Modification of N-heterocyclic carbene scaffolds : insights into reactivity and electronic properties

Starting from the initial efforts to prepare, study, and utilize carbenes, the choice of substituents has been recognized as a critical factor in determining their properties. Following the isolation of stable carbenes, a further aspect of design has become apparent; creation of a supporting scaffold to provide influence over the carbene’s reactivity and electronic properties as well as providing a protective envelope to ensure stability. Modification of previous N-heterocyclic carbene scaffolds to provide a new range of diamidocarbenes, which demonstrated enhance electrophilic properties. Further elaboration of these scaffolds has allowed the synthesis of novel carbenes with tailored properties. A series of six-membered carbenes featuring adjoining amino and/or amido groups were studied to determine the effect of substituent modification. A mono-amino/amido carbene (MAAC), a diamidocarbenes, and a diaminocarbene were systematically compared using crystallographic, spectroscopic, electrochemical, and density functional theory methods. Using single crystal X-ray diffraction analysis, the free MAAC was found to exhibit inequivalent nitrogen-carbon bond lengths Iridium complexes of the carbenes were also evaluated and the collected data revealed that the introduction of carbonyl groups to the carbene-containing scaffold had a nearly linear, additive effect on the E [subscript 1/2] potential of the carbene-ligated iridium I/II redox couple (+165 mV per carbonyl added) as well as the TEP value of the corresponding carbene-Ir(CO)₂Cl complex. Beyond attenuated ligand donicity, the introduction of carbonyl groups expanded the carbene’s reactivity: unlike prototypical NHCs, the MAAC was found to couple to isonitriles to form the respective ketenimines. Additionally, remotely substituted diamidocarbenes (DACs) were prepared and characterized. These carbenes were compared to their parent carbene via spectroscopic and density functional theory methods, and subjected to reactivity trials to determine the effects of remote substitution. Spectroscopic examination of the carbene-Ir(CO)₂Cl complexes demonstrated a difference in TEP value, indicating a small effect of substitution on the carbene’s electronic state. However, treatment of the differently substituted carbenes with substrates known to react with the parent DAC indicated no significant difference in reactivity scope; additionally, computational methodology demonstrated similarities in calculated geometries and orbital energy levels.Chemistr

Adaptive Paddle Board

This Final Design Review (FDR) document outlines the Adaptive Paddle Board senior project, done by four Mechanical Engineering Students at California Polytechnic State University and provides detail on the project and what the team has accomplished. The goal was to create a universally adaptive paddle board that can be used by the Central California Adaptive Sports Center for a wide range of persons with disabilities. This document highlights current research from patents and existing products, details regarding customer specifications, results from concept generation, the manufacturing and testing that went into the final design, and the process taken to get there. Testing has proven the final design to crucial specifications such as cost, reproducibility, and tipability

Injectable diblock copolypeptide hydrogel provides platform to maintain high local concentrations of taxol and local tumor control

Abstract Introduction Surgical resection and systemic chemotherapy with temozolomide remain the mainstay for treatment of glioblastoma. However, many patients are not candidates for surgical resection given inaccessible tumor location or poor health status. Furthermore, despite being first line treatment, temozolomide has only limited efficacy. Methods The development of injectable hydrogel-based carrier systems allows for the delivery of a wide range of chemotherapeutics that can achieve high local concentrations, thus potentially avoiding systemic side effects and wide-spread neurotoxicity. To test this modality in a realistic environment, we developed a diblock copolypeptide hydrogel (DCH) capable of carrying and releasing paclitaxel, a compound that we found to be highly potent against primary gliomasphere cells. Results The DCH produced minimal tissue reactivity and was well tolerated in the immune-competent mouse brain. Paclitaxel-loaded hydrogel induced less tissue damage, cellular inflammation and reactive astrocytes than cremaphor-taxol (typical taxol-carrier) or hydrogel alone. In a deep subcortical xenograft model, of glioblastoma in immunodeficient mice, injection of paclitaxel-loaded hydrogel led to a high local concentration of paclitaxel and led to local tumor control and improved survival. However, the tumor cells were highly migratory and were able to eventually escape the area of treatment. Conclusions These findings suggest this technology may be ultimately applicable to patients with deep-seated inoperable tumors, but as currently formulated, complete tumor eradication would be highly unlikely. Future studies should focus on targeting the migratory potential of surviving cells

Voluntary simplicity strongly backed by all three main normative-ethical traditions

We examine the growing ‘Voluntary Simplicity’ (VS) movement from the perspectives of Utilitarianism, Kantian deontology, and Virtue Ethics. We argue that, from each of these three diverse perspectives, there is a compelling argument to the conclusion that citizens of the ‘developed’ world ought to embrace such simplicity in their own lives, and to facilitate its greater adoption societally and globally. We conclude by asking why it is that this compelling conclusion has not already been more widely found and acted upon. In reflecting on this question we outline some arguments for why a culture of voluntary simplicity may be needed to drive political and macroeconomic change

Man With Bilateral Leg Swelling

A 52-year-old man without known medical history presented with painful, progressive, bilateral lower extremity edema over a two-week period. An abdominal exam noted a firm left upper quadrant mass. Emergency department (ED) point-of-care ultrasound (POCUS) revealed a hyperechoic, heterogeneous structure in the inferior vena cava that was determined to represent a tumor thrombus extending from a primary renal cell carcinoma. This case demonstrates how POCUS was valuable in rapidly diagnosing this rare cause of lower extremity edema and its usefulness in directing the initial ED management of this patient

Housing and Mobility Toolkit for San Mateo County

Since the end of the Great Recession, San Mateo County has attracted new workers at a record rate without building anywhere near enough housing. This jobs-housing imbalance drives the cost of housing up and forces many moderate and lower-income employees and their families out of the County. A lack of access to quality affordable housing in the County and the entire Bay Area along with limited transportation options means that an increased number of employees drive in and out of the County every workday. The resultant congestion, gridlock, and long commutes along with other negative environmental, social, and economic impacts create a major concern for communities in the County and beyond. Clearly, this problem has two distinct but interrelated dimensions: housing development and transportation planning. A select group of Mineta Transportation Institute (MTI) Research Associates worked closely with representatives from the San Mateo County Home for All initiative to help address this challenge by developing a toolkit of successful case studies with a holistic approach to housing development and transportation planning

Perceptions of Outdoor Recreation Professionals Toward Place Meanings in Natural Environments: a Q-method Inquiry

The purpose of this study was to describe the perceptions of outdoor recreation professionals toward place meanings in natural environments. The study describes the views of outdoor recreation professionals with varied backgrounds and professional experiences toward the ways they find meaning in outdoor settings of personal significance. Participants in the study included 15 men and 15 women who either work or worked in various areas of the outdoor recreation profession. Q methodology was utilized to illuminate the ways this group thinks about meanings in outdoor places. Each participant completed a sorting procedure (called a Q-sort) according to the following condition of instruction: "How do you find meaning in a place in the out-of-doors?" Analysis consisted of statistical procedures including correlation of the sorts and factor analysis for computation of the factor scores. Varimax rotation was performed on a three-factor solution, which best represented statistical and theoretical significance. Z-scores were calculated for each item on each factor to interpret each of the theoretical factor arrays along with distinguishing statements, demographic information, and exit question. The three views toward place meanings were interpreted as: 1) Relational, 2) Natural, and 3) Spiritual. The findings from this study show three distinct views toward place meanings among a group of outdoor recreation professionals. Additionally, the affective domain of attachment to nature was a defining phenomenon within each perspective. These findings delineate some of the ways that place meanings in the out-of-doors operate. Further, these findings can help the outdoor recreation profession in clarifying perceptions of place meaning views, which may potentially be used to promote intentional use of environmental values and beliefs.Electrical Engineering Technolog