Thermally Averaged Magnetic Anisotropy Tensors via Machine Learning Based on Gaussian Moments.

We propose a machine learning method to model molecular tensorial quantities, namely, the magnetic anisotropy tensor, based on the Gaussian moment neural network approach. We demonstrate that the proposed methodology can achieve an accuracy of 0.3-0.

On the Accuracy of Mean-Field Spin-Orbit Operators for 3d Transition-Metal Systems.

We present an extensive study of the performance of mean-field approximations to the spin-orbit operators on realistic molecular systems, as widely used in applications like single-molecule magnets, molecular quantum bits, and molecular spintronic devices. The test systems feature a 3d transition-metal center ion (V, Cr, Mn, Fe, Co, and Ni) in various coordinations and a multitude of energetically close-lying open-shell configurations that can couple via the spin-orbit operator. We performed complete active space spin-orbit configuration interaction calculations and compared the full two-electron Breit-Pauli spin-orbit operator to different approximations: the one-center approximation, the spin-orbit mean-field approach with electron densities from different state-averaging procedures, and the atomic mean-field integral approximation.

The laryngeal twitch response - Can it avoid unnecessary two-stage thyroidectomy? - A retrospective cohort study.

Background: The objective of this study was to determine if the laryngeal twitch response, when compared to neuromonitoring, can predict postoperative vocal cord function and can thus be used in case of technical failure of the EMG-recording electrode.

Methods: A total of 640 nerves at risk were included in this study based on a prospective protocol. The laryngeal twitch response and the EMG-records were compared with the results of the postoperative laryngoscopy.

Correction: Determination of the electronic structure of a dinuclear dysprosium single molecule magnet without symmetry idealization.

[This corrects the article DOI: 10.1039/C8SC03170C.].

Determination of the electronic structure of a dinuclear dysprosium single molecule magnet without symmetry idealization.

We present the in-depth determination of the magnetic properties and electronic structure of the luminescent and volatile dysprosium-based single molecule magnet [Dy(bpm)(fod)] (Hfod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione, bpm = 2,2'-bipyrimidine). calculations were used to obtain a global picture of the electronic structure and to predict possible single molecule magnet behaviour, confirmed by experiments. The orientation of the susceptibility tensor was determined by means of cantilever torque magnetometry.

Comparing the inferior colliculus of young and old gerbils (Meriones unguiculatus) with an emphasis on GABA.

Indicators of an age-dependent down-regulation of GABA (gamma amino butyric acid) have been well-documented in the inferior colliculus (IC) of several rat strains. In the present study, we performed a quantitative light microscopic analysis of GABA-immunostained IC sections to characterize the effect of age on the cross-sectional area of the IC, the number and density of GABAergic cells and the expression of GABA in gerbils. Compared to young gerbils, a significant shrinkage of the IC but no loss of GABAergic cells was found resulting in an increased density of GABAergic cells in old gerbils.

Hebbian-type stimulation during robot-assisted training in patients with stroke.

Background: Training-related improvements in motor function are associated with changes in movement representation of the primary motor cortex (M1). In healthy individuals, transcranial magnetic stimulation (TMS) of M1 delivered in a strict temporal relationship (Hebbian-type stimulation) during execution of movements enhances these effects and is superior to random stimulation.

Objective: The authors tested whether training combined with Hebbian-type M1 stimulation enhances M1 reorganization in patients with stroke.

Functional retrograde amnesia: a multiple case study.

Functional retrograde amnesia (RA) is a rare pathology and has been rarely studied in detail across different patients. We extensively examined five functional RA patients and compared their neuropsychological profile including anterograde and retrograde memory performance, executive functions, emotional processing, and formally assessed psychiatric symptoms. Across patients, neuropsychological deficits beyond RA were most consistently seen in executive functions and attention suggesting that these dysfunctions contribute to the remote memory deficit.

Relationship between interhemispheric inhibition and motor cortex excitability in subacute stroke patients.

Background: Studies of stroke patients using functional imaging and transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) demonstrated increased recruitment and abnormally decreased short interval cortical inhibition (SICI) of the M1 contralateral to the lesioned hemisphere (contralesional M1) within the first month after infarction of the M1 or its corticospinal projections.

Objective: The authors sought to identify mechanisms underlying decreased SICI of the contralesional M1.

Methods: In patients within 6 weeks of their first ever infarction of the M1 or its corticospinal projections, SICI in the M1 of the lesioned and nonlesioned hemisphere was studied using paired-pulse TMS.

Remote changes in cortical excitability after stroke.

Changes in the cerebral metabolism and the excitability of brain areas remote from an ischaemic brain lesion have been reported in animals and humans and implicated as a mechanism relevant to functional recovery. The aim of the present study was to determine whether changes in the inhibitory and excitatory activity in motor cortex of the non-affected hemisphere are present in stroke patients, and whether these changes are related to the extent of the patients' recovery of function. Transcranial magnetic stimulation (TMS) was used to study the first dorsal interosseus muscle (FDI) of the non-affected hand in 13 patients with good recovery of hand function after stroke, and was compared with left hemispheric stimulation in 13 healthy age-matched volunteers.

[Interactive driving simulation--a new approach to diagnosis and rehabilitation of driving skills].

Until recently, major methodological problems were faced in the assessment and rehabilitation of driving ability in neurological patients, concerning practical driving lessons and driving tests as well as neuropsychological tests and therapies. The use of highly-advanced driving simulators may solve parts of this problem. However, a basic requirement for effective rehabilitation is the patients' acceptance of this method.

Reorganization of motor output in the non-affected hemisphere after stroke.

Motor evoked responses to focal transcranial magnetic stimulation were investigated over the unaffected hemisphere in 15 patients with hemiparesis after ischaemic stroke and compared with data from normal control subjects. Whereas responses to muscles ipsilateral to the stimulated hemisphere could only be elicited at maximal intensities in two out of 12 normal control subjects, such ipsilateral responses were recorded after stimulation of the unaffected hemisphere in patients with poor recovery after stroke at significantly lower thresholds, but not in patients with good recovery. These responses occurred with a somewhat longer (on average 6 ms) latency than the typical contralateral response.

Delay in simple reaction time after focal transcranial magnetic stimulation of the human brain occurs at the final motor output stage.

It is known that the execution of the motor response in a simple reaction time (RT) task can be delayed by transcranial magnetic stimulation (TMS). This paper is aimed at determining the site of action where the delay in RT occurs. A delay in RT was obtained only at those TMS sites over the motor cortex contralateral to the responding hand, which produced also a muscle twitch in the responding hand.

Hemispheric asymmetry of transcallosal inhibition in man.

The transcallosal connecting fibres linking corresponding projection areas of the same muscles of the right and left primary motor cortex may play an important role in control of unilateral movements. It appears that they have mainly inhibitory effects. This was further evaluated by transcranial magnetic stimulation using two focal coils placed on the optimal positions, i.

Contactless impedance measurement by magnetic induction--a possible method for investigation of brain impedance.

Using a primary coil that induces eddy currents in a volume conductor, and a pair of secondary coils configured to form a differential transformer, it is possible to measure the conductivity of a volume conductor by the magnetic fields of the induced eddy currents. This method is especially favourable for measuring impedance of the brain, as the low conductance of the surrounding skull interferes only very slightly with the measuring process. In a simulation experiment a life-size skull model was filled with NaCl solutions of different concentrations in each half, so as to model the impedances of a normal and an oedematous hemisphere.

Spinal and supraspinal mechanisms contribute to the silent period in the contracting soleus muscle after transcranial magnetic stimulation of human motor cortex.

In the voluntarily activated muscle, transcranial magnetic stimulation (TMS) of motor cortex produces subsequently to the motor evoked potential (MEP) a silent period (SP) in the electromyogram. We studied the time course of soleus motoneuron (MN) pool excitability after conditioning TMS by Hoffmann reflex (HR) testing, to determine whether inaccessibility of MNs after corticospinal input contributes to the SP. Coincidently with the early part of the SP, and only in the contracting soleus, MN depression was obtained that covaried with the degree of preinnervation, and with the size of the preceding MN discharge.

Intact conduction of fastest corticospinal efferents is not sufficient for normal voluntary muscle strength: transcranial motor cortex stimulation in patients with tetraplegia.

In six patients with chronic severe tetraparesis, caused by closed head injury (3 cases), basilar thrombosis (2 cases) or global hypoxia (1 case), responses of suprathreshold transcranial magnetic stimulation of motor cortex to thenar and abductor hallucis muscles on both sides were studied. Results showed in most patients normal thresholds and latencies (17 out of 24 latencies within normal +/- 2 S.D.

Transcranial stimulation of motor cortex in upper motor neurone syndrome: its relation to the motor deficit.

The purpose of this investigation was to clarify the functional significance of the fastest cortico-motoneuronal connections in chronic upper motor neurone syndromes. Using magneto-electrical stimulation of motor cortex the intactness of cortico-motoneuronal connections was assessed in 51 patients presenting with variable degrees of impairment. There was a gross correlation between clinical impairment of the patient and the degree of pathology of cortico-motoneuronal efferents.

The opiate antagonist naloxone does not arouse man from natural delta sleep.

To see if the opiate receptor/endorphin system plays a part in the regulation of natural sleep in humans the effects of the opiate antagonist naloxone on delta sleep were examined. The sleep behaviour of each of six healthy male volunteers aged 20-32 years was monitored by continuous recordings of EEG, EOG, EMG, heart rate and respiratory rate for 3 nights. The sleep stages were evaluated according to Rechtschaffen and Kales.

Cerebral potentials during skilled slow positioning movements.

Movement-related potentials recorded from the scalp of man were investigated in two skilled positioning tasks, requiring flexions at different joints of the upper extremities. The average response time was approximately 1 sec. Subjects paced their movements themselves and performed without visual control or other external cues.