Small Amount Of Barium Research Articles

Processing and Electrical Characteristics of Barium Doped CaCu3Ti4O12

In this communication, the effect of a small amount of barium (15%) substitution on structural micro-structural, electrical (dielectric, impedance and conductivity) properties of CaCu3Ti4O12 (i.e., Ca0.85Ba0.15Cu3Ti4O12 = CBCTO15) in different experimental conditions is presented. The polycrystalline sample of the material has been prepared by a cost-effective solid-state reaction technique. Rietveld refinement of XRD data has confirmed that the CBCTO15 sample crystallizes in cubic system bearing space group Im3. The surface micrograph depicts the dense packing of grains. The comprehensive studies of dielectric parameters [relative dielectric constant (er), and loss tangent (tanδ)] are characterized over a wide range of temperature and frequency. The complex impedance and electrical modulus spectroscopy techniques have been employed which postulates the association of various effects (grain, grain boundary, electrode) and shed light on the conduction as well as the relaxation mechanism in the material.

Pooling of barium at mucosotomy site after peroral endoscopic myotomy on Barium Swallow Study

Peroral endoscopic myotomy (POEM) is a minimally invasive, incisionless alternative to Heller myotomy for treatment of Achalasia. It is still an evolving procedure done only at expert centers. We report an interesting post-procedure radiological finding that might be helpful in managing patients undergoing this procedure. A 24-year-old woman with advanced Achalasia underwent POEM performed in the standard method after which she was kept nil per oral on intravenous antibiotics. Barium swallow study done on the next day showed free passage of barium into stomach with no leak but there was pooling of a small amount of barium in the submucosal space at the upper end of the mucosotomy site without passage down the tunnel into the mediastinum. X-ray showed intact endoscopic clips at the mucosotomy site. Patient was afebrile and only had the expected post-procedure mild chest discomfort. She was continued nil per oral for an additional day and Barium swallow study was repeated which did not show any further pooling of barium at the mucosotomy site and the barium had passed freely into the stomach without a leak. Pooling of a small amount of barium at the mucosotomy site was likely due to the passage of barium into the submucosal space between the clips as they might not have created watertight closure of mucosotomy. This finding is usually of no clinical consequence if barium does not leak out through the tunnel into the mediastinum. Starting myotomy at least 2–3 cm distal to mucosotomy site such that the submucosal space closes off by mucosal flap above the myotomy site and meticulous, watertight closure of mucosotomy site may prevent such occurrence.

PP23 ARGON PLASMA COAGULATOR IN A 2-MONTH-OLD CHILD WITH TRACHEO-OESOPHAGEAL FISTULA

A 2 month-old boy was admitted to the authors’ hospital because of regurgitation and persistent cough during breastfeeding. A chest X-ray examination and a barium esophagogram disclosed small amounts of barium passing in the trachea, suggesting a tracheoesophageal fistula (TEF). Bronchoscopy combined with upper gastrointestinal (GI) endoscopy performed with the patient under general anesthesia confirmed the fistula. The TEF was treated by injection of 1 ml Glubran 2 from the esophageal side. A nasogastric tube was placed for feedings, and 7 days later, a barium esophagogram showed a reduction of caliber but not complete closure of the TEF. Unsuccessful fistula obliteration with Glubran was attributed to technical difficulties in catheterization of the fistula orifice, mainly resulting from its close proximity to the upper esophageal sphincter and to its small caliber. Therefore, an argon plasma coagulator (APC) probe with a circumferentially oriented nozzle was used from the esophageal side as an alternative technique to fulgurate the residual fistula orifice (see video). A nasogastric tube was placed for feedings. Oral feeding was started 7 days later when a barium esophagogram confirmed complete fistula closure. At the 2-year follow-up visit, the boy was asymptomatic, and the barium esophagogram was negative. This report describes a case in which esophagoscopy gave a clear view of the fistula due to its direction from esophagus to trachea. Complete fistula obliteration was not obtained with Glubran. However, APC was successfully used to close the residual fistula orifice. The authors suggest that APC can be used as an alternative endoscopic technique to repair TEF when other techniques fail.

Remnant stomach-jejunal dual pathways reconstruction after laparoscope-assisted radical proximal gastrectomy

Objective To investigate the value of remnant stomach-jejunal dual pathways reconstruction after laparoscope-assisted radical proximal gastrectomy in the treatment of upper gastric cancer. Methods Twenty-five patients with upper gastric cancer underwent laparoscope-assisted radical proximal gastrectomy and the remnant distal stomach was preserved for side-to-side remnant stomach-jejunal anastomosis and end-to-side jejuno-jejunal anastomosis to reconstruct dual pathways. Results The mean operation time was (240±35) minutes, the mean number of lymph nodes dissected were 22±5, and all the incised margins were negative. No anastomotic leakage, obstruction or stenosis occurred. All patients received postoperative barium meal examination. A large amount of barium directly entered the jejunum, leaving a small amount of barium entered the jejunnum via the route of remnant stomach-duodenum, and was detained in the remnant stomach for 30-60 minutes. No esophageal reflux of barium was observed. All the patients were followed up for 4-18 months, no reflux esophagitis was detected and the short-term life quality was satisfactory. Conclusions Remnant stomach-jejunal dual pathways reconstruction prevents the reflux esophagitis and dumping syndrome, preserves the pathway of duodenum and promotes the life quality of patients. Key words: Gastric cancer; Laparoscope; Reconstruction of digestive tract

A Young Man With a New Diagnosis of Achalasia

d Clinical Scenario A 32-year-old man began to experience food sticking ntermittently in the midchest about 2 years ago. By the time he resents to the gastroenterology clinic, he is complaining of ysphagia at every meal for most hard, solid foods (ie, bread, eats, uncooked vegetables), and for the past 4 months he has oted dysphagia for liquids, especially cold beverages. Once or wice a week, after his large evening meal, he experiences reguritation of recently eaten food with a nonacidic taste. His wife omplains he “gurgles” at night and sometimes awakes her with oughing. He denies chest pain, but does complain of “hearturn,” improving with over-the-counter Prilosec (Proctor & amble, Cincinnati, OH). His weight is down 10 lb. The complaints of dysphagia for both solids and liquids aise the suspicion of achalasia. A barium esophagram shows a ildly dilated esophagus with a column of barium maintained ust below the clavicles with no emptying in the upright posiion over a 5-minute period. The distal esophagus has narowed, with a small amount of barium intermittently streaming nto the stomach. No orderly peristalsis is seen on fluoroscopy. sophageal manometry confirms the diagnosis, finding a high ower esophageal sphincter (LES) pressure (56 mm Hg) with ncomplete relaxation and low-amplitude, simultaneous mirror mage waves after all swallows of water. The patient and his wife return to your office after completng his tests. They have read extensively about achalasia on the nternet. They have many questions: Will I ever be able to eat ormally? Can you cure this disease? What is the best treatent—pneumatic dilation, surgical myotomy, or botulinum oxin injections? What are the side effects and which one will ive me the most relief for a long time?

Solid state 47,49Ti, 87Sr and 137Ba NMR characterisation of mixed barium/strontium titanate perovskites

Solid state 47,49Ti, 137Ba, 87Sr NMR spectra have been recorded on Ba x Sr 1− x TiO 3 (0 ⩽ x ⩽ 1) perovskite samples prepared by the powder sintering method. Multinuclear solid state NMR shows great potential for characterising such systems since the quadrupolar parameters are very sensitive to any geometric deformation around the studied nucleus. 47,49Ti NMR powder lineshapes appear strongly influenced by the presence of even a small amount of barium (or strontium) in the coordination second sphere of the probed titanium site: substitution of strontium by barium induces the broadening of the peaks, due to quadrupolar effects, while the isotropic chemical shift increases. 137Ba NMR spectra exhibit a distribution of the quadrupolar interaction, that could be tentatively quantified, C Q increasing with the amount of strontium. Preliminary results were also obtained on 87Sr NMR showing behaviour comparable to 137Ba NMR, i.e. a broadening of the peaks due to an increasing quadrupolar interaction with the amount of barium distorting the environment of the strontium sites.

Barium as a secondary promoter for Ni–Mo catalyst supported on alumina

The addition of barium, as a secondary promoter, to alumina-supported Ni–Mo (nickel oxide–molybdenum oxide) catalyst was investigated. The results of thiophene hydrodesulfurization experiments carried out on the catalysts show that the addition of small amounts of barium (<0.7 wt%) leads to a significant improvement in their thiophene hydrodesulfurization. Experiments carried out in an autoclave also show that the presence of barium leads to improvement in the properties of the products obtained after gas oil processing. These results may help in developing catalysts with improved activities, as only a small amount of barium secondary promoter is required.

Effects of non-stoichiometry and chemical inhomogeneity on the order-disorder phase formation in the complex perovskite compounds, Ba(Ni1/3Nb2/3)O3and Ba(Zn1/3Nb2/3)O3

The order-disorder phase formation of the complex perovskite compounds, Ba(Ni1/3Nb2/3)O3 and Ba(Zn1/3Nb2/3)O3, was investigated by various heat treatments. Heat-treated samples were characterized using X-ray diffraction, SEM, and EDS, interactively. On the basis of lattice parameter measurements, the defect concentration in the complex perovskite compounds was thought to control ordered or disordered phase formation. The chemical inhomogeneity in the calcined powder was responsible for the formation of a liquid phase in the non-equilibrium state. These compounds are postulated to melt incongruently above temperature at which the ordered phase forms. Irrespective of extended heat treatments, second phases were observed but could not be identified by XRD due to lack of information. The second phase in BNN was unreacted NiO with a small amount of barium and niobium, and the second phase in BZN was a pyrochlore-like compound of which the composition was Ba∶Nb = 1∶1 with a small amount of zinc.

Transmission electron microscope studies of the crystal structure of Y2Cu2O5 and the nature of nonperiodic planar defects in Y2Cu2O5

An account is given of transmission electron microscope studies of the crystal structure of Y2Cu2O5 discovered within samples of YBa2Cu3O7-x and Y1.85Sr0.15CuO4- delta ceramic compounds. Conventional and high-resolution electron microscope investigations confirmed that Y2Cu2O5 is isostructural with Ho2Cu2O5 and has a space group P21nb with lattice parameters a=1.247 nm, b=1.081 nm and c=0.3495 nm. The nature of planar defects discovered within the crystallites of Y2Cu2O5 is discussed. It is proposed that small amounts of barium that do not react to form a solid solution with Y2Cu2O5 segregate to the lines of defects. The displacement vector for the planar defects was found to be 1/2(014).

Authigenic Barite as an Indicator of Fluid Movement through Sandstones Within the Colorado Plateau

ABSTRACT Sandstones of the Salt Wash Member, Late Jurassic Morrison Formation, contain abundant authigenic barite on the east side of the northern Colorado Plateau (mean = 0.5 g barite/kg rock) and systematically less barite (mean = 0.02 g barite/kg rock) in the western part. The area containing abundant barite coincides approximately with the extent of bedded evaporites in the underlying Pennsylvanian Hermosa Formation. A genetic link between the barite and solutes from the Hermosa Formation is supported by sulfur isotope data. Most barites from the abundant barite zone have 34S values that range from +8 to +14 per mil, which is similar to the range of bedded gypsum and anhydrite in the Hermosa Formation. Sulfate derived from t e evaporites probably entered the Morrison Formation in solutions that moved along faults. Measured 87Sr/86Sr ratios of barite in the abundant barite zone are indicative of fault-controlled solution flow. Strontium contents and 87Sr/86Sr ratios (0.7103 to 0.7084) in barite decrease with increasing distance from faults. These trends reflect mixing of radiogenic strontium in the saline waters that ascended faults (87Sr/86Sr = 0.7100), with strontium originally contained in early diagenetic carbonate cements within the sandstones (87Sr/86Sr = 0.7080). Because measured 87Sr/86Sr values exceed the ratios in Hermosa anhydrite, it is concluded that radiogenic strontium was added to the rising brines by reaction between the evaporite-derived saline solutions and arkosic san stones along the flow path. Morrison sandstones within the abundant barite zone were altered by saline waters that added sulfate and strontium. Barite formation in this zone was limited by the availability of dispersed barium in the host rock. The zone of sparse barite on the western side of the Colorado Plateau was not affected by the same warm saline waters. Instead, intraformational redistribution of small amounts of barium, strontium, and sulfate formed the relatively sparse barite in this area.

ChemInform Abstract: BARIUM CALCIUM HYDROXYAPATITE SOLID SOLUTIONS

AbstractÄhnlich wie bereits am System Ba‐Ca‐Fluoroapatit beobachtet, lassen sich auch im Titelsystem homogene Mischkristalle nicht lückenlos erhalten.

Barium calcium hydroxyapatite solid solutions

The replacement of calcium by barium in the hydroxyapatite structure by solid-state reaction at different temperatures and by precipitation from an aqueous system has been investigated by X-ray diffraction and i.r. absorption analyses. The products obtained by solid-state reaction at 1 200 °C are solid solutions over the range of barium concentration 60–100 atom %. The lattice dimensions and the i.r. frequencies of the solid solutions vary linearly with the atom % of barium. Only small amounts of barium can be incorporated in hydroxyapatite by precipitation from the aqueous system.

Predictability of rectal incontinence on barium enema examination.

The aim of this study was to determine if digital assessment of anal sphincter tone predicts whether a rectal balloon is needed to prevent incontinence during a barium enema examination. During an 8 month , 306 patients scheduled for barium enema examination were evaluated. Immediately before each examination as good, fair, or poor. The barium enema was then performed in a conventional manner. Leakage of even small amounts of barium was scored as rectal incontinence. Ability to retain the barium enema correlated closely with the strength of rectal bone, regardless of patient sex or age. For different sphincter tones the incidence of rectal incontinence was: good, 2%, fair, 30%; and poor, 90%. From these findings it is recommended that, irrespective of patient age and sex, the use of rectal balloon catheters be limited to patients with poor or fair rectal tone.

DETERMINATION OF BARIUM IN THE PRESENCE OF A LARGE AMOUNT OF CALCIUM BY MEANS OF THE COMBINATION OF THE SOLVENT EXTRACTION BY 18-CROWN-6 WITH THE ATOMIC ABSORPTION SPECTROPHOTOMETRY

Abstract A small amount of barium (2.0×10−5-5.00×10−4M) in the presence of a large amount of calcium (5.00×10−2M) was easily and precisely determined by means of the combination of the solvent extraction procedure by 18-crown-6 with the atomic absorption spectrophotometry using the dinitrogen oxide-acetylene flame. Average recovery of barium was 100±3%.

The primary double-contrast examination of the postoperative stomach.

Examination of the postoperative stomach is a difficult and often confusing procedure. Traditional methods of investigation have depended on using small amounts of barium as well as appropriate pressure and positioning. The authors feel that the well-established technique of double-contrast radiography of the upper gastrointestinal tract (with appropriate modifications) is both easier and more diagnostic; moreover, with the exception of suspected perforation or anastomotic rupture, there are no contraindications to the use of gastrointestinal hypotonia, distension, and barium coating of the mucosa regardless of the presenting symptomatology or the acuteness or chronicity of complaints.

The structure of a barium niobium silicon oxide with the probable composition [formula omitted

Reaction of BaO, Nb 2O 5, and Nb in mole ratios of 2.4:1.6:1 in an evacuated silica capsule at 1250°C produces a mixture of at least two products, one of which has the probable composition Ba 6+x Nb 14Si 4O 47 (x ⋍ 0.23) . This compound has an hexagonal unit cell of dimensions a = 9,034 ± 0.004 Å, c = 27.81 ± 0.02 Å, probable space group P6 3 mcm , Z = 2 . Its structure has been determined from 942 independent reflections collected by a counter technique and refined by least squares methods to a conventional R value of 0.062. The basic structure consists of strings of four NbO 6 octahedra sharing opposite corners, each string joined to the next by edge sharing of the end octahedra, so that the c axis corresponds to the length of a strand of seven corner-linked octahedra. Chains of three such strands are formed by corner sharing between the strands. The chains in turn are joined by NbO 6 octahedra and Si 2O 7 groups in which the SiOSi linkage is linear. Barium atoms are in sites between the chains coordinated by 13 oxygen atoms. A second site, 15 coordinated, probably has a small amount of barium as well; the fractional occupancy for barium in this site is 0.076.

Disabilities of the pharynx in amyotrophic lateral sclerosis as demonstrated by cineradiography.

During the clinical progression of amyotrophic lateral sclerosis (ALS) various disorders of the motor effector mechanisms of the pharynx may develop, impairing its functions of airway maintenance, swallow, or speech. Among ALS patients the disorders vary in distribution and sequence, but potentially affect each of these functions. Cineradiography is of strategic value in distinguishing the particular mechanisms of motor disability, whether paralysis, contracture, or atrophy, and also in the identification of motor compensations (6, 9). It is useful in demonstrating severity of disabilities and their potentially critical elements, as failure of laryngeal occlusion in swallowing. This information is essential for therapy, for facilitation of care and comfort, and at times for survival. Cineradiography, now generally available in medical centers, should be employed consistently in the evaluation and care of the ALS patient. Procedures Observations on 6 ALS subjects were selected from data of continuing studies of oral and pharyngeal function in neurologically impaired persons (3, 4, 7, 10). Each patient was clinically identified by standard criteria of neurological examination, including history of rapidly progressing neuromotor disability, electromy-ographic and muscle biopsy indications of motor unit involvement, and indications of higher level motor coordination. Each was free of intercurrent illness or of medication possibly affecting the motor disorder. The studies were performed when the subjects were well rested, and were programmed to avoid fatigue. Cineradiography was in transverse projection. This view demonstrates the spatial arrangement of cervical vertebrae, cranium, mandible, and the functionally related structures of tongue, hyoid, and larynx. It also shows diminution in mass of tongue or of prevertebral muscles. During variations in posture at the neck, possible contractures of the hyoid suspensory muscles may be shown and the cricopharyngeal bar abnormality may be seen during swallow. We particularly sought evidences of contracture in these muscles which might occasion additional specific methods of therapy, but none were found in these 6 patients. The laxity of the lateral walls of the pharynx is shown less well than in anteroposterior projection, but in the lower pharynx it may usually be inferred from the contours of the lateral pharyngeal or piriform sinuses as they are seen in transverse projection. In preparation for cineradiography, the anterior midline of face and neck was lined with barium paste. Unless the subjects were entirely lacking in swallow, a small amount of barium was given by mouth and also instilled into the nose. Subjects were “at ease” in upright position or, if their defense of pharyngeal airway was to be evaluated, they were supine. Their performances of flexion or extension, feeding, and speech were rehearsed until familiar. The trunk and lower portion of neck were lead-shielded.

Control of gastric function after subtotal gastrectomy

A new technic for subtotal gastrectomy has been used on a consecutive series of 135 personally performed operations. Although a longer follow up is necessary, results to date justify the original premise that success depends to a considerable degree upon (1) the construction of a gastric pouch that functions in a normal manner and (2) a more complete utilization of the buffers provided by nature. This can only be achieved by careful attention to certain technical details which have been emphasized. Postoperative studies of gastric function have been made in seventy-one of the 135 cases. A standard meal to which a small amount of barium had been added was used. This method has been of value in explaining variations in end results that occur after surgery. Forty-nine operations have been performed by this technic since the study discussed herein was completed.

Development of low-loss steatite bodies using Jaipur talc

Steatite bodies were developed using Jaipur talc and small amounts of barium and magnesium carbonate as bonding agents. The bodies were tested for shrinkage, absorption, density, thermal expansion, thermal endurance and electrical properties including dielectric strength, DC resistivity, power factor and loss factor. Effect of replacing barium carbonate by magnesium carbonate and lead silicate was also studied. Some of the compositions conform to the A.S.A. specifications for the highest grade of low-loss insulators.

Histochemical detection of barium and strontium.

SMALL amounts of barium and strontium can be detected in the tissues of many insects by means of the extremely sensitive rhodizonate reaction. This reaction was described for microchemical use by Feigl1, who has since investigated its limitations2,3. In the present histochemical method, tissues are fixed in carefully neutralized 10 per cent formalin in 70 per cent alcohol and immersed for 30–60 min. in a freshly prepared 1 or 2 per cent solution of sodium rhodizonate, in distilled water or in phosphate buffer at pH 7. Excess sodium rhodizonate is afterwards removed by washing in dilute alcohol. Stained tissues can be sectioned in the usual manner and permanent preparations obtained.