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Despite advances in medical care, we still come across pregnancy in Eisenmenger syndrome. Eisenmenger syndrome represents the severe end of the spectrum for disease in pulmonary artery hypertension associated with CHD. Due to very high maternal and perinatal morbidity and mortality, pregnancy is contraindicated among these women. Current guidelines also recommend that the women who become pregnant should opt for early termination of pregnancy. Here, we present a case series of 11 women of Eisenmenger syndrome and their pregnancy outcome.
Methods:
It was a retrospective analysis of 12 pregnancies among 11 women with Eisenmenger syndrome who were managed in a tertiary care referral centre of Northern India.
Results:
The mean age of these women was 28 ± 4 years (range 22 to 36 years). Almost 80% of them (9/11) were diagnosed with Eisenmenger syndrome during pregnancy. The commonest cardiac lesion was Ventricular Septal defect (54.5%) followed by Atrial Septal defect (27.3%) and Patent Ductus arteriosus (9.1%). Only three women opted for medical termination of pregnancy, rest eight continued the pregnancy or presented late. Pregnancy complications found include pre-eclampsia (50%), abruption (22%), and fetal growth retardation (62.5%). There were three maternal deaths (mortality rate 27%) in postpartum period.
Conclusion:
This case series highlights the delay in diagnosis and treatment of CHD despite improvement in medical care. Women with Eisenmenger syndrome require effective contraception, preconceptional counselling, early termination of pregnancy, and multidisciplinary care.
Drug-induced movement disorders (DIMDs) form an important subgroup of secondary movement disorders, which despite conferring a significant iatrogenic burden, tend to be under-recognized and inappropriately managed.
Objective
We aimed to look into phenomenology, predictors of reversibility, and its impact on the quality of life of DIMD patients.
Methods
We conducted the study in the Department of Neurology at a tertiary-care centre in India. The institutional ethics-committee approved the study. We assessed 55-consecutive DIMD patients at presentation to our movement disorder clinic. Subsequently, they followed up to evaluate improvement in severity-scales (UPDRS, UDRS, BARS, AIMS) and quality of life (EuroQol-5D-5L). Wilcoxan-signed-rank test compared the scales at presentation and follow-up. Binary-logistic-regrerssion revealed the independent predictors of reversibility.
Results
Fourteen patients (25.45%) had acute-subacute DIMD and 41 (74.55%) had tardive DIMD. Tardive-DIMD occurred more commonly in the elderly (age 50.73±16.92 years, p<0.001). Drug-induced-Parkinsonism (DIP) was the most common MD, followed by tardivedyskinesia. Risperidone and levosulpiride were the commonest culprit drugs. Patients in both the groups showed a statistically significant response to drug-dose reduction /withdrawal based on follow-up assessment on clinical-rating-scales and quality of life scores (EQ-5D-5L). DIMD was reversible in 71.42% of acute-subacute DIMD and 24.40% of patients with chronic DIMD (p=0.001). Binary-logistic-regression analysis showed acute-subacute DIMDs and DIP as independent predictors of reversibility.
Conclusion
DIP is the commonest and often reversible drug-induced movement disorder. Levosulpiride is notorious for causing DIMD in the elderly, requiring strict pharmacovigilance.
Surface roughness (SR) is one of the major parameters used to govern the quality of the fused deposition modeling (FDM)-printed products, and the FDM process parameters can be easily regulated in order to obtain a good surface finish. The surface quality of the product produced by the FDM is generally affected by the staircase effect that needs to be managed. Also, the production time (PT) to fabricate the product and volume percentage error (VPE) should be minimized to make the FDM process more efficient. The aim of this paper is to accomplish these three objectives with the use of the parametric optimization technique integrating the artificial neural network (ANN) and the whale optimization algorithm (WOA). The FDM parameters which have been taken into consideration are layer thickness, nozzle temperature, printing speed, and raster width. Experimentation has been conducted on printed samples to examine the impact of the input parameters on SR, VPE, and PT according to Taguchi's L27 orthogonal array. The ANN model has been built up using the experimental data, which was further used as an objective function in the WOA with an aim to minimize output responses. The robustness of the proposed method has been validated on the optimal combinations of FDM process parameters.
Recently, global-remote group studying has been made possible via digital video conferencing platforms. In preparation for the December 2020 MRCPsych part A exam, a study group was formed comprising 30 International Medical Gaduates (IMG) logging-in from different countries via 3 hour Zoom-study sessions hosted daily from 28th September until 12th December 2020 (1800-2100 GMT time). This study demonstrates the impact of online group study in preparation for the MRCPsych A exam for s via data collected through questionnaires.
Method
The data of the study were collected through the questionnaires given to the group study members containing a total of 17 questions, 5 of which were open-ended.
The participants totalled 30 International Doctors who responded to an advertisement to form an online study group on Facebook. They logged-in for the sessions from seven different countries: Malaysia, India, Bangladesh, Ireland, Nigeria, Saudi Arabia, and the United Kingdom. The participants represented different working grades incuding experiences in psychiatry ranging from 0 to 5 years.
Data were analysed using percentage. The answers given to the open-ended questions were each examined using descriptive interpretation methods.
Result
Thematic analysis demonstrated that online group study made learning faster and easier. 96.6% support using online study sessions for future exams citing that they fostered cooperation, respect for diverse opinions and motivation for regular studying. 93.1% and partly 6.9% found the experience enjoyable and enabled the cultivation of different ideas. Indeed, 89.7% relied on it as a big part of their preparation with 26 saying it contributed to their passing of the exam success.
Almost three quarter of participants in the group also forged friendships and a sense of trust. It also became a platform for expressing opinions comfortably and developing communication and interpersonal skills.
Different working hours and time zones represented a challenge with most linking in at odd hours. Cultural differences were ultimately accepted including aspects of delivery of information which made a few participants appear abrupt.
Conclusion
With the ease in which social media connects us on a global scale, online study groups connecting IMGs from various backgrounds and diverse cultures not only makes exam preparations stimulating and easier to pass but also fosters interpersonal skills and connections that would be an asset in the long run.
While other mental health care outpatient facilities were moved to COVID-centers in March 2020 during the COVID-19 pandemic, the Institute of Mental Health and Neurosciences in Kashmir remained the only functional outpatient facility in the region. It is the only mental health care hospital in the country with a residential facility for psychiatric inpatients catering to the whole population of Jammu and Kashmir, India. The Mental Health Care Act 2017 that neccesitated “halfway homes” is yet to be implemented in the state leaving it's inpatients entirely under the institution's care. This study is to investigate the seroprevalence of antibodies to SARS-COVID-19 virus in the 34 residential inpatients in separate male (23 patients) and female (11 patients) wards. This was done as an audit to strategies and measures taken by the institute in protecting it's inpatients.
Method
3 to 5 ml of peripheral venous blood samples were collected and plasma extracted and analysed using the CE-IVD Roche Cobas Elecsys AntiSARS-CoV-2, Electrochemiluminescence Immunoassay (ECLIA) for the qualitative detection of total Immunoglobulins (IgG, IgM and IgA; Pan Ig) generated against SARS-CoV-2 (Roche Diagnostics, Indianapolis, IN, USA). The test was performed according to the manufacturer's instructions.
Result
Out of the 34 inpatients, 2 male inpatients tested positive for antibodies against SARS-CoV-2 (seroprevalence of 5.88%). In comparison, based on a report conducted by the government's Department of Community Medicine and Biochemistry on the 28th of October 2020, out of 2,361 participants in the community, 959 tested positive (seroprevalence of 40.6%).
One of the inpatients that tested positive was re-admitted after testing negative via RT-PCR. The second patient was admitted after being found homeless. He was tested negative on day 1 via RAT and on day 5 via RT-PCR. We believe both of them aquired the infection in the community.
Conclusion
This audit shows that the strategies implemented by the institute were effective in the prevention of the spread of COVID-19. Practical implementations of what works and improvisations are the proven methods of decreasing the mortality and morbidity in vulnerable populations while continuously providing vital mental health services.
To assess the level of understanding and difficulties encountered when obtaining sexual health details of their patients among mental health clinicians.
Background
People with mental health problems, especially those treated with psychiatric medication experience greater rates of sexual difficulties than those in the general population. Mental health practitioners need to examine personal beliefs and attitudes about sexuality among people with mental health problems. Providing information about sexuality and sexual practice benefits and enhances the quality of life of people with mental health problems. Therefore taking a sexual history should be an integral part of psychiatric assessment.
Method
An online survey consisted of 17 questions to cover 3 areas of objectives mentioned above was created using Survey Monkey. A link to the survey was emailed to all the clinicians who perform psychiatric assessments. Response collection and data analysis was performed by the trust IT team.
Result
Total of 54 clinicians participated in the survey representing nurses, junior, middle grade doctors and consultants. Almost all stated that mental health patients have capacity to make appropriate decisions about their sexual behaviour patterns. 43% thought people with mental health problems don't have similar patterns of sexual behaviour compared to people without mental health problems. 11% stated that people with mental health problems do not experience greater rates of sexual difficulties than those in the general population. Nearly a third did not believe that telling patients about potential sexual side effects may lead to poor compliance. Nearly 70% stated taking a sexual history should be an integral part of psychiatric assessment. 44% reported lack of knowledge and skills when talking about sexual health and 33% avoided asking about sexual health due to lack of knowledge. Half of the clinicians avoided asking about sexual health due to the fear of embarrassing or causing distress to patients while 16% avoided asking about sexual health due to self-embarrassment. 65% talk about sexual health issues only if patients brought them up.
During last 3 clinical encounters majority never asked about sexual difficulties, high risk behaviour and drug side-effects related to sexual difficulties. A significant proportion of clinicians never asked about contraception from their female clients.
Conclusion
Survey revealed majority of mental health clinicians lack understanding and skills about sexual health issues highlighting the importance of raising awareness among clinicians about sexual health issues.
COVID-19 is an on-going pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Recent evidence suggests that SARS-CoV-2 may be associated with various neuropsychiatric symptoms, including mania. We present a case of a middle aged man presenting with acute mania with psychotic symptoms 20 days post COVID infection in the absence of prior psychiatric illness. This report highlights the need for rigorous neuropsychiatric assessment in patient with symptoms of SARS-CoV-2 infection.
Method
A 52-year-old man of West African origin with past history of hypertension and no previous history of mental health illness presented with acute manic symptoms on background of two weeks of high fever, diarrhoea, mild headache, dry cough and anosmia. He was tested positive for SARS-CoV-2 infection on COVID PCR test. He was under self-isolation along with his family members who exhibited mild symptoms of SARS-CoV-2, none of them required hospital admission. He was initially fearful to seek medical attention but was brought in by family after exhibiting behaviour changes, obsession with toilet cleaning, reckless spending and getting aggressive approximately two weeks after the onset of acute upper respiratory symptoms. He presented elated in mood with pressure of speech and grandiose ideas. Investigations like neuroimaging and bloods were unremarkable. Initial psychiatric assessment found symptoms consistent with acute mania and he was detained under the Mental Health Act. During admission, he was sexually disinhibited and agitated on the ward requiring IM antipsychotics. He was treated with high dose of Olanzapine and Sodium valproate and his symptoms subsided within two weeks.
Result
This case emphasises the manifestation of neuropsychiatric illness post COVID-19 without a background of psychiatric illness, hypoxemia and cerebral infarction.
Based on the CORONERVE Programme and latest retrospective Lancet cohort studies, the period between 14 and 90 days after diagnosis, 5.8% COVID-19 survivors had their first recorded diagnosis of psychiatric illness.
It is also important to consider other organic disease given the simultaneous diagnosis of COVID-19. Although it is not yet possible to confirm here due to the lack of a validated CSF-PCR assay, previous reports have implicated SARS-CoV-2 in the development of viral encephalitis, and this remains an important differential.
Conclusion
Clinicians should be alert to the possibility of patients with COVID-19 developing neuropsychiatric complications post SARS-CoV-2 infection, mandating the need for vigilant initial neuropsychiatric assessment and possibly follow-up care in 3 months.
Agility in educational delivery has been catalyzed in response to national restrictions mandated by the recent COVID-19 pandemic. Increased use of assistive technologies further aligns with the General Medical Council's aims that medical educators provide an 'accessible training experience'. The study examined medical students' receptiveness to different types of interactive teaching. Two undergraduate cohorts received teaching on the Mental State Examination, either socially-distanced delivered by traditional powerpoint or remotely by mind-mapping software on a tablet hand-held digital device. We required an effective program which would retain the popular interactive elements of Psychiatry teaching and promote inclusivity across students' diverse learning styles.
Method
Two cohorts of Year 2 students from the Universities of Dundee and St Andrew's Scottish Graduate-Entry Medicine (scotGEM) course took part in an Introduction to Psychiatry seminar which involved a presentation of the Mental State Examination. One was conducted in a face-to-face setting via traditional PowerPoint. The second was conducted via remote-conferencing with mindmaps of key concepts drawn and screen-shared live to students as teaching progressed.
This was a qualitative study, with online links to questionnaires for 24 student participants across 5 domains. (1. The tutorial met my learning objectives, 2. The format was suitable for me, 3. The balance of theory and cases was suitable for me, 4. The tutorial was of appropriate length, 5. I was satisfied with the performance) Response options included: strongly disagree, disagree, neutral, agree, strongly agree. A section was also included with open-ended questions pooled for thematic analysis.
Result
Response rate reached >60% with >80% respondents answering strongly agree across all domains. Thematic results demonstrated positive responses across both teaching sessions, with the interactive elements valued by students. Comments included: “great job was done with the delivery of the session considering it was online rather than in person”; “drawing element was fantastic”; “Good: interactivity of the session drawing and creativity element”.
Conclusion
The Mental State Examination (MSE) via live-drawn mind-maps allows salient clinical information to be conceptualised in non-linear diagramatic format. This paediological approach can offer further access points across wide range of learning styles. This pilot study demonstrated such interactive components of Psychiatry teaching continue to be well received and can be effectively delivered remotely. Such sessions also serve to promote inclusivity, linking those who are geographically distant in addition to the visual learner and the neurodiverse. We aim to incorporate these dynamic teaching sessions into our online induction programs and disseminate Intelligent Tutorials to our remote and rural learners throughout Scotland.
The artificial magnetic conductor (AMC) formed by meta-materials is used in the micro-strip antenna design for microwave sensor applications. The AMC structures with two uniplanar layers, which include modified square split-ring resonator cells, are repeated and formed into a 5 × 3 array. The antenna's operational bandwidth result is significant, and it is in the range of 2.8–10 GHz with a maximum gain of 11.8 dB. Cancer or malignant tumor cells have entirely different electrical properties than healthy breast tissue. Principal component analysis and specific absorption rate (SAR) are used as a parameter to identify cancer or malignant tumor cells in the breast. The SAR values have been calculated for each layer of the 3D breast model. The results show a difference in the SAR values based on the size and tumors' locations.
There is a paucity of scientific analysis that has examined spatial heterogeneities in the socioeconomic vulnerabilities related to coronavirus disease 2019 (COVID-19) risk and potential mitigation strategies at the sub-national level in India. The present study examined the demographic, socioeconomic, and health system-related vulnerabilities shaping COVID-19 risk across 36 states and union territories in India.
Methods:
Using secondary data from the Ministry of Health and Family Welfare (MoHFW), Government of India; Census of India, 2011; National Family Health Survey, 2015-16; and various rounds of the National Sample Survey, we examined socioeconomic vulnerabilities associated with COVID-19 risk at the sub-national level in India from March 16, 2020, to May 3, 2020. Descriptive statistics, principal component analysis, and the negative binomial regression model were used to examine the predictors of COVID-19 risk in India.
Results:
There persist substantial heterogeneities in the COVID-19 risk across states and union territories in India. The underlying demographic, socioeconomic, and health infrastructure characteristics drive the vulnerabilities related to COVID-19 in India.
Conclusions:
This study emphasizes that concerted socially inclusive policy action and sustained livelihood/economic support for the most vulnerable population groups is critical to mitigate the impact of the COVID-19 pandemic in India.
In this work, the authors report the operation of a cylindrical dielectric resonator antenna (CDRA) in the high gain HEM13δ mode, for the first time. This mode, excited with a standard microstrip slot, radiates in the broadside direction with gain in the range of 8−10 dBi. It is shown that through feed optimization, the HEM13δ mode can be excited dominantly by suppressing the fundamental HEM11δ mode of the CDRA. Detailed simulation studies show that the HEM13δ mode is supported by cylindrical dielectric resonators with an aspect ratio (radius to height ratio or a/d) >1, and it resonates at a frequency approximately 2.2 times that of the fundamental HEM11δ mode. The above features of the HEM13δ mode CDRA can be used as approximate design rules. For a CDRA with dielectric constant ɛr = 24, diameter 2a = 19.43 mm, and height d = 7.3 mm (a/d = 1.3), the HEM13δ mode is excited at 6.125 GHz with a peak gain of 10.14 dBi in simulation. Corresponding values from prototype measurement are 5.981 GHz and 9.62 dBi, respectively for the resonant frequency and the gain, verifying the simulation.
This paper presents the design and analysis of a rectangular slot antenna for producing a directional radiation pattern over a wide bandwidth of 6–9 GHz. A basic wideband slot antenna is designed for the desired frequency band by microstrip offset feed technique. This antenna is then loaded with a superstrate and a reflector, both made of conducting sheets. Analogous to a three-element Yagi antenna, the superstrate enhances the boresight gain, while the reflector improves the front-to-back ratio (FBR) of the basic slot antenna. The antenna is optimized for superior wideband performance with boresight gain ≥5 dBi, peak cross-pol level ≤−10 dB and FBR ≥10 dB, over the −10 dB impedance band of 6–9 GHz, which in this paper is termed as the radiation bandwidth. Prototype measurement demonstrates a radiation bandwidth of 6.05–8.22 GHz (or 30.41%), which is in decent agreement with the simulation.
Variation of stress across the length and thickness of a cantilever during creep allows obtaining multiple pairs of strain rates and stress under steady-state condition. This work applies digital image correlation (DIC) and conjugate analytical models to obtain several such “strain rate–stress” pairs during steady-state creep by testing a single cantilever at a constant applied load. Furthermore, these strain rate–stress pairs are used to accurately determine the stress exponent of the material (e.g., Al and Pb). In addition, an empirical observation of plotting strain rate as a function of stress at fixed strain during primary creep for estimating stress exponent is extended to bending creep, wherein strain rates of the points in the cantilever lying on an iso-strain contour were plotted against the moment at the point to determine stress exponent. This study, thereby, proves that the “bending creep–DIC” combination is a high throughput test methodology for studying steady-state creep.
The stress and hence strain fields in a cantilever deforming as per power-law creep vary across the length and thickness of the sample, which allow obtaining multiple stress–strain pairs from a single test. Here, a high-throughput method is described to quantify the primary-cum-steady-state creep response of materials by testing a single cantilever sample in bending and mapping strain fields using digital image correlation. The method is based on the existence of stress invariant points in a cantilever, where the value of stress does not change during creep. It is demonstrated that strain evolution throughout primary and steady-state stages at these points is identical to the creep response obtained under uniaxial tests. Furthermore, the gained insights were exploited to obtain various parameters of a power-law type primary-cum-steady-state creep equation by testing only one cantilever sample. The developed method allows obtaining uniaxial creep curves at multiple stresses by testing a single cantilever, thereby reducing the time and number of samples required to understand the creep behavior of a material. The method has been validated by performing bending tests on Al and comparing the results with those of corresponding uniaxial tests.
The authors report effects of placing a very thin metallic interlayer, such as W and Ni, in between the Cu film and the Si substrate on cyclic thermal stress-induced interfacial sliding and hillock growth in Cu. Cu–Si samples with no interlayer were the most prone to both interfacial sliding and hillock growth, whereas samples with the Ni interlayer were the most resistant against these deleterious phenomena. While the rate of interfacial sliding decreased with each consecutive thermal cycle, hillocks continued to grow undeterred. The obtained experimental results are discussed, considering the compressive stress field generated in the Cu film.
To assess the strength of correlation and agreement between mid-upper arm circumference (MUAC) and BMI, and determine suitable MUAC cut-offs, to detect wasting and severe wasting among non-pregnant adult women in India.
Design:
Cross-sectional studies were conducted in five high-burden pockets of four Indian states.
Setting:
Prevalence of malnutrition among women and children is very high in these pockets and the government plans to implement community-based pilot projects to address malnutrition in these areas.
Participants:
Anthropometric measurements were carried out on 1716 women with children <5 years of age. However, analyses were conducted on 1538 non-pregnant adult women.
Results:
The results showed a strong correlation between MUAC and BMI in the non-pregnant women, with correlation coefficient of 0·860 (95 % CI 0·831, 0·883; P < 0·001). Cohen’s κ of 0·812 and 0·884 also showed good agreement between MUAC and BMI in identifying maternal wasting and severe wasting, respectively. The univariate regression model between MUAC and BMI explained 0·734 or 73 % of the variation in BMI. The MUAC cut-offs for wasting (BMI < 18·5 kg/m2) and severe wasting (BMI < 16·0 kg/m2) were calculated as 232 and 214·5 mm, respectively.
Conclusions:
MUAC is a strong predictor of maternal BMI among non-pregnant women with children <5 years in high-burden pockets of four Indian states. In a resource-constrained setting where BMI may not be feasible, the MUAC cut-offs could reliably be used to screen wasting and severe wasting in non-pregnant women for providing appropriate care.
OBJECTIVES/SPECIFIC AIMS: In the first aim, we will evaluate the proportion of highly HIV-susceptible memory CD4+ T cells present in the rectal mucosa, based on the proliferation status and expression of the HIV susceptibility markers, CCR5 and α4β7, between HIV-negative adolescent MSM and adult MSM engaging in RAI. The second aim will assess differences between the two study groups in the ratio of Th17 cells (CD4+ IL17+) to Treg cells (CD4+ FoxP3+ CD25+) in the rectal mucosa as a determinant of mucosal inflammation. Finally, in the third aim, we will utilize ex vivo rectal biopsy explant challenge experiments to examine whether HIV target cell availability and the Th17/Treg ratio influence rectal mucosal HIV susceptibility. METHODS/STUDY POPULATION: Rectal biopsy specimens are being collected from healthy, HIV-negative men that comprise the two study groups: 40 adolescent MSM 18-21 years of age who have engaged in RAI at least once previously in their lifetime and 40 adult MSM ≥35 years of age who have engaged in RAI for the previous 5 consecutive years with a minimum of 12 episodes annually. To identify CD4+ subsets of interest for aims 1 and 2, rectal mucosal mononuclear cells are isolated and phenotyped with CD45, CD3, CD4, CD45RA, CCR7, CD69, CCR5, α4β7, Ki67, FOXP3, and CD25 antibodies. To identify the Th17 cell subtype, the cells are stimulated with PMA/Ionamycin and stained with an antibody specific to IL-17A. Using cross-sectional analyses, we will compare the frequencies of mucosal CD4+ T cells that express certain phenotypic characteristics and evaluate differences in the Th17/Treg ratio between adolescent and adult MSM. For aim 3, rectal biopsy specimens are inoculated with HIV virus and the culture supernatant is assayed for p24 concentration on days 3, 7, 10 14, and 18. Longitudinal analyses will be performed to detect differences in p24 concentration at each time point and assess associations with mucosal target cell availability and with the Th17/Treg ratio. RESULTS/ANTICIPATED RESULTS: We hypothesize that younger age will be associated with enhanced memory CD4+ T cell proliferation and increased expression of HIV susceptibility markers (CCR5 and/or α4β7). In addition, we expect that the rectal mucosa of adolescent MSM will demonstrate a higher Th17/Treg ratio as compared to adult MSM, which could facilitate HIV transmission. It is also anticipated that rectal mucosal immune phenotypes characterized by increased HIV target cell availability and high Th17/Treg ratios will be associated with enhanced mucosal HIV susceptibility in the explant challenge model. DISCUSSION/SIGNIFICANCE OF IMPACT: There is a paucity of information regarding the mechanisms of rectal HIV transmission, and no studies to date investigate the immunologic effects of aging on transmission in the rectal mucosa. The results from this study will provide important information regarding age-related differences in the immune cell composition of the rectal mucosa as a critical step in better understanding immunologic factors that influence rectal HIV transmission.
Wall-resolved large-eddy simulation (LES) is used to simulate flow over an axisymmetric body of revolution at a Reynolds number, $Re=1.1\times 10^{6}$, based on the free-stream velocity and the length of the body. The geometry used in the present work is an idealized submarine hull (DARPA SUBOFF without appendages) at zero angle of pitch and yaw. The computational domain is chosen to avoid confinement effects and capture the wake up to fifteen diameters downstream of the body. The unstructured computational grid is designed to capture the fine near-wall flow structures as well as the wake evolution. LES results show good agreement with the available experimental data. The axisymmetric turbulent boundary layer has higher skin friction and higher radial decay of turbulence away from the wall, compared to a planar turbulent boundary layer under similar conditions. The mean streamwise velocity exhibits self-similarity, but the turbulent intensities are not self-similar over the length of the simulated wake, consistent with previous studies reported in the literature. The axisymmetric wake shifts from high-$Re$ to low-$Re$ equilibrium self-similar solutions, which were only observed for axisymmetric wakes of bluff bodies in the past.
This paper aims at investigating the dependence of the impedance and the radiation characteristics of a cylindrical dielectric resonator antenna (DRA), on the feed point of the DRA. It is demonstrated that the resonant frequency, bandwidth, radiation pattern symmetry, and cross-polarized radiation levels depend highly on the feed point. Three standard single-ended feed mechanisms such as the microstrip line, the microstrip slot, and the coaxial probe are taken as examples, to demonstrate the feed-point dependence of the DRA performance. Standard commercial EM simulation tools (ANSYS HFSS and CST Microwave Studio) are used for generating insightful results to help the discussion. This analysis also provides a functional comparison among the above said three feed mechanisms with respect to the feed-point dependence, which is further verified through measurements of DRA prototypes employing the three feeds.