saeed sohrabpour
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Long non-coding RNAs (lncRNAs) have recently emerged as critical regulators of oncogenic or tumor-suppressive pathways in human cancers. LINC01133 is a lncRNA that has exhibited dichotomous roles in various malignancies but to the best of our knowledge, the role of LINC01133 in laryngeal squamous cell carcinoma (LSCC) has not been previously investigated. This study aimed to investigate the expression, clinical significance, and potential functions of the LINC01133 in LSCC. Integrative bioinformatics analysis of sequencing data obtained from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets revealed LINC01133 as a differentially expressed lncRNA in head and neck/laryngeal cancers. Experimental validation via quantitative real-time PCR in 41 pairs of stage III and IV LSCC tissues and normal tissues adjacent to the tumor (NAT) demonstrated significant downregulation of LINC01133 in tumors (p<0.0001). Decreased LINC01133 expression associated with advanced tumor stage (p=0.0206) and lymph node metastasis (p=0.0203). The receiver operating characteristic analysis indicated potential diagnostic utility (AUC=0.7115, p=0.001). Bioinformatic predictions and literature mining suggested two potential competing endogenous RNA (ceRNA) mechanisms whereby LINC01133 may act as a tumor suppressor by sponging miR-205-5p to derepress the leucine-rich repeat kinase 2 (LRRK2) and androgen receptor, leading to dysregulation of cancer-related signaling cascades. This study provides initial evidence that loss of lncRNA LINC01133 expression may promote LSCC tumorigenesis, possibly by dysregulating microRNA interactions. Further verification of its regulatory mechanisms and diagnostic value is warranted.Keywords: Laryngeal Squamous Cell Carcinoma, Long Non-Coding RNA, LINC01133, LRRK2, Competing Endogenous RNA, Androgen Receptor
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Background
The University of Washington quality of life questionnaire (UW-QOL) is widely used to evaluate the quality of life for head and neck cancer patients. The purpose of this study is translation of the UW-QOL questionnaire's into Persian.
MethodsAfter translation and cultural adaptation of the UW-QOL, the questionnaire was distributed among 100 head and neck cancer patients. Internal reliability of the translated UW-QOL was determined using Cronbach's alpha coefficient. The validity was determined by Spearman correlation coefficient between UW-QOL and 12-Item Short Form Survey (SF-12). The test – retest reliability was measured by Intraclass Correlation Coefficient (ICC) after one week.
ResultsCronbach's alpha coefficient was more than 0.75 and ICC coefficient was more than 0.80 in all variables. The UW-QOL questionnaire composite score had a positive significant association with SF-12 questionnaire total score (Spearman's Correlation Coefficient= 0.70, P< 0.0001).
ConclusionIn conclusion Persian translation of the UW-QOL questionnaire has acceptable reliability and validity and is as valid as the original English version in evaluating the quality of life for patients with head and neck cancer.
Keywords: UW-QOL Questionnaire, Validity, Head, Neck Cancer, Reliability -
Omega-3 Adjunctive Therapy in Idiopathic SSNHL: A Randomised, Triple-Blind, Placebo-Controlled TrialIntroductionIdiopathic Sudden Sensorineural Hearing Loss as a subset of sensorineural hearing loss will be confirmed by a progressive hearing loss of at least 30 dB at three contiguous frequencies over 72 hours or less. A sudden or abrupt hearing loss correlates with the time course, and a vascular event is presumptive aetiology. There is an inverse association between Omega-3 consumption and hearing loss. This study aimed to evaluate the efficacy of Omega-3 adjunctive therapy in Idiopathic Sudden Sensorineural Hearing Loss by audiometric assessments.Materials and MethodsIn this randomised, triple-blind, placebo-controlled trial, all participants aged 18-70 with a history of sudden deafness (within 12 hours and ≤ 30 days) were eligible for enrollment. They were included if audiology diagnostic tests confirmed the SSNHL. Ultimately, they were randomised to the Omega-3 group and the placebo group.ResultsThirty-three patients were randomly allocated to the Omega-3 group and thirty-two to the placebo group. Vertigo (32.3% of all patients) and underlying conditions had significant relationships with complete response (C.R.)-final hearing level ≤of 25 dB in pure-tone average (P < 0.05). There was no significant difference between both groups before and after treatment. Although it was not statistically significant, patients in the Omega-3 group had faster recovery than placebo.ConclusionsOmega-3 adjunctive therapy did not have a therapeutic effect on SSNHL patients. Moreover, C.R. happened in half the patients. Vertigo and underlying conditions considerably worsen the recovery from SSNHL.Keywords: Omega-3, Sudden sensorineural hearing loss (SSNHL), vertigo
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Since the late 2019 months’ pandemic of Corona Virus Disease-2019 (COVID-19), it has spread globally and claimed abundant lives due to its expeditious interpersonal transmission and high mortality rate. Early studies showed that the upper aerodigestive tract procedures had the highest rates of nosocomial spread due to high viral load in upper respiratory and pharyngeal secretions. Between March 10 and April 10, 2020, a total of 28 rigid endoscopies were performed under general anesthesia for the removal of esophageal foreign bodies at our center. All the patients were screened on admission for symptoms of COVID-19 and a chest CT scan was performed and they were later followed up for further investigations. No patient had symptoms of COVID-19 (fever, cough, and dyspnea) on admission, and only one patient (3.57 %) had a suspicious CT scan for COVID-19. The mean age of 27 asymptomatic cases, including 14 men and 13 women, was 45.2 years old. Their average hospital stay was 0.8 days. all patients were later interviewed, inspected, and closely observed for any upcoming symptoms which would raise suspicion for COVID-19 during isolation. Of the 27 patients who cooperated, none showed COVID-19 symptoms. What makes this experiment prominent is that with suitable plans in a careful and precautionary manner, we can provide first-rate care for patients and meanwhile protect physicians during this pandemic promptly. Conclusion what makes this experiment prominent is that with suitable plans in careful and precaution manner, we are able to provide first-rate care for patients and meanwhile protect physicians during this epidemic in a timely manner.
Keywords: Upper aero digestive tract procedures, Esophageal foreign bodies, Rigid endoscopies, Coronavirus disease 2019(COVID-19), Coronavirus -
A 35- year- old woman presented with massive enlargement of the tongue. She had suffered this problem since a week ago when her tongue became enlarged with a sudden onset and eventually did not fit her mouth. Chronic tongue enlargement since childhood is noted. Patient had history of mental problems, namely cerebral palsy, and as she is not able to walk, she uses a wheelchair. Furthermore, due to severe scoliosis, right lung was atelectatic.Soon after initial assessments, she was carried to surgery room and as she could not lie down to supine position, was intubated in sitting position with a rigid laryngoscope. During the whole process, patient was sedated. Afterwards, tracheostomy was per- formed.After 5 days, no improvement in the size of tongue was observed. Diagnosis was revised in a medical commission and despite inflammatory pathology, the bulging tongue was resected.After recovery, patient could bear oral feeding and was dismissed with good general health. After a week, the devised airway created by tracheostomy was removed with- out any complication. During one-year follow up, no sequelae were observed.
Keywords: Massive enlargement of thetongue, Glossitis, Lingualhypertrophy -
BackgroundA major problem with the University of Pennsylvania Smell Identification Test (UPSIT) is its poor sensitivity for malingering detection in a group of people familiar with the test mechanism. This study aimed to evaluate the modification of UPSIT to detect anosmia malingering.MethodsThis was a pilot experimental study conducted in 2019 in Tehran. The participants were 60 healthy subjects classified into two groups of 30 people. The first group was requested to deliberately feign a negative result on the Iranian version of UPSIT, Iran Smell Identification Test (ISIT) (malingering group). The second group consisted of participants, who did not scratch the odorant part of ISIT during the tests (anosmia group). ISIT was modified in two steps. At each step, one incorrect option was deleted from the available choices. The number of each group’s answers, altered away from the correct choice, was then calculated and compared.ResultsThe coached malingering group participants were able to feign anosmia in the original ISIT exam. In the modified ISIT, the number of answers changed from correct to wrong during the second stage (from three available choices to two choices) was significantly higher in the anosmia group (P<0.001). In the ROC analysis, the area under the curve was 0.92 (P<0.001). The cut-off of 4.5 for this test showed 93% sensitivity, 82% specificity, and 90% PPV and NPV.ConclusionThe ISIT is not capable of detecting malingering in the coached participants, yet by deleting the choices step-by-step, the sensitivity and specificity of the test increased.Keywords: Smell, Malingering, Anosmia
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Vascular anomalies form a significant portion of congenital defects and venous malformations are the most prevalent type among adults. Multiple imaging modalities have been proposed for pre-operation assessments. Although some studies have reported Magnetic Resonance Imaging (MRI) as the most valuable modality, in many situations, CT scan remains the equipment of choice due to its availability. In each case, a precise assessment of the malformation is needed. In two cases mentioned in our study, prior to the operations, only a monophasic CT scan was performed that resulted in missing evidence of severity and extent of venous malformation. One of the imaging procedures is a three-phase CT scan. Although in the monophasic CT scans, a delay of 65 seconds is applied, in three-phase CT, both filling in and washing out are notable, which gives three-phase CT a more predictive value about flow pattern over monophasic CT.
Keywords: Vascular anomalies, Venousmalformations, Head andneck neoplasms, Computedtomography angiography -
A Solitary Fibrous Tumor (SFT) is a soft tissue tumor that appears exceedingly rare in the parotid gland. The literature review suggested that approximately 12%-22% of these cases behave aggressively. Besides, only 4 cases of histological malignant parotid gland SFT are reported in the English literature. We presented a 65-year-old cigarette-smoker man with a fix and tender mass over the left parotid and submandibular areas. On physical examination, the marginal branch of the facial nerve was paralyzed. The left total parotidectomy and neck dissection levels 1 and 2 were performed with preoperative embolization procedure and adjuvant radiotherapy for the patient. The results of the follow-up examination were unremarkable after 11 months. In this case report, we aimed to increase awareness on SFTs, although rare, among clinicians and pathologists. Accordingly, it should be considered in the differential diagnosis of soft-tissue tumors in the major salivary glands for better management.
Keywords: Solitary fibrous tumor, Hemangiopericytoma, Parotidgland neoplasm, Major salivary glands tumor -
خانم 49 ساله با سابقه بیماری های دیابت ملیتوس و هایپوتیروییدی، با شکایت از تنگی نفسی که از سه هفته قبل شروع شده بود به بخش اورژانس مراجعه کرد. با توجه به استریدور دمی و بازدمی در معاینه بالینی، برای ایشان ضایعه در محل نای مطرح شد. در سی تی اسکن (بدون تزریق) از گردن و قفسه سینه، ضایعه شبیه تومور بدخیم نای با گسترش به اطراف نای در گردن بیمار دیده شد. در ادامه، دیسترس تنفسی بیمار بدتر شد و تحت بیهوشی عمومی تراکیوستومی شد. در زمان تراکیوستومی، یک ضایعه سفید تا کرم رنگ که شبیه نکروز بود به همراه گرانولاسیون فراوان، که دور تا دور نای را گرفته بود، دیده شد، و از آن بیوپسی گرفته شد. در گزارش هیستوپاتولوژی شواهد التهاب حاد و مزمن و نکروز به همراه قارچ های بدون سپتا که موید بیماری موکورمایکوزیس بود، دیده شد. در ابتدا، آمفوتریسین- Bلیپوزومال وریدی، به عنوان داروی آنتی فونگال انتخاب شد که به دلیل عارضه نارسایی کلیه حاد ناشی از دارو، قطع شد. سوسپانسیون پسوکونازول به عنوان داروی آنتی فونگال جایگزین شد. بعد از حدود 6 هفته بیمار با حال عمومی خوب از بیمارستان مرخص شد. برخلاف مطالعات معدودی که در منابع موجود تاکنون، در مورد بیماری موکورمایکوزیس نای و راه های هوایی تحتانی، وجود دارد، با توجه به محدود بودن بیماری به نای در بیمار ما، ما از دبریدمان محل درگیری خودداری کردیم و سعی بر کنترل بیماری با استفاده از کنترل بیماری زمینه ای ایشان و داروی آنتی فونگال نمودیم و نهایتا نتیجه مطلوب حاصل شد. البته قابل ذکر است تمام بیمارانی که در مطالعات گذشته بررسی و منتشر شده اند درگیری وسیع تری از بیمار ما داشته اند. بنابراین با توجه به نبود درمان استاندارد برای این بیماری، می توان رویکرد درمانی ما در این مطالعه را به عنوان یکی از گزینه های درمانی این بیماری در فرم محدود، در نظر گرفت.
کلید واژگان: موکور مایکوزیس, نای, پسوکونازول, تراکئوستومی, عفونت قارچیA 49-year-old woman with a history of diabetes mellitus (DM), and hypothyroidism referred to the emergency ward complaining of shortness of breath which had lasted for three weeks. Due to inspiratory and expiratory stridor in the clinical examination, a tracheal lesion was proposed for her. In computed tomography (CT) scan (without contrast) of the neck and chest, a lesion resembling a malignant tracheal tumor was observed spreading around the cervical trachea. Subsequently, the patientchr('39')s respiratory distress worsened and she underwent tracheostomy under general anesthesia. During tracheostomy, a white to creamy lesion that resembled necrosis with extensive granulation was seen in cervical trachea, and a biopsy was taken. Histopathological reports showed evidence of acute and chronic inflammation, in necrotic background, along with aseptate fungi which confirmed mucormycosis. Initially, intravenous liposomal amphotericin-B was selected as an antifungal drug which was discontinued due to drug-induced acute renal failure. Posaconazole suspension was replaced as an antifungal drug. After about six weeks, the patient was discharged from the hospital in good general condition. Contrary to few previous studies on mucormycosis of the trachea and lower airways, tracheal disease was limited in our patient; therefore, we avoided debridement of the conflict site and tried to control the disease by controlling the underlying disease (DM), and antifungal therapy. Finally, the desired result was achieved. It should be noted that all patients who have been reviewed in the previous published studies have had a wider conflict sites compared to our patient. Therefore, due to the lack of standard treatment for this disease, our therapeutic approach in this study can be considered as an option in limited and localized cases.
Keywords: Fungal infection, Mucormycosis, Posaconazole, Trachea, Tracheostomy -
پیش زمینه و هدف
سرطان سلول سنگفرشی 85 درصد بدخیمی های حنجره را شامل می شود. در برخی موارد غدد لنفاوی علیرغم اینکه درگیر سرطان شده اند هیچ علایم خاصی را از خود بروز نمی دهند. مطالعات قبلی نشان داده اند میزان عود بیماری در بیمارانی که تحت درمان دیسکسیون انتخابی غدد لنفاوی گردن قرارمی گیرند به طور معنی داری پایین تر از بیمارانی است که این عمل در آن ها صورت نمی گیردس. در این مطالعه بر آن شدیم تا میزان فراوانی درگیری پنهان غدد لنفاوی گردن را در مبتلایان به سرطان سلول سنگفرشی حنجره بررسی نموده و از این طریق گام مهمی در انجام هدفمند دیسکسیون انتخابی غدد لنفاوی گردن در این بیماران برداریم.
مواد و روش هااین مطالعه از نوع توصیفی، گذشته نگر و مقطعی بوده و شامل بررسی پرونده بالینی بیماران مبتلا به سرطان حنجره مراجعه کننده به بیمارستان امیراعلم طی 5 سال از آغاز سال 1391 لغایت پایان سال 1396 است که پس از بررسی های بالینی و رادیولوژیک نشان داده شد که 66 نفر آنان مبتلا به سرطان سلول سنگفرشی حنجره و در مرحله N0 هستند این گروه از بیماران به عنوان نمونه آماری تحقیق در نظر گرفته شدند. تعدادی از بیماران با وضعیت مشابه به دلیل کامل نبودن اطلاعات پرونده از مطالعه خارج شدند. نهایتا" داده ها پس از جمع آوری به وسیله نرم افزار SPSS V.22 آنالیز شد.
یافته هااز مجموع بیماران موردمطالعه 29 نفر (44 درصد) مبتلا به سرطان چاکنای، 29 نفر (44 درصد) مبتلا به سرطان فوق چاکنای و 8 نفر (12 درصد) مبتلا به سرطان زیر چاکنای بودند. در بین این بیماران در 26 نفر (5/39 درصد) متاستاز به غدد لنفاوی وجود داشت (متاستاز پنهان یافت شده در پاتولوژی بعد از عمل). در 40 نفر (5/60 درصد) متاستاز در غدد لنفاوی وجود نداشت. از 26 بیماری که متاستاز غدد لنفاوی داشتند 11 مورد مبتلا به سرطان چاکنای و 13 بیمار مبتلا به سرطان فوق چاکنای و 2 مورد مبتلا به سرطان زیر چاکنای بودند.
بحث و نتیجه گیرینظر به شیوع نزدیک به 20 درصدی متاستاز مخفی غدد لنفاوی در مبتلایان به سرطان سلول های سنگفرشی حنجره که در مرحله 0N هستند توصیه می شود در کنار جراحی تومور نسبت به دیسکسیون انتخابی غدد لنفاوی گردن اقدام گردد چراکه این اقدام سبب کاهش عود بیماری در بیماران موردنظر خواهد شد.
کلید واژگان: سرطان سلول سنگفرشی, دیسکسیون انتخابی گردن, متاستاز مخفی لنفاویBackground & AimsSquamous cell carcinoma (SCC) accounts for 85% of laryngeal cancers. In some cases, lymph nodes do not show any specific symptoms despite being involved by cancer. Previous studies showed that patients undergoing selective neck lymph node dissection (SND) had significantly lower recurrence rates. We investigated the prevalence of occult neck lymph node involvement in patients with laryngeal SCC, and this is an important step in performing targeted selective neck lymph node dissection (SND) in these patients.
Materials & MethodsThis is a descriptive, retrospective, cross-sectional study involving the clinical records of patients with laryngeal carcinoma referred to Amir Alam Hospital from 2012 to 2017. Clinical and radiologic data showed that 66 patients had laryngeal SCC and were in the N0 stage. This group of patients was considered as the statistical sample of the study. A number of patients with similar status were excluded because of incomplete case data. Data analysis was done with SPSS v.22 software.
ResultsOf the total number of patients 29(44%), were diagnosed with glottic cancer, 29 (44%) with supraglottic cancer and 8 (12%) with subglottic cancer. 26 (39.5%) of these patients had lymph node metastasis (occult metastasis approved by post-operative pathology report). No metastasis in lymph nodes was found in 40(60.5%) patients. Of the 66 targeted patients, only 13 underwent radiotherapy before surgery. Of the 26 patients who had lymph node metastasis, 11 were diagnosed with glottic cancer and 13 patients with supraglottic cancer and 2 cases with subglottic cancer.
ConclusionConsidering the nearly 20% prevalence of occult lymph node metastasis in patients with laryngeal squamous cell carcinoma who are in the N0 stage, it is recommended to selectively excise the neck lymph nodes in addition to the tumor surgery as this will reduce the recurrence rate of the disease.
Keywords: squamous cell carcinoma, selective neck dissection, occult lymphatic metastasis -
Carbon dioxide (CO2) laser surgery as a conservative tool plays a peculiar role in the management of head and neck cancer. Numerous patients who were candidates for transoral laryngeal microsurgery have forced us to eliminate frozen-section evaluation of surgical margins and use a magnified view of the larynx. The present study evaluated surgeon-judged negative margins with permanent microscopic pathologic evaluation.Materials and MethodsIn this cross-sectional study, we evaluated the permanent pathologic margins of the resected laryngeal specimen which were considered negative by judgment of surgeons. Patients consisted of 61 pathologic proven T1-T2 laryngeal squamous cell carcinoma (SCC) cases. In all patients, tumor resection was performed via a transoral route with CO2 laser, and no residual laryngeal tumor was observed according to judgment of the surgeon. The patients with positive margin (s) underwent another resection. Patients were followed up for 18 months for tumor recurrence.ResultsThe obtained results demonstrated that pathologic margins were reported in 6 patients, with the deep margin being the most common positive margin. During the 18-month follow-up, 8 cases of recurrence were detected.ConclusionJudgment of the surgeon was in agreement with permanent pathologic evaluation in transoral laryngeal laser resection at the early stages of laryngeal SCC in most cases. Nevertheless, it is suggested that further direct studies be conducted to evaluate the frozen section on oncologic outcomes in transoral laser surgery for laryngeal cancer.Keywords: Laryngeal Squamous Cell Carcinoma, Laser microsurgery, Pathological study
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Oncocytic cysts of the larynx are benign and rare lesions constituting a pathologically distinct sub-group of cysts. In this report, we present a case with dyspnea with two large masses on false vocal cord identified by video laryngoscopy. Fiberoptic nasotracheal intubation revealed oncocytic laryngeal cysts.
Keywords: Larynx, Laryngeal cysts, Oncocytic -
Buccal Fat Pad is an encapsulated mass of adipose tissue located within the buccal facial spaces, between the buccinator and masseter muscles. Intraoral traumatic herniation of Buccal Fat Pad, often seen in young children, has been reported as a rare case. In this report, we present a case of traumatic Buccal Fat Pad herniation which at first was misdiagnosed as a malignant tumor.Keywords: Buccal fat pad, Oral mass, Traumatic herniation
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Scientia Iranica, Volume:25 Issue: 3, May - June 2018, PP 1835 -1848The rotational and translational motion of nanocars and nanotrucks as well as their motion regimes at different temperatures are investigated. In recent years, few similar types of molecular machines have been simulated. In contrast to previous studies which have used the Rigid-Body Molecular Dynamics (RB MD) method, an all-atom model and classic atomistic dynamics have been employed in this paper to achieve better accuracy. Our results demonstrated that the flexibility of the chassis and its attachment to the gold surface play important roles in the motion of a nanocar. In fact, a heavier and more flexible nanocar chassis reduces its speed compared to a nanotruck. In addition, simulations results are compared with available data from experimental studies done in recent years, and an acceptable agreement between the simulation results and experiments was observed. It was found that both molecules have three different regimes of motion, and the translational and rotational motion are not correlated. Results of this paper increase the knowledge and understanding of thermally-driven fullerene-based nanocars, and can be used to help design nanomachines with high controllability and maneuverability.Keywords: fullerene, nanocar, molecular machines, nanotruck, Molecular dynamics, diffusive motion
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در این مقاله، رفتار خمشی یک تیر کامپوزیتی متشکل از یک بخش موج دارکه حفره های آن با ماده پلیمری حافظه دار پر شده است، مورد بررسی قرار گرفته است. تیر موردنظر یک تیر ساندویچی ازجنس پلیمر حافظه دار است که بدنه ای موج دار از جنس پلیمری دارد. این تیر در سنسورها و فعال کننده ها کاربرد فراوانی دارد. از آنجایی که در پروفیل های موج دار نسبت استحکام به وزن در راستای عمود به موج بیشتر است، لذا تیرهایی که بخش موج دار در راستای عرضی تیر قرار دارد، نسبت به تیرهایی که بخش موج دار در راستای طولی است، مستحکم تر هستند. با استفاده از مدل ساختاری ارائه شده توسط چن ولاگوداس برای مواد پلیمری حافظه دار و همچنین باکمک تئوری تیر اویلر- برنولی، رفتار تیر کامپوزیتی بررسی شده است. به دلیل اینکه مدل ساختاری استفاده شده به فرم انتگرالی است، از روش تفاضلات محدود برای جداسازی معادلات استفاده شده است. با استفاده از یک نرم افزار المان محدود نیز نتایج تحلیل خمشی تیر بدست آمده است وبا نتایج روش تفاضلات محدود مقایسه گردیده است. نتایج نشانگر دقت بالای روش تفاضلات محدود در حل این مسئله است. نتایج تحلیل خمشی تیر با هسته موج دار دارای شکل های مثلثی، سینوسی و ذوزنقه ای بدست آورده و بایکدیگر مقایسه شده اند. نتایج نمایانگر آن است که توانایی حمل بار در تیر کامپوزیتی در مقایسه با تیر پلیمری خالص افزایش یافته است. توانایی تحمل بار بیشتر، با اندکی کاهش در تثبیت شکل تیر بدست می آید. در نهایت، شرایط مربوط به چرخه بازیابی تنش مقید نیز برروی تیر کامپوزیتی اعمال و نتایج مربوط به این چرخه نیز بدست آمده اند.کلید واژگان: پلیمرهای حافظه دار, تیر ساندویچی, تئوری تیر اویلر- برنولی, سازه موج دار, روش تفاضلات محدودIn this paper, a sandwich beam of a SMP material which have a corrugated core is studied. The corrugated core is from a polymeric material. Structures with corrugated profiles show higher stiffness-to-mass ratio in the transverse to corrugation direction compared to flat structures. As a result, the beam with corrugation along the transverse direction is stiffer than the one with corrugation along the beam length. The flexural behavior of the composite corrugated beam is studied employing a developed constitutive model for SMP and the Euler-Bernoulli beam theory. The constitutive model utilized is in integral form and is discretized employing finite difference scheme. To verify the results of the Euler-Bernoulli beam theory and finite difference method, finite element models of different corrugated sections have been simulated in a 3D finite element program. The results demonstrate that the developed model for the composite beam presented in this study predicts the behavior of the beam successfully. The sandwich beam with different corrugated cores (triangular, sinusoidal and trapezoidal shapes) are compared with each other. Also, results show that the shape fixity is decreased a little, like any other reinforcing method. This decrease in shape fixity results in increase of load capacity in composite beams. The stress-free strain recovery and constrained stress-recovery cycles are both studied.
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IntroductionDefinite Meniere's diseaseis associated with two or more definitive periods of vertigo along with hearing loss, plus tinnitus or aural fullness or both. This study aimed to compare the effect of intratympanic dexamethasone and methylprednisolone on the functional-level scale of pure-tone audiometry (PTA), and class outcome measures of vertigo.Materials And MethodsIn this clinical study, 69 patients with definite Meniere's disease, referred to the tertiary otolaryngology center, were randomly assigned to two groups: 36 patients were treated with intratympanic dexamethasone (4mg/dl) and 33 patients were treated with intratympanic methylprednisolone (40mg/dl). Each group received three weekly injections. After a follow-up of 1 and 6 months, PTA changes and vertigo control were evaluated.ResultsThere was no statistically significant difference between the two groups with regard to control of vertigo (P=0.866, P=0.879 for 1 and 6 months post injection, respectively). PTA improvement was statistically significantly higher in the methylprednisolone group (P=0.006).ConclusionIn summary, intratympanic corticosteroid is an effective treatment for Meniere's disease and can prevent other invasive treatments. Intratympanic methylprednisolone can improve hearing level to a greater extent than intratympanic dexamethasone, but the two groups were similarly beneficial in controlling vertigo. However, there was a trend toward a more sustained benefit with methylprednisolone.Keywords: Dexamethasone, Intratympanic injection, Meniere disease, Methylprednisolone, Vertigo
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Wheel wear is one of the major costs in railway tracks consisting of sharp curves. In this paper wear behavior of the S1002 profiles of wheels in the «Southern Line» of Irans railway, which consists of a large number of distinct and/or consecutive sharp curves, is studied using the field data measuring technique. Based on wear behavior analysis of all wheels, an optimal wagon maintenance technique called first and second limits is suggested to minimize the wagons cost per traveled distance. The results show that: 1) A severe wheel flange wear occurs for all wheels in comparison to the wheel tread wear in normal tracks. 2) A wagons detachment for repair of critical wheels on its four axles occurs at the traveled distances of 40, 000, km, 54000 km, 71000 km, and 75000 km, respectively (much less than the normal traveled distance of 500, 000 km). 3) A fifth order polynomial function can be appropriated to represent the wear behavior of the wheels. 4) By implementing the suggested technique, the cost per traveled distance decreased by 38. 64%, and the travelled distance increased by 45%.Keywords: Wheel Wear, Maintenance Technique, Sharp Curves, Empirical Study, Wheel Longevity Enhancement, Wheel Flange Wear Behavior, Wagon's Maintenance Cost Enhancement
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