A brief journey through collision models for multipartite open quantum dynamics

The quantum collision models are a useful method to describe the dynamics of an open quantum system by means of repeated interactions between the system and some particles of the environment, which are usually termed "ancillas". In this paper, we review the main collision models for the dynamics of multipartite open quantum systems, which are composed of several subsystems. In particular, we are interested in models that are based on elementary collisions between the subsystems and the ancillas, and that simulate global and/or local Markovian master equations in the limit of infinitesimal timestep. After discussing the mathematical details of the derivation of a generic collision-based master equation, we provide the general ideas at the basis of the collision models for multipartite systems, we discuss their strengths and limitations, and we show how they may be simulated on a quantum computer. Moreover, we analyze some properties of a collision model based on entangled ancillas, derive the master equation it generates for small timesteps, and prove that the coefficients of this master equation are subject to a constraint that limits their generality. Finally, we present an example of this collision model with two bosonic ancillas entangled in a two-mode squeezed thermal state.Comment: Submitted to a special issue of Open Syst. Inf. Dyn. devoted to the memory of Prof. A. Kossakowski. Comments and suggestions are welcom

Bath-Induced Collective Phenomena on Superconducting Qubits : Synchronization, Subradiance, and Entanglement Generation

A common environment acting on a pair of qubits gives rise to a plethora of different phenomena, such as the generation of qubit-qubit entanglement, quantum synchronization, and subradiance. Here, time-independent figures of merit for entanglement generation, quantum synchronization, and subradiance are defined, and an extensive analytical and numerical study of their dependence on model parameters is performed. A recently proposed measure of the collectiveness of the dynamics driven by the bath is also addressed, and it is found that it almost perfectly witnesses the behavior of entanglement generation. The results show that synchronization and subradiance can be employed as reliable local signatures of an entangling common-bath in a general scenario. Finally, an experimental implementation of the model based on two transmon qubits capacitively coupled to a common resistor is proposed, which provides a versatile quantum simulation platform of the open system in any regime.Peer reviewe

Sudden valproate-induced hyperammonemia managed with L-carnitine in a medically healthy bipolar patient: Essential review of the literature and case report

Valproic Acid is a commonly used psychiatric drug primarily used as a mood stabilizer. Mild hyperammonemia is a Valproic Acid common adverse effect. This report presents an example of treated hyperammonemia on Valproic acid therapy managed with L-carnitine administration in BD patients characterized by sudden vulnerability

Soothing and anti-itch effect of quercetin phytosome in human subjects: A single-blind study

Background: We evaluated the ability of quercetin, a natural antioxidant formulated in a specific delivery system, to reduce skin inflammation induced by a variety of stimuli, including UV radiation, stimulation with a histamine solution, or contact with chemical irritants. In particular, we tested the soothing and anti-itch effect of Quercevita\uc2\uae, 1% cream for external use, a formulation characterized by a phospholipids-based delivery system. Patients and methods: The study was a monocentric, single blind trial that enrolled a group of 30 healthy volunteers. The back of each subject was examined to identify four quadrants with no previous skin damage or naevi that were treated in order to induce a controlled and reversible form of skin stress. The areas were treated as follows: no product; Quercevita\uc2\uae 1% cream, 2 mg/cm2; placebo; positive control (a commercially available topical formulation containing 1% dexchlorpheniramine). Results: Only quercetin phospholipids 1% and dexchlorpheniramine 1% achieved a significant reduction in erythema with comparable results: (\ue2\u80\u9310.05% [P=0.00329] for quercetin phospholipids 1% vs \ue2\u80\u9314.05% [P=0.00046] for the positive control). Moreover, quercetin phospholipids 1% and dexchlorpheniramine 1% were both associated with a significant decrease in mean wheal diameter: (\ue2\u80\u9313.25% and \ue2\u80\u9312.23% for dexchlorpheniramine 1%, respectively). Similar findings were reported for the other tested parameters. Conclusion: Quercetin has a skin protective effect against damage caused by a variety of insults, including UV radiation, histamine, or contact with toxic chemical compounds. Indeed, quercetin is able to reduce redness, itching, and inflammation of damaged skin; it may also help restore skin barrier function, increasing hydration, and reducing water loss

Depression, obesity and their comorbidity during pregnancy : effects on the offspring's mental and physical health

Depression and obesity represent two of the most common complications during pregnancy and are associated with severe health risks for both the mother and the child. Although several studies have analysed the individual effects of depression or obesity on the mothers and their children, the effects associated with the co-occurrence of both disorders have so far been poorly investigated. The relationship between depression and obesity is very complex and it is still unclear whether maternal depression leads to obesity or vice versa. It is well known that the intrauterine environment plays an important role in mediating the effects of both depression and obesity in the mother on the fetal programming, increasing the child's risk to develop negative outcomes.Peer reviewe

Local versus global master equation with common and separate baths: superiority of the global approach in partial secular approximation

Open systems of coupled qubits are ubiquitous in quantum physics. Finding a suitable master equation to describe their dynamics is therefore a crucial task that must be addressed with utmost attention. In the recent past, many efforts have been made toward the possibility of employing local master equations, which compute the interaction with the environment neglecting the direct coupling between the qubits, and for this reason may be easier to solve. Here, we provide a detailed derivation of the Markovian master equation for two coupled qubits interacting with common and separate baths, considering pure dephasing as well as dissipation. Then, we explore the differences between the local and global master equation, showing that they intrinsically depend on the way we apply the secular approximation. Our results prove that the global approach with partial secular approximation always provides the most accurate choice for the master equation when Born?Markov approximations hold, even for small inter-system coupling constants. Using different master equations we compute the stationary heat current between two separate baths, the entanglement dynamics generated by a common bath, and the emergence of spontaneous synchronization, showing the importance of the accurate choice of approach

Intranasal delivery of BDNF rescues memory deficits in AD11 mice and reduces brain microgliosis

A decrease in brain-derived neurotrophic factor (BDNF), a neurotrophin essential for synaptic function, plasticity and neuronal survival, is evident early in the progression of Alzheimer's disease (AD), being apparent in subjects with mild cognitive impairment or mild AD, and both proBDNF and mature BDNF levels are positively correlated with cognitive measures. BDNF delivery is, therefore, considered of great interest as a potentially useful therapeutic strategy to contrast AD. Invasive BDNF administration has indeed been recently used in animal models of AD with promising results in rescuing memory deficits, synaptic density and cell loss. Here, we tested whether non-invasive intranasal administration of different BDNF concentrations after the onset of cognitive and anatomical deficits (6 months of age) could rescue neuropathological and memory deficits in AD11 mice, a model of NGF deprivation-induced neurodegeneration. In addition to AD hallmarks, we investigated BDNF effects on microglia presence in the brain of AD11 mice, since alterations in microglia activation have been associated with ageing-related cognitive decline and with the progression of neurodegenerative diseases, including AD. We found that intranasal delivery of 42 pmol BDNF (1 mu M), but not PBS, was sufficient to completely rescue performance of AD11 mice both in the object recognition test and in the object context test. No further improvement was obtained with 420 pmol (10 mu M) BDNF dose. The strong improvement in memory performance in BDNF-treated mice was not accompanied by an amelioration of AD-like pathology, A beta burden, tau hyperphosphorylation and cholinergic deficit, but there was a dramatic decrease of CD11b immunoreactive brain microglia. These results reinforce the potential therapeutic uses of BDNF in AD and the non-invasive intranasal route as an effective delivery strategy of BDNF to the brain. They also strengthen the connection between neuroinflammation and neurodegenerative dementia and suggest microglia as a possible mediator of BDNF therapeutic actions in the brain

Efficiency of fungicide chemical group in the preventive and curative control of Puccinia sorghi in corn and Cercospora zeae-maydis sporulation in different culture media

The chemical control of diseases is one of the most used measures, especially for a rapid and precise control. The objectives of this work were to verify the behavior of three chemical groups of fungicides applied in a preventive and curative way aiming the control of common corn rust and the sporulation of Cercospora zeae-maydis in different culture media. Two experiments were installed, one for chemical control and the other for sporulation. For the chemical control experiment, propiconazole, azoxystrobin, ciproconazole + azoxystrobin and benzovindiflupir + azoxystrobin were the fungicides preventively and curatively applied for the control of common corn rust in a random block experimental design with three replicates. In relation to cercosporiosis sporulation experiment, five culture media were used: potato sucrose agar (PSA), V8 agar juice (V8), (LCHA), corn leaf extract (CL) and seasoned tomato extract (STE) were used. Discs with Mycelial of the fungus were placed on the media and submitted to the 12-hour light/12-hour dark continuous dark in a double factorial (culture media and light treatments) experimental design with four replicates. The fungicides azoxystrobin and ciproconazole + azoxystrobin were efficient for up to 21 days after inoculation of P. sorghi, the fungicide azoxystrobin was efficient for the curative control of P. sorghi. The greatest sporulation of the fungus was verified in the medium with seasoned tomato extract submitted to the photoperiod

AVALIAÇÃO DA QUALIDADE DE CÁPSULAS DE OMEPRAZOL PRODUZIDAS EM FARMÁCIAS MAGISTRAIS

Objetivo: Avaliar a qualidade de seis formulações de cápsulas contendo Omeprazol. Metodologia: Foram realizadas análises de peso médio, uniformidade de conteúdo, teor de princípio ativo e cinética de dissolução. As formulações A, B, C e D, corresponderam às cápsulas de farmácias magistrais, E e F corresponderam ao medicamento de referência e ao produto similar, respectivamente. Resultados: Todas as amostras foram aprovadas na análise de peso médio. As formulações C e D foram reprovadas nos ensaios de teor e uniformidade de conteúdo, a formulação F foi reprovada quanto à uniformidade de princípio ativo. Quanto à cinética de dissolução, o medicamento de referência e a formulação B condizem com as especificações. O perfil de dissolução do Peprazol®, comparado às formulações magistrais e ao similar é bastante diferenciado. Conclusões: Os resultados mostram que a maioria dos medicamentos manipulados e os produtos similares são inadequados quanto a qualidade de suas formulações. Descritores: Omeprazol; Qualidade; Farmácias