers including random forest, K-Nearest Neighbors, Neural Network and Decision Tree. A combined model was built by incorporating radiomics signature, clinical variables and MRI radiological characteristics using multivariate logistic regression analysis, and a nomogram was established to predict the expression of Ki-67 individually. The predictive performances of the models were evaluated using area under receiver operating characteristic curve (AUC) and decision curve analysis (DCA). RESULTS: Radiomics signatures were independent predictors of the expression level of Ki-67 (OR: 2.523, P < 0.001). RF radiomics models had the highest accuracy (0.934 in the training set and 0.811 in the external validation set) and F1 Score (0.920 in the training set and 0.836 in the external validation set). The clinic-radiologic-radiomics nomogram showed better predictive performance with AUCs of 0.877(95 % CI: 0.837-0.918) in the training set and 0.866(95 % CI: 0.774-0.957) in the external validation set. The calibration curve and DCA demonstrated goodness-of-fit and improved benefits in clinical practice of the nomogram. CONCLUSIONS: Nomograms integrating MRI-based radiomics and clinical-radiological characteristics could effectively predict Ki-67 PI in primary PCNSL.
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The second messenger cyclic diguanylate monophosphate (c-di-GMP) regulates a wide range of bacterial behaviours through diverse mechanisms and binding receptors. Single-domain PilZ proteins, the most widespread and abundant known c-di-GMP receptors in bacteria, act as trans-acting adaptor proteins that enable c-di-GMP to control signalling pathways with high specificity. This study identifies a single-domain PilZ protein, XAC3402 (renamed N5MapZ), from the phytopathogen Xanthomonas citri subsp. citri (Xcc), which modulates Xcc virulence by directly interacting with the methyltransferase HemK. Through yeast two-hybrid, co-immunoprecipitation and immunofluorescent staining, we demonstrated that N5MapZ and HemK interact directly under both in vitro and in vivo conditions, with the strength of the protein-protein interaction decreasing at high c-di-GMP concentrations. This finding distinguishes N5MapZ from other characterized single-domain PilZ proteins, as it was previously known that c-di-GMP enhances the interaction between those single-domain PilZs and their protein partners. This observation is further supported by the fact that the c-di-GMP binding-defective mutant N5MapZR10A can interact with HemK to inhibit the methylation of the class 1 translation termination release factor PrfA. Additionally, we found that HemK plays an important role in Xcc pathogenesis, as the deletion of hemK leads to extensive phenotypic changes, including reduced virulence in citrus plants, decreased motility, production of extracellular enzymes and stress tolerance. Gene expression analysis has revealed that c-di-GMP and the HemK-mediated pathway regulate the expression of multiple virulence effector proteins, uncovering a novel regulatory mechanism through which c-di-GMP regulates Xcc virulence by mediating PrfA methylation via the single-domain PilZ adaptor protein N5MapZ.
Subject(s)
Bacterial Proteins , Cyclic GMP , Methyltransferases , Xanthomonas , Xanthomonas/pathogenicity , Xanthomonas/metabolism , Xanthomonas/genetics , Cyclic GMP/metabolism , Cyclic GMP/analogs & derivatives , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Methyltransferases/metabolism , Methyltransferases/genetics , Virulence , Plant Diseases/microbiology , Protein BindingABSTRACT
Diabetic nephropathy (DN) is a common complication of diabetes, characterized by renal fibrosis and poor patient prognosis. Hederagenin (HDG) has shown promising improvement in chronic kidney disease (CKD) kidney fibrosis, but its mechanism in DN-induced kidney fibrosis remains unclear. In this study, a model of diabetic nephropathy (DN) in mice was induced by intraperitoneal injection of streptozocin (50 mg/kg), while in vitro, high glucose (25 mM) was used to induce HK2 cell damage, simulating tubular injury in DN kidneys. The improvement of HDG treatment intervention was evaluated by observing changes in renal function, pathological structural damage, and the expression of fibrosis-related proteins in renal tubular cells. The results demonstrate that HDG intervention alleviates renal dysfunction and pathological damage in DN mice, accompanied by reduced expression of fibrotic markers α-smooth muscle actin (α-SMA), fibronectin (FN) and Collagen-I. Mechanistically, this study found that HDG can inhibit ferroptosis and fibrosis induced by the ferroptosis inducer Erastin (1 µM) in renal tubular cells. Phosphorylation of Smad3 promotes ferroptosis in renal tubular cells. After using its specific inhibitor SIS3 (4 µM), the expression of downstream target protein NADPH oxidase 4 (NOX4) significantly decreases, while the level of glutathione peroxidase 4 (GPX4) is notably restored, mitigating ferroptosis. Smad3 overexpression attenuates the therapeutic effect of HDG on tubular cell fibrosis induced by high glucose. These results demonstrate HDG inhibits Smad3 phosphorylation, thereby reducing the expression of NOX4 and enhancing the expression of GPX4, ultimately attenuating ferroptosis induced renal fibrosis. These findings suggest that HDG offer therapeutic potential for DN renal fibrosis by targeting Smad3-mediated ferroptosis in renal tubular cells.
Subject(s)
Diabetic Nephropathies , Ferroptosis , Fibrosis , Mice, Inbred C57BL , NADPH Oxidase 4 , Oleanolic Acid , Signal Transduction , Smad3 Protein , Animals , Ferroptosis/drug effects , Smad3 Protein/metabolism , Diabetic Nephropathies/drug therapy , Diabetic Nephropathies/pathology , Diabetic Nephropathies/metabolism , NADPH Oxidase 4/metabolism , NADPH Oxidase 4/genetics , Humans , Mice , Signal Transduction/drug effects , Male , Cell Line , Oleanolic Acid/analogs & derivatives , Oleanolic Acid/pharmacology , Oleanolic Acid/therapeutic use , Kidney Tubules/pathology , Kidney Tubules/drug effects , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolismABSTRACT
Type VI secretion systems (T6SS) are bacterial macromolecular complexes that secrete effectors into target cells or the extracellular environment, leading to the demise of adjacent cells and providing a survival advantage. Although studies have shown that the T6SS in Pseudomonas aeruginosa is regulated by the Quorum Sensing system and second messenger c-di-GMP, the underlying molecular mechanism remains largely unknown. In this study, we discovered that the c-di-GMP-binding adaptor protein PA0012 has a repressive effect on the expression of the T6SS HSI-I genes in P. aeruginosa PAO1. To probe the mechanism by which PA0012 (renamed TssZ, Type Six Secretion System -associated PilZ protein) regulates the expression of HSI-I genes, we conducted yeast two-hybrid screening and identified HinK, a LasR-type transcriptional regulator, as the binding partner of TssZ. The protein-protein interaction between HinK and TssZ was confirmed through co-immunoprecipitation assays. Further analysis suggested that the HinK-TssZ interaction was weakened at high c-di-GMP concentrations, contrary to the current paradigm wherein c-di-GMP enhances the interaction between PilZ proteins and their partners. Electrophoretic mobility shift assays revealed that the non-c-di-GMP-binding mutant TssZR5A/R9A interacts directly with HinK and prevents it from binding to the promoter of the quorum-sensing regulator pqsR. The functional connection between TssZ and HinK is further supported by observations that TssZ and HinK impact the swarming motility, pyocyanin production, and T6SS-mediated bacterial killing activity of P. aeruginosa in a PqsR-dependent manner. Together, these results unveil a novel regulatory mechanism wherein TssZ functions as an inhibitor that interacts with HinK to control gene expression.
Subject(s)
Bacterial Proteins , Gene Expression Regulation, Bacterial , Pseudomonas aeruginosa , Transcription, Genetic , Type VI Secretion Systems , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Cyclic GMP/analogs & derivatives , Cyclic GMP/metabolism , Electrophoretic Mobility Shift Assay , Immunoprecipitation , Mutation , Promoter Regions, Genetic , Protein Binding , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/metabolism , Pyocyanine/metabolism , Quorum Sensing , Second Messenger Systems , Two-Hybrid System Techniques , Type VI Secretion Systems/genetics , Type VI Secretion Systems/metabolismABSTRACT
Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide. The phloem-restricted bacterium Candidatus Liberibacter asiaticus (CLas) is considered to be the main pathogen responsible for HLB. There is currently no effective practical strategy for the control of HLB. Our understanding of how pathogens cause HLB is limited because CLas has not been artificially cultured. In this study, 15 potential virulence factors were predicted from the proteome of CLas through DeepVF and PHI-base searches. One among them, FlgI, was found to inhibit yeast growth when expressed in Saccharomyces cerevisiae. The expression of the signal peptide of FlgI fused with PhoA in Escherichia coli resulted in the discovery that FlgI was a novel Sec-dependent secretory protein. We further found that the carboxyl-terminal HA-tagged FlgI was secreted via outer membrane vesicles in Sinorhizobium meliloti. Fluoresence localization of transient expression FlgI-GFP in Nicotiana benthamiana revealed that FlgI is mainly localized in the cytoplasm, cell periphery, and nuclear periphery of tobacco cells. In addition, our experimental results suggest that FlgI has a strong ability to induce callose deposition and cell necrosis in N. benthamiana. Finally, by screening a large library of compounds in a high-throughput format, we found that cyclosporin A restored the growth of FlgI-expressing yeast. These results confirm that FlgI is a novel Sec-dependent effector, enriching our understanding of CLas pathogenicity and helping to develop new and more effective strategies to manage HLB.
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Introduction: Human-in-the-loop optimization has made great progress to improve the performance of wearable robotic devices and become an effective customized assistance strategy. However, a lengthy period (several hours) of continuous walking for iterative optimization for each individual makes it less practical, especially for disabled people, who may not endure this process. Methods: In this paper, we provide a muscle-activity-based human-in-the-loop optimization strategy that can reduce the time spent on collecting biosignals during each iteration from around 120 s to 25 s. Both Bayesian and Covariance Matrix Adaptive Evolution Strategy (CMA-ES) optimization algorithms were adopted on a portable hip exoskeleton to generate optimal assist torque patterns, optimizing rectus femoris muscle activity. Four volunteers were recruited for exoskeleton-assisted walking trials. Results and Discussion: As a result, using human-in-the-loop optimization led to muscle activity reduction of 33.56% and 41.81% at most when compared to walking without and with the hip exoskeleton, respectively. Furthermore, the results of human-in-the-loop optimization indicate that three out of four participants achieved superior outcomes compared to the predefined assistance patterns. Interestingly, during the optimization stage, the order of the two typical optimizers, i.e., Bayesian and CMA-ES, did not affect the optimization results. The results of the experiment have confirmed that the assistance pattern generated by muscle-activity-based human-in-the-loop strategy is superior to predefined assistance patterns, and this strategy can be achieved more rapidly than the one based on metabolic cost.
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Indian mustard (Brassica juncea L. Czern and Coss) is an important oil and vegetable crop frequently affected by seasonal drought stress during seed germination, which retards plant growth and causes yield loss considerably. However, the gene networks regulating responses to drought stress in leafy Indian mustard remain elusive. Here, we elucidated the underlying gene networks and pathways of drought response in leafy Indian mustard using next-generation transcriptomic techniques. Phenotypic analysis showed that the drought-tolerant leafy Indian mustard cv. 'WeiLiang' (WL) had a higher germination rate, antioxidant capacity, and better growth performance than the drought-sensitive cv. 'ShuiDong' (SD). Transcriptome analysis identified differentially expressed genes (DEGs) in both cultivars under drought stress during four germination time points (i.e., 0, 12, 24, and 36 h); most of which were classified as drought-responsive, seed germination, and dormancy-related genes. In the Kyoto Encyclopedia of Genes and Genome (KEGG) analyses, three main pathways (i.e., starch and sucrose metabolism, phenylpropanoid biosynthesis, and plant hormone signal transduction) were unveiled involved in response to drought stress during seed germination. Furthermore, Weighted Gene Co-expression Network Analysis (WGCNA) identified several hub genes (novel.12726, novel.1856, BjuB027900, BjuA003402, BjuA021578, BjuA005565, BjuB006596, novel.12977, and BjuA033308) associated with seed germination and drought stress in leafy Indian mustard. Taken together, these findings deepen our understanding of the gene networks for drought responses during seed germination in leafy Indian mustard and provide potential target genes for the genetic improvement of drought tolerance in this crop.
Subject(s)
Germination , Transcriptome , Germination/genetics , Mustard Plant/genetics , Mustard Plant/metabolism , Droughts , Seeds , Gene Expression Profiling , Hormones/metabolism , Gene Expression Regulation, PlantABSTRACT
Interstitial fibrosis is the key pathological characteristics of chronic kidney diseases (CKD). In this study, we reported that hederagenin (HDG) can effectively improve the renal interstitial fibrosis and its mechanism. We constructed CKD animal models of ischemia reperfusion injury (IRI) and unilateral ureteral obstruction (UUO) respectively to observe the improvement effect of HDG on CKD. The results showed that HDG can effectively improve the pathological structure of kidney and the renal fibrosis in CKD mice. Meanwhile, HDG can also significantly reduce the expression of α-SMA and FN induced by TGF-ß in Transformed C3H Mouse Kidney-1 (TCMK1) cells. Mechanistically, we performed transcriptome sequencing on UUO kidneys treated with HDG. By real time PCR screening of the sequencing results, we determined that ISG15 plays an important role in the intervention of HDG in CKD. Subsequently, we knocked-down ISG15 in TCMK1 and found that ISG15 knock-down significantly inhibited TGF-ß-induced fibrotic protein expression and JAK/STAT activation. Finally, we performed electrotransfection and used liposomes to transfect ISG15 overexpression plasmids to up-regulate ISG15 in kidney and cells, respectively. We found that ISG15 can aggravate renal tubular cell fibrosis and abolish the protection of HDG on CKD. These results indicated that HDG significantly improves renal fibrosis in CKD by inhibiting ISG15 and its downstream JAK/STAT signaling pathway, which provides a new drug and research target for the subsequent treatment of CKD.
Subject(s)
Renal Insufficiency, Chronic , Ureteral Obstruction , Mice , Animals , Mice, Inbred C3H , Kidney/pathology , Renal Insufficiency, Chronic/pathology , Ureteral Obstruction/drug therapy , Signal Transduction , Transforming Growth Factor beta/metabolism , Fibrosis , Transforming Growth Factor beta1/metabolismABSTRACT
Disruption of the cell cycle is a common strategy shared by many viruses to create a conducible cellular microenvironment for their efficient replication. We have previously shown that infection of cells with gammacoronavirus infectious bronchitis virus (IBV) activated the theataxia-telangiectasia mutated (ATM) Rad3-related (ATR)/checkpoint kinase 1 (Chk1) pathway and induced cell cycle arrest in S and G2/M phases, partially through the interaction of nonstructural protein 13 (nsp13) with the p125 catalytic subunit of DNA polymerase delta (pol δ). In this study, we show, by GST pulldown, co-immunoprecipitation and immunofluorescent staining, that IBV nsp12 directly interacts with the p50 regulatory subunit of pol δ in vitro and in cells overexpressing the two proteins as well as in cells infected with a recombinant IBV harbouring an HA-tagged nsp12. Furthermore, nsp12 from severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 was also able to interact with p50. These interactions play a synergistic role with nsp13 in the induction of S phase arrest. The fact that subunits of an essential cellular DNA replication machinery physically associate with two core replication enzymes from three different coronaviruses highlights the importance of these associations in coronavirus replication and virus-host interaction, and reveals the potential of targeting these subunits for antiviral intervention.
Subject(s)
COVID-19 , Infectious bronchitis virus , Humans , DNA Polymerase III/chemistry , DNA Polymerase III/genetics , DNA Polymerase III/metabolism , S Phase , Coronavirus RNA-Dependent RNA Polymerase , RNA Helicases/genetics , RNA Helicases/metabolism , SARS-CoV-2/metabolism , Cell Cycle Checkpoints , Infectious bronchitis virus/genetics , Infectious bronchitis virus/metabolism , DNA DamageABSTRACT
With the rapid development of computer vision, the application of computer vision to precision farming in animal husbandry is currently a hot research topic. Due to the scale of goose breeding continuing to expand, there are higher requirements for the efficiency of goose farming. To achieve precision animal husbandry and to avoid human influence on breeding, real-time automated monitoring methods have been used in this area. To be specific, on the basis of instance segmentation, the activities of individual geese are accurately detected, counted, and analyzed, which is effective for achieving traceability of the condition of the flock and reducing breeding costs. We trained QueryPNet, an advanced model, which could effectively perform segmentation and extraction of geese flock. Meanwhile, we proposed a novel neck module that improved the feature pyramid structure, making feature fusion more effective for both target detection and instance individual segmentation. At the same time, the number of model parameters was reduced by a rational design. This solution was tested on 639 datasets collected and labeled on specially created free-range goose farms. With the occlusion of vegetation and litters, the accuracies of the target detection and instance segmentation reached 0.963 (mAP@0.5) and 0.963 (mAP@0.5), respectively.
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OBJECTIVE: Neuropathic pain (NP) plays an important role in patients with knee osteoarthritis (KOA). However, the prevalence of NP at different treatment stages including outpatient, awaiting and after total knee arthroplasty (TKA) have not been compared. The understanding of this issue and identify risk factors can help physicians develop individualized strategies to manage the pain of KOA. Therefore, the aim of the study is to investigate the prevalence and risk factors of NP at different treatment stages of KOA. METHODS: Patients diagnosed as KOA between August 2016 and August 2020 were enrolled in this cross-sectional study and divided into three groups according to treatment stage, including outpatient stage, awaiting TKA stage (pre-TKA) and after TKA stage (post-TKA). A numeric rating scale (NRS) and PainDETECT questionnaire were used to evaluate nociceptive pain and NP. Patient demographics, radiological assessments using Kellgren-Lawrence (K-L) grade, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were analyzed. Data analysis and statistics were processed using SPSS 20.0 and examined by ANOVA with/without Bonferroni correction or Kruskal-Wallis test. A chi-square test was used to determine cross-table data and calculate the odds ratio (OR) value. RESULTS: Of the 921 patients, the prevalence of possible and likely NP was 17.5% (56/320) and 2.5% (8/320) in the pre-TKA group compared with 3.4% (8/233) and 0.4% (1/233) in the outpatient group and 1.4% (5/368) and 0.5% (2/368) in the post-TKA group, respectively. In the pre-TKA group, higher NRS (NRS >3; OR = 10.65, 95% CI: 3.25-34.92, P < 0.001) and WOMAC pain score (score > 10; OR = 4.88, 95% CI: 2.38-10.01, P < 0.001) conferred an increased risk of unclear pain. Age, gender, BMI and K-L grade showed no significant differences among the unlikely, possible and likely NP groups. CONCLUSION: Prevalence of NP is different at stages of out-patient, awaiting and after TKA in patients with KOA. Patients awaiting TKA have the highest prevalence of NP compared with patients in outpatient and post-TKA groups. In the patients waiting for TKA, higher NRS (NRS >3) and WOMAC pain scores (score > 10) are risk factors of NP.
Subject(s)
Arthroplasty, Replacement, Knee , Neuralgia , Osteoarthritis, Knee , Humans , Osteoarthritis, Knee/surgery , Outpatients , Prevalence , Cross-Sectional Studies , Neuralgia/surgery , Risk Factors , Knee Joint/surgery , Treatment OutcomeABSTRACT
Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), seriously affects fruit quality and yield, leading to significant economic losses around the world. Understanding the mechanism of Xcc virulence is important for the effective control of Xcc infection. In this report, we investigate the role of a protein named HemK in the regulation of the virulence traits of Xcc. The hemK gene was deleted in the Xcc jx-6 background, and the ΔhemK mutant phenotypically displayed significantly decreased motility, biofilm formation, extracellular enzymes, and polysaccharides production, as well as increased sensitivity to oxidative stress and high temperatures. In accordance with the role of HemK in the regulation of a variety of virulence-associated phenotypes, the deletion of hemK resulted in reduced virulence on citrus plants as well as a compromised hypersensitive response on a non-host plant, Nicotiana benthamiana. These results indicated that HemK is required for the virulence of Xcc. To characterize the regulatory effect of hemK deletion on gene expression, RNA sequencing analysis was conducted using the wild-type Xcc jx-6 strain and its isogenic ΔhemK mutant strain, grown in XVM2 medium. Comparative transcriptome analysis of these two strains revealed that hemK deletion specifically changed the expression of several virulence-related genes associated with the bacterial secretion system, chemotaxis, and quorum sensing, and the expression of various genes related to nutrient utilization including amino acid metabolism, carbohydrate metabolism, and energy metabolism. In conclusion, our results indicate that HemK plays an essential role in virulence, the regulation of virulence factor synthesis, and the nutrient utilization of Xcc.
Subject(s)
Citrus , Xanthomonas , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Citrus/metabolism , Methyltransferases/metabolism , Nutrients , Plant Diseases/microbiology , Virulence/geneticsABSTRACT
Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is a quarantine disease that seriously affects citrus production worldwide. The use of microorganisms and their products for biological control has been proven to be effective in controlling Xanthomonas disease. In this study, a novel Xcc antagonistic strain was isolated and identified as Bacillus amyloliquefaciens F9 by morphological and molecular analysis. The lipopeptide extract of B. amyloliquefaciens F9 (F9LE) effectively inhibited the growth of Xcc in an agar diffusion assay and restrained the occurrence of canker lesions in a pathogenicity test under greenhouse conditions. Consistent with these findings, F9LE treatment significantly inhibited the production of extracellular enzymes in Xcc cells and induced cell wall damage, with leakage of bacterial contents revealed by scanning electron microscopy and transmission electron microscopy analyses. In addition, F9LE also showed strong antagonistic activity against a wide spectrum of plant pathogenic bacteria and fungi. Furthermore, using electrospray ionization mass spectrometry analysis, the main antimicrobial compounds of strain F9 were identified as three kinds of lipopeptides, including homologues of surfactin, fengycin, and iturin. Taken together, our results show that B. amyloliquefaciens F9 and its lipopeptide components have the potential to be used as biocontrol agents against Xcc, and other plant pathogenic bacteria and fungi.
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Background: Thirty per cent supramolecular salicylic acid (SSA) is a water-soluble, sustained release salicylic acid (SA) modality, which is well tolerated by sensitive skin. Anti-inflammatory therapy plays an important role in papulopustular rosacea (PPR) treatment. SSA at a 30% concentration has a natural antiinflammatory property. Aims: This study aims to investigate the efficacy and safety of 30% SSA peeling for PPR treatment. Methods: Sixty PPR patients were randomly divided into two groups: SSA group (30 cases) and control group (30 cases). Patients of the SSA group were treated with 30% SSA peeling three times every 3 weeks. Patients in both groups were instructed to topically apply 0.75% metronidazole gel twice daily. Transdermal water loss (TEWL), skin hydration and erythema index were assessed after 9 weeks. Results: Fifty-eight patients completed the study. The improvement of erythema index in the SSA group was significantly better than that in the control group. No significant difference was found in terms of TEWL between the two groups. The content of skin hydration in both the groups increased, but there was no statistical significance. No severe adverse events were observed in both the groups. Conclusion: SSA can significantly improve the erythema index and overall appearance of skin in rosacea patients. It has a good therapeutic effect, good tolerance and high safety.
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The aging population is now a global challenge, and impaired walking ability is a common feature in the elderly. In addition, some occupations such as military and relief workers require extra physical help to perform tasks efficiently. Robotic hip exoskeletons can support ambulatory functions in the elderly and augment human performance in healthy people during normal walking and loaded walking by providing assistive torque. In this review, the current development of robotic hip exoskeletons is presented. In addition, the framework of actuation joints and the high-level control strategy (including the sensors and data collection, the way to recognize gait phase, the algorithms to generate the assist torque) are described. The exoskeleton prototypes proposed by researchers in recent years are organized to benefit the related fields realizing the limitations of the available robotic hip exoskeletons, therefore, this work tends to be an influential factor with a better understanding of the development and state-of-the-art technology.
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BACKGROUND: Pathological gaits of children may lead to terrible diseases, such as osteoarthritis or scoliosis. By monitoring the gait pattern of a child, proper therapeutic measures can be recommended to avoid the terrible consequence. However, low-cost systems for pathological gait recognition of children automatically have not been on market yet. Our goal was to design a low-cost gait-recognition system for children with only pressure information. METHODS: In this study, we design a pathological gait-recognition system (PGRS) with an 8 × 8 pressure-sensor array. An intelligent gait-recognition method (IGRM) based on machine learning and pure plantar pressure information is also proposed in static and dynamic sections to realize high accuracy and good real-time performance. To verifying the recognition effect, a total of 17 children were recruited in the experiments wearing PGRS to recognize three pathological gaits (toe-in, toe-out, and flat) and normal gait. Children are asked to walk naturally on level ground in the dynamic section or stand naturally and comfortably in the static section. The evaluation of the performance of recognition results included stratified tenfold cross-validation with recall, precision, and a time cost as metrics. RESULTS: The experimental results show that all of the IGRMs have been identified with a practically applicable degree of average accuracy either in the dynamic or static section. Experimental results indicate that the IGRM has 92.41% and 97.79% intra-subject recognition accuracy, and 85.78% and 78.81% inter-subject recognition accuracy, respectively, in the static and dynamic sections. And we find methods in the static section have less recognition accuracy due to the unnatural gesture of children when standing. CONCLUSIONS: In this study, a low-cost PGRS has been verified and realize feasibility, highly average precision, and good real-time performance of gait recognition. The experimental results reveal the potential for the computer supervision of non-pathological and pathological gaits in the plantar-pressure patterns of children and for providing feedback in the application of gait-abnormality rectification.
Subject(s)
Gait , Walking , Child , Feedback , Humans , Machine LearningABSTRACT
Mechanical anisotropy is an essential property for many biomolecules to assume their structures, functions and applications, however, the mechanisms for their direction-dependent mechanical responses remain elusive. Herein, by using a single-molecule nanopore sensing technique, we explore the mechanisms of directional mechanical stability of the xrRNA1 RNA from ZIKA virus (ZIKV), which forms a complex ring-like architecture. We reveal extreme mechanical anisotropy in ZIKV xrRNA1 which highly depends on Mg2+ and the key tertiary interactions. The absence of Mg2+ and disruption of the key tertiary interactions strongly affect the structural integrity and attenuate mechanical anisotropy. The significance of ring structures in RNA mechanical anisotropy is further supported by steered molecular dynamics simulations in combination with force distribution analysis. We anticipate the ring structures can be used as key elements to build RNA-based nanostructures with controllable mechanical anisotropy for biomaterial and biomedical applications.
Subject(s)
Biochemical Phenomena , Exoribonucleases/genetics , Exoribonucleases/metabolism , RNA, Viral/chemistry , Zika Virus/genetics , Anisotropy , Humans , Magnesium/metabolism , Mechanical Phenomena , Molecular Dynamics Simulation , Nucleic Acid Conformation , RNA Folding , RNA, Viral/genetics , Zika Virus Infection/virologyABSTRACT
The type VI secretion system (T6SS), a multifunctional protein secretion device, plays very important roles in bacterial killing and/or virulence to eukaryotic cells. Although T6SS genes have been found in many Xanthomonas species, the biological function of T6SSs has not been elucidated in most xanthomonads. In this study, we identified two phylogenetically distinct T6SS clusters, T6SS1 and T6SS2, in a newly sequenced Chinese strain GX01 of Xanthomonas oryzea pv. oryzicola (Xoc) which causes bacterial leaf streak (BLS) of rice (Oryza sativa L.). Mutational assays demonstrated that T6SS1 and T6SS2 are not required for the virulence of Xoc GX01 on rice. Nevertheless, we found that T6SS2, but not T6SS1, played an important role in bacterial killing. Transcription and secretion analysis revealed that hcp2 gene is actively expressed and that Hcp2 protein is secreted via T6SS. Moreover, several candidate T6SS effectors were predicted by bioinformatics analysis that might play a role in the antibacterial activity of Xoc. This is the first report to investigate the type VI secretion system in Xanthomonas oryzae. We speculate that Xoc T6SS2 might play an important role in inter-bacterial competition, allowing this plant pathogen to gain niche advantage by killing other bacteria.
Subject(s)
Microbial Interactions , Oryza/microbiology , Plant Diseases/microbiology , Type VI Secretion Systems , Xanthomonas/physiology , Computational Biology/methods , Gene Expression Regulation, Bacterial , Genome, Bacterial , Mutation , Phenotype , Phylogeny , Virulence/geneticsABSTRACT
The type VI secretion system (T6SS) is widely distributed in Gram-negative bacteria, whose function is known to translocate substrates to eukaryotic and prokaryotic target cells to cause host damage or as a weapon for interbacterial competition. Pseudomonas aeruginosa encodes three distinct T6SS clusters (H1-, H2-, and H3-T6SS). The H1-T6SS-dependent substrates have been identified and well characterized; however, only limited information is available for the H2- and H3-T6SSs since relatively fewer substrates for them have yet been established. Here, we obtained P. aeruginosa H2-T6SS-dependent secretomes and further characterized the H2-T6SS-dependent copper (Cu2+)-binding effector azurin (Azu). Our data showed that both azu and H2-T6SS were repressed by CueR and were induced by low concentrations of Cu2+. We also identified the Azu-interacting partner OprC, a Cu2+-specific TonB-dependent outer membrane transporter. Similar to H2-T6SS genes and azu, expression of oprC was directly regulated by CueR and was induced by low Cu2+. In addition, the Azu-OprC-mediated Cu2+ transport system is critical for P. aeruginosa cells in bacterial competition and virulence. Our findings provide insights for understanding the diverse functions of T6SSs and the role of metal ions for P. aeruginosa in bacteria-bacteria competition.
Subject(s)
Bacterial Proteins/metabolism , Copper/metabolism , DNA-Binding Proteins/metabolism , Pseudomonas aeruginosa/pathogenicity , Type VI Secretion Systems/metabolism , Virulence/physiology , Animals , Mice , Pseudomonas Infections/metabolism , Pseudomonas aeruginosa/metabolismABSTRACT
The infections caused by Dickeya zeae become a severe problem in recent years, but the regulatory mechanisms that govern the bacterial virulence remain to be fragmental. Here we report the investigation of potential involvement of polyamines in regulation of D. zeae virulence. We showed that null mutation of speA encoding arginine decarboxylase dramatically decreased the bacterial swimming motility, swarming motility and biofilm formation, and exogenous addition of putrescine effectively rescues the defective phenotypes of D. zeae. HPLC and mass spectrometry analysis validated that speA was essential for production of putrescine in D. zeae. In addition, we demonstrated that D. zeae EC1 could detect and response to putrescine molecules produced by itself or from host plant through specific transporters. Among the two transporters identified, the one represented by PotF played a dominated role over the other represented by PlaP in modulation of putrescine-dependent biological functions. Furthermore, we provided evidence that putrescine signal is critical for D. zeae EC1 bacterial invasion and virulence against rice seeds. Our data depict a novel function of putrescine signal in pathogen-host communication and in modulation of the virulence of an important plant bacterial pathogen.