Side Of Cavity Research Articles

Plasmonic refractive index sensor with multi-channel Fano resonances based on MIM waveguides

A multi-channel Fano resonant structure is proposed and analyzed based on subwavelength metal–insulator–metal (MIM) waveguides. First, two MIM output ports associated with specific side-coupled cavities are designed to locate at the center and quarter positions of an end-coupled cavity, respectively. Since the interference between the dark and bright modes, dual-channel Fano resonances with asymmetrical lines shapes are obtained at both ports, respectively. High sensitivity and figure of merits are investigated. Besides, phase shifts are also investigated leading to positive and negative group delays available at the Fano peaks and dips, respectively. Likewise, two extra output ports with identical resonant cavities are placed on the other side of the end-coupled cavity. In this case, four-channel Fano resonances with considerable performances are obtained. The proposed structure is analyzed by the coupled mode theory and the finite difference time domain method. It is believed this device can be used as a chip-scale refractive index sensor and optical filter.

The First Report of an Ovarian Cyst in the Bosca’s Newt, <i>Lissotriton boscai</i> (Lataste, 1879)

The Bosca’s newt (Lissotriton boscai) is a small species of newt from the family Salamandridae, endemic in the western part of the Iberian Peninsula. Reproductive disorders in amphibians are not common and are poorly described. The newt, an adult female, originated from the Espiríto Santo creek in Miramar (Vila Nova de Gaia, Portugal), was admitted to the Wildlife Rehabilitation Centre of the Biologic Park of Gaia in November 2017, with a dilatation on the left side, and difficulties in swimming and diving. Radiologic exam revealed an oval hypoechoic structure on the left side of the celomic cavity that compresses internal organs and causes spine deviation. In post mortem exam, the cranial portion of the left ovary presented an oval structure with 112 × 53 mm, of a translucid whitish-pink coloration containing a serous-like fluid. At histopathologic examination an ovarian luteinized cyst was diagnosed. It is the first time this type of lesion has been described in amphibians. In this animals, female’s reproductive problems are quite rare, with only a few cases reported, mostly in captivity animals. This report is important to improve the knowledge on reproductive pathology in amphibians, especially in the Bosca’s newt and evidence the importance of the post mortem exam in captive and wild amphibians.

Thoracoscopic surgery approach to mediastinal mature teratomas: a single-center experience

BackgroundMediastinal mature teratomas are rare tumors with diverse surgical approaches. The aim of this study is to review our experience of thoracoscopic surgery management in patients with teratomas.MethodsWe retrospectively reviewed 28 consecutive patients with mediastinal mature teratomas who underwent thoracoscopic surgery at Viet Duc University Hospital from January 2008 to August2018. Patients were divided into 2 groups with 2 types of thoracoscopic surgery, closed thoracoscopic surgery (CTS) group and video-assisted thoracoscopic surgery (VATS) group. The selection of sugical approach was based on sizes, locations and characteristics of tumors. Post-operative outcomes were assessed and compared between these 2 groups.ResultsThere were 14 female and 14 male patients with a median age of 41.2 ± 13.8 years. A total of 22 teratomas were located on the right side of the chest cavity and 6 on the left side. We performed CTS in 21 patients (75%) and VATS in 7 patients (25%) for tumor resection. There were 3 cases (10.7%) required conversion to minithoracotomy (5 cm in incision length). Skin appendages accounted for the highest rate (96.4%) in pathology. There was no record of mortality or tumor recurrence detected by computerized tomography.ConclusionA thoracoscopic surgery for a mediastinal mature teratoma was a feasible choice. Challenging factors such as large tumors, intraoperative bleeding and strong tumor cell adhesion were considered handling by conversion to mini-thoracotomy that could ensure safety procedures and complete removal of tumors. Extraction of tumor contents might be performed for patients with large mature cystic teratomas to facilitate thoracoscopic surgery.

Simulation Examination for Nanoparticle Flow in a Permeable Enclosure via CVFEM Involving MHD Effect

In the present investigation, innovative complex porous enclosure is chosen to simulate the MHD (magnetohydrodynamic) natural convection. One side of porous cavity packed with radiative nanofluid (CuO–water) has curve-shaped triangular wave pattern. To gain insight into outputs, CVFEM (control volume-based finite element method) has been used. Nanofluid behavior is inspected by employing two-temperature model for solid matrix and nanoliquid and KKL model for effective properties of nanofluid with an extensive range of key parameters acting as Hartmann number, radiation parameter, buoyancy impact, phase interacting heat transfer factor. Not only imposing magnetic field but also wavy surface and dispersion of nanomaterial have been considered in the current paper. New numerical approach has been utilized to demonstrate the behavior of nanomaterial through the porous tank. Interrelation of average Nusselt number with involved parameters is also proposed. Outcomes reveal that radiation term has straightforward association with Nusselt number. Greater vortex generates with the rise in shape factor.

Aggressive inflammatory myofibroblastic tumor of the tongue (clinical case)

The study objective is to present a rare clinical case of an aggressive myofibroblastic tumor of the tongue.Clinical case. A 24-year-old patient was revealed a 44 × 25 × 50 mm volumetric formation of the left side of the tongue spreading to the contralateral side and bottom of the oral cavity. The patient denied injuries or chronic autoimmune diseases. Additional studies did not reveal failure of other organs or systems. Histological conclusion: malignant spindle-polymorphic cell neoplasm with myxomatosis, perineal growth, muscle fiber infiltration and their death. An immunohistochemistry revealed expression of vimentin, CD34, S100; Ki-67 – 30 % in tumor cells. He was diagnosed with T3N0M0 fibrosarcoma of the tongue. Subtotal resection of the tongue with simultaneous microsurgical plasty via re-activated radiation autograft was performed. According to morphological study of the removed tissues, he was finally diagnosed with an aggressive inflammatory myofibroblastic tumor of the tongue. Observation period at the time of writing was 15 months. The patient eats solid food, sound pronunciation is restored in full. There are no signs of relapse or metastasis.Conclusion. Diagnostics of an inflammatory myofibroblastic tumor of the oral cavity is complex and depends on clinical and morphological features of a particular tumor. We need reliable criteria to differentiate aggressive forms of inflammatory myofibroblastic tumor of the tongue from non-aggressive ones to choose treatment. The main difficulties arise in determining the resection volume and predicting relapse or metastasis.

Establishment of an animal model of intrauterine adhesions after surgical abortion and curettage in pregnant rats.

Intrauterine adhesion (IUA), also referred to as Asherman syndrome, is a complication with partial or complete adhesion of the uterine cavity due to fibrotic proliferation after endometrial and uterine wall injury of the newly pregnant uterus. Currently, all IUA research models are based on non-pregnant animals which are ill-suited in mimicking its pathogenesis. This study aimed to establish an animal IUA model caused by surgical abortion and curettage in pregnant rats that is more in line with clinical etiology, and to provide a more ideal animal model for further exploration of the pathogenesis and treatment for IUA. Fifteen, 13-to-15-day pregnant Sprague-Dawley (SD) rats aged 10 weeks were selected. After incising and removing the embryos, we randomly selected one side of the uterine cavity as the study group (n=15) and scraped it with a curette; the contralateral side of the uterine cavity that underwent no special procedures was used for inclusion in the control group (n=15). Five rats were euthanized and dissected on the 3rd, 7th, and 14th day after surgery respectively. The changes in tissue morphology, the number of endometrial glands, the ratio of endometrial fibrotic area, and the expression level of the transforming growth factor beta (TGF-β) in the endometrium were compared between the 2 groups. The endometrial granular cell number in the study group on the 7th and 14th day postoperatively was 3.87±0.72 & 2.59±0.90 in each visual field (×100) respectively, which was significantly lower than that of the control group (6.48±0.96 & 7.53±1.10; P<0.05). The ratio of the endometrial stromal fibrotic area in the study group was significantly higher than that of the control group post-operatively on the 3rd day (0.0974±0.0430 vs. 0.0584±0.05110), 7th day (0.1551±0.0348 vs. 0.0328±0.0152), and 14th day (0.1518±0.0477 vs. 0.0311±0.0128) (P<0.05). The endometrial TGF-β expression in the study group was positive on the 14th day postoperatively while weakly expressed in the control group, and the integrated optical density (IOD) value (5,608.8±2,887.3) was higher than that of the control group (388.3±98.6) (P<0.05). The endometrial TGF-β expression in the study group and control group was relatively weak on the 3rd and 7th day after surgery, and there was no significant difference when compared with that of the control group (P>0.05). The establishment of an animal model of IUA after surgical abortion and curettage in pregnant rats was successful and is thus feasible for further studies; the model may be a more effective mimic for the generation of human IUA.

Discovery of a Small Side Cavity in Sphingosine Kinase 2 that Enhances Inhibitor Potency and Selectivity.

The sphingosine-1-phosphate (S1P) signaling pathway is an attractive drug target due to its involvement in immune cell chemotaxis and vascular integrity. The formation of S1P is catalyzed by sphingosine kinase 1 or 2 (SphK1 or SphK2) from sphingosine (Sph) and ATP. Inhibition of SphK1 and SphK2 to attenuate levels of S1P has been reported to be efficacious in animal models of diseases such as cancer, sickle cell disease, and renal fibrosis. While inhibitors of both SphKs have been reported, improvements in potency and selectivity are still needed. Toward that end, we performed structure-activity relationship profiling of 8 (SLM6031434) and discovered a heretofore unrecognized side cavity that increased inhibitor potency toward SphK2. Interrogating this region revealed that relatively small hydrophobic moieties are preferred, with 10 being the most potent SphK2-selective inhibitor (Ki = 89 nM, 73-fold SphK2-selective) with validated in vivo activity.

A simulation study of parameters influencing microwave heating of seaweed (Eucheuma cottonii)

Currently, the process of drying seaweed has been using conventional technology, utilizing sunlight directly. It depends on weather conditions when the rainy season arrives, the drying process will take longer time even 3-4 days. The longer duration of drying causes seaweed’s quality degenerate. Previous studies have proved that drying materials use microwave energy can reduce processing time significantly. Heat transfer and electromagnetic field effect on seaweed drying in a microwave oven were studied using a three-dimensional simulation. The parameters observed included variations of power microwave (400, 500, and 600 W), seaweed thickness (3, 5, 7 cm), and waveguides position (top and side). Variation of magnetron energy in microwave heating is affecting the electromagnetic field’s value and changing seaweed temperature. As increasing received energy from the magnetron, seaweed temperature and electromagnetic field are ascending. Seaweed that is heated in 3 cm thickness results rising temperature higher than 5 cm and 7 cm thickness. Waveguide located at the top cavity is generating electromagnetic field value higher than it located at the side cavity. As verification method, heating fresh seaweed use microwave oven was resulting similar pattern both electromagnetic field and temperature. The lowest moisture content of seaweed is achieved at the treatment of 600 watt magnetron energy and 3 cm thickness of seaweed.

Design of 2D GaN photonic crystal based on hole displacement for L3 cavity

In this article, we report modeling, simulation, and analysis of shifting 2D photonic crystal cavity side holes in GaN-AlN-sapphire layered structure. The design was simulated with Lumerical finite-difference time-domain. A lattice constant a, 157 nm, and a hole diameter d, 106 nm, were used in the design. The cavities are based on L3, which we demonstrated by simply shifting two holes away from a line cavity with distances of 132, 142, and 152 nm, respectively. The highest quality factor, Q, value achieved is 2.25 × 104 at 152-nm cavity distance.

Investigation on the cause of the furnace effect of high-temperature fixed points

Investigation into the cause of the furnace effect, encountered in the realization of high-temperature fixed points (HTFPs), was conducted at the copper point. Modifications of the cavity design reduced the furnace effect, which indicates that the furnace effect is caused by the interaction between the furnace and the cavity through reflection at the cavity side wall, linked to the design of the HTFP cells. It was shown that the effect could be mitigated by applying a small aperture at the cavity opening. The difference of the realized temperature from that in the absence of the furnace effect was considered, and it was shown that the effect at the copper point in a HTFP furnace was estimated to be around 14 mK or less, the realized temperature being lower than the true temperature.

Free Convection in a Triangular Cavity Filled with Hybrid-Nanofluid along with Sinusoidal Heat

A numerical study on convective heat transfer of hybrid nanofluid packed in a right angled triangular cavity heated by a sinusoidal temperature maintained from lower side and subjected to a constant magnetic field have been studied in this work. The hypotenuse side of the triangular cavity has been kept in uniform cool temperature while the remaining side is insulated. The governing equations of the problem have been discretized numerically with help of finite element method. A fixed Prandtl number Pr=6.2 has been used for the numerical solution. Several values of Rayleigh number Ra=102-106 , and Hartmann number Ha=0-100 which are the non-dimensional governing parameters have been examined. The volume fraction =0.01, 0.05, 0.1 and the heat generation parameter Q = 1 have been taken for this work. Calculate and the graph of Nusselt number corresponding to different parameters have been presented. The results show that Nusselt number has been decreasing function of nanoparticles Rayleigh number and also it is a decreasing function of Hartmann number. Obtained results has been compared with previously obtained data by other authors.

Free Convection in a Triangular Cavity Filled with Hybrid-Nanofluid along with Sinusoidal Heat

A numerical study on convective heat transfer of hybrid nanofluid packed in a right angled triangular cavity heated by a sinusoidal temperature maintained from lower side and subjected to a constant magnetic field have been studied in this work. The hypotenuse side of the triangular cavity has been kept in uniform cool temperature while the remaining side is insulated. The governing equations of the problem have been discretized numerically with help of finite element method. A fixed Prandtl number Pr=6.2 has been used for the numerical solution. Several values of Rayleigh number Ra=102-106 , and Hartmann number Ha=0-100 which are the non-dimensional governing parameters have been examined. The volume fraction =0.01, 0.05, 0.1 and the heat generation parameter Q = 1 have been taken for this work. Calculate and the graph of Nusselt number corresponding to different parameters have been presented. The results show that Nusselt number has been decreasing function of nanoparticles Rayleigh number and also it is a decreasing function of Hartmann number. Obtained results has been compared with previously obtained data by other authors.

Buoyancy-Induced Convection in Water From a Pair of Horizontal Heated Cylinders Enclosed in a Square Cooled Cavity

Buoyancy-driven convention from a pair of horizontal heated cylinders, set side by side inside a square cooled cavity filled with water, is studied numerically. The system of the conservation equations of mass, momentum and energy expressed in dimensionless form is solved through a control-volume formulation of the finite-difference method. The pressure-velocity coupling is handled using the SIMPLE-C algorithm. Numerical simulations are executed for different values of the Rayleigh number based on the cylinder diameter, as well as the width of the cavity, the inter-cylinder spacing and the distance of the cylinders from the bottom wall of the cavity normalized by the cylinder diameter. Two heat and fluid flow configurations are generally found to establish inside the cavity, according as the cylinders are located at close distance or at such a distance that the effects of the lateral walls of the cavity become important, each of these configurations being distinguished by the existence of an optimum inter-cylinder spacing which maximizes the overall heat transfer rate. Moreover, when the inter-cylinder spacing is such that the cylinders are located sufficiently close to the cavity sides, a periodic flow arises.

Multiphase modelling of the transient flow for Sn-15Pb and 357.0 alloys in semi-solid die casting process

Abstract The transient flow behavior of the semi-solid slurries for Sn-15Pb and 357.0 alloys during die casting process is investigated by experimental and numerical methods. A model for the transient-state three-dimensional multiphase flow based on the kinetic theory of granular flow is developed. This model is applied to investigate the distribution of solid concentration, flow state, pressure variation of the semi-solid slurry in the die casting process. The three important aspects of the multiphase flow, flow regime, particle-particle interaction and particle-liquid interaction, are interpreted according to the characteristic of the system. The model is verified by partial filling and in-situ observation experiments. Then it is applied for the phase segregation study of an elbow cavity encountered in practice. Results indicate that the 3D multiphase model can depict the flow characteristics of the semi-solid slurry very well. The inner arc side of the elbow cavity is easier to have liquid phase segregation than the outer arc side for the lower velocity gradients of the solid and liquid phases.

REMOVAL NOTICE: Field research study for investigating wetting and drying characteristics in wood-framing walls subjected to cold climate

A field research study was conducted to investigate the wetting and drying characteristics in three 2 × 6 wood-framing wall specimens when they were subjected to different heat, air, and vapor flow transmission. The stud cavity of the wall specimens were filled with glass-fiber insulation having a nominal thermal resistance of R-20. The three wall specimens consisted of an exterior oriented strand board sheathing of 11-mm thick, spun-bonded olefin membrane, and vinyl siding. To investigate the effect of air/vapor barrier on the moisture performance, the first and second wall specimens, referred in this paper as “W1” and “W2,” included a 6-mil polyethylene sheet that was installed on the interior side of the stud cavity, behind a painted drywall. However, in the third wall specimen, referred as “W3,” the interior side of the stud cavity was closed by painted drywall without air/vapor barrier. To investigate the effect of the exterior insulation on the moisture performance of wood-framing walls with an air/vapor barrier, an insulation board made of extruded polystyrene (XPS) (50 mm thick and having a nominal thermal resistance of R-10) was installed in the wall specimen W2 on the exterior side of the spun-bonded olefin membrane. With and without air/vapor barrier, and with and without exterior insulation, this research study accounted for different parameters that may affect the wetting and drying characteristics in the wall specimens. These parameters included the pressure differential across the wall specimens, indoor humidity, outdoor cold climates, and air leakage as a result of creating deficiencies that provided a path for air leakage in the wall specimens. A test protocol was developed in this study that permitted investigating the effects of these parameters on the hygrothermal performance of wood-framing wall systems.

Cartilage Trap-Door Flap Technique for Correction of High Nasal Septum Deflection.

To introduce a novel cartilage trap-door flap technique in endonasal septoplasty to correct high dorsal deviation of the cartilaginous septum, and confirm its effectiveness. Prospective observational study. Medical center. 46 patients who had underwent septoplasty using the cartilage island flap technique to correct the high dorsal deviation from November 2014 to November 2015. The subjective symptoms were measured using the Nasal Obstruction Symptom Evaluation scale. The objective evaluations of the surgical results were analyzed using acoustic rhinometry. Post-operative status of the nasal septum was estimated by nasal endoscopic examination. Among 46 patients, 32 cases (69.57%) were "complete correction", 14cases (30.43%) were "improved" with residual deviation and there was not "no-change" or "even worse" case based on endoscopic examination. Minimal cross-sectional area in convex side of nasal cavity was significantly changed from 0.22cm to 0.56cm after the surgery, and nasal volume in narrower side of nasal cavity was significantly changed from 2.44mL to 6.22 mL. The patients' nasal obstruction symptoms significantly reduced from 10.43 before the surgery to 1.45 after the surgery. During the follow-up period, the authors have not experienced any obvious complications such as saddle nose, septal perforation, and bleeding. The proposed cartilage trap-door flap technique provides easy and effective results for dorsal deviations of the cartilaginous septum in selected cases without significant complications.

The effect of topical epinephrine 1:1000 with and without infiltration of 1% lidocaine with epinephrine 1:100,000 on endoscopic surgical field visualization: a double-blind randomized controlled study.

The objective of this study is to determine whether the infiltration of 1% lidocaine with 1:100,000 epinephrine in addition to topical application of 1:1000 epinephrine significantly improves surgical field grading scale score over topical 1:1000 epinephrine alone. A prospective, double-blind, randomized, controlled study was performed of 40 patients undergoing bilateral endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS). Patients were enrolled and randomly assigned to receive infiltration with 1% lidocaine with 1:100,000 epinephrine on 1 side of the nasal cavity vs plain saline on the other side in preparation for ESS. Both groups received topical application of 1:1000 epinephrine. Surgical videos were recorded and Wormald surgical field grading scale was assigned by 2 blinded reviewers. The number of extra 1:1000 epinephrine pledgets used during the surgery, estimated blood loss, and surgical duration were also recorded. There were no statistically significant differences in Wormald surgical field grading scale, number of extra pledgets used, or estimated blood loss between the nasal cavity side infiltrated with 1% lidocaine with 1:100,000 epinephrine in comparison to infiltration with saline. The side infiltrated with 1% lidocaine with 1:100,000 epinephrine had a reduced operative time compared to the side infiltrated with saline (p = 0.002). There were no differences in postoperative bleeding from questionnaire completed by patient at the first postoperative visit. Addition of infiltration of 1% lidocaine with epinephrine 1:100,000 to topical application of epinephrine 1:1000 for preparation of ESS does not significantly improve surgical field of view compared to topical epinephrine alone.

The recurrence of colonic volvulus due to nonrotation after intestinal resection in adulthood: a case report

BackgroundIntestinal nonrotation is a rare congenital condition that causes fatal colonic volvulus at any age. Once volvulus attack occurs, radical surgical therapy is required for treatment and the prevention of recurrence. This report describes the case of an adult female patient with a recurrence of cecum volvulus due to intestinal nonrotation after transverse colon resection for colonic volvulus.Case presentationA 27-year-old female visited our emergency room (ER) with intermittent abdominal pain and nausea. Enhanced computed tomography (CT) showed enlargement of the level of the ascending and transverse colon and an obstruction with a whirlpool sign at the transverse colon. The small intestine was distributed on the right side of the abdominal cavity, and the large intestine occupied the left side. She was diagnosed with volvulus with intestinal nonrotation, and emergency surgery was performed. Surgical examination indicated that the ascending colon to the transverse colon was not fixed to the retroperitoneum, and the transverse colon was rotated 180° clockwise. The axis of the volvulus was a mesenteric adhesion of the transverse colon. The involved transverse colon was resected, and the intestine was reconstructed by functional end-to-end anastomosis (FEEA). Six years after the initial surgery, the patient presented to the ER with abdominal fullness and lower abdominal pain. Enhanced CT revealed that the cecum, ascending colon, and remaining transverse colon were dilated with an obstruction. The appendix was located in the left upper abdominal cavity. The clinical diagnosis was cecal volvulus with intestinal nonrotation. An emergency laparotomy revealed that the cecum was rotated 180° clockwise. The terminal ileum to the remaining transverse colon was resected, and FEEA was performed. Seven months later, she suffered obstruction of the intestine caused by an operative adhesion, and conservative treatment was successful. The patient has had no abdominal symptoms for one and a half years so far.ConclusionsSurgeons should realize that nonrotation of the intestines induces volvulus in adulthood and should familiarize themselves with its clinical findings, appropriate treatment, and prognosis. Even after surgical treatment, awareness of the recurrence of volvulus should be maintained to avoid a late diagnosis.

The influence of different shapes of nanoparticle on Cu–H[formula omitted]O nanofluids in a partially heated irregular wavy enclosure

In this work, a complex nature structure is presented to deal with the flow and heat transfer characteristics of Cu–H2O nanofluid within the irregular triangular enclosure. Influences of the various shape of Cu nanoparticles are also considered to deal with this mechanism. The irregular side (sinusoidal) of the triangular cavity is partially heated from the bottom. A fixed magnetic field is horizontally applied to the enclosure. The governing equations are derived in the form of nonlinear coupled partial differential equations comprising energy, momentum, and continuity equations. These equations are firstly nondimensionalized before being numerically simulated via Control Volume based Finite Element Method (CVFEM). The relation among the diverse parameters is defined in the form of correlation for Nusselt number. The study concludes that the heat transfer rate is ascended owing to the ascendant in Rayleigh number and descended owing to the ascendant in Hartmann number. Particle shape factor also plays a crucial role in the heat transfer rate within and at the surface of the enclosure.

Effect of Diode Laser combined with Hyaluronic Acid Gel in Treatment of Recurrent Aphthous Stomatitis in Children: Randomized Clinical Trial

Background: Recurrent Aphthous Stomatitis (RAS) is a painful rounded ulcer characteristic by erythematous margin and pseudo yellowish- gray membrane in its center. All forms of RAS have bad effects on quality of life that interfere with daily activities. Hyaluronic acid has essential part in tissue hydrodynamics, cell migration, proliferation and differentiation. It shows an anti-inflammatory role so; it prevents tissue destruction and helps in tissue healing. Low level laser therapy is recognized with various terminologies such as “biostimulator,” and “cold laser,” It has role in the management of RAS, it has a wide spectrum of clinical applications which include herpes labialis, angular cheilitis, trismus, paresthesia, dentin hypersensitivity, temporomandibular joint pain, and in the postoperative phase.Materials and Method: Forty five normal healthy males and females children aged from (4-10 years) suffering from aphthous lesions were used in this study. Children were examined in Outpatient clinic pediatric Dentistry Department, Faculty of Dentistry, Suez canal University by a clinician. Each patient had one minor RAS of less than 72 h duration or two nearby minor aphthous lesions of less than 72 h at the same side of oral cavity. Patients were evenly divided into three groups (15 patients in each) with the method of simple randomization, Patients of group I were treated with topical application of hyaluronic acid gel , those of group II were treated with diode laser and group III patients were treated with diode laser followed by topical application of hyaluronic acid gel. The patients were evaluated at (0, 2nd, 4th and 6th) days, for measuring ulcer size and pain score. Results: At the 2nd, 4th and 6th days there was statistical significance decrease in mean size of the ulcer of group III when compared to both groups (I) and (II) . On other hands, at days 2 and 6 there was statistical significance decrease in mean of pain score in group III when compared to group I. There was also statistical significance decrease in mean of pain score in group II when compared to group I at the 4th day of evaluation.Conclusion: Hyaluronic acid gel combined with diode laser are effective in treatment of RAS.