Grade V renal trauma management: results from the multi-institutional genito-urinary trauma study

PURPOSE

To investigate management trends for American Association for the Surgery of Trauma (AAST) grade V renal trauma with focus on non-operative management.

METHODS

We used prospectively collected data as part of the Multi-institutional Genito-Urinary Trauma Study (MiGUTS). We included patients with grade V renal trauma according to the AAST Injury Scoring Scale 2018 update. All cases submitted by participating centers with radiology images available were independently reviewed to confirm renal trauma grade. Management was classified as expectant, conservative (minimally invasive, endoscopic or percutaneous procedures), or operative (renal-related surgery).

RESULTS

Eighty patients were included, 25 of whom had complete imaging and had independent confirmation of AAST grade V renal trauma. Median age was 35 years (Interquartile range (IQR) 25-50) and 23 (92%) had blunt trauma. Ten patients (40%) were managed operatively with nephrectomy. Conservative management was used in nine patients (36%) of which six received angioembolization and three had a stent or drainage tube placed. Expectant management was followed in six (24%) patients. Transfusion requirements were progressively higher with groups requiring more aggressive treatment, and injury characteristics differed significantly across management groups in terms of hematoma size and laceration size. Vascular contrast extravasation was more likely in operatively managed patients though a statistically significant association was not found.

CONCLUSION

Successful use of nonoperative management for grade V injuries is used for a substantial subset of patients. Lower transfusion requirement and less severe injury radiologic phenotype appear to be important characteristics delineating this group.

Malignant Germ Cell Tumors of the Ovary

Ovarian malignant germ cell tumors are a diverse set of masses originating from the primitive gonadal germ cells, often in young females. They have useful imaging and clinical features, including serum tumor marker elevation, that may aid the radiologist at the time of diagnosis, and also during follow-up. Accurate and timely diagnosis is essential, as standard-of-care therapies lead to a high rate of cancer remission.

Lost in descent: Complications of cryptorchidism

Cryptorchidism is a relatively common and important clinical entity and can lead to an array of downstream complications if it is not corrected in a timely manner, most notably with the development of testicular germ cell tumors. However, beyond the development of malignancy, there are other rare complications associated with cryptorchid testicular germ cell tumors which are more commonly seen in females with ovarian germ cell tumors, including torsion, rupture, and paraneoplastic syndromes. Presented is an instructive case (with literature review) of a patient who presented with NMDA encephalitis due to a torsed mixed germ cell tumor of an undescended testis, which subsequently ruptured leading to growing teratoma syndrome.

143 Intestinal Failure: Epidemiology, Catheter Related Sepsis and Challenges

Background

The aforementioned service provides specialist intestinal failure care to patients in Leicestershire and surrounding counties.

Aim

To study the epidemiology of IF cases referred to the service & review outcomes particularly the indications and delivery of parenteral nutrition (PN). To review catheter-related sepsis (CRS) rates and identify areas for improvement.

Method

Service data from January 2016 to November 2017 was analysed retrospectively. Descriptive and inferential statistical analysis was carried out. Chi-square/ Fisher Exact tests were used to identify significance on categorical data and non-parametric settling was used for qualitative data analysis.

Results

365 patients were referred to the service from January 2016 to November 2017. 58% patients had grade I intestinal failure. 34% and 24% referrals were made by the colorectal and hepato-pancreato-biliary (HPB) units respectively. Gut rest (27%) and bowel obstruction (25%) were the most common indications for nutritional support. Duration of PN requirements varied greatly, but most patients (39%) patients required it for up to 7 days. Single lumen PICC line (64%) and cephalic vein (54%) were the most commonly used catheter and site of vascular access respectively. Chronicity of IF and number of vascular catheters required to provide PN were significantly associated with rates of CRS.

Conclusions

CRS was found to be statistically significantly associated with chronic IF and number of vascular access catheters required to provide PN. Cost implication and morbidity of CRS could be analysed further to identify other ways to provide safer and cost-efficient parental nutrition for patients with intestinal failure.

Supercomputer-Based Ensemble Docking Drug Discovery Pipeline with Application to Covid-19

We present a supercomputer-driven pipeline for in silico drug discovery using enhanced sampling molecular dynamics (MD) and ensemble docking. Ensemble docking makes use of MD results by docking compound databases into representative protein binding-site conformations, thus taking into account the dynamic properties of the binding sites. We also describe preliminary results obtained for 24 systems involving eight proteins of the proteome of SARS-CoV-2. The MD involves temperature replica exchange enhanced sampling, making use of massively parallel supercomputing to quickly sample the configurational space of protein drug targets. Using the Summit supercomputer at the Oak Ridge National Laboratory, more than 1 ms of enhanced sampling MD can be generated per day. We have ensemble docked repurposing databases to 10 configurations of each of the 24 SARS-CoV-2 systems using AutoDock Vina. Comparison to experiment demonstrates remarkably high hit rates for the top scoring tranches of compounds identified by our ensemble approach. We also demonstrate that, using Autodock-GPU on Summit, it is possible to perform exhaustive docking of one billion compounds in under 24 h. Finally, we discuss preliminary results and planned improvements to the pipeline, including the use of quantum mechanical (QM), machine learning, and artificial intelligence (AI) methods to cluster MD trajectories and rescore docking poses.

Supercomputer-Based Ensemble Docking Drug Discovery Pipeline with Application to Covid-19

We present a supercomputer-driven pipeline for in-silico drug discovery using enhanced sampling molecular dynamics (MD) and ensemble docking. We also describe preliminary results obtained for 23 systems involving eight protein targets of the proteome of SARS CoV-2. THe MD performed is temperature replica-exchange enhanced sampling, making use of the massively parallel supercomputing on the SUMMIT supercomputer at Oak Ridge National Laboratory, with which more than 1ms of enhanced sampling MD can be generated per day. We have ensemble docked repurposing databases to ten configurations of each of the 23 SARS CoV-2 systems using AutoDock Vina. We also demonstrate that using Autodock-GPU on SUMMIT, it is possible to perform exhaustive docking of one billion compounds in under 24 hours. Finally, we discuss preliminary results and planned improvements to the pipeline, including the use of quantum mechanical (QM), machine learning, and AI methods to cluster MD trajectories and rescore docking poses.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Acute Ureteral Obstruction by Deeply Inserted Menstrual Cup

Mechanical complications from menstrual cups are rare, with only four reported cases of ureteral obstruction. Clinicians should be aware of gynecologic devices in patients with acute abdominopelvic pain because simple removal may obviate the need for further expensive work-up or exposure to ionizing radiation.

Determination of Neutral Lactase Activity in Industrial Enzyme Preparations by a Colorimetric Enzymatic Method: Collaborative Study

Thirteen laboratories participated in a collaborative study to validate a colorimetric assay for determining neutral lactase activity in industrial enzyme preparations. Each laboratory received 5 duplicate samples with activity levels of 2000 and 5000 neutral lactase units provided by 4 commercial suppliers. Two laboratories did not return results. Method performance was calculated according to AOAC guidelines. From the 11 remaining laboratories, 3 were excluded from statistical analysis because of invalid data determined during initial review by Youden pair, value versus laboratory. Repeatability relative standard deviation (RSDr) values ranged from 3.20 to 8.62%, and reproducibility relative standard deviation (RSDR) values ranged from 8.77 to 16.35%. With outliers excluded, RSDr values ranged from 2.94 to 5.01%, and RSDRvalues ranged from 7.50 to 13.84%. The colorimetric enzymatic method for determining neutral lactase activity in industrial enzyme preparations has been adopted first action by AOAC INTERNATIONAL.

MON-253 Severe Infantile Hypercalcemia in Williams-Beuren Syndrome

Background: Williams-Beuren Syndrome (WBS) is due to a microdeletion on chromosome 7q11, and is associated with facial dysmorphisms, supravalvular aortic stenosis, a sociable personality and infantile hypercalcemia that is clasically mild and transient. Here we describe an infant found to have incidental severe hypercalcemia that led to a diagnosis of WBS. Case: A 9 month old girl, born at 36 weeks, developed failure to thrive (FTT) thought to be due to poor appetite. She failed to gain weight despite fortification of formula to 24 kcal/oz three months ago. Her medical history included delayed motor milestones, transverse hypoplastic aortic arch, persistent pulmonary stenosis and constipation managed with prune juice. On exam, heart rate was 134 bpm, BP 100/48 (>95^th%ile for height). Her weight was 5.9 kg (<1^st%ile) and length 66.4 cm (3^rd%ile). She was noted to have facial dysmorphisms (stellate iris, epicanthal folds, broad nasal tip, long philtrum, thick vermilion of upper lip, and micrognathia). She was able to sit briefly without support, and was generally hypotonic. She also had a grade II murmur at the left lower sternal border (LLSB). Due to persistent FTT, labs were obtained and showed serum calcium (Ca) of 17.3 mg/dL (9.0-11.0), which was repeated and was 18.6 mg/dL, prompting admission. On admission: iCa 2.60 mmol/L (1.08-1.30), Mg 2.1 mg/dL (1.6-2.2), ALP 164 (32-117 U/L), Phos 3.1 mg/dL (3.7-6.5), BUN 21 mg/dL (5-18), Cr 0.51 mg/dL(0.38-0.96), PTH 12 pg/mL (15-65), urine Ca:Cr ratio 0.56 (<0.60), 25-vitD 43 ng/mL (31-80) and 1,25-vitD 5.3 pg/mL (15-60), with abnormal values bolded. An EKG showed normal sinus rhythm and normal QTc. Renal US showed bilateral medullary nephrocalcinosis. She was given IV fluids (NS D5) at 1.5x maintenance, switched to a low-calcium diet (Calcilo^TM) and daily vit-D supplementation was discontinued. Despite IV hydration for 36 hours, she remained hypercalcemic (Ca 15.6 mg/dL; iCa 1.96 mmol/L) and thus received two doses of IV furosemide to aid diuresis. She was weaned off IV fluids after calcium was <13mg/dL, and iCa 1.29 mmol/L. A genetic micro-array was sent and showed the deletion of chr7.q11.23, consistent with WBS. She was discharged on a low calcium diet and calcium levels have ranged between 10.0-10.8 mg/dL. Her appetite improved, and her weight increased to the 20^th%ile without any other dietary changes, by her 15 month visit. Conclusion: Hypercalcemia in WBS can be severe, with the noted calcium level being the highest reported in the literature. The etiology of hypercalcemia in WBS remains unknown and can typically be managed with a low calcium diet and minimizing vitamin D intake. In severe hypercalcemia, IV hydration is the mainstay for acute management, with furosemide, bisphosphonates and other methods reserved for resistant hypercalcemia.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

A Randomized Safety and Efficacy Study of Somavaratan (VRS-317), a Long-Acting rhGH, in Pediatric Growth Hormone Deficiency

CONTEXT

Somavaratan (VRS-317) is a long-acting form of recombinant human GH under development for children and adults with GH deficiency (GHD).

OBJECTIVES

To determine the optimal somavaratan dose regimen to normalize IGF-1 in pediatric GHD and to evaluate safety and efficacy of somavaratan over 6 months.

DESIGN

Open-label, multicenter, single ascending dose study followed by 6-month randomized comparison of 3 dosing regimens.

SETTING

Twenty-five United States pediatric endocrinology centers.

PATIENTS

Naive-to-treatment, prepubertal children with GHD (n = 68).

INTERVENTION(S)

Patients received single sc doses of somavaratan (0.8, 1.2, 1.8, 2.7, 4.0, or 6.0 mg/kg) during the 30-day dose-finding phase, then were randomized to somavaratan 1.15 mg/kg weekly, 2.5 mg/kg twice monthly, or 5.0 mg/kg monthly for 6 months.

MAIN OUTCOME MEASURES

Safety, pharmacokinetics, pharmacodynamics, 6-month height velocity (HV).

RESULTS

Somavaratan pharmacokinetics was linearly proportional to dose; dose-dependent increases in the magnitude and duration of IGF-1 responses enabled weekly, twice-monthly or monthly dosing. A single dose of somavaratan sustained IGF-1 responses for up to 1 month. No somavaratan or IGF-1 accumulation occurred with repeat dosing. Mean annualized HVs for somavaratan administered monthly, twice monthly, or weekly (7.86 ± 2.5, 8.61 ± 2.7, and 7.58 ± 2.5 cm/y, respectively) were similar between groups. Adverse events were mostly mild and transient.

CONCLUSIONS

Somavaratan demonstrated clinically meaningful improvements in HV and IGF-1 in prepubertal children with GHD, with no significant differences between monthly, twice-monthly, or weekly dosing.

Oil and Anthropology

In addition to its established interest in the relationships among states, corporations, and communities near extraction sites, recent anthropological and allied interdisciplinary interest in oil extends to encompass pipeline infrastructures, financial and commodity markets, reserve estimates and calculations, international legal battles, and the creation of geological, environmental, and petrochemical knowledge. This review suggests that, across these issues and around the world, two analytic issues have emerged as topics of special interest: temporality and materiality. The former includes the ways in which the oil complex shapes senses of cyclical boom and bust, of acceleration and deceleration, and of past, present, and future. The latter includes the ways in which humans encounter, transform, and represent various qualities and properties of oil as a substance.

Petrobarter: oil, inequality, and the political imagination in and after the Cold War

Petrobarter--the exchange of oil for goods and services without reference to monetary currency--has been a widespread and underappreciated practice among corporations, states, and state agencies over the past half century. Analyzing this practice with reference to anthropological theories of barter adds to our understandings of two significant and intertwined concerns in contemporary social science: (1) the production and reproduction of inequality at various scales, from subnational regions to the international system as a whole, and (2) the generation and fate of mobilizing political imaginaries that challenge the abstracted, universalizing imaginaries so often associated with monetized exchange, especially in capitalist contexts. Barter exchanges featuring oil are, therefore, as analytically significant as the much more commonly studied transactions of oil and money. Ethnographic and historical case studies of petrobarter are drawn from the Perm region of the Russian Urals in the post-Soviet period and the global oil trade in the early Cold War. This view from the perspective of the socialist and postsocialist world, it is argued, provides an instructive counterpoint to the many existing studies of oil and money, both in and beyond anthropology, that are situated in the European-American colonial and postcolonial periphery.

Evaluation of the Maquet Neonatal and Pediatric Quadrox I with an integrated arterial line filter during cardiopulmonary bypass

BACKGROUND

Perfusion equipment has evolved since its introduction into clinical practice more than fifty years ago to include smaller cardiopulmonary bypass (CPB) circuits and components. Perfusionists are now exploring the function of new oxygenators with an integrated arterial line filter (IALF). The purpose of this trial was to examine the Maquet Quadrox-I Neonatal and Pediatric oxygenators with IALF in a clinical setting, with respect to gas transfer, heat exchange co-efficiency (HEC), trans-membrane pressure (TMP) gradient and clinical experience.

METHODS

The Maquet Quadrox-I Neonatal oxygenator was used on 30 patients ranging from 2.2-13.1 kg. The Maquet Quadrox-I Pediatric oxygenator was used on 15 patients ranging from 12.7-24.5 kg. Arterial and venous blood gases were taken once the patient was stable on CPB and, subsequently, every 30 minutes afterwards, as per institution protocol. The values for gas transfer rates, HEC and TMP gradient were stratified into three main categories with each oxygenator: normothermia, cooling and re-warming.

RESULTS

During all conditions, the gas transfer rate with both oxygenators was efficient. The HEC values showed efficient heat exchanger performance during all conditions with both oxygenators. While maintaining CPB flow within the manufacturer's recommended flow rate for each oxygenator, the TMP gradient range for the Neonatal Quadrox-I was 10-40 mmHg and the Pediatric Quadrox-I was 10-60 mmHg. During the clinical trial, foam was shown to break through the cardiotomy on several occasions when high sucker return was required.

CONCLUSION

This new line of oxygenators performed well with regards to gas transfer, HEC and TMP gradient, but there were clinical experiences that did not meet expectations. There were repeated incidences with the venous reservoir which ultimately cast a negative light on the design of this new product from Maquet. In the future, the authors would like to evaluate updated versions of this product from Maquet and any other pediatric perfusion devices that could help the patient in the clinical arena.

SU-E-T-482: A More Accurate Bare 12 5I Spectrum

PURPOSE

To compare measured energy spectra of ¹²⁵ I brachytherapy seeds with Monte Carlo calculated energy spectra when using the bare ¹²⁵ I energy spectrum recommended by TG43 and the one presented in NCRP Report 58 and to determine the impact of these different spectra on the calculation of the dose rate constant.

METHODS

The energy spectrum, absorbed dose at 1 cm on the bisector and air kerma strength of 10 different ¹²⁵ I seeds were calculated using the EGSnrc BrachyDose Monte Carlo code. Energy bin width was 0.2 keV. The simulations were done with the bare ¹²⁵ I energy spectrum recommended by TG43 or NCRP Report 58. Statistical uncertainties for the energy spectra were 0.02% and 0.1% or less for the other clinical parameters. Results are compared with published measuredvalues.

RESULTS

There is close agreement between the measured and calculated branching ratio generated by ¹²⁵ I seeds when simulated using the spectrum presented in NCRP58. However, for all seeds a 7% lower value is observed in the 31 keV peak when using data suggested by TG43. On the other hand, differences in the average energy, air kerma, absorbed dose and dose rate constant are undetectable (less than statistical uncertainty, <0.1%) when performed with either spectrum.

CONCLUSIONS

For dosimetric parameter calculations, the bare ¹²⁵ I energy spectra presented in TG43 and NCRP58 produce indistinguishable results. However, for branching ratio investigation purposes, there is a clear difference in the 31 keV peak between values obtained using the different ¹²⁵ I bare energy spectra. Measured ¹²⁵ I branching ratios are in close agreement with those calculated using the bare ¹²⁵ I energy spectrum presented in NCRP58. Reassessment of the bare ¹²⁵ I energy spectrum recommended in TG43 is suggested.

A systematic evaluation of the core communication skills expected of a perfusionist

Background: The objective of this systematic evaluation was to identify the sentinel standards necessary to obtain a core level of communication required of a clinical perfusionist during cardiopulmonary bypass (CPB). Once these sentinel standards were identified and a core level of communication was established (via four simulated case scenarios), a team of cardiac healthcare professionals was assembled to interpret both the accuracy of response and the speed of response encountered in each case scenario.

Methods: Four simulated case scenarios were utilized in order to replicate the typical patterns of verbal exchange that occur during surgeries using extracorporeal technology. The simulated case scenarios included CPB interactions associated with preparation, initiation, maintenance, termination and post CPB. For all CPB interactions, two variables were measured: accuracy of the perfusionist’s response and speed of the perfusionist’s response. The cases took place in a controlled setting within an empty operating room at The Children’s Hospital of Philadelphia. Four clinical perfusionists each represented the role of the “perfusionist” in all simulated case scenarios.

Results: When analyzing the accuracy and speed of the responses, each clinical perfusionist recorded an average score of 96.3% or higher with all case scenarios. Since the clinical perfusionists who participated in the scenarios were primarily pediatric perfusionists, the scores were best during the pediatric case scenario, 99.3% (Case Scenario #4). The lowest scores were captured during Case Scenario #3 (96.3%) which involved a more intense adult patient scenario.

Conclusion: The systematic evaluation of both response accuracy and response time (presented in various adult and pediatric patient case scenarios) can be beneficial within the realm of perfusion education. Students will be introduced to core communication concepts within the clinical realm. This study supports the idea that simulation and evaluation may ease the transition for students from the didactic to clinical realm in terms of communication. Further studies need to be developed in order to define “standard” CPB communication guidelines for perfusion students.

Multi-format all-optical processing based on a large-scale, hybridly integrated photonic circuit

We investigate through numerical studies and experiments the performance of a large scale, silica-on-silicon photonic integrated circuit for multi-format regeneration and wavelength-conversion. The circuit encompasses a monolithically integrated array of four SOAs inside two parallel Mach-Zehnder structures, four delay interferometers and a large number of silica waveguides and couplers. Exploiting phase-incoherent techniques, the circuit is capable of processing OOK signals at variable bit rates, DPSK signals at 22 or 44 Gb/s and DQPSK signals at 44 Gbaud. Simulation studies reveal the wavelength-conversion potential of the circuit with enhanced regenerative capabilities for OOK and DPSK modulation formats and acceptable quality degradation for DQPSK format. Regeneration of 22 Gb/s OOK signals with amplified spontaneous emission (ASE) noise and DPSK data signals degraded with amplitude, phase and ASE noise is experimentally validated demonstrating a power penalty improvement up to 1.5 dB.