10 research outputs found
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A Pest and Beneficial Insect Short Course Program for the Pacific Northwest: Train-the-trainer
Direct, biomimetic synthesis of (+)-artemone via a stereoselective, organocatalytic cyclization
We present a four-step synthesis of (+)-artemone from (â)- linalool, featuring iminium organocatalysis of a doubly diastereoselective conjugate addition reaction. The strategy follows a proposed biosynthetic pathway, rapidly generates stereochemical complexity, uses no protecting groups, and minimizes redox manipulations
Beyond Born-Mayer: Improved Models for Short-Range Repulsion in ab Initio Force Fields
Short-range repulsion
within intermolecular force fields is conventionally
described by either Lennard-Jones (<i>A</i>/<i>r</i><sup>12</sup>) or BornâMayer (<i>A</i> expÂ(â<i>Br</i>)) forms. Despite their widespread use, these simple functional
forms are often unable to describe the interaction energy accurately
over a broad range of intermolecular distances, thus creating challenges in the development of ab initio
force fields and potentially leading to decreased accuracy and transferability.
Herein, we derive a novel short-range functional form based on a simple
Slater-like model of overlapping atomic densities and an iterated
stockholder atom (ISA) partitioning of the molecular electron density.
We demonstrate that this SlaterâISA methodology yields a more
accurate, transferable, and robust description of the short-range
interactions at minimal additional computational cost compared to
standard Lennard-Jones or BornâMayer approaches. Finally, we
show how this methodology can be adapted to yield the standard BornâMayer
functional form while still retaining many of the advantages of the
Slater-ISA approach
New Angles on Standard Force Fields: Toward a General Approach for Treating Atomic-Level Anisotropy
Nearly all standard force fields
employ the âsum-of-spheresâ
approximation, which models intermolecular interactions purely in
terms of interatomic distances. Nonetheless, atoms in molecules can
have significantly nonspherical shapes, leading to interatomic interaction
energies with strong orientation dependencies. Neglecting this âatomic-level
anisotropyâ can lead to significant errors in predicting interaction
energies. Herein, we propose a simple, transferable, and computationally
efficient model (MASTIFF) whereby atomic-level orientation dependence
can be incorporated into ab initio intermolecular force fields. MASTIFF
includes anisotropic exchange-repulsion, charge penetration, and dispersion
effects, in conjunction with a standard treatment of anisotropic long-range
(multipolar) electrostatics. To validate our approach, we benchmark
MASTIFF against various sum-of-spheres models over a large library
of intermolecular interactions between small organic molecules. MASTIFF
achieves quantitative accuracy, with respect to both high-level electronic
structure theory and experiment, thus showing promise as a basis for
ânext-generationâ force field development
"Now he walks and walks, as if he didn't have a home where he could eat": food, healing, and hunger in Quechua narratives of madness
In the Quechua-speaking peasant communities of southern Peru, mental disorder is understood less as individualized pathology and more as a disturbance in family and social relationships. For many Andeans, food and feeding are ontologically fundamental to such relationships. This paper uses data from interviews and participant observation in a rural province of Cuzco to explore the significance of food and hunger in local discussions of madness. Carersâ narratives, explanatory models, and theories of healing all draw heavily from idioms of food sharing and consumption in making sense of affliction, and these concepts structure understandings of madness that differ significantly from those assumed by formal mental health services. Greater awareness of the salience of these themes could strengthen the input of psychiatric and psychological care with this population and enhance knowledge of the alternative treatments that they use. Moreover, this case provides lessons for the global mental health movement on the importance of openness to the ways in which indigenous cultures may construct health, madness, and sociality. Such local meanings should be considered by mental health workers delivering services in order to provide care that can adjust to the alternative ontologies of sufferers and carers
Multifunctional Role of Bcl-2 in Malignant Transformation and Tumorigenesis of Cr(VI)-Transformed Lung Cells
B-cell lymphoma-2 (Bcl-2) is an antiapoptotic protein known to be important in the regulation of apoptosis in various cell types. However, its role in malignant transformation and tumorigenesis of human lung cells is not well understood. We previously reported that chronic exposure of human lung epithelial cells to the carcinogenic hexavalent chromium Cr(VI) caused malignant transformation and Bcl-2 upregulation; however, the role of Bcl-2 in the transformation is unclear. Using a gene silencing approach, we showed that Bcl-2 plays an important role in the malignant properties of Cr(VI)-transformed cells. Downregulation of Bcl-2 inhibited the invasive and proliferative properties of the cells as well as their colony forming and angiogenic activities, which are upregulated in the transformed cells as compared to control cells. Furthermore, animal studies showed the inhibitory effect of Bcl-2 knockdown on the tumorigenesis of Cr(VI)-transformed cells. The role of Bcl-2 in malignant transformation and tumorigenesis was confirmed by gene silencing experiments using human lung carcinoma NCI-H460 cells. These cells exhibited aggressive malignant phenotypes similar to those of Cr(VI)-transformed cells. Knockdown of Bcl-2 in the H460 cells inhibited malignant and tumorigenic properties of the cells, indicating the general role of Bcl-2 in human lung tumorigenesis. Ingenuity Pathways Analysis (IPA) revealed potential effectors of Bcl-2 in tumorigenesis regulation. Additionally, using IPA together with ectopic expression of p53, we show p53 as an upstream regulator of Bcl-2 in Cr(VI)-transformed cells. Together, our results indicate the novel and multifunctional role of Bcl-2 in malignant transformation and tumorigenesis of human lung epithelial cells chronically exposed to Cr(VI)
In Situ, Time-Resolved, and Mechanistic Studies of MetalâOrganic Framework Nucleation and Growth
Supplementary Material - An examination of the communal coping process in recently diagnosed diabetes
<p>Supplementary Material for An examination of the communal coping process in recently diagnosed diabetes by Meredith Van Vleet, Vicki S. Helgeson, Howard J. Seltman, Mary T. Korytkowski, and Leslie R. M. Hausmann in Journal of Social and Personal Relationships</p