COVID-19 DIAGNOSIS BY POINT OF CARE LUNG ULTRASOUND: A NOVEL DEEP LEARNING ARTIFICIAL INTELLIGENCE METHOD

BACKGROUND

METHODS AND RESULTS

CONCLUSION

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Quantum efficiency of black silicon photodiodes at VUV wavelengths

Black silicon (b-Si) is an emerging material made by modifying silicon with nanostructures for improved photon detection. It has been demonstrated that when used in photodetectors b-Si significantly improves photon detection and extends spectral sensitivity from NIR to the visible wavelengths. However, no data have been reported in the Vacuum Ultraviolet (VUV) range, which is increasingly becoming important for many applications. Here, we have measured the spectral response of n-type b-Si light-trapping photodiodes under VUV radiation at ambient and cryogenic temperatures. The device exhibited a near-unity quantum efficiency above the 1.1 eV intrinsic bandgap of silicon. Quantum efficiency increased linearly with photon energy above the electron-hole pair creation energy of silicon ∼3.6 eV and the device had a responsivity of 0.2 A/W at 175 nm at room temperature in vacuum. These results demonstrate new technology in UV detection and could pave way for the development of a high quantum efficiency black silicon photomultiplier device (b-SiPM) needed for direct VUV photon detection in noble gas and liquid scintillating detectors.

P959 Handheld echocardiography in a real world scenario: concordances compared to standard echo reports

Background

Handheld echocardiography devices(HH) arise as a common tool in clinical examination and screening for various cardiovascular disorders. Despite of it, studies with this method are small, with unselected patients and limited scope of diagnostic comparison.

Purpose

Assess the usefulness of the new miniaturized HH and compare its concordances with the standard high definition echocardiography study(STD).

Methods

Between April and May of 2016 adult patients who were scheduled to regular STD, were also submitted to a HH exam. Experienced sonographers performed and an experienced echocardiographer reviewed the STD exam, and an experienced echocardiographer performed and reviewed the HH study - reviewers were blinded to the other study results. STD exams included 2-dimensional images, Color Doppler and hemodynamics analysis. With the HH hemodynamic assessment was not performed as the machine does not include such technology. Agreement between the reports was analyzed.

Results

110 patients were included. Mean age was 62.4 ± 16.7 years. The κ values(Table) show good correlation between HH and STD on the analysis of left ventricular global and segment functions, right ventricle size and function, mitral and aortic stenosis. On the evaluation of left ventricle hypertrophy, mitral and aortic regurgitations the correlation was modest, while poor correlation was found for pulmonary and tricuspid regurgitations.

Conclusion

In a daily practice scenario with experienced hands, HH demonstrates good results for the assessment of ventricles size and function, while the evaluation of right heart valves was the least reliable performance. Dissemination of HH should occur with considerations and caution.

K Values for Echocardiography Analysis Echocardiography analysis K value Global estimated LV dysfunction 0.85 Wall motion abnormalities 0.78 LV hypertrophy 0.6 RV size 0.83 RV function 0.82 Mitral regurgitation 0.42 Aortic regurgitation 0.56 Mitral stenosis 0.96 Aortic stenosis 0.82 Tricuspid regurgitation 0.26 Pulmonary regurgitation 0.25 LV: left ventricle; RV: right ventricle.

Correction to "Automatic Quality Assessment of Echocardiograms Using Convolutional Neural Networks: Feasibility on the Apical Four-Chamber View"

In the above paper [1], the first footnote should have indicated the following information: A. H. Abdi and C. Luong are joint first authors.

Correlation of gastric heterotopia and Meckel's diverticular bleeding in children: a unique association

PURPOSE

Meckel's diverticular bleeding is the commonest cause of major gastrointestinal (GI) haemorrhage in children. We hypothesise that gastric heterotopia (GH) is associated with increased risk of bleeding and, therefore, may affect initial management.

METHODS

Paediatric patients with histological diagnosis of Meckel's diverticulum (MD) following diverticulectomy from 1995 to 2011 were reviewed retrospectively, focusing on histological correlation to bleeding. GH identified on histology was regarded as GH+, and where GH was not found was regarded as GH-. Two-tailed Chi-square test and Fisher's exact test were used, p < 0.05 was statistically significant.

RESULTS

Thirty-nine patients underwent Meckel's diverticulectomy. The number of patients with GH+, GH-, and bowel necrosis were 21, 15, and 3. Eighteen children with MD had GI bleeding. GI bleeding was more commonly associated with GH+ (14/21) than GH- (4/15) (67 vs 27 %, p = 0.02). Further analysis revealed all four GH- bleeding originated from other sources than the MD. GH+ had no significant association with other presentations. GH+ was present in 8/8 (100 %) positive Meckel's scans and 2/5 (40 %) negative scans. Meckel's scan had a sensitivity of 8/10 (80 %), and specificity of 3/3 (100 %).

CONCLUSION

This study confirmed that GH positive MD is a unique entity presenting typically with GI bleeding.

Management of boys with abnormal appearance of meatus at circumcision for balanitis xerotica obliterans

INTRODUCTION

The aim of this study was to develop a standardised management plan for boys with abnormal appearance of meatus at circumcision for balanitis xerotica obliterans (BXO).

METHODS

Between 1995 and 2008, 107 boys underwent circumcision for BXO (confirmed on histology). Of these, 23 had abnormal appearance of the meatus at operation; their case notes were reviewed for age, presenting symptoms, management, outcome and follow up.

RESULTS

The age range at operation was 3-15 years (mean: 9 years). Patients commonly presented with phimosis and balanitis. Seven patients had an additional procedure at circumcision: six had meatotomy, one had meatal dilatation. Thirteen were treated with topical steroid cream post-operatively. Eight of these (62%) subsequently required meatotomy. Three patients were observed and did not require further intervention. Meatotomy was required in 9 patients, 6-29 months after circumcision (mean: 11 months). Two patients required dilatation, including one with a previous intraoperative meatotomy, who required multiple dilatations.

CONCLUSIONS

We propose the following standardised management plan: 1. With clinical evidence of BXO at circumcision, prepuce should be sent for histology. 2. If BXO is confirmed but the meatus appears normal, patients should be seen once post-operatively to give information about meatal stenosis. 3. When the meatus appears scarred with a narrowed lumen at operation, a meatotomy should be performed, with follow up for at least two years. 4. If the lumen is scarred but adequate, patients should be followed up in clinic for the same period for possible development of stenosis. 5. Topical steroid cream can be considered for voiding discomfort without decreased urine stream.

Laparoscopic repair of Amyand's hernia in an 8-week-old infant

Amyand's hernia is a rare type of hernia in which the appendix is found in the inguinal canal. A case of an 8-week-old boy who was diagnosed and managed laparoscopically is presented. To the authors' knowledge, this is the first report of emergency laparoscopic surgery for an Amyand's hernia in a young infant.

Optical beam profile monitor and residual gas fluorescence at the relativistic heavy ion collider polarized hydrogen jet

A gas fluorescence beam profile monitor has been implemented at the relativistic heavy ion collider (RHIC) using the polarized atomic hydrogen gas jet, which is part of the polarized proton polarimeter. RHIC proton beam profiles in the vertical plane of the accelerator are obtained as well as measurements of the width of the gas jet in the beam direction. For gold ion beams, the fluorescence cross section is sufficiently large so that profiles can be obtained from the residual gas alone, albeit with long light integration times. We estimate the fluorescence cross sections that were not known in this ultrarelativistic regime and calculate the beam emittance to provide an independent measurement of the RHIC beam. This optical beam diagnostic technique, utilizing the beam induced fluorescence from injected or residual gas, offers a noninvasive particle beam characterization and provides visual observation of proton and heavy ion beams.

Optical diagnostics of mercury jet for an intense proton target

An optical diagnostic system is designed and constructed for imaging a free mercury jet interacting with a high intensity proton beam in a pulsed high-field solenoid magnet. The optical imaging system employs a backilluminated, laser shadow photography technique. Object illumination and image capture are transmitted through radiation-hard multimode optical fibers and flexible coherent imaging fibers. A retroreflected illumination design allows the entire passive imaging system to fit inside the bore of the solenoid magnet. A sequence of synchronized short laser light pulses are used to freeze the transient events, and the images are recorded by several high speed charge coupled devices. Quantitative and qualitative data analysis using image processing based on probability approach is described. The characteristics of free mercury jet as a high power target for beam-jet interaction at various levels of the magnetic induction field is reported in this paper.

Experimental characterization of superradiance in a single-pass high-gain laser-seeded free-electron laser amplifier

In this Letter we report the first experimental characterization of superradiance in a single-pass high-gain free-electron laser (FEL) seeded by a 150 femtosecond (FWHM) Ti:sapphire laser. The nonlinear energy gain after an exponential gain regime was observed. We also measured the evolution of the longitudinal phase space in both the exponential and superradiant regimes. The output FEL pulse duration was measured to be as short as 81 fs, a roughly 50% reduction compared to the input seed laser. The temporal distribution of the FEL radiation as predicted by a numerical simulation was experimentally verified for the first time.

Induced sputum inflammatory measures correlate with disease severity in children with obstructive sleep apnoea

OBJECTIVE

To establish the association between airway inflammation and severity of obstructive sleep apnoea (OSA) in children.

METHODS

Consecutive children presenting with symptoms suggestive of OSA were recruited. They completed a sleep apnoea symptom questionnaire, underwent physical examination, spirometry, sputum induction and an overnight polysomnography. Adequate sputum contained <50% squamous epithelial cells, and OSA was diagnosed if the obstructive apnoea index was >1.

RESULTS

73 children with a median (interquartile range (IQR)) age of 11.3 (10.0-13.2) years were recruited. There were 21 girls and the median body mass index of the group was 24.0 (18.0-27.0) kg/m2. The most common presenting symptoms were habitual snoring, mouth breathing and prone sleeping position. Sputum induction was successful in 43 (59%) children, of whom 14 were found to have OSA. Children with OSA had significantly greater percentage sputum neutrophil than those without OSA (18.5 (IQR 8.0-42.0) v 4 (IQR 3.0-11.3), p = 0.006). On multiple regression analysis, percentage sputum neutrophil was significantly associated with OSA (odds ratio = 1.1, p = 0.013).

CONCLUSION

Children with OSA had airway inflammation characterised by a marked increase in neutrophils. Further studies are needed to confirm these findings and to better define the downstream cellular interactions and molecular pathogenesis in childhood OSA.

The six-minute walk test in healthy children: reliability and validity

The aim of this study was to assess the reliability and validity of the 6-min walk test (6MWT) in healthy children. Chinese secondary school students were randomly recruited. They attended the current authors' unit on two occasions, separated by 2 weeks. Physical examination and standardised maximum incremental exercise testing on a treadmill were performed on the first visit. Spirometry and 6MWT were carried out on the second visit. A randomly selected subgroup was invited to return for repeat 6MWT at an interval of 2-4 weeks. Seventy-eight subjects were recruited; however, four failed to achieve maximal effort on exercise test. The final group included 43 young females and the mean+/-sd age of the subjects was 14.2+/-1.2 yrs. Physical examination was unremarkable in all cases. The mean+/-sd per cent predicted forced expiratory volume in one second was 91.4+/-10.2%. Concurrent validity was demonstrated by good correlation between the 6-min walking distance and maximum oxygen uptake determined on the exercise treadmill. Test-retest reliability was undertaken in 52 subjects, and the intraclass correlation coefficient (95% confidence interval) was calculated as 0.94 (0.89-0.96). In addition, Bland and Altman plots demonstrated a high degree of repeatability. In healthy children, the 6-min walk test is a reliable and valid functional test for assessing exercise tolerance and endurance.

Urinary retention in an abnormal preputial pouch of a 6-month-old boy

Images

Frequency-resolved optical-gating measurements of ultrashort pulses using surface third-harmonic generation

We demonstrate what is to our knowledge the first frequency-resolved optical gating (FROG) technique to measure ultrashort pulses from an unamplified Ti:sapphire laser oscillator without direction-of-time ambiguity. This technique utilizes surface third-harmonic generation as the nonlinear-optical effect and, surprisingly, is the most sensitive third-order FROG geometry yet.

Omphalocele and pericardial effusion: possible sonographic markers for the pentalogy of Cantrell or its variants

BACKGROUND

The pentalogy of Cantrell consists of defects involving the diaphragm, abdominal wall, pericardium heart, and lower sternum.

CASES

We report three cases of the pentalogy of Cantrell (variant form), involving an omphalocele complicated by an anterior diaphragmatic hernia. In two cases, a pericardial effusion was noted at antenatal scanning; the case without a pericardial effusion had an intact diaphragmatic pericardium at surgical repair.

CONCLUSION

The presence of a pericardial effusion in association with an omphalocele should prompt a detailed search for other features of the pentalogy of Cantrell or its variants.

Patterns of practice in emergency department management of chest pain of suspected cardiac origin: clinical utility of single stat creatine kinase (CK)

The patterns of practice and the clinical utility of a single stat creatine kinase (CK) level in the emergency department management of chest pain of suspected cardiac origin were examined by a prospective observational study using a two-part questionnaire, completed by physicians before and after availability of CK results. The results showed that of the 776 patients in the study, 135 were admitted to hospital with acute myocardial infarction (AMI), 285 were admitted for reasons other than AMI, 343 were discharged, and 13 died or were transferred to another hospital. Although initial and final diagnoses in the emergency department did not differ in 597 patients (77%), initial decisions to admit or discharge were made in only 244 (31%) patients without waiting for CK results, and in 401 (52%) cases, decisions on patient disposition were deferred. Of 218 patients who had elevated CK levels, 193 (89%) were admitted, 121 for AMI. Only five (< 1%) patients who would otherwise have been discharged were admitted because of elevated CK levels. Of the 343 discharges, 245 (71%) occurred after the physicians knew the CK results. It is concluded that emergency department physicians routinely make changes in their diagnostic and management decisions based on current information and as it becomes updated. This study also suggests that there appears to be a heavy reliance on a single CK assay, although the relative importance of this diagnostic test compared to other factors is not known. Further studies are necessary.

Reflected optical harmonics from dielectric mirrors

Optical second and third harmonics were generated in reflection from commercially available laser dielectric mirrors. Although most dielectric coatings on laser mirrors are centrosymmetric, the inversion symmetry is broken at the dielectric-air interface. When intense femtosecond laser pulses are reflected off the dielectric mirrors, a second-order dipole contribution to surface second-harmonic generation can exist and is detected. More dramatically, at a laser fluence of ∼10 GW/cm(2) the normally much weaker electric-dipole-allowed third-harmonic generation that originated in the bulk accentuates the second-harmonic generation. These reflected harmonics are, in some cases, nonnegligible in many sensitive experiments.

Hereditary multiple intestinal atresia--ultrasound findings and outcome of pregnancy in an affected case

A case of multiple intestinal atresia is described. Dilatation of the bowel was observed at 17 weeks' gestation during routine ultrasound scan of a healthy Caucasian primigravida from a non-consanguineous marriage. Amniocentesis was performed. The karyotype was normal male and cystic fibrosis screening was negative. Regular scans were performed throughout the pregnancy and a simple bowel obstruction was suspected. The baby was delivered at 37 weeks' gestation in good condition. Initial clinical examination was normal but abdominal distension developed during the first day. At laparotomy, prepyloric septal atresia, a distal duodenal membrane, and multiple intestinal atresia were found. The baby died aged 4 days. Post-mortem examination of the abdomen confirmed the absence of lumen from long segments of the small intestine together with areas of colonic atresia. Histology and distribution were consistent with those reported in familial multiple intestinal atresia. The pitfalls in the interpretation of prenatal ultrasound scans and the possibility of prenatal diagnosis in future pregnancies are discussed.