The effects of wellbore stone materials and fluid density on the shock wave induced by plasma pulse system propagation in rock: An analytical and experimental study.

A pulsed plasma system is a highly efficient tool for linking wells to reservoirs to repair near-wellbore damage and restore production. This research aims to create a computational model and experimental setup to delve into the generation and spread of shock waves from electrical discharge. It also explores the influence of different stone wall materials such as limestone, sandstone, and dolomite, along with varied fluid densities such as saline water and drilling mud. Results show that when an electrical current passes through a metal wire, the wire explosively disintegrates, creating a plasma pulse that applies pressure shock to the stone walls, leading to crack formation. It is important to note that the explosion's energy can be increased by raising the capacitor's energy and modifying the circuit's inductance. Analyzing the impact of fluid density on the shock wave reveals that enhancing the plasma pulse system and attaining higher energy levels can be achieved by using materials with higher viscosity. In terms of stone wall materials, limestone demonstrates superior mechanical stability, dolomite exhibits moderate stability, and sandstone shows relatively lower stability in crack growth.

Optimizing some parameters of air-filled ion pulse ionization chambers for effective radon detection.

Air-filled ionization chambers in pulse ion mode can provide precise low-level detection of indoor/outdoor radon. However, it suffers from relatively high collection duration of positive and negative charges as well as environmental changes. In order to overcome these shortcomings, the Garfield++ software which is a powerful toolkit to develop a realistic simulation framework for radiation detectors was applied. Also, Garfield++ interface to Magboltz was used to calculate the gas parameters for air at various humidity conditions for a wide range of electric field strengths in order to compare the results with other available data in the literature. The Garfield++ software was also used to calculate maximum charge collection duration for a wide range of tube radii, wire radii, and electric potentials which are the main parameters affecting the charge collection duration. Furthermore, the influence of environmental conditions including air pressure, temperature, and humidity on the charge collection duration was investigated. The results show that for an air-filled radon ionization chamber with a moderate size (e.g. 1 L) with a bias voltage of hundreds of volts, the time constant of the external circuit can be chosen to be less than 100 ms, which is much lower than the values used in other studies. Therefore, with a proper design of an ionization chamber and its electronic system, it is possible to determine radon activity concentrations of up to a few tens of kBq.m-3 in pulse mode. In conclusion, the data obtained in this study assists in developing radon air-filled ionization chambers in order to determine chamber dimensions and bias voltage as well as designing the readout electronics according to the characteristics required in an intended application.

TiCrN-TiAlN-TiAlSiN-TiAlSiCN multi-layers utilized to increase tillage tools useful lifetime.

For the first time, a hard wear-resistant multi-layer of TiCrN-TiAlN-TiAlSiN-TiAlSiCN was deposited on carbon steel CK45-based tillage tools to increase their useful lifetime. The layers were deposited by using an arc-PVD method without post-annealing procedures. XRD and EDX data indicated that TiCrN, TiAlN, TiAlSiN, and TiAlSiCN formed individually and as a multi-layer of high-quality crystalline layers with mostly cubic structures. The studies on the multi-layers coating morphology, roughness and hardness gave reasonable results as a roughness of 35 nm and a hardness of 32.2 GPa. The coated sweep duck blade tillage tools were tested on the field along with a soil bin to obtain their wear behavior at different traveling distances. The draft force of all blades showed promising results. As the coated layers were worn off, their draft force increased. In comparison with single-layer coatings, the multi-layer structure demonstrated an increase in the useful lifetime of the blades.

Two hump-shaped angular distributions of neutrons and soft X-rays in a small plasma focus device.

Angular distributions of soft X-rays (SXRs) and neutrons emitted by a small plasma focus device (PFD) were investigated simultaneously using TLD-100 dosimeters and Geiger-Muller activation counters, respectively. The distributions represented two humps with a small dip at the angular position 0° and reduced from the angles of ± 15° and ± 30° for the neutrons and SXRs, respectively. The maximum yield of 2.98 × 108 neutrons per shot of the device was obtained at 13.5kV and 6.5mbar. A time of flight (TOF) of 75.2ns between the hard X-ray and the neutron peaks corresponds to neutrons with energy of 2.67MeV. A similar behavior was observed between the angular distributions of neutron and soft X-ray emissions.

Breakthrough in 4π ion emission mechanism understanding in plasma focus devices.

Ion emission angular distribution mechanisms in plasma focus devices (PFD) have not yet been well developed and understood being due to the lack of an efficient wide-angle ion distribution image detection system to characterize a PFD space in detail. Present belief is that the acceleration of ions points from "anode top" upwards in forward direction within a small solid angle. A breakthrough is reported in this study, by mega-size position-sensitive polycarbonate ion image detection systems invented, on discovery of 4π ion emission from the "anode top" in a PFD space after plasma pinch instability and radial run-away of ions from the "anode cathodes array" during axial acceleration of plasma sheaths before the radial phase. These two ion emission source mechanisms behave respectively as a "Point Ion Source" and a "Line Ion Source" forming "Ion Cathode Shadows" on mega-size detectors. We believe that the inventions and discoveries made here will open new horizons for advanced ion emission studies towards better mechanisms understanding and in particular will promote efficient applications of PFDs in medicine, science and technology.

Serum interleukin-1beta and tumor necrosis factor-alpha in febrile seizures: is there a link?

PURPOSE: Febrile seizures are induced by fever and are the most common type of seizures in children. Although numerous studies have been performed on febrile seizures, their pathophysiology remains unclear. Recent studies have shown that cytokines may play a role in the pathogenesis of febrile seizures. The present study was conducted to identify potential links between serum interleukin-1beta (IL-1ß), tumor necrosis factor-alpha (TNF-α), and febrile seizures. METHODS: Ninety-two patients with simple or complex febrile seizures (46 patients per seizure type), and 46 controls with comparable age, sex, and severity of temperature were enrolled. RESULTS: The median concentrations of serum IL-1ß in the simple, complex febrile seizure, and control groups were 0.05, 0.1, and 0.67 pg/mL, respectively (P=0.001). Moreover, the median concentrations of TNF-α in the simple, complex febrile seizure, and control groups were 2.5, 1, and 61.5 pg/mL, respectively (P=0.001). Furthermore, there were significant differences between the case groups in serum IL-1ß and TNF-α levels (P<0.05). CONCLUSION: Unlike previous studies, our study does not support the hypothesis that increased IL-1ß and TNF-α production is involved in the pathogenesis of febrile seizures.

Are clinical, laboratory, and imaging markers suitable predictors of vesicoureteral reflux in children with their first febrile urinary tract infection?

PURPOSE: This study was conducted to determine the predictive value of clinical, laboratory, and imaging variables for the diagnosis of vesicoureteral reflux in children with their first febrile urinary tract infection. MATERIALS AND METHODS: One hundred fifty-three children with their first febrile urinary tract infection were divided into two groups according to the results of voiding cystourethrography: 60 children with vesicoureteral reflux and 93 children without. The sensitivity, specificity, positive and negative predictive value, likelihood ratio (positive and negative), and accuracy of the clinical, laboratory, and imaging variables for the diagnosis of vesicoureteral reflux were determined. RESULTS: Of the 153 children with febrile urinary tract infection, 60 patients (39.2%) had vesicoureteral reflux. There were significant differences between the two groups regarding fever>38℃, suprapubic pain, C-reactive protein quantitative level, number of red blood cells in the urine, and results of renal ultrasound and dimercaptosuccinic acid renal scanning (p<0.05). There were significant positive correlations between fever>38.2℃ and dimercaptosuccinic acid renal scanning and vesicoureteral reflux. Also, there were significant positive correlations between the erythrocyte sedimentation rate, positive urinary nitrite test, hyaline cast, and renal ultrasound and high-grade vesicoureteral reflux. CONCLUSIONS: This study revealed fever>38.2℃ and dimercaptosuccinic acid renal scanning as the best predictive markers for vesicoureteral reflux in children with their first febrile urinary tract infection. In addition, erythrocyte sedimentation rate, positive urinary nitrite test, hyaline cast, and renal ultrasound are the best predictive markers for high-grade vesicoureteral reflux.

Are serum procalcitonin and interleukin-1 beta suitable markers for diagnosis of acute pyelonephritis in children?

Rapid diagnosis of acute pyelonephritis is important because of its association with long-standing complications. This study was conducted to compare the reliability of serum procalcitonin (PCT) and interleukin-1 beta (IL-1ß) with conventional laboratory parameters for diagnosis of acute pyelonephritis in children. Seventy nine children with urinary tract infection were divided into two groups based on the result of Tc-99m dimercaptosuccinic acid renal scan: acute pyelonephritis (n=33) and lower UTI (urinary tract infection) (n=46) groups. White blood cell (WBC) count, neutrophil count, erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), PCT and IL-1ß concentrations of both groups were measured and compared. WBC count, neutrophil count, ESR, serum CRP, PCT and IL-1ß concentrations were higher in acute pyelonephritis patients than in the lower UTI group (P<0.05). The sensitivity and specificity of serum PCT and IL-1ß for diagnosis of acute pyelonephritis were 31, 84.7% and 27.2, 90% respectively (using a cut-point value of 0.5 ng/ml for PCT and 6.9 pg/ml for IL-1ß). The sensitivity of PCT and IL-1ß for diagnosis of acute pyelonephritis was less than that of conventional markers such as ESR and CRP. This study revealed that serum PCT and IL-1ß are not good biologic markers for differentiating acute pyelonephritis from lower UTI. It seems that conventional inflammatory markers such as ESR and CRP besides the clinical findings are more reliable for the diagnosis of acute pyelonephritis in children.

Eau de Dalibour vs. alcohol for umbilical cord care.

This study was conducted to compare the effects of Eau de Dalibour and ethanol on preventing omphalitis and also on umbilical cord separation time in neonates. In this clinical trial, 178 randomly selected, healthy term neonates were investigated. To disinfect the umbilical cords, Eau de Dalibour was used for 84 infants (case group) and ethanol for 94 infants (control group). No cases of omphalitis were observed in either group. Umbilical cord separation time was significantly shorter in the Eau de Dalibour group than in the ethanol group: 4.04 ± 1.61 days vs. 6.3 ± 1.82 days, p = 0.001. This study revealed that although Eau de Dalibour and ethanol were equally effective in preventing the incidence of omphalitis in neonates, Eau de Dalibour induced the separation of umbilical cord significantly quicker in the infants. Thus, Eau de Dalibour could be used as a suitable replacement for ethanol in neonates' umbilical cord care.

The effect of clofibrate on hyperbilirubinemia of term neonates.

Clofibrate is a glucuronosyl transferase inducer that has been proposed to increase the elimination of bilirubin in neonates with hyperbilirubinemia. This study was conducted to determine the therapeutic effect of clofibrate in term neonates with non-hemolytic jaundice. This study was conducted on 52 newborns with pathologic unconjugated jaundice in Qazvin children hospital. Newborns divided randomly in two groups. Case group treated with clofibrate and intensive phototherapy, while control group treated only with intensive phototherapy. Serum bilirubin level was measured before and 6, 12, 24 and 48 hours after treatment. Results were compared and analyzed. The mean serum level of bilirubin before treatment in the case and control groups were 20.78 ± 2.38 and 20.52 ± 2.44 mg/dl, respectively (P=0.69). The mean serum level of bilirubin in 6, 12, 24 and 48 hours after treatment in the case group were 18.20 ± 2.20, 14.70 ± 2.06, 10.72 ± 2.40 and 8.90 ± 0.83 mg/dl , respectively. These values in control group were 18.26 ± 2.42, 15.36 ± 2.59, 12.29 ± 2.28 and 10.23 ± 1.50 mg/dl, respectively. There was significant difference between two groups regarding mean serum level of bilirubin 24 hours (P=0.019) and 48 hours after treatment (P=0.005). In conclusion, clofibrate was effective in reducing neonatal jaundice and its effect appeared 24 hours after treatment.

Intentional replantation: a procedure as a last resort.

AIM: To address the indications, contraindications, surgical procedure, complications following treatment, factors influencing the results and success rate of intentional replantation procedure. BACKGROUND: Intentional replantation is extraction of a tooth to do extraoral root canal therapy, curettage of apical lesion when present, and its replacement in its socket. It has been proposed as an alternative to routine extraction; however, it should be considered a last resort because the root may be fractured during extraction. RESULTS: The success rate of intentional replantation is far below than routine endodontic treatment or apical surgery. Difficultness of tooth extraction, the possibility of fracture during extraction and the risk of external resorption are some limitations of this treatment. The most common causes of failure in intentionally replanted teeth are external inflammatory resorption or replacement resorption and ankylosis caused by periodontal ligament damage. CONCLUSION: The success rate up to 95% with an average retention of 3 to 5 years, has been reported. CLINICAL SIGNIFICANCE: In some cases, endodontic retreatment or apical surgery is impossible or impractical. In these situations, intentional replantation may be considered as a last resort for preserving the tooth, so all clinicians should know about its indications/contraindications, surgical procedure and complications following treatment.

Keratocystic odontogenic tumor: a 10-year retrospective study of 83 cases in an Iranian population.

A retrospective analysis was conducted on patients diagnosed with and treated for keratocystic odontogenic tumor (KCOT) at Mashhad School of Dentistry between 1996 and 2006. The patients comprised 44 men and 30 women with a mean age of 27.08 years. Among the total of 83 lesions, 56 (67.5%) occurred in the mandible and 27 (32.5%) in the maxilla. Swelling tended to be the most common complaint (45.8%), while 24.1% of the lesions were diagnosed incidentally. Six patients (8.1%) with a total of 15 lesions had nevoid basal cell carcinoma syndrome; 28 lesions (33.7%) were associated with an impacted tooth, and 12 (14.5%) presented daughter cysts. Sixty-six KCOTs were treated by enucleation [5 recurrences (7.6%)], 6 by marsupialization [2 recurrences (33.3%)] and 11 by marsupialization followed by enucleation (no recurrences). KCOTs in the mandible showed a higher recurrence rate than those in the maxilla (10.7% vs 3.7%). Although the demographics of Iranian patients are closely similar to those of other nationalities, in this series KCOTs tended to develop in younger patients with a peak in teenagers. The posterior region of the mandible showed the highest likelihood of KCOT occurrence and recurrence. Marsupialization followed by enucleation resulted in the lowest recurrence rate.