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Mixing of fluids in a coaxial jet is studied under four distinct viscosity ratios, $m=1$, $10$, $20$ and $40$, using highly resolved large-eddy simulations (LES), particle image velocimetry and planar laser-induced fluorescence. The accuracy of predictions is tested against data obtained by the simultaneous experimental measurements of velocity and concentration fields. For the highest and lowest viscosity ratios, standard RANS models with unclosed terms pertaining to viscosity variations are employed. We show that the standard Reynolds-averaged Navier–Stokes (RANS) approach with no explicit modelling for variable-viscosity terms is not applicable whereas dynamic LES models provide high-quality agreement with the measurements. To identify the underlying mixing physics and sources of discrepancy in RANS predictions, two distinct mixing modes are defined based on the viscosity ratio. Then, for each mode, the evolution of mixing structures, momentum budget analysis with emphasis on variable-viscosity terms, analysis of the turbulent activity and decay of turbulence are investigated using highly resolved LES data. The mixing dynamics is found to be quite distinct in each mixing mode. Variable viscosity manifests multiple effects that are working against each other. Viscosity gradients induce additional instabilities while increasing overall viscosity decreases the effective Reynolds number leading to laminarization of the turbulent jet, explaining the lack of dispersion and turbulent diffusion. Momentum budget analysis reveals that variable-viscosity terms are significant to be neglected. The scaling of the energy spectrum cascade suggests that in the TLL mode the unsteady laminar shedding is responsible for the eddies observed.
The aim of this study is to ascertain the psychological impacts of coronavirus disease (COVID-19) among the Pakistani health care workers (HCWs) and their coping strategies.
This web-based, cross-sectional study was conducted among HCWs (N = 398) from Punjab Province of Pakistan. The generalized anxiety scale (GAD-7), patient health questionnaire (PHQ-9), and Brief-COPE were used to assess anxiety, depression, and coping strategies, respectively.
The average age of respondents was 28.67 years (SD = 4.15), with the majority being medical doctors (52%). Prevalences of anxiety and depression were 21.4% and 21.9%, respectively. There was no significant difference in anxiety and depression scores among doctors, nurses, and pharmacists. Females had significantly higher anxiety (P = 0.003) and depression (P = 0.001) scores than males. Moreover, frontline HCWs had significantly higher depression scores (P = 0.010) than others. The depression, not anxiety, score was significantly higher among those who did not receive the infection prevention training (P = 0.004). The most frequently adopted coping strategies were religious coping (M = 5.98, SD = 1.73), acceptance (M = 5.59, SD = 1.55), and coping planning (M = 4.91, SD = 1.85).
A considerable proportion of HCWs are having generalized anxiety and depression during the ongoing COVID-19 pandemic. Our findings call for interventions to mitigate mental health risks in HCWs.
In Tharparkar, south-east Pakistan, over 300 kilometres of roads are being constructed to facilitate access to a coalfield intended to provide power to an electricity-starved country. The new roads are often sold as harbingers of great change and signs of modernity. Industry and the sought-after prize of foreign direct investment are presented as being just around the corner. I was often told that Thar (Tharparkar) would become ‘a Dubai’, which represented an ultimate symbol of modernity. Scholars have argued that neoliberalism's achievements are double: narrowing the window of political debate, while promising prospects without limit. In Tharparkar, the immediate roads effect has been increased land speculation, with little tangible improvements with regards to local employment. I argue that the ‘transition rhetoric’ being used by the state and the local political elite has no relation to the actual economic and political processes, except to veil interests of the elite groups. The material from Tharparker demonstrates that roads as symbols of ‘modernity’ can be used to deconstruct some of the contradictions at the heart of many modernization myths.
The many gatherings held in the offices of Mahesh Kumar, president of the Taluka Council of Islamkot in the district of Tharparkar in Pakistan, were often attended by local businessmen, largely Hindu, and one's absence meant that the individual was no longer part of the informal network of Hindu traders who dominated local politics. During one such meeting held in December 2016 at the municipal offices, to which I had invited myself, Mahesh was effusive: ‘We are very happy with the developments. It's going to be a Dubai. You will see. There is talk of a special economic zone. And, of course, now we are in the China-Pakistan Economic Corridor.’
There was genuine excitement among those present, including the opposition leader on the town council, Nikhil Vanya. The men were known to be rivals, changing parties but never a member of the same party at the same time, yet here they were in this crowded room in complete agreement.
COVID-19 outbreak has been accompanied by a massive infodemic, however, many vulnerable individuals such as illiterate or low-literate, older adults and rural populations have limited access to health information. In this context, these individuals are more likely to have poor knowledge, attitudes, and preventive practices related to COVID-19. The current study was aimed to investigate COVID-19’s awareness of the illiterate population of Pakistan.
A cross-sectional survey was conducted among illiterate Pakistanis of ages ≥ 18 years through a convenient sampling approach. The study participants were interviewed face to face by respecting the defined precautionary measures and all data were entered and analyzed using SPSS version 22 (IBM, Armonk, NY).
The mean age of the study participants’ (N = 394) was 37.2 ± 9.60 years, with the majority being males (80.7%). All participants were aware of the COVID-19 outbreak and television news channels (75.1%) were the primary source of information. The mean knowledge score was 5.33 ± 1.88, and about 27% of participants had a good knowledge score (score ≥ 7) followed by moderate (score 4 - 6) and poor (score ≤ 3) knowledge in 41.6%, and 31.5% of respondents, respectively. The attitude score was 4.42 ± 1.22 with good (score ≥ 6), average (score 4 - 5), and poor attitude (score ≤ 3) in 19%, 66%, and 15% of the participants, respectively. The average practice-related score was 12.80 ± 3.34, with the majority of participants having inadequate practices.
COVID-19 knowledge, attitude, and preventive practices of the illiterate population in Pakistan are unsatisfactory. This study highlights the gaps in specific aspects of knowledge and practice that should be addressed through awareness campaigns targeting this specific population.
This study aims to assess the stress levels, stress busters (stress relievers), and coping mechanisms among Saudi dental practitioners (SDPs) during the coronavirus disease (COVID-19) pandemic outbreak.
A self-administered questionnaire was sent to SDPs via Google Forms. Cohen’s stress score scale was used for stress evaluation, and the mean scores were compared based on age, gender, qualification, and occupation. In addition, comparisons of the utilization of stress coping mechanisms and stress busters based on gender, age, and occupation were evaluated. Descriptive statistics were carried out using SPSS Version 21.0 (IBM Corp, Armonk, NY).
A total of 206 SDPs (69% males and 31% females) participated in the study. Male SDPs showed a higher score than females (P > 0.05). SDPs around age 50 years and above obtained high stress scores (25 ± 7.4) as compared with other age groups (P < 0.05). The occupational level showed higher stress scores (22.6 ± 4.6 than the other occupation groups (P < 0.05). The majority of the SDPs used watching TV/mobile/computer (80%) as a stress buster, followed by binge eating (64%), exercise (44%), smoking (32%), do-it-yourself (DIY; 23%), and meditation (17%).
SDPs are experiencing stress levels during the COVID-19 pandemic. Male SDPs above age 50 years and private practitioners showed higher levels of stress scores. An overall commonly used stress buster was smoking in males and meditation in females.
ABSTRACT IMPACT: Olfactory dysfunction is a defining symptom of COVID-19 infection. As the number of total, confirmed COVID-19 cases approaches 7 million in the United States, it is estimated that there will be up to 500,000 new cases of chronically diminished smell. We offer a promising treatment. OBJECTIVES/GOALS: The primary aim is to explore the main effects and interaction of bimodal visual-olfactory training and patient-preferred scents on olfactory training in patients with post-COVID-19 hyposmia or anosmia. METHODS/STUDY POPULATION: The study will utilize a 2x2 factorial design. The two effects we will explore are unimodal versus bimodal training and conventional versus patient-preferred odors. All 4 arms will undergo 12 weeks of olfactory training. Participants will be assessed pre and post-intervention. Measurements of olfactory function include the objective smell identification test and subjective measures including the Clinical Global Impression Scale and Olfactory Dysfunction Outcomes Rating. Individuals eligible for the study include men and women between 18 and 70 years of age with olfactory dysfunction of at least 3 months duration initially diagnosed within 2 weeks of a COVID-19 infection. Of note, we will enroll nationally. RESULTS/ANTICIPATED RESULTS: We anticipate that the bimodal, patient-preferred scents training group will have the greatest improvement in smell scores, number of responders, and patient-reported sense of smell and health-related quality of life due to an additive interaction between the bimodal visual-olfactory and patient-preferred interventions. DISCUSSION/SIGNIFICANCE OF FINDINGS: The pathophysiology of COVID-19 olfactory dysfunction is mediated through damage to the peripheral and central olfactory pathways. This suggests that interventions most likely to be efficacious target both pathways, as olfactory training does.
Pandemics and subsequent lifestyle restrictions such as ‘lockdowns’ may have unintended consequences, including alterations in body weight. This systematic review assesses the impact of pandemic confinement on body weight and identifies contributory factors. A comprehensive literature search was performed in seven electronic databases and in grey sources from their inception until 1 July 2020 with an update in PubMed and Scopus on 1 February 2021. In total, 2361 unique records were retrieved, of which forty-one studies were identified eligible: one case–control study, fourteen cohort and twenty-six cross-sectional studies (469, 362 total participants). The participants ranged in age from 6 to 86 years. The proportion of female participants ranged from 37 % to 100 %. Pandemic confinements were associated with weight gain in 7·2–72·4 % of participants and weight loss in 11·1–32·0 % of participants. Weight gain ranged from 0·6 (sd 1·3) to 3·0 (sd 2·4) kg, and weight loss ranged from 2·0 (sd 1·4) to 2·9 (sd 1·5) kg. Weight gain occurred predominantly in participants who were already overweight or obese. Associated factors included increased consumption of unhealthy food with changes in physical activity and altered sleep patterns. Weight loss during the pandemic was observed in individuals with previous low weight, and those who ate less and were more physically active before lockdown. Maintaining a stable weight was more difficult in populations with reduced income, particularly in individuals with lower educational attainment. The findings of this systematic review highlight the short-term effects of pandemic confinements.
High levels of stress are expected when crises affect people’s lives. Therefore, this Web-based, cross-sectional study was conducted among university students from Pakistan to investigate the psychological impairment and coping strategies during the coronavirus disease 2019 (COVID-19) pandemic. Google Forms were used to disseminate the online questionnaire to assess anxiety (Generalized Anxiety Disorder-7), depression (Patient Health Questionnaire-9), and coping strategies (Brief-COPE). A total of 1134 responses (age, 21.7 ± 3.5 y) were included. The frequency of students having moderate-severe anxiety and depression (score ≥ 10) were ≈ 34% and 45%, respectively. The respondents’ aged ≥ 31 y had significantly lower depression score than those ≤ 20 y (P = 0.047). Males had significantly less anxiety (6.62 ± 5.70 vs 7.84 ± 5.60; P = 0.001) and depression (8.73 ± 6.84 vs 9.71 ± 7.06; P = 0.031) scores. Those having family members, friends, or acquaintances infected with disease had significantly higher anxiety scores (8.89 ± 5.74 vs 7.09 ± 5.56; P < 0.001). Regarding coping strategies, the majority of respondents were found to have adopted religious/spiritual coping (6.45 ± 1.68) followed by acceptance (5.58 ± 1.65), self-distraction (4.97 ± 1.61), and active coping (4.81 ± 1.57). In conclusion, COVID-19 caused significant impairment on mental health of the students. The most frequent coping strategies adopted by students were religious/spiritual and acceptance coping. During epidemics, mental health of students should not be neglected.
Guidelines are lacking for management of acute ischemic stroke and stroke prevention in patients with immune thrombocytopenia (ITP). Our aim is to highlight the dilemma inherent in managing patients with both significant bleeding and thrombotic risk factors. In this review, we present two patients with history of ITP who presented with acute ischemic stroke and received tissue plasminogen activator (tPA) and endovascular thrombectomy (EVT), a rare management strategy in this patient population. In addition, we identified 27 case reports of ischemic stroke in patients with ITP; none of them received tPA or EVT. Furthermore, there are 92 patients with significant thrombocytopenia with no available data regarding the cause of thrombocytopenia, who were acutely treated with tPA or EVT. Conclusive evidence cannot be determined based on these limited number of cases. Future multicenter prospective cohort studies in patients with ITP are needed to provide better evidence-based treatment plans. At present, treatment of acute ischemic stroke in patients with ITP requires close collaboration between hematology and vascular neurology experts to find a balance between the benefit and risk of hemorrhagic complications.
B-cell non-Hodgkin lymphoma (B-cell NHL) is the second commonest malignancy in the stomach. We determined the distribution of Helicobacter pylori outer membrane protein Q (HopQ) allelic type, cytotoxin-associated gene (cag)-pathogenicity activity island (cag-PAI) and vacuolation activating cytotoxin A (vacA) genes, respectively, in patients with B-cell NHL. We also compared them with their distribution in non-ulcer dyspepsia (NUD). H. pylori was cultured from gastric biopsy tissue obtained at endoscopy. Polymerase chain reaction was performed. Of 170 patients enrolled, 114 (63%) had NUD and 56 (37%) had B-cell NHL. HopQ type 1 was positive in 66 (58%) in NUD compared with 46 (82%) (P = 0·002) in B-cell NHL; HopQ type 2 was positive in 93 (82%) with NUD compared with 56 (100%) (P < 0·001) in B-cell NHL. Multiple HopQ types were present in 46 (40%) in NUD compared with 46 (82%) (P < 0·001) in B-cell NHL. CagA was positive in 48 (42%) in NUD vs. 50 (89%) (P < 0·001) in B-cell NHL; cagT was positive in 35 (31%) in NUD vs. 45 (80%) (P < 0·001) in B-cell NHL; left end of the cagA gene (LEC)1 was positive in 23 (20%) in NUD vs. 43 (77%) (P < 0·001) in B-cell NHL. VacAs1am1 positive in B-cell NHL in 48 (86%) (P < 0·001) vs. 50 (44%) in NUD, while s1am2 was positive in 20 (17%) in NUD vs. 46 (82%) (P < 0·001) in B-cell NHL. H. pylori strains with multiple HopQ allelic types, truncated cag-PAI evidenced by expression of cagA, cagT and cag LEC with virulent vacAs1 alleles are associated with B-cell NHL development.
Optic neuritis (ON) is associated with a 38% ten-year risk of developing multiple sclerosis (MS) in Western populations, but the corresponding risk in non-Western populations is unclear. We conducted this study to estimate the risk of progression to MS after an episode of ON in a South Asian population.
Two hundred and fifty-three patients with idiopathic ON were identified by reviewing records of visual evoked potentials and chart notes from a single academic center spanning the years 1990-2007. A structured telephone interview was then conducted to identify patients who had subsequently received a diagnosis of MS. The diagnosis was corroborated from chart notes, where possible. Cumulative probability of conversion to MS was calculated using Kaplan-Meier survival analysis.
The five-year risk of developing MS was 14.6% and the ten-year risk was 24%. Patients (N=218) who had one or more typical demyelinating lesions on baseline brain magnetic resonance imaging (MRI) had a 68% 10-year risk; those with no lesions or non-typical lesions had a 14% risk (p<0.001). Female gender, recurrent ON, and occurrence of ON in winter months were also associated with increased risk (p≤ 0.001). Severity of ON and likelihood of detecting cerebrospinal fluid (CSF) oligoclonal bands were higher in patients who developed MS.
Idiopathic ON in Pakistan carries a lower risk of progression to MS compared with Western data. As in Western populations, however, presence of abnormal baseline brain MRI and CSF oligoclonal bands correlate with increased MS risk.
Electromyography (EMG) for suspected cervical or lumbosacral root compression is often negative, producing expense and physical discomfort that could have been avoided. To improve patient selection for testing, we sought to identify clinical features that would accurately predict presence of radiculopathy on EMG.
Adult patients consecutively evaluated for suspected cervical or lumbosacral root compression at an academic clinical neurophysiology laboratory were prospectively enrolled. Presence of clinical features suggesting root disease (neck or back pain, dermatomal pain or numbness, myotomal weakness, segmental reflex loss, and straight leg-raising) was recorded prior to testing. EMG examination to confirm root compression was conducted per standard protocols. Analysis was based on computation of sensitivity, specificity, predictive values, and accuracy.
A total of 200 patients (55% male; mean age 46.4 years; 38% suspected of cervical and 62% of lumbosacral disease) were included. EMG evidence of root disease was detected in 31% of cervical and 62% of lumbosacral referrals. Dermatomal pain was the most sensitive, and segmental reflex loss and myotomal weakness the most specific individual predictors of root disease. Combined presence of dermatomal pain or numbness with segmental reflex loss and myotomal weakness approached specificities of 78% (lumbosacral disease) and 99% (cervical disease). In all cases, myotomal weakness was the most accurate predictor of root disease.
The diverse symptoms and signs of cervical and lumbosacral root compression predict a positive electrodiagnosis of radiculopathy with varying degrees of accuracy, and may be used to guide patient selection for EMG testing.
A 51-year-old man presented with a 5-day history of progressive facial swelling, sensation of head fullness, increasing shortness of breath and paroxysmal nocturnal dyspnea. He denied chest pain, syncope or presyncope. Pastmedical history included mechanical aortic valve replacement 7 years prior and atrial fibrillation treated with warfarin. A clinical diagnosis of acute superior vena cava (SVC) syndrome was made. Portable chest radiograph showed a widened superior mediastinum. Computed tomography scan of the thorax demonstrated a large type A aortic dissection almost completely effacing the SVC. Acute type A aortic dissection (AD) is an emergency requiring prompt diagnosis and treatment. Patients typically present with acute onset of chest and/or back pain, classically described as “ripping” or “tearing.” SVC syndrome is rarely, if ever, mentioned as a presentation, as it is usually due to more chronic conditions. This case illustrates a rare incidence of type A AD actually presenting as SVC syndrome.
We describe experiments on self-heating and melting of nanocrystalline silicon microwires using single high-amplitude microsecond voltage pulses, which result in growth of large single-crystal domains upon resolidification. Extremely high current densities (>20 MA/cm2) and consequent high temperatures (1700 K) and temperature gradients (1 K/nm) along the microwires give rise to strong thermoelectric effects. The thermoelectric effects are characterized through capture and analysis of light emission from the self-heated wires biased with lower magnitude direct current/alternating current voltages. The hottest spot on the wires consistently appears closer to the lower potential end for n-type microwires and to the higher potential end for p-type microwires. The experimental light emission profiles are used to verify the mathematical models and material parameters used for the simulations. Good agreement between experimental and simulated profiles indicates that these models can be used to predict and design optimum geometry and bias conditions for current-induced crystallization of microstructures.
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