Phoenix

A novel chiral coordination polymer, [Cu­(C₆H₅CH­(OH)­COO)­(μ-C₆H₅CH­(OH)­COO)] (<b>1</b>-L and <b>1</b>-D), was synthesized through a reaction of copper acetate with l-mandelic acid at room temperature. Although previously reported copper mandelate prepared by hydrothermal reaction was a centrosymmetric coordination polymer because of the racemization of mandelic acid, the current coordination polymer shows noncentrosymmetry and a completely different structure from that previously reported. The X-ray crystallography for <b>1</b>-L revealed that the copper center of the compound showed a highly distorted octahedral structure bridged by a chiral mandelate ligand in the unusual coordination mode to construct a one-dimensional (1D) zigzag chain structure. These 1D chains interdigitated each other to give a layered structure as a result of the formation of multiple aromatic interactions and hydrogen bonds between hydroxyl and carboxylate moieties at mandelate ligands. The coordination polymer <b>1</b>-L belongs to the noncentrosymmetric space group of C2 to show piezoelectric properties and second harmonic generation (SHG) activity

Vestibular stimulation-induced facilitation of cervical premotoneuronal systems in humans.

It is unclear how descending inputs from the vestibular system affect the excitability of cervical interneurons in humans. To elucidate this, we investigated the effects of galvanic vestibular stimulation (GVS) on the spatial facilitation of motor-evoked potentials (MEPs) induced by combined pyramidal tract and peripheral nerve stimulation. To assess the spatial facilitation, electromyograms were recorded from the biceps brachii muscles (BB) of healthy subjects. Transcranial magnetic stimulation (TMS) over the contralateral primary motor cortex and electrical stimulation of the ipsilateral ulnar nerve at the wrist were delivered either separately or together, with interstimulus intervals of 10 ms (TMS behind). Anodal/cathodal GVS was randomly delivered with TMS and/or ulnar nerve stimulation. The combination of TMS and ulnar nerve stimulation facilitated BB MEPs significantly more than the algebraic summation of responses induced separately by TMS and ulnar nerve stimulation (i.e., spatial facilitation). MEP facilitation significantly increased when combined stimulation was delivered with GVS (p < 0.01). No significant differences were found between anodal and cathodal GVS. Furthermore, single motor unit recordings showed that the short-latency excitatory peak in peri-stimulus time histograms during combined stimulation increased significantly with GVS. The spatial facilitatory effects of combined stimulation with short interstimulus intervals (i.e., 10 ms) indicate that facilitation occurred at the premotoneuronal level in the cervical cord. The present findings therefore suggest that GVS facilitates the cervical interneuron system that integrates inputs from the pyramidal tract and peripheral nerves and excites motoneurons innervating the arm muscles

QRS Morphological Analysis using Two Layered Self-Organizing Map for Heartbeat Classification

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Protective effect of 3-hydroxybutyrate against endoplasmic reticulum stress-associated vascular endothelial cell damage induced by low glucose exposure.

The aim of this study was to elucidate the mechanism by which severe hypoglycemia accelerates vascular complications. Furthermore, we assessed the possible protective effect of ketone bodies against the endothelial cell damage caused by glucose deficiency.Human umbilical vein endothelial cells (HUVECs) were cultured at a glucose level of either 0.56 or 5.6 mmol/L with or without 3-hydroxybutyrate (3-HB) supplementation. Cell viability was assessed with a CCK-8 assay and a lactate dehydrogenase (LDH) release assay. The activity of caspases was measured using fluorogenic substrates. The expression of genes associated with endothelial cell function and endoplasmic reticulum (ER) stress was evaluated by real-time quantitative PCR. Protein levels of ER stress-related molecules were assessed by Western blotting.Culture of HUVECs in low-glucose medium for 24 or 48 h resulted in reduction of cell viability accompanied by activation of caspase-3/7 and caspase-8. The addition of a pan caspase inhibitor attenuated the cell death. After incubation in the low-glucose medium, we found reduced mRNA and protein levels of endothelial nitric oxide synthase. ER stress responses mediated by phosphorylation of protein kinase RNA-like ER kinase (PERK) and cleavage of activating transcription factor 6 (ATF6) were augmented, but X-box binding protein 1 (Xbp1) splicing was reduced. Most of these responses to glucose deficiency were significantly attenuated by supplementation with 3-HB.These observations showed that exposure to low glucose induces ER stress, caspase activation, endothelial cell dysfunction and cell death. The beneficial effects of 3-HB shown in this study suggest that hypoketonemic severe hypoglycemia induced by insulin injections or insulin secretagogue administration may be more harmful than hyperketonemic severe hypoglycemia

Schematic of the methodology and potential premotoneuronal pathways in the cervical cord.

<p>The wiring pattern is oversimplified for better understanding. Black and red solid lines represent direct (monosynaptic) connections, whereas purple and green dashed lines represent indirect (non-monosynaptic) connections no matter whether its effect is facilitatory or inhibitory. The pyramidal tract volleys (a red arrow) that are produced by transcranial magnetic stimulation (TMS) over the contralateral motor cortex and the afferent volleys (a green arrow) that are produced by electrical stimulation of the ipsilateral ulnar nerve (NERVE) at the wrist converge onto a common cervical interneuron (IN) that projects to motoneurons (MNs) of the biceps brachii (BB) muscle, which results in extra facilitation of motor-evoked potentials (MEPs) in the BB. The TMS and NERVE are timed so that the pyramidal tract and afferent volleys simultaneously arrive at the upper cervical cord. The inputs produced by galvanic vestibular stimulation (GVS) through the bilateral mastoid processes also converge on the IN pool. FDI: first dorsal interosseous muscle, EMG: electromyogram.</p

The effects of galvanic vestibular stimulation (GVS) on the firing probability of single motor units (MUs) after combined motor cortex and ulnar nerve stimulation.

<p><b>A</b>–<b>H</b> show the peristimulus time histograms (PSTHs) of a single MU in the biceps brachii (BB) muscle after separate ulnar nerve stimulation (NERVE) at 1.0 × motor threshold (MT) of the first dorsal interosseous muscle (<b>A</b>, <b>E</b>), separate transcranial magnetic stimulation (TMS) (<b>B</b>, <b>F</b>) over the contralateral primary motor cortex at 1.25 × active motor threshold of the BB, and combined stimulation (COMB) (<b>C</b>, <b>G</b>) in the control (<b>A</b>–<b>D</b>) and anodal GVS conditions (<b>E</b>–<b>H</b>). Each PSTH was obtained after 50 stimuli. The counts in these PSTHs were subtracted by the mean counts during a 50 ms prestimulus period. <b>D</b> and <b>H</b> show differential PSTHs after subtraction of the summed PSTHs after separate stimuli from the PSTHs of the COMB. The number of counts in each bin was normalized by the number of triggers. The vertical dashed line represents the onset of the excitatory peak in the PSTH after separate TMS. The superimposed waveforms in the upper right corner of each PSTH show the MU action potentials (n = 50) obtained from each stimulus trial. <b>I</b>–<b>L</b> indicate the peak counts of the MU firings in the differential PSTHs in the control and anodal GVS conditions obtained from 31 MUs that were investigated with the NERVE set at 1.0 × MT (<b>I</b>, <b>J</b>) and 20 MUs that were investigated with the NERVE set at 0.75 × MT (<b>K</b>, <b>L</b>). The error bars represent 1 standard deviation. The analysis window was set at a predefined period (1.0 ms duration) that started 1.0 ms after the onset of the TMS-induced excitatory peak in the PSTH. **<i>p</i> < 0.01.</p

The effects of galvanic vestibular stimulation (GVS) on ulnar nerve-induced facilitation of motor-evoked potentials in a single subject.

<p>Full-wave rectified and averaged electromyograms (EMGs) in the biceps brachii (BB) muscle after separate ulnar nerve stimulation (NERVE) at 1.0 × the motor threshold of the first dorsal interosseous muscle (<b>A</b>, <b>E</b>, <b>I</b>), separate transcranial magnetic stimulation (TMS) over the contralateral primary motor cortex at 1.1 × the active motor threshold of the BB (<b>B</b>, <b>F</b>, <b>J</b>), and the combination (COMB) of NERVE and TMS (<b>C</b>, <b>G</b>, <b>K</b>). These waveforms were obtained without GVS (left panels), during anodal GVS (middle panels), and during cathodal GVS (right panels) at 2.0 × the perceptual threshold of the head sway. The grey waveforms in <b>C</b>, <b>G</b>, and <b>K</b> represent the summation (SUM) of the averaged EMG waveforms after separate TMS and NERVE. The waveforms in <b>D</b>, <b>H</b>, and <b>L</b> represent the COMB waveforms with the SUM waveforms subtracted.</p

The pooled data for the effects of galvanic vestibular stimulation (GVS) on the ulnar nerve-induced facilitation of motor-evoked potentials (MEPs) across subjects.

<p>The pooled data for the mean areas of the MEPs in the biceps brachii muscle after separate ulnar nerve stimulation (NERVE), separate transcranial magnetic stimulation (TMS) over the contralateral primary motor cortex, and the combination (COMB) of NERVE and TMS in the control (<b>A</b>, <b>E</b>), anodal GVS (<b>B</b>, <b>F</b>), and cathodal GVS conditions (<b>C</b>, <b>G</b>). <b>D</b> and <b>H</b> show the average of the amount of spatial facilitation in the control and GVS conditions. The areas of the MEPs after the combined stimuli were normalized by the summation of the areas of the MEPs recorded after separate TMS and NERVE. <b>A</b>–<b>D</b> and <b>E</b>–<b>H</b> illustrate the data from experiments involving ulnar nerve stimulation at 1.0 and 0.75 × the motor threshold (MT) of the first dorsal interosseous muscle, respectively. The error bars represent standard errors of the mean. The asterisks indicate a statistically significant difference between conditions (*<i>p</i> < 0.05, **<i>p</i> < 0.01).</p