Composite Blades of Wind Turbine: Design, Stress Analysis, Aeroelasticity, and Fatigue

In this chapter, four main topics in composite blades of wind turbines including design, stress analysis, aeroelasticity, and fatigue are studied. For static analysis, finite element method (FEM) is applied and the critical zone is extracted. Moreover, geometry, layup, and loading of the turbine blades made of laminated composites are calculated and evaluated. Then, according to the stress analysis, critical layer is specified and safety factor is studied based on Tsai-Wu failure criterion. Aeroelasticity is the main source of instability in structures that are subjected to aerodynamic forces. One of the major reasons of instability is the coupling of bending and torsional vibration of flexible bodies, which is known as flutter and considered in this study. Numerical and analytical methods are applied for considering the flutter phenomenon of the blades. For numerical method, the FEM and Joint Aviation Requirements (JAR-23) standard and for analytical method, two-degree freedom flutter and Lagrange’s equations are utilized. Also, lifetime prediction of a horizontal axis wind turbine composite blade is investigated. Accumulated fatigue damage modeling is employed as a damage estimation rule based on generalized material property degradation

Beneficial effect of soy isoflavones and soy isoflavones plus soy protein on serum concentration of C-reactive protein among postmenopausal women : An updated systematic review and meta-analysis of randomized controlled trials

Financial support: This systematic review and meta-analysis was financially supported by Neyshabur University of Medical Sciences (Grant number: 98-01-149. Ethical code: IR.NUMS.REC.1399.006). We are extremely grateful to the data collection team at the Neyshabur University of Medical Sciences.Peer reviewedPublisher PD

Anticonvulsive Effects of Licofelone on Status Epilepticus Induced by Lithium-pilocarpine in Wistar Rats: a Role for Inducible Nitric Oxide Synthase

BACKGROUND AND PURPOSE: Status epilepticus (SE) is a neurological disorder with high prevalence and mortality rates, requiring immediate intervention. Licofelone is a cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) inhibitor, which its effectiveness to treat osteoarthritis has been approved. Increasing evidence suggests an involvement of COX and LOX enzymes in epileptic disorders. Thus, in the present study we investigate possible effects of licofelone on prevention and termination of SE. We also evaluated whether the nitrergic system could participate in this effect of licofelone. METHODS: We have utilized lithium-pilocarpine model of SE in adult Wistar rats to assess the potential effect of licofelone on seizure susceptibility. Licofelone was administered 1 h before pilocarpine. To evaluate probable role of nitric oxide (NO) system, L-arginine (60 mg/kg, i.p.), as a NO precursor; L-NAME (15 mg/kg, i.p.), as a non-selective nitric oxide synthase (NOS) inhibitor; aminoguanidine (100 mg/kg, i.p.), as an inducible NOS (iNOS) inhibitor and 7-nitroindazole (60 mg/kg, i.p.), as a neuronal NOS inhibitor were injected 15 min before licofelone. Also, licofelone and diazepam 10 mg/kg were administered 30 minutes after onset of SE. RESULTS: Pre-treatment with licofelone at the dosage of 10 mg/kg, significantly prevented the onset of SE in all subjects (p \u3c 0.001). L-arginine significantly inverted this anticonvulsant effect (p \u3c 0.05). However, L-NAME and aminoguanidine, potentiated the anticonvulsant effect of licofelone (p \u3c 0.05, p \u3c 0.01). Licofelone could not terminate seizures after onset which was terminated by diazepam. CONCLUSIONS: Our findings showed that anticonvulsive effects of licofelone on SE could be mediated by iNOS. Also, we suggest that COX/5-LOX activation is possibly required in the initial stage of onset but SE recruits extra excitatory pathways with prolongation

Nintinol Self-Expandable Metallic Stenting in Management of Malignant Obstructive Jaundice: A Case Series

Background and Aims: Palliation therapy is the only available therapeutic method for most patients with tumor-induced obstructive jaundice. Metallic stents are now performed percutaneously as an alternative route to the endoscopic approach. It is widely accepted because of its safety, good patency rate, and minimal invasiveness. This study was designed to evaluate the long-term results of metallic self-expandable stent insertion in patients with malignant stenosis of the biliary tree. Methods: It is a longitudinal study of patients with percutaneously biliary stenting from September 2005 to March 2009. The patients had unresectable malignant biliary obstruction with unsuccessful endoscopic stenting and access. Percutaneous transhepatic cholangiogram performed after adequate local anesthesia, under sonographic or fluoroscopic guidance. Stenting or balloon dilation was performed through the hydrophilic guide wire. Among 50 patients, 45 stents were placed in biliary tree stenosis sites. Patients' follow-up was during the first, second, third, and then the sixth month after insertion of biliary stents. Stent patency was considered successful in our patients, when there were no lab results or sonographic appearance of biliary tree obstruction. Results: 10(20) patients' stent placement treatment failed because of unsuccessful technical procedure. The stenosis of biliary tract was complete and passage of guide wire was not possible through the tumor growth. 6 (15 ) patients with successful stent placements died within one month (mean, 22 days). Total serum bilirubin resolved to below 1.5 mg/dl within 30 days for 36 (90) patients with successful stent placements. Early complications not leading to death occurred in 28 of cases. The mean survival time for all patients who underwent stent placement was 140 days (16-420days). The mean patency rate for all stents was 147 days. Conclusions: Percutaneous biliary stenting is a safe procedure with few technical complications and a high success rate of palliation for patients with malignant biliary jaundice. Early complications are mostly managed conservatively and death is mainly due to systemic effects of the malignant disease

Levosimendan exerts anticonvulsant properties against PTZ-induced seizures in mice through activation of nNOS/NO pathway: Role for K<inf>ATP</inf> channel

Aims Although approving new anticonvulsants was a major breakthrough in the field of epilepsy control, so far we have met limited success in almost one third of patients suffering from epilepsy and a definite and reliable method is yet to be found. Levosimendan demonstrated neuroprotective effects and reduced mortality in conditions in which seizure can be an etiology of death; however, the underlying neuroprotective mechanisms of levosimendan still eludes us. In the light of evidence suggesting levosimendan can be a KATP channel opener and nitrergic pathway activator, levosimendan may exert antiseizure effects through KATP channels and nitrergic pathway. Main methods In this study, the effects of levosimendan on seizure susceptibility was studied by PTZ-induced seizures model in mice. Key findings Administration of a single effective dose of levosimendan significantly increased seizures threshold and the nitrite level in the hippocampus and temporal cortex. Pretreatment with noneffective doses of glibenclamide (a KATP channel blocker) and L-NAME (a non-selective NOS inhibitor) neutralize the anticonvulsant and nitrite elevating effects of levosimendan. While 7-NI (a neural NOS inhibitor) blocked the anticonvulsant effect of levosimendan, Aminoguanidine (an inducible NOS inhibitor) failed to affect the anticonvulsant effects of levosimendan. Cromakalim (a KATP channel opener) or L-arginine (an NO precursor) augmented the anticonvulsant effects of a subeffective dose of levosimendan. Moreover, co-administration of noneffective doses of Glibenclamide and L-NAME demonstrated a synergistic effect in blocking the anticonvulsant effects of levosimendan. Significance Levosimendan has anticonvulsant effects possibly via KATP/nNOS/NO pathway activation in the hippocampus and temporal corte

Evaluating the Reliability of Anatomic Landmarks in Safe Lumbar Puncture Using Magnetic Resonance Imaging: Does Sex Matter?

Aim. To determine the level of the conus medullaris-Tuffier's line, and conus medullaris-Tuffier's line distance using imaging and evaluate their relation to age and gender. Methods. We performed a cross-sectional study of 189 adult participants, who underwent MR imaging of lumbosacral spine. Each vertebra was divided into 3 equal segments (upper, middle, and lower), and intervertebral disc space was also assumed as one segment. All segments from T12 upper segment to L5S1 intervertebral disc were numbered consecutively. The position of conus medullaris and Tuffier's line was determined by the vertebral segment or intervertebral disc space at the same level. The patients were stratified into high/low conus medullaris position (cutpoint: L1 middle segment) and short/long conus-Tuffier's distance (cutpoint: 14 segments). Results. Women with low conus were significantly more than men, in patients older than 50 years old (72.7% in females versus 55.3% in males; P < .05), whereas there was not such a sexual dimorphism in patients younger than 50 years old. Similarly, short conus-Tuffier's distance was more frequent among women than men in patients older than 50 years old (59.7% in females versus 39.5% in males; P < .05), whereas there was not any gender difference in patients younger than 50 years old. Conus-Tuffier's distance was negatively correlated with age (r = −0.32, P < .001) in all studied population. Conclusion. Anatomical landmarks vary according to age and gender, with a lower end of conus medullaris in women, so clinicians should use more caution on the identification of the appropriate site for lumbar puncture, particularly in elderly women

Effect of Lenalidomide on Pentylenetetrazole-Induced Clonic Seizure Threshold in Mice: A Role for N-Methyl-D-Aspartic Acid Receptor/Nitric Oxide Pathway

Background and Purpose: Accumulating evidence suggest that lenalidomide, a structural analog of thalidomide, has neuro-modulatory and neuroprotective properties. In the present study, we investigated effects of acute administration of lenalidomide on clonic seizure threshold in mice induced by pentylenetetrazole (PTZ) and possible role of N-methyl-D-aspartic acid receptor (NMDAR) and nitric oxide (NO) pathway. Methods: We have utilized a clonic model of seizure in NMRI mice induced by PTZ to evaluate the potential effect of lenalidomide on seizure threshold. Different doses of lenalidomide (5, 10, 20, and 50 mg/kg, intraperitoneal [i.p.]) were administered 1 hour before PTZ. To evaluate probable role of NMDAR/NO signaling, the non-selective NO synthase inhibitor L-N (G)-nitroarginine methyl ester (L-NAME; 10 mg/kg, i.p.), neuronal NOS (nNOS) inhibitor 7-nitroindazole (7-NI; 30 mg/kg, i.p.), selective inducible NOS inhibitor aminoguanidine (AG; 100 mg/kg, i.p.), selective NMDAR antagonist MK-801 (0.01 mg/kg, i.p.), and selective NMDAR agonist D-serine (30 mg/kg, i.p.) were injected 15 minutes before lenalidomide. Results: Lenalidomide at 10 and 20 mg/kg significantly elevated the PTZ-induced seizure thresholds. Interestingly, L-NAME (10 mg/kg, i.p), 7-NI (30 mg/kg, i.p), and AG (100 mg/kg, i.p) reversed the anticonvulsive effect of lenalidomide (10 mg/kg). Moreover, treatment with the NMDAR agonist D-serine (30 mg/kg, i.p.) did not alter the anticonvulsive properties of lenalidomide (10 mg/kg, i.p). However, the NMDAR antagonist MK-801 (0.01 mg/kg, i.p) significantly reversed the anticonvulsive effects of lenalidomide (10 mg/kg). Conclusions: Our study demonstrated a role for the NMDAR/NO pathway in the anticonvulsive effects of lenalidomide on the PTZ-induced clonic seizures in mice

Comparing morphologic features and complications of main clear corneal incision between junior and senior residents observed using anterior segment optical coherence tomography

Background: Wound construction is a critical step in phacoemulsification. Using anterior segment optical coherence tomography (AS-OCT), we compared the morphological features and complications of main incisions made by junior or senior residents during phacoemulsification. Methods: This cross-sectional comparative study included eyes with senile cataracts that underwent uneventful phacoemulsification with a clear corneal incision made by seven senior and eight junior ophthalmology residents. All eyes underwent postoperative image acquisition using AS-OCT on day one and at three months, examining for morphological features and potential complications of the main incision. Results: We included 50 eyes of 50 patients with a male-to-female ratio of 22 (44%) to 28 (56%); 26 (52%) were operated on by junior residents and 24 (48%) by seniors. The mean geometric features of the main incisions and the frequency of early and late wound complications were comparable between the two groups (all&nbsp;P&nbsp;&gt; 0.05). A significant correlation was found between the incision length and angle with the superior (r = + 0.80;&nbsp;P&nbsp;&lt; 0.001 and r = - 0.63;&nbsp;P&nbsp;&lt; 0.001, respectively) and inferior (r = + 0.84;&nbsp;P&nbsp;&lt; 0.001 and r = - 0.68;&nbsp;P&nbsp;&lt; 0.001, respectively) areas of the incision, as well as between the length and angle of incision (r = - 0.74;&nbsp;P&nbsp;&lt; 0.001). The number of planes in the wound architecture was not significantly different according to senior or junior resident status (P&nbsp;&gt; 0.05). Although the number of eyes with stromal hydration was significantly greater for junior residents than for seniors (P&nbsp;&lt; 0.001), the corneal thickness at the entrance to the cornea or the anterior chamber, presence of endothelial wound gaping, and Descemet’s membrane detachment were comparable between eyes with and without stromal hydration (all&nbsp;P&nbsp;&gt; 0.05). At three months, 29 (58%) patients returned for examination, in whom seven (24%) had late wound complications. Conclusions: This study found no significant differences in the performances of junior and senior residents in terms of wound construction or its associated complications. However, considering the overall rate of some observed wound-related complications, we recommended revision of the resident educational curriculum concerning the structure and complications of the main incision