Our goal was to examine the therapeutic effect of a self-designed digital six-axis external fixator technique for the correction of severe lower extremity deformities.Between January 2017 and December 2020, our institution employed self-developed digital hexapod external fixator technology (QSF), based on CT data, to gradually correct 28 severe tibial deformities, and 15 femurs underwent osteotomy and internal fixation. The mean patient age was 32.6 ± 14.3 years, and the mean follow-up duration was 27.4 ± 16.1 months. We also recoded and analyzed the values of preoperative and final follow-up MAD, mFTA, MPTA, LLD, mLDFA, LEFS, KSS, and functional score.The QSF adjustment duration was 21.4 ± 10.8 days, and the healing duration of the tibial osteotomy site was 17.6 ± 7.0 weeks. The preoperative MAD, mFTA, and MPTA were 54.1 ± 26.2 mm, 167.7 ± 15.7°, and 75.2 ± 12.0°, respectively. At the last follow-up, the MAD was 8.2 ± 9.9 mm, mFTA was 177.6 ± 3.4°, and MPTA was 87.6 ± 2.4°. Based on these data, we achieved significant improvement post operation. The preoperative LLD and mLDFA values were 13.8 ± 18 mm and 83.7 ± 10.8°, respectively, and the values were 7.6 ± 7.6 mm and 87.8 ± 2.6°, respectively, at the last follow-up. This indicated no significant difference in these values before and after the operation. Finally, the LEFS, KSS, and functional scores improved from preoperative 51.6 ± 11.2, 68.5 ± 11.7, and 67.8 ± 11.2 to postoperative 72.3 ± 6.1, 92.9 ± 3.4, and 94.2 ± 6.3, respectively.Based on our analyses, the QSF technique accurately corrected severe multiplanar tibial deformities in adults. When combined with femoral osteotomy, satisfactory lower extremity alignment was obtained while correcting for femoral deformity. This technology has the advantages of simple operation, reliable fixation, less trauma, and less complications. Lower extremity deformities can result from trauma, as well as congenital, developmental, and degenerative diseases. The appropriate reconstruction of the normal lower extremity alignment is a key factor in obtaining satisfactory results after limb reconstruction. Severe lower extremity deformities are often combined with coronal, sagittal, and axial planes, as well as shortening deformities. As a result, orthopedic treatment becomes very challenging. Correction of lower extremity deformity using internal fixation alone generates a great impact on the bone blood supply, and it is necessary to ensure a successful one-time osteotomy, as postoperative adjustment cannot be performed. Alternately, the external fixation technique employs a “tension-stress”  effect aRelative to the Ilizarov frame, the computer-aided six-axis frames, such as Taylor spatial frame (TSF) can simultaneously correct coronal, sagittal, and axial deformities. Moreover, they are easy to use and have greater accuracy. Therefore, TSF has become the treatment of choice for multiplanar deformities in recent years , 3, 9–12In 2017, we developed a new six-axis spatial frame technology known as Qiao spatial frame (QSF), wherein the main structure was similar to TSF  were treated with QSF external fixator at our institution. All patients presented with at least two deformities . Our exclusion criteria were as follows: (1) lower extremity deformities that occurred due to neurological or metabolic diseases. (2) presence of tumor.One patient was eliminated from analysis due to the presence of multiple osteochondromatosis, and one additional patient due to spina bifida. Finally, 21 patients, with 28 lower extremities, were included for analysis. Among them, 10 were males, 11 were females, 16 suffered from left lower extremity deformities, and 12 suffered from right lower extremity deformities. The average patient age was 32.6 years (range 13–64 years). Out of the 21 patients, 13 had Blount's disease, 3 had rickets, and 5 had tibial fracture malunion. The mean follow-up duration was 27.4 months  was selected as the osteotomy site, and 4 osteotomies were carried out in the middle of the femoral shaft, and 11 in the distal femur. Prior to the operation, the Solidworks™ software was used to measure the correction angle, closed gap, distal femoral varus osteotomy selection of the distal femur anteromedial incision, and to expose the femoral distal medial cortex. The self-designed osteotomy guide sleeve  was placNext, we performed fibula and tibial osteotomies. A longitudinal incision was made on the lateral side of the middle of the fibula, and a 1–2 cm long fibula was cut at the middle and lower 1/3 of the fibula. A partial transverse osteotomy was performed 1 cm below the tibial tubercle to facilitate the installation of an external fixator. A 2/3 ring was selected at the proximal end, and a full ring at the distal end. Based on the upper tibial deformity, the configuration of the six-axis external fixator was pre-adjusted. The adjusting nut on the connecting rod was loosened, and the top screw was tightened. At this time, the QSF configuration was basically stable. About 1–1.5 cm below the knee joint line, a 2.0 mm diameter Kirschner wire was placed from outside to inside, parallel to the tibial plateau, and the position of the proximal ring was adjusted and fixed, so that the opening direction of the 2/3 ring faced the rear to avoid affecting the knee joint flexion. Then, secure the proximal ring with the K-wire, loosen the top screw, at this time, the length of the connecting rod can be adjusted at will. Adjust the position of the distal ring to make it as perpendicular to the tibial axis as possible, then tighten the top screw on the connecting rod, and use 4 half pins to fix the distal ring. The proximal ring was fixed with two 2.0 mm diameter Kirschner wires and two half pins, or a 2.0 mm diameter Kirschner wire and three half pins. Fluoroscopy confirmed that the fixation was firm and the fixation pin was in a good position. Record the length of each connecting rod as the original length. Loosen the top screw on the QSF connecting rod, twist the two rings to make the osteotomy site completely fractured. Then reduced the osteotomy position and restored the length of each connecting rod to its original length.Following the operation, we scanned the entire lower limb lengths using CT. The data were then entered into the supporting software to calculate the electronic prescription for six-axis external fixator adjustment. One week following the operation, the adjustment was initiated to slowly correct (speed: 0.7–1 mm/d) the deformities, based on the prescription. Following discharge, the patients adjusted the fixator themselves, according to the prescription. Upon the completion of deformity correction, the full-length AP weight-bearing X-ray of the lower extremity was taken. Based on the results, we determined the necessity for fine-tuning. Once the alignment adjustment was considered satisfactory, the strut was locked. X-rays were reviewed monthly, and the external fixator was removed after the osteotomy site had completely healed. During the correction process, the patient was instructed to perform knee and ankle range of motion exercises to prevent joint stiffness, and allow the affected limb to walk with tolerable weight-bearing activities.The lower limb alignment and leg length difference were recorded prior to the operation and after osteotomy site healing. The lower limb alignment was assessed via the mechanical axis deviation (MAD) and mechanical femorotibial axis (mFTA). The tibial alignment was evaluated by the medial proximal tibial angle (MPTA). Finally, the femoral alignment was assessed via the mechanical lateral distal femoral angle (mLDFA).The lower limb length was recorded from the top of the femoral head to the center of the ipsilateral ankle joint on the anteroposterior standing whole-leg radiograph. The difference in the bilateral lower limb lengths was the leg length discrepancy (LLD). All measurements were conducted on the picture archiving and communication systems (PACS) . These measurements were carried out by 2 observers, who did not participate in the operation. After 3 weeks, the measurements were performed again by a single observer. The intraclass correlation coefficient (ICC) was applied to determine the reliability of all measurements. The ICC values were characterized as follows: poor agreement (< 0.40), fair to good agreement (0.40–0.75), and excellent agreement beyond chance (> 0.75).The clinical outcome assessment was performed using the lower extremity functional scale (LEFS), KSS, and functional score before surgery and at the final follow-up.P < 0.05 was considered statistically significant.The SPSS version 26  was employed for all data analyses. The Kolmogorov–Smirnov test examined all dependent variables for normal distribution. The Paired t test was used to compare the MAD, mFTA, MPTA, LLD, mLDFA, LEFS, KSS, and functional scores prior to surgery and at the final follow-up. Based on the Kolmogorov–Smirnov test, all data followed a normal distribution pattern. Moreover, the ICC and interclass correlation coefficients for the reproducibility of all parameters were > 80% Table .Table 2It = 1.859, P = 0.074). The mLDFA of the 15 femoral osteotomies went from preoperative 83.7 ± 10.8° to postoperative 87.8 ± 2.6°. Hence, relative to the preoperative values, there was no significant improvement in the mLDFA values . The postoperative LEFS (72.3 ± 6.1) was significantly higher than the preoperative (51.6 ± 11.2) values . The KSS and functional score were significantly improved after the surgery , compared to pre-surgery  .The average QSF-based adjustment time was 21.4 ± 10.8 d, and the time from the end of adjustment to osteotomy site healing was 17.6 ± 7.0 weeks. The preoperative MAD was 54.1 ± 26.2 mm, mFTA was 167.7 ± 15.7°, and MPTA was 75.2 ± 12.0°. At the last follow-up, MAD was 8.2 ± 9.9 mm, mFTA was 177.6 ± 3.4°, and MPTA was 87.6 ± 2.4° (Table All patient wounds healed within 2 weeks after the operation, and the sutures were removed without nonunion, neurovascular injury, needle tract infection, osteomyelitis, and other complications. Only mild calf discomfort was reported in the later stage of the external frame adjustment. Typical cases of deformity correction are presented in Figs. Severe lower extremity deformities are often accompanied by coronal, sagittal, and axial deformities, and they are difficult to completely correct with a one-time internal fixation. In contrast, gradual correction can completely correct the three-dimensional deformity via tension–stress effects and distraction osteogenesis mechanisms. The single-arm external fixator is part of the eccentric fixation, and it cannot effectively resist the rotational stress and vertical deformation capacity. Relative to the acute correction of severe lower extremity deformities, gradual correction is, therefore, more attractive and effective .The Ilizarov external fixator has been the standard versatile fixator for deformity correction for numerous years. Despite its many advantages, the correction of complex deformities using the Ilizarov frame requires a long learning curve, and the correction of rotational deformities still remains quite challenging . In addiRelative to the Ilizarov technique, the computer-assisted hexapods are increasingly popular in deformity correction surgery, particularly, over the past few years. This is because of their ease of application and accuracy in correcting multiplanar deformities . AriyawaReitenbach et al. evaluated 33 lower extremity deformities treated with TSF and 20 deformities corrected by the Ilizarov frame, and reported that the TSF axial deviation and pin infection were significantly less than those observed in Ilizarov-based fixation. The authors concluded that the TSF ring fixator produces fewer challenges, fewer secondary axial translations, and fewer pin infections  .TSF is also effective in correcting femoral deformity. Hughes et al.  employedSaw et al.  treated The CT data-based QSF, developed by our institution, was composed of 6 mutually angled telescope struts and 2 connected plane rings, similar to the structure of the TSF. The ball-and-socket joint at both ends of the strut had no gap, and there was a top screw between the inner rod and the outer rod, so the overall QSF was very stable. In addition, its supporting software was based on the three-dimensional data of CT, so the precision was higher, and the precision of the prescription was 0.01 mm. Moreover, there were no special restrictions for the mounting position of the ring and the connection of the struts. Thus, the operation was simpler.Since QSF was based on CT data, there was also no need to measure complicated parameters. The realignment result was not affected by the shooting angle of the X-ray film. Therefore, theoretically, the correction accuracy was higher than the X-ray-based TSF data. In addition, the advantages of QSF were that it had a short learning curve, was mastered without professional training, and was firmly fixed. In case of complex deformity correction, full weight bearing was achieved postoperatively.The disadvantage of this study was the relatively small sample size and short follow-up time. Another limitation was that the radiograph measurement did not calculate the magnification rate. Based on the Sabharwal's study , the magThe QSF technology can accurately correct severe multiplanar deformity of the lower limb in adults. When combined with femoral osteotomy, QSF can be effectively used to correct lower extremity deformities, and to achieve satisfactory lower extremity alignment. This technology has the advantages of precision, simple operation, reliable fixation, short learning curve, less trauma and fewer complications. Therefore, it has a relatively high clinical application value.


Pleurotus ostreatus) using maltodextrin as a carrier. Morphology (scanning electron microscopy- SEM), yield, moisture content (MC), and water activity (aw) were also evaluated in the samples. Our examinations revealed significant structural differences between powders microencapsulated by the drying methods. As compared to non-encapsulated powder, the SD powder with yield of 44.38 ± 0.55% exhibited more reduced (p < 0.05) values for aw (0.456 ± 0.001) and MC (8.90 ± 0.44%) than the FD one . In addition, the highest values for β-glucan content (72.39 ± 0.38%), TPC (3.40 ± 0.17 mg GAE/g), and TFC (3.07 ± 0.29 mg QE/g) have been detected in the SD powder. Our results allow for the conclusion that the SD microencapsulation method using maltodextrin seems to be more powerful in terms of the β-glucan powder yield and its contents of β-glucan, TP, and TF as compared to the FD technique.The study compares the impact of freeze- and spray-drying  microencapsulation methods on the content of β-glucan, total polyphenols (TP), total flavonoids (TF), phenolic acids (PA), and antioxidant activity (AA) in commercially β-glucan powder ( Pleurotus species) possess a plethora of bioactive properties including hypocholesterolemic, antioxidant, anti-bacterial, anti-diabetic, hepatoprotective, anti-carcinogenic, anti-viral, anti-arthritic, and immune-modulatory ones [Pleurotus (P.) ostreatus as a main edible mushroom also contains different types of phenolic compounds, including phenolic acids and flavonoids [To improve human health in association with energy intake, modulation of metabolic and inflammatory processes, oxidative stress , enzymes and receptor activities, and many others, the intake of bioactive compounds in foods is of primary importance ,2. Of thory ones . In addiory ones , Pleurotavonoids , and exhavonoids .w), and easier transport and storage [To preserve the biological activity and improve the stability of the bioactive compounds as well as ensure the controlled release of the latter , their e storage . It is e storage , and it  storage . In cont storage . Another storage . On the  storage , first i storage . Althoug storage  which is storage ,53.w, the presence of selected biologically active compounds , and AA produced by two different microencapsulation techniques (SD and FD) to choose the best one for further research into food products with this β-glucan powder addition. Taking into account the fact that β-glucan is usually employed in experiments as a coating material, our study as a first report can illuminate this unexplored research area, and the new knowledge can bring innovation to the scientific community on a large scale.The current study was designed to evaluate and compare microparticle structures and alterations in powder yield, MC, aP. ostreatus) was produced by a commercial producer Dimenzia Ltd. . The extract was microencapsulated using two different methods , thereby taking into consideration three samples to be evaluated: control sample (non-encapsulated β-glucan powder), Treatment 1 (powder encapsulated by FD), and Treatment 2 (powder encapsulated by SD).Powder extract of β-glucan  was used.Maltodextrin  was used as a coating material in both microencapsulation techniques applied. To prepare the MD solutions, ultrapure water  or Megazyme .w/v) concentration. Then, an active β-glucan concentrate was added in 0.5% (w/w of MD) concentration, and the final liquid formulation was magnetically stirred for 30 min.First, the MD solution was prepared by dissolving it in ultrapure water in 20%  of the FD and SD powders was established for each system studied and was expressed as a ratio of obtained powder (M1) reported to the introduced amount of solid raw materials (M2) applied according to Equation (1):w) was measured using a Lab Master aw Standard . For this purpose, 1.0 g of each sample was placed into a sample pan. The value of aw was measured automatically at 25 °C for 10–15 min.Water activity (aMoisture content (MC) was determined using the moisture analyser DBS 60-3 . In this case, 1.0 g of each sample was weighed on the sample plate, and measurement was performed at 120 °C for 5–10 min.The surface morphology and size of the FD and SD microparticles were investigated by scanning electron microscopy (SEM) using a Quanta 250 FEG microscope . A thin layer of the powders was deposited on carbon tape, and the samples were consequently recovered by a thin palladium layer (0.5 nm) prior to analysis. The SEM images were acquired with a 20 kV accelerating voltage using the hivac mode.g for 10 min in Rotofix 32A . To determine AA, total polyphenols content (TPC), phenolics acid content (PCA), and flavonoids content (FC) obtained supernatants were used.Prior to analyses, ethanolic extracts were prepared from all investigated samples. For each extraction, 0.2 g of each sample was extracted by 20 mL of 80% ethanol for 2 h and centrifuged at 4000× Antioxidant capacity of the samples was measured with 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical; the procedure has been previously described by Valková et al. . In brie−1 sodium carbonate, and 8.8 mL of distilled water. After 30 min in darkness, the absorbance at 700 nm was measured using a Jenway 6405 UV/Vis spectrophotometer . Gallic acid was used as a standard, and the results were expressed in milligrams of gallic acid equivalents (GAE) per g of dry weight (dw). The calibration curve followed Equation (3).Total PC was measured by the method of Valková et al.  using th−1 hydrochloric acid, 0.5 mL Arnow reagent (100 g L−1 sodium nitrite and 100 g L−1 sodium molybdate), 0.5 mL of 1 mol L−1 sodium hydroxide, and 0.5 mL of distilled water. Absorbance at 490 nm was measured using a Jenway 6405 UV/Vis spectrophotometer . Caffeic acid was used as a standard, and the results were expressed in milligrams of caffeic acid equivalents (CAE) per gram of dw. The calibration curve followed Equation (4).The content of PA was determined using a previously published method . A volumw/v) ethanolic solution of aluminum chloride, 0.1 mL of 1 M potassium acetate, and 4.3 mL of distilled water. After 30 min in darkness, the absorbance at 415 nm was measured using a Jenway 6405 UV/Vis spectrophotometer . Quercetin was used as a standard. The results were expressed in milligrams of quercetin equivalents (QE) per gram of dw. The calibration curve followed Equation (5).Flavonoids content was determined by the method of Ivanišová et al. . A quant2SO4 , 18 M H2SO4  was used. The methodological procedure’s accuracy was also determined within our analyses by using the control yeast β-glucan preparation (49% of β-glucan content) as an enclosed substance of the analytical kit. Various appliances were used during the research work, including laboratory scales KERN ABT 220-DM ; vortex mixer bioSan V-1 plus, Personal Vortex ; water bath Memmert U 1.28 ; centrifuge Hettich Mikro 185 ; and spectrophotometer UV/Vis Cary 60 .The β-glucan content in the samples was determined using the enzymatic kit β-glucan Assay kit (Mushroom and Yeast) K-YBGL . The β-glucan determination procedure was implemented in accordance with the manufacturer’s methodical instructions that are included in the kit, and all instructions are listed in Mushroom and Yeast Beta-Glucan Assay procedure K-YBGL 11/19, with our minor methodical optimization. Instead of 12 M, Hp < 0.05), the Tukey HSD post hoc test was performed. All determinations were performed in triplicate.For statistical comparison of our data, software GraphPad Prism 8.0.1  and One-way ANOVA were applied. In statistically significant results . Using MD as a coating material, both microencapsulation techniques of the originally fine-grained, slightly yellow powder resulted in white-colored powders with finer structures being the finest one in the SD samples. Scanning EM displayed that FD  led to tp < 0.05) influenced by the drying method employed. Indeed, 44.38 ± 0.55% of the yield was produced by the SD technique, while the FD one led to a lower value (27.97 ± 0.33%) for the powder yield.Powder yield was significantly  than those determined in the non-encapsulated (control) ones  ones .Owing to the ability of bioactive compounds to stabilize via the structuring of systems that preserve their chemical, physical, and biological properties, and their release (or delivery) under desired conditions , microenMalpighia emarginata DC) pulp and saffron (Crocus Sativus L.) petal phenolic extracts have also been visualized by SEM in the scientific research of Rezende et al. [Moringa oleifera leaf extract microencapsulated with MD by the SD method [Since the protection capacity of polymeric wall materials in the encapsulated products is associated with the degree of porosity and integrity of individual microparticles ,67, the e et al. , and Ahme et al. , respecte et al. . In thise et al. . The sphe et al. . On the e et al. ,69. Moste et al. ,70. In lD method . MoreoveD method . Based oD method  in FD-enD method . UltimatD method , and theD method  are respD method , the iniw to provide a complete moisture analysis [w describes the energy state of water in food, it has an ability to act as a solvent participating in both chemical/biochemical (oxidation and enzymatic) reactions and microorganism growth [w in foods commonly increases the lag phase of microorganisms and declines the growth rate of vegetative microbial cells, germination of spores, and toxin production by molds and bacteria [w < 0.60 , which is in accordance with our findings considering non-encapsulated (control) β-glucan powder. In addition, its value for aw (0.51 ± 0.001) was in the range of those obtained from P. sajor-caju dried using sun (0.57 ± 0.02), a lab oven (0.57 ± 0.01), and low heat air blow (0.49 ± 0.03) [w of the product during various kinds of processing  is critical [w were reported in FD powders prepared from an anthocyanin-rich extract of a blackberry by-product [w of SD infant formula produced in a laboratory scale to be between 3.7 (± 0.6) and 9.9 (± 1.1)% wet basis (wb) and between 0.10 (± 0.01) and 0.85 (± 0.04), respectively, being in line with our study. Likewise, Tangarife et al. [p < 0.05) in reduction of the powder aw and MC than the FD one, suggesting its outstanding greater increase in product stability. Similarly, Daza et al. [w and MC in SD samples of Eugenia dysenterica extract powder compared to those dried by freezing. We propose that this higher effectiveness of the SD method (than FD) in the context of declining powder MC can be associated mainly with the parameters of SD processing, particularly with high temperature which has a marked impact on MC of powders. Indeed, an increase in inlet temperature during the SD process results in an increased rate of water evaporation through enhanced heat transfer between air and droplets [w were considerably (p < 0.05) higher. In effect, there is an overall trend that aw almost always increases with increasing MC, but the relationship is not linear. However, at a few distinct points, MC becomes lower as aw increases [w might be due to the high percentage of amorphous sugars with high hygroscopicity absorbing more free water from ambient air. Increased aw of our FD powder can be attributed to the higher water retention of MD due to the high number of ramifications with hydrophilic groups [w lower than 0.6 [Powder production yield belongs to the most important indicator showing the efficiency of the drying process  and signanalysis . Indeed,m growth . So, redbacteria , prolongbacteria . Accordibacteria , dried o ± 0.03) . To prescritical . In acco-product , an SD G-product , and ras-product , all of -product  have dete et al.  have foue et al. ,87. In tdroplets ,88, rapincreases . Accordincreases , this inc groups  or highec groups  during pthan 0.6 ,92, the Lentinula edodes Berk. and five Pleurotus species) to range from 15 to 22% per dry matter. Similarly, Khan et a. [Agaricus bisporus, P. ostreatus, and Coprinopsis atramentarius to be 8.51 ± 2.45%, 14.18 ± 0.57%, and 17.02 ± 0.95%, respectively, which is contrary to our control displaying its higher content (58.78 ± 0.54%). This fact can indicate a better β-glucan extraction technique from oyster mushrooms; however, we must also keep in mind other factors (mainly growing conditions) contributing to this discrepancy between the studies. Additionally, significantly (p < 0.05) higher values for β-glucan content in the powders have been achieved by their microencapsulation using both drying methods as compared to the control one. Furthermore, this effect on the content of β-glucan was again shown to be more obvious in the SD samples than in those dried by freezing which is in line with the study conducted by Karthik and Anandharamakrishnan [It is well-known that fungal β-glucan has a stimulating action on the human immune system with proven effects in the treatment of different illnesses . Hence, an et a.  have foukrishnan  showing krishnan ,98, the p < 0.05) contents of TP and TF in our SD samples than in the non-encapsulated (control) ones, a greater power of the SD technique to stabilize these bioactive compounds of the β-glucan powder compared to that of the FD one must be taken in consideration. In effect, microencapsulation by SD is widely employed to protect polyphenols in various matrices [Physalis angulata L. leaf extract obtained using the addition of various concentrations of MD to aqueous or ethanol solvents in comparison with those solely extracted by aqueous or ethanol solvents. Maltodextrin as a convenient encapsulating agent for polyphenol compounds obtained from diverse natural plant matrices has been shown in many reports [P. eryngii isolates [P. ostreatus extract [P. ostreatus [Saccharomyces cerevisiae) [Avena sativa) [Between both powders produced by two different microencapsulation techniques used in our study, no significant differences in AA, TPC, PAC, and FC have been observed, suggesting their same effectiveness with respect to the bioactive compounds’ preservation. On the other hand, based on the findings of demonstrably higher  , and oat sativa) . In addi sativa) ,115. To In summary, the results of all our analyzes revealed the SD microencapsulation of β-glucan powder to be a more appropriate method as compared to the FD one which is in accordance with other studies ,118,119.w, AA, and the content of selected biologically active substances. Our results showed that the SD microparticles of β-glucan powder exhibited a more or less spherical form of various sizes ranging from 2–3 to 20–30 µm. Their values for MC (8.90 ± 0.44%) and aw (0.456 ± 0.001) were demonstrably lower as compared to the control  and FD  microencapsulated samples. Moreover, our findings revealed that the product yield of the SD sample (44.38 ± 0.55%) was significantly higher in comparison with the FD (22.97 ± 0.33%) one. The use of this drying method even led to improved contents of β-glucan (72.39 ± 0.38%), TPC (3.40 ± 0.17 mg GAE/g), and flavonoids (3.07 ± 0.29 mg QE/g). Thus, the SD microencapsulation technique seems to have a greater beneficial impact on the enhancement of the β-glucan powder yield and functional status related to bioactive compounds content which is extremely favorable for the food industry. The SD microencapsulated β-glucan powder will be included next in our bakery experiments to assess its improved quality after food processing. In such a way, its potential for practical use in the development of products with added nutritional value will be explored.The current study provides valuable knowledge concerning a novel approach of commercial β-glucan powder microencapsulation by FD and SD techniques using MD as a wall material. The non-encapsulated sample was compared with the microencapsulated ones in terms of the structural appearance, MC, a


To evaluate the efficacy and safety of galcanezumab in patients with migraine in a real-world setting in Japan.Galcanezumab is the first anti-calcitonin gene-related peptide monoclonal antibody approved in Japan. To the best of our knowledge, no real-world studies on galcanezumab have been published in any international journal from Japan.We retrospectively examined patients with migraine who received three doses of galcanezumab between August 2021 and February 2022 at the Keio University Hospital. We assessed changes in monthly migraine days, responder rate, and migraine-associated and premonitory symptoms. We also investigated injection site reactions and adverse events.Fifty-two patients received three doses of galcanezumab during the study period. Compared with those at baseline, the monthly migraine days decreased by 5.9 days  at 3 months. The 50% responder rate was 61.5% at 3 months. A total of 64.9%, 50.0%, and 63.9% of patients showed improvement in the severity of photophobia, phonophobia, and nausea/vomiting, respectively. Premonitory symptoms without subsequent headache were reported in 62.5% of patients. Moreover, injection site reaction was the most common adverse event (34.6%).This study revealed the efficacy and safety of galcanezumab for migraineurs in Japan. Galcanezumab also improved migraine-associated symptoms. However, despite a reduction in headaches, premonitory symptoms without subsequent headache were reported in > 50% of the patients at 3 months.The online version contains supplementary material available at 10.1186/s12883-022-03041-1. Migraine is a neurological disorder with a high prevalence and burden on patients , 2. MigrClinical studies have indicated the efficacy and safety of galcanezumab, an anti-CGRP monoclonal antibody, in patients with episodic migraine (EM) and chronic migraine (CM) , 5. GalcCriteria for the administration of galcanezumab differ between Japan and other countries. In Japan, galcanezumab can be used for patients with ≥ 4 migraine days per month and for those who have undergone treatment with at least one migraine-preventive drug  with ineffectiveness, intolerance, or strong concern about side effects . OnabotuReal-world studies have recently reported the efficacy and safety of galcanezumab in Europe, the United States, and South Korea , 15–19. Migraineurs experience headaches and several associated symptoms  during migraine. Moreover, migraineurs have premonitory symptoms  hours or days before the headache phase , 21. To This study evaluated the efficacy and safety of galcanezumab in real-world settings in Japan. We also assessed the effects of galcanezumab on migraine-associated symptoms and premonitory symptoms.We conducted a single-center, observational, retrospective, cohort study. The observation period was 3 months (3 M). This study was approved by the Ethics Committee of the Keio University School of Medicine , Tokyo, Japan. Patients were informed about this observational study via the institute’s website, and they could opt out of the study. The need for informed consent was waived by the Ethics Committee of the Keio University School of Medicine, in accordance with national regulations . All methods were carried out in accordance with relevant guidelines and regulations.rd edition (ICHD-3) [The inclusion criteria were as follows: receipt of three doses of galcanezumab (240 mg/120 mg/120 mg) monthly from the headache group of the Keio University Hospital between August 2021  and February 2022; fulfillment of the diagnostic criteria for migraine (including probable migraine) according to the International Classification of Headache Disorders, 3We retrospectively collected demographic data , medical history, and the following headache characteristics: age at onset, family history of headache, migraine characteristics , and the presence of aura. The Generalized Anxiety Disorder-7 (GAD-7) , 26 and The headache specialist (TT) explained the criteria for migraine based on the ICHD-3 to all patients, who were asked to track their headache and migraine days (including probable migraine days). Patients completed a questionnaire on the monthly migraine days (MMDs), monthly headache days (MHDs), monthly acute medication intake days (AMDs), pain intensity , and associated symptoms  at baseline and after the first, second, and third months. The headache specialist verified the accuracy and reliability of the completed questionnaire by interviewing and occasionally reviewing each patient’s headache diary.Patients were classified as having EM or CM according to the ICHD-3. Patients were also diagnosed with medication overuse headache (MOH) based on the ICHD-3.Information on the injection site (forearm or abdomen), injection site reaction  and severity , and other adverse reactions were also collected in the questionnaire.Patients were asked about their satisfaction level  and premonitory symptoms (whether they had premonitory symptoms without subsequent headache) 3 M after receiving galcanezumab.We investigated the efficacy and safety of the therapy. As for efficacy, we investigated changes in the MMD, MHD, NRS, AMD, associated symptoms, and premonitory symptoms. We also analyzed the satisfaction level with galcanezumab administration.The primary endpoints were a change in the MMD from baseline and 50% responder rate (RR). The 50% RR was calculated as the percentage of patients with MMD reduction from baseline by ≥ 50%. The secondary endpoints were changes from baseline in the MHD; NRS; AMD; 25%, 75%, and 100% RR; associated symptoms; premonitory symptoms; and satisfaction level with galcanezumab.For safety, we investigated the injection site, injection site reaction, and other adverse reactions.P-values for comparisons of differences from baseline were adjusted using the Bonferroni correction. We excluded missing data. All two-sided p-values < 0.05 were considered statistically significant. Statistical analyses were performed using SAS version 9.4 .Data are presented as number (percent) and mean ± standard deviation. Differences from baseline in MMD, MHD, AMD, and NRS and the least-squares means of them were analyzed using the mixed-effect model for repeated measures with time as a fixed effect and individual as a random effect, and the correlation structure was defined as unstructured. Normality was visually assessed using residual plots. The chi-squared test was used to compare the categorical data in the subgroup analysis. Fifty-two patients older than 18 years old were diagnosed with migraine by the headache specialist (TT) and received three doses of galcanezumab during the study period. The vast majority of the patients were women, and the mean age was 48.3 ± 12.9  years. At baseline, approximately half of the patients were classified as having EM. The mean MMD, MHD, and AMD were 12.6 ± 7.5 days/month, 15.6 ± 8.0 days/month, and 9.7 ± 7.0 days/month, respectively, and 30.8% patients were diagnosed with MOH. The NRS was 6.5 ± 1.5. Approximately half of the patients had premonitory symptoms , 11 21.2%), 36 (69.2%), 19 (36.5%), and 10 (19.2%) patients received lomerizine, propranolol, valproate, amitriptyline, and topiramate, respectively. Thirty-four (46.2%) patients used only one preventive drug, and the mean number of previous migraine preventives used was 2.0 ± 1.3. Twenty-five (48.1%) patients were using migraine preventives at the time of initiating galcanezumab. Three (12%) of the relevant patients discontinued consumption of migraine preventives at the first dose and 22 (88%) continued consuming them  at 1 month (1 M), 4.9 days  at 2 months (2 M), and 5.9 days  at 3 M). The MHD, AMD, and NRS were also significantly reduced at 1 M compared with baseline  at 1 M, 46.2%  at 2 M, and 61.5%  at 3 M; a 100% RR was observed in 9.6% of patients at 3 M  at 1 M, 3.3 days  at 2 M, and 4.4 days  at 3 M. The MHD, AMD, and NRS were also significantly reduced at 1 M compared with baseline  at 1 M, 56.0%  at 2 M, and 76.0%  at 3 M; a 100% RR was observed in 20.0% of patients at 3 M  at 1 M, 6.4 days  at 2 M, and 7.3 days  at 3 M. The MHD, AMD, and NRS were also significantly reduced at 1 M compared with baseline  at 1 M, 37.0%  at 2 M, and 48.1%  at 3 M; a 100% RR was observed in only two patients (7.4%) at 2 M, but not at 3 M . There was no tendency in the 50% RR between GAD-7 ≥ 5 and GAD-7 < 5 at 3 M.Supplementary Figs. The severity of the associated symptoms  at baseline and post-treatment are presented in Supplementary Fig. p-value, responders showed a higher percentage of improvement and disappearance for each associated symptom numerically compared to non-responders.Supplementary Fig. Twenty-four (46.1%) patients had premonitory symptoms at baseline; among them, 15 (62.5%) reported premonitory symptoms without subsequent headache after three doses of galcanezumab.Most patients opted to receive the second and third dose in the upper arm Table A. Fourten = 4, 7.7%), fatigue , burning sensation , lightheadedness , and others   were very satisfied with the therapy, 20 (40.0%) were somewhat satisfied, and 9 (18.0%) were not satisfied.To the best of our knowledge, this is the first, real-world study of galcanezumab and CGRPmAb in migraineurs from Japan to be reported in any international journal. Our results suggest that galcanezumab is effective and relatively safe in the Japanese population. In addition, galcanezumab improved migraine-associated symptoms, such as photophobia, phonophobia, and nausea/vomiting. The proportion of patients in whom nausea/vomiting disappeared was higher than that in whom the other two symptoms disappeared. However, premonitory symptoms remained in 62.5% of patients with 3 months of galcanezumab treatment.The efficacy and safety of galcanezumab have been confirmed by randomized controlled trials such as EVOLVE-2 for EM and REGAIN for CM , 7. In tThree real-world studies on galcanezumab from Italy, Spain, and South Korea have been published , 17, 18.All three associated symptoms improved in patients in the present study. Nausea and vomiting disappeared in a higher number of patients than photophobia and phonophobia . A reason for this high rate of resolution of nausea and vomiting symptoms may be that the number of MMDs with nausea and vomiting at baseline was lower than that with photophobia and phonophobia in the previous study  . HoweverApproximately 50% of patients had premonitory symptoms at baseline. While the effects of galcanezumab were observed in some patients, 62.5% of the patients felt that the residual of premonitory symptoms even though subsequent headaches were inhibited, after three doses of galcanezumab. A post hoc analysis of data from clinical trials showed that galcanezumab reduced the frequency of migraine headache days with premonitory symptoms ; howeverIn patients who received the three doses of galcanezumab, no serious adverse events were observed, and the most frequent adverse events were injection site reactions. However, three patients who were not included in the study owing to discontinuation of the therapy  after the first or second visit contributed to a 94.5% continuation rate for 3 M. Nevertheless, the drug continuation rates for 3 M remained high. In our study, one patient had side-effect of eczema (mild), and another patient stopped galcanezumab before three doses due to eczema. Eczema has previously been reported in a patient on erenumab with asthma . InteresThe satisfaction rate was also high at 82.0%. High satisfaction with anti-CGRP monoclonal antibodies has been reported in a real-world study . This stThis study has some strengths. It is the first real-world study from Japan that described the efficacy and safety of galcanezumab in migraineurs in detail. Moreover, we analyzed the migraine-associated and premonitory symptoms that have not been studied in a real-world setting. However, the study also has some limitations—small sample size, retrospective nature, single-center design, and a short 3-month observation period. The primary endpoint (migraine days) was mainly assessed with questionnaires and not by the actual headache diaries which were only checked in some cases. Thus, further research is necessary to elucidate the effects of anti-CGRP monoclonal antibodies in the Japanese population.This study revealed that galcanezumab is effective and safe for the prevention of migraine in Japan. Anti-CGRP monoclonal antibody use improved the migraine-associated symptoms and even resulted in disappearance of nausea and vomiting in nearly half of the patients at 3 months. However, despite a reduction in headaches, premonitory symptoms without subsequent headaches were observed in > 50% of the patients at 3 M.Additional file 1: Supplementary Figure 1. Changes in (A) MMD, (B) MHD, (C)AMD, and (D) NRS **～*** represents a statistically significant change. **adjusted p<0.01; ***adjusted p<0.001. Line graphs are expressed as mean and bars represent 95% CI. MMD, monthly migraine day; MHD, monthly headache day; AMD, monthly acute medication intake days; NRS, numerical rating scale; EM, episodic migraine; CM, chronic migraine; ALL, all patients; 1 M, 1 month; 2 M, 2 months; 3 M, 3 months.Additional file 2: Supplementary Figure 2. Fifty percent responder rate in patients with or without medication-overuse headache. MOH: Medication-overuse headache. Responder rate was based on monthly migraine days.Additional file 3: Supplementary Figure 3. Fifty percent responder rate in patients in GAD-7 < 5 and GAD-7 ≥ 5 (anxiety). GAD-7: Generalized Anxiety Disorder-7. Responder rate was based on monthly migraine days.Additional file 4: Supplementary Figure 4. Degree of associated symptoms at baseline and after 1-3 M of galcanezumab. (A) Photophobia, (B) Phonophobia, and (C) Nausea/vomiting. 1 M: 1 month, 3 M: 3 months.Additional file 5: Supplementary Figure 5. Improvement and disappearance in associated symptoms in patients with or without 50% responder rate in MMD. (A) Photophobia, (B) Phonophobia, and (C) Nausea/vomiting non-Res: non-responder (<50% responder rate), Res: responder (≥50% responder rate), MMD: monthlymigraine days. Responder rate was based on monthly migraine days.


The Visual Analog Scale (VAS) scores of both groups decreased greatly associated to those before surgery (P < 0.05). The levels of cortisol (COR) and immune adhesion inhibitor (FEIR) in the experimental group were significantly dissimilar from those in the control group (P < 0.05). The tumor necrosis factor-alpha (TNF-α) was 96.4 ± 21.8 ng/L in the experimental group, observably lower than that in the control group (P < 0.05). The postoperative diamine oxidase (DAO) and D-lactate (D-lac) were 62.4 ± 9.3 μmol/mL and 33.8 ± 7.2 ng/L, respectively, in the experimental group, much lower than those in the control group (P < 0.05). There were also significant differences in the initial recovery of bowel sounds, defecation, and total length of hospital stay (LOHS) between the groups (P < 0.05). DEX anesthesia had ideal sedative and analgesic effects, improving the prognosis of patients during surgery, and shortening the LOHS. Thus, it deserved a clinical application value.It was to investigate the influence of perioperative dexmedetomidine (DEX) anesthesia on the prognosis of elderly patients with gastrointestinal tumor (GIT) surgery. 90 patients who underwent laparoscopic radical gastrectomy for GIT were included. They were randomly divided into the experimental group (45 cases) with DEX+general anesthesia, and the control group (45 cases) with epidural anesthesia+general anesthesia. The indicators after surgery were compared between the two groups. The mean arterial pressure (MAP) was 74.8 ± 3.5 mmHg and the heart rate (HR) was 52.7 ± 8.2 beats/min With the development of modern society, the population is gradually showing an aging trend, and the proportion of elderly patients undergoing surgeries is increasing. When people become old, various organs in the body undergo degenerative changes gradually, the defense ability is weakened, and the metabolic efficiency of the body is also reduced . TreatmeSome clinical studies have found that as the probability of pain after laparoscopic surgery increases, the probability of opioid use also increases. But the use of opioids will cause many adverse reactions, such as mental dependence, nausea and vomiting, constipation, and respiratory depression . Some stα2 adrenergic receptor agonists with the effect of improving immune function, but its specific mechanism of action is not clear [Epidural anesthesia has a good postoperative analgesic effect. It can inhibit the conductions of sympathetic nervous excitation and noxious stimulation, so that the application of opioids can be reduced. This anesthesia method can also advance immune function and reduce the probability of stress response effectively . Howeverot clear . DEX canot clear . Howeverot clear . CompareTherefore, in this research, patients undergoing laparoscopic radical gastrectomy for GIT were selected. The patients were divided and given two different surgical anesthesia methods, respectively. Effect of DEX anesthesia on the prognosis of patients with GIT surgery was discussed, to further advance the therapeutic effect and provide reference for the clinical surgical treatment of GIT.According to the standards of American Society of Anesthesiologists, the patients were in grade II or IIIThe patients had no history of other gastrointestinal surgery. Exclusion criteria were also enactedPatients had severe cardiovascular, cerebrovascular, or respiratory diseasesPatients had severe liver and renal dysfunctionPatients suffered from endocrine and metabolic diseasesPatients had a history of mental illnessPatients got the second-degree atrioventricular blockThose were allergic to anestheticsThose could not perform epidural puncture90 patients who underwent laparoscopic radical gastrectomy for GIT in the First Affiliated Hospital of Harbin Medical University from March 2020 to October 2021 were selected. These patients were randomly divided into the experimental group (45 cases) and the control group (45 cases). For patients in the former, DEX+general anesthesia was given, while epidural anesthesia+general anesthesia were given in the latter. There were 46 males and 34 females, aged 62-83 years old, with a mean age of 68.5 ± 3.8 years old. They weighted 52-71 kg, with a mean weight of 63.6 ± 6.4 kg. Inclusion criteria were as follows:μg/kg, etomidate 0.2 mg/kg, and rocuronium bromide 0.6 mg/kg. Intravenous anesthesia was maintained, and propofol was pumped intravenously to the patient at 4-8 mg/kg/h, as well as remifentanil at 0.05-0.2 μg/kg/min. On the foundation of general anesthesia, patients in the experimental group were pumped with 1.0 μg/kg DEX for 10 min before anesthesia induction; it was also pumped as 0.5 μg/kg half an hour before the end of the surgery. The control group was given epidural anesthesia, for which the patients took the left lateral position. The puncture space was selected according to the surgical site, with the depth of the catheter was 3.5 cm. Before the anesthesia induction, 5 mL of 2% lidocaine was given. 5 min later, the effect of anesthesia was blocked and the level of anesthesia were tested. 5 mL of 0.2% ropivacaine was given through epidural space injection at the start of surgery, followed by regular administration for 50 min/time.Two hours before surgery, the patients in both groups were given with 375 mL of surgical energy drink orally. After being into the operating room, blood pressure, heart rate (HR), electrocardiogram, etc. were routinely monitored. During surgery, the goal-directed fluid therapy was performed according to the pulse pressure variation. The conventional general anesthesia induction was applied with sufentanil 0.4-0.5 The mean arterial pressure (MAP) and HR of the two groups of patients were recorded before and after surgery, respectively; venous blood was collected before and after surgery to detect stress indicators. Serum norepinephrine (NE) concentration and serum cortisol (COR) concentration were determined by enzyme-linked immunosorbent assay (ELISA). The rate of direct tumor erythrocyte rosette (DTER), an immune stress indicator, was detected; the determination method was expounded as follows. 0.1 mL of fresh serum from normal people and 0.1 mL of Ehrlich ascites cancer solution were mixed well and had a water bath at 37°C for 30 min. Normal saline was filled up, and the mixture was washed and then horizontally centrifugated (2000 rpm/min). After 5 min, 0.05 mL of erythrocyte suspension to be tested  was added to mix well; then, water bath was performed again at 37°C for 30 min. After taken out, it was added with 0.1 mL of normal saline and mixed well; afterwards, 0.05 mL of 0.25% glutaraldehyde was also added for mixing. After horizontal smear and Wright's staining, tumor cells became blue, erythrocytes were in red, and a tumor cell with 3 or more erythrocytes was denoted as a rosette. With 100 tumor cells, the DTER rate was calculated. The immune adhesion inhibitor (FEIR) was determined by Guo's method. The time of the first anal exhaust, time of first defecation, and the recovery time of bowel sounds, the time to get out of bed, the Visual Analog Scale (VAS) pain score, respiratory depression, nausea and vomiting, and the total length of hospital stay (LOHS) after surgery were recorded.Criteria for postoperative cognitive dysfunction (POCD) were as below. According to the developer's suggestions, if the object had less than 12 years of education, 1 point was added to the total score, so as to adjust for the influence of culture. A score below 26 indicated POCD . For theα) and interleukin-6 (IL-6) were communal indicators of the degree of inflammation. D-lactate (D-lac) and diamine oxidase (DAO) were common indicators of intestinal permeability. Blood was drawn from the patients and centrifuged, then the supernatant was collected for testing. The contents of D-lac, DAO, TNF-α, and IL-6 in blood were determined strictly according to the instructions of the ELISA kit [μL of sample for direct determinationD-lac determination: 40 The tumor necrosis factor-alpha  was diluted into 5 different concentrations using the standard substance diluent, which were in 15 μmol/mL, 30 μmol/mL, 60 μmol/mL, 120 μmol/mL, and 240 μmol/mL, respectively.Secondly, the standard substance was diluted. Five centrifuge tubes were marked as S1, S2, S3, S4, and S5, respectively. The standard substance stock solution ; the remaining steps were the same. 40 Fourthly, the solution was confected in the following principles. The ratio of fresh medical double distilled water: concentrated washing solution was 30 : 1. It was shaken gently to keep the concentration uniform and then was put at room temperature for use.Fifthly, washing. The sealing film was slowly peeled off, the liquid was discarded, and the remains was spin-dried. It was necessary to fill each well with the washing solution, and then placed for 30 seconds before discarding. It was repeated 5 times according to the above principles, and finally the ELISA plate was pat-dried with absorbent paper.μL of color developer A was added to each well in order; then, 50 μL of color developer B was also added to each well. The plate was shaken gently to make the concentration of reagent uniform. The corresponding wells were placed at a temperature of 37°C and protected from light for the reaction for 10 min.Sixthly, color development. 50 μL of terminating agent was added to each well, the reaction could be terminated (the color changed from blue at first to yellow.)Seventhly, the reaction was terminated. As 50 Eighthly, the optical density (OD) wanted to be measured at 450 nm of the microplate reader.Ninthly, the sample content was calculated according to the prepared standard curve. The calculation equation was shownμL was sampled for direct determination(2) DAO determination: 40 Firstly, it was needed to put the DAO kit at room temperature for about 40 min before the determination of DAO. For using the reagent, it was shaken gently to make the reagent keep a uniform concentration.μmol/mL) into 5 different concentrations of 15, 30, 60, 120, and 240 μmol/mL, respectively.Secondly, for dilution of standard substance, 5 centrifuge tubes were noticeable as S1, S2, S3, S4, and S5, respectively. The standard substance diluent was utilized to dilute the standard substance stock solution  Determination of TNF-α kit at room temperature for about 40 min before the determination. For the use of the reagent, it should be shaken gently for a uniform concentration.Firstly, it was needed to put the TNF-μmol/mL) was diluted with standard substance diluent into 5 different concentrations for use. These were in 30 μmol/mL, 60 μmol/mL, 120 μmol/mL, 240 μmol/mL, and 480 μmol/mL, respectively.Secondly, the dilutions of standard substance were made. With 5 centrifuge tubes marked as S2, S3, S4, S5, and S6, the standard substance stock solution  IL-6 assay: serum homogenate was taken directly for testingFirstly, before the assay of IL-6, the IL-6 kit needed to be placed at room temperature for about 40 min. The reagent should be surprised or oscillated gently for an even concentration.μmol/mL) was diluted into 5 different concentrations of 20, 40, 80, 160, and 320 μmol/mL, respectively.Secondly, the standard substance was diluted. Five centrifuge tubes were denoted as S2, S3, S4, S5, and S6, respectively. With standard substance diluent, the standard substance stock solution  ≤ 90% under inhalation condition. In the event of respiratory depression, oxygen should be given through a mask timely, and artificial ventilation should be performed to assist respiration if necessary. If the above situation could not be better, the case was excluded from the experiment.The possible special circumstances during the experiment mainly comprised (severe) hypotension, (severe) bradycardia, and respiratory depression. HR and arterial blood pressure-based HR and blood pressure at rest 5 min after arterial puncture catheter placement were monitored. Bradycardia was defined as HR < 60 beats/min or less than the 20% of baseline value, and the treatment was a single intravenous injection of atropine 0.1-0.3 mg. Plain bradycardia was defined as HR < 50 beats/min or lower than 30% of the baseline value. For the treatment measures, intravenous injection of atropine 0.3-0.5 mg was given. Intermittent intravenous injection of isoproterenol 2-10 t-test was adopted for comparisons between the two groups, and the repeated-measurement analysis of variance was used for the comparisons among multiple groups. The enumeration data were expressed as the number of cases (%), while the unordered classification data were expressed by the χ2 test. P < 0.05 was considered the condition of a statistically significant difference.The statistical software SPSS 22.0 was used for processing in this research, and the measurement data were expressed as (P > 0.05). The MAP 74.8 ± 3.5 mmHg and HR 52.7 ± 8.2 beats/min−1 in the experimental group were remarkably lower compared with those before surgery and were also significantly lower than the 88.7 ± 10.2 mmHg and 60.2 ± 8.8 beats/min−1 in the control group. The differences above were all statistically significant (P < 0.05), which could be observed in The hemodynamic test results of the two groups of patients suggested that, compared with preoperative levels, the MAP and HR of both groups were decreased, but the control group showed no significant change (P > 0.05). The COR was 104.9 ± 16.2 ng/mL in the experimental group and 104.6 ± 15.7 ng/mL in the control group, both of which observably increased compared to those before surgery with statistically significant differences (P < 0.05). The FEIR was 17.6 ± 2.1% in the experimental group and 17.2 ± 2.3% in the control group were greatly lower than those before surgery, showing the differences of statistical significance (P < 0.05). As presented in P > 0.05).As the stress and immune indicators were detected, it was shown that the levels of NE and DTER in the two groups did not change much compared with preoperative levels, and the differences were not statistically significant (P > 0.05). After surgery, the average VAS score of the experimental group was 4.7 ± 2 and that of the control group was 4.6 ± 2.3, significantly lower than those before surgery with differences of statistical significance (P < 0.05). No significant difference was between the groups (P > 0.05), which could be discovered in Before surgery, there was not a significant difference in VAS scores between two groups (P > 0.05). More details were displayed in Postoperative POCD evaluation was performed on the patients. The results illustrated that POCD occurred in both groups, with 6 cases in the control group and 4 cases in the experimental group. Although there were differences, which were not significant between groups (P > 0.05). TNF-α96.4 ± 21.8 ng/L was highly lower than that before surgery, and the difference was of statistical significance (P < 0.05). Compared to the control group, postoperative TNF-α115.3 ± 24.6 ng/L, the difference was also statistically significant (P < 0.05) as presented in There was no significant difference in IL-6 before and after surgery in the experimental group (P > 0.05). The postoperative DAO was 62.4 ± 9.3 μmol/mL, and D-lac was 33.8 ± 7.2 ng/L in the experimental group, observably lower than the preoperative levels with statistically significant differences (P < 0.05). In the control group, the postoperative DAO was 72.7 ± 15.2 μmol/mL and D-lac was 38.2 ± 6.4 ng/L. The levels in the experimental group were considerably lower compared with those of the control, and the differences were proved to be statistically significant (P < 0.05) in Not a significant change was found in serum DAO and D-lac levels in the control group before and after surgery, without a difference of statistical significance (P > 0.05). In the experimental group, the average postoperative recovery time of bowel sounds was 2.8 ± 0.7 d, the average time of first defecation postoperatively was 6.1 ± 1.8 d, the average LOHS was 17.9 ± 8.1 d, and 2 cases had vomiting reaction. In the control group, the average recovery time of bowel sounds, the average time of first defecation, and the average LOHS postoperatively was 3.9 ± 1.2 d, 7.4 ± 1.6 d, and 25.5 ± 8.6 d, respectively. There were 6 patients got vomiting in the control group. Each indicator was markedly higher compared to the experimental group, and the differences were thought of statistical significance (P < 0.05)  .GIT has developed into a common digestive tract tumor nowadays, which has a serious impact on the life and health of human beings, especially the elderly. Epidural anesthesia can inhibit sympathetic nerve conduction and sympathetic nerve excitation, thereby reducing the synthesis of catecholamines. Epidural anesthesia can also inhibit the hypothalamic-pituitary-adrenal axis pathway, reducing the secretion of COR and improving immune function . DEX, as−1 in the experimental group decreased dramatically compared with those preoperatively. MAP of 88.7 ± 10.2 mmHg and HR of 60.2 ± 8.8 beats/min−1 in the control group were significantly lower compared to the experimental group with statistically significant differences (P < 0.05). It was suggested that DEX had a stabilizing effect on hemodynamic situation and could inhibit the increase in HR and MAP effectively in patients undergoing extubating surgery. Similar previous study has shown that DEX can reduce the occurrence of agitation during the recovery period in patients with tonsillectomy after general anesthesia and has obvious sedative and analgesic effects [P < 0.05). There was not a significant difference between the two groups (P > 0.05). Two patients in the experimental group had vomiting reactions, while 6 patients in the control group had vomiting reactions. A study has also confirmed that DEX can reduce the stress response effectively, enhance immunity, and relieve postoperative pain and the incidence of adverse reactions in patients undergoing radical gastrectomy for gastric cancer [The results exposed that, compared with preoperative levels, MAP and HR in both groups decreased. The MAP of 74.8 ± 3.5 mmHg and HR of 52.7 ± 8.2 beats/min effects . After sc cancer . This isP < 0.05). Therefore, the application effect of DEX was better and it was worthy of promotion. At present, there is no unified standard for the optimal timing of POCD assessment. Generally, POCD can be divided into early, mid-term, and long-term cognitive changes. Within 1 week after surgery, it is the early POCD cognitive change, the mid-term cognitive change is within 3 months after surgery, and 1-2 years after surgery, it is the POCD long-term cognitive change. Some study has shown that the possibility of patient death within 3 months after surgery can be predicted by early POCD assessment [P > 0.05), perhaps because of the small sample size included. Thus, the effect of DEX could not be fully determined.COR can be utilized to reflect the degree of stress in the body , and FEIsessment , so it iα of 96.4 ± 21.8 ng/L in the experimental group was memorably lower than that before surgery, showing the difference of statistical significance (P < 0.05). It was also statistically and greatly different from the postoperative TNF-α of 115.3 ± 24.6 ng/L in the control group (P < 0.05). It was suggested that DEX had an anti-inflammatory effect. A number of animal experiments have shown that DEX can significantly inhibit the excessive generation of inflammatory factors such as TNF-α, IL-1β, and IL-6 [μmol/mL and D-lac of 33.8 ± 7.2 ng/L were much lower than those before surgery in the experimental group, which were statistically different (P < 0.05). Compared with the postoperative DAO of 72.7 ± 15.2 μmol/mL and D-lac of 38.2 ± 6.4 ng/L in the control group, those in the experimental group were statistically lower (P < 0.05). Recent studies have suggested that stimulating vagal activity can play an important protective role in the intestinal barrier function damage triggered by inflammatory factors by regulating the cholinergic anti-inflammatory pathway [P > 0.05). The average recovery time of postoperative bowel sounds, the average time postoperative first defecation, and the average total LOHS was 2.8 ± 0.7 d, 6.1 ± 1.8 d, and 17.9 ± 8.1 d, respectively, in the experimental group. Those were 3.9 ± 1.2 d, 7.4 ± 1.6 d, and 25.5 ± 8.6 d, respectively, in the control group. Each indicator was remarkably and statistically higher than that of the experimental (P < 0.05). Some study has also revealed that perioperative application of DEX can promote the recovery of gastrointestinal function and shorten the time of intestinal paralysis in patients with laparoscopic colorectal radical surgery [Studies have also proved that DEX can reduce systemic inflammatory response effectively in cases of elderly malignant GIT treated by laparoscopic surgery, which is conducive to the rapid recovery of patients after surgery . This woand IL-6 . The pos pathway . In accu surgery . It is cThrough the comparison with epidural anesthesia, it was found that DEX anesthesia could improve postoperative stress response and immune function effectively and had ideal sedative and analgesic effects. It could also dismiss postoperative inflammatory response and reduce incidence of postoperative nausea and vomiting. Thus, the intestinal function of patients could be protected, and the LOHS of patients could also be shortened, which were beneficial to improve the prognosis of patients after surgery. It deserved a clinical application value. However, due to limited conditions, the included sample size was small, the study time was short, and some results showed no significant difference. The long-term prognosis of DEX anesthesia for patients with GIT surgery needed additional exploration. It illustrates that DEX can improve the intestinal permeability of patients and maintain the barrier function of the intestinal tract compared to epidural anesthesia.


No standard of anatomical variables, including stoma size, limb length, pouch size, and volume, has been determined for laparoscopic Roux-en-Y gastric bypass yet. Herein, we evaluated the effect of two different techniques for creating the gastric pouch on short-term postoperative weight loss.This retrospective cohort was conducted on patients with a laparoscopic Roux-en-Y gastric bypass history from January 2019 to September 2020. Patients were divided into two groups: in one group, patients’ gastric pouch was made using two 60 mm linear staplers, while in the other group, the gastric pouch was made using three 60 mm linear staplers. Anthropometric data, including weight, height, and body mass index (BMI), were measured preoperatively and six months following surgery. Weight outcomes, such as weight loss, a decrease in BMI, excess weight loss (%EWL), and total weight loss (%TWL), were calculated as short-term weight outcomes.Two groups, each containing 50 patients, were included. Patients with smaller pouches (two staplers) had 32.4 ± 9.2 kg weight loss, and those with larger pouches (three staplers) had a 31.42 ± 10.3 kg weight loss. Also, %EWL was 69.7 ± 14.9 and 63.0 ± 20.9, and %TWL was 28.2 ± 6.0 and 26.14 ± 7.5 in patients with two stapler pouches and three stapler pouches, respectively. None of the weight outcome parameters were significantly different between the groups .Various studies have been conducted, resulting in different conclusions regarding the effect of the size of the gastric pouch on weight loss. One of the major differences contributing to varying literature studies results is the measurement method used for gastric pouch size. We conclude that using two staplers is not a way to achieve a better result. As the best measurement method has not been defined, studies comparing different methods are suggested; here, the aim was to use a more simple and clinical method regarding this issue. •The historical consideration of a small gastric pouch for better weight results.•Incompatibility of study results due to different measurements for pouch size.•No significant differences in weight outcomes between two and three staplers.•The need for further high-quality studies to determine the best measurement method. BariatrUnfortunately, there is still no standard for anatomical variables, such as stoma size, limb length, pouch size, and volume ,10. So fIn addition, some efforts have been made to achieve a standard for pouch size. A study conducted in the Netherland in 2018 showed that using the calibration tube for gastric pouch creation may result in higher excess weight loss (%EWL) and total weight loss (%TWL) at two years of follow-up . Also, mIn this study, we evaluated the short-term effect of two techniques for creating the gastric pouch in laparoscopic Roux-en-Y gastric bypass on %EWL and %TWL. We hypothesized that using only two staplers to create the gastric pouch may lead to higher %EWL and %TWL than three staplers.2The study was designed as a retrospective cohort conducted on patients with a history of laparoscopic Roux-en-Y gastric bypass in Mother and Child hospital, affiliated with Shiraz University of Medical Sciences, Shiraz, Iran, from January 2019 to September 2020. Adult patients aged 18–65 years were considered for bariatric surgery if they had body mass index (BMI) > 40 kg/m2 or >35kg/m2 with obesity-related comorbidity. If indicated, all patients were preoperatively evaluated by a multidisciplinary team consisting of dietitians, bariatric surgeons, endocrinologists, and psychologists. Patients with a history of smoking, alcohol use, psychiatric problems, inflammatory and infectious diseases, cancer, and heart and/or lung failure were excluded. Moreover, patients with reversal or previous bariatric surgery were excluded from the study.All patients underwent classic Roux-en-Y gastric bypass with the standard method ,20 and tInformed consent was obtained from all individual participants included in the study. The study protocol conforms to the provisions of the Declaration of Helsinki, and the Shiraz University of Medical Sciences Ethics Committee approved this study protocol based on the code of IR.SUMS.MED.REC.1400.344. The work has been reported in line with the STROCSS criteria .2.1Anthropometric data, including weight, height, and BMI, were carefully measured at preoperative and six-month postoperative medical visits. Using these data, the percentages of TWL and EWL that are the primary outcomes of this study were calculated. The percentage of TWL was defined as weight loss divided by weight before surgery, and the percentage of EWL was defined as weight loss divided by excess weight before surgery above a normal BMI of 25 kg/m2. The patients' age, sex, exercise activities, and underlying diseases were also recorded.2.2t-test was used to compare the mean changes of quantitative variables. The Mann-Whitney test was used to compare variables that did not have a normal distribution. P-value<0.005 was considered statistically significant.All data were expressed as mean ± standard deviation and were analyzed using SPSS software, version 17. The Kolmogorov-Smirnov test was used to follow the data from the normal distribution. Chi-square was done for nominal variables, and an independent 33.1A total of 100 patients were included in the study. The mean age of patients was 35.8 ± 10.1 years. In the group of patients with a smaller pouch, which was made by using two 60 mm staplers, the mean age was 35.7 ± 9.1 years, and in the group of patients with a larger pouch, which made by using three 60 mm staplers, the mean age was 35.9 ± 11.1. In the former group, 20% of patients were male with a mean BMI of 42.4 ± 3.4; in the latter group, 28% were male with a mean BMI of 46.4 ± 22.1. Demographic and preoperative clinical data of patients are shown in 3.2Patients with smaller pouches had 32.4 ± 9.2 kg weight loss after six months, with a 12.0 ± 3.2 decrease in their BMI. The group of patients with pouches made using three staplers had 31.42 ± 10.3 kg weight loss and a 12.2 ± 7.3 decrease in their BMI after six months. %EWL in patients with two stapler pouches and three stapler pouches were 69.7 ± 14.9 and 63.0 ± 20.9, respectively. The %EWL in the two-stapler and three-stapler groups were 32.31–111.29 and 31.25–108.70, respectively. Besides, four (8%) in the two-stapler group and 16 (32%) in the three-stapler group had an %EWL lower than 50%. As shown in 4The size of the gastric pouch has been postulated to be an influential variable for gastric bypass outcomes in such a way that a small pouch was considered an important factor for better weight outcomes . AlthougIn a study by Nishie et al. , authorsA systematic review in 2020 gathered studies that evaluated the gastric pouch or gastrojejunostomy size on weight outcomes following Roux-en-Y gastric bypass; of fourteen studies found, five reported poorer results for larger pouches , while oOne of the most important factors contributing to these conflicting results is the measurement technique used, and an optimal method has not been introduced yet. Studies have used various techniques in the literature, including contrast study, 3D computed tomography scan (CT), barium swallow, and even cottage cheese test ,13,29,30The pouch sizes in our study were based on the number of staplers, and it is conceivable that the two-stapler group was not small enough to affect the average change in weight loss significantly. Therefore, studies with an accurate method for measuring of gastric pouch size are suggested. Otherwise, malabsorption or hormonal changes rather than mechanical restriction could be more effective regarding weight outcome .Our study was not without limitations. This was a retrospective study with its limitations compared to the prospective ones. Although we aimed to assess the short-term weight outcomes in this study, follow-up of more than six months is suggested for further studies showing the results in the long term. We had two groups, each containing fifty cases; although the sample size was not small, larger sample sizes are suggested for more reliable results. As the measurement of choice for gastric pouch size is unknown and different conclusions have been achieved in previous studies, more high-quality studies are needed to determine the best measurement method.5The small gastric pouch has been historically considered an important factor for better weight outcomes. Various studies have been conducted to evaluate this issue, resulting in different conclusions. One of the major differences contributing to the studies’ results is the measurement method used for gastric pouch size. We used two different procedures as a clinical method of measurement. And our hypothesis regarding higher %EWL and %TWL in the two-stapler procedure was not supported based on our outcomes. Therefore, the result of a number of studies showing poorer weight outcomes with larger pouches is questioned. Here, we conclude that using two staplers is not a way to achieve better weight loss. As the best measurement method has not been defined, studies comparing different methods are suggested; in this study, the aim was to use a more simple and more clinical method for this issue.The University Ethics Committee approved this study protocol based on the code of IR.SUMS.MED.REC.1400.344.10.13039/501100004320Shiraz University of Medical Sciences, Iran.The present study was supported by a grant from the Vice-chancellor for Research, Neda Haghighat: Data collection and interpretation, writing and revising the paper.Hooman Kamran: Data analysis, writing the paper.Mohammad Naser Moaddeli: Data gathering, revising the paper.Babak Hosseini: Data interpretation, revising the paper.Ali Karimi: Data interpretation, revising the paper.Iman Hesameddini: Data collection, writing the paper.Masoud Amini: Data interpretation, revising the paper.Seyed Vahid Hosseini: Supervising, revising the paper.Abtin Vahidi: Data interpretation, writing the paper.Nader Moeinvaziri: Study concept and design, data interpretation, revising the paper.1. Name of the registry: Vice-chancellor for Research, Shiraz University of Medical Sciences, Iran2. Unique Identifying number or registration ID: IR.SUMS.MED.REC.1400.344https://ethics.research.ac.ir/ProposalCertificateEn.php?id=226325&Print=true&NoPrintHeader=true&NoPrintFooter=true&NoPrintPageBorder=true&LetterPrint=true3. Hyperlink to your specific registration (must be publicly accessible and will be checked): Nader Moeinvaziri, MD.Informed consent was obtained from all individual participants included in the study.Not commissioned, externally peer-reviewed.None declared.


To understand cation–sulfonate interactions better, we study both NaLAS colloidal solutions in the presence of CaCl2 and precipitates forming at higher salt concentrations. Upon addition of CaCl2, we find the surface tension and critical micelle concentration of NaLAS to decrease significantly, in line with earlier findings for alkylbenzylsulfonates in the presence of divalent cations. Strikingly, an increase in the surface tension is discernible above 0.6 g L–1 NaLAS, accompanied by the decrease of apparent micelle sizes, which in turn gives rise to transparent systems. Thus, there appears to be a second critical concentration indicating another micellar equilibrium. Furthermore, the maximum salt tolerance of the surfactant is 0.1 g L–1 Ca2+, above which rapid precipitation occurs yielding sparingly soluble CaLAS2∙2H2O.Anionic surfactants, such as sodium linear alkylbenzene sulfonates (NaLAS), are utilized in various fields, including industry, household, and agriculture. The efficiency of their use in aqueous environments is significantly affected by the presence of cations, Ca One of the most commonly applied anionic surfactants are long-chain alkyl aryl sulfonates , as theyThe behavior of surfactants in an aqueous environment depends on a number of physicochemical parameters, such as temperature and salt concentration. Sulfonates can be tolerant to very high temperatures up to 200 °C) as compared to sulfate detergents ,19. Howe0 °C as cIn particular, a marked decrease in the surface tension as well as CMC with increasing salt concentration is observed at the presence of electrolytes at a fixed temperature ,33,34,35–, ions with higher charge density tend to salt out the surfactant at a lower salt concentration. That is, they more readily induce micellization and, eventually, precipitation [4+ < Na+ < Mg2+ < Ca2+ has been found for precipitating NaDBS from an aqueous solution [2+ alkyl aryl sulfonates below CMC has been quantified in terms of thermodynamic products [2+, ca. 1.3–1.7∙10–4 M [+ one, 1.4–4.6∙10–3 M [As for DBSpitation ,28,29,30solution , which iproducts ,39,40. B7∙10–4 M ,39,40, t2+ for surfactant precipitation, which may in turn lead to a significant loss of sulfonate surfactant. Thus, characterizing Ca2+–surfactant interactions is important to describe the overall performance of a given surfactant in industrial systems. To this end, we study the effect of CaCl2 on the properties of sodium linear alkylbenzene sulfonate (NaLAS) aqueous solutions with varying cation and surfactant concentrations in a wide range, both below and above CMC. We find upon increasing the concentration of Ca2+ ions a marked decrease in the air–water surface tension as well as CMC in dilute solutions (0.01–0.1 g L–1 Ca2+). Interestingly, there appears to be a second critical concentration at high surfactant concentrations, associated with another chemical equilibrium. Further enhancement of the amount of CaCl2 yields the sparingly soluble CaLAS2∙2H2O salt, suggesting the maximum salt tolerance of NaLAS to be ~0.1 g L–1 Ca2+.The above examples illustrate the high propensity of Ca2·2H2O, ACS reagent grade; VWR, Radnor, PA, USA), magnesium chloride hexahydrate , sodium ‘dodecylbenzensulfonate’ , ethylenediamine tetraacetic acid disodium salt dihydrate , and methanol  were used as received. The metal-ion content of the hydrated salts was checked by complexometric titration using Na2EDTA as titrant.Calcium chloride dihydrate . Furthermore, samples were always freshly prepared before tensiometric and dynamic light scattering (DLS) measurements, since long-term aggregation of micelles or particle cohesion may alter the samples properties significantly.2+-ion (0.01–5.00 g L–1) was prepared from CaCl2∙2H2O. This solution was then filled into a volumetric flask containing the necessary amount of solid NaLAS. The thus-obtained aqueous mixtures (cNaLAS = 0.05–5.00 g L–1) were stirred for 24 h at room temperature. To avoid the incidental adsorption of either Na+, Ca2+, Cl–, or LAS– ions onto the glass surface of the flask, plastic vessels were used to store all colloidal solutions and filtrates. In case of precipitate formation, the samples were filtered, washed with 20 mL water, and dried. In addition, several precipitates were calcined at 900 °C for 24 h or at 1000 °C for 16 h under air in a Nabertherm L9 furnace .First, solution with an appropriate concentration of Ca–1 (50 ppm) NaLAS aqueous solution was prepared and a water: methanol mixture at 85:15 volume ratio was used as eluent. The mass spectrum was carried out in negative-ion mode, scanning the m/z region of 150–445.The composition of the surfactant was deduced using a 1260 Infinity II HPLC setup coupled to a G6125B LC-MSD (mass selective detection) from Agilent , applying electrospray ionization (ESI). For analysis, an ~0.05 g L–1) required to pull the ring off the surface is measured. Here, additional experiments were performed for solutions prepared from MgCl2∙6H2O as described above.The surface tensions at the air–water interface and the critical micelle concentration (CMC) values of a set of surfactant solutions with different electrolyte concentration were determined at (25.0 ± 0.1) °C using a tensiometer , with the aid of the Wilhelmy plate method. In the tensiometer, a platinum–iridium ring is suspended from a torsion balance, and the force (in mN mλ = 633 nm). The measurements were performed in back-scattering mode at 173° and at (25.0 ± 0.1) °C. The samples were stirred for 24 h prior to the measurements. For each sample, three to four repetitions were carried out and the size was taken as the arithmetic mean of the volume-averaged hydrodynamic diameters.The average micelle size in a set of samples was determined with a Malvern NanoZS dynamic light scattering (DLS) instrument  operating with a 4 mW helium–neon laser light source (cNaLAS (0.05–5.00 g L–1) at cCa2+ = 0.01 g L–1, the apparent absorbance arising from light absorption and light scattering due to colloidal particles was measured in the UV range  at (25.0 ± 0.1) °C, using a Specord 210 PLUS spectrophotometer .For several samples with varying θ = 4–60° range with 4°/min scanning speed, using CuKα radiation source (λ = 1.5418 Å).The X-ray diffractograms of the precipitated as well as calcined solids were obtained using a MiniFlex II type diffractometer from Rigaku  in the 2–1 by the accumulation of 256 scans at a resolution of 4 cm–1. The spectrometer was equipped with a ZnGe attenuated total reflectance accessory and deuterated triglycine sulfate detector.FT-IR measurements were carried out using a JASCO FT/IR-4700 spectrometer . Spectra were acquired between 4000 and 500 cm2+:Na+ molar ratios in the solids were determined by energy-dispersive X-ray (EDX) spectroscopy. To record the spectra, a Röntec QX2 spectrometer  equipped with Be window and coupled to a Hitachi S-4700 scanning electron microscope  was used at 18 kV acceleration voltages. For each solid, spectra were taken at least four different spots to obtain realistic representation of the elemental distribution.The CacCa2+ ≤ 0.1 g L–1 for all surfactant concentrations (0.01–5.00 g L–1), the solutions are transparent or opalescent without the formation of filterable precipitates, whereas at cCa2+ > 0.1 g L–1 for all surfactant concentrations, a solid appears immediately or after a few hours of stirring . In possession of this information, we analyzed the colloidal and solid systems according to different aspects to get insights into the behavior of the overall system.We started our study with scoping experiments to separate the concentration regions based on the appearance of precipitate. Accordingly, the samples can be divided into two groups: at 2+-ion concentration on the CMC of the aqueous samples via surface tension measurements, shown in 2, we find the surface tension to decrease markedly. This observation is in line with earlier reports [2+ ions screens the electrostatic repulsion between spatially adjacent head-groups, thus facilitating the migration of surfactants to the air–water interface [First, we studied the effect of Ca reports ,33 and interface ,36,41,42–1, i.e., 2.0 mmol L–1 for neat NaLAS, which falls in the range published in the literature, 1.2–2.9 mM [2 is present, we observe a marked reduction in the associated CMC, similar to the surface tension: the value found for neat NaLAS, 668 mg L–1 (2.0 mmol L–1), decreases to 7 mg L–1 (0.02 mmol L–1) in the presence of 0.1 g L–1 Ca2+, depicted in – ions and causing micellization at lower surfactant concentrations [cCa2+ = 0.05 g L–1. Such variation of CMC can be expected on the basis of theoretical considerations [Regarding CMC, we obtained 668 mg L2–2.9 mM ,13,14,152–2.9 mM . When Catrations . It is aerations .–1), only in the presence of Ca2+ ions , which is much higher than the value of ~32 mN m–1 obtained for 0.1 g L–1 Ca2+  to ~10 nm (cNaDBS = 69 g L–1), in the presence of 0.2 M NaCl [In the concentration range of 2 M NaCl . However2 M NaCl ,55. Neve2 M NaCl ,53,54. W2, the samples become opaque already at low surfactant concentrations with particle diameters clearly exceeding ~200 nm. That is, dissolved species aggregate to a high degree signaling the onset of precipitation, which in turn can be explained by the very low thermodynamic solubility of alkyl aryl sulfonates [In the presence of CaCllfonates ,39,40. Tlfonates . In addicCa2+ = 0.01 g L–1 and cNaLAS = 0.625 g L–1, which was confirmed by the drop in the absorbance as well; see 2+, however, the sample turns transparent only around cNaLAS = 5 g L–1. That is, higher Ca2+ concentrations required larger amounts of surfactant for the cloudiness to disappear. This trend is similar to the above regarding the reversal of the surface tension: higher cCa2+ required higher cNaLAS for γ to increase (γ (cCa2+ = 0.075 g L–1); see Strikingly, the samples become transparent upon further increasing the surfactant concentration, which is consistent with the well-known redissolution of poorly soluble sulfonate salts in more concentrated surfactant solutions ,39,40. Fincrease a, inset.rease  is 0.1 g L–1 Ca2+, i.e., 0.28 g L–1 CaCl2.Having the aqueous phase analyzed, we now turn to the characterization of solids forming at higher metal-ion and surfactant concentrations. We find that above –1: 2956 and 2870 (–CH3 asymmetric and symmetric stretching), 2924 and 2854 (–CH2– asymmetric and symmetric stretching), 1601, 1496 and 1408 (aromatic –C=C– stretching), 1461 (–CH2 scissoring), 1378 (–CH3 symmetric bending), 1182 and 1042 (–S=O asymmetric and symmetric stretching), 1129 and 1012 (aromatic =CH in-plane bending), 831 (aromatic =CH out-of-plane bending), 688 (–SO3 bending); see The thus-obtained precipitates are all largely amorphous, similar to the poorly crystalline sodium salt, as shown in the X-ray diffractogram in 2+ ions, most peak positions remain unaltered (within 4 cm–1), with the exception of the –S=O stretching bands which shift from 1182 to 1992 cm–1 and 1042 to 1049 cm–1, respectively. That is, Na+/Ca2+ exchange affects mostly the sulfonate moiety, consistent with this group being the metal-ion coordination site. This is consistent with previous calculations for the DBS– anion in the presence of Na+, Mg2+, and Ca2+ ions [2+ having a high affinity toward oxygen-donor ligands. In addition, the variation of the –S=O bands are in line with those reported for the incorporation of the DBS– anion in the interlayer gallery of Mg-Al- [2+ ion in the precipitate, whereas for LDHs, it is connected to the hydrated metal ions via hydrogen-bonding [–1), in line with previous findings [+ and Ca2+.Upon binding of Caa2+ ions ,57, and f Mg-Al- ,58, as wf Mg-Al- . Neverthf Mg-Al- ,58,59. M-bonding ,58,59,60findings , suggest–1 in the spectrum of NaLAS, which corresponds to the –OH stretching region, becomes much more intensive for the calcium salt. In parallel, a peak at 1653 cm–1 shows up, which belongs to the scissoring mode of water [Furthermore, the very broad peak around 3000 cmof water ,62. Cons2+:LAS– = 1:2 molar ratio by calcining numerous precipitates both at 900 °C (for 24 h) and at 1000 °C (for 16 h). The X-ray diffractograms in 4 (JCPDS No. 74-2421), with some amorphous CaSO4 or residual organics in a few cases . Nevertheless, differences of 2–11% still remain. Based on the infrared spectra, this difference can be attributed to the presence of hydrating water in the solid phase. Accounting for this water fraction, we obtain 2.3 ± 1.6 water molecules per surfactant unit and thus an average stoichiometry of CaLAS2∙2H2O. These calculations together with the weight losses are listed in These findings are also corroborated by the satisfactory agreement between the mass of the calcined solids and the ‘theoretical’ one, assuming the exclusive formation of CaSO2+ and linear alkylbenzene sulfonate (LAS–) ions both in the colloidal and heterogeneous systems. We find the CMC (2.0 mmol L–1) of the neat surfactant to agree well with the range reported previously, and it is consistent with the C11 chain being the largest fraction. The addition of CaCl2 gives rise to a marked decrease in the surface tension and the CMC simultaneously, as a result of cation–sulfonate interactions. Surprisingly, a further increase in the metal-ion concentration results in a sharp increase in the surface tension above ~0.6 g L–1 NaLAS, supported by tensiometric curves obtained in the presence of Mg2+ ions as well. This ‘second critical’ concentration corresponding to the reversal of the surface tension increases with increasing salt concentration, which is the opposite to the trend commonly observed for CMC. This hints at another micellar equilibrium, being either the transition of rather spherical micelles to ellipsoidal or rod-like aggregates and/or the collapse of micelles, both associated with Ca2+-ion binding by the sulfonate group.In this contribution, we studied the interaction between CaThese observations are also strongly correlated with the volume-averaged particle diameters as determined from dynamic light scattering experiments. Here, the diameters drop significantly at a certain surfactant concentration, giving rise to macroscopically transparent solutions. These characteristic concentrations are very similar to those corresponding to the onset of increasing surface tension, indicating that both phenomena have the same molecular origin.2+ ions to the samples results in rapid precipitate formation at all surfactant concentrations. Consequently, the salt tolerance, i.e., the maximum salt concentration without the appearance of filterable precipitate, is 0.1 g L–1 Ca2+. All solids are amorphous and identical in their infrared spectra. Na+ ions are essentially absent in these precipitates, indicating the exclusive formation of CaLAS2. In addition, the weight losses upon calcination for a wide range of initial sample compositions allow us to conclude that CaLAS2 precipitates as a dihydrate salt.Further addition of Ca