bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence and correlates of suicidal behaviour among adults in Malawi: a nationally representative cross-sectional survey in 2017
Authors: Pengpid Supa , Peltzer Karl
Published: June 2021

Background

The study aimed to assess the prevalence and associated factors of suicidal behaviour (SB) among adults in Malawi.

Methods

Data were analysed from 4187 persons aged 18–69 years (median age: 32 years) that took part in the nationally representative cross-sectional “2017 Malawi STEPS survey.”

Results

The prevalence of ever suicide attempt was 0.8%, and the prevalence of SB (ideation, plan and/or attempt) in the past year was 7.9% (6.0% among men and 9.6% among women). In adjusted logistic regression analysis, among men, being 30 years and older and having an alcohol family problem were positively and obesity was negatively associated with SB in the past year. Moreover, in univariate analysis, early smoking initiation was positively and not using active transportation was negatively associated with SB in the past year. Among women, having an alcohol family problem, death from suicide of a close family member, having a cardiovascular incident (heart attack, stroke, or angina) and not using active transportation increased the odds of SB in the past year. In addition, in univariate analysis, low systolic blood pressure (< 100 mmHg), not taking antihypertensive medication, and current alcohol use were associated with past year SB.

Conclusion

Almost one in ten participants engaged in SB in the past year and several associated factors were identified that can inform intervention programmes.
A framework for handling missing accelerometer outcome data in trials
Authors: Tackney Mia S. , Cook Derek G. , Stahl Daniel , Ismail Khalida , Williamson Elizabeth , Carpenter James
Published: June 2021

Accelerometers and other wearable devices are increasingly being used in clinical trials to provide an objective measure of the impact of an intervention on physical activity. Missing data are ubiquitous in this setting, typically for one of two reasons: patients may not wear the device as per protocol, and/or the device may fail to collect data (e.g. flat battery, water damage). However, it is not always possible to distinguish whether the participant stopped wearing the device, or if the participant is wearing the device but staying still. Further, a lack of consensus in the literature on how to aggregate the data before analysis (hourly, daily, weekly) leads to a lack of consensus in how to define a “missing” outcome. Different trials have adopted different definitions (ranging from having insufficient step counts in a day, through to missing a certain number of days in a week). We propose an analysis framework that uses wear time to define missingness on the epoch and day level, and propose a multiple imputation approach, at the day level, which treats partially observed daily step counts as right censored. This flexible approach allows the inclusion of auxiliary variables, and is consistent with almost all the primary analysis models described in the literature, and readily allows sensitivity analysis (to the missing at random assumption) to be performed. Having presented our framework, we illustrate its application to the analysis of the 2019 MOVE-IT trial of motivational interviewing to increase exercise.
Letter on “Sharing trial results directly with trial participants and other stakeholders after the SARS-CoV-2 pandemic hit the UK – experience from the ActWELL trial”
Authors: Bruhn Hanne , Anderson Annie S. , Hickman Amy , Macaskill E. Jane , Treweek Shaun
Published: June 2021

After the SARS-CoV-2 pandemic took hold in the UK, the ActWELL trial team’s plans to present the trial results to participants and other stakeholders had to change. Instead of face-face events, three online events were planned and hosted successfully. In this article, we describe the choices made in planning and organisation of the online events including things we would do differently if we were to do it again. We think that online events are a useful platform when informing participants and other stakeholders of the results of your trial, even beyond the SARS-CoV-2 pandemic, and we hope this article can help other trial teams to plan their own online events.
Anti-peptidylarginine deiminase-4 antibodies at mucosal sites can activate peptidylarginine deiminase-4 enzyme activity in rheumatoid arthritis
Authors: Demoruelle M. Kristen , Wang Hong , Davis Ryan L. , Visser Ashley , Hoang Johnny , Norris Jill M. , Holers V. Michael , Deane Kevin D. , Darrah Erika
Published: June 2021

Background

Mucosal sites are hypothesized to play a role in the development of rheumatoid arthritis (RA). Since serum anti-peptidylarginine deiminase (PAD)4 antibodies, including a subset that cross-react with PAD3 (PAD3/4), are specific for RA and associate with severe disease, we sought to examine whether anti-PAD4 and anti-PAD3/4 antibodies were present in the lung and oral mucosa of subjects with RA and “at-risk” for RA.

Methods

We included 37 RA, 25 healthy control, and 46 subjects “at-risk” for RA based on familial RA and/or serum anti-citrullinated protein antibody (ACPA) positivity. Paired serum, sputum, and saliva were evaluated for anti-PAD4 and anti-PAD3/4 using immunoprecipitation and ACPA using ELISA. Immunoglobulins (Ig) were purified from representative samples, and their effect on citrullination of histone H3 by recombinant human PAD4 was measured by anti-citH3 immunoblot.

Results

Anti-PAD4 antibodies were detected in the serum of 6/37 (16.2%), sputum of 3/37 (8.1%), and saliva of 3/33 (9.1%) RA subjects and in the serum and sputum of 1/46 (2.2%) at-risk subjects. None of the healthy controls had anti-PAD4 antibodies at any site. Serum, sputum, and salivary anti-PAD4 antibodies were more prevalent in RA subjects with RA duration >2 years. Purified antibodies from representative anti-PAD4-positive and anti-PAD3/4-positive sputum were primarily of the IgA isotype and able to increase PAD4 enzymatic activity.

Conclusions

Anti-PAD4 antibodies are present in the sputum and saliva of a portion of RA patients and are infrequent in at-risk subjects. Importantly, the ability of anti-PAD4, and particularly anti-PAD3/4, antibodies in the sputum to enhance PAD4 enzymatic activity suggests that anti-PAD4 may play an active role in the RA lung.
The association of laminin levels with insulin resistance and non-alcoholic hepatosteatosis
Authors: Altun Özgür , Arman Yücel , Yoldemir Şengül Aydın , Pala Ayşe Selcen , Gümüşkaya Perihan Özkan , Özcan Mustafa , Karataş Mustafa , Dikker Okan , Tükek Tufan
Published: June 2021

Background

Laminin, one of the largest glycoproteins of the basement membrane, is an important component of the extracellular matrix. Functions of the basement membrane include regulation of cell signaling behaviors and structural support. Laminin plays a critical role in the regulation of insulin action in muscle, liver, and adipose tissue. The study mainly investigates an association between the change in serum laminin levels and insulin resistance and non-alcoholic hepatosteatosis.

Methods

This prospective study included a total of 90 participants; 60 patients diagnosed with Grade 2–3 non-alcoholic hepatosteatosis and 30 age- and sex-matched healthy controls between December 2019 and December 2020. Routine laboratory tests including glucose, insulin, homeostatic model of assessment-insulin resistance (HOMA-IR), alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and C-reactive protein and laminin levels were measured in the serum of the patient and control groups. Enzyme-linked immunosorbent assay was used for the measurement of laminin levels.

Results

The median serum laminin levels were lower in patients with hepatic steatosis, compared to the control group (72 ng/L vs. 82 ng/L, respectively; p = 0.003). In the patients with insulin resistance, median laminin levels were lower, regardless of the presence of non-alcoholic hepatosteatosis (67 ng/L vs. 85 ng/L, respectively; p = 0.007). There was a weak, negative correlation between the laminin levels and HOMA-IR.

Conclusions

Our study results suggest that, although there is no exact link between laminin and non-alcoholic hepatosteatosis, serum laminin levels are lower in patients with insulin resistance by regulating the insulin effect through integrins.
Generalized Jensen’s functional on time scales via extended Montgomery identity
Authors: Ramzan Sofia , Nosheen Ammara , Bibi Rabia , Pečarić Josip
Published: June 2021

In the paper, we use Jensen’s inequality for diamond integrals and generalize it forn-convex functions with the help of an extended Montgomery identity. Moreover, the bounds have been suggested for identities associated with the generalized Jensen-type functional.
Analytical solitons for the space-time conformable differential equations using two efficient techniques
Authors: Neirameh Ahmad , Parvaneh Foroud
Published: June 2021

Exact solutions to nonlinear differential equations play an undeniable role in various branches of science. These solutions are often used as reliable tools in describing the various quantitative and qualitative features of nonlinear phenomena observed in many fields of mathematical physics and nonlinear sciences. In this paper, the generalized exponential rational function method and the extended sinh-Gordon equation expansion method are applied to obtain approximate analytical solutions to the space-time conformable coupled Cahn–Allen equation, the space-time conformable coupled Burgers equation, and the space-time conformable Fokas equation. Novel approximate exact solutions are obtained. The conformable derivative is considered to obtain the approximate analytical solutions under constraint conditions. Numerical simulations obtained by the proposed methods indicate that the approaches are very effective. Both techniques employed in this paper have the potential to be used in solving other models in mathematics and physics.
A study of a nonlinear coupled system of three fractional differential equations with nonlocal coupled boundary conditions
Authors: Ahmad Bashir , Hamdan Soha , Alsaedi Ahmed , Ntouyas Sotiris K.
Published: June 2021

In this research we introduce and study a new coupled system of three fractional differential equations supplemented with nonlocal multi-point coupled boundary conditions. Existence and uniqueness results are established by using the Leray–Schauder alternative and Banach’s contraction mapping principle. Illustrative examples are also presented.
Neuropathological hallmarks of fetal hydrocephalus linked to CCDC88C pathogenic variants
Authors: Marguet Florent , Vezain Myriam , Marcorelles Pascale , Audebert-Bellanger Séverine , Cassinari Kévin , Drouot Nathalie , Chambon Pascal , Gonzalez Bruno J. , Horowitz Arie , Laquerriere Annie , Saugier-Veber Pascale
Published: June 2021

The prevalence of congenital hydrocephalus has been estimated at 1.1 per 1000 infants when including cases diagnosed before 1 year of age after exclusion of neural tube defects. Classification criteria are based either on CSF dynamics, pathophysiological mechanisms or associated lesions. Whereas inherited syndromic hydrocephalus has been associated with more than 100 disease-causing genes, only four genes are currently known to be linked to congenital hydrocephalus either isolated or as a major clinical feature: L1CAM, AP1S2, MPDZ and CCDC88C. In the past 10 years, pathogenic variants in CCDC88C have been documented but the neuropathology remains virtually unknown. We report the neuropathology of two foetuses from one family harbouring two novel compound heterozygous pathogenic variants in the CCDC88C gene: a maternally inherited indel in exon 22, c.3807_3809delinsACCT;p.(Gly1270Profs*53) and a paternally inherited deletion of exon 23, c.3967-?_c.4112-?;p.(Leu1323Argfs*10). Medical termination of pregnancy was performed at 18 and 23 weeks of gestation for severe bilateral ventriculomegaly. In both fetuses, brain lesions consisted of multifocal atresia-forking along the aqueduct of Sylvius and the central canal of the medulla, periventricular neuronal heterotopias and choroid plexus hydrops. The second fetus also presented lumbar myelomeningocele, left diaphragmatic hernia and bilateral renal agenesis. CCDC88C encodes the protein DAPLE which contributes to ependymal cell planar polarity by inhibiting the non-canonical Wnt signaling pathway and interacts with MPDZ and PARD3. Interestingly, heterozygous variants in PARD3 result in neural tube defects by defective tight junction formation and polarization process of the neuroepithelium. Besides, during organ formation Wnt signalling is a prerequisite for planar cell polarity pathway activation, and mutations in planar cell polarity genes lead to heart, lung and kidney malformations. Hence, candidate variants in CCDC88C should be carefully considered whether brain lesions are isolated or associated with malformations suspected to result from disorders of planar cell polarity.
α-Synuclein pathology in Parkinson disease activates homeostatic NRF2 anti-oxidant response
Authors: Delaidelli Alberto , Richner Mette , Jiang Lixiang , van der Laan Amelia , Bergholdt Jul Christiansen Ida , Ferreira Nelson , Nyengaard Jens R. , Vægter Christian B. , Jensen Poul H. , Mackenzie Ian R. , Sorensen Poul H. , Jan Asad
Published: June 2021

Circumstantial evidence points to a pathological role of alpha-synuclein (aSyn; gene symbol SNCA), conferred by aSyn misfolding and aggregation, in Parkinson disease (PD) and related synucleinopathies. Several findings in experimental models implicate perturbations in the tissue homeostatic mechanisms triggered by pathological aSyn accumulation, including impaired redox homeostasis, as significant contributors in the pathogenesis of PD. The nuclear factor erythroid 2-related factor (NRF2/Nrf2) is recognized as ‘the master regulator of cellular anti-oxidant response’, both under physiological as well as in pathological conditions. Using immunohistochemical analyses, we show a robust nuclear NRF2 accumulation in post-mortem PD midbrain, detected by NRF2 phosphorylation on the serine residue 40 (nuclear active p-NRF2, S40). Curated gene expression analyses of four independent publicly available microarray datasets revealed considerable alterations in NRF2-responsive genes in the disease affected regions in PD, including substantia nigra, dorsal motor nucleus of vagus, locus coeruleus and globus pallidus. To further examine the putative role of pathological aSyn accumulation on nuclear NRF2 response, we employed a transgenic mouse model of synucleionopathy (M83 line, expressing the mutant human A53T aSyn), which manifests widespread aSyn pathology (phosphorylated aSyn; S129) in the nervous system following intramuscular inoculation of exogenous fibrillar aSyn. We observed strong immunodetection of nuclear NRF2 in neuronal populations harboring p-aSyn (S129), and found an aberrant anti-oxidant and inflammatory gene response in the affected neuraxis. Taken together, our data support the notion that pathological aSyn accumulation impairs the redox homeostasis in nervous system, and boosting neuronal anti-oxidant response is potentially a promising approach to mitigate neurodegeneration in PD and related diseases.
Anti-Tr/DNER antibody paraneoplastic cerebellar degeneration preceding a very late relapse of Hodgkin Lymphoma after 12 years
Authors: Christensen Peter Broegger , Gregersen Henrik , Almasi Charlotte
Published: June 2021

Background

Paraneoplastic cerebellar degeneration (PCD) is a classic neurological syndrome where the presence of Anti-Tr/DNER antibodies is strongly associated with Hodgkin Lymphoma (HL). Awareness of the syndrome is important because with prompt treatment the prognosis of HL is good. The diagnosis can be a challenge in some patients. The importance of PCD in the detection of a cancer relapse is not clarified. We report the case of a 76-year-old man where a PCD, initially misdiagnosed as a stroke led to a diagnosis of a very late relapse of HL after 12 years.

Case presentation

A 76-year-old male with a 3-week history of unstable walking, slow speech and dizziness was admitted to our stroke unit apparently because the symptoms started acutely. With a diagnostic delay of 3–4 weeks a correct diagnosis of relapse HL was made based on cerebrospinal fluid changes with a strong positive reaction to anti-Tr/DNER antibodies, FDG-PET/CT scan, and biopsy findings. The medical history revealed that the patient had been diagnosed with HL previously, but has been in complete remission for 12 years. The patient was treated with intravenous immunoglobulin, chemo- and radiation therapy. Over the following 6–8 weeks he improved.

Conclusions

Late relapse in HL is very rare. If it occurs it presents as a symptomatic lymphadenopathy. Our case shows, that PCD can be the only presenting symptom of a very late relapse of HL. Paraneoplastic neurological syndromes (PNS) should be considered even in patients with very long cancer remission. PCD can in rare cases mimic a stroke within the posterior circulation. If MR imaging in severe acute/subacute cerebellar syndrome is normal further investigation is mandatory to rule out a PNS, particular in patients with a previous cancer.
Protein secondary structure prediction (PSSP) using different machine algorithms
Authors: Afify Heba M. , Abdelhalim Mohamed B. , Mabrouk Mai S. , Sayed Ahmed Y.
Published: June 2021

Background

The computational biology approach has advanced exponentially in protein secondary structure prediction (PSSP), which is vital for the pharmaceutical industry. Extracting protein structure from the laboratory has insufficient information for PSSP that is used in bioinformatics studies. In this paper, the support vector machine (SVM) model and decision tree are presented on the RS126 dataset to address the problem of PSSP. A decision tree is applied for the SVM outcome to obtain the relevant guidelines possible for PSSP. Furthermore, the number of produced rules was fairly small, and they show a greater degree of comprehensibility compared to other rules. Several of the proposed principles have compelling and relevant biological clarification.

Results

The results confirmed that the existence of a particular amino acid in a protein sequence increases the stability for the forecast of protein secondary structure. The suggested algorithm achieved 85% accuracy for the E|~E classifier.

Conclusions

The proposed rules can be very important in managing wet laboratory experiments intended at determining protein secondary structure. Lastly, future work will focus mainly on large protein datasets without overfitting and expand the amount of extracted regulations for PSSP.
Association Between Serum 25-hydroxyvitamin D Concentrations and Mortality Among Adults With Prediabetes
Authors: Lu Qi , Wan Zhenzhen , Guo Jingyu , Liu Liegang , Pan An , Liu Gang
Published: June 2021

Objectives

To investigate the association of circulating 25-hydroxyvitamin D [25(OH)D] levels with mortality among adults with prediabetes.

Methods

This retrospective cohort study included 15,195 adults with prediabetes (aged ≥20 years) from the National Health and Nutrition Examination Survey (NHANES) III and NHANES 2001-2014. Mortality from all causes, cardiovascular disease (CVD), and cancer was linked to National Death Index mortality data.

Results

The median (interquartile range) concentration of serum 25(OH)D was 60.5 (45.3, 77.4) nmol/L, and only 23.1% had sufficient vitamin D (≥75 nmol/L). Elevated serum 25(OH)D concentrations were significantly associated with lower levels of insulin, homeostasis model assessment of insulin resistance, triglyceride, and C-reactive protein, and higher levels of high-density lipoprotein at baseline (all Ptrend < 0.05). During a median follow up of 10.7 years, 3765 deaths (including 1080 CVD deaths and 863 cancer deaths) were identified. Compared with participants with 25(OH)D <30 nmol/L, the multivariate-adjusted hazard ratios and 95% confidence intervals for participants with 25(OH)D ≥ 75 nmol/L were 0.66 (0.53, 0.82) for all-cause mortality (Ptrend < 0.001), 0.66 (0.48, 0.89) for CVD mortality (Ptrend = 0.001), and 0.82 (0.49, 1.35) for cancer mortality (Ptrend = 0.32). For per-unit increment in ln-transformed 25(OH)D, there was a 27% lower risk of all-cause mortality and a 34% lower risk of CVD mortality (both P < 0.01).

Conclusions

These findings suggested that higher serum 25(OH)D concentrations were associated with lower all-cause and CVD mortality among individuals with prediabetes.
Resistance to Song: A Modernist View of Early Modern Lyric
Authors: Altieri Charles
Published: June 2021

In Theory of the Lyric Jonathan Culler makes powerful arguments for analogies between lyric and song, especially with regard to each medium’s commitment to producing pleasure and separating the speaking voice from individual psychology. But his case runs the risk of avoiding or oversimplifying lyric poems that resist these analogies. These poems call for interpretive acts that fully engage the work of syntax and structure in establishing distinctive modes of experience. Here Shakespeare’s sonnets demonstrate the roles syntax and structure can play, especially in cultivating complex acts of self-consciousness for which Hegel provides our best critical lens. With this focus, some important roles played by metaphysical conceits also become clear. The conceit forces acts of intense reflection. In the poetry, quintessentially in Donne’s “The Extasie,” there emerges a drama of the agents carrying out distinctive acts of self-interpretation: the fullness of love depends on hearing themselves speak and trying to imagine the objective difference that hearing is making in their behavior toward the other lover.
Moving beyond the label: Needs not diagnosis…
Authors: Alston Sara
Published: June 2021

For many parents and too many professionals, the diagnosis is seen as a magic answer and the solution to a child's difficulties – but it is not. Sara Alston discusses the risks involving diagnostic labels and looks at how we must provide SEN support based on need
Boost pastoral outcomes by investing in your staff
Authors: Sobel Daniel
Published: June 2021

Drawing on the excellent work of Cardiff High School and The Marlborough School, Daniel Sobel discusses how ensuring the wellbeing of your students begins with prioritising the wellbeing of your staff
Comparison of data-driven landslide susceptibility assessment using weight of evidence, information value, frequency ratio and certainly factor methods
Authors: Farooq Salman
Published: June 2021

Landslide susceptibility assessment is essential for development activities and disaster management in the mountainous regions to identify the landslide-prone areas. The present study aimed to evaluate and compare the efficacy of data driven quantitative models of landslide susceptibility assessment using geospatial tools in Jhelum valley of the Himalayas. This area suffers from extreme rainfall events due to the local climate and has experienced significant and widespread landslide events in recent years. Four probabilistic data-driven models are employed for this purpose, which includes the weight of evidence (WOE), information value method (IVM), frequency ratio (FR), and certainty factor (CF). These assessed models are based on integrating landslide contributing factors and a ground truthing-based landslide inventory of 437 landslides. The landslide susceptibility maps were presented by categorizing the study area into very low to very high susceptibility zone by Jenks natural breaks method. The performance of models was evaluated by a sensitivity analysis using Receiver Operator Curve (ROC) method. The ROC-validated results of success rate curves for WOE, IVM, FR and CF were 80 %, 78 %, 77 %, and 76 % respectively. The prediction rate curve of WOE, IVM, FR, and CF was 78 %, 77 %, 75 %, and 78 % respectively. The results showed the reasonable efficiency of applied models for landslide susceptibility assessment in the study area and applicable to regions with similar geomorphological conditions. Conclusively, the comparison of applied models revealed the promising results of used approaches.
Survey on Strategies to Promote Social Inclusion Through Sports
Authors: Grandisson Marie , Chrétien-Vincent Myriam , Ouellet Béatrice , Marcotte Justine , Lamontagne Marie-Eve , Milot Élise
Published: June 2021

A survey was conducted to document the perspectives of stakeholders in Quebec (Canada) on seven strategies that could promote social inclusion of people with intellectual disability through sports and physical activities. These strategies are associated with Unified Sports, awareness raising, training to coaches, supports through a companion, a peer or a resource person, and involvement in another role. A total of 229 individuals completed the survey. Their openness and desire to be involved was generally high for all seven strategies. Two strategies came out as most frequently prioritized: providing training to coaches and reinforcing awareness raising activities.
General Educators' Involvement in Interventions for Students With Intellectual Disability
Authors: Kuntz Emily M. , Carter Erik W.
Published: June 2021

General educators are crucial players in efforts to support inclusive education for students with intellectual disability. In this systematic review, we examined the roles of general educators within interventions delivered and evaluated in their middle and high school classrooms. Among these 40 intervention studies, the involvement of general educators could be characterized as mixed and often minimal. Across studies, general educator involvement spanned six different areas: developing the intervention, arranging peer involvement, implementing intervention components, providing perspectives, collecting data, and delivering class instruction. The ways in which general educators have contributed to the delivery of interventions in their classrooms remains uneven. We offer recommendations for research and practice aimed at increasing the involvement of general educators in providing support to students with intellectual disability.
Choosing Home: The Impact of Choosing Where to Live on People With Intellectual and Developmental Disabilities' Emergency Department Utilization
Authors: Friedman Carli
Published: June 2021

Social determinants of health are conditions, factors, and environments that impact people's health. One such metric of people's health is emergency department utilization, but there is less research exploring how social determinants impact the emergency department use of people with intellectual and developmental disabilities (IDD). This exploratory study examined the relationship between people with IDD choosing where and with whom to live—a social determinant of health—and emergency department utilization. We analyzed secondary Personal Outcome Measures data, and emergency department data from 251 people with IDD. Our findings revealed people with IDD who chose where and with whom to live had a 74% decrease in emergency department visits, regardless of their impairment severity. Choice in housing may improve people with IDD's health outcomes.
Polarization image demosaicking using polarization channel difference prior
Authors: Wu Rongyuan , Zhao Yongqiang , Li Ning , Kong Seong G.
Published: June 2021

This paper presents a simple, yet effective demosaicking technique using polarization channel difference prior for polarization images captured by division of focal plane imaging sensors. The polarization channel difference prior embodies that high frequency energy of difference between orthogonal channels tends to be larger than that between non-orthogonal channels. This paper theoretically proves that this prior is physical valid. For each missing polarization channel at a pixel position, three initial predictions are recovered using different channel differences. The missing polarization channel is estimated by the weighted fusion of the three initial predictions, where the weights are determined by the proposed polarization channel difference prior. The prior helps recover polarization information of the edges, fast and effectively. Experiment results on the polarization dataset demonstrate the effectiveness of the polarization channel difference prior for polarization image demosaicking. The proposed polarization demosaicking method consists of only 16 convolution operations, which makes it fast and parallelizable for GPU acceleration. An image of size 1024×1024 can be processed in 0.33 sec on Ryzen 7 3700X CPU and approximately 60 times faster with RTX 2700 SUPER GPU.
Mobile THz communications using photonic assisted beam steering leaky-wave antennas
Authors: Lu Peng , Haddad Thomas , Tebart Jonas , Steeg Matthias , Sievert Benedikt , Lackmann Jörg , Rennings Andreas , Stöhr Andreas
Published: June 2021

THz communications is envisaged for wide bandwidth mobile communications eventually reaching data capacities exceeding 100 Gbit/s. The technology enabling compact chip-integrated transceivers with highly directive, steerable antennas is the key challenge at THz frequencies to overcome the very high free-space path losses and to support user mobility. In this article, we report on mobile and multi-user THz communications using a photonic THz transmitter chip featuring 1D beam steering for the first time. In the proposed approach, 1D THz beam steering is achieved by using a photodiode excited leaky-wave antenna (LWA) in the transmitter chip. The on-chip LWA allows to steer the directive THz beam from 6° to 39° within the upper WR3-band (0.28-0.33 THz). The antenna’s directivity is 14 dBi which is further increased to 23 dBi using an additional hemicylindrical Teflon lens. The 3-dB beam width and coherence bandwidth of the fabricated THz transmitter chips with lens are 9° and 12 GHz, respectively. The proposed approach allows steering the THz beam via the beat frequency of an optical heterodyne system at a speed up to 28°/s. Without using a THz amplifier in the transmitter chip, a data rate of 24 Gbit/s is achieved for a single user for all beam directions and at short wireless distances up to 6 cm. The wireless distance is successfully increased to 32 cm for a lower data rate of 4 Gbit/s, still without using a transmitter amplifier. Also, multi-user THz communications and the overall capacity of the developed THz transmitter chip is studied revealing that up to 12 users could be supported together with a total wireless data capacity of 48 Gbit/s. Fully integrated 2D transmitter chips are expected to reach wireless distances of several meters without additional amplifiers.
Reconfigurable time-frequency division multiplexing metasurface: giving a helping hand to high signal-to-noise ratio and high data holographic imaging
Authors: Tian Jianghao , Cao Xiangyu , Gao Jun , Li Sijia , yang HuanHuan , ZHang Zhiyun , Han Bowen
Published: June 2021

A holographic imaging system based on reconfigurable time-frequency division multiplexing metasurface (RTFDMM) has been designed, in an attempt to address the problems of insufficient flexibility, low signal-to-noise ratio (SNR), and low data of traditional metasurface imaging devices. The modified Gerchberg-Saxton (MGS) algorithm in the front end of this system has been proposed to calculate the phase distribution required by the diffraction metasurface at the back end. The 1-bit low loss reconfigurable metasurface has been desiged in X-band. To obtain the best imaging results, the appropriate ranges of imazging distance, pixel size and resolution ratio are given by adjusting the phase distribution of metasurface. Based on the MGS algorithm and the 1-bit metasurface, the high-quality imaging system has been successfully established through the time-frequency division multiplexing (TFDM) technology. The high SNR imaging can be generated with the expansion of the time domain, while the high data imaging can be yielded with the quantization of the frequency domain. The proof-of-concept has demonstrated that the high data, high SNR, and high flexibility of the RTFDMM are critical technologies for the advancement of detection imaging equipment. Therefore, there are great possibilities for RTFDMM holographic imaging system to be applied in the intelligent detection platform in the future.
Copper-assisted catalyzed etching for nanotextured black silicon with enhanced photoelectric-conversion properties
Authors: Zhou Yang , Tu Baoxing , Weng Yuyan , Zheng Fengang , Su Xiaodong , You Lu , Fang Liang
Published: June 2021

Black silicon contains high-aspect-ratio micro/nanostructures with greatly suppressed front-surface reflection, thus possessing superior property in photoelectric devices. In this report, by a two-step copper-assisted chemical etching method, we have fabricated pyramid n+p-black silicon with optimized morphology and anti-reflectance capability, through systematically tuning the concentration of both copper ions and reducing agents, as well as the etching time. The improved optical absorption and superior charge transfer kinetics validate n+p-black silicon as a highly active photocathode in photoelectrochemical cells. The onset potential of 0.21 V vs. RHE and the saturation photocurrent density of 32.56 mA/cm2 are achieved in the optimal n+p-black silicon. In addition, the nanoporous structure with lower reflectance is also achieved in planar p-silicon via the same etching method. Moreover, the photodetectors based on planar p-black silicon show significantly enhanced photoresponsivity over a broad spectral range. This study offers a low-cost and scalable strategy to improve the photoelectric-conversion efficiency in silicon-based devices.
Double Minerals Ions Co-substituted Nano-Hydroxyapatite
Based Biocomposite Implant for Biomedical Applications
Authors: Sangeetha R. , Madheswari D. , Priya G. , Lavanya P.
Published: June 2021

The biocomposite of cerium(III)-copper(II) minerals co-substituted hydroxyapatite (Ce-Cu-HA)/
poly(methyl methacrylate) (PMMA) was developed using a process of solvent evaporation. The analysis
of X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscope-energy
dispersive X-Ray spectroscopy (SEM-EDX) confirmed the formation of Ce-Cu-HA in the PMMA
matrix. In addition, the fabricated biocomposite demonstrated high antibacterial activity on Escherichia
coli, which might be attributed to the action of Ce3+ and Cu2+ ions release on the substrate that blocks
the cell transport pathways contributing to apoptosis. Biocomposites have been tested in osteoblast-like
cells for their biological properties (biocompatibilty, alkaline phosphatase (ALP) activity and calcium
deposition). Based on the present findings, it was proposed that Ce-Cu-HA/PMMA biocomposite
could be a possible therapeutic candidate for bone tissue regeneration.
Synthesis and Physico-chemical Characterization of Solid Solution (1-x)CCTO−xPbTiO3
Authors: Slaoui M. , Gouitaa N. , Lahrichi A. , Harrach A. , Haddad M. , amcharfi T. L
Published: June 2021

The composite materials of (1-x)CaCu3Ti4O12, xPbTiO3((1-x)CCTO−xPT) were prepared by a modified
solid-state method in several steps. The Rietveld refinement indicates the formation of the pure cubic
and tetragonal phases for calcium copper titanate (CCTO) and lead-titanate (PT) pure ceramics,
respectively. While for CCTO-PT composites, the coexistence of the two cubic and tetragonal phases
was detected with the space group Im-3 and P4mm, respectively. The Raman spectra confirmed these
phase formations. The SEM images indicated a change in grains shape from quadratic to semi-spherical
with increases of PT contents and a reduce in average grains size with increase of PT content. The
dielectric measurements as function of temperature showed two anomalies which exhibit a
relaxation-like phenomenon and a clear diffuseness behaviour for all the samples. In addition, the
conductivity of these materials decreases and the resistance of grain boundaries was found to increase
with the increase of PT addition.
Synthesis, Structure, Magnetic and Catalytic Competency of a
Tetradentate (NNOO) Schiff Base Mediated Dimeric Copper(II) Complex
Authors: Chowdhury Habibar , Bera Rajesh , Adhikary Chandan
Published: June 2021

One dinuclear copper(II) complex {μ-[2,2′-{ethane-1,2-diylbis[(azanylylidene)methanylylidene]}-
bis(phenolato)]}-{μ-[2,2′-{ethane-1,2-diylbis[(azanylylidene)methanylylidene]}bis(phenolato)]}-
dicopper(II), [Cu2(salen)2] (1) [salen2− = [2,2′-{ethane-1,2-diylbis[(azanylylidene)methanylylidene]}-
bis(phenolato)] has been isolated and characterized by X-ray diffraction analysis and spectroscopic
studies. X-ray single crystal structure examination revealed that each Cu(II) center in the asymmetric
unit of 1 adopts a distorted square planar geometry with a CuN2O2 chromophore, where two asymmetric
units are attached through congregation of Salen involving Cu-O bond to form dinuclear molecular
unit [Cu2(salen)2]. In crystalline state, these dinuclear entities in 1 are extended through C-H···π
interactions and π···π interactions displaying a 3D network structure. The variable-temperature magnetic
susceptibility measurement asserted a dominant antiferromagnetic interaction between the copper(II)
centers through Cu-O-Cu linkage in 1 with J = -1.46 cm-1. The catalytic efficacy of complex 1 was
studied in a series of solvents for the oxidation of styrene and cyclooctene using tert-butyl-hydroperoxide
(TBHP) as an active oxidant under mild conditions. The catalytic reaction mixture has been analyzed
by gas chromatography and it displayed that the yield of the epoxidation and its selectivity is optimum
in acetonitrile medium.
Synthesis and Evaluation of Fe(III) Embedded Silane Grafted Layered
Double Hydroxide with Reduced Graphene Oxide Support as an
Efficient Adsorbent for V(V) and Se(IV) from Aqueous Systems
Authors: Suma S. , Seema S. , Manoj S.V. , Sumi V.S. , Rijith S.
Published: June 2021

The objectives of present work emphasize the successful usage of Fe(III) modified layered double
hydroxide clays with reduced graphene support (Si-rGO/LDH-Fe) for the removal of V(V) and Se(IV)
from aqueous systems. The precursors along with the modified and sorbent loaded materials were
successfully characterized by BET surface area analyzer, SEM-EDS mapping, FTIR, potentiometric
titrations and XPS analysis. Sorption performance of Si-rGO/LDH-Fe towards V(V) and Se(IV) under
optimized conditions such as pH, temperature and concentration were investigated. The equilibrium
and kinetic investigations revealed that the adsorption of V(V) and Se(IV) onto Si-rGO/LDH-Fe follows
non-linear Langmuir isotherm and pseudo-second-order model, respectively. The equilibrium reached
within 120 min and the Langmuir isotherm fit well with the experimental data. The adsorption
mechanism was proposed to be ligand exchange with electrostatic interactions. Such results indicated
that V(V) and Se(IV) species interact by the protonated hydroxyl moieties on the surface of
Si-rGO/LDH-Fe. The practical efficacy and effectiveness of Si-rGO/LDH-Fe was also compared with
some of the related works reported so far. The regeneration capacity and reusability of Si-rGO/LDH-Fe
were also tested by employing four cycles of desorption experiments.
Degradation Studies of Lacidipine: Identification, Isolation and Structural Characterization
of Stress Degradation Products using LCMS, Mass mediated Prep-HPLC, NMR and HRMS
Authors: Pulletikurthi K.V.K. Mohan , Chakravarthy Kotha S.S.K. , Doddipalla Raju , Rumalla Chidananda Swamy , Kaliyaperumal Muralidharan , Korupolu Raghu Babu
Published: June 2021

The stability of lacidipine drug under stress conditions and the identification of the degradation products,
according to ICH guidelines Q1A (R2) were investigated in the hydrolytic and oxidative stress
conditions. The drug degradation occurred under hydrolytic conditions like (acidic and basic) while it
was stable in the oxidative condition. Three degradation products were formed under acidic condition
and one degradation product was formed under basic condition, which was separated by using APMS
(Auto Purification Mass Spectrometer) and gradient elution with C18 column. The four degradants
have not been characterized earlier and in the present study all the structures were established and
characterized using NMR spectroscopy (1D and 2D) and HRMS (high resolution mass spectrometer).
Ion-Solvent Interactions Investigated by Isentropic Compressibility Measurements of
Lithium and Sodium Salts in Binary Mixtures of Acetonitrile and Nitromethane at 298.15 K
Authors: Anand Hardeep , Singh Narender , Kumar Suresh
Published: June 2021

Ultrasonic velocities (u) and densities (ρ) of lithium perchlorate (LiClO4), sodium perchlorate (NaClO4),
sodium tetraphenylborate (NaBPh4), tetrabutylammonium tetraphenylborate (Bu4NBPh4) and
tetrabutylammonium perchlorate (Bu4NClO4) were measured in the concentration range 0.001-0.25
mol kg-1 in acetonitrile (AN) and nitromethane (NM) binary mixtures consisting of 0, 20, 40, 60, 80
and 100 mol%NM in AN at 298.15 K. The isentropic compressibility (Ks) and apparent molal isentropic
compressibility (Ks,f) values of the above salts in all solvent mixtures have been evaluated from
experimental data. Limiting apparent molal isentropic compressibilities (Ko
s,φ) for various salts were
evaluated and split into the ionic contributions (Ko
s,φ)±. The variation of (Ko
s,φ)± with solvent compositions
shows that Li+ and Na+ ions have very large negative (Ko
s,φ)± values indicating strong solvation of both
Li+ and Na+ ions in AN + NM mixtures over whole binary solvent composition range. Stronger solvation
was further observed in the intermediate compositions of AN + NM mixtures. Li+ ions, however,
showed much higher solvation as compared to Na+ ions at all compositions. The ClO4
– ions showed
feeble solvation in AN + NM mixtures through some interaction with AN binary mixtures with higher
mol% of AN. The positive values of (Ko
s,φ)± with large magnitude for Bu4N+ and Ph4B– ions indicate
solvophobic type of interaction with the solvent molecules, which is stronger in the intermediate
compositions of AN + NM mixtures.
Inner Canthal Distance, Inter Pupillary Width, and Golden Proportion, as Predictors of Width of the Maxillary Central Incisors - An In Vivo Study
Authors: Shetty Sanath Kumar , Malli Prakyath , D’ Souza Joana , Shenoy Kamalakanth , Chunduri Surya Teja , Fernandes Kevin
Published: June 2021

BACKGROUND The mesio-distal width of anterior teeth can be determined by certain anthropometric measurements of face. The inter pupillary width is a facial landmark that is stable and does not modify after the age of 14 years. This study intended to determine if any relationship exists between inner canthal distances (ICD), inter-pupillary width (IPW), and golden proportion in determining the association between them and the maxillary central incisor width (CIW). METHODS 252 adult dentate subjects of age group 18 - 26 years who were free from dentofacial deformities were evaluated in the present in vivo study. The mesiodistal measurement of each maxillary central incisor, inner canthal distance (ICD), interpupillary width (IPW) was measured. The inner canthal distance of each subject was multiplied by a decreasing function of the geometric progression value (0.618) to provide the total width of two central incisors. The product was divided by 2 to get the width of a maxillary central incisor. A 't' test was used to establish significant differences if any in the mesiodistal width of the maxillary central incisors (CIW), inner canthal distance (ICD), and inter-pupillary width (IPW). Concurrence between the measured and calculated central incisor widths was evaluated using Pearson's correlation coefficients. RESULTS The mean ICD of male and female subjects was 33.03 ± 3.037 mm and 30.75 ± 2.89 mm, respectively. The mean IPW of male and female subjects was 62.26 ± 2.99 mm and 58.46 ± 2.73 mm, respectively. The mean CIW of male and female subjects was 19.98 ± 1.96 mm and 18.54 ± 1.87 mm, respectively. A high correlation was found between the measured and calculated width of central incisors (r=0.954 and r=0.974 in males and females). CONCLUSIONS There is a high positive correlation between ICD and CIW and it exists in the golden proportion. On the other hand, it was seen that the IPW and CIW were not in golden proportion. The mean of calculated CIW was significantly higher compared to the measured CIW in both males and females. ICD was seen as a significant factor in determining the CIW in males and females. All the facial and dental measurements were greater for men than for women; however, no significant differences were found between sexes with respect to ICD. KEY WORDS Inner Canthal Distance (ICD), Inter Pupillary Width (IPW), Central Incisor Width (CIW), Golden Proportion
Medical Students’ Perspective about Attributes of Role Models - The Other Side of Story
Authors: Aslam Fatima , Jawad Unaiza , Hotiana Usman Amin , Mahboob Usman , Ashfaq Sara , Jawad Muhammad Youshay
Published: June 2021

BACKGROUND Role modelling exponentially affects the attitude and behaviours of medical students and act as a key factor in developing professional attributes in them. Medical students observe role models and learn from them more than through formal teaching. This study investigates the determining elements that make a teacher a role model, so that role modelling can be used as an effective educational tool. METHODS A qualitative exploratory study was conducted on fifth year medical students of three medical colleges of Lahore, Pakistan. Fifteen, telephonic, semi structured interviews were included in the study. Thematic analysis was done by manual coding of transcribed interviews. RESULTS A total of 374 codes were generated in the first cycle of coding, that were further merged to 42 in the second cycle. These codes led to 5 subthemes that finally emerged as two themes. The first theme was “Finding ways around their blaring blunders - are we blind?” highlighting the attributes of negative role models which include humiliation of students and juniors, poor teaching and communication skills, lack of empathy for patients and unethical relationship with pharmaceutical industry. The second theme was “Walking the Line” focusing on the components of positive role modelling like formal workplace attire, candid approach in teaching, strategic dealing with students, empathetic attitude towards patients and prioritising fair treatments. CONCLUSIONS Medical education is not only about acquisition of new knowledge and skills but is also about acquiring physician’s character and identity. The study findings suggest that the medical students pay attention to both positive and negative attributes of their teachers and their influence on promoting professionalism and character development. It is suggested that both teachers and administrators should understand the significance of role models and advocate excellence in role modelling. KEY WORDS Role Models, Professional Development, Medical Student, Medical Teacher
Aggressive Embryonal Orbital Rhabdomyosarcoma in an Adolescent
Authors: Ling Ting Jacqueline Yih , Talib Norlaila , Mustapha Mushawiahti
Published: June 2021

Rhabdomyosarcoma is a highly malignant neoplasm originating mainly from undifferentiated mesenchymal tissue. It is one of the commonest soft tissue neoplasms in the head and neck region, with an incidence of 4.3 cases per million.1 Approximately 10 % of the cases reported occur in the orbit. It is considered a disease of young children with strong male prevalence.2 This article presents a case of a 12- year-old girl with embryonal orbital rhabdomyosarcoma which is a rare occurrence among adolescents and its management challenges.
Editorial
Authors: Carlyle Serian
Published: June 2021

Editorial for the Summer 2021 edition of Slovo, written by Serian Carlyle (Editor-in-Chief)