Effect of Cerium Oxide Nanostructures on CO Oxidation.

Cerium oxide particles with different morphologies, namely nanoparticles, nanofibers, nanocubes, and rice grains have been prepared by simple chemical routes. The shape and size of the synthesized morphologies have been studied using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). X-ray diffraction (XRD) and selected area electron diffraction (SAED) techniques have been used to determine their crystal phases. Both nanoparticles and nanocubes of cerium oxide exclusively crystallize in fluorite structure of CeO2 as observed in XRD patterns, whereas nanofibers and rice grains are characterized by the presence of CeO2, Ce2O3, and Ce(OH)3 phases. X-ray photoelectron spectroscopy (XPS) has been employed to evaluate Ce species present in the different cerium oxide morphologies and to estimate their relative surface concentrations. As evident from Ce 3d core level spectra cerium oxide nanoparticles and nanocubes are basically CeO2 having Ce in the +4 oxidation state along with some amount of Ce3+ species. In contrast, Ce is in +3 oxidation state on its surface in cerium oxide nanofibers and rice grains that contain intermediate phases like Ce2O3 and Ce(OH)3 as endorsed by XRD patterns. CO oxidation has been carried out over these cerium oxide morphologies and among all morphologies lowest temperature CO oxidation has been demonstrated by the nanocube morphology.

Correction: Citrate combustion synthesized Al-doped CaCu3Ti4O12 quadruple perovskite: synthesis, characterization and multifunctional properties.

Correction for 'Citrate combustion synthesized Al-doped CaCu3Ti4O12 quadruple perovskite: synthesis, characterization and multifunctional properties' by Kamalesh Pal et al., Phys. Chem. Chem. Phys., 2020, 22, 3499-3511, DOI: 10.1039/C9CP05005A.

Citrate combustion synthesized Al-doped CaCu3Ti4O12 quadruple perovskite: synthesis, characterization and multifunctional properties.

The facile synthesis of the Al-doped CaCu3Ti4O12 quadruple perovskite, a well-known and vastly studied material for various technological applications, using the modified citrate combustion route along with structural, microstructural, and X-ray photoelectron spectroscopic (XPS) characterization and magnetic, dielectric and electrical properties has been investigated and reported here. The possible applications of the material as a Schottky barrier diode (SBD) in optoelectronic devices and as a catalyst in methanol steam reforming (MSR) reaction for hydrogen generation, hitherto unreported in the open literature, have also been explored. The compound is crystallized in the cubic body centered Im3[combining macron] space group and the particle size is found to be in nanodimension with rather narrow size distribution. The enhanced resistivity could be attributed to the grain boundary effect, and consequently, it exhibits better performance as a SBD compared to the undoped sample. Desired cationic composition with expected valence states within the probe range is confirmed by XPS analysis. A better catalytic activity towards MSR is noticed for the Al-doped CaCu3Ti4O12 compared to the undoped composition. These new findings, namely MSR activity and applicability in the Schottky device, have highlighted further the multifunctional nature of the material in energy related issues and would thus be of interest to the materials community searching for functional materials.

A revisit to the effect of annealing temperature on magnetic properties of LaFe0.5Mn0.5O3.

We report an experimental study for the structural and magnetic properties of highly pure LaFe0.5Mn0.5O3 perovskite phase. The impurity free LaFe0.5Mn0.5O3 has been prepared by sol-gel technique at 500 °C and annealed at different temperatures up to 1000 °C. Previous works on LaFe0.5Mn0.5O3 revealed presence of secondary phases along with contradicting magnetic properties. Such as, Bhame et al (2005 Phys. Rev. B 72 054426-7) reported the superparamagnetic or spin-glass like behavior for 200 °C treated sample that persisted even at 700 °C sample. However, Wei et al (2012 Mater. Chem. Phys. 136 755-61) claimed room temperature ferromagnetism in all the samples annealed in the range of 600 °C-700 °C where the saturation magnetization decreases with the increase in temperature. These contradicting results lead us to revisit the effect of annealing temperature on the magnetic properties of LaFe0.5Mn0.5O3. We noticed a gradual increase in magnetization with increase in annealing temperatures without any signature of long range spin ordering for pure single phase samples. The increased magnetic moment with annealing temperatures has been attributed to the suppression of surface contribution of disordered spin. The low temperature magnetic behaviors can be explained by the interacting cluster glass behavior for the pristine as well as for 1000 °C annealed samples.

Ultra-high sensitivity of luminescent ZnCr2O4 nanoparticles toward nitroaromatic explosives sensing.

Here, we report the luminescence based sensing of trace amounts of nitroaromatic explosive organic compounds. The luminescence emission of nanosized spinel oxide ZnCr2O4 with high chemical and thermal stabilities has been used as a potential probe to detect such organic explosives. Low temperature solution combustion synthesized ZnCr2O4 oxide with an average particle size of ∼9 nm exhibits strong luminescence emission at 410 nm upon excitation at 260 nm in an aqueous suspension. The presence of nitroaromatics in ZnCr2O4 suspension dramatically suppresses the luminescence emission providing an opportunity to detect it quantitatively. The detection limit for 2,4,6-trinitrophenol (TNP) is as low as 23 ppb. A number of organic compounds have been investigated for a comprehensive understanding. The astonishing sensitivity of ZnCr2O4 nanoparticles towards nitro explosives is appealing for sensing application. A plausible explanation of such luminescence quenching has been ascribed to a two-fold mechanism. The underling mechanism is further substantiated by a similar study on ZnO nanoparticles.

Diversion proctocolitis and response to treatment with short-chain fatty acids--a clinicopathological study in children.

OBJECTIVE: Diversion proctocolitis (DPC) frequently develops in the colorectum after diversion of the fecal stream characterized by bleeding from the inflamed mucosa. Short-chain fatty acids (SCFA) are responsible for growth and differentiation of enterocytes. Adult series have reported variable response of DPC to luminal SCFA. There is dearth of studies in children. We aimed to study incidence, clinical, endoscopic, and histopathological characteristics of DPC and effect of SCFA in children. METHODS: Prospectively clinical, endoscopic, and histopathological evaluation was done for DPC in children undergoing fecal diversion. Patient characteristics, type and duration of stoma, symptoms, endoscopy and biopsy findings, duration of treatment and response to SCFA, time of closure of stoma, and any associated gut anomaly were recorded. RESULTS: Fifteen children completed the study. Anorectal malformation was the commonest indication for stoma. Sixty percent were symptomatic within 2-9 months, excessive mucous discharge being the commonest symptom. All had at least one positive endoscopic finding; erythema, edema, and exudates being the commonest findings. All DPCs improved clinically and endoscopically following SCFA. Histological resolution was seen in 78 %, while 22 % had persistent disease. Closure of stoma showed complete resolution of DPC. CONCLUSION: DPC was common (87 %) following stoma formation in children with strong male preponderance (6.5:1). The commonest indication for stoma was anorectal malformation (67 %). Clinical, endoscopic, and histopathological changes appeared within 2-9 months with symptomatic DPC in 60 %. All patients (100 %) had at least one positive endoscopic finding, histopathological examination confirmed the diagnosis. SCFA led to symptomatic, endoscopic, and histopathological resolution of DPCs. Closure of stoma cured all the persistent DPCs.

Esophageal lung resection and prosthesis placement in a preterm neonate.

This report describes a successful outcome in a preterm baby with an esophageal atresia and tracheo-esophageal fistula, who initially underwent a primary esophageal repair; but a persistent nonexpanding lung on the side of surgery led to further investigations. A further diagnosis of an esophageal lung resulted in pneumonectomy and prophylactic placement of an intra-thoracic prosthesis to prevent post-pneumonectomy syndrome. To the best of our knowledge, this is the first report of a prophylactic placement of an intra-thoracic prosthesis in a neonate with the condition of esophageal atresia and tracheo-esophageal fistula and associated esophageal lung.

Staged Closure of Giant Omphalocele using Synthetic Mesh.

Giant omphalocele is difficult to manage and is associated with a poor outcome. A male newborn presented to our hospital with a giant omphalocele. We performed a staged closure of giant omphalocele using synthetic mesh to construct a silo and then mesh abdominoplasty in the neonatal period that led to a successful outcome within a reasonable period of hospital stay.

Management of associated anomalies of oesophageal atresia and tracheo-oesophageal fistula.

Tracheo-oesophageal fistula (TEF)/oesophageal atresia is one of the most common and serious congenital malformation. Despite progresses made in the field of early diagnosis, surgical techniques, ventilatory support and control of chest infections; morbidity and mortality still remains quite high and differs a lot from one to another centre particularly in the developing countries; as the availability and the level of neonatal care facilities are different. Associated anomalies play a significant role in dictating the outcome, timing of intervention and even the approach to management. The objectives of this review article is to outline the spectrum of associated anomalies, emphasise need of standardised system of documentation of anomalies, prognosis and management issues that would influence timing and approach of TEF repair.

Granulomatous appendicitis in children: a single institutional experience.

BACKGROUND: Granulomatous appendicitis (GA) is a rare entity, mostly mentioned in adults. There have been anecdotal case reports describing GA in the paediatric population. This study was aimed at reviewing the cases of appendectomies to assess the incidence and characteristics of GA in children in a tertiary care University hospital. MATERIALS AND METHODS: Records of children (<13 years age) with biopsy proven granulomatous lesions in the appendectomy specimen, treated during 1991-2011, were analysed. Data regarding demography, clinical presentation, radiological findings, intra-operative finding, histology, diagnosis and follow-up were recorded and descriptively analysed. RESULTS: Twelve out of 1150 (1.04%) appendectomies were biopsy proven GA. Male to female ratio was 8:4. Four had Yersinia enterocolitis, two had Crohn's disease (CD; one isolated Crohn's Appendicitis, one Ileo-cecal Crohn' with appendicitis) and five were idiopathic. Remaining one case, initially diagnosed as idiopathic GA, developed full blown ileo-cecal CD at 2 nd month post-operative. Age ranged between 4 and 11 years with inflammatory bowel disease (IBD) affecting older children and Yersinia, seen in younger children. Majority (10/12) remained asymptomatic at a maximum of 5 years of follow-up. Two patients had recurrent symptoms; one with sub-acute obstruction (2 years follow-up) and another with flaring of Crohn's ileitis (2 months follow-up). CONCLUSIONS: GA in children is a rare entity, with incidence of 1.04% and male preponderance in our series. Idiopathic causes were the most common followed by Yersinia enterocolitis and CD. Although majority remained asymptomatic, IBD should be ruled out in case of recurrence of pain or alteration of bowel habit. Therefore, a long-term follow-up (at least for 5 years) of idiopathic GA is suggested in children.

Effect of lidocaine-prilocaine eutectic mixture of local anaesthetic cream compared with oral sucrose or both in alleviating pain in neonatal circumcision procedure.

BACKGROUND: Neonatal circumcision is one of the oldest and most frequently performed surgical procedures on males. Newborns demonstrate strong endogenous reaction to pain and therefore modalities are being explored for optimum pain relief during circumcision. Pediatric nurses have a vital role for the use of these modalities and minimising the pain response during the neonatal minor procedures. AIM: The aim of this study was to assess the effectiveness of eutectic mixture of local anaesthetic (EMLA) cream compared with oral sucrose and both in alleviating pain in neonatal circumcision. MATERIALS AND METHODS: This study was conducted in the Day Care Surgery Department of Maternity and Children Hospital, Dammam City, KSA. 90 full-term newborn males who underwent circumcision were divided randomly into three groups (30 each). Each group was assigned to receive a different type of analgesics such as EMLA cream (Group A), oral sucrose (Group B) or combination of EMLA cream and oral sucrose (Group C). Neonatal pain agitation and sedation scale (N-PASS) was used 5 min before, during and 5 min after the circumcision procedure to assess the neonatal response to pain. RESULTS: N-PASS scores were significantly lower in Group C (median Group C = 5.2, Group A = 5.8, Group B = 8.5; P< 0.001). The endogenous response to pain in terms of escalation of heart rate and reduction in O 2 saturation were minimal among Group C (P < 0.0001). Duration of crying was comparable among all the groups. CONCLUSION: The combination of sucrose and EMLA cream revealed a higher analgesic effect and minimal adverse response to pain than either EMLA cream or sucrose alone during neonatal circumcision.

Congenital hernia of the umbilical cord associated with extracelomic colonic atresia and perforation of gut in a newborn.

Congenital hernia of the umbilical cord (CHUC) is a rare congenital entity compared to more common post-natally occurring umbilical hernia. Although recognized as a distinct entity since 1920s, CHUC is often misdiagnosed as a small omphalocele, resulting in its underreporting. We present the first case report of CHUC associated with extracelomic colonic atresia, complicated by perinatal perforation in a newborn. We also discuss the differentiating features from other anterior abdominal wall defects such as omphalocele and gastroschisis including its embryogenesis.

Phlegmonous appendicitis and mobile cecum syndrome simulating ileal duplication cyst in a 9 year old girl.

Mobile cecum syndrome is a rare entity that produces recurrent lower abdominal pain mimicking appendicitis. Appendicitis developing in a mobile cecum at an abnormal location eludes the clinical diagnosis and confuses the clinicians unless a high index of suspicion is harbored. We present an unusual case of phlegmonous appendicitis in a mobile cecum masquerading as duplication cyst of ileum in a 9 years old girl.

Laparoscopy in the management of emphysematous cholecystitis and secondary appendicitis in an 11-year-old child with insulin-dependent diabetes mellitus.

Acute abdomen in a diabetic child may cause diagnostic dilemma. Acalculous emphysematous cholecystitis (EC), although reported among critically ill or diabetic adults, is an uncommon occurrence in the children. It may complicate the presentation due to its varied manifestations; especially when associated with other concomitant intra-abdominal inflammatory pathologies. We encountered a rare concurrence of acute EC complicated with pericholecystic fluid collection and secondary appendicitis causing non-specific acute abdomen in an 11-year-old obese boy with insulin-dependent diabetes mellitus. Laparoscopy proved to be a highly useful tool in the diagnosis and treatment of this surgical dilemma.

Modified port placement and pedicle first approach for laparoscopic concomitant cholecystectomy and splenectomy in children.

AIM: Laparoscopy is becoming the preferred modality for concomitant cholecystectomy and splenectomy (CAS). Usually, six to seven ports are employed for CAS, and spleen is removed by classical lateral approach or anterior approach. We report here our modified five-port and pedicle first approach for CAS in children to minimize the intraoperative bleeding and maximize the access. MATERIALS AND METHODS: Twenty-one children underwent laparoscopic CAS with this new approach and their data were recorded prospectively. Following cholecystectomy (with ports 1-4), left side was elevated by 30°. The spleen was lifted by a grasper/fan retractor through port no. 5. The pedicle was dissected and splenic vessels were divided by ligasure (vessels < 8 mm), and for bulkier pedicle, vascular endo-GIA stapler was used. Short gastric and gastrosplenic ligament, lower pole and phrenico-colic attachments and upper pole attachments were dissected by ligasure in that sequence. Spleen was placed in endosac and delivered by digital fracture technique. Occasionally, lower transverse incision was made to deliver a massive spleen. RESULTS: There were 12 males and 9 females with an average age of 8 years. Fourteen had sickle cell disease (SCD) and 7 had SCD and beta thalassemia. All CAS were completed successfully without any complication. Total duration was 160 minutes. Cholecystectomy took an average of 35 minutes. Average blood loss was 140 ml. The mean splenic weight was 900 g and mean length was 20 cm. Duration of hospitalization was 3-4 days. CONCLUSION: CAS can be successfully performed by five ports. The pedicle first approach is extremely helpful in moderate to massive spleens as it reduces splenic size, vascularity and bleeding from capsular adhesions or inadvertant lacerations.

Sanjad-Sakati syndrome in a neonate.

Congenital hypoparathyroidism, growth retardation and dysmorphism is a rare autosomal recessive syndrome among Arab population commonly known as Sanjad-Sakati syndrome(SSS).Several metabolic and septic complications are known to manifest in the neonatal age. We describe the first report of morbid pathological fractures affecting a neonate with SSS.

Serial perfusion study depicts pulmonary vascular growth in the survivors of non-extracorporeal membrane oxygenation-treated congenital diaphragmatic hernia.

BACKGROUND: Pulmonary growth in the survivors of congenital diaphragmatic hernia (CDH) still remains an intriguing issue. In the literature there are conflicting reports on pulmonary vascular growth in CDH. OBJECTIVE: In a cohort of CDH patients treated without extracorporeal membrane oxygenation (ECMO), serial perfusion studies were conducted prospectively to follow the growth of pulmonary vasculature. MATERIAL AND METHODS: Survivors of CDH repair between January 2000 and January 2003 were studied prospectively. Patient demography, time of presentation, arterioalveolar oxygen gradient (A-aDO(2)), time to complete lung expansion, and respiratory symptoms were noted. Lung perfusion studies were done at 3 months, 9 months, and 6 years of follow-up. RESULTS: 24 neonates completed the study. Mean presentation was 6.9 h, and preoperative A-aDO(2) was 288.8. 16/24 were managed by conventional ventilation and 8/24 required high-frequency ventilation and nitric oxide therapy (none were treated with ECMO). Mean duration of preoperative stabilization was 26.5 h, time to full lung expansion was 2.8 days, and postoperative ventilation was 3.7 days. Mean perfusion (%) of ipsilateral lung was 33.7% at 3 months, 43.2% at 9 months, and 46.8% at 6 years. Perfusion of ipsilateral lung improved by 9.4% from 3 to 9 months (p < 0.001), 13.1% from 3 months to 6 years (p < 0.001), and 3.7% from 9 months to 6 years postoperatively (p < 0.001). Respiratory symptoms were seen in 45% (11/24) of survivors at 3 months, 14% (4/24) at 9 months, and 12.5% (3/24) at 6 years postoperatively. CONCLUSIONS: There was reduced perfusion of affected lung at 3 months which improved significantly at 9 months and at 6 years. Recovery of pulmonary vascular function correlated with amelioration of respiratory symptoms. The majority of survivors showing a significant vascular growth lead a symptom-free life.

Visceral myopathy causing chronic intestinal pseudoobstruction and intestinal failure in a child with Sanjad-Sakati syndrome.

Sanjad-Sakati syndrome is a rare autosomal recessive disorder mainly occurring in the Arab Peninsula. This condition is associated with metabolic and septic complications starting in the neonatal period. Chronic intestinal pseudoobstruction owing to visceral myopathy is a rare disabling condition. We report a rare concurrence of Sanjad-Sakati syndrome and chronic intestinal pseudoobstruction in a Saudi child complicated by intestinal failure, sepsis, and early mortality.

Occult enterorrhagia from jejunal duplication causing diagnostic dilemma in an infant.

Occult enterorrhagia in infancy may become obscured and lead to diagnostic dilemma. Abnormal findings on investigative modalities, if not properly interpreted and clinically correlated, might complicate the matter leading to missed diagnosis and chronic anaemia. Occult enterorrhagia is an uncommon presentation of intestinal duplications. We describe the intriguing case of chronic anaemia in an infant, where concomitant endoscopic findings misled the diagnosis of jejunal duplication cyst as the cause of enterorrhagia.

Successful laparoscopic treatment of hemorrhage from ileal duplication cyst in a 10-year-old Saudi boy.

Lower gastrointestinal hemorrhage often produces diagnostic difficulty in children. Endoscopy, radionuclide scans, computed tomography/magnetic resonance angiography, and conventional angiography have been the usual armamentarium for locating the site of bleeding. In recent times, laparoscopy has offered an effective tool for diagnosing various intra-abdominal, especially extraluminal, pathologies elusive to other modalities of diagnosis. In this paper, we present a case of massive hemorrhage from an ileal duplication cyst in a 10-year-old Saudi boy diagnosed and treated by laparoscopy. We believe this is the first such reported case from the Kingdom of Saudi Arabia.