The outcome of olfactory impairment in patients with otherwise paucisymptomatic coronavirus disease 2019 during the pandemic.

OBJECTIVE: This study aimed to measure the duration and recovery rate of olfactory loss in patients complaining of recent smell loss as their prominent symptom during the coronavirus disease 2019 outbreak. METHOD: This was a prospective telephone follow-up observational study of 243 participants who completed an online survey that started on 12 March 2020. RESULTS: After a mean of 5.5 months from the loss of smell onset, 98.3 per cent of participants reported improvement with a 71.2 per cent complete recovery rate after a median of 21 days. The chance of complete recovery significantly decreased after 131 days from the onset of loss of smell (100 per cent sensitive and 97.7 per cent specific). Younger age and isolated smell loss were associated with a rapid recovery, whereas accompanying rhinological and gastrointestinal symptoms were associated with longer loss of smell duration. CONCLUSION: Smell loss, occurring as a prominent symptom during the coronavirus disease 2019 pandemic, showed a favourable outcome. However, after 5.5 months from the onset, around 10 per cent of participants still complained of moderate or severe hyposmia.

Renoprotective effects of prazosin on ischemia-reperfusion injury in rats.

BACKGROUND: Renal ischemia-reperfusion (IR) injury is one of the main leading causes of acute kidney injury associated with inflammation, oxidative stress and cell apoptosis. We studied the effects of prazosin, as a specific blocker of α1-AR, on renal IR injury. METHODS: Rats were divided into normal control; untreated IR and prazosin-treated IR (1 mg/kg body weight). Prazosin was administered by intraperitoneal injection 30 min prior to IR induction. The level of urea/creatinine and oxidative factors were detected by colorimetric methods. Apoptosis-associated factors, inflammatory, and signaling proteins were analyzed in renal tissue. The abnormalities of renal histopathology were detected by immunohistochemistry. RESULTS: Administration of prazosin to IR rats ameliorated serum urea and creatinine and IR-induced histopathological damages. Lipid peroxidation was significantly improved after treatment by prazosin in IR injury rats, however, antioxidant status was not affected. Rats subjected to IR injury activated Bax protein and NF-κB mediated inflammatory response. Moreover, treatment with prazosin inhibited renal NF-κB activation, resulting in a significant decline in pro-inflammatory cytokine of IL-6. CONCLUSION: These findings suggest that prazosin could be a good candidate to attenuate renal IR injury due to its ability to modulate renal function, apoptosis and inflammation.

Strategies for improving the emission performance of hybrid electric vehicles.

Low emission vehicle technologies need widespread adoption in the transport sector to overcome its significant decarbonisation challenges. Hybrid Electric Vehicles (HEVs) represent an intermediate technology between pure electric vehicles and internal combustion engines that have proven capability in reducing petroleum consumption. HEV customers often cite improved fuel economy as a major benefit from adopting this technology; however, outstanding questions remain regarding their respective emission levels. Through an extensive literature study, we show that several issues remain with HEV emissions performance which stem from frequent high-power cold starts, engine calibration issues and inefficient operating conditions for catalytic converters. HEVs have more NOx, HC, CO and particle number emissions compared to conventional vehicles by up to 21.0, 5.8, 9.0 and 23.3 times, respectively. Improved engine control algorithms, after-treatment design and thermal design of three-way catalysts emerge as research priorities for improving the emissions performance of HEVs.

The irradiated fuel-burnup experiment of Tehran Research Reactor using nondestructive gamma-ray spectroscopy.

In this work, a nondestructive gamma scanning technique has been applied to determine the irradiated fuel burnup of Tehran Research Reactor (TRR). Thereby, a system was designed and installed at the rim of the TRR pool, which includes a High-Purity Germanium (HPGe) detector and associated electronics-devices, a proper shield, a collimator, and an elevator to radioactive fuel handling for any longitudinal and transverse fuel movement. In the system, it also was possible to measure fuel burnup for fuels with short cooling times at the minimum distance between the fuel and the detector. Five Standard Fuel Elements (SFEs) have been studied with U3O8Al fuel in burnup range of 14%-60% FIMA and cooling time range of 60 days-550 days. Then, by analyzing the gamma-ray emitted from 137Cs isotope as a fuel burnup indicator, an axial profile of fuel burnup was measured in the active fuel length of 61.5 cm and an active width of 6 cm. Finally, verification of results from reactor physics calculations was conducted based on fuel burnup measurements using a nondestructive gamma scanning technique that represents a well enough agreement between calculations and measurements.

Falconry graft: a predictable technique to restore soft triangle defects in rhinoplasty.

The nasal soft triangles are extremely vulnerable subunits of the nose that are prone to severe unaesthetic deformities. A technique to overcome these problems, comprising an effective simple modification of the shield graft, is presented. Using this technique, many existing soft triangle deformities, notches, and defects are easily restored. It may also be applied effectively in susceptible cases in order to avoid these complications. This article presents technical details and the cases of two patients treated with the technique, which indicate its potential utility.

Adenosine deaminase inhibition.

Adenosine deaminase is a critical enzyme in purine metabolism that regulates intra and extracellular adenosine concentrations by converting it to inosine. Adenosine is an important purine that regulates numerous physiological functions by interacting with its receptors. Adenosine and consequently adenosine deaminase can have pro or anti-inflammatory effects on tissues depending on how much time has passed from the start of the injury. In addition, an increase in adenosine deaminase activity has been reported for various diseases and the significant effect of deaminase inhibition on the clinical course of different diseases has been reported. However, the use of inhibitors is limited to only a few medical indications. Data on the increase of adenosine deaminase activity in different diseases and the impact of its inhibition in various cases have been collected and are discussed in this review. Overall, the evidence shows that many studies have been done to introduce inhibitors, however, in vivo studies have been much less than in vitro, and often have not been expanded for clinical use.

Sonographic Indices in Patients with Severe Acute Tubular Necrosis during Early Post-Kidney Transplantation Period.

BACKGROUND: Kidney transplantation is the most effective and optimal treatment for end-stage renal disease. OBJECTIVE: To investigate the association between serially measured ultrasound indices during the early post-operative period to determine severe acute tubular necrosis (ATN) in kidney allografts. METHODS: In a prospective study, we assessed sonographic renal indices including interlobar arteries peak systolic velocity (PSV), end-diastolic velocity (EDV), resistance index (RI), pulsatility index (PI), power doppler grading (PDG), acceleration time (AT), and renal volume on the 3rd and 9th days after kidney transplantation in 46 adult recipients who had no other significant complications except ATN. Biopsies were performed in patients with prolonged delayed graft function (DGF) to exclude other pathologies, especially acute rejection. RESULTS: 12 (20%) recipients experienced biopsy-proven severe ATN. The differences in the ultrasound indices and their measured discrepancies on the 1st and 2nd examinations between the groups were not statistically significant except for the 1st examined RI (p=0.029) and PI (p=0.04). No patient had PDG of >2. The first RI, with a cut-off value of 0.66, had a sensitivity of 91.7% and a specificity of 50% for predicting severe ATN (area under the ROC curve = 0.71). To compensate for the low specificity of this index, we suggest using the first PDG scale of equal to 2 with a specificity of 85.3%. Overall sensitivity, specificity, and positive and negative predictive values in established severe ATN throughout early post-operative days for a 3rd day RI >0.66 and PDG = 2, were 38%, 92.5%, 64.1%, and 80.9%, respectively. CONCLUSIONS: The RI and the PDG measured on the 3rd day after renal transplantation are useful indices for the diagnosis of established severe ATN in kidney allografts. Furthermore, donor characteristics, post-harvesting organ preservation status, main renal vascular anastomosis, and early post-operative recipient's clinical situations may also influence the incidence of severe ATN. Although the 1st ultrasound examination on the 3rd day in early post-transplantation provides important diagnostic and prognostic information, repeated assessment about one week later provides no more valuable information.

An efficient method for detecting damaged FAs; burnup and PPF estimations by gamma spectroscopy.

The purpose of this study is to provide a quick and efficient experimental method to identify and find damaged fuel assemblies (FAs) among all assemblies of the core. This method is based on gamma spectroscopy by measuring the activity ratio of the desired fission fragments that leaked into the coolant. Using the 134Cs/137Cs activity ratio, and considering the history factor for each FA, we determine the fuel burnup. Furthermore, from the 133I × 135I /133Xe activity ratio, the power peaking factor can be determined. This spectroscopy is carried out for the Tehran Research Reactor to find its failed FA positions. Then, the spectrum at different cooling times has been studied. Specifically, from the 134Cs/137Cs (0.1212 ±â€¯0.003) activity ratio and the fuel history factor (2.1023), the fuel burnup of damaged fuel is anticipated to be 33.9%, and the result of the computational codes is found to be 33.1%; these two results are consistent with each other. The results of both experiment and code analysis show the relatively reasonable estimation of this method in finding the location of damaged FAs.

Development and implementation of a novel panel consisting 20 markers for the detection of genetic causes of male infertility.

Azoospermia factor (AZF) genes are involved in spermatogenesis. Deletions in the region of these genes have been recognised as a major genetic cause of infertility due to defects in spermatogenesis. Klinefelter syndrome (KS) is the other main cause of male infertility. This study was performed to establish a novel method for the detection of genetic causes of infertility in males and also to investigate the prevalence, extent and position of Y chromosome microdeletions in Iranian infertile men. We developed a newly designed panel of fluorescent multiplex-PCR method to amplify 20 markers (15 sequence-tagged sites (STSs) markers which are placed in the Y chromosome AZF region, 2 short tandem repeats (STRs) and 3 segmental duplications (SDs)). This multifunctional method is for the simultaneous detection of Y chromosome microdeletions and KS. Among 149 studied infertile men, one was detected to suffer from KS and seven (4.7%) were detected with the presence of one or more deleted STS loci. The main cause of infertility for the remaining patients would be nongenetic factors. This strategy is represented as a fast and accurate method to determine the frequencies of different AZF microdeletions which are suitable for use in clinical purposes.

A computational continuum model of poroelastic beds.

Despite the ubiquity of fluid flows interacting with porous and elastic materials, we lack a validated non-empirical macroscale method for characterizing the flow over and through a poroelastic medium. We propose a computational tool to describe such configurations by deriving and validating a continuum model for the poroelastic bed and its interface with the above free fluid. We show that, using stress continuity condition and slip velocity condition at the interface, the effective model captures the effects of small changes in the microstructure anisotropy correctly and predicts the overall behaviour in a physically consistent and controllable manner. Moreover, we show that the performance of the effective model is accurate by validating with fully microscopic resolved simulations. The proposed computational tool can be used in investigations in a wide range of fields, including mechanical engineering, bio-engineering and geophysics.

Component columella augmentation in cleft nose rhinoplasty: a preliminary study.

The purpose of this study was to evaluate the outcome of a component columella augmentation technique in cleft nose rhinoplasty. This prospective study included rhinoplasty procedures in bilateral cleft nose patients treated by component columella augmentation technique. After surgery, all patients were followed up daily for the first week, and then at 1 month and 6 months postoperative. The following four parameters were assessed: nasal tip projection, infratip lobule length, infratip lobule-to-base distance, and columella-labial angle. Thirteen rhinoplasty patients were included. Tip projection was increased (5.6±3.5mm) in all cases postoperatively (P<0.05); the increase was seen mostly in the lobule-to-base length (4.5±0.4mm), with a minimal change in lobule length (1.1±3.6mm). Preoperative and postoperative lobule lengths were not statistically different (P>0.05). With this technique, it is not necessary to involve the upper and lower lips. Therefore, the non-aesthetic vertical scars and tissue distortion that may occur with local flaps are easily avoided. Compared to composite augmentation, each part of the deformity (cartilage and skin) is precisely and separately restored with this technique.

Nasal radix augmentation in rhinoplasty: suggestion of an algorithm.

The purpose of this study was to evaluate four standard techniques for radix augmentation during primary rhinoplasty: Skoog, crushed septal cartilage, temporalis fascia, and crushed cartilage wrapped in temporalis fascia. The main criterion for a patient to be included in this study was the need for radix augmentation, which was determined through preoperative evaluations. All patients requiring total dorsal augmentation were excluded from the study. This study included 63 rhinoplasty patients who underwent radix augmentation. The Skoog technique was applied in 15 patients, crushed septal cartilage in 16, temporalis fascia in 17, and crushed cartilage wrapped in temporalis fascia in 15. In those undergoing the Skoog technique, sharp edges of graft were palpable in three patients and were even visible in one patient. In the crushed cartilage group, seven patients showed irregularities during the postoperative follow-up. The results of this study indicate that all four autologous grafts represent acceptable graft material for radix augmentation. The algorithm suggests using the easier techniques first and that secondary donor sites should be considered only when the ideal result is not achieved.

Effect of Ferula assa-foetida oleo-gum-resin on renal function in normal Wistar rats.

In traditional Iranian medicine, asafoetida, an oleo-gum-resin obtained from the roots of Ferula assa-foetida, has been prescribed as a diuretic. This study was undertaken to investigate the diuretic effect of asafoetida in normal rats. Asafoetida was administered orally at the doses of 25 and 50 mg/kg and furosemide (10 mg/kg, intraperitoneal) was used as positive control. The diuretic effect was evaluated by measuring urine volume and sodium, potassium, urea, and creatinine content in urine and serum. Urine volume, excretion of sodium, and potassium were significantly increased by asafoetida as compared to the control group. A significant increase in creatinine clearance was observed in the groups treated with asafoetida at the doses of 25 and 50 mg/kg (P < 0.05). We conclude that asafoetida induced a diuretic effect comparable to that produced by the reference diuretic furosemide. This study provides a quantitative basis for explaining the folkloric use of asafoetida as a diuretic agent.

External Nasal Valve Efficacy Index: a simple test to evaluate the external nasal valve.

Many methods and techniques have been proposed for the assessment of the nasal valve, most requiring special equipment. Furthermore the main focus has been on the internal valve, while the role of the external nasal valve (ENV) has usually been underestimated. An index to assess ENV is presented herein. Two photographs of the basal view of the nose are taken, one in the resting position and the other after deep inspiration. These two life-size views are used to calculate the External Nasal Valve Efficacy Index (ENVE Index). Using simple software, the surface area of the nostril in the resting view (A) and breathing view (B) is measured. The ENVE Index is calculated by dividing the deep inspiration surface area by the resting surface area (B/A). The clinical indications for the use of the ENVE Index include rhinoplasty treatment planning, postoperative evaluation to assess the effects of surgery with regard to improvement or deterioration of the airway, and orthognathic surgery and the planning of appropriate postoperative care (such as elastic or intermaxillary fixation) according to the airway patency. The ENVE Index is a relatively simple, reproducible, and documentable test. This index can help the surgeon to make better decisions during treatment planning and postoperative care.

Breast dosimetry in transverse and longitudinal field MRI-Linac radiotherapy systems.

PURPOSE: In the framework of developing the integration of a MRI-Linac system, configurations of MRI-Linac units were simulated in order to improve the dose distribution in tangential breast radiotherapy using transverse and longitudinal magnetic field geometries of Lorentz force for both medial and lateral tangential fields. METHODS: In this work, the geant4 Monte Carlo (MC) code was utilized to compare dose distributions in breast radiotherapy for Linac-MR systems in the transverse and longitudinal geometries within humanoid phantoms across a range of magnetic field strengths of 0.5 and 1.5 T. The dose increment due to scattering from the coils was investigated for both geometries as well. Computed tomography images of two patients were used for MC simulations. One patient had intact breast while the other was mastectomized. In the simulations, planning and methods of chest wall irradiation were similar to the actual clinical planning. RESULTS: In a longitudinal geometry, the magnetic field is shown to restrict the lateral spread of secondary electrons to the lung, heart, and contralateral organs, which reduced the mean dose of the ipsilateral lung and heart by means of 17.2% and 6% at 1.5 T, respectively. The transverse configuration exhibits a significant increase in tissue interface effects, which increased dose buildup in the entrance regions of the lateral and medial tangent beams to the planning target volume (PTV) and improved dose homogeneity within the PTV. The improved relative average homogeneity index for two patients to the PTV at magnetic field strength of 1.5 T with respect to no magnetic field case evaluated was 11.79% and 34.45% in the LRBP and TRBP geometries, respectively. In both geometries, the simulations show significant mean dose reductions in the contralateral breast and chest wall skin, respectively, by a mean of 16.6% and 24.9% at 0.5 T and 17.2% and 28.1% at 1.5 T in the transverse geometry, and 10.56% and 14.6% at 0.5 T and 11.3% and 16.3% at 1.5 T in the longitudinal geometry. Considering the scattered photons which reflected from the coils, the average relative dose of each voxel is slightly increased by 0.53% and 0.32% in the LRBP and TRBP geometries, respectively. CONCLUSIONS: Orienting the B0 magnetic field parallel to the photon beam axis, LRBP geometry, tends to restrict the radial spread of secondary electrons which resulted in dose reduction to the lung. Dosimetry issues observed in both Linac-MR geometries, such as changes to the lateral dose distribution, significantly exhibited dose reduction in the contralateral organs on a representative breast plan. Further, the results show sharper edge dose volume histogram curves at 1.5 T for both geometries, especially in the LRBP configuration.

Passive appendages generate drift through symmetry breaking.

Plants and animals use plumes, barbs, tails, feathers, hairs and fins to aid locomotion. Many of these appendages are not actively controlled, instead they have to interact passively with the surrounding fluid to generate motion. Here, we use theory, experiments and numerical simulations to show that an object with a protrusion in a separated flow drifts sideways by exploiting a symmetry-breaking instability similar to the instability of an inverted pendulum. Our model explains why the straight position of an appendage in a fluid flow is unstable and how it stabilizes either to the left or right of the incoming flow direction. It is plausible that organisms with appendages in a separated flow use this newly discovered mechanism for locomotion; examples include the drift of plumed seeds without wind and the passive reorientation of motile animals.

Improvement of dose distribution in breast radiotherapy using a reversible transverse magnetic field Linac-MR unit.

PURPOSE: To investigate the improvement in dose distribution in tangential breast radiotherapy using a reversible transverse magnetic field that maintains the same direction of Lorentz force between two fields. The investigation has a potential application in future Linac-MR units. METHODS: Computed tomography images of four patients and magnetic fields of 0.25-1.5 Tesla (T) were used for Monte Carlo simulation. Two patients had intact breast while the other two had mastectomy. Simulations of planning and chest wall irradiation were similar to the actual clinical process. The direction of superior-inferior magnetic field for the medial treatment beam was reversed for the lateral beam. RESULTS: For the ipsilateral lung and heart mean doses were reduced by a mean (range) of 45.8% (27.6%-58.6%) and 26.0% (20.2%-38.9%), respectively, depending on various treatment plan setups. The mean V20 for ipsilateral lung was reduced by 55.0% (43.6%-77.3%). In addition acceptable results were shown after simulation of 0.25 T magnetic field demonstrated in dose-volume reductions of the heart, ipsilateral lung, and noninvolved skin. CONCLUSIONS: Applying a reversible magnetic field during breast radiotherapy, not only reduces the dose to the lung and heart but also produces a sharp drop dose volume histogram for planning target volume, because of bending of the path of secondary charged particles toward the chest wall by the Lorentz force. The simulations have shown that use of the magnetic field at 1.5 T is not feasible for clinical applications due to the increase of ipsilateral chest wall skin dose in comparison to the conventional planning while 0.25 T is suitable for all patients due to dose reduction to the chest wall skin.

Antinociceptive effect of Ferula assa-foetida oleo-gum-resin in mice.

Ferula assa-foetida L. is distributed throughout central Asia and Mediterranean area and grows wildly in Iran and Afghanistan. Asafoetida is an oleo-gum-resin that is the exudates of the roots of Ferula assa-foetida and some other Ferula species. In Iranian traditional medicine, asafoetida is considered to be sedative, analgesic, carminative, antispasmodic, diuretic, antihelmintic, emmenagogue and expectorant. The aim of this study was to evaluate the antinociceptive effect of asafoetida in mice. The analgesic activity of asafoetida (25, 50 and 100 mg/kg) was compared with that of sodium diclofenac (30 mg/kg) or morphine sulfate (8 mg/kg) by using hot plate and acetic acid induced writhing tests. In hot plate test, the percentage of maximum possible effect (%MPE) against the thermal stimulus at 15 min post treatment time point for all doses of asafoetida was significantly greater than the control group. The number of writhes in all three doses of asafoetida was significantly less than the control group. GraphPad Prism 5 software was used to analyze the behavioral responses. Data were analyzed using repeated measure one-way ANOVA and P<0.05 was considered as the significant level. According to our findings, asafoetida exhibited a significant antinociceptive effect on chronic and acute pain in mice. These effects probably involve central opioid pathways and peripheral anti-inflammatory action.

Observation of liquid-crystal formation during melting of D-(+)-glucose.

Liquid crystals, observed as maltese crosses under cross-polarized light, form in D-(+)-glucose immediately upon melting, at ∼416 K, and become an isotropic liquid at ∼500 K. Differential scanning calorimetry (DSC) results show two overlapping endothermic peaks corresponding to the formation and disappearance of the liquid crystals. Thermogravimetric analysis (TGA) confirmed that D-(+)-glucose undergoes thermal decomposition upon melting. Cooling and reheating isotropic samples previously heated to 500 K do not lead to the reappearance of the liquid crystals. The formation of liquid crystals is irreversible. Further study is required to determine which components among the decomposition intermediates or products of D-(+)-glucose are responsible for the formation of liquid crystals and whether they have process or product applications.

Transition delay using control theory.

This review gives an account of recent research efforts to use feedback control for the delay of laminar-turbulent transition in wall-bounded shear flows. The emphasis is on reducing the growth of small-amplitude disturbances in the boundary layer using numerical simulations and a linear control approach. Starting with the application of classical control theory to two-dimensional perturbations developing in spatially invariant flows, flow control based on control theory has progressed towards more realistic three-dimensional, spatially inhomogeneous flow configurations with localized sensing/actuation. The development of low-dimensional models of the Navier-Stokes equations has played a key role in this progress. Moreover, shortcomings and future challenges, as well as recent experimental advances in this multi-disciplinary field, are discussed.