Design and finite element analysis of formula student braking system

The present project focuses on the research and design of a braking system for sports vehicles. The braking system will be included in a vehicle being developed by the IPB Motorsport Team in order to participate in an annual worldwide collegiate design competition called Formula Student. The competition evaluates a Formula style car's engineering, performance, and cost. Since it was the first vehicle of this style to be designed at IPB, the values were analysed and estimated for the under-design vehicle. A methodology has been developed using the theory of vehicle dynamics to design a braking system capable of meeting the technical requirements of the competition. Another part of this research included analysing the behaviour of brake rotors made of various materials (Gray Cast Iron, Aluminium Alloy) and Geometry (Drilled, Solid) using Finite Element Analysis (FEA) more precisely the ANSYS software version 21. Static and thermal simulations were conducted for the design. As a result, a brake system assembly capable of achieving a four-wheel lock is demonstrated. Gray cast iron has superior thermal and static capabilities than aluminium, and the rotor geometry has an effect on the stress distribution. The simulations proved to be very useful in determining the most suitable brake rotor material and cooling shape for the brake rotors.O presente projeto centra-se na investigação e concepção de um sistema de travagem para veículos desportivos. O sistema de frenagem será incluído em um veículo que está sendo desenvolvido pela IPB Motorsport Team para participar de uma competição universitária anual de design chamada Formula Student. A competição avalia a engenharia, o desempenho e o custo de um carro estilo Fórmula. Por ter sido o primeiro veículo desse estilo a ser projetado no IPB, os valores foram analisados e estimados para o veículo em projeto. Foi desenvolvida uma metodologia a partir da teoria da dinâmica veicular para projetar um sistema de frenagem capaz de atender aos requisitos técnicos da competição. Outra parte desta pesquisa incluiu a análise do comportamento dos rotores dos freios feitos de diversos materiais (Ferro Fundido Cinza, Liga de Alumínio) e da Geometria (Perfurada, Sólida) utilizando a Análise de Elementos Finitos (FEA), mais precisamente o software ANSYS versão 21. Estático e térmico simulações foram realizadas para o projeto. Como resultado, é demonstrado um conjunto de sistema de freio capaz de obter um travamento nas quatro rodas. O ferro fundido cinzento tem capacidades térmicas e estáticas superiores do que o alumínio, e a geometria do rotor tem um efeito na distribuição de tensões. As simulações provaram ser muito úteis para determinar o material do rotor do freio e a forma de refrigeração mais adequados para os rotores do freio

Transperineal ultrasound evaluation of females with stress urinary incontinence

Background: Urinary incontinence has a significant influence on the well-being of affected females. No standard imaging modality is mandatory in initial evaluation of patients with urinary incontinence. Transperineal ultrasound has been proposed as a reliable method to assess female stress urinary incontinence. This study was conducted to evaluate the transperineal ultrasound findings in females with stress urinary incontinence.Methods: A case-control study including 40 females diagnosed to have stress urinary incontinence and 40 healthy females as their controls. The proximal pubo-urethral distance, the posterior urethro-vesical angle (β-angle) and the angle of urethral inclination (α-angle) were measured at rest and during straining.Results: On analyzing the transperineal ultrasound findings, no statistical significant difference was found between cases and controls at rest, but on straining, statistical significant difference was found regarding dynamic posterior urethral angle and dynamic pubo-urethral distance (p <0.001). Of the included 40 cases with SUI, 27 (67.5%) had cysto-urethrocele, and 5 (12.5%) had intrinsic sphincter defect (ISD). Urethral diameter was significantly different in patients with ISD (6.64±1.23 mm) when compared with patients with SUI without ISD (4.83±1.16 mm).Conclusions: Transperineal ultrasound is a simple, noninvasive, and easily conducted examination that can be used in the diagnostic workup of stress incontinence

Factors influencing CAD/CAM accuracy in fibula free flap mandibular reconstruction

La tecnologia CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) ha migliorato sia i risultati funzionali che morfologici nella chirurgia ricostruttiva mandibolare. L\u2019obiettivo del nostro studio \ue8 stato quello di valutare questo tipo di tecnologia ed i fattori che possono influenzare la sua precisione. Un totale di 26 casi di ricostruzione mandibolare con lembo libero di fibula, utilizzando tecnologia CAD/CAM sono stati operati presso l\u2019Unit\ue0 Maxillofacciale della Fondazione IRCCS Ca\u2019 Granda Ospedale Maggiore Policlinico di Milano, da giugno 2014 a febbraio 2018. Abbiamo valutato l\u2019accuratezza confrontando i files STL di pianificazione chirurgica virtuale (obiettivo pianificato) con il file STL di una scansione TC postoperatoria precoce (risultato postoperatorio ottenuto). Entrambi i file STL sono stati importati su Geomagic Studio 2016 (Geomagic Gmbh). In base alla posizione della placca di ricostruzione (punto di riferimento fisso), abbiamo confrontato la deviazione sul condilo sinistro, gonion sinistro, gnathion, gonion destro e condilo destro, per calcolare l\u2019errore medio di deviazione. L\u2019errore medio di deviazione varia da 0,6 mm a 2,2 mm. Solo 2 dei 26 casi analizzati avevano un errore medio uguale o superiore a 2 mm (7,7%). L\u2019area mediana (symphysis-gnathion) ha mostrato una variazione pi\uf9 bassa (1,05 \ub1 0,92 mm) mentre l\u2019area di gonion ha mostrato maggiore variazione (la variazione media del gonion destro e sinistro era rispettivamente di 1,6 mm e 1,46 mm). Nessuno dei possibili fattori (tempi di ricostruzione, malignit\ue0 o benignit\ue0, sito o dimensione del difetto) che potrebbero influenzare la precisione del CAD/CAM, ha mostrato un\u2019influenza significativa. La tecnologia CAD/CAM nella ricostruzione microvascolare dei difetti mandibolari mediante lembo libero di fibula minimizza gli errori umani ed \ue8 considerato come un intervento chirurgico indipendente dall\u2019operatore con alto grado di accuratezza e riproducibilit\ue0.Computer-aided design/computer-aided manufacturing (CAD/CAM) technology has im-proved the functional and morphological results of mandibular reconstructive surgery. The purpose of this study was to objectively assess this technology and factors affecting its accuracy.Fibula free flap mandibular reconstruction was performed in 26 cases us-ing CAD/CAM technology at the Maxillofacial Unit of Fondazione IRCCS Ca\u2019 Gran-da Ospedale Maggiore Policlinico, Milan, between June 2014 and February 2018. We evaluated the technology\u2019s accuracy by comparing the virtual surgical planning STL file (planned-target mesh) with the STL file from an early postoperative CT scan (postopera-tive-achievement mesh) in each case. The STL files were imported into Geomagic Studio 2016 (Geomagic GmbH). According to the position of the reconstruction plate (fixed reference point), we assessed deviations at the right condyle, right gonion, gnathion, left gonion and left condyle, calculating mean, minimum and maximum error values.Mean error values ranged from 0.6 to 2.2 mm; they were 65 2 mm in only 2 (7.7%) cases. The midline area (symphysis-gnathion) showed the least variation (1.05 \ub1 0.92 mm), and the gonion area showed the greatest variation (right and left means of 1.6 and 1.46 mm, respectively). Among all possible factors that could affect CADCAM accuracy, nothing showed significant influence, including the timing of reconstruction, site and size of the defect and malignancy status. CAD/CAM technology has a high degree of accuracy and reproducibility for microvascular reconstruction of mandibular defects using fibula free flaps, regardless of the defect site and length, use of a single- or double-barrel graft or timing of reconstructio

Anti-Müllerian hormone and response to ovulation induction with clomiphene citrate in women with polycystic ovary syndrome

Background: Anti-Müllerian hormone (AMH) is suggested as an important marker for women with polycystic ovary disease (PCOS). Several studies have found serum level of AMH correlate well to ovarian response to ovulation induction in women with PCOS. This study was conducted to assess the relationship between AMH in women with PCOS and response to ovulation induction with clomiphene citrate.Methods: Prospective observational cohort study conducted at Ain-Shams university maternity hospital from February 2013 to February 2014. 100 women with PCOS were recruited from the infertility outpatient clinic. Serum AMH levels were measured by enzyme linked immunosorbent assay in the early follicular phase (days 3-5). Ovulation induction by clomiphene citrate was started on day 5 as 50 mg daily tablet for 5 days. Ovulation was documented by transvaginal ultrasonography and women who failed to ovulate till day 35 were considered anovulatory.Results: 72 women ovulated within 12 to 33 days of the menstrual cycle, while 28 had undetectable ovulation till day 35. The median serum AMH level was significantly higher in women with failed ovulation [4.05 ng/mL (3.7 - 4.4)] than in ovulating women [2.7 ng/mL (1.9 - 3.1)] (p<0.001). Receiver-operating characteristic (ROC) curve analysis found the best cutoff value of AMH for prediction of successful ovulation ≤3.6 ng/mL (sensitivity = 97.2%, specificity = 82.1%).Conclusions: Anti-Müllerian hormone is a very useful predictor of poor responders to clomiphene citrate among women with polycystic ovary disease

Tissue trauma and inflammatory response following laparoscopic versus abdominal hysterectomy: a prospective randomized clinical trial

Background: Laparoscopic surgery is associated with more favorable clinical outcome than conventional open surgery. This might be related to the magnitude of tissue trauma and tissue stress response. This study compares the intensity of tissue injury by assessing plasma C-reactive protein (CRP), lactic dehydrogenase (LDH), and cancer antigen 125 (CA 125) in patients undergoing laparoscopic hysterectomy compared to abdominal hysterectomy.Methods: This study was conducted at Ain Shams University Maternity Hospital from May 2018 to February 2020. 74 women candidate for hysterectomy were recruited and randomized into two groups: group A included 37 cases who underwent abdominal hysterectomy, and group B included 37 cases that underwent laparoscopic hysterectomy.Results: CRP, LDH and CA125 significantly increased post-operatively in both groups. Postoperative mean serum CRP, LDH and CA125 were significantly higher in the laparotomy group (10.84±2.47, 262.21±76.77, and 13.41±2.6 respectively) compared to laparoscopy group (7.92±2.25, 148.53±43.56, 11.79±2.77 respectively) (p<0.05).Conclusions: Surgery is a significant cause of tissue injury that can be assessed by specific markers. We suggest that laparoscopic surgery causes less tissue damage as assessed by lower postoperative CRP and LDH values, which might account for the earlier recovery and reduced hospital stay in laparoscopic surgery

Modified technique for sacrospinous-sacrotuberous ligament complex colpopexy in apical prolapse: preliminary results of a pilot randomized study

Background: Apical prolapse is frequently encountered following vaginal hysterectomy either or as a primary finding in patients with pelvic organ prolapse. This pilot comparative study introduces a modified sacrospinous sacrotuberous ligament fixation with biologic mesh augmentation which necessitates no special kits to be performed.Methods: This study was conducted at Department of Obstetrics and gynecology, Ain Shams University, Cairo, Egypt, and Department of Women Health of Bethanien Hospital, Iserlöhn, Germany from March 2018 to May 2020. 40 women with either utero-vaginal or vaginal vault prolapse were randomized to either; group (A): 20 women scheduled for modified sacrospinous-sacrotuberous fixation procedure, or group (B): 20 women scheduled for conventional sacrospinous-sacrotuberous fixation procedure.Results: Improvement of the Pelvic organ prolapse quantification system (POP-Q) stage from the base line pre-operative stage was 1 stage higher in the modified SS/ST-F group compared to the conventional SSF group (3 stage improvement from baseline in SS/ST-F group versus 2 stage improvement only in conventional SSF group).Conclusions: This pilot study provides a modified sacrospinous sacrotuberous ligament colpopexy technique which is easier to be performed and mastered, does not need the use of special devices, provides better improvement of grade of prolapse and less complications compared to the conventional technique.

A Double-Blind, RCT Testing Beneficial Modulation of BDNF in Middle-Aged, Life Style-Stressed Subjects: A Clue to Brain Protection?

Introduction: The aim of this prospective study was to see whether LD-1227, a quality-controlled marine nutraceuticals shown to protect experimental stress-induced hyppocampal degeneration, could beneficially modulate BDNF, as measured in the serum, in otherwise healthy but work-stressed individuals. Materials and Methods: Forty-eight men and women between the ages of 38 and 62 reporting high-demanding work activity but with an overall positive attitude towards their personal life were recruited. Subjects were divided in two group (24 patients each) and blindly supplemented for 2 month with: a) LD-1227 400mg or b) placebo. A third group of healthy non-stressed subjects was used as well. Blood samples were taken before and after the supplementation period. Unstimulated saliva was collected and tested for amylase while serum levels were used to measure BDNF. State Trait Anxiety Inventory (STAI), Pittsburgh Sleep Quality Index (PSQI) and psychological wellbeing assessment (PSWB) were measured too. Patients with Val66Met functional polymorphism of BDNF excluded those given their reported association with an impaired release of BDNF. Results: Results showed that, as compared to healthy, nonstressed individuals, stressed ones has a trend decrease of BDNF and this was significantly increased by LD 12-1227 supplementation and the same inverse phenomenon occurred to salivary amylase (p<0.05). No change was noted in the PSQI score but, either STAI or PSWB tests scored better in LD-1227 supplemented subjects. Conclusion: The present data suggest that LD-1227 is beneficially affecting neuromodulation and related symptoms during common stressful life conditions and may have the potential as tools in a neuroprotective clinical strategy

Bile Cast Nephropathy: A Pathologic Finding with Manifold Causes Displayed in an Adult with Alcoholic Steatohepatitis and in a Child with Wilson’s Disease

Bile cast nephropathy (BCN) is seen in patients who have acute kidney injury and severe hyperbilirubinemia due to a wide range of hepatobiliary system diseases. Findings seen by renal biopsy include acute tubular injury with necrotic and sloughed epithelial cells, yellow-green pigment within tubular epithelial cells, and pigmented granular casts. Hall’s special stain for bile turns these casts green. In recent years, BCN has been described in a small number of case reports and clinical studies primarily in the setting of severe liver dysfunction. We present 2 diverse cases of BCN. The first involves an adult with hepatorenal syndrome secondary to alcoholic steatohepatitis and early cirrhosis. Second, we describe the first reported case of BCN in a child with fulminant hepatic failure due to Wilson’s disease. Our cases expand the spectrum of causative diseases, and they provide further evidence that BCN is a distinct pathologic entity which may be found in both adult and pediatric patients with a variety of severe liver diseases