Thin-film wafer-scale mid-IR Fabry Perot cavity gas sensor.

We demonstrate a miniaturized wafer-scale optical gas sensor that combines the gas cell, an optical filter, and integrated flow channels. We present the design, fabrication and characterization of an integrated cavity-enhanced sensor. Using the module, we demonstrate absorption sensing of ethylene down to 100 ppm level.

Polar Semiconducting Scandium Nitride as an Infrared Plasmon and Phonon-Polaritonic Material.

The interaction of light with collective charge oscillations, called plasmon-polariton, and with polar lattice vibrations, called phonon-polariton, are essential for confining light at deep subwavelength dimensions and achieving strong resonances. Traditionally, doped-semiconductors and conducting metal oxides (CMO) are used to achieve plasmon-polaritons in the near-to-mid infrared (IR), while polar dielectrics are utilized for realizing phonon-polaritons in the long-wavelength IR (LWIR) spectral regions. However, demonstrating low-loss plasmon- and phonon-polaritons in one host material will make it attractive for practical applications. Here, we demonstrate high-quality tunable short-wavelength IR (SWIR) plasmon-polariton and LWIR phonon-polariton in complementary metal-oxide-semiconductor compatible group III-V polar semiconducting scandium nitride (ScN) thin films. We achieve both resonances by utilizing n-type (oxygen) and p-type (magnesium) doping in ScN that allows modulation of carrier concentration from 5 × 1018 to 1.6 × 1021 cm-3. Our work enables infrared nanophotonics with an epitaxial group III semiconducting nitride, opening the possibility for practical applications.

Applying LEAN Healthcare in Lean Settings: Launching Quality Improvement in Resource-Limited Regions.

BACKGROUND: Lean methodology is frequently utilized in high income settings to maximize capacity and operational efficiency during process improvement (PI) initiatives. To date there has been little published on the application of these techniques in low- and-middle-income countries (LMIC) despite the potential benefits in resource limited settings. We describe a pilot project developed in 2018 to promote sustainable operating theater efficiency at two hospitals in Abuja, Nigeria. This study details the first known attempt to use Lean techniques to improve surgical care systems in LMIC. METHODS: Perioperative committees were established at two Nigerian institutions to evaluate current processes, identify problems, and compile a list of priorities. A physician champion and a PI specialist in conjunction with local physician-partners held a workshop to teach practical applications of PI methodology as part of an ongoing collaboration. Pre and post-workshop surveys were administered, and theme coding was used to categorize free responses. Results were compared with a chi-square test. RESULTS: In total, 42 individuals attended the PI workshop. After the workshop, 37 respondents reported the workshop as valuable both personally and for the perioperative committee (P < 0.001), and all reported that PI methodology could benefit the institution overall. CONCLUSIONS: By identifying stakeholders, holding a workshop to teach tools of PI, and establishing a committee for ongoing improvement, it is possible to implement quality improvement techniques at LMIC hospitals, which may be of future benefit. Sustainability in this project will be facilitated by tele mentoring, and future efforts include expansion beyond the perioperative setting.

Minimizing Variance in Gastroschisis Management Leads to Earlier Full Feeds in Delayed Closure.

BACKGROUND: Limited guidance exists regarding appropriate timing for feed initiation and advancement in gastroschisis. We hypothesized that implementation of a gastroschisis management protocol would allow for standardization of antibiotic and nutritional treatment for these patients. METHODS: We conducted a retrospective comparison of patients with simple gastroschisis at two pediatric hospitals before and after initiation of our gastroschisis care protocol. Complicated gastroschisis and early mortality were excluded. The control group extended from January 2012 to January 2014 and the protocol group from July 2014 to July 2016. Variables of interest included time to feed initiation, time to goal feeds, length of stay, and National Surgical Quality Improvement Program-defined complications. We performed a subgroup analysis for primary versus delayed gastroschisis closure. Statistical analyses, including F-tests for variance, were conducted in Prism. RESULTS: Forty-seven patients with simple gastroschisis were included (control = 22, protocol = 25). Protocol compliance was 76% with no increase in complication rates. There was no difference in length of stay or time from initiation to full feeds overall between the control and protocol groups. However, neonates who underwent delayed closure reached full feeds significantly earlier, averaging 9 d versus 15 d previously (P = 0.04). CONCLUSIONS: For infants undergoing delayed closure, the time to full feeds in this group now appears to match that of patients undergoing primary closure, indicating that delayed closure should not be a reason for slower advancement. Additional studies are needed to assess the impact of earlier full enteral nutrition on rare complications and rates of necrotizing enterocolitis.

Minimizing variance in pediatric surgical care through implementation of a perioperative colon bundle: A multi-institution retrospective cohort study.

BACKGROUND: Employing an institutional initiative to minimize variance in pediatric surgical care, we implemented a set of perioperative bundled interventions for all colorectal procedures to reduce surgical site infections (SSIs). METHODS: Implementation of a standard colon bundle at two children's hospitals began in December 2014. Subjects who underwent a colorectal procedure during the study period were analyzed. Demographics, outcomes, and complications were compared with Wilcoxon Rank-Sum, Chi-square and Fisher exact tests, as appropriate. Multivariable logistic regression was performed to assess the influence of time period (independent of protocol implementation) on the rate of subsequent infection. RESULTS: One hundred and forty-five patients were identified (preprotocol=68, postprotocol= 77). Gender, diagnosis, procedure performed and wound classification were similar between groups. Superficial SSIs (21% vs. 8%, p=0.031) and readmission (16% vs. 4%, p=0.021) were significantly decreased following implementation of a colon bundle. Median hospital days, cost, reoperation, intraabdominal abscess, and anastomotic leak were unchanged before and after protocol implementation (all p > 0.05). Multivariable logistic regression found time period to be independent of SSIs (OR: 0.810, 95% CI: 0.576-1.140). CONCLUSION: Implementation of a standard pediatric perioperative colon bundle can reduce superficial SSIs. Larger prospective studies are needed to evaluate the impact of colon bundles in reducing complications, hospital stay and cost. LEVEL OF EVIDENCE: III - Retrospective cohort study.

A Natural History of Gastrojejunostomy Tubes in Children.

BACKGROUND: Gastrojejunostomy (GJ) tubes are frequently used to provide nutrition in patients who do not tolerate gastric feeding. Despite their widespread use, there is little literature on the lifespan of GJ tubes, reasons for failure, and recommendations for optimal techniques and timing of replacement. We aimed to evaluate the natural history of GJ tubes in pediatric patients. MATERIALS AND METHODS: We reviewed all pediatric patients who underwent GJ tube placement or exchange at our institution from January 2012 to July 2018. Demographic data, time, and indication for replacement or removal of GJ tubes were collected. End points were permanent removal of GJ tube or mortality. RESULTS: Seventy-nine patients underwent 205 GJ tube procedures with a median of 2 GJ tubes per patient. Median GJ tube lifespan was 98 d (interquartile range = 54-166). The two most common indications for tube exchange were structural or mechanical problems (43.1%) and GJ tube dislodgement (34.6%). Although most GJ tube exchanges (66%) were performed under general anesthesia or with moderate sedation, 34% of exchanges were done without sedation. During the study period, 12 patients (15.2%) died from their primary disease, nine patients (11.4%) required subsequent fundoplication, one (1.3%) underwent a jejunostomy, and 23 (29.1%) progressed to gastric feeds without fundoplication at a median time of 208 d. CONCLUSIONS: GJ tubes offer a safe and effective feeding option in patients intolerant of gastric feeding. GJ tubes fail most commonly from intrinsic structural or mechanical issues, and many patients ultimately tolerate gastric feeds without need for further intervention. Exchange of tubes without anesthesia is a viable option.