Analysis of the Asymmetrical Rolling of Ultra-Thin Strips Considering Elastic Deformation of the Strips.

In normal cold rolling, the elastic deformation of the strip is typically ignored because of the dominant plastic deformation. However, this neglect may introduce additional errors when the strip is very thin. The aim of this study is to investigate the characteristics of the deformation region and thickness reduction in the asymmetrical rolling of ultra-thin strips. Mathematical models were developed based on the slab method, with consideration of the elastic deformation of the strips, and employed in the simulation calculation. The percentage of the three zones and the thickness reduction were analyzed using the simulation results. An increase in the speed ratio results in an increase in the reduction ratio, which is influenced by parameters, such as front tension, back tension, friction coefficient, and entry thickness. The elastic deformation of the strip reduces the tension and the roll pressure and causes the reduction ratio to decrease. The findings and conclusions of this study may be helpful to the mill operating in the asymmetrical rolling process of ultra-thin strips.

Photochemistry of plateau lake-derived dissolved organic matter: Reactive species generation and effects on 17ß-estradiol photodegradation.

Naturally strong ultraviolet irradiation at high altitudes causes photobleaching of plateau lake DOM (P-DOM) and affects its photochemical activity. However, the photoreactivity of P-DOM has remained unclear under natural photobleaching condition. Here, six P-DOM samples isolated from plateau lakes in Yunnan Province, China as well as two reference DOM as comparisons were used to explore the photogeneration of reactive species (RS) and their effects on 17ß-estradiol photodegradation. Compared with SRHA/SRFA, P-DOM has lower aromaticity, average molecular weight, and electron-donating capacity. The quantum yields of triplet state P-DOM (3P-DOM*), 1O2, and ∙OH produced in P-DOM solutions were greatly higher than those of reference DOM. The RS quantum yields had positive linear correlations with E2/E3 and SR, whereas were negatively linear correlated with SUVA25. Radical quenching experiments showed that 3P-DOM* was the prominent RS for 17ß-estradiol photodegradation, and its contribution exceeded 70% for each of P-DOM. 3P-DOM*-mediated photodegradation was mainly attributed to the electron-transfer reactions with an average second-order rate constant of 4.62 × 109 M-1s-1, indicating the strong photoreactivity towards 17ß-estradiol. These findings demonstrate that P-DOM is an efficient photosensitizer for RS production, among which 3P-DOM* may play an important role in enhanced photodegradation for organic micropollutants in plateau lake enriched with DOM.

Encapsulation of Enzymes into Hydrophilic and Biocompatible Metal Azolate Framework: Improved Functions of Biocatalyst in Cascade Reactions and its Sensing Applications.

Multiple enzyme-triggered cascade biocatalytic reactions are vital in vivo or vitro, considering the basic biofunction preservation in living organisms and signals transduction for biosensing platforms. Encapsulation of such enzymes into carrier endows a sheltering effect and can boost catalytic performance, although the selection and preparation of an appropriate carrier is still a concern. Herein, focusing on MAF-7, a category of metal azolate framework (MAF) with superiority against the topologically identical ZIF-8, this enzyme@MAF system can ameliorate the sustainability of encapsulating natural enzymes into carriers. The proposed biocatalyst composite AChE@ChOx@MAF-7/hemin is constructed via one-pot in situ coprecipitation method. Subsequently, MAF-7 is demonstrated to exhibit an excellent capacity of the carrier and protection against external factors in the counterpart of ZIF-8 through encapsulated and free enzymes. In addition, detections for specific substrates or inhibitors with favorable sensitivity are accomplished, indicating that the properties above expectation of different aspects of the established platform are successfully realized. This biofunctional composite based on MAF-7 can definitely provide a potential approach for optimization of cascade reaction and enzyme encapsulation.

Iron-Doped Polymer Dots with Enhanced Fluorescence and Dual Enzyme Activity for Versatile Bioassays.

Nanozymes with multiple functionalities endow biochemical sensing with more sensitive and efficient analytical performance by widening the sensing modes. Meanwhile, the target-oriented design of multifunctional nanozymes for certain biosensing remains challenging. Herein, a constructive strategy of doping iron into polymer dots (PDs) to achieve nanozymes with excellent oxidase-mimicking and peroxidase-mimicking activity is proposed. Compared with the Fe-free PDs prepared under the same mild condition, the Fe-doped PDs (Fe-PDs) exhibit greatly boosted fluorescence at 500 nm. While applying 3,3',5,5'-tetramethylbenzidine (TMB) as a chromogenic substrate, the fluorescence of the Fe-PDs can be further quenched by oxTMB due to the inner filter effect (IFE). Inspired by this, a simple but efficient colorimetric and fluorometric dual-mode sensing platform is developed for monitoring the reducing substances ascorbic acid (AA), α-glucosidase (α-Glu), and its inhibitors (AGIs). We believe that such multifunctional enzyme-mimic materials will provoke the exploration of multimode sensing strategy with strong practicality to serve as a versatile tool in biochemical sensing.

Fluorescent assay for acetylcholinesterase activity and inhibitor screening based on lanthanide organic/inorganic hybrid materials.

It is of great significance for the clinical diagnosis of Alzheimer's disease (AD) to achieve the on-site activity evaluation of acetylcholinesterase (AChE), the hydrolase of acetylcholine (ACh). Herein, we have developed a biosensing method endowed with considerable superiority based on the organic-inorganic hybrid composite Eu(DPA)3@Lap with excellent stability and fluorescent properties for this purpose by loading Eu3+ ions and 2,6-dipicolinic acid (DPA) into LAPONITE® (Lap). Through the comprehensive consideration of the specific hydrolysis of acetylthiocholine (ATCh) into thiocholine (TCh) by AChE, the high binding affinity of TCh to copper ion (Cu2+), and the selective fluorescence quenching ability of Cu2+, a simple Eu(DPA)3@Lap-based assay was developed to realize the rapid and convenient evaluation of AChE activity. Owning to the facile signal on-off-on response mode with a clear PET-based sensing mechanism, our assay presents favorable selectivity and sensitivity (LOD of 0.5 mU mL-1). Furthermore, the fluorescent assay was successfully applied for assessing AChE activity in human serum samples and screening potential AChE inhibitors, showing potential for application in the early diagnosis and drug screening of AD, as a new development path of AD therapy.

A New Regression Model for the Prediction of the Stress-Strain Relations of Different Materials.

Experimental flow stress-strain data under different stress states are often used to calibrate the plastic constitutive model of anisotropic metal materials or identify the appropriate model that is able to reproduce their plastic deformation behavior. Since the experimental stress-strain data are discrete, they need to be mathematically returned to a continuous function to be used to describe an equivalent hardening increment. However, the regression results obtained using existing regression models are not always accurate, especially for stress-strain curves under biaxial stress loading conditions. Therefore, a new regression model is proposed in this paper. The highest-order term in the recommended form of the new model is quadratic, so the functional relationships between stress-strain components can be organized into explicit expressions. All the experimental data of the uniform deformation stage can be substituted into the new model to reasonably reproduce the biaxial experimental stress-strain data. The regression results of experimental data show that the regression accuracy of the new model is greatly improved, and the residual square sum SSE of the regression curves of the new model reduced to less than 50% of the existing three models. The regression results of stress-strain curves show significant differences in describing the yield and plastic flow characteristics of anisotropic metal materials, indicating that accurate regression results are crucial for accurately describing the anisotropic yielding and plastic flow behaviors of anisotropic metal materials.

Analysis of Mechanical Parameters in Multi-Pass Asymmetrical Rolling of Strip by Slab Method.

Mechanical parameters, time consumption and energy consumption are important considerations in the application of a certain rolling process. This study aims to investigate characteristics of the roll force, roll torque, roll power, rolling time and total work in multi-pass asymmetrical rolling of strip. Mathematic models were built using the slab method to calculate parameters in the asymmetrical rolling process, and the characteristics of these parameters were analyzed on the basis of simulation results. Mechanical parameters are affected by the change of deformation region type. When the speed ratio is less than the critical speed ratio, the roll force, absolute values of roll torque and roll power are found to increase with the increase in the speed ratio. After the speed ratio reaches the critical speed ratio, the roll force, roll torque and lower roll power keep constant, but the upper roll power continues increasing. The upper roll torque and upper roll power required by asymmetrical rolling are much greater than that by symmetrical rolling, which indicates that stronger drive shafts and more powerful drive motors are required by asymmetrical rolling. Compared with symmetrical rolling, asymmetrical rolling requires less roll force to obtain the same thickness reduction, especially for thin and hard strips. Rolling time can be saved at the cost of more energy consumption by using asymmetrical rolling with the same roll force to attain the same final thickness. The results and conclusions of this study can provide a reference for mill design and application of asymmetrical rolling in strip manufacturing.

Red mud with enhanced dealkalization performance by supercritical water technology for efficient SO2 capture.

The total de-alkalization treatment of industrial solid waste red mud (RM) has been a worldwide challenge. Removing the insoluble structural alkali fraction from RM is the key to enhancing the sustainable utilization of RM resources. In this paper, supercritical water (SCW) and leaching agents were used for the first time to de-alkalize the Bayer RM and to remove sulfur dioxide (SO2) from flue gas with the de-alkalized RM slurry. The results showed that the optimum alkali removal and Fe leaching rates of RM-CaO-SW slurry were 97.90 ± 0.88% and 82.70 ± 0.95%, respectively. Results confirmed that the SCW technique accelerated the disruption of (Al-O) and (Si-O) bonds and the structural disintegration of aluminosilicate minerals, facilitating the conversion of insoluble structural alkalis to soluble chemical alkalis. The exchangeable Ca2+ displaced Na+ in the remaining insoluble base, producing soluble sodium salts or alkalis. CaO consumed SiO2, which was tightly bound to Fe2O3 in RM, and released Fe2O3, which promoted Fe leaching. RM-SCW showed the best desulfurization performance, which maintained 88.99 ± 0.0020% at 450 min, followed by RM-CaO-SW (450 min, 60.75 ± 6.00%) and RM (180 min, 88.52% ± 0.00068). The neutralization of alkaline components, the redox of metal oxides, and the liquid-phase catalytic oxidation of Fe contributed to the excellent desulfurization performance of the RM-SCW slurry. A promising approach shown in this study is beneficial to RM waste use, SO2 pollution control, and sustainable growth of the aluminum industry.

Potential risk of eutrophication in the deepest lake of Southwest China: Insights from phosphorus enrichment in bottom water.

Large deep lakes in plateau regions provide crucial ecosystem services but are susceptible to eutrophication due to their long water residence time. To date, the water quality of deep lakes has not received as much attention as that of shallow lakes owing to logistical challenges. This study investigated the seasonal variation and vertical distribution of phosphorus and related environmental variables in a large deep lake in the Yunnan Plateau, China (Fuxian Lake). Generally, the concentrations of total phosphorus (TP, R2 = 0.862), total dissolved phosphorus (TDP, R2 = 0.922), and dissolved inorganic phosphorus (DIP, R2 = 0.889) exhibited a linear increase with the greater water depth, whereas the pH and dissolved oxygen (DO) showed decreasing trends. The TP, TDP, and DIP values were 0.012, 0.006, and 0.004 mg/L, respectively, in surface waters (0.5 m depth), and increased to 0.074, 0.065, and 0.062 mg/L, respectively, at 140.0 m depth. The averaged over ordering method demonstrated that DO and air temperature accounted for a higher proportion of the explained variance of TP, TDP, and DIP in the shallow water layer (0.5-20.0 m). In contrast, DO and pH accounted for a higher proportion of the explained variance of TP, TDP, and DIP in deeper water layers (40.0-150.0 m). As a warm monomictic lake, the higher observed phosphorus concentrations in deeper water and sediment potentially pose a risk of future eutrophication in the Fuxian Lake. Our findings demonstrate that more efficient technical and management measures should be taken to reduce the external phosphorus load to Fuxian Lake, so that the load to and from the sediment will decrease eventually.

Lnc-TMEM132D-AS1 as a potential therapeutic target for acquired resistance to osimertinib in non-small-cell lung cancer.

Acquired resistance is a major obstacle to the therapeutic efficacy of osimertinib in non-small-cell lung cancer (NSCLC). Current knowledge about the role of long non-coding RNAs (lncRNAs) in this phenomenon is insufficient. In this study, we screened the differentially expressed lncRNAs between osimertinib-sensitive and -resistant NSCLC cell lines, and determined that lnc-TMEM132D-AS1 was significantly upregulated in osimertinib-resistant NSCLC cells, as well as in the plasma of osimertinib-resistant NSCLC patients. Lnc-TMEM132D-AS1 markedly decreased the osimertinib sensitivity of NSCLC cells. After osimertinib exposure, it increased the cell proliferation and colony formation, decreased the cell apoptosis, and induced M2/G-phase cell cycle arrest. After identifying its cytoplasmic localization, a functional lnc-TMEM132D-AS1-miRNA-mRNA interaction network and a protein-protein interaction (PPI) network were constructed to analyze its putative target genes and biological functions. Lnc-TMEM132D-AS1 could directly bind to miR-766-5p and lead to the upregulation of ectonucleoside triphosphate diphosphohydrolase-1 (ENTPD1), resulting in an increase in cell proliferation. Moreover, upregulated ENTPD1 was also associated with enhanced tumor infiltration of immunosuppressive cells and poor prognosis in NSCLC patients. In summary, lnc-TMEM132D-AS1 plays a crucial role in osimertinib resistance. It may serve as a prognostic biomarker and a potential therapeutic target for acquired resistance to osimertinib in NSCLC.

Development of fluorophores for the detection of oligomeric aggregates of amyloidogenic proteins found in neurodegenerative diseases.

Alzheimer's disease and Parkinson's disease are the two most common neurodegenerative diseases globally. These neurodegenerative diseases have characteristic late-stage symptoms allowing for differential diagnosis; however, they both share the presence of misfolded protein aggregates which appear years before clinical manifestation. Historically, research has focused on the detection of higher-ordered aggregates (or amyloids); however, recent evidence has shown that the oligomeric state of these protein aggregates plays a greater role in disease pathology, resulting in increased efforts to detect oligomers to aid in disease diagnosis. In this review, we summarize some of the exciting new developments towards the development of fluorescent probes that can detect oligomeric aggregates of amyloidogenic proteins present in Alzheimer's and Parkinson's disease patients.

Colorimetric Assay for Acetylcholinesterase Activity and Inhibitor Screening Based on Metal-Organic Framework Nanosheets.

Alzheimer's disease (AD) is a common chronic neurodegenerative disease that manifests as cognitive impairment and behavioral deficits and severely threatens the health of the elderly. Acetylcholinesterase (AChE) plays a vital role in biological signaling and is an essential target for the early diagnosis and treatment of AD. Herein, 2D Zn-TCPP(Fe) nanosheets (NSs) employing Zn2+ and Fe-bound tetrakis(4-carboxyphenyl)porphyrin ligands were prepared through a surfactant-assisted synthetic method. The ultrathin two-dimensional (2D) metal-organic framework structures exhibited high peroxidase-like activity, which allowed the catalysis of the H2O2-initiated oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxidized TMB (ox-TMB). Such catalytic performance inspired us to develop a convenient, rapid, and sensitive acetylcholinesterase activity assay, during which AChE can catalyze the substrate acetylthiocholine (ATCh) to produce thiocholine (TCh), and TCh could especially enable the degradation of 2D Zn-TCPP(Fe) NSs accompanied by the reduction of ox-TMB production. Our proposed sensing system exhibited favorable selectivity and sensitivity (LOD of 0.029 mU/mL) and has excellent potential to evaluate AChE activity in human serum samples and to screen AChE inhibitors. This colorimetric assay could provide an alternative pathway for early diagnosis and drug screening of AD, facilitating the development of AD therapy.

A fluorescence turn-on biosensor utilizing silicon-containing nanoparticles: Ultra-sensitive sensing for α-glucosidase activity and screening for its potential inhibitors.

A facile and sensitive method for sensing α-glucosidase (α-glu) and screening its inhibitors based on fluorescence monitoring of water-solute silicon-containing nanoparticles (Si CNPs) was proposed and demonstrated. Such fluorescent nanoparticles can be easily produced by mixing (3-aminopropyl) trimethoxysilane (APTMS) and ascorbate sodium (AS) (both without fluorescence signals) at room temperature and pressure. If the ascorbate sodium was replaced by L-ascorbic acid-2-O-α-D-glucopyranosyl (AA2G), which can be hydrolyzed into the former by α-glu, the fluorescence "turn-on" biosensor for α-glu activity can be established. The sensing platform showegd a linear relationship from 10 to 140 U/L and a low detection limit of 0.42 U/L, which is superior to most approaches that have been reported. However, the hydrolysis procedure and subsequent fluorogenic reaction could be blocked in the presence of α-glu inhibitors (AGIs), giving the possibilities of screening various inhibitors from different compounds. Furthermore, detection in human serum and applications in AGIs screening by using this method were also constructed, and showed satisfying results as well. It is proved that this developed biosensor can provide an alternative strategy for potential clinic diagnosis and medicine development.

Analysis of Mechanical Parameters of Asymmetrical Rolling Dealing with Three Region Percentages in Deformation Zones.

A series of mathematical models were proposed to calculate the roll force, torque and power for cold strip asymmetrical rolling by means of the slab method, taking the percentages of the forward-slip, backward-slip and cross-shear zones into account. The friction power, plastic work and total energy consumption can be obtained by the models. The effects of variable rolling parameters-such as the speed ratio, entry thickness, friction coefficient and front and back tension-on the process of asymmetrical rolling are analyzed. In all cases, an increase in speed ratio leads to an increase in friction work and its proportions. The increase in entry thickness and deformation resistance causes both friction work and plastic deformation work to increase. The proportion of friction work decreases with increasing deformation resistance, entry thickness, front tension and back tension. In the circumstances of a thin strip being rolled with a large speed ratio, the proportion of friction work could exceed that of plastic deformation work. The concept of a threshold point of friction work was proposed to explain this phenomenon. As an example, threshold points T1, T2, T3 with the effect of the entry thickness and S1, S2, S3 with the effect of the friction coefficient have been obtained by computation. Finally, the experiment of the strip asymmetrical rolling was conducted, and a maximum error of 9.7% and an RMS error of 5.9% were found in the comparison of roll forces between experimental measurement values and calculated ones.

Efficacy and safety of floating needle therapy in the treatment of knee osteoarthritis: A protocol for systematic review and meta-analysis.

BACKGROUND: Knee osteoarthritis (KOA) is a common clinical degenerative disease of the joints, which is prone to occur in middle-aged and elderly people. Its early manifestations include knee redness, swelling, pain, effusion, sound, and so on. With the development of the disease, KOA will also lead to joint deformity and disability, which will seriously affect the living ability of patients. It not only brings physical pain and dysfunction to patients, but also leads to anxiety, helplessness, depression, and social disorder in social psychology, which seriously affects patients' daily life, social function and life quality, and also brings huge economic burden and pressure to family and social medical treatment. Floating needle therapy has shown strong advantages in the treatment of KOA, and the curative effect is accurate. Therefore, this paper will carry out a systematic evaluation and meta analysis of the efficacy and safety of floating needle therapy in the treatment of KOA. METHODS: We will search 8 electronic databases, including PubMed, Embase, Web of Science, Cochrane Library, the China National Knowledge Infrastructure, Chinese Science and Technology Periodical Database, Wanfang Database, and Chinese Biomedical Literature Database. We will search above electronic databases from the beginning to January 2021, without any language restriction. Clinical efficacy, including total effective rate or cure rate, visual analogue scale pain score, and recurrence rate will be accepted as the primary outcomes. The changes of traditional Chinese medicine symptom score, inflammatory factor level change, knee function score will be used as secondary outcomes. RevMan 5.3 software will be used for statistical analysis. The result about the curative effect and safety of floating needle therapy for knee osteoarthritis will be presented as risk ratio for dichotomous data and mean differences with a 95% confidence interval for continuous data. RESULTS: Only when we finish this meta analysis can we get the result, no results are available at this timed. CONCLUSIONS: The results of this study will provide reliable evidence for the efficacy and safety of floating needle therapy in the treatment of knee osteoarthritis. INPLASY REGISTRATION NUMBER: INPLASY2020120145.

Complete genome sequence of bile-isolated Enterococcus avium strain 352.

BACKGROUND: Enterococcus avium is a Gram-positive pathogenic bacterium belonging to the family Enterobacteriaceae. E. avium can cause bacteremia, peritonitis, and intracranial suppurative infection. However, the mechanism of its pathogenesis and its adaptation to a special niche is still unclear. RESULTS: In this study, the E. avium strain 352 was isolated from human bile and whole genome sequencing was performed. The E. avium strain 352 consists of a circular 4,794,392 bp chromosome as well as an 87,705 bp plasmid. The GC content of the chromosome is 38.98%. There are 4905 and 99 protein coding sequences in the chromosome and the plasmid, respectively. The genome of the E. avium strain 352 contains number of genes reported to be associated with bile adaption, including bsh, sbcC, mutS, nifI, galU, and hupB. There are also several virulence-associated genes including esp, fss1, fss3, ecbA, bsh, lap, clpC, clpE, and clpP. CONCLUSIONS: This study demonstrates the presence of various virulence factors of the E. avium strain 352, which has the potential to cause infections. Moreover, the genes involved in bile adaption might contribute to its ability to live in bile. Further comparative genomic studies would help to elucidate the evolution of pathogenesis of E. avium.

BONE FRAGILITY, FRACTURE RISK AND TRAUMA:A COMPLICATED TRIANGLE IN CHILDREN.

OBJECTIVE: To analyze whether association between bone fragility and risk of fracture depends on the trauma level. METHOD: All participants along with their mothers underwent DXA scan and body measurements. The subjects answered a self-report questionnaire about their physical activities and the precipitating causes. The questionnaire results were associated with DXA performed at the baseline visit. RESULTS: A total 374 children with available DXA scan and complete follow-up of 5 years were included in the final analysis. Of the 374 children, 53 (14.2%) had one fracture, and 11 (20.7%) had more than one fracture. Based on the modified Landin classification, the trauma level was determined. Of the 53 (14.2%) children who had one fracture, 39 (73.6%) were classified, namely 19 (48.7%) with mild trauma, 16 (41%) with moderate trauma and four (10.2%) with severe trauma. Trauma level could not be assigned to 14 (26.4%) children due to limited information. Children without fractures had significantly higher values in all bone parameters compared to those with fractures caused by mild trauma. CONCLUSION: Subjects with mild trauma fractures had an inversely proportional ratio between bone fragility parameters and fracture risk compared with subjects without fractures. Level of Evidence IV, Case Series.

OBJETIVO: Analisar se a associação entre fragilidade óssea e risco de fratura depende do nível de trauma. MÉTODO: Todos os participantes, juntamente com suas mães, foram submetidos à DEXA e medições corporais. Os participantes responderam um questionário de autorrelato sobre atividades físicas e descrição de como o trauma ocorreu. Os resultados do questionário foram associados à DEXA realizada na primeira visita do estudo. RESULTADOS: Um total de 374 crianças com DEXA disponível e acompanhamento completo de 5 anos foi incluído na análise final. Das 374 crianças, 53 (14,2%) tiveram uma fratura e 11 (20,7%) tiveram mais de uma fratura. Com base na classificação de Landin modificada, foi determinado o nível de trauma. Das 53 (14,2%) crianças que tiveram uma fratura, 39 (73,6%) foram classificadas, sendo 19 (48,7%) com trauma leve, 16 (41%) com trauma moderado e quatro (10,2%) com trauma grave. O nível de trauma não pôde ser atribuído a 14 (26,4%) crianças, devido a informações limitadas. As crianças sem fraturas apresentaram valores significantemente mais altos em todos os parâmetros ósseos, em comparação com os que tinham fraturas causadas por trauma leve. CONCLUSÃO: Os indivíduos com fraturas por trauma leve apresentaram relação inversamente proporcional entre os parâmetros fragilidade óssea e o risco de fratura em comparação com indivíduos sem fratura. Nível de Evidência IV, Série de Casos .

BONE FRAGILITY, FRACTURE RISK AND TRAUMA:A COMPLICATED TRIANGLE IN CHILDREN / FRAGILIDADE ÓSSEA, RISCO DE FRATURA E TRAUMA:UM TRIÂNGULO COMPLICADO EM CRIANÇAS

ABSTRACT Objective: To analyze whether association between bone fragility and risk of fracture depends on the trauma level. Method: All participants along with their mothers underwent DXA scan and body measurements. The subjects answered a self-report questionnaire about their physical activities and the precipitating causes. The questionnaire results were associated with DXA performed at the baseline visit. Results: A total 374 children with available DXA scan and complete follow-up of 5 years were included in the final analysis. Of the 374 children, 53 (14.2%) had one fracture, and 11 (20.7%) had more than one fracture. Based on the modified Landin classification, the trauma level was determined. Of the 53 (14.2%) children who had one fracture, 39 (73.6%) were classified, namely 19 (48.7%) with mild trauma, 16 (41%) with moderate trauma and four (10.2%) with severe trauma. Trauma level could not be assigned to 14 (26.4%) children due to limited information. Children without fractures had significantly higher values in all bone parameters compared to those with fractures caused by mild trauma. Conclusion: Subjects with mild trauma fractures had an inversely proportional ratio between bone fragility parameters and fracture risk compared with subjects without fractures. Level of Evidence IV, Case Series.

RESUMO Objetivo: Analisar se a associação entre fragilidade óssea e risco de fratura depende do nível de trauma. Método: Todos os participantes, juntamente com suas mães, foram submetidos à DEXA e medições corporais. Os participantes responderam um questionário de autorrelato sobre atividades físicas e descrição de como o trauma ocorreu. Os resultados do questionário foram associados à DEXA realizada na primeira visita do estudo. Resultados: Um total de 374 crianças com DEXA disponível e acompanhamento completo de 5 anos foi incluído na análise final. Das 374 crianças, 53 (14,2%) tiveram uma fratura e 11 (20,7%) tiveram mais de uma fratura. Com base na classificação de Landin modificada, foi determinado o nível de trauma. Das 53 (14,2%) crianças que tiveram uma fratura, 39 (73,6%) foram classificadas, sendo 19 (48,7%) com trauma leve, 16 (41%) com trauma moderado e quatro (10,2%) com trauma grave. O nível de trauma não pôde ser atribuído a 14 (26,4%) crianças, devido a informações limitadas. As crianças sem fraturas apresentaram valores significantemente mais altos em todos os parâmetros ósseos, em comparação com os que tinham fraturas causadas por trauma leve. Conclusão: Os indivíduos com fraturas por trauma leve apresentaram relação inversamente proporcional entre os parâmetros fragilidade óssea e o risco de fratura em comparação com indivíduos sem fratura. Nível de Evidência IV, Série de Casos .

Research on the mechanical properties of a glass fiber reinforced polymer-steel combined truss structure.

An assembled plane truss structure used for vehicle loading is designed and manufactured. In the truss, the glass fiber reinforced polymer (GFRP) tube and the steel joint are connected by a new technology featuring a pretightened tooth connection. The detailed description for the rod and node design is introduced in this paper, and a typical truss panel is fabricated. Under natural conditions, the short-term load test and long-term mechanical performance test for one year are performed to analyze its performance and conduct a comparative analysis for a reasonable FEM model. The study shows that the design and fabrication for the node of an assembled truss panel are convenient, safe, and reliable; because of the creep control design of the rods, not only does the short-term structural stiffness meet the design requirement but also the long-term creep deformation tends towards stability. In addition, no significant change is found in the elastic modules, so this structure can be applied in actual engineering. Although the safety factor for the strength of the composite rods is very large, it has a lightweight advantage over the steel truss for the low density of GFRP. In the FEM model, simplifying the node as a hinge connection relatively conforms to the actual status.

Structural performance of a hybrid FRP-aluminum modular triangular Truss system subjected to various loading conditions.

A novel hybrid FRP-aluminum truss system has been employed in a two-rut modular bridge superstructure composed of twin inverted triangular trusses. The actual flexural behavior of a one-rut truss has been previously investigated under the on-axis loading test; however, the structural performance of the one-rut truss subjected to an off-axis load is still not fully understood. In this paper, a geometrical linear finite element model is introduced and validated by the on-axis loading test; the structural performance of the one-rut truss subjected to off-axis load was numerically obtained; the dissimilarities of the structural performance between the two different loading cases are investigated in detail. The results indicated that (1) the structural behavior of the off-axis load differs from that of the on-axis load, and the off-axis load is the critical loading condition controlling the structural performance of the triangular truss; (2) under the off-axis load, the FRP trussed members and connectors bear certain out-of-plane bending moments and are subjected to a complicated stress state; and (3) the stress state of these members does not match that of the initial design, and optimization for the redesign of these members is needed, especially for the pretightened teeth connectors.