MET behaves as a ‘stress-response’ gene, and relies on ligand stimulation to sustain cancer cell ‘scattering’, invasion, and protection form apoptosis. Moreover, the MET/HGF axis is involved in the crosstalk between cancer cells and the surrounding microenvironment. Pancreatic cancer  is an aggressive malignancy characterized by an abundant stromal compartment that is associated with early metastases and resistance to conventional and targeted therapies. Here, we discuss the role of the MET/HGF axis in tumor progression and dissemination considering as a model pancreatic cancer, and provide a proof of concept for the application of dual MET/HGF inhibition as an adjuvant therapy in pancreatic cancer patients.The ‘onco-receptor’ MET (Hepatocyte Growth Factor Receptor) is involved in the activation of the invasive growth program that is essential during embryonic development and critical for wound healing and organ regeneration during adult life. When aberrantly activated, MET and its stroma-secreted ligand HGF (Hepatocyte Growth Factor) concur to tumor onset, progression, and metastasis in solid tumors, thus representing a relevant target for cancer precision medicine. In the vast majority of tumors, wild-type  MET gene was then mapped on chromosome 7q21-31 and its product identified as the tyrosine-kinase transmembrane protein, which is the high-affinity receptor for the Hepatocyte Growth Factor (HGF) [MET was originally identified from a chemically transformed human osteosarcoma cell line as an oncogene resulting from the chromosomal rearrangement of the MET tyrosine kinase domain with a dimerization domain (TRP-MET) . The METor (HGF) . The extor (HGF) ) composeor (HGF) ; (ii) a or (HGF) . The intor (HGF) ,10; (ii)or (HGF) ,12  . Since tMET genetic lesions—either mutations [MET genetic lesions act as drivers of malignant transformation, and confer a growth advantage to tumor cells [In a limited number of tumors, utations  or ampliutations —lead to utations , as wellutations . In the utations ,53. Bothor cells . In thisor cells . As a coThe generation of a MET/HGF autocrine loop by anomalous co-expression of ligand and receptor in the same cell is another way by which cancer cells may achieve continuous MET activation. This mechanism has been described mainly in non-epithelial human tumors, such as osteosarcomas , glioblaMET and HGF gene promoters contain binding sites for transcription factors, including hypoxia-inducible factor 1α (HIF1α) and nuclear factor-κB (NF-κB), that are induced or activated by stress conditions [MET activation represents a strategy harnessed by otherwise transformed tumor cells to overcome barriers to their progression and to boost their malignant phenotype. This condition is defined as ‘oncogene expedience’ [However, in the vast majority of tumors, aberrant MET signaling derives from the upregulation of wild-type MET or HGF transcription, leading to receptor and/or ligand overexpression ,62, or fnditions . Differeedience’ : cancer edience’ . In lighThe contribution of the tumor microenvironment (TME) to cancer progression is becoming increasingly relevant. It is now well-established that the malignant phenotype does not develop in a strictly cell-autonomous way, but through a complex interplay that takes place between the tumor cells and the surrounding stroma . Tumors The malignant behavior of cancer cells is nurtured by the collateral pro-angiogenic activity of the MET/HGF axis in endothelial (ECs) and stromal cells . MET uprFurthermore, MET pathway activation also influences macrophage polarization, inducing a shift of their phenotype from an immunological active phenotype (M1) to a trophic, growth-stimulating state (M2), promoting an immunosuppressive environment ,79.In order to allow for the execution of the multifaceted metastatic process, a favorable microenvironment around the tumor tissue is mandatory, as well as plasticity and migration of cancer cells. Metastases arise from a selected cell subpopulation that resides in the heterogeneous primary tumor . The acqKRAS mutations followed by mutation of p16 and loss of p53 and SMAD4 are often considered as initiating events in pancreatic cancers [Since the pioneer studies published in 1995 , the MET cancers , dysregu cancers . Compare cancers ,96,97, a cancers .Interestingly, PSCs seem to be capable of travelling within the body together with cancer cells to colonize distant organs : in patiThe MET/HGF pathway is involved in the complex crosstalk between tumor and stroma, in particular in the interaction between cancer cells and activated PSCs . In thisMET gene in a mouse model of spontaneous pancreatic neoplasia resulted in a reduction of neoplastic cell proliferation, a predictive marker for chemotherapeutic responses and clinical prognosis [Although tumor resection remains the keystone of treatment for pancreatic cancer, only a small fraction of patients are candidates for surgery at the time of diagnosis , as earlrognosis . Finallyrognosis ,115.K842E, a soluble MET receptor endowed with HGF-sequestering ability. MvDN30 is a chimeric Fab fragment that acts as a potent MET inhibitor by promoting the physical removal of the MET receptor from the cell surface, thus shutting off MET signaling [K842E). This sequence modification, which does not affect the affinity for HGF, is sufficient to completely abrogate the interaction between decoyMET and the antibody, thus preventing the reciprocal neutralization of either component.Since the tumor microenvironment significantly contributes to cancer progression and metastasis, and since the malignant phenotype of cancer cells may be exacerbated by the presence of overexpressed/overactivated wild-type MET in dialogue with stromal-derived HGF, the development of a strategy aimed at disrupting this crosstalk by concomitantly targeting receptor and ligand can be envisaged. MET and HGF co-targeting has been previously investigated in MET-addicted tumors and in cancers expressing a MET/HGF autocrine loop. In these contexts, the combination treatment improves the efficacy of each monotherapy ,117. In ignaling . Upon biignaling  and by iK842E targeted directly human cancer cells, strongly impairing MET phosphorylation in primary tumors, and affecting the stromal component of primary tumors. In fact, the combo treatment induced a reversion of the EMT phenotype (measured as vimentin/E-cadherin ratio) as well as a decrease of activated α-SMA positive fibroblasts  built by orthotopic injection of human PDAC cells—expressing wild-type MET—in SCID (severe combined immunodeficient) mice genetically modified to secrete physiological levels of human HGF (hHGF knock-in) that bypass the problem of ligand/receptor species-specificity. In this model, the combination of MvDN30 and decoyMETroblasts . In lineConsistent with our results, a ‘triple therapy’ (inhibition of both HGF and MET combined with gemcitabine) has been recently shown to achieve stronger inhibition of both primary tumor growth and metastatic dissemination compared to the single treatments or dual combinations in a mouse model of pancreatic cancer .Activation of the MET/HGF pathway is at the same time a catalyst and a consequence of the pro-tumoral microenvironment. TME represents a significant source of HGF, which may trigger signaling cascades in cancer cells, thus fostering their survival and dissemination. Conversely, MET/HGF signaling influences TME by acting directly on stromal MET-expressing cells, either resident or attracted from blood circulation.K842E suggest that the dual decoy/antibody strategy on one side may revert the EMT process of cancer cells, and on the other may act on the stromal component by reducing CAFs activation and ECM deposition. These results support the hypothesis of a bidirectional signaling between stroma and cancer through the MET/HGF axis, indicating that tumor cells might prompt the activation of the stromal compartment.The results obtained with the combination of MvDN30 and decoyMETMoreover, the MET/HGF co-targeting may represent an option as an adjuvant therapy in pancreatic cancer. The standard treatment for advanced pancreatic cancer is chemotherapy, namely Gemcitabine alone or in combination with Nab-paclitaxel. However, often patients undergo resistance to chemotherapy. One of the causes of PDAC chemoresistance relies on the presence of an extensive desmoplastic reaction that surrounds the tumor, creating a physical barrier to drug penetration. In this context, the reduction of the metastatic potential of cancer cells on one hand and the re-education of a dysfunctional tumor microenvironment on the other could be beneficial for the treatment of pancreatic cancer as well as of other tumors sustained by a highly active stroma, such as breast cancer .


Antibiotic resistance (AR) remains a global crisis. However, the literature on public awareness about antibiotic use and AR in the highland provinces of Vietnam has been constrained. This study explores the awareness of antibiotic use and resistance among general people in highland provinces in Vietnam and detects associated factors. A cross-sectional study was performed in five highland provinces with 1000 households. Information about socioeconomic status and awareness regarding prescription medicine use, antibiotic use, and AR was surveyed. Multivariate logistic regression was used to identify associated factors with awareness. 64.2% of people were aware of prescription drugs. More than two-thirds (67.4%) of participants were aware of antibiotic use, of whom only 55.8% were aware of AR. Higher age, education, and family income were positively associated with being aware of prescription medicine, antibiotic, and AR. Females had a lower likelihood of being aware of prescription medicine  compared to male counterparts. Those being freelancers were more likely to be aware of antibiotic resistance  compared to those working in agriculture/fishery/forestry sector. Compared to Kinh ethnic, most ethnic minorities were less likely to be aware of prescription medicine, antibiotic, and AR. This study showed a low awareness regarding prescription medicine, antibiotic use, and AR among public people in the highland provinces of Vietnam. Further systemic and didactic educational interventions targeting females, low education, low income, ethnic minorities, and those working in agriculture/fishery/forestry sector in this setting should be performed and evaluated to improve the awareness about antibiotic use and resistance. Antibiotic resistance (AR) is a condition when bacteria change against antibiotics which are developed to cure the illnesses they cause . It is aAs inappropriate antibiotic use is the primary cause of AR, responses to this phenomenon prioritize to promote public awareness about AR . NonetheIn Vietnam, the inappropriate use of antibiotics and prescription drugs are pervasive, particularly in hospitals. A study in Ho Chi Minh City found that 93% of patients admitted to the intensive care unit had resisted to at least one antibiotic . AnotherWe conducted a cross-sectional survey from July to November 2018 in five highland provinces of Vietnam including Kon Tum, Gia Lai, Dak Lak, Dak Nong, and Lam Dong. A multistage sampling method was employed to recruit participants. First, a list of districts and communes in each province was developed by the local authorities. A total of 721 communes in 62 districts were listed in the sample frame. Then, by using computer software, we randomly selected two districts in each province (10 districts/5 provinces), and after that, two communes per district (20 communes/10 districts). Then, we randomly selected five villages in each commune and ten households per village. Door-to-door recruitment strategy was used to enroll participants until reaching sufficient sample size.The sample size was calculated by using the formula for estimating a population proportion with specified absolute precision. We expected that the prevalence of residents being aware of AR was 50%. With a marginal error (absolute precision) = 0.07 and a confident level = 95%, the total sample size for each province was 196 households. We also added 5% of sample size for preventing if the household's representative refused to participate or they incompletely answered the interview. A total of 1029 households were randomly selected from the sampling frame. The participants were invited if they were 1, aged from 18 years or more, and 2, head of households or individuals who were responsible for purchasing medicines for the household.Face-to-face interviews were performed to collect the data from 15 to 20 minutes. A structured questionnaire was developed for the survey. A pilot survey was conducted with ten households in Dak Lak province. Data of these households were not included in the final dataset. After the pilot, we received the feedbacks from households about the content, language, and logical order of items in the questionnaire. A major revision was performed to ensure the cultural appropriateness of the questionnaire. The final version of questionnaire was produced and approved by the local authorities. A two-day training course was conducted by the principal investigator and the research team who had expertise in antibiotic use and resistance. Interviewers consisted of local health workers who had experiences in working with households. They were informed about the objectives of the survey and the content of the questionnaires, as well as trained necessary interview skills to collect data consistently with high quality.The questionnaire included information about the socioeconomic status of respondent  and household . People belonging to other ethnics instead of “Kinh” ethnic were classified as “ethnic minorities” since “Kinh” has been the dominant ethnic in Vietnam.The other parts of the questionnaire were questions about “awareness of prescription drug”, “awareness of antibiotic use”, and “awareness of antibiotic resistance”. In this study, antibiotics are defined as drugs that are used to “prevent and treat bacterial infection” according to the World Health Organization . Our queData were analyzed using Stata version 14.0. Descriptive analysis including mean, standard deviation, frequency, and the percentage was performed to describe the variables. Two-tailed chi-squared and student t-tests were used to assess the differences in socioeconomic characteristics and awareness between males and females. Multivariate logistic regression was used to identify the factors associated with “Being aware of prescription drugs” and “Being aware of antibiotic”, and “Being aware of AR”. The independent variables included in the models were socioeconomic status of respondent  and household . Stepwise backward selection strategies were applied in combination with regression models, using a p-value of log likelihood test at 0.2 as a threshold for selecting the variables to the reduced models. A p-value of less than 0.05 was treated as statistical significance.The study protocol was approved by the Institutional Review Board of the Vietnam Ministry of Health. Participants had the rights to stop the interview or withdraw to the study at any time without any barriers. Written informed consent was obtained if they agreed to participate in the study. They did not receive any incentives or reimbursement for participation. The questions were anonymous, and no personal information was collected during the interview.Among 1029 households selected, after excluding households that had incomplete data, information of 1000 households was used for data analysis (response rate 97.2%). A total of 1000 people in 1000 households participated in the study. The demographic characteristics of respondents are indicated in There were 64.2% of people being aware of prescription drugs. This rate in males was significantly higher than that in females (p<0.05). More than two-thirds (67.4%) of participants were aware of antibiotics. Most of them understood that using antibiotic required prescriptions (83.5%), of whom 94.9% were aware that antibiotics had to be prescribed by physicians at the medical facility. There were 8.0% concerning drug sellers at the drug store as qualified prescribers. More than half of participants (53.9%) would reexamine health if antibiotics worked ineffectively, while above one-fifth of people (21.8%) would replace to other antibiotics. Only 18.8% knew AR as a negative effect of antibiotic use, and only 55.8% were aware of AR. Most people being aware of AR knew that AR was where bacteria changed to respond to the use of antibiotic, while only 25.3% knew the causes of AR. Higher age, education, and family income were positively associated with being aware of prescription medicine, antibiotics, and AR. Females had a lower likelihood of being aware of prescription medicine  compared to males. Those being freelancers were more likely to be aware of antibiotic resistance  compared to those working in agriculture/fishery/forestry sector. Compared to Kinh ethnic, most of the ethnic minorities were less likely to be aware of prescription medicine, antibiotic, and AR. People who were Mnong ethnic were more likely to know prescription medicine but less likely to know AR .In this study, the results indicated a lack of awareness about appropriate prescription medicine use and antibiotic use as well as AR among the general population in highland areas of Vietnam. Moreover, by using multivariate regression model, we highlighted the most vulnerable populations to the insufficient awareness of these terms, including females, low age, low education, low income, ethnic minorities, and those working in agriculture/fishery/forestry sector. Escherichia coli found among wastewater samples in Vietnamese hospitals resisted to at least one antibiotic, and 32% could resist multiple antibiotics [In recent years, Vietnam has been a hotspot of AR in the world due to the shortage of legislation and regulations to manage self-medication as well as poor prescription drug and antibiotic use practices . A previibiotics . Despiteibiotics , and 59.ibiotics . The resOur study was in line with previous surveys worldwide that age, education, and gender were significant predictors to the awareness of antibiotics use –47. SpecMeanwhile, the findings demonstrated the susceptibility of ethnic minorities in AR since they were less likely to be aware of antibiotic and AR. Ethnics minorities in Vietnam have been found to have limited health care service and health information access , 51. TheThis study has several methodological issues that should be acknowledged. First, the causal relationships between the awareness and its associated factors could not be established due to the nature of study design. Second, the self-reported approach might result in recall bias when we asked them to report annual household income and social desirability bias when respondents might give the answers that were viewed favorably by interviewers. However, we have trained the data collection team carefully and developed the data collect guideline to reduce the bias. Third, several critical information was not included in the study, for example, participants' behaviors, impacts of family and social relationships, or health service quality. Moreover, although we conducted the study on a large scale with 1000 households, our generalizability might be limited and not represent to other settings. Thus, our findings should be used in caution. Further studies should be warranted to fill the knowledge gap in the awareness about prescription medicine use, antibiotic use, and AR among highland residents.This study shows a low awareness regarding prescription medicine and antibiotic use among public people in highland provinces in Vietnam. The findings also indicated that females, low education, low income, ethnic minorities, and those working in agriculture/fishery/forestry sector should be the target groups in future interventions in this setting.


In men ≤65 years, the best combination was hip, BMI, and height (AUROC = 0.79). In women ≥66 years, the best discriminatory model contained only waist-to-hip ratio (AUROC = 0.67), whereas in women ≤65 years, the best combination was hip and BMI (AUROC = 0.68). A narrow hip reasonably reflects small gluteal muscles. This finding might suggest an association between MI and sarcopenia, possibly related to deficiencies in physical activity and nutrition.We compared weight, height, waist and hip circumferences (hip), body mass index (BMI), and waist-to-hip ratio in acute myocardial infarction (MI) patients and individually sex- and age-matched control subjects from the general population in the catchment area of the patients and predicted the risk of MI status by these basic anthropometric measures. The study cohort comprised 748 patients ≤80 years of age with acute MI from a major Swedish cardiac center and their individually sex- and age-matched controls. The analyses were stratified for sex and age (≤65/≥66 years). Risk of MI was assessed by conditional logistic regression. A narrow hip in men ≥66 years was the single strongest risk factor of MI among the anthropometric measures. The combination of  Additionally, two quotients derived from these measures, body mass index  event. Thus, the anthropometric measures in acute MI patients are reasonably valid at least for a few months before the MI event.Prospective studies have demonstrated an association between future coronary events and high BMI and weight gain , 2 as weContrarily to prospective follow-up studies, there are few case-control studies of anthropometric measures involving MI patients. Yusuf et al.  reportedThe objective of this study was to explore the associations between basic anthropometric phenotypes and MI status in a sex- and age-matched case-control population.https://clinicaltrials.gov/ct2/show/NCT01452178. The hospital is the only referral center for a geographical area with around 180,000 inhabitants. 748 of 1015 eligible acute MI patients ≤80 years of age were individually sex- and age-matched with one control subject, without previous MI, selected from the population registry of the catchment area of the MI patients. The reasons for not matching an eligible patient are shown in a flow chart  recruited consecutive acute MI patients admitted to the coronary care unit of the Hospital of Vastmanland, Vasteras, Sweden, between November 2005 and May 2011; ow chart . All parECG and troponin I criteria recommended by the European Society of Cardiology (ESC) were used for diagnosing acute MI . TroponiA preliminary study revealed major difficulties in recruiting controls >80 years of age. Thus, the study was restricted to individuals ≤80 years of age (69.5% of the 1459 patients in the VAMIS project), see flow chart, Anthropometric measurements of patients were performed at inclusion of the patients in the study in the cardiac ward of the hospital. Only two nurses were involved in the anthropometric measurements of patients and controls. The two nurses controlled that their measurement techniques and results were consistent.Body weight was measured to the nearest 0.1 kg with participants wearing underwear or light clothing. Height was measured to the nearest 1 cm. Waist was measured to the nearest 1 cm in the horizontal plane at the midpoint between the lowest rib and the iliac crest. Hip was measured to the nearest 1 cm around the widest portion of the buttocks. Each individual was measured once with a nonstretchable 1.5 m tape in standing position if the medical condition permitted. No case or control was excluded due to having too large circumference or being too heavy.Self-reported diagnoses of previous MI, angina pectoris, stroke, diabetes, and drug-treated hypertension were verified from medical records. Current smoking was defined as daily smoking during the month before onset of acute MI or index examination of controls.t-test for continuous and by McNemar's test for categorical variables. If the number of discordant pairs were 10 or fewer, an exact version of McNemar's test based on the binomial distribution was applied. Confidence intervals for unpaired categorical data were calculated according to Gardner and Altman [Categorical variables were summarized as numbers and percentages (%). Continuous variables were summarized as means and standard deviations (SD) or, in the case of skewed distributions, by medians and interquartile ranges. Differences between cases and controls were assessed by the paired R2 was used to assess the variability explained by the model. A best subset approach with Schwarz Bayesian information criterion (BIC) was used to find the best conditional logistic regression models. BIC, which is a penalized version of the log likelihood function , was chosen to avoid overfitting. The results were reported as odds ratios (OR) with 95% confidence intervals (CI).Crude and adjusted associations between basic anthropometric measures and MI were assessed by conditional logistic regression for matched pairs. Nagelkerke's generalized The area under the receiver operating characteristic (AUROC) curve was used to assess the classification ability of individual and combined anthropometric measures.Internal validation was performed using 10-fold cross-validation. The sample was split into 10 roughly equal-sized random parts, retaining the pair structure. Of the 10 subsamples, a single subsample was used as a validation set, and the remaining 9 subsamples were used to estimate the parameters of the model. This process was repeated 10 times, using each of the 10 subsamples once as validation set. Finally, the 10 resulting classification tables were merged. The best discriminating functions were derived by logistic regression analysis.Feed forward neural network models with one hidden layer and a hyperbolic and a sigmoid activation function were assessed to check if the AUROC curves and the discriminating abilities could be markedly improved by including nonlinearities and interactions into the models.P value < 0.05 was regarded statistically significant. IBM SPSS Statistics 24 was used for all statistical analyses except the best subset conditional logistic regression analyses which were run in SAS 9.4.A two-sided The study comprised 486 male and 202 female case-control pairs corresponding to 68% of eligible patients as illustrated in a flow chart . The meaCrude and adjusted associations of individual basic anthropometric measures and MI status were assessed by conditional logistic regression . The strR2.The total variability in MI status explained by all anthropometric measures  simultaneously was 0.50 for men ≤65 yr, 0.62 for men ≥66 yr, 0.23 for women ≤65 yr, and 0.32 for women ≥66 yr as assessed by Nagelkerke's 2) + 0.067 ∗ height (cm) − 0.30 ∗ hip (cm)) evaluated for the heights 160, 170, 180, and 190 cm, using the relation weight = BMI ∗ height2. Using 10-fold cross-validation, we achieved a sensitivity of 0.66 and a specificity of 0.72.Best subset conditional logistic regression analyses were performed to find the combination of individual anthropometric measures which best predicted the MI status in the different sex- and age-categories . Notably, the AUROC curve for a model including hip and waist was larger than for a model including waist/hip alone except for women ≥66 yr . If restIn addition to the logistic regression models used to estimate the AUROC curves, we also assessed feed forward neural network models with one hidden layer and a hyperbolic tangent and a sigmoid activation function. These models can model both nonlinearities and interactions. Applying the neural network models only marginally increased the AUROC curves: men ≥66 yr  from 0.82 to 0.83 and men ≤65 yr  from 0.79 to 0.80. Since the gain was very marginal, it was decided to only present the results from the logistic regression analyses.The most striking finding in the present study was the high proportion of MI among elderly men with a narrow hip and a disproportionally high weight (0.88). We are not aware of any previous data on this topic. Our observation that a large waist/hip was related to MI in all sex- and age-categories, confirms present knowledge.There are few case-control studies concerning acute MI –8. The sIn contrast to case-control studies of acute MI, there are many prospective studies concerning the relations between anthropometric measures in general populations and future outcomes such as all-cause mortality , 11–20 aHeitmann and Lissner  presenteThe hip is affected by the dimension of the pelvic girdle, subcutaneous fat, and the gluteal muscles. The gluteal muscles constitute the largest muscle group in the body and are reasonably a major determinant of hip circumference. Therefore, the relation between MI and a narrow hip among elderly men in the present study suggests an association between MI and age-related loss of muscle mass, that is, sarcopenia . ReasonaIn men, the AUROC curve of hip and waist in the same model is larger than in a model including waist/hip alone. Thus, the full strength of the association between waist, hip, and MI risk was not fully reflected by waist/hip but became apparent when both waist and hip were included in the same model. This finding is consistent with a systematic literature review of prospective studies of anthropometric measures .In prospective cohort studies, the risk factors in future event subjects and nonevent subjects are typically registered several years before the event. Contrarily, the risk factors in matched case-control studies are, in both cases and controls, registered at about the time as the index event. This implies a fundamental difference from prospective follow-up studies that register phenotypes of future cases and noncases at a considerable time, usually several years, before the event. The difference in the life trajectory of an anthropometric measure, such as weight, between case and control reasonably varies over the life span. There is an abundance of data on the relationship between anthropometric measures from several years before the patient had a MI but very few anthropometric data from the period close before. Anthropometric measures may change significantly during these years. Consequently, the relations between the levels of potential risk factors in cases and controls may differ considerably between case-control and prospective studies. For example, a difference in hip registered in an MI case-control study may depend on decreasing hip in cases but not in their controls during the years before the MI event. Thus, studies of development of anthropometric measures over time in the same individual are of great importance.Hughes et al.  studied Since the anthropometric measures in acute MI patients are reasonably valid at least for a few months before the MI event, the case-control study may be more suitable than a prospective cohort study to examine the relations between MI status and anthropometric measures.Strength of the present study was the clearly defined recruitment of the cases and controls, which enabled us to select the controls in an unbiased fashion. This strength is, however, partly offset by the difficulty in generalizing our findings to those from other geographical areas. A further possible limitation is the lack of consensus regarding the optimal protocol for measuring hip circumference. Regarding waist, a systematic review has shown that variation of waist measurement protocols has no substantial influence on the associations between waist and different outcomes found in prospective studies, but there are no corresponding analyses concerning hip .An inevitable limitation of the case-control design in the present setting is that data from patients dying before hospitalization are unobtainable, which might cause a minor selection bias.Our finding that a phenotype with a narrow hip combined with a disproportionally high weight is associated with MI among elderly men may be clinically useful, but further studies in similar populations are needed. Non-MI patients with this phenotype may deserve attention for undiagnosed cardiac disease. Recommendations for appropriate nutrition and physical activity to maintain muscle mass as well as research on the relations between dietary habits and anthropometric phenotypes are required.The most noteworthy finding in this study was the evidently narrower hip in the elderly male MI patients compared to their controls. This raises the suspicion of smaller gluteal muscles, due to more advanced sarcopenia, in elderly male MI patients. Such sarcopenia may reflect general aging.In general, over all four sex- and age-categories, a phenotype characterized by the combination narrow hip circumference, high body weight, and short length was the most highly associated with an increased risk of myocardial infarction . This also points on the striking finding that the association between anthropometric measures and myocardial infarction is much stronger in males than in females.


Fibre-reinforced polymer (FRP) is used widely in concrete structures owing to its noncorrosive, light-weight, nonmagnetic, and high tensile-strength properties. However, the FRP-reinforced concrete flexural member exhibits low ductility owing to the linear–elastic property of FRP reinforcement. Hybrid steel—FRP-reinforced concrete members exhibit good strength and ductility under flexure owing to the inelastic deformation of steel reinforcement. The existing investigations have focused on the mechanical behaviours of the hybrid steel—FRP-reinforced flexural members. Only few studies have been reported on the members under combined flexural and compression loads, such as columns, owing to the poor compressive behaviour of FRP bars. We herein propose a new type of hybrid steel—FRP-reinforced concrete—engineered cementitious composite (ECC) composite column with ECC applied to the plastic hinge region and tested it under reversed cyclic loading. The hybrid steel—FRP-reinforced concrete column was also tested for comparison. The influence of matrix type in the plastic hinge region on the failure mode, crack pattern, ultimate strength, ductility, and energy dissipation capacity, of the columns were evaluated systematically. We found that the substitution of concrete with ECC in the plastic hinge zone can prevent the local buckling of FRP bars efficiently, and subsequently improve the strength and ductility of the column substantially. The corrosion of reinforcing steel is a significant problem for reinforced concrete (RC) structures subjected to aggressive environments, such as marine structures, bridges, and parking garages. The corrosion process could cause the loss of serviceability or even the failure of load-carrying capacity. Composite materials made of fibres embedded in a polymeric resin, also known as fibre-reinforced polymer (FRP), is an alternative to steel reinforcement in RC structures, because of its noncorrosive property ,10,11,12The combination layout of steel and FRP reinforcement can improve the mechanical behaviour of concrete flexural members. A large number of experiments have been conducted on hybrid steel–FRP-reinforced concrete beams ,23,24,25High-performance fibre-reinforced cement-based composites (HPFRCCs) can effectively improve the safety and integrity of structures. Among them, engineered cementitious composite (ECC) is an important representative. ECC is a new building material with ultrahigh tensile ductility and excellent crack control ability. Under uniaxial tension, the tensile strain capacity can reach 3% with a crack spacing of 3—5 mm, and a crack width of approximately 60 μm ,28. UndeRecently, Ge et al.  investigcrl is the critical ECC pouring height, L is the column height, yM1 is the yield moment of the hybrid reinforced concrete section, and yM2 is the yield moment of the hybrid reinforced ECC section. Provided that the ECC pouring height is slightly greater than the critical height crl, the plastic hinge zone and final failure region will occur in the ECC area.Owing to the higher cost of ECCs than that of concrete, it is not economical to use ECCs throughout the column height. For the concrete–ECC composite column, ECCs should be used strategically in the critical stress area, to fully exploit the superior deformation ability of ECCs to improve the seismic performance of the member. Hence, the concrete–ECC composite column uses only the ECC near the column base, and conventional concrete is used in other areas, as shown in Two specimens: a hybrid steel—FRP-reinforced concrete (RC) column and a hybrid steel—FRP-reinforced concrete—ECC (RC-ECC) composite column, were tested. Both columns exhibit the same cross section of 250 mm × 250 mm, and length of 1750 mm. The columns were connected to a 450 mm × 900 mm × 1050 mm stub, as shown in cuf) of concrete and ECC were 35.8 MPa and 47.3 MPa, respectively. The elastic modulus and tensile strength of the GFRP bars were measured to be 42.3 GPa and 752 MPa, respectively, as shown in To determine the tensile property of the ECC, three specimens of dimensions 350 mm × 50 mm × 15 mm were prepared and tested. For all specimens, the ultimate strain at the crack localization reached as large as 3%, and the tensile strength exceeded 4.5 MPa. A group of ECCs and concrete cubes of dimensions 100 mm × 100 mm × 100 mm were also prepared and tested under uniaxial compression. Compression strength tests were performed at the age of the column tests. The measured cube strengths  were attached on one of the steel bars at each side at a spacing of 80 mm, and measured during tests. Further, four strain gauges were attached on the GFRP bars to monitor the strain variations. The detailed arrangement of the strain gauges is shown in The RC column has a shear/span ratio of 6.4, a reinforcement ratio of 2.57%, and an axial force ratio of 0.3. The first flexural crack appeared near the column base at the lateral displacement of 4 mm and the corresponding load of 10.4 kN. With increasing displacement up to 8 mm, the cracks appeared in the range of 200 mm from the column base. At the lateral displacement of 16 mm, flexural cracks developed throughout the entire column section, accompanied by the appearance of longitudinal splitting cracks. The specimen yielded at the displacement of 23.5 mm and the corresponding load of 46.9 kN. Beyond yielding, the lateral resistance remained almost constant with the increase in lateral displacement. At the displacement of 32 mm, significant concrete spalling was observed owing to the reversed cyclic loads. With an evident “bang” sound, the GFRP bars buckled at the displacement of 40 mm owing to the loss of lateral confinement. Immediately after that, the lateral load resistance decreased rapidly to 80% of its peak load and the test was terminated. Finally, the specimen failed by concrete crushing with severe concrete spalling, as shown in The RC-ECC composite column exhibits the same geometric dimensions and loading configurations as the RC column, while the matrix in the plastic hinge region is replaced by ECCs. The initial tiny crack occurred at the displacement of 8 mm. Subsequently, multiple tiny cracks were observed at the ECC segment. Compared with the RC column, the crack width is smaller and the crack number is significantly greater. The specimen yielded at the displacement of 24 mm at the lateral load of 61.56 kN. With increasing displacement up to 40 mm, flexural crack localised at the column base. Subsequently, new cracks no longer appear while the crack width of the existing cracks continued to develop. The specimen finally failed by ECC crushing at the displacement of 80 mm. However, no evident ECC spalling and GFRP bar buckling was observed during the tests, as shown in P) versus lateral displacement (Δ) hysteresis curves of the RC and RC-ECC composite columns. An evident pinch effect was observed for both columns owing to the linear–elastic property of the GFRP bars. At the displacement level of 64 mm, the residual displacements of the RC column and RC-ECC composite column are only 28.96 mm and 18.21 mm, respectively. The ductility index in the present study is defined by the ratio of ultimate displacement to the yield displacement. The ductility index of the RC column is only 1.92, compared with 3.33 for the RC-ECC composite column. The much higher ductility of the composite column compared with that of the RC column is owing to the higher compressive strain at the peak stress, as well as the higher integrity of the ECC compared with that of concrete. The cumulative dissipated energy for both columns at each displacement level are provided, as shown in The failure mode hybrid steel—FRP-reinforced concrete—ECC composite column was different from that of the hybrid steel—FRP-reinforced concrete column. Severe matrix spalling and local buckling of FRP bar were observed in the reinforced concrete column, but did not appear in the composite column. ECC can provide a more stable confinement on the GFRP bars than that of concrete.The anchoring scheme in the present study could present the bond-slip failure between GFRP bars and concrete effectively.With the substitution of ECC with concrete in the plastic hinge region, the load carrying capacity, ductility, and energy dissipation capacity of the hybrid steel—FRP-reinforced column increased by 39.62%, 73.44%, and 72.46%, respectively.We herein proposed a new type of hybrid steel—FRP-reinforced concrete—ECC composite column with ECC in the plastic hinge zone and concrete in other parts. The mechanical behaviours of the composite column were tested under reversed cyclic loading, which had not been investigated previously. The hybrid steel—FRP-reinforced concrete column was also tested for comparison. The effect of matrix type in the plastic hinge region on the failure model, crack pattern, ultimate strength, ductility, and energy dissipation capacity of the hybrid steel—FRP-reinforced columns was evaluated in detail. The conclusions from the present study are as follows:


Recently, the early-age strength prediction for RC (reinforced concrete) structures has been an important topic in the construction industry, relating to project-time reduction and structural safety. To address this, numerous destructive and NDTs (non-destructive tests) are applied to monitor the early-age strength development of concrete. This study elaborates on the NDT techniques of ultrasonic wave propagation and concrete maturity for the estimation of compressive strength development. The results of these comparative estimation approaches comprise the concrete maturity method, penetration resistance test, and an ultrasonic wave analysis. There is variation of the phase transition in the concrete paste with the changing of boundary limitations of the material in accordance with curing time, so with the formation of phase-transition changes, changes in the velocities of ultrasonic waves occur. As the process of hydration takes place, the maturity method produces a maturity index using the time-feature reflection on the strength-development process of the concrete. Embedded smart temperature sensors (SmartRock) and PZT (piezoelectric) sensors were used for the data acquisition of hydration temperature history and wave propagation. This study suggests a novel relationship between wave propagation, penetration tests, and hydration temperature, and creates a method that relies on the responses of resonant frequency changes with the change of boundary conditions caused by the strength-gain of the concrete specimen. Calculating the changes of these features provides a pattern for estimating concrete strength. The results for the specimens were validated by comparing the strength results with the penetration resistance test by a universal testing machine (UTM). An algorithm used to relate the concrete maturity and ultrasonic wave propagation to the concrete compressive strength. This study leads to a method of acquiring data for forecasting in-situ early-age strength of concrete, used for secure construction of concrete structures, that is fast, cost effective, and comprehensive for SHM . Concrete is an extensively used material in construction owing to its rich qualities, including being cost-effective, durable, and moldable into shapes, permitting the construction of safe and reliable structures. By contrast, the complex mixture  and field uncertainties make concrete susceptible to imprecise determinations of strength in the early stages of curing; managing these factors is important in preventing structures from unexpected accident or failure due to the premature removal of a framework or immature concrete. It is necessary to understand the materials used for construction to ensure the efficiency and longevity of the structures being built. Several types of structures are built using concrete. It is important to study and determine the properties of cement and concrete at different stages of construction as they directly affect the strength and durability of the structures. In the project schedule for construction, the idle time required for the hardening of concrete is a crucial influencing factor, especially in construction of high rise or multi-staged projects. Unscheduled removal or early removal of the supportive framework sometimes causes huge losses, such as the incident that took place in the construction of 2000 Commonwealth Avenue, Boston ; one sidUltrasonic wave propagation through the concrete medium is studied widely. The variations of these approaches lay in the methodology used for analyzing the wave propagation. For this purpose, different parameters are analyzed related to concrete stiffness and compressive strength properties. Normally the technique of direct transmission of waves through the concrete medium is used. By using the ultrasonic waves analysis method, three types of data can be acquired when dynamic loads or vibrations are applied to a concrete structure: (i) compressional waves or P-waves, (ii) Rayleigh or surface waves, and (iii) shear waves or S-waves ,33. The fc represents the compressive strength, V is the velocity of the longitudinal waves, and a and b are the parameters determined by P. Turgut [In this equation . Turgut  using th. Turgut . AccordiS is the speed of the wave, t represents the time, and x is the path length.In Equation (2), For measurement of stressed zones, the waves speed can be used. The wave speed depends on the density and Young’s modulus according to,E and In Equation (3), Young’s modulus and the density of the material are represented by tion (4) ,(4)S=Eρv is the Poisson ratio of the material, which is incorporated to give the value for the speed of the waves in the material.In this equation, Because the stiffness and rigidity grow with the curing time of the concrete, the velocity of the waves increases as a function of time. This variation in stiffness molds the velocity of the waves. The stiffness of the material is related to the Young’s modulus of material . Thus, wAccording to the wave equation, the relation of wave speed, Young’s Modulus, and density of material is defined as,E is Young’s modulus, t is the time, x is the path length, and In Equation (5), This study of concrete comparative strength-development monitoring was prepared using three different results: (i) the maturity method of concrete strength estimation, (ii) ultrasonic wave propagation in concrete, and (iii) UTM-based concrete compressive strength estimation, which was composed of smart PZT sensors and temperature sensors (SmartRock) to monitor the commencement of dynamical changes in the concrete specimens.For the experiment, a cubic meter sample composition was prepared according to quantities given in Ordinary Portland cement of type ASTM C 150 was used in the preparation of the specimens. The gradation of aggregates, determined by sieve analysis, is given in Concrete specimens of dimensions 400 mm × 100 mm × 100 mm were casted for the test of ultrasonic waves and maturity method strength monitoring. The PZT transducers and temperature sensors were embedded in the specimens during pouring of the concrete. Simultaneously, cylindrical samples were cast for the compressive strength test by penetration resistance using a UTM from the same concrete mixture. Two types of specimens of the same concrete mix were poured for the experiment, the specimens of which dimensions are aforementioned were used for the ultrasonic wave propagation monitoring and SmartRock sensors. The cylindrical samples were poured for the destructive test to be placed as part of the penetration resistance test. The average value of three specimens was considered the value for each specific day during the strength-development monitoring; monitoring was completed on days 1, 2, 3, 7, 14, and 28.The PZT material has the ability to interconvert mechanical and electrical energies and sense the dynamical vibration in paste and solid media. These rich properties enable PZT materials to be used both as sensors and actuators ,38,39,40For data acquisition, PZT materials were used to actuate and sense the responses of propagated signals from the medium. The specific PZT material used in this experiment was APC 850 (American Piezo Ceramics), which has high sensitivity characteristics and large displacement effect; these PZT transducers were embedded in the concrete with large damping effects. The material of size 10 mm × 10 mm was attached to 300 mm × 30 mm steel plates such that two PZT specimens were placed on each face of a steel plate separated by 140 mm , as shown in The PZT transducers were embedded in concrete specimens to actuate and produce guided ultrasonic waves and were considered as a sensor to observe the internal dynamic changes of the subjected material . The senBecause the electrical behavior of the material is linear,D is the displacement of the electric charge density, E is the electric field strength, and ε is the permittivity of a free body. The factor of proportionality relating the electric field strength and electric displacement is defined as the medium’s dielectric constant. The tensor of the displacement of the electric charge density is also represented in Equation (6).In Equation (6), The strain–stress relationship is in accordance with Hooke’s Law,S represents the strain and T represents the stress produced in the body.In this equation, Equations (6) and (7) can be written asIn Equation (8), The approach for conducting experiments for this study encompassed embedding smart PZT transducers in a concrete specimen to measure the ultrasonic waves variation of center frequencies in the range of 100–300 kHz and thus to monitor the hardening process of concrete by the gradual divergence of phase-transition as the specimens cured. Especially in the liquid phase to the initial sitting time, the strength measuring process is critical, in that it depends on the mixture type and sometimes varies with the measuring approaches. In the initial sitting time, the frequencies of waves indicate the dynamic change in the medium. In this study, we monitored the phase changes of the A-mode and S-mode of signals.The experiment was carried out with a concrete mixture ratio given in u/∂t, or that of the local velocity/speed shift of the elements transmitting the wave through sections. The time-of-flight is used for the specification of the velocity change of the waves. The velocity of waves is modified by dynamic variations of the material thickness. The elastic properties of the transmuting medium, density, and Poisson’s ratio define the wave speed, s. In this study, all the wave speed values are assumed constant. Hence, the results were compared for all three methods.In the process of ultrasonic wave propagation, to consider the analogy of phase transition, the simplified one-dimensional equation fits adequately because the ultrasonic pulse detector or receiver focuses only on the first arrival of the signal of the longitudinal wave and the subsequent signals are ignored by the system. Furthermore, ultrasonic waves were analyzed through the functionality of the solid-medium wave-transformation analogy. Studies of the phase transition state that for the monitoring of composite structures, the A-mode of Lamb waves gives a clearer and more appropriate result than the S-mode ,45. WhenThe hydration temperature history uses data for the NDT to reveal hydration-temperature-related features to monitor compressive strength of fresh concrete. This method relies on the combined parameters of temperature and time and can be used for in-place concrete during construction ,46.When water is added to the mixture, the hydration process commences, and the chemical reaction of disilicate, trisilicate, aluminate, and other admixtures begins, so the hydration temperature of concrete rapidly increases. The temperature rises rapidly during the initial hours of pouring until two days later, after which it stays constant with the development of the material’s internal bonding and increased concrete strength . In the t, t0 is the time at initial sitting, and k is a constant rate, which in a molecular system is when the energy is transferred between the molecules due to collisions during their constant motion. The kinetic energy of the molecules increases as the system heats up and molecules surmount the barrier of energy required for lower-energy reaction products. Thus, the rate of reaction increases with increasing temperature observed as a constant rate k [In this equation, S represents the strength with respect to time t rate k .While we can define the datum temperature of the mixture according to the properties of cement and other admixtures, when admixtures are added, the datum temperature can be different. In slack seasons of concrete pouring, freezing-temperature effects on the strength-gaining process of inter-particle bonding must be considered when specifying the datum temperature .The product of time and hydration temperature of concrete is used for strength estimation. The 1950s Nurse–Saul maturity Function is given in Equation (10) (10)M=∑0Equation (10) shows the datum temperature effect is neglected to prominently pursue the strength development.In monitoring the strength-development process of concrete through ultrasonic wave analysis, the dynamic change of the phase in the material observed for the initial sitting stages used the phase-transition phenomena. At the same time, the hydration-temperature history produced the maturity curve to predict the strength using the maturity index. The comparison of these results was established by measuring the strength of the cylindrical simples by the penetration resistance test using a UTM. The results of the maturity method and the compressive strength were clear and similar to the ultrasonic waves analysis result.The velocity variations in the wave propagation were observed in the transmuting of phases of the concrete sample. The phase changes were due to the formation of new boundary conditions with curing and strength development, as the strength of the inter-particle bonding caused the expansion in the boundaries of the concrete structure. The velocity change of A-mode compared to S-mode for the specimens is shown in Pattern irrelevancy in the raw signals can be observed for the amplitude change in The velocity change in the term of the material stiffness factor occurs prominently in The hydration temperature was monitored continuously after pouring the concrete and the smart temperature sensors produced the data for the estimation of the maturity of concrete with curing time. The datum temperature was calculated as −2 °C per ASTM ,17. The The data of hydration-temperature history was applied to the Nurse–Saul curing function to predict the maturity index. As the datum temperature and time limit were defined, the results showed that hydration temperature was elevated in the initial hours and increased rapidly; that elevation continued to be observed until 28 h after curing, reaching a rise of 20 °C. As time passed, the strength-development improved and the temperature was observed to show lower peaks, as compared with the initial hours, owing to the completion of chemical processes. The experiment was composed of two specimens in the same environmental conditions. Consequently, the temperature data did not show a prominent deviation in curves. The data for the maturity with curing time is shown in Because the temperature data for the concrete specimen 2 appeared slightly higher than that of specimen 1 of concrete, the cured strength was also calculated to be somewhat higher. The strength was calculated from the data shown in Using the Nurse–Saul function with the datum temperature measured as −2 °C, the maturity index data were calculated as shown in The results of compressive strengths were compared to the penetration test results performed in the laboratory on the specimens for penetration-resistance tests. The data for all indicated dates were the average values of the results for the three cylindrical-specimen tests on each date. After 24 h of curing, the average strength of three cubes for the penetration resistance test was calculated as 3.97 MPa, which rapidly increased until 48 h when the strength value reached 9.58 MPa, as shown in The variations in the results can be observed by the data, which was due to categorizing the rise of amplitudes in the data of the ultrasonic wave signals in The strength prediction for the described methods produced a simultaneous curing process for the gain of strength, and the results were calculated as 16.48 MPa and 17.68 MPa for the UTM test and ultrasonic wave analysis, respectively.The deviation of the data and specification of the strength-development monitoring is compared by fitting a curve to the analyzed data of the ultrasonic waves propagation data and the maturity method results to make the comparison with compressive strength measured by the penetration resistance test. The fitness of regression for the data model was 0.997, implying a valid fit and permitting a novel modified relation for predicting ultrasonic wave velocities in concrete and the maturity of the concrete at an early age. This is specified in Equation (11),v represents the wave propagated data, and m is the maturity method result for the estimated compressive strength. The equation provides a promising result for all the data and is in good agreement with the data shown in Here, The experiments were performed with a controlled temperature, but in addition to temperature, other factors like water/cement ratio, type of bonding agents, aggregates, and age of concrete may affect the concrete-strength process ,49. As sOn day 14, the average strength of the penetration test was calculated as 19.47 MPa and that of the waves analysis was measured as 19.56 MPa, nearly the same for both specimens, while the result of the maturity method was calculated as 20.02 MPa, as shown in This modified new relationship of maturity and ultrasonic waves data results predict a comparative function for estimation in-situ of concrete early-age strength by NDT methods, which is a novel approach for early-age strength estimation. Concrete strength at day 28 by the destructive test of penetration resistance of concrete cubes through a UTM had the strength of 25.62 MPa, while the result according to the equation calculated the strength as 25.50 MPa at day 28. This relationship of data in the study attempts to predict the compressive strength by different means, leading to safe, promising structural health monitoring.This study covers the limitations of early-age strength development of concrete through an analysis that incorporates different test methodologies. The relationship of the maturity method and the ultrasonic wave propagation is that the hydration temperature results become higher in the initial hours of the hydration process; the wave propagation is slow as the concrete mix paste changes from a liquid paste to a semisolid form, the observed fluctuation of the waves was due to the medium form variation. The results predicted by the data, illustrated in The data suggest that the behavior of the signals and time of wave propagation to the boundary of the higher rigidity in the concrete sample results in a higher value of the wave propagation velocity.For the maturity of concrete, the datum temperature plays a basic role in the results of the maturity index, as the maturity method result gave a smooth output and was a little higher than that of the ultrasonic waves. So, for each mix, the datum temperature should be defined according to mix proportions, as the hydration temperature directly affects the strength development. Furthermore, from the results, it has been concluded that high temperature during concrete curing causes rapid strength gains in the structural elements.The results qualify the proposed method for structural health monitoring in a wide range of industrial multi-stepped project monitoring. The procedure can be advanced in the future for the integration of methodology to the equipped systems for synthesis in the modified polymers.


We demonstrated a fiber in-line Mach-Zehnder interferometer (MZI) coated with platinum (Pt) for the simultaneous measurement of strain and temperature. The sensor was fabricated by splicing a section of multimode fiber (MMF) between two single mode fibers (SMFs) and the Pt coating was prepared by iron sputtering technology. Fine interference fringes of over 20 dB with a compact size of 20 mm were achieved. The experimental results of the two different resonant dips showed strain sensitivities of −2.06 pm/με and −2.21 pm/με, as well as temperature sensitivities of 55.2 pm/°C and 53.4 pm/°C, respectively. Furthermore, it was found that the Pt coating can improve the strain sensitivity significantly, resulting in an increase of about 54.5%. In addition, the sensor has advantages of easy fabrication, low cost, and high sensitivity, showing great potential for the dual-parameter sensing of strain and temperature. In ge2 laser , FBGs co2 laser , various2 laser  or plast2 laser , photoni2 laser  or few-m2 laser , cascade2 laser , partial2 laser  or selec2 laser , dual-co) tapers , and oth) tapers ,17,18,19) tapers  reported) tapers  presente) tapers  or use a) tapers . HoweverIn this paper, a compact optical fiber MZI coated with Pt was proposed and experimentally demonstrated for the simultaneous measurement of strain and temperature. The MZI was fabricated by splicing an MMF with a length of 20 mm between two SMFs with a slight core-offset of about 7.5 μm, and the metal coating was prepared by an iron sputtering method. The experimental results demonstrated that the strain sensitivities of the MZI with Pt coating for two resonant dips were −2.06 pm/με and −2.21 pm/με in the range of 0~2000 με, respectively. Meanwhile, the corresponding temperature sensitivities of 55.2 pm/°C and 53.4 pm/°C were achieved in the range of 20 °C to 70 °C. Furthermore, the contrast experiments found that the Pt coating could enhance the strain sensitivity significantly. In addition, the sensor has many advantages including simple fabrication, low cost, and high fringe visibility, demonstrating its great application potential in the fields of health monitoring and structure quality monitoring.The Pt coating was achieved using an ion sputtering coater , which can be well controlled merely by adjusting the splash time. This deposition technology is relatively simple and cheap compared with the chemical vapor deposition (CVD) method and atomic layer deposition (ALD) technology, as it does not require complex equipment or a sophisticated process control. To characterize the morphology and the average thickness of the Pt coating, Pt coating was sprayed on a silicon substrate with the same sputtering time of 200 s. The morphology of the Pt coating was observed by a scanning electron microscope (SEM), as shown in In addition, a broadband light source ranging from 1528 nm to 1602 nm and an optical spectrum analyzer  with a resolution of 10 pm were employed to trace the transmission spectrum evolution of the MZI during the fabrication and testing processes.λ is the wavelength of the light; and L is the length of the MMF. According to Equation (1), the optimal interference fringes can be obtained under the condition of m is an integer. It can be seen from Equation (2) that the resonant wavelength is closely related to the length (L) and L). So, the wavelength variation can be denoted as follows [T represents the change of temperature. When the sensor is heated, the change in the length of the MZI depends on the thermal expansion coefficients of the fiber and coating materials. Since the thermal expansion coefficient of the Pt coating is much higher than that of the silica, the effects of thermal expansion mainly depend on the coating. In general, the coating could cause changes in According to  follows :(2) λm=2wn below :(3) Δλm  follows :(4) Δλm −1 and 0.0674 nm−1, respectively. This means that the order of dominant cladding modes excited in the MZI with Pt coating is higher than that without coating. So, the value of The experimental setup for strain testing is illustrated in Reference . The proThe two dips of the MZI without and with Pt coating were chosen to analyze their strain and temperature sensing characteristics for the simultaneous measurement of strain and temperature. 7 pm/με) , the MZI7 pm/με) , and the7 pm/με) .The temperature was controlled by using a heating plate, and the temperature changed from 20 °C to 100 °C with a step of 10 °C. With the increase of temperature, all the resonant dips exhibited a red shift, as shown in When strain and temperature are simultaneous applied to the sensor, the wavelength shifts of dip 1 and dip 2 can be expressed using the standard matrix demodulation method, as reported in Reference :(5) [Δλ1 follows :(6) [ΔT According to the above experimental results and Equation (6), for the proposed MZI with Pt coating, the simultaneous measurement of strain and temperature can be achieved by calculating the sensitivity as below:λ1) and δ(Δλ2) at two wavelengths, the theoretical strain and temperature resolutions of the sensor, δ(∆ε) and δ(∆T), can be given by [According to this equation, the temperature and strain variation can be obtained by monitoring the wavelength shifts of two corresponding dips. According to the error analysis method given in Reference , if an ogiven by :(8) [δ. In summary, an MZI coated with Pt was proposed for the simultaneous sensing of strain and temperature. The experimental results showed that the Pt coating could enhance the strain sensitivity obviously; the obtained sensitivities were increased by about 54.5%, from −1.43 pm/με to −2.21 pm/με. The simultaneous measurement of strain and temperature with the strain sensitivities of −2.06 pm/με and −2.21 pm/με, as well as temperature sensitivities of 55.2 pm/°C and 53.4 pm/°C, were realized through the demodulation matrices. Owing to its advantages of high sensitivity, low cost, fine fringe visibility of up to 20 dB, and simple manufacturing, the proposed sensor exhibited high potential for applications of physical sensing and structural health monitoring, etc.


In South Korea, the number of vehicles is gradually increasing. The number of heavy vehicles in 2010 increased up to 19% in less than five years. Therefore, the chances of heavy vehicle-concrete median barrier (CMB) collision also became higher than in the past; therefore, a need to study a stricter design level for improving the current CMB (CMB-15) under harsher environments arose. Accordingly, in the present study, a new concrete median barrier was designed under a stricter impact severity, SB6(420 kJ), compared to the current design impact severity, SB5-B (270 kJ). In particular, shock absorbing devices to absorb impact energy were applied to the CMB. An empty space allows the dowel bars to deform and absorb collision energy. Therefore, deformable CMB was designed and tested. The key parameters selected in our study were dowel bar and wire-mesh. A series of numerical analyses were conducted to evaluate the proposed new deformable CMB designs with shock absorbers. Finally, the optimal design, CMB-17S, was proposed after several evaluations of the proposed designs and a full-scale field test. It was found that, although the developed model did not accurately predict the impact sequence due to certain differences between the actual truck and the truck model, the permanent deformation after collision could be well predicted. Based on the observations from a full-scale impact test, it was recommended that the top part of the CMB should be strengthened since major volume loss occurred due to local impact, which appeared to be due to punching shear failure. In South Korea, the number of vehicles that use the highway is gradually increasing, and the rate of increase is also growing according to Kim et al. . In anotIn order to develop a high-performance concrete median barrier (CMB-17S), a numerical model was developed first using LS-DYNA, and a key parametric study was conducted. The name (CMB-17S) of the high-performance concrete median barrier denotes that the developed CMB was tested at full scale in the summer of 2017.The simulation results were compared with the data from the previously conducted field tests, namely, CMB-15 (designed for SB5-B) and CMB-16 (designed for SB5-B (20A)), Kim et al. [Volume loss is defined as the volume of broken pieces of concrete that fall apart from the original concrete body. Therefore, less volume loss means less chance of secondary accident by flying or broken concrete fragmentations. The volume loss (%) ratio was estimated using Equation (1). All the proposed CMBs in our study were evaluated with respect to volume loss.After verification of the developed model, section design of CMB-17S was conducted using the model. The size of wire-mesh and the size of the dowel bar in shock absorbers were selected as the key design parameters. The shape of the CMB was not changed, since it was originally developed for the occupant protection performance. The spacing between the dowel bars was also not changed, as the optimal design of the spacing was already found by Kim et al. .In order to develop CMB-17S, first, verification of the model was conducted in combination with certain key parameters. Based on Kim et al. ,5, the sAnother important key parameter is overstress. The overstress limits the dynamic increment factor at high strain rate in compression and tension separately. In the current study, the range of stress value was considered from 30 to 40 MPa. A more detailed discussion and the specific equations on overstress can be found in Murray ,7. The oIn order to develop a new CMB under harsher conditions, materials such as fiber reinforced concrete (FRC) can be considered as good materials against impact or blast. Some studies on impact resistance of FRC have shown that FRC limits the extent of damage more than the ordinary concrete median barriers ,21. HoweAccordingly, in this study, instead of using FRC for new design, the concept of deformable CMB was applied to the new design of CMB. The deformable concrete median barrier was first introduced by Kim et al. . The smaFor the section design of CMB-17S, a parametric study using the developed model was performed after verification of the model. A detailed discussion for a model verification can be found in For developing CMB-17S in this study, the additional 50 mm width was not applied; instead, the same width and the same slope of the side face as those of the CMB-15  of wire mesh and dowel bar for shock absorbers, were considered in the parametric study, and the results are shown in In Both 3.5 and 4.5 mm wire-mesh a,b showeType B deformable CMB was an efficient and conservative design compared to Type A, as shown previously. For selection of proper dowel bar size, a more severe level of impact severity SB6(100V) was considered, since the results from SB6 level showed similar results regardless of the size of dowel bar used when 7.6 mm or larger sized wire-mesh was used. SB6(100V) was the test level with a combination of 25 ton mass, 100 km/h impact speed, and 15° impact angle. It was named as SB6(100V), since only the impact speed (V) was changed, keeping the other conditions the same as those of SB6. Under the harsher impact severity of the SB6(100V) condition, D13 and D16 dowel bars were fractured, while the D19 resisted under SB6(100V), as shown in The fractured dowel bar . Therefore, 7.6 mm wire-mesh with a D19 dowel bar was selected as the first design, and a field test was conducted for the final verification for low fragmentations, which were less than 3.5%. Furthermore, since most of the damage was localized at the upper part, it was not necessary to use the same spacing (100 mm) of wire-mesh in the lower part as that in the top part of the CMB. Accordingly, different spacings between the horizontal wires (which could reduce the reinforcement ratio in the lower part of CMB without losing any impact resistance capability) were attempted, and 250 to 270 mm spacing between the horizontal wires was selected for the lower part. The vertical wires were not removed, because the number of wires (steel ratio) in the top part would be reduced. The first design of CMB under SB6 was named as CMB-17S, as shown in Using a developed FE-model, the structural performance of CMB-17S was compared with that of CMB-15. In this study, elements in plastic strain conditions were considered as damaged zones. As shown in As previously explained, the new CMB-17S was proposed after conducting several numerical analyses. However, the obtained design was only associated with the simulation results. When a new design of concrete median barrier is developed for installation on a road, the new design becomes valid when full-scale truck-CMB collision test results meet the recommended performance criteria specified by the government . In SoutA comparison of the impact severity of different countries  is presented in Before pouring concrete, the wire-meshes were aligned along the length of the CMB, and the D19 dowel bars were installed at a spacing of 1.0 m for an intended deformation, as shown in A 25 ton truck with a 14.5 ton curb weight was used, as shown in During the impact, the deformation of the CMB was carefully measured using several linear variable differential transformers (LVDTs), as shown in A total of 14 LVDTs were used to measure the lateral displacement of CMB-17S due to impacts. To evaluate the body deformation of CMB-17S, the four LVDTs , a larger amount of volume loss (8.7%) was measured. This indicated that the developed model was not accurate for estimating volume loss caused by local impact (second impact). Furthermore, it was found that a larger amount of steel ratio was required for the top part of the CMB under SB6 load.The maximum deformations obtained along the length of CMB-17S from both testing and analysis had similar results, as shown in The phase difference between the test and the analysis during the impact sequence is shown in In this study, a deformable concrete median barrier was designed and tested. The small empty spaces were intentionally formed using the Styrofoam at every location of dowel bars so that the dowel bar could deform via shearing under impact loading.A deformable CMB could experience shock absorbing effects as well as dispersed deformations along the length of the CMB, which dispersed the impact energy over a much larger area of CMB.A numerical model was developed to find volume loss under truck impact. In the model, a deformed dowel bar was modeled to predict any lateral displacement. After verification of the model, several parametric studies were conducted. The selected parameters were dowel bar size and wire-mesh size.From the numerical analysis, it was found that the deformed dowel bar due to addition of Styrofoam under lateral load could successfully absorb a significant portion of energy by allowing a certain displacement between the CMB and the foundation.The final proposed design comprised one layer of 7.6 mm wire-mesh and D19 dowel bars. The spacing between the wires was fixed to 100 mm, while the spacing between the dowel bars was fixed to 1000 mm.It was found that the dowel bars that had a relatively smaller size (D13 or D16) were fractured under a harsher loading condition such as SB6(100V). By contrast, the larger dowel bars, such as D22 or D25, did not deform or absorb the energy fully and resulted in a larger amount of concrete fragmentation.A full-scale collision test between a 25 ton truck and the developed CMB-17S was performed, and the installed dowel bar worked fine as intended.Due to local impact from the lower corner zone of the steel cargo compartment at second impact, stress concentration occurred, causing a large amount of concrete fragmentation. This phenomenon was not accurately captured by our developed model. For more accurate prediction of volume loss, development of a local model is required.A comparison of the analysis and the test results revealed that the final permanent deformation could be well captured by the developed model; however, volume loss, location of the maximum deformation, and sequence of the three major impacts were rather different. It is thought that this difference was due to the differences between the actual dimension and the material properties of the truck and the truck model.For better performance of our developed CMB-17S, the top part of the CMB should be better strengthened by more wire-mesh, since major volume loss occurred due to local impact, which appeared to be due to punching shear failure.A new concrete median barrier (CMB-17S) was designed under impact severity SB6(420 kJ). While the current design  can cover 50% of the total vehicle-CMB collision accidents, the newly proposed design level  could cover 85% of the total vehicle-CMB collision accidents in South Korea. In the present study, no FRC was considered, nor was the cross-sectional shape of CMB changed. Keeping all the other conditions the same as in CMB-15, only the designs of the wire-mesh and the dowel bar type shock absorbers were modified. Several past parametric studies have adopted various dowel bars and wire-meshes to find the optimal design under SB6. The proposed new design in the current study, CMB-17S, was finally tested in the field with a full-scale truck. As intended, the lateral displacement of the shock absorbers occurred between the soffit of the CMB and the surface of the concrete foundation. However, a relatively larger amount of concrete fragmentation was observed from local impact by the tested truck. The following conclusions can be drawn from the current study.