Probing the Radial Chemistry of Getter Components in Light Water Reactors via Controlled Electrochemical Dissolution.

Getters are among the key functional components in the tritium-producing burnable absorber rods (TPBARs) of light water reactors (LWRs) and are used to capture the released tritium gas. They are nickel-plated zircaloy-4 tubes that, upon exposure to irradiation or tritium in the light water reactors, undergo alteration in structure, chemical composition, and chemistry. Understanding the radial tritium distribution is key to gaining insight into the evolution of new chemistry upon irradiation to predict getter performance. The holy grail is to develop a method akin to selectively peeling off the layers of an onion in an effort to get a radial map of elements and particularly tritium across the getter. Toward this goal, the overall aim of this work is to establish a correlative technique that can be used to determine radial tritium distribution across getters. To this end, this work specifically focuses on the validation of a correlative method for controlled radial dissolution of nickel-plated getters. Here, pristine getters as well as getters loaded with different mass ratios of hydrogen and deuterium are used as the nonradioactive surrogates of tritium, the idea being that the methodology can be readily extended to tritiated getter components. Here, the surface nickel layers as well as the bulk zirconium layers are sequentially dissolved in a controlled, uniform way using voltage-assisted electrochemical dissolution techniques. The dissolution is complemented by periodic elemental analysis of the electrolyte solution during and post dissolution. This is complemented by microscopic analyses on the exposed surfaces to provide a correlative technique for a complete picture of the radial distribution of various elements across the getter.

An electrochemical technique for controlled dissolution of zirconium based components of light water reactors.

Zircaloy-4 (Zr-4) based liners and getters are the principle functional components of Tritium-Producing Burnable Absorber Rods (TPBARs) in light water nuclear reactors where they reduce tritiated water into tritium gas. Upon tritium exposure, zirconium tritide is formed, which changes the chemical composition, structure and morphology of these materials. Their thermodynamic properties are affected by (i) the hydride phase identity, (ii) radial and spatial tritide/hydride (T/H) distribution, and (iii) the changes in structure and morphology of the material upon T/H-migration, and their comprehensive knowledge is needed to predict performance of these materials. This work demonstrates that controlled potential electrochemistry techniques to be highly efficient for controlled oxidative radial dissolution of Zr-4 based liners (both unloaded and loaded with hydride/deuteride as chemical surrogates for tritium). The electrodissolution is further combined with microscopic techniques to accurately determine the distribution of hydride phases. This work demonstrates a reliable technique for radially etching the liners after irradiation to provide insight into the radial and spatial distribution of tritium within the TPBAR, improving the fundamental understanding of tritium transport and providing a basis for validating predictive models.

The discovery of Arylex™ active and Rinskor™ active: Two novel auxin herbicides.

Multiple classes of commercially important auxin herbicides have been discovered since the 1940s including the aryloxyacetates (2,4-D, MCPA, dichlorprop, mecoprop, triclopyr, and fluroxypyr), the benzoates (dicamba), the quinoline-2-carboxylates (quinclorac and quinmerac), the pyrimidine-4-carboxylates (aminocyclopyrachlor), and the pyridine-2-carboxylates (picloram, clopyralid, and aminopyralid). In the last 10 years, two novel pyridine-2-carboxylate (or picolinate) herbicides were discovered at Dow AgroSciences. This paper will describe the structure activity relationship study that led to the discovery of the 6-aryl-picolinate herbicides Arylex™ active (2005) and Rinskor™ active (2010). While Arylex was developed primarily for use in cereal crops and Rinskor is still in development primarily for use in rice crops, both herbicides will also be utilized in additional crops.

The FERMI free-electron lasers.

FERMI is a seeded free-electron laser (FEL) facility located at the Elettra laboratory in Trieste, Italy, and is now in user operation with its first FEL line, FEL-1, covering the wavelength range between 100 and 20 nm. The second FEL line, FEL-2, a high-gain harmonic generation double-stage cascade covering the wavelength range 20-4 nm, has also completed commissioning and the first user call has been recently opened. An overview of the typical operating modes of the facility is presented.

Psychosocial and developmental characteristics of civilly committed sex offenders.

A convenience sample of 38 civilly committed sex offenders completed questionnaires on selected psychosocial and developmental characteristics. More than half (61%) demonstrated an external locus of control. They had higher levels of empathy compared to normative data for the general population, and their levels of anger, aggression, and hostility were similar to male college students. Somatization was comparable to psychiatric outpatients. A high proportion reported at least one form of childhood trauma (87%), with 66% reporting childhood sexual abuse. Issues related to the use of self-report instruments with this patient population are discussed and recommendations for future studies are suggested.

Valoración de actividades básicas de la vida diaria y de deterioro cognitivo en centenarios: concordancia entre las escalas utilizadas / Assessment of basic activities of daily living and cognitive impairment in centenarians: correlation between the scales used

Objetivo. Analizar la concordancia entre escalas de actividades básicas de la vida diaria (ABVD) y de deterioro cognitivo en centenarios. Método. Entrevista domiciliaria a todos los centenarios de nuestra área, cumplimentándose tres escalas de ABVD (índice de Katz [IK], índice de Barthel [IB] e índice de incapacidad física de la Cruz Roja [IFCR]), y dos de valoración de deterioro cognitivo (miniexamen cognoscitivo [MEC], y el índice de incapacidad psíquica de la Cruz Roja [IPCR]). Se valoró la concordancia mediante el índice kappa. Resultados. Se entrevistó a 80 centenarios, 26 hombres y 64 mujeres, media de edad, 100,8±1,3 años. Más de la mitad de los centenarios presentaron independencia funcional o dependencia leve, siendo los hombres independientes con más frecuencia (IB 70±34,4 frente a 50,4±36,3; p=0,005). Al valorar deterioro cognitivo, los resultados fueron discordantes, aunque los hombres presentaron menos deterioro cognitivo que las mujeres (MEC, 16,5±9,1 vs. 11,6±8,1; p=0,008). Los tres cuestionarios que miden ABVD (IK, IB, IFCR) clasificaron uniformemente a los centenarios; el IK y el IB clasifican igual al 95% de los centenarios (kappa, 0,899), el IB y el IFCR al 97,5% (kappa, 0,95) y el IK e IFCR al 97,5% (kappa, 0,95). La concordancia en los cuestionarios de deterioro cognitivo fue muy baja; se clasificaron igual al 58,8% de los centenarios (kappa, 0,295). Conclusiones. Cualquiera de las tres escalas de ABVD es útil en pacientes centenarios. Sin embargo, está por definir cómo valorar el deterioro cognitivo(AU)

Objective. To analyse the concordance between different scales used to assess basic activities of daily living and cognitive impairment in centenarians. Method. A domiciliary interview was carried out with all centenarians in our area. Three scales of basic activities of daily living (Katz index [KI], Barthel index [BI], Red Cross physical impairment index [RCPI]), and two of cognitive impairment assessment(Mini cognoscitive test [MCT], Red Cross psychic impairment index [RCPI]) were completed. Results. A total of 80 centenarians were interviewed, 26 men and 64 women, mean age 100.8±1.3. More than half of centenarians had functional independence or slight dependence. Men were more frequently independent than women (BI 70±34.4 vs. 50.4±36.3; P=.005). The results of cognitive impairment tests were discordant, although men had less cognitive impairment than women (MCT 16.5±9.1 vs. 11.6±8.1; P=.008). The three scales of basic activities of daily living uniformly classified the centenarians, with a high level of concordance between them: KI and BI similarly classified up to 95% of the centenarians (Kappa 0.899), BI and RCPI to 97.5% (kappa 0.95), KI and RCPI to 97.5% (Kappa 0.95). Nevertheless, the concordance between the cognitive impairment measured by RCPI and MCT was low; only 58.8% of centenarians were equally classified (Kappa 0.295). Conclusions. Any of three scales analysed for assessment of basic activities of daily living is useful in centenarians. Nevertheless, the best way to assess cognitive impairment in these patients needs to be defined(AU)

[Assessment of basic activities of daily living and cognitive impairment in centenarians: correlation between the scales used]. / Valoración de actividades básicas de la vida diaria y de deterioro cognitivo en centenarios: concordancia entre las escalas utilizadas.

OBJECTIVE: To analyse the concordance between different scales used to assess basic activities of daily living and cognitive impairment in centenarians. METHOD: A domiciliary interview was carried out with all centenarians in our area. Three scales of basic activities of daily living (Katz index [KI], Barthel index [BI], Red Cross physical impairment index [RCPI]), and two of cognitive impairment assessment(Mini cognoscitive test [MCT], Red Cross psychic impairment index [RCPI]) were completed. RESULTS: A total of 80 centenarians were interviewed, 26 men and 64 women, mean age 100.8±1.3. More than half of centenarians had functional independence or slight dependence. Men were more frequently independent than women (BI 70±34.4 vs. 50.4±36.3; P=.005). The results of cognitive impairment tests were discordant, although men had less cognitive impairment than women (MCT 16.5±9.1 vs. 11.6±8.1; P=.008). The three scales of basic activities of daily living uniformly classified the centenarians, with a high level of concordance between them: KI and BI similarly classified up to 95% of the centenarians (Kappa 0.899), BI and RCPI to 97.5% (kappa 0.95), KI and RCPI to 97.5% (Kappa 0.95). Nevertheless, the concordance between the cognitive impairment measured by RCPI and MCT was low; only 58.8% of centenarians were equally classified (Kappa 0.295). CONCLUSIONS: Any of three scales analysed for assessment of basic activities of daily living is useful in centenarians. Nevertheless, the best way to assess cognitive impairment in these patients needs to be defined.

[Staging gastritis with the OLGA system: prevalence of advanced stages of gastric atrophy in Mexican patients]. / Estadificación de la gastritis con el sistema OLGA; prevalencia de estadios avanzados de atrofia gástrica en pacientes mexicanos.

INTRODUCTION: Gastric adenocarcinoma of intestinal type is preceded by inflammation, which produces mucosal atrophy and intestinal metaplasia, progressing eventually to dysplasia and invasive cancer. Recently an international group, the Operative Link on Gastritis Assessment (OLGA) proponed a staging system for gastric biopsies. OBJECTIVE: To recognize the distribution of advanced stages of gastric mucosal atrophy in Mexican patients with dyspepsia according to the OLGA system. METHODS: We apply the OLGA system for cancer risk (Stages 0 to IV) to 322 gastric biopsies from consecutive patients with dyspepsia. Using the Sydney protocol, we recorded the presence of atrophy, dysplasia and the relationship with ulcer disease. We report the stage of atrophy for each region and the Helicobacter pylori infection status. RESULTS: We documented 72 (22.4%) cases with atrophy, 50 of them (69.4%) were metaplastic-type. Overall, nine biopsies (2.78%) were stage III (all of them with metaplastic-type atrophy) and there was not stage IV cases. We did not find high-grade dysplasia or intramucosal carcinoma. In 8 of subjects with stage III, we observed low-grade dysplasia. We documented gastric ulcer in 5 patients with stage II, 60% of them with associated low-grade dysplasia. Five patients with duodenal ulcer were found in stages 0 and I. CONCLUSIONS: We found low prevalence of advanced stages of mucosal gastric atrophy among patients with dyspepsia. However we recognized 9 patients with stage III according to OLGA system worthy of follow-up because the high risk for developing gastric cancer.

[Level of satisfaction from patients who undergone an endoscopic procedure and related factors]. / Nivel de satisfacción de pacientes tras un procedimiento endoscópico y factores asociados.

BACKGROUND: Patient satisfaction is a cognitive and emotional evaluation of the patient on the performance of health staff and is based on relevant aspects of their experience in health care. AIM: To determine the satisfaction level of patients after an endoscopic procedure in the gastrointestinal endoscopy service Specialty Hospital National Medical Center La Raza and to evaluate associated factors. MATERIAL AND METHODS: A modified and validated questionnaire was applied to assess patient satisfaction after an endoscopic procedure (mGHAA-9) in patients who underwent a gastroscopy or colonoscopy. Factors that influenced patient satisfaction were assessed. RESULTS: Two-hundred questionnaires were applied (response rate: 89.5%), in 62 men (34.6%) and 117 women (65.4%). Mean patient age was 51.3 years. The average score for the overall group was 30.9 (maximum score of 35). In the overall assessment of satisfaction patients reported 60.9% excellent, very good 29.6%, good 8.9% and 0.6% regular. Factors that influenced patient satisfaction were: waiting time for appointment (OR 3.104), explaining and answering questions (OR 2.961) and waiting time for performing the procedure (OR 2.408) Some factors did not influence on patient satisfaction: Sex: Male 58.1%, female 62.4% (p = 0.63), age 52 vs. 50 years (p = 0.48) and sedation 64.7% vs. 60.5% (p = 0.8) CONCLUSIONS: The level of satisfaction of patients undergoing a gastroscopy or colonoscopy is good. The factors that influence the satisfaction of these patients are related to communication between doctor and patient, and waiting time for the study.

Analysis of the factors determining survival of alcoholic withdrawal syndrome patients in a general hospital.

AIM: To investigate the clinical variables associated with the risk of dying and the causes of death during the course of alcoholic withdrawal syndrome (AWS) in a general hospital. METHODS: Cohort study of AWS patients admitted to Xeral Hospital in Lugo, Spain between 1987 and 2003. The characteristics of patients who died were contrasted with those who survived. The different clinical, epidemiological and biochemical variables reflective of alcohol consumption habits, basal health status and presentation features of the syndrome and its complications were all recorded. RESULTS: There were 539 episodes of hospitalization for AWS in 436 patients (mean age 45.0, SD 12.0, 91.3% males), 71.1% of whom presented with delirium tremens. A total of 29 patients died, yielding a 6.6% mortality rate (95% confidence interval, CI: 4.2-9.1%). Eighteen patients (62%) died after being admitted to the intensive care unit (ICU). The following independent variables were associated with the risk of dying in a multivariate logistic regression model: cirrhosis [odds ratio (OR) 4.8 (95% CI 1.5-14.6), P = 0.006]; presenting with delirium tremens at diagnosis [OR 3.5 (95% CI 1.3-8.9), P = 0.008]; the existence of an underlying chronic pathology other than liver disease [OR 2.5 (95% CI 1-6.1), P = 0.01]; and the need for orotracheal intubation [OR 2.9 (95% CI 1.1-7.9), P = 0.03], especially if pneumonia requiring ICU is added [OR 8 (95% CI 3-21.3), P < 0.001]. Receiver operating characteristic analysis revealed an area under the curve of 0.818 (95% CI 0.742-0.894). CONCLUSIONS: The factors determining survival after admission to a general hospital for alcoholic withdrawal syndrome depend on the intensity of clinical manifestations (delirium tremens, ICU, orotracheal intubation) and the presence of associated comorbidity.

Risk factors for delirium tremens in patients with alcohol withdrawal syndrome in a hospital setting.

BACKGROUND: The clinical expressions of alcohol withdrawal syndrome (AWS) may vary and the factors determining these variations are not well-known. It would be useful to have a set of clinical tools capable of predicting which patients are likely to develop the more severe forms of the syndrome. AIM: To analyse the clinical variables associated with the development of delirium tremens (DTs) in patients who were admitted to a general hospital with AWS. METHODS: Cohort study of AWS patients admitted to the Xeral Hospital in Lugo, Spain, between 1987 and 2003. The characteristics of patients with the syndrome who did not develop delirium tremens were contrasted with those who did. Cases presenting with DTs at diagnosis were excluded. The different clinical, epidemiological and biochemical variables reflective of alcohol consumption habits, basal health status and presentation features of syndrome were all recorded. RESULTS: Data from 156 episodes of AWS that coursed without DTs were compared with 147 cases that coursed with it. Three independent variables for development of DTs were identified in a multivariate logistic regression model: number of seizures [1 or 2: OR 2.2 (CI 95% 1.2-3.8), p=0.005; 3 or more: OR 2.6 (CI 95% 1.04-6.8), p=0.04]; systolic blood pressure >150 mm Hg [OR 1.9 (CI 95% 1.1-3.8), p=0.03] and axillary temperature >38 degrees C [OR 1.9 (CI 95% 1.05-3.5), p=0.01]. ROC analysis revealed an area under the curve of 0.679. CONCLUSION: Three clinical findings (seizures, blood pressure and temperature) can aid in identifying patients with AWS who are likely to develop DTs. The model's predictive capacity is not high.

Genetics and mapping of adult plant rust resistance in soybean PI 587886 and PI 587880A.

Two soybean accessions, PI 587886 and PI 587880A, previously identified as having resistance to Phakospora pachyrhizi Syd. (soybean rust, SBR) were used to create two populations (POP-1 and POP-2) segregating for SBR resistance. F(2)-derived F(3) (F(2:3)) families from each population were grown in a naturally SBR-infected field in Paraguay to determine inheritance and map resistance genes. Over 6,000 plants from 178 families in POP-1 and over 5,000 plants from 160 families in POP-2 were evaluated at R5 for lesion type: immune reaction (IR), reddish-brown (RB), or tan (TAN) colored lesions. Based on the lesion type present, each F(2:3) family was rated as resistant, segregating or susceptible and this classification was used to infer the F(2)-phenotype and genotype. For both populations, the F(2) segregation ratios fit a 1:2:1 (resistant:segregating:susceptible) ratio expected for a single gene (P > 0.05). The RB lesions occurred almost exclusively in the heterozygous class, indicating incomplete dominance under the conditions of this study. Molecular markers flanking the locations of the known resistance genes were used to map the resistance gene in both populations to the Rpp1 locus. However, evaluation of PI 587886 and PI 587880A against eight P. pachyrhizi isolates indicated that the resistance allele in these two accessions was different from Rpp1. This test also demonstrated that these accessions were resistant to at least one P. pachyrhizi isolate collected in the southern US. This is the first report of using an adult plant field-screen with natural rust pressure to map SBR resistance.

Analysis of new generation explosives in the presence of u.s. EPA method 8330 energetic compounds by high-performance liquid chromatography.

U.S. EPA Method 8330 was evaluated and modified for the analysis of DNAN (2,4-dinitroanisole) and MNA (n-methyl-p-nitroaniline) by high-performance liquid chromatography in various aqueous media in the presence and absence of the 14 energetic compounds currently assigned to the method. DNAN and MNA are two of the four components in PAX-21, a new generation explosive formulation. An optimized method was developed to separate all 14 energetic compounds from DNAN and MNA using a tertiary mobile phase of water-methanol-acetonitrile (68:28:4) in an isocratic run of 35 min. The limit of detection (LOD, 3S(0)) was calculated to be 10 ppb for both MNA and DNAN. The limit of quantitation (LOQ, 10S(0)) was 40 ppb for both compounds. The dynamic ranges for the two compounds were very wide, a nearly 5 orders of magnitude range from 0.02 to 1,000 parts per million (ppm). The spike recoveries of MNA and DNAN in environmental matrix samples were excellent for DNAN, from 87% to 113%. For MNA, the recoveries were slightly high at the low level (60 ppb), probably due to some contamination in the ditch and pond matrices; but they were satisfactory at higher levels ranging from 85% to 121%.

Design, synthesis, and biological evaluation of combretastatin nitrogen-containing derivatives as inhibitors of tubulin assembly and vascular disrupting agents.

A series of analogs with nitro or serinamide substituents at the C-2'-, C-5'-, or C-6'-position of the combretastatin A-4 (CA4) B-ring was synthesized and evaluated for cytotoxic effects against heart endothelioma cells, blood flow reduction to tumors in SCID mice, and as inhibitors of tubulin polymerization. The synthesis of these analogs typically featured a Wittig reaction between a suitably functionalized arylaldehyde and an arylphosphonium salt followed by separation of the resultant E- and Z-isomers. Several of these nitrogen-modified CA4 derivatives (both amino and nitro) demonstrate significant inhibition of tubulin assembly as well as cytotoxicity and in vivo blood flow reduction. 2'-Aminostilbenoid 7 and 2'-amino-3'-hydroxystilbenoid 29 proved to be the most active in this series. Both compounds, 7 and 29, have the potential for further pro-drug modification and development as vascular disrupting agents for treatment of solid tumor cancers and certain ophthalmological diseases.

Antineoplastic agents. 445. Synthesis and evaluation of structural modifications of (Z)- and (E)-combretastatin A-41.

A series of cis- and trans-stilbenes related to combretastatin A-4 (1a), with a variety of substituents at the 3'-position of the aryl B-ring, were synthesized and evaluated for inhibitory activity employing six human cancer cell lines (NCI-H460 lung carcinoma, BXPC-3 pancreas, SK-N-SH neuroblastoma, SW1736 thyroid, DU-145 prostate, and FADU pharynx-squamous sarcoma) as well as the P-388 murine lymphocyte leukemia cell line. Several of the cis-stilbene derivatives were significantly inhibitory against all cell lines used, with potencies comparable to that of the parent 1a. All were potent inhibitors of tubulin polymerization. The corresponding trans-stilbenes had little or no activity as tubulin polymerization inhibitors and were relatively inactive against the seven cancer cell lines. In terms of inhibition of both cancer cell growth and tubulin polymerization, the dimethylamino and bromo cis-stilbenes were the most potent of the new derivatives, the latter having biological activity approaching that of 1a. As part of the present study, the X-ray crystal structure of the 3'-O-phosphate of combretastatin A-4 (1b) was successfully elucidated. Compound 1b has been termed the "combretastatin A-4 prodrug", and it is currently undergoing clinical trials for the treatment of human cancer patients.

Breeding for Resistance to Soybean Rust.

Soybean rust occurs in all major soybean-growing regions of the world including the North American mainland. Soybean rust, caused by Phakopsora pachyrhizi, is the most destructive foliar disease of soybean, and yield losses of over 50% are common when environmental conditions are conducive for disease development. Heavily infected plants defoliate and mature more rapidly than plants not infected with rust. P. pachyrhizi has a broad host range and can infect many other legumes including some native to Australia. A number of physiological races of the fungus have been reported on these native legumes from Australia and on soybean. In addition, four single genes for rust resistance were previously identified in four different soybean plant introductions. These sources of resistance also have been reported to be susceptible in some field locations and when challenged with certain isolates of P. pachyrhizi. Partial resistance, expressed as reduced pustule number and increased length of latent period, has also been reported but has not been widely used in breeding programs. Yield stability has been used in the past and compares percentage of yields in fungicide and nonfungicide plots. Cultivars or lines with a higher percentage of yield have greater yield stability in the presence of rust. Although soybean rust only recently was found in the continental United States, a proactive project to evaluate the USDA soybean germ plasm collection for rust resistance was initiated in 2002 at the Fort Detrick plant biocontainment facility and at six international locations. Part of this project is to discover soybean lines with greater yield stability, and additional single and partial resistance. To help minimize the impact of soybean rust, the first line of defense will be fungicides, with host resistance and yield stability augmenting the long-term management of soybean rust.

Reactivation of aged model Pd/Ce0.68Zr0.32O2 three-way catalyst by high temperature oxidising treatment.

A deactivated (aged under redox-cycled model TWC feed-stream) Pd/Ce(0.68)Zr(0.32)O(2) catalyst is remarkably reactivated when subjected to a high temperature oxidising treatment whereas this effect is only marginal for Pd/Al(2)O(3), which indicates the key role of such treatment in restoring the Pd-Ce(0.68)Zr(0.32)O(2) interactions leading to highly active catalysts.

Trace level analysis of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and its biodegradation intermediates in liquid media by solid-phase extraction and high-pressure liquid chromatography analysis.

The use of solid-phase extraction for the analysis of liquid media containing low microg/L levels of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), mononitroso-RDX (MNX), dinitroso-RDX (DNX), and trinitroso-RDX (TNX) is examined. Aqueous samples (100 mL) consisting of water and a microbiological basal medium are spiked with known concentrations of RDX, MNX, DNX, and TNX. The compounds are extracted from the liquid media using a Porapak RDX cartridge and then eluted from the cartridge with 5 mL of acetonitrile. The eluent is concentrated to 1 mL before analysis by high-pressure liquid chromatography (HPLC). The method detection limits for RDX are 0.1 microg/L in water and 0.5 microg/L in the basal medium after a 100-fold concentration. For MNX, DNX, and TNX, the method detection limits are approximately 0.5 microg/L in water and approximately 1 microg/L in the basal medium after a 100-fold concentration. Interferences in the basal medium and a contaminant in the standard made quantitation for MNX and TNX, respectively, is less accurate below the 1 microg/L level. Solid-phase extraction of the liquid media gave good recoveries of nitramines and nitroso intermediates from a microbiological basal medium, allowing HPLC detection of RDX and the nitroso intermediates in the low microg/L (ppb) range.

Clinical considerations in the diagnosis of otitis media.

Acute otitis media and otitis media with effusion are commonly encountered by both general practitioners and specialists. The diagnosis of otitis media requires a focused history and accurate physical examination. Unfortunately, many practitioners are either unaware of the criteria needed to make the diagnosis, or they incorrectly perform or misinterpret the physical examination. We review the pertinent historical and physical examination findings needed to accurately diagnose otitis media. Additionally, we examine the accessory tests that might help make the correct diagnosis in difficult cases. Finally, we address the issues involved in ensuring that both current and future physicians are appropriately trained in the diagnosis of this common illness.

Encapsulation of individual pancreatic islets by sol-gel SiO2: a novel procedure for perspective cellular grafts.

Pancreatic rat islets are encapsulated by a siliceous layer deposited on the surface of single islets upon reaction with gaseous siliceous precursors. The process preserves original islet dimensions and does not suppress viability or function. The encapsulated material is homogeneously distributed on the islet surface, and layer thickness can be controlled in the 0.1-2.0 microm interval. Dynamic perfusion experiments with glucose stimulation were carried out in both encapsulated and non-encapsulated islets. Results were treated according to a kinetic model presented here for the analysis of perfusion data; the model tested by literature data, was used to substantiate the diffusion features of the siliceous layer, which does not affect mass transfer of insulin but which modifies the texture of the islet surface tissue. The clinical potential of silica encapsulation was demonstrated by in vivo experiments using encapsulated islets transplanted into diabetic rats. Transplantation was carried out in both inbred and outbred rats and indicated prolonged restoration of normal glycaemia levels and protection from immunological attack.