Clinical practice guideline-inconsistent management of fever and neutropenia in pediatric oncology: A Children's Oncology Group study

BACKGROUND

The primary objective was to measure the proportion of episodes where care delivery was inconsistent with selected recommendations of a clinical practice guideline (CPG) on fever and neutropenia (FN) management. The influence of site size on CPG-inconsistent care delivery, and association between patient outcomes and CPG-inconsistent care were described.

METHODS

This retrospective, multicenter study included patients less than 21 years old with cancer who were at high risk of poor FN outcomes and were previously enrolled to a Children's Oncology Group (COG) study at participating National Cancer Institute Community Oncology Research Program (NCORP) institutions from January 2014 through December 2015. Patients were randomly selected for chart review by participating sites from a COG-generated list. Care delivered in each episode was adjudicated (CPG-consistent or CPG-inconsistent) against each of five selected recommendations.

RESULTS

A total of 107 patients from 22 sites, representing 157 FN episodes, were included. The most common CPG-inconsistent care delivered was omission of pulmonary computerized tomography in patients with persistent FN (60.3%). Of 74 episodes where assessment of four (episodes without persistent FN) or five (episodes with persistent FN) recommendations was possible, CPG-inconsistent care was delivered with respect to at least one recommendation in 63 (85%) episodes. Site size was not associated with CPG-inconsistent care delivery. No statistically significant association between CPG-inconsistent care and fever recurrence was observed.

CONCLUSIONS

In this cohort of pediatric patients at high risk of poor FN outcomes, CPG-inconsistent care was common. Opportunities to optimize resource stewardship by boosting supportive care CPG implementation are highlighted.

Hyperbranched polymers: growing richer in flavours with time

Hyperbranched polymers (HBPs) have been studied for over three decades now; yet several interesting aspects continue to draw the attention of researchers worldwide. This is because of the simplicity of synthesis, their unique globular structure, and the numerous peripherally located functional groups that can be utilised to impart a variety of attributes, such as core-shell amphiphilicity, Janus amphiphilicity, clickable polymeric scaffolds, multifunctional crosslinkers, etc. Several reviews have been written on HBPs with a focus on synthetic strategies, structural diversity, and their potential applications; in this short feature article, we have taken an alternate approach to highlight some of the unique structural features of HBPs and their influence on the properties of HBPs. We also discuss their versatility and adaptability for the generation of several interesting functional polymeric systems. In the latter half, we focus on the utilisation of HBPs as multifunctional scaffolds, that rely on the numerous peripheral terminal groups. We conclude by drawing a structuro-functional analogy between the range of peripherally functionalised HBPs and other analogous, but more complex, polymeric systems. We believe that this review will serve as a visual sounding board that would encourage the development of several other applications for this class of unique polymers.

Amphiphilic Polymer Hydrogel-supported Catalysts: Tuning the Accessibility to the Catalytic Site by Molecular Jacketing

Amphiphilic hydrogels, prepared using a peripherally clickable hyperbranched polyester (HBP) and PEG-diazides of different molecular weights, were used to ligate Cu utilizing the triazole rings formed by the alkyne-azide click reaction. Since only a fraction of the peripheral propargyl groups in the HB polyester are needed to generate the crosslinked polymer, the remaining were clicked with different types of azides, such as MPEG azide, decyl azide or 4-methylbenzyl azide, to create a molecular jacket around the catalytic sites that can potentially influence the catalytic activity and reaction outcome. The crosslinked films ligated with Cu functioned very effectively to catalyse alkyne-azide click reactions, both in water and in organic solvents; the nature of the molecular jacket around the catalytic site has a clear influence the reaction rate, which depended upon the relative solubilities of the reactants. The gel-supported catalysts films can be recycled multiple times with little loss in catalytic activity.

Muscle Fatigue Analysis by Visualization of Dynamic Surface EMG Signals Using Markov Transition Field

Muscle fatigue analysis is important in the diagnosis of neuromuscular diseases. Analysis of surface electromyography (sEMG) signals by non-linear probabilistic approach is useful in studying their transitions and thus the neuromuscular system. In this study, a method to visualize sEMG signals using Markov transition field (MTF) under fatigue conditions is proposed. sEMG signals are acquired from 45 healthy participants during biceps curl exercise. They are filtered and divided into ten equal segments. Markov transition matrix is constructed and corresponding MTF image is generated. The average self-transition probability is extracted and compared for both non-fatigue and fatigue segments. It is observed that the extracted feature shows high statistical significance with p value less than 0.001. The increase in average self-transition probability under fatigue condition correlates with the reduction in the degree of signal complexity. Thus, encoding of sEMG signals to images is helpful in analyzing the complexity of the neuromuscular system. Clinical Relevance- This approach may be helpful in analyzing muscle fatigue related with various myoneural conditions.

Efficacy of add-on Ayurveda and Yoga intervention in health care workers of tertiary care hospital during COVID-19: Randomized controlled trial

Background

The present study aimed to evaluate the safety and prophylactic efficacy of add-on Comprehensive Ayurveda and mindfulness-based Yoga (CAY) regimen to standard care among HealthCare Workers (HCWs) against COVID-19.

Materials and methods

This prospective single-blind (outcome assessor-blinded) RCT was conducted in tertiary care hospital in Delhi during July 2020–April 2021. HCWs of both sexes were randomized to add-on CAY intervention or control group. The primary outcomes were the incidence of confirmed COVID-19 positive cases and influenza-like illness events (ILI). Secondary outcomes were anxiety (GAD-7), depression (PHQ-9), and quality of life (SF-36) at the end of 12 weeks.

Results

Three hundred fifty-six participants (181 in intervention and 175 in the control group) were randomized. With the modified intention to treat approach, we analyzed 309 participants. The mean age for the intervention and control group was 39.3 ± 10.1 and 36.6 ± 10 years, respectively. Incidence of COVID-19 event was higher in control group compared to CAY group (16 of 164 [9.8%] vs. 11 of 145 [7.6%]; P = 0.50). The incidence of ILI events was also higher in the control group as compared to the CAY group (14 of 164 [8.5%] vs 9 of 145 [6.2%]). The health change domain of the SF-36 questionnaire showed statistically significant improvement in the CAY group as compared to the control group (P < 0.01).

Conclusion

Incidence of COVID-19 and ILI events was lower in the CAY group compared with the contr ol group, though the difference is not statistically significant.

A unique bilateral accessory forearm flexor muscle

Muscular and neurovascular variations in the upper extremity are of utmost clinical significance. Here we report a unique bilateral accessory muscle in the forearm and palm of an 89-year-old male cadaver. The accessory muscle presented two bellies on the right side, one in the forearm, innervated by the anterior interosseous nerve, and the other in the palm, innervated by a branch of the median nerve. A long tendon interconnected the two bellies. On the left side, the muscle had a single belly in the palm, which began at the end of a long tendon that extended from the forearm. However, on both sides, the muscle originated from the posterior surface of the flexor digitorum superficialis belly and inserted along with the first lumbrical muscle into the dorsal digital expansion of the index finger. The proximal parts of the variant muscles were sandwiched between the flexor digitorum muscles. The palmar bellies coursed distally through the carpal canal and lay deep to the superficial palmar arch, and superficial to the first lumbrical, between the thenar muscles and the lateral-most tendon of the flexor digitorum superficialis. Arguably, the accessory muscle might be a variant of a lumbrical muscle, as reported before, but innervation of the proximal belly by the anterior interosseous nerve suggests that the muscle may well be a deep accessory muscle at the forearm, probably appeared as a diverted part of the flexor digitorum profundus. Its space-occupying course through the forearm and palm, especially through the carpal canal, might be clinically significant as it might contribute to nerve compression pathologies in the upper extremity. This accessory muscle also indicates the complex nature of individual muscle formation and evolution of the upper extremity with constant changes in the morphology of muscles based on their changing functions.

Cervical cancer diagnosis based on modified uniform local ternary patterns and feed forward multilayer network optimized by genetic algorithm

Cervical cancer is one of the most common types of cancer for women. Early and accurate diagnosis can save the patient's life. Pap smear testing is nowadays commonly used to diagnose cervical cancer. The type, structure and size of the cervical cells in pap smears images are major factors which are used by specialist doctors to diagnosis abnormality. Various image processing-based approaches have been proposed to acquire pap smear images and diagnose cervical cancer in pap smears images. Accuracy is usually the primary objective in evaluating the performance of these systems. In this paper, a two-stage method for pap smear image classification is presented. The aim of the first stage is to extract texture information of the cytoplasm and nucleolus jointly. For this purpose, the pap smear image is first segmented using the appropriate threshold. Then, a texture descriptor is proposed titled modified uniform local ternary patterns (MULTP), to describe the local textural features. Secondly, an optimized multi-layer feed-forward neural network is used to classify the pap smear images. The proposed deep neural network is optimized using genetic algorithm in terms of number of hidden layers and hidden nodes. In this respect, an innovative chromosome representation and cross-over process is proposed to handle these parameters. The performance of the proposed method is evaluated on the Herlev database and compared with many other efficient methods in this scope under the same validation conditions. The results show that the detection accuracy of the proposed method is higher than the compared methods. Insensitivity to image rotation is one of the major advantages of the proposed method. Results show that the proposed method has the capability to be used in online problems because of low run time. The proposed texture descriptor, MULTP is a general operator which can be used in many computer vision problems to describe texture properties of image. Also, the proposed optimization algorithm can be used in deep-networks to improve performance.

Superconductivity in Heusler compound ScAu2Al

We report superconducting state properties and electronic structure of a full Heusler material ScAu₂Al. The resistivity measurement indicates a zero-field (at nominal Earth's field) superconducting transition temperature,T_c= 5.12 K (in contrary to the previously reported value of 4.4 K), which falls in the highestT_c-regime among the Heusler superconductors. The magnetization data shows that ScAu₂Al is a moderate type-II superconductor, where the critical field values can be estimated from the Ginzburg-Landau-Abrikosov-Gorkov theory. The field-dependent magnetization response further shows signatures of flux jump in ScAu₂Al. A sharp jump in the temperature dependent specific heat (C_p) data confirms bulk superconductivity. We report that the electron-phonon coupling constant,λ_e-ph= 0.77, suggesting a moderate electron-phonon coupling in ScAu₂Al. Further, we show that the observedλ_e-phvalue in ScAu₂Al is the highest amongst the reported Heusler superconductors, indicating strong correlation betweenT_candλ_e-phvalues and significant role of electron-phonon coupling in mediating superconductivity in Heusler superconductors. Finally, we discuss the electronic properties and reveal the existence of van Hove singularity near the Fermi level in ScAu₂Al.

Probing Polymer Chain Folding in Solution Using Second Harmonic Light Scattering

Periodically grafted amphiphilic copolymers (PGACs) were earlier shown by us to adopt a zigzag folded conformation in the solid state, which enabled the backbone and pendant segments to segregate and occupy alternate layers in a lamellar structure. The conformational transition from a random coil to a zigzag folded chain in solution is an interesting problem, which is largely unexplored. To examine this, an orthogonally clickable parent polyester was sequentially clicked with two types of poly(ethylene glycol) (PEG) segments: one is a simple PEG and the other is a PEG that carries a dipolar chromophore. These two hydrophilic PEG segments, installed in a periodic and alternating fashion along the hydrocarbon-rich (HC) polyester backbone, ensure that the Janus folded chains are formed upon folding and carry chromophoric dipoles oriented along the same direction, thereby generating a large net dipole. The folding-induced alignment of chromophores in solution was followed using second harmonic light scattering (SHLS), wherein the intensity of the frequency-doubled scattered light (I_2ω) is measured. Folding was induced by adding a polar solvent, like methanol, to a chloroform solution of the polymer; methanol desolvates the HC backbone but solubilizes the pendant PEG segments, thus inducing folding. The second harmonic intensity (I_2ω) increased initially with methanol concentration and then saturated; in contrast, I_2ω remained invariant with the solvent composition in the case of an analogous model chromophore. Furthermore, in a model PGAC carrying chromophore-bearing PEG segments on every repeat unit, I_2ω decreased with increasing methanol composition, revealing the formation of a centrosymmetric folded chain, wherein the chromophoric dipoles on either side cancel each other. Thus, this study clearly reveals that the zigzag chain folding of PGACs can be induced by a segment-selective solvent, resulting in the rather elusive directional ordering of chromophoric dipoles in solution.

Fine-Tuning Crystallization-Induced Gelation in Amphiphilic Double-Brush Polymers

A series of amphiphilic double-brush polymers based on itaconate diesters were synthesized with the objective of tailoring the thermal and mechanical properties of hydrogels formed by them; the amphiphilic itaconate diesters carried an MPEG350 segment and an alkyl chain, whose length was varied from C12 to C18. As was reported by us earlier (Macromolecules 2017, 50, 5004), the formation of the hydrogel was due to the crystallization of alkyl segments, as confirmed by the match of the rheological gel-to-sol transition with that of differential scanning calorimetry melting transition of the gel. In an effort to fine-tune the hydrogel-melting temperature and its strength, we varied the length of the alkyl chain length while keeping the hydrophilic segment length constant at MPEG350; apart from varying the alkyl chain length, an oxyethylene spacer was incorporated to examine the effect of decoupling the alkyl side-chain crystallization from the backbone. With these modifications, the melting temperature of the hydrogel was varied from 30 to 56 °C. Likewise, the strength of the hydrogel, as reflected by its storage modulus, varied from around 220 to 970 Pa; the softer gels typically exhibited a slightly larger critical shear strain beyond which the gel transformed into a sol. The thermal and shear-induced gel-to-sol transitions were reversible; however, the modulus after the shear-induced transition did not fully recover instantly (∼80%), suggesting that the formation of the extended gel network is slow. Further fine-tuning could be achieved by copolymerization of two different amphiphilic itaconate monomers, namely, those with C16 and C18, which provided an intermediate gel-melting temperature; however, co-gelation of the two preformed homopolymer gels yielded two distinct gel-melting transitions. Thus, this class of tuneable stimuli-responsive polymeric hydrogels prepared from biobenign components, namely, itaconic acid, 1-alkanols, and MPEGs, could serve as potential candidates for biomedical applications.

Role of dietary polyphenols on gut microbiota, their metabolites and health benefits

The beneficial health roles of dietary polyphenols in preventing oxidative stress related chronic diseases have been subjected to intense investigation over the last two decades. As our understanding of the role of gut microbiota advances our knowledge of the antioxidant and anti-inflammatory functions of polyphenols accumulates, there emerges a need to examine the prebiotic role of dietary polyphenols. This review focused onthe role of different types and sources of dietary polyphenols on the modulation of the gut microbiota, their metabolites and how they impact on host health benefits. Inter-dependence between the gut microbiota and polyphenol metabolites and the vital balance between the two in maintaining the host gut homeostasis were discussed with reference to different types and sources of dietary polyphenols. Similarly, the mechanisms behind the health benefits by various polyphenolic metabolites bio-transformed by gut microbiota were also explained. However, further research should focus on the importance of human trials and profound links of polyphenols-gut microbiota-nerve-brain as they provide the key to unlock the mechanisms behind the observed benefits of dietary polyphenols found in vitro and in vivo studies.

Differentiation of fluctuations in uterine contractions associated with Term pregnancies using adaptive fractal features of electromyography signals

Analysis of uterine contractions using electromyography signals is gaining importance due to its capability to measure the dynamics of uterus. Uterine electromyography (uEMG) provides information on the nature of uterine contractions non-invasively. In this study, the fluctuations in uEMG signals associated with Term pregnancies are analyzed. For this, Term uEMG signals corresponding to second (T1) and third (T2) trimesters are considered. The signals are subjected to Adaptive Fractal Analysis (AFA), wherein a global trend is obtained by using overlapping windows of three orders namely, 25%, 50% and 75%. The signals are detrended and the fluctuation function is estimated. Two Hurst exponent features computed at short range (Hs) and long range (Hl) are extracted and statistically analyzed. Results show that AFA is able to characterize variations in the fluctuations of Term delivery signals. The feature values are observed to vary significantly during different weeks of gestation. It is found that features of T2 signals are higher than that of T1 signals for all the considered overlaps, indicating that T2 signals possess smoother characteristics than T1 signals. Further, coefficient of variation is observed to be low, indicating that these features are able to handle the inter-subject variations in Term signals. Therefore, it appears that the proposed approach could aid in investigation of progressive changes in uterine contractions during Term pregnancies.

Main-chain liquid crystalline polymers bearing periodically grafted folding elements

Inclusion of non-mesogenic pendant segments, such as alkyl, PEG and fluoroalkyl, at periodic intervals along the backbone of main-chain LCPs, that contain flexible spacers, provides an interesting alternative to control the mesophase structure and the layer periodicity.

Left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is not an isolated RV disease. Left ventricular (LV) or biventricular involvement is being increasingly diagnosed in such patients. There is available research to show that the LV peak strain calculated from feature tracking (FT) cardiac MRI is impaired even before the impairment of function. If present, such involvement is an adverse prognostic marker.

Purpose

The aim of this study is to calculate LV involvement in patients with ARVC using FT cardiac MRI.

Methods

27 patients of ARVC who underwent cardiac MRI with late gadolinium enhancement (LGE) in our department were identified. 10 healthy volunteers (controls) were also assessed using non-contrast cardiac MRI. LV strain analysis was performed using Cvi42 Circle cardiovascular imaging software; and global LV peak radial, circumferential and longitudinal strain values were calculated. Patients were divided into two sub groups: those with preserved LV ejection fraction (LVEF) and those with reduced LVEF. Peak LV strain values were compared between the two groups of ARVC patients; and between ARVC patients with preserved LVEF and healthy volunteers.

Results

The LV peak global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) were −17.7±2.47, −18.16±2.65, 31.04±6.07 respectively in healthy volunteers. LV global longitudinal (GLS), circumferential (GCS), and radial strain (GRS) were significantly impaired in ARVC/D patients (GLS: −11.97±4.34%, GCS: −14.35±4.32%, GRS: 22.1±7.39%). ARVC patients were divided into 2 subgroups: the preserved LV ejection fraction (LVEF) group (LVEF ≥55%, n=9) and the reduced LVEF group (LVEF &lt;55%, n=18). In ARVC patients with reduced LVEF, the peak GLS was −9.99±3.94, GCS was −12.88±4.08 and GRS was 19.57±7.56. With preserved LVEF these values were −15.1±3.02, −17.3±3.3 and 27.1±3.67 respectively. In ARVC patients with preserved LVEF, the peak LV strain were impaired when compared with healthy volunteers with significant difference in peak GLS in between the two groups (p=0.05).

Conclusion

In patients with ARVC, cardiac MRI feature tracking can detect early LV dysfunction and thus adverse prognostic marker. Even in patients with normal LVEF, GLS was found to be significantly impaired as compared to healthy controls.

Calculation of longitudinal strain

Funding Acknowledgement

Type of funding source: None

A Method to Differentiate Fatiguing Conditions in Surface Electromyography Signals using Instantaneous Spectral Centroid

The nonstationarity measure of surface Electromyography (sEMG) signals provide an index for muscle fatigue conditions. In this paper, a new framework has been proposed for the analysis of sEMG signal using Instantaneous Spectral Centroid (ISC). The novelty of the proposed work is use of topological signal processing method to quantify the nonstationarity of sEMG signal. For this, the signals are recorded from the biceps brachii muscles of 25 healthy subjects in isometric contraction. The analytical signals corresponding to nonfatigue and fatigue segments are computed using Hilbert Transform. Further, topological features such as center of gravity (CoG), triangular area function (TAF) and ISC are calculated from the geometrical representation of a transformed signal. The result indicates the increase of TAF in fatigue condition and the significant right shift of CoG in x-axis for 80% of subjects. Importantly, the ISC estimate is decreased by 17% upon fatiguing for 84% of subjects. The obtained results show statistical significance with p < 0.05. It is observed that the shape parameters are varied in accordance with the changes observed in global characteristics of sEMG signals during muscle fatigue. The preliminary results show that the topological features are able to quantify the nonstationarity in sEMG signal. Therefore, the proposed method can be used as a fatigue index for diagnosing various neuromuscular disorders.Clinical Relevance-This method can be used to establish metrics of muscle fatigue for the benefit of physicians especially in the field of fitness, sports, pre and post-surgery surveillance and rehabilitation.

Low-dose gamma irradiation effect on structural and optical properties of PANI-ZnO composite thin films

The effects of different low doses of gamma irradiation on polyaniline-zinc oxide composite thin films were studied. The structural and optical properties of the sample were investigated using X-ray diffraction, ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy and photoluminescence spectroscopy. The variation in the structural and optical properties shown in this analysis will be helpful in correlating the properties with low-dose radiation dosimetry.

1072 Post-traumatic Stress Disorder Is Associated With Increased Oscillatory Frequency Of Sleep Spindles

Introduction

Patients with post-traumatic stress disorder (PTSD) often suffer from sleep disturbances. Sleep spindles are an electrophysiological hallmark of non-rapid eye movement sleep and believed to be involved in sleep protection and sleep-dependent memory consolidation. Here, we sought to examine whether sleep spindles are altered in PTSD and whether the findings are reproducible across nights and subsamples of the study population.

Methods

We obtained 64-channel electroencephalogram (EEG) recordings from 78 combat-exposed Veteran men with (n = 31) and without (n = 47) PTSD during two consecutive nights of sleep. We identified slow (10-13 Hz) and fast (13-16 Hz) sleep spindles during N2 and N3 sleep using an automatic algorithm and performed topographical analyses of spindle parameters (amplitude, duration, oscillatory frequency, and density) on both nights. To assess reproducibility, we used the first 47 consecutive participants (18 with PTSD) for initial discovery and the remaining 31 participants (13 with PTSD) for replication assessment.

Results

In the discovery analysis, compared to participants without PTSD, those with PTSD exhibited 1) increased oscillatory frequency of slow spindles over the antero-frontal regions on both nights (Night 1: p = .020, Cohen’s d = 0.92; Night 2: p = .014, Cohen’s d = 1.07) and 2) increased oscillatory frequency of fast spindles over the centro-parietal regions on the second night (p = .018, Cohen’s d = 0.76). Notably, these trends were preserved in the replication analysis. In contrast, we found no significant group differences in the amplitude, duration, or density of slow or fast spindles.

Conclusion

The elevated sleep-spindle frequency in PTSD may reflect reduced thalamocortical inhibition and, hence, deficient sleep protection. Our findings provide the basis for an initial understanding of sleep-spindle abnormalities in PTSD. The findings, if independently validated, may assist in the development of sleep-focused diagnostics and interventions for PTSD.

Support

This work was sponsored by U.S. Defense Health Program (grant No. W81XWH-14-2-0145) and managed by the U.S. Army Military Operational Medicine Program Area Directorate, Ft. Detrick, MD. The study was also supported by the Clinical and Translational Science Institute at the University of Pittsburgh (UL1 TR001857).

A short review on antibody therapy for COVID-19

The beginning of the novel SARS-CoV-2 human coronavirus in Wuhan, China, has triggered a worldwide respiratory disease outbreak (COVID-19). By April 07, 2020, SARS-CoV-2 has affected more than 1.36 million people worldwide and caused more than 75,900 deaths. To date, the anti-malaria drug hydroxychloroquine found to be a treatment option for SARS-CoV-2. In addition to supportive treatment, such as oxygen supply in moderate cases and extracorporeal membrane oxygenation in critically ill patients, unique medications for this condition are also under investigation. Here we reviewed the antibody therapy might be an immediate strategy for emergency prophylaxis and SARS-CoV-2 therapy.

Ceria Stabilized by Titanium Carbide as a Sustainable Filler in the Nafion Matrix Improves the Mechanical Integrity, Electrochemical Durability, and Hydrogen Impermeability of Proton-Exchange Membrane Fuel Cells: Effects of the Filler Content

Cerium oxide-anchored titanium carbide (CeO₂-TiC) is realized as a potential inorganic filler when modifying the Nafion matrix of a proton-exchange membrane fuel cell (PEMFC). A hydrothermal strategy was employed to synthesize CeO₂-TiC of high crystallinity as a filler to mitigate the problematic properties of a proton-exchange membrane (PEM). CeO₂-TiC with a weight ratio of 0.5, 1, 1.5, or 2% was incorporated into a Nafion matrix to form a hybrid by adopting a solution-casting procedure. Reinforcement owing to the presence of TiC provides increased tensile strength to PEM, and the addition of CeO₂ improves the durability of PEM by scavenging free radicals. The microstructural, thermomechanical, physiochemical, and electrochemical properties of PEM, including contact angle, water sorption, water uptake, and proton conductivity, were extensively studied. Random dispersion of CeO₂-TiC in the Nafion matrix improves the thermal stability, tensile strength, and water uptake while retaining proton conductivity, as compared with those of pristine Nafion. As a result, optimized Nafion/CeO₂-TiC (1 wt %) achieved undiminished PEMFC performance compared to that of pristine Nafion while operating the device at 60 °C and 100% relative humidity. In addition, Nafion/CeO₂-TiC (1 wt %) experienced the degradation of merely 0.6 mV h^-1 during 200 h operation under identical conditions. Compared to that of Nafion/CeO₂-TiC (1 wt %), pristine Nafion and Nafion-212 displayed accelerated and comparable degradation (for pristine Nafion, 1.3 mV h^-1; for Nafion-212, 0.4 mV h^-1). PEMFC power output, hydrogen permeability, and morphology of samples were examined after the durability test; the results indicate that Nafion/CeO₂-TiC (1 wt %) is extremely stable. Since various Nafion hybrids have been reported as highly durable PEMs, this study is expected to open up new perspectives to expanding their applications, especially in sustainable PEMFC technology.

Precise control of grafting density in periodically grafted amphiphilic copolymers: an alternate strategy to fine-tune the lamellar spacing in the sub-10 nm regime

By exactly locating pendant PEG550 segments at varying intervals along a hydrocarbon-rich polyester backbone, the lamellar dimension has been precisely tuned.

Method Validation for Determination of the 15 European-Priority Polycyclic Aromatic Hydrocarbons in Primary Smoke Condensates by Gas Chromatography/Mass Spectrometry: Interlaboratory Study

A collaborative study was conducted to validate an analytical method for quantification of the 15 polycyclic aromatic hydrocarbons (PAHs) regarded in 2002 as a health concern by the former Scientific Committee on Food of the European Commission (SCF) in primary smoke condensates. The method is based on gas chromatography/mass spectrometry of a cyclohexane extract with solid-phase cleanup through silica gel. The analytes were detected in the selected-ion monitoring mode and quantified by using 3 isotopically labeled internal standard compounds. Seventeen laboratories participated in the collaborative validation study, of which 12 reported valid results. The data were subjected to Cochran, single Grubbs, and double Grubbs tests for statistical outliers. A maximum of 2 outliers was eliminated before further statistical evaluation of the method performance characteristics. Depending on the analyte, the results showed relative standard deviations for repeatability between 4.2 and 30% and for reproducibility from 9.9 to 60%. The recoveries varied between about 50 and 85%, except those for cyclopenta[cd]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene. Nevertheless, because Commission Directive 2005/10/EC allows for a recovery range of 50120% for (BaP) benzo[a]pyrene in various foods, it can be concluded that the method performs appropriately within the analytical range between 5 and 25 μg/kg of primary smoke condensate. For BaP the validated analytical range covered 520 μg/kg, and for benzo[a]anthracene (BaA) 1025 μg/kg. The method is suitable for monitoring BaP and BaA at their respective maximum permitted levels of 10 and 20 μg/kg. Three analytes, benzo[b]-, benzo[j]-, and benzo[k]-fluoranthene could not be separated by all of the participants and were therefore treated as the sum. Nevertheless, with this method the pattern of the respective concentrations of these 15 PAHs can be monitored in primary smoke condensate as suggested by the SCF.

Indian guidelines for indications and timing of intervention for common congenital heart diseases: Revised and updated consensus statement of the Working group on management of congenital heart diseases

A number of guidelines are available for the management of congenital heart diseases (CHD) from infancy to adult life. However, these guidelines are for patients living in high-income countries. Separate guidelines, applicable to Indian children, are required when recommending an intervention for CHD, as often these patients present late in the course of the disease and may have coexisting morbidities and malnutrition. Guidelines emerged following expert deliberations at the National Consensus Meeting on Management of Congenital Heart Diseases in India, held on August 10 and 11, 2018, at the All India Institute of Medical Sciences. The meeting was supported by Children's HeartLink, a nongovernmental organization based in Minnesota, USA. The aim of the study was to frame evidence-based guidelines for (i) indications and optimal timing of intervention in common CHD; (ii) follow-up protocols for patients who have undergone cardiac surgery/catheter interventions for CHD; and (iii) indications for use of pacemakers in children. Evidence-based recommendations are provided for indications and timing of intervention in common CHD, including left-to-right shunts (atrial septal defect, ventricular septal defect, atrioventricular septal defect, patent ductus arteriosus, and others), obstructive lesions (pulmonary stenosis, aortic stenosis, and coarctation of aorta), and cyanotic CHD (tetralogy of Fallot, transposition of great arteries, univentricular hearts, total anomalous pulmonary venous connection, Ebstein's anomaly, and others). In addition, protocols for follow-up of postsurgical patients are also described, disease wise. Guidelines are also given on indications for implantation of permanent pacemakers in children.

Study of the effect of external noise pickups on the performance of a cryogenic bolometer

This paper reports the detailed noise characterization, investigation of various noise sources, and its mitigation to improve the performance of a cryogenic bolometer detector for the TIN.TIN experiment. The noise spectrum has been measured for a sapphire bolometer test setup with an indigenously developed neutron transmutation doped Ge sensor in the cryogen free dilution refrigerator system at Mumbai. The effect of external noise, arising either from ground loops in the system or from the diagnostic and control electronics of the cryostat, on the performance of the bolometer is assessed. A systematic comparison of the influence of different noise pickups on the bolometer resolution is also presented. The best-achieved resolution (σ_E) at 15 mK is ∼15 keV for heater pulses and appears to be mainly limited by the noise due to the pulse tube cryocooler.

Order Frequency Spectral Correlation Based Cyclo-nonstationary Analysis of Surface EMG Signals in Biceps Brachii Muscles

Surface Electromyogram (sEMG) is an indicator of fatigue progression during isometric or dynamic contraction of skeletal muscle. Estimation of fatigue index provides clinically relevant data for the diagnosis of neuromuscular disorders. The major challenge is that the signal is highly nonstationary upon dynamic contraction of muscles. Therefore, an advanced signal processing method is essential for the analysis of such signals to measure fatigue indices. Cyclo-nonstationary (CNS) analysis reveals the hidden periodicities of a highly nonstationary signal which is not firmly established for muscle fatigue analysis. In this work, an attempt has been made for the cyclo-nonstationary analysis of sEMG signal in biceps brachii muscle using Order-Frequency Spectral Correlation function (OFSC) method. For this, signals are recorded from fifty healthy volunteers with well-defined protocol. The preprocessed signals are equally partitioned into three segments namely, nonfatigue, progression of fatigue and fatigue. Further, OFSC is computed using the Welch-based estimator. In addition, the OFSC statistical features such as area under the curve, skewness, kurtosis and six entropies are estimated to evaluate fatigue condition with CNS analysis. The preliminary results show that OFSC features are able to differentiate the fatigue condition. The obtained results are statistically significant with p <; 0.002. Therefore, OFSC-based CNS analysis can be used for the fatigue index estimation to diagnose neuromuscular disorders.

Analysis of Muscle Fatigue Conditions in Surface EMG Signal with A Novel Hilbert Marginal Spectrum Entropy Method

Surface Electromyogram is the superposition of action potentials generated during muscle contraction that provides useful indices for biomechanics. Such signals are nonstationary and the measure of its time varying components are essentially needed to identify the progression of fatigue. In this work, an attempt has been made to identify the muscle fatigue condition using Hilbert-Huang Marginal Spectrum. The novelty of the proposed framework is that the Marginal Spectrum is computed by ordering the instantaneous frequency of an Intrinsic Mode Function obtained for a signal to be analyzed. For this purpose, signals are recorded from the biceps brachii muscles of 50 healthy volunteers using isometric and dynamic contraction exercise protocols. Initially, each signal is equally partitioned into 10 segments, where the 1^st, 5^th and 10^th segments are analyzed. Further, metrics estimated from marginal spectrum such as area under the curve, skewness and kurtosis are calculated for the considered three segments. The preliminary results show that the estimated metrics are able to distinguish the fatiguing conditions. The recorded signals show low amplitude and high frequencies in nonfatigue region and vice-versa. The obtained results are statistically significant with p <; 0.005. It appears that the instantaneous frequency based marginal spectrum estimator is able to measure the fatigue index. Therefore, the proposed method can be useful in analyzing fatigue condition of skeletal muscles.

Characterization of Alzheimer conditions in MR images using volumetric and sagittal brainstem texture features

BACKGROUND AND OBJECTIVE

Brainstem analysis in Magnetic Resonance Images is essential to detect Alzheimer's condition in the preclinical stages. In this work, an attempt has been made to segment the brainstem in sagittal (2D) and volumetric (3D) images and evaluate texture changes to differentiate Alzheimer's disease (AD) stages.

METHOD

The images obtained from a public access database are spatial normalized, skull stripped and contrast enhanced. Morphological Reconstruction based Fast and Robust Fuzzy 'C' Means technique is used to cluster the brain tissue in preprocessed images into three groups namely cerebrospinal fluid, grey matter and white matter. Brainstem is segmented from the white matter tissue using connected component labelling. Texture features from volumetric and sagittal brainstem slices are extracted and its statistical significance is evaluated.

RESULTS

Results show that the proposed approach is able to segment the brainstem from all the considered images. Variation in texture is observed to be less than 2% among sagittal brainstem slices. Additionally, midsagittal and volumetric features are correlated, suggesting that midsagittal brainstem structure gives an estimate of brainstem volume. Texture features extracted from midsagittal slice shows significant variation (p < 0.05) and is able to differentiate AD classes.

CONCLUSION

Midsagittal brainstem texture features are able to capture the changes occurring in the early stages of disease condition. As the distinction of AD in preclinical stage is complex and clinically significant, this approach could be useful for early diagnosis of the disease.

Ultrafine Pt Nanoparticles Stabilized by MoS2/N-Doped Reduced Graphene Oxide as a Durable Electrocatalyst for Alcohol Oxidation and Oxygen Reduction Reactions

Direct alcohol fuel cells play a pivotal role in the synthesis of catalysts because of their low cost, high catalytic activity, and long durability in half-cell reactions, which include anode (alcohol oxidation) and cathode (oxygen reduction) reactions. However, platinum catalysts suffer from CO tolerance, which affects their stability. The present study focuses on ultrafine Pt nanoparticles stabilized by flowerlike MoS₂/N-doped reduced graphene oxide (Pt@MoS₂/NrGO) architecture, developed via a facile and cost-competitive approach that was performed through the hydrothermal method followed by the wet-reflux strategy. Fourier transform infrared spectra, X-ray diffraction patterns, Raman spectra, X-ray photoelectron spectra, field-emission scanning electron microscopy, and transmission electron microscopy verified the conversion to Pt@MoS₂/NrGO. Pt@MoS₂/NrGO was applied as a potential electrocatalyst toward the anode reaction (liquid fuel oxidation) and the cathode reaction (oxygen reduction). In the anode reaction, Pt@MoS₂/NrGO showed superior activity toward electro-oxidation of methanol, ethylene glycol, and glycerol with mass activities of 448.0, 158.0, and 147.0 mA/mg_Pt, respectively, approximately 4.14, 2.82, and 3.34 times that of a commercial Pt-C (20%) catalyst. The durability of the Pt@MoS₂/NrGO catalyst was tested via 500 potential cycles, demonstrating less than 20% of catalytic activity loss for alcohol fuels. In the cathode reaction, oxygen reduction reaction results showed excellent catalytic activity with higher half-wave potential at 0.895 V versus a reversible hydrogen electrode for Pt@MoS₂/NrGO. The durability of the Pt@MoS₂/NrGO catalyst was tested via 30 000 potential cycles and showed only 15 mV reduction in the half-wave potential, whereas the Pt@NrGO and Pt-C catalysts experienced a much greater shift (Pt@NrGO, ∼23 mV; Pt-C, ∼20 mV).