Work Extraction from Unknown Quantum Sources.

Energy extraction is a central task in thermodynamics. In quantum physics, ergotropy measures the amount of work extractable under cyclic Hamiltonian control. As its full extraction requires perfect knowledge of the initial state, however, it does not characterize the work value of unknown or untrusted quantum sources. Fully characterizing such sources would require quantum tomography, which is prohibitively costly in experiments due to the exponential growth of required measurements and operational limitations. Here, we therefore derive a new notion of ergotropy applicable when nothing is known about the quantum states produced by the source, apart from what can be learned by performing only a single type of coarse-grained measurement. We find that in this case the extracted work is defined by the Boltzmann and observational entropy in cases where the measurement outcomes are, or are not, used in the work extraction, respectively. This notion of ergotropy represents a realistic measure of extractable work, which can be used as the relevant figure of merit to characterize a quantum battery.

Generation of Pseudo-Random Quantum States on Actual Quantum Processors.

The generation of a large amount of entanglement is a necessary condition for a quantum computer to achieve quantum advantage. In this paper, we propose a method to efficiently generate pseudo-random quantum states, for which the degree of multipartite entanglement is nearly maximal. We argue that the method is optimal, and use it to benchmark actual superconducting (IBM's ibm_lagos) and ion trap (IonQ's Harmony) quantum processors. Despite the fact that ibm_lagos has lower single-qubit and two-qubit error rates, the overall performance of Harmony is better thanks to its low error rate in state preparation and measurement and to the all-to-all connectivity of qubits. Our result highlights the relevance of the qubits network architecture to generate highly entangled states.

Lossy Micromaser Battery: Almost Pure States in the Jaynes-Cummings Regime.

We consider a micromaser model of a quantum battery, where the battery is a single mode of the electromagnetic field in a cavity, charged via repeated interactions with a stream of qubits, all prepared in the same non-equilibrium state, either incoherent or coherent, with the matter-field interaction modeled by the Jaynes-Cummings model. We show that the coherent protocol is superior to the incoherent one, in that an effective pure steady state is achieved for generic values of the model parameters. Finally, we supplement the above collision model with cavity losses, described by a Lindblad master equation. We show that battery performances, in terms of stored energy, charging power, and steady-state purity, are slightly degraded up to moderated dissipation rate. Our results show that micromasers are robust and reliable quantum batteries, thus making them a promising model for experimental implementations.

Entanglement Dynamics and Classical Complexity.

We study the dynamical generation of entanglement for a two-body interacting system, starting from a separable coherent state. We show analytically that in the quasiclassical regime the entanglement growth rate can be simply computed by means of the underlying classical dynamics. Furthermore, this rate is given by the Kolmogorov-Sinai entropy, which characterizes the dynamical complexity of classical motion. Our results, illustrated by numerical simulations on a model of coupled rotators, establish in the quasiclassical regime a link between the generation of entanglement, a purely quantum phenomenon, and classical complexity.

Quantum Charging Advantage Cannot Be Extensive without Global Operations.

Quantum batteries are devices made from quantum states, which store and release energy in a fast and efficient manner, thus offering numerous possibilities in future technological applications. They offer a significant charging speedup when compared to classical batteries, due to the possibility of using entangling charging operations. We show that the maximal speedup that can be achieved is extensive in the number of cells, thus offering at most quadratic scaling in the charging power over the classically achievable linear scaling. To reach such a scaling, a global charging protocol, charging all the cells collectively, needs to be employed. This concludes the quest on the limits of charging power of quantum batteries and adds to other results in which quantum methods are known to provide at most quadratic scaling over their classical counterparts.

Dominance of Replica Off-Diagonal Configurations and Phase Transitions in a PT Symmetric Sachdev-Ye-Kitaev Model.

We show that, after ensemble averaging, the low temperature phase of a conjugate pair of uncoupled, quantum chaotic, non-Hermitian systems such as the Sachdev-Ye-Kitaev (SYK) model or the Ginibre ensemble of random matrices is dominated by saddle points that couple replicas and conjugate replicas. This results in a nearly flat free energy that terminates in a first-order phase transition. In the case of the SYK model, we show explicitly that the spectrum of the effective replica theory has a gap. These features are strikingly similar to those induced by wormholes in the gravity path integral which suggests a close relation between both configurations. For a nonchaotic SYK, the results are qualitatively different: the spectrum is gapless in the low temperature phase and there is an infinite number of second order phase transitions unrelated to the restoration of replica symmetry.

Semmes-Weinstein monofilament: A tool to quantify skin sensation in macular lesions for leprosy diagnosis.

INTRODUCTION: Hypochromatic macules with altered sensitivity are the first manifestations of skin leprosy. Validation of this sensory loss assists in the confirmation of the clinical diagnosis. AIMS: The aim of the study was to quantify the loss of sensation in leprosy lesions using the Semmes-Weinstein monofilament to strengthen the clinical diagnosis mainly of macular forms. METHODS: Seventy-four hypochromatic macules in the macular leprosy subgroup, 27 typical borderline leprosy subgroup lesions and 49 macules of other macular dermatoses (non-leprosy group) were evaluated using the 0.05 g force Semmes-Weinstein monofilament to quantify the alteration of sensitivity within and outside of the lesions. The esthesiometric change index was established as the total number of points with altered sensation divided by the total number of tested points within the lesions to calculate the internal esthesiometric change index and outside the lesions to calculate the peripheral esthesiometric change index; these indexes were calculated for all groups. The difference (Δ) between the esthesiometric change indices of the lesional area and the adjacent skin was calculated for the leprosy and nonleprosy groups. RESULTS: The percentage of points with touch sensitivity alterations within the macular and typical borderline leprosy lesions was higher in leprosy than in the non-leprosy group. The borderline and macular leprosy presented higher esthesiometric change index within injured areas than outside injured areas or in the nonleprosy group (P < 0.005). When internal esthesiometric change index values in the macular and borderline leprosy groups were higher than 0.53 and 0.5, respectively, the receiver operating characteristic curve showed 98% sensitivity and approximately 99% specificity for both groups (P < 0.0001). Regarding the difference between indices, borderline and macular leprosy had values that were higher and closer to one than in the nonleprosy group (P < 0.0001), with 100% sensitivity and 96.5% specificity for leprosy diagnosis when ΔLG was higher than 0.34. A limitation was the inability to perform a double-blind study. CONCLUSION: Semmes-Weinstein esthesiometry is a simple, useful and low-cost tool to quantify the focal alteration of cutaneous sensitivity to improve clinical leprosy diagnosis, especially for macular lesions.

Unveiling Operator Growth Using Spin Correlation Functions.

In this paper, we study non-equilibrium dynamics induced by a sudden quench of strongly correlated Hamiltonians with all-to-all interactions. By relying on a Sachdev-Ye-Kitaev (SYK)-based quench protocol, we show that the time evolution of simple spin-spin correlation functions is highly sensitive to the degree of k-locality of the corresponding operators, once an appropriate set of fundamental fields is identified. By tracking the time-evolution of specific spin-spin correlation functions and their decay, we argue that it is possible to distinguish between operator-hopping and operator growth dynamics; the latter being a hallmark of quantum chaos in many-body quantum systems. Such an observation, in turn, could constitute a promising tool to probe the emergence of chaotic behavior, rather accessible in state-of-the-art quench setups.

Quantum Advantage in the Charging Process of Sachdev-Ye-Kitaev Batteries.

The exactly solvable Sachdev-Ye-Kitaev (SYK) model has recently received considerable attention in both condensed matter and high energy physics because it describes quantum matter without quasiparticles, while being at the same time the holographic dual of a quantum black hole. In this Letter, we examine SYK-based charging protocols of quantum batteries with N quantum cells. Extensive numerical calculations based on exact diagonalization for N up to 16 strongly suggest that the optimal charging power of our SYK quantum batteries displays a superextensive scaling with N that stems from genuine quantum mechanical effects. While the complexity of the nonequilibrium SYK problem involved in the charging dynamics prevents us from an analytical proof, we believe that this Letter offers the first (to the best of our knowledge) strong numerical evidence of a quantum advantage occurring due to the maximally entangling underlying quantum dynamics.

A bump: what to do next? Ultrasound imaging of superficial soft-tissue palpable lesions.

Soft-tissue palpable lesions are common in clinical practice, and ultrasound (US) represents the first imaging option in the evaluation of a patient with a soft-tissue swelling. A full and systematic US assessment is necessary, however. This includes grayscale, color- and power-Doppler, spectral-Doppler, and possibly elastography facilities, as well as a trained operator. Several lesions showing characteristic US features can be diagnosed confidently, without any further work-up, and the high spatial resolution of ultrasound in the superficial layers can be a powerful tool to discriminate their etiologies. Second-level options, to be reserved for indeterminate cases or those suspected malignant at initial ultrasound, include magnetic resonance imaging, percutaneous fine-needle aspiration or biopsy, and surgical-excision biopsy. In this article, we discuss the proper US approach for addressing superficial soft-tissue lesions.

Diastasis of rectus abdominis muscles: patterns of anatomical variation as demonstrated by ultrasound.

PURPOSE: The aim of our study was to categorise the anatomical variations of rectus abdominis muscle diastasis (diastasis recti) by using ultrasound (US). MATERIAL AND METHODS: In a one-year period 92 women were evaluated with US because of suspected diastasis of rectus muscles. Patients were examined in a supine position, with head extended, upper limbs aligned to the trunk, and knees flexed. US was performed with high-frequency, broad-band transducers. Trapezoid field-of-view and extended field-of-view were employed to measure diastasis exceeding 5 cm. Diastasis was defined as a margin-to-margin distance > 20 mm at rest and classified according to the following anatomical patterns: open only above the navel, open only below the navel, open at the navel level, open completely but wider above the navel, and open completely but wider below the navel. RESULTS: Diastasis was found in 82 patients (30-61 years old, mean age 35 years). The width was 21-97 mm, mean 39 mm. The prevalence and severity of the anatomical patterns was as follows: open only above the navel in 48 patients (21-88 mm, mean 40 mm), open only below the navel in one patient (33 mm), open at the navel level in seven patients (23-39 mm, mean 34 mm), open completely but wider above the navel in 24 patients (21-97 mm, mean 41 mm), open completely but wider below the navel in two patients (21-29 mm, mean 25 mm). CONCLUSIONS: The above-navel patterns of recti muscle diastasis are the most common. Even when open completely, diastasis is usually wider above the navel. Knowledge of the anatomical type of rectus muscle diastasis could be of value to the patient (exercises to do and to avoid) and to the surgeon (abdominoplasty planning).

Parapelvic cysts, a distinguishing feature of renal Fabry disease.

Background: Fabry's disease (FD) is a rare, multi-organ lysosomal disease, caused by the deficiency of the enzyme α-galactosidase A, and is difficult to diagnose. Although parapelvic cysts (PC) were previously associated with FD, their prevalence and significance are unclear. Methods: The present study aimed to: (i) evaluate, by renal ultrasound, the real prevalence of PC and of their determinants in a multicentre, nationwide cohort of FD patients (n = 173, Study 1) and (ii) ascertain whether a greater accuracy of PC detection improved their identification, in FD patients from a single centre (n = 67, Study 2). In both studies, for each FD patient, an age- and renal function-matched subject was selected for comparison (1:1). Results: In Study 1, PC were detected in 28.9% of FD subjects and in only 1.1% of control subjects (P < 0.001). The presence of other renal abnormalities did not differ between the groups, nor differences exist in the main demographic and laboratory parameters between the groups. In Study 2, the greater accuracy of ultrasound increased PC prevalence from 29.8% to 43.3% in the same subjects (P < 0.05). In both studies, no correlation was detected between PC and the main demographic, clinical and biochemical parameters, including use of enzyme replacement therapy (P < 0.1, minimum value). Finally, no difference existed between FD patients with and without PC. Conclusions: The present study suggests that the presence of PC in renal patients should alert physicians to consider the diagnosis of FD, primarily in subjects with an unclear family history of renal disease and in the presence of other stigmata of the disease.

Corpus callosum involvement: a useful clue for differentiating Fabry Disease from Multiple Sclerosis.

PURPOSE: Multiple sclerosis (MS) has been proposed as a possible differential diagnosis for Fabry disease (FD). The aim of this work was to evaluate the involvement of corpus callosum (CC) on MR images and its possible role as a radiological sign to differentiate between FD and MS. METHODS: In this multicentric study, we retrospectively evaluated the presence of white matter lesions (WMLs) on the FLAIR images of 104 patients with FD and 117 patients with MS. The incidence of CC-WML was assessed in the two groups and also in a subgroup of 37 FD patients showing neurological symptoms. RESULTS: WMLs were detected in 50 of 104 FD patients (48.1%) and in all MS patients. However, a lesion in the CC was detected in only 3 FD patients (2.9%) and in 106 MS patients (90.6%). In the FD subgroup with neurological symptoms, WMLs were present in 26 of 37 patients (70.3%), with two subjects (5.4%) showing a definite callosal lesion. CONCLUSION: FD patients have a very low incidence of CC involvement on conventional MR images compared to MS, independently from the clinical presentation and the overall degree of WM involvement. Evaluating the presence of CC lesions on brain MR scans can be used as a radiological sign for a differential diagnosis between MS and FD, rapidly addressing the physician toward a correct diagnosis and subsequent treatment options.

Humongous right atrial lipoma: a correlative CT and MR case report.

A 66-year-old man was referred to our department for further investigation of a right atrial mass incidentally discovered on ultrasound examination (US). US showed an oval mass arising from the free wall of the right atrium and projecting into the atrial cavity. The mass was hypoechoic and had a broad base of attachment on the free wall of the right atrium. This case was referred to our department in order to perform an MR cardiac examination. Our diagnosis was supported by a CT scan study that confirmed the diagnosis of a cardiac lipoma subsequently confirmed at surgery.

Atypical Presentation of Ewing's Sarcoma with a Single Left Orbital Metastasis.

BACKGROUND: We present an uncommon case of Ewing's sarcoma in a 16-year-old boy. CASE REPORT: This case can be considered unique because of the atypical presentation, normal laboratory tests and absence of the typical symptoms such as pain, masses or swelling, fatigue or weight loss, breathing problems linked to lung metastases or pathologic fractures. The only event that brought the patient to our attention was the sudden onset of left proptosis. CONCLUSIONS: The final histopathology together with CT and PET-CT findings led to the diagnosis of a multi-metastatic Ewing's sarcoma involving the orbit, skeleton, bone marrow and lymph nodes.

Erratum to: AdS6 solutions of type II supergravity.

[This corrects the article DOI: 10.1007/JHEP11(2014)099.].

Lobular intraepithelial neoplasia arising within breast fibroadenoma.

BACKGROUND: Fibroadenomas are the second most common breast pathology occurring in young women under the age of 35 years old. Fibroadenomas can be classified as simple or complex according to histological features. Complex fibroadenomas differ from simple fibroadenomas because of the presence of cysts (3 mm), sclerosing adenosis, epithelial calcifications, or papillary apocrine changes. Most fibroadenomas are clinically identifiable. In 25% of cases, fibroadenomas are non-palpable and are diagnosed with mammography and ultrasound. Differential diagnosis with well differentiated breast cancer is often necessary, particularly with medullary or mucinous tumors. Calcification findings within fibroadenomas by mammogram have to be investigated. The age of a lump is usually reflected by calcifications. Microcalcification can hide foci of carcinoma in situ when they are small, branching type, and heterogeneous. However, many morphological possibilities may not be reliable for deciding whether a certain calcification is the product of a malignant or a benign process. From a radiological point of view, fibroadenomas containing foci of carcinoma in situ can be indistinguishable from benign lesions, even if the incidence of carcinoma within fibroadenomas is estimated as 0.1-0.3%, and it could be a long-term risk factor for invasive breast cancer. CASE PRESENTATION: A 44-year-old woman presented with a 1.5-cm palpable, smooth, mobile lump in the lower-inner quadrant of her right breast. Standard mediolateral oblique and craniocaudal mammograms showed a cluster of eccentric popcorn-like calcifications within the fibroadenoma. After lumpectomy, a definitive histological examination confirmed the intra-operative diagnosis of a benign mass. However, lobular intraepithelial neoplasia foci were found, surrounded by atypical lobular hyperplasia. CONCLUSIONS: The possibility of an old benign breast lump might be supported by fine needle aspiration biopsy or core biopsy before initiating follow-up. According to our experience, when patients are older than 40 years and have a familial history of breast cancer, we prefer to carry out lumpectomy with follow up to avoid the risk of underestimation in situ foci within the lump.

Eritema elevatum diutinum como diagnóstico diferencial das doenças reumatológicas: relato de caso / Eritema elevatum diutinum como diagnóstico diferencial das doenças reumatológicas: case report

O eritema elevatum diutinum é uma vasculite leucocitoclástica cutânea crônica e rara, caracterizada por pápulas, placas e nódulos vermelhos, purpúreos e amarelados, distribuídos simetricamente sobre as superfícies extensoras das extremidades. Está associado a vários processos autoimunes, neoplásicos e infecciosos, principalmente malignidades hematológicas (cerca de 30 por cento dos casos). Artralgia e artrite são sintomas frequentes, que afetam por volta de 40 por cento dos pacientes, o que indica a necessidade de sua inclusão no diagnóstico diferencial das doenças reumatológicas, principalmente se em conjunto com outras apresentações da vasculite leucocitoclástica, caracterizadas pela combinação de manifestações reumáticas com alterações cutâneas características. Descrevemos o caso de uma paciente de 18 anos que desenvolveu eritema elevatum diutinum, cujo diagnóstico baseou-se nas características morfológicas, no padrão de distribuição das lesões cutâneas e nos achados histopatológicos de vasculite leucocitoclástica. O principal sintoma sistêmico era uma artrite severa.

Erythema elevatum diutinum is a chronic and rare cutaneous leukocytoclastic vasculitis, characterized by red, purple and yellow papules, plaques and nodules, distributed symmetrically on the extensor surfaces of the limbs. It is associated with several autoimmune, neoplastic and infectious processes, mainly hematological malignancies in about 30 percent of the cases. Joint pain and arthritis are frequent symptoms, affecting approximately 40 percent of the patients, indicating the need for its inclusion in the differential diagnosis of rheumatic diseases, chiefl y the other presentations of leukocytoclastic vasculitis, which are characterized by the combination of rheumatic manifestations and peculiar cutaneous lesions. We report the case of an 18-year-old female patient who developed erythema elevatum diutinum and whose diagnosis was based on the morphologic characteristics, the distribution pattern of the cutaneous lesions and the histopathological fi ndings of leukocytoclastic vasculitis. The major systemic symptom was severe arthritis.

Eritema elevatum diutinum as a differential diagnosis of rheumatic diseases: case report.

Erythema elevatum diutinum is a chronic and rare cutaneous leukocytoclastic vasculitis, characterized by red, purple and yellow papules, plaques and nodules, distributed symmetrically on the extensor surfaces of the limbs. It is associated with several autoimmune, neoplastic and infectious processes, mainly hematological malignancies in about 30% of the cases. Joint pain and arthritis are frequent symptoms, affecting approximately 40% of the patients, indicating the need for its inclusion in the differential diagnosis of rheumatic diseases, chiefly the other presentations of leukocytoclastic vasculitis, which are characterized by the combination of rheumatic manifestations and peculiar cutaneous lesions. We report the case of an 18-year-old female patient who developed erythema elevatum diutinum and whose diagnosis was based on the morphologic characteristics, the distribution pattern of the cutaneous lesions and the histopathological findings of leukocytoclastic vasculitis. The major systemic symptom was severe arthritis.

Pyodermatitis-pyostomatitis vegetans: case report and review of medical literature.

Pyodermatitis-pyostomatitis vegetans is a rare inflammatory dermatosis of unknown etiology, with a typical mucocutaneous involvement. We report the case of a woman with pustular and vesicular lesions in the axillae, evolving with vegetating plaques and pustules with annular grouping. The disease progressed with vulvar and inguinal involvement as well as involvement of the oral, nasal and ocular mucous membranes. She started the treatment with prednisone (40 mg/day), with remission of the lesions after one month of use of such medication. Association with inflammatory bowel disease occurs in 70% of the cases. Immunofluorescence, which is typically negative, helps to characterize the disease. A rapid response to systemic steroids is expected.