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Objective: Necrotizing enterocolitis (NEC) is the most prevalent gastrointestinal emergency in premature infants and is characterized by a dysfunctional gut microcirculation. Therefore, there is a dire need for in vivo methods to characterize NEC‐induced changes in the structure and function of the gut microcirculation, that is, its vascular phenotype. Since in vivo gut imaging methods are often slow and employ a single‐contrast mechanism, we developed a rapid multicontrast imaging technique and a novel analyses pipeline for phenotyping the gut microcirculation. Methods: Using an experimental NEC model, we acquired in vivo images of the gut microvasculature and blood flow over a 5000 × 7000 μm2 field of view at 5 μm resolution via the following two endogenous contrast mechanisms: intrinsic optical signals and laser speckles. Next, we transformed intestinal images into rectilinear "flat maps," and delineated 1A/V gut microvessels and their perfusion territories as "intestinal vascular units" (IVUs). Employing IVUs, we quantified and visualized NEC‐induced changes to the gut vascular phenotype. Results: In vivo imaging required 60–100 s per animal. Relative to the healthy gut, NEC intestines showed a significant overall decrease (i.e. 64–72%) in perfusion, accompanied by vasoconstriction (i.e. 9–12%) and a reduction in perfusion entropy (19%)within sections of the vascular bed. Conclusions: Multicontrast imaging coupled with IVU‐based in vivo vascular phenotyping is a powerful new tool for elucidating NEC pathogenesis. [ABSTRACT FROM AUTHOR]

There is an increasing national trend toward initial venovenous (VV) extracorporeal membrane oxygenation (ECMO) for infants and children with respiratory disease; however, some proportion of patients initiated on VV ECMO will ultimately require conversion to venoarterial (VA) support for circulatory augmentation. The purpose of this work is to describe patients who required conversion from VV to VA ECMO and to highlight the increased mortality in this population. Demographic and disease-specific data on children who underwent VV-to-VA ECMO conversion were extracted from the Extracorporeal Life Support Organization registry. Survival comparisons to age-matched patients undergoing unconverted ECMO runs were made using the 2016 Extracorporeal Life Support Organization International Summary report. The relative risk (RR) of death associated with VV-to-VA conversion was calculated, and statistical analysis of survival was performed using a chi-squared test with P < 0.05 for significance. This study cohort consisted of 1382 patients who required VV-to-VA conversion. The overall hospital survival rate for neonates requiring conversion was 60%, compared with 83% for unconverted VV runs and 64% for unconverted VA runs (RR 1.23; 95% confidence interval, 1.14-1.34). Similarly, the survival of older children requiring conversion was 46% compared with 66% and 51%, respectively (RR 1.16; 95% confidence interval, 1.06-1.27). VV-to-VA conversion does occur and is associated with increased mortality. The need for conversion from VV to VA ECMO may represent an early failure to recognize physiologic parameters or disease severity that would be better managed with initial VA support. Further research is needed to pinpoint the cause of increased mortality and to identify predictors of VV failure to optimize initial mode selection. [ABSTRACT FROM AUTHOR]

Introduction: Solid pseudopapillary neoplasm (SPN) is the most commonly encountered pancreatic tumor in adolescents. Owing to its malignant potential, the current recommendation for management is complete surgical resection; however, there is no broad consensus on the operation of choice to accomplish this. Herein, we describe three consecutive laparoscopic spleen-preserving distal pancreatectomies for SPN in adolescents. Materials and Methods: Our cohort included all patients <18 years of age treated at our institution from 2015 to 2018 who underwent surgical resection of an SPN. Results: Three patients (age 13-16) were identified. Two of the patients were male. All patients underwent laparoscopic distal pancreatectomy with preservation of the main splenic artery and vein. No patients suffered from postoperative pancreatic fistula. Median length of stay was 5 days. Final histology revealed SPN in all 3 cases, with tumor size ranging from 2 to 10 cm in greatest dimension. All margins were negative for tumor. All 3 patients have been followed (mean: 6 months) with surveillance ultrasound demonstrating a normal remnant pancreas and normal splenic perfusion. Conclusions: Laparoscopic spleen-preserving distal pancreatectomy is a safe and effective treatment for SPNs of the body and tail of the pancreas in adolescents. This approach achieves the margin negative resection that is appropriate for the disease without subjecting children to the risk of postsplenectomy sepsis or the need for antibiotic prophylaxis, and may be associated with a reduction in perioperative morbidity. Therefore, laparoscopic distal pancreatectomy with splenic preservation is our preferred operation in adolescents presenting with SPN. [ABSTRACT FROM AUTHOR]

• Social distancing orders have been justifiably required to slow the spread of the Covid-19 pandemic. • Little is known regarding the secondary health consequences of these mandates. • There was an increased proportion of physical child abuse injuries at our level I pediatric trauma center during the Covid-19 pandemic. • Heightened awareness of this unintended consequence of social distancing can help to protect vulnerable children. The Covid-19 pandemic has forced mass closures of childcare facilities and schools. While these measures are necessary to slow virus transmission, little is known regarding the secondary health consequences of social distancing. The purpose of this study is to assess the proportion of injuries secondary to physical child abuse (PCA) at a level I pediatric trauma center during the Covid-19 pandemic. A retrospective review of patients at our center was conducted to identify injuries caused by PCA in the month following the statewide closure of childcare facilities in Maryland. The proportion of PCA patients treated during the Covid-19 era were compared to the corresponding period in the preceding two years by Fisher's exact test. Demographics, injury profiles, and outcomes were described for each period. Eight patients with PCA injuries were treated during the Covid-19 period (13 % of total trauma patients), compared to four in 2019 (4 %, p < 0.05) and three in 2018 (3 %, p < 0.05). The median age of patients in the Covid-19 period was 11.5 months (IQR 6.8–24.5). Most patients were black (75 %) with public health insurance (75 %). All injuries were caused by blunt trauma, resulting in scalp/face contusions (63 %), skull fractures (50 %), intracranial hemorrhage (38 %), and long bone fractures (25 %). There was an increase in the proportion of traumatic injuries caused by physical child abuse at our center during the Covid-19 pandemic. Strategies to mitigate this secondary effect of social distancing should be thoughtfully implemented. [ABSTRACT FROM AUTHOR]

Abstract: Study aim: Adherence to Advanced Trauma Life Support (ATLS) protocol has been associated with improved management of injured patients. The objective of this study is to determine factors associated with delayed and omitted ATLS primary and secondary survey tasks at a level 1 pediatric trauma center. Methods: Video recorded resuscitations of 237 injured patients<18 years old obtained over a four month period at our hospital were evaluated to assess completeness and timeliness of essential tasks in the primary and secondary survey of ATLS. Multivariate analyses were performed to identify features associated with decreased ATLS performance. Results: Primary survey findings were stated less often in patients with burn injuries compared to those with blunt injuries (RR=1.72; 95% CI: 1.26–2.35) and less often during the overnight shift [11PM–7AM] (RR=1.22; 95% CI: 1.02–1.46). Secondary survey findings were verbalized less often in patients with penetrating injures (RR=2.30; 95% CI: 1.06–5.00). Time to statement of primary surveys findings was delayed in patients with burn injuries (HR=0.69; 95% CI: 0.48–0.98) and among those transferred from another hospital. Completeness and timeliness of ATLS task performance were not associated with age or injury severity score. Conclusions: Mechanism of injury and hospital factors are associated with incomplete and delayed primary and secondary surveys. Interventions that address deficient ATLS adherence related to these factors may lead to a reduction in errors during this critical period of patient care. [Copyright &y& Elsevier]

Abstract: Copper filling of small features using a potential-controlled technique in electrolytic bath containing organic additives in a selected potential range is shown to be highly beneficial. End-points filling detection in features with width of less than 150nm are observed in the current–time profile. This behavior is obtained once potential is applied in a selected potential range, capable of providing efficient copper deposition suppression on flat wafer surface sites. Thus, achieving a controlled feature filling with a clear end-point of copper super-filling with minimum copper overburden is feasible in a potentiostatic operation mode. Copper filling rate depends primarily on the selected potential value and the feature dimension characteristics (aspect ratio). Selective copper filling during potentiostatic deposition is favorable (over galvanostatic deposition) in high aspect ratio patterned wafers. Illustrations of i–t curve profiles during copper super-filling of complex wafer patterns in a potentiostatic mode are presented. [Copyright &y& Elsevier]

Electron energy loss spectroscopy (EELS) in both fixed-probe transmission electron microscopy (TEM) and scanning TEM (STEM) was used to measure elemental profiles of Si, O, and N in the SiO[sub x]/Si[sub x]N[sub y]/SiO[sub x]/poly-Si stacks deposited on silicon. The results revealed radiation-induced nitrogen segregation to both the Si/SiO[sub x] and SiO[sub x]/poly-Si interfaces; the extent of nitrogen segregation increased visibly with increasing the radiation dose. The nitrogen diffusion through the oxide layers apparently was accompanied by the diffusion of oxygen into the nitride. Low-noise artifact-free nitrogen profiles across the Si/SiO[sub x] interfaces were obtained in STEM by scanning the beam parallel to the layers. These measurements indicated lack of detectable nitrogen segregation to the interfaces. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Problem: Although early environmental influences are thought to influence the development of inflammatory bowel disease (IBD), little is known about the role of the in utero environment on subsequent IBD risk. We hypothesized that prenatal exposure to bacterial lipopolysaccharide (LPS) could modify the subsequent development of dextran sulfate sodium (DSS)‐induced ulcerative colitis in adulthood by influencing the associated cellular and immune response. Method of Study: To test this hypothesis, we exposed developing mice in utero to LPS or saline (PBS) at E17.5, and then induced colitis at 5 weeks. We then assessed colitis severity and effects on the microbiome. In order to define the developmental impact of any potential LPS effect, we also exposed 1‐week‐old mice to either LPS or saline before inducing colitis at 5 weeks. Results: Mice that had been exposed to LPS but not saline in utero were protected from subsequent colitis development, and their intestinal barrier integrity and tight junction expression distribution were similar to that of control mice that were not exposed to DSS. By contrast, mice exposed to either LPS or saline at day 7 of life all developed severe colitis upon subsequent DSS exposure. Conclusion: These results identify an informative time window during fetal development during which exposure to an otherwise pro‐inflammatory agent like LPS protects against an inflammatory disease in adulthood. [ABSTRACT FROM AUTHOR]

Angiotensin-converting enzyme 2 (ACE2) is a potent negative regulator capable of restraining overactivation of the renin- angiotensin system, which contributes to exuberant inflammation after bacterial infection. However, the mechanism through which ACE2 modulates this inflammatory response is not well understood. Accumulating evidence indicates that infectious insults perturb ACE2 activity, allowing for uncontrolled inflammation. In the current study, we demonstrate that pulmonary ACE2 levels are dynamically varied during bacterial lung infection, and the fluctuation is critical in determining the severity of bacterial pneumonia. Specifically, we found that a pre-existing and persistent deficiency of active ACE2 led to excessive neutrophil accumulation in mouse lungs subjected to bacterial infection, resulting in a hyperinflammatory response and lung damage. In contrast, pre-existing and persistent increased ACE2 activity reduces neutrophil infiltration and compromises host defense, leading to overwhelming bacterial infection. Further, we found that the interruption of pulmonary ACE2 restitution in the model of bacterial lung infection delays the recovery process from neutrophilic lung inflammation. We observed the beneficial effects of recombinant ACE2 when administered to bacterially infected mouse lungs following an initial inflammatory response. In seeking to elucidate the mechanisms involved, we discovered that ACE2 inhibits neutrophil infiltration and lung inflammation by limiting IL-17 signaling by reducing the activity of the STAT3 pathway. The results suggest that the alteration of active ACE2 is not only a consequence of bacterial lung infection but also a critical component of host defense through modulation of the innate immune response to bacterial lung infection by regulating neutrophil influx. [ABSTRACT FROM AUTHOR]