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Heterotaxy syndrome (HS) affects right-left anatomical development in 3% of children with congenital heart disease. Commonly, these patients have intestinal rotation abnormalities (IRA) that differ from typical malrotation. In this prospective study, we examine the development of a management pathway, imaging findings, and clinical course of patients with HS and IRA. After literature review, a multispecialty focus group designed a pathway for HS. Participants from a single institution were prospectively enrolled from 2016 to 2019. They underwent an abdominal ultrasound and UGI, however timing was variable based on symptoms. Symptomatic IRA was defined as feeding intolerance, bilious or non-bilious vomiting, bloating, severe reflux, and intermittent pain or abdominal distention. Screening for symptoms occurred every three months for the first two years and then annually. 18 participants were followed for a median of 5.0 years. Three clinical categories were identified: 1) asymptomatic, not requiring intestinal surgery, 72.2%, 2) symptomatic with feeding intolerance or failure to thrive requiring gastrostomy placement and diagnostic laparoscopy with Ladd procedure, 16.7%, and 3) symptomatic requiring urgent exploration for suspicion of volvulus, 11.1%. Need for surgery did not necessarily correlate with US and/or UGI findings. In children with HS and IRA, postnatal imaging did not inform the need for intestinal surgery. Although rare, volvulus or other forms of proximal obstruction can be anticipated, and symptomatic patients should be offered surgical intervention. A multidisciplinary care pathway for patients with HS and IRA can coordinate care and help counsel families on the likelihood of needing intestinal surgery for IRA. Level II. Prospective Cohort Study. • Screening and management practices of intestinal rotational abnormalities in heterotaxy syndrome are debated. • A multidisciplinary pathway permits safe and close follow-up with intervention when clinically indicated. • Ultrasound and upper intestinal contrast studies do not always predict the need for intervention. [ABSTRACT FROM AUTHOR]

Flame-formed carbon nanoparticles exhibit apparent size-dependent optical and electronic band gaps, consistent with the quantum confinement effect found in semiconductor materials. Understanding the effect of chemical composition on the band gap variations in carbon nanoparticles requires the investigation of the HOMO-LUMO gap of large aromatics. Geometry optimization with empirical force fields, followed by a density functional theory calculation, is employed here to enable the calculation of HOMO-LUMO gaps of aromatic species of sizes substantially larger than those reported in the past. Large hexagonal polycyclic aromatic hydrocarbons (PAHs) are shown to have diminishing HOMO-LUMO gaps, consistent with the behavior of two-dimensional quantum dots and approaching the zero band gap of graphene, while the HOMO-LUMO gap of polyacenes levels off at a finite value. The HOMO-LUMO gap of an aromatic cluster is found to be determined mostly by the large PAH molecules with smaller HOMO-LUMO gaps; small PAH molecules in the cluster make small or negligible contributions to the gap size of the overall cluster. Thus, if the quantum confinement of flame-formed carbon nanoparticles must be understood within the context of particle composition, the dependency of the band gap on particle size may be explained simply by the fact that larger flame-formed carbon nanoparticles contain larger PAH molecules or perhaps more precisely, have higher probabilities of containing more light absorbing species, e.g., large PAH molecules. [ABSTRACT FROM AUTHOR]

Perforated peptic ulcer is a morbid emergency general surgery condition. Best practices for postoperative care remain undefined. Surgical dogma preaches practices such as peritoneal drain placement, prolonged nil per os, and routine postoperative enteral contrast imaging despite a lack of evidence. We aimed to evaluate the role of postoperative enteral contrast imaging in postoperative perforated peptic ulcer care. Our primary objective was to assess effects of routine postoperative enteral contrast imaging on early detection of clinically significant leaks. We conducted a multicenter retrospective cohort study of patients who underwent repair of perforated peptic ulcer between July 2016 and June 2018. We compared outcomes between those who underwent routine postoperative enteral contrast imaging and those who did not. Our analysis included 95 patients who underwent primary/omental patch repair. The mean age was 60 years, and 54% were male. Thirteen (14%) had a leak. Eighty percent of patients had a drain placed. Nine patients had leaks diagnosed based on bilious drain output without routine postoperative enteral contrast imaging. Use of routine postoperative enteral contrast imaging varied significantly between institutions (30%–87%). Two late leaks after initial normal postoperative enteral contrast imaging were confirmed by imaging after a clinical change triggered the second study. Two patients had contained leaks identified by routine postoperative enteral contrast imaging but remained clinically well. Duration of hospital stay was longer in those who received routine postoperative enteral contrast imaging (12 vs 6 days, median; P =.000). Routine postoperative enteral contrast imaging after perforated peptic ulcer repair likely does not improve the detection of clinically significant leaks and is associated with increased duration of hospital stay. [ABSTRACT FROM AUTHOR]

Using recombinant DNA techniques, nested deletions have been made upstream of the Escherichia coli nirB transcription start site and their effects on the regulation of nirB promoter activity have been measured. Nucleotide sequences downstream of -73 are sufficient for FNR-dependent induction of activity by anaerobic growth conditions. However, nucleotide sequences between -87 and -149 are essential for further induction by nitrite in the growth medium. The nucleotide sequence at the galP1 CRP binding site located from -31 to -5 2 displays some similarities with the same region at the nirB promoter. When the gatP1 sequence from -3 0 to -54 was replaced by the corresponding nirB sequence, expression from galP1 became inducible by FNR under anaerobic growth conditions. [ABSTRACT FROM AUTHOR]