Study of the microstructure information of GaAs epilayers grown on silicon substrate using synchrotron radiation.

Williamson-Hall (WH) analysis is a well established method for studying the microstructural properties of epilayers grown on foreign substrates. However, the method becomes inapplicable in specific cases where the structure factor considerations and the presence of anti-phase domains forbid the data acquisition for certain reflections in conventional high-resolution X-ray diffraction (HRXRD) measurements. Here, this limitation is overcome by exploiting the large intensity (25 µW mm(-2)) and high photon energy (15.5 keV) of the X-ray beam obtained from a synchrotron radiation source. The lateral coherence length, vertical coherence length, tilt and micro-strain of GaAs epilayers grown on Si substrate have been successfully measured using the conventional WH analysis. The microstructure information obtained from the conventional WH analysis based on the data acquired at the synchrotron radiation source is in reasonable agreement with the results obtained from atomic force microscope and surface profiler measurements. Such information cannot be obtained on a laboratory-based HRXRD system where modification of the WH method by involving a set of parallel asymmetric crystallographic planes is found to be essential. However, the information obtained from the modified WH method is along a different crystallographic orientation.

Surgical checklist application and its impact on patient safety in pediatric surgery.

BACKGROUND: Surgical care is an essential component of health care of children worldwide. Incidences of congenital anomalies, trauma, cancers and acquired diseases continue to rise and along with that the impact of surgical intervention on public health system also increases. It then becomes essential that the surgical teams make the procedures safe and error proof. The World Health Organization (WHO) has instituted the surgical checklist as a global initiative to improve surgical safety. AIMS: To assess the acceptance, application and adherence to the WHO Safe Surgery Checklist in Pediatric Surgery Practice at a university teaching hospital. MATERIALS AND METHODS: In a prospective study, spanning 2 years, the checklist was implemented for all patients who underwent operative procedures under general anesthesia. The checklist identified three phases of an operation, each corresponding to a specific period in the normal flow of work: Before the induction of anesthesia ("sign in"), before the skin incision ("time out") and before the patient leaves the operating room ("sign out"). In each phase, an anesthesiologist,-"checklist coordinator," confirmed that the anesthesia, surgery and nursing teams have completed the listed tasks before proceeding with the operation and exit. The checklist was used for 3000 consecutive patients. RESULTS: No major perioperative errors were noted. In 54 (1.8%) patients, children had the same names and identical surgical procedure posted on the same operation list. The patient identification tag was missing in four (0.1%) patients. Mention of the side of procedures was missing in 108 (3.6%) cases. In 0.1% (3) of patients there was mix up of the mention of side of operation in the case papers and consent forms. In 78 (2.6%) patients, the consent form was not signed by parents/guardians or the side of the procedure was not quoted. Antibiotic orders were missing in five (0.2%) patients. In 12 (0.4%) cases, immobilization of the patients was suboptimal, which led to displacement of diathermy grounding pad. In 54 (1.8%) patients, the checklist was not used at all. In 76 (2.5%) patients the checklist was found to be incompletely filled. CONCLUSIONS: Our study supports the use of the checklist as an essential safety tool and reinforcement of the same. The checklist may act as a valuable prompt to focus the team, to ensure that even the simple things have been cared for.

Needle in a haystack: Intraoperative breakage of pediatric minimal access surgery instruments.

The search for tiny bits of broken pediatric minimal access surgery (MAS) instruments in an operative field is akin to the search for a needle in a haystack. With the extension of MAS to the pediatric age group, instruments are becoming smaller and equitably more prone to breakage. When breakages occur, retrieval, especially in the pediatric abdominal cavity, can be challenging. Inability to do so would affect patient safety and also lead to a web of medico legal and ethical issues. We present two cases of intraoperative breakage: An eyeless 3-0 polyamide suture needle and a 2-mm grasper blade both of which were successfully retrieved and fortuitously escaped becoming retained surgical items.

Carotid sheath lipoma: first case report in the English literature.

Lipomas are the most commonly encountered benign mesenchymal tumour, arising in any location where fat is normally present. Lipomas in the head and neck are rare in all age groups. Cases of vascular sheath lipomas in the femoral region have only been reported in adults. In children, vascular sheath lipomas have not been described to date. We report the first case of a carotid sheath lipoma in a seven-year-old boy. He had a non-tender soft mass with ill defined borders occupying the left upper part of the neck. Magnetic resonance imaging showed a mass at the bifurcation of the left common carotid artery without involving the same. The mass was hyperintense on T1 and T2 weighted sequences, suggestive of a lipoma. The lipoma was enucleated after incising the carotid sheath, safeguarding its contents. Histopathology confirmed it as a lipoma.

Review of video-assisted thoracoscopy in children.

Open thoracotomy is the standard procedure for various thoracic diseases against which other procedures are compared. Currently Video Assisted Thoracoscopic Surgery (VATS) has gained widespread acceptance in the management of a variety of thoracic disorders. It decreases the morbidity and duration of hospital stay. A total of 133 children with various thoracic diseases who presented at a University Teaching Hospital in the Department of Pediatric Surgery, from June 2000 to December 2007, were included. Of the 133 patients,116 patients had empyema, all of whom were subjected to VATS, and an attempt at debridement/decortication and drainage was made. Other thoracic disorders treated included lung abscesses, lung biopsies, hydatid cysts, and so on. Patients with empyema were treated according to their stage of disease. Of the 116 patients who underwent thoracoscopy, 16 had to be converted to open surgery due to various reasons. The mean duration for removal of drain was three days and the average total duration of hospital stay was six days. Similarly the application of VATS was advantageous in other thoracic diseases.

Investigation of optical limiting in iron oxide nanoparticles.

We present the study of optical limiting in iron oxide nanoparticles of diameters 31, 44, and 61 nm dispersed in toluene under exposure to nanosecond laser pulses at 532 nm. In the low fluence region smaller size nanoparticles show better optical limiting compared to larger size nanoparticles while in the high fluence region all the three samples show same limiting performance. Experimental results were compared with the well reported limiter fullerene C(60) dissolved in toluene. Iron oxide nanoparticles show better optical limiting compared to C(60) in the intermediate fluence region and comparable performance in the high fluence region. The pico-second Z-scan studies indicate that the contribution of electronic nonlinear refractive index and the two-photon absorption to the optical limiting is negligible. Our observations further indicate that the dominant mechanism for the optical limiting in iron oxide nanoparticles is nonlinear scattering.

A study of blood glucose in paediatric laparoscopy.

BACKGROUND: There are few studies on stress responses to laparoscopic surgery in children. This study was conducted to assess the blood glucose levels in children undergoing laparoscopy. We also studied the effect of two different intravenous (i.v.) solutions on blood glucose in open and laparoscopic procedures. METHODS: One hundred and twenty healthy children, aged 2-12 years, undergoing either open or laparoscopic surgery, were randomized to receive either dextrose normal saline (DS) or Ringer's lactate peri-operatively (RL). All patients had blood glucose measurements performed immediately after induction but prior to the i.v. infusion of any fluid. Blood glucose was again measured 1 h after induction in the open cases and 1 h after insufflation in the laparoscopy cases. RESULTS: In the groups, baseline blood glucose values were comparable. In all groups, blood glucose concentrations increased from the immediate post-induction (baseline) values. When RL was infused, the 1-h blood glucose was higher in the laparoscopy group as compared with the open group. However, when DS was infused the difference between the 1-h blood glucose in the open and laparoscopic procedures was not statistically significant. In the laparoscopy group, the 1-h blood glucose value was significantly higher in the patients receiving dextrose solution. CONCLUSION: Laparoscopic procedures in children are associated with a rise in blood glucose levels similar to open surgery. The hyperglycaemic response was more pronounced when dextrose-containing solutions were infused peri-operatively.

Metallic foreign body in the lung: a case report.

We present the case of an 11-year-old girl with a history of needle ingestion. Radiological investigations revealed that the foreign body had migrated into the lung parenchyma. We report the use of fluoroscopy and thoracoscopy to aid localization and facilitate removal of a metallic foreign body in the thorax.

Primary pulmonary hydatid cysts in children-a report of three cases.

Three children with a total of six primary pulmonary hydatid cysts, all of whom underwent surgical management, are presented. Of these six hydatid cysts, two were treated with thoracotomy with cyst enucleation and capittonage, three with thoracoscopy-assisted minithoracotomy with enucleation and capittonage, and one with limited resection.

Minimal access surgery in children - 5 years institutional experience.

CONTEXT: Minimal access surgery (MAS) in children are common place and performed worldwide with gratifying results as the learning curve of the surgeon attains plateau. We share our experience of this technically evolving modality of surgery, performed at our setup over a period of 5 years. We also review and individually compare the data for commonly performed procedures with other available series. Author also briefly discuss potential advantages of MAS in certain debatable conditions performed quickly and with cosmesis as open procedure. MATERIALS AND METHODS: We performed 677 MAS in children aged between 7 days and 12 years. Five hundred and sixty-eight of these were Laparoscopic procedures and 109 were Video assisted thoracoscopic surgeries (VATS). In all laparoscopic procedures, the primary port placement was by the Hasson's open technique. We have used 5, 3 and 2 mm instruments. Our study include 259 inguinal hernia, 161 Appendectomies, 95 VATS for empyema, 51 orchiopexies, 49 diagnostic laparoscopy, 29 cholecystectomies, 22 adhesionlysis and other uncommonly performed procedures. RESULTS: The ultimate outcome of all the performed procedures showed gratifying trend, the data of which are discussed in detail in the article. CONCLUSION: As we gained experience the operating time showed a decreasing trend, the complication rates and conversion rate also reduced. The advantages we came across were better postoperative appearances, less pain and early return to unrestricted activities.

Esophageal atresia with distal tracheoesophageal fistula associated with situs inversus.

The presence of situs inversus (SI) causes difficulty in the repair of esophageal atresia with tracheoesophageal fistula (EA/TEF). We report two cases: the first infant had situs SI abdominis with a right-sided aortic arch and the second had situs inversus totalis. To our knowledge, these are the first reported cases of repair of EA/TEF in a patient with SI.

Anomalous pancreaticobiliary union and chronic pancreatitis: rare presentation with biliary peritonitis.

Anomalous pancreaticobiliary union (APBU) has varied presentations. We report the case of a 12-year-old female who presented with biliary peritonitis due to a perforation of the common bile duct due to impaction of a pancreatic calculus at the duodenal papilla. She had a long common-biliary channel and pancreas divisum with chronic calcific pancreatitis involving the pancreatic head and neck. To our knowledge, this is the first such reported case in the literature.

Primary lymphedema of the penis: surgical correction by preputial unfurling.

Primary lymphedema of the penis (PLP) is a rare disease. We report a case in a 2-year-old, uncircumcised boy where the uninvolved inner preputial skin was unfurled to cover the penile shaft. The uninvolved inner preputial skin is often elongated, and provides a suture-free cover of sufficient length for the small penile shaft of pediatric patients.

Color flow Doppler sonography: a reliable alternative to voiding cystourethrogram in the diagnosis of vesicoureteral reflux in children.

OBJECTIVES: In children with urinary tract infection, the incidence of vesicoureteral reflux (VUR) is nearly 30% to 40%. The standard for the diagnosis of VUR is voiding cystourethrography (VCUG). This study assessed the role of color flow Doppler sonography (CFDS) in the diagnosis of VUR and ureteral jets. METHODS: CFDS imaging was performed in 36 patients aged 6 months to 13 years during a 4-year period. All patients underwent CFDS and VCUG within 24 to 48 hours, but the findings of the VCUG were not reported to the sonologist. The ultrasound examinations were done using a color Doppler real-time machine. Representative images of the bladder events were recorded with a multiformat camera and on VHS videotape. RESULTS: The duration of the Doppler signal varied from 0.4 to 7.5 seconds. In 31 (86.1%) of 36 patients, the results of CFDS correlated well with VCUG findings. There were three false-negative and two false-positive results in the present study. Six patients underwent reimplantation during the course of their treatment. CFDS was used as a follow-up modality at the end of 6 months, and the results correlated well with standard VCUG in 4 of these patients. In the remaining 2 patients, only CFDS was performed and correlation with VCUG was not possible. VCUG was considered the reference standard in assessing the sensitivity of CFDS. CONCLUSIONS: CFDS of the bladder during the filling and micturating phases is a reliable and sensitive modality for identifying VUR and demonstrating ureteral jets. CFDS nullifies the danger of exposure to ionizing radiation and avoids the unpleasant catheterization many of these children fear.

Comparison of corneal endothelial image analysis by Konan SP8000 noncontact and Bio-Optics Bambi systems.

PURPOSE: Compare corneal endothelial image analysis by Konan SP8000 and Bio-Optics Bambi image-analysis systems. METHODS: Corneal endothelial images from 98 individuals (191 eyes), ranging in age from 4 to 87 years, with a normal slit-lamp examination and no history of ocular trauma, intraocular surgery, or intraocular inflammation were obtained by the Konan SP8000 noncontact specular microscope. One observer analyzed these images by using the Konan system and a second observer by using the Bio-Optics Bambi system. Three methods of analyses were used: a fixed-frame method to obtain cell density (for both Konan and Bio-Optics Bambi) and a "dot" (Konan) or "corners" (Bio-Optics Bambi) method to determine morphometric parameters. RESULTS: The cell density determined by the Konan fixed-frame method was significantly higher (157 cells/mm2) than the Bio-Optics Bambi fixed-frame method determination (p<0.0001). However, the difference in cell density, although still statistically significant, was smaller and reversed comparing the Konan fixed-frame method with both Konan dot and Bio-Optics Bambi comers method (-74 cells/mm2, p<0.0001; -55 cells/mm2, p<0.0001, respectively). Small but statistically significant morphometric analyses differences between Konan and Bio-Optics Bambi were seen: cell density, +19 cells/mm2 (p = 0.03); cell area, -3.0 microm2 (p = 0.008); and coefficient of variation, +1.0 (p = 0.003). There was no statistically significant difference between these two methods in the percentage of six-sided cells detected (p = 0.55). CONCLUSION: Cell densities measured by the Konan fixed-frame method were comparable with Konan and Bio-Optics Bambi's morphometric analysis, but not with the Bio-Optics Bambi fixed-frame method. The two morphometric analyses were comparable with minimal or no differences for the parameters that were studied. The Konan SP8000 endothelial image-analysis system may be useful for large-scale clinical trials determining cell loss; its noncontact system has many clinical benefits (including patient comfort, safety, ease of use, and short procedure time) and provides reliable cell-density calculations.

The effects of glutathione glycoside in acetaminophen-induced liver cell necrosis.

The hepatotoxic effects of high-dose acetaminophen (400 and 600 mg/kg body weight) were evaluated by determining the glutathione (GSH) and malondialdehyde (MDA) levels and the histological changes in the liver at 6 and 12 h, using C57BL/6J mice. Massive centrilobular hepatocyte necrosis associated with severe reduction of liver GSH and a significant increase in MDA levels were observed following acetaminophen intoxication. Administration of glutathione glycoside (GSH-glyc), a compound newly synthesized in our laboratory, 2 h after acetaminophen injection prevented changes in the GSH and MDA preserving their levels nearly to those of controls; in addition, histological evidence of hepatocyte necrosis was either abolished or severely reduced in the majority of animals. GSH-glyc is a nontoxic compound that can be used to transport GSH into cells, including those of brain and liver, and may prove to be useful for the prophylaxis and therapy of toxic tissue injury, including that induced by overdosage of acetaminophen.