Analyzing the performance of synthesized nano-catalysts for transesterification of waste cooking oil as environment friendly drilling fluid.

Ester-based drilling fluids (EBDF) are preferred over oil-based drilling fluids (OBDF) and water-based drilling fluids (WBDF) because of their great biodegradability, low toxicity, and improved performance. In this work, waste cooking oil methyl ester (WCOME) was used to prepare an environmentally friendly EBDF. Through a transesterification process utilizing a modified calcium oxide based heterogenous catalyst, the waste cooking oil is transformed into waste cooking oil methyl ester. Response surface approach was used to strengthen the transesterification. The optimize conditions for CaO/Al2O3 resulted in the highest yield of 96.56% at a molar ratio of 11.9:1, 3.19 wt % of CaO/Al2O3, 53.79 °C, and 76.86 min. In contrast, CaO/TiO2 yielded 98.15% at a molar ratio of 11.99:1, with a CaO/TiO2 of 2.53 wt % at 59.79 in 68.14 min. Additionally, two separate densities of 9 ppg and 12 ppg EBDF are formulated with two distinct oil-to-water ratios (70:30 and 80:20) using synthesized WCOME. To assess the effectiveness of formulated EBDF thorough rheological investigation is conducted at 150°. Additionally, the filtration loss at HPHT conditions, emulsion stability, and Barite sag analysis of the drilling fluid are all analyzed at before ageing and after dynamic ageing. With better rheological features, less fluid loss, good emulsion stability, and minimal barite sagging, the designed EBDF performs efficiently. The drilling fluid met the API requirement and demonstrated stability even after ageing at 250 °F for 72 h, suggesting that it may be used for extended periods of time in drilling.

Controls on Barite (BaSO4) Precipitation in Unconventional Reservoirs.

Barite (BaSO4) precipitation is one of the most ubiquitous examples of secondary sulfate mineral scaling in shale oil and gas reservoirs. Often, a suite of chemical additives is used during fracturing operations to inhibit the accumulation of mineral scales, though their efficacy is widely varied and poorly understood. This study combines experimental data and multi-component numerical reactive transport modeling to offer a more comprehensive understanding of the geochemical behavior of barite accumulation in shale matrices under conditions typical of fracturing operations. A variety of additives and conditions are individually tested in batch reactor experiments to identify the factors controlling barite precipitation. Our experimental results demonstrate a pH dependence in the rate of barite precipitation, which we use to develop a predictive model including a pH-dependent term that satisfactorily reproduces our observations. This model is then extended to consider the behavior of three major shale samples of highly variable mineralogy (Eagle Ford, Marcellus, and Barnett). This data-validated model offers a reliable tool to predict and ultimately mitigate against secondary mineral accumulation in unconventional shale reservoirs.

Double-contrast barium enema is no longer justified as a backup examination for colonoscopy in the population screening program: Population study in an organized fecal immunochemical test-based screening program.

BACKGROUND AND AIM: Currently, some countries still acknowledge double-contrast barium enema (DCBE) as a backup confirmatory examination when colonoscopy is not feasible or incomplete in colorectal cancer (CRC) screening programs. This study aims to compare the performance of colonoscopy and DCBE in terms of the risk of incident CRC after negative results in the fecal immunochemical test (FIT)-based Taiwan Colorectal Cancer Screening Program. METHODS: Subjects who had positive FITs and received confirmatory exams, either colonoscopy or DCBE, without the findings of neoplastic lesions from 2004 to 2013 in the screening program comprised the study cohort. Both the colonoscopy and DCBE subcohorts were followed until the end of 2018 and linked to the Taiwan Cancer Registry to identify incident CRC cases. Multivariate analysis was conducted to compare the risk of incident CRC in both subcohorts after controlling for potential confounders. RESULTS: A total of 102 761 colonoscopies and 5885 DCBEs were performed after positive FITs without neoplastic findings during the study period. By the end of 2018, 2113 CRCs (2.7 per 1000 person-years) and 368 CRCs (7.6 per 1000 person-years) occurred in the colonoscopy and DCBE subcohorts, respectively. After adjusting for major confounders, DCBE had a significantly higher risk of incident CRC than colonoscopy, with an adjusted HR of 2.81 (95% CI = 2.51-3.14). CONCLUSIONS: In the FIT screening program, using DCBE as a backup examination was associated with a nearly threefold risk of incident CRC compared with colonoscopy, demonstrating that it is no longer justified as a backup examination for incomplete colonoscopy.

Differential Effects of Laxatives on Barium Sulfate Coating and Image Quality in Double-Contrast Barium Enema.

BACKGROUND: Diagnostic accuracy of double-contrast barium enema (DCBE) depends upon the barium sulfate coating efficiency in the colon. OBJECTIVE: To evaluate effects of three laxatives on barium sulfate coating efficiency in the large intestine, sigmoid colon, and hepatic flexure in DCBE. METHODS: This retrospective study included patients receiving DCBE after pre-procedure cleansing with Dulcolax® with castor oil (DC), Klean-Prep® (KP), or Fleet® . Patients' DCBE images were reviewed. RESULTS: Among 373 cases of DCBE, 151 received DC, 147 received KP, and 75 received Fleet. For DCBE, the optimal extent of barium sulfate residue coated on the wall of the large intestine is less than one-fourth of bowel wall width; the DC group had a higher percentage of less than one-fourth of bowel wall than that of the KP or Fleet group (both p < 0.0167). DC, KP and Fleet have comparable barium sulfate coating efficiency in the sigmoid colon. However, in the hepatic flexure, the DC group had a higher percentage of barium sulfate coating without interruption than that of the KP or Fleet groups (both p < 0.0167). CONCLUSION: DC has a better barium sulfate coating efficiency in the hepatic flexure compared with KP and Fleet.

Review on treatment and utilization of barium slag in China.

Barium slag (BS) is generated as a by-product waste during the production of barium salts from barite. A large amount of BS is discharged annually threating the ecological environment and restricting the development of the barium salts industry. In China, BS is classified as hazardous waste due to its corrosivity, and more importantly because of its extraction toxicity of barium. Soluble barium is toxic and can result in barium poisoning for environment and human beings. The current review presents a detailed summary on general characteristics, discharge and disposal status, harmless treatment pathways and comprehensive utilization of BS in China. BaO, SiO2, CaO, and SO3 occur as main chemical compositions in BS, especially BaO accounting approximately for 35-40%. The mineral compositions include unreacted barite, quartz, clay minerals, newly-formed phases from the side reactions such as BaCO3, BaSiO3 and BaSO3, and residual carbon. A special attention is given to the assessment of the harmless treatment methods for BS from hazardous waste to general waste, which will decrease its management costs. Precipitation and solidification of soluble barium is the common pathway for harmless treatment of BS, and the using of other industrial waste can realize cost-saving. Methods for comprehensive utilization of BS include recovery of barium and carbon, application in building materials, and using as adsorbents for wastewater treatment. In particular, we analyzed and discussed the advantages and disadvantages of these existing process routes, intending to promote potentials for comprehensive utilization of BS in the future.

Selenite and Selenate Sequestration during Coprecipitation with Barite: Insights from Mineralization Processes of Adsorption, Nucleation, and Growth.

Coprecipitation of selenium oxyanions with barite is a facile way to sequester Se in the environments. However, the chemical composition of Se-barite coprecipitates usually deviates from that predicted from thermodynamic calculations. This discrepancy was resolved by considering variations in nucleation and growth rates controlled by ion-mineral interactions, solubility, and interfacial energy. For homogeneous precipitation, ∼10% of sulfate, higher than thermodynamic predictions (<0.3%), was substituted by Se(IV) or Se(VI) oxyanion, which was attributed to adsorption-induced entrapment during crystal growth. For heterogeneous precipitation, thiol- and carboxylic-based organic films, utilized as model interfaces to mimic the natural organic-abundant environments, further enhanced the sequestration of Se(VI) oxyanions (up to 41-92%) with barite. Such enhancement was kinetically driven by increased nucleation rates of selenate-rich barite having a lower interfacial energy than pure barite. In contrast, only small amounts of Se(IV) oxyanions (∼1%) were detected in heterogeneous coprecipitates mainly due to a lower saturation index of BaSeO3 and deprotonation degree of Se(IV) oxyanion at pH 5.6. These roles of nanoscale mineralization mechanisms observed during composition selection of Se-barite could mark important steps toward the remediation of contaminants through coprecipitation.

Computed tomographic colonography versus double-contrast barium enema for the preoperative evaluation of rectal cancer.

PURPOSE: We investigated whether or not computed tomographic colonography (CTC) is a viable alternative to double-contrast barium enema (BE) for a preoperative rectal cancer evaluation. METHODS: The size and distance from the anal canal to the lower or upper tumor borders were laterally measured in 147 patients who underwent CTC and BE. Measurements were grouped into early cancer, advanced, and after chemoradiation therapy (CRT). RESULTS: In the early and advanced cancer groups, all lesions were visualized by BE. In contrast, 3 (7.8%) early and 8 (7.3%) advanced cases, located at the anterior wall near the anal canal, were not visualized by CTC because of liquid level formation. In the CRT group, 16 (23.5%) and 4 (5.8%) cases were not visualized by CTC and BE, respectively. The BE and CTC size measurements were similar among cohorts. However, the distance from the anal canal's superior margin tended to be longer with BE, especially in early cancer. The differences in distance from the anal canal were significantly larger in the early cancer group than in the other two groups (p = 0.0024). CONCLUSION: CTC may be a viable alternative imaging modality in some cases. However, BE should be employed in anterior wall cases near the anal canal and CRT cases.

Machine learning-based quantitative analysis of barium enema and clinical features for early diagnosis of short-segment Hirschsprung disease in neonate.

OBJECTIVE: To develop a mathematical model based on a combination of clinical and radiologic features (barium enema) for early diagnosis of short-segment Hirschsprung disease (SHSCR) in neonate. METHODS: The analysis included 54 neonates with biopsy-confirmed SHSCR (the cases) and 59 neonates undergoing barium enema for abdominal symptoms but no Hirschsprung disease (the control). Colon shape features extracted from barium enema images and clinical features were used to develop diagnostic models using support vector machine (SVM) and L2-regularized logistic regression (LR). The training cohort included 32 cases and 37 controls; testing cohort consisted 22 cases and 22 controls. Results were compared to interpretation by 2 radiologists. RESULTS: In the analysis by radiologists, 87 out of 113 cases were correctly classified. Six SHSCR cases were mis-classified into the non-HSCR group. In the remaining 20 cases, radiologists were unable to make a decision. Both the SVM and LR classifiers contained five clinical features and four shape features. The performance of the two classifiers was similar. The best model had 86.36% accuracy, 81.82% sensitivity, and 90.91% specificity. The AUC was 0.9132 for the best-performing SVM classifier and 0.9318 for the best-performing LR classifier. CONCLUSION: A combination of clinical features and colon shape features extracted from barium enemas can be used to improve early diagnosis of SHSCR in neonate.

An Unusual Presentation of Intussusception.

This is the case of a 9-month-old female infant who presented to the emergency department with a history of several episodes of nonbilious and nonbloody emesis. The patient was found to be afebrile with normal vital signs and an otherwise normal physical examination. Initial plain film radiography was concern for possible obstruction. Imaging studies with ultrasonogram demonstrated intussusception. This was an unusual case of intussusception because children are typically more ill-appearing with vomiting, diarrhea, fevers, lethargy, and blood in stool. Management options included surgery, pneumatic enema reduction, and barium enema reduction. Pneumatic enema reduction was performed. This procedure has been shown to have superior outcomes in infants with intussusception. Advanced practice providers need to provide a detailed history, complete a thorough physical examination, order the appropriate diagnostics, and be vigilant of the clinical manifestation of intussusception.

Intraperitoneal Barium From Gastrointestinal Perforations: Reassessment of the Prognosis and Long-Term Effects.

OBJECTIVE. The purpose of this study was to reassess the outcome and potential consequences of intraperitoneal barium leakage during radiologic evaluation of the gastrointestinal tract. MATERIALS AND METHODS. This retrospective study included 18 patients who had significant intraperitoneal leakage of barium from gastrointestinal perforations that were not suspected or diagnosed before the radiologic procedures. This complication occurred during a barium enema examination in nine patients, an upper gastrointestinal study in seven, and a small bowel series in two patients. All patients underwent urgent laparotomy for repair of perforation, with vigorous peritoneal lavage and antibiotic therapy. RESULTS. All patients had an uneventful recovery and were followed for 4-17 years (mean, 8.5 years). Radiographs obtained during this interval showed that a significant amount of residual barium was retained in the abdominal cavity. Six patients had a total of 10 subsequent abdominal operations for unrelated conditions, and some had developed barium granulomas and peritoneal adhesions. However, none of the patients in this series experienced intestinal obstruction or any clinical symptoms related to barium deposits in the abdominal cavity. CONCLUSION. Intraperitoneal leakage of barium is a rare complication of radiologic gastrointestinal examinations, and this series of 18 cases reflects 3 decades of experience at two major medical centers. The presented data indicate that the commonly held and perpetuated concept about the high rate of morbidity and mortality of this complication would not be valid in the modern era of medical and surgical management.

ESTIMATION OF THE EFFECTIVE DOSES FROM TYPICAL FLUOROSCOPIC EXAMINATIONS WITH BARIUM CONTRAST.

The current study aimed to estimate the effective doses and conversion coefficients (CCs) for typical barium swallow (BS), barium meal (BM) and barium enema (BE) protocols and to evaluate the impact of different examination parameters on the resulting CCs. Data were collected in surgical and therapy departments in St. Petersburg Urban Mariinsky Hospital. Computational models were developed using PCXMC 2.0 software. CCs (µSv × µGy-1 × m-2) were estimated, as follows, for over couch and under couch exposure geometries, respectively: 2.3 and 1.7 for BS (surgical department); 2.4 and 2.0 for BM (surgical department); 2.6 and 2.1 for BE (surgical department) 2.5 and 3.8 for BM (therapy department). The effective doses and CCs are mainly influenced by the combination of different fluoroscopic series and X-ray images taken in different projections, the irradiation field size and the energy characteristics of the X-ray beam.

Pulsion diverticula of the rectum: Radiological diagnosis and clinical implications.

INTRODUCTION: The aim of this study was to investigate the appearance of acquired rectal diverticula on barium enema and computed tomography (CT) and to review the pertinent clinical data about this entity. METHODS: This series included 3 men and 6 women, who ranged in age from 47 to 82 years (average: 64 years). Air-contrast barium enema in 6 patients with history of anorectal disease or obstructed defecation demonstrated rectal diverticula. In these cases, multiple radiographs of the rectosigmoid region were obtained in upright position while the patient was relaxing or straining without any attempt to evacuate the barium. In 3 cases, the lateral rectal diverticula were incidental finding on CT studies that were performed for various unrelated abdominal complaints. RESULTS: Pulsion type of diverticulum presenting as a wide-neck outpouching was detected on the lateral rectal wall in 5 and on the posterior wall in 4 patients. They measured 2-3 cm in diameter when filled with contrast material or gas, and became even larger when the intraluminal pressure was increased by straining. CONCLUSION: Pulsion diverticula of the rectum present as a wide-neck outpouching of the lateral or posterior rectal wall in adult patients. This acquired abnormality is usually associated with coexisting anorectal lesions or defecation disorders. The practising radiologists and colorectal surgeons should be aware of this uncommon condition, its appearance on barium enema and other imaging studies, and its clinical implications.

Ultrasound-guided hydrostatic reduction versus fluoroscopy-guided air reduction for pediatric intussusception: a multi-center, prospective, cohort study.

BACKGROUND: Intussusception is the most common abdominal emergency in children. The first line treatment of uncomplicated pediatric intussusception is enema reduction. Until now, there have been no multi-center studies comparing the effectiveness and safety of UGHR and FGAR in the treatment of pediatric intussusception. The aim of this study was to compare the effectiveness and safety of the two most commonly used enema methods of pediatric intussusception: ultrasound-guided hydrostatic reduction (UGHR) and fluoroscopy-guided air reduction (FGAR). METHODS: From November 1, 2017 to October 31, 2018, we conducted a multi-center, prospective, cohort study. Children diagnosed with intussusception in four large Children's Medical Centers in China were divided into UGHR and FGAR groups. Stratified analysis and subgroup analysis were used for further comparison. The success and recurrence rates were used to evaluate the effectiveness of enema reduction. The perforation rate was used to evaluate the safety of enema reduction. RESULTS: A total of 2124 cases met the inclusion criteria (UGHR group: 1119 cases; FGAR group: 1005 cases). The success and recurrence rates in the UGHR group were higher than in the FGAR group (95.80%, 9.28% vs. 93.13%, 10.65%) (P < 0.05, P > 0.05), respectively. The perforation rate in the UGHR group was 0.36% compared with 0.30% in the FGAR group (P > 0.05). Subgroup analysis showed the success rates in the UGHR group were higher than in the FGAR group of patients with onset time between 12 and 24 h (95.56% vs. 90.57%) (P < 0.05). Of patients aged 4 to 24 months, the success rates in the UGHR group were also higher than in the FGAR group (95.77% vs. 91.60%) (P < 0.05). Stratified analysis showed the success rates in the UGHR group were higher than in the FGAR group in patients with the symptom of bloody stool (91.91% vs 85.38%) (P < 0.05). CONCLUSIONS: UGHR and FGAR are safe, nonsurgical treatment methods for acute pediatric intussusception. UGHR is superior to FGAR, no radiation risk, its success rate is higher, without a difference in perforation rate, especially for patients aged 4-24 months. LEVEL OF EVIDENCE: Level II.

Performance of radiographic imaging after incomplete colonoscopy for nonmalignant causes in clinical practice.

BACKGROUND AND AIMS: CT colonography (CTC) or barium enema are commonly ordered to complete colorectal imaging after an incomplete colonoscopy. We evaluated the sensitivity of radiographic studies performed for this purpose in clinical practice outside clinical trials. METHODS: Adult patients referred to an expert endoscopist for incomplete colonoscopy because of a redundant colon or a difficult sigmoid and who underwent previous radiographic imaging between July 2001 and July 2019 were identified. None of the patients had a malignant obstruction as the cause of incomplete colonoscopy. Data on polyp size, location, and pathology were obtained from colonoscopy and radiology reports. Polyps identified on imaging and colonoscopy were matched based on polyp size and location. RESULTS: Among 769 patients referred for incomplete colonoscopy, we identified 65 with a radiographic examination performed within 36 months of colonoscopy at our center. Per-patient sensitivity for CTC was suboptimal (70%) and was very low for barium enema (26.7%). Per-polyp sensitivity for both CTC and barium enema was poor (23.8% and 7.6%). Quality of the examination did not seem to affect procedure sensitivity. CONCLUSIONS: Radiographic imaging after incomplete colonoscopy for reasons other than malignant obstruction had poor sensitivity for polyps. Patients with incomplete colonoscopies should be considered for repeat colonoscopy by an expert.

Neuromuscular electrical stimulation improves feeding and aspiration status in medically complex children undergoing feeding therapy.

OBJECTIVES: Neuromuscular electrical stimulation (NMES) therapy in the head and neck has been effectively used to rehabilitate swallowing in adult patients with acquired dysphagia. Limited data is available for the effectiveness of NMES in medically complex children with dysphagia and aspiration. This study intends to determine the efficacy of NMES as a therapeutic adjunct to improve aspiration and feeding status in medically complex children with severe dysphagia undergoing comprehensive speech and swallow therapy. STUDY DESIGN: Case series. SETTING: Tertiary children's hospital. SUBJECTS: and Methods: Medically complex children undergoing treatment for dysphagia using NMES during a three year period were included. Duration of treatment routinely ranged from 20 to 26 weeks. Demographic information, pre and post-NMES treatment aspiration status via modified barium swallow (MBS), and pre and post-NMES treatment feeding status were examined. RESULTS: 15 medically complex children underwent NMES as a component of their feeding therapy. The mean age was 2.51 ±â€¯3.20 years. Mean pre-treatment Functional Oral Intake Scale(FOIS) was 3.07 ±â€¯1.94. Following NMES, FOIS improved to 4.47 ±â€¯2.26 (p < 0.0001). Fourteen patients were evaluated with MBS prior to NMES. Pre-treatment aspiration and penetration were noted in 10 and 2 patients respectively. Two patients did not aspirate on pre-treatment MBS. Improvement was noted in 9 of 11 children with post-treatment MBS. CONCLUSION: NMES was safely completed in all children without complication. Improvement in aspiration status was seen in 83.3% of patients with pre- and post-treatment MBS. Feeding status as measured by textures was advanced in all patients with a significant improvement in FOIS. Future prospective studies are required to investigate the specific role in children with acquired and congenital dysphagia.

Evaluation of the ability of calcite, bentonite and barite to enhance oil dispersion under arctic conditions.

A test program was conducted at laboratory and pilot scale to assess the ability of clays used in drilling mud (calcite, bentonite and barite) to create oil-mineral aggregates and disperse crude oil under arctic conditions. Laboratory tests were performed in order to determine the most efficient conditions (type of clay, MOR (Mineral/Oil Ratio), mixing energy) for OMA (Oil Mineral Aggregate) formation. The dispersion rates of four crude oils were assessed at two salinities. Dispersion was characterized in terms of oil concentration in the water column and median OMA size. Calcite appeared to be the best candidate at a MOR of 2:5. High mixing energy was required to initiate OMA formation and low energy was then necessary to prevent the OMAs from resurfacing. Oil dispersion using Corexit 9500 was compared with oil dispersion using mineral fines.