COVID-19 SAFETY MEASURES AND THEIR EFFECTS ON GAMBLING HABITS: AN INVESTIGATIVE STUDY

This study looked at the way COVID-19 was starting to affect gambling during first six weeks of emergency actions. The following factors were evaluated: the economic effect of COVID-19 on internet gambling, according to COVID-19, psychological issues, addiction to drugs, and risky gambling habits and intentions. Online survey with cross-sectional data of 2015 gamblers was conducted, with a subsample of 1048 people who gambled online (age 18 and older). Numerous metrics of correlation and probability ratio analyses were performed. The Issue of Gambling Intensity Index's extremely dangerous gamblers and those who have gambled online are more likely to engage in gambling online, according to the outcomes, even though there was an obvious transition toward physical gaming. The most predicted indicators for high-risk gamblers on the internet were moderate to severe depression and anxiety, reduced work weeks, convincing themselves to gamble by COVID-19, gambling under the effects of alcohol or cannabis, and dangerous gambling motivations related to psychological disorders, such as gambling to relieve anxiety and depressive disorders, chasing gambling damages, and trying to make money from gambling. This research has validated numerous risk connections associated with gambling risk, psychological issues, and substance use reported in previous studies on the worldwide recession and upcoming COVID-19-related investigations. In contrast to many other inquiries, the current research considers each component comprehensively. It offers more information on the risk factors associated with online gambling throughout the epidemic.

Adding to her woes: child bride's higher risk of hypertension at young adulthood

BACKGROUND

Child marriage is associated with various adverse socio-economic and pregnancy outcomes. However, there remains a dearth of research on the long-term health implications of child marriage. As such, this study sought to expand upon the growing literature on child marriage, specifically examining the associations between child marriage and hypertension during young adult age.

METHODS

We obtained data of 5369 women aged 20-34 from the Tajikistan Demographic and Health Survey 2017. Using multivariable logistic regression framework, we estimated the adjusted odds in favor of being hypertensive for women who were married before the age of 18. We also explored the presence of several stressors to understand the role of probable medication factors.

RESULTS

We found that the odds of being hypertensive for young adult women married before the age of 18 were 1.6 (95% confidence interval: 1.1-2.4) times that of those who were not. Likelihood of having stressors, such as pregnancy loss or child death, marital control and spousal violence, was found higher among child brides compared to their peers.

CONCLUSIONS

Findings suggest that child marriage may increase the risk of hypertension among young adult women. This work reinforces recommendations by the United Nations to the end child marriage.

SIR-Spheres activity measurements reveal systematic miscalibration

Purpose: Accurate dosimetry-guided radiopharmaceutical therapy fundamentally relies on knowledge of the quantity of radioactivity administered to patients. The purpose of this work was to perform an independent and NIST-traceable activity measurement of ⁹⁰Y SIR-Spheres®. Methods: Gamma spectroscopic measurements of the ⁹⁰Y internal pair production decay mode were made using a high-purity germanium detector. Un-modified patient SIR-Spheres® vials were placed within a high-density polyethylene source holder positioned at a distance of 210 cm from the detector, with acquisition durations of 3 - 6 hours. Measured annihilation radiation detection rates were corrected for radioactive decay during acquisition, dead time, source attenuation, and source geometry effects. Detection efficiency was determined by two independent and NIST-traceable methods. Resulting ⁹⁰Y activity measurements were compared against the manufacturer activity calibration. Results: Measured SIR-Sphere® vials (n = 5) were found to contain more activity than specified by the manufacturer calibration - on average the ratio of measured activity to calibrated was 1.233 ± 0.030. Activity measurements made using two distinct efficiency calibration methods were found to agree within 1%. Uncertainty in individual measurements was dominated by counting statistical uncertainty (~2.5%), uncertainty in the internal pair production branching ratio of ⁹⁰Y (1.5%), and efficiency calibration (1.2% - 1.9%). Conclusion: The primary SIR-Spheres® activity calibration appears to be a significant underestimate of true activity. This mis-calibration has likely been consistent for as long as the SIR-Sphere® product has been available. This finding should be independently verified, and steps should be taken by the manufacturer to establish an accurate and traceable activity standard.

Molecular detection of Salmonella isolated from commercial chicken

BACKGROUND

Salmonella in chicken, specially, the motile salmonellae, causes the food chain unsafe from farm to table and is considered a significant global threat to public health.

AIMS

The present study was carried out for molecular detection of Salmonellae in commercial poultry using PCR.

METHODS

The study was conducted for eight months, from July 2019 to February 2020, and a total of 26 poultry farms, including 15 broiler and 11-layer farms, were visited individually. Pooled faecal samples were obtained from the sheds. A total of 189 necropsy cases were examined for gastrointestinal lesions. Isolation and identification of the organism were done using microbe culture method, and the molecular characterization was performed via PCR targeting invA and ent genes.

RESULTS

The prevalence of salmonellosis in the broiler and layer farms was recorded at 20.0% and 45.4%, respectively, through the traditional gold standard culture method. From 189 necropsy birds, salmonellosis was recorded at 1.58% dead cases. Molecular detection of Salmonella isolates by PCR targeting invA gene was confirmed in 13.33% of the broiler farms and 36.3% of the layer farms. Further detection of Salmonella enteritidis was performed by PCR targeting ent gene by which 11.11% positivity was determined.

CONCLUSION

This study, focused on the Salmonella prevalence, highlighted the zoonotic importance of the bacterium in the commercial poultry farms, which can subsequently be dispersed into the human food chain causing harmful health effects.

Monte Carlo evaluation of hypothetical long axial field-of-view PET scanner using GE discovery MI PET front-end architecture

PURPOSE

The development of total-body PET scanners is of growing interest in the PET community. Investigation into the imaging properties of a hypothetical extended axial field-of-view (AFOV) GE Healthcare SiPM-based Discovery MI (DMI) system architecture has not yet been performed. In this work, we assessed its potential as a whole-body scanner using Monte Carlo simulations. The aim of this work was to (1) develop and validate a Monte Carlo model of a 4-ring scanner and (2) extend its AFOV up to 2 m to evaluate performance gain through NEMA-based evaluation.

METHODS

The DMI 4-ring geometry and its pulse digitization scheme were modeled within the GATE Monte Carlo platform using published literature. The GATE scanner model was validated by comparing results against published NEMA performance measurements. Following the validation of the 4-ring model, the model was extended to simulate 8, 20, 30, and 40-ring systems. Spatial resolution, sensitivity, NECR, and scatter fraction were characterized with modified NEMA NU-2 2018 standards; however, the image quality measurements were not acquired due to computational limitations. Spatial resolutions were simulated for all scanner ring configurations using point sources to examine the effects of parallax errors. NEMA count rates were estimated using a standard 70 cm scatter phantom and an extended version of scatter phantom of length 200 cm with (1-800) MBq of ¹⁸ F for all scanners. Sensitivity was evaluated using NEMA methods with a 70 cm standard and a 200 cm long line source.

RESULTS

The average FWHM of the radial/tangential/axial spatial resolution reconstructed with filtered back-projection at 1 and 10 cm from the scanner center were 3.94/4.10/4.41 mm and 5.29/4.89/5.90 mm for the 4-ring scanner. Sensitivity was determined to be 14.86 cps/kBq at the center of the FOV for the 4-ring scanner using a 70 cm line source. Sensitivity enhancement up to 21-fold and 60-fold were observed for 1 m and 2 m AFOV scanners compared to 4-ring scanner using a 200 cm long line source. Spatial resolution simulations in a 2 m AFOV scanner suggest a maximum degradation of ∼23.8% in the axial resolution compared to the 4-ring scanner. However, the transverse resolution was found to be relatively constant when increasing the axial acceptance angle up to ±70°. The peak NECR was 212.92 kcps at 22.70 kBq/mL with a scatter fraction of 38.9% for a 4-ring scanner with a 70 cm scatter phantom. Comparison of peak NECR using the 200 cm long scatter phantom relative to the 4-ring scanner resulted in a NECR gain of 15 for the 20-ring and 28 for the 40-ring geometry. Spatial resolution, sensitivity, and scatter fraction showed an agreement within ∼7% compared with published measured values.

CONCLUSIONS

The 4-ring DMI scanner simulation was successfully validated against published NEMA measurements. Sensitivity and NECR performance of extended 1 and 2 meters AFOV scanners based upon the DMI architecture were subsequently simulated. Increases in sensitivity and count-rate performance are consistent with prior simulation studies utilizing extensions of the Siemens mCT architecture and published NEMA measurements with the uEXPLORER system. This article is protected by copyright. All rights reserved.

Malaria, COVID-19 and angiotensin-converting enzyme 2: what does the available population data say?

The etiopathogenesis of COVID-19 and its differential geographic spread suggest some populations are apparently 'less affected' through many host-related factors that involve angiotensin-converting enzyme 2 (ACE2) protein, which is also the entry receptor for SARS-CoV-2. The role of ACE2 has been well studied in COVID-19 but not in the context of malaria and COVID-19. We have previously suggested how malaria might intersect with COVID-19 through ACE2 mutation and here we evaluate the currently available data that could provide a link between the two diseases. Based on the existing global and Indian data on malaria, COVID-19 and the suggested ACE2 mutation, the association could not be examined robustly, neither accepting nor refuting the suggested hypothesis. We strongly recommend targeted evaluation of this hypothesis through carefully designed robust molecular epidemiological studies.

POS1331 LONG-TERM OUTCOME IN CHILDREN WITH JUVENILE DERMATOMYOSITIS FROM SOUTHERN INDIA

Background:

There is paucity of data regarding long-term outcome and cumulative damage in children with juvenile dermatomyositis (JDM) from the Indian subcontinent.

Objectives:

To assess the long-term outcome and cumulative damage in children with JDM receiving treatment at a tertiary hospital in southern India.

Methods:

Retrospective review of records and cross-sectional assessment of outcome and damage in 29 patients with JDM at a tertiary hospital in Kochi, India. The disease course was categorized as monocyclic, polycyclic and chronic progressive. Cumulative damage was assessed using the IMACS myositis damage index (MDI).

Results:

Twenty-nine patients (male-16) diagnosed with definite or probable juvenile dermatomyositis based on the Bohan and Peter criteria and having a minimum follow-up period of 3 years each were enrolled. Of these, 20 children were diagnosed and initiated on treatment at our institute (inceptional) and 9 were diagnosed elsewhere and referred to our centre for further management (non-inceptional). The mean age at disease onset was 7.01 ± 3.34 years (range 1.0 to 13.5 years). The median interval from onset to diagnosis was 3 months (range- 3 weeks to 8.75 years). Delayed diagnosis defined as interval from onset to diagnosis exceeding 6 months was noted in case of 8 children. Among patients in the non-inceptional group, six were considered to have not received standard of care treatment prior to referral to our centre. Standard of care treatment was defined as initiation of a treatment regimen comprising of a combination of glucocorticoids with an immunosuppressive agent within 4 weeks of diagnosis. A total of 11 children had a delayed diagnosis and/or had not received standard of care treatment prior to referral.

At our centre, all patients received oral steroids and subcutaneous methotrexate as standard therapy. Pulse steroids were used to induce remission in 12 patients and as a rescue for relapses in 2 patients. Intravenous immunoglobulin was used in 10 children with severe myositis, oropharyngeal weakness, refractory cutaneous disease including calcinosis and concomitant infection, where affordable with good results. Hydroxychloroquine was added in 15 patients with dominant cutaneous manifestations. Mycophenolate mofetil, azathioprine and tacrolimus were used in patients refractory or intolerant to methotrexate. Cyclophosphamide and rituximab were used in 4 patients each with refractory disease and extra-muscular manifestations such as interstitial lung disease. Seven patients with refractory calcinosis received pamidronate infusions.

The total follow-up duration was 121.06 patient-years. A monocyclic course was observed in 11/29 (37.9%), chronic progressive course in 16/29 (55.2%) and polycyclic course in 2/29(6.9 %). Nearly half of the patients (14/29) had damage in at least one organ using the MDI (MDI ≥1). 38% of the patients (11/29) had at least one sign of cutaneous damage, the most common being calcinosis (n=11) and lipodystrophy (n=4). This was followed by skeletal damage (n=6, joint contractures-5, osteoporosis with fracture-1), muscle and pulmonary (pulmonary fibrosis) damage in 3 patients each, endocrine damage in 2 patients (diabetes mellitus-1, growth failure and delayed development of secondary sexual characteristics-1) and chronic infection in one patient. All patients with damage in at least one organ had a chronic progressive course, indicating damage accrual. Delayed diagnosis and lack of standard of care treatment prior to referral (i.e., longer duration of untreated/ sub-optimally treated disease) were associated with an increased risk of cumulative damage (p< 0.05).

Conclusion:

Nearly half of the patients had damage in at least one organ using the MDI. Cutaneous damage was the most common, followed by skeletal, muscle, pulmonary and endocrine damage. Longer duration of untreated/ sub-optimally treated disease significantly increases the risk of cumulative damage, highlighting the need for an early diagnosis and referral to pediatric rheumatology services.

Disclosure of Interests:

None declared

Should COVID-19 patients >75 years be Ventilated? An Outcome Study

BACKGROUND

Elderly patients with COVID-19 disease are at increased risk for adverse outcomes. Current data regarding disease characteristics and outcomes in this population are limited.

AIM

To delineate the adverse factors associated with outcomes of COVID-19 patients ≥75 years of age.

DESIGN

Retrospective cohort study.

METHODS

Patients were classified into mild/moderate, severe/very severe and critical disease (intubated) based on oxygen requirements. The primary outcome was in-hospital mortality.

RESULTS

A total of 355 patients aged ≥75 years hospitalized with COVID-19 between 19 March and 25 April 2020 were included.Mean age was 84.3 years. One-third of the patients developed critical disease. Mean length of stay was 7.10 days. Vasopressors were required in 27%, with the highest frequency in the critical disease group (74.1%). Overall mortality was 57.2%, with a significant difference between severity groups (mild/moderate disease: 17.4%, severe/very severe disease: 71.3%, critical disease: 94.9%, P < 0.001).Increased age, dementia, and severe/very severe and critical disease groups were independently associated with increased odds for mortality while diarrhea was associated with decreased odds for mortality (OR: 0.12, 95% CI: 0.02-0.60, P < 0.05). None of the cardiovascular comorbidities were significantly associated with mortality.

CONCLUSION

Age and dementia are associated with increased odds for mortality in patients ≥75 years of age hospitalized with COVID-19. Those who require intubation have the greatest odds for mortality. Diarrhea as a presenting symptom was associated with lower odds for mortality.

POS1262 A COHORT STUDY OF COVID-19 RELATED MULTISYSTEM INFLAMMATORY SYNDROME IN CHILDREN AND ADOLESCENTS FROM MULTIPLE TERTIARY CARE CENTRES IN SOUTH INDIA

Background:

After the peak of COVID 19 pandemic, a surge of cases with multi-system involvement and hyperinflammatory state was reported in children, at multiple tertiary care centers across the world. (1) This COVID-19 associated multisystem inflammatory syndrome in children and adolescents is also known as multisystem inflammatory syndrome in children (MIS-C). There is a paucity of literature of clinical profile of MIS-C patients from India.

Objectives:

To study the clinical manifestations and treatment outcomes of COVID-19 related multisystem inflammatory syndrome in children (MIS-C) and adolescents.

Methods:

It was a cohort study including cases defnied as per the case definitions of MIS-C by World Health Organisation (WHO) or Centre for Disease Control and Prevention(CDC).(2)The clinical parameters, laboratory parameters (including inflammatory markers, D dimer and NT ProBNP), electrocardiogram, 2D echocardiogram, course in hospital, and immediate outcomes were noted.

Results:

Twenty five patients (male-14) with a mean age of 6.22 ±4.25 years and a mean body mass index of 16.21 ±3.36 kg/m2 were enrolled on the study. Average length of hospital stay was 8.12±5.76 days. Associated comorbidities were present in 4 of our patients (16%). Figure 1 shows the frequency of clinical features in our study patients. Table 1 shows the clinical, laboratory, imaging findings, disease course and outcomes.

Figure 1.

Frequency of clinical features in our MIS-C cohort patients

Table 1.

Clinical characteristics of MIS-C patients (n)=25

Clinical Phenotypes:Incomplete/ Atypical Kawasaki Disease (KD)18 (72%)Macrophage activation syndrome (MAS)11 (44%)Unexplained Shock13 (52%)Fever with gastrointestinal symptoms17 (68%)Fever with neurological symptoms9 (36%)Fever with respiratory symptoms5 (20%)COVID chronology:MISC with acute COVID 19 with MAS1 (4%)MISC with acute COVID 19 with incomplete/atypical KD1 (4%)COVID 19 tests:COVID 19 RTPCR positive2 (8%)COVID 19 RTPCR negative23 (92%)COVID 19 IgG positive20 (80%)COVID 19 IgM positive6 (24%)COVID 19 IgG and IgM both positive2 (8%)COVID 19 IgG and IgM not done4 (16%)Other laboratory investigations(Peak/ trough values):Anaemia20 (80%)Leukopenia2 (8%)Thrombocytopenia6 (24%)Pancytopenia2 (8%)Positive CRP23 (92%)High Procalcitonin9 (36%)High ferritin10 (40%)High D- dimer17 (68%)High NT ProBNP23 (92%)Hypoalbuminemia14 (56%)Sterile pyuria7 (28%)Proteinuria4 (16%)Cardiac assessment:Abnormal Electrocardiogram (ECG)5 (20%)Abnormal Echocardiography15 (60%)Coronary dilation/prominence/non-tapering9 (36%)Coronary aneurysm1 (4%)LAD Z score (Mean±SD)2.12 ± 1.11Decreased Ejection fraction (EF)5 (20%)Systolic Dysfunction5 (20%)Pericardial effusion9 (36%)Global/septal hypokinesia4 (16%)Mitral Valve regurgitation3 (12%)Complete heart block1 (4%)

Twenty patients (80%) had severe illness requiring intensive care. Fourteen patients (56%) required inotropic support, 8 patients (32%) required supplemental oxygen, 5 patients (20%) required mechanical ventilation and 2 patients (8%) expired. A total of 23 patients (92%) received pulse steroids followed by oral/iv steroids, 22 patients (88%) received IVIG (2g/kg) and 3 patients (12%) required anticoagulation.

Conclusion:

Our MIS-C cohort had varied clinical manifestations ranging from the mild cutaneous and gastrointestinal symptoms to fatal multiorgan dysfunctions. In contrast to western cohorts, our study cohort had higher number of patients from younger age group and lower BMI.

References:

[1]Ahmed M, Advani S, Moreira A, Zoretic S, Martinez J, Chorath K et al. Multisystem inflammatory syndrome in children: A systematic review. EClinicalMedicine. 2020;26:100527.

[2]Jiang L, Tang K, Levin M, Irfan O, Morris S, Wilson K et al. COVID-19 and multisystem inflammatory syndrome in children and adolescents. The Lancet Infectious Diseases. 2020;20(11):e276-e288.

Disclosure of Interests:

None declared

Cerebral Venous Thrombosis in COVID-19: A New York Metropolitan Cohort Study

BACKGROUND AND PURPOSE

Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection is associated with hypercoagulability. We sought to evaluate the demographic and clinical characteristics of cerebral venous thrombosis among patients hospitalized for coronavirus disease 2019 (COVID-19) at 6 tertiary care centers in the New York City metropolitan area.

MATERIALS AND METHODS

We conducted a retrospective multicenter cohort study of 13,500 consecutive patients with COVID-19 who were hospitalized between March 1 and May 30, 2020.

RESULTS

Of 13,500 patients with COVID-19, twelve had imaging-proved cerebral venous thrombosis with an incidence of 8.8 per 10,000 during 3 months, which is considerably higher than the reported incidence of cerebral venous thrombosis in the general population of 5 per million annually. There was a male preponderance (8 men, 4 women) and an average age of 49 years (95% CI, 36-62 years; range, 17-95 years). Only 1 patient (8%) had a history of thromboembolic disease. Neurologic symptoms secondary to cerebral venous thrombosis occurred within 24 hours of the onset of the respiratory and constitutional symptoms in 58% of cases, and 75% had venous infarction, hemorrhage, or both on brain imaging. Management consisted of anticoagulation, endovascular thrombectomy, and surgical hematoma evacuation. The mortality rate was 25%.

CONCLUSIONS

Early evidence suggests a higher-than-expected frequency of cerebral venous thrombosis among patients hospitalized for COVID-19. Cerebral venous thrombosis should be included in the differential diagnosis of neurologic syndromes associated with SARS-CoV-2 infection.

Unconventional Transverse Transport above and below the Magnetic Transition Temperature in Weyl Semimetal EuCd_{2}As_{2}

As exemplified by the growing interest in the quantum anomalous Hall effect, the research on topology as an organizing principle of quantum matter is greatly enriched from the interplay with magnetism. In this vein, we present a combined electrical and thermoelectrical transport study on the magnetic Weyl semimetal EuCd_{2}As_{2}. Unconventional contribution to the anomalous Hall and anomalous Nernst effects were observed both above and below the magnetic transition temperature of EuCd_{2}As_{2}, indicating the existence of significant Berry curvature. EuCd_{2}As_{2} represents a rare case in which this unconventional transverse transport emerges both above and below the magnetic transition temperature in the same material. The transport properties evolve with temperature and field in the antiferromagnetic phase in a different manner than in the paramagnetic phase, suggesting different mechanisms to their origin. Our results indicate EuCd_{2}As_{2} is a fertile playground for investigating the interplay between magnetism and topology, and potentially a plethora of topologically nontrivial phases rooted in this interplay.

Imaging and dosimetric characteristics of 67 Cu

In recent years the use of beta-emitting radiopharmaceuticals for cancer therapy has expanded rapidly following development of therapeutics for neuroendocrine tumors, prostate cancer, and other oncologic malignancies. One emerging beta-emitting radioisotope of interest for therapy is ⁶⁷Cu (t_1/2: 2.6 d) due to its chemical equivalency with the widely-established positron-emitting isotope ⁶⁴Cu (t_1/2: 12.7 h). In this work we evaluate both the imaging and dosimetric characteristics of ⁶⁷Cu, as well as producing the first report of SPECT/CT imaging using ⁶⁷Cu. To this end, ⁶⁷Cu was produced by photon-induced reactions on isotopically-enriched ⁶⁸Zn at the Low-Energy Accelerator Facility (LEAF) of Argonne National Laboratory, followed by bulk separation of metallic ⁶⁸Zn by sublimation and radiochemical purification by column chromatography. Gamma spectrometry was performed by efficiency-calibrated high-purity germanium (HPGe) analysis to verify absolute activity calibration and establish radionuclidic purity. Absolute activity measurements corroborated manufacturer-recommended dose-calibrator settings and no radionuclidic impurities were observed. Using the Clinical Trials Network anthropomorphic chest phantom, SPECT/CT images were acquired. Medium energy (ME) SPECT collimation was found to provide the best image quality from the primary 185 keV gamma emission of ⁶⁷Cu. Reconstructed images of ⁶⁷Cu were similar in quality to images acquired using ¹⁷⁷Lu. Recovery coefficients were calculated and compared against quantitative images of ^99mTc, ¹⁷⁷Lu, and ⁶⁴Cu within the same anthropomorphic chest phantom. Production and clinical imaging of ⁶⁷Cu appears feasible, and future studies investigating the therapeutic efficacy of ⁶⁷Cu-based radiopharmaceuticals are warranted.

Cylinder-flat-surface contact mechanics during sliding

Using molecular dynamics we study the dependency of the contact mechanics on the sliding speed when an elastic block (cylinder) with a cos(q_{0}x) surface height profile is sliding in adhesive contact on a rigid flat substrate. The atoms on the block interact with the substrate atoms by Lennard-Jones potentials, and we consider both commensurate and (nearly) incommensurate contacts. For the incommensurate system the friction force fluctuates between positive and negative values, with an amplitude proportional to the sliding speed, but with the average close to zero. For the commensurate system the (time-averaged) friction force is much larger and nearly velocity independent. For both types of systems the width of the contact region is velocity independent even when, for the commensurate case, the frictional shear stress increases from zero (before sliding) to ≈0.1MPa during sliding. This frictional shear stress, and the elastic modulus used, are typical for polydimethylsiloxane rubber sliding on a glass surface, and we conclude that the reduction in the contact area observed in some experiments when increasing the tangential force must be due to effects not included in our model study, such as viscoelasticity or elastic nonlinearity.

Adhesion paradox: Why adhesion is usually not observed for macroscopic solids

The adhesion paradox refers to the observation that for most solid objects no adhesion can be detected when they are separated from a state of molecular contact. The adhesion paradox results from surface roughness, and we present experimental and theoretical results that show that adhesion in most cases is "killed" by the longest-wavelength roughness. In addition, adhesion experiments between a human finger and a clean glass plate were carried out, and for a dry finger no macroscopic adhesion occurred. We suggest that the observed decrease in the contact area with increasing shear force results from nonadhesive finger-glass contact mechanics, involving large deformations of complex layered material.

Absorbed dose distributions from beta-decaying radionuclides: Experimental validation of Monte Carlo tools for radiopharmaceutical dosimetry

PURPOSE

This study aims to experimentally validate the Monte Carlo generated absorbed doses from the beta particles emitted by ⁹⁰ Y and ¹⁷⁷ Lu using radiochromic EBT3 film-based dosimetry.

METHODS

Line sources of ⁹⁰ Y and ¹⁷⁷ Lu were inserted longitudinally through blocks of low-density polyethylene and tissue-equivalent slabs of cortical bone and lung equivalent plastics. Radiochromic film (Gafchromic EBT3) was laser cut to accommodate orthogonal line sources of radioactivity, and the film was sandwiched intimately between the rectangular blocks to achieve charged particle equilibrium. Line sources consisted of plastic capillary tube of length (13 ± 0.1) cm, with 0.42-mm inner diameter and a wall thickness of 0.21 mm. ⁹⁰ Y line sources were prepared from a solution of dissolved ⁹⁰ Y resin microspheres. ¹⁷⁷ Lu line sources were prepared from an aliquot of ¹⁷⁷ Lu-DOTATATE. Film exposures were conducted for durations ranging from 10 min to 38 h. Radiochromic film calibration was performed by irradiation with 6-MV-bremsstrahlung x rays from a calibrated linear accelerator, in accordance with literature recommendations. Experimental geometries were precisely simulated within the GATE Monte Carlo toolkit, which has previously been used for the generation of dose point kernels.

RESULTS

The mean percentage difference between measured and simulated absorbed doses were 5.04% and 7.21% for ⁹⁰ Y and ¹⁷⁷ Lu beta absorbed dose in the range of (0.1-10) Gy. Additionally, 1D gamma analysis using a local 10%/1 mm gamma criterion was performed to compare the absorbed dose distributions. The percentage of measurement points passing the gamma criterion, averaged over all tests, was 93.5%.

CONCLUSIONS

We report the experimental validation of Monte Carlo derived beta absorbed dose distributions for ⁹⁰ Y and ¹⁷⁷ Lu, solidifying the validity of using Monte Carlo-based methods for estimating absorbed dose from beta emitters. Overall, excellent agreement was observed between the experimental beta absorbed doses in the linear region of the radiochromic film and the GATE Monte Carlo simulations demonstrating that radiochromic film dosimetry has sufficient sensitivity and spatial resolution to be used as a tool for measuring beta decay absorbed dose distributions.

The Impact of Tissue Type and Density on Dose Point Kernels for Patient-Specific Voxel-Wise Dosimetry: A Monte Carlo Investigation

We report the generation of dose point kernels for clinically-relevant radionuclide beta decays and monoenergetic electrons in various tissues to understand the impact of tissue type on dose point kernels. Currently available voxel-wise dosimetry approaches using dose point kernels ignore tissue composition and density heterogeneities. Therefore, the study on the impact of tissue type on dose point kernels is warranted. Simulations were performed using the GATE Monte Carlo toolkit, which encapsulates GEANT4 libraries. Dose point kernels were simulated in phantoms of water, compact bone, lung, adipose tissue, blood and red marrow for radionuclides 90Y, 188Re, 32P, 89Sr, 186Re, 153Sm and 177Lu and monoenergetic electrons (0.015-10 MeV). All simulations were performed by assuming an isotropic point source of electrons at the center of a homogeneous spherical phantom. Tissue-specific differences between kernels were investigated by normalizing kernels for effective pathlength. Transport of 20 million particles was found to provide sufficient statistical precision in all simulated kernels. The simulated dose point kernels demonstrate excellent agreement with other Monte Carlo packages. Deviation from kernels reported in the literature did not exceed a 10% global difference, which is consistent with the variability among published results. There are no significant differences between the dose point kernel in water and kernels in other tissues that have been scaled to account for density; however, tissue density predictably demonstrated itself to be a significant variable in dose point kernel distribution.

Deep Transfer Learning Based Classification Model for COVID-19 Disease

The COVID-19 infection is increasing at a rapid rate, with the availability of limited number of testing kits. Therefore, the development of COVID-19 testing kits is still an open area of research. Recently, many studies have shown that chest Computed Tomography (CT) images can be used for COVID-19 testing, as chest CT images show a bilateral change in COVID-19 infected patients. However, the classification of COVID-19 patients from chest CT images is not an easy task as predicting the bilateral change is defined as an ill-posed problem. Therefore, in this paper, a deep transfer learning technique is used to classify COVID-19 infected patients. Additionally, a top-2 smooth loss function with cost-sensitive attributes is also utilized to handle noisy and imbalanced COVID-19 dataset kind of problems. Experimental results reveal that the proposed deep transfer learning-based COVID-19 classification model provides efficient results as compared to the other supervised learning models.

P268 Anomalies of pulmonary arteries in Tetralogy of Fallot in developing countries: study of 100 cases in indian population

Introduction

Right ventricular outflow tract (RVOT) obstruction in some or other form is one of the major components of Tetralogy of Fallot. It can occur at any level, isolated or in combination, from Infundibulum (most common), Pulmonary valve, Main pulmonary artery, Right and Left pulmonary arteries and up to their segmental branches. Incidence of pulmonary artery anomalies are reported between 15-20%, though some reported as high as 40%. 

Purpose

 The objective of this retrospective  observational study is to determine the presence and degree of pulmonary artery  abnormalities and associated cardiac defects in patients with Tetralogy of Fallot and to  define the pulmonary arterial anatomy to guide the further surgical management.

Method

A total of 100 newly diagnosed or follow up cases of TOF irrespective of age (range 5 days- 32 years) and gender (32 female, 68 male) who were planned for surgical management and referred for evaluation of pulmonary artery anatomy. All patient underwent non-ECG gated CT pulmonary Angiography in Toshiba 64 slice CT scanner.  CT data was analyzed retrospectively to look for cardiac and pulmonary artery anatomy by one independent observer having experience in cardiac radiology.

Results

92 patient had infundibular and valvular stenosis and 8 patients has atretic pulmonary valve with additional supravalvar pulmonary stenosis in 17% patient. Out of total 100 patients, 35% had pulmonary artery abnormalities. This included 19 patient (19%) with isolated main pulmonary artery (MPA) abnormality, 6 % had isolated left pulmonary artery (LPA) abnormality, 2 had isolated right pulmonary artery abnormality, 4% had  combined MPA and LPA  abnormality, 2% had combined MPA and RPA abnormalities and 1% patient had all 3 (MPA,LPA,RPA) involvement in form of stenosis or hypoplasia. As TOF is commonly associated with other cardiac structural anomalies, we encountered following associations in our study – aortopulmonary collaterals (37%), Patent ductus arteriosus (29%), right sided aortic arch (19%), bilateral superior vena cava (10%), bovine arch (3%), double aortic arch (2%), d malposition of great vessels (2%), l malposition of great vessels (1%), situs inversus (1%), dextrocardia (1%), annuloaortic ectasia (1%) aortopulmonary window (1%) and cardiac totally anomalous pulmonary venous connection (1%).

Conclusions

Anomalies of pulmonary arteries are important determinant of surgical outcome of TOF patients. CT angiography is now established modality to delineate pulmonary artery and other anatomical details in TOF patient. Pulmonary artery anomaly can range from isolated branch pulmonary stenosis to diffuse hypoplasia of pulmonary vasculature, based on which management can differ from complete correction to palliative or medical management only. Our study emphasize the importance of pulmonary artery evaluation and its variation among patients of TOF.

Abstract P268 Figure.

Accurate calculation of zero point energy from molecular dynamics simulations of liquids and their mixtures

The two-phase thermodynamic (2PT) method is used to compute the zero point energy (ZPE) of several liquids and their mixtures. The 2PT method uses the density of states (DoS), which is computed from the velocity autocorrelation (VAC) function obtained from a short classical molecular dynamics trajectory. By partitioning the VAC and the DoS of a fluid into solid and gaslike components, quantum mechanical corrections to thermodynamical properties can be computed. The ZPE is obtained by combining the partition function of the quantum harmonic oscillator with the vibrational part of the solidlike DoS. The resulting ZPE is found to be in excellent agreement with both experimental and ab initio results. Solvent effects such as hydrogen bonding and polarization can be included by the utilization of ab initio density functional theory based molecular dynamics simulations. It is found that these effects significantly influence the DoS of water molecules. The obtained results demonstrate that the 2PT model is a powerful method for efficient ZPE calculations, in particular, to account for solvent effects and polarization.

A case report of carcinoma of uterine cervix throwing heterochronous metastasis to the skin, spleen, and pancreas: the role of multimodality treatment approach

BACKGROUND

Cancer of cervix often fails locally and/or within the pelvis. One to two percent of cervical squamous cell carcinoma patients have lung metastases at presentation, and 5-35% develop pulmonary metastases later on. Common sites of metastases are the liver, bone, and bowel. We report a rare case presentation of cervical squamous cell cancer where heterochronous metastasis occurred in the skin, spleen, and pancreas without loco-regional recurrence and skipping of visceral organs such as the lung, liver, and brain.

CASE PRESENTATION

A 55-year-old, postmenopausal lady presented with a complaint of bleeding of the vagina for 2 months duration. Cervical biopsy revealed squamous cell carcinoma of the cervix, and she was staged as a case of FIGO stage IIIB. She received external beam-beam radiotherapy of 50 Gy in 25 fractions along with concurrent weekly cisplatin at 35 mg/m² followed by 3 fractions of intracavitary brachytherapy of 6 Gy each. After 30 months of follow-up, she presented with a skin lesion of 6 × 5 cm² in the infrascapular region for 2 months duration. Biopsy revealed metastatic squamous cell carcinoma. Her metastatic work-up revealed no other lesions. Palliative radiotherapy to local site of 8 Gy in single fraction was delivered. The lesion disappeared within 4 weeks. She was given 6 cycles of cisplatin and paclitaxel salvage chemotherapy. After 30 months of follow-up, she presented with a skin lesion of 6 × 5 cm² in the infrascapular region. Biopsy revealed metastatic squamous cell carcinoma. Her metastatic work-up revealed no other lesions. Palliative radiotherapy to the local site was planned, and a dose of 8 Gy in a single fraction was delivered. The lesion disappeared within 4 weeks. She was given 6 cycles of cisplatin and paclitaxel salvage chemotherapy. Six months after the completion of salvage therapy, she reported with the complaints of recurrent bouts of hematemesis and melena. Her CECT scan revealed 2 × 1.5 cm² growth in the body of the pancreas and a subcentric splenic hilum node. She underwent open splenectomy with distal pancreatectomy. Histopathology report showed metastatic infiltration in pancreatic tissue by squamous cell carcinoma and one metastatic node in the splenic hilum. Post-treatment, 6 months, the patient was asymptomatic with no recurrence.

CONCLUSIONS

This is a rare heterochronous metastatic presentation of cervical cancer without loco-regional recurrence and visceral organs such as the lung, liver, and brain. The optimal treatment remains undefined for these patients. Multimodality treatment is necessary to manage the patients.

Physics of suction cups

We have developed a theory of air leakage at interfaces between two elastic solids with application to suction cups in contact with randomly rough surfaces. We present an equation for the airflow in narrow constrictions which interpolates between the diffusive and ballistic (Knudsen) air-flow limits. To test the theory, we performed experiments using two different suction cups, made from soft polyvinylchloride (PVC), in contact with sandblasted polymethylmethacrylate (PMMA) plates. We found that the measured time to detach (lifetime) of the suction cups was in good agreement with theory, except for surfaces with a root-mean-square (rms) roughness below ≈1 μm, where diffusion of plasticizer from the PVC to the PMMA surface caused blockage of critical constrictions. The suction cup volume, stiffness, and elastic modulus have a huge influence on the air leakage and hence the failure time of the cups. Based on our research we propose an improved biomimetic design of suction cups that could show improved failure times with varying degrees of roughness under dry and wet environments.

Rolling friction of elastomers: role of strain softening

We study the temperature and velocity dependency of rolling friction. Steel and PMMA cylinders are rolled on sheets of nitrile butadiene rubber (NBR), with and without filler, and fluoroelastomer (FKM) with filler. Measurements of the rolling friction are performed for temperatures between -40 °C and 20 °C, and for velocities between 5 μm s^-1 and 0.5 cm s^-1. For the unfilled NBR, a smooth rolling friction master curve is obtained using the bulk viscoelastic frequency-temperature shift factor a_T. For the filled rubber compounds, a small deviation from the bulk viscoelastic shift factor is observed at low temperatures. The experimental data are analyzed using an analytical theory of rolling friction. For the filled compounds, good agreement with theory is obtained when strain softening is included, which increases the rolling friction by a factor ∼2 for the filled FKM and ∼3 for the filled NBR compounds. For the unfilled NBR, the maximum of the rolling friction occurs at higher sliding speeds than predicted by the theory. We discuss the role of the adhesive (crack-opening) contribution to the rolling friction, and the role of frozen-in elastic deformations as the rubber is cooled down below the rubber glass transition temperature.

Unusual presentation of chondroblastoma mimicking Trevor's disease

Chondroblastoma is a benign bone tumor, represents 1%–2% of all primary bone tumors, typically seen in patients 10–25-year-old and more common in males. It occurs most frequently in the distal femur, proximal tibia, and proximal humerus. Soft tissue extension is extremely rare. Adjacent joints may develop effusions, but the tumor mass protruding into the joint has never been seen in case of chondroblastoma. We report a rare case of intra-articular chondroblastoma arising from proximal tibia in a 16-year-old boy and growing into the knee joint mimicking an intra-articular osteochondroma.

Vitamins for Cancer Prevention and Treatment: An Insight

Over a few decades a strong interlink between oxidative damage and cancer has been investigated by various scientists across the world on the basis of epidemiological observations of the effects of fruits and vegetables used in the diet for cancer patients. Primarily, Vitamin C, Vitamin D and Vitamin E are reported to be involved in the amelioration of side effects which occur in chemotherapy and radiation therapy of lungs, stomach, prostate, colorectal, gastric head and neck cancers. The vitamins acting as antioxidant adjuvants are found to have apoptotic and antiangiogenesis potential as well as inhibitory effects against metastasis in cancer cells. This chapter explicitly discusses the key aspects concerned with the vitamins in relation to cancer prevention and treatment. It describes vitamins and their natural resources, role of vitamins in the body, and vitamins as prime ingredients in the diet and their effects on cancer biology with reference to recent research reports. Moreover, this paper also includes the emerging potential of pharmaceutical advances to enhance bioavailability of the vitamins to cancer patients with improved safety and efficacy. Clinicians and researchers must mull over the nutritional requirements of individual cancer patient so as to treat cancer and increase life expectancy.

Adhesion between rubber and glass in dry and lubricated condition

We study the adhesion between differently processed glass and filled bromobutyl rubber in dry conditions, in water, and in silicone oil. The boundary line between contact and non-contact in adhesion experiments can be considered as a mode I crack, and we show that viscoelastic energy dissipation, close to the opening (or closing) crack tip and surface roughness, strongly affects the work of adhesion. We observe strong adhesion hysteresis and, in contrast to the Johnson-Kendall-Roberts theory prediction for elastic solids, this results in a pull-off force (and work of adhesion) which depends on the loading force and contact time. In particular, for the system immersed in water and silicone oil, we register very weak adhesive bonding. For glass ball with baked-on silicone oil, the pull-off force is nearly independent of the contact time, but this is not observed for the unprocessed glass surface.

Rubber friction: The contribution from the area of real contact

There are two contributions to the friction force when a rubber block is sliding on a hard and rough substrate surface, namely, a contribution F_ad = τ_f A from the area of real contact A and a viscoelastic contribution F_visc from the pulsating forces exerted by the substrate asperities on the rubber block. Here we present experimental results obtained at different sliding speeds and temperatures, and we show that the temperature dependency of the shear stress τ_f, for temperatures above the rubber glass transition temperature T_g, is weaker than that of the bulk viscoelastic modulus. The physical origin of τ_f for T > T_g is discussed, and we propose that its temperature dependency is determined by the rubber molecule segment mobility at the sliding interface, which is higher than in the bulk because of increased free-volume effect due to the short-wavelength surface roughness. This is consistent with the often observed reduction in the glass transition temperature in nanometer-thick surface layers of glassy polymers. For temperatures T < T_g, the shear stress τ_f is nearly velocity independent and of similar magnitude as observed for glassy polymers such as PMMA or polyethylene. In this case, the rubber undergoes plastic deformations in the asperity contact regions and the contact area is determined by the rubber penetration hardness. For this case, we propose that the frictional shear stress is due to slip at the interface between the rubber and a transfer film adsorbed on the concrete surface.

Rubber contact mechanics: adhesion, friction and leakage of seals

We study the adhesion, friction and leak rate of seals for four different elastomers: Acrylonitrile Butadiene Rubber (NBR), Ethylene Propylene Diene (EPDM), Polyepichlorohydrin (GECO) and Polydimethylsiloxane (PDMS). Adhesion between smooth clean glass balls and all the elastomers is studied both in the dry state and in water. In water, adhesion is observed for the NBR and PDMS elastomers, but not for the EPDM and GECO elastomers, which we attribute to the differences in surface energy and dewetting. The leakage of water is studied with rubber square-ring seals squeezed against sandblasted glass surfaces. Here we observe a strongly non-linear dependence of the leak rate on the water pressure ΔP for the elastomers exhibiting adhesion in water, while the leak rate depends nearly linearly on ΔP for the other elastomers. We attribute the non-linearity to some adhesion-related phenomena, such as dewetting or the (time-dependent) formation of gas bubbles, which blocks fluid flow channels. Finally, rubber friction is studied at low sliding speeds using smooth glass and sandblasted glass as substrates, both in the dry state and in water. The measured friction coefficients are compared to theory, and the origin of the frictional shear stress acting in the area of real contact is discussed. The NBR rubber, which exhibits the strongest adhesion both in the dry state and in water, also shows the highest friction both in the dry state and in water.

Retrospective study of efficacy and safety of neoadjuvant docetaxel, carboplatin, and trastuzumab in HER2-positive locally advanced and oligometastatic breast cancer: An Indian experience

BACKGROUND

The neoadjuvant chemotherapy in HER2-positive breast cancer consists of a chemotherapy backbone and HER2-directed therapy. The increase in cardiotoxicity by the use of trastuzumab with an anthracycline-based regimen has led to the use of nonanthracycline-based alternative regimens. The docetaxel, carboplatin, and trastuzumab (TCH) are one such regimen. The efficacy and toxicity of this regimen have not been widely studied in Indian patients.

AIMS

This retrospective study aims to evaluate the efficacy and toxicity of neoadjuvant TCH regimen in locally advanced and oligometastatic HER2-positive breast cancer in Indian patients.

METHODOLOGY

The hospital records between January 2014 and December 2016 were reviewed to identify patients with locally advanced and oligometastatic HER2-positive breast cancer treated with uniform 3-weekly neoadjuvant chemotherapy protocol-containing docetaxel (75 mg/m2), carboplatin (AUC = 6), and trastuzumab (8 mg/kg loading followed by 6 mg/kg) (TCH). The primary outcome was the pathologic complete response (pCR), which was defined as an absence of invasive and noninvasive cancer in breast or lymphnode.

RESULTS

Thirty-two patients with mean age 46 years met our inclusion criteria, of these 24 patients had locally advanced breast cancer, and eight patients had oligometastatic breast cancer. 13 (40.6%) patients had hormone-positive breast cancer. The objective response rate as assessed clinically was 100%, and pCR rate was 36.3%. The patients with oligometastatic breast cancer also showed a good response to chemotherapy with three patients showing pCR and four patients showing resolution disease at metastatic sites. The patients experienced very few Grade III/IV toxicities, and no patient had clinical congestive heart failure.

CONCLUSION

The TCH protocol is an efficacious neoadjuvant chemotherapy regimen for locally advanced and oligometastatic breast cancer and is safe and well tolerated in this population.

Introducing leprosy post-exposure prophylaxis into the health systems of India, Nepal and Indonesia: a case study

Background

Leprosy has a wide range of clinical and socio-economic consequences. India, Indonesia and Nepal contribute significantly to the global leprosy burden. After integration, the health systems are pivotal in leprosy service delivery. The Leprosy Post Exposure Prophylaxis (LPEP) program is ongoing to investigate the feasibility of providing single dose rifampicin (SDR) as post-exposure prophylaxis (PEP) to the contacts of leprosy cases in various health systems. We aim to compare national leprosy control programs, and adapted LPEP strategies in India, Nepal and Indonesia. The purpose is to establish a baseline of the health system’s situation and document the subsequent adjustment of LPEP, which will provide the context for interpreting the LPEP results in future.

Methods

The study followed the multiple-case study design with single units of analysis. The data collection methods were direct observation, in-depth interviews and desk review. The study was divided into two phases, i.e. review of national leprosy programs and description of the LPEP program. The comparative analysis was performed using the WHO health system frameworks (2007).

Results

In all countries leprosy services including contact tracing is integrated into the health systems. The LPEP program is fully integrated into the established national leprosy programs, with SDR and increased documentation, which need major additions to standard procedures. PEP administration was widely perceived as well manageable, but the additional LPEP data collection was reported to increase workload in the first year.

Conclusions

The findings of our study led to the recommendation that field-based leprosy research programs should keep health systems in focus. The national leprosy programs are diverse in terms of organizational hierarchy, human resource quantity and capacity. We conclude that PEP can be integrated into different health systems without major structural and personal changes, but provisions are necessary for the additional monitoring requirements.

Electronic supplementary material

The online version of this article (10.1186/s12913-017-2611-7) contains supplementary material, which is available to authorized users.