This study examines the behavioural intentions of international tourists travelling to Beijing when faced with smog pollution. An extended MGB  was employed as the theoretical framework by integrating mass-media effect and perception of smog. The role of mass-media effect and perception of smog were considered as new variables in the international tourist’s decision-making process for travel to Beijing. Structural equation modelling (SEM) was employed to identify the structural relationships among research variables. Our research results showed a strong correlation between positive anticipated emotion and desire. The mass-media effect is a significant (direct) predictor of both the perception of smog and behavioural intention. The Chinese government could attach great importance to the mass-media effect to reduce the negative impact caused by smog pollution on inbound tourism. NotablySmog pollution is widely considered to be a primary reason for the decline in the number of China’s inbound tourists in recent years . Xu and The mass media plays an important role in information dissemination, public opinion guidance, and persuasion . Mass me2.5 was above 500, indicating that the air quality of Beijing was “crazy bad”. Subsequently, the U.S. embassy’s reading was widely retweeted. Individuals were advised to avoid outdoor activities to reduce the possibility of exposure to smog or wear a mask when going out [Media coverage and publicity are the main communication channels to arouse public awareness of smog pollution . Hong, Koing out . The laroing out ,27. Expooing out . It is coing out .Severe smog is assumed to threaten the sustainable development of tourism destinations by jeopardizing their attractiveness and competitiveness . IndividThe MGB is an advanced theoretical framework to explain and predict individual behaviour. It addresses the limitation of the Theory of Planned Behaviour (TPB) by integrating emotional factors, past behaviour, and desire . PeruginSeveral studies are employing the MGB as a theoretical framework to explain and predict individuals’ behavioural intention or actual behaviour in leisure and tourism ,40,41,42The MGB is an advanced model developed from TPB: the antecedent variables  in TPB are proven to affect behavioural intention directly. In the MGB, AT refers to an individual’s overall appraisal of performing a certain behaviour; SN reflects individual perceived social pressure from significant others on whether to carry out a particular behaviour; and PBC examines an individual’s overall perception of the ease or difficulty in performing a specific behaviour . These tHypothesis 1 (H1).AT is positively correlated with desire.Hypothesis 2 (H2).SN is positively correlated with desire.Hypothesis 3 (H3).PBC is positively correlated with desire.Hypothesis 4 (H4).PBC is positively correlated with behavioural intention.Hypothesis 5 (H5).PAE is positively correlated with desire.Hypothesis 6 (H6).NAE is negatively correlated with desire. Hypothesis 7 (H7).FPB is positively correlated with desire. Hypothesis 8 (H8).FPB is positively correlated with behavioural intention.Hypothesis 9 (H9).DE is positively correlated with behavioural intention. The media is an important communication channel for the public to access information, and it is also influential in affecting public perception and awareness ,45. MediHypothesis 10 (H10).MME is positively correlated with perception of smog.The correlation between mass media and public perceptions has been widely discussed in social studies . The widHypothesis 11 (H11).MME is positively correlated with desire.Hypothesis 12 (H12).MME is positively correlated with behavioural intention.Psychological research suggested that an individual is likely to avoid the object when he/she holds negative cognition/perception of the object . Tasci aHypothesis 13 (H13).POS is positively correlated with desire.Hypothesis 14 (H14).POS is positively correlated with behavioural intention.Beijing is the capital city of China and one of China’s most popular international tourism destinations owing to its long history and rich cultural tourism appeal. It is also one of the hardest-hit areas in terms of the frequency of smog pollution and the severity of particulate matter in the atmosphere . InboundA self-administrated questionnaire was distributed to the target sample: international tourists arriving in Beijing, China. This research gives an opportunity to interview on-site international tourists in Beijing, a rarity in the current smog studies. A formal survey was conducted twice to make the sample more representative. The first survey was conducted from January to February 2018 in the Capital International Airport in an area near the Palace Museum and China’s National Museum in Beijing. The second survey was conducted from April to May 2018 at the same places. A total of 528 completed surveys from 550 international tourists were received with a total response rate of 96.0%. A total of 26 questionnaires were further eliminated because of incomplete responses or irregularities. Finally, a total of 502 questionnaires were coded and used for further analysis.In this section, the general operationalisation of the EMGB framework to measure international tourist’s behavioural intention was suggested under the threat of smog pollution in Beijing. The questionnaire in this study included three sections. The first section measured the original MGB’s parameter using 29 items addressing AT, SN, PBC, PAE, NAE, DE, BI, and FPB. Respondents could rate their level of agreement with each statement guided by a 5-point Likert scale (1 = strongly disagree and 5 = strongly agree). The second section measured integrated variables associated with MME and POS, which were generated from the prior studies of smog pollution or climate change. Respondents also rated their level of agreement with each statement guided by a 5-point Likert scale (1 = strongly disagree and 5 = strongly agree). The last section measured respondents’ demographic information: gender, nationality, age, marriage status, education, and occupation.In this study, R-statistic was applied to perform descriptive statistics, confirmatory factor analysis (CFA), and structural equation modelling (SEM). Specifically, this study used CFA to test the EMGB measurement model’s appropriateness and determine the internal consistency of the items and its construct validity. Finally, the structural relationships between the EMGB variables were verified by SEM.The demographic characteristics of the respondents are shown in First, this study performed CFA to estimate the measurement model for all the EMGB variables . Mardia’The measurement model satisfied the convergent validity, with all factor loadings see  exceededConstruct validity was verified via convergent and discriminant validity. All average variance extracted (AVE) and composite reliability (CR) in the measurement model for the EMGB were greater than the criteria of 0.5 and 0.7, respectively . This inAT→DE = 0.170, t = 2.316, p < 0.05), SN , PBC , PAE , NAE , and FPB  were positively associated with desire to visit Beijing, while POS  was negatively associated with desire to visit Beijing, supporting H1, H2, H3, H4, H5, and H7. However, MME  was not statistically significant to predict the desire to visit Beijing, thereby rejecting H11.The structural model of the EMGB was found to fit the data well with better goodness of fit . The results of the EMGB are shown in PBC→BI = 0.067, t = 2.128, p < 0.05; βDE→BI = 0.759, t = 27.844, p < 0.001; βMME→BI = −0.101, t = −2.737, p < 0.01), supporting H6, H9, H12. However, the FPB and POS  were not statistically significant to predict behavioural intention to visit Beijing, thereby rejecting both H8 and H14.The relationships among PBC, MME, desire, and BI were found to be positive and significant  could be added to the original MGB. This finding is consistent with Ajzen’s  study, wSecond, the current study emphasized the role of mass-media coverage in individual perception formation and decision-making process regarding to health issues. In prior studies, mass media was proven to accelerate the spread of such risk events, like disease , natural disasters , and terrorism, which will further shape individuals’ risk perception or negative image of a destination . This st2.5 reduced to 34 μg/m3 [Practical implications were also provided by analysis findings. As revealed in the study, mass media can strengthen the perception of smog of international tourists. Therefore, in order to minimize the negative impact of air pollution mass-media coverage on inbound tourism, it is priority for Chinese government to take efforts to reduce air pollution. That is because mass-media coverage is a main source for the international community to be educated about China’s environmental issues. For example, since 2013, whenever a severe smog episode occurred in China, the number of media reports has exponentially increased. Among them, the neighbouring countries  reported that China’s smog is responsible for the decline of air quality in their countries to some extent, while the Chinese media would complain about such reports . This wa34 μg/m3 . However2.5 exceeded over 36 μg/m3 in an hour. Sales of smog-resistance products increase significantly in Korea during bouts of serious air pollution in China [It could be implied that the international tourist’s desire to visit Beijing may be reduced because of their concern about whether Beijing’s smog may damage their health. For example, Korean and Japanese media have reported that smog increases the human mortality rate. According to Air Korea , outdoorin China . The masin China . Therefoin China . It may This study has some limitations that may help those conducting future studies. The first limitation is that the results may be different depending on seasonality and weather condition because the survey of the current study was conducted only for international tourists in spring and winter, which has poorer air quality than other seasons. In addition, the effect of smog as a tourism risk may have been overestimated because the study was conducted in a year other than the year when smog was most prevalent. As smog levels occur differently with different seasons and times, international tourists visiting Beijing may have different perceptions of smog accordingly . TherefoSecond, although air pollution is one main constraint factor for China’s inbound tourism, there are still some crossed factors which may also affect international tourists’ behavioural intention, such as monetary elements of the exchange rate, world economic situation, and so on. These crossed factors can be taken into consideration in future studies.Third, there is limitation of language bias, as the questionnaire was only translated into three languages: English, Korean, and Japanese. European countries are also main resource countries of Beijing travel, but many European people, for example, French, German, and Spanish, cannot read English very well. Additionally, many tourists from Southeast Asia do not speak English. Therefore, our questionnaire respondents from Europe and Southeast Asia were the tourists who can read English. In order to get generalized respondents, questionnaires in various languages should be made although this may also enhance the difficulty in conducting the survey.Fourth, the sample size in the current study is not balanced, with more questionnaires spread to western tourists, which do not satisfy the requirements of a multi-group test. In further studies, a variety of survey methods can be used to equalize the sample size of eastern and western tourists. It will be a good trial for future research to compare the difference of decision-making processes between western tourists and eastern tourists in order to understand the sensitivity level of air pollution in different environmental/cultural atmospheres.Finally, future researchers may focus on how to decrease the negative impact caused by mass-media effect. Understanding the specific forming mechanism of smog perception and how to respond to air pollution issues by referring to the prior studies or cases in the media would be helpful to minimize adverse impact caused by air pollution.Environment sustainability is one main foci in tourism destination. The current study examined international tourists’ behavioural intention for Beijing travel under the threat of air pollution by extending MGB. Results proved that the EMGB could predict the behavioural intention of Beijing international tourists under the threat of smog pollution because the nine constructs of the EMGB significantly predicted the behavioural intention of international tourists directly or indirectly.Specially, positive anticipated emotion generates stronger effect on desire to travel to Beijing compared to other constructs in original MGB, whereas perception of smog was proven to be negatively correlated with this desire. Findings also indicated that mass media can affect behavioural intention indirectly through perception of smog and desire. It implies that desire is a crucial factor to intention formation, and mass-media effect and perception of smog also closely related with international tourist’s behavioural intention. Overall, this study emphasized the crucial role of mass media in the formation of perception and behavioural intention under the guidance of MGB.


During in-situ testing, the stiffnesses of supports were determined. The model of the rectified structure was then defined and it was shown that its parameters can be described by means of three matrices: stiffness, displacement forms of the elevated object and displacement forms of supports. Absolute values of elements of the stiffness matrix increased as the stiffness and number of supports increased. At the same time, values of elements of the matrix of displacement forms of the elevated object increased. The conducted energy analysis demonstrated that the amount of energy required for the vertical displacement of the structure decreased with an increasing stiffness and number of supports. This means that placing a greater number of supports under rectified structures and ensuring more rigid supports is beneficial to the rectification. Results of the conducted analyses were confirmed during in-situ tests.The vertical deflection of building structures is a common problem. However, the rectification of objects is rarely carried out due to the lack of information about the parameters of objects requiring rectification. The subject of the analysis are parameters of rectified water tank 950 m Vertical deflection is a common defect of building structures. This effect is mainly caused by insufficient load-bearing capacity of subsoil ,2. This 3 in volume. This structure was built on human-altered soil which caused its deflection.Hence, this paper defines a model of structure elevated in a non-uniform way with the foundation slab. Model parameters are determined for fire fighting storage tank of 950 mThe steel tank has a cylindrical shape with an inner diameter of 12.221 m and a height of 8.520 m . Its sheThe tank is placed on a reinforced concrete foundation slab of octagonal shape and a side length equal to 5.413 m. The slab has a thickness of 300 mm a. Howeveuobj was 200 mm, and the maximum 431 mm  to (5)  to (5) a. Each in jacks, on which the tank is placed, can operate as active or passive jack during lifting. The piston forced extension by the value ujext, was forced in the active j-th jack  generated an increase in the force by j,jQ and resulted in the following changes at the point of the installed jack  was assumed to be linearj,jk is the structure stiffness at the point of forced displacement ujext,.The relationship between a change in the force value j-th active jack changed the force in the i-th passive jack of value iQj,, caused the free piston extension ui,jpist, of this jack and caused the following effects at the point of the installed i-th passive jack , calculated from (1) and ikj, (i ≠ j) calculated from (2).Changes in values of jack forces resulting from any forced piston extension can be expressed as:j-th jack cause displacements of elevated tank and jack supports. It was assumed that those displacements are represented by two vectors denoted as vectors of displacement forms of the elevated object and of the jack supportsfi,jobj, was calculated from (4), and fi,jfou, was calculated from (5). Those vectors define with accuracy to the constant factor, the distribution of displacements of the elevated object and of the jack supports. The vector fjobj, was used to denote the j-th form of displacements of the elevated tank, and fjfou, was the j-th form of displacements of jack supports. The forced piston extension in the fjobj, formed a matrix of displacement forms of the elevated partfjfou, formed a matrix of displacement forms of the jack supportsA set of vectors uobj of displacement of all n points of the elevated tank can be expressed asufou of displacement of all n jack supports can be expressed asTherefore the vector uo-f for the elevated tank against the jack support was equal toThe displacement vector fi,jfou, of the matrix ffou tend to zero, which corresponds to the rigid jack supports, then the displacements uobj can be expressed asIf the elements jW done by the active support (i = j), in which there is the force jQ, resulted from the work of this force acting upon the forced piston extension ujext, and deformation of the whole structure, was equal toThe work iQ in the i-th jack resulted from the value gQi, and the history of forced piston extensions uext. Assuming that the piston extension was forced in the jacks denoted by letters from r to s, thenThe force value W done by all n jacks when the forced extension in each of them was equal ujext, = uextBased on the Equations (17) and (18), the relationship was derived for work uext occurred, expresses a change in potential energy of the construction as the rigid body. The second member at the symbol (uext)2 defines a change in potential energy of deformed jacks, the elevated part and the supports.The expression (19) is a sum of two members. The first member, where the displacement k, fobj and ffou of the rectified tank, including real stiffness of elements of the tank supports. Therefore, in-situ testing of the tank placed on n = 16 jacks was performed before and after the rectification. These tests were used to determine stiffness for the support elements kjack, kpist, kfou, and the stiffness jkj,  with an accuracy of 0.001 mm by measuring ur)foufou and ur)pistpistjackjack( (ur)foufou b. Displa support c against support d. The plj,jk of the structure at the points j  defined by the expression (1) were determined after the rectification. Consequently, the piston extension ujext, in the j-th jack was forced for each support and a change in the force j,jQ produced by a given jack was recorded.The stiffness k, the matrix fobj of displacement forms of the elevated tank and the matrix ffou of displacement forms of jack supports. The stiffness values kfou, kjack and kpist determined from the in-situ tests, were taken for this model. The elements jkj, of the matrix k were compared with the values jkj, determined during the in-situ tests.Parameters of the tank placed on the jacks were determined from numerical calculations performed for the model of the structure. These parameters included the stiffness matrix Ec = 28.3 GPa, shear modulus Gc = 11.79 GPa, the Poisson’s ratio ν = 0.2 and weight density γc = 25 kN/m3, was used as the model of reinforced concrete foundation slab  divided by the relevant change ,  and . Moreover, kpist = 110 MN/m, kjack = 2579 MN/m and kfou = 150 MN/m.Changes in the force  jack 1-a were caon upist b, changet  as presented in j,jQ  of the jacks are shown in j-th jack were denoted as uj,Iext, and the extension after increasing oil pressure was denoted as uj,IIext,. The corresponding force values of the j-th jack were denoted as jQ,I and jQ,II.The extension jQ,I, jQ,II, uj,Iext, and uj,IIext, are compared in two tables. j = 1, 3, 5, 7, 9, 11, 13, 15), while the values corresponding to the jacks installed at the midpoint of the foundation side  are summarised in j,jk in these tables were determined as relevant values  divided by . The determined values j,jk are displayed in j,jk corresponding to the jacks installed in the corners , and in red mean stiffness values j,jk corresponding to the jacks installed at the midpoint of the side .The values of kpist = 110 MN/m, kjack = 2579 MN/m and kfou = 150 MN/m. They were used to verify correctness of the used numerical model of the rectified tank.The calculations were made for this model taking into account stiffness of the support elements determined from the in-situ tests which were as follows: k, fobj and ffou which formed the matrices, each in size of 16 × 16. Each j-th column was a vector corresponding to the effects produced by forced piston extension in the j-th jack by the unit value. The first column described the effects caused by the piston extension in the jack installed at the point j = 1 by uext,1 = 1, the second column specified the effects produced by the piston extension in the jack installed at the point j = 2 by the unit value uext,2 = 1, etc. Due to the structure symmetry, the column 3 related to the effects produced by the piston extension in the jack installed at the point j = 3 had the same values as the first column. However, the values in the column 3 of the matrix were finally shifted by two positions with reference to the column 1 in such a way that for the matrix k we obtain k1,1 = k3,3 = … = k15,15 and k2,2 = k4,4 = … = k16,16. Thus, values of the elements from two columns defined each of the matrices k, fobj and ffou. For the matrix k these values were ik,1 and ik,2 , for the matrix fobj they were vectors fobj,1 and fobj,2 having values equal to fi,1obj, and fi,2obj, , and for the matrix ffou they were vectors f1fou, and ffou,2 of values fi,1fou, and fi,2fou, . These values are summrised in j,jk for the model corresponding to the jack installed in the corner was equal to 37.260 MN/m, and the mean value jkj, for j = 1, 3, …, 15, which was determined from the in-situ tests, was equal to 38.10 MN/m. Moreover, the calculated value j,jk related to the jack installed at the mid-point of the foundation slab was 45.960 MN/m, and the relevant mean value j,jk determined from the in-situ tests for j = 2, 4, …, 16 was equal to 43.36 MN/m. Differences between these values which were experimentally obtained and determined for the model were equal to 6%, which was considered as the satisfactory conformity. These values presented in The calculated results were the parameters k2,2 was greater than stiffness k1,1. Moreover, the forced displacement ujext, in the j-th active jack caused an increase in the force. Simultaneously, a drop in the force was observed for the adjacent passive jacks. While the force in the jack 1 was exerted, the force dropped in four adjacent jacks  was forced, ca.70% of this extension  was transferred to the motion towards the top of the tank slab at that point. Moreover, the upward displacements were found for four adjacent points with reference to the points, at which the active jacks were operated  was forced, was observed to be displaced downwards. This displacement was equal to ffou,1,1 = 0.287 for the jacks installed in the corners, and ffou,1,1 = 0.306 for the jacks installed at the mid-point of the side, which contributed to 28.7–30.6% of the forced value uext. The supports for four adjacent jacks were displaced upwards, while others did not move or were slightly displaced downwards  on the matrices k, fobj and ffou of the structure, which was the tank on the jacks that were placed on the jack supports.The analysis further focused on the effect of variables k for the structure was a rectangular array of elements i,jk of the size n × n, where n is the number of the jacks, on which the tank was placed. For n = 3, all elements i,jk were equal to zero, which means that the forced extension ujext, in any j-th jack did not cause a change in the force i,jQ in any support. In other cases (n > 3), the diagonal elements j,jk (i = j) were always different than zero and took positive values, which means that the forced extension ujext, of the jack piston at the j-th support caused an increase in the force j,jQ (i = j) in the j-th support. Other matrix elements could take negative, positive or zero values. For the element i,jk lower than zero, the extension ujext, caused a drop in the force in the i-th support.The stiffness matrix n = 4, the values of three elements of the matrix found in the first column: k1,1, k2,1 and k3,1 were sufficient for the explicit description of the matrix k. The elements for the analysed stiffness kfou of the supports are presented in k4,1 was equal to k2,1. Additionally, all diagonal elements were equal to each other. Thus, other columns could be also determined as the matrix was symmetric.When n = 8. Considering the position of the jacks in the slab corners, which was a regular hexagon, first five elements of the first column: k1,1, k2,1, k3,1, k4,1, k5,1 were sufficient to define the whole matrix. Other elements of the matrix were determined as all diagonal elements were equal and the matrix was symmetrical. The elements describing the matrix k, when n = 8, for the analysed values kfou are compared in A similar situation occurred when n = 16, the matrix k had two different vectors. The first element ik,1  defines changes in the values of forces in the supports caused by the unitary forced piston extension in the slab corner, and the second element ik,2 defines the values of forces in the supports caused by the unitary forced piston extension at the midpoint of the slab side. Each of the 16-element columns was clearly described by nine elements. Other elements of the first and second columns, and other columns could be determined from properties of the symmetric matrix taking into account that k1,1 = k3,3 = … = k15,15 and k2,2 = k4,4 = … = k16,16. The elements describing the matrix k, when n = 16, for the analysed values kfou are compared in For k when n = 32. Each of these columns was clearly described by 17 elements. Data presented in ik,1, ik,2, ik,3. The absolute value of other elements was lower than 3.27 MN/m.Three columns had to be determined to define the matrix k for the analysed support stiffness kfou are graphically presented in the following figures. n = 4, while n = 8. ik,1 and ik,2 when n = 16. ik,1, ik,2 and ik,3 for n = 32.The selected elements of the matrix n number of the jacks, on which the tank was placed, the values of diagonal elements j,jk were also increasing. At the same time, the structures of greater stiffness kfou had higher values j,jk. For n = 4, the values k1,1 corresponding to stiffness kfou = 50 MN/m were equal to 2.352 MN/m, and for the rigid support k1,1 were equal to 2.848 MN/m  always took negative values. For n = 4 and n = 8, two elements i,ik-1 and i,ik+1 adjacent to j,jk took negative values, for n = 16 six elements adjacent to j,jk took negative values, and for n = 32 eight elements adjacent to i,ik took negative values.By analysing the fobj displacement forms of the elevated tank was similar to the structure of the stiffness matrix. This means that the matrix could be defined without the need to write the whole elements. Therefore, fi,1obj, of the vector fobj,1 when n = 3, 4, and 8, fobj,1 and fobj,2 for n = 16, and fobj,1, fobj,2 and fobj,3 for n = 32. When n = 3, the elements fj,jobj, (i = j) took the value 1, and the other elements fi,jobj, (i ≠ j) took the value 0 regardless of the support stiffness kfou. In other cases, the values fi,jobj, depended on stiffness kfou. The values fj,jobj, (i = j) were higher for higher values kfou and took lower values for a greater number n of the jacks. When n = 4, fj,jobj, (i = j) took values from 0.952 to 0.998  were within the range from 0.387 to 0.930 for the jacks in the corners  were higher for lower values fkou and took higher values for a greater number n of the jacks. When n = 4, fj,jfou, (i = i) took values from −0.047 to −0.011  corresponding to the jacks installed in the corner took values from −0.433 to −0.173  were within the range from −0.596 to −0.296 for the jacks in the corners  were higher or lower than zero. Higher absolute values fi,jobj, (i ≠ j) were determined for lower values kfou, regardless of the number of jacks.For ess kfou . In otheo −0.011 a, and who −0.070 b. The elo −0.173 a, and fro −0.173 b. When n  depended on both the n number of the jacks and the support stiffness kfou, and uobj-mean was increasing as stiffness kfou and the jack number n were increasing  was the same for n = 3, 4 and 8 jacks, did not depend on kfou and was equal to1.347 kJ. For n = 16, this work depended on stiffness kfou and was equal to 1.366 kJ at kfou = 50 MN/m and 1.350 kJ at the rigid support  are illustrated in kfou = 50 MN/m, and in The total work  support . For n =uobj-mean expressed as (20). This comparison indicates that lifting the building by 1 mm required the least energy when the number of supports was n = 32 and the jack support was rigid. Then, the result was 0.497 kJ/mm. Lifting the structure by 1 mm required the highest energy for n = 3 jacks. Then, the result was 1.367 kJ/mm. It can be concluded that installing a significant number of the jacks and providing the rigid jack support for them was the most favourable conditions during the rectification.n hydraulic piston jacks installed under the tank were described using three matrices: stiffness matrix k, matrix fobj of displacement forms of elevated tank, and matrix ffou of displacement forms of jack supports. The parameters of the rectified tank placed on n = 3, the structure was statically determinate. Hence, the matrices k and ffou had entries equal to zero, and the matrix fobj was the identity matrix. With an increasing number n of the jacks, on which the tank was placed, the values of diagonal elements j,jk were also increasing. At the same time, the structures of greater stiffness kfou had higher values j,jk. For n = 4, the values j,jk corresponding to stiffness kfou = 50 MN/m were equal to 2.352 MN/m, and 2.848 MN/m for the rigid support kfou. For n = 32, the values j,jk ranged from 29.79 MN/m to 122.72 MN/m. The values i,jk (i ≠ j) were lower for a greater number of the jacks and higher stiffness values kfou, which meant a bigger drop in forces in the active support at the same forced extension uext.When fj,jobj, (i = j) were higher for higher stiffness values kfou and took lower values for a greater n number of the jacks. For n = 4, fj,jobj, (i = j) took values from 0.952 to 0.998. For n = 32, the values fj,jobj, (i = j) were within a range of 0.335–0.930.The values n number of jacks and stiffness kfou were increasing, the amount of work required to provide the vertical displacement of the object was decreasing. For n = 3, the work required to elevate the object by 1 mm was 1.347 kJ. For n = 32 and the rigid support for the jacks, 0.497 kJ of energy was sufficient to elevate the object by 1 mm. Thus, it can be concluded that installing a significant number of the jacks and providing the rigid jack support for them was the most favourable condition during the rectification. On the other hand, increasing the number of jacks increases the investment cost. For this reason, the number of jacks used for the tank rectification was limited to 16.The conducted energy analysis demonstrated that as the


Water caltrop starch paste showed less shear-thinning behavior with cHMT. Meanwhile, the viscosity and tendency to form strong gel were enfeebled with modification. cHMT significantly changed predicted glycemic index (pGI) value, especially in samples that underwent the most cycles of treatment, which showed the lowest pGI compared to native and other treatment. These results suggested that cHMT water caltrop starch was effectively modified and showed diversified properties.This study focused on the effect of cycled heat-moisture treatment (cHMT) on the in vitro digestibility, rheological, and physicochemical properties of water caltrop starch. The amylose content increased significantly by cHMT, whereas damaged starch content decreased only in the groups with more than two cycles applications. cHMT generally increased the weight-average molecular weight, except for single cycle treatment which showed the reverse result. In thermal properties, the onset temperature (T Trapa taiwanensis Nakai) are aquatic crops cultivated in shallow water ponds especially in Southern Taiwan. The kernels are mainly composed of starch and can reach a maximum content of 79.4% (d.b.) during growth [0), peak temperature (Tp), and conclusion temperature (Tc) than corn and potato starch [Water caltrops  is one of the widely used approaches to physically modifying the properties of starch . The advAlthough single and multiple HMT have exhibited promising effects on physicochemical properties and digestibility in many studies ,26,27, fTrapa taiwanensis Nakai) were cultivated and harvested in Tainan, Taiwan. The α-amylase, amyloglucosidase, amylose kit, and damaged starch kit were purchased from Megazyme . All chemical substances applied in this study were of analytical grade.Water caltrops (w/v) sodium hydroxide solution. The mixture was placed at 4 °C for 12 h; thereafter, the upper brown liquid was decanted, and the starch precipitate was washed with distilled water and left to precipitate. The washing process was repeated until the starch was clean and the pH value of starch dispersion reached neutral. After removing the impurities, the starch pellet was dried at 40 °C for 72 h, ground, passed through a 100-mesh sieve, and stored at room temperature. The unmodified starch was designated as Native-S.The extraction of starch was applied in accordance with a previous report with slight modifications . In the A previous method was applied including some modifications . The moiThe amylose and damaged starch content of water caltrop starch was determined by using a Megazyme amylose kit (K-AMYL) and a damaged starch kit (K-SDAM), respectively, with the procedures recommended by the manufacturer.The molecular weight distribution profile of water caltrop starch was evaluated by gel permeation chromatography (GPC) using a column (2.6 × 90 cm diameter/height) packed with Sepharose CL-2B agarose gel. Sample preparation was according to a method from previous research . A 5 mL In Equation (1), Mi is the molecular weight at ith fraction, and Ci is the glucose concentration at ith fraction (μg/mL).0), peak temperature (Tp), conclusion temperature (Tc), and gelatinization enthalpy (ΔH) were recorded during the heating process.Thermal properties of water caltrop starch were measured by using differential scanning calorimetry  according to the previous method . Samplesw/w) was prepared by using RVA  at a rotation speed of 160 rpm, heated from 50 to 95 °C for 3.5 min, and held at 95 °C for 3 min for full gelatinization. Then, the starch sample was rapidly poured into a rotational concentric cylinders, equilibrated at 25 °C for 3 min before analysis, and continuously sheared in the gap (0.099 mm) between the inner cylinder  and the outer cylinder (radius: 28.922 mm) from shear rate of 1 to 100 s−1. Herschel–Bulkley model was applied to describe the flow behavior of the samples at steady shear:Steady shear properties were measured according to the previous method  with a r0 is the yield stress (Pa), K is the consistency index (Pa.sn), −1), and n is the flow behavior index (dimensionless).In Equation (2), σ is the shear stress (Pa), σThe dynamic properties of water caltrop starch were measured using the same rheometer equipped with a parallel plate (diameter: 50.00 mm) and with a 1 mm gap using the previous method with slight modifications . MeanwhiThe in vitro kinetics and predicted glycemic index were inspected with the method reported previously ,34 with In Equation (3), Gt is the glucose concentration (μg/0.1 mL) at time t. The curve of enzyme hydrolysis followed a first-order equation. For reference, dried white toast was used. The calculation of predicted glycemic index followed the equations:∞ is the equilibrium hydrolysis percentage, k is the kinetic constant, t is the chosen time, AUCsamples is the area under curve of samples, and AUCreference is the area under curve of the reference white bread.In Equations (4)–(7), HP is the hydrolysis percentage at time t, HPp < 0.05).The measurements were performed in triplicate, and the data were analyzed with one-way analysis of variance (ANOVA) followed by Duncan’s multiple range test with SPSS 20.0 at a significance level of 95% , the damaged starch content significantly lowered. This was possibly due to the accelerated recrystallization during cHMT, which enhanced the resistance to the tested enzymes and reduced the damaged starch content . These rGel permeation chromatograms of native and cHMT water caltrop starch are presented in lopectin . Hence, lopectin ,42.0, Tp, and Tc were observed in cHMT water caltrop starch; this was possibly related to higher amylose content, which resulted in more interactions between the starch molecules. Therefore, a higher temperature would be needed to disrupt the order of starch granules [p with no significant difference, indicating their similarity and better heat stability after cHMT. The decrement of ΔH may be due to lower amylopectin content, which contributed to fewer double helices inside the crystalline domain and lower enthalpy acquired for gelatinization [As shown in granules . cHMT ingranules , sweet pgranules , and whegranules . cHMT2-Snization .The curves of steady shear measurement of native and cHMT water caltrop starch pastes are presented in 2) of each sample ranged from 0.968 to 0.999, suggesting that the Herschel–Bulkley model fitted well to the profile of rheological characteristics. The flow behavior index (n) reflects the similarity to Newtonian fluid; n = 1 equals Newtonian fluid and a lower value of n indicates a higher degree of shear-thinning properties. Both native and cHMT samples showed n values of less than 1.0, implying that water caltrop starch pastes exhibited shear-thinning behavior. Furthermore, with increasing cycles of cHMT, the n value also increased progressively, indicating that cHMT samples showed less shear-thinning behavior. The K value and σ0 could be considered as the gel viscosity and stress to initiate the flow, respectively [0, indicating that modified starch had lower viscosity and required less stress to start the flow.The parameters of the Herschel–Bulkley model used to describe the flow curves are presented in ectively . CompareThe storage modulus (G′) is the amount of deformation energy stored in the sample during shear, and it represents the elasticity of the sample. In contrast, the loss modulus (G″) is the amount of deformation energy consumed during shear and represents the viscosity of the sample . The ratAfter modification, the G′ and G″ values were gradually reduced as the number of cycles decreased, and the parameters are shown in Tan 𝛿 can be used to describe the characteristics of the gel. When tan 𝛿 is less than 1, the material shows great elasticity; when the value of tan 𝛿 is between 0.1 and 1, it is classified as weak gel; and a tan 𝛿 less than 0.1 shows strong gel characteristics. Tan 𝛿 of water caltrop starch ranged from 0.039 to 0.072, which indicated strong gel properties. Furthermore, cHMT1-S showed the highest value, which may be explained by the strong disruption by a single cycle of cHMT.∞), hydrolysis rate (k), hydrolysis index (HI), and predicted GI value (pGI). The sample hydrolyzed rapidly in the first 60 min and gradually slowed down with the extension of working time , water caltrop starch increased slightly after modification. cHMT1-S showed greater pGI than Native-S, while the values of cHMT2-S, cHMT4-S, and cHMT8-S were significantly lower than Native-S, indicating that multiple cycles of heat-moisture treatment did reduce the digestibility of water caltrop starch. Lower digestibility may be affected by the amylose content. In previous studies, it was found that starch with a higher proportion of amylose showed lower digestibility and hydrolysis rate because the space occupied by amylose is smaller than that of amylopectin, so the structure of starch could be stacked tighter and not easily digested by enzymes ,50,51. In value and lower gel-forming ability with lower G′ and G″ values. After cooking, cHMT water caltrop starch treated with an increased number of cycles showed lower pGI, which could be explained by the increasing amylose content and more compact structure of starch granules, which led to better resistance to the enzymes. The simulated pGI test may not completely reflect the exact starch digestibility in vivo, and more research was needed to employ cHMT starch as ingredient for application. Such a study would provide a better understanding of the physicochemical properties, digestibility, and potential application of cHMT water caltrop starch, which may be a prospective alternative for common starch resources such as corn and potato.This study showed that cHMT changed the in vitro digestibility, rheological properties, and physicochemical properties of water caltrop starch. The amylose content increased by modification due to the breakage of amylopectin which turned into small amylose fragments. The damaged starch content also significantly decreased in samples treated with an increased number of cycles because of recrystallized structure that expelled the testing enzyme. Single-cycle cHMT decreased the amylopectin peak in the GPC graph and lowered the weight-average molecular weight, but the weight-average molecular weight increased with multiple cycles because repeated cooling in cHMT may have promoted the integration of amylopectin, which had larger molecular weight. Better resistance to the heat and lower enthalpy needed for gelatinization was confirmed by DSC. Furthermore, modification gave water caltrop starch less shear-thinning behavior with higher


Background: Stroke survivors with impaired control of the ankle due to stiff plantarflexors often experience abnormal posture control, which affects balance and locomotion. Forceful stretching may decrease ankle stiffness and improve balance. Recently, a robot-aided stretching device was developed to decrease ankle stiffness of patient post-stroke, however, their benefits compared to manual stretching exercises have not been done in a randomized controlled trial, and the correlations between the ankle joint biomechanical properties and balance are unclear.Objective: To compare the effects of robot-aided to manual ankle stretching training in stroke survivors with the spastic ankle on the ankle joint properties and balance function post-stroke, and further explore the correlations between the ankle stiffness and balance.Methods: Twenty inpatients post-stroke with ankle spasticity received 20 minutes of stretching training daily over two weeks. The experimental group used a robot-aided stretching device, and the control group received manual stretching. Outcome measures were evaluated before and after training. The primary outcome measure was ankle stiffness. The secondary outcome measures were passive dorsiflexion ranges of motion, dorsiflexor muscle strength, Modified Ashworth Scale (MAS), Fugl-Meyer Motor Assessment of Lower Extremity (FMA-LE), Berg Balance Scale (BBS), Modified Barthel Index (MBI), and the Pro-Kin balance test.Results: After training, two groups showed significantly within-group improvements in dorsiflexor muscle strength, FMA-LE, BBS, MBI (P < 0.05). The between-group comparison showed no significant differences in all outcome measures (P > 0.0025). The experimental group significantly improved in the stiffness and passive range of motion of dorsiflexion, MAS. In the Pro-Kin test, the experimental group improved significantly with eyes closed and open (P < 0.05), but significant improvements were found in the control group only with eyes open (P < 0.05). Dorsiflexion stiffness was positively correlated with the Pro-Kin test results with eyes open and the MAS (P < 0.05).Conclusions: The robot-aided and manual ankle stretching training provided similar significant improvements in the ankle properties and balance post-stroke. However, only the robot-aided stretching training improved spasticity and stiffness of dorsiflexion significantly. Ankle dorsiflexion stiffness was correlated with balance function.Clinical Trial Registration:www.chictr.org.cn ChiCTR2000030108. Stroke is a leading cause of mortality, and approximately 2.5 million people experience a stroke annually in China . Stroke Many treatments to improve balance ability in stroke survivors are aimed at improving the posture control of the trunk and lower limbs including the use of strengthening exercises, functional neuromuscular stimulation, and visual feedback balance training –16. AnklRecently, an intelligent robot-aided stretching device was developed to decrease ankle stiffness of patients with neurological impairment due to stroke, spinal cord injury, multiple sclerosis, or cerebral palsy. Significant improvements were found in the ROM, maximum voluntary contraction, ankle stiffness, and comfortable walking speed , 27–29. At present, there is a lack of RCT comparing the effects of robot-aided to manual ankle stretching training on the ankle joint properties and balance function post-stroke. The primary aim of this study was to evaluate the effects of the intelligent robot-aided stretching and manual stretching therapies on the ankle properties and balance function post-stroke. A secondary aim was to study how ankle stretching affects balance. We hypothesized ankle stretching would improve balance function for changing the neural and musculoskeletal characteristics of the ankle joint, and there may be different mechanisms between manual and intelligent stretching. A third aim was to investigate the relationship between ankle stiffness and balance function post-stroke.This is an assessor-blinded, randomized controlled trial. The aim was to compare the effects of robot-aided to manual ankle stretching training in stroke survivors with the spastic ankle on the ankle properties and balance function post-stroke, and further explore the correlations between the stiffness of the ankle and balance. The study was conducted according to the tenets of the Declaration of Helsinki, the guidelines for Good Clinical Practice, and the Consolidated Standards of Reporting Trials (CONSORT), approved by the local Ethics Committee “Beijing Tsinghua Chang Gung Hospital Medical Ethics” (18172-0-01), and registered at clinical trial (ChiCTR2000030108).This RCT was conducted at the Beijing Tsinghua Chang Gung Hospital in China. Inpatients with stroke in the rehabilitation department of the hospital were recruited between May 2019 and November 2019. The inclusion criteria were: (1) ages between 18 and 75 years; (2) first-ever stroke with less than 6 months duration of spasticity of the affected ankle ; (3) medically stable; and (4) ability to stand independently without aids for at least 1 minute. Exclusion criteria were: communication problems, dementia based on clinical diagnosis, comorbidities affecting motor performance such as orthopedic, arthritic, inflammatory conditions that could influence balance, and limited ankle movement.Subjects in the experimental and control group had 10-session stretching training using the intelligent robot-aided stretching or manual stretching respectively . During the 2-week period, both groups continued movement exercises for ankle mobility and strength.An ankle rehabilitation robot  was used for intervention and outcome evaluations. While the subject was comfortably seated, the leg of the subject was strapped to leg support with the knee at 30° flexion and the foot was strapped onto a footplate with ankle dorsiflexion (DF) at 0°. The foot was secured to a footplate at the dorsal side and the heel using adjustable straps. The footplate was fixed to the motor shaft, and a torque sensor was aligned with the motor shaft to measure the ankle joint torque . The ankThe ankle rehabilitation robot was driven by a servomotor controlled by a digital signal processor . BrieflyClinical and demographic data were collected at enrollment. Subjects were evaluated before and after the interventions by a designated physiotherapist blinded to the group assignment. The primary outcome of the study was the change of stiffness of the ankle after the training, due to its relevance in physiologic control of the ankle. The secondary outcomes of the study were divided into three categories: biomechanical evaluations, clinical evaluations, and the Pro-Kin balance test . The assessments included pre-assessment , post-assessment (after the tenth exercise session). The assessment sessions were done at the same time of the day with the assessments in the same order.Evaluations included the DF PROM (passive ranges of motion measured in dorsiflexion direction movement), DF and PF stiffness (stiffness measured in dorsiflexion and plantarflexion direction movement), and dorsiflexor muscle strength. ROM and muscle strength were measured using the HogganMicroFET3 portable device . The Stiffness is defined as the ratio of ground reaction moment to angular deflection of the specific joint. Ankle stiffness measured in DF or PF passive movement was assessed as K = ΔT/Δθ, where K (Nm/°) was the quasi-static stiffness and ΔT was the passive torque increment during a certain amount of ankle angular movement (Δθ). As Δθ becomes infinitely small, the quasi-static stiffness approaches the slope of a tangential line of the torque-angle curve at a specific ankle position , 33. TheEach subject completed the following functional assessments during clinical evaluation sessions. MAS  was used to measure the calf muscle hypertonia . Fugl-Me2), standard deviation medial/lateral (M/L SD measured in mm), standard deviation forward/backward (F/B SD measured in mm), average speed medial/lateral (M/L AS measured in m/s), and average speed forward/backward (F/B AS measured in m/s). Smaller values of the six parameters indicated the subject had a better balance function  to assess balance function, based on the instantaneous data of postural sway using the force platform from movements of the center of pressure (COP)  Figure . The COPfunction .*Power 3.1.7 (http://www.gpower.hhu.de/). The effect size was estimated using our pilot data regarding decreases in DF stiffness after training  would be able to reveal a large effect size of Cohen's d = 1.24, at a power of 0.8 and an α level of 0.05 assuming a non-directional hypothesis. Thus, in the current study, a large effect size f = 0.4 was assumed in the Mann–Whitney U test model, with an α value of 0.05, power of 0.8, and an attrition rate of 10%, the minimum required sample size was estimated to be 18 subjects for this study.The sample size calculation was conducted using GAfter recruited subjects presented written informed consent, they were randomly assigned into the experimental group or control group in 1:1 ratio by drawing lots. The lots were designated as “experimental” or “control” by stratified randomization with random numbers generated from statistical software and presented in sealed opaque envelopes. Each subject received a sealed envelope that indicated the group they were assigned to. The researchers in charge of recruitment and randomization procedures were different, and the designated therapist was responsible for the assessment was kept blinded to the group allocation throughout the trial.P < 0.05). Under a small sample size, T-distribution was used to compute a 95% confidence interval (95% CI). All statistical analyses were performed with SPSS version 21.0. .Baseline characteristics were compared between the two groups by using Fisher's exact test for categorical variables and the Mann-Whitney U test for continuous and ordinal variables. The continuous variables were tested using the Shapiro-Wilk test to verify whether they met the normal distribution and using the homogeneity of variance test. Change with each intervention and during an observation period of two weeks were examined between the groups with a Mann-Whitney U test. Bonferroni corrections were applied to account for multiple comparisons (α = 0.0025) to reduce the probability of Type-I error. The Wilcoxon Signed Rank test was used to compare pre-and post-intervention measurements in each group. Furthermore, to more deeply understand the effects of ankle stiffness on balance function, the Spearman correlation analysis was performed for testing the association between stiffness and the Pro-Kin test, and the Kendall rank correlation coefficient (τ) for the correlation between MAS and ankle stiffness . Besides, significant decreases in DF stiffness and improvements in DF PROM were found for subjects in the experimental group , but not in the control group . No significant differences in biomechanical evaluations were found between the two groups after training (P > 0.0025)    .P = 0.005, 0.007, and 0.041, respectively). We also found significant improvement in FMA-LE, BBS, and MBI in the experimental group . Besides, significant decreases were found in MAS for subjects in the experimental group (P = 0.046) but not in the control group (P = 0.317). No significant differences in clinical evaluations were found between the two groups after training (P > 0.0025)    .P = 0.005, 0.013, 0.012, 0.005, and 0.041, respectively). The trajectory length and M/L AS with opened eyes decreased significantly after the 2-week training period in the control group . No significant difference in the Pro-Kin balance test results was found between the two groups after training (P > 0.0025)  .P = 0.003; γ = 0.313, P = 0.049; γ = 0.386, P=0.014; γ = 0.466, P = 0.002, respectively). The DF stiffness was also significantly correlated with MAS     .The RCT showed significant within-group improvements in DF muscle strength, motor function of lower limbs, balance function, and activities of daily living after a 10-session training in two groups. However, the experimental group showed additional improvements in the DF stiffness, DF PROM, and MAS. Between-group comparisons represented no differences in all outcome measures. We believe the intelligent stretching robot could be an effective and safe alternative to manual stretching for therapists. Also, the intelligent stretching robot has the potential to use in stretching the ankle with spasticity and/or contracture regularly without the daily involvement of clinicians or physiotherapists.Several studies have already been shown that continuous passive stretching can effectively reduce ankle stiffness , 20, 44.In this study, the Pro-Kin was used to quantitatively evaluate the static balance of subjects, excluding the influences of the hip and stride strategy, and further explore the role of ankle strategy in posture control independently . The expBalance disorders of stroke survivors have various causes, such as muscle weakness, limited range of motion, spasticity, sensory changes, loss of coordination, and impaired central integration. In particular, stiff plantar flexors and weak dorsiflexors on the affected side increasing the risk to cause the muscular imbalance of the ankle . In our An ankle strategy is typically used on a solid base supporting a small amount of body sway , 62. ThiThe central controller uses sensory information to generate descending commands that produce corrective muscle forces to stabilize the body . The cenThis study had limitations in methodological. First, given the number of samples available, between-group comparisons represented no differences in the biomechanical properties or balance function. Future studies with more subjects involved might show further group differences and increase the power of the study. Second, this study lacks a quantitative assessment of proprioception of the ankle joint, which is important in exploring the mechanisms of balance control recovery after stretching exercises. Third, the long-term effects of stretching training were unknown due to the absence of a follow-up period. Besides, our study only investigated the correlations between ankle stiffness and static balance in stroke survivors. The effects of ankle properties on dynamic balance need further investigation. Furthermore, muscle activations around the ankle joint will be collected using EMG for analysis as a function of ankle ROM, balance control, etc. Another limitation is the lack of a third group treated without stretching exercises. We plan to add one group of patients without stretching exercises to eliminate the improvement of ankle joint properties and balance function due to the natural history of stroke and better evaluate the effectiveness of the stretching therapy in the future. Future studies will further address these issues.The robot-aided and manual ankle stretching training provided similar significant improvements in the ankle properties, balance, motor function, and ADL post-stroke. The robot-aided stretching devices provided labor-saved, high-intensity, and well-controlled passive stretching to stroke survivors with ankle impairments, which showed additional improvements across more parameters including the spasticity and stiffness of the ankle. Findings in this study suggested that robot-aided rehabilitation may be a beneficial addition to current rehabilitation programs. As an important part of posture control, the ankle joint properties were important in keeping the upright stance. In particular, ankle stiffness was correlated with balance function post-stroke. As a biomechanical property of the ankle joint, dorsiflexion stiffness may be a sensitive indicator for evaluating the balance ability post-stroke and predicting the risk of falls in the future.The datasets used and analyzed during the current study are available from the corresponding author upon appropriate request.The studies involving human participants were reviewed and approved by the Medical Ethics Committee of Beijing Tsinghua Changgung Hospital (18172-0-01). The patients/participants provided their written informed consent to participate in this study.YP and L-QZ contributed to the study design, analysis, and interpretation of data and revisions to the manuscript. QW contributed to the analysis and interpretation of data. XZ contributed to the study design, data collection, analysis, interpretation of data, and drafting of the manuscript. Data collection was performed by XZ, XL, and QX. YZ and SF performed experiments. All authors read and approved the manuscript submitted and agree to be accountable for all aspects of the work.This study was supported by Beijing Municipal Natural Science Foundation (L182028) and Beijing Municipal Science and Technology Commission (Z181100009218003 and Z181100003118004). No additional external funding was received for this study. The funders had no role in study design, data collection, and analysis, decision to publish, or preparation of the manuscript.L-QZ holds an equity position in Beijing LTK Science and Technology Co., which made the ankle rehabilitation robot used in this study. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Introduction: Vascular graft infection is a life threatening situation with significant morbidity and mortality. Bacterial graft infection can lead to false aneurysms, bleeding and sepsis. There are a lot of risky situations where grafts can become infected. It is therefore highly desirable to have a vascular graft that is resistant to infection. In this retrospective clinical study, a silver-impregnated vascular graft was evaluated in various indications. Methods: Our study included a total of 71 patients who received a silver-impregnated vascular graft during the period from 2013 to 2018. Patients had an aortoiliac localization of vascular graft in 61 cases (86%), and a peripheral localization on the lower limbs in 10 cases (14%). Indications for the use of these special vascular grafts were trophic lesions or gangrene in the lower limbs in 24 cases (34%), suspicious mycotic abdominal aortic aneurysm (mAAA) in 4 cases (5.5%), salmonela aortitis or aneurysms in 4 cases (5.5%), infection of the previous vascular graft in 11 cases (15.5%), other infections in 12 cases (17%), AAA rupture in 10 cases (14%) and other reasons  in 6 cases (8.5%). Thirty-day mortality, morbidity, the need for reintervention and amputation, primary and secondary graft patency, and finally the presence of a proven vascular graft infection were evaluated. Results: The 30-day mortality was 19.7%, and morbidity was 42.2%. The primary patency of the vascular graft was 91.5%. Reoperation was necessary in 10 cases (14%) and amputation was necessary in 10 cases (14%). The median length of hospital stay was 13 days and the mean follow-up period was 48 ± 9 months. During the follow-up period, six patients (8.5%) died from reasons unrelated to surgery or without any relation to the vascular graft. Secondary patency after one year was 88%. Infection of the silver graft was observed in three patients (4.2%). Conclusions: Based on our results, the silver graft is a very suitable alternative for solving infectious, or potentially infectious, situations in vascular surgery. In particular, in urgent or acute cases, a silver graft is often the only option. Despite ever-improving vascular grafts, better antibiotic prophylaxis and better and earlier specific diagnostic methods, prosthetic vascular graft infection remains one of the worst surgery procedure-related complications. A way to prevent and possibly address these serious situations is still being discussed. The use of venous autografts is obviously limited, and the use of allografts carries its own specific problems and complications ,3,4,5,6.Staphylococcus aureus, Psedomonas aeruginosa, Salmonella enteritidis and others. Infections caused by fungi are less common [Staphylococcus aureus or major intra-abdominal trauma requiring vascular reconstruction. The authors also discuss the question of necessary long-lasting antibiotic treatments in these specific situations.Creating an artificial vascular graft that is resistant to infection is one of the goals of current research in the field of vascular surgery. Infection in an artificial vascular graft has significant mortality and morbidity . Bacteris common ,9. Accors common ,10,11. Ts common ,5. Operas common . We are s common . It is ts common ,14. Antis common ,17,18,19s common . The mics common ,21, but s common ,23. The This is a monocentric retrospective clinical study that retrospectively analyzed the data of patients in whom a silver-impregnated vascular graft was implanted for various indications.Our study included a total of 71 patients, 53 men (75%) and 18 women (25%), who received a silver-impregnated vascular graft during the period from 2013 to 2018 at the Vascular Surgery Dpt., University Hospital, in Pilsen.The mean age of the patients was 65.7 years. Patients had an aortoiliac localization of the vascular graft  in 61 cases (86%), and a peripheral localization in the lower limbs  in 10 cases (14%) . We haveThe reasons for using silver grafts are described in All data were obtained from the University Hospital clinical database. Thirty-day mortality, morbidity, the need for reintervention and amputation, primary and secondary graft patency, and finally the presence of a proven vascular graft infection were evaluated.30-day mortality in our cohort was 19.7% 14 patients), the most common causes of death being hemorrhagic shock, sepsis and multiorgan failure. Our mortality rate was fully comparable with literature data on these major vascular emergencies  patients,24. MorbThe primary patency rate of vascular grafts at 1 year was 91.5%. Early graft closure (within 30 days) occurred in six cases. Predictors of primary patency loss were the presence of critical limb ischemia, diabetes mellitus and the necessity of below-the-knee bypasses. There was no difference in patency between the silver graft and regular graft cohorts. Reoperation was necessary in 10 cases (14%); the reason was mainly graft occlusion (8.5%), bleeding (10%), wound infection (8.5%) or a combination of the above. Amputation was necessary in 10 cases (14%). The median length of hospital stay was 13 days and the mean follow-up period was 48 ± 9 months. During the follow-up period, six patients (8.5%) died from reasons unrelated to surgery or without any relation to the vascular graft. Secondary patency after 1 year was 88%. All of this data corresponded with data for common cohorts, where a normal graft was used (our own unpublished data).d-glucose (FDG) uptake was observed in vascular grafts and also by positive cultures. Staphylococcus aureus was cultured in two cases (haemoculture) and Salmonella enteritidis in one case as a monoinfection not only from blood cultures but also from the silver graft. Thus, there was no doubt that these agents were the cause of infection. In one case, the vascular graft was explanted and replaced with an aortic allograft. Salmonella enteritidis. The probable source of infection was diarrhea 2 months before clinical signs of sepsis occurred. The other two cases of peripheral silver graft infection were treated conservatively with very good results . Regular CT and PET/CT examinations were performed to follow the treatment success. All three patients with silver graft infections recovered very well without any severe complications. Patients with an aortic allograft had no clinical or PET/CT signs of re-infection, and both patients with left infected peripheral vascular reconstructions had no clinical signs of infection, although the PET/CT images indicated persistent high uptake values of 18F-fluoro-2-deoxy-glucose (18F-FDG). They are, at present, without antibiotic treatment.Proven infection of the silver graft was only observed in three patients (4.2%) during the follow-up period . The infInfection of any artificial materials implanted into the human body is always a very serious problem, whether it is an artificial joint, heart valve, hernia mesh or artificial vascular graft. Especially in vascular surgery, infection of an artificial vascular graft is a nightmare for every vascular surgeon. These situations are associated with significant morbidity and mortality . The useStaphylococcus aureus (MRSA), Escherichia coli, and Candida albicans), the silver graft demonstrated a more sustainable and efficient 7-day antimicrobial activity than the rifampicin-soaked graft [The use of cryopreserved or fresh allografts is one of the alternatives for managing these catastrophic situations. According to a number of authors, the results are very good and comparable to the use of silver grafts based on the results of a number of studies . The proed graft ,29. Thised graft ,31,32.Our own clinical experiences with antibiotic grafts are also very poor. We only implanted 12 rifampicin-soaked vascular grafts in this time period, but the results were unsatisfactory; six patients showed signs of reinfection within the 1-year follow up.On the other hand, a number of data are available that demonstrate the very good results of silver grafts, the good long-term patency of these vascular grafts and especially a low percentage of infection ,7,22. ThOur retrospective study focused on the long-term results of silver graft use in various indications. The primary aim was to obtain information about the long-term patency of these vascular grafts, other complications associated with the grafts and especially about their infection. Our values of primary and secondary patency  are fully in line with the use of common vascular grafts in non-risk situations. We did not observe any allergic reactions to the silver grafts in our cohort. Infection in the graft occurred only in three patients (4.2%), despite very risky infectious situations. In one of them, we had to explant the graft and use a fresh aortic allograft, while in the remaining two patients conservative therapy was used (long-term antibiotic treatment).Our very good experience with silver grafts makes us consider the possible expansion of indications for the use of these highly-resistant vascular grafts; for example, in immunosuppressed patients or in combination procedures, where the risk of infection is multiplied . The novelty of the study is the use of silver-impregnated grafts in various risky indications with very good results.The immediate availability of silver grafts in their various variants is of particular importance, especially in the field of urgent and acute vascular surgery. It is known that the floridity of the inflammatory process in the vascular graft area can fluctuate, and thus in some cases, the situation can be managed with long-term antibiotic therapy. However, there are situations where a sudden onset of an attenuated infection does not give time to plan an elective solution and obtain an allograft for urgent surgery, especially in the case of sudden bleeding, e.g., from a rupture of a pseudoaneurysm in one of the anastomoses. A similar situation can occur in the case of the development of prosthetic-enteric fistula with associated, mostly massive, bleeding into the affected part of the gastrointestinal tract. Equally urgent are cases of AAA rupture, where we perioperatively find the cause of the aortitis, most often of salmonella origins. Similarly, a previously unknown infection in a stent-graft implanted in AAA can only manifest by its rupture, especially in non-compliant patients who have not been monitored on a regular basis. Infection in stent-grafts is often mentioned as a severe EVAR complication . To avoiHowever, silver grafts are not only used in aortoiliac surgery, but also in peripheral blood vessels. It is well-known that many patients do not have a venous graft available for vascular reconstruction, whether that is due to gracility, varicosity or saphenous vein trunk stripping. Here again, the use of silver grafts is available as a suitable alternative, especially in patients with trophic lesions in the lower limbs, whether of ischemic, diabetic, venous or combined etiology.The use of silver grafts is contraindicated in known allergies to silver and palladium, which is very rare in the population. We have not observed this situation. The disadvantage is the slightly higher price of silver grafts compared to a conventional vascular grafts, but when compared with the costs associated with obtaining an allograft or the treatment of infectious complications of common vascular grafts, the price of silver grafts is still relatively lower . More reBased on our results, silver grafts are a very suitable alternative for solving infectious or potentially infectious situations in vascular surgery. High primary and secondary patency, low graft-infection rate and optimal costs are the crucial factors that allow us to draw such conclusions. Especially in urgent or acute cases, silver grafts are often the only option. This is, in our opinion, the biggest advantage of using silver-impregnated grafts. Even if it was just a bridge to buy time for a possible final solution, it is worth having this method in our portfolio. Furthermore, the physical condition of the patient must be considered in the decision of which strategy will be selected. Our study shows very reasonable and acceptable results in situations where infection would certainly occur using a common vascular graft. A large randomized trial in this field would certainly be desirable; the problem is if this study is feasible with the heterogeneity of the group of patients in whom silver graft use is indicated. Therefore, a number of biases can logically be expected. Based on our own experience, and also on the basis of a number of literary data, the use of silver-impregnated grafts is beneficial. Future results can be even better thanks to a new generation of vascular grafts where silver salts are combined with other bactericidal substances.


Journal clubs are a common educational experience for medical physics residents as a forum to discuss current research within the field. While journal clubs are valued by educational programs and accrediting bodies, there are a wide variety of ways in which these sessions are conducted. Unfortunately, there are currently few studies that have assessed the effectiveness of this educational method. This review defines journal club in the context of a medical physics residency and provides historical background for the meetings. Reasons why journal clubs are valued are presented, and several methods are described for conducting journal clubs. The format of journal clubs and scaffolding methods for guiding residents in gaining independence in critical reading skills are discussed. While the traditional journal club is a meeting, an alternative online virtual journal club is also described. Finally, a model of how a journal club can be applied in a medical physics residency is presented. And the most pressing task is to teach people how to learn.”After the completion of graduate school, many medical physics students transition into a residency program where they spend time gaining in depth knowledge of the clinical aspects of their specialty. Since the shift is from didactic training to an apprenticeship model, the medium for education shifts as well. One of the components found in almost every medical physics residency is a journal club. While journal clubs are valued by educational programs and accrediting bodies, there is a wide variety of ways in which these sessions are conducted. There are currently few studies that have assessed the effectiveness of this educational method. The goal of this paper is to present reasons why journal clubs are valued, what methods are used for conducting journal clubs, how discourse is used in these educational settings, and a model for implementing a journal club program within a residency.1.1While the earliest beginnings of the notion of journal club are somewhat unclear, the first recorded meetings were started by Sir James Page in London between 1835 and 1854 and Sir William Osler at McGill University in 1875.1.2Now, journal clubs commonly take place within the clinic or hospital during the workday as open meetings for residents, faculty, and staff. Modern journal clubs are defined as educational forums for discussing new scientific research and critically evaluating its applications for improving patient care.1.3While journal clubs have been established in the medical community, some have extended the model into other areas of education including teaching science to undergraduates. Similarities between the two settings include the focus on increasing scientific literacy, providing a venue to effectively communicate ideas, applying research from the literature, and developing critical thinking. However, the main differences are found in the expectations for the students based on their education and the format of how the journal clubs are conducted.A traditional approach for beginning a journal club involves asking a student to read an article. However, students often approach the task unprepared to analyze the text since expecting a novice to comprehend a technical article can be frustrating to an individual has not been trained to do so. The consequence of this model is that it has the potential to decrease one's enthusiasm for scientific research.RobertsSince there is typically little guidance on how students to evaluate literature, RobertsonThe literature from the undergraduate perspective provides some insightful methods of helping students prepare for the future by scaffolding their skills in scientific literacy and their capacity to integrate new ideas into application. While there are several varying definitions and applications of the term “journal club,” the remainder of this paper will focus on the definition in the context of medical physics residency.1.4It is recommended by AAPM that clinical medical physics residency training programs provide opportunities for structured conferences and opportunities for participation in scholarly activities including the recommendation inclusion of residents to presentation in journal clubs.1.4.1As many as 42% of journal clubs do not have well‐defined goals for their program,The initial goal of learning the latest research, practices, and technology is still a primary goal of the journal club. However, it is also an avenue for learning valuable professional skills. The first of these skills is being able to use computer and internet literacy to search for and retrieve a quality scientific article. Second is the ability to read and think critically to analyze scientific literature. Being able to critique research affords residents the chance to develop their reading skills, comprehend the content of journal articles, and create a deeper understanding of research design. By understanding the research presented, the residents are also able to gain specific skills like biostatistical knowledge for evaluating how the data were interpreted within the article.Reading the article is not enough for practicing evidence‐based medicine. It also requires the residents to find ways to utilize the research in clinical application.Residents are evaluated in many ways throughout their daily interactions with the clinical team. However, one of the formal methods for progress and competency is through their presentations in journal club.1.4.2Unlike the original journal clubs from a century ago, most journal clubs are conducted at the work place. They are commonly held before the clinic starts or during lunch or dinner to promote attendance. However, there are still some groups that meet regularly outside of the clinic. It has been noted that the longevity of journal clubs has been associated with several factors including presenting original articles, meeting regularly, and scheduling around a meal.It has been shown that having regularly scheduled meetings emphasizes the importance of journal club to the department.1.4.3The goal of any educational endeavor is success, but how this is defined may vary depending on the context. AlguireWhen the medical residency program directors were asked what factors were involved in their level of satisfaction for the journal club, they mentioned the importance of regular attendance of the physicians in the department. Their attendance demonstrates the value of the meetings, not only the residents presenting but also the others in the department to promote the continued support of the educational experience. Interestingly, it was also mentioned that there was higher satisfaction from members if the meetings were held in a faculty member's home. Successful journal clubs have leadership for sustaining the program. Having a designated organizer of the meetings has been shown to increase satisfaction from the program directors and quality of the meetings. The clubs can be led by the director of the program or a faculty member for continuity throughout the lifetime of the program. Another option is for the sessions to be managed by a chief resident or small group of senior residents.1.4.4There are many challenges to establishing and maintaining a healthy journal club. Some of these challenges include a lack of time of both physicians and residents in the busy clinic. Because of this lack of time, even if a journal club is scheduled for an hour during the work week, the residents may not spend time preparing for the session. If there is insufficient preparation, the sessions are usually unstructured and are therefore not highly valued by the members decreasing educational potential for the participants.1.4.5The content and the format of the journal club should reflect the goals that have been defined for the meetings. AlguireOthers recommend the use of several articles to give a wider overview of a topic or issue. Sadeghi and KakhkiWhether one or several papers are discussed, Joorabchi1.5It has been noted in the literature that there are shortcomings to the traditional way journal club is conducted. The resident is often ill‐equipped to select an appropriate article for discussion because they have not been trained in how to conduct a search for a quality research article or assess the article critically.A resident should be able to evaluate the strengths and limitations of the article. One way of accomplishing this is to start by providing an outline for the residents to fill out with keys on how to identify important elements of the article. A paper may initially be selected with the help of a support committee, giving the resident several options for acceptable papers so the resident can focus their initial efforts on understanding and critiquing the content of the article.One critical skill is being able to search and find an appropriate research article. This scientific literacy involves knowing how to navigate medical and scientific journals for relevant articles. Residents should be able to evaluate key parts of the paper like the title, author, references, and abstract when initially assessing a paper. Since the ability to read scientific journals is a life‐long learning experience, residents should learn how to efficiently sort the good articles from the bad early in their career. After finding quality articles, it is also a valuable skill to know how to organize and store the literature for future reference or for citing later when writing their own papers.The critical piece to the scaffolding model in gaining scientific literacy is the guidance from a mentor to help the resident gain progressive independence. While there are many role‐models in the clinic, it is often helpful to have a designated journal club leader or committee that can invest time and answer questions for the resident in a busy clinic.1.6There have been a few limited studies showing the effectiveness of journal clubs. These studies either rely on self‐reported perceived gains of the residents or by assessments without formal validation. Ebbert, Montori, and SchultzMost of the studies are based on self‐reports from residents. The one randomized controlled trial by LinzerAnother approach to evaluating journal club effectiveness is to provide an opportunity for residents to demonstrate gains instead of self‐reporting their perceived gains. Green1.7(p. 216) because it should involve the facilitator motivating and engaging participants. The opportunity for “open and free discussion is the heart of the journal club.”(p. 216) Journal club provides a unique opportunity for both residents and physicists to have social interaction where the faculty should be able to share their passion and excitement in introducing new members to the world of medical research and education.While it is stated that the goal of these meetings is to promote discussion among both residents and faculty, there is very little description or explanation of how this discourse takes place in this type of setting. Jamal makes the distinction that the session “is called ‘Club’ not a seminar”Audience participation is key to a healthy journal club. The best education for the residents occurs when there is an exchange of ideas among the club members to stimulate learning and the synthesis of new information. One way suggested to promote this discourse is to arrange the participants in circle or round table so that participants can have eye contact and clearly communicate with others in the group.Ways that are described in the literature to promote discourse in journal club include having meetings that are structured and well organized by the facilitator. Topics can be selected that are controversial in regards to claims or methodology presented in the article. Opposing viewpoints can also be introduced to encourage argument stimulating interest and discussion among the group members.There are also negative factors that confine the contributions of members to the overall conversation. One limitation for discourse involves the skills and/or preparation of the facilitator of the session. Depending on the resident, the critical reading and presentation skills can affect the quality of the journal club session. Residents may not have sufficient background knowledge about the topic or could feel intimidated by contributing to the discussion for a variety of reasons.One of the most common challenges to discussion in journal club is the senior faculty members usurping the conversation.1.HThe journal clubs discussed so far have taken place physically at an institution and are conducted face‐to‐face with the participants. However, with advances in technology, capabilities of social media, and necessity of thinking outside of traditions due to the COVID‐19 pandemic, the definition and venue for journal clubs is continuing to expand. Virtual meeting platforms, blogs, and social media give residents and doctors beyond the academic institutions a chance to participate in these discussions.Benefits for online journal clubs include increased access and democratic nature to information and discourse. With the accessibility of the internet, anyone can now access relevant and accurate information about medicine.As of 2015, there were 24 known medical journal clubs using Twitter. The online journal clubs are gaining in popularity with progressive increases in the number of followers and number of Tweets from users over time.Online journal clubs have been either arranged to occur at a certain time and date where people can participate together or have been conducted over a longer amount of time for asynchronous discussion. The latter has the advantage of allowing professionals from all over the world to contribute to the discussion at a convenient time. For example, the International Urology Journal Club (#uroJC) provides notification about the topic about a week before the scheduled meeting, and the asynchronous club meets for 48 consecutive hours.The Medical Physics Leadership Academy launched their leadership journal club initiative in the fall of 2020.1.IWhile there have been some mention of strategies for ways that discourse can be incorporated in journal clubs from the literature, this section will provide some additional methods for these beginning or refining their own journal club. First the leader of the session should explain the rationale for the use of discourse in the journal club. The ground rules should be established for creating a safe environment for the exchange of ideas within the group. Both the facilitator and the members should demonstrate good listening skills and practice building responses on one another's comments.Facilitators can increase opportunities for dialog by moving away from a traditional lecture and asking high‐quality open‐ended questions to the audience to promote discussion. Small groups can be tasked with specific questions for discussion or two people can work together as a think‐pair‐share team for stimulating discourse. The facilitator can also call on individuals for answers during the session. Members should be encouraged to provide reasoning and justification for their ideas which is consistent with evidence based medicine. The facilitator should always seek multiple answers and explanations from the group to promote involvement from each individual.1.JReview a research article using an outline for key aspects. The resident will complete assigned readings reviewing journal club and review video on writing good scientific papers. The resident will identify a topic of interest and mentors will help identify a good paper on the topic. The resident will fill out a worksheet to help guide the understanding of the structure and purpose of the article. The resident will share what he has learned in a physics education session using active learning strategies.Learn how to search for and select a good journal article. The resident will be introduced to scientific journals within medical physics and radiation oncology by reviewing videos on differences between journals in medical physics through the AAPM Virtual Library. They will be introduced to impact factor and the process of publication and review. The resident will also be exposed to citation management software and select one for download and use. The resident will select a topic of interest and propose three articles within a topic of interest. One final article will be selected after discussion with mentors for presentation to the group during the journal club meeting.Compare and contrast a strong and weak article on the same topic. The resident will review videos from the AAPM Virtual Library discussing what journal article reviewers are looking for in a manuscript. The resident will select a topic of interest and review several articles within a topic of interest. The resident will rank the articles and select an example of a strong article and weak article and defend why they believe so. The resident will schedule a meeting with mentors to review and justify his choice. The two final articles will be compared and contrasted for presentation to the group using active learning strategies during journal club meeting.Research and defend one side of an argument in a point/counterpoint. Resident will coordinate with another coresident to select a topic for a point/counterpoint discussion that will be held during the journal club. Any topic of interest may be selected, but topics are encouraged from the AAPM list of past articles, which can be found in either of the two volumes of “Controversies in Medical Physics: a Compendium of Point/Counterpoint Debates.”We began a journal club for our medical physics residency in 2015 with the goal of promoting accountability for reading scholarly work in the field. After reflecting upon the literature, it has shown me that we should provide more than just a forum to present something that has been published in the form of an educational lecture. While our traditional model was a way of transmitting the knowledge to those within the department, we shifted the focus to mentoring residents and gradually building their skills through scaffolding. Teaching how to evaluate the quality of a research article and how to promote a meaningful discussion in a way that is more interactive will provide an environment that is more meaningful for the attendees. We have incorporated a four‐phase model to journal club in our residency program shown in Fig. This journal club model has been adopted by our residency program and educational materials have been developed such that it would be simple to expand the educational curriculum to other institutions. Appendices A and B provide supplementary reference material for beginning a new program or adapting a current program based on our current curriculum. After several years of implementation and refinement, we have received positive feedback from the residents for the guided approach in learning these valuable skills and feedback from the physicists in the increased quality of resident presentations using learner‐centered approaches. While this review presents a model for the educational program, work is ongoing work to help evaluate the efficacy of this educational approach. This four‐stage model can be expanded to many different audiences in the medical community as a format for not only physicists and physicians, but all health professions as a prototype for interacting with and presenting academic literature.2By the time a medical physicist completes his or her residency, he or she is well versed in the practice of their specialty. A universal skill desired and expected for all clinicians is the ability to retrieve, analyze, and present scientist knowledge from medical and research journals. While journal clubs may be different from institution to institution, there are core ideas that should define the quality educational experience the venue is intended to provide. This paper presented the idea that journal clubs are a valuable space for analyzing scientific literature, promoting analytical reading skills, and provides a setting for intellectual discourse. Several methods were described in how to define appropriate goals, select topics, and provide methods for conducting successful journal club experiences for resident education. Finally, discourse methods were highlighted for application in both a traditional and online setting.There is currently very little literature in terms of how discourse is used within journal club settings. Future work can be expanded on how journal clubs are conducted with a focus on the conversation or lack thereof within residencies. By first knowing what kind of discourse is currently in the sessions, we can then expand to evaluating the effectiveness of types of discourse to improve the educational experience for medical residents. Finally, these findings can be generalized and tested within other settings like journal clubs at the undergraduate level.