Background: Hypothyroidism can cause hypertension, hypercholesterolemia, cardiac dysfunction, and both hypo-and hypercoagulability; all of which are risk factors for stroke.Objectives: To explore the association between thyroid disease and occlusion of large vessels as well as functional outcome in patients with ischemic stroke. Material and Methods:A retrospective study was conducted among all acute ischemic stroke patients, secondary to large vessel occlusion, admitted to King Fahad Medical City (KFMC), Riyadh, Kingdom of Saudi Arabia, provided that thyroid hormones were measured for those patients.The electronic charts of all eligible patients admitted between January 2021 and June 2022 were reviewed.Severity of stroke was measured through the National Institute of Heath Stroke scale (NIHSS).Functional disability one month after discharge was assessed using the modified Rankin scale (mRS).Levels of thyroid hormones (thyroxine "T4", Triiodothyronine "T3" and thyroid stimulating hormone "TSH"), low density lipoprotein (LDL) as well as glycated hemoglobin (HbA1c) were extracted from patients` electronic files.Results: A total of 177 patients included in the study.Their age ranged between 17 and 100 years (60.74 ± 15.55).Males represented 56.3% of patients.Almost half (47.1%) of cases were categorized as severe stroke while 39.1% were mild to moderate.None of the studied patients` characteristics (age, gender, TSH, T3, T4, LDL, HbA1c) was significantly associated with stroke severity.Concerning functional disability one month after discharge, moderately severe and severe disabilities were observed among 27.7% and 21.5% of patients, respectively whereas death was reported in 15.8% of cases.Patients` age was highest in patients of category 5 (severe disability) (69.0 ± 14.6 years) and lowest among those of category 0 (no disability), p = 0.001.LDL level was highest among patients of category 2 (slight disability) and lowest among those of category 6 (dead) (3.2 ± 1.4 and 2.2 ± 1.1, respectively), p = 0.031.There was a statistically significant association between severity of stroke based on NIHSS scale and impact on functional outcome based on modified ranking scale, p<0.001. Conclusion:Thyroid disorders were not associated with severity of stroke.Older patients had more severe functional disability while LDL was lowest among dead patients.Stroke severity was associated with functional disability.

Introduction: Functional impairments accumulated after the stroke significantly affect daily living activities, and these patients often need assistance in performing basic life activities.The study aimed to assess the gender differences in functional disabilities among stroke survivors in home care facilities in the Bisha City of Saudi Arabia.Methodology: An institutional survey was conducted using a standardized proforma.The proforma had the provision for recording sociodemographic details, and post-stroke functional status (degree of disability) was recorded using the Modified Rankin Scale (MRS).Pearson's chi-square test was used to see the association of degrees of disability with various sociodemographic and medical status of the stroke survivors. Results:The mean mRS score was found to be 3.87 ± 0.8, where male stroke survivors showed significantly higher scores (4.10 ± 0.9) compared to females (3.70 ± 0.7) (p = 0.034).The IRS assessment also showed that severe disability was seen in 25.9% of patients, and it was comparatively higher in male stroke survivors.The degree of disability was also significantly higher among stroke patients who didn't involve in any physical activities (p = 0.047). Conclusion :Functional status was more severe in male stroke survivors than females.Understanding the gender differences in the health profile would help the health professional for a better orientation of rehabilitative care in order to improve current intervention and/or implement new treatment strategies.

The broadband gain properties of fiber optical parametric amplifiers pumped both by one and two chirped pump pulses are investigated for the amplification of ultrashort pulses, analytically with the gain spectrum calculated in both the anti-Stokes' and Stokes' side. The influence of chirp rate and time delay on the gain spectrum of fiber-based optical parametric chirped pulse amplification is mainly explored. It is shown that the chirp rate and time delay distinctly affect the second order dispersion and phase mismatching, leading to the gain variation; the two pump scheme provides broader gain bandwidth, especially under the condition of the two chirp rate with low absolute value; and a genetic algorithm is employed to optimize the gain characteristics for realizing a flatter and wider, high gain that is useful for the ultrashort pulse system.

In this paper, we present a comprehensive analytical model of Tm able to take into account direct cross-relaxation process. We show that by using an appropriate set of parameters the model is able to properly fit the first part of the fluorescence decay of Tm-doped tellurite glasses for different dopant concentration values. We also compare the model with a full numerical model to investigate its limitations. We assess the model is a valid tool to fit fluorescence properties but for precisely predicting population inversion is limited to doping level up to about 1%. In fact, we show the reverse cross-relaxation process becomes significant in case of higher doping level.

A two-pump fiber optical parametric amplifier (FOPA) based on the photonic crystal fiber (PCF) with As2S3 background in the mid-infrared (MIR) region is investigated numerically. The genetic algorithms are used to optimize the gain of the FOPA, and the amplifier peak gain, bandwidth and flatness are investigated in detail for the variety of the fiber length, the input signal and pump power. In addition, the comparison of the gain spectra between considering and neglecting the loss of the PCF is given. The results show that the wideband gain spectra with high peak gain can be obtained by using a short length of the PCF with the relatively low pump power, which show the great potential of the FOPA at wavelengths in the MIR region.

Cerebral palsy (CP) is a common disorder in children.Dickkopf-1 (Dkk1) inhibits the canonical Wnt signaling pathway.The study aimed to assess the serum levels of Dkk1 in boys with CP and to evaluate its correlations with body mass index (BMI) and bone turnover markers (BTMs).This study included 32 Saudi boys with different physical disabilities as a result of CP and muscular dystrophy and 39 healthy Saudi boys were enrolled as a control group.The serum levels of Dkk1, N-terminal propeptide of type I collagen (P1NP), bone alkaline phosphatase (B-ALP), and C-terminal cross-linking telopeptide of type I collagen (β-CTX) were measured using enzyme link immunosorbent assay (ELISA) kits.Serum Dkk1 levels were higher in boys with CP than in controls.Further, level of PINP, TSH, FT4, calcium, and phosphorus were also reported significantly higher in CP boys than in controls.While, level of BMI, β-CTX, 25-hydroxyvitamin D and PTH were significantly lower in patients than in controls.Serum Dkk1 levels were moderately correlated with calcium (=0.361,=0.0240) in the controls.Dkk1 may play a role in bone loss in boys with CP experiencing weight loss.Dkk1 could aid in the assessment of boys with CP and abnormal bone turnover.

In this paper we numerically investigate the effect of the reverse cross-relaxation process on the inversion population of laser levels in Tm-doped glass based active system. We show the impact may be significant when high inversion population is required.

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text A. Albalawi, M. Kochanowicz, J. Zmojda, P. Miluski, D. Dorosz, and S. Taccheo, "Fluorescence spectrum of an Yb:Er:Tm:Ho Doped Germanate Glass," in Laser Congress 2018 (ASSL), OSA Technical Digest (Optica Publishing Group, 2018), paper ATu2A.4. Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

Background: Physical disability is common in children. Dickkopf-1 (Dkk1) is a protein marker for the inhibition of bone formation. This study aimed to assess the level of Dkk1in girls with physical disability and evaluate its correlation with bone turnover markers (BTMs) and body mass index (BMI). Methods: This study included 36 physically disabled Saudi girls recruited from the Disabled Children's Association in Jeddah, Saudi Arabia. Forty healthy Saudi girls were enrolled as a control group. The serum levels of Dkk1, the correlation between serum Dkk1 with N-terminal propeptide of type I collagen (P1NP), alkaline phosphatase (ALP), and Cterminal cross-linking telopeptide of type I collagen (β-CTX), as well as body mass index (BMI) were determined. Results: Dkk1, PINP and ALP levels were significantly higher in the physically disabled girls than in the control girls. In the control girls, β-CTX were significantly higher than in the physically disabled girls. A moderately significant positive correlations between Dkk1, BMI and ALP in addition to a weak correlation with PINP in the physically disabled girls were presented, however, the Dkk1 did not correlate with β-CTX. Conclusions: The results indicated that Dkk1 might have a role in bone changes in physically disabled girls. Dkk1 may assist in the assessment of patients with aberrant bone turnover. Further studies are needed to establish the exact role in bone metabolism. [Zahra Ali AL-Balawi, Hala Salim. Sonbol, Mohammed Saleh Aradwi. Determination of Dickkopf-1 in serum of physically disabled Saudi girls and its correlation with BMI and bone turnover markers. J Am Sci 2017;13(10):39-45]. ISSN 1545-1003 (print); ISSN 2375-7264 (online). http://www.jofamericanscience.org. 5. doi:10.7537/marsjas131017.05.

We show the reverse cross-relaxation process parameter can be calculated by fitting the slow decaying fluorescence tails emitted when pump level is almost depopulated. We also shows more precise measure requires high pump intensity.

In this paper, we numerically investigate the fluorescence decay of Tm-doped tellurite glasses with different dopant concentrations. The aim is to find a set of data that allows the prediction of material performance over a wide range of doping concentrations. Among the available data, a deep investigation of the reverse cross-relaxation process (F-3(4),F-3(4), -> H-3(6),H-3(4)) was not yet available. The numerical simulation indicates that the reverse cross-relaxation process parameter can be calculated by fitting the slow decaying H-3(4) fluorescence tails emitted when the pump level is almost depopulated. We also show that the floor of the H-3(4) decay curve is indeed related to a second exponential constant, half the F-3(4) lifetime, kicking in once the H-3(4) level depopulates. By properly fitting the whole set of decay curves for all samples, the proposed value for the reverse cross-relaxation process is 0.03 times the cross-relaxation parameter. We also comment on the measurement accuracy and best set-up. Excellent agreement was found between the simulated and experimental data, indicating the validity of the approach. This paper therefore proposes a set of parameters validated by fitting experimental fluorescence decay curves of both the H-3(4) and F-3(4) levels. To the best of our knowledge, this is the first time a numerical simulation has been able to predict the fluorescence behavior of glasses with doping levels ranging from 0.36 mol% to 10 mol%. We also show that appropriate calculations of the reverse cross-relaxation parameter may have a significant effect on the simulation of laser and amplifier devices. (C) 2017 Optical Society of America

Ytterbium-doped optical amplifiers have become common tools for industrial applications due to their high efficiency, relatively low cost and potentially very high output power level. The efficiency of an ytterbium-doped fiber amplifier depends mainly on the absorption of pump radiation, and, therefore, optimum pump wavelengths have been proposed such as 915 nm. However, the semiconductor pump diodes batch supplied by manufacturers may exhibit a spread in the output wavelength. This paper theoretically investigates the performance of Yb-doped amplifiers for different pump wavelengths and defines the pump power penalty when the pump source does not emit at the optimum wavelength. The penalty has been defined as normalized excess pump power required to achieve the desired gain.