34 resultados para 5-DOF haptic interaction
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
A new haptic interface device is suggested, which can be used for functional magnetic resonance imaging (fMRI) studies. The basic component of this 1 DOF haptic device are two coils that produce a Lorentz force induced by the large static magnetic field of the MR scanner. A MR-compatible optical angular encoder and a optical force sensor enable the implementation of different control architectures for haptic interactions. The challenge was to provide a large torque, and not to affect image quality by the currents applied in the device. The haptic device was tested in a 3T MR scanner. With a current of up to 1A and a distance of 1m to the focal point of the MR-scanner it was possible to generate torques of up to 4 Nm. Within these boundaries image quality was not affected.
Resumo:
We examined 89 normal volunteers using Cloninger's Temperament and Character Inventory (TCI). Genotyping the 102T/C polymorphism of the serotonin 5HT2A receptor gene and the ser9gly polymorphism in exon 1 of the dopamine D3 receptor (DRD3) gene was performed using PCR-RFLP, whereas the dopamine transporter (DAT1) gene variable number of tandem repeats (VNTR) polymorphism was investigated using PCR amplification followed by electrophoresis in an 8% acrylamide gel with a set of size markers. We found a nominally significant association between gender and harm avoidance (P=0.017; women showing higher scores). There was no association of either DAT1, DRD3 or 5HT2A alleles or genotypes with any dimension of the TCI applying Kruskal-Wallis rank-sum tests. Comparing homozygote and heterozygote DAT1 genotypes, we found higher novelty seeking scores in homozygotes (P=0.054). We further found a nominally significant interaction between DAT1 and 5HT2A homo-/heterozygous gene variants (P=0.0071; DAT1 and 5HT2A genotypes P value of 0.05), performing multivariate analysis of variance (MANOVA). Examining the temperamental TCI subscales, this interaction was associated with persistence (genotypes: P=0.004; homo-/heterozygous gene variants: P=0.0004). We conclude that an interaction between DAT1 and 5HT2A genes might influence the temperamental personality trait persistence.
Resumo:
Numerical simulations based on plans for a deep geothermal system in Basel, Switzerland are used here to understand chemical processes that occur in an initially dry granitoid reservoir during hydraulic stimulation and long-term water circulation to extract heat. An important question regarding the sustainability of such enhanced geothermal systems (EGS), is whether water–rock reactions will eventually lead to clogging of flow paths in the reservoir and thereby reduce or even completely block fluid throughput. A reactive transport model allows the main chemical reactions to be predicted and the resulting evolution of porosity to be tracked over the expected 30-year operational lifetime of the system. The simulations show that injection of surface water to stimulate fracture permeability in the monzogranite reservoir at 190 °C and 5000 m depth induces redox reactions between the oxidised surface water and the reduced wall rock. Although new calcite, chlorite, hematite and other minerals precipitate near the injection well, their volumes are low and more than compensated by those of the dissolving wall-rock minerals. Thus, during stimulation, reduction of injectivity by mineral precipitation is unlikely. During the simulated long-term operation of the system, the main mineral reactions are the hydration and albitization of plagioclase, the alteration of hornblende to an assemblage of smectites and chlorites and of primary K-feldspar to muscovite and microcline. Within a closed-system doublet, the composition of the circulated fluid changes only slightly during its repeated passage through the reservoir, as the wall rock essentially undergoes isochemical recrystallization. Even after 30 years of circulation, the calculations show that porosity is reduced by only ∼0.2%, well below the expected fracture porosity induced by stimulation. This result suggests that permeability reduction owing to water–rock interaction is unlikely to jeopardize the long-term operation of deep, granitoid-hosted EGS systems. A peculiarity at Basel is the presence of anhydrite as fracture coatings at ∼5000 m depth. Simulated exposure of the circulating fluid to anhydrite induces a stronger redox disequilibrium in the reservoir, driving dissolution of ferrous minerals and precipitation of ferric smectites, hematite and pyrite. However, even in this scenario the porosity reduction is at most 0.5%, a value which is unproblematic for sustainable fluid circulation through the reservoir.
Resumo:
Plectin, a cytolinker of the plakin family, anchors the intermediate filament (IF) network formed by keratins 5 and 14 (K5/K14) to hemidesmosomes, junctional adhesion complexes in basal keratinocytes. Genetic alterations of these proteins cause epidermolysis bullosa simplex (EBS) characterized by disturbed cytoarchitecture and cell fragility. The mechanisms through which mutations located after the documented plectin IF-binding site, composed of the plakin-repeat domain (PRD) B5 and the linker, as well as mutations in K5 or K14, lead to EBS remain unclear. We investigated the interaction of plectin C terminus, encompassing four domains, the PRD B5, the linker, the PRD C, and the C extremity, with K5/K14 using different approaches, including a rapid and sensitive fluorescent protein-binding assay, based on enhanced green fluorescent protein-tagged proteins (FluoBACE). Our results demonstrate that all four plectin C-terminal domains contribute to its association with K5/K14 and act synergistically to ensure efficient IF binding. The plectin C terminus predominantly interacted with the K5/K14 coil 1 domain and bound more extensively to K5/K14 filaments compared with monomeric keratins or IF assembly intermediates. These findings indicate a multimodular association of plectin with K5/K14 filaments and give insights into the molecular basis of EBS associated with pathogenic mutations in plectin, K5, or K14 genes.Journal of Investigative Dermatology advance online publication, 10 July 2014; doi:10.1038/jid.2014.255.
Resumo:
It is now generally accepted that complex mental disorders are the results of interplay between genetic and environmental factors. This holds out the prospect that by studying G x E interplay we can explain individual variation in vulnerability and resilience to environmental hazards in the development of mental disorders. Furthermore studying G x E findings may give insights in neurobiological mechanisms of psychiatric disorder and so improve individualized treatment and potentially prevention. In this paper, we provide an overview of the state of field with regard to G x E in mental disorders. Strategies for G x E research are introduced. G x E findings from selected mental disorders with onset in childhood or adolescence are reviewed [such as depressive disorders, attention-deficit/hyperactivity disorder (ADHD), obesity, schizophrenia and substance use disorders]. Early seminal studies provided evidence for G x E in the pathogenesis of depression implicating 5-HTTLPR, and conduct problems implicating MAOA. Since then G x E effects have been seen across a wide range of mental disorders (e.g., ADHD, anxiety, schizophrenia, substance abuse disorder) implicating a wide range of measured genes and measured environments (e.g., pre-, peri- and postnatal influences of both a physical and a social nature). To date few of these G x E effects have been sufficiently replicated. Indeed meta-analyses have raised doubts about the robustness of even the most well studied findings. In future we need larger, sufficiently powered studies that include a detailed and sophisticated characterization of both phenotype and the environmental risk.
Resumo:
29I is one of the major dose-determining nuclides in the safety analysis of deep storage of radioactive waste. Iodine forms anionic species that hardly sorb on the surfaces of common host-rock minerals. Recently, interest has arisen on the role of pyrite, an accessory mineral capable of binding anionic selenium. Whereas the interaction of selenium with pyrite is well documented, corresponding results on iodine sorption are still scarce and controversial. Pyrite is present in argicilleous rocks which are being considered in many countries as potential host rocks for a radioactive waste repository. The uptake of iodide (I−) on natural pyrite was investigated under nearly anoxic conditions (O2 < 5 ppm) over a wide concentration range (10−11–10−3 M total I−) using 125I as the radioactive tracer. Weak but measurable sorption was observed; distribution coefficients (R d) were less than 0.002 m3 kg−1 and decreased with increasing total iodide concentration. Iodide sorption was connected to the presence of oxidized clusters on the pyrite surface, which were presumably formed by reaction with limited amounts of dissolved oxygen. The results obtained indicated that pyrite cannot be considered as an effective scavenger of 129I under the geochemical conditions prevailing in underground radioactive waste geologic storage.
Resumo:
The cardiac sodium current (INa) is responsible for the rapid depolarization of cardiac cells, thus allowing for their contraction. It is also involved in regulating the duration of the cardiac action potential (AP) and propagation of the impulse throughout the myocardium. Cardiac INa is generated by the voltage-gated Na(+) channel, NaV1.5, a 2016-residue protein which forms the pore of the channel. Over the past years, hundreds of mutations in SCN5A, the human gene coding for NaV1.5, have been linked to many cardiac electrical disorders, including the congenital and acquired long QT syndrome, Brugada syndrome, conduction slowing, sick sinus syndrome, atrial fibrillation, and dilated cardiomyopathy. Similar to many membrane proteins, NaV1.5 has been found to be regulated by several interacting proteins. In some cases, these different proteins, which reside in distinct membrane compartments (i.e. lateral membrane vs. intercalated disks), have been shown to interact with the same regulatory domain of NaV1.5, thus suggesting that several pools of NaV1.5 channels may co-exist in cardiac cells. The aim of this review article is to summarize the recent works that demonstrate its interaction with regulatory proteins and illustrate the model that the sodium channel NaV1.5 resides in distinct and different pools in cardiac cells. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Cardiac Pathways of Differentiation, Metabolism and Contraction.
Resumo:
Anti-sperm antibodies (ASA) have been described to be involved in immunological infertility. A possible antigen for ASA is the human cysteine-rich secretory protein 2 (CRISP-2), a sperm surface protein important in sperm-oocyte interaction. Furthermore, anti-CRISP-2 antibodies were shown to decrease fertility rates in vitro. Recently, we have reported cross-reacting antibodies recognizing CRISP-2 and antigen 5 from yellow jacket venom (Ves v 5) in human serum.
Resumo:
The results from the Sub-keV Atom Reflecting Analyzer (SARA) experiment onboard Chandrayaan-1 have revealed several hitherto unknown and interesting aspects about the interaction of solar wind with the Moon. The SARA experiment had two sensors — CENA and SWIM. The Chandrayaan-1 energetic neutrals analyzer (CENA), detected energetic neutral atoms (ENAs), and the Solar Wind Monitor (SWIM) measured ions of solar wind origin. In this review, we summarize the observations made by the SARA experiment, which are: (1) substantial (~20%) and sustained backscattering of solar wind protons from lunar surface as energetic neutral hydrogen,1 (2) minimagnetosphere around magnetic anomalies on Moon using the backscattered ENAs,2 (3) reflection of solar wind protons from the Moon surface,3 (4) huge (~50%) deflection of solar wind protons over strong magnetic anomalies,4 and (5) presence of protons in the near-lunar plasma wake.5 These results have implications on the lunar plasma environment, implantation of solar wind hydrogen on lunar surface, and behavior of small scale magnetic anomalies on planetary bodies. The SARA observations suggest that similar processes may happen on other airless bodies covered with regolith in the solar system as well as in extra-solar system. This paper presents a review of the results obtained from the SARA observation.
Resumo:
Context: In the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly - Pivotal Fracture Trial (HORIZON-PFT), zoledronic acid (ZOL) 5 mg significantly reduced fracture risk. Objective: To identify factors associated with greater efficacy during ZOL 5 mg treatment. Design, Setting and Patients: Subgroup analysis (preplanned and post hoc) of a multicenter, double-blind, placebo-controlled, 36-month trial in 7765 women with postmenopausal osteoporosis. Intervention: Single infusion of ZOL 5 mg or placebo at baseline, 12 and 24 months. Main Outcome Measures: Primary endpoints: new vertebral fracture and hip fracture. Secondary endpoints: non-vertebral fracture, change in femoral neck bone mineral density (BMD). Baseline risk factor subgroups: age, BMD T-score and vertebral fracture status, total hip BMD, race, weight, geographical region, smoking, height loss, history of falls, physical activity, prior bisphosphonates, creatinine clearance, body mass index (BMI), concomitant osteoporosis medications. Results: Greater ZOL induced effects on vertebral fracture risk with younger age (treatment-by-subgroup interaction P=0.05), normal creatinine clearance (P=0.04), and BMI >/=25 kg/m(2) (P=0.02). There were no significant treatment-factor interactions for hip or non-vertebral fracture or for change in BMD. Conclusions: ZOL appeared more effective in preventing vertebral fracture in younger women, overweight/obese women and women with normal renal function. ZOL had similar effects irrespective of fracture risk factors or femoral neck BMD.
Resumo:
BACKGROUND: Propofol and sevoflurane display additivity for gamma-aminobutyric acid receptor activation, loss of consciousness, and tolerance of skin incision. Information about their interaction regarding electroencephalographic suppression is unavailable. This study examined this interaction as well as the interaction on the probability of tolerance of shake and shout and three noxious stimulations by using a response surface methodology. METHODS: Sixty patients preoperatively received different combined concentrations of propofol (0-12 microg/ml) and sevoflurane (0-3.5 vol.%) according to a crisscross design (274 concentration pairs, 3 to 6 per patient). After having reached pseudo-steady state, the authors recorded bispectral index, state and response entropy and the response to shake and shout, tetanic stimulation, laryngeal mask airway insertion, and laryngoscopy. For the analysis of the probability of tolerance by logistic regression, a Greco interaction model was used. For the separate analysis of bispectral index, state and response entropy suppression, a fractional Emax Greco model was used. All calculations were performed with NONMEM V (GloboMax LLC, Hanover, MD). RESULTS: Additivity was found for all endpoints, the Ce(50, PROP)/Ce(50, SEVO) for bispectral index suppression was 3.68 microg. ml(-1)/ 1.53 vol.%, for tolerance of shake and shout 2.34 microg . ml(-1)/ 1.03 vol.%, tetanic stimulation 5.34 microg . ml(-1)/ 2.11 vol.%, laryngeal mask airway insertion 5.92 microg. ml(-1) / 2.55 vol.%, and laryngoscopy 6.55 microg. ml(-1)/2.83 vol.%. CONCLUSION: For both electroencephalographic suppression and tolerance to stimulation, the interaction of propofol and sevoflurane was identified as additive. The response surface data can be used for more rational dose finding in case of sequential and coadministration of propofol and sevoflurane.