Reinforcement learning assisted recursive QAOA

In recent years, variational quantum algorithms such as the Quantum Approximation Optimization Algorithm (QAOA) have gained popularity as they provide the hope of using NISQ devices to tackle hard combinatorial optimization problems. It is, however, known that at low depth, certain locality constraints of QAOA limit its performance. To go beyond these limitations, a non-local variant of QAOA, namely recursive QAOA (RQAOA), was proposed to improve the quality of approximate solutions. The RQAOA has been studied comparatively less than QAOA, and it is less understood, for instance, for what family of instances it may fail to provide high-quality solutions. However, as we are tackling NP-hard problems (specifically, the Ising spin model), it is expected that RQAOA does fail, raising the question of designing even better quantum algorithms for combinatorial optimization. In this spirit, we identify and analyze cases where (depth-1) RQAOA fails and, based on this, propose a reinforcement learning enhanced RQAOA variant (RL-RQAOA) that improves upon RQAOA. We show that the performance of RL-RQAOA improves over RQAOA: RL-RQAOA is strictly better on these identified instances where RQAOA underperforms and is similarly performing on instances where RQAOA is near-optimal. Our work exemplifies the potentially beneficial synergy between reinforcement learning and quantum (inspired) optimization in the design of new, even better heuristics for complex problems.

[Interventionnal bronchoscopy for the treatment of tracheobronchomalacia]

Tracheobronchomalacia is usually characterized by more than 50% expiratory narrowing in diameter of the trachea and the bronchi. The expiratory collapse includes two entities: (1) the TBM related to the weakness of the cartilaginous rings, and (2) the Excessive Dynamic Airway Collapse (EDAC) due to the excessive bulging of the posterior membrane. Patients have nonspecific respiratory symptoms like dyspnea and cough. Diagnosis is confirmed by dynamic tests: flexible bronchoscopy and/or computed tomographic scan of the chest. There are different forms of tracheobronchomalacia in adults: primary (genetic, idiopathic) or secondary to trauma, tracheotomy, intubation, surgery, transplantation, emphysema, infection, inflammation, chronic bronchitis, extrinsic compression; or undiagnosed in childhood vascular rings. Some management algorithms have been proposed, but no specific recommendation was established. Only symptomatic patients should be treated. Medical treatments and noninvasive positive pressure ventilation should be the first line therapy, after evaluation of various quality measures (functional status, performance status, dyspnea and quality of life scores). If symptoms persist, therapeutic bronchoscopy permits: (1) patient's selection by stent trial to determine whether patient benefit for surgical airway stabilization; (2) malacic airways stenting in patients who are not surgical candidates, improving QOL despite a high complication rate; (3) the management of stent-related complication (obstruction, plugging, migration granuloma); (4) alternative therapeutics like thermo-ablative solution. Lasty, the development of new types of stents would reduce the complication rates. These different options remained discussed.

Quantum machine learning beyond kernel methods

Machine learning algorithms based on parametrized quantum circuits are prime candidates for near-term applications on noisy quantum computers. In this direction, various types of quantum machine learning models have been introduced and studied extensively. Yet, our understanding of how these models compare, both mutually and to classical models, remains limited. In this work, we identify a constructive framework that captures all standard models based on parametrized quantum circuits: that of linear quantum models. In particular, we show using tools from quantum information theory how data re-uploading circuits, an apparent outlier of this framework, can be efficiently mapped into the simpler picture of linear models in quantum Hilbert spaces. Furthermore, we analyze the experimentally-relevant resource requirements of these models in terms of qubit number and amount of data needed to learn. Based on recent results from classical machine learning, we prove that linear quantum models must utilize exponentially more qubits than data re-uploading models in order to solve certain learning tasks, while kernel methods additionally require exponentially more data points. Our results provide a more comprehensive view of quantum machine learning models as well as insights on the compatibility of different models with NISQ constraints.

Operationally meaningful representations of physical systems in neural networks

To make progress in science, we often build abstract representations of physical systems that meaningfully encode information about the systems. Such representations ignore redundant features and treat parameters such as velocity and position separately because they can be useful for making statements about different experimental settings. Here, we capture this notion by formally defining the concept of operationally meaningful representations. We present an autoencoder architecture with attention mechanism that can generate such representations and demonstrate it on examples involving both classical and quantum physics. For instance, our architecture finds a compact representation of an arbitrary two-qubit system that separates local parameters from parameters describing quantum correlations.

Neonatal cardiogenic shock revealing obstructive cardiac Hibernoma: case report

Background

Cardiac Hibernomas are very rare benign tumors and usually remain asymptomatic. Neonatal cardiogenic shock due to cardiac tumors is extremely very rare. Until this date a few cases of cardiac hibernoma have been reported in the literature.

Transthoracic echocardiography help in the differential diagnosis, but the definitive diagnosis is histological. The management strategy is not clearly codified.

The Aim is to report and discuss the clinical features of a cardiac Hibernoma and review the relevant literature.

Case presentation

We describe a case of a 2-day-old Caucasian full-term male neonate admitted in neonate intensive care with cardiogenic shock, having fluid resuscitation and inotropic drugs. Ventilatory support was started immediately with the subsequent reestablishment of normal blood pressure. Then he was transferred to the echocardiography laboratory.

Transthoracic echocardiography showed two echogenic masses in the right atrium and right ventricle.

The masses were extended to the pulmonary trunk. Pulmonary artery flow measurements showed the presence of pulmonary and tricuspid obstruction.

Surgery was rapidly considered since the baby was hemodynamically unstable.

Intraoperative evaluation showed a mass embedded in the interventricular septum that occupy the right ventricular cavity and the right atrium. The tumor involved also the chordae of the tricuspid. Partial resection was done. Tricuspid valve repair was performed by construction of new chordae from the autologous pericardium. The specimen was sent for histopathological analysis. The baby died immediately after surgery.

Histological examination of the surgical specimen revealed clear multivacuolated cells filled with lipid droplets and granular intense eosinophilic cytoplasm which confirms the diagnosis of Hibernoma.

Conclusion

Cardiac Hibernomas are rare benign tumors. The prognosis and treatment strategy is closely dependent on the location, initial clinical presentation and possible complications. The prognosis can be unfavorable if the tumor was obstructive and infiltrate the myocardium.

Genomic analysis of in vivo acquired resistance to colistin and rifampicin in Acinetobacter baumannii

Acinetobacter baumannii is an opportunistic pathogen in healthcare facilities responsible for nosocomial infections mostly in immunocompromised patients. Colistin resistance is increasingly reported worldwide in A. baumannii. Here we describe the in vivo selection of colistin and rifampicin resistance in carbapenem-resistant A. baumannii. Antimicrobial susceptibility testing, plasmid analysis and whole-genome sequencing (WGS) were performed to fully characterise the resistome of two clinical isolates (AbS1 and AbS2) selected during treatment. Clinical isolate AbS1 remained susceptible to colistin, rifampicin and tigecycline, whilst AbS2 was susceptible only to tigecycline. PCR analysis revealed the presence of a bla_OXA-23-like carbapenemase gene. Kieser extraction revealed an ca. 74 kb plasmid harbouring bla_OXA-23. WGS revealed genomes of 3.8 Mbp in size with a G + C content of 38.9%, and both belonged to ST281 according to the Oxford MLST scheme and ST641 according to the Institut Pasteur scheme. The resistome was also composed of naturally occurring β-lactamases, i.e. ADC-25 cephalosporinase and OXA-82 oxacillinase, aminoglycoside resistance genes [aac(3)-Ia, aadA1 and aph(3')-VIa (aphA6)], and mutations in DNA gyrases explaining fluoroquinolone resistance. Single nucleotide polymorphism analysis revealed that both isolates were identical except for a 30-nucleotide duplication within the pmrB gene and a point mutation in the rpoB gene resulting in colistin and rifampicin resistance, respectively. This study highlights the genomic plasticity of A. baumannii under antibiotic pressure. The 10-amino acid duplication in PmrB affects colistin susceptibility by regulating lipopolysaccharide modification through the PmrAB two-component system. These findings provide further information on the molecular mechanisms leading to colistin resistance in A. baumannii.

[Prenatal diagnosis of a giant cystic lymphangioma in the axillothoracic wall]

Cystic lymphangiomas are benign malformative tumors of the lymphatic vessels, rare but potentially serious and usually located in the cervical region. The diagnosis is usually easy, but the treatment is sometimes difficult because of their location and extension into the surrounding tissue. We report a case of giant cystic lymphangioma of the right axillary-thoracic wall diagnosed by prenatal ultrasound at 20 weeks gestation. The male infant was born at 37 weeks gestation with a large, swelling, lateral parietal right chest. Ultrasound soft tissue and chest CT scan confirmed the diagnosis of giant cystic lymphangioma of the right axillary-thoracic wall. Surgical excision was performed on the 21st day after birth and the mass was excised incompletely. The postoperative course was uncomplicated. Ultrasound soft tissue follow-up showed the persistence of multiple cystic structures in the axilla. Prenatal diagnosis of these tumors is essential for planning multidisciplinary management in early postnatal care.

[Idiopathic intracranial hypertension and factor V Leiden mutation]

Activated proteinC resistance is a frequent prothrombotic abnormality. In most cases it is due to factorV Leiden mutation by nucleotide G1691A substitution. This recently described thrombophilic defect of activated proteinC resistance has been postulated to be implicated in the pathogenesis of idiopathic intracranial hypertension (IIH). We report a case of factorV Leiden mutation in association with IIH and their likely link and implication in the management of IIH.

[Vertebral primary hydatid cyst with mediastinal involvement and paraplegia]

INTRODUCTION

The vertebrae are the most common localization of hydatid disease of bone. This can lead to fatal consequences.

CASE REPORT

We report the case of a 40-year-old-man, from a rural area, who had symptoms of medullary compression. The diagnosis of primary vertebral hydatid cyst, already suspected on the imaging data, was confirmed. A right posterolateral thoracotomy allowed drainage of the cyst and relief of the medullary compression. Medical treatment with albendazole was continued for 4 months. The postoperative course was uneventful and the symptoms of medullary compression resolved progressively. No recurrence was observed during a follow-up of 24 months.

CONCLUSION

Vertebral localization of hydatid disease is the most common and serious skeletal complication. Thoracotomy allows drainage of the cyst and the pleural cavity, and relieves the medullary compression.

[Bilateral popliteal artery complications of multiple hereditary exostosis]

The osseous exostose is a rare benign tumor of the bone from which the vascular complications can be of venous or arterial order, are translated in various boards. We report the case of a young adult who presents a forgery aneurysm of the right popliteal artery with the popliteal artery booby-trapped to the left. The patient benefited from surgical treatment with good clinical and radiological evolution.

Hashimoto's thyroiditis and severe hypothyroidism, associated with a single hot nodule

We report the case of a 27 year-old man with symptoms of severe hypothyroidism that have evolved since his adolescence. He was found to have an 11 mm right lobe thyroid nodule. On thyroid ultrasound, the nodule was solid, heterogeneous with markedly atrophic hypoechoic surrounding tissue. Thyroid scintigraphy revealed increased (99m)Tc pertechnetate and (131)I uptake, with persistence of (131)I hyperfixation after 24 h. There was no fixation of the radiotracer in the remaining tissue. Thyroid function tests found TSH > 100 mIU/l, free thyroxine level 0.9 pmol/l (normal values 11.5-21.8), anti-thyroid peroxydase antibodies strongly positive > 1,000 IU/ml, and anti-thyroglobulin antibodies negative. One year after levothyroxine therapy, the nodule decreased to 40% of its original size. Hashimoto's thyroiditis may present as a single hot nodule and severe hypothyroidism. Data of reported cases suggest that the hot nodule corresponds to a localized hyperplasia of the less diseased portions of the thyroid. Chronic stimulation by TSH may have promoted nodular growth and isotopes uptake.

[Early surgery in patients with native valve endocarditis]

Between January 1990 and December 2006, 93 patients with infective endocarditis on native valves were operated in the active phase of the disease. The average age of our patients was 32 years with a male ascendancy. The causal heart disorder was found in 89 % of the cases, dominated by rheumatoid arthritis. The germ in cause was isolated in 52.6 % of the cases. The operative indication was hemodynamic in 29 cases, infectious in nine cases, mixed in 29 cases and embolic in 26 cases. The average operating delay was of 13 days with regard to the beginning of the antibiotic treatment. We realized a valvular aortic replacement at 32 patients with reconstruction of the ring in six cases, a valvular mitral replacement at 29 patients, a mitroaortic replacement at 21 patients, a reconstructive mitral surgery in nine cases, a valvular tricuspid replacement in one case and a reconstructive tricuspid surgery in one case. The early mortality was 13 %. The follow-up was 89 % with an average recession of 3.1 years and a late mortality of 5 %. The aim of this study is to analyze the immediate and late results of the surgery of infective endocarditis in the active phase and to bring to light the prognostic factors of mortality.

[Surgery of 56 patients having a partial atrioventricular septal defect]

Between January 1991 and December 2006, 56 patients having a partial atrioventricular septal defect (AVSD) were operated. The purpose of this retrospective study is to analyze the immediate and long-term results of the surgery by granting of the importance to two main problems which are the disturbances of the rhythm and the conduction and the residual mitral regurgitation (MR). The mean age of our patients is of 10 and a half years with a net feminine ascendancy. Ninety-three percent of the patients were in regular sinus rhythm. No case of complete atrioventricular block (AVB) was noted. The MR was of grade I in 28.5% of the cases, grade II in 60% of the cases and grade III and IV in 7.5% of the cases. The MR was mild in 4% of the cases. The correction was made under cardiopulmonary bypass (CPB) and consisted of a suture of the mitral cleft in most of the cases with lock of the ostium primum by a patch of pericardium. The perioperative mortality was 1,8% of the cases. The disturbances of the rhythm and the conduction were noted in 34% of the cases. All the patients were controlled with a mean follow-up of six years and seven months. The secondary mortality was nil. The MR, at mid-term follow-up, was mild in 78% of the cases. The partial AVSD is a congenital heart disease, the spontaneous evolution of which can be burdened by complications, notably the disturbances of the rhythm and the conduction, as well as the heart failure. This justifies a premature surgical repair.

[Coronary artery fistula: case report and review of the literature]

The coronary fistula is a rare abnormality making communicate a coronary artery with a cardiac cavity or a great vessel, so bypassing the myocardial capillary network. The majority of these fistulas are congenital but can nevertheless arise after a cardiac surgery. The right coronary artery and the left anterior descending coronary artery are mostly concerned. The circumflex coronary artery is rarely involved. The most frequent site of drainage is the right ventricle. We report the case of a 2-year-old child, brought by his parents for dyspnoea of effort. The diagnosis of coronary fistula was confirmed by the coronary angiography which showed an aneurysmal circumflex artery, draining into the right ventricle. The intervention was led under cardiopulmonary bypass. We proceeded to the longitudinal opening of the aneurysm then to the blindness of the fistula. The postoperative course was simple.

[Maxillo-facial location of hydatic cyst]

OBJECTIVE

A maxillofacial location of a hydatid cyst is rare, accounting 2% of cases. The purpose of this study was to review clinical and radiological features by emphasizing diagnostic difficulties.

MATERIALS AND METHODS

Two observations of hydatid cyst with a maxillofacial location are presented. Two cases were investigated by panoramic dental radiography, an ultrasound and CT scan. MRI was done in one case.

RESULTS

The first observation reports a 23-year-old woman who consulted for jugal tumefaction with pharyngeal extension evolving in spurts. The second observation was a 16-year-old girl, which consulted for a genian and masseter tumefaction with a tight trismus. In both cases, the imaging studies suggested the diagnosis of the hydatid cyst confirmed by the anatomopathologic exam.

CONCLUSION

The hydatid cyst is an endemic parasitic pathology involving most often the lung and the liver. The maxillofacial location is exceptional. In cases of a cyst mass in an endemic zone, the diagnosis of the hydatid cyst must be entertained. CT scan and MRI provided a complete lesion workup. Treatment is surgical.