Electrodeposition and Properties of Composite Ni Coatings Modified with Multilayer Graphene Oxide

Within the framework of this study, Ni-based composite electrochemical coatings (CECs) modified with multilayer graphene oxide (GO) processed using microwave radiation have been deposited. The process of these coatings' electrodeposition in the potentiodynamic mode has been studied. The structure of Ni-GO and Ni-GO (MW) CECs has been studied using X-ray phase analysis (XPA) and scanning electron microscopy (SEM).It has been shown that the addition of GO into a nickel deposit contributes to the formation of uniform fine-grained coatings. As a result, the microhardness of the Ni-GO (MW) CECs increases by 1.40 times compared to Ni without GO. The corrosion-electrochemical behavior of nickel CECs in 0.5 M H2SO4 solution was researched. It was established that the corrosion rate of the nickel-GO (MW) CEC in 3.5% NaCl decreases by about 1.70 times in contrast to unmodified nickel coatings. This effect is due to the absence of agglomeration of the graphene oxide in the volume of the nickel matrix and the impermeability of GO particles to the corrosive environment.

Light-Sensitive Open Channel Block of Ionotropic Glutamate Receptors by Quaternary Ammonium Azobenzene Derivatives

Glutamate ionotropic receptors mediate fast excitation processes in the central nervous system of vertebrates and play an important role in synaptic plasticity, learning, and memory. Here, we describe the action of two azobenene-containing compounds, AAQ (acrylamide-azobenzene-quaternary ammonium) and QAQ (quaternary ammonium-azobenzene-quaternary ammonium), which produced rapid and fully reversible light-dependent inhibition of glutamate ionotropic receptors. The compounds demonstrated voltage-dependent inhibition with only minor voltage-independent allosteric action. Calcium-impermeable AMPA receptors had weaker sensitivity compared to NMDA and calcium-permeable AMPA receptors. We further revealed that the compounds bound to NMDA and calcium-permeable AMPA receptors in different modes. They were able to enter the wide selectivity filter of AMPA receptors, and strong negative voltages caused permeation into the cytoplasm. The narrow selectivity filter of the NMDA receptors did not allow the molecules to bypass them; therefore, QAQ and AAQ bound to the shallow channel site and prevented channel closure by a foot-in-the-door mechanism. Computer simulations employing available AMPA and NMDA receptor structures readily reproduced the experimental findings, allowing for the structure-based design of more potent and selective drugs in the future. Thus, our work creates a framework for the development of light-sensitive blockers of calcium-permeable AMPA receptors, which are desirable tools for neuroscience.

Resting-state Functional Connectivity within Frontoparietal Network in Schizophrenia Patients and Healthy Individuals with Better and Worse Executive Functions

Introduction

Patients with schizophrenia spectrum disorders (SP) demonstrate heterogeneity in executive functions (EF) associated with the quality of outcome. However, neurobiological mechanisms of this heterogeneity are understudied.

Objectives

We aimed to identify features of resting-state functional connectivity (FC) within the frontoparietal network (FPN) that discriminate between SP and healthy individuals (HI) with better and worse EF.

Methods

Twenty-five SP (mean age 20.8±3.23, illness duration 1.3±2.1 years, all males) and twenty-six HI (mean age 25.17±3.46, all males) underwent EF assessment (4 verbal fluency tests and a modified Stroop task) as well as resting-state fMRI (3T).

Results

We used k-means clustering based on EF scores to divide all participants into groups with worse (15 SP, 6 HI) and better EF (10 SP, 20 HI). These groups differed in productivity of all verbal fluency tasks and performance time of the Stroop task. Differences between four subgroups (HI/SP with worse/better EF) were revealed in FC between the cingulate and lateral prefrontal cortex in the left hemisphere (ANCOVA, p-uncorrected<.005, p[FDR]<.05; Fig. 1). SP and HI within each group demonstrated a similar FC pattern. SP with poorer EF had increased FC, compared to HI with higher EF. HI with poorer EF demonstrated increased FC, compared to HI and SP with better EF.

Conclusions

FC within FPN may be one of the neurophysiological underpinnings of EF heterogeneity in SP as well as in HI. Further machine learning fMRI studies are needed to clarify whether FC within FPN is a prognostic marker in schizophrenia.

Disclosure

The study was supported by RFBR Grant 20-013-00748.

Different trajectories of the first-episode psychosis remission in young adults

Introduction

Analysis of the first-episode psychosis remission, including post-psychotic affective and primary negative symptoms as well as personality changes, is necessary to personalize therapy and rehabilitation.

Objectives

We aimed to identify different trajectories of psychosis remission in young adults.

Methods

First-episode psychosis patients (n=56, mean age 19.8±2.5 years, all males) underwent psychopathological assessment at the stage of remission.

Results

Three trajectories of remission were identified. The thymopathic trajectory (33.93%, 19 patients) was characterized by the gradual increase of subclinical affective symptoms and resulted with a high-quality remission. In 63.61% cases in this group persistent depressed mood was present after a psychotic episode. Some patients (36.84%) became prone to depressive reactions. The pathocharacterological trajectory (39.28%, 22 patients) was characterised by personality changes with increase of existing traits or the development of traits previously not present. Types with an increase of schizoid (14.29%), histrionic (19.64%), and anxiety-hypochondriacal (5.36%) traits were identified. Patients in this group had high- as well as low-quality remission. The destructive trajectory (26.79%, 15 patients) was characterised by residual positive or single negative symptoms. Patients in this subgroup had low-quality remission with poor functioning and signs of treatment resistance.

Conclusions

Analysis of trajectories of the first-episode psychosis remission allowed us to choose the most effective strategy for personalized supportive treatment.

Disclosure

No significant relationships.

Decreased Resting-state fMRI Local Coherence in Schizophrenia Patients with Poor Long-term Outcome

Introduction

Schizophrenia is heterogeneous in terms of symptoms and outcome, but neurobiology of this heterogeneity is not well-studied. Local correlation analysis of fMRI data provides a measure of local coherence, i.e., average correlation between BOLD-signal in a voxel and its neighbours. Local correlation is a promising approach, and it seems important to find links between local brain coherence and schizophrenia outcome.

Objectives

We aimed to compare brain local coherence between schizophrenia patients with varied long-term outcomes and healthy controls (HC).

Methods

Patients with chronic schizophrenia spectrum disorders (37 males, mean age 41.5±5.5) and HC (17 males, mean age 38±7.7) underwent resting-state fMRI (3T). Cluster analysis based on PANSS and PSP allowed us to allocate patients into two subgroups (N = 13/24). The second subgroup had significantly more marked negative and general psychopathology symptoms and worse functioning than the first subgroup. Local coherence in the brain was compared between clinical subgroups and HC (ANOVA, p<.001 voxelwise, p[FDR]<.05 clusterwise).

Results

Local coherence in the paracingulate gyri bilaterally ({-2; 58; 14}; 2712 mm³) differentiated the groups. Post hoc analysis revealed decreased local coherence in the subgroup with poorer outcome compared to HC, along with the absence of differences between the subgroup with better outcome and HC. There were no differences between clinical subgroups.

Conclusions

Hypoactivity of the cingulate cortex is related to negative symptoms (Bersani et al., 2014). Their severity, in turn, is strongly associated with outcome. Thus, local coherence in the cingulate cortex may be one of the factors which underlie outcome heterogeneity.

Disclosure

No significant relationships.

Dynamics of immune markers in different variants of post-psychotic depression after first-episode psychosis in young adult age

Introduction

Research in recent decades focuses on understanding the role of the immune system in First-Episode Psychosis (FEP) at a young age. Our studies indicate that different stages of schizophrenia differ in the spectrum of inflammation markers. These indicators reflect the activity of the pathological process, using them as markers of the clinical state of patients at different stages of the disease.

Objectives

To assess the relationship of immune markers with the clinical features of remission in patients after FEP.

Methods

Fifty patients aged 15-25 years with post-psychotic depression (PD) after FEP (F20, F25) and 30 healthy men were included in the study. The follow-up period was two years. PD typological variants with positive affectivity (PA) (n=30) and negative affectivity (NA) (n=20) were distinguished. Leukocyte elastase (LE), a1-proteinase inhibitor (a1-PI) activity, and S-100B autoantibodies in plasma samples were measured.

Results

The increase of LE and a1-PI activity in plasma of both types of PD patients compared to controls was detected (p<0.01). There was the highest LE activity and S-100B autoantibodies in PD with NA (p<0.05). The different dynamics of immune markers in both groups were correlated to the clinical features of remission. PD with PA was associated with a decrease in inflammatory markers (p<0.05) and a favorable prognosis. PD patients with NA had a further increase in LE activity and S-100B autoantibodies (p<0.01), and an unfavorable prognosis.

Conclusions

The results confirm using the immune indicators as markers to assess the quality of remission after FEP in young adult age and the risk of recurrent psychotic attacks.

Disclosure

No significant relationships.

Characterizing materials for superconducting radiofrequency applications-A comprehensive overview of the quadrupole resonator design and measurement capabilities

Test cavities to characterize superconductor samples are of great interest for the development of materials suitable for superconducting radio frequency (SRF) accelerator systems. They can be used to investigate fundamental SRF loss mechanisms and to study the material limitations for accelerator applications. Worldwide, this research is based on only few systems that differ in operating frequency, sample size and shape, and the accessible parameter space of frequency, temperature, and RF field strength. For useful performance predictions in future accelerators, it is important that the operating parameter range is close to that employed in accelerating systems. Since 2014, the Helmholtz-Zentrum Berlin has operated such a system built around a redesigned Quadrupole Resonator (QPR). It is based on a system originally developed at CERN. Important new design modifications were developed, along with new measurement techniques and insight into their limitations. In the meantime, an increasing number of laboratories are adopting the QPR for their measurement campaigns. This paper provides a comprehensive overview of the state-of-the-art, the wide spectrum of measurement capabilities, and a detailed analysis of measurement uncertainties, as well as the limitations one should be aware of to maximize the effectiveness of the system. In the process, we provide examples of measurements performed with Nb₃Sn and bulk niobium.

Achievement of remission after first-episode psychosis in youth

Introduction

Dynamic assessment of remission achievement after first-episode psychosis (FEP) is necessary for early detection of post-psychotic depression, negative symptoms and changes in personality traits. The latter allows to decrease suicide risk and optimize treatment and social rehabilitation.

Objectives

We aimed to analyze achievement of remission after FEP in youth and to define prognostic criteria for psychosis outcome.

Methods

Fifty-six patients (16-25 y.o., mean age 19,8 ±2,5 y.o.) after FEP have been receiving follow-up outpatient visits for 3 years. PANSS was applied to assess psychotic symptoms. Depressive symptoms were assessed with HAMD-21.

Results

Remission achievement after FEP is a three-stage process. The stage of reduction and modification of psychotic symptoms is characterized by diminishing personality deterioration and decrease of leading positive symptoms. The second stage, stabilization, is defined through the presence of depressive symptoms with positive (HAMD-21 17,49 ± 7,49) and negative affectivity (HAMD-21 23,68 ± 9,24) with preponderance of emotional, volitional, and cognitive deficits as well as high suicide risk. The third stage, reintegration, is characterized by the combination of negative symptoms with preserved personality resources. There are three reintegration trajectories, with predominant affective or negative symptoms or personality deficits. Mean decrease of PANSS scores was 54,88 ± 6,17 during the overall remission. In the majority of cases (62,5%) the stage of reintegration was finished with the achievement of high-quality remission, coinciding with international remission criteria. The study was supported by RFBR grant 18-013-01214

Conclusions

Our approach to remission assessment allowed us to decrease suicide risk and to provide optimal treatment.

Disclosure

No significant relationships.

Bromination Mechanism of closo-1,2-C2 B10 H12 and the Structure of the Resulting 9-Br-closo-1,2-C2 B10 H11 Determined by Gas Electron Diffraction

9-Br-closo-1,2-C₂ B₁₀ H₁₁ has been prepared and its gas-phase structure has been examined by means of gas electron diffraction. The structure of the carbaborane core is similar to the structure of the parent compound, which is of C_2v symmetry. A DFT-based search for the corresponding reaction pathway of the bromination of closo-1,2-C₂ B₁₀ H₁₂ revealed that the catalytic amount of aluminum reduces the barrier of the initial attack of the bromination agent toward the negatively charged part of the icosahedral carbaborane, i. e., the first transition state, from about 40 to about 27 kcalmol^-1 . The Br-Br bond is weakened by an intermediate binding to the large π-hole on the aluminum atom of AlBr₃ , which is the driving force for the AlBr₃ -catalyzed bromination.

Executive Function Assessment in Young Hospitalized Schizophrenic Patients with the “CANTAB Schizophrenia Battery” (Russian Sample)

Introduction

Impairment of executive function is the fundamental feature of the cognitive dysfunction in schizophrenia has to be measured throughout the illness regularly. Computerized technologies for assessment of cognitive dysfunction are widely used. However, their applicability in hospitalized schizophrenic patients setting should be specially examined.

Objective

Executive function in schizophrenia.

Aims

To test the applicability of “CANTAB” neurocognitive battery for measurement of executive function in young hospitalized schizophrenic patients in Russian sample.

Methods

Fifteen inpatients diagnosed with schizophrenia according to ICD-10 (F 20.хх), 13 males and 2 females, aged 23.5(SD 3.2), disease duration is 5(SD 1.6) years and 16 healthy individuals, 7 males and 9 females, aged 21.3(SD 0.7). Spatial Working Memory (SWM) (Mnemonic Executive function), Stockings of Cambridge (OTS) (Planning Executive function), Intra/Extra-Dimensional Shift (IED) (Cognitive flexibility) were administered.

Results

The majority of patients and controls easily understood the test instructions. Both groups did not have any difficulties with the touchpad. The “CANTAB” demonstrated sensitivity to the impairments of executive function. As a group, patients with schizophrenia performed significantly worse than controls on almost all tests: SWM–Between errors (P = 0.028), Total errors (P = 0.019), Strategy (P = 0.03), Mean time to last response (P = 0.001); OTS–Mean choices to correct (P = 0.044), Problems solved on first choice (P = 0.009), Probability of error given correct (P = 0.021); IED–Total errors (P = 0.015), Total trials (P = 0.002).

Conclusion

The “CANTAB” is an applicable instrument for assessment of the executive function in young hospitalized schizophrenic patients. It can be used both for experimental and clinical needs.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Effect of flumazenil on GABAA receptors in isolated rat hippocampal neurons

Using whole cell patch-clamp recordings from pyramidal cells acutely dissociated from rat hippocampal slices, Ro-15 1788 (flumazenil, FLU) was shown to enhance the GABAA-receptor mediated currents evoked by application of gamma-aminobutyric acid (GABA) and to antagonize the enhancing effect of the benzodiazepine agonist flurazepam (FZP) on the GABAA response. Both FLU and FZP increased the peak and the steady-state components of the responses and accelerated the current decay. This suggests that both agents act via a common mechanism on GABA transmission. It is concluded that FLU possesses high affinity for the binding site, but low efficacy on the GABAA-benzodiazepine receptor. This suggests that FLU acts as a partial agonist on GABAA receptors.

Solid-phase synthesis and biological evaluation of a combinatorial library of philanthotoxin analogues

The modular structure of philanthotoxins was exploited for construction of the first combinatorial library of these compounds using solid-phase parallel synthesis. (S)-Tyrosine and (S)-3-hydroxyphenylalanine were used as amino acid components, spermine, 1,12-dodecanediamine, and 4,9-dioxa-1,12-dodecanediamine as amine components, and butanoyl, phenylacetyl, and cyclohexylacetyl as N-acyl groups. Following automated preparative HPLC, the resulting 18 compounds were isolated as the S-forms in 40-70% yields. The purity of the products was determined by HPLC with evaporative light scattering detection and by (1)H and (13)C NMR. The thus obtained philanthotoxins were tested electrophysiologically for their antagonist properties on human muscle-type nicotinic acetylcholine receptors (nAChR) expressed in TE671 cells and on rat brain non-NMDA glutamate receptors (non-NMDAR) expressed in Xenopus oocytes. 4-Hydroxy analogues lacking the secondary amino groups (PhTX-12 and 4,9-dioxa-PhTX-12 and their analogues) were inactive on non-NMDAR, whereas the potency of the spermine derivatives (PhTX-343 and its analogues) increased with steric bulk of the N-acyl group. The analogue of PhTX-343 in which the N-butanoyl group was replaced by phenylacetyl group had IC(50) of 15 +/- 4 nM on non-NMDAR. Increasing the steric bulk of the N-acyl group was not advantageous for activity at nAChR, and a sharp decrease in potency with increased steric bulk was observed with the derivatives of PhTX-12. 3-Hydroxy analogues generally exhibited lower activity and different response to alterations of the N-acyl groups as compared to the 4-hydroxy analogues. Since the acyl group alterations in PhTX-343 and 4,9-dioxa-PhTX-12 have a similar effect on potency, which is distinctly different from that observed for PhTX-12, the two former compounds may bind to nAChR in a similar fashion but differently from that of PhTX-12. The combinatorial library approach described in this work represents a prototype methodology for future exploration of structure-activity relationships of philanthotoxins.