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In the current research, a mathematical model is developed to simulate a commercial ethylene dichloride thermal cracker assuming pseudo-steady state condition. The considered reaction network includes 19 elementary and reversible reactions, 14 molecules, and 6 radical species. To prove the validity of the proposed model, the simulation results are compared with the available plant data. The results show that the coke build-up and deposition on the inner surface of the coil tube increases the heat transfer resistance during the process run time and has a negative effect on the production rate and pressure drop. Afterward, a sensitivity analysis is performed to investigate the effects of the feed and firebox temperatures on the ethylene dichloride cracking severity and selectivity. The results show that increasing the firebox and feed temperatures enhance the vinyl chloride monomer production rate. In the next step, a dynamic optimization problem is formulated and considered to calculate the optimal dynamic trajectory of the feed and furnace temperatures to achieve the maximum vinyl chloride monomer production rate. The programmed optimization problem is solved by the genetic algorithm method. The results show that applying the optimal trajectory of the decision variables can enhance the VCM production rate by 2.5%. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a semi-analytic procedure for deriving the response spectrum of the synthetic acceleration records generated using the Double-Frequency Model (DFM). DFM is a filtered white noise method for fully non-stationarity synthetic acceleration records. The proposed semi-analytic procedure is based on the theory of the first passage problem, which precludes time and computationally extensive methods such as Monte Carlo simulations. Assuming a slowly-varying envelope and evolutionary transfer functions, the procedure of estimating the elastic response of a structure is implemented in both time and frequency domains. Comparing the results of our model with previous models and approximations, we concluded that for a set of 10000 realizations of the DFM model, the semi-analytic model produces an error of less than 10% for 92% of the realizations. The accuracy of estimations is higher in the short-period compared to the long-period ranges of the response spectrum. Comparing the accuracy of approximations used to arrive at peak factors, results show that Michaelov approximation executed in the frequency domain yields the best results compared to Poisson or Vanmarcke procedures. [ABSTRACT FROM AUTHOR]

Background and Objectives: Happiness is one of the basic human needs and a component of mental health which is the cause of increase of social capital. The aim of this study was to investigate the status of happiness in students of Kerman Dental School. Materials and Methods: In this descriptive study, the statistical population included students of Kerman Dental School in the academic year 2017-2018. Oxford Happiness Questionnaire was used to collect data and 241 students who were selected randomly with the proportionate stratification method participated in the study. Data analysis was performed using Mann-Whitney U and Kruskal-Wallis H tests. Results: 151 (62.7%) of the students were girls and 90 (37.3%) were boys. The mean score of student's happiness was 40.04±0.78. Students' happiness status in different demographic variables such as gender (p=0.779), academic year (p=0.092), marital status (p=0.865) and residence (p=0.425) did not show any significant difference. Conclusion: The happiness status of Kerman Dental students was at an acceptable level, but necessary measures must be taken to upgrade it to the excellent level. [ABSTRACT FROM AUTHOR]

Aim: To characterize the role of orexin‐1 receptors (OX1Rs) in ventrolateral periaqueductal grey matter (vlPAG) on modulation of capsaicin‐induced pulpal nociception in rats. Methodology: Sixty‐six adult male Wistar rats (2 months old) weighing between 230 and 260 g were used. The animals were cannulated for microinjection of drugs into the vlPAG matter. Pulpalgia was induced by intradental application of capsaicin solution (100 μg) into the incisor teeth of the rats. Ten min prior to capsaicin application, orexin‐A (50, 100 and 150 pmol L−1 per rat) was administered. Orexin‐A (150 pmol L−1) was also co‐administrated with SB‐334867 (40 nmol L−1 per rat), an OX1Rs antagonist; or bicuculline (1 μg per rat), a GABAA receptors antagonist. Moreover, treatment effects on the release of pro‐nociceptive modulator substance P (SP) in vlPAG and trigeminal nucleus caudalis (Vc) of rats were explored using an immunofluorescence technique. One‐way analysis of variance was used for the statistical analysis. Results: Orexin‐A dose‐dependently decreased capsaicin‐induced nociceptive behaviour. However, SB‐334867 (40 nmol L−1 per rat) pretreatment (P < 0.05), but not bicuculline (1 μg per rat), attenuated the analgesic effect of orexin‐A (150 pmol L−1). The level of SP was significantly increased in Vc and decreased in vlPAG of capsaicin‐treated rats (P < 0.05). Capsaicin‐induced changes in SP levels, however, were prohibited by orexin‐A treatment (150 pmol L−1) (P < 0.05). Conclusions: Orexin‐A administration into the vlPAG was associated with an inhibitory effect on capsaicin‐induced pulpal nociception and bidirectional effects on the induction of SP in vlPAG and Vc of rats. Central activation of OX1Rs is a potential therapeutic tool for pulpalgia. [ABSTRACT FROM AUTHOR]

Aim: To assess the effects of central administration of α‐pinene alone and in combination with either bicuculline or naloxone, as GABAA and μ‐opioid receptor antagonists, respectively, on capsaicin‐induced dental pulp stimulation in rats. Methodology: Forty‐eight adult male Wistar rats aged 2 months (230–270 g) were cannulated via their lateral ventricles for the central administration of the drugs. α‐Pinene was injected at 0.1, 0.2 and 0.4 μmol L−1. Then, dental pulp stimulation was induced by intradental application of capsaicin solution (100 μg), and nociceptive scores were recorded for up to 40 min. For investigation of the anti‐inflammatory effects of α‐pinene, expression of COX‐2 in the subnucleolus caudalis (Vc) of rats was determined using immunofluorescence staining. Nonparametric repeated measure Friedman and Kruskal–Wallis tests as well as parametric one‐way analysis of variance were used for the statistical analysis. Results: α‐Pinene at 0.2 and 0.4 μmol L−1 was able to decrease capsaicin‐induced nociception. Moreover, there was a significant increase in the expression of COX‐2‐positive cells in the Vc of capsaicin‐treated rats (P < 0.01). This effect was prohibited by α‐pinene (0.4 μmol L−1). Co‐administration of bicuculline (1 μg per rat) or naloxone (6 μg per rat) with α‐pinene (0.4 μmol L−1), however, prevented the inhibitory effects of α‐pinene on both capsaicin‐induced pulp nociception and COX‐2 over‐expression. Conclusions: Pinene exhibited significant curable effects on capsaicin‐induced pulpal nociception and inflammation mainly via pharmacological interfacing with GABAA and μ‐opioid receptors. [ABSTRACT FROM AUTHOR]

Acceptable estimation of reference Evapotranspiration (ET0) values by the Penman-Monteith FAO (PM FAO) equation requires accurate solar radiation (Rs) data. Rs values could be estimated using the Angstrom's radiation model. The aim of this study was to determine the as and bs coefficient (as Angstrom's parameters) for the Ardabil plain as an arid and cold region. Angstrom's radiation model and PM FAO equation were calibrated for the study area, by optimizing the as and bs parameter using Generalized Reduced Gradient (GRG) method. Measured Rsdata were collected from the Ardabil Synoptic Station and measured ET0 data were determined using three lysimeters that were installed at the Hangar Research Station. Calibrated results showed that optimized as and bs values were 0.117 and 0.384, respectively. Compared to the original models, errors including RMSE, AE and RE values were decreased and fitted parameters including R² and regression line slope (m) were improved in the calibrated models. The GMER values for the original models showed that Angstrom's radiation model overestimated the Rs values and PM FAO equation underestimated the ET0 values. Locally calibrated models estimated Rs and ET0 values better than the original one. Nash-Sutcliffe efficiency coefficient (NSE) values proved that Rs and ET0 estimation by the original models were not satisfactory, but were acceptable in the case of the calibrated models. However, calibration of Angstrom's radiation model and PM FAO equation is necessary for each region. [ABSTRACT FROM AUTHOR]

Aim: To investigate the role of rostral ventromedial medulla orexin‐1 receptors in the modulation of orofacial nociception as well as nociception‐induced learning and memory impairment in adult male rats. Methodology: Pulpal nociception was induced by intradental application of capsaicin (100 μg) into the incisors of rats. Orexin‐1 receptors agonist (orexin‐A, 10, 25 and 50 pmol L−1 rat−1) and antagonist (SB‐334867‐A, 40 and 80 nmol L−1 rat−1) were microinjected into the rostral ventromedial medulla prior to capsaicin administration. Total time spent on nocifensive behaviour was recorded by direct visualization of freely moving rats whilst learning and memory were evaluated by the Morris water maze test. One‐way analysis of variance and repeated‐measures were used for the statistical analysis. Results: Capsaicin‐treated rats had a significant increase of nocifensive behaviours (P < 0.001), as well as learning and memory impairment (P < 0.001). However, intraventromedial medulla prior micro‐injection of orexin‐A (50 pmol L−1 rat−1) significantly reduced the nociceptive behaviour (P < 0.001). This effect was blocked by pre‐treatment with SB334867‐A (80 nmol L−1 rat−1). Orexin‐A (50 pmol L−1 rat−1) also inhibited nociception‐induced learning and memory deficits. Moreover, administration of SB‐334867‐A (80 nmol L−1 rat−1) plus orexin‐A (50 pmol L−1 rat−1) had no effect on learning and memory deficits induced by capsaicin. Conclusions: The data suggest that rostral ventromedial medulla orexin‐A receptors are involved in pulpal nociceptive modulation and improvement of learning and memory deficits induced by intradental application of capsaicin. [ABSTRACT FROM AUTHOR]

Background: Selected studies have reported improved outcomes in laparoscopic compared with open distal pancreatic resection. Concerns regarding failure to achieve proper oncological resection and compromised long‐term outcomes remain. This study investigated whether postoperative outcomes and long‐term survival after laparoscopic distal pancreatectomy are comparable to those after an open procedure. Methods: This retrospective case–control study included patients who underwent distal pancreatectomy for resectable pancreatic adenocarcinoma between 2010 and 2013, identified from the National Cancer Database. Propensity score nearest‐neighbour 1 : 1 matching was performed between patients undergoing laparoscopic or open distal pancreatectomy based on all relevant co‐variables. The primary outcome was overall survival. Results: Of 1947 eligible patients, 605 (31·1 per cent) underwent laparoscopic distal pancreatectomy. After propensity score matching, two well balanced groups of 563 patients each were analysed. There was no difference in overall survival at 3 years after laparoscopic versus open distal pancreatectomy (41·6 versus 36·0 per cent; hazard ratio 0·93, 95 per cent c.i. 0·77 to 1·12; P = 0·457). The overall conversion rate was 27·3 per cent (165 of 605). Patients who underwent laparoscopic distal pancreatectomy had outcomes comparable to those of patients who had an open procedure with regard to median time to chemotherapy (50 versus 50 days; P = 0·342), median number of nodes examined (12 versus 12; P = 0·759); 30‐day mortality (1·2 versus 0·9 per cent; P = 0·562); 90‐day mortality (2·8 versus 3·7 per cent; P = 0·403), 30‐day readmission rate (9·6 versus 9·2 per cent; P = 0·838) and positive margin rate (14·9 versus 18·5 per cent; P = 0·110). However, median duration of hospital stay was shorter in the laparoscopic group (6 versus 7 days; P < 0·001). Conclusion: Laparoscopic distal pancreatectomy is an acceptable alternative to open distal pancreatectomy with no detriment to survival. [ABSTRACT FROM AUTHOR]

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Background Neoadjuvant radiation therapy for locally advanced rectal adenocarcinoma decreases lymph node yield. This study investigated the association between survival and number of lymph nodes evaluated in patients with pathologically negative nodes after neoadjuvant therapy. Methods Patients with locally advanced rectal adenocarcinoma who underwent neoadjuvant therapy and had pathologically negative lymph nodes were included from the Surveillance, Epidemiology, and End Results ( SEER) database over a 7-year interval (January 2004 to December 2010). Systematic dichotomization for optimal cut-off point identification was performed using statistical modelling. Results A total of 3995 patients met the inclusion criteria. The majority had T3 (66·7 per cent) and moderately differentiated (71·5 per cent) tumours. The median number of lymph nodes retrieved was 12 (i.q.r. 7-16). An optimal cut-off of nine lymph nodes was identified. Increasing age ( P < 0·001), increasing T category ( T4 versus T1, P < 0·001; T3 versus T1, P = 0·010), response to neoadjuvant therapy ( P < 0·001) and number of nodes evaluated ( P < 0·001) were significant factors for overall survival in univariable analysis. After adjustment in the multivariable model, the group with nine or more nodes examined had significantly better overall survival (hazard ratio ( HR) 0·76, 95 per cent c.i. 0·65 to 0·88, P < 0·001; 5-year survival 83·2 versus 78·0 per cent) and cancer-specific survival ( HR 0·76, 0·64 to 0·92, P = 0·004; 5-year survival 87·9 versus 85·1 per cent) than the group with one to eight nodes examined. Conclusion Overall and cancer-specific survival were worse where fewer than nine lymph nodes were identified after neoadjuvant therapy for locally advanced rectal cancer. [ABSTRACT FROM AUTHOR]

Castor ( Ricinus communis L.) is an important industrial oilseed crop grown worldwide. Wilt caused by Fusarium oxysporum f. sp. ricini is a devastating disease of this crop. The objective of this research was to identify stable sources of wilt resistance among the global castor germplasm collections available in India for use in cultivar improvement. The global collections comprising 1,779 Indian and 190 exotic accessions from 36 countries were screened against wilt in wilt sick plots at two sites in India in preliminary screening. None of the accessions showed high resistance to wilt, 133 accessions comprising 111 Indian and 22 exotic accessions representing 13 countries exhibited resistance. Thirteen of the 133 resistant accessions were tested further for multiple years in wilt sick plots and glasshouse under controlled artificial inoculation at two sites. All the 13 accessions consistently showed wilt resistance in both wilt sick plot and glasshouse at both sites in multiple years. Eleven of these 13 accessions were from India and two were from former USSR. Evaluation for agro-morphological traits identified high seed yielding and early maturing resistant accessions. Diversity analyses precisely revealed diversity among the resistant accessions. These 13 resistant accessions would be great value as donors of resistance. [ABSTRACT FROM AUTHOR]

In the present work, mercaptopropionic acid (MPA) capped CdTe and CdHgTe quantum dots (QDs) are synthesized using a method based on the bottom up approach in aqueous medium. The CdTe QDs were prepared with a two different ratios of Cd:Te (3:1 and 4:1). It was noticed that there was a minimum concentration of MPA for each Cd:Te ratio. The resulting QDs were characterized using optical absorption spectroscopy, energy dispersion X-ray (EDX) and high resolution transmission electron microscopy (HRTEM). It was found that the EDXs of CdTe and CdHgTe QDs showed that the stiochiometric ratios of CdTe obtained with Cd:Te ratio of 3:1 is 50:50 and for CdHgTe is 40:26:34 for 100 % of Hg. The band gap of CdHgTe QDs varies slightly with composition from 2.21 eV for a pure CdTe to 1.4 eV for a CdHgTe with 100 % of Hg. The HRTEM image showed a good dispersed nano-crystalline structure for the CdTe QDs with average size of 3-4 nm. The existence of the lattice planes on the HRTEM images of the QD indicated that the CdTe QDs are highly crystalline. In addition, the CdHgTe QDs size is 12 nm for 100 % of Hg. [ABSTRACT FROM AUTHOR]

Aim To compare the subcutaneous tissue response to grey mineral trioxide aggregate (GMTA), white mineral trioxide aggregate (WMTA) and a new experimental cement (calcium enriched cement, CEM). Methodology Thirty-six Wistar male albino rats each received three implants, containing one of the tested materials, and an empty tube as a control. Seven, 30 and 60 days after implantation, the animals were sacrificed. After histological preparation and H&E staining, the specimens were evaluated for capsule thickness, necrosis, and for the type, the severity, and the extent of inflammation. Kruskal Wallis and Chi-square tests were used for data analysis. Results After 1 week, CEM produced no necrosis compared to both types of WMTA and GMTA (P = 0.007). After 30 days, GMTA specimens had significantly less inflammation compared with WMTA and CEM (P = 0.011). After 60 days, less inflammation was associated with CEM specimens (P = 0.0001) compared to the other materials. Dystrophic calcifications in the connective tissue adjacent to all experimental material were detected. Conclusion Histological observation illustrated that all materials were well tolerated by the subcutaneous tissues. Keywords: biocompatibility, grey, mineral trioxide aggregate, novel cement, white. [ABSTRACT FROM AUTHOR]

Background: Data on esophageal sphincters in obese individuals during anesthesia are sparse. The aim of the present study was to evaluate the effects of different respiratory maneuvers on the pressures in the esophagus and esophageal sphincters before and during anesthesia in obese patients. Methods: Seventeen patients, aged 28-68 years, with a BMI≥35 kg/m2, who were undergoing a laparoscopic gastric by-pass surgery, were studied, and pressures from the hypopharynx to the stomach were recorded using high-resolution solid-state manometry. Before anesthesia, recordings were performed during normal spontaneous breathing, Valsalva and forced inspiration. The effects of anesthesia induction with remifentanil and propofol were evaluated, and positive end-expiratory pressure (PEEP) 10 cmH2O was applied during anesthesia. Results: During spontaneous breathing, the lower esophageal sphincter (LES) pressure was significantly lower during end-expiration compared with end-inspiration (28.5 ± 7.7 vs. 35.4 ± 10.8 mmHg, P<0.01), but barrier pressure (BrP) and intra-gastric pressure (IGP) were unchanged. LES, BrP ( P<0.05) and IGP ( P<0.01) decreased significantly during anesthesia. BrP remained positive in all patients. IGP increased during Valsalva ( P<0.01) but was unaffected by PEEP. Esophageal pressures were positive during both spontaneous breathing and mechanical ventilation. Esophageal pressures increased during PEEP from 9.4 ± 3.8 to 11.3 ± 3.3 mmHg ( P<0.01). Conclusion: During spontaneous breathing, the LES pressure was the lowest during end-expiration but there were no differences in BrP and IGP. LES, BrP and IGP decreased during anesthesia but BrP remained positive in all patients. During the application of PEEP, esophageal pressures increased and this may have a protective effect against regurgitation. [ABSTRACT FROM AUTHOR]