The suggested damage constitutive method is highly applicable, which is of great significance to the microscopic mechanical analysis of foamed light concrete and the structural design in civil engineering.Foamed lightweight concrete has been applied in different fields of civil engineering because of its superior properties, but the related research considering internal pore damage is limited. Based on statistical damage theory and considering the uneven distribution of fracture damage and strength between the pores of light concrete, a damage constitutive model of foamed lightweight concrete was established based on the Weibull function. The parameters of the damage model were determined through a triaxial compression test, and the rationality was verified by combining the existing test data. Comparative tests show that the theoretical calculation results of the proposed statistical damage model of foamed light soil are consistent with the general trend of the experimental results, reflecting the value of the peak stress and strain and describing the overall development law of the stress and strain. The best fit was obtained when the confining pressure was 0.3 MPa and the density was 700 kg·m Foamed lightweight concrete is an excellent cementitious material with the advantages of low bulk capacity, high strength, low thermal conductivity, and sound insulation and has been widely used in construction and transportation ,2,3. TheThe microstructure of concrete affects the stress distribution. Cracks will be caused between the foam voids under the action of load, which will affect the structural strength ,8. To inMany new methods are applied to the study of concrete microstructure with the development of technology. Batool and Bindiganavile  combinedThe statistical damage theory of rock and conventional concrete provides a useful reference for the analysis of lightweight concrete. Su  construcIn this study, the fracture damage and strength distribution between the pores of foam lightweight concrete are considered, and a statistical damage constitutive model of foamed lightweight concrete is established on the basis of statistical damage theory to intensively study the fracture damage evolution process of foam lightweight concrete.Foamed lightweight concrete is a lightweight cement-based material formed by preparing an aqueous solution of foaming agent into foam; mixing it with water, cement, additives, and other materials at a specific ratio; and hardening it. The preparation is shown in Foam lightweight concrete can be applied to many building structures and foundation projects in practical engineering by mixing on-site, spraying, or making prefabricated blocks. As shown in Many initial pores exist inside foam lightweight concrete, and the nature of its damage process is the damage evolution process of the compression, closure, and connectivity of internal bubble pores. Therefore, the fine structure of foam lightweight concrete can be generalized into three parts: the lightweight concrete matrix, the pores, and the fracture channels existing between pores, as shown in The notations involved in this paper are summarized in When lightweight concrete is compressed, numerous inter-pore fracture channels are generated internally and develop gradually with the increasing strain, leading to a rapid reduction in the elastic modulus of lightweight concrete. Therefore, the fracture damage variable of foam lightweight concrete can be defined as shown in Equation (1):The bubble pores inside the foam lightweight concrete are irregular and randomly distributed, while the lightweight concrete element contains many microscopic cracks and fissures, with varied strength values. The Weibull-based probability distribution function is easy to integrate, and its mean and range of values are greater than 0, which satisfies the features of foam lightweight concrete damage . Therefom0 and K0 are the Weibull parameters of the foam lightweight concrete in the lossless pore state, and m(C) and K(C) are the Weibull parameters of the foam lightweight concrete in the fracture damage state.The Weibull parameter of the foam lightweight concrete in the fracture damage state is expressed as Equation (3):fN and N are the number of micro-elements destroyed and the total number, respectively.In this study, the total damage of the foam lightweight concrete is determined as the ratio of micro-elements to the total damage items at a certain stress state, as in Equation (4):D can be obtained as in Equation (6).According to statistical damage theory , the micσ = (1 – D)σ′.In the case of axial compression, the relationship between strain and stress in the undamaged part of the lightweight concrete can be obtained according to the generalized Hooke’s law. The stress equation considering damage is organized to obtain Equation (7):The damage evolution equation for the foam lightweight concrete considering fracture damage is shown in Equation (8):c is the cohesive force of the foam lightweight concrete, and φ is the internal friction angle of the foam lightweight concrete.The Mohr–Coulomb criterion (hereafter referred to as the M-C criterion)  is introcσ, and the corresponding strain is threshold strain cε. The damage constitutive model of the foam lightweight concrete in the damage state (after the damage threshold) is shown in Equation (10):When the stress level is lower than the critical cracking stress, the fissures will not expand significantly and can be regarded as a non-damaged state. Thus, this critical stress can be described by threshold stress Combining Equations (8) and (10), the statistical damage constitutive model of foam lightweight concrete with fracture damage is proposed as Equation (11):E0, v, c, and φ in the proposed statistical damage constitutive model for foam lightweight concrete are relatively common and can be obtained based on conventional uniaxial or triaxial compression tests. The internal nominal stresses  and nominal strain (ε1) in lightweight concrete can also be obtained through compression tests. Therefore, the parameters m, and K in the damage model need to be determined.Parameters f is calculated by Equation (13):Equation (12) can be obtained from Equation (11):pσ and peak strain pε exist in the stress–strain relationship of the foam lightweight concrete. The first derivative of stress with respect to strain at this position is zero, as shown in Equation (14):During triaxial compression, peak stress m and K can be obtained by combining Equation (14), as shown in Equation (15):The computational equations for The constitutive curves for the compression deformation of foam lightweight concrete have continuous stress values at the threshold stress, and the first derivatives of stress with respect to strain remain consistent, as shown in Equations (17) and (18):Equation (19) for The related parameters have been determined in the constitutive model of statistical damage theory for foam lightweight concrete. The model can be further validated and analyzed by combining specific triaxial compression test data of lightweight concrete.Given the difficulty of detecting the internal fracture damage of foam lightweight concrete by conventional methods, the degree of damage is difficult to quantitatively describe. Therefore, the reasonableness of the proposed statistical damage model for lightweight concrete can be verified by example analysis for foam lightweight concrete under fissure-free damage conditions. To verify the proposed statistical damage theory, the existing data under different density conditions  were selThe data are substituted into the theoretical model to obtain the computational parameters of the foam lightweight concrete constitutive model under different densities. Then, the stress–strain theoretical curves are plotted and compared with the experimental results, as in The results show that the theoretical results of the damage constitutive model show an overall consistent trend with the experimental data of Yuan et al. , reflectWith the decrease of material density, the model fits better. This phenomenon may be due to the fact that in the case of smaller density, the pore structure inside the foamed lightweight soil is more significant, which leads to the material being more prone to damage. The proposed damage model takes into account the damage of the pores and the heterogeneity of the strength distribution, which can more accurately simulate the response of the material in the case of small density.−3 density at 0.1, 0.2, 0.3, and 0.4 MPa peritectic pressure were selected for analysis. The test data are shown in Triaxial compression test data  for powdThe test data show  that theThe fitting effect is poor when the confining pressure is 0.1, 0.2, and 0.4 MPa. This may be because when the confining pressure is too small, a portion of the pores are closed, and the concrete has uneven deformation. When the confining pressure is too large, more severe deformation and fracture will occur inside the material, resulting in a poor fitting effect. But, the overall pattern of change is consistent. In addition, increasing the envelope pressure within a certain range can increase the maximum stress and critical strain of lightweight concrete by analyzing the effect of various confining pressures on the relationship curves of stress and strain. This phenomenon shows that a reasonable increase in the surrounding pressure can effectively limit the development of internal fractures and, thus, improve the compressive deformation performance.E), Poisson’s ratio (ν), and internal friction force and angle . We changed the values of the studied parameters in turn and fixed all other parameters. The sensitivity of the corresponding parameters is studied by observing the curve changes at different parameter values. The benchmark values of the parameters are as follows: elastic modulus E0 = 1011 MPa, Poisson’s ratio ν0 = 0.21, internal friction force c0 = 0.7 MPa, and internal friction angle φ0 = 18°.These values correspond to the compression test with ρ = 800 kg·m−3 in i) were set to 0.8, 0.9, 1.0, 1.1, and 1.2, and the test values  of the parameters were obtained by multiplying the reference values by the coefficients, as indicated in We performed a single-factor analysis of the constructed statistical damage model for foam lightweight concrete to evaluate the influence of each factor on the predictive effect of stress–strain relationships. The main damage parameters involved include elastic modulus of the material  can improve the fit of the simulated curve to the actual stress–strain curve.The comparison results show that the change in a single parameter has a minimal effect on damage factors We analyzed the internal pore damage mechanism of foam lightweight concrete and proposed a damage constitutive model considering microstructural fragmentation based on the statistical damage theory. The influence of each parameter on the predicted values was analyzed with relevant triaxial test data. The following detailed conclusions can be extracted from this study:A damage constitutive model of foamed lightweight concrete on the basis of statistical damage theory is proposed, fully considering the strength heterogeneity caused by the micro-pore damage of foamed lightweight concrete under external load.The key parameters of the damage model were deduced by combining the Weibull function and the M-C criterion, and the rationality of the damage constitutive model was determined.−3. The model is sensitive to the friction angle and cohesion, and the optimal correction coefficient is 1.1.The triaxial compression test data verify that the damage constitutive method can fit the stress–strain curve of the foamed lightweight concrete under external load well, and the best results are obtained when the confining pressure is 0.3 MPa and the density is 700 kg·mAlthough the selected density and confining pressure are widely used in different types of structures and engineering, there will be more structural and load conditions in actual engineering. Therefore, future research can verify the accuracy and applicability of the model through data from more projects.Due to the equipment limitation, theoretical analysis is mainly used. It is a significant expansion direction to consider the fracture channel in combination with CT scanning technology.Despite the ideal results of the study, the following deficiencies remain:


Geosite Inventory of Catalonia, but it does not have any special protection yet, despite decades of efforts to claim the need for protection and conservation in front of the constant deterioration and loss of outcrops due to strong urban and touristic pressure. A project of restoration, access improvement, and dissemination of geological values was finally executed between 2020 and 2021. The Roses case study leads us to the remark that urban and periurban geosites offer a good opportunity for promoting geological research, education, and tourism, provided its protection based on geoconservation criteria and a strong sustainable conservation management plan.The coastal cliffs around the Roses Lighthouse  display deformation structures generated during the emplacement of a syntectonic granodiorite and associated rocks (quartzdiorite enclaves and leucocratic dykes). These rocks were subjected to shearing and spectacular shear zones are present, which have been object of several scientific publications. The outcrops are considered of international high scientific value, being regularly visited by researchers and students from several European universities. In 2005, the site was included in the  The high anthropogenic pressure of these spaces in terms of urbanization and human impact  which has been recently restored after decades of gradual degradation due to urban pressure.The outcrops are located in the southwestern coast of the Cap de Creus massif (northern Costa Brava and easternmost end of the Pyrenean Range) along a narrow rocky coastal fringe in the periurban area of Roses Fig. . The sitAt the first stages of emplacement, when the granodiorite was still partially molten, a rather homogeneous magmatic foliation developed because of coeval deformation and magmatic flow. Such foliation is defined by the preferred orientation of feldspar and biotite crystals. At this stage, quartzdiorite enclaves became elongated sub-parallel to the foliation Fig. a.Ongoing deformation at high-temperature solid state allowed the emplacement and solidification of residual magmas along fractures in the form of dykes and veins of aplite and pegmatite Fig. b.At lower temperature conditions (when the pluton was completely solidified), deformation progressively localized, giving rise to a network of predominantly sinistral and minor dextral ductile shear zones. Spectacular exposures of cm- to decametric-sized shear zones and associated mylonitic rocks are present , includes the first shear zones and associated mylonitic rocks that were recognized in Catalonia in the early 1970s. In 1979, an International Conference on Shear Zones in Rocks took place in Barcelona and Cap de Creus, attended by specialists from all over the world. In the early 1980s, visitors (geology students and researchers) and publications , outcrops were clean and did not present invasive vegetation or debris.Despite the worldwide recognition acquired by the geosite and the evidences of progressive deterioration due to increasing urban pressure, legislation and conservation policies based on the protection of “natural elements” lead to the exclusion of the Roses Lighthouse site from the Cap de Creus Natural Park designated in 1998 as a protected area , which is subjected to restrictions on private use and building.The elegant outcrops at Roses show more features idealised in “textbook” shear zones than any others I have seen in Scotland, the Alps or elsewhere .I have no doubt that the loss of this area would be a great disaster for science. This area should be preserved and protected for international science .The magnificent shear zones observable on the coast of Roses are at risk of becoming inaccessible to observation in the very short term; some have already disappeared due to excessive urbanization .The exceptional exposures display the best exposed and most accessible examples of ductile shear zones that I have encountered in my nearly 30 years of field research and excursions. For geologists, nothing can replace actually visiting classic localities and observing the rocks and structures first-hand .Researchers who had visited the area became concerned of the dangers and agreed that recovering these outcrops was an obligation. Here are some comments from geoscientists regarding the geological relevance of the Roses outcrops and the need for their protection:Carpobrotus edulis, see Fig. However, urbanization of the area proceeded, and a coastal pathway was built in the early 2000s, causing partial hiding of some relevant exposures due to the accumulation of gravel and the growth of invasive plants . They are made of a wood-covered steel structure built on the slope next to the outcrops whose access was formerly very difficult.Facilitate accessibility from the road and coastal pathway and a viewpoint, for which a walkway consisting of a staircase and a platform were designed and constructed , which is part of the Roses cultural heritage signaling project carried out by the Roses City Council. A more specialized, larger itinerary  is attempted with the purpose of highlighting whether the pursued goals have been achieved and which issues should be improved through further management actions.Multiple methods have been proposed in the last decades for the quantitative or semiquantitative assessment of geosite values and conservation Brilha . A majorScientific, educational, and touristic values have experienced a significant increase after recovering some outcrop exposures, improving access and visibility conditions and implementing the dissemination project. There are still a few big boulders laying on top of some outcrops which should be removed.The value of on-site and website geological information has switched from almost non-existent to conform a notable geotourism resource, which can still be improved if such information is supplied in several languages.As for the accessibility criteria, we distinguish between outer and inner accessibility. Outer accessibility refers to how to arrive to a given geosite , while inner accessibility is referred to on-site, “touch the rock” chances  and a regular maintenance plan to avoid endangerment and deterioration.Further recover of outcrop exposures by removal of boulders and also further improvement of inner accessibility and dissemination materials.Creation of a specific figure of legal protection which should be based on geconservation and historical-cultural criteria, independent of the degree of anthropization and not subjected to naturality or aesthetic beauty restrictions. Scientific, educational and tourist use of the geosite should also be properly regulated.Design and implementation of a strong sustainable conservation management plan in order to ensure a balance between tourist/leisure developments and geoconservation needs, preventing deterioration due to high visitor concurrence.The Roses Lighthouse geosite is a paradigm of a periurban locality with valuable geological outcrops  which suffered transformation into a strongly degraded site due to natural processes and urban pressure (decades of 1990–2010). It has been recently (2021) partially restored with geoconservation criteria, after an effective cooperation between professionals and academics of geology and landscape architecture. The results were an important improvement in outcrop access and visibility and dissemination of their scientific and educational values to the general public throughout on-site and website information. However, we consider that these actions, performed with limited financial resources, are insufficient. The following actions are needed to guarantee the full conservation and sustainability of the site:We believe that the issues emerged from this case study can be extrapolated to other geosites located in periurban areas or to similar contexts where anthropization prevails.


In this paper, the shear horizontal (SH) wave scattering by a circular pipeline in an inhomogeneous concrete with density variation is studied. A model of inhomogeneous concrete with density variation in the form of a polynomial-exponential coupling function is established. By using the complex function method and conformal transformation, the incident and scattering wave field of SH wave in concrete are obtained, and the analytic expression of dynamic stress concentration factor (DSCF) around the circular pipeline is given. The results show that the inhomogeneous density parameters, the wave number of the incident wave and the angle of the incident wave in concrete are important factors affecting the distribution of dynamic stress around the circular pipe in concrete with inhomogeneous density. The research results can provide a theoretical reference and a basis for analyzing the influence of circular pipeline on elastic wave propagation in an inhomogeneous concrete with density variation. In recent years, there has been significant interest in studying the propagation of elastic waves in solids, as it is crucial for understanding wave propagation mechanisms in engineering applications such as non-destructive testing of structures and the use of new materials ,5,6,7,8.In practical engineering structures, the uneven density of concrete can significantly impact the mechanical properties of materials and structures. For example, Lu and Liu  analyzedμ is considered to be a constant value of μ0. The density of the concrete is expressed as a polynomial and exponential coupling function, which changes with x and y in two directions simultaneously and continuously. This problem model is shown in A is the polynomial structure of x and y, the expression of function B is the exponential form.The density of concrete will change in the actual engineering structure . In addiSince the numerical value of the density of the concrete should exist and be real, neither the inhomogeneous parameters k is given by the following formula:Then, the expression of wave number R, and the center of the circular pipeline coincides with the coordinate origin O. The density inhomogeneous parameter x-axis. Based on the symmetry of density in the concrete, the incident SH wave is assumed to incident horizontally along the x-axis. When The scattering field model is shown in x and y.In the Cartesian coordinate system, the wave equation in the concrete with inhomogeneous density is given by the following equation:Based on the complex function theory, a set of complex variables, To solve wave Equation (5), we need to introduce a new set of variables By introducing a new set of variables, the Helmholtz equation with variable coefficients can be transformed into the standard one, allowing for the easy derivation of analytic solutions for displacement and stress fields using the separation of variables method. The standard form of the Helmholtz equation is expressed as:The propagation direction of the incident wave is horizontal and the incident angle is 0°. In the nth order.In addition, a circular pipeline exists in an infinite inhomogeneous concrete, and the scattering waves In the concrete, the displacement field should be the superposition of incident waves and scattering waves displacement, so the displacement fields in the concrete with inhomogeneous density can be expressed as:r, z are the cylindrical coordinates.In the complex plane, the expression of hoop stresses and radial stresses in the concrete with inhomogeneous density is given by the following equation,By introducing variables By substituting the displacement of incident waves and scattering waves into Equations (15) and (16), the stresses field in the infinite inhomogeneous concrete in the According to the relationship between the infinite concrete and the circular pipeline, it can be determined that the stress freedom should be satisfied on the boundary of the circular pipeline. Therefore, the radial stresses should be zero on this boundary (According to Equation (21), the radial stresses expressions of the incident and scattered waves are substituted into Equation (19), and the following expressions can be obtained,To solve the unknown coefficient Then the dynamic stress concentration factor around the circular pipeline in the concrete can be obtained, which is given by the following formula,After establishing the scattering model of elastic waves by circular pipeline in the infinite inhomogeneous concrete, the DSCFs around the circular pipeline can be obtained when SH waves propagate in the horizontal direction. The distribution and variation rule of the DSCFs around the circular pipeline are analyzed and discussed. The dimensionless variables used in the analysis are reference wave number x-axis, and SH waves are also positively incident along the x-axis, the distribution of the DSCFs around the circular pipeline is also symmetric. When the reference wave numbers To analyze the impact of different values of inhomogeneous parameters on DSCF, the values of inhomogeneous parameters adopted in this paper were based on the selected variables in the study of reference . The valBy comparing the results of the DSCFs around the circular pipeline in the radial and linear terms of the density given by Jiang , the disThe values of DSCFs under different reference wave numbers In the discussion of the influence of reference wave number The distribution of DSCFs around the circular pipeline with The distribution of DSCF around a circular pipeline is shown in The results of the values of DSCF at positions In In It can be observed in In In (1)When the density inhomogeneous parameters (2)When the value of (3)At 30° of the circular pipeline, with the dimensionless parameter increasing, the DSCF values at this position will have an obvious oscillation phenomenon. At this position, when In this paper, the scattering of SH waves by circular pipeline in inhomogeneous concrete with polynomial-exponential coupling density distribution is studied based on the method of complex variable function. The analytical solution of dynamic stress concentration around circular pipeline is derived under this type of concrete with density variation. This paper discusses the effect of different dimensionless parameters on the distribution of DSCF around the circular pipeline. It provides a theoretical reference and a basis for analyzing the influence of defects on wave propagation in an inhomogeneous concrete with density variation. The specific conclusions are as follows:The conformal transformation method used in this paper requires a high level of expression for the non-uniformity of concrete density, which is not yet achievable in reality. Although the inhomogeneous concrete model we presented does not exist in reality, we hope that in the future, the changing form and structural model of concrete density we proposed can be applied to concrete materials, and our research method can be applied to the elastic dynamic research of other inhomogeneous concrete forms.


The postoperative burden remains significant due to the possibility of prolonged hospitalization, escalated healthcare costs, and patient distress caused by postorthopedic surgical site infections (SSIs). Orthopedic surgery is likewise faced with a significant challenge posed by these conditions. A positive association has been observed between the presence of postorthopedic SSIs and heightened susceptibility to adverse health outcomes, along with elevated rates of morbidity and mortality. Systemic antibiotic prophylaxis (SAP) reduces the risk of acquiring an SSI. Closed fractures, open fractures, arthroplasty, and percutaneous fixation each possess distinct attributes that impact the data and antimicrobial therapy. When implementing SAP, it is crucial to strike a delicate equilibrium between maintaining effective antibiotic stewardship protocols and preventing the occurrence of SSIs. This practice effectively prevents both the incidence of negative consequences and the emergence of antibiotic resistance. The objective of this study was to examine the existing literature on the use of surgical antibiotic prophylaxis in orthopedic surgery and explore the potential consequences associated with the inappropriate administration of antibiotics. In the realm of modern medicine, orthopedic surgery is a testament to the extraordinary breakthroughs that have been made in enhancing the well-being of a large number of people . OrthopeWhile orthopedic surgery has intrinsic good qualities, it is important to carefully evaluate potential negative effects. The emergence of SSIs, which can lead to extended hospital stays, heightened healthcare costs, patient distress, and, in some cases, significant morbidity ,4, is a Antibiotic prophylaxis is an intentional practice of administering antibiotics prior to surgical treatments, with the aim of mitigating the risk of infection, particularly at the surgical site . This meThis comprehensive study aims to give a comprehensive review of antibiotic prophylaxis in the context of orthopedic surgery. This crucial component of perioperative care is the focus of this research, and its purpose is to undertake a complete review of the current body of information, evaluate recent advancements, and give insights into the numerous complicated aspects that impact this essential aspect of perioperative care. We are about to begin an in-depth investigation of the use of antibiotic prophylaxis in the context of orthopedic surgery. Meanwhile, we would like to extend an invitation to readers to investigate the existing body of research, ongoing debates, and emerging tendencies in this field. The shared goal of enhancing the safety and efficacy of orthopedic therapies is what motivates this pursuit of excellence.Reasons for the need of antibiotic prophylaxis in orthopedic surgeryAntibiotic prophylaxis, often known as prophylactic antibiotics, is the practice of giving antibiotics to patients before a medical operation or other potentially infectious occurrences -15. AntiAntibiotic Precautions in Typical CasesIt is occasionally advised to take antibiotics before surgery to lower the risk of SSIs. The likelihood of bacterial infection is particularly high following abdominal procedures, knee replacements, and heart valve replacements . In addiFactors to Think AboutIsolated antibiotics: When choosing antibiotics for prophylactic measures, it is important to take into account the bacterial strains that are most likely to be present during the treatment or event in question. This helps ensure that the appropriate medication is administered. Antibiotics that are capable of killing particular germs are what are going to be used . ProphylThe moment: Time will tell how things turn out. The drug is typically given right before surgery -20 so thImportance of SSI Prevention The reduction of the risk of SSIs in the medical field is essential for a variety of reasons -5.Patient well-being and safety: The health and safety of the patient is the first priority. In extreme circumstances, SSI can result in considerable difficulties, including extended hospital stays, higher expenditures associated with medical treatment, and even death . PuttingReduced costs of healthcare: The treatment for SSI can be expensive. When they are avoided, patients and the healthcare system are relieved of the additional financial load that they cause . This maDecreased lengths of stay in hospital: SSI usually leads to increased lengths of stay in the hospital, which can cause major disruptions in a patient's life and raise the risk of various issues linked with healthcare . The redThe predominant approach for managing SSIs entails the administration of antibiotics. However, it is important to note that excessive or inappropriate utilization of antibiotics might contribute to the emergence of antimicrobial-resistant bacteria. The issue of antibiotic resistance is a global concern, and one potential strategy to address this problem is to decrease the frequency of antibiotic usage for the treatment of infections occurring at surgical sites.Increases in reliability and confidence: Healthcare facilities that can avoid SSIs on a continuous basis earn a reputation for delivering excellent treatment . PatientConsidering the law and our values: It is the ethical and moral responsibility of those who work in the healthcare industry to offer treatment that is both safe and effective . If propInvestigation and experimentation: It is important to prevent SSIs because doing so encourages research and development in the healthcare industry, which in turn leads to advancements in surgical procedures, infection control, and the development of new technology and products that are intended to prevent SSIs -9.Concerning the public: The effects of SSI can be felt on the public's health -14. InfeIn conclusion, the prevention of SSIs is critical for the health of patients, the continued economic sustainability of healthcare systems, and the overall improvement of the quality of healthcare. This involves maintaining proper cleanliness, adhering strictly to infection control policies, providing appropriate preoperative and postoperative care, and ensuring that medical workers get ongoing education and training.Current guidelines and recommendationsThese recommendations aim to reduce the incidence of SSIs by recommending the use of antibiotics both before and after orthopedic procedures. Given that policies may be susceptible to change over time, it is important to review these organizations' most current changes. We'll go through a summary of the ground rules for a few illustrious professional organizations in the sections that follow.American Academy of Orthopedic SurgeonsThe guidelines for antibiotic prophylaxis in orthopedic surgery are provided by the American Academy of Orthopedic Surgeons (AAOS). They highlighted how important it is to provide prophylactic antibiotics one hour before making the incision for the surgical procedure. The type of surgery being performed, the prevalent bacterial resistance patterns in the area, and any known patient sensitivities all factor into the decision of which antibiotics to prescribe. Cefazolin and vancomycin are two antibiotics that are frequently used when specific conditions are present. In most cases, prophylaxis is given no later than 24 hours following surgery, unless there are exceptional conditions that require it to be given earlier .Infectious Diseases Society of AmericaIn the context of surgical procedures, especially orthopedic operations, the Infectious Diseases Society of America (IDSA) provides guidelines for the use of antibiotic prophylaxis. The recommendations take into account a number of different criteria, among which include the particular surgical operation, the patient's medical history, and regional trends in bacterial resistance. Cefazolin is the antibiotic of choice for the majority of surgical procedures involving the musculoskeletal system .Surgical Care Improvement Project The Surgical Care Improvement Project (SCIP) is a national project that aims to reduce postoperative complications such as SSIs. It details the regimen and choice of antibiotics that should be used during surgical operations, including orthopedics. The SCIP suggests that prophylactic antibiotics be given either within two hours after the surgical incision in the case of vancomycin and fluoroquinolones or within one hour in the case of other antibiotics. The selection of antibiotics must be appropriate for the surgical treatment, and the duration of prophylaxis should not go beyond 24 hours .Centers for Disease Control and Prevention The Centers for Disease Control and Prevention (CDC) provides guidelines for reducing the risk of SSIs across a range of medical settings and procedures. Although these recommendations do not focus on orthopedic surgery in particular, the advice they offer for avoiding infections is invaluable. Recommendations about the appropriate time of prophylactic antibiotics and factors to consider before stopping antibiotic treatment after surgical procedures are among the most important .It is critical to keep in mind that these recommendations might be revised in light of newly discovered information and altered patterns of antibiotic resistance. In addition, exact suggestions may change depending not just on the kind of orthopedic operation being performed but also on the unique qualities of the patient.Discussion of recommended antibiotics and their dosages on antibiotic prophylaxis in orthopedic surgeryAntibiotic prophylaxis is crucial in reducing the risk of infection during orthopedic surgery. The type of procedure to be performed, the patient's individual circumstances, and the regional incidence of antibiotic resistance should all be considered when deciding which antibiotics to use and how much to deliver. Careful administration of antibiotics is required not just to prevent superbug infections but also to lessen the likelihood of antibiotic resistance and adverse consequences.List of Popular Antibiotics and Their Dosages for Various Orthopedic SurgeriesStaphylococcus aureus, one of the germs most likely to be responsible for SSIs, is well defended against by this substance. The typical dosage consisted of a single dose of 1-2 g given by intravenous administration within 30 minutes following the surgical incision. If the surgery is going to take a long time, you might want to give the patient an extra dosage every four hours.Cefazolin: Cefazolin  is the aClindamycin: Clindamycin  is an exStaphylococcus aureus (MRSA) or those who are at high risk for MRSA should not take vancomycin [Vancomycin: Those with known or suspected infections caused by methicillin-resistant ncomycin . In mostAminoglycosides like gentamicin: Cefazolin may be used with aminoglycosides like gentamicin in some surgical procedures, such as total joint arthroplasty . In mostCefuroxime: This medication may be used for patients undergoing operations that impact the lower extremities or for situations in which more gram-negative coverage is necessary . The norCiprofloxacin: Ciprofloxacin may be used in certain situations, such as when there is a high risk of infection with gram-negative germs . When thPrior to starting the surgical incision, it is essential to highlight the quick delivery of prophylactic antibiotics. Antibiotic concentrations in tissue at the moment of incision are most effective if they are administered at the optimal time ,31. AntiGuidance and recommendations may vary depending on criteria such as the nature of the orthopedic procedure being performed, the patient's individual risk factors, and the prevalence of antibiotic resistance in the area. As a result, orthopedic surgeons should consult infectious disease specialists for guidance or follow the guidelines established by their institutions to guarantee that the antibiotics selected and doses administered are suitable for each patient.Importance of timing and duration of antibiotic prophylaxis in orthopedic surgery Antibiotic prophylaxis, namely its timing and duration, is crucial in avoiding SSIs. Antibiotic prophylaxis is when antibiotics are given to a patient before surgery in order to protect them from getting an infection . AntibioTiming of Preoperative EventsAntibiotics have to be given to the patient before the incision is made during surgery, ideally within 30-60 minutes. This scheduling guarantees that a suitable concentration of the medicine will be present in the bloodstream throughout the surgical process. If antibiotics are administered too early, this might result in medication levels that are less than ideal during surgery; nevertheless, if they are administered too late, this could result in inadequate protection -35.Intraoperative DosingIt may be necessary to administer extra antibiotic doses in order to maintain effective medication levels after some orthopedic operations, particularly those that last for an extended period of time or involve a considerable amount of blood loss. These intraoperative dosages must be administered in a way that considers both the antibiotic's pharmacokinetics and the length of the procedure .Postsurgical DosingIf the operation takes a long time or there is a significant possibility of infection, a postoperative dosage can be required. On the other hand, postoperative supplementation is not suggested following the majority of orthopedic surgeries. Extended prophylaxis is typically discouraged as a practice since doing so can lead to unnecessary antibiotic exposure as well as the development of antibiotic resistance .The DurationFollowing surgical procedures, antibiotic prophylaxis is often administered for a short period of time, typically no longer than 24 hours. It is possible that the probability of developing an illness that is resistant to antibiotics may increase if preventive antibiotics are used for a lengthy period of time. In certain circumstances, such as when the patient is undergoing joint replacement surgery, the prophylaxis period may be prolonged for an extra 24 to 48 hours depending on the precise recommendations that are being followed and the risk factors that are associated with the patient ,36.Patient Risk FactorsThere are a variety of patient-specific characteristics that might influence the antibiotics used, the administration schedule, and the length of treatment. Prophylaxis may need to be administered for a longer period of time to patients who are at a higher risk, such as those who have diabetes, obesity, or a weaker immune system -37.Guidelines and Recommended MethodsThe recommendations and best practices for antibiotic prophylaxis are often developed by surgical societies and infectious disease experts. Orthopedic surgeons are required to adhere to these guidelines and best practices. These guidelines, which are based on the most recent available information, have been developed with the intention of improving patient outcomes while simultaneously reducing the likelihood of antibiotic resistance -26.The timing and duration of antibiotic prophylaxis are two of the most critical variables in lowering the incidence of SSIs following orthopedic surgery. During surgery, antibiotics must be timed for optimal therapeutic levels. On the other hand, reducing the length of time that antibiotic prophylaxis is taken can help lower the risk of antibiotic resistance. When deciding whether to start taking antibiotics and for how long, orthopedic surgeons and other healthcare practitioners need to stick to the established recommendations and take the patient's unique circumstances into account -37.Effectiveness of antibiotic prophylaxisProphylactic Antibiotics Have Been Shown to Be Useful in the Prevention of Orthopedic Surgery InfectionsIn orthopedic surgery, the use of prophylactic antibiotics is crucial for preventing SSIs. These infections may result in severe repercussions, such as a failure of an implant, a protracted hospital stay, and greater medical costs. In this article, we examine the strong body of evidence supporting the value of antibiotic prophylaxis in orthopedic surgery .Solid Historical StatisticsThe use of antibiotics as a prophylactic measure during surgical operations extends back decades. There has been a discernible drop in the number of SSIs as a direct consequence of the use of preventive antibiotic regimens in orthopedic surgeries, as indicated by historical data -21. ThesInstructions and RecommendationsNumerous organizations, including the AAOS, the CDC, and the WHO, have advocated for the use of prophylactic antibiotics prior to orthopedic surgery -24. The Reduction of SSIs: Prophylactic antibiotics have been shown to reduce the incidence of SSIs after orthopedic surgery in a number of clinical trials and observational studies. A meta-analysis conducted by Classen et al.  indicateEconomic efficiency: Antibiotics used as a preventative measure have been proven to be cost-effective, in addition to the clinical advantages they provide ,37. SSIsClinical outcomes: To improve a patient's overall quality of life is the overarching goal of orthopedic surgery ,38. The Antibiotic resistance considerations: Even though the benefits of using antibiotics for preventative purposes are obvious, antibiotic stewardship is still very important -34,37-38According to the conclusion, the data that supports the usefulness of prophylactic antibiotics in orthopedic surgery is substantial and persuasive. Antibiotic prophylaxis has been proven, time and time again, to minimize the occurrence of SSIs, improve patient outcomes, and save healthcare costs. It is crucial that healthcare practitioners continue to adhere to established guidelines and practices responsible for antibiotic stewardship in order to guarantee the continuous efficacy of these interventions in orthopedic surgery. These recommendations and practices were developed to reduce the risk of antibiotic resistance.Studies Showing a Reduction in SSIs With Antibiotic Prophylaxis in Orthopedic SurgeryAntibiotic prophylaxis' effect on postoperative infections in orthopedic surgery was studied by Classen et al. in the New England Journal of Medicine . The stuDespite the fact that these studies showed that antibiotic prophylaxis can effectively reduce SSIs during orthopedic surgery, it is important to remember that prophylaxis effectiveness can vary depending on a variety of factors, including the kind of antibiotic used, when it is administered, the patient's characteristics, and how strictly infection control procedures are followed. Clinical standards and practices might alter over time, so it's critical to evaluate the most recent research and recommendations to get the most up-to-date information possible.Discussion of the impact on surgical outcomes with regard to antibiotic prophylaxis usageAntibiotic prophylaxis -38 has bThe Antibiotics Selection Antibiotics used for prophylaxis must be chosen with great caution -40. It nWhen to Administer It and How to Do ItIt is of the utmost importance to provide antibiotics at the most appropriate moment. In most cases, antibiotics have to be provided a short while before surgical incisions in order to guarantee that therapeutic doses are available in the tissues at the time that potential bacterial exposure takes place. The "golden hour" technique is absolutely necessary in order to achieve the highest possible level of preventative effectiveness .The Length of Time In most cases, prophylactic antibiotics should be stopped within 24 hours following surgery -37,42. TFactors of Potential Harm and the Selection of Patients In some surgical procedures, the use of antibiotic prophylaxis is not required . EvaluatEfficiency in Terms of Costs Antibiotic prophylaxis may result in a rise in short-term healthcare costs as a result of drug expenses; however, it typically results in a reduction in long-term healthcare costs by lowering the incidence of SSIs, which are known to lead to longer hospital stays and further operations .In conclusion, antibiotic prophylaxis is an essential component of modern surgical practice since it considerably lowers the risk of SSIs, which is common and can lead to major complications after surgical procedures. However, it must be utilized prudently, with great attention given to the time of antibiotic administration, patient variables, and the antibiotic choice. Maintaining a healthy equilibrium between the advantages of infection prevention and the hazards of antibiotic resistance is a task that never goes away. Therefore, healthcare practitioners need to keep up with the latest research and guidelines in order to optimize the benefits of surgical procedures while simultaneously reducing any collateral damage.Controversies and challengesExplanation of Antibiotic Resistance and Its ImplicationsResistance to antibiotics, drugs used to kill or slow the growth of bacteria and other microorganisms, is known as antibiotic resistance . It's coMechanisms Underlying Antimicrobial ResistanceMutation: Bacteria have the ability to produce mutations in their genetic material that allow them to survive after being exposed to antibiotics ,47.Transfer of genes between different species: Bacteria are able to acquire resistance genes from other bacteria, even those of different species, through the processes of conjugation, transformation, and transduction .Efflux pumps: Bacteria have the ability to get rid of antibiotics before they have the chance to do their job. Antibiotics may become useless because certain microbes develop enzymes that counteract their effects ,50.Consequences for Orthopedic SurgeryAntibiotics are routinely given in a preventative manner prior to orthopedic surgery in order to ward against the development of postoperative infections -54. HoweMitigation and PreventionStewardship of antibiotics: Orthopedic surgeons and healthcare facilities should adhere to antibiotic stewardship programs in order to guarantee the proper use of antibiotics and to limit the risk of antibiotic resistance ,56.Containment of infections: In hospital operating rooms and other settings, as well as elsewhere in the healthcare industry, strict infection control procedures can help prevent the development of antibiotic-resistant bacteria as well as their dissemination. Patients must be made aware of the necessity of finishing the courses of antibiotic treatment that they have been prescribed in order to forestall the development of antibiotic resistance . For a sIn conclusion, orthopedic surgery and other areas of medicine are growing more concerned about the development of antibiotic resistance. This can result in postoperative infections that are more difficult to treat, increased healthcare expenses, and consequences that might possibly be deadly. Antibiotic resistance may be prevented and addressed via the employment of a multidimensional approach that includes responsible antibiotic use, infection control measures, and continuing research and development of novel medicines. This approach is necessary to assure the sustained effectiveness of orthopedic procedures and the safety of patients.Discussion of potential risks associated with antibiotic prophylaxis and strategies to minimizeAntibiotic prophylaxis, often known as the use of antibiotics, to protect against infection, is a standard procedure in the medical field. It is utilized in a number of settings, such as right before dental or surgical treatments, as well as in specific medical problems ,59. AntiPotential DangersAntibiotic resistance: The formation of bacteria that are resistant to antibiotic treatment can be caused by the inappropriate or excessive use of antibiotics. Microbes can acquire resistance to antibiotics when they are supplied when it is not necessary to do so, which makes it more difficult to treat illnesses in the future ,61. AntiDisturbing the balance of the microbiome: Antibiotics have the potential to upset the delicate bacterial equilibrium that exists inside the body, which can result in gastrointestinal distress, fungal infections (such as candidiasis), and even possible long-term health problems due to the alteration of the microbiome. Infections that are resistant to antibiotics are also known as "superinfections" -65. AntiStrategies for Minimizing DangersProphylactic antibiotic treatment should only be used when it provides more advantages than it poses a threat. When determining the likelihood of infection for each individual patient, it is important to consider all possible mitigation strategies, including improved sanitation and other preventative steps .Antibiotics with a limited spectrum are optimal: Antibiotics with a narrow spectrum are optimal because they target the specific bacteria that are most likely to cause an illness . This haEffectiveness and recommended dosage: It is imperative that antibiotics be provided at the proper dose and for the shortest amount of time that is practicable -71. It iReporting and surveillance: Healthcare institutions should set up reporting and surveillance systems to monitor antibiotic utilization and trends of resistance ,71. ThesJustification of antibiotic prophylaxis in orthopedic surgeryAntibiotic prophylaxis is warranted in orthopedic treatments for a variety of reasons, the most important of which are to preserve the safety of the patient and to improve the outcomes of the surgical procedure. The most important ones are as follows: Lessening the possibility of contracting an infection: During orthopedic treatments, it is possible for foreign items such as screws or joint prostheses to be placed in the patient. If the disease spreads, these implants might constitute a breeding ground for germs. Antibiotic prophylaxis reduces the number of germs present during surgery, which in turn reduces the likelihood that the surgical site will get infected. When left untreated, SSI can result in serious complications such as deep tissue infections, the formation of abscesses, and even sepsis in the worst-case scenarios. In extreme cases, the effects of these factors may lead to an extended stay in the hospital, further surgical procedures, a lifelong impairment, or even death. Antibiotic prophylaxis is a preventative measure that is used to avoid the potentially disastrous repercussions of the infection. Improving postoperative recovery infections can make the recovery process take longer, can slow wound healing, and can make pain worse. Antibiotic prophylaxis can help patients return to normal activities following surgery more quickly by reducing their risk of contracting infections.Savings on Medical ExpensesThe treatment of SSIs can be expensive since it often involves lengthy hospital stays, additional operations, and the need for long-term antibiotic treatments. Antibiotic prophylaxis, on the other hand, is an inexpensive choice since it has the potential to cut the total cost of orthopedic surgeries by a substantial amount.Normative Phrases Taking ObservationGuidelines have been produced promoting antibiotic prophylaxis in certain orthopedic procedures by a number of healthcare organizations and regulatory authorities, including the WHO and the CDC. The professionals in the healthcare industry adhere to these principles in order to provide their patients with the highest possible level of care.Antibiotic Resistance PreventionEven in cases when surgery requires the administration of antibiotics, a strategy known as single-dose prophylaxis can help lower the probability that bacteria will develop resistance to antibiotics. The emergence of antibiotic-resistant bacteria is a significant threat to the general population since antibiotics can be misused or overused, both of which contribute to the problem. Antibiotics for prophylaxis could be chosen for a patient depending on the particular needs of that patient as well as any known allergies or sensitivities that the patient might have. This customization lessens the likelihood of patients experiencing adverse effects while also ensuring that they receive the required preventative care. As a consequence of this, antibiotic prophylaxis in orthopedic surgery is a tried-and-true strategy that aims to prevent SSIs, minimize complications, improve patient outcomes, and save costs associated with medical care. It is an essential component of the surgical care that is provided today, and the implementation of it is guided by guidelines that are based on evidence.Antibiotic prophylaxis, in conclusion, plays an essential part in the prevention of infections in a number of medical contexts; nevertheless, it must be provided with discretion and care in order to be effective. Antibiotic prophylaxis necessitates the utilization of a multifaceted strategy including not only patients but also healthcare practitioners and institutions, with a significant focus on antibiotic stewardship and infection control measures. This is necessary in order to reduce the potential adverse effects of antibiotic prophylaxis.


The search for new sources of high-quality non-crystalline silica as a construction material for high-performance concrete has attracted the interest of researchers for several decades. Numerous investigations have shown that highly reactive silica can be produced from rice husk, an agricultural waste that is abundantly available in the world. Among others, the production of rice husk ash (RHA) by chemical washing with hydrochloric acid prior to the controlled combustion process has been reported to provide higher reactivity because such a process removes alkali metal impurities from RHA and provides an amorphous structure with higher surface area. This paper presents an experimental work in which a highly reactive rice husk ash (TRHA) is prepared and evaluated as a replacement for Portland cement in high-performance concretes. The performance of RHA and TRHA was compared with that of conventional silica fume (SF). Experimental results showed that the increase in compressive strength of concrete with TRHA was clearly observed at all ages, generally higher than 20% of the strength obtained with the control concrete. The increase in flexural strength was even more significant, showing that concrete with RHA, TRHA and SF increased by 20%, 46%, and 36%, respectively. Some synergistic effect was observed when polyethylene–polypropylene fiber was used for concrete with TRHA and SF. The chloride ion penetration results also indicated that the use of TRHA had similar performance compared to that of SF. Based on the results of statistical analysis, the performance of TRHA is found to be identical to that of SF. The use of TRHA should be further promoted considering the economic and environmental impact that will be achieved by utilizing agricultural waste. High-performance concrete (HPC) can be defined as a type of concrete that can overcome limitations that cannot always be achieved with conventional materials and normal mixing, placing, and curing practices alone ,2. This 2 emissions from the cement industry [HPC could be produced from Portland cement alone or from a combination of cement and mineral admixtures, which are used to improve the properties of concrete in both the fresh and hardened states . By replindustry ,14,15,16industry ,17. The industry ,20,21,22Pozzolanic materials, for example, have a double effect when combined with Portland cement: they exert a chemical reaction in the cement paste and a filling action that causes the closure of pores and voids ,23,24,25Silica fume  is one of the most active pozzolanic materials and one of the most widely used admixtures in high-performance concretes ,28,29. WRice husk ash (RHA), obtained from the controlled burning and grinding of rice husks, a by-product of an agricultural process, is classified as another highly reactive pozzolanic material  that canAcid washing of rice hulls removes a high percentage of impurities that contribute to the crystallization of silica . AccordiIt should be noted that RHA is an organic waste source with reactive silica that is abundantly available worldwide and could be used as a cementitious admixture with superior pozzolanic properties than silica fume (SF) for the development and application of HPC. Well-manufactured RHA can be an ideal alternative to SF, as SF can be several times more expensive than RHA due to the critical shortage of SF. However, the importance of RHA as a reactive pozzolanic material has not been emphasized as much as SF and metakaolin, and therefore there are much fewer studies reported in the literature. A direct evaluation of the performance of cementitious composites between RHA with and without acid washing, as well as a comparison of the performance of RHA with SF, has not been well documented.To address this need, this paper presents the evaluation of the effect of two RHA, one thermally treated and the other chemically and thermally treated, on the mechanical and durability properties of high-performance concrete mixes, comparing the results with those obtained in mixes containing SF at the same replacement levels. In the experimental phase, high-performance concrete mixes were designed and prepared to evaluate their compressive strength, modulus of elasticity, flexural strength, flexural toughness, and durability properties. Some cement pastes were also prepared to determine the hydration products and understand their effect on the final properties of the concrete.A commercial type V Portland cement (PC), compatible with ASTM type I Portland cement , without2/Kg, whereas RHA had 24,000 m2/Kg. This extremely high specific surface area could be due to an internal pore network originally derived from the rice husk. Other researchers [Previous tests  showed tearchers  have fouDue to the high specific surface area of the RHA and SF, it was necessary to use a superplasticizer. In this study, a polycarboxylate-based superplasticizer was used. Municipal drinking water was used for all concrete mixes.3.Polymeric fibers were added to the fiber-reinforced concretes to evaluate their mechanical properties. For this purpose, commercial polymeric fibers were used, whose commercial brand is STRUX 90/40, and whose specifications, provided by the manufacturer , are shoTo evaluate the effect of mineral additions on Portland cement hydration processes, cementitious pastes were prepared with the two RHAs and SF. The mineralogical composition and microstructure of the products formed during these hydration processes were evaluated using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The cementitious pastes contained percentages of 0% (control) and 10% of each of the mineral additions as partial replacements for Portland cement. All pastes were prepared with a water/cementitious materials ratio of 0.45 and the mixing and curing procedures were carried out according to ASTM C 305 . The pro3 and a water content of 198 L per cubic meter. Two sets of concrete mixes were evaluated, one set of plain concrete mixes and one set of mixes reinforced with polymer fibers. All concrete mixes were produced using the same parameters as specified in Concrete mixes containing RHA, TRHA, and SF were designed and produced following a previous study ,49. RHA,The concrete was mixed in a laboratory tilting drum mixer for a total of nine minutes. The mixing procedure was in accordance with ASTM C192 . ImmediaThe mechanical performance of the hardened concrete was tested according to ASTM standards. Compressive strength was determined using 100 × 200 mm cylinders according to ASTM C39  at 28, 5It can be observed in A statistical analysis of the results was performed with Tukey’s post-ANOVA test to compare the means of the mixtures of the pore diameter variable. It was found, with a 5% significance level (95% confidence level), that the TRHA and SF pastes presented a smaller average pore diameter and a higher porosity compared to the data of the control paste; these results are similar to those presented by Poon et al. , who useSimilarly, the high superplasticizer requirements of the RHA mixes, although lower than those of the treated ash mixes, are higher than those of the silica fume mixes. During the preparation of the mixes with RHA and SF, there were no problems of rapid loss of slump, as occurred in the mixes with TRHA. All the fiber-reinforced mixes, with and without admixtures, had higher water requirements than the plain concrete mixes. According to previous studies ,64, the The results of the compressive strength tests are shown graphically in The maximum value of the compressive strength of the unreinforced concrete was 58 MPa for the mix with TRHA at 180 days, whereas the maximum strength for the SF mix was 57 MPa at the same curing age. These results with SF are comparable to those reported previously ,64,65,66Although the increase in compressive strength of the mixes with TRHA is not statistically significant compared to the SF mixes, it can be said that this chemically treated ash could be a substitute for SF as a supplementary cementitious material to obtain concretes with better performance than normal mixes. These results show the high reactivity of the TRHA, especially in the early stages of hardening, which can be observed in Statistical analysis of the data obtained was performed using the Tukey test to compare the means of the mixtures. It was found that the means within each group were statistically similar at the 5% level of significance. It can be observed that the samples with TRHA were the group with the highest compressive strengths. It was also observed that the fiber-reinforced TRHA sample was statistically equal to the mixture with SF and that the mixtures with RHA were statistically equal to the control mixtures. This gives an indication of how these additions can act as a replacement for both SF and Portland cement, respectively.The modulus of elasticity of the concrete mixes was calculated according to ASTM C469 . The tesThe statistical analysis of the variable modulus of elasticity, the results of Tukey’s multiple comparison tests with a significance level of 0.05, showed that the mixes with TRHA produced the highest strength performance among all the mixes, especially when compared to the control mix. It was also found that the results obtained between the mixes with TRHA and SF are comparable, which means that the addition of SF can be replaced by the addition of TRHA. The statistical analysis also shows that the control and RHA blends are statistically similar, so it is possible to state that the replacement of this addition by PC does not have any negative consequences, on the contrary, the effect on the modulus of elasticity is positive, representing an increase in its magnitude. As for the effect of the addition of fibers on the results of the modulus of elasticity, it can be observed that they do not play a significant role in the values of this property, since the increase in the modulus of elasticity does not make the samples statistically different from the plain concrete mixes.Comparing the flexural strength results of the control mixes with those of the fiber reinforced concretes, the combined effect of the pozzolanic admixtures and polypropylene fibers on flexural strength becomes significant. The increases in flexural strength were 28% for the RHA mix, 41% for the SF mix, and 50% for the TRHA mix, so it can be said that there was a good interaction between the fibers and the admixtures.Tukey’s statistical test for multiple comparisons shows, at a 5% level of significance, that the highest performance in flexural strength is presented by the fiber-reinforced mixes with TRHA and SF, respectively, and in third place by the unreinforced concrete mix added with TRHA. As in the modulus of elasticity test, the control and RHA samples are statistically similar, as well as the samples with TRHA and SF. As mentioned above, the fracture toughness analysis of both plain and fiber-reinforced concrete beams was performed according to the methodology described in ASTM C 1018 . This stThe values of the toughness indices are indicative of the elastic behavior of the material; thus, results of 5, 10, 20, 30, and 60 for the toughness indices I5, I10, I20, I30, and I60 represent a linear elastic evolution of the material before the appearance of the first crack and a pseudoplastic development after this appearance. Similarly, values close to 2 for the ratios I10/I5, I20/I10, I60/I30, and 1.5 for the ratio I30/I20 also indicate a perfectly plastic behavior of the material between the deflections associated with these ratios; values lower than these indicate a lower behavior of the material. In the case of unreinforced concretes, the results of all the toughness indices are equal to 1, due to the total absence of the load-bearing capacity of the material.The values corresponding to the toughness indices of the concrete beams with SF were higher than those of all the mixtures with pozzolanic materials, although they were close to those obtained for the concrete with RHA, and the highest values were found in the control mixtures without admixtures. The relationships between the toughness indices do not indicate a response close to an elastoplastic behavior of the added materials, partly due to the low effectiveness of the reinforcing fibers, which did not allow large deflections of the material due to their smooth texture, their low modulus of elasticity and their low percentage content.The unreinforced and reinforced concrete mixes were tested for the following durability properties after 56 days of curing: resistance to chloride penetration, ASTM C1202 , and conThe results of the chloride penetration resistance test are shown in 2 content, and %HR: 65–70%. After 56 days, the specimens were cut in half and the carbonation depth was determined by spraying a fine mist of an aqueous solution of 1% phenolphthalein in 70% ethyl alcohol, used as a pH indicator, on the broken surface of the specimens [Samples with a diameter of 75 mm and a height of 150 mm were subjected to accelerated carbonation; the samples were placed in a storage room at 29 °C, 3% COpecimens . The carpecimens , who expIn this work, experimental work was planned to investigate the effect of a highly reactive RHA and SF on the mechanical and durability performance of high-performance concretes. According to our work, although the addition of SF, RHA, and TRHA led to a significant reduction in the workability of fresh mixes, the incorporation of these pozzolanic materials increased the compressive and flexural strength as well as the modulus of elasticity of concrete. For compressive strength, the TRHA showed the highest strength at all curing ages. At 28 days, the strength was about 17% higher than the control mix, 12.3% higher than concrete with the RHA, and 3% higher than concrete with the SF; at 180 days. No statistical differences were found when comparing the results between the TRHA and SF mixes, and the increase was 10% and 12% with respect to the RHA and control mixes, respectively. In general, the performance of TRHA was identical to that of SF , but the performance of RHA was not as superior to that of TRHA.The effect of the incorporation of SF and TRHA on the flexural strength of concrete mixes is similar to the effect on the compressive strength. In plain concretes the incorporation of RHA increased flexural strength by 20% over the control mix, whereas SF and TRHA increased strength by 36 and 46%, respectively. The combined effect of the pozzolanic admixtures and the polypropylene fibers on the flexural strength of the control concrete is of the order of 28% for the mix with RHA, 41% for the mix with SF, and 50% for the mix with TRHA. All these experimental results indicate that there is a good synergetic interaction between the polymeric fibers and SF, RHA, and TRHA.2 content in concrete by the pozzolanic reaction. However, unlike the case of RHA, TRHA has a higher surface area than RHA with less crystallization due to the leaching of K+ from the rice husk structure during the acid washing process. Such a difference caused TRHA to provide more sites for Ca(OH)2 to react with, resulting in a higher efficiency to refine pore structure, reduce porosity, reduce Ca(OH)2 content, and increase the amount of C-S-H in the concrete matrix. Due to such beneficial effects, concrete with TRHA showed the lowest chloride ion penetration, which is identical to that with SF.It should be noted that incorporation of the RHA into the pastes and concretes would reduce the porosity and Ca(OH)2 during growth . The authors strongly believe that the use of TRHA can be an ideal alternative to SF when the method to reduce the amount of acid waste is developed.It is concluded that the performance of TRHA as a pozzolanic material is identical to that of SF. As noted earlier, the price of SF is one of the most expensive materials to produce concrete, so the use of RHA should be more facilitated considering the economic benefits as well as the standpoint of agricultural waste disposal. Burning the husk is not an environmental issue because rice absorbs COTHRA is a highly reactive pozzolanic material that, when added to concrete mixes, produces superior results in both strength and durability.The pozzolanic reactions that occur with the incorporation of RHA in cementitious mixtures generate denser hydration products (CSH gel) that eliminate most of the capillary porosity, causing the formation of finer pores, resulting in a refinement of the porous network of the material, reducing its permeability and increasing its strength and durability properties.The increase in compressive strength of the mixes with TRHA is more pronounced at short ages, with values higher than 20% of the strength obtained with the control mix. This high initial reactivity is due to the high specific surface area and the higher purity of silica in the ash. At higher ages, the increase in strength is comparable to that caused by SF, with percentage values 12% higher than the strength of the control mix.The incorporation of RHA increased flexural strength even more significantly. The flexural strength of concrete with RHA, TRHA, and SF increased by 20%, 46%, and 36%, respectively.The incorporation of polyethylene–polypropylene fibers into the HPC mixtures does not significantly affect the values of compressive strength and modulus of elasticity of the concrete mixtures. However, for the flexural strength, it increases up to 50% for the mixture with TRHA compared to the strength of plain concrete and is of the order of 28% for the mixture with RHA and 41% for the mixture with SF.The results of the chloride ion penetration and carbonation test were negatively affected by the addition of polyethylene–polypropylene fibers due to the higher porosity in the interface between polymeric fiber and cement paste.Despite TRHA is a material with pozzolanic properties that is identical to SF, it is necessary to perform further research to demonstrate its effectiveness under different environmental conditions. Such activity is important because this agricultural waste is abundantly available in several countries of the planet.According to the experimental results obtained from this work, the following conclusions can be drawn:


To allow the identification of IgG4-related disease (IgG4-RD) from a subclinical phase as it is important to understand the risk of elevated serum IgG4 levels. We planned to evaluate serum IgG4 levels in the participants of the Nagasaki Islands Study (NaIS), a large-scale health checkup cohort study.This study included 3,240 individuals who participated in the NaIS between 2016 and 2018 and consented to participate in the study. Serum IgG4, IgG, and IgE levels and human leukocyte antigen (HLA) genotyping results of the NaIS subjects as well as lifestyle habits and peripheral blood test results were analyzed. The magnetic bead panel assay (MBA) and the standard nephelometry immunoassay (NIA) were used to measure serum IgG4 levels. The data were evaluated using multivariate analysis to identify lifestyle and genetic factors associated with elevated serum IgG4 levels.Serum IgG4 levels measured with the NIA and MBA showed a tight positive correlation between the two groups (correlation coefficient 0.942). The median age of the participants in the NaIS was 69 years [63–77]. The median serum IgG4 level was 30.2 mg/dL [IQR 12.5–59.8]. Overall, 1019 (32.1%) patients had a history of smoking. When the subjects were stratified into three groups based on the smoking intensity (pack-year), the serum IgG4 level was significantly higher among those with a higher smoking intensity. Accordingly, the multivariate analysis identified a significant relationship between smoking status and serum IgG4 elevation.In this study, smoking was identified as a lifestyle factor correlating positively with elevated serum IgG4 levels. IgG4-RDHLA)-DRB1 region as an IgG4-RD susceptibility locus and has shown significant associations of IgG4-RD manifestation with DRB1*04:06, DRB1*09:01, and DQB1*03:03. In these alleles, the disease risk increases (odds ratio [OR] 2.01) when the 7th amino acid residue of the antigen-presenting Gβ domain of the HLA-DRB1 protein (DRB1-GB-7) is valine. In addition to HLA-DRB1*04:06, HLA-DRB1*04:03, HLA-DRB1*04:05, and HLA-DRB1*04:10 can pose disease risk when the DRB1-GB-7 amino acid residue is valine. While several clinical studies on IgG4-RD have been reported, few studies analyzing the lifestyle factors and genetic predispositions associated with serum IgG4 levels and their elevation in healthy people have been reported. No large-scale analyses or genetic predisposition analyses have been performed in this field. Small-scale studies have shown higher serum IgG4 levels in men and elderly subjects (IgG4-RD is classified and diagnosed according to the American College of Rheumatology/European League Against Rheumatism classification criteria for IgG4-RD  and the subjects  A study subjects . ExploriMultiple methods are available for measuring IgG4 levels. The nephelometry immunoassay (NIA) is the predominantly used method, but it requires approximately 0.5 mL each of serum samples. A large-scale cohort is often used for multiple research purposes. The NaIS cohort, which was used in this study, is also a multipurpose large-scale cohort, and only a limited volume of serum sample is available for a single test. Meanwhile, the magnetic bead panel assay  requires 2 µl each of serum samples  for quantitative IgG4 measurement; however, the MBA has not been evaluated with human serum samples. Hence, in this study, we compared serum IgG4 measurements with the NIA and MBA to validate the use of the latter for estimating IgG4 in human serum samples. Based on the result, we measured serum IgG4 levels in the multipurpose, large-scale NaIS cohort and attempted to identify lifestyle and genetic factors associated with elevated serum IgG4 levels in healthy adults.22.1We conducted a community-based prospective cohort study [the Nagasaki Island Study (NaIS)] involving annual medical health checkups in Goto City, Nagasaki Prefecture, in the western part of Japan . This la® MAP Human Isotyping Magnetic Bead Panel kit  using 947 samples collected from participants in Ishikawa Prefecture resident health checkups conducted by Kanazawa University . We assessed the correlation between serum IgG4 measurements with the two methods and calculated the MBA-based serum IgG4 level corresponding to the cutoff value in the NIA . Of the 3,623 samples, 383 samples was excluded due to lack of serum samples for measuring serum IgG4 levels. Subsequently, serum IgG4 levels in 3240 NaIS samples  were measured with the MBA. According to the protocol, the MBA measurement was repeated at a higher sample dilution, as appropriate, when the median fluorescence value of a sample was equal to or greater than the median fluorescence value at the highest concentration used for the calibration curve. Similarly, the MBA measurement was repeated at a lower dilution, as appropriate, when the median fluorescence value of a sample was equal to or smaller than the limit of detection. An elevated serum IgG4 level was defined as an MBA-based serum IgG4 level higher than the cutoff value in the NIA . Nevertheless, 74 samples were excluded from the analysis because HLA genotyping did not yield accurate values. Finally, we utilized 3,166 samples for this project.The MBA was used to measure the IgG4 levels in serum samples from the large-scale NaIS cohort. Prior to this assay, we compared the serum IgG4 levels measured with the NIA-based IgG subclass BS-NIA IgG4 kit  and the MBA-based MILLIPLEX® Human Immunoglobulin IgE Single Plex Magnetic Bead Kit , respectively, according to the measurement protocols. All assays were performed at our laboratory according to the respective manufacturer’s instructions.Among the NaIS samples, serum total IgG and IgE levels were also measured with the MBA for 200 samples in the elevated serum IgG4 group and 300 samples selected from the normal serum IgG4 group using Monte Carlo simulation with the assumption of uniform distribution. The total IgG and IgE levels were measured with the Bio-Plex Pro Human IgG Total Isotyping Assay  and MilliplexHLA genotypes were analyzed by the Center for Genomic Medicine, Graduate School of Medicine, Kyoto University .Nagasaki Prefecture, particularly Goto City, in which the participants of our cohort reside, is a highly endemic region for human T-cell leukemia virus type 1 (HTLV-1). There are at least 5–10 million HTLV-1-infected people in the world, including approximately 1 million infected people in Japan . In Goto2.22. Of the blood test parameters, uric acid, serum creatinine, estimated glomerular filtration rate (eGFR), and low-density lipoprotein-cholesterol values were evaluated in this study.In this study, we evaluated the lifestyle and metabolic factors according to a previously reported Spanish cohort study . In brieDRB1*03:01,*04:06, *04:03, *04:05, *04:10 and *15:01 were considered as disease susceptibility genes and DRB1*09:01 and DQB1*03:03 considered as disease prevention genes, and their associations with the serum IgG4-positive status were examined.Based on the findings of Terao et al.  and Kone2.3® Pro 16.0.0 was used for all analyses. Spearman’s rank correlation test was used to compare the measurements with the NIA and those with the MBA. The MBA-based measurement corresponding to the NIA-based cutoff value (135 mg/dL) was determined to maximize Youden’s J statistic on the receiver operating characteristic curve(ROC). The MBA-based cutoff value were used to determine the sensitivity and specificity. Wilcoxon’s rank sum test was used to determine the associations of the serum IgG4 levels with the clinical items that were continuous variables and the smoking intensity. Pearson’s chi-square test was used to determine the associations of the serum IgG4 levels with the clinical items that were binary variables. Statistical significance was defined as p < 0.05. The items for which p-values were <0.05 in the univariate analysis, except for pack-years, were used in the multivariate logistic regression analysis. The significance threshold for HLA susceptibility alleles was considered significant for all statistical testing. The significance threshold for HLA susceptibility alleles was set using the Bonferroni correction at p = 8.3 × 10–3, because six HLA alleles were compared.JMP33.1Serum IgG4 levels in 951 serum samples from Kanazawa University were measured with the NIA and MBA. Subject demographics were as follows: 439 men (46.2%); 512 women (53.8%); and median age, 62 (interquartile range [IQR] 54–69) years. The correlation of serum IgG4 levels between the NIA group and the MBA group showed a very tight positive correlation  and 1,998 were women (63.1%). The median serum IgG4 level was 30.4 mg/dL [IQR 12.6–59.9]. Serum IgG4 levels <146.4 mg/dL (≈NIA IgG4 <135 mg/dL) and ≥146.4 mg/dL (≈NIA IgG4 ≥135 mg/dL) were classified as the normal IgG4 group and the elevated IgG4 group, respectively. Correlations between MBA-based IgG4 levels and different items, such as lifestyle habits, patient background factors, comorbidities, and HLA alleles, were compared between the normal IgG4 group (IgG4 levels < 146.4 mg/dL) and the elevated IgG4 group (IgG4 levels ≥ 146.4 mg/dL) Table 1.HLA-DRB1*03:01,*04:06, *04:03, *04:05, *04:10, *15:01), or resistance genes . The multivariate analysis conducted with clinical items showing significant differences in the univariate analysis, except for the smoking intensity (pack-years), revealed a significant association between the smoking status and serum IgG4 elevation OR 1.63, 95% confidence interval [CI] 1.09–2.45, p < 0.05, The univariate analysis of IgG4 levels revealed that the elevated IgG4 group was characterized by statistically significantly greater proportions accounted for by men and smokers (p < 0.001) and statistically significantly higher smoking intensity, uric acid level, and serum creatinine level. The elevated serum IgG4 levels were not associated with anti-HTLV-1 antibodies, previously reported IgG4-RD susceptibility genes . A previous study has reported that patients with IgG4-RD were 1.8 times more likely to be smokers than those without IgG4-RD  . MoreoveIn the Spanish study , there wHLA  and resistance genes  identified in the genome-wide comprehensive analysis but found no associations with serum IgG4 elevation ; Kanazawa, Japan). The patients/participants provided their written informed consent to participate in this study.YT involved in data analysis, interpretation of data, drafting. MaT involved in conception, data acquisition, data analysis, interpretation of data, revising. TK involved in data analysis, interpretation of data, revising. AK involved in conception, interpretation of data, revising. FN, KN, S-YK, HF, MK, HN, HY, KaA, KiA and TM involved in data acquisition, interpretation of data. MeT, SK and FM involved in data acquisition, data analysis, interpretation of data. All authors contributed to the article and approved the submitted version.