Z-axis of the printout. The sample compressive strength of 24–43 MPa decreased to 8–19 MPa after the fire resistance tests as a result of moisture evaporation, weight loss, thermal deformation, and crack development. Importantly, the residual compressive strength of the hybrid samples was 1.5- to 2- fold higher than the concrete samples. Therefore, it can be concluded that the addition of geopolymer to the concrete improved the fire resistance of the samples.In recent years, 3D concrete printing technology has been developing dynamically. Intensive research is still being carried out on the composition of the materials dedicated to innovative 3D printing solutions. Here, for the first time, concrete-geopolymer hybrids produced with 3D printing technology and dedicated environmentally friendly building construction are presented. The concrete-geopolymer hybrids consisting of 95% concrete and 5% geopolymer based on fly ash or metakaolin were compared to standard concrete. Moreover, 3D printed samples were compared with the samples of the same composition but prepared by the conventional method of casting into molds. The phase composition, water leachability, compressive, and flexural strength in the parallel and perpendicular directions to the printing direction, and fire resistance followed by compressive strength were evaluated. Concrete-geopolymer hybrids were shown to contain a lower content of hazardous compounds in leaches than concrete samples. The concentration of toxic metals did not exceed the limit values indicated in the Council Decision 2003/33/EC; therefore, the materials were classified as environmentally neutral. The different forms of Si/Al in fly ash and metakaolin resulted in the various potentials for geopolymerization processes, and finally influenced the densification of the hybrids and the potential for immobilization of toxic elements. Although the compressive strength of concrete was approximately 40% higher for cast samples than for 3D printed ones, for the hybrids, the trend was the opposite. The addition of fly ash to concrete resulted in a 20% higher compressive strength compared to an analogous hybrid containing the addition of metakaolin. The compressive strength was 7–10% higher provided the samples were tested in the parallel direction to the  Nowadays, concrete is one of the most commonly used substances all over the world, second only to water . OrdinarDespite its easy accessibility , relativ2, and can reduce the usage of natural resources and the carbon footprint as compared to OPC [2/Al2O3 ratio [An attractive and more sustainable alternative to OPC is a geopolymer, an inorganic polymer produced by the alkaline activation of silicon-aluminum raw materials, such as red mud, fly ash, metakaolin, slag, rice husk, and glass waste. This reaction is called the polymerization process. Geopolymer production requires lower energy consumption, generates less COd to OPC . The intd to OPC ,19,20,21d to OPC ,23, incld to OPC , curing d to OPC ,26, liqud to OPC , type ofd to OPC ,29, mix d to OPC , SiO2/AlO3 ratio ,32,reinfO3 ratio ,34, and O3 ratio ,36.4 and AlO4 tetrahedrons, cross-linked by bridging oxygen. The alkali cations  fill the cavities in these networks, balancing the negative charge of Al3+ [According to their classification ,37,38, g of Al3+ . However of Al3+ .Additive Manufacturing (AM), commonly known as 3D printing, is a process that enables the production of three-dimensional elements from various materials on small and large scales ,45. The The 3D printing of concrete has become increasingly popular in the construction industry as well as in the research community ,58. NumeWater-leaching tests, mineralogical and mechanical analysis, and fire resistance tests were performed. The 3D printed samples were compared with samples of the same composition that were prepared by the conventional method of casting into molds. Moreover, the effects of printing directions on the mechanical properties of the samples were investigated.In this study, OPC, fly ash, metakaolin, and fine aggregate river sand were used as the starting raw materials.Górażdże Cement S.A.  supplied the commercial cement CEM I 42.5 for this study. The cement used meets the requirement of PN-EN 197-1. The quartz sand was purchased from a local supplier . Fly ash was supplied from the Skawina CHP plant . Based on the chemical composition , the flyFly ash or metakaolin was mixed with sand (1:1) in the GEOLAB cement mortar mixer for 3 min . Alkaline activators were prepared 24 h before geopolymer production. The mixture of alkaline activators consisted of 10 M sodium hydroxide and an aqueous solution of sodium silicate  in a ratio of 2.5:1. The mixture was kept at ambient temperature. Then, the alkaline activator was added to the raw materials. The solid to liquid ratio was 0.25 in geopolymers that contained fly ash; and 0.35 in the case of geopolymers based on metakaolin. The components were mixed for 15 min at a speed of approximately 100 rpm.The cement and sand were mixed with a 1:1 ratio. The liquid to solid ratio was 0.125.To prepare the concrete-geopolymer hybrids, the geopolymer and the concrete mixture were prepared separately. Then, both components were mixed for 15 min at a speed of approximately 100 rpm. The obtained blends were formed by means of a 3D printing or casting method. The compositions of the produced samples are shown in For the casting method, the blend was filled into the mold, and rigorous shaking was applied to evenly distribute the blend throughout the mold. Samples were subsequently cured for 24 h at 75 °C and after demolding, the specimens were kept for ambient curing.−1. Layers of 30 mm thickness were printed with a print head diameter of 15 mm.In the case of the 3D printing method, the geometry of the sample was designed in the open-source and free 3D computer graphics Blender software. Samples were printed using the ATMAT Galaxy  3D printer. The quantity of material mixture used in the printing process was 50 kg. The printing speed was 150 mm sThe mineralogical investigation and the Rietveld quantitative phase analysis of the concrete and concrete-geopolymer hybrids based on fly ash and metakaolin were determined using X-ray diffraction (XRD). The X-ray diffraction patterns were recorded on a PANalytical Aeris  diffractometer in the scan range from 10° to 80° 2θ using Cu-Kα radiation, with a step size of 0.003° (2θ) and a time per step of 340 s. The High Score Plus software  and the ICDD  crystallographic database were used to identify the XRD diffractograms.− and SO42− was measured with ion chromatography, whereas the content of Hg was measured with the Cold Vapor Atomic Absorption (CVAA) spectroscopy. The concentrations of Zn, Cd, Cu, Pb, Ni, Ba, Cr, As, Se, Mo, and Sb were measured via Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The content of the total dissolved solids (TDS) was analyzed with the gravimetric method and the dissolved organic carbon (DOC) was examined by Fourier Transform Infrared Spectroscopy (FTIR).The leaching test was carried out in accordance with the 12457-4:2006 standard. The pH of solutions was determined by potentiometry. The concentration of the ClFlexural strength tests were performed via a three-point bend test using the concrete press MATEST 3000 kN  in accordance with the PN-EN 12390-5:2019 standard. The dimensions of the specimens were 50 mm × 50 mm × 200 mm, and the tests were carried out in the perpendicular and parallel directions relative to the print direction in the same way as for the compression test after 28 days of curing. Measurements for each of the analyzed material variants were performed with at least three repetitions.The compressive strength test of geopolymers was conducted using the concrete press MATEST 3000 kN  in accordance with the PN-EN 12390-3:2019 standard. The measurements were carried out on cubic samples 50 mm × 50 mm × 50 mm after 28 days of curing. Moreover, for 3D printed samples, the tests were carried out in two different directions, as shown in Fire-proof resistance testing was carried out based on the PN-EN ISO 1182:2020 standard. The dried samples were set into the preheated electric laboratory oven at 750 °C for a 30 min soaking time. The specimens were cooled down to environmental temperature inside the furnace afterward. The mass loss of the examined samples was measured by weighing the specimens before and after the investigation using a Radwag PS 200/2000R2  balance . MeasureThe weight loss for each sample was determined according to the following equation:Moreover, compressive testing was performed on the samples after the fire resistance test. Measurements for each of the analyzed materials variants were performed with at least three repetitions.2, ref. code: 01-089-8938), alite , calcite , C-S-H in the form of rosenhahnite , and ettringite (Ca6Al2(SO4)3(OH)12·26H2O, ref. code: 04-013-3691).The qualitative results of XRD  and thei2O3 content in the FA than in the cement; the partial replacement of cement with FA could lead to a reduction in the SO3/Al2O3 ratio in the mixture. The formation of ettringite generally promotes the densification of the concrete [In all samples, the major peaks with the highest intensity were related to quartz; they were found at approximately 25–28° and 68°. The peak at 68° corresponded to alite. The quantitative analysis of the tested samples showed that the quartz content was higher in the samples prepared from hybrid materials. Particularly, quartz content was the highest in the 95% C + 5% FA sample. The different forms of Si/Al suggested the various potentials for geopolymerization processes. The crystalline quartz phase, due to the aluminosilicate compounds, can improve the physical and mechanical properties of geopolymers. Partially replacing the cement with fly ash reduced the clinker phase, i.e., alite. A similar effect was observed in the studies of Jain et al. . Burduhoconcrete ,66 and iconcrete .Comparing the XRD patterns shown in 2S), and tricalcium silicate (C3S) hydration reactions that form portlandite can be also considered.The major physico-chemical characteristics of the leachates of concrete and concrete-geopolymer hybrids are presented in 3 was observed. Dissolved organic carbon is also a parameter important when evaluating the effectiveness of the geopolymerization process. The addition of geopolymers to the concrete reduced the concentration of DOC. In the 95% C + 5% FA sample, the DOC content was found at the level of 5.76 mg/dm3. The 95% C + 5% MK sample has the lowest DOC value of 4.76 mg/dm3. Although the obtained DOC values were common, thus confirming that FA and MK were suitable raw materials for high-efficiency geopolymerization, it is worth noting that the residual carbon in materials can result from an inefficient coal combustion process  in the power plant. Generally, the residual carbon can absorb water and chemical admixtures, resulting in a changed air–void system in the material. It can negatively affect the production of building materials and reduce their frost resistance [The total dissolved substances decreased in the following order: concrete-geopolymer hybrids based on fly ash (95% C + 5% FA) > metakaolin (95% C + 5% MK) > concrete (100% C). Analysis revealed the presence of low values of chlorides, fluorides, and sulfates; all of which were most abundant in the concrete. Potentially toxic elements such as Zn, Cu, Pb, Ba, and Cr were present; however, the concentrations of all toxic metals in the tested materials were below the limit values for inert waste in landfills according to Council Decision 2003/33/EC . The remsistance .Z-axis of the printout.Samples prepared by the conventional method were analyzed in the direction perpendicular to the casting, while, samples prepared with 3D printing technology were analyzed in both directions, i.e., parallel and perpendicular to the Among the tested samples, a higher flexural strength was recorded for concrete (100% C) when compared to cement with geopolymer additions (95% C + 5% FA and 95% C + 5% MK) . Within Z-axis of the printout (Z-axis of the printout. It was due to the compression effect of the bottom layer exerted by the gravitational force of the top layers during printing. Therefore, the compaction effect of the bottom area of the 3D printed sample was better. This increased the load capacity of the bottom layer, which resulted in a higher flexural strength [The flexural strength of the 3D printed samples showed anisotropy depending on the direction of sample loading in the parallel or perpendicular direction to the printout . The 3D printout . For thistrength .Z-axis of the printout. Particularly, in the case of 95% C + 5% FA printed samples, anisotropic behavior was clearly visible. According to the research conducted by other authors, concrete has a better mean compressive strength in the perpendicular direction compared to the parallel direction [The results of compressive strength for the samples produced by means of the two methods and under different loading directions for 3D printed samples are presented in irection . Howeverfl in accordance with the PN-EN ISO 1182:2020 standard.It is well known that concrete structures must provide sufficient fire resistance. The key problems of this building material, however, are cracking and the loss of mechanical strength after exposure to fire. Exposure to high temperatures causes shrinkage or thermal expansion, which in turn causes macrocracks . Indeed,The chemical analysis of concrete and hybrid leachates showed that the concentration of toxic metals was below the limit values; therefore, the materials can be classified as environmentally neutral. The concentration of toxic metals in the tested samples did not exceed 5% of the permissible values that are indicated in Council Decision 2003/33/EC. In general, the leachate of concrete-geopolymer hybrids had a lower content of hazardous compounds compared to concrete samples. Thus, the addition of geopolymer makes the obtained composites more environmentally friendly than concrete.Z-axis of the printout.The compressive strength of concrete was approximately 40% higher for cast samples than for 3D printed ones. However, for hybrids, this trend was reversed. The addition of fly ash to concrete resulted in a 20% higher compressive strength compared to analogous hybrid mixtures containing the addition of metakaolin. Furthermore, the compressive strength of the samples tested in the parallel direction was 7–10% higher compared to the specimens analyzed in the perpendicular direction to the fl.The sample compressive strength of 24–43 MPa decreased to 8–19 MPa after fire resistance tests. This resulted from moisture evaporation, weight loss, thermal deformation, and crack development. The residual compressive strengths of all the investigated hybrid samples were 1.5- to 2-fold higher than for the concrete samples. Therefore, it can be stated that the addition of geopolymer to the concrete improved the fire resistance of the samples. The 95% C + 5% FA hybrids had a 4% higher residual compressive strength than the 95% C + 5% MK samples. It was also observed that the samples produced by the 3D printing process showed smaller cracks after fire resistance tests compared to the cast samples. On the basis of the obtained results, it was concluded that all the tested materials can be classified as class A1This work presents innovative concrete-geopolymer hybrids, successfully produced by 3D printing technology and dedicated for use as environmentally friendly building materials. The objective of this study was the production of hybrids with an optimal composition i.e., consisting of 95% concrete and 5% geopolymer, which is based on fly ash or metakaolin. Along with the usage of appropriate raw materials, the pre-optimized printing parameters such as the layer thickness, print speed, and print nozzle geometry determined the precise prints. On the basis of the results, it can be concluded that:Future research will concern the use of concrete-geopolymer hybrids for printing on large-format 3D printers. Ultimately, the components produced in this way could be used in the construction industry.


In the dry state, the total thermal resistance of this structure was 5.59 m2.0 C/W, which corresponds to a thermal conductivity coefficient of 0.057 m °C/W. The influence of both horizontal and vertical joints of lightweight steel concrete wall panels and the absence of thermoprofiles on thermal properties was insignificant when using heat-insulating gaskets. The actual total thermal resistance of the structure was 2.5–2.8 times higher than that obtained by calculation under high-humidity conditions (29–32%). At the same time, the decrease in the value compared to the same value at an equilibrium humidity of 5% was only 4–6%. This indicates the good workability even of a structure with high-humidity foam concrete if the reduced total thermal resistance is complied with by the standardized one.The paper presents the thermal properties of lightweight steel concrete wall panels under different humidity conditions: under normal operation conditions and high moisture of the structure. The total thermal resistance  of the enclosing lightweight steel concrete structure with a thickness of 310 mm using monolithic low-density foam concrete (density grade of D200), at an equilibrium humidity of 5% and 8%, was experimentally established. It was equal to 4.602 m Lightweight steel concrete structures consist of a steel profile (profile steel frame) with a monolithic low-density foam concrete and panel sheathing . The use of these structures in various buildings is possible in the form of slabs, and external (bearing and enclosing) and internal walls. In such structures, monolithic foam concrete is used as a heat-insulating material, which does not have the disadvantages of the main traditional ones ,3,4.Monolithic foam concrete is a noncombustible material , has a lThe authors of  describeThe authors of  found th2·K). The authors of 3 to 13003. Further studies are needed to determine the thermal properties of external wall panels consisting of a steel frame filled with low-density foam concrete.However, there is little research on foam concrete as part of lightweight steel concrete structures. The closest is the work , which cThe object of the study was a lightweight steel concrete wall panel.This work aimed to study the thermal properties of lightweight steel concrete wall panels under different humidity conditions: under normal operation conditions and high moisture of the structure.Experimental determination of the thermal properties of lightweight steel concrete wall panels under normal 5% humidity conditions.Determination by the calculation method of the thermal properties of lightweight steel concrete wall panels under high humidity conditions and a dry state based on the experiment.Experimental determination of the thermal properties of a structure under the worst operating conditions: the presence of a horizontal field joint of two wall panels; increased structure humidity; absence of a thermoprofile in the steel frame composition.The same, in the presence of a vertical field joint of panels.Tasks of the research:Monolithic foam concrete with D200 density grade based on Portland cement and foaming agent. Foam concrete manufactured by SOVBI Ltd. . The SOVBI technology makes it possible to obtain nonshrinking foam concrete with a fine cellular structure that has a stable quality.Sheets “Steklotsem” with thickness of 8 mm manufactured by Stroyevolyutsiya Ltd. .Galvanized steel profiles PN (channel profile) and PSt (thermoprofile) manufactured by Stal-Profil Ltd. .For the production of lightweight steel concrete wall panels, the following materials were used:The research model was represented by three specimens of lightweight steel concrete structures. The specimens consisted of steel profiles, monolithic foam concrete with D200 density grade, and “Steklotsem” sheets, which had a fixed formwork see .The first test specimen see  was usedThe second test specimen see  consisteThe composition of specimen No. 2 was similar to that of specimen No. 1, but nonperforated profiles of PS type were used as a load-bearing framework instead of thermoprofiles of the PSt type.The third test specimen see  consisteThe composition of sample No. 3 was identical to that of sample No. 2, except for the dimensions of the left half-panel.The input data were external temperature, internal temperature, specimen dimensions, and climatic chambers dimensions. Output data of the study were the R-value of foam concrete and R-value of foam concrete in the places of the field joint.The tested models were placed in the design position. Further, the TX-500 climatic chamber was installed on one side, and the temperature in the cold (outer) part of the chamber was set at −30 °C. On the opposite side, there was the second heat-moisture-drying chamber SM 5/100–500; the temperature in the warm (inner) part of the chamber was set at +20 °C at a humidity of 60%. The part of the structure that did not fall into the screens of the chamber was insulated with heat-insulating materials to prevent the loss of cold and warm air from both sides of the structure.Temperature sensors and heat flow sensors were installed on the surface of the sample. The models were tested in chambers until the state of a steady thermal process from 1 to 4 days, depending on the type of construction.Specimen No. 1 with installed heat flow and temperature sensors is shown in The purpose of the experiment was to determine the thermal resistance of the zones of pure foam concrete and the zones of the structure part with a steel profile. Based on the data obtained, the most temperature-stabilized estimated time intervals were selected, and graphs of temperature on the specimen No. 1 surface versus time and of heat flow versus time were plotted see .The apparent thermal resistance in sensors 1–5 is calculated by Formula (1):The thermal conductivity is calculated by Formula (2):Substituting (2) into (1), we obtainThe total thermal resistance calculation of an inhomogeneous enclosure structure was carried out by determining the planes parallel to the direction of the heat flow. The enclosing structure (or part of it) was conditionally cut into sections. Some sections could be homogeneous (single-layer) and consist of one material, and others could be heterogeneous and consist of different materials see .kR of the tested wall fragment is calculated by Formula (4):The weighted average thermal resistance value The total thermal resistance of the tested wall fragment along the surface of the wall structure 2 °C according to Russian State Standard SNIP 23-02 “Thermal performance of the buildings”; 2 °C according to Russian State Standard SNIP 23-101 “Thermal performance design of buildings”.Thermal transmittance (according to ISO 9869-1:2014(E)) is calculated by Formula (6):2·°C/W, which indicates good thermal insulation properties of monolithic foam concrete.For comparison, the required total thermal resistance of newly erected external walls in St. Petersburg is 3.08 mδ = 0.310 mm is calculated by Formula (7):In this case, the average coefficient of thermal conductivity of a wall fragment with a thickness of It should be noted that the indicated value corresponds to the structures only at actual humidity. In practice, it is necessary to use the thermal resistances values at the normalized equilibrium moisture content of 5% and 8% and in a dry state.The actual moisture content of foam concrete samples was determined according to Russian State Standard GOST 12730.2-2020 “Concretes. Method of determination of moisture content”. After the end of the experiment, a core with dimensions of 100 × 100 × 300 (mm) was drilled out, weighed in a wet state and placed in a low-temperature laboratory electric furnace SNOL 67/350, and dried at a temperature of +105 °C to a constant mass . After re-weighing, the moisture content of the sample was calculated by Formula (8):The graph shows that the plane of maximum masonry moisture is at a distance of 2/3 of its thickness when measured from the inner surface of the test fragment. The thermal resistance of the tested wall fragment at an equilibrium moisture of 8%, following STB EN 1745-2008, is calculated according to Formula (9):Total thermal resistance is calculated by Formula (5):Thermal transmittance is calculated by Formula (6): The theoretical value of thermal resistance in the state at zero moisture is:The average coefficient of thermal conductivity for a dry wall fragment is:The theoretical value of total thermal resistance in the state at zero moisture is:The thermal transmittance is:Next, consider the theoretical values of the reduced thermal resistance in wetting the main heat-insulating layer—foam concrete to moisture values of 29% and 32%.The theoretical values of the reduced thermal resistance, total thermal resistance, and thermal transmittance under high-humidity conditions (29% and 32%) are, respectively:These values are low, but they are only theoretical ones. Next, we consider an experimental study of the thermal resistance of samples at high humidity and prove their performance, considering the zones of the junction of the panels.Sample No. 2, which has a horizontal field joint of two wall panels with installed thermal and temperature sensors, is shown in Based on the data obtained, the most temperature-stabilized estimated time intervals were selected, and graphs of temperature on the specimen No. 2 surface versus time and of heat flow versus time were plotted see .The weighted average thermal resistance value The total thermal resistance of the tested wall fragment along the surface of the wall structure Thermal transmittance is:The moisture content of the sample is:The sample moisture content of 29% does not correspond to 3–8% operating conditions. However, the total thermal resistance value, even with increased moisture of the sample, is quite high ) and meets the requirements for thermal protection of buildings, for example, in St. Petersburg, which indicates the actual performance of the structure even when the foam concrete becomes wet.Sample No. 3, which has a vertical field joint of two wall panels with installed thermal and temperature sensors, is shown in Based on the data obtained, the most temperature-stabilized estimated time intervals were selected, and graphs of temperature on the specimen No. 3 surface versus time and of heat flow versus time were plotted see .The weighted average thermal resistance value The total thermal resistance of the tested wall fragment along the surface of the wall structure Thermal transmittance is:The moisture content of the sample is:The sample moisture content of 32% does not correspond to 3–8% operating conditions. However, the total thermal resistance value, even with increased moisture of the sample, is quite high ) and meets the requirements for thermal protection of buildings, for example, in St. Petersburg, which indicates the actual performance of the structure even when the foam concrete becomes wet.2.0 K/W and 4.1 m2.0 K/W, respectively, which corresponds to U-values equal to 0.217 W/m2.0 K and 0.244 W/m2.0 K, respectively.The total thermal resistance  of the enclosing lightweight steel concrete structure with a thickness of 310 mm using monolithic low-density foam concrete (density grade of D200), at an equilibrium humidity of 5% and 8%, was established by calculation based on experimental data. It was equal to 4.602 m2.0 C/W, which corresponds to a thermal conductivity coefficient of 0.057 m °C/W and U-value equal to 0.179 W/m2.0 K.In the dry state, the total thermal resistance of this structure was 5.59 mThe influence of both horizontal and vertical joints of lightweight steel concrete wall panels and the absence of thermoprofiles on thermal properties was insignificant when using heat-insulating gaskets.The presence or absence of perforation in the steel profile of lightweight steel concrete wall panels did not significantly affect their thermal properties.2.0 K/W and 4.33 m2.0 K/W, respectively, which corresponds to U-values of 0.226 W/m2.0 K and 0.231 W/m2.0 K, respectively.The total thermal resistance  of the considered structure at an increased humidity of 29% and 32% was established by calculation based on experimental data. It was equal to 4.43 mThe actual total thermal resistance of the structure was 2.5–2.8 times higher than that obtained by calculation based on experimental data under high-humidity conditions (29–32%). At the same time, the decrease in the value compared to the same value at an equilibrium humidity of 5% was only 4–6%. This indicates good workability even of a structure with high-humidity foam concrete if the reduced total thermal resistance is complied with by the standardized one.The thermal properties of lightweight steel concrete wall panels were studied by experimental methods. From this research, the following conclusions can be obtained:


On renal biopsy, AAV typically reveals necrotizing and crescentic glomerulonephritis. A subset of AAV cases can show increased IgG4+ plasma cells in the kidney and in other organs.The patients’ clinical characteristics are shown in All 10 patients had renal mass(es) that were predominantly cortical based, and heterogeneous on ultrasonography with low to intermediate density on computerized tomography (CT) imaging see . One of Extrarenal radiographic findings included cystic lesion in pancreatic tail (1 of 10), hepatic lesions (2 of 10), bilateral hilar and mediastinal lymphadenopathy (1 of 10), pleural thickening (1 of 10), leptomeningeal thickening (1 of 10), pulmonary nodules or infiltrates (3 of 10), lacrimal gland enlargement (1 of 10), pituitary and infundibular enlargement (1 of 10), and sinus opacification or membrane thickening (3 of 10).Seven patients had renal needle core biopsies, 1 had a renal wedge biopsy, and 2 underwent partial nephrectomy. The renal specimen findings are detailed in Immunofluorescence (IF) and electron microscopy (EM) were performed in 5 cases. IF was negative or showed a pauci-immune staining pattern in glomeruli; no cases showed tubular basement membrane deposits. EM showed an absence of tubular basement membrane immune deposits in all examined cases.AAV is a systemic vasculitis associated with a positive serum ANCA that can involve multiple organs, including the retroperitoneum and rarely presents as unilateral or bilateral renal masses.IgG4-RD is an immune mediated fibroinflammatory condition associated with increased serum IgG4 in most patients. It can involve multiple organs, including pancreas, salivary glands, lacrimal glands, kidney, and the retroperitoneum.S9Retroperitoneal fibrosis may be a manifestation of IgG4-RD or AAV.et al.et al.et al.Notably, 4 of 10 cases (40%) in our study did not show a necrotizing and crescentic glomerulonephritis; these cases in particular may be misdiagnosed as IgG4-RD. These cases showed focal to diffuse interstitial inflammation comprised of a mixed inflammatory infiltrate, including neutrophils, and IgG+ and IgG4+ plasma cells. The histological findings of dense lymphoplasmacytic infiltrates with increased IgG4+ plasma cells is reported in AAV, similar to IgG4-RD. Chang In this study, histological findings of focal interstitial karyorrhexis, necrosis, or neutrophilic infiltrates were identified in all AAV cases with or without crescentic and necrotizing glomerulonephritis. These histological findings are helpful in determining renal masses to be associated with AAV despite having increased IgG4+ plasma cells in the interstitial inflammatory infiltrate and a background of “storiform” fibrosis see . GranuloThe clinical significance of distinguishing between AAV and IgG4-RD lies in the differences in prognosis and management strategies. AAV and IgG4-RD are both treated with corticosteroids and rituximab, however there is difference in the drug schedules.In conclusion, we identified histological findings that can distinguish AAV associated renal masses from those seen in IgG4-RD. Inflammatory infiltrates with elevated IgG4+ plasma cells and elevated IgG4+/IgG+ plasma cell ratio in a background of fibrosis should raise the differential diagnoses of mass-forming AAV and IgG4-RD. Interstitial karyorrhexis/necrosis, neutrophils, and glomerulonephritis favor a diagnosis of AAV despite dense lymphoplasmacytic infiltrates with increased IgG4+ plasma cells and storiform fibrosis. The distinction between AAV and IgG4-RD is important due to differences in prognosis and management. It is also important for pathologists to remember that renal masses with increased plasma cells can be seen in other conditions. These causes can be distinguished based on clinical and additional histopathologic findings in conjunction with appropriate laboratory testing.All the authors declared no competing interests.


FA was replaced with slag at four different substitution percentages, including 0%, 30%, 50%, and 100% of the total weight of the binder. The fresh properties of the produced SCGC specimens were investigated in terms of slump flow diameter, T50 flow time, and L-box height ratio. Additionally, the following mechanical properties of SCGC specimens were investigated: modulus of elasticity and fracture parameters. The water permeability and freezing–thawing resistance were studied to determine the durability behavior of SCGC. In this study, the optimum curing temperature was 85 °C for the duration of 24 h, which provided the maximum compressive strength. The results confirmed that adding slag affected the workability of SCGC mixtures. However, the mechanical characteristics, fracture parameters, and durability performance of SCGC were improved for slag-rich mixtures. When using 50% slag instead of FA, the percentage increase in compressive, flexural, elastic module, and fracture energy test values were about 100%, 43%, 58%, and 55%, respectively, whilst the percentage decrease in water permeability was 65% and the resistance to freeze–thaw test in terms of surface scaling was enhanced by 79%.This investigation evaluates the influence of various curing conditions and slag inclusion on the fresh, mechanical, and durability properties of self-compacting geopolymer concrete (SCGC) based on fly ash (FA). Curing temperature and curing time have a vital role in the strength and microstructure of geopolymer concrete. Therefore, to begin the research, the impacts of different curing conditions (curing temperature and curing time) and slag content on the compressive strength of FA-based SCGC were examined to determine the optimum curing method. A series of four SCGC mixes with a fixed binder content (450 kg/m Additionally, it uses a large number of raw materials for quarrying and minerals, which may lead to the prospective depletion of these materials in the future. Almost a ton of CO2 is released for every ton of ordinary Portland cement (OPC), depending on the manufacturing method used, which accounts for 5% of worldwide CO2 emissions [2 emissions from OPC manufacturing are predicted to be more than double the aforementioned levels [Globally, cement use is increasing steadily, resulting in a considerable increase in carbon dioxide  is a superior category of concrete that may be consolidated completely into framework corners due to its own weight. SCC development intends to attain proper compaction and to assist the placing of concrete in congested elements and narrow openings ,17,18,192 than conventional concrete [Alkali-activated or geopolymer concrete is an environmentally friendly material that also performs well in the hardened stage. Additionally, it consumes less energy during the manufacturing process and emits less COconcrete ,23,24. Gconcrete . Accordiconcrete , the 56-concrete  investigThe freeze–thaw effect is the most serious durability issue for concrete in cold climates. Dams and concrete pavement surfaces with large open zones are particularly vulnerable to frost in cold climates . This deCuring conditions (or curing regimes) in terms of varying curing temperatures and curing times are the vital key parameters in the synthesizing of geopolymer concrete . It has To produce self-compacting geopolymer concrete (SCGC), class F fly ash (FA) was utilized as a binder according to DIN EN 450-1 . In the 3. For the activation process in geopolymer concrete, a variety of alkaline solutions are commonly utilized. The alkaline solution (AL) utilized in this experiment was a mixture of sodium-silicate (Na2SiO3) and a sodium-hydroxide (NaOH) solution. The mass of sodium silicate (Na2SiO3) used in the production of SCGC was 45% dry content and 55% water content. 2SiO3. The sodium hydroxide (NaOH) employed in this study has a purity of 99%. By dissolving the NaOH solid particles in water, the NaOH solution was created. The molarity (M) of NaOH is used to express its concentration. The molarity used in this study was fixed at 12 M. MC Power flow evo 502 is a polycarboxylate ether-based superplasticizer (SP) that meets the requirements of EN 934-2: T3.1/3.2 which was used. It has a yellowish color and a density of 1.03 kg/mThe water was utilized in this study to improve workability. The water utilized in the experiments was clean tap water that was readily available in the civil engineering lab at FH Erfurt. The natural coarse aggregates provided by the Amagard company were river gravel. The gravel size ranged from 16.0 to 4.0 mm, and the fine aggregates used in the SCGC mixes were river sand. The physical characteristics of gravel and sand were tabulated in 3 [3 for the entire experimental study. These mixtures were designed with different slag contents with the same aggregate content, binder content, molarity (M), superplasticizer (SP), and water. Slag was used as the only parameter in this stage to replace the FA at different percentage levels . Furthermore, the effects of slag on various properties of the FA-based SCGC were investigated. 3 of the SCGC made in this study. In the following mix codes, G0 indicates that the binder content is 100% FA and 0% slag. Four mixes of self-compacting geopolymer concrete (SCGC) were designated with an alkaline/binder (AL/B) ratio of 0.5 and a total binder content of 450 kg/m3 . Water wA similar mixing procedure was used to achieve consistent homogeneity and uniformity in each mixture. In the first stage, all the dry ingredients, such as coarse and fine aggregates, FA, and slag as a binder, were mixed in the electrical concrete mixer, with a 75-litre capacity and a rotation speed of 70 rpm, for about 2 min. After mixing the dry ingredients, the premixed liquids of AL and water (mixed for one hour prior to mixing time) were introduced to the mixer and continued for 2 more minutes. Then, the superplasticizer was supplied to the wet batch and the mixing procedure proceeded for an additional 2 min. The temperature of the SCGC mixtures ranged between 26 to 28 °C. The SCGC fresh batch was tested for flowability, viscosity, and passing ability properties after the mixing process was completed, and the specimens for hardened state properties were then prepared. The fresh concrete was mixed again in the mixer for half a minute before the casting stage to maintain the homogeneity of the mix. The specimen shapes were cubical specimens , cylindrical specimens (Ø150 × 300 mm), and beam-like specimens (100 × 100 × 500 mm), and they were cast with no means of compaction due to the self-consolidating property under their own weight. Moreover, after casting, the specimens’ surfaces were scraped using a finishing trowel to eliminate excessive material and achieve a smooth surface. Finally, the cast specimens of SCGC were placed under ambient curing for the curing process to begin.The curing process of SCGC specimens starts immediately after the mixing and casting stages are completed. Before being exposed to curing, the samples were stored in the lab for 24 h . In thisSCGC specimens were kept at room temperature (22 °C with a relative humidity of 60 ± 5%) until the testing date. If the requirement for minimum compressive strength for structural applications can be achieved, this method would be the most preferable one related to low energy consumption. SCGC specimens in room curing were kept for the duration of 7, 14, and 28 days before testing for strength.A digitalized UIM 800 oven machine manufactured by the MEMMERT GmbH company was used to apply step curing to specimens. The step curing cycle lasts 24 h per day; 9 h at room temperature, 2 h of rising heating temperature to reach the target degree of 40 °C and maintain that degree for 11 h, and finally, end the cycle with 2 h of cooling down in the chamber. This curing method continued for 7, 14, and 28 days (cycles), and the samples were taken out of the oven for two hours before testing.For the oven curing or heat curing method, three curing temperatures, such as 40, 60, and 85 °C, were selected. A digitalized oven is used for curing SCGC specimens at a constant temperature of 40 °C for 3, 7, 14, and 28 days. Moreover, the specimens are kept at ambient condition for 2 h before testing. Furthermore, an electric oven set to a maximum temperature of 300 °C was used to apply 60 °C to the SCGC samples for the periods of 24 and 48 h, then kept at an ambient temperature until the testing date (7 days of age). Another method of elevated heat curing is to place the specimens in an electric oven set to 85 °C for a period of 24 h. The delay time was also examined in this approach. The delay time refers to the time period before the specimens are placed in the oven . A 24 h cu at Gif is compressive strength at various slag content , and cu at Gf0 is compressive strength with no slag (100% FA). Percentage increases in compressive strength can be calculated based on the following formula:Fresh tests were performed on the mixtures of SCGC conducted in this investigation after the mixing process to meet EFNARC’s guidelines . The floAn average of three cylinders (Ø150 × 300 mm) were taken at 28 days of age to determine the static elastic modulus of elasticity (Es), confirming EN 12390-13 . The casmax is defined as the highest load that the beam can support without regard for notch sensitivity [To implement the flexural strength test, an average of three 100 × 100 × 500 mm beams were taken for each measurement, confirming the RILEM 50-FMC/198 committee . During sitivity ,71.(2)NFG) was estimated using the following formula:2), δ is the specified displacement of the beam (m), S is the span length (mm), U is the length of the beam (mm), B is the width of the beam (mm), W is the depth of the beam (mm), and a is the notch depth of the beam (mm). After obtaining the load-displacement curve at the midspan of the beam specimens, the fracture energy  in the dry state is recorded with 0.0001 g accuracy. Before filtering, the mass of the filter (fμ) is measured. The scaled material (sμ) in grams is then measured as follows:After filtering the scaled material in the solution, the mass of the scaled material , the quantity of scaled material per each measurement (g), and the area of the test surface area (mm2). Following the nth cycle, the following equation is utilized to compute the relative increase in mass of each sample (nw):nw, w0, w1, and nw denote the weight of moisture absorption (uptake) of each sample specimen following the nth cycle in percentage, the reference weight of each sample (g), each reference sample with the weight of sealed material (g), and the weight of each sample for each selected cycle (g). After the nth cycle, Equation (5) was used to calculate the overall scaled material removed from the test side region for the selected specimens.cst is the total transit time at the end of capillary suction (cs) in ms before starting the test, nt is the total transit time after 28 cycles of freeze–thaw, in ms, and ct is the transit time in the coupling medium in ms. Internal damage occurs when the microstructure of concrete deteriorates, resulting in a change in the characteristics of the concrete. The RILEM TC 176 method  was usedBased on the curing conditions, geopolymer concrete can display various types of properties and behaviors. For synthesized geopolymers, the curing phase is a critical parameter. In this section, the influence of curing conditions, which comprise curing temperature and curing time, on the compressive strength of fly ash (FA)-based self-compacted geopolymer concrete (SCGC), was investigated. The effect of replacing FA with ground granulated blast furnace slag (slag) was also investigated. For this reason, four mixes with various slag content  were selected. The cube samples (100 × 100 × 100 mm) were subjected to different curing conditions, including curing at room temperature, step temperature, 40, 60, and 85 °C for a variety of curing times, and then tested for their compressive strength.At 7 days of age, based on the reference mix (G0), the rate of strength increment with increasing slag content is higher than that of 14 and 28 days. For instance, with the increment of slag addition at the following ratios of 30%, 50%, and 100% of the total binder content, the compressive strength increased at the following rates: 282.5%, 487.7%, and 790.6%, respectively, with regard to the 7 days of age See a. WhereaBesides, a prolonged curing time provides a lower improvement in the compressive strength than a shorter curing time. This was observed for the SCGC mixes that are rich in slag compared to the mixes made with 100% FA (G0R0). The compressive strength behavior of SCGC for different curing times is shown in The rate of strength growth increased as the slag content increased, irrespective of the curing period, as shown in Geopolymer concrete curing at room temperature has a compressive strength that is insufficient in comparison to concrete mixes curing in an oven. This is due to the alkaline solution and binder starting to partially polymerize at an initial age. Additionally, heat curing was required to create a rapid geopolymerization technique capable of achieving an appropriate strength in a very short time, which is a critical criterion for the synthesis of geopolymers ,11. The Geopolymer materials require heat treatment to achieve a compressive strength equivalent to or superior to that of normal concrete. This form of curing is advantageous for the dissolving and repolymerizing of the silica and alumina gel and also leads to an increase in the material’s early-age strength ,85,86,87In terms of early strength development, the elevated heat curing process has been shown to be the best approach for curing geopolymer concrete. This form of curing, however, is challenging to achieve in cast-in-place applications . HoweverLikewise, the strength increment rate for the 1 h and 24 h delay times with respect to the slag content is displayed in The compressive strength of SCGC specimens was also studied in relation to the duration of heat curing at 85 °C, as illustrated in The influence of incorporating slag on the performance of fly ash (FA)-based self-compacted geopolymer concrete (SCGC) mixes was examined and the results were compared with the limitations of EFNARC recommendations . The fres) versus various slag levels are depicted in s values in this investigation ranged from 18.3 to 27.6 GPa. The SCGC mixes with the use of slag had a considerably greater Es compared to the mixes without slag. The peak Es result was attained for the geopolymer concrete mix produced with 100% slag content (G100R0). The result values demonstrate that the Es were increased by using more slag. The same behavior was also observed in the compressive strength test. Li et al. [s is highly reliant on the physical parameters of the concrete and the utilized aggregate (such as density and porosity). Nath and Sarkar [s was enhanced as the concrete strength increased. It was detected that the Es of geopolymer concrete is comparatively lower than that of normal concrete of similar strength. Normal concrete had an Es of 30.6 GPa at 28 days, corresponding to 40 MPa of compressive strength. Additionally, for the parallel strength of geopolymer concrete, the Es obtained values ranged between 21.6 and 23.2 GPa for the same testing age. This is nearly 30% lower than the result of PC concrete. Furthermore, the elastic modulus of geopolymer concrete was found to be much lower than that of normal concrete, even though the compressive strength of geopolymer concrete is comparable to or higher than that of normal concrete. As a result, it is possible that geopolymer binders can sustain more deformations in an elastic state than OPC binders [s values increase by 50.8% when the slag content is increased from 0% to 100%, whereas the highest development rate in the static modulus of 43% was achieved as the slag addition reached 50% of total binder content. Hager et al. [s of geopolymer concrete improves with increasing compressive strength, but it is significantly less than that of conventional concrete with equivalent compressive strength. [The Young modulus is a critical property of a material that is used in the structural concrete design parts because it provides vital information about the ability of concrete to resist deformation at its elastic limit ,94. The i et al.  establisd Sarkar  investig binders . Figure r et al.  also foutrength. ,100. The net flexural strength of the SCGC mixes was measured by Equation (2) and shown in The SCGC load vs. displacement profile for the prisms with various slag replacement levels  is shown in FG) in determining the ultimate stress at the crack tip, it is a function of displacement rather than strain. It is defined as the amount of energy necessary to open a fracture surface of a unit area [FG indicates the concrete’s greater ductility [FG outcomes of SCGC versus various slag content are illustrated in FG compared to the reference mix made with 100% FA. For instance, the mix with 100% FA recorded 103.51 N/m as the minimum value of FG conducted in this investigation, whereas the maximum value of FG of 176.35 N/m was obtained for the mix made with 100% slag. This behavior for the FA and slag blended SCGC was also reported by other studies [FG increment rate of the mixes beyond 50% of slag content seems to be a steady increase, whereas a sharp increase in FG was seen for the replacement level of FA with slag of up to 50%. These characteristics were also noted in the mechanical properties investigated in this investigation. Generally, as SCGC compressive strength increases, the fracture energy tends to improve. Midhun et al. [FG of FA-based geopolymer concrete cured via oven improved with increasing compressive strength. Despite the importance of fracture energy  is shown in 2, respectively. The percentage decrease in results was 79% as the slag content increased from 0% to 50%. Previously, it was stated that the higher compressive strength of concrete led to less surface scaling. The allowable range for surface scaling is 1500 gr/cm2 following the RILEM TC117-FDC [2, individually [The results of the SCGC samples exposed to 28 cycles of freeze–thaw using distilled water are discussed in this section. According to test values, the minimum values of the surface scaling were achieved with the utilization of 50% slag. This might be related to the higher compressive strength of the slag and FA blended SCGC specimens in comparison to the reference mix. The result values for the 0% slag and 50% slag were 325 and 68 g/mC117-FDC . For insvidually . It is gvidually  studied The results of moisture uptake were also conducted in this study. The test values displayed a comparable trend to the scaling outcomes. Clearly, the increase in the pore system led to an increase in the SCGC samples’ moisture absorption rates. This impact can be linked to the insufficient ability of FA-based SCGC compared to the slag rich mixes. The moisture uptake values achieved ranged between 1.45 and 3.58 in mass percentage. For high strength concrete, a moisture uptake of less than 0.5 was achieved, whereas higher values were recorded for normal concrete . As described in the CIF testing procedures, the damage condition is lower than 80% . The relIn all curing conditions , replacing FA with slag positively affects the strength of the SCGC. When the slag content increases, the compressive strength of the SCGC also increases, regardless of the curing temperature. Prolonged curing time has a remarkable influence on the strength development of FA-based SCGC mixes compared to mixes having slag content. One-day delay time is essential for SCGC specimens prior to being subjected to oven curing.Optimum curing condition: based on the compressive strength, 24 h of oven curing at 85 °C has been found to be the optimum curing condition.Optimum combination binder: in geopolymer SCGC mixtures, the majority of strength growth occurred at 50% slag inclusion. Beyond that content, strength improvement is insignificant.The slump flow diameter of SCGC mixes was greatly affected by the replacement level of FA with slag. Adding slag causes a dramatic reduction in slump flow diameter. However, all the results were within EFNARC’s limits.A systematic increase in the static modulus of elasticity of SCGC specimens was detected as slag content increased. With the increasing slag level from 0% to 100%, the elastic module values increased by about 50%, from 18.30 to 27.60 GPa.The net flexural strength values enhanced as the percentage of slag level increased compared to the reference mix (100% FA). The net flexural strength values were 3.00 MPa and 4.87 MPa for the slag replacement levels of 0% and 100%, respectively.The fracture energy of SCGC specimens is enhanced with the increase in slag inclusion. As slag content increased from 0% to 30%, 50%, and 100%, the percent increase in fracture energy was 30%, 54.9%, and 70.4%, respectively.The water permeability of SCGC was enhanced as the slag content increased. Increasing slag content from 0% to 100% causes a considerable reduction in water pentation depth from 40.5 mm to 12.5 mm.2 to 68 g/cm2, respectively.Freeze–thaw resistance of SCGC specimens improves with the rise in compressive strength and also increases with the increase in slag content. As slag inclusion increases from 0% to 50%, the surface scaling reduces from 325 g/cmIn this investigation, the effects of different curing conditions (curing temperature and time) and slag content were studied on the compressive strength of FA-based self-compacted geopolymer concrete (SCGC) to determine the optimum mixture and curing regime. Furthermore, the mechanical and durability properties of SCGC mixes were investigated. The following are the major conclusions:


Splenic lymphangiomas (SL) are very rare benign cystic lesions found in pediatric population. Their occurrence in adults is exceptional. Splenectomy is the common management of splenic lesions for diagnostic and/or therapeutic purpose. Our aim is to report additional cases of SL diagnosed on splenectomy specimens at our Pathology laboratory with literature review.This is a retrospective study including all cases of splenectomy recorded at our Pathology laboratory (June 2020–August 2022). We performed a comparison of clinicopathological features between patients with SL and those with other benign splenic diseases.Sixteen cases of splenectomy were included. The mean age was 30.25 years (range of 6–70 years). The final histopathological diagnoses were congestive spleens in all cases of sickle cell disease (SCD) , splenic cystic lymphangiomas , capsular splenic infiltration by gastric and colic cancers , splenic abscess  and splenic rupture with subcapsular hematoma . 12/16 patients (75%) had benign splenic conditions . Patients with SL were older than those with other benign splenic conditions (mean age of 28.27 years versus 20.87 years). Also patients with SL presented with massive splenomegaly . Open surgery was performed in 15/16 patients (93.75%).Unlike previous studies, our series shows that SL are a common indication for splenectomy and occur in older patients with massive cystic splenomegaly. Open splenectomy is still an usual surgical practice in our country. Splenic lymphangioma (SL) is a very rare cystic lesion affecting usually children and less commonly reported in adult persons –7. TheseSplenectomy either total or partial, laparoscopic or open, is the common management of splenic lesions for diagnostic and/or therapeutic purpose , 16–18, As the current literature offers only some case reports and rare case-series of SL, our aim is to report additional cases of SL diagnosed on splenectomy specimens at our newly operative pathology laboratory , with comparison of clinicopathological features between SL and other spleen diseases that have been the indications for splenectomy.This is a retrospective study including all cases of splenectomy recorded at the Pathology laboratory of the Niamey National Hospital  from June 2020 to August 2022. As the unique Pathology laboratory in public hospital , we receive specimens from all medical centers of the country. Our cases of splenectomy were from 3 main National hospitals of the capital city of our country  and 1 regional hospital . We have collected patients data such as: age, sex, preoperative diagnosis (indication for splenectomy), spleen weight and size , splenic gross features, the type of surgical resection  and histopathological final diagnosis.All cases have been diagnosed by routine histopathological techniques performed on surgical resected splenic specimens: formalin fixation, paraffin-embedding, microtome sectioning (4 microns thick) and hematoxylin–eosin (HE) staining. All cases have been analysed by using optic microscopy.Continuous variables are presented as means and ranges, categorical variables as percentages. We have grouped benign splenic diseases into 2 groups: a group of splenic lymphangioma (SL) and a group of ther benign splenic conditions. We performed a comparison between these 2 groups. In the comparison, we have excluded spleens resected for malignancies as they had all normal gross features, the indications were not primary spleen malignancies and the splenic parenchyma was not involved by the tumors .All descriptive statistical analyses were performed by using IBM SPSS Statistics 23.0.The Table The final histopathological diagnoses were congestive spleens in all cases of SCD  Fig. A, B, 3 cOur series included 4 cases (25%) of spleen resections associated with malignant tumors of adjacent organs  that superficially invaded the spleen capsule. The gross features of the spleen (weight and size particularly) in these cases were quite normal. The remaining cases  had benign splenic conditions .The Table We report from a Subsaharan African country a series of patients that underwent total splenectomy for a variety of diseases. Open surgery was performed in almost all cases ; SCD , SL  and malignant intra-abdominal tumors with suspected extension to the spleen , were the most indications for the splenectomy. Benign splenic conditions were the most frequent indications for surgery , among them SCD  and SL  were the leading causes of surgery. Hematologic diseases have been reported to be the major indication for splenectomy in the literature , 21–28, Since its introduction in surgical clinical practice in early 1990 s, laparoscopic splenectomy (LS) has become a gold standard in the management of patients with splenic diseases either benign or malignant , 23, 25.In our study, patients with SL were older than patients with other benign splenic conditions (mean age of 28.25 versus 20.87 years), because of many children with SCD in this subgroup of benign splenic conditions. Also, patients with SL presented with heavier spleens and massive splenomegaly (mean weight and size of 1675 g and 19.62 cm) whereas patients with other benigh splenic conditions had mild splenomegaly (mean weight and size of 418.75 g and 14.43 cm). In fact in this subgroup, the indications for splenectomy were acute symptoms such as abdominal pain, fever and hypersplenism, rather than the importance of the splenomegaly and abdominal distension in comparison with patients that had SL.Echinococcus granulosus infection and are endemic in certain areas of the World [In the literature, SL are usually reported in children as asymptomatic or rarely symptomatic lesions, with few case reports in adults , 15, 36.he World . On histhe World .As a retrospective analysis, our study has some limitations, especially a small number of patients. The data about imaging techniques and follow-up are not available. However some provisional conclusions could be drawn, until the availability of larger studies on SL in the future.Unlike previous literature reports, our series shows that splenic lymphangiomas (SL) are a common indication for splenectomy. They occur in older patients and present with massive cystic splenomegaly. Open splenectomy is still an usual surgical practice in poor countries. The definitive diagnosis of SL relies on the histopathological analysis of the resected splenic specimens.


Mu heavy chain disease is a rare lymphoid neoplasm characterized by vacuolated bone marrow plasma cells and secretion of defective mu immunoglobulin heavy chains. The biological basis of mu heavy chain disease is poorly understood.MYD88 L265P mutation and deletion of 6q, genetic aberrations that are both strongly associated with lymphoplasmacytic lymphoma/Waldenström macroglobulinemia. Identification of the truncated mu immunoglobulin was facilitated by mass spectrometric analysis of the patient’s serum.We report a case of mu heavy chain disease with MYD88 mutation in mu heavy chain disease, argues that at least a significant subset of cases are more similar to lymphoplasmacytic lymphoma than to chronic lymphocytic leukemia.Mu heavy chain disease has been described as similar to chronic lymphocytic leukemia; however, the frequency of lymphocytosis in mu heavy chain disease has not been previously reported. We reviewed all previously published mu heavy chain disease reports and found that lymphocytosis is uncommon in the entity. This finding, along with the emerging genetic feature of recurrent  MYD88 L265P mutation along with deletion of 6q, supporting a biologic relationship between mu-HCD and lymphoplasmacytic lymphoma (LPL), a lymphoma that most often presents as Waldenström macroglobulinemia (WM).Mu heavy chain disease (mu-HCD) is an exceptionally rare entity described as resembling chronic lymphocytic leukemia (CLL), with vacuolated plasma cells and secretion of a defective mu heavy chain . We repo9/L. A PET/CT scan did not demonstrate any lytic bone lesions or enlarged lymph nodes; the spleen size was reported as at the upper limit of normal. A bone marrow biopsy and aspirate were obtained. The bone marrow was markedly hypercellular due to a diffuse proliferation of small lymphocytes and plasma cells with prominent cytoplasmic vacuolization . The patient had an absolute lymphocyte count (ALC) of 2.2 × 10MYD88 L265P mutation and deletion of 6q, both common abnormalities in LPL [MYD88 L265P mutations, although vacuolated plasma cells were described in only one case and none were illustrated [MYD88 mutations are recurrent in mu-HCD, suggesting a relationship with LPL. The generalizability of this finding is difficult to assess as mu-HCD is extraordinarily rare, with only 30–40 cases previously reported; however, additional indirect evidence suggests that a relationship with LPL is plausible in many mu-HCD cases.This case of mu-HCD with classic morphologic, phenotypic, and serologic features demonstrates genetic similarity to LPL with a s in LPL , 5. Verg9/L, and the patient was clinically diagnosed with CLL [sine qua non of CLL, but the frequency of lymphocytosis in mu-HCD is not established, as it has not been summarized in previous reviews of the entity. We attempted to review all prior reports of mu-HCD, collecting peripheral blood white blood cell and differential count information from 29 previously reported patients with mu-HCD [9/L), and only 5 reported patients have had ALC greater than 10 × 109/L  was negative for CD5 [Nearly all cases of CLL are positive for CD5, but the immunophenotypic characteristics of mu-HCD are not well established, as many of the reports of mu-HCD predate comprehensive immunophenotyping of lymphoid neoplasia and the recognition of the CD5 antigen on CLL cells . However for CD5 , as was  for CD5 . CD5 may for CD5 , and so  for CD5 .These features suggest that most previously reported cases of mu-HCD are unlike CLL as currently understood. Our case and those of Vergneault and colleagues  establisMYD88 mutation and establish a rationale for potential LPL-directed management of this rare entity.This report additionally underscores the value of novel techniques such as MASS-FIX in the detection of abnormal serum proteins. mu-HCD may be underrecognized, and patients with increased free serum light chains or Bence-Jones proteinuria without a corresponding serum heavy chain should be considered for further assessment using methods such as MASS-FIX to better evaluate for abnormal proteins that could be missed using conventional serologic techniques. Discrimination between a B-cell neoplasm with plasmacytic differentiation and a plasma cell neoplasm is highly clinically relevant, and accurate M-protein characterization is a critical component of the diagnosis. Our findings suggest that mu-HCD cases should be screened for


The objectives of the study were (a) to describe the patterns of antibiotic usage against four major clinical problems and (b) to evaluate factors that were associated with their use on small ruminant farms. Sheep and goat farmers mostly administered the antibiotics to animals at the dose prescribed (80.4%) and observed the necessary withdrawal period (98.7%), but fewer farmers (22.3%) weighed the animals to calculate their bodyweight before antibiotic administration. For the treatment of clinical mastitis, oxytetracycline, penicillin and streptomycin were the antibiotics used more frequently; 2.03 different antibiotics were used per sheep flock and 2.06 per goat herd, most frequently administered in injectable forms (88.8% of farms). In cases of abortion, oxytetracycline was administered more frequently; 1.12 different antibiotics were used per sheep flock and 1.03 per goat herd. In 94 farms (21.2%), routine administration of antibiotics was performed to newborns; oxytetracycline and ampicillin were administered more often. For the treatment of pneumonia in newborns, oxytetracycline, penicillin and tulathromycin were used more frequently; 1.33 antibiotics were used per sheep flock and 1.29 per goat herd. For the treatment of diarrhoea in lambs and kids, oxytetracycline, amoxicillin and penicillin were the antibiotics used more frequently; 1.34 antibiotics were used per sheep flock and 1.59 per goat herd. Results of multivariable analyses indicated 16 variables associated with the various outcomes for usage of antibiotics for the treatment of the above clinical problems. Of these, 11 variables were associated with the farmers: education of farmers was significant for three outcomes; the age, the experience, the professional involvement and farming family tradition of farmers and the daily period spent at the farm were each significant for one outcome. The appropriate and correct use of pharmaceutical products in sheep and goat farming is important for ensuring correct health management and maintenance of animal welfare standards on the farms, as well as for public health with regard to drug residues in animal products. Thus, knowledge of antibiotic usage patterns in the livestock industry can support the animal health industry to ensure that drugs are being used prudently.In general, there is a scarcity of relevant information internationally regarding the use of pharmaceutical products, including antibiotics, on sheep and goat farms. In a relevant study performed in Canada, Moon et al.  collecte3 [Dairy sheep and goat farming is an important sector of the agricultural industry in Greece, with significant annual milk production. Data derived from the Hellenic Milk Board indicate that total deliveries of sheep and goat milk from these farms to dairy factories were approximately, respectively, 645,000 and 143,000 mDespite the importance of small ruminant farming for the food production sector in Greece, the patterns of usage of antibiotics on the farms in cases of infections have not been investigated and described. However, there is scope for monitoring their usage, as recent investigations have highlighted the presence of bacterial resistance to antibiotics ,7. MoreoThis paper reports findings regarding antibiotic usage on small ruminant farms, as found during an extensive countrywide investigation performed in 325 sheep flocks and 119 goat herds throughout Greece. The objectives of the study were (a) to describe the patterns of antibiotic usage against four major infections on small ruminant farms and (b) to highlight factors that were associated with their use on the farms.A cross-sectional study involving 325 sheep flocks and 119 goat herds was performed from April 2019 to July 2020. The work covered all the 13 administrative regions of Greece . The floVeterinarians active in small ruminant health management around Greece were contacted by telephone and asked if they wished to collaborate in the investigation ; 47 veteInitially, the veterinarian accompanying the investigators to the respective farm introduced them to the farmer. The senior investigator (author G.C.F.) explained to the farmer the objectives and the details of the study and also introduced the interviewer (author D.T.L.) to the farmer. The interview was performed using a structured detailed questionnaire. Before the start of the main study, the questionnaire used to collect data from the farmers had been tested for content validity . The intDuring the visit to each sheep flock and goat herd, four milk samples (20 mL each) were collected aseptically directly from the bulk-tank of the farm. Two milk samples were used for composition analysis and somatic cell counting and the other two were used for bacteriological examinations.Before laboratory analysis, two 10 mL subsamples were created and processed; therefore, each separate test was performed four times (each one in different subsamples). Milk composition and somatic cell counting were performed within 4 h after collection on each of the four relevant subsamples, as previously detailed ,10,11. MTransportation of the samples to the laboratory was made by the investigators and by car; samples collected from farms in the islands were also transported as accompanying luggage by airplane  or by boat . Samples were transported in portable refrigerators at 0.0 to 4.0 °C.Data were entered into Microsoft Excel and analysed using SPSS v. 21 . Details of the following general characteristics of usage of antibiotics on the farms were assessed: method of calculation of bodyweight for the administration of antibiotics, administration of antibiotics to animals at the dose prescribed, observation of the withdrawal period after administration of antibiotics and routine administration of antibiotics to newborn lambs/kids. Moreover, the following four clinical problems were studied in detail: mastitis and abortion in ewes and does and pneumonia and diarrhoea in lambs and kids; these four clinical entities are significant problems and important causes of production losses in small ruminant farms and their therapeutic management includes the administration of antibiotics. Initially, basic descriptive analyses were performed. Exact binomial confidence intervals (CI) were obtained.10 as described previously [The analysis results for the two subsamples from each of the two milk samples collected from the bulk tank were averaged, then the two means were again averaged for the final result regarding each bulk-tank milk. For statistical analysis, the somatic cell counts were transformed to somatic cell scores and the total bacterial counts were transformed to logeviously ,10,11; tcalculation of bodyweight for the administration of antibiotics by weighing’, ‘administration of antibiotics to animals at the dose prescribed’, ‘observation of the withdrawal period after administration of antibiotics’, ‘the number of antibiotics used for the treatment of clinical mastitis’, ‘use of antibiotics in cases of abortion’, ‘routine administration of antibiotics to newborn lambs/kids’, ‘use of antibiotics for the treatment of pneumonia in lambs/kids’, ‘use of antibiotics for the treatment of diarrhoea in lambs/kids’. Τhe variables evaluated for potential associations with the above outcomes are in p < 0.2 in the respective univariable analyses. Variables were removed from the initial model by backward elimination. The p-value of removal of a variable was assessed by the likelihood ratio test, and for those with a p-value of >0.2, the variable with the largest probability was removed. This process was repeated until no variable could be removed with a value of >0.2. The variables required for the final multivariable models constructed for each outcome are shown in The following eight outcomes were considered: ‘p < 0.05.In all analyses, statistical significance was defined at n = 357; 80.4% (76.5–83.8%)) and that they observed the withdrawal period after administration of antibiotics ). Fewer farmers responded that they weighed the animals for calculation of the proper dosage for the administration of antibiotics ). In total, 74 farmers (16.7% (13.5–20.4%)) performed all three practices correctly  and the number of animals on the farm (p = 0.020) for sheep farms and with the education of the farmer (p = 0.018) for goat farms (p = 0.029); for goat farms, no significant associations emerged . For the observation of the withdrawal period, a significant association was found for sheep farms only, specifically with the farmer’s education (p = 0.030); for goat farms, only a tendency emerged with the farmer’s involvement in the work (p = 0.08). The results of the multivariable analyses are in The results of the univariable analyses for assessment of potential associations of these practices with the studied variables are in at farms . For thep < 0.0001). The annual incidence rates of clinical mastitis in sheep flocks and goat herds were 3.9% (95% CI: 3.8–4.0%) and 2.8% (95% CI: 2.6–3.0%), respectively (p < 0.0001). Of these, treatment of the cases of mastitis was performed in 270 flocks (99.3%) and 71 herds (100.0%) (p = 0.47).Of the 325 sheep flocks and 119 goat herds in the study, cases of clinical mastitis were reported in 272  and 71 , respectively (p = 0.19), treatment involved the simultaneous administration of antibiotics and the non-steroid anti-inflammatory agent flunixin meglumine, which can be administered to alleviate pain, inflammation and fever in affected animals.On 302 farms (88.6%) (236 flocks and 66 herds), treatment of clinical mastitis involved only the administration of antibiotics. On the remaining 39 farms (11.4%) (34 flocks and 5 herds) (p = 0.81). The most frequently used antibiotic on its own was oxytetracycline , whilst the most frequently used combination of antibiotics was penicillin with streptomycin . These three antibiotics (on their own or in various combinations) were used in 219 flocks (81.1%) and 64 herds (90.1%). The frequency of use of the various antibiotics used is detailed in p > 0.18 for all comparisons)  .p = 0.12).On both sheep and goat farms, administration of antibiotics was most frequently performed in injectable form only  for intramuscular or subcutaneous injection according to the licenced route of administration. Less frequently, it was performed in intramammary form only , whilst, in some sheep flocks, both forms were employed   (6 versus 0.501 × 106 and 0.743 × 106 cells mL−1 (p = 0.07) and 309 × 103 versus 407 × 103 and 1413 × 103 cfu mL−1 (p = 0.035), respectively  . Moreoveectively .p = 0.0002)  . However 0.0002) .p = 0.011 for sheep flocks, p = 0.015 for goat herds)  .p = 0.92). The annual incidence rates of abortion in sheep flocks and goat herds were 2.0% (95% CI: 1.9–2.1%) and 2.7% (95% CI: 2.5–2.9%), respectively (p < 0.0001). Of these, use of antibiotics was reported in 68 flocks (44.2%) and 40 herds (70.2%) (p = 0.0008).Of the 325 sheep flocks and 119 goat herds in the study, cases of abortion were reported in 154  and 57 , respectively , use of pharmaceutical products involved only the administration of antibiotics.p = 0.17). The most frequently used antibiotic was oxytetracycline . The frequency of the various antibiotics used is detailed in On average, 1.12 ± 0.05 antibiotics were used per flock and 1.03 ± 0.03 antibiotics were used per herd , the daily period spent at the farm (p = 0.010) and the age of the farmer (p = 0.012), and additionally the season of the start of the lambing period (p = 0.007) were found as significant factors (p = 0.05) emerged as a significant factor .Of the 325 sheep flocks and 119 goat herds in the study, routine administration of antibiotics to newborn lambs/kids was reported in 65  and 29 , respectively (The most frequently used antibiotic (on its own or in combination) was oxytetracycline . Two antibiotics, namely oxytetracycline and amoxicillin (on their own or in various combinations) were the ones which were more frequently routinely administered to newborn lambs/kids; specifically, they were administered in 45 flocks (69.2%) and 20 herds (69.0%). The frequency of the various antibiotics used is detailed in p = 0.047) emerged as a significant factor, whilst for goat farms no significant associations were found (p > 0.11)  .p < 0.0001). In contrast, the respective findings for the incidence rate of diarrhoea were conflicting . The annual incidence rates of lamb/kid pneumonia in sheep flocks and goat herds were 1.7% (95% CI: 1.6–1.8%) and 1.5% (95% CI: 1.3–1.6%), respectively (p = 0.013). Of these, treatment of the cases of the disorder was performed in 71 flocks (74.0%) and 17 herds (73.9%) (p = 0.99).Of the 325 sheep flocks and 119 goat herds in the study, cases of pneumonia in lambs/kids were reported in 96  and 23 , respectively , its treatment involved only the administration of antibiotics. In no case was the administration of non-steroid anti-inflammatory drugs reported.p = 0.83). The most frequently used antibiotic (on its own or in combination) was oxytetracycline , whilst the most frequently used combination of antibiotics was oxytetracycline with penicillin . Three antibiotics, namely oxytetracycline, penicillin and tulathromycin (on their own or in various combinations) were used in 56 flocks (78.9%) and 14 herds (58.3%). The frequency of the various antibiotics used is detailed in On average, 1.33 ± 0.07 antibiotics were used per flock and 1.29 ± 0.11 antibiotics were used per herd .There was a clear difference between the frequency of antibiotics given routinely to lambs/kids and that of antibiotics given in cases of pneumonia , whilst for goat farms, no significant associations emerged (p > 0.15)  .p = 0.75). The annual incidence rates of lamb/kid diarrhoea in sheep flocks and goat herds were 9.6% (95% CI: 9.5–9.8%) and 13.7% (95% CI: 13.3–14.1%), respectively (p < 0.0001). Of these, treatment of the cases of the disorder was performed in 169 flocks (87.1%) and 64 herds (92.8%) (p = 0.21).Of the 325 sheep flocks and 119 goat herds in the study, cases of diarrhoea in lambs/kids were reported in 194  and 69 , respectively (On 195 farms (141 flocks and 54 herds), treatment of diarrhoea in lambs and kids involved the administration of antibiotics. On 62 farms (41 flocks and 21 herds) treatment involved solely  or in addition to antibiotics , the administration of anticoccidial drugs  in the therapeutic schemes.p = 0.21). The most frequently used antibiotic (on its own or in combination) was oxytetracycline , whilst the most frequently used combination of antibiotics was penicillin with streptomycin . Three antibiotics, namely oxytetracycline, amoxicillin and penicillin (on their own or in various combinations) were used in 103 flocks (60.9%) and 38 herds (70.4%). The frequency of the various antibiotics used is detailed in On average, 1.34 ± 0.05 antibiotics were used per flock and 1.59 ± 0.30 antibiotics were used per herd .There was some difference between the antibiotics given routinely to lambs/kids and to antibiotics given in cases of diarrhoea  and the routine administration of antibiotics to newborns (p = 0.048) emerged as significant factors, whilst for goat farms, no significant results were found (p > 0.10)  .Results of the multivariable analyses with a statistical significance are summarized in Small ruminant farming is currently the most important animal farming business in Greece, generating 18% of the total primary sector income . Small rThe present study investigated patterns of antibiotic usage in small ruminant farms in an extensive countrywide investigation of 444 farms. Moreover, the study evaluated potential associations with some management practices and the human resources on the farms. Farms from all regions of Greece were included in the study, allowing that situations and conditions present in all the parts of the country were taken into account and factors of regional importance weighed less. As far as we are aware, and to the best of our knowledge, this was the largest sample size used to investigate these issues. The farms studied in the present work represent approximately 1% of the total sheep and goat farms in the country, in accordance with the data of the Hellenic Milk Board [Inappropriate antibiotic use in food animals can contribute to development of resistance to antibiotics, and relevant evidence has been available for many years . In turnConvenience selection of study farms was employed, which allowed inclusion of flocks and herds with farmers willing to participate in the study and provide relevant answers. Some degree of stratification was also applied, as farms from all 13 administrative regions of the country were included in the study. The established limitations of questionnaire surveys certainly also applied in this work  . HoweverThe majority of farmers observed the withdrawal period after antibiotic administration and also administered the drugs at the dose prescribed. However, only few farmers weighed the animals for accurate calculation of dosage per bodyweight before drug administration. This practice certainly includes a contradiction as the estimation of the bodyweight of animals may not always lead to correct guessing of the actual bodyweight of animals. Visual estimation of the weight of animals can lead to errors, especially in crossbreed animals  as body Strict enforcement of regulations and the application of continuous assessments for detection of residues in animal products in the country motivate farmers to maintain withdrawal periods after antibiotic use. Nevertheless, a recent study in Greece reported that in 12.1% of raw milk samples from sheep, antibiotic residues were detected , which iIn cases of mastitis in small ruminants, early initiation of treatment is important, to minimize mammary lesions and to restore the health of the affected animals. Ideally and to preserve susceptibility of pathogens to the available drugs, treatment must be performed using a narrow-spectrum drug specifically effective against the causal bacteria of each particular case; administration of the drug should follow identification of the bacteria and establishment of their susceptibility patterns. Nevertheless, this may not be always possible, because of two conflicting factors: (i) the necessity for early instigation of treatment and (ii) the time required to perform a complete bacteriologic examination  . TherefoA non-steroid anti-inflammatory agent, in all cases flunixin meglumine, was used in only 11% of farms. Nevertheless, the use of flunixin meglumine in cases of mastitis promotes rapid resolution of clinical signs ,23, thusThe increased proportion of farmers preferring the systematic administration of antibiotics in comparison to the intramammary route may possibly reflect the lack of antibiotic products specifically licenced for use in small ruminants. This use is clearly reflected in the significantly smaller number of antibiotics used for the treatment of the infection in farms using intramammary administration in comparison to farms using injectable or mixed administration. Whilst, in principle, treatment of mastitis should be performed by using intramammary antibiotic tubes , obviousChlamydia abortus or Coxiella burnetii [Oxytetracycline is used in the vast majority of outbreaks of abortion, as the drug is administered metaphylactically in cases caused by burnetii ,26, whicCryptosporidium spp., Giardia spp., Rotavirus) [The rationale for routine administration of antibiotics to newborns is the prevention of neonatal infections in these animals. This practice should be discouraged, as, first and foremost, it is a paramount factor for the development of antibiotic resistance among bacteria prevailing on the farms. Moreover, from the viewpoint of the potential efficacy, the results do not justify the practice: the incidence rate of pneumonia was higher on farms, on which the practice was taking place and no beneficial effects were seen for the incidence rate of diarrhoea on the farms. In the first case, it should be noted that pneumonia in newborns is predisposed by various management-related factors . Errors tavirus) . These aThe above become particularly evident from the significant differences between the antibiotics given routinely to lambs/kids and those administered in cases of pneumonia or diarrhoea on the farms. This confirms the development of infection despite a prophylactic administration of antibiotics and the necessity for administering other products to treat the infections .The results of the univariable and multivariable analyses performed with regard to the use of antibiotics on the farms indicated that in most circumstances human resources were the predictors with significant associations for the use of antibiotics on the farms. In fact, human resource-related variables were found to be more important than factors related to management on the farms.Complex interactions exist as part of various-type social contacts  as part of various procedures , storage, food preparation) or between the physical environment , as well as in human use patterns  .With regard to the consumption of antibiotics by people, socio-demographic characteristics were found to be important. Among these traits, people who lived in farming regions were the ones with significantly higher antibiotic consumption . AdditioThe present findings indicate that similar trends are apparent in the usage of antibiotics for animals and socio-demographic characteristics of farmers are thus important determinants of the antibiotic usage patterns. Hence, education and updating of farmers regarding correct use of antibiotics should be continued, which can help achieve the prevention of the development of antibiotic resistance, as well as improved treatment of sheep and goat diseases on the farms.Extensive campaigns on antibiotic stewardship have been performed aiming to encourage prudent use of antibiotics and to limit their unnecessary usage. The ultimate objective of such actions is to preserve their efficacy for serious and life-threatening infections of humans ,33.The study explored the antibiotic usage patterns on small ruminant farms. The study presented another facet of the interactions between people and farm animals in the food-producing chain. Improved antimicrobial usage, based on correct scientific principles and compliance with regulations and policies, coupled with surveillance on the farms are important for improving the welfare of farm animals and also minimizing development of antibiotic resistance. These people–animal interactions can possibly be considered as another approach within the ‘One Health’ concept. Through the present results, the importance of training farmers regarding correct usage of antibiotics became prominent. In turn, correct use of antibiotics, as guided by surveying studies, will contribute to a reduction in bacterial resistance to these drugs.