Distinctive clinical features of spontaneous pneumoperitoneum in neonates: A retrospective analysis

BACKGROUND Spontaneous pneumoperitoneum(SP) without gastrointestinal perforation rarely occurs in neonates, with most SP cases being idiopathic. Although SP usually follows a benign clinical course with favorable prognosis, it can become lifethreatening in certain situations. In these cases, urgent surgical intervention may be required. Therefore, it may be difficult to decide when or how to perform prompt interventions.AIM To demonstrate the distinct clinical features of SP to guide appropriate management by comparing characteristics between SP and typical pneumoperitoneum secondary to gastrointestinal perforation.METHODS We retrospectively reviewed electronic medical records and identified 37 neonates with radiological evidence of pneumoperitoneum who were treated at our institution. Clinical variables were compared between neonates with SP without gastrointestinal perforation(Group A) and those with pneumoperitoneum secondary to gastrointestinal perforation(Group B). Clinical variables between groups were compared using Student’s t-test and the chi-square test. The risk factors related to mortality were examined using multi-logistic regression analysis.RESULTS Group A comprised 35.1%(13/37) of the patients. The frequency of persistent pulmonary hypertension(53.8%) and pneumothorax(46.2%) before the development of pneumoperitoneum was significantly higher in group A than in group B(P =0.004). Platelet count and partial pressure of arterial oxygen(PaO) were significantly lower in group A(P = 0.015 and 0.025, respectively). Overall mortality was significantly higher in group A than in group B(76.9% vs 16.7%, P = 0.001). Only preterm infants were significantly associated with high mortality(P = 0.041;odds ratio = 18.0). Accompaniment with persistent pulmonary hypertension and pneumothorax were also significantly high(P = 0.004) in group A, but these were not strongly associated with high mortality.CONCLUSION This study identified a higher mortality rate in patients with SP than that described in previous reports. Neonates with SP were more likely to have thrombocytopenia, pneumothorax, and persistent pulmonary hypertension. Prematurity was the most significant factor affecting mortality.

Surgical perspectives of symptomatic omphalomesenteric duct remnants: Differences between infancy and beyond

BACKGROUND The clinical manifestations of omphalomesenteric duct remnant(OMDR)can vary with the age at diagnosis,from asymptomatic incidental findings to symptoms related to gastrointestinal complications.The lifelong complication rates are reported as 4%-34%,and complications are more common in patients younger than 2 years of age.The authors attempted to identify different clinical features and management for the various pediatric age groups.AIM To find surgical perspectives for the pediatric age-related variants of OMDR and make recommendations for optimal management.METHODS The medical records of pediatric patients diagnosed with OMDR were reviewed retrospectively.Fifteen patients diagnosed based on incidental findings during other surgeries were excluded.The patients were divided into two groups based on age:<12 mo(infants)and>12 mo(beyond infancy).We analyzed the demographic characteristics,clinical manifestations,diagnostic tools,surgical procedures,and clinical outcomes of the patients and compared them for the age groups.Chi-squared and Fisher's exact tests were used for nominal scales and a Mann-Whitney test was used for ratio scales.RESULTS A total of 35 patients(7 infants,28 children beyond infancy)were finally included.In both groups,Meckel's diverticulum(MD)was the most common type of OMDR,while umbilical lesions were more common in the infant group(P=0.006).Hematochezia and abdominal pain were common in the beyond infancy group,while umbilical lesions were the most frequent symptoms in the infant group.Several diagnostic tools were used,but Meckel's scan was most useful in diagnosing OMDR in patients with painless rectal bleeding.Minimally invasive surgery was more commonly performed for children than for infants(P=0.016).Single-incision laparoscopic surgery(SILS)was performed for fifteen patients who underwent laparoscopic surgery.There were only three cases of postoperative complications,and all patients survived in good condition.CONCLUSION The clinical type of OMDR varies with age,umbilical lesions in infants,and MD beyond infancy.SILS is effective for managing children with MD regardless of age.

Deep-learning-based gas identification by timevariant illumination of a single micro-LEDembedded gas sensor

Electronic nose(e-nose)technology for selectively identifying a target gas through chemoresistive sensors has gained much attention for various applications,such as smart factory and personal health monitoring.To overcome the crossreactivity problem of chemoresistive sensors to various gas species,herein,we propose a novel sensing strategy based on a single micro-LED(μLED)-embedded photoactivated(μLP)gas sensor,utilizing the time-variant illumination for identifying the species and concentrations of various target gases.A fast-changing pseudorandom voltage input is applied to the μLED to generate forced transient sensor responses.A deep neural network is employed to analyze the obtained complex transient signals for gas detection and concentration estimation.The proposed sensor system achieves high classification(~96.99%)and quantification(mean absolute percentage error~31.99%)accuracies for various toxic gases(methanol,ethanol,acetone,and nitrogen dioxide)with a single gas sensor consuming 0.53 mW.The proposed method may significantly improve the efficiency of e-nose technology in terms of cost,space,and power consumption.

Electrically driven, phosphor-free, white light-emitting diodes using gallium nitride-based double concentric truncated pyramid structures

White light-emitting diodes(LEDs)are becoming an alternative general light source,with huge energy savings compared to conventional lighting.However,white LEDs using phosphor(s)suffer from unavoidable Stokes energy converting losses,higher manufacturing cost,and reduced thermal stability.Here,we demonstrate electrically driven,phosphor-free,white LEDs based on three-dimensional gallium nitride structures with double concentric truncated hexagonal pyramids.The electroluminescence spectra are stable with varying current.The origin of the emission wavelength is studied by cathodoluminescence and high-angle annular dark field scanning transmission electron microscopy experiments.Spatial variation of the carrier injection efficiency is also investigated by a comparative analysis between spatially resolved photoluminescence and electroluminescence.

Phase separations in graded-indium content InGaN/GaN multiple quantum wells and its function to high quantum efficiency

Phase separations have been studied for graded-indium content In_xGa_(1-x)N/GaN multiple quantum wells(MQWs) with different indium contents by means of photoluminescence(PL),cathodeluminescence(CL) and time-resolved PL(TRPL) techniques.Besides the main emission peaks,all samples show another 2 peaks at the high and low energy parts of the main peaks in PL when excited at 10 K.CL images show a clear contrast for 3 samples,which indicates an increasing phase separation with increasing indium content.TRPL spectra at 15 K of the main emissions show an increasing delay of rising time with indium content,which means a carrier transferring from low indium content structures to high indium content structures.