Reinforced concrete specimens were periodically monitored within two years using the following techniques: linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS). Polarization measurements were conducted in a three-electrode arrangement, in which a rebar in concrete served as a working electrode, stainless steel sheet was used as an auxiliary electrode, and Cl−/AgCl,Ag was a reference electrode. Comparative tests of changes in the density of corrosion current in concrete specimens without chloride additives basically demonstrated no development of corrosion, and possible passivation was expected in case of black steel. Higher densities of corrosion current were observed for galvanized steel during first days of testing. The reason was the dissolution of zinc after the contact with initially high pH of concrete pore solution. Six-month measurements demonstrated a higher density of corrosion current in concrete specimens with high concentration of chlorides, which unambiguously indicated corrosion in concrete reinforced with galvanized or black steel. Densities of corrosion current determined for selected specimens dramatically decreased after an 18-month interval in measurements. Corrosion was even inhibited on black steel as an insulating barrier of corrosion products was formed. The above observations were confirmed with structural studies using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. Results obtained from corrosion  and structural  tests on specimens of concrete reinforced with steel B500SP demonstrated a very favorable impact of zinc coating on steel by providing two-year protection against corrosion in the environment with very high chloride content.Corrosion-induced damage to concrete reinforced with bars is a serious problem regarding technical and economic aspects and strongly depends on used materials, corrosion environment, and service life. Tests described in this paper refer to a two-year evaluation of the effectiveness of protection provided by zinc-coated low-carbon reinforcing steel of grade B500SP in concrete against chloride corrosion. Performed tests were comparative and included measurements conducted on four groups of concrete test elements with dimensions of 40 mm × 40 mm × 140 mm reinforced with a bar having a diameter of ϕ8 mm. Particular groups were a combination of different types of concrete with or without chloride additives, with galvanized or black steel. Chlorides as CaCl Issues addressed to the durability of reinforced concrete structures have been much tested and described in scientific papers of an interdisciplinary nature ,2. BondsA combination of two different construction materials, being advantageous from the mechanical point of view, can create serious difficulties and complications related to the evaluation of the structure safety with reference to its durability ,9,10. ThToday effects of degradation of reinforced concrete structures can be reduced or prevented using various methods. They include cathodic protection of reinforcement which provides permanent and controlled over time reduction of steel reinforcement potential in concrete to the level, at which metal exhibits resistance to corrosion. However, the use of the above method has to be preceded with the advanced diagnostic of corrosion employing such electrochemical methods as measurement of corrosion potential , measureIn fact, protective epoxy and zinc coating is the latest possibility of direct protection of reinforcing steel in concrete against corrosion. Epoxy coatings on steel reinforcement in concrete behave like a typical electric insulator, which as a plastic material acts as a hardly permeable barrier cutting off steel from corrosive agents present in the concrete cover . Unfortu2 gas dissolves [Zinc coatings prepared in HDG  process ,31,32,33issolves . If carbissolves , zinc coissolves ,41 than issolves  with refissolves , whereasissolves  mentionsissolves  or, accoissolves  4×–5× grThe majority of described studies on galvanized reinforcing steel embedded in concrete refers to short time periods, that is, a few or more than ten weeks. The authors of this paper decided to perform comparative tests on the effectiveness of protection against chloride corrosion of zinc-coated low-carbon reinforcing steel of grade B500SP in concrete within over ten months. Apart from fundamental electrochemical polarization tests employing LPR and EIS techniques, the concrete-coating-reinforcement contact was additionally evaluated after two years of measurements using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques.3 of CEM I 42.5—SR3/NA cement, 1669 kg/m3 of sand and aggregate of grain size of 2–8 mm. Water-cement ratio (w/c) was 0.45. About 3% of CaCl2 by cement weight, dissolved in batched water, was added to one of those mixes. In conclusion, six test elements were prepared from concrete without any additives, and another group of six specimens was prepared from concrete with chloride additives.Twelve concrete test elements with dimensions of 40 mm × 40 mm × 140 mm, reinforced with single steel bars were prepared for tests. Two batches of standard concrete mixes were used to place the concrete . In bothEach concrete test element was reinforced with a single ribbed rebar with a diameter of ϕ8 mm, made of steel of grade B500SP classified to steel class C of high ductility . As claiIn accordance with the primary purpose of studies, half of rebars made of steel of grade B500SP, used as the reinforcement in concrete test elements, was coated in the HDG process. For that purpose, holders were welded to cleaned bars cut to 1.5 m long pieces to provide galvanizing in a vertical position. Rebars placed on plating racks were successively immersed in a degreasing, pickling and finally fluxing bath. Prior to the immersion in the galvanizing bath, rebars were dried in a dryer. Bathing in molten zinc, at a temperature of ca. 450 °C, lasted 120 s. The obtained zinc coatings on steel rebars had an average thickness of ca. 100 µm, which met standard requirements ,50. BefoBefore concreting the specimens, galvanized or black steel rebars were cut into sections of 15 cm in length. Ends of each rebar were protected with shrink film against crevice corrosion in zones, where rebars expanded from concrete. Then, the rebars were stabilized in standard moulds for preparing specimens of masonry mortar, and then concreted. After two days from concreting, the specimens were stripped from the mould. Two weeks after concreting, polarization measurements of the reinforcement began.B symbol—black steel in concrete without any additives,blue color and G symbol—galvanized steel in concrete without any additives,green color and B-Cl symbol—black steel in concrete with chlorides,red color and G-Cl symbol—galvanized steel in concrete with chlorides.violet color and In summary, six concrete test elements were reinforced with galvanized rebars, and other six with black steel rebars. As two concrete mixes were used during tests, the total number of twelve test elements was divided into four groups, each of them containing three identical specimens. To differentiate clearly those groups, different colors and symbols were assigned to each of them as shown schematically in Assigned symbols and colors are consequently used in this paper to describe and analyze performed tests.−/AgCl,Ag) was placed in a vertical ballast guide 6 to provide its stabilisation during tests. The ballast 6 was used to provide the proper adhesion of the auxiliary electrode 3 through the felt 4 to the top surface of the concrete specimen 2. All three electrodes were connected to the potentiostat 7 Gamry Reference 600.Polarization measurements of the reinforcement in concrete test elements were conducted in a three-electrode arrangement illustrated in 7 and changes of gradually stabilizing potential were observed with the reference electrode 5 for 60–120 min. When potential changes were at the level of 0.1 mV/s, EIS methods were performed on the steel reinforcement in concrete. Testing was performed at the fixed range of frequencies of 0.01 Hz–1 kHz in the potentiostatic mode with a disturbing sinusoidal signal at the potential amplitude of 10 mV over the corrosion potential. Then, after a few minutes or a longer interval when changes in the corrosion potential did not exceed the level of 0.1 mV/s, LPR tests were conducted in the potentiodynamic mode. The reinforcement was polarized at a rate of 1 mV/s within the range of potential changes from −150 mV to +50 mV regarding the corrosion potential.Electrochemical tests were performed on the above measuring system using the following techniques: linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS). The specimens were kept at ca. 20 ± 2 °C and the relative humidity of 50 ± 10%. Prior to beginning polarization tests on a given day, the top surface of the concrete specimen was immersed in tap water to the depth up to 5 ± 1 mm for ca. 30 min to ensure better conductivity of concrete cover in the tested reinforcement during measurements. After taking from water, the specimens were connected to the potentiostat B, G, B-Cl, and G-Cl groups. At the final testing stage, results obtained from polarization measurements were compared with microscopic observations and analyses.The first measuring series began two weeks after placing specimens in concrete. Other five measuring series were conducted in one- and two-week intervals. At the next stage, six measuring series were taken at a two-week interval. Final measuring series took place in a month interval. After 18 months, prior to scheduled microscopic measurements, EIS and LPR tests were repeated but only on four specimens representing each of The specimens for structural tests were cut out perpendicularly to the rebar axis. Metallographic specimens were prepared from those cut pieces of concrete with rebars made of steel B500SP. Tests on the macrostructure of concrete specimens were performed at the stand specially prepared for macro testing. And microstructure of concrete was tested using Olympus SZX9 stereo microscope and GX51 inverted microscope (LM) .Advanced tests on the specimen structure at selected points were performed with HITAHI S-3400N scanning electron microscope (SEM)  at an accelerating voltage within the range of 15–25 kV. Tests on chemical composition at selected micro-areas of the specimens were performed with the energy dispersive spectroscopy (EDS) using the spectrometer by THERMO NORAN company with SYSTEM SIX software . As microscopic tests are invading into the structure of the specimen material, they were performed after the final stage of electrochemical tests. Therefore, those tests should be only related to results obtained after the last, 792 day of measurements.Core tests were conducted in less than six months and restarted after about an 18-month interval, but only on four selected specimens that were further subjected to microscopic tests.Linear polarization resistance (LPR) tests were the last tests from the group of electrochemical tests performed on the reinforced concrete specimen. Contrary to electrochemical impedance spectroscopy (EIS) tests regarded as complementary measurements, LPR tests were conducted on each test element from each measuring series. The whole period of testing produced a total of 160 polarization curves, in which exemplary shapes for three selected measuring series are illustrated in B and B-Cl was −0.28 V and −0.45 V, respectively. For the groups G and G-Cl, it was equal to −0.73 V and −0.91 V, respectively. However, the most significant information obtained from the analysis of polarization curves was the polarization resistance Rp was inversely proportional to the density of corrosion current icorr. The Stern-Geary Equation (1) was used to calculate values of icorr, taking into account coefficients of rectilinear slope for segments of polarization curves—anodic ba and cathodic bc.On day 4 of measurements, shapes of polarization curves a were moicorr are shown in icorr,mid = 0.31 µA/cm2 was obtained for the specimens from the group B. Because of naturally high alkaline pH (pH > 12.5) of concrete pore solution without additives, the obtained current density could indicate the passivation of reinforcing steel in concrete. Adding calcium chloride to the concrete mix caused the same black steel started to corrode in the specimens from the group B-Cl with icorr.mid = 1.65 µA/cm2. And the zinc coating on the reinforcement also began to dissolve electrochemically at pH > 13.3 when in direct contact with highly alkaline pore solution. The mean density of corrosion current icorr.mid = 0.93 µA/cm2 calculated for the group G could with high probability indicate that occurrence typical for the initial phase of concrete curing. The final, the highest mean density of corrosion current icorr.mid = 1.98 µA/cm2 referred to galvanized reinforcing steel in concrete with chloride additives. For the specimen group G-Cl, it could indicate the accumulation of zinc corrosion caused by high pH of concrete pore solution and aggressive impact of chloride ions.Parameters of the Equation (1) taken for calculations of Ecorr.mid = −0.40 V, and in concrete with chlorides the potential slightly increased to Ecorr.mid = −0.37 V. For galvanized steel in concrete without chlorides, a clear drop in potential to the value Ecorr.mid = −0.85 V was observed with the simultaneous increase in potential to the following level Ecorr.mid = −0.79 V. The comparison of graphical distributions of polarization curves from the beginning of tests  because its corrosion potential largely increased to −0.04 V, but what is more important, the density of corrosion current dramatically decreased to just 0.01 µA/cm2. Taking into account the fact the analyzed reinforced concrete specimen was potentially the most vulnerable to corrosion, the only possible explanation for the above situation was the high likelihood of the large accumulation of corrosion products (rust) around the steel rebar, and consequently, a serious limitation of direct access for oxygen and humidity to its surface. Hence, electrode processes on steel were stopped. For galvanized reinforcing steel in concrete with chlorides (G10-Cl), the corrosion current density dropped to 0.34 µA/cm2. The likely reason was the accumulation of corrosion products of zinc on the coating slightly slowing down its further dissolution. After two years of measurements, black steel (B1) and galvanized steel (G4) in the concrete specimens without chlorides had stable but low density of corrosion current , which suggested the reinforcement corrosion was not likely to develop.After about two years of measurements (day 792), prior to the commencement of microscopic tests, polarization curves for individual specimens representing each of four groups  showed aElectrochemical impedance spectroscopy (EIS) tests on the specimens of concrete with reinforcement were additional to core polarization tests performed by linear polarization resistance (LPR) method. Impedance tests focused only on three selected measuring series on day 4, 74, and 792.ϕ against the logarithm of measurement frequency f. For the specimens from groups B and G made of concrete without chlorides, spectra at the Nyquist plots  of concrete pore solution.st plots a exhibitB-Cl and G-Cl made of concrete with chlorides, the size of spectra at the Nyquist plot was much smaller and the second time-constant was clearly noticeable. Shapes of those spectra were rather characteristic for the development of metal (Fe or Zn) corrosion in concrete. Observations made for the Nyquist plot (B and G) displayed quite wide angles of phase shift (−20°–−40°), whereas the specimens of concrete with chlorides (groups B-Cl and G-Cl) reached the maximum level of −15°. The observed shapes of those spectra, which were very distinctive, quite explicitly indicated the corrosion of metal in the specimens from groups B-Cl and G-Cl. For galvanized steel (group G) the situation was slightly less favorable, which could suggest not so intensive processes of zinc dissolution.For the specimens from groups ist plot a were adist plot b. Low frCPE0. Parameter Rc is resistance of concrete, Rt is charge transfer resistance across the interface. The electric circuit shown in Rf—resistance of the coating layer and CPEf—constant phase element characterizing its quasi capacity. The Simplex method was used to find numerical values of elements in equivalent circuits, and those values are presented in CPE0—Y0 and α0 and CPEf—Yf and α0.The above qualitative analysis of obtained spectra was confirmed by the quantitative analysis. For that purpose, the equivalent electrical circuit illustrated in On day 74 of measurements, the impedance spectra at the Nyquist plot a obtaineFor the specimens of concrete with chlorides, day 74 of measurements revealed a small drop in the intensity of corrosion processes of galvanized and black steel. The presented deduction resulted from the quantitative analysis on the basis of the equivalent electrical circuits illustrated in B1, G4, B7-Cl, G10-Cl) being the one-element representation of all four groups  of test elements. The Nyquist plot (B7-Cl) and three considerably smaller spectra near the beginning of the coordinate system. For better clearness of the results, those three spectra are again presented below, in the second complex plane with 20-time smaller values of complex and real impedance. The clear dominance of one spectrum over others indicated the impedance of the whole steel-concrete system in the specimen B7-Cl was about 20 times greater than the impedance of the other three specimens. As all impedance measurements on the final measuring series (day 792) were conducted within a broader range of frequencies 0.01 Hz–100 kHz, particularly the spectrum B7-Cl had a rather interesting shape. It had (from the left side) a high-frequency, slightly oblate semi-circle expressing electrochemical properties of concrete, and from the point of contraflexure a rectilinear part changing into the arc shape. The last described part could indicate diffusion control over the corrosion process. The spectrum shape for B7-Cl in the complex plane and at the Bode plot demonstrated a very strong slowdown on day 792 of measurements, comparable to the situation, in which dissolution of reinforcing steel in concrete was inhibited despite the presence of aggressive chloride ions. A continuous increase in the volume of corrosion products was supposed to inhibit seriously the access of oxygen to the steel surface, and consequently to eliminate the agent required for the development of electrochemical corrosion of steel in concrete.The last series of impedance measurement was made on day 792, that is, after about two years of measurements and included only four specimens  at the Nyquist plot were rather similar in shape, particularly with reference to the low-frequency range describing the properties of metal in concrete. The qualitative analysis conducted with the electrical equivalent circuit illustrated in Rt = 34 k–50 kΩcm2, which corresponded to very low densities of corrosion current icorr = 0.29–0.35 µA/cm2. According to criteria published in [G4 had the lowest resistivity, and concrete in the specimen G10-Cl had the highest resistivity.Impedance spectra of the other three specimens  to over 400 µm (434 µm) a. MorphoThe comparison of the thickness of zinc coating on steel in concrete without chlorides  and withcorrE of steel reinforcement in concrete very clearly demonstrated (B), and with chlorides (group B-Cl) was relatively close within the range of −0.1–−0.5 V. While evaluating obtained results with reference to standard criteria [G-Cl was considerably greater than for the group B-Cl.The analysis of changes in a function of time of corrosion potential nstrated  that corcriteria  for testicorr within two years of measurements, obtained on the basis of analyses of polarization curves of reinforcing steel in the concrete specimens. Results for galvanized steel (G) and black steel (B) in concrete without additives are shown in From a scientific perspective, the analysis of results from electrochemical tests (particularly density of corrosion current) seems to be very interesting during a 2-year period of performed tests. B) generally had stable but the low density of corrosion current through the whole period of measurements, which in accordance with criteria for evaluating corrosion risk to steel in concrete, could indicate the passivation. Microscopic tests (As shown in ic tests b demonstG), elevated values of corrosion current density (oscillating around 1 µA/cm2) were observed in the initial phase of measurements (until day 18 of measurements). Then, corrosion current density stabilized at the level of 0.3–0.5 µA/cm2, which was a slightly better result than for black steel. The already mentioned quite a rapid increase in corrosion rate for galvanized steel in concrete without chloride content was related to zinc corrosion in highly alkaline concrete pore solution. At pH > 13.3 corrosion of galvanized coat on reinforcement was initiated.In case of galvanized steel reinforcement in concrete without chlorides  and structural  tests on the specimens of concrete reinforced with steel B500SP demonstrated a very favorable impact of zinc coating on rebars by providing effective protection against corrosion in chloride environment.The following conclusions can be drawn from two-year comparative tests on efficiency of the hot-dip galvanized zinc coating applied on reinforcing steel B500SP in concrete.


Although upfront surgery has been the gold standard for pancreatic adenocarcinoma that is planned for resection, it should be compared with the alternative strategy of neoadjuvant therapy. Despite the many reports of the efficacy of neoadjuvant therapy, most of them were not comparative. Recently Prep‐02/JSAP05 study clearly demonstrated the significant survival benefit of neoadjuvant chemotherapy over upfront surgery for pancreatic adenocarcinoma that is planned for resection. These findings opened a new chapter of neoadjuvant therapy. Ongoing trials are expected to confirm the evidence. This review summarizes the past, present, and future perspectives of neoadjuvant therapy and its optimization. Recently, Prep‐02/JSAP05 study demonstrated the significant survival benefit of neoadjuvant chemotherapy over upfront surgery for pancreatic adenocarcinoma that is planned for resection. This review summarizes the past, present, and future perspectives of neoadjuvant and its optimization. Adjuvant therapy (adjuvant) is administered for macroscopically curatively resected PDAC with full recovery in the planned postoperative period and without immediate early recurrence Figure . This co3As well as upfront surgery, neoadjuvant followed by surgery has patient selection during the neoadjuvant period, in addition to surgical selection Figure . In retrSeveral meta‐analyses investigated the efficacy of neoadjuvant.4Unfortunately, limited reports of RCTs of neoadjuvant compared with upfront surgery have been published. Golcher et alP = .015).Unno and Motoi et alSeveral RCTs of neoadjuvant compared with upfront surgery as the control have been ongoing. Heinrich et al5Two cycles of the GS regimen, which was used in the Prep‐02/JSAP05 study, have been a standard regimen for NAC, at least in Japan, for potentially resectable PDAC.6Two major regimens for UR PDAC have been provided as standard based on the results of RCTs. Conroy et alIn the adjuvant setting, the modified FOLFIRINOX was more active than gemcitabine.7Chemoradiotherapy is an attractive modality in the treatment of PDAC for local disease control. In the neoadjuvant setting, an increase of R0 resection, which would decrease local relapse after resection, is expected for NACRT. Many prospective non‐randomized trials of NACRT have been reported.8The duration of neoadjuvant was about 2 months in most previously reported trials for R PDAC.For neoadjuvant for UR and BR PDAC including the concept of “conversion surgery,” several reports demonstrated longer duration of the treatment before surgery.9To compare many types of interventions, surrogate endpoints are needed to select the optimal intervention. Surrogate endpoints for OS have not been established for PDAC in the neoadjuvant setting. Although the R0 resection rate has been considered to be the main goal for cancer surgery, it might only be a minimal requirement for long‐term survival. Actually, no significant difference of the R0 resection rate between NAC and upfront surgery was observed in the Prep‐02/JSAP05 trial, where a significant difference in OS was observed.The pathological effect after neoadjuvant might be another candidate surrogate endpoint for OS. Pathological CR following neoadjuvant has been shown to be associated with long‐term survival in other types of cancer, including breastRadiological response would be a candidate surrogate endpoint. Radiological assessment, which could be performed before surgery, is superior to pathological assessment in clinical decision‐making. Radiological CR could reflect pathological CR, which could be a surrogate endpoint of survival in the other types of cancer described above. As well as pathological CR, radiological CR of PDAC is rarely obtained even after multi‐modal treatment.Serum tumor markers and their kinetics are other promising candidates as surrogate endpoints. CA19‐9, which is increased in most PDACs at baseline, is widely used as a tumor marker. A decrease of tumor markers after therapy reflects a good response and longer survival for responders.10Recently evidence opened a new chapter of the neoadjuvant era for PDAC. However, it was only a beginning, and further efforts are needed to optimize it with adequate surrogate markers.Conflict of Interest: Author FM and MU received lecture fee from Taiho Pharmaceutical. Author MU was supported by grant from Takeda Pharmaceutical Company.


Nitrofurantoin is a common treatment for urinary tract infections. Acute lung injury resulting from nitrofurantoin is a rare, life‐threatening complication with women being at greater risk. Symptoms include respiratory distress with fevers, rash, eosinophilia, and new‐onset atrial fibrillation. Treatment includes discontinuing the drug and possibly glucocorticoids for persistent oxygen demand. Nitrofurantoin is a common treatment for urinary tract infections. Acute lung injury resulting from nitrofurantoin is a rare, life‐threatening complication with women being at greater risk. Symptoms include respiratory distress with fevers, rash, eosinophilia, and new‐onset atrial fibrillation. Treatment includes discontinuing the drug and possibly glucocorticoids for persistent oxygen demand. The pain started 6 hours before presentation when she was on a 3‐hour drive home after visiting her daughter. She initially went to Urgent Care where she took some aspirin, but her pain did not improve prompting her visit to the ED. She reported some associated nausea, but otherwise denied fevers, chills, shortness of breath, abdominal pain, vomiting, diarrhea, headache, tingling, or dizziness. Her chronic medications included amlodipine, aspirin, atorvastatin, losartan‐hydrochlorothiazide, metformin, and metoprolol. She was started on nitrofurantoin, twice daily, 2 days prior to presentation for a urinary tract infection (UTI), which was discontinued on admission. She did not use any supplemental oxygen at home and her most recent cardiac stress test 1 year prior to admission was normal. On physical exam, she had a regular heart rate and rhythm without any murmurs, rubs, or gallops. Her lungs were clear to auscultation bilaterally without any wheezing, rales, or rhonchi. She did not have any extremity edema, cyanosis, calf tenderness, and had 2+ pulses bilaterally. Her abdomen was soft and nondistended and she was alert and oriented without any focal neurological deficits. Her oxygen saturation was 89% on room air and remaining vital signs were within normal limits.While in the emergency room, serial troponins were negative, D‐dimer, and BNP were within normal limits, and EKG was unremarkable. She had mild leukocytosis with elevated eosinophils and transaminitis, but an initial liver ultrasound was unremarkable Table . She was3A follow‐up CT scan of her chest, abdomen, and pelvis with contrast showed enlarged mediastinal lymph nodes without any evidence of a hilar or lung parenchymal mass. Figure  PulmonolOn the third day following admission, the patient developed a fever and new‐onset atrial fibrillation for which she was started on rivaroxaban and an increased metoprolol dose. She also received doxycycline for suspected hospital‐acquired pneumonia given her fever and imaging findings. Shortly after, she developed a maculopapular rash across her abdomen and back while becoming hypoxic with increased work of breathing and 6 L oxygen demand. A CT angiogram of her chest ruled out a pulmonary embolism and showed bilateral pleural effusions. Antibiotics were broadened to piperacillin/tazobactam and vancomycin, and she was admitted to the intensive care unit (ICU).42 requirement with persistent eosinophilia and was started on high dose prednisone. Eosinophils dramatically improved and she was able to be weaned off O2 completely. She passed her home O2 evaluation and was discharged on 20 mg PO that was gradually tapered over 3 weeks, furosemide, and rivaroxaban in addition to her prior to admission medications. At her follow‐up 1 week after discharge, her eosinophil count and leukocyte count returned to within normal limits and her shortness of breath improved markedly. She continued showing improvement at subsequent monthly follow‐up visits and per her most recent follow‐up in July 2020 she remains symptom free.She had a 2‐day ICU stay where she was on BiLevel Positive Airway Pressure (BiPAP) support, supplemental oxygen, and IV furosemide diuresis. Infectious disease was consulted and given negative blood cultures, absence of clinical or radiological evidence of pneumonia, or a cardiac cause of fluid overload, a diagnosis of nitrofurantoin‐induced lung injury was suspected. This was supported by the patient's fever, worsening dyspnea, pleural effusion, new‐onset atrial fibrillation, erythema multiforme rash, and eosinophilia. All antibiotics, including ceftriaxone, piperacillin/tazobactam, vancomycin, and doxycycline were discontinued. The patient's symptoms improved, and she was gradually weaned off oxygen and downgraded. Despite improvement, she still had a 2 L O5Lung injury following nitrofurantoin use is a rare complication in the acute setting. Previous studies indicate the incidence of pulmonary injury due to nitrofurantoin use to be between 0.0001% and 0.001%, with 90% of these cases being acute.For first‐time users, acute pulmonary reactions presented on average 8.7 days after nitrofurantoin use, 24 hours with repeat exposure.Physical exam and imaging for nitrofurantoin‐induced lung injury are nonspecific. Patients may show respiratory distress, rales, crackles, or nothing on physical exam.2 and eosinophilia following nitrofurantoin use were indications to start the patient on high dose prednisone. After the addition of the prednisone the patient O2 requirements were weaned off and eosinophil levels decreased to normal levels. It is unclear whether this was due to more time following nitrofurantoin discontinuation or as a result of the glucocorticoid.Treatment for nitrofurantoin‐induced lung injury in the acute setting is the discontinuation of the drug. Patients experience improvement of symptoms in a relatively short time period, days to weeks.6Nitrofurantoin has been proven to be an effective first‐line antibiotic for the treatment of lower UTI in the general population. In this particular case, our patient most likely suffered from a rare but serious adverse effect of nitrofurantoin therapy leading to a presentation of acute lung injury. With the initiation of nitrofurantoin 2 days prior to presentation as well as the exclusion of other possible etiologies such as pulmonary embolism, malignancy, and myocardial infarction, this points to nitrofurantoin as the most likely causative agent. Although the mechanism behind the cause of acute lung injury is still unclear, the management of this rare presentation includes discontinuation of nitrofurantoin with possible initiation of oral glucocorticoids if there is suspicion of respiratory distress.The authors declare no conflict of interest.RK: initiated this case report; performed literature review and wrote the final manuscript draft. KS: performed literature review and contributed substantially to this manuscript's contents. IS: reviewed the manuscript for intellectual content and contributed key content. KS: advised authors and reviewed this manuscript for intellectual content.This case report does not contain any clinical studies with human participants performed by any of the authors.Patient provided written consent for the publication of this case report.


Ants have strict requirements on the building materials of the nest, such as the size, weight, luster and color of soil particles. The soil of underground ant nests is composed of clay particles cemented together to form a hard brick-like material. The ant nest powder shows pozzolanic activity after calcination, which can meet the requirements for active admixture of concrete. Under the standard curing condition, the influence of calcined ant nest clay powder (CANCP) on the durability of concrete is evaluated by chloride penetration resistance, carbonization resistance and freeze–thaw resistance, and the influence of the powder content is investigated. The results show that when the content of CANCP is less than 10%, the chloride penetration resistance of concrete increases with content of CANCP. In the early stage of carbonation, the greater the content of CANCP, the higher the carbonization rate of concrete. In the middle and later stage of carbonation, the carbonation rate of CANCP concrete is significantly lower than that in the early stage, and the carbonation depth is linearly related to the carbonation time. When the content of CANCP is less than 20%, the freeze–thaw resistance of CANCP concrete is better than that of the reference concrete. Ants have strict requirements on the building materials of the nest, such as the size, weight, luster and color of soil particles. The underground ant nest is generally composed of soil and gravel, and is mixed with organic substances such as dead plant bodies and ant secretion, and the clay content is large. Compared with the common clay around the ant nest, its physical and chemical properties have changed greatly. The soil of underground ant nests is composed of clay particles cemented together to form a hard brick-like material. Most of the natural clays have pozzolanic activity after calcination . At presThe calcined ant nest clay powder (CANCP) can partially replace cement and the associated influence on the compressive strength of concrete has been studied . After cPO 42.5 ordinary Portland cement was used , and theA standard mix proportion of design strength of C50 was used as reference concrete (CT for short) in this test, and the calculated mix proportions were shown in CANCP was obtained from the underground nest soil of iridomyrmex anceps after calcination at 800 °C for 2 h and grinding for 60 min by SM-500 ball crusher . The phy2, Al2O3 and Fe2O3 in CANCP reached 88.76% which is greater than the 70% specified in the ASTM  standard for concrete mineral admixtures [The total content of SiOmixtures . The cheD of chloride ion was measured. The vibration forming and test process of the specimens are shown in In this test, the electric flux method of ASTM C1202  was usedIn this test, the method of GB/T 50082-2009  was used2 concentration (20% ± 3%), relative humidity (70% ± 5%), and temperature (20 ± 2 °C).Standard curing was adopted, and the specimens were taken out from the standard curing room two days before the test, and then they were dried for 48 h in the electric air blast drying oven at 60 °C After drying, except one side of the specimen, the other three sides were sealed with heated paraffin. On the exposed side, parallel lines were drawn with a pencil at a distance of 10 mm along the length direction as the measurement point of the predetermined carbonation depth. HTX-12X microcomputer concrete carbonation test chamber was used in the test, and the test was carried out under the conditions of COThe specimens were taken out when the carbonization process reached 3, 7, 14 and 28 d, and the splitting method was used on the pressure testing machine to start the fracture from 50 mm at one end. After the fracture, the cross section was sealed with paraffin again, and the remaining specimen was put into the carbonization test chamber to continue carbonization until the next carbonization age. The residual powder was removed on the section of the specimen obtained by splitting, and 1% phenolphthalein reagent was sprayed immediately on the cross section. After 30 s, the carbonation depth of 10 measuring points was measured respectively. The average value of carbonation depth at each test point was calculated, as the carbonation depth of the specimen, and the calculation accuracy was 0.001 mm. The determination carbonation depth of specimens is shown in First, 100 mm × 100 mm × 400 mm prism specimen was adopted for the quick freeze–thaw test . The speThe mass loss rate ΔW and the relative dynamic elasticity modulus reduction rate ΔD are taken as the indexes to evaluate the freeze–thaw resistance performance of concrete. The mass and transverse fundamental frequency of the specimens were measured every 25 freeze–thaw cycles, as shown in 0 and the chloride ion penetration depth value XD were measured, and the results are shown in According to the electric flux method of ASTM C1202 , the 6 hIt can be seen from the test results that the chloride penetration resistance of concrete increases first and then decreases after adding CANCP. When the content of CANCP is less than 10%, the chloride penetration resistance of concrete increases with the increase of the content of CANCP, and the electric flux of concrete containing 5% and 10% CANCP is 1310.1C and 998.9C, which is 8.8% and 30.4% lower than that of the reference concrete CT. When the content of CANCP is more than 10%, the chloride penetration resistance of concrete decreases with the increase of the content of CANCP, and the electric flux of concrete containing 15% and 20% CANCP is 1639.5C and 2207.1C, which is 14.2% and 53.7% higher than that of the reference concrete CT. On the contrary, the initial current value and chloride penetration depth value of concrete first decreased and then increased after adding CANCP. When the content of CANCP is less than 10%, the initial current value and chloride penetration depth of concrete decrease with the increase of the content of CANCP; when the content of CANCP is more than 10%, the initial current value and chloride penetration depth of concrete increase with the increase of the content of CANCP.2 is 0.964, and there is a good linear correlation between the initial current and 6 h electric flux. Therefore, the initial current can be used to calculate the electric flux to accelerate the test efficiency. The 28 d initial current can be used as the evaluation index to accelerate the detection of the chloride penetration resistance of CANCP concrete.Feldman believes that there is a good linear correlation between the initial current or conductivity and the 6 h electric flux for the same type of concrete. Therefore, it can be considered to provide a fast and convenient evaluation method for the chloride penetration resistance of concrete by testing the initial current or conductivity . The lin2 is 0.943, and there is a good linear correlation between chloride penetration depth and 6 h electric flux. Therefore, the penetration depth XD can be calculated by measuring the electric flux Q, and then the permeability coefficient of chloride ion in the specimen can be obtained according to Nernst–Planck equation.The linear correlation analysis of chloride penetration depth and 6 h electric flux is shown in According to JGJ/T 193-2009 , the carThe carbonation depth histogram and the carbonation depth-time curve of concrete with different content of CANCP are shown in It can be seen from the histogram that the carbonation depth of the concrete with CANCP in each curing age is greater than that of the reference concrete. With the increase of the content of CANCP, the carbonation depth gradually increases. The carbonation time is 28 days, and the carbonation depth of concrete with 20% of CANCP is 9.863 mm, which is more than twice of that of concrete without CANCP. As shown in The mass loss rate and relative dynamic elastic modulus curve of different content of CANCP with the number of freeze–thaw cycles, as shown in It can be seen from The dynamic modulus of elasticity is closely related to the internal structure of materials, that is, the dynamic modulus of elasticity of concrete is more sensitive to the internal structure damage. Under the action of the freeze–thaw cycle, the internal structure of the concrete gradually changes from compact to loose, and the concrete itself inevitably has some original microcracks and defects. With the increase of freeze–thaw cycle times, the microcracks and defects in the concrete continue to expand, the section strength gradually decreases, the internal microstructure of concrete is disturbed, resulting in the decrease of dynamic elastic modulus of the concrete.The decrease of dynamic modulus of elasticity of each content is not obvious in the early stage of the freeze–thaw cycle (before 100 cycles), and the accelerated failure appears in the middle and later stage of the test. The accelerated failure occurred after 150 freeze–thaw cycles for the reference group without CANCP and the group with 20% of CANCP, while the accelerated failure occurred after 225 cycles for the group with 10% of CANCP. The concrete with 10% of CANCP demonstrated the best freeze–thaw resistance.b is used to estimate the freeze–thaw resistance of concrete:The freeze–thaw resistance durability index KIn the formula: P is the relative dynamic elastic modulus of concrete after n freeze–thaw cycles; N is the number of freeze–thaw cycles that the concrete can withstand.The calculated freeze–thaw resistance durability index of CANCP concrete is shown in 2 and Al2O3 in CANCP can generate more hydrated calcium silicate and aluminum silicate with Ca(OH)2, which can increase the binding capacity of concrete to chloride ions and reduce the content of free chloride ions [SiOide ions .Micro filling effect and micro aggregate effect . The fin2 is consumed in the hydrated cement paste, and C-S-H gel is increased during the process of pozzolanic reaction. The pozzolanic effect of CANCP can transform Ca(OH)2 to C-S-H gel, and fill between cement hydration products, which can effectively improve the performance of concrete. Meanwhile, the pozzolanic C-S-H gel with low Ca/Si ratio will produce when CANCP has second pozzolanic reactions with traditional C-S-H gel in the hydrated cement paste, and the pozzolanic C-S-H gel is relatively stable which can improve the performance of the traditional C-S-H gel to improve the performance of the concrete. The addition of CANCP can improve the microstructure of the concrete, reduce the porosity, refine the pore size and make the concrete more dense, and all of these increase the diffusion resistance of the concrete to chloride penetration [2 in concrete containing 10% CANCP, and it shows that concrete containing 10% CANCP has a high degree of hydration; C-S-H gel in concrete with 10% of CANCP is more dense and clustered to a higher degree than ordinary concrete.Pozzolanic activity and pozzolanic effect of CANCP promotes the secondary hydration reaction of cement, resulting in a large number of C-S-H gels. A large amount of Ca(OH)etration . It can When the content of CANCP is not more than 10%, it can effectively improve the chloride penetration resistance of concrete. The reasons are listed below:2, Al2O3 and Fe2O3 in CANCP with the main products of cement hydration is as follows [The secondary hydration reaction of the active components SiO follows :(2)CaO+H2, resulting in C-S-H gel and C-A-H gel with low calcium–silicon ratio. At the same time, the active silicon in CANCP will react directly with the C-S-H gel generated from the cement to form C-S-H gel with low calcium–silicon ratio [2 and Al2O3 in the admixture react with Ca(OH)2 generated by secondary hydration of the cement clinker, which reduces the alkali reserve in the cementitious paste [CANCP has active ingredients, and its secondary hydration requires consumption of Ca(OH)on ratio ,25. Althus paste . When th3 have filling effect. The internal pore structure of cementitious materials is improved, resulting in slow carbonation reaction.The carbonization rate of CANCP concrete at the early stage of carbonization is much larger than that in the middle and later stage of carbonation. This is due to the large number of pores in cementitious material in the early stage. In the middle and later stage, the pozzolanic reaction occurred, and the products of C-S-H gel and carbonization reaction product CaCOThe pozzolanic effect by CANCP can result in the formation of low alkaline calcium silicate hydrate with high strength, increasing the amount of hydration cementitious material in concrete, improving the ability of the traditional C-S-H gel, thereby improving the performance of hardened cement paste and improving the freeze–thaw resistance property of concrete. At the same time, micro filling effect by CANCP can result in denser paste, and improved freeze–thaw resistance property ,28.The content of CANCP should be controlled at a proper proportion, and the best proportion is 10%. When the content is more than 20%, the hydration of CANCP will not be complete. At the same time, non-active components in CANCP remain in the concrete to form more pores which increases the porosity of concrete. Under the action of the freeze–thaw cycle, micro cracks will be formed in the concrete, which lead to the deterioration of the internal structure of the concrete.When the content of CANCP is less than 10%, the initial current value and chloride penetration depth of concrete decrease with the increase of the content of CANCP and it can effectively improve the chloride penetration resistance of concrete.The addition of CANCP can accelerate the carbonation process of concrete. When the CANCP content is not more than 20%, the carbonation resistance grade of concrete is not impacted.When the content of CANCP is less than 10%, the concrete with CANCP can still keep the internal structure compact under the action of freeze–thaw and it can effectively improve the freeze–thaw resistance of concrete.It is proved that CANCP can be used as green concrete admixture, which provides favorable evidence for the feasibility of CANCP as ecological building materials.This paper attempts to prove that CANCP can be used as a mineral admixture to improve the durability of concrete. Based on the experimental tests and the data analyses, the following conclusions can be drawn:


MET-amplified gastric cancer cells are extremely sensitive to MET inhibition in vitro, whereas clinical efficacy of MET inhibitors is disappointing. The compensatory activation of other oncogenic growth factor receptors may serve as an underlying mechanism of resistance. In this study, we analyzed the role of HER receptors, in particular HER3 and its ligand heregulin, in this respect. This also included the chromatin-organizer protein SATB1, as an established regulator of HER expression in other tumor entities. In a panel of MET-amplified gastric carcinoma cell lines, cell growth under anchorage-dependent and independent conditions was studied upon inhibitor treatment or siRNA-mediated knockdown. Expression analyses were performed using RT-qPCR, FACS, and immunoblots. Signal transduction was monitored via antibody arrays and immunoblots. As expected, MET inhibition led to a growth arrest and inhibition of MAPK signaling. Strikingly, however, this was accompanied by a rapid and profound upregulation of the oncogenic receptor HER3. This finding was determined as functionally relevant, since HER3 activation by HRG led to partial MET inhibitor resistance, and MAPK/Akt signaling was even found enhanced upon HRG+MET inhibitor treatment compared to HRG alone. SATB1 was identified as mediator of HER3 upregulation. Concomitantly, SATB1 knockdown prevented upregulation of HER3, thus abrogating the HRG-promoted rescue from MET inhibition. Taken together, our results introduce the combined HER3/MET inhibition as strategy to overcome resistance towards MET inhibitors. Gastric cancer is one of the most common cancer types ,2. WorldDiscrepancies between preclinical data and the clinical reality are particularly striking in the case of the inhibition of the HGF/MET axis in gastric cancer cells harboring a MET amplification, which occurs in 3–7% of gastric tumors ,11. In tIt has been proposed that members of the HER family of RTKs, especially HER2 or HER3, could compensate for a reduced MET function, thus contributing to tumor resistance against MET inhibitors. In fact, stimulation of MET-amplified gastric cancer cells with the HER agonist heregulin (HRG) could ameliorate the cytotoxic effects of MET inhibitors ,16,17. FIn this study, we address the functional relevance of HER receptors, and in particular of HER3, in MET-amplified gastric cancer cell lines. This also includes the role of SATB1 in this process. We show a rapid and substantial increase in HER3 expression upon inhibiting MET, which is mediated by SATB1 and leads to an even enhanced heregulin (HRG)/HER3 signaling. This establishes the role of HRG/HER3 signaling in mediating resistance of gastric cancer cells towards MET inhibition. Thus, our findings provide an avenue towards increasing the efficacy of MET-directed therapeutic interventions. To investigate the role of HER receptors in resistance of gastric cancer cells against MET inhibitors, we used a panel of five gastric cancer cell lines, three of which  were described as MET-amplified and sensitive to MET inhibition, and two (MKN7 and MKN74) are not MET-amplified. Expression analyses on the mRNA level confirmed the exceptionally high MET expression in the three MET-amplified cell lines A. MET-amIt has been described previously in non-gastric cancer cell lines that resistance of HER receptor overexpressing cells towards inhibition or knockdown can be attributed to the adaptive activation of other HER family members ,14 for rA,B and pAdditionally, various responses were noted with regard to HER1 and HER2 levels: in MKN45 cells, HER1 mRNA was slightly reduced upon MET inhibitor treatment A, but noThe interplay between MET inhibition and alterations in HER receptor expression levels suggested the possibility that the very profound anti-proliferative effects of the MET inhibitor may be counteracted by HER3 activation in the presence HER receptor ligands. Indeed, addition of heregulin (HRG) in the physiological concentration of 20 ng/mL to the culture media led to a partial rescue of MET inhibitor-mediated (0.2 µM of PF04217903) arrest in proliferation in MKN45 cells. This was even true in the constant presence of the inhibitor and thus under conditions of sustained MET inhibition A. In theWhen analyzing the percentages of viable and dead cells in a live/dead cell assay, a substantial > 4-fold increase in apoptotic cells upon exposure to the MET inhibitor was observed. Again, however, this was markedly reduced in the combined treatment scenario with MET inhibitor plus HRG, indicating the pro-survival effects of HER3/HRG signaling under MET inhibition E. The functional relevance of HER3 was further explored by siRNA-mediated parallel HER3 knockdown. In negative control transfected cells and in the absence of MET inhibitor, no further stimulation of cell proliferation was obtained upon addition of HRG or the HER1 ligand EGF F, left. To further characterize the pathways involved in the cellular effects of MET inhibition and HRG stimulation/rescue, phospho-antibody arrays were performed for analyzing changes in MAPK activities . Upon adWe further analyzed the underlying molecular mechanism of this counter-upregulation. We did not find any evidence that the blockade of MAPK or AKT signaling induced by MET inhibition was involved in HER3 regulation, since the inhibition of MAPK by the MAPKK inhibitor PD98059 (10 µM for 48 h) or the blocking of AKT signaling via PI3K inhibition with LY294002 (10 µM for 48 h) did not reproduce the effects of MET inhibition on HER3 levels . Since PKC is a known MET target, we next tested its role by pretreating MKN45 or SNU5 cells with the PKC inhibitor BIM II (10 µM) for 24 h, prior to the addition of the MET inhibitor PF 04217903 (0.2 µM for 48 h). Under these conditions the upregulation of HER3 was abrogated in MKN45 A, left aTreatment of MKN45 cells with MET inhibitor again led to ~ 50% decreased HER1 mRNA levels, independent of prior transient transfection with SATB1 siRNA or a non-specific negative control siRNA C, left. The SATB1-dependent regulation of HER3 expression upon MET inhibition was also found on the protein level. While the MET inhibitor led to a pronounced increase in HER3 expression in control transfected cells E. NotablIn the present study, we demonstrate that treatment of MET-amplified gastric cancer cells with a MET inhibitor leads to a SATB1-mediated upregulation of HER3. In the absence of HER3 ligands in cell culture, which are not endogenously produced by the tumor cells, this adaptive and rapid induction of HER3 did not confer resistance towards MET inhibition. In contrast, in the presence of the HER3 ligand heregulin, a scenario, which resembles more closely the in vivo situation in tumors (see below), a partial rescue of the cancer cells from the detrimental effects of MET inhibition was observed. It has been shown previously that MET inhibition in monocultured gastric cancer cells with MET amplification exerts dramatic anti-proliferative effects, in parallel with abrogation of ERK and Akt phosphorylation. This can be overcome in part by HER activation ,16,22. HThe fact that Akt phosphorylation after MET inhibition is more efficiently restored by HRG treatment of gastric cancer cells than by EGF treatment is in line with previous findings  and indiRemarkably, MET inhibition led to a substantial upregulation of HER3, the critical signaling molecule responsible for heregulin-promoted survival. Of note, HER3 has been characterized as a significant factor for tumor progression in gastric cancer and is often upregulated in this tumor entity , HER2, HER3, and HER4 in breast cancer cells . In contAs mentioned above, in the absence of HER3 ligand MET inhibition was found to decrease ERK and Akt phosphorylation and to completely abrogate cellular proliferation despite of the elevated HER3 expression. This indicates that HER3 overexpression, even after the pronounced increase in HER3 levels upon treatment with MET inhibitors or siRNA, is insufficient to compensate for the blocking of MET-dependent pathways in tumor cells that do not endogenously express heregulin. Thus, 2D cell culture insufficiently reflects the in vivo situation where heregulin expressing and secreting stroma cells are present within the gastric tumor. Notably, heregulin stimulation of MKN45 cells pretreated with MET inhibitor yielded even a higher activation of ERK and Akt signaling than heregulin stimulation of cells with intact MET signaling. Taken together, the induction of HER3 after MET inhibition represents a critical factor in HRG-promoted resistance against MET inhibitors. This can severely impair the effect of MET inhibition, even in tumors with an amplification of MET, and may well explain—at least in part—the poor clinical outcomes of MET inhibitor treatment. The further elucidation of the mechanisms involved in regulation of HER3 expression in gastric cancer could provide the basis for novel strategies improving the efficacy of RTK-targeted therapies. It is noteworthy in this context that heregulin secretion by fibroblasts is a critical homeostatic signal to maintain the integrity of the gastric epithelial lining  and that® 647 (#4410S) were purchased from Cell Signaling . Anti-HER3 purified antibody (clone 1B4C3) was purchased from BioLegend®. Secondary antibodies were from Sigma–Aldrich . Protran Nitrocellulose Transfer membranes were purchased from Whatman . The enhanced chemiluminescence systems  were from Thermo-Scientific . The WST-1 kit was from Roche Applied Science . The PCK inhibitor bisindolylmaleimide II (BIM II), the MET inhibitor PF04217903, and the HER1 inhibitor AG1478 were from Tocris . The HER2 inhibitor CP724714 was purchased from Selleckchem . Heregulin and 12-O-Tetradecanoylphorbol 13-acetate  were obtained from Sigma–Aldrich . The human phospho-MAPK Array Kit was from R&D . All other chemicals used were purchased from Carl Roth  unless indicated otherwise.Cell culture media, phosphate buffered saline, and fetal bovine serum were obtained from Invitrogen . Antibodies against Akt, phospho-Akt, p44/42 MAPK, phospho-p44/42 MAPK, actin, and anti-mouse IgG Alexa Fluorv/v) heat-inactivated fetal bovine serum (FBS). SNU5 cells were cultured in Iscove’s Modified Dulbecco’s Medium plus 20% (v/v) FBS. The cell line Hs746T was cultivated in Dulbecco’s Modified Eagle’s Medium  supplemented with 10% (v/v) FBS. All media were used without antibiotics and cells were incubated at 37 °C in a humidified atmosphere containing 5% CO2 and passaged every 2–3 days.Human gastric cancer cell lines MKN7, MKN74, MKN45, SNU5, and Hs746T were obtained from the American Type Culture Collection . Cell line authentication was monitored regularly by genotyping . MKN cells were cultured in RPMI 1640 medium  supplemented with 10%  at 1000 cells/well and incubated overnight, prior to siRNA transfection or incubation with inhibitors. At the time points indicated, 10 µl WST solution was added to each well, and after incubation at 37 °C for 60 min, absorbance at 450 nm was measured in a PolarSTAR plate reader from BMG .5 cells growing in normal growth medium in 25 cm2 cell culture flasks were treated with the respective agent for 48 h. Afterwards, cells were trypsinized and counted using a hemocytometer. One thousand cells per condition were re-seeded into a 6-well plate and incubated in normal growth medium (without any further treatment) for 7 days. Thereafter, the medium was aspirated. The colonies were gently washed with PBS, and then stained by use of 0.5% (w/v) methylene blue in a 1:1 mixture (v/v) of ethanol and water. The colonies were incubated for 15 min with the staining solution, then gently washed with deionized H2O and dried at room temperature. Colonies of more than 50 cells were included in the evaluation.Five × 10Total RNA from cells was isolated using the guanidinium thiocyanate–phenol–chloroform extraction procedure . The first-strand synthesis was carried out using the RevertAid H Minus First Strand cDNA Synthesis Kit from Fermentas . Products were amplified using specific, intron-spanning primer pairs, with β-actin or RPLP0 serving as loading controls  NP-40 in PBS. Upon determination of protein concentration using DC™ Protein Assay  lysates containing 25 µg of protein were dissolved in loading buffer (125 mM Tris (pH 6.8), 20% glycerol, 4% SDS, 2% β-mercaptoethanol, and 10 µg/mL bromophenol blue). Twenty microliters of lysate/lane was resolved on 9% SDS-polyacrylamid gels and electroblotted onto nitrocellulose membranes using transfer buffer . Blots were incubated for 1 h in Rotiblock to saturate non-specific binding sites, washed in Tris-buffered saline with Tween® 20 (TBST), and incubated in a 1:500 dilution of the phospho-specific anti-p44/42 MAPK or anti-Akt mouse monoclonal antibody in 5% milk powder (w/v) in TBST. An anti-p44/42 MAPK rabbit monoclonal antibody specific for total (phosphorylated and unphosphorylated) MAPK or Akt served for loading controls. Subsequently, blots were incubated with peroxidase-conjugated secondary antibodies (1:5000). Signals were revealed using enhanced chemiluminescence , and visualization was carried out using the Chemismart detection system from Peqlab Biotechnologie . For Western blot analysis, cells were seeded in their respective medium at 2 × 10http://www.heatmapper.ca/) and as a bar diagram.For monitoring the expression of a larger set of MAP kinases, the commercially available Human Phospho-MAPK Array Kit  was employed. Lysates were analyzed in the antibody array according to the manufacturer’s protocol and visualized by chemiluminescence as described above. Signal intensities were quantitated using ImageJ and are shown as heat map  with 0,125 µg HER3-antibody per sample and incubated at 4 °C overnight. Cells were washed 2 times in staining buffer and incubated with anti-mouse Alexa Fluor® 647 antibody for 1 h at room temperature in the dark before FACS analysis was carried out on a Attune® Acoustic Focusing Cytometer using Attune® Cytometric Software.Cells were harvested and washed 2 times with phosphate buffered saline (PBS). Consequently, cells were resuspended in 100 µL staining buffer  water/ethanol to visualize colony spread and formation of distant colonies.Tumor spheroids were generated by seeding 1000 cells into agarose-coated 96-well plates. Cells were incubated under normal conditions for 96 h and subsequently analyzed (3D growth) or were transferred into normal 12 well microtiter plates for determination of spheroid outgrowth. For this purpose, transferred spheroids were incubated for further 6 days in normal growth medium. Thereafter, the cells were fixated and stained using 0.5 mg/mL methylene blue in 50% . Statistical significance of differences in all assays was assessed by ANOVA with Shapiro–Wilk test using SigmaPlot 13, with *, <0.05; **, <0.01, and ***, <0.001.


In recent years, the overuse and exploitation of coal resources as fuel in industry has caused many environmental problems as well as changes in the ecosystem. One way to address this issue is to recycle these materials as an alternative to aggregates in concrete. Recently, non-destructive tests have also been considered by the researchers in this field. As there is limited work on the evaluation of the compressive strength of concrete containing coal waste using non-destructive tests, the current study aims to estimate the compressive strength of concrete containing untreated coal waste aggregates using the ultrasonic pulse velocity (UPV) technique as a non-destructive testing approach. For this purpose, various concrete parameters such as the compressive strength and UPV were investigated at different ages of concrete with different volume replacements of coarse and fine aggregates with coal waste. The test results indicate that 5% volume replacement of natural aggregates with untreated coal waste improves the average compressive strength and UPV of the concrete mixes by 6 and 1.2%, respectively. However, these parameters are significantly reduced by increasing the coal waste replacement level up to 25%. Furthermore, a general exponential relationship was established between the compressive strength and the UPV associated with the entire tested concrete specimens with different volume replacement levels of coal waste at different ages. The proposed relationship demonstrates a good correlation with the experimental results. The production of global solid waste is persistently accelerating with the advancement of industry and emerging technology applications, as well as the increase in the human population. In this regard, coal is considered as one of the most essential sources of energy throughout the world, the extraction and exploitation of which lead to the production of waste materials ,2. Coal On account of the uncertainties present in the strength assessment of concrete specimens, as well as the localized damages induced by weathering, fire, and chemical attacks, civil engineers are increasingly demanding advanced and reliable methods for the evaluation and quality control of the concrete. In this respect, non-destructive test methods have attracted the attention of civil engineers due to the reduction in testing time, convenience of testing, and low cost compared to destructive approaches. Besides, these procedures have demonstrated promising results in inspecting and evaluating the quality of existing concrete structures ,13,14,153, compressive strength of about 25 MPa, and fineness modulus of about 2.9. The chemical properties and the gradation curves of both replacement levels of waste coal used in this study are presented in In this study, crushed stone was used as coarse aggregate with a maximum nominal size of 12.5 mm. The crushed sand was also used as fines with a fineness modulus of 2.92 and a maximum grain size of 4.75 mm. The gradation curves of coarse and fine aggregates are illustrated in In this study, a total of 99 cubes with 100-mm dimensions were fabricated in 11 experimental groups to evaluate the influence of coal waste on compressive strength and pulse velocity at 7, 14, and 28 days of concrete age. The test results are the average of three similar specimens made from the same concrete and tested at the same age.The mix design proportions for one cubic meter of concrete, according to the ACI 211.1R specifications , are preIn order to prepare the concrete specimens, the gravel and sand were first mixed with coal waste aggregates in the mixer for 1 min. The cement was then added and mixed for another 1 min. Afterward, water was gradually added to the mixture in 30 s, and the mixture was stirred for 2 min. After the mixing process, the slump test of concrete mixtures was measured according to ASTM C143  to speciThe notation of the mixtures, listed in An ultrasonic non-destructive electronic machine with an accuracy of 0.1 µs was used to measure the UPV complying with ASTM C597 . The nonOnce the transmission time test results were determined, the ultrasonic pulse transmission speed in concrete was obtained by dividing the transmission distance (distance between the measuring points) by the transmission time. Subsequently, the compression test was conducted on cubes at a loading rate of 0.25 MPa/s, conforming to the BS EN 12,390 specifications . The comIn this section, the relationship between the effective parameters, including the specimen age, coal waste content, and the replacement scheme on the pulse velocity and compressive strength, is discussed. The results of compressive strength and UPV of concrete specimens after 7, 14, and 28 days are presented in The effect of the type and amount of coal waste on compressive strength of concrete at different ages is presented in The results of the pulse velocity test for all specimens after 7, 14, and 28 days of curing are presented in The relationship between the concrete age and the compressive strength can be seen separately in The relationship between the compressive strength and the UPV of concrete specimens versus curing time is shown in 2) are also incorporated in these figures for the entire specimens. The closer this coefficient is to 1, the lower the scatter will be. 2), for all mix designs.When UPV is used to characterize the concrete compressive strength, no specific relationship can be established between them. However, the elastic modulus of concrete is correlated with the compressive strength. Besides, the UPV is connected with the modulus of elasticity and density of concrete. Thereby, a priori motive to investigate the concrete compressive strength based on UPV can be discerned. Several researchers , 20], ,  have cor2 = 0.89.Nonlinear regression analysis, including all test results of concrete specimens containing coal waste at different ages, was performed in order to provide a generic relationship between the compressive strength and the UPV, as expressed by Equation (2). It can be seen in To further assess and validate the proposed model, the compressive strength prediction results were compared in The UPV in concrete specimens is reduced significantly as the replacement level of coarse and fine aggregates with coal waste is increased. However, UPV is increased at 5% substitution of coal waste.The compressive strength of specimens is improved as 5 vol.% of natural aggregates is replaced with coal waste. However, further addition of coal decreases the compressive strength at different ages.As the age of concrete specimens increases, the UPV gains value. In this respect, the maximum pulse velocity corresponds to the 28-day specimen with 5% of coal waste replacing coarse aggregates. In contrast, the minimum velocity belongs to the 7-day specimen, with 20% of fine coal waste aggregates.The maximum compressive strength for the 28-day specimen with a replacement level of 5% of coarse coal waste is 40.3 MPa, which is approximately 6% higher than the control specimen at the same age. On the contrary, the lowest compressive strength for the 7-day specimen is 19.2 MPa with a 25% replacement of fine coal waste, indicating an approximate reduction of 29% compared to the control specimen at that age.The exponential relationship between the compressive strength and the transmission speed of ultrasonic pulses, obtained in this experiment, shows the acceptable regression analysis results. Therefore, a generic exponential relationship between the compressive strength and UPV was proposed for the entire concrete specimen results with different volume replacement levels of coal waste at different ages, which correlates well with the test results.In this study, the compressive strength of concrete containing coal waste aggregates was estimated using the non-destructive ultrasonic pulse velocity approach. For this purpose, concrete specimens were made in 11 experimental groups, and the parameters of compressive strength and UPV were investigated at different ages of concrete with different volume replacement levels of coarse and fine aggregates with coal waste. The results of this research are as follows:


Inappropriate antibiotic use is linked to the spread of antimicrobial resistance worldwide, but there are limited systemic data on antibiotic utilization in low- and middle-income countries. The purpose of this study was to evaluate the prevalence and patterns of antibiotic prescription in an ambulatory care setting in Sri Lanka.This cross-sectional survey was conducted at the Outpatient Department of a public tertiary medical center in Southern Province, Sri Lanka from February to April 2019. Among consecutive outpatients presenting for care, questionnaires were verbally administered to a systematic random sample to capture information about patient demographics, illness characteristics, and visit outcomes. Prescription data were obtained from the outpatient pharmacy’s electronic prescribing system.Of 409 surveyed patients, 146 (35.7%) were prescribed an antibiotic. The most frequently prescribed agents were amoxicillin  and first-generation cephalosporins . Respiratory indications were the most common reason for antibiotic use, comprising 69 (47.3%) of all antibiotic prescriptions. Antibiotics were prescribed for 66.1% of patients presenting with cough and 78.8% of those presenting with rhinorrhea or nasal congestion. Among all antibiotic recipients, 6 (4.1%) underwent diagnostic studies.A high prevalence of antibiotic prescription was observed, in particular for treatment of respiratory conditions. These data support the need for improved antimicrobial stewardship in the Sri Lankan outpatient setting.The online version contains supplementary material available at 10.1186/s12879-021-05804-6. The emergence and spread of antimicrobial resistance (AMR) poses a serious global public health threat. Annually, antimicrobial-resistant infections contribute to an estimated 23,000 deaths in the United States and 25,000 deaths in Europe , 2. WhilAlthough epidemiologic surveillance of AMR in Sri Lanka has only recently been implemented, available data reveal a high prevalence of infections caused by drug-resistant organisms. In a multi-center study of gram-negative bacterial bloodstream infections, organisms producing extended-spectrum beta-lactamases (ESBLs) accounted for nearly one-quarter of isolated pathogens . AdditioDecades of widespread antibiotic use have created selective pressure for the development of AMR, with increasing antibiotic consumption especially pronounced in LMICs . A recenIn this study, we determined the point prevalence of antibiotic prescription and assessed demographic and clinical patterns associated with antibiotic prescription among outpatients at a public tertiary healthcare facility in Southern Province, Sri Lanka.This cross-sectional study was conducted at a 1600-bed public tertiary teaching hospital located in the Southern Province of Sri Lanka. The hospital provides both inpatient and outpatient services free of cost. Outpatient services include an Outpatient Department (OPD) offering ambulatory acute care services to upwards of 1000 patients per day. The majority of OPD patients are local residents who present by self-referral. The hospital has an on-site outpatient pharmacy to which OPD prescriptions are electronically sent.Pre- and post-visit questionnaires were developed explicitly for this study  database. Statistical analysis was performed in R version 3.6.3 . Missing responses were omitted from denominators used to calculate simple proportions. Fisher’s exact test with odds ratios and 95% confidence intervals was used to identify demographic and clinical features associated with antibiotic prescription. Two-tailed Of 409 total patients enrolled, 88 21.6%) were children under 18 years of age and 153 (37.5%) were male (Table .6% were Twenty-three (5.6%) patients reported that they had been given a diagnosis by the physician during their clinical encounter. The majority of patients  were not asked to undergo further laboratory or radiographic studies as part of the diagnostic workup. Among patients who received further evaluation, the most frequently ordered studies were full blood count , urinalysis , blood glucose testing , radiography , and electrocardiogram . Medications were prescribed for 292 (71.4%) patients, of whom 56 (19.2%) reported that they were informed about the purpose of the prescribed medication(s) by their physician.Antibiotics were prescribed for 146 (35.7%) patients, with the most common antibiotics being amoxicillin , first-generation cephalosporins , and amoxicillin/clavulanate . Figure p = 0.08). Among adults, the likelihood of antibiotic prescription was similar among patients ≥65 years and patients 18–64 years . Adult patients reporting fever  or illness duration less than 7 days  were more likely to receive an antibiotic prescription; those who had prior evaluations for their current illness were less likely to receive an antibiotic  were more likely to receive an antibiotic. Antibiotic prescription did not significantly differ between respondents with ≥12th grade education compared to those with <12th grade education .Of the 141 antibiotic recipients with a documented duration of therapy, 135 (95.7%) received a 3-day course of antibiotic medication, the standard duration for medications dispensed through the OPD pharmacy. Diagnostic studies were ordered for 6 (4.1%) antibiotic recipients, and study results were not reviewed for any patient prior to receiving an antibiotic prescription. There was a non-significant trend towards increased antibiotic prescription among pediatric patients compared to adult patients  among patients receiving antibiotic therapy. Among patients with a presenting symptom of cough, 39 (66.1%) were prescribed antibiotics and 4 (7.7%) of these antibiotic recipients reported fever. Among those with rhinorrhea or congestion, 26 (78.8%) received antibiotics and none reported fever. Antibiotics were prescribed to 3 (60%) of 5 patients with a presenting symptom of wheezing and 1 (25%) of 4 patients with a presenting symptom of shortness of breath. The most frequently prescribed antibiotics among patients with respiratory indications were first-generation cephalosporins , amoxicillin , and second-generation cephalosporins . Among all antibiotic recipients with a respiratory presenting symptom, 2 (2.9%) underwent a diagnostic study and none underwent radiography.During pre-visit interviews, 359 (88.2%) respondents expected to be prescribed a medication during their visit and 2 (0.6%) specifically expected an antibiotic prescription. In post-visit interviews, 36 (9.1%) respondents reported knowledge regarding the purpose of antibiotics. After being provided with the definition of an antibiotic, 118 (29.4%) respondents thought that an antibiotic would be helpful for their illness. Among respondents who were prescribed an antibiotic, 32 (22.4%) were aware that they had been prescribed one, and 50 (35.2%) thought that an antibiotic would be helpful for their illness.p = 0.05). Visit satisfaction was also greater among antibiotic recipients compared to those receiving prescriptions for other medications . The most frequently reported reasons for visit satisfaction included prescription of medications , satisfaction with the physical examination , and feeling that the physician listened to the patient . Among dissatisfied patients, 3 (5.1%) reported that lack of medication prescriptions contributed to visit dissatisfaction. Ninety (22.4%) patients planned to visit a different provider for their health concern.Visit satisfaction was reported among 330 (84.8%) of all respondents. Among all respondents, there was a trend towards increased proportion of visit satisfaction among antibiotic recipients (OR 1.9, 95% CI 1.0–3.9, This single-center point-prevalence survey demonstrates a high prevalence of outpatient antibiotic prescription at a public tertiary medical center in southern Sri Lanka. Antibiotics were prescribed to approximately one-third of patients in this study, similar to the proportions of 33–54% reported in a 2015 World Health Organization audit of Sri Lankan OPDs as well as antibiotic prescribing figures reported in other South East Asian countries , 9. ThesOur survey revealed limited knowledge and awareness of antibiotics and resultant low prevalence of expectations for antibiotic prescription among patients, suggesting that antibiotic prescribing behavior may have been driven by healthcare providers rather than by patient demand. These data support previous qualitative data from this outpatient setting showing that patient expectations for antibiotic prescription were uncommon . In contOf note, a high proportion of antibiotic prescriptions was given for treatment of respiratory syndromes. Patients with respiratory symptoms comprised nearly one-half of all antibiotic recipients. Conversely, a majority of patients with respiratory illnesses received an antibiotic prescription. These findings parallel previous observations in the inpatient setting in Sri Lanka, where lower respiratory tract infections were the most common indication for antibiotic therapy among hospitalized patients, as well as data from high-income countries showing high rates of outpatient antibiotic prescription for acute respiratory conditions , 10, 15.This study has several limitations. As a point prevalence survey, our data do not capture potential temporal variation in antibiotic prescribing practices in relation to seasonal illnesses such as influenza and dengue. The single center nature of this study precludes the generalization of findings to Sri Lanka due to potential differences between the public and private healthcare sector, primary and secondary/tertiary facilities, and different regions of the country in terms of physician prescribing behavior and patient population. Additionally, all clinical information except for antibiotics prescribed was based on patient self-report and thus may have been subject to reporting bias.Antimicrobial stewardship represents a growing priority in Sri Lankan public health as well as the global health arena. Our study highlights a particular need for antimicrobial stewardship in ambulatory settings, for which there is limited experience in LMICs and a dearth of best practice guidelines. The development and scale-up of strategies to provide ongoing surveillance of antibiotic use, increase access to and utilization of diagnostic testing, and reinforce rational antibiotic prescribing practices will be important components in global efforts to control the spread of antimicrobial resistance.Additional file 1: Supplementary file 1. OPD pre- and post-visit questionnaires. English version pre- and post-visit study questionnaires.


Detailed information about temperature distribution can be important to understand structural behavior in fire. This study develops a method to image three-dimensional temperature distributions in steel–concrete composite slabs using distributed fiber optic sensors. The feasibility of the method is explored using six 1.2 m × 0.9 m steel–concrete composite slabs instrumented with distributed sensors and thermocouples subjected to fire for over 3 h. Dense point clouds of temperature in the slabs were measured using the distributed sensors. The results show that the distributed sensors operated at material temperatures up to 960 °C with acceptable accuracy for many structural fire applications. The measured non-uniform temperature distributions indicate a spatially distributed thermal response in steel–concrete composite slabs, which can only be adequately captured using approaches that provide a high density of through-depth data points. Material temperature distribution can play a significant role in the safety and durability of civil engineering structures. During normal operation, temperature affects the energy efficiency of the building  and largIn the literature, methods to assess material temperature distributions during a fire can be grouped into two categories. The first category is based on computer simulations of fire dynamics and heat transfer to predict temperature distributions in structures . TypicalThe second category of methods is based on physical measurement of temperature. Infrared cameras can image temperature distributions on the surface of structures . With thRecently, various fiber optic sensors have been developed for structural fire applications. These include fiber Bragg grating (FBG) sensors, long-period fiber grating (LPFG) sensors, interferometer sensors, and distributed fiber optic sensors . FBG senIf temperatures in structural members during a fire can be measured with sufficiently fine spatial resolution, analyzing the structural response due to thermal loading will become more tractable. Recently, distributed fiber optic sensors have been proven feasible to measure temperature and strain at high temperatures ,20. DiffThis study has three objectives: (1) develop a method to image three-dimensional temperature distributions in concrete members; (2) develop a method to install distributed sensors following a procedure feasible for building construction practice; and (3) implement and evaluate the methods in six small steel–concrete composite slabs to understand their response under severe fire conditions. The measurements are used to generate three-dimensional information on temperature fields in the concrete and compared with temperatures measured using co-located thermocouples and an infrared camera. The remainder of the paper is organized as follows: Each concrete slab was 1219 mm long and 914 mm wide and cast on 0.9 mm thick, trapezoidal metal decking (Vulcraft 3VLI20), which served as stay-in-place formwork. Consequently, the depth of the concrete slab varied from 83 mm to 159 mm, as illustrated in Each end of the two parallel steel beams was connected by a perpendicular, welded rectangular steel tube so that the beams maintained their position during fabrication.A 1219 mm × 914 mm rectangular wood formwork was prepared.The trapezoidal metal decking was laid on top of the beams inside the formwork.The headed studs were welded through the metal decking to the steel beams .The welded wire mesh was supported by plastic chairs 8 mm above the metal decking.Optical fibers and thermocouples were deployed as detailed in Concrete was poured into the formwork. Concrete placement using a hand trowel as well as placement directly from the chute on the concrete truck was used.The sides of the formwork were tapped using a rubber mallet to consolidate concrete at the edges; no mechanical vibrators were used.The cast specimen was covered under wet burlap and a plastic sheet, demolded after 1 day, and cured at room temperature (22 °C ± 3 °C).Each steel–concrete composite specimen was fabricated as follows:®) with a nominal diameter of 38 μm and length between 13 mm and 19 mm were added to the mix at a dosage of 2.37 kg/m3 of concrete to reduce temperature-induced spalling [The concrete mix was 0.193: 0.105: 0.315: 1.0: 1.136 by mass for water: Class C fly ash: Type I Portland cement: river sand: expanded slate lightweight aggregate (LWA). With a binder composed of 25% fly ash and 75% Portland cement, this mix corresponded to a water-to-binder ratio of 0.46. The river sand had a diameter up to 4.75 mm. The lightweight aggregate used had low water-retention characteristics and high desorption ,24,25. Tspalling . The con3 at 28 days. The compressive strength of concrete was 38 ± 3 MPa at 28 days and 41 ± 3 MPa at 56 days, which were determined in accordance with American Society for Testing and Materials (ASTM) C39/C39M [During concrete casting, ten standard cylinders measuring 102 mm in diameter and 203 mm in height were prepared for concrete material testing. Five cylinders were tested and analyzed to determine the average ± standard deviation of each concrete property. Specifically, the concrete density was 2070 ± 80 kg/mC39/C39M . A relatyf), the ultimate strength (uf), and the modulus of elasticity (E) of various types of steel adopted in this study, as specified by the manufacturers.® (model: NBX-7020), based on Brillouin scattering, as elaborated in a prior study [T denotes temperature (°C). Additional information about the Brillouin scattering technique and fiber calibration are provided in [The distributed fiber optic sensor (DFOS) used in this study was a simplex fiber optic cable composed of a polymer sheath, an aramid yarn, and an optical fiber, as illustrated in or study . The insor study . The relor study . The senvided in .DFOS-1 was laid directly on top of the metal decking along its flutes, which is perpendicular to the steel beams. DFOS-2 was attached on top of the welded wire mesh and also ran parallel to the flutes of the specimen. DFOS-3 was also attached on top of the welded wire mesh but ran perpendicular to the flutes of the specimen. For reference, the curved portions of the distributed sensors were labeled as B1 to B14 for sensor DFOS-1, T1 to T7 for sensor DFOS-2, and L1 to L4 for sensor DFOS-3. The two sensors running transverse to the steel beams (DFOS-1 and DFOS-2) entered the concrete from a polyvinyl chloride (PVC) cap at Point A, and the longitudinal sensor DFOS-3 entered the concrete from a PVC cap at Point C. Each cap measured 100 mm in diameter and was used to store the lengths (500 mm) of each distributed sensor at the two ends during concrete casting and transport of the specimens. The gap between the cup and formwork was small enough to prevent the leaking of concrete. The cup provided mechanical protections and ensured that the distributed sensors were free from the concrete. After the specimens were demolded, the length of each distributed sensor stored in cup was connected to data acquisition system for measurement. Sensor DFOS-4 was attached on the top surface of the concrete after the concrete was cured for one year. A thin groove (depth ≈ 3 mm) was cut into the concrete using a grinding wheel to accommodate the optical fiber and a thin layer (≈1 mm) of cement mortar was used to cover the sensor. The distributed sensor passed across the specimen in six paths perpendicular to the flutes of the slab, denoted by Path I to Path VI, as shown in ®) was used to image the surface temperature of select specimens, with emphasis on the top surface of each concrete slab.In addition to the fiber optic sensors and thermocouples, a high-speed mid-wavelength infrared camera . The test setup was not intended to represent a particular structure, but rather to investigate the performance of distributed sensors in a typical steel–concrete composite structure. All specimens were subjected to a similar fire protocol with a peak heat release rate (HRR) of 200 kW. No mechanical load beyond self-weight was applied. The magnitude of fire was controlled through the burner’s calculated heat release rate. The heat release rate was held approximately constant at 50 kW, 100 kW, 150 kW, and 200 kW. Each of the first three levels was maintained for 2 min; the last level (200 kW) was maintained for 210 min, before the fire was extinguished. In total, each specimen was heated for approximately 216 min (3 h 36 min). For specimens CS-1 to CS-3 and CS-6, the upper layer gas temperature was 897 °C ± 38 °C (mean ± standard deviation) when heat release rate was 200 kW, as shown in All of the distributed fiber optic sensors survived the installation, concrete casting and curing process without damage. The two methods of concrete placement, careful hand troweling and direct pouring from a concrete truck chute, did not make a difference on the integrity of installed sensors.Shortly after a heat release rate of 200 kW was achieved, popping sounds were heard from the specimen; however, no cracking or spalling was observed on visible surfaces. The sounds were attributed to spalling of the concrete at the interface with the metal decking. After approximately 10 min at 200 kW, separation between the metal decking and concrete was observed, as shown in After the fire test, several cylinders measuring 76 mm in diameter were cored from the specimens using a diamond core drill, as depicted in After a constant heat release rate had been achieved, temperature distributions along the length of the distributed sensors DFOS-1, DFOS-2, and DFOS-3 in specimen CS-1 at various time instants are plotted in In In The first 10 peaks in As demonstrated in For further comparison between the thermocouples and distributed sensors, the surface temperature measurements from CS-5 and CS-6 at 120 min are plotted in In this study, temperature distributions were measured using distributed fiber optic sensors installed in steel–concrete composite slab specimens exposed to fire. Compared with traditional point sensors, e.g., thermocouples, this approach provided significantly higher spatial resolution of temperatures.This limited set of data suggests that the investigated polymer-sheathed optical fibers survived, during the concrete casting process in typical building construction. The temperatures measured using the distributed sensors were in reasonable agreement with the results from thermocouples deployed close to the distributed fiber optic sensors. The measured temperature discrepancies between the fiber optic sensors and the thermocouples was attributed to position differences in the specimens. Further study is recommended to verify this. Material temperatures up to 960 °C were measured at the interface between the concrete and the metal deck.The measured temperatures from a distributed fiber optic sensor indicate highly non-uniform patterns of temperature distribution in each composite slab specimen, which are often neglected in engineering design and analysis. Deploying the distributed fiber optic sensors in large-scale structural fire tests has the potential to improve our understanding of the performance of infrastructure in fires and, thus, fire safety.