Self-assembly of a columnar polymeric calcium phosphinate derived from camphene

(2,2-Dimethylbicyclo[2.2.1] hept-3-ylmethyl)phosphinic acid (RPO₂H₂), readily prepared from camphene and hypophosphorous acid, formed a polymeric calcium salt [{Ca(RPO₂H) ₂ (RPO₂H₂)(H₂O)}n], with both terminal and triply bridging phosphinate groups, and an overall columnar structure with an inorganic core and a pseudo-close-packed sheath of terpene moieties

Raman Spectroscopic and Computational Analysis of the Effects of Noncovalent Interactions on DMSO

Dimethyl sulfoxide (DMSO) is a widely used chemical in synthetic chemistry and also has unique and important biological applications. In the pure liquid, DMSO forms chain like structures of alternating sulfur and oxygen atoms due to its high self-association. However, it is known that DMSO/water mixtures form solutions with unique physical characteristics depending on the mole ratio. For instance, at a 1:2 ratio of DMSO/water a eutectic mixture forms with a freezing point of-70 C. Vibrational spectroscopy allows us to study the effects of noncovalent interactions when water and DMSO interact in solution. Spectral shifts can be analyzed in order to give a clearer picture of the structure of DMSO in DMSO/water mixtures and also in solutions with other hydrogen bond donors that cannot form as extensive hydrogen bonded networks. The anomalous properties of DMSO/water mixtures have been the subject of a large number of studies. It has been previously established that the reason for the unique properties of such solutions lies in the formation of strong hydrogen bonds between water and DMSO. Despite the many studies there is still no clear picture of the structure of DMSO in the water mixture. When a DMSO/water mixture is formed there is great increase in temperature of the solution. This suggests a significant perturbation of water’s hydrogen bond network due to interactions with DMSO. Here, the hydrogen bonding geometries of DMSO/water mixtures are studied using Raman spectroscopy and computational chemistry

Linking metacognition and mindreading: Evidence from autism and dual-task investigations

Questions of how we know our own and other minds, and whether metacognition and mindreading rely on the same processes, are longstanding in psychology and philosophy. In Experiment 1, children/adolescents with autism (who tend to show attenuated mindreading) showed significantly lower accuracy on an explicit metacognition task than neurotypical children/adolescents, but not on an allegedly metacognitive implicit one. In Experiment 2, neurotypical adults completed these tasks in a single-task condition, or a dual-task condition that required concurrent completion of a secondary task that tapped mindreading. Metacognitive accuracy was significantly diminished by the dual-mindreading-task on the explicit task, but not the implicit task. In Experiment 3, we included additional dual-tasks to rule out the possibility that any secondary task (regardless of whether it required mindreading) would diminish metacognitive accuracy. Finally, in both experiments 1 and 2, metacognitive accuracy on the explicit task, but not the implicit task, was associated significantly with performance on a measure of mindreading ability. These results suggest that explicit metacognitive tasks (used frequently to measure metacognition in humans) share metarepresentational processing resources with mindreading, whereas implicit tasks (which are claimed by some comparative psychologists to measure metacognition in non-human animals) do not

PHOSPHENE IMAGES OF THALAMIC SLEEP RHYTHMS INDUCED BY SELF-HYPNOSIS

A medical writer describes internally-generated light sensations (phosphenes) induced by a technique of self-hypnosis that combines relaxation, convergent eye movement, and attentive fixation. The phosphene images include: (1) a threshold sequence of receding annuli, (2) amorphous phosphene mists or clouds, and (3) phosphene clouds with two levels of brightness and color saturation. These images share some similarities with visions of light reported by religious mystics. Based on an analysis of the distinctive spatiotemporal characteristics exhibited by the phosphenes. the author proposes the hypothesis that they are generated by thalamic sleep rhythms oscillating in the lateral geniculate nucleus (LGN). Since humans usually lose consciousness at the onset of non-rapid-eye-movement sleep (NREMS), the author also proposes the hypothesis that his technique of phosphene induction preserves consciousness, despite the operation of thalamic sleep rhythms, because eye movements and attentive fixation send excitatory feedback to the visual pathways. This selective facilitation of visual neurons appears to preserve their signal-processing capacity even though synchronous sleep rhythms may be installed in the non-visual thalamus. The author speculates that this selective disruption of sleep rhythm activity in the visual pathways may be the mechanism that produces the cutaneous analgesia (hypnoanalgesia) he experiences when he induces phosphenes

A Retrospective Clinical Study to Evaluate Treatment Outcomes of Vital Pulp Therapy with ProRootRTM Mineral Trioxide Aggregate, EndosequenceRTM Root Repair Material, and Biodentine RTM

The aim of this study was to evaluate success rates of vital pulp therapy cases completed exclusively by endodontic residents at West Virginia University School of Dentistry with 3 different bioactive calcium silicate cements. The materials used were ProRootRTM Mineral Trioxide Aggregate (MTA) white, EndosequenceRTM Root Repair Material (ERRM), and BiodentineRTM. Failures were also examined to observe trends toward failure associated with multiple factors.;All follow-up examinations included a clinical and radiographic evaluation, which included multiple examiners that read each radiograph. Associations between procedure failure rates and the factors of interest were examined through non-parametric tests due to the small number of failures relative to the overall sample size. Fisher\u27s exact tests were used to investigate associations between failure rate and each categorical factor. Wilcoxon rank sum tests were employed to assess associations between procedure failure rates and the continuous factors of patient age and follow-up time.;A total of 130 cases were completed by endodontic residents. Fifty cases were successfully recalled, and 41 cases met the inclusion criteria after a retrospective chart review. All cases were completed between 2010 and 2013. The age of patients ranged from 7-58 years with an average age of 14.3 years. The follow-up time for successful cases ranged from 160 to 1000 days with an average of 730 days. Failure follow-up ranged from 7-38 days with an average of 24 days. The overall success rate of the 41 cases was 87.8%. Those patients receiving ERRM materials had over twice the odds of failure compared to those patients receiving ProRootRTM MTA. (OR: 2.29 (0.32,16.51)). ERRM materials included both ERRM putty (8 patients) and ERRM syringeable (1 patient). Those patients with trauma-related procedures had over three times the odds of failure compared to those patients with caries/decay-related procedures. (OR: 3.22 (0.44, 23.65)). Also, one out of the four patients who received cotton and TriageRTM instead of immediate restoration were reported as failed cases. Nearly every patient with a failed procedure was older than the median age of patients that had a successful case. None of the factors examined were statistically significant.;Vital pulp therapy in this study had a success rate of 87.8% with an average of 730 days follow-up. While each of our conservative statistical tests did not indicate statistical significance, they are potentially clinically relevant. The factors of age, cases completed with ERRM, trauma vs. caries, and immediate restoration vs. temporizing should be examined in future studies

EMPIRICAL STUDIES OF MEDITATION: DOES A SLEEP RHYTHM HYPOTHESIS EXPLAIN THE DATA?

This article reviews the findings of important empirical studies of meditators and shows that these findings can be explained by the hypothesis that meditation is generated by induction of slow wave sleep rhythms. This hypothesis explains why radionucleide imaging (PET, SPECT, and fMRI) studies report increases in neuronal activity in the thalamus (where sleep rhythms are generated) and in the hippocampus (which receives a barrage of vision-related signals caused by manipulations of attention and sleep rhythm activity). It also explains the diverse findings of EEG/QEEG studies, for example, the observed short-term increases in alpha band frequencies and coherence, the subsequent shifts to slower theta/delta frequencies, and the reports of a sudden frequency-splitting and amplitude-doubling concurrent with ecstatic raptures. The author suggests that existing studies of meditation do not account for the likelihood that the theta/delta frequency distribution associated with meditation can be generated by two very different mechanisms: (1) by induction of a drowsy, hypnagogic state ("stage 1" NREMS), an experience familiar to many people and thus easily achievable by novice meditators, and alternatively, (2) by inducing the full progression of thalamic sleep rhythms, an option available only to advanced meditators who are able to move beyond "stage 1" NREMS ro induce thalamic spindle-burst typical of "stage 2" NREMS, then beyond that to induce delta waves typical of "stage 3" NREMS. These thalamic delta waves, after augmentation by intracortical circuits, register in the cortical EEG as low-theta/high-delta band activity, making it easy to mistake the underlying mechanism as stage 1 NREMS

EMPIRICAL STUDIES OF MEDITATION: DOES A SLEEP RHYTHM HYPOTHESIS EXPLAIN THE DATA?

This article reviews the findings of important empirical studies of meditators and shows that these findings can be explained by the hypothesis that meditation is generated by induction of slow wave sleep rhythms. This hypothesis explains why radionucleide imaging (PET, SPECT, and fMRI) studies report increases in neuronal activity in the thalamus (where sleep rhythms are generated) and in the hippocampus (which receives a barrage of vision-related signals caused by manipulations of attention and sleep rhythm activity). It also explains the diverse findings of EEG/QEEG studies, for example, the observed short-term increases in alpha band frequencies and coherence, the subsequent shifts to slower theta/delta frequencies, and the reports of a sudden frequency-splitting and amplitude-doubling concurrent with ecstatic raptures. The author suggests that existing studies of meditation do not account for the likelihood that the theta/delta frequency distribution associated with meditation can be generated by two very different mechanisms: (1) by induction of a drowsy, hypnagogic state ("stage 1" NREMS), an experience familiar to many people and thus easily achievable by novice meditators, and alternatively, (2) by inducing the full progression of thalamic sleep rhythms, an option available only to advanced meditators who are able to move beyond "stage 1" NREMS ro induce thalamic spindle-burst typical of "stage 2" NREMS, then beyond that to induce delta waves typical of "stage 3" NREMS. These thalamic delta waves, after augmentation by intracortical circuits, register in the cortical EEG as low-theta/high-delta band activity, making it easy to mistake the underlying mechanism as stage 1 NREMS