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Copyright of Česká a Slovenská Neurologie a Neurochirurgie is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We propose a protocol for conditional suppression of losses in direct quantum state transmission over a lossy quantum channel. The method works by noiselessly attenuating the input state prior to transmission through a lossy channel followed by noiseless amplification of the output state. The procedure does not add any noise; hence, it keeps quantum coherence. We experimentally demonstrate it in the subspace spanned by vacuum and single-photon states, and consider its general applicability. [ABSTRACT FROM AUTHOR]

Localizability of entanglement in fully inseparable states is a key ingredient of assisted quantum information protocols as well as measurement-based models of quantum computing. We investigate the existence of fully inseparable states with nonlocalizable entanglement, that is, with entanglement which cannot be localized between any pair of subsystems by any measurement on the remaining part of the system. It is shown, that the nonlocalizable entanglement occurs already in suitable mixtures of a three-qubit GHZ state and white noise. Further, we generalize this set of states to a two-parametric family of fully inseparable three-qubit states with nonlocalizable entanglement. Finally, we demonstrate experimentally the existence of nonlocalizable entanglement by preparing and characterizing one state from the family using correlated single photons and linear optical circuit. [ABSTRACT FROM AUTHOR]

We propose an efficiently measurable lower bound on quantum process fidelity of N-qubit controlled-Z gates. This bound is determined by average output state fidelities for N partially conjugate product bases. A distinct advantage of our approach is that only fidelities with product states need to be measured while keeping the total number of measurements much smaller than what is necessary for full quantum process tomography. As an application, we use this method to experimentally estimate quantum process fidelity F of a three-qubit linear optical quantum Toffoli gate and we find that F⩾0.83. We also demonstrate the entangling capability of the gate by preparing Greenberger-Horne-Zeilinger-type three-qubit entangled states from input product states. [ABSTRACT FROM AUTHOR]

Background: Headache is a prevalent and disabling non-respiratory symptom of COVID-19, posing a persistent challenge in post-COVID syndrome. This study aimed to determine the prevalence, phenotypes, risk factors and biomarkers associated with COVID-related headaches. Methods: A retrospective analysis of 634 hospitalized COVID-19 patients was conducted, with 295 participants being followed up 12-15 months post-discharge via telephone call. Initial laboratory workups, including complete blood count and various biochemical parameters, were compared between headache and non-headache groups. Results: One-third of hospitalized patients experienced headaches, predominantly younger individuals ( p < 0.001) and women ( p = 0.002). Non-dominant headaches were characterized as dull (56.9%) and holocranial (26.5%), while dominant headaches were unilateral (31.3%) with photophobia (34.3%) and nausea (56.3%). Persistent headaches were unilateral (40%) and pulsating (38%) with phonophobia (74%). Decreased CD4 T cells independently predicted COVID-associated headaches, with elevated IL-6 levels noted in the dominant-headache group ( p = 0.040). Remarkably, 50% of patients reported persistent headaches 12-15 months post-infection. Dexamethasone administration significantly reduced the likelihood of long-COVID headaches (52% vs. 73%, p = 0.029). Conclusions: Headache was present in one-third of patients with heterogenous phenotypes: tension headache in the non-dominant group, and migraine in the dominant and persistent headache groups. Persistent headache remains a challenge, with dexamethasone showing potential in reducing its incidence, emphasizing the need for tailored approaches in managing long-COVID headaches.

Introduction: Bradykinesia is an essential diagnostic criterion for Parkinson's disease (PD) but is frequently observed in many non-parkinsonian movement disorders, complicating differential diagnosis, particularly in disorders featuring tremors. The presence of bradykinetic features in the subset of dystonic tremors (DT), either "pure" dystonic tremors or tremors associated with dystonia, remains currently unexplored. The aim of the current study was to evaluate upper limb bradykinesia in DT patients, comparing them with healthy controls (HC) and patients with PD by observing repetitive finger tapping (FT)., Methods: The protocol consisted of two main parts. Initially, the kinematic recording of repetitive FT was performed using optical hand tracking system (Leap Motion Controller). The values of amplitude, amplitude decrement, frequency, frequency decrement, speed, acceleration and number of halts of FT were calculated. Subsequently, three independent movement disorder specialists from different movement disorders centres, blinded to the diagnosis, rated the presence of FT bradykinesia based on video recordings., Results: Thirty-six subjects participated in the study (12 DT, 12 HC and 12 early-stage PD). Kinematic analysis revealed no significant difference in the selected parameters of FT bradykinesia between DT patients and HC. In comparisons between DT and PD patients, PD patients exhibited bigger amplitude decrement and slower FT performance. In the blinded clinical assessment, bradykinesia was rated, on average, as being present in 41.6% of DT patients, 27.7% of HC, and 91.7% of PD patients. While overall inter-rater agreement was moderate, weak agreement was noted within the DT group., Discussion: Clinical ratings indicated signs of bradykinesia in almost half of DT patients. The objective kinematic analysis confirmed comparable parameters between DT and HC individuals, with more pronounced abnormalities in PD across various kinematic parameters. Interpretation of bradykinesia signs in tremor patients with DT should be approached cautiously and objective motion analysis might complement the diagnostic process and serve as a decision support system in the choice of clinical entities., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Matejicka, Kajan, Goga, Straka, Balaz, Janovic, Minar, Valkovic, Hajduk and Kosutzka.)

Pathogenic variants in LRRK2 are one of the most common genetic risk factors for Parkinson's disease (PD). Recently, the lesser-known p.L1795F variant was proposed as a strong genetic risk factor for PD, however, further families are currently lacking in literature. A multicentre young onset and familial PD cohort (n = 220) from 9 movement disorder centres across Central Europe within the CEGEMOD consortium was screened for rare LRRK2 variants using whole exome sequencing data. We identified 4 PD cases with heterozygous p.L1795F variant. All 4 cases were characterised by akinetic-rigid PD phenotype with early onset of severe motor fluctuations, 2 receiving LCIG therapy and 2 implanted with STN DBS; all 4 cases showed unsatisfactory effect of advanced therapies on motor fluctuations. Our data also suggest that p.L1795F may represent the most common currently known pathogenic LRRK2 variant in Central Europe compared to the more studied p.G2019S, being present in 1.81% of PD cases within the Central European cohort and 3.23% of familial PD cases. Together with the ongoing clinical trials for LRRK2 inhibitors, this finding emphasises the urgent need for more ethnic diversity in PD genetic research., Competing Interests: Confiict of Interest The authors declare no confiicts of interest.

Background: The long-term sequelae of coronavirus disease 2019 (COVID-19) significantly affects quality of life (QoL) in disease survivors. Delayed development of the adaptive immune response is associated with more severe disease and a worse prognosis in COVID-19. The effects of delayed immune response on COVID-19 sequelae and QoL are unknown. Methods: We conducted a prospective study to assess the relationship between the delayed antibody response in the acute phase of infection in naïve unvaccinated patients suffering from severe or critical COVID-19 and their QoL 12 months after hospital discharge. The 12-item Short Form Survey (SF-12) questionnaire was used for assessment of QoL. The SF-12 evaluates both mental and physical components of QoL, incorporating a mental component score (MCS-12) and a physical component score (PCS-12). A delayed antibody response was defined as testing negative for anti-spike SARS-CoV-2 antibodies at the time of hospital admission. Results: The study included 274 patients (154 men and 120 women). Of the enrolled patients, 144 had a delayed immune response. These patients had a significantly lower MCS-12 ( p = 0.002), but PCS-12 ( p = 0.397) was not significantly different at the 12-month follow-up compared to patients with positive anti-spike SARS-CoV-2 antibodies. The MCS-12 at the time of follow-up was negatively associated with delayed antibody response irrespective of possible confounders ( p = 0.006; B = 3.609; ηp2 = 0.035; 95% CI = 1.069-6.150). An MSC-12 below 50 points at the time of follow-up was positively associated with delayed antibody response ( p = 0.001; B = 1.092; OR = 2.979; 95% CI = 1.554-5.711). Conclusions: This study confirmed that, in patients with severe and critical COVID-19, a negative result for anti-spike SARS-CoV-2 antibodies at the time of hospital admission is associated with a lower mental component of QoL in unvaccinated patients naïve to COVID-19 one year after hospital discharge.

Objective: Strong evidence supports the benefits of exercise for healthy ageing, including reduced risk of neurodegenerative diseases. Recent studies suggested interorgan crosstalk as a key element of systemic adaptive response, however, the role of specific molecules in mediating exercise effects on the human brain are not fully understood. In the present study, we explored the exercise-related regulation of Growth Differentiation Factor 11 (GDF11) in cerebrospinal fluid (CSF) and blood., Methods: The samples of serum, plasma and CSF were obtained before and 60min after acute exercise (90min run) from twenty healthy young individuals. Additional serum and plasma samples were collected immediately after run. GDF11 protein content (immunoblotting), body composition (bioelectrical impedance), physical fitness (VO 2 max, cycle spiroergometry) and cognitive functions (standardized computerized tests, Cogstate) were evaluated., Results: Running decreased GDF11 protein content in CSF (-20.6%. p=0.046), while GDF11 in plasma and serum were not regulated. Two GDF11-specific antibodies of different origin were used to corroborate this result. Individuals with higher physical fitness displayed greater exercise-induced decrease of GDF11 in CSF than those with lower physical fitness (p=0.025). VO 2 max correlated positively with GDF11 in serum (r=0.63, p=0.020) as well as with the exercise-induced change in GDF11 levels in CSF (r=0.59, p=0.042). Indirect measure of blood-brain barrier permeability (i.e. CSF/serum albumin ratio) tended to positively correlate with CSF/serum GDF11 ratio (p=0.060). CSF levels of GDF11 correlated positively with cognitive functions, including working memory, both before and after run (p<0.05)., Conclusion: Running-induced down-regulation of the GDF11 protein in the cerebrospinal fluid of healthy young individuals indicates the potential role of GDF11 in the exercise-induced cross-talk between periphery and the brain., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Schön, Marček Malenovská, Nemec, Alchus Laiferová, Straka, Košutzká, Matejička, Valkovič, Ukropec and Ukropcová.)

Objective: There are conflicting data regarding the relationship between Parkinson's disease (PD) and the atherosclerotic process. This study aimed to compare endothelial function in patients with PD and matched controls. In PD subjects, we searched for factors contributing to endothelial dysfunction as well. Traditional vascular risk factors, PD characteristics, and PD medication were considered., Results: We prospectively enrolled 41 patients with PD and 41 controls matched for age, sex, body mass index, and vascular risk factors. Endothelial function (EF) was assessed using peripheral arterial tonometry (EndoPAT 2000 device) and expressed as reperfusion hyperemia index (RHI). Clinical characteristics including PD medication were recorded. RHI was non-significantly lower in the PD group than in controls (1.8 ± 0.5 vs. 1.9 ± 0.5, p = 0.478). In PD patients, in linear regression analysis, smoking (beta = -0.453, p = 0.008) and use of dopamine agonists (beta = -0.365, p = 0.030) were significant contributors in a model predicting RHI. Despite non-significant differences in endothelial dysfunction between PD patients and controls, our results suggest an association between smoking, dopamine agonists, and impaired EF in PD patients. The small sample size, as well as the absence of an extended search for traditional and non-traditional vascular risk factors, are the most important factors limiting the interpretation of the current results., (© 2022. The Author(s).)

Metabolomics has emerged as a powerful new tool in precision medicine. No studies have yet been published on the metabolomic changes in cerebrospinal fluid (CSF) produced by acute endurance exercise. CSF and plasma were collected from 19 young active adults (13 males and 6 females) before and 60 min after a 90-min monitored outdoor run. The median age, BMI, and VO 2 max of subjects was 25 years (IQR 22-31), 23.2 kg/m 2 (IQR 21.7-24.5), and 47 ml/kg/min (IQR 38-51), respectively. Targeted, broad-spectrum metabolomics was performed by liquid chromatography, tandem mass spectrometry (LC-MS/MS). In the CSF, purines and pyrimidines accounted for 32% of the metabolic impact after acute endurance exercise. Branch chain amino acids, amino acid neurotransmitters, fatty acid oxidation, phospholipids, and Krebs cycle metabolites traceable to mitochondrial function accounted for another 52% of the changes. A narrow but important channel of metabolic communication was identified between the brain and body by correlation network analysis. By comparing these results to previous work in experimental animal models, we found that over 80% of the changes in the CSF correlated with a cascade of mitochondrial and metabolic changes produced by ATP signaling. ATP is released as a co-neurotransmitter and neuromodulator at every synapse studied to date. By regulating brain mitochondrial function, ATP release was identified as an early step in the kinetic cascade of layered benefits produced by endurance exercise., (© 2022 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Parkinson's disease (PD) is currently considered progressive neurodegeneration of both the central and peripheral nervous systems. Widespread neuropathological changes lead to a complex clinical presentation with typical motor (hypokinesia, tremor, and rigidity) and various nonmotor symptoms. Orthostatic hypotension is one of the most disabling nonmotor features contributing to increased morbidity and mortality and decreased quality of life (QoL). Our study aimed to disclose the effect of a continuous infusion of levodopa-carbidopa intestinal gel (LCIG) on symptoms of orthostatic hypotension. Nine patients indicated for LCIG and eight matched patients on optimized medical treatment (OMT) were examined with scales for orthostatic symptoms (SCOPA-AUT), nonmotor symptoms and motor fluctuations (MDS-UPDRS), and QoL (PDQ39) at both baseline and after six months. The scores of "light-headedness after standing" and "fainting" decreased in the LCIG group compared to the OMT group. Treatment with LCIG was associated with a significantly higher decrease in the score of "light-headedness after standing". Change in the PDQ39 correlated positively with fluctuation improvement and with change in the scores of both "light-headedness" and "fainting". LCIG treatment improved symptoms of orthostatic hypotension in patients with PD mainly by a reduction in motor complications. Decreased severity in both motor and nonmotor fluctuations was connected also with improved QoL. Continuous treatment with LCIG should be considered not only in the case of severe motor fluctuation but also in patients with nonmotor fluctuations responsive to dopaminergic treatment.

Improvement of adherence to pharmacotherapy in patients with Parkinson's disease (PD) is a challenge in routine clinical practice. Our study was aimed at the effect of pillbox organizers with alarms improving adherence to pharmacotherapy and its impact on clinical outcomes. Forty nonadherent patients with PD being treated with ≥ 3 daily doses of levodopa and/or dopamine agonists were pseudorandomized and consecutively ranked to groups A (early-start intervention) and B (delayed-start intervention). We used the following validated diagnostic instruments: MMAS-8 (adherence), PDQ-8 (quality of life, QoL), GDS (depression), NMSS (non-motor symptoms), MDS-UPDRS III (motor involvement), MDS-UPDRS IV, and WOQ-9 (motor and non-motor fluctuations and dyskinesias). We proved a significantly improved rate of adherence with the use of pillbox organizers with alarms. Moreover, after only four weeks of using the pillbox organizer, we detected an improvement in QoL scores, motor involvement, motor-, and non-motor fluctuations. Our study showed that pillbox organizers with alarms are efficient in improving adherence to pharmacotherapy in PD. It also could contribute to better motor states, less severe fluctuations, and improved QoL.

Objectives: We aimed to disclose the relationship between restless leg syndrome (RLS) and antiparkinsonian treatment, and its effect on quality of life (QoL) in patients with Parkinson's disease (PD)., Background: Previous studies documented the prevalence of RLS among patients with PD to be higher than in the general population, but conclusions regarding the aetiology and impact were contradictory., Methods: We examined 101 patients with idiopathic PD. All participants completed the five-dimension/five-level-EuroQoL questionnaire (EQ-5D-5L) and the International Restless-Legs-syndrome-study-group rating Scale (IRLS)., Results: The prevalence of RLS was 22.77 %. There were no statistically significant differences in levodopa or dopamine agonists (DA) doses between RLS-positive and negative participants. However, the use of levodopa as the last night-time medication was connected with a higher risk of RLS (OR=2.049, p=0.041). There was significantly lower prevalence of RLS in patients after surgical treatment for PD (p=0.024). Participants with RLS were at a greater risk for sleep disturbances (OR=3.866, p=0.023) and excessive daytime sleepiness (OR=7.202, p<0.001). Greater RLS symptoms were associated with worse QoL (higher IRLS score predicted higher EQ5D5L score, p=0.023)., Conclusion: RLS is prevalent among PD patients and night-time dopaminergic over-excitation with levodopa plays an important role in its pathogenesis. Since the symptoms of RLS are associated with decreased QoL, early accurate diagnosis and appropriate adjustment of dopaminergic therapy can lead to immediate relief from RLS symptoms and to QoL improvement (Tab. 4, Fig. 1, Ref. 34).

We report a measurement workflow free of systematic errors consisting of a reconfigurable photon-number-resolving detector, custom electronic circuitry, and faithful data-processing algorithm. We achieve an unprecedented accurate measurement of various photon-number distributions going beyond the number of detection channels with an average fidelity of 0.998, where the error is primarily caused by the sources themselves. Mean numbers of photons cover values up to 20 and faithful autocorrelation measurements range from g^{(2)}=6×10^{-3} to 2. We successfully detect chaotic, classical, nonclassical, non-Gaussian, and negative-Wigner-function light. Our results open new paths for optical technologies by providing full access to the photon-number information without the necessity of detector tomography.

Background: Gait disorders (GD) are frequent and disabling symptoms in patients with Parkinson's disease, mostly because they significantly limit mobility and often lead to fear of falls or actual falls. Nowadays, rehabilitation is considered to be the most effective nonpharmacological approach to reduce risk of falls. Using paradigms in virtual reality (VR) is a promising tool in neurorehabilitation because of the potential improvement in motor learning and improvement in daily functioning by replicating everyday real-life scenarios. Objective: To identify the most prevalent everyday situations which impair gait in PD that could be simulated in virtual reality (VR) environment. Methods: A newly developed self-report questionnaire consisting of 15 binary response items (YES/NO) encompassing everyday walking situations was administered to 62 patients diagnosed with idiopathic PD according to MDS Clinical Diagnostic Criteria. We included patients able to walk unassisted for at least 10 min and without significant cognitive impairment. Mokken Scale Analysis was used to evaluate psychometric properties of the scale. Results: Questionnaires from 58 patients were analyzed (31 men, age = 63 ± 9.9 y, disease duration = 7.02 ± 4.03 y, LEDD = 1115 ± 549.4 mg, H&Y = 2.4 ± 0.6). Only 10 items (out of 15) were identified as scalable and these were included in Gait Disorders Questionnaire (GDQ). The most prevalent trigger of gait disorders was walking under time pressure, followed by gait in crowded places and walking while dual-tasking. The total score of GDQ significantly correlated with the disease duration ( r s = 0.347, p = 0.008) and modified H&Y staging ( r s = 0.288, p = 0.028). Conclusion: With the use of GDQ we identified the most prevalent everyday transition activities that provoke gait disorders in patients with PD. The results may be useful for further development and systematic application of VR paradigms for physiotherapy of PD patients., (Copyright © 2019 Kosutzka, Kusnirova, Hajduk, Straka, Minar and Valkovic.)

Background: Once-daily treatment formulation is associated with better adherence in comparison to more complex medication regimens. The study aimed to detect the extent of adherence to pharmacotherapy in Parkinson disease (PD) patients who take a minimum of three daily doses of drugs, and to identify factors associated with lower levels of adherence. Methods: The cohort was selected from non-demented PD patients. The 8-Item Morisky Medication Adherence Scale (MMAS-8), 8-Item Parkinson's Disease Questionnaire (PDQ-8), Geriatric Depression Scale (GDS), Non-Motor Symptom Assessment Scale (NMSS), 9-Item Wearing-off Questionnaire (WOQ-9), MDS-UPDRS III (motor examination), and IV (motor complications) scales were used in this study. Results: From a total of 124 subjects, 33.9% reported a high level of adherence, 29.8% reported a medium level of adherence, and 36.3% reported a low level of adherence to their pharmacotherapy. The level of non-adherence correlated with gender, longer disease duration, higher scores of PDQ-8, NMSS, WOQ-9, and MDS-UPDRS IV. Detailed analysis of NMSS demonstrated a correlation between the level of adherence and domains sleep/fatigue, mood/cognition, perceptual problems/hallucinations, attention/memory, and urinary symptoms. Independent risk factors for non-adherence were excessive daytime sleepiness, anhedonia, and forgetfulness. Conclusion: Non-adherence to more complicated medication regimens is frequent in PD patients and is associated with gender, longer PD duration, poorer quality of life, frequency and severity of non-motor symptoms, and more severe motor and non-motor fluctuations. Non-adherence was predicted by non-motor symptoms including fatigue, mood disturbances, and subjective cognitive complaints.

Light is an essential tool for connections between quantum devices and for diagnostic processes in quantum technology. Both applications deal with advanced nonclassical states beyond Gaussian coherent and squeezed states. Current development requires a loss-tolerant diagnostic of such nonclassical aspects. We propose and experimentally verify a faithful hierarchy of genuine n-photon quantum non-Gaussian light. We conclusively witnessed three-photon quantum non-Gaussian light in the experiment. Measured data demonstrate a direct applicability of the hierarchy for a large class of real states.

Background: Parkinson disease (PD) is the second most common neurodegenerative disease with various motor and nonmotor symptoms. Progressive course of PD requires frequent medication adjustments. Various combinations of drugs and dose regimens could be used to control symptoms. Thus, not surprisingly, adherence to pharmacotherapy is frequently suboptimal in these patients having negative effect on motor control and patient's quality of life., Methods: In this article, we offer up-to-date review of adherence in PD compared with other chronic conditions. In addition, we summarize factors influencing level of adherence, ways of measuring, and methods of adherence optimization. For the review of adherence in PD, a literature search was undertaken using PubMed database and relevant search terms. Articles were screened for suitability and data relevance., Results: PubMed and Scopus databases were systematically searched in 2016 and data extraction was a multistep process based on the PRISMA Guidelines., Conclusion: According to the recent data, sufficient control of motor symptoms and adequate quality of life are primary goals in the treatment of PD. Adherence to pharmacotherapy play a key role in this process, thus the medication should be tailored for each patient. In order to improve level of suboptimal adherence, these patients should have got recommended various dosing devices or alarms. Good communication with the patients and their relatives or caregivers is also essential.

Hyper-encoding enables storing several qubits in a single photon using its different degrees of freedom like polarization and spatial ones. This approach enables feasible implementation of multi-qubit operations. One of the basic manipulations of two or more qubits is to swap their quantum state. Here we report on feasible and stable experimental implementation of a deterministic single photon two-qubit SWAP gate that interchanges path and polarization qubits. We discuss the principle of its operation and give detailed information about experimental demonstration employing two Mach-Zehnder interferometers with one common arm. The gate characterization is done by full quantum process tomography using photons produced by heralded single-photon source. The achieved quantum process fidelity reached more than 0.94 with an effective phase uncertainty of the whole setup, evaluated by means of Allan deviation, below 2.5 deg for 2.5 h without any active stabilization. Our design provides a contribution to the hyper-encoded linear quantum optics toolbox.

We propose and experimentally demonstrate a device for generating light with arbitrary classical photon-number distribution. We use programmable acousto-optical modulation to control the intensity of light within the dynamic range of more than 30 dB and inter-level transitions faster than 500 ns. We propose a universal method that allows the high-fidelity generation of user-defined photon statistics. Extremely high precision <0.001 can be reached for lower photon numbers, and faithful tail behavior can be reached for very high photon numbers. We demonstrate arbitrary statistics generation for up to 500 photons. The proposed device can produce any classical light statistics with given parameters including Poissonian, super-Poissonian, thermal, and heavy-tailed distributions like log-normal. The presented method can be used to simulate communication channels, calibrate the response of photon-number-resolving detectors, or probe physical phenomena sensitive to photon statistics.

Regular exercise ameliorates motor symptoms in Parkinson's disease (PD). Here, we aimed to provide evidence that exercise brings additional benefits to the whole-body metabolism and skeletal muscle molecular and functional characteristics, which might help to explain exercise-induced improvements in the clinical state. 3-months supervised endurance/strength training was performed in early/mid-stage PD patients and age/gender-matched individuals ( n  = 11/11). The effects of exercise on resting energy expenditure (REE), glucose metabolism, adiposity, and muscle energy metabolism ( 31 P-MRS) were evaluated and compared to non-exercising PD patients. Two muscle biopsies were taken to determine intervention-induced changes in fiber type, mitochondrial content, and expression of genes related to muscle energy metabolism, as well as proliferative and regenerative capacity. Exercise improved the clinical disability score (MDS-UPDRS), bradykinesia, balance, walking speed, REE, and glucose metabolism and increased muscle expression of energy sensors (AMPK). However, the exercise-induced increase in muscle mass/strength, mitochondrial content, type II fiber size, and postexercise phosphocreatine (PCr) recovery ( 31 P-MRS) were found only in controls. Nevertheless, MDS-UPDRS was associated with muscle AMPK and mechano-growth factor (MGF) expression. Improvements in fasting glycemia were positively associated with muscle function and the expression of Sirt1 and Cox7a1 , and the parameters of fitness/strength were positively associated with the expression of MyHC2, MyHC7 , and MGF . Moreover, reduced bradykinesia was associated with better muscle metabolism (maximal oxidative capacity and postexercise PCr recovery; 31 P-MRS). Exercise training improved the clinical state in early/mid-stage Parkinson's disease patients, including motor functions and whole-body metabolism. Although the adaptive response to exercise in PD was different from that of controls, exercise-induced improvements in the PD clinical state were associated with specific adaptive changes in muscle functional, metabolic, and molecular characteristics., Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02253732.

Generation of nonclassical light is an essential tool for quantum optics research and applications in quantum information technology. We present realization of the source of nonclassically correlated photon pairs based on the process of spontaneous four-wave-mixing in warm atomic vapor. Atoms are excited only by a single laser beam in retro-reflected configuration and narrowband frequency filtering is employed for selection of correlated photon pairs. Nonclassicality of generated light fields is proved by analysis of their statistical properties. Measured parameters of the presented source promise further applicability for efficient interaction with atomic ensembles.

We experimentally characterize a quantum photonic gate that is capable of converting multiqubit entangled states while acting only on two qubits. It is an important tool in large quantum networks, where it can be used for re-wiring of multipartite entangled states or for generating various entangled states required for specific tasks. The gate can be also used to generate quantum information processing resources, such as entanglement and discord. In our experimental demonstration, we characterized the conversion of a linear four-qubit cluster state into different entangled states, including GHZ and Dicke states. The high quality of the experimental results show that the gate has the potential of being a flexible component in distributed quantum photonic networks.

We propose and experimentally verify a cooling limit for a quantum channel going through an incoherent environment. The environment consists of a large number of independent non-interacting and non-interfering elementary quantum systems--qubits. The qubits travelling through the channel can only be randomly replaced by environmental qubits. We investigate a conditional cooling limit that exploits an additional probing output. The limit specifies when the single-qubit channel is quantum, i.e. it preserves entanglement. It is a fundamental condition for entanglement-based quantum technology.

We introduce and experimentally explore the concept of the non-Gaussian depth of single-photon states with a positive Wigner function. The depth measures the robustness of a single-photon state against optical losses. The directly witnessed quantum non-Gaussianity withstands significant attenuation, exhibiting a depth of 18 dB, while the nonclassicality remains unchanged. Quantum non-Gaussian depth is an experimentally approachable quantity that is much more robust than the negativity of the Wigner function. Furthermore, we use it to reveal significant differences between otherwise strongly nonclassical single-photon sources.

We experimentally demonstrate optical Mach-Zehnder interferometer utilizing displaced Sagnac configuration to enhance its phase stability. The interferometer with footprint of 27×40 cm offers individually accessible paths and shows phase deviation less than 0.4° during a 250 s long measurement. The phase drift, evaluated by means of Allan deviation, stays below 3° or 7 nm for 1.5 h without any active stabilization. The polarization insensitive design is verified by measuring interference visibility as a function of input polarization. For both interferometer's output ports and all tested polarization states the visibility stays above 93%. The discrepancy in visibility for horizontal and vertical polarization about 3.5% is caused mainly by undesired polarization dependence of splitting ratio of the beam splitter used. The presented interferometer device is suitable for quantum-information and other sensitive applications where active stabilization is complicated and common-mode interferometer is not an option as both the interferometer arms have to be accessible individually.

We report on the experimental verification of quantum non-Gaussian character of a heralded single-photon state with a positive Wigner function. We unambiguously demonstrate that the generated state cannot be expressed as a mixture of Gaussian states. Sufficient information to witness the quantum non-Gaussian character is obtained from a standard photon anticorrelation measurement.