83 research outputs found
Response of a CMS HGCAL silicon-pad electromagnetic calorimeter prototype to 20-300 GeV positrons
The Compact Muon Solenoid Collaboration is designing a new high-granularity
endcap calorimeter, HGCAL, to be installed later this decade. As part of this
development work, a prototype system was built, with an electromagnetic section
consisting of 14 double-sided structures, providing 28 sampling layers. Each
sampling layer has an hexagonal module, where a multipad large-area silicon
sensor is glued between an electronics circuit board and a metal baseplate. The
sensor pads of approximately 1 cm are wire-bonded to the circuit board and
are readout by custom integrated circuits. The prototype was extensively tested
with beams at CERN's Super Proton Synchrotron in 2018. Based on the data
collected with beams of positrons, with energies ranging from 20 to 300 GeV,
measurements of the energy resolution and linearity, the position and angular
resolutions, and the shower shapes are presented and compared to a detailed
Geant4 simulation
Performance of the CMS High Granularity Calorimeter prototype to charged pion beams of 20300 GeV/c
The upgrade of the CMS experiment for the high luminosity operation of the
LHC comprises the replacement of the current endcap calorimeter by a high
granularity sampling calorimeter (HGCAL). The electromagnetic section of the
HGCAL is based on silicon sensors interspersed between lead and copper (or
copper tungsten) absorbers. The hadronic section uses layers of stainless steel
as an absorbing medium and silicon sensors as an active medium in the regions
of high radiation exposure, and scintillator tiles directly readout by silicon
photomultipliers in the remaining regions. As part of the development of the
detector and its readout electronic components, a section of a silicon-based
HGCAL prototype detector along with a section of the CALICE AHCAL prototype was
exposed to muons, electrons and charged pions in beam test experiments at the
H2 beamline at the CERN SPS in October 2018. The AHCAL uses the same technology
as foreseen for the HGCAL but with much finer longitudinal segmentation. The
performance of the calorimeters in terms of energy response and resolution,
longitudinal and transverse shower profiles is studied using negatively charged
pions, and is compared to GEANT4 predictions. This is the first report
summarizing results of hadronic showers measured by the HGCAL prototype using
beam test data.Comment: To be submitted to JINS
LIQUID LIQUID EQUILIBRIA OF WATER PLUS ACETIC-ACID PLUS PHTHALIC ESTERS (DIMETHYL PHTHALATE AND DIETHYL PHTHALATE) TERNARIES
Experimental liquid-liquid equilibria of water + acetic acid + dimethyl phthalate and water + acetic acid + diethyl phthalate systems were investigated at 293.16 +/- 0.20 K. The reliability of experimental tie-line data was ascertained through an Othmer-Tobias plot. Distribution coefficients and separation factors were evaluated over the immiscibility region. It is concluded that the high-boiling solvents dimethyl phthalate and diethyl phthalate are suitable separating agents for dilute aqueous acetic acid solutions
Risk factors and clinical outcomes of sinus membrane perforation during lateral window sinus lifting: analysis of 120 patients
PubMedID: 29655818The aim of this study was to identify the risk factors associated with sinus membrane perforation and the effect of sinus membrane perforation and other risk factors on graft success and postoperative sinusitis. Sinus membrane perforation, graft failure, and postoperative sinusitis were tested for an association with age, sex, operator experience, side of the operation, residual bone height, presence of septa, presence of a mucous retention cyst, and smoking (?2 test). Logistic regression analysis was used to model the odds ratio (OR) with corresponding risk factors. One hundred and twenty patients were included in this study. A total of 22 (18.3%) perforations occurred. A residual bone height of 3–6 mm (OR 6.808, P = 0.002) and presence of septa (OR 4.023, P = 0.025) were identified as significant risk factors. Twenty-eight (23.3%) sinus grafts were classified as failed. Membrane perforation (OR 16.819, P < 0.005) and residual bone height of 3–6 mm (OR 5.363, P = 0.01) were identified as significant risk factors for graft failure. None of the risk factors investigated in this study was significantly associated with postoperative sinusitis. These results suggest that the presence of septa and a residual bone height of 3–6 mm are associated with an increased risk of sinus membrane perforation, and that sinus membrane perforation has a negative effect on graft success. © 2018 International Association of Oral and Maxillofacial Surgeon
Effects of low-level laser therapy on soft and hard tissue healing after endodontic surgery
PubMedID: 29713842The aim of this prospective study was to examine possible benefits of low-level laser therapy (LLLT) on soft and hard tissue healing after endodontic surgery. Seventy-six endo-surgery cases on maxillary incisors were included. The patients were assigned randomly into control and laser groups. In the laser group, gallium-aluminum-arsenide (GaAlAs) diode laser irradiation (810 nm, 129 mW, 3.87 J/cm2) was performed immediately after surgery and daily for postoperative 7 days from buccal and palatal surfaces (5 min for each side). In the control group, patients were not subjected laser therapy. The patients were compared in terms of pain, clinical and radiological findings, and life quality indexes [Oral Health Impact Profile-14 (OHIP-14) and General Oral Health Assessment Index (GOHAI)]. Seventy-one patients completed the study (n = 37 for control group, n = 34 for laser group). The laser group showed better results in edema, wound healing, and the number of analgesic tablets used on the 1st, 3rd, and 7th postoperative days. Significant reduction in ecchymoses was observed in the laser group on the postop 3rd and 7th days. The patients had significantly lower pain on the 1st and 3rd postop days in laser group. The laser group showed significantly better results in OHIP-14 and GOHA indexes on postop days 1 and 3. The laser group showed significantly favorable results in terms of bone density, defect volume and area, and periapical index in the postop 3rd month. This study concluded that LLLT improved soft and hard tissue healing after endodontic surgery and also showed favorable effects on pain and life quality of patients especially in the early phase of healing period. © 2018, Springer-Verlag London Ltd., part of Springer Nature.TDH-2016-5792Funding The present study was supported by the Cukurova University Scientific Research Fund (Project no.: TDH-2016-5792)
Effects of size and insertion angle of orthodontic mini-implants on skeletal anchorage
PubMedID: 31375232Introduction: The primary aim of this in vitro study was to compare the insertion torque (IT) and anchorage force (AF) values of 4 different sizes of orthodontic mini-implants with 2 different angles. The second aim was to evaluate the relationship between IT and AF values under different diameter, length, and insertion angle variables. Methods: A total of 160 mini-implants, including 20 implants in each group, with 4 different sizes (1.6 × 8 mm, 1.6 × 10 mm, 2.0 × 8 mm, and 2.0 × 10 mm) at 2 different angles (70° and 90°), were inserted into bovine iliac bone segments. The IT and AF values leading to 1.5 mm deflection were compared. The correlations between IT and AF values under different variables were also analyzed. Results: The mini-implants with greater diameter and length showed greater IT and AF values (P <0.05). The IT and AF values of mini-implants inserted at 70° angle were significantly greater than those of mini-implants inserted at 90° angle (P <0.001). Significant correlations were found between IT and AF values in all variables. Conclusions: The diameter, length, and insertion angle of orthodontic mini-implants have significant effects on IT and AF values. Insertion angle and diameter of mini-implants are more effective than implant length on skeletal anchorage. Significant correlations are present between IT and AF values of mini-implants regardless of their diameters, lengths, and insertion angles. © 2019 American Association of Orthodontist
Liquid-liquid equilibria of propionic acid - water - solvent (n-hexane, cyclohexane, cyclohexanol and cyclohexyl acetate) ternaries at 298.15 K
The experimental liquid-liquid equilibrium data on propionic acid-water-solvent ternary mixtures at a temperature of 298.15 K are presented. The solvents are n-hexane, cyclohexane, cyclohexanol and cyclohexyl acetate. The distribution coefficients and separation factors are reported. The tie line data are correlated using the methods of Othmer-Tobias and Hand. The experimental results are compared with the values predicted by the UNIFAC group-contribution method
Effects of glucosamine-chondroitin combination on synovial fluid IL-1ß, IL-6, TNF-? and PGE2 levels in internal derangements of temporomandibular joint
PubMedID: 25662545Background: The aim of the present study was to evaluate the effects of glucosamine-chondroitin sulphate combination on internal derangements of temporomandibular joint in clinical and biochemical manners. Material and Methods: This randomized clinical study included 31 cases reporting joint tenderness, in which disc displacement was detected on MR imaging. In all patients, synovial fluid sampling was performed under local anesthesia. In the study group, the patients were prescribed a combination of 1500 mg glucosamine and 1200 mg chondroitin sulphate, while patients in the control group were only prescribed 50 mg tramadol HCl (twice daily) for pain control. After 8 weeks, synovial fluid sampling was repeated in the same manner. The levels of pain, maximum mouth opening (MMO), synovial fluid IL-1ß, IL-6, TNF-? and PGE2 measured before and after pharmacological intervention were compared. Results: The reduction in pain levels was significant in both groups. There was no significant difference between two groups in terms of pain reduction. The improvement in MMO was significant in the study group but it was not in the control group. The MMO improvement was significantly higher in the study group compared to the control group. In the study group, significant decrease was observed in PGE2 level, while the decreases in IL-1ß, IL-6 and TNF-? levels were not significant. In the control group, no significant decrease was observed in any of the inflammatory cytokines after 8 weeks, moreover IL-1ß and IL-6 levels were increased. Alterations of IL-1ß and IL-6 levels were significant in study group while TNF-? and PGE2 levels were not, compared to control group. Conclusions: In conclusion, these results might suggest that glucosamine-chondroitin combination significantly increases the MMO and decreases the synovial fluid IL1ß and IL6 levels in internal derangements of TMJ compared to tramadol. The modifications of synovial fluid TNF-? and PGE2 levels do not reach statistical significance. This combination also provides efficient pain relief in similar level with tramadol, a narcotic analgesic. © 2015, Medicina Oral, Patologia Oral y Cirugia Bucal. All rights reserved
Comparison of the effectiveness of three different treatment methods for temporomandibular joint disc displacement without reduction
PubMedID: 28222947The aim of this study was to compare the effectiveness of three treatment methods for unilateral temporomandibular joint (TMJ) disc displacement without reduction (DDwoR). One hundred and twenty patients with unilateral TMJ DDwoR were assigned randomly to one of three treatment groups (40 patients in each): group 1 received arthrocentesis, group 2 received stabilization splint therapy following arthrocentesis, and group 3 received splint therapy only. The groups were compared in terms of pain (visual analogue scale), joint function (maximum mouth opening and laterotrusive movements), disability and psychological status (validated questionnaire), and success rates. These were recorded before treatment and during follow-up after treatment (1, 3, and 6 months). The between-group and within-group differences in the data were analyzed statistically. The baseline characteristics were similar in all groups (P > 0.05). Significant improvements were noted in all parameters compared to baseline values in all groups (all P < 0.01). Groups 1 and 2 showed comparable outcomes that were superior to those of group 3. Arthrocentesis reduces pain and functional impairment more rapidly and effectively than splint therapy. Simultaneous splint application has no additional effect on the effectiveness of arthrocentesis for the treatment of unilateral DDwoR. © 2017 International Association of Oral and Maxillofacial Surgeon
Cone-beam computed tomographic evaluation of styloid process: A retrospective study of 208 patients with orofacial pain
PubMedID: 24528515Introduction: The purpose of this study was to assess the structural characteristics of styloid process (SP) by cone-beam computed tomography (CBCT) examination in a patient population suffering from orofacial pain. The second aim was to assess the prevalence of elongated SP and its relation to gender, site and subjective symptoms in the study population.Methods: Clinical and radiographic records of 208 patients were evaluated retrospectively. Radiological examinations including measurements of the structure, length, and medial angulations of SP were performed on CBCT images.Results: Out of 208 patients, 96 (46%) had not-elongated SP, 28 (13%) had left side, 16 (8%) had right side, and 68 (33%) had bilateral elongation of SP. The patients with elongated SP had significantly decreased angle values. There were no statistically significant differences in length values of SP between males and females in both groups. Significantly increased prevalence of symptoms except headache was observed in patients with elongated SP.Conclusions: This study presents the CBCT as an alternative method to CT or panoramic radiographs for the measurement and the assessment of the styloid process. Patients suffering from orofacial pain, who also had elongated SP, had increased rate of corresponding neurological complaints compared with non-elongated ones. © 2014 Öztunç et al.; licensee BioMed Central Ltd
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