The paper presents the results of experimental tests of the rolling process of Mg/Al bimetallic bars in two systems of classic passes  and modified . The feedstock in the form of round bimetallic bars with a diameter of 22 mm and 30% of the outer aluminum layer was made through explosive welding. The bimetallic bars consisted of an AZ31 magnesium core and a 1050A aluminum outer layer. Bars with a diameter of 17 mm were obtained as a result of rolling in four passes. The rolling process in the passes was conducted at two temperatures of 300 and 400 °C. Based on the analysis of the test results, it was found that the use of modified passes and a lower rolling temperature (300 °C) ensures a more homogenous distribution of the plating layer around the circumference of the core and results in an even grain decreasing, which improves the corrosion resistance of bimetallic bars compared to rolling bars in a classic system of passes and at a higher temperature (400 °C). Products made of magnesium alloys have been drawing more and more attention in many industries for over a dozen years. It relates to the low mass density and high strength of Mg alloys ,2, whileIn order to increase the homogeneity of deformation during the rolling of homogeneous bars ,37,38, aThat is why the main purpose of using the modified grooves is to increase the uniform distribution of the outer Al layer to increase the corrosion resistance of Mg/Al bimetallic bars. In the existing work, there are no data on the impact of the shape of the grooves and process parameters on the corrosion resistance of Mg/Al bars. Thus, the novelty and the main aim of this work was to determine the impact of the shape of the grooves and the rolling temperature on the corrosion resistance of the bars by using an outer aluminum layer. As part of this research, the rolling process was conducted in two systems of elongating grooves: classic  and modified . The rolling process was conducted in four passes. The obtained Mg/Al bimetallic bars were subjected to complex tests of the layer thickness distribution around the perimeter, structural tests, microhardness, and corrosion resistance tests.The bimetallic feedstock in the form of Mg/Al round bars used for rolling in grooves was obtained by the explosive welding method. The explosive welding process was conducted in cooperation with the Explomet company . The parameters of explosive welding have been described in detail in the previous works of some authors ,32. EighAfter explosive welding, the obtained Mg/Al bimetallic feedstocks were 400 mm long. The average diameter of the Mg/Al bimetallic feedstocks after explosion welding was 22.5 mm. The obtained bimetallic feedstocks were marked by a slight difference in the thickness of the outer aluminum layer around the perimeter of the magnesium core. The average thickness of the aluminum layer was 1.67 mm and its share in the cross-section of the bimetallic bar was 28% .One of the deciding factors impacting the even distribution of the plating layer is the shape of the grooves and the distribution of deformations in individual passes. Two systems of elongating grooves were designed for the rolling process: the classic system of grooves, oval-circle-oval-circle (variant I), and its modification, multi-radial horizontal oval-multi-radial vertical oval-multi-radial horizontal oval-circle (variant II). In the case of both variants, the rolling process took place in four passes. The finished round pass was the same in both variants. The rolling feedstock was round bars with 22.5 mm diameter and 100 mm length. After rolling, the obtained round bars had a 17-mm diameter.Computer simulations with the use of a computer program based on finite element method (FEM) were used to develop the design of the new passes. The assumption of using multiple radii in oval passes was to create the right conditions during deformation, limiting the controlled plastic flow of the magnesium core plating layer and, thus, obtaining a more even distribution of the plating layer around the perimeter of the magnesium core. The deformation pattern for individual variants is presented in Temperature-deformation parameters were selected based on the results of physical and numerical modelings of compression tests of two-layer Mg/Al samples ,40. The platK plating layer [tmax) to the minimum thickness (tmin), in the cross-section of the finished Mg/Al bimetallic bars, which can be determined using the following Equation (1):In order to determine the distribution of the plating layer for each sample collected after a particular pass, 32 measurements were conducted, which corresponded to the multiple of the angle of 11.25°, starting from the orientation  in the N direction. The evenness of the thickness distribution of the 1050A layer on the core of the AZ31 bar was determined using the coefficient of unevenness of the thickness distribution of the ng layer , definedplatK is presented in [A detailed description of the methodology used to determine the analyzed coefficient ented in ,41. In oMicrostructural tests of Mg/Al bimetallic bars included observations on an optical microscope Olympus LEXT OLS 4100  and a scanning microscope JEOL JSM-6610 . The samples were included in the resin, sanded with 80, 320, 500, 800, 1200, 2400, and 4000 gradations, and then polished with a diamond paste of 3 mm and 1 mm. In order to reveal the microstructure of the AZ31 alloy, samples were etched with a reagent composed of 19 mL of ethanol, 2 mL of acetic acid, and 1 g of picric acid (digestion time of 30 s). Revealing the microstructure of 1050A was carried out using 1% HF with an etching time of 60 s.2SO4 solution acidified to pH = 4.0. The electrodes in the form of rotating disks were used for electrochemical tests, in which fragments of the side surfaces of the tested samples with an area of 0.2 cm2 were used for the electrodes. All potentiodynamic tests were performed at the temperature of 25 ± 0.1 °C, with the rotational speed of the disc equal to 12 rpm−1 and the scanning speed of the potential of 0.005 V∙s−1 using its shift from E0 value of 0.3 V lower than Ecorr to E1 = +0.5 V (regarding AgCl/Ag). This type of methodology ensured the production of repeatable passive layers , and, on the other hand, it limited material consumption, thanks to fast scanning and turning off polarization at relatively low potential values. Each time before drawing the potentiodynamic curve, the test sample was held for 15 min in the corrosive solution, i.e., until the corrosion potential reached a stationary value.To assess the impact of the groove shape and the rolling temperature on the corrosion resistance of Mg/Al bimetallic bars, potentiodynamic polarization curves were conducted in a 0.5M NaThe collected templets after individual passes were analyzed in terms of changes in shape and dimensions on the cross-section. The data presented in platK coefficient calculated for finished bars rolled in two systems of passes.The main idea of using modified grooves (variant II) was to limit the uncontrolled plastic flow of the plating layer, thanks to which it will be possible to obtain Mg/Al bars with a more even distribution of the plating layer around the perimeter of the magnesium core. Limiting the local thinning of the plating layer on the perimeter and obtaining its even distribution is an important factor impacting the corrosion resistance of Mg/Al bars. platK coefficient, marked by the uneven distribution of the plating layer, was close to 1 (platK = 1.12). Due to the fact that rolling in passes is marked by a spatial state of deformation and the lack of possibility to fully control the flow of the bimetallic band, it is natural that platK for bimetallic bars, after rolling in grooves, will increase in relation to the bimetallic feedstock. The modification of the shape of the passes, consisting of replacing the single-radius surface with multi-radial surfaces with straight sections, had a positive effect on the change in the deformation distribution and the evenness of the plastic flow of individual components in the Mg/Al bimetallic bar during rolling in the rolling gap (variant II). The new shape of the grooves enabled us to limit the accumulation of the plating layer material at the ends of the grooves towards the horizontal axis of the pattern symmetry and to reduce the thinning of the layer towards the bending at the same time. Thus, regardless of the rolling temperature, platK coefficient increased to a smaller extent in variant II in relation to Mg/Al bimetallic bars rolled in the classic system of passes (variant I). Rolling bars at the temperature of 300 °C, regardless of the applied rolling variant, had a positive effect on the evenness of deformation and plastic flow of the bimetal components. Thus, for Mg/Al bars rolled at 300 °C, platK coefficient was lower compared to the bars rolled at 400 °C. The most even distribution of the plating layer was obtained for Mg/Al bars rolled in passes modified for the rolling temperature of 300 °C. Detailed changes of platK coefficient for individual rolling variants are presented in The data presented in platK coefficient in relation to the bimetallic feedstock totaled below 10%, and for the temperature of 400 °C, only 15%. Both values obtained for the rolled bars according to variant II, regardless of the rolling temperature used, were lower than the values obtained for bars rolled in the classic system of grooves (variant I). Comparing the obtained platK coefficients for individual variants, a greater evenness of the plating layer can be found for modified grooves, a reduction of platK by 8% for 300 °C and 11% for 400 °C, respectively. The data analysis in Based on the analysis of the microstructure, it can be concluded that bimetallic bars rolled at a lower temperature a,b are mThe microstructural analysis of the 1050A outer layers for most of the tested samples enabled the identification of large inhomogeneities in the grain sizes, regardless of the applied process parameters. The grain size ranged from 20 µm up to 200 µm. Most of the samples showed the dominance of the coarse-grained microstructure. The sample taken from the bar rolled in passes modified at the temperature of 300 °C b, in whiThe implemented modification of the passes, consisting of substituting the single-radial pass surface with multi-radial surfaces with straight line segments, had the favorable effect of changing the strain, stress distribution, and the plastic flow of individual components in the Mg/Al bimetallic bar in the roll gap during rolling. It affected the higher decrease of the grain size. The modified roll pass design helped to limit the build-up of the cladding layer material and the ends of the passes in the direction of the axis of symmetry of the pass and, at the same time, to reduce the layer thinning in the rolling reduction direction. The new pass shape of passes reduced the non-uniform distribution of the deformation and stress value in the rolling direction. Additionally, lowering the rolling temperature to 300 °C had a favorable effect on the homogeneity of the deformation and plastic flow of the bimetal components and, consequently, the decreasing of the grain size. The most uniform distribution of the cladding layer and lower grain size was obtained for the modified passes for the rolling temperature of 300 °C.More homogenous deformation in individual passes for the system of modified grooves and a lower rolling temperature resulted in a more homogenous grain size for the analyzed sample.2Al3) on the aluminum side and γ (Mg17Al12) on the magnesium side [2Al3 and 3 μm Mg17Al12. In the sample taken from bars rolled in modified passes, the zone was slightly smaller and was characterized by a thickness of approx. 11 µm with the presence of 7 µm Mg2Al3 and 4 μm Mg17Al12.To determine the diffusion zone, the EDS analysis was performed for samples taken from rolled bars in two variants and at two temperatures, including a map of alloying elements on the AZ31–1050A joint surface . Microstium side . In the ia) reached values of approx. 270 mA/cm2, while they did not exceed 1.4·10−2 mA/cm2 for aluminum. As it is known, in solutions with a pH of range from 4 to 8, in contrast to magnesium and its alloys, a permanent hydroxide was formed on the surface of aluminum, which was a passive layer, effectively protecting the surface of this material against corrosion [The obtained polarization curves were drawn for material in their initial state  and for Mg/Al bimetals rolled in two systems of elongating passes: classic (variant I) and modified (variant II) are shown in orrosion . Ecorr) and, thus, the earliest etching of the surface. In addition, the highest values of anode currents (ia) were also found for this type of rolling. Modification of the rolling process (variant II) caused a significant shift of Ecorr towards more positive values. Such an increase of Ecorr was observed for samples after rolling according to variant II (system of modified passes), regardless of the temperature used in this process, and it proved that the processes of active etching of the surface were delayed. Precise values of Ecorr and ia read at E = 0.25 V are presented in Comparing the schemes of the potentiodynamic curves of bimetals after rolling in the grooves, presented in Rp), which is a parameter that determines the corrosion rate, was calculated. E =E − Ecorr = f (Δi) for equal potentials Ecorr ± 20 mV for bimetals after various rolling variants. For comparison, Ecorr = ±20 mV), i.e., in the range in which the Stern–Hoar equation [Rp) inversely proportional to the corrosion rate (icorr). Ecorr), anode current (ia), and corrosion current density (icorr), determined based on the value of the polarization resistance (Rp) [To determine the corrosion rate of Mg/Al bimetals, based on the drawn polarization curves, the polarization resistance (equation  is fulfince (Rp) .icorr and ia) than Al, from which the coating was made. This slight improvement in the corrosion parameters of aluminum was probably due to the reduction of the grain size of the material due to the fragmentation of the primary grains during the deformation of the bars in individual passes. Similar results of an increase in the corrosion resistance of aluminum as a result of grain refinement were obtained after the forging (RS) [As can be seen from the data in ing (RS)  and anguing (RS)  processeing (RS) . While cicorr), the samples rolled at 300 °C are worthy of noticing. Regardless of the applied rolling variant, these bimetals corroded at the same rate, of 0.3·10−3 mA/cm2, while after rolling at 400 °C they corroded slightly faster (icorr = 1.1·10−3 mA/cm2). However, while the corrosion rates of the bimetals rolled at lower temperatures were the same, it should be noted that the more favorable values of both the corrosion potential and the anode currents were achieved by rolling with the modified method. The best corrosion characteristics obtained for Mg/Al bars rolled in modified passes for the rolling temperature of 300 °C probably reflect the fine-grained structure [From a corrosive point of view, due to the slowest corrosion processes  in combination with the applied deformation in the particular passes and the modification contributes to reaching bimetallic bars with high geometric accuracy of the cross-section. A more even deformation in the Al plating layer resulting from the deformation method and the reduced temperature results in an even grain fragmentation, which improves the corrosion resistance of bimetallic bars.Rolling of Mg/Al bimetallic bars in modified passes at a temperature of 300 °C causes the smallest grain size of aluminum, which results in higher corrosion resistance of the final bars. In addition, it was found that bars rolled in modified passes are characterized by a slightly thinner diffusion zone and a lower presence of cracks and delamination in the joint area compared to bars rolled in a classic pass system, regardless of the rolling temperature.platK coefficient. The increase in the uniform distribution of the outer layer of Al as a result of the use of modified blanks amounted to approx. 10%, which had a direct impact on the general corrosion resistance of the entire Mg/Al system.The corrosion resistance of Mg/Al bimetallic bars is strictly dependent on both the temperature and the applied rolling method (the shape of the grooves). Conducting the rolling processes at the temperature of 300 °C slows down the etching processes of the bimetal surfaces, effectively reducing their corrosion rate. Moreover, the corrosion resistance of the Mg/Al bars is closely related to the thickness and uniform distribution of the plating layer, defined as the Ecorr values of the samples after modified rolling may prove that this treatment (compared to classic rolling) may additionally delay the start of etching of the bimetal surface in a corrosive environment.Among the applied rolling variants, bimetals rolled in modified passes are marked by better corrosion parameters, which is reflected in the shift of the corrosion potential towards the positive and lower anode currents. Higher The use of multi-radial modified elongating passes for rolling Mg/Al bimetallic bars, which were influenced by the plastic flow of the bimetal components and ultimately resulted in the finished bars with a uniform cladding layer distribution on the core, resulted in small dimensional deviations. Moreover, the determination of the effect of cladding layer thickness distribution and the cladding layer thickness on the magnesium core on the corrosion resistance of Mg/Al bimetallic bars has not been the subject of research so far.


This study aims to identify the relationship between social anxiety (SA) and internet addiction (IA) in a group of Chinese college students by controlling for the effects of physical exercise (PE), demographic, and academic variables. A sample of 4,677 students from five major regions of China participated in this survey. The findings revealed that: (1) SA had a direct effect on IA; (2) regular and active participation in physical exercise can relieve SA and IA effectively; (3) the level of SA and IA is strongly linked to sex; (4) the levels of SA and IA are different among students of different majors; (5) students in the middle phase of their academic career are more likely to have IA than those in the starting phase. The study is significant because few existing studies discuss the role of PE on SA and IA. Additionally, the study found that college students with more PE would have a lower level of SA and a lower probability of IA. Internet addiction (IA) caused by the overuse of computers and smartphones has become a major public health problem worldwide, especially for the youth . The gloSeveral studies have investigated the negative effects of IA (including smartphone use) on academic performance, sleep quality, depression, anxiety, and physical fitness. It has been identified that there is a negative correlation between the daily time spent on smartphones and academic performance; specifically, using a smartphone for 100 min on an average per day corresponded to a 6.3 point reduction in the position of a student in the ranking in school in Brazil . MoreoveIn addition to IA, social anxiety (SA) is considered another common and debilitating psychiatric disorder in college students . AccordiPhysical exercise may positively treat both IA and SA . For exaSome limitations should be acknowledged while exploring IA or SA. First, the most existing studies focus more on the harm and influence of IA or SA, respectively, and few studies have focused on the impact of PE on IA and SA. For example, Accordingly, this study aims to utilize the generalized mixed linear model to examine the relationship between IA and SA, taking into account the variables of PE, sex, major, grade, and age among Chinese college students. The results of this study can help reduce the levels of IA and SA in Chinese college students with different backgrounds through PE approaches. Based on the reviewed literature, this study hypothesized that: (1) A positive relationship would exist between IA and SA. (2) PE would be negatively associated with IA and SA.A self-reported standard scale was used for the cross-sectional survey in this study. Further, the survey was conducted from April 9th to 23rd, 2020. A stratified cluster sampling method was adopted to acquire subjects. According to the existing criterion, the territory of China can be divided into five regions . Twenty major cities in these five regions were selected, and each region included four cities. Sequentially, 42 universities were chosen. Each class of these universities has been viewed as a cluster. Further, the sample has been randomly selected from all the classes of these universities. All currently selected students who were able to complete the questionnaire independently were included in our sample, composed of 4,677 participants, including undergraduates and postgraduates. All 4,677 college students participated in the survey, which was completed anonymously and confidentially online, and all questionnaires were collected voluntarily. After further examination, 30 questionnaires were found to be invalid due to missing data or incorrect or incomplete answers and hence were deleted from the sample. The age, sex, and major distribution of the final sample are shown in r = 0.82)  . Its val = 0.82) .Internet addiction was assessed using the Internet Addiction Diagnostic Questionnaire (IADQ) . We chosr = 0.80)  , which i = 0.80) .Generalized mixed linear modeling was performed using Proc Glimmix in the University Edition of Statistical Analysis System (version SAS Studio 3.6). Two separate regressions were run in the model. First, Poisson regression was achieved by taking SA as the dependent variable and PE and IA as predictor variables. Second, a binomial logistic regression was employed by taking IA as the dependent variable and PE and SA as predictor variables. Fixed effects of sex, age, single child (SC), major, and grade were added to both regression models.Social anxiety is the summed value of all items in the IAS, with a possible range of 15–75. PE was calculated from the three items of the PARS-3 using the following equation: exercise intensity × (exercise duration-1) × exercise frequency, with a possible range of 0–100 . IA was In the Poisson regression model, the differences in the mean SA for all groups of nominal variables were compared. For the effects of PE and age (numeric variables), the difference in the mean SA of a typically low value (one SD below the mean) and a typically high value (1 SD above the mean) was estimated . In the Descriptive statistics of the dependent and independent variables are shown in p < 0.0001) than the students with NIA. The level of SA of the students with high (1 SD above the mean) PE values was lower  than the students with low (1 SD below the mean) PE values. Students with an age of 1 SD above the mean age had a lower SA level of 2.27%  than those aged below the mean. Female students had a higher SA level  than male students. Single child students had a lower level  of SA than NSC. The SA levels of students majoring in arts were lower than those majoring in social sciences  and natural sciences . Meanwhile, the SA levels of students majoring in sports were also lower than those majoring in social sciences  and natural sciences . The level of SA of students of PG1 were lower than students of UG1 , UG2 , and UG3 .Results from the Poisson regression showed that the SA level of the students with IA was higher  higher probability of IA than those with a SA level under the mean. Students with a PE level above the mean would have a 6.28%  lower probability of IA than those with a PE level below the mean. Female students had a lower probability of IA than male students . Students majoring in sports had a higher probability of IA than students majoring in social sciences , natural sciences , and arts . Students in UG2 , UG3 , and PG2  were more likely to have IA than students in UG1. PG1 students had a lower probability of IA than students in UG3  and PG2 . PG3 students had a lower probability of developing IA than students in PG2  and DR .Results from the binomial logistic regression showed that the college students, with a SA level at 1 SD above the mean level, had a 23.67%  and the middle child had a higher prevalence rate (61.5%) . Due to When considering the effects of majors of college students, our results showed that the SA level of students majoring in arts and sports is lower than that of students majoring in natural and social sciences, which is supported by prior research . This reThe effects of age and grade were investigated. We find that the SA of students of PG1 is lower than that of UG1, UG2, and UG3, which is partially consistent with the research of Additionally, this study shows that students in the middle of the academic period  are more likely to develop IA than students at the start of the academic period (UG1 and PG1). This finding is consistent with the findings of Two major limitations of the current study should be acknowledged. First, considering a large number of surveys in questionnaire distribution and collection, this study adopted the IADQ (created by Young in 1998 with only eight questions) to measure the level of IA of participants, which means that future studies are encouraged to utilize the newest questionnaires, like the Internet Addiction Test. Second, the distribution of academic status of the students in this study was unequal (most of them were undergraduate students); therefore, further studies may wish to expand the number of postgraduate students.Chinese college students with IA have a higher level of SA than students without IA, while students with a higher degree of SA have a greater likelihood of IA. Meanwhile, college students with more PE would have a lower level of SA and a lower probability of IA. The SA of single children was lower than that of non-single children. The SA level of female students was higher than that of men, while male students were more prone to IA. Students majoring in arts and sports have lower levels of SA than students majoring in other subjects, but students majoring in sports are more prone to IA. Students in the middle phase of their academic careers were more likely to have IA than those in the starting phase. This study helps to better understand the relationship between PE, SA, and IA in Chinese college students, which could offer a precise exercise prescription for those who suffer from SA and IA in different situations.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.SY and HL contributed to the conception, design, and the examination of data of this research. HC and SY contributed to the collection and examination of data. SY and ZZ were responsible for writing. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.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.


The aim of the present study was to explore the feasibility of real-time monitoring and quantitative guiding the repair of enamel white spot lesions (WSLs) with resin infiltration by optical coherence tomography (OCT). Seven New Zealand rabbits were treated with 37% phosphoric acid etchant for 15 min to establish the model of enamel demineralization chalk spots of upper incisors, which were repaired by Icon resin infiltrant. OCT, stereo microscope (SM) imaging, scanning electron microscope (SEM) imaging and hematoxylin eosin (HE) staining were used to image each operation step. The changes of WSLs of enamel before and in the process of restoration with resin infiltrant showed specific performance in OCT images, which were consistent with the corresponding results of stereomicroscope and SEM. OCT can non-invasively and accurately image the whole process of repairing enamel demineralization layer with resin infiltration real-time, which can effectively guide the clinical use of resin infiltrant to repair enamel WSLs and be used as an imaging tool to evaluate the process and effect of restoration with resin infiltrant at the same time. Orthodontic brackets or plaque accumulation demineralize the tooth surface, leaving white spot lesions (WSLs) ,2,3,4,5.As a new method for minimally invasive repair of enamel white spot lesions , resin iHowever, at present, due to the limitation of imaging resolution (mm), cone-beam CT (CBCT) and other types of imaging equipment commonly used in the clinic are unable to distinguish abnormal enamel white spot lesions from normal dental tissues. At the same time, due to the high transmissivity of resin infiltrant, the above two imaging methods cannot visualize the image of the materials, nor can distinguish the restored tooth tissue from the unrepaired demineralized tissue and penetration depth of the resin. Therefore, the clinical evaluation of the effect of resin infiltrant restoration is still limited to the morphology and color changes of the tooth surface before and after restoration . The autIn the 1990s, Huang et al. ,21,22,23In the present study, the OCT device was used to scan and image the whole process of enamel white spot lesions of artificial rabbit teeth restored with resin infiltrant. The results were compared with a stereoscopic microscope, SEM, and HE staining at the same time to investigate the feasibility of the OCT device to monitor and guide the resin infiltrant restoration of WSLs in real-time.All animal procedures were performed in accordance with the Guidelines for Institutional Animal Care and Use Committee and approved by the Guangdong quality supervision inspection station for healthcare devices . Seven healthy male New Zealand rabbits (3 to 4 months old) with similar weights were purchased from Guangdong Medical Laboratory Animal Center. All rabbits had no oral disease, and the shapes of maxillary incisors were complete without white spots on the surfaces. Before experiments, the animals were housed in standard plastic cages and maintained on a 12 h light-dark cycle at an ambient temperature of 23–24 °C, and received routine feeding for 1 week.The experimental rabbits were randomly numbered from #1 to #7. Before the experiment, all rabbits fasted for 12 h. The rabbits were anesthetized by intravenous administration of pentobarbital sodium at a dose of 30 mg/Kg. The rabbits were fixed to expose their maxillary incisors.The following steps were carried out in order. Step 1: the surfaces of maxillary incisors were clean only with a brush and pure water. Step 2: 37% phosphate etching agent  was evenly applied to the labial surfaces of maxillary incisors. After static placement of 15 min, the surfaces were washed with flowing water for 30 s and were dried with compressed air. Step 3: Icon-Etch  was smeared evenly on the labial surfaces of maxillary incisors for 30 s, rinsed with flowing water for 30 s, and dried with compressed air. Step 4: Icon-Dry  was smeared evenly on the labial surfaces of maxillary incisors and kept for 1 min, after which the surfaces were dried with compressed air. Step 5: Icon-Infiltrant  was smeared evenly on the labial surfaces of maxillary incisors for 1 min and light-cured with a curing light  for 40 s.Step 1 was performed on Rabbit #3. Steps 1 and 2 were performed on Rabbit #4. Steps 1, 2 and 3 were performed on Rabbit #5. Steps 1, 2, 3 and 4 were performed on Rabbit #6. Steps 1, 2, 3, 4 and 5 were performed on Rabbits #1, #2 and #7.Immediately after every preparatory step, the specimens of Rabbits #1 and #2 were scanned by an OCT system  , and the images were recorded at 200, 500, 1000, 2000, and 3000 magnifications.The extracted right incisors of Rabbits #3, #4, #5, #6 and #7 were immersed in an EDTA decalcifying solution  . After rP < 0.05 was considered statistically significant. Quantitative data were expressed as mean ± standard deviation. Statistical analyses were performed using Statistics 25 . GraphPad Prism 8  and Origin 2021  were used to draw graphs based on the data obtained.The OCT images were analyzed to obtain the light intensity of each pixel on the OCT cross-sectional image by MATLAB 2020b . All researchers discussed and determined the data acquisition standards and methods of analysis to ensure data uniformity. The two researchers were familiar with the standard and method through training, and conducted standard consistency test. The kappa value obtained was greater than 0.8. One of the researchers completed data collection and analysis independently, and another researcher verified it. Twenty locations on each OCT image of Rabbits #1 and #2 were randomly selected, and the light signal reflection/scattering bright band thickness of the enamel layer and dentin layer of each tooth was measured according to the change of light intensity. Baseline calibration was performed on each surface line of the selected locations, and the surface roughness of the sample was measured according to the arithmetic mean of the absolute value of the distance between each point on the sample surface and the baseline . The surIn Step 1, a smooth light signal reflection bright band was observed on the surface of the enamel, without obvious scattering on the deep enamel and dentin A. In SteAn image intensity profile was extracted from the OCT image of the rabbit tooth for quantitative analysis of the enamel-dentinal junction and the resin layer . The halFor SM images, the enamel on the surface of the teeth in Step 1 was smooth and shiny A. A largThe second column of As for histology, the enamel surface in Step 1 C was comp < 0.05) (p = 0.043), suggesting that the pores of the enamel white spots were reduced after being repaired by resin infiltrant, but the normal enamel could not be completely restored. < 0.05) A. Among p < 0.001), suggesting that the light consumption of the enamel layer in this group is reduced, which may be related to the decrease of mineral composition and the increase of pores in the demineralized enamel layer. In the process of resin infiltrant restoration, the thickness of the strong signal bright band of the dentin layer increased, suggesting that the resin infiltrant consumes less light than the air in the pores.The comparison of the thickness of the strong signal bright band of the dentin layer among the groups was shown in p > 0.05), it can still be observed from In the present study, 37% phosphoric acid etching was used to successfully establish the enamel white spot lesions model on rabbit maxillary incisors, which is similar to humans in the general structure of enamel and dentin [p < 0.001). After treatment with Icon-Etch and Icon-Dry, the morphology of enamel rods was exposed (as they were shown in p < 0.001), and still thickened compared to the natural surface (p = 0.043). Because the light scattering intensity of enamel is related to the number of micropores in the enamel [Considering the existence of heartbeat, respiration, and muscle activity, this study simulated the interference of body activity on the imaging process during OCT imaging in living animals, so as to ensure that the research results were closer to the actual situation. The results prove that, based on the intensity profile of the OCT image, a quantitative evaluation of the enamel white spot lesions during the repairing process is feasible. As it was shown in e enamel , the decThe present study illustrates that OCT brings a new way to evaluate the effect of resin infiltrant before and after repair. Seeliger et al.  used OCTp < 0.001).SEM and HE staining can obtain the information of enamel white spot lesions before and after the restoration of resin infiltrant. However, there is irreversible damage to the tissue and the operation is complicated and time-consuming, so it is not operable in clinics. OCT is a high-resolution, non-destructive biological tissue optical imaging technology , which cIn summary, OCT technology can be used for the whole process of resin infiltrant repair of enamel white spot lesions, with the advantages of non-invasion, high resolution, no ionizing radiation, and real-time in-vivo tissue imaging. It can effectively guide clinical practice and can be used as an imaging tool to evaluate the process and effect of resin infiltrant. Coupled with its significant advantages in monitoring tooth demineralization, OCT has great potential in monitoring tooth caries and restoration. However, OCT devices still have some shortcomings, such as poor flexibility of the scanning probe, heavy equipment, and shallow imaging depth, which limit its clinical application and require continuous improvement. This study discussed the morphological changes and OCT images of enamel white spot lesions before and after restoration with resin infiltrant. The prospect of the practical application of OCT technology in the restoration of enamel white spot lesions with resin infiltrant still needs further study. In this study, the central wavelength of the OCT system is 840 nm. Due to the influence of refraction and scattering, the longer central wavelength of the OCT system allows deeper penetration in a certain range ,46,47,48


Industrial waste discharged by heavy pollution industry is one of the main causes of global environmental degradation. Research on the environmental efficiency of high-polluting industry is necessary to tackle the problem of global environmental pollution. Using panel data of 19 sub-industries in China’s heavy pollution industry from 2001 to 2015, this article employs Data Envelopment Analysis (DEA) and Malmquist index (MI) to measure the environmental efficiency of heavy pollution industry from both the dynamic and static perspectives. The results show that the environmental efficiency of China’s heavy pollution industry maintains an upward trend but did not reach the optimal level. The general trend shows a phased trend of increasing first and then decreasing. Besides, there are inter-industry differences in the environmental efficiency across the examined sub-industries. Based on the research findings, this article proposes a set of corresponding countermeasures to solve the global pollution problem, such as reducing energy inputs and minimizing the volumes of the main categories of emissions in high-polluting industry, as well as improving the production management in the group of high environmental efficiency and strengthening technical capabilities in the group of low environmental efficiency. Due to economic globalization, the economies of most countries in the world are constantly developing. However, the serious consequence of that process is environmental pollution. Many scholars have studied the relationship between environmental pollution and economic growth. For instance, scholars verified the validity of the Environmental Kuznets Curve (EKC) ,2,3. In For the definition of environmental efficiency, this article adopts the definition proposed by Li and Luo 2016) “Environmental efficiency means that a certain area uses less environmental resources and produces less ecological impact, so as to provide products and services that meet human needs”  “Environ. The evaThere are numerous methods of evaluating environmental efficiency, including life cycle approach, balanced scoring method, analytic hierarchy process and fuzzy comprehensive evaluation method. Later, the research community saw the emergence and development of Data Envelopment Analysis (DEA). DEA is increasingly applied in the evaluation of environmental efficiency . When evTherefore, this article selects China as the research object of this article. China is a representative developing economy or one of the most representative developing economies in the world. Besides, some data about production in China would make the need for such analysis easier to present and they might be helpful in the context of results and conclusions. This paper studies the environmental efficiency of China’s heavy pollution industry, with a view to putting forward policies and suggestions on environmental pollution problems in China and the world.The main purpose of this article is to measure and analyze the environmental efficiency of high-polluting industries as a whole. Research on the high-polluting industries as a whole is conducive to proposing targeted measures to improve environmental efficiency, which is different from other industries. At the same time, we try to study the differences between sub-sectors of high-polluting industries, so that different polluting industries can take different measures according to their industry characteristics to solve pollution problems.The second part of this article is to sort out and analyze the literature related to heavy pollution industry and environmental efficiency. The third part is to briefly introduce the methods used in this article, including DEA model with undesirable output and MI. In addition, not only does this part explain the source of the data, but it also determines the research object. The fourth part is the data analysis and results. The last part summarizes the conclusions of this research, and then puts forward corresponding policy recommendations based on the research findings.The literature examined in this article mainly concerns heavy pollution industry, environmental efficiency and methods used to measure environmental efficiency.2 emissions were the undesirable output. The results of the study showed that the average environmental efficiency score of each state in the United States was less than 0.64. Le et al. (2019) conducted a study on agricultural production efficiency and environmental efficiency in nine Southeast Asian countries from 2002 to 2010 [2 and solid waste emissions as undesirable output [Based on previous studies, this article finds that as the pollution problem becomes more severe, people increasingly focus on the measurement of environmental efficiency in different countries and regions. Park et al. 2018) conducted a study on the transportation industry of 50 states in the United States from 2004 to 2012 and measured their environmental efficiency . Capital to 2010 . In addi conducte to 2010 . The ind to 2010 . An et ae output . The stuIn a small number of studies on industrial environmental efficiency and pollution problems, scholars often focus on a specific heavy pollution industry, studying the pollution and other problems it causes to the environment. Seklaoui et al. 2016) selected the mining industry and conducted a scientific assessment of the environmental pollution caused by it . Hutton  selectedFor the measurement of environmental efficiency, different scholars have adopted different methods, but they are roughly divided into two categories. One is the relatively simple single ratio method, which Sun (2020) elaborated in its overview of the development of environmental efficiency at home and abroad, and the other is the DEA method . With thThis article adopts the DEA model that includes undesirable output to measure the environmental efficiency of 19 sub-industries of China’s high pollution industry from 2001 to 2015. In order to evaluate the environmental efficiency level of China’s heavy pollution industry comprehensively, this article uses MI to further analyze the change in the environmental efficiency of China’s heavy pollution industry.In order to evaluate non-parametric efficiency, Charnes, Cooper and Rhodes first proposed DEA , which iAt present, the most commonly used methods to deal with undesirable output are the directional distance function and the slack based model (SBM) . The dirConsider a production possibility set that contains bad outputx is the input, gy is the desirable output, by is the undesirable output, and λ is a weight vector.The expression of the SBM model including undesirable output isThe MI was first proposed by Sten Malmquist in 1953 . It paysδ1 1, δ2 2 respectively represents the efficiency score of the input and output in the first period corresponding to the frontier of the first period, and the input and output of the second period corresponding to the efficiency score of the frontier in the second period.δ2 1) × δ21) respectively represents the efficiency value of input-output in period 1 relative to the frontier of period 2 and the efficiency value of input-output in period 2 relative to the frontier of period 1.Therefore, when MI ≥ 1, the environmental efficiency of the industry is increasing, when MI < 1, it means that the environmental efficiency of the industry is decreasing; when TECH ≥ 1, the frontier movement is beneficial to efficiency, and when TECH < 1, the frontier movement is not good for efficiency; when EFF ≥ 1 means that the efficiency of a certain industry has improved compared with the previous year, when EFF < 1, the opposite is true.Regarding the classification of heavy pollution industry, this article combines the 16 high-polluting industries specified in the Guidelines for Environmental Information Disclosure of Listed Companies issued by the Ministry of Environmental Protection in 2010 with the classification standards of Chinese national economic industries in the National Standards of the People’s Republic of China. A total of 19 heavy pollution sub-industries have been identified, namely, Mining and Washing of Coal (B06); Extraction of Petroleum and Natural Gas (B07); Mining and Processing of Ferrous Metal Ores (B08); Mining and Processing of Non-Ferrous Metal Ores (B09); Manufacture of Liquor, Beverages and Refined Tea (C15); Manufacture of Textile (C17); Manufacture of Textile, Wearing Apparel and Accessories (C18); Manufacture of Leather, Fur, Feather and Related Products and Footwear (C19); Manufacture of Paper and Paper Products (C22); Processing of Petroleum, Coking and Processing of Nuclear Fuel (C25); Manufacture of Raw Chemical Materials and Chemical Products (C26); Manufacture of Medicines (C27); Manufacture of Chemical Fibres (C28); Manufacture of Rubber and Plastics Products (C29); Manufacture of Non-metallic Mineral Products (C30); Smelting and Pressing of Ferrous Metals (C31); Smelting and Pressing of Non-ferrous Metals (C32); Manufacture of Metal Products (C33), and Production and Supply of Electric Power and Heat Power (D44).In order to evaluate the environmental efficiency of the above 19 heavy pollution sub-industries comprehensively and to find the key factors that affect the sustainable development of the heavy pollution industry, this article focuses on the representativeness and quantification when selecting indicators. Combining the existing research on environmental efficiency and taking into account the availability of data related to the research objects of this article, the input and output indicators of this article are as follows.Input indexes. Input indexes are mainly divided into three categories: energy input, labor input and capital input. This article refers to the indicators used by Sheng (2012) to measure environmental efficiency when studying the relationship between industrial environmental regulations and environmental efficiency . The comOutput indexes. The output indicators mainly include desirable output and undesirable output. This article refers to the research of Liu and Zhang (2012), taking the main business income of each industry as the desirable output . AccordiChina Industry Statistical Yearbook and China Statistical Yearbook, and the data of wastewater discharge, exhaust gas discharge, and solid waste discharge in various industries come from the China Statistical Yearbook and China Statistics Yearbook on Environment.The research objects of this article are 19 sub-industries of China’s heavy pollution industry from 2001 to 2015. The data sources are as follows: the comprehensive energy consumption of each industry comes from the China Energy Statistical Yearbook, the number of employees in each industry and the main business income comes from the The descriptive statistics of various indicators in the environmental efficiency evaluation model of high-polluting industry are shown in Analyze the correlation between the indicators of the environmental efficiency model of high-polluting industries. This paper finds that there are significant correlations between energy input and capital input, between desirable output and energy input, labor input, and capital input, and between exhaust emissions and energy input, capital input, and main business income. There is no significant correlation between other variables.This article adopts the DEA model with undesirable output on the environmental efficiency of 19 sub-industries of China’s heavy pollution industry and uses DEA-Solver-Pro 13.1  to calculate the environmental efficiency values of China’s heavy pollution industry.On the whole, the environmental efficiency of China’s heavy pollution industry demonstrated an upward trend from 2001 to 2015, but the growth rate was not high . It incrThis article calculates the average environmental efficiency of China’s heavy pollution industry from 2001 to 2015 through the environmental efficiency values of 19 heavy pollution sub-industries and finds that the environmental efficiency of China’s high-polluting industry has obvious industry differences .Among the 19 industries, B07, C18, C19, C25, C27, C29, and C33 have the best efficiency. B07 ranks high in terms of fixed asset input, while the emissions of three wastes have always been in the bottom five. C18 energy input is less, and the emissions of three wastes are in the bottom three, so the efficiency reaches the best level. C19 energy input is the bottom one, fixed assets is the second bottom, and the emissions of three wastes are also at the bottom. The desirable output of C25 is higher, which leads to the best efficiency. C27 has less investment, but the amount of solid waste discharge is lower. The discharge of wastewater of C29 is the second to last, which improves the efficiency of resource utilization. The desirable of C33 ranks relatively high, and the discharge of wastewater and solid waste is relatively low. The industries with lower environmental efficiency are D44, C26, C31, C22, C30, and B06. D44 ranks fourth in energy input and first in fixed asset investment. Although its main business is also relatively high, it also ranks first in waste gas emissions. C26 ranks first in energy input and wastewater discharge, and its resource utilization rate is very low. C31 ranks first in energy input and second in capital investment, but the emissions of the three wastes are also large, and resources are not used effectively. The investment of C22 is moderate, but its wastewater discharge volume ranks first, resulting in low environmental efficiency. The wastewater discharge volume of C30 is actually not high, but its waste gas and solid waste discharge volume is relatively large, ranking in the top five. B06 has high investment in human and financial resources, but its main business income is low, and its solid waste emissions rank first, resulting in its lowest environmental efficiency. For other sub-industries, B08 ranks third in solid waste emissions, B09 ranks second in solid waste emissions, C15 has low input and output and high wastewater emissions, and C17 has high labor input and ranked third in wastewater emissions. The main business income of C28 is third from the bottom, and the exhaust emissions of C32 is fifth. All these have led to low environmental efficiency.The environmental efficiency value of B06 reached 1 in 2011 because its main business income increased by 33.05% compared to 2010. The reason why the environmental efficiency value of B08 reached 1 in 2010 was because the investment in assets increased by 66.40% compared to 2009. The environmental efficiency value of B09 in 2009 is due to a reduction of 42.28% in waste gas emissions compared to 2008. The reason why the environmental efficiency value of C17 fluctuates greatly from 2011 to 2013 is because the fluctuating value of exhaust gas emissions is relatively large. The fluctuation of C28 in 2003 was due to the decrease of solid waste discharge and the increase of main business income. In 2013, C30′s main business revenue increased by 18.14%, exhaust gas emissions decreased by 57.12%, and solid waste emissions decreased by 70.51%. C31′s main business income increased by 30.71% in 2008. C32′s solid waste discharge in 2003 was only 20,000 tons. In 2011, D44 had less labor input and only 45,100 tons of solid waste discharge, which led to an environmental efficiency value of 1.According to the 15-year environmental efficiency value, the high-pollution industries in China are divided into three groups: high, medium, and low, from high to low .To further study the changes in environmental efficiency of 19 high-polluting sub-industries in China, this article also uses solverpro13.0 to calculate the MI of 19 sub-industries in high-polluting industry.From the results of the MI of the heavy pollution industry as a whole , China’sFrom the perspective of specific sub-industries , the difFrom the perspective of changes in the MI of the industry groupings , the oveIn this section, we divide each industry into three groups according to the environmental efficiency and analyze the efficiency changes of the sub-industries.From the perspective of the efficiency change of the catch-up effect , the higFrom the perspective of the frontier effects of sub-industries , the froBy observing the catch-up effect and frontier effect change trends of sub-industries , We findThis article examines the environmental efficiency of 19 heavy pollution sub-industries in China from 2001 to 2015 and uses the DEA model that includes undesirable output and MI in order to analyze the topic from both the static and dynamic perspectives.From a static analysis of environmental efficiency, we obtained that the overall environmental efficiency of China’s heavy pollution industry has generally maintained an upward trend, but the overall environmental efficiency has not reached 1. The environmental efficiency of China’s highly polluting industries is still not at its best. Wu et al. (2019) conducted a study on 38 industrial sectors in China and confirmed that the environmental efficiency of 38 industrial sectors has been increasing from 2007 to 2011 as well, which is consistent with the results of this paper . Xiao etFrom the perspective of dynamic analysis of environmental efficiency, the overall trend of environmental efficiency follows a regular pattern of a periodic fluctuation that first increases and then decreases. This trend change reflects China’s policy towards heavy pollution industries, from high pollution, high energy consumption, large emissions to low pollution, low energy consumption, and small emissions, and from environmental damage to new energy and new technologies to the development of a green economy. The change in the catch-up effect has become flat since 2009, and the trend of the frontier effect is basically consistent with MI, which shows that the improvement of environmental efficiency depends on the improvement of technological capabilities. In addition, the MI is relatively close, but there is a phenomenon of low environmental efficiency and high MI. This is because high-polluting industries with lower environmental efficiency have greater potential for environmental improvement, and therefore, under the premise of the country’s continuous environmental policies, environmental efficiency has improved at a faster rate.In view of the obtained results, this article puts forward the following countermeasures and suggestions:Reduce energy input in high-polluting industry. From 2001 to 2015, the overall environmental efficiency of China’s heavy pollution industry did not reach 1, which means that environmental efficiency has not reached the optimal level in 15 years. In order to improve the environmental efficiency of high-polluting industry, on the one hand, the authorities should implement corresponding policies to limit energy input in various industries to reduce energy consumption and, on the other hand, increase capital and labor input in various industries. In this way, the technical level of various industries may be increased, thereby improving environmental efficiency. In particular, the Smelting and Pressing of Ferrous Metals (C31), which has low environmental efficiency, requires a lot of energy input and needs to limit the energy consumption of the industry.Reduce the volumes of the three main categories of emissions . The policymakers can formulate various rules and regulations in order to limit the emissions of different form, minimizing undesirable output. The Production and Supply of Electric Power and Heat Power (D44), the Manufacture of Paper and Paper Products (C22), and the Mining and Washing of Coal (B06) rank first in the emissions of waste gas, wastewater, and solid waste. It is necessary to increase efforts to cut down the emissions of exhaust gas, wastewater, and solid waste in these three industries.There are obvious differences in environmental efficiency between high-polluting industries, so the government can formulate different policies for different industries. According to the classification of high-pollution industries in this article, more attention should be paid to the low environmental efficiency group, and the low-efficiency group should learn from the high environmental efficiency group to enhance energy conservation and emission reduction.The annual average EFF of the high environmental efficiency group in the heavy pollution industry is less than 1, indicating that the high pollution industries in the high environmental efficiency group may have problems with production management and other aspects, which need to be resolved. The EFF and TECH of the low environmental efficiency group are lower than the average level of the high-polluting industries. The technical capabilities of these industries should be further strengthened. The government should increase capital and labor input to improve the technical capabilities of the industry.


Significant public health emergencies greatly impact the global supply chain system of production and cause severe shortages in personal protective and medical emergency supplies. Thus, rapid manufacturing, scattered distribution, high design degrees of freedom, and the advantages of the low threshold of 3D printing can play important roles in the production of emergency supplies. In order to better realize the efficient distribution of 3D printing emergency supplies, this paper studies the relationship between supply and demand of 3D printing equipment and emergency supplies produced by 3D printing technology after public health emergencies. First, we fully consider the heterogeneity of user orders, 3D printing equipment resources, and the characteristics of diverse production objectives in the context of the emergent public health environment. The multi-objective optimization model for the production of 3D printing emergency supplies, which was evaluated by multiple manufacturers and in multiple disaster sites, can maximize time and cost benefits of the 3D printing of emergency supplies. Then, an improved non-dominated sorting genetic algorithm (NSGA-II) to solve the multi-objective optimization model is developed and compared with the traditional NSGA-II algorithm analysis. It contains more than one solution in the Pareto optimal solution set. Finally, the effectiveness of 3D printing is verified by numerical simulation, and it is found that it can solve the matching problem of supply and demand of 3D printing emergency supplies in public health emergencies. In recent years, there has been a series of public health emergencies around the world, such as SARS, influenza A H1N1), Escherichia coli outbreaks in Europe, Ebola in West Africa, and COVID-19. In particular, the recent Covid-19 epidemic has basically affected the whole society, including health care, economic structure and social relationships. A global response included countries and states have instituted lockdowns, businesses closed down and some of the supplies appeared to be in a state of shortage. For instance, Personal protective equipment lacks supply capacity. As a result, this leaves both the patient and the caregiver in high-risk situations. Recently, the health and wellness sector has begun to look into how 3DP can help address global needs  occurs, due to the large area and large population affected by the disaster, the emergency supplies collected only by the above means may not be able to meet the emergency needs; thus, relevant manufacturers need to be urgently mobilized for emergency production. In order to successfully complete the emergency production task, manufacturers with a strong emergency material production capacity and close to the disaster site should be selected. If the raw material reserves of manufacturers are insufficient, suppliers with a strong raw material supply capacity and close to the manufacturers should also be selected as the manufacturers. The purpose of this paper is to build a mathematical model considering the above conditions and provide an emergency production plan and emergency material supply plan with the shortest task times and the lowest costs. Due to the complexity of the production situation in emergency situations, the following assumption are proposed:(1) The time and unit transportation costs of materials delivered by each 3D printing supplier to each affected user are known;(2) The production capacity per unit time of 3D printing manufacturers is known;(3) After all emergency supplies are produced by 3D printing manufacturers, they will transport them to the affected users.Imanufacturing tasks T1, T2, T3,Jmanufacturing service providers M1, M2.M3, Mj, the multi-objective function and constraint mathematical model are used to describe the 3D printing emergency material scheduling in public health emergencies. In this article, we assume that a print-type manufacturing service can only perform subtasks of a specific print type, and that a manufacturer can receive multiple subtasks of the same type simultaneously. ForT = {T1, T2, ⋯, Ti}, and the set of 3D printing equipment is M = {M1, M2, ⋯, Mj}. The first goal of the scheduling model for 3D-printed emergency material in public health emergencies is to minimize the cost of emergency materials. In the formula, the cost of emergency supplies is composed of the printing cost of each item of 3D printing equipment and the transportation cost in the logistics process. The transportation cost is the sum of the product of the distance between the affected user and service provider and the logistics cost factor. Its objective function is as follows:(1) We assume that there are multiple disaster-affected users with different needs for 3D printing emergency supplies at the same time. The order set of 3D printing emergency supplies is (2) The second goal of the scheduling model for 3D-printed emergency supplies in public health emergencies is to minimize the time of emergency supplies. In the formula, the time of emergency supplies is composed of the processing time of each item of 3D printing equipment and the transportation time in the logistics process. The transportation time is the sum of the distance between the affected demander and service provider and the logistics speed factor. Its objective function is:Equation (3), (4), and (5) indicate that the length, width, and height of the order task are less than or equal to the length, width and height of the 3D printing device, respectively; Equation (6) indicates that the type of the 3D printing device is the same as the required device type of the order; Equation (7) indicates that the printing accuracy of the 3D printing device is less than or equal to the accuracy required by the order; Equation (8) indicates that the order number and the 3D printing equipment number are less than or equal to the order number and the 3D printing equipment number, respectively.The NSGA-II algorithm  introducIn this paper, an improved NSGA-II algorithm is used to solve the scheduling model for 3D printing tasks. This method is improved by two aspects based on the traditional non-dominated sorting genetic algorithm.a is a random variable, because of the search scope is limited, easy to appear the problem such as local optimum and evolutionary process is not stable. In view of the deficiency of SBX operator, the normal distribution is introduced into the crossover operator SBX, That is 1.481 replaces a to expand the search space, as shown in Equation (10). In order to further enhance the spatial search capability, the discrete recombination operation of evolutionary strategy is introduced into Equation (11).The NSGA-II algorithm operating SBX operators are adopted to simulate the evolution process of binary crossover operator, individual creation way as shown in type (9), In this paper, the NDX operator is introduced into the NSGA-II algorithm. The Pareto optimal solution can be uniformly extended to the whole Pareto domain, ensuring the diversity of the population and improving the quality of the Pareto optimal solution. This algorithm is applied to 3D printing task scheduling, which not only pro-vides as many representative non-inferior solutions as possible for the 3D printing service platform but also facilitates it to make more reasonable decisions.o1and . For the i variable, the crossover process is as follows: a random number r ∈  is generatedAssuming the parent generation and the NDX is used to generate the child generation oi1, is the i th variable on the progeny chromosome; pi1, and pi2, is the i th variable on the paternal chromosome. When|N|is a normal distribution random variable.Type:1and f2are the two objective functions of the problem as showed in Zi−1, and Zi+1are all non-dominated solutions of the first layer. Then, the crowding distance of the individual is the sum of the distances between the former Zi−1and the latter Zi+1 on the two objective functions, which is a+b. In order to ignore the difference between different objective function value domains, it is also necessary to divide the difference between the extreme points in this hierarchy.Crowding distance has an important influence on the diversity of the population of the NSGA-II algorithm. Good population diversity not only enables individuals to have good uniform distribution characteristics but also keeps a certain distance between individuals. fd[Zi] of individual is calculated by Equation (12), and the distribution among individuals is evaluated based on this.From this, it can be concluded that when there are k objective functions, the crowding distance f(Zi+1)m and f(Zi−1)m are the fitness values of the Zi+1 and Zi−1 individuals to the m-th target, respectively and where m is the dimension of the target; The introduction of crowding distance can make the distribution of the optimal solution more uniform and maintain the diversity of the population. As shown in (1) If the number of individuals in the current non-dominated set is greater than the specified population number, the surplus individuals are eliminated at one time according to the crowding distance from small to large. This strategy is somewhat crude, as only one population maintenance process needs to calculate the crowding distance of individuals once. If all individuals with small crowding distance are eliminated at one time, there will be individual deletions among individuals, making the distribution of solutions poor.(2) At the same level, when point A and point B are relatively crowded, point B is eliminated according to the exclusion mechanism of the current NSGA-II algorithm, thus preserving point A. However, in the actual whole population distribution, because there are more individuals in the upper layer around A, it is not necessarily the best selection strategy to keep point A. It can be seen that the crowding mechanism based on crowding distance cannot view the density around individuals from the perspective of the whole population distribution.Zi is calculated according to the following formula:With the aim of shortening the congestion distance mentioned above, this paper proposes a diversity maintenance strategy called dynamic congestion distance. For the first deficiency, this paper adopts the following strategy: in the process of population maintenance, the remaining crowding distance in the population is recalculated for each individual eliminated. For the second deficiency, the dynamic congestion distance of individualZi adjacent to targets in all dimensions. The larger the variance, the sparser the distribution among individuals but the closer the distribution. Through the dynamic crowding distance method, individuals with small difference values are eliminated, and individuals with large difference values are retained, thus greatly improving the diversity of the algorithm population.Where The improvement of the NSGA-II algorithm is achieved with the following steps:Ti corresponds to an alternative set of 3D printing equipmentMjallowing real number coding to be adopted. The coding rules are as follows: each 3D printing emergency material Ti is numbered 1, 2, 3, etc. t; each chromosome of the genetic algorithm is composed of t genes; and each gene represents a 3D-printed emergency supply. There are m items of 3D printing equipment in the form of service providers, and t 3D printing emergency orders are allocated to m 3D printing equipment. In the process of scheduling emergency supplies, each item of 3D printing equipment can produce multiple 3D printing emergency supplies, but each 3D printing emergency supply can only be allocated to a single piece of 3D printing equipment.Step 1: In the 3D printing emergency resource scheduling, each 3D printing emergency material Mj for 3D printing emergency supplies. The encoded chromosome structure is shown in Ti and the gene value represents the 3D printing equipment produced by it as shown in The value on each gene of the initial individual is randomly generated from the alternative 3D printing equipmentn = 0.Step 2: The initial population of N individuals is randomly generated under the constraint conditions of Equations (3)–(7), and the evolutionary algebra Step 3: According to fitness functions (1) and (2), fast non-dominant sorting was conducted for all population individuals, and the crowding degree of each population individual was calculated.Pn were selected by the binary championship selection operation, crossover of NDX operators, and mutation to produce offspring Xn.Step 4: Randomly selected individuals in populationPn and Xnare merged to produce Qnand calculate the value of the objective function, and a quick non-dominant sort operation on Qnis performed.Step 5: Qn (adopting the improved crowding distance mentioned above), the optimal N individuals are formed into a new generation population Pn+1.Step 6: By calculating the crowding degree and crowding distance of individuals in The improved NSGA-II algorithm was used to solve the scheduling flow diagram of the distributed 3D printing emergency supplies, as shown in The feasibility and validity of the model and algorithm are verified by an example. The parameter settings are shown in In the context of public health emergencies in relation 3D printing equipment resources, the matching strategy is an NP-hard problem, and the true Pareto front is unknown. In order to verify that the validity of the NSGA-II algorithm had improved, using the convergence and running time of the algorithm as the evaluation standards, the results of both the new and traditional NSGA-II algorithm under the same parameters and over 10 runs each were analyzed. Using the above experimental data to compare the NSGA-II algorithms crossover probability was set at 0.9, mutation probability at 0.05, the population size at 100, and the largest iterative algebra at 500. The simulation environment was the Intel (R) Core (TM) i5-4460S, CPU@2.50GHz, RAM4GB, system, Windows 10 and Simulation platform Matlab2015a. (1) In terms of the convergence of the algorithm, it can be seen from (2) In regard to the algorithm running time, In conclusion, compared with the traditional NSGA-II algorithm, the improved NSGA-II algorithm has a slight improvement in overall performance. Usage of the optimal solution set in the improved NSGA-II algorithm is shown in In this study, combining with current public health emergencies, this paper proposes the scheduling and distribution scheme of emergency supplies produced by 3D printing technology. In terms of the model, a 3D printing production emergency material scheduling model was built to solve the resource matching problem between supply and demand and maximize the production cost and time benefit. In algorithm, orthogonal crossover strategy was applied to algorithm in the process of the cross, and introducing the adaptive hybrid mutation operator, get an improved the NSGA-II algorithm, and compared with the traditional NSGA-II algorithm, the results show that the improved algorithm has higher precision and faster convergence speed, convergence of optimization result is closer to the global optimal solution, and more effectively solve the multi-objective problem. It is proved that the improved NSGA-II algorithm can obtain better performance, which has a certain theoretical significance. We suggest that, under the background of Covid-19 epidemic, the study on supply and demand matching of 3D printing emergency supplies can solve the problem of concealment of some organizations in material distribution. Meanwhile, managers can reasonably allocate emergency supplies according to different disaster situations in each disaster area, which is of certain practical significance.This study solves the scheduling problem of 3D-printed emergency supplies in the event of public health emergencies, but the workflow of emergency supplies requirements selected by the model is static. However, the most significant impact of 3D printing on users' emergency supplies is the dynamic change in demand; Therefore, the next step will be to conduct research on 3D printing scheduling of dynamic emergency supplies for public health emergencies under the same constraint conditions as the optimization objective.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.JH came up with the topic idea selection and structured the manuscript ideas. GL designed the research plan, constructed the model, and wrote the thesis. TM analyzed the selected articles to verify their relevance for the study. TL wrote conclusion and collect data. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The analysis of the mean square displacement of the ions revealed that Li+ and Na+ ions exhibit superior diffusion behaviors within the polyelectrolyte system. The O-atoms of the charged groups bind strongly with the divalent ions (Mg2+ and Ca2+), which raises their diffusion energy barrier and consequently lowers their rate of permeation. In contrast, the monovalent ions exhibit weaker interactions, with Na+ being slightly above Li+, enabling the permeation of Li+ ions. The present study demonstrates the role of both charged groups in cation-exchange membranes in promoting the diffusion of Li+ and Na+ ions, and could serve as a guide for the design of effective membranes for the recovery of these ions from brine.Lithium-ion consumption has risen significantly in recent years due to its use in portable devices. Alternative sources of lithium, which include the recovery from brine using the sustainable and eco-friendly electrodialysis technology, has been explored. This technology, however, requires effective cation-exchange membranes that allow the selective permeation of lithium ions. In this study, we have investigated, via molecular dynamics simulations, the role of the two common charged groups, the sulfonic and the phosphoric groups, in promoting the adsorption of monovalent ions from brine comprising Li The forcefields assigned for the ions were lithium, +1 ion for Li+; sodium, +1 ion for Na+; calcium, +2 ion for Ca2+; magnesium, +2 ion for Mg2+; and chlorine, −1 ion for Cl−. The water molecules were modeled and a rigid planar simple-point charge SPC-like water model was obtained [The structural backbone of typical cation-exchange membranes generally contains fixed-charge acid groups, mainly the sulfonic, the phosphoric, or the carboxylic acid groups. The present membrane material was constructed by mixing two aromatic moieties containing the sulfonic and the phosphoric groups. Initially, the two monomers, namely, 4-ethylbenzene sulfonate , a balanced charge of chloride ions , and 500 molecules of water. The constructed simulation box was geometrically optimized using the Forcite module and the system maintained electrical neutrality, as presented in 2-H2O system.The simulation box was built using the amorphous cell module. The polyelectrolyte-metal chloride aqueous system was modeled as amorphous in a cubic cell with an edge length of 30 Å. The periodic boundary conditions are applied in the three orthogonal directions. The density of the system was set to 1.05 g/cm−4 GPa, T = 298 K) to stabilize the system with a simulation time of 500 ps and a time step of 0.001 ps. The molecules of the polyelectrolyte chain from the last frame generated from the NPT simulation were fixed using the constraints toolbar, and the cations were indicated as set. The system was subjected to the dynamics simulation under the constant volume-constant temperature (NVT) ensemble with a total simulation time of 1.5 ns, and the trace file recording was output at every 5000 steps (5 ps). The starting velocity of the atoms at a given temperature was designated randomly by the Boltzmann distribution, the summation method was atom-based, and a truncation radius of 18.5 Å was chosen for the non-bonded interaction energy. The Particle–Particle Particle–Mesh (PPPM) method of summing up the coulombic electrostatic potential energy was chosen, and the Berendsen constant temperature thermal bath and the constant pressure system was selected for temperature and pressure control. The total energy of the system under the NVT ensemble was determined to confirm the attainment of equilibrium. The total energies of the CaCl2, LiCl, NaCl, and the MgCl2 systems fluctuated around 27,000, 21,700, 21,000, and 30,000 kCal/mol, respectively, as presented in Molecular dynamics simulations were conducted using the Forcite module. The initial systems were structurally optimized using the congruent gradient, followed by a dynamics simulation on the constant pressure-constant temperature (NPT) ensemble  and ix(t) are the initial positions of the i ion and the position of the ion at time t, respectively.The diffusion properties of the ions within the polyelectrolytes were determined by estimating the mean square displacement (MSD). The MSD indicates the average separation of all particles from their corresponding initial positions at time D, was estimated following the Einstein Equation, as follows:The diffusion coefficient of the ions, t should give a slope of unity, which, when divided by six, yields the diffusion coefficient of the ions.A plot of log (MSD) vs. log x and y depict the two interacting systems, V represents the volume of the system, r the separation between them, xN and yN the number of particles of x and y, and where xyN stands for the number of similar x and y particles and xir and yjr for the 3D coordinates of x in i and y in j, respectively.The description of the counterion distribution in the vicinity of the fixed-charge groups was estimated by the pair correlation function (PCF), using the expression:xyE represents the total energy of the entire system, and xE and yE are the energies of the PE–aqueous system and the counterions, respectively.The interaction energies of the counterions towards the fixed-charge groups were estimated as follows:− ions were constructed and subjected to NVT dynamic simulation. The diffusion of the ions through the membrane were analyzed by the mean square displacement (MSD) analysis. The MSD–t curves of the polyelectrolyte–aqueous system comprising Li+, Na+, Mg2+, and Ca2+ ions are presented in + and Na+) increases linearly with time, implying the diffusion of these ions within the polyelectrolyte system. The divalent ions (Mg2+ and Ca2+), in contrast, exhibited a relatively stronger interaction with the charged groups on the polyelectrolyte promoted by their effective nuclear charges. Compared to the previous report on isolated sulfonic and phosphoric fixed-charge systems [A MD simulation was conducted to investigate the counterion migration within the polyelectrolyte membrane material. A system comprising the polyelectrolyte, 500 molecules of water, 20 cations, and charge-balanced Cl systems , the pre2O, 50 cations, and a balanced charge of Cl− ions to maintain electrical neutrality. The density of the aqueous system was set to 1.05 g/cm3 while the other simulation conditions were maintained as before. The mean square displacement as a function of time (MSD–t) curves of the NVT simulation  curve for the Li+ ions , which increased the energy barrier between them, resulting in the lowering of their diffusion characteristics. The order of interaction energies (Mg2+ > Ca2+ > Na+ > Li+) indicates the selective permeation of monovalent ions through the system.The permeability of the ions was further investigated by constructing an ensemble consisting of the polyelectrolyte chain, 500 molecules of Hd method . The int+, Na+, Mg2+, and Ca2+ ions in brine through the polyelectrolyte membrane materials containing sulfonic and phosphoric pendant groups by means of molecular dynamics simulations. It was revealed that the O-atoms of the charged groups exhibit stronger attractions for the divalent ions, resulting in a rise in the diffusion energy barrier and, consequently, lowering their diffusion through the membrane material. The analysis of the mean square displacement of the ions revealed that Li+ and Na+ ions exhibit greater values due to the weak attraction by the charged groups. In the presence of higher concentrations of Mg2+ ions, the radial distribution function of the O-Li atoms decreases, suggesting the diffusion of Li+ ions through the polyelectrolyte system. This study demonstrates the role of both the sulfonic and the phosphoric pendant groups in promoting the diffusion of monovalent ions. Our results could serve as a guide for the design of effective cation-exchange membranes for the recovery of Li+ and Na+ ions from brine.We have investigated the diffusion of Li


In this paper, we propose and validate an artificial neural network-based equalizer for the constant power 4-level pulse amplitude modulation in an optical camera communications system. We introduce new terminology to measure the quality of the communications link in terms of the number of row pixels per symbol Optical camera communication (OCC) systems, which are part of the optical wireless communications (OWC), leverage the use of off-the-shelf conventional, complementary metal-oxide-semiconductor (CMOS) image sensors (ISs) and standard light-emitting diodes (LEDs) as the receiver (Rx) and the transmitter (Tx), respectively. bR applications, such as the Internet of Things (IoT) , motion capturing Rb up to bR of 2.66 Mbps over a 20 cm long transmission link was achieved. Note, the concept of D2D is one form of the multiple-input multiple-output system, where every pixel is transmitted and detected. Similarly, to allow transmission and reception of information under bad weather conditions, a convolution neural network (CNN)-based OCC was proposed in , Pbit-symbol payload, and 3-symbol post-amble [1.5 1.5 1.5]. The schematic block diagram of the proposed OCC system is shown in Qth Tx packet at different The symbols in the overhead signal  were chosen to ensure constant average optical power when compared with the payload. The signal was then sequentially uploaded onto an arbitrary wave generator , see Texp of 2 ms was adopted in this study. The observed frames Algorithm 1 Signal Extraction AlgorithmAt the Rx, a diffuser was used to scatter the light over the capturing area of the IS (Thorlabs DCC1645C RS) with a standard Qth Tx packet per Qth Tx packet to maintain the synchronization between both the Tx and the Rx.Next, to ensure that a full packet was captured by the IS, Algorithm 2 was applied to select the optimum frame  for each Qth Tx packet and received Qth packet using a moving average filter. Note, the window size of the filter was set to Algorithm 2 Find the frame with full packet inclusion A resampling process was then applied to resize the signal length based on the packet size observed in pixels. Next, a correlation algorithm was used to maintain the synchronization between the transmitted Texp of 2 ms are highlighted in The experimental work was focused on deploying an MLP-based equalization to mitigate the ISI due to the limited modulation bandwidth of the CMOS IS-based Rx. The measured and simulated CIS for Pbit of up to 70 symbols per packet. Pbit of 5, 10, 15, 20, 50, and 70, i.e., Qth packet and the recorded Fs are 666 pixels and 13.31 kHz, respectively, based on the demodulated signal, see i) the threshold levels can be differentiated for Pbit of 5 and 20 symbols, see Pbit of 50 and 70 symbols as in see ii) the five levels are shown in the eye diagrams, where one of the levels represents the packet overhead designed to maintain the same average power for CP 4-PAM; and (iii) the overhead level is removed at the Rx side using Algorithm 1. The captured frames at the Rx are processed with An example of transmitted and received signals with and without equalizer for The eye linearity of the received signals is measured based on the average amplitude levels is given by :(15)Eye Texp of 2 ms. Note, we have used −3. Note, at the FEC limit the bR  is estimated by:Next, we measured the BER as a function of bR of 24.4 and 12.2 kbps for fR of 60, and 30 fps, respectively, can be achieved compared with the case of no equalizer with bR of 18.6, and 9.3 kbps for fR of 60, and 30 fps, respectively. The effective bR of 24.4 kbps. The quality of received signals was measured based on the eye-diagram opening, eye linearity, and the BER. We demonstrated the ability to mitigate the intersymbol interference and hence to transmit a signal with an acceptable BER (below the FEC limit) for We proposed an ANN-based equalization technique for a CP 4-PAM based OCC system. An experimental setup was developed to demonstrate non-flickering communications using a single light-emitting diode with a transmission rate of


Human epididymis protein 4 (HE4) is an ovarian cancer marker. Various cut-off values of the marker in blood are recommended, depending on the method used for its determination. An alternative biosensor for HE4 determination in blood plasma has been developed. It consists of rabbit polyclonal antibody against HE4, covalently attached to a gold chip via cysteamine linker. The biosensor is used with the non-fluidic array SPRi technique. The linear range of the analytical signal response was found to be 2–120 pM, and the biosensor can be used for the determination of the HE4 marker in the plasma of both healthy subjects and ovarian cancer patients after suitable dilution with a PBS buffer. Precision (6–10%) and recovery (101.8–103.5%) were found to be acceptable, and the LOD was equal to 2 pM. The biosensor was validated by the parallel determination of a series of plasma samples from ovarian cancer patients using the Elecsys HE4 test and the developed biosensor, with a good agreement of the results (a Pearson coefficient of 0.989). An example of the diagnostic application of the developed biosensor is given—the influence of ovarian tumor resection on the level of HE4 in blood serum. Human epididymis protein 4 (HE4), also known as recombinant WAP four disulfide core domain protein 2 (WFDC2), is used as an ovarian cancer marker. HE4 may be used as a marker of ovarian cancer alone or jointly with the other ovarian cancer marker CA 125 as a component of ROMA  ; therefoThe non-fluidic array version of the SPRi technique, already used for the determination of the ovarian marker CA 125 , and no Serous ovarian cancer samples exhibit an HE4 concentration above 150 pM, with maximal values above 850 pM . The cutHuman epididymis protein 4 (HE4) (MW of 44 kDa) , rabbit polyclonal antibody against HE4 , cysteamine hydrochloride, N-ethyl- N’-(3-dimethylaminopropyl) carbodiimide (EDC), human albumin , and N-hydroxysuccinimide (NHS)  were used. The bases of the biosensors were chips covered with a layer of gold .A complete list of materials and reagents is given in The plasma samples used for the tests came from donors from the Regional Blood Donation and Blood Treatment Center in Bialystok, as well as from patients with ovarian cancer and endometrial cyst from the Maria Sklodowska-Curie Oncology Center. All samples were provided after obtaining the consent of the Bioethical Commission.−1 was applied to the biosensor active sites and then washed several times with redistilled water before being dried under a stream of argon.In the first stage of antibody immobilization, the gold chip was covered with cysteamine linker by immersion in a 20 nM ethanolic cysteamine solution for at least 12 h; the chip was subsequently rinsed with absolute ethanol and water, and it was dried under an argon stream. The chip with cysteamine was stable over several months. Antibody immobilization was performed following the EDS/NHS protocol, as described (for example) in , with raSPRI measurements were performed as previously described ,20. A ho−1 was selected as the optimal value for further experiments.The optimization of the concentration of the rabbit polyclonal antibody against HE4 was performed at a constant HE4 concentration (114 pM). A description of these experiments is given in −1. The results are plotted in The analytical response of the developed biosensor was investigated for a range of HE4 concentrations between 2 and 1140 pM. Experiments were performed as described in Three series of experiments were performed to investigate the precision and recoveries of the developed biosensor. The selected spikes of HE4 are located at the beginning, middle, and end of the linear section of the calibration graph. Each series consisted of 24 single measurements. The obtained results are shown in The results showed that the precision and recoveries of the measurements of HE4 concentration made using the developed biosensor were acceptable and typical for such a determination. The limit of detection determined on the basis of three SD of blank was 2 pM.The specificity of the analytical response of the developed biosensor is a crucial factor, because in natural samples, the HE4 marker is present in an environment containing a huge number of other biologically active substances. Albumin and markers (cancer antigen 125 (CA 125), carcinoembryonic antigen (CEA), interleukin 6 (IL-6), aromatase, and metalloproteinase 2 (MMP 2)) were selected for these experiments. The highest excess of albumin and the CA 125 marker (1000:1) was applied because albumin is the most common protein in human blood and CA 125 is frequently used jointly with HE4 in ovarian cancer diagnosis. A constant HE4 concentration (114 pm), together with different excesses of potential interferents, was used in all tests. The results are shown in The results showed that none of the investigated potential interferents had a significant influence on the HE4 analytical signal.The validation of the developed biosensor was performed by the parallel determination of HE4 by the developed biosensor and a standard method in a series of blood serum samples from patients with ovarian cancer. The standard method was the Elecsys HE4 electrochemiluminescence performed on COBAS E-411. The results showed an acceptable correlation (a Pearson coefficient of 0.989). For a better comparison of the results of both methods, a Bland–Altman plot was made .The plot indicated the acceptable agreement of both methods. The results obtained with the developed biosensor exceeded those of the standard method by approximately 20 pM. This difference was acceptable when considering that four currently used automatic methods for HE4 determination give different results ,7. Thus,To demonstrate the diagnostic effectiveness of the developed biosensor, the HE4 concentration in the blood serum of ovarian cancer patients before and after tumor resection was investigated. Serum from seven patients was tested for HE4 concentration before resection and after 6 h, 24 h, and 5 days after resection. Average values are shown in A very fast decrease in the HE4 concentration after resection was observed, as was a much higher HE4 level in the serum of ovarian cancer patients than in healthy donors. These experiments confirmed that the developed biosensor may be a useful tool in the diagnosis of the disease.A biosensor suitable for HE4 determination in the blood plasma of both healthy subjects and ovarian cancer patients was developed. The biosensor exhibited a linearity of the analytical signal response and acceptable precision and recovery. It was validated by the parallel determination of a series of plasma samples from ovarian cancer patients using the Elecsys HE4 test and the developed biosensor, with an acceptable agreement of the results. The influence of ovarian tumor resection on the level of HE4 in the blood serum, as determined by the developed biosensor, provided examples of its diagnostic application. The developed biosensor can extend the series of previously developed biosensors used with the non-fluidic array version of the SPRi technique, including biosensors for the determination of cathepsins B, D, G, L, and S; laminin-5; fibronectin; collagen IV; proteasome 20S and immunoproteasome 20S; UCHL-1; MMP-1 and MMP-2; aromatase; podoplanin; leptin; CA 125; CEA; and cystatin C. Many of these biosensors have been used in clinical investigations. Thus, a new diagnostic tool has been added to this series. Certainly, the simple construction of biosensors in the non-fluidic array version of the SPRi technique has some limitations. To resolve more complex analytical problems such as microRNA  and anti