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The Ca0.6−xSr0.4HoxMnO3−δ (x = 0.05, 0.10, and 0.15) manganites with an orthorhombic crystal structure (space group Pbnm) have been produced via citrate–nitrate route in air. The electron donor holmium (Ho3+) and oxygen nonstoichiometry strongly affect the electrical conductivity (σ), Seebeck coefficient (S), thermal conductivity (κ), and thermal expansion. The increase in the absolute values of S with temperature and the decline of σ above 500 K are explained by the decrease in the concentration of Mn3+ ions due to their disproportionation into Mn2+ and Mn4+ ions. The equilibrium constant of disproportionation, the concentration and mobility of charge carriers depend on temperature and can be derived from the data for S(T) and σ(T). The formation of Mn3+ ions as a result of partial removal of oxygen from the manganites has a strong influence on their properties above 1000 K. Temperature-activated character of mobility and the values of S are consistent with the adiabatic small polaron transport mechanism in Ca0.6−xSr0.4HoxMnO3−δ. [ABSTRACT FROM AUTHOR]

Mesoscopic conductance fluctuations were discovered in a weak localization regime of a strongly disordered two-dimensional HgTe-based semimetal. These fluctuations exist in macroscopic samples with characteristic sizes of 100 μ m and exhibit anomalous dependences on the gate voltage, magnetic field, and temperature. They are absent in the regime of electron metal (at positive gate voltages) and strongly depend on the level of disorder in the system. All the experimental facts lead us to the conclusion that the origin of the fluctuations is a special collective state in which the current is conducted through the percolation network of electron resistances. We suppose that the network is formed by fluctuation potential whose amplitude is higher than the Fermi level of electrons due to their very low density. [ABSTRACT FROM AUTHOR]

Introduction: Deep brain stimulation (DBS) is an established treatment for Parkinson's disease (PD) and other movement disorders. The ventral intermediate nucleus of the thalamus is considered as the target of choice for tremor disorders, including tremor-dominant PD not suitable for DBS in the subthalamic nucleus (STN). In the last decade, several studies have shown promising results on tremor from DBS in the posterior subthalamic area (PSA), including the caudal zona incerta (cZi) located posteromedial to the STN. The aim of this study was to evaluate the long-term effect of unilateral cZi/PSA-DBS in patients with tremor-dominant PD. Methods: Thirteen patients with PD with medically refractory tremor were included. The patients were evaluated using the motor part of the Unified Parkinson Disease Rating Scale (UPDRS) off/on medication before surgery and off/on medication and stimulation 1–2 years (short-term) after surgery and at a minimum of 3 years after surgery (long-term). Results: At short-term follow-up, DBS improved contralateral tremor by 88% in the off-medication state. This improvement persisted after a mean of 62 months. Contralateral bradykinesia was improved by 40% at short-term and 20% at long-term follow-up, and the total UPDRS-III by 33% at short-term and by 22% at long-term follow-up with stimulation alone. Conclusions: Unilateral cZi/PSA-DBS seems to remain an effective treatment for patients with severe Parkinsonian tremor several years after surgery. There was also a modest improvement on bradykinesia. [ABSTRACT FROM AUTHOR]

The steel 30CrMnSiNiWMo used in the aircraft industry is studied. The temperature and time ranges of austenite transformation during continuous cooling are established using the dilatometric method. The dilatometric modeling of various modes of quenching–partitioning and austempering heat treatment is carried out. The features of transformations occurring in the studied steel at different stages of the heat treatment are revealed. The analysis of mechanical properties after austempering, quenching–partitioning and oil quenching and tempering is carried out. It is shown that the implementation of isothermal hardening does not lead to the expected increase in the level of mechanical properties of the studied steel. [ABSTRACT FROM AUTHOR]

Background/Aim: Deep brain stimulation (DBS) is an established neurosurgical treatment that can be used to alleviate symptoms in essential tremor (ET) and other movement disorders. The aim was to develop a method and software tool for the prediction of effective DBS electrode contacts based on probabilistic stimulation maps (PSMs) in patients with ET treated with caudal zona incerta (cZi) DBS. Methods: A total of 33 patients (37 leads) treated with DBS were evaluated with the Essential Tremor Rating Scale (ETRS) 12 months after surgery. In addition, hand tremor and hand function (ETRS items 5/6 and 11–14) were evaluated for every contact during stimulation with best possible outcome without inducing side effects. Prediction of effective DBS electrode contacts was carried out in a retrospective leave-one-out manner based on PSMs, simulated stimulation fields, and a scoring function. Electrode contacts were ranked according to their likelihood of being included in the clinical setting. Ranked electrode contacts were compared to actual clinical settings. Results: Predictions made by the software tool showed that electrode contacts with rank 1 matched the clinically used contacts in 60% of the cases. Contacts with a rank of 1–2 and 1–3 matched the clinical contacts in 83 and 94% of the cases, respectively. Mean improvement of hand tremor and hand function was 79 ± 21% and 77 ± 22% for the clinically used and the predicted electrode contacts, respectively. Conclusions: Effective electrode contacts can be predicted based on PSMs in patients treated with cZi DBS for ET. Predictions may in the future be used to reduce the number of clinical assessments that are carried out before a satisfying stimulation setting is defined. [ABSTRACT FROM AUTHOR]

Many current-generation biomedical implants are fabricated from the Ti-6Al-4V alloy because it has many attractive properties, such as low density and biocompatibility. However, the elastic modulus of this alloy is much larger than that of the surrounding bone, leading to bone resorption and, eventually, implant failure. In the present study, we synthesized and performed a detailed analysis of a novel low elastic modulus Ti-based alloy (Ti-28Nb-5Zr-2Ta-2Sn (TNZTS alloy)) using a variety of methods, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and tensile test. Additionally, the in vitro biocompatibility of the TNZTS alloy was evaluated using SCP-1, SaOs-2, and THP-1 cell lines and primary human osteoblasts. Compared to Ti-6Al-4V, the elastic modulus of TNZTS alloy was significantly lower, while measures of its in vitro biocompatibility are comparable. O2 plasma treatment of the surface of the alloy significantly increased its hydrophilicity and, hence, its in vitro biocompatibility. TNZTS alloy specimens did not induce the release of cytokines by macrophages, indicating that such scaffolds would not trigger inflammatory responses. The present results suggest that the TNZTS alloy may have potential as an alternative to Ti-6Al-4V. [ABSTRACT FROM AUTHOR]

Introduction: Deep Brain Stimulation (DBS) is an established neurosurgical treatment that can be used to alleviate symptoms in essential tremor (ET) and other movement disorders. Objective: To develop a method and software tool for prediction of effective DBS electrodes based on probabilistic stimulation maps in patients with ET treated by DBS. Methods: 34 patients (39 leads) treated with DBS in the caudal zona incerta were evaluated with the Essential Tremor Rating Scale (ETRS) at 12 months after surgery. In addition, hand tremor and hand function (ETRS items 5/6 & 11-14) were evaluated for every electrode contact during stimulation with best possible outcome without inducing side effects. Prediction of effective electrode contacts was carried out in a retrospective leave-one-out manner based on probabilistic stimulation maps (PSMs), simulated stimulation fields, and a scoring function. Electrode contacts were ranked according to their likelihood of being used in the clinical setting. Ranked electrodes contacts were compared to actual clinical settings. Results: Predictions made by the software tool showed that electrodes with a rank of 1 matched the clinically used electrode contacts in 62% of the cases. Electrode contacts with a rank of 1-2, and 1-3 matched the clinical electrode contacts in 79% and 97% of the cases, respectively. Improvement of hand tremor and hand function was 79% (SD 21%) and 77% (SD 22%) for the clinically used and the predicted electrode contacts, respectively. Conclusions: Effective electrode contacts can be predicted based on PSMs in patients treated with DBS for ET. Predictions may in the future be used to reduce the number of clinical assessments that are carried out before a satisfying stimulation setting is defined. [ABSTRACT FROM AUTHOR]

Objective: OCD is a sometimes debilitating psychiatric disease with a 2% lifetime prevalence. Up to 10% of patients do not respond to conservative treatment. For severe cases, DBS targeting the Nacc/ALIC is a viable option, receiving CE-mark in 2009. However, because of variable success rates and side effects, 8 different targets have been proposed for OCD in the last 18 years - the search for a hotspot continues. In this study, using a novel visualization software, we correlated lead position and resulting volume of tissue activated (VTA) with clinical outcome and side effects in order to narrow down the optimal target area. Methods: We analyzed data for 16 consecutive patients treated at our center over a period of 3 years with DBS of the Nacc/ALIC, following a routine targeting procedure. Based on improvement on the Yale-Brown obsessive compulsive scale (YBOCS) and clinical profit at 12 months follow up, four outcome groups were defined. Subgroups were also designated for unexpected side effects. Individual ROIs from all patient hemispheres were stacked to create a median intensity image, and then registered to the resulting intermediate to create a common anatomical space (Patient average MRI, PAM). Using the Suretune Expert Tuning Tool software (Medtronic), the location of the individual contacts used and the resulting VTA were aggregated into the PAM and probabilistic stimulation maps (PSM) were calculated. The adapting Yelnik-Bardinet atlas was aligned to the PAM as an anatomical reference. Results: The graphical analysis indicates anatomical localization to be correlating with both clinical outcome as well as sideeffects. PSM of non- and fair responders were revealed to be distinct from - but nearby to - the PSM of good and excellent responders. All patients reporting unwanted weight-gain had their active contacts clustered in a circumscript area, independent of their improvement in OCD. These patients are followed up with a multidisciplinary approach to further elucidate the underlying mechanism. Conclusion: While data and analysis is preliminary, this novel tool shows promise for correlation of lead location and clinical effect in the way that PSM suggest an area of best profit. The results also open the way for further research into the insufficiently understood side effect of weight gain through DBS in OCD. [ABSTRACT FROM AUTHOR]