203 research outputs found
Activation and Deactivation of a Robust Immobilized Cp*Ir-Transfer Hydrogenation Catalyst: A Multielement in Situ X-ray Absorption Spectroscopy Study
A highly robust immobilized [Cp*IrCl2]2 precatalyst on Wang resin for transfer hydrogenation, which can be recycled up to 30 times, was studied using a novel combination of X-ray absorption spectroscopy (XAS) at Ir L3-edge, Cl K-edge, and K K-edge. These culminate in in situ XAS experiments that link structural changes of the Ir complex with its catalytic activity and its deactivation. Mercury poisoning and “hot filtration” experiments ruled out leached Ir as the active catalyst. Spectroscopic evidence indicates the exchange of one chloride ligand with an alkoxide to generate the active precatalyst. The exchange of the second chloride ligand, however, leads to a potassium alkoxide–iridate species as the deactivated form of this immobilized catalyst. These findings could be widely applicable to the many homogeneous transfer hydrogenation catalysts with Cp*IrCl substructure
Gas-phase Meerwein reaction of epoxides with protonated acetonitrile generated by atmospheric pressure ionizations
The Role of Regional Disease and Patterns of Treatment Failure in Primary Sinonasal Malignancies
BACKGROUND
The question how to treat the clinically negative neck in sinonasal malignancies is controversial.
OBJECTIVES
To investigate patterns of treatment failure and to assess outcome measures in patients with primary sinonasal malignancies.
METHODS
Retrospective cohort study of patients treated for primary malignant sinonasal malignancies.
RESULTS
Lymph node (LN) metastases at initial presentation were present in 8 of 152 patients (5.3%). Ipsi- and contralateral LN levels 1 and 2 were identified as nodal basins at risk. We found a 5-year overall survival (OS) of 75.2% and disease free survival of 61.1%. Among patients with cN0 neck, nodal recurrence free survival was not different between patients with and without elective neck treatment (P  =  .23). On logistic regression analysis, we found initial T classification as an independent factor for achievement of complete remission (CR) and OS.
CONCLUSIONS
LN metastases at initial presentation are rare and initial T classification was identified as the most important prognostic factor for OS and CR, emphasizing the need for a thorough initial staging of the primary tumor
Totale Thyreoidektomie bei amiodaroninduzierter Hyperthyreose : Wann ĂĽbersteigt das Risiko der konservativen Therapie das Risiko der chirurgischen Behandlung?
Amiodarone plays a pivotal role in the treatment of ventricular and supraventricular arrhythmias. However, amiodarone-induced hyperthyroidism (AIH) is one of the most feared complications, which necessitates interdisciplinary treatment and careful balancing of the risks of conservative treatment against those of total thyroidectomy. In this article we discuss the pharmacological aspects of amiodarone and its diverse effects on the thyroid. Furthermore, we present diagnostic and therapeutic strategies and report our positive experiences with total thyroidectomy in patients with AIH. Particularly in patients for whom continuation of amiodarone treatment is compulsory, a well-timed total thyroidectomy is a reliable therapeutic option, with minimal complication rates and immediate amelioration of symptoms
Organoboron compounds Communication 15. organoboron compounds having an asymmetric boron atom
IRMPD Spectra of Protonated Hydroxybenzaldehydes: Evidence of Torsional Barriers in Carboxonium Ions
Impact of Design on Emotional, Psychological, or Social Well-Being for People With Cognitive Impairment
Aim: The objective of this article is to identify and analyze what is known about characteristics in and around the home that support well-being for those with cognitive impairment. This could provide direction for designers of homes in general, but specifically for designers trying to meet the needs of people with cognitive impairment. Background: It has been established that there is a relationship between psychological well-being and a person’s environment. Research also shows that particular design aspects can reduce the impact of cognitive impairment. However, there is limited design expertise in the Australian housing market to create supportive spaces which will help to reduce the impact of the disability for those with cognitive impairment. Method: A literature review was carried out to determine the extent and details of what is known about the relationship of home design and its impact on emotional, psychological, or social well-being for people with cognitive impairment. Conclusions: The study indicates that researchers in various disciplines understand that pragmatic design inputs such as thermal comfort and adequate lighting are important for people with cognitive impairment. In addition, some researchers have shown or surmise that there are other “intangible” designer-controlled elements that have beneficial impacts on people with cognitive impairment. Details of these intangible elements are sparse, and how much they might improve the quality of life for a person with cognitive impairment is not well understood. Further research is required to meet a growing need
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