Structure and thermodynamics of H3O+(H2O)8 clusters: A combined molecular dynamics and quantum mechanics approach

We have studied the structure and stability of (H3O+)(H2O)8 clusters using a combination of molecular dynamics sampling and high-level ab initio calculations. 20 distinct oxygen frameworks are found within 2 kcal/mol of the electronic or standard Gibbs free energy minimum. The impact of quantum zero-point vibrational corrections on the relative stability of these isomers is quite significant. The box-like isomers are favored in terms of electronic energy, but with the inclusion of zero-point vibrational corrections and entropic effects tree-like isomers are favored at higher temperatures. Under conditions from 0 to 298.15 K, the global minimum is predicted to be a tree-like structure with one dangling singly coordinated water molecule. Above 298.15 K, higher entropy tree-like isomers with two or more singly coordinated water molecules are favored. These assignments are generally consistent with experimental IR spectra of (H3O+)(H2O)8 obtained at 150 K.

Upregulation of defensins in burn sheep small intestine.

OBJECTIVE: The aim of this study was to visualize and localize the sheep antimicrobials, beta-defensins 1, 2, and 3, (SBD-1, SBD-2, SBD-3), sheep neutrophil defensin alpha (SNP-1), and the cathelicidin LL-37 in sheep small intestine after burn injury, our hypothesis being that these compounds would be upregulated in an effort to overcome a compromised endothelial lining. Response to burn injury includes the release of proinflammatory cytokines and systemic immune suppression that, if untreated, can progress to multiple organ failure and death, so protective mechanisms have to be initiated and implemented. METHODS: Tissue sections were probed with antibodies to the antimicrobials and then visualized with fluorescently labeled secondary antibodies and subjected to fluorescence deconvolution microscopy and image reconstruction. RESULTS: In both the sham and burn samples, all the aforementioned antimicrobials were seen in each of the layers of small intestine, the highest concentration being localized to the epithelium. SBD-2, SBD-3, and SNP-1 were upregulated in both enterocytes and Paneth cells, while SNP-1 and LL-37 showed increases in both the inner circular and outer longitudinal muscle layers of the muscularis externa following burn injury. Each of the defensins, except SBD-1, was also seen in between the muscle layers of the externa and while burn caused slight increases of SBD-2, SBD-3, and SNP-1 in this location, LL-37 content was significantly decreased. CONCLUSION: That while each of these human antimicrobials is present in multiple layers of sheep small intestine, SBD-2, SBD-3, SNP-1, and LL-37 are upregulated in the specific layers of the small intestine.

Jakob zu Bethel. Predigt nebst Gebeten, gehalten bei der feierlichen Grundsteinlegung der Hauptsynagoge zu Frankfurt am Main, Donnerstag, den 28. Juni 1855

von Leopold Stein

Diffusible, nonfibrillar ligands derived from Aβ1–42 are potent central nervous system neurotoxins

Aβ1–42 is a self-associating peptide whose neurotoxic derivatives are thought to play a role in Alzheimer’s pathogenesis. Neurotoxicity of amyloid β protein (Aβ) has been attributed to its fibrillar forms, but experiments presented here characterize neurotoxins that assemble when fibril formation is inhibited. These neurotoxins comprise small diffusible Aβ oligomers (referred to as ADDLs, for Aβ-derived diffusible ligands), which were found to kill mature neurons in organotypic central nervous system cultures at nanomolar concentrations. At cell surfaces, ADDLs bound to trypsin-sensitive sites and surface-derived tryptic peptides blocked binding and afforded neuroprotection. Germ-line knockout of Fyn, a protein tyrosine kinase linked to apoptosis and elevated in Alzheimer’s disease, also was neuroprotective. Remarkably, neurological dysfunction evoked by ADDLs occurred well in advance of cellular degeneration. Without lag, and despite retention of evoked action potentials, ADDLs inhibited hippocampal long-term potentiation, indicating an immediate impact on signal transduction. We hypothesize that impaired synaptic plasticity and associated memory dysfunction during early stage Alzheimer’s disease and severe cellular degeneration and dementia during end stage could be caused by the biphasic impact of Aβ-derived diffusible ligands acting upon particular neural signal transduction pathways.

Hādhihi Tarjamat quṭb al-wāṣil��n wa-ghawth al-sālikīn al-ʻārif billāh Sayyidī Shams al-Dīn Muḥammad Abī al-Maḥāsin al-Qāwuqj�� al-Ḥasanī

min qalam ʻAbd al-Qādir al-Adʹhamī al-Ṭarābulusī.

Kifāyat al-ṣibyān fīmā yajibu min ʻaqāʼid al-īmān wa-ʻamal al-arkān

li-Muḥammad al-Qāwūqj��.

Hādhihi Istighāthah tataḍammanu al-tawassul bi-al-anbiyāʼ al-kirām wa-awliyāʼ Allāh al-ʻiẓām wa-mashāyikh wālidinā

Muḥammad al-Qāwuqj�� al-mashʹhūr bi-Abī al-Maḥāsin. Wa-yal��hi tawassul ākhar, thumma yal��himā takhmīs nasab Abī al-Aqṭāb maljaʼ al-ṭullāb mumidd kull wal�� Sayyidunā ʻAl�� ibn ʻAbd Allāh Abī al-Ḥasan al-Shādhil�� / li-Ḥammūdah Ḥasan al-Nabdāwī al-Buqallūl��.

Kitāb Hadīyat al-aḥbāb wa-minḥat al-khullān wa-al-aṣḥāb

li-Muḥammad al-Qāwūqj�� al-Ṭarābulusī al-Shāmī al-shahīr bi-Abī al-Maḥāsin.

Imperium in imperio /

Wright, L.H. Amer. fiction, 1876-1900,

The Canada porcupine : a study of the learning process.

Originally presented as author's thesis (Ph.d.)-- Clark University, 1910.