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关键词： CONCEPTUAL structures (Information theory)   COUNSELING   CRITICALLY ill   DECISION making   EMOTIONS (Psychology)   MEDICAL personnel   PATIENTS   PEDIATRICS   PHYSICIAN-patient relations   STRESS (Psychology)   ADVANCE directives (Medical care)   SOCIAL responsibility   SOCIAL support   PATIENTS' families   PHYSICIANS -- Attitudes   FAMILIES   ATTITUDES  

摘要： Shared decision-making in pediatrics is based on a trusting partnership between parents, clinicians, and sometimes patients, wherein all stakeholders explore values and weigh options. Within that framework, clinicians often have an obligation to provide guidance. We describe a range of ethically justifiable clinician directiveness that could be appropriate in helping families navigate serious pediatric illness. The presentation of default options and informed nondissent as potential strategies are discussed. The degree of clinician directiveness may vary even for decisions that are equally shared. A myriad of factors affect how directive a clinician can or should be. Some of the most important factors are the degree of prognostic certainty and the family's desire for guidance, but others are important as well, such as the urgency of the decision;the relationship between the clinician, patient, and family;the degree of team consensus;and the burdens and benefits of therapy. Directiveness should be considered an important tool in a clinician's armamentarium and is one that can be used to support families in stressful and emotionally difficult situations.

关键词： carboxymethylamylose   conformational transitions   potentiometric titration   small-angle X-ray scattering   UV/VIS spectra  

摘要： Hydroxyl groups of amylose are barely dissociated into ions at pH lower than about 12, and so amylose is almost insoluble in neutral and acidic aqueous solutions and its conformation in solution has been a question under debate. Carboxymethylamylose (CMA) has much better solubility in aqueous solution than amylose and the conformation of CMA is expected to reflect that of the parent amylose. In the present study, CMA was prepared by substituting H of 24.5 mol.% hydroxyl groups of amylose with carboxymethyl groups, and the conformation of CMA in KI aqueous solution was studied as a function of the concentration of iodine I-2 and the degree of ionization alpha by potentiometric titration. Different conformational behaviors were observed in different alpha domains: In a low-alpha domain, CMA in KI/I-2 aqueous solution and in KI aqueous solution behaves as a tightly-wound helical chain and a loosely-wound helical chain, respectively. The helical- and psedo-helical-chain are gradually collapsed to extended-coils as alpha increases and CMA equally behaves as an extended-coil in a medium-alpha domain and as a more extended-coil in a higher-alpha domain. Such a conformational change was reflected in a change of persistence length of a chain with alpha, which was clarified by small-angle X-ray scattering study.

关键词： Moscow   analytical chemistry   Division   universities   Countries (nations)   division   State Universities  

关键词： EDTA titration method   cement content   cement mixing pile   curing period   water content   water glass   soil type   cement type   SEM   microstructure  

摘要： The uniformity of cement mixing piles is visually tested on the drilled core samples, significantly relying on experience and extremely inaccurate. The cement content of core samples is an important parameter to quantify the uniformity of cement mixing piles. However, there were no well-accepted methods of testing the cement content of core samples. EDTA titration method is widely used as an effective way to test the cement content of cement-stabilized soil in highway subgrade. However, the cement mixing piles cannot be drilled until 28 days after construction, which causes remarkable change of water content and cement hydration during this period. In addition, factors affecting the EDTA titration results should be investigated before standard EDTA titration curves are constructed. In this paper, effects of different factors including curing method, curing period, soil type, content of water glass, and cement type, on EDTA titration testing results were investigated. It is found that cement type and soil type will significantly affect the test result. It is critical to keep the curing environment and soil unsieved before testing. Water glass will reduce the EDTA solution consumptions at early stages of curing. The EDTA titration results are verified by the proposed density estimation method.

关键词： Upper-Division Undergraduate   Analytical Chemistry   Interdisciplinary/Multidisciplinary   Hands-On Learning/Manipulatives   Instrumental Methods   Laboratory Equipment/Apparatus  

摘要： In a university third-year instrumental chemistry laboratory students build a laser based polarimeter for determining light scattering with commercially available optical components used in modern optics research laboratories. During this laboratory experiment, students learn that solutions containing molecules which scatter light also influence the polarization properties of the laser beam by measuring Stokes parameters to calculate the degree of linearly polarized light. They also discover how the polarization properties of a laser beam are affected by half- and quarter-wave plates. Lastly, students are asked to recognize and assess the sources of error associated with the experiment including background intensity, integration time, and polarizer angle accuracy when measuring the Stokes parameters. A majority of students who completed the experiment agreed that this laboratory experiment required more critical thinking than traditional building instrumentation modules that they were exposed to, and that it improved their ability to learn independently and perform research.

关键词： Troponin C   calcium and magnesium   Heart   isothermal titration calorimetry  

摘要： P1-09

关键词： Phenylketonuria   PKU   Recombinant Anabaena variabilis pegylated   phenylalanine ammonia lyase   Pegvaliase  

摘要： Background: Phenylketonuria (PKU) is caused by a deficiency in phenylalanine hydroxylase enzyme activity that leads to phenylalanine (Phe) accumulation in the blood and brain. Elevated blood Phe levels are associated with complications in adults, including neurological, psychiatric, and cognitive issues. Even with nutrition and pharmacological management, the majority of adults with PKU do not maintain blood Phe levels at or below guideline recommended levels. Pegvaliase, PEGylated recombinant Anabaena variabilis phenylalanine ammonia lyase (PAL), converts Phe to trans-cinnamic acid and ammonia, and is an investigational enzyme substitution therapy to lower blood Phe in adults with PKU. Methods: Pegvaliase was administered using an induction, titration, and maintenance dosing regimen in adults with PKU naive to pegvaliase treatment. Doses were gradually increased until blood Phe 5 600 mol/L was achieved. The maintenance dose was the dose at which participants achieved and sustained blood Phe < 600 mol/L for at least 4 weeks without dose modification. Analyses were performed for participants who achieved (Group A, n = 11) and did not achieve (Group B, n = 13) maintenance dose during the first 24 weeks of study treatment. Results: Baseline mean blood Phe for Group A and Group B were 1135 mol/L and 1198 mol/L, respectively. Mean blood Phe 600 mol/L was achieved for Group A by Week 11 (mean blood Phe of 508 483 mol/L) and for Group B by Week 48 (mean blood Phe of 557 389 mol/L). The most common adverse events involved hypersensitivity reactions, which were mostly mild to moderate in severity and decreased over time. One participant in Group B had four acute systemic hypersensitivity events of anaphylaxis consistent with clinical National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network criteria;all events were non-IgE mediated and resolved without sequelae, with pegvaliase dosing discontinued after the fourth event. The incidence and tite

关键词： antibody titration   column agglutination technique   pretransplantation   tube test technique  

摘要： Background and Objectives Materials and Methods Determination of the anti-A/-B titre pre- and post-transplantation is beneficial for treatment selection. Currently, the recommended method for antibody titration is the tube test (TT) assay. Dithiothreitol (DTT) is used for IgM antibody inactivation. Recently, a fully automated antibody titration assay using the column agglutination technique (CAT) was developed (auto-CAT). Our aim was to compare the auto-CAT and TT techniques for ABO antibody titration, to evaluate the effectiveness of DTT-treated plasma for use with auto-CAT and to define the cut-off value for antibody titration by auto-CAT. We enrolled 30 healthy individuals, including 10 each for blood types A, B and O. We performed antibody titre measurement using the TT technique and auto-CAT simultaneously. Auto-CAT uses the bead column agglutination technology. Results Conclusion With the auto-CAT cut-off value set to weak (w)+ with DTT treatment plasma, the concordance rate was 45%, and the weighted kappa value between TT and auto-CAT results was 0 center dot 994 in all subjects. Furthermore, there was a significant positive correlation between the anti-A/-B titre results obtained using the TT technique and auto-CAT in all blood types. Moreover, a positive bias (falsely elevated end-points due to agglomeration of A/B cells) was not observed in auto-CAT testing using DTT-treated plasma. Our results show that 1+ agglutination using the TT technique is equivalent to w+ agglutination obtained using auto-CAT. We recommend that DTT may be used with auto-CAT to measure antibody titres. Thus, we suggest that auto-CAT is useful for antibody titration in routine examination.

关键词： fuel ethanol   syringe pump   multicommuted flow analysis   spectrophotometric titration   LED-based photometer  

摘要： An automatic photometric titration procedure was developed to determine the acidity of fuel ethanol. The procedure was implemented by using a binary search algorithm and a multicommuted flow analysis approach. Solution-handling setup included a homemade syringe pump and a set of solenoid valves, which were assembled to treat the solution-handling as a time function controlled by a microcomputer. Photometer detection was performed using a compact homemade light emitting diode (LED)-based photometer. Aiming to evaluate the accuracy, samples were analyzed by employing the methodologies recommended by the Brazilian Association of Technical Standards (ABNT) and the American Society for Testing and Materials (ASTM). Accuracy was assessed by applying the Student's t-test for paired samples at the 95% confidence level (n = 4), which shown that there is no significant difference between results. Other useful features included relative standard deviation of < 1% and waste generation volume ten times lower than those produced by ABNT and ASTM methods.