Experimental and Theoretical Studies on Acid Corrosion Inhibition of API 5L X70 Steel with Novel 1-N-α-d-Glucopyranosyl-1H-1,2,3-Triazole Xanthines.

A series of novel 1-N-α-d-glucopyranosyl-1H-1,2,3-triazole xanthines was synthesized from azido sugars (glucose, galactose, and lactose) and propargyl xanthines (theophylline and theobromine) using a typical copper (I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition. The corrosion inhibition activities of these new carbohydrate-xanthine compounds were evaluated by studying the corrosion of API 5 L X70 steel in a 1 M HCl medium. The results showed that, at 10 ppm, a 90% inhibition efficiency was reached by electrochemical impedance spectroscopy. The inhibitory efficiency of these molecules is explained by means of quantum chemical calculations of the protonated species with the solvent effect, which seems to better represent the actual situation of the experimental conditions. Some quantum chemical parameters were analyzed to characterize the inhibition performance of the tested molecules.

A General Use QSAR-ARX Model to Predict the Corrosion Inhibition Efficiency of Drugs in Terms of Quantum Mechanical Descriptors and Experimental Comparison for Lidocaine.

A study of 250 commercial drugs to act as corrosion inhibitors on steel has been developed by applying the quantitative structure-activity relationship (QSAR) paradigm. Hard-soft acid-base (HSAB) descriptors were used to establish a mathematical model to predict the corrosion inhibition efficiency (IE%) of several commercial drugs on steel surfaces. These descriptors were calculated through third-order density-functional tight binding (DFTB) methods. The mathematical modeling was carried out through autoregressive with exogenous inputs (ARX) framework and tested by fivefold cross-validation. Another set of drugs was used as an external validation, obtaining SD, RMSE, and MSE, obtaining 6.76%, 3.89%, 7.03%, and 49.47%, respectively. With a predicted value of IE% = 87.51%, lidocaine was selected to perform a final comparison with experimental results. By the first time, this drug obtained a maximum IE%, determined experimentally by electrochemical impedance spectroscopy measurements at 100 ppm concentration, of about 92.5%, which stands within limits of 1 SD from the predicted ARX model value. From the qualitative perspective, several potential trends have emerged from the estimated values. Among them, macrolides, alkaloids from Rauwolfia species, cephalosporin, and rifamycin antibiotics are expected to exhibit high IE% on steel surfaces. Additionally, IE% increases as the energy of HOMO decreases. The highest efficiency is obtained in case of the molecules with the highest ω and ΔN values. The most efficient drugs are found with pKa ranging from 1.70 to 9.46. The drugs recurrently exhibit aromatic rings, carbonyl, and hydroxyl groups with the highest IE% values.

4-Phenylcoumarin (4-PC) Glucoside from Exostema caribaeum as Corrosion Inhibitor in 3% NaCl Saturated with CO2 in AISI 1018 Steel: Experimental and Theoretical Study.

The corrosion inhibition of 5-O-ß-D-glucopyranosyl-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin (4-PC) in AISI 1018 steel immersed in 3% NaCl + CO2 was studied by electrochemical impedance spectroscopy (EIS). The results showed that, at just 10 ppm, 4-PC exerted protection against corrosion with Õ² = 90% and 97% at 100 rpm. At static conditions, the polarization curves indicated that, at 5 ppm, the inhibitor presented anodic behavior, while at 10 and 50 ppm, there was a cathodic-type inhibitor. The inhibitor adsorption was demonstrated to be chemisorption, according to the Langmuir isotherm for 100 and 500 rpm. By means of SEM-EDS, the corrosion inhibition was demonstrated, as well as the fact that the organic compound was effective for up to 72 h of immersion. At static conditions, dispersion-corrected density functional theory results reveal that the chemical bonds established by the phenyl group of 4-PC are responsible of the chemisorption on the steel surface. According with Fukui reactivity indices, the molecules adsorbed on the metal surface provide a protective cover against nucleophilic and electrophilic attacks, pointing to the corrosion inhibition properties of 4-PC.

Bowel function and associated risk factors at preschool and early childhood age in children with anorectal malformation type rectovestibular fistula: An ARM-Net consortium study.

BACKGROUND: Outcome of patients operated for anorectal malformation (ARM) type rectovestibular fistula (RVF) is generally considered to be good. However, large multi-center studies are scarce, mostly describing pooled outcome of different ARM-types, in adult patients. Therefore, counseling parents concerning the bowel function at early age is challenging. Aim of this study was to evaluate bowel function of RVF-patients at preschool/early childhood age and determine risk factors for poor functional outcome. METHODS: A multi-center cohort study was performed. Patient characteristics, associated anomalies, sacral ratio, surgical procedures, post-reconstructive complications, one-year constipation, and Bowel Function Score (BFS) at 4-7 years of follow-up were registered. Groups with below normal (BFS < 17; subgroups 'poor' ≤ 11, and 'fair' 11 < BFS < 17) and good outcome (BFS ≥ 17) were formed. Univariable analyses were performed to detect risk factors for outcome. RESULTS: The study included 111 RVF-patients. Median BFS was 16 (range 6-20). The 'below normal' group consisted of 61 patients (55.0%). Overall, we reported soiling, fecal accidents, and constipation in 64.9%, 35.1% and 70.3%, respectively. Bowel management was performed in 23.4% of patients. Risk factors for poor outcome were tethered cord and low sacral ratio, while sacral anomalies, low sacral ratio, prior enterostomy, post-reconstructive complications, and one-year constipation were for being on bowel management. CONCLUSIONS: Although median BFS at 4-7 year follow-up is nearly normal, the majority of patients suffers from some degree of soiling and constipation, and almost 25% needs bowel management. Several factors were associated with poor bowel function outcome and bowel management. LEVEL OF EVIDENCE: Level III.

Entre la voluntad de Allah y las balas de los jnun la epidemia de peste de 1799 y 1800 en Marruecos / Between the will of Allah and the bullets of the jnun the plague epidemic of 1799 and 1800 in Morocco

La peste que golpeó Marruecos en 1799 y 1800 fue una epidemia sin precedentes. En este artículo, examino algunas observaciones hechas sobre la peste por el agente comercial británico James Grey Jackson, en particular sus ideas sobre las comprensiones islámicas locales de la agencia de los jnūn y de Dios (Allāh) en la aparición de esta enfermedad (AU)

Study of SCC of X70 Steel Immersed in Simulated Soil Solution at Different pH by EIS.

An electrochemical study of stress corrosion cracking (SCC) of API X70 steel in a simulated soil solution at different pH values (3, 8 and 10) was carried out. The stress conditions were implemented by slow strain rate stress test (SSRT) and the SCC process was simultaneously monitored by electrochemical impedance spectroscopy (EIS). Fracture surface analysis and corrosion product analysis were performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The results show that the susceptibility to SCC was higher as the pH decreases. In the acid solution, hydrogen evolution can occur by H+ and H2CO3 reduction, and more atomic hydrogen can diffuse into the steel, producing embrittlement. EIS results indicated that the anodic dissolution contributed to SCC process by reducing the charge transfer resistances during the SSRT test. While SEM micrographs shown a general corrosion morphology on the longitudinal surface of samples. At higher pH (pH 8 and pH 10), the SCC susceptibility was lower, which it is attributed to the presence of corrosion products film, which could have limited the process. Using the angle phase (φ) value it was determined that the cracking process started at a point close to the yield strength (YS).

Use of 5-mm Staple in Neonatal Intestinal Surgery.

Introduction: The use of staples to perform intestinal anastomosis in children has gained popularity in the past years. The aim of this study is to evaluate the outcomes of pediatric patients who underwent intestinal anastomosis with a 5-mm staple in a tertiary health care center. Material and Methods: From April 2017 to November 2019, the records of all pediatric patients who underwent intestinal anastomosis with a 5-mm staple were retrospectively revised. The reconstruction technique was functional end-to-end anastomosis. Results: A total of 12 intestinal anastomoses were evaluated. Mean age at surgery was 120 days. Small bowel anastomosis was the most frequently performed procedure (eight cases). Stapling difficulties were found in 3 patients. The anastomosis could not be performed with the 5-mm endostapler in one of these patients. The median follow-up was 26 months (interquartile range 20-40 months). Postoperative complications included one bowel obstruction that was surgically treated. Conclusions: Mechanical suturing with 5-mm staple is a safe alternative technique to perform intestinal anastomosis in neonates and infants. The use of this staple has proven to be safe and feasible in pediatric patients. It is necessary to select patients carefully according to their bowel characteristics.

Daily changes in GFAP expression in radial glia of the olfactory bulb in rabbit pups entrained to circadian feeding.

When food is restricted daily to a fixed time, animals show uncoupled molecular, physiological and behavioral circadian rhythms from those entrained by light and controlled by the suprachiasmatic nucleus. The loci of the food-entrainable oscillator and the mechanisms by which rhythms emerge are unclear. Using animals entrained to the light-dark cycle, recent studies indicate that astrocytes in the suprachiasmatic nucleus play a key role in the regulation of circadian rhythms. However, it is unknown whether astrocytic cells can be synchronized by circadian restricted feeding. Studying the olfactory bulb (OB) of rabbit pups entrained to daily feeding, we hypothesized that the expression of glial fibrillary acidic protein (GFAP) and the morphology of GFAP-immunopositive cells change in synchrony with timing of feeding. By using pups fed at 1000 h or 2200 h, we found that GFAP protein expression in the OB changes with a nadir at feeding time and a peak 16 h after feeding. We also found that length of radial glia processes, the most abundant GFAP+ cell in the rabbit pup OB, shows a daily change also coupled to feeding time. These temporal changes of GFAP were expressed in anti-phase to the rhythms of locomotor activity and c-Fos immunoreactivity. The results indicate that GFAP expression and elongation-retraction of radial glia processes are coupled by feeding time and suggest that glia cells may play an important functional role in food entraining of the OB circadian oscillator.

Thoracoscopic esophagoesophagostomy for a refractory stricture in a patient with esophageal atresia.

Anastomosis stricture is a well-known complication after esophageal atresia repair. Endoscopic dilatation is the gold standard treatment for esophageal stenosis. However, surgical interventions are indicated for refractory cases. We present a 2-year-old girl with esophageal stricture refractory to regular endoscopic dilatation after esophageal atresia repair that underwent thoracoscopic stricture resection and reanastomosis. Although thoracoscopic approach is widely used for esophageal atresia repair, this approach has not been used before for the treatment of anastomosis stricture.

Thoracoscopic approach for complications after esophageal atresia repair: initial experience.

INTRODUCTION: Improvements in technology and health care have helped reduce morbidity and mortality in patients with esophageal atresia. However, postoperative complications such as dehiscences, strictures, and recurrent fistulas still occur in a large percentage of patients. Here, we present our initial experience using the thoracoscopic approach for complications after esophageal atresia repair. METHODS: We retrospectively analyzed the medical records of patients who developed complications after esophageal atresia repair and underwent thoracoscopic reoperation at two centers. Anastomotic leakage, anastomotic stricture, and recurrent tracheoesophageal fistula were assessed as complications after esophageal atresia repair. RESULTS: We reoperated on four patients (range of age 3 days - 2 years) by thoracoscopy. Two patients who had undergone thoracoscopic atresia repair presented with anastomotic dehiscence. The anastomoses were thoracoscopically reconstructed without tension. One patient had undergone thoracoscopic atresia repair presented with esophageal stricture refractory to endoscopic dilatations. Thoracoscopic esophagoesophagostomy was performed in this 2-year-old patient. One patient who had undergone esophageal atresia repair and tracheoesophageal fistula closure by thoracotomy presented with a recurrent fistula at 1 year of age. The patient underwent thoracoscopic fistula closure with a 5-mm endostapler. All patients remain asymptomatic after reoperation. CONCLUSIONS: Reoperation after esophageal atresia repair is challenging and carries a relatively high risk of developing complications. Compared to conventional surgery, the thoracoscopic approach in experienced hands offers better visualization and more accurate dissection and drainage of the thoracic cavity. Therefore, we want to encourage the use of thoracoscopy in the treatment of complications after esophageal atresia repair.

The Accuracy of Silk Glove Sign Compared with Inguinal Bulge in the Diagnosis of Indirect Inguinal Hernia in Children.

Introduction: The diagnosis of indirect inguinal hernia is usually based on clinical grounds. Physical examination generally showed an inguinal bulge. However, when no bulge is seen, the silk glove sign (SGS) or palpating the processus vaginalis over the pubic tubercle can be useful. The aim of our study is to compare the accuracy of the presence of inguinal bulge with the presence of SGS. Materials and Methods: We conducted a retrospective of all patients undergoing laparoscopic inguinal hernia repair between January 2002 and November 2015. Preoperative diagnosis was obtained by physical examination. The presence of an inguinal bulge or SGS was considered diagnostic of indirect inguinal hernia. Intraoperative diagnosis was made to laparoscopic findings. The sample was divided into two groups: group 1 including the patient with inguinal bulge and group 2 including those with SGS. Results: A total of 1024 inguinal canals were evaluated. Inguinal bulge was observed in 379 inguinal canals (group 1), whereas SGS was detected in 196 (group 2). There were statistically significant differences between both groups regarding gestational age, birth weight, surgical age, and surgical weight. Prematurity and previous episodes of incarceration were statistically more common in group 1 (P < .001). The positive predictive value in group 1 was 98.7%, whereas in group 2 was 86.73% (P < .001). Conclusions: Although we have found that the success rate for accurate diagnosis is higher in patients with inguinal bulge, SGS can be useful in detecting indirect inguinal hernia.

Torsión simultánea de epidídimo y quiste epididimario / Simultaneous torsion of epididymis and an epididymal cyst

No disponible

Thoracoscopic recurrent tracheo-oesophageal fistula repair with mini endostapler: promising solution.

Recurrent tracheo-oesophageal fistula (TOF) is a common complication in children who underwent oesophageal atresia repair. The traditional surgical approach performed either by thoracotomy or cervicotomy is associated with a high rate of morbidity, mortality and new recurrence. In the last decades, endoscopic techniques have emerged as the minimally invasive alternative. However, it seems that the optimal treatment is still unknown. We present a patient with a recurrent TOF who underwent thoracoscopic closure using a 5.8 mm endostapler. The patient was extubated at the end of the procedure, and he started feeding the day after surgery. At 15 months of follow-up, he is asymptomatic. Thoracoscopic closure of TOF using endostaplers seems to be a safe alternative with some possible benefits compared with traditional and endoscopic approach.

Association between gallbladder agenesis and choledochal cyst: cause or coincidence?

This case report describes an extremely rare association between gallbladder agenesis and choledochal cyst (CC). A 9-year-old girl presented with recurrent abdominal pain in the right upper quadrant. Radiological studies revealed a CC type IVa and an agenesis of gallbladder and cystic duct. Due to the possibility of biliary neoplasm, the patient underwent cyst resection and hepaticoduodenostomy. Histopathological findings showed inflamed fibrous tissue covered by biliary epithelium with no evidence of malignancy.

Is the Laparoscopic Approach Safe for Inguinal Hernia Repair in Preterms?

Introduction: Although laparoscopic inguinal hernia repair in children has gained popularity in the last decades, this approach remains uncommon in preterm infants. The aim of this study was to compare the characteristics and the outcomes of indirect inguinal hernias in term and preterm infants. Material and Methods: From January 2002 to November 2015, all charts of the pediatric patients who underwent laparoscopic indirect inguinal hernia repair in one single institution within the first 6 months of life were revised. The data of 156 patients were analyzed retrospectively. Patients were divided in two groups: group I, including the preterm patients, and group II, including the term patients. Results: A total of 90 preterm infants and 66 term infants were included. In the group I, preoperative diagnosis was right-sided inguinal hernia in 20% of patients, left sided in 22.2%, and bilateral in 57.5%; while in the group II, preoperative diagnosis was right-sided inguinal hernia in 42.4% of infants, left sided in 15.2%, and bilateral in 42.4% (P = .01). In group I intraoperative diagnosis was right-sided inguinal hernia in 10% of patients, left sided in 16.7%, and bilateral in 73.3%; while in the group II, intraoperative diagnosis was right-sided inguinal hernia in 25.8% of infants, left sided in 12.1%, bilateral in 60.6%, and there was no hernia in one patient (P = .02). However, there was no statistically significant difference in the correct intraoperative diagnosis between both groups (P = .59). No statistical significance was observed between the two groups regarding postoperative complications. Conclusions: Bilateral inguinal hernia is more frequent in preterm infants compared to term infants, whereas the incidence of right-sided inguinal hernia is higher in term patients. Laparoscopic inguinal hernia repair in preterm infants seems to be safe and effective.

Adsorption and corrosion inhibition behaviour of new theophylline-triazole-based derivatives for steel in acidic medium.

The design and synthesis of a series of theophylline derivatives containing 1,2,3-triazole moieties are presented. The corrosion inhibition activities of these new triazole-theophylline compounds were evaluated by studying the corrosion of API 5 L X52 steel in 1 M HCl medium. The results showed that an increase in the concentration of the theophylline-triazole derivatives also increases the charge transference resistance (R ct) value, enhancing inhibition efficiency and decreasing the corrosion process. The electrochemical impedance spectroscopy under static conditions studies revealed that the best inhibition efficiencies (approx. 90%) at 50 ppm are presented by the all-substituted compounds. According to the Langmuir isotherm, the compounds 4 and 5 analysed exhibit physisorption-chemisorption process, with exception of the hydrogen 3, bromo 6 and iodo 7 substituted compounds, which exhibit chemisorption process. The corrosion when submerging a steel bar in 1 M HCl was studied using SEM-EDS. This experiment showed that the corrosion process decreases considerably in the presence of 50 ppm of the organic inhibitors. Finally, the theoretical study showed a correlation between EHOMO, hardness (η), electrophilicity (W), atomic charge and the inhibition efficiency in which the iodo 7 substituted compound presents the best inhibitor behaviour.

Impact of the appendiceal position on the diagnosis and treatment of pediatric appendicitis / Impacto da posição do apêndice sobre o diagnóstico e tratamento de apendicite da infância

ABSTRACT Objective: To investigate how symptoms vary according to the appendiceal position in pediatric patients and to demonstrate that the laparoscopic approach is safe and effective in any appendiceal location by comparing each location to another. Methods: The medical records of 1,736 children aged 14 or younger who underwent laparoscopic appendectomy over a period of 14 years were analyzed retrospectively. Patients were divided according to the position of the appendiceal tip into four groups: anterior, pelvic, retrocecal and subhepatic. The Kruskal-Wallis and chi-square tests were used with the Bonferroni correction, with a significant p<0.05. Results: The appendiceal location was anterior in 1,366 cases, retrocecal in 248 cases, pelvic in 66 cases and subhepatic in 56 cases. There were no significant differences between the groups in terms of patient age and gender. Abdominal pain was the only symptom with statistically significant differences between the groups. The rate of perforated appendicitis was higher in the subhepatic and pelvic positions. Intraoperative complications and conversions were not statistically significant. Technical difficulties and operative time were higher in subhepatic position. The rate of postoperative complications was similar between the different locations, except for bowel obstruction, which was higher in pelvic appendicitis. Conclusions: The clinical symptoms of appendicitis hardly ever change with the position of the appendix. The laparoscopic approach is safe and effective, regardless the appendiceal location.

RESUMO Objetivo: Investigar como os sintomas variam de acordo com a posição do apêndice em pacientes pediátricos e demonstrar que a laparoscopia é segura e eficaz em qualquer posição do apêndice, comparando-as. Métodos: Os prontuários de 1.736 pacientes pediátricos com idade ≤14 anos submetidos à apendicectomia laparoscópica em um período de 14 anos foram analisados retrospectivamente. Os pacientes foram divididos de acordo com a posição do apêndice: anterior, pélvica, retrocecal e sub-hepático. Os testes de Kruskal-Wallis e do qui-quadrado foram usados com a correção de Bonferroni, sendo significante p<0,05. Resultados: A posição do apêndice era anterior em 1.366 casos, retrocecal em 248 casos, pélvica em 66 casos e sub-hepática em 56 casos. Não houve diferenças significativas entre os grupos quanto às variáveis idade e sexo. A dor abdominal foi a única variável com diferenças estatisticamente significantes entre os grupos. A taxa de apêndice perfurado foi superior nas posições sub-hepática e pélvica. As complicações intraoperatórias e a taxa de conversão não foram estatisticamente significativas. As dificuldades técnicas e o tempo cirúrgico foram superiores em posição sub-hepática. A taxa de complicações pós-operatórias foi semelhante entre as diferentes posições, exceto a obstrução intestinal, que foi superior em posição pélvica. Conclusões: Os sintomas da apendicite dificilmente variam com a posição do apêndice. A laparoscopia é segura e eficaz, independentemente da posição do apêndice.

IMPACT OF THE APPENDICEAL POSITION ON THE DIAGNOSIS AND TREATMENT OF PEDIATRIC APPENDICITIS.

OBJECTIVE: To investigate how symptoms vary according to the appendiceal position in pediatric patients and to demonstrate that the laparoscopic approach is safe and effective in any appendiceal location by comparing each location to another. METHODS: The medical records of 1,736 children aged 14 or younger who underwent laparoscopic appendectomy over a period of 14 years were analyzed retrospectively. Patients were divided according to the position of the appendiceal tip into four groups: anterior, pelvic, retrocecal and subhepatic. The Kruskal-Wallis and chi-square tests were used with the Bonferroni correction, with a significant p<0.05. RESULTS: The appendiceal location was anterior in 1,366 cases, retrocecal in 248 cases, pelvic in 66 cases and subhepatic in 56 cases. There were no significant differences between the groups in terms of patient age and gender. Abdominal pain was the only symptom with statistically significant differences between the groups. The rate of perforated appendicitis was higher in the subhepatic and pelvic positions. Intraoperative complications and conversions were not statistically significant. Technical difficulties and operative time were higher in subhepatic position. The rate of postoperative complications was similar between the different locations, except for bowel obstruction, which was higher in pelvic appendicitis. CONCLUSIONS: The clinical symptoms of appendicitis hardly ever change with the position of the appendix. The laparoscopic approach is safe and effective, regardless the appendiceal location.