93 research outputs found
Cottrell Scholars Collaborative New Faculty Workshop: Professional Development for New Chemistry Faculty and Initial Assessment of Its Efficacy
The Cottrell Scholars Collaborative New Faculty Workshop (CSC NFW) is a professional development program that was initiated in 2012 to address absences in the preparation of chemistry faculty at research universities as funded researchers and educators (i.e., teacher–scholars). The primary focus of the workshop is an introduction to evidence-based teaching methods; other topics including mentoring, work–life balance, time management, and grant writing are also addressed. A longer-term aim of the workshop is to develop lifelong teacher–scholars by encouraging workshop participants to engage with teaching-focused faculty learning communities through the CSC NFW and at their institutions. The workshop also provides a platform to investigate the adoption of student-centered pedagogies among new faculty, and a study of that process was initiated concurrently. Thus, the aim of the workshop program is to address professional development needs as well as understand the efficacy of that effort
Measuring perceived benefit and disease-related burden in young cancer survivors: validation of the Benefit and Burden Scale for Children (BBSC) in the Netherlands
Item does not contain fulltextPURPOSE: Perceiving favourable changes from one's illness may go hand in hand with experiencing harmful psychosocial effects. Each of these constructs should be considered when examining children's levels of psychological adjustment following stressful life events. A paediatric instrument that accounts for both positive and negative impact of stressful events has not been investigated in The Netherlands before. The aim of the study was to investigate psychometric properties of the Dutch version of the Benefit and Burden Scale for Children (BBSC), a 20-item questionnaire that intends to measure potential benefit and burden of illness in children. METHODS: Dutch paediatric survivors of childhood cancer aged 8-18 (N = 77) completed the BBSC and other psychological questionnaires: Pediatric Quality of Life Inventory (health-related quality of life), State-Trait Anxiety Inventory for Children (anxiety), Children's Revised Impact of Event Scale (posttraumatic stress) and Strengths and Difficulties Questionnaire (behavioural functioning). Reliability and validity were evaluated. RESULTS: Internal consistency (Cronbach's alpha, benefit 0.84, burden 0.72), test-retest reliability (benefit r = 0.74, burden r = 0.78) and homogeneity (mean inter-item correlation, benefit r = 0.34, burden r = 0.22) were satisfactory. Burden was associated with HRQoL (-), anxiety (+), posttraumatic stress symptoms (+) and behavioural problems. Benefit did not correlate with the psychological outcomes. CONCLUSIONS: The Dutch version of the BBSC shows promising psychometric properties. Perceived benefit and disease-related burden are distinct constructs; both should be considered when examining children's psychological adjustment to potentially traumatic experiences. The BBSC may be useful as monitoring and screening instrument
Human monoclonal antibodies targeting carbonic anhydrase IX for the molecular imaging of hypoxic regions in solid tumours
BACKGROUND: Hypoxia, which is commonly observed in areas of primary tumours and of metastases, influences response to treatment. However, its characterisation has so far mainly been restricted to the ex vivo analysis of tumour sections using monoclonal antibodies specific to carbonic anhydrase IX (CA IX) or by pimonidazole staining, after the intravenous administration of this 2-nitroimidazole compound in experimental animal models.METHODS: In this study, we describe the generation of high-affinity human monoclonal antibodies (A3 and CC7) specific to human CA IX, using phage technology.RESULTS: These antibodies were able to stain CA IX ex vivo and to target the cognate antigen in vivo. In one of the two animal models of colorectal cancer studied (LS174T), CA IX imaging closely matched pimonidazole staining, with a preferential staining of tumour areas characterised by little vascularity and low perfusion. In contrast, in a second animal model (SW1222), distinct staining patterns were observed for pimonidazole and CA IX targeting. We observed a complementary pattern of tumour regions targeted in vivo by the clinical-stage vascular-targeting antibody L19 and the anti-CA IX antibody A3, indicating that a homogenous pattern of in vivo tumour targeting could be achieved by a combination of the two antibodies.CONCLUSION: The new human anti-CA IX antibodies are expected to be non-immunogenic in patients with cancer and may serve as broadly applicable reagents for the non-invasive imaging of hypoxia and for pharmacodelivery applications. British Journal of Cancer (2009) 101, 645-657. doi: 10.1038/sj.bjc.6605200 www.bjcancer.com Published online 21 July 2009 (C) 2009 Cancer Research U
Securitization, Deregulation, Economic Stability, And Financial Crisis, Part II - Deregulation, the Financial Crisis, and Policy Implications
Equilibration Time of Solid Contact Ion-Selective Electrodes
Papers published on ion-selective electrodes (ISEs) generally report on the performance characteristics of these devices after long, extensive conditioning. Conditioning refers to the equilibration of the ion-selective electrode in an aqueous solution before the measurement of the sample. The requirement for long and repeated conditioning is a significant burden in a variety of applications, for example, single-use sensors aimed for in vivo or field applications and solid contact (SC) ISEs, which were developed to provide simple, mass-produced sensors that have the potential to be implemented without calibration and extensive conditioning. In this study we recorded the potential of SC K+, Na+, and H+ ISEs as a function of time following their first contact with an aqueous electrolyte solution and used these transients to determine their equilibration times. The SC electrodes were built on Au, Pt, and glassy carbon (GC) substrates using galvanostatically deposited conductive polymer (PEDOT(PSS-), poly(3,4-ethylenedioxythiophene) polystyrenesulfonate) as ion-to-electron transducer (solid internal contact) between the ion-selective membrane and the substrate. The SC electrodes built on GC and Au had significantly shorter equilibration times (between 5 and 13 min) than the SC electrodes built on Pt substrates (\u3e60 min). Such significant differences in the equilibration times of SC ISEs built on different substrate electrodes are reported here for the first time. These unexpected findings suggest that the interface between the conductive polymer and the electron-conducting substrate (EC) has significant influence on the long-term dynamic behavior of SC ISEs. (Graph Presented)
Poly(3-octylthiophene) as solid contact for ion-selective electrodes: contradictions and possibilities
The hydrophobic conductive polymer, poly(3-octylthiophene) (POT), is considered as uniquely suited to be used as an ion-to-electron transducer in solid contact (SC) ion-selective electrodes (ISEs). However, the reports on the performance characteristics of POT-based SC ISEs are quite conflicting. In this study, the potential sources of the contradicting results on the ambiguous drift and poor potential reproducibility of POT-based ISEs are compiled, and different approaches to minimize the drift and the differences in the standard potentials of POT-based SC ISEs are shown. To set the potential of the POT film, it has been loaded with a 7,7,8,8-tetracyanoquinodimethane (TCNQ/TCNQ·−) redox couple. An approximately 1:1 TCNQ/TCNQ·−ratio in the POT film has been achieved through potentiostatic control of the potential of the redox couple-loaded conductive polymer. It is hypothesized that once the POT film has a stable, highly reproducible redox potential, it will provide similarly stable and reproducible interfacial potentials between the POT film and the electron-conducting substrate and result in SC ISEs with excellent reproducibility and potential stability. Towards this goal, the potentials of Au, GC, and Pt electrodes with drop-cast POT film coatings were recorded in KCl solutions as a function of time. Some of the POT films were loaded with TCNQ and coated with a K+-selective membrane. The improvement in the potential stabilities and sensor-to-sensor reproducibility as a consequence of the incorporation of TCNQ in the POT film and the potentiostatic control of the TCNQ/TCNQ·−ratio is reported
Differences in Electrochemically Deposited PEDOT(PSS) Films on Au and Pt Substrate Electrodes: A Quartz Crystal Microbalance Study
Studying the responses of potassium ion-selective electrodes with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), PEDOT(PSS), as solid contact (SC) revealed significant differences in the equilibration times and standard potentials of the electrodes fabricated on Au or Pt as substrate electrodes. To trace the source of these differences, PEDOT(PSS) films were deposited under the same conditions onto Au and Pt electrodes on the surface of 10 MHz quartz crystals. During the galvanostatic polymerization, the frequency decrease of the quartz crystal was monitored by an electrochemical quartz crystal microbalance (EQCM). In the initial 15 seconds of the electrochemical deposition, the rate of PEDOT(PSS) polymer growth was significantly faster on Au compared to Pt although the current density used for the deposition was the same. Consequently, the total frequency change after a given electrolysis time was always larger on Au compared to Pt, indicating a larger deposited mass or PEDOT(PSS) layer thickness. The differences in the thicknesses of the PEDOT(PSS) films on Au and Pt could be quantitatively confirmed by X-ray photoelectron spectroscopy (XPS) etching studies. Scanning electron microscopy (SEM) analysis of PEDOT(PSS) films on Au and Pt also showed characteristic differences
Ammonolysis of Tantalum Alkyls: Formation of Cubic TaN and a Trimeric Nitride, [Cp*MeTaN]3
Ammonolyses of precursor alkyl complexes have been employed to generate nitrides of tantalum. Treatment of (*BuCH2)3Ta=CHtBu (1) with NH3led to the formation of an orange precipitate, best formulated as an oligomer, [TaN2.14H1.35], (2), on the basis of ammonia uptake, neopentane loss, and combustion analysis. Upon thermolysis of 2 at 400 °C (24 h), a ~6% weight loss occurred and amorphous TaN was generated; crystalline cubic TaN (Fm3m, 95%) was formed after further heating at 820 °C (3 days). Under ambient light, a similar ammonolysis of 1 afforded another oligomer, [TaC, 41H3.90N1.90.]„ (2\u27); thermolysis of 2\u27 (400 °C, 24 h) resulted in a ~ 14% weight loss and amorphous TaN that was subsequently annealed to pure, crystalline cubic TaN (820 °C, 3 days, XRD, Fm3m). Cp*TaMe4(3, Cp* =?5-C5Me5) was exposed to excess NH3in order to model the ammonolysis process. The uptake of 1 equiv of ammonia/equiv of Ta was noted, 3 equiv of CH4was released, and [Cp*MeTaN]3(4) formed in 90% yield. Cyclic trimer 4 contains equivalent TaN distances (1.887 (17) Å) akin to those of related phosphazenes. Crystal data: monoclinic, P21/c, a = 16.951 (5) Å, b = 8.920 (3) Å, c = 23.141 (6) Å, 0 = 91.47 (2)°, Z = 4, T =-100 °C. EHMO calculations revealed why a structure containing alternating double and single TaN bonds was not favored. The low-lying LUMO of 4 was predicted to be nonbonding; consequently, 4 was reduced with Na/K to yield [K-nEt2O]+[|Cp*MeTaN|3]~ (5). A reversible reduction wave at E°\u27 =-2.5 V vs SSCE was also observed. Similar IR spectra of 4 (v(TaNTa) = 960 cm-1) and 5 (v(TaNTa) = 964 cm-1) support the contention that the LUMO is nonbonding. The relationship of 4 to the solid-state nitrides produced via ammonolysis is addressed. © 1990, American Chemical Society. All rights reserved
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