Ultrastrong coupling probed by Coherent Population Transfer.

Light-matter interaction, and the understanding of the fundamental physics behind, is the scenario of emerging quantum technologies. Solid state devices allow the exploration of new regimes where ultrastrong coupling strengths are comparable to subsystem energies, and new exotic phenomena like quantum phase transitions and ground-state entanglement occur. While experiments so far provided only spectroscopic evidence of ultrastrong coupling, we propose a new dynamical protocol for detecting virtual photon pairs in the dressed eigenstates. This is the fingerprint of the violated conservation of the number of excitations, which heralds the symmetry broken by ultrastrong coupling. We show that in flux-based superconducting architectures this photon production channel can be coherently amplified by Stimulated Raman Adiabatic Passage, providing a unique tool for an unambiguous dynamical detection of ultrastrong coupling in present day hardware. This protocol could be a benchmark for control of the dynamics of ultrastrong coupling architectures, in view of applications to quantum information and microwave quantum photonics.

Chagas disease knocks on our door: a cross-sectional study among Latin American immigrants in Milan, Italy.

OBJECTIVES: We aimed to assess the prevalence and risk factors for Chagas disease (CD) in Latin American immigrants and to evaluate the accuracy of diagnostic tests. Moreover, we offered to all positive subjects a complete free-of-charge clinical/instrumental evaluation as well as benznidazole treatment in order to stage the disease and verify drug tolerability. METHODS: A cross-sectional survey of CD among Latin Americans living in Milan and its metropolitan area was conducted between July 2013 and July 2014. Blood samples were tested for serologic evidence of CD together with a questionnaire covering demographic and clinical-epidemiological information. RESULTS: Forty-eight (9.6%) of the 501 tested subjects were conclusively diagnosed as having CD. The highest prevalence of CD was among those from Bolivia (43/169, 25.4%) and El Salvador (4/68, 5.9%). Older age (adjusted odds ratio (aOR)] 1.05, p =0.004), a Bolivian origin (aOR 8.80; p =0.003), being born in the department of Santa Cruz (aOR 3.72, p =0.047), having lived in mud houses (aOR 2.68; p =0.019), and having an affected relative (aOR 12.77, p =0.001) were independently associated with CD. The ARCHITECT Chagas test showed the highest sensitivity (100%) and specificity (99.8%). Twenty-nine of the subjects with CD (60.4%) underwent disease staging, 10 of whom (35.7%) showed cardiac and/or digestive involvement. Benznidazole treatment was associated with high frequency of adverse reactions (19/27, 70.4%) and permanent discontinuation (8/27, 29.6%). CONCLUSIONS: CD is highly prevalent among Bolivians and Salvadorans living in Milan. Regions with a large Latin American immigrant population should implement programmes of active detection and treatment.

Direct-acting antivirals in hepatitis C virus (HCV)-infected and HCV/HIV-coinfected patients: real-life safety and efficacy.

OBJECTIVES: Clinical trials of all-oral direct-acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection reported high response rates in HCV/HIV coinfection, similar to those obtained in HCV monoinfection. We evaluated the safety and efficacy of these regimens in a clinical practice setting. METHODS: In this prospective observational study, all the HCV-monoinfected and HCV/HIV-coinfected patients undergoing HCV treatment with all-oral DAA regimens in a routine clinical setting from December 2014 to December 2015 were included in the analysis. Sustained virological response 12 weeks after the end of therapy (SVR12) and reported adverse events (AEs) were evaluated. Resistance-associated variants (RAVs) were analysed in a subgroup of patients at baseline and at the time of viral rebound in those with virological failure. RESULTS: One-hundred and nine patients (51 HCV-infected and 58 HCV/HIV-coinfected) were enrolled in the study. Sixty per cent had cirrhosis and 52% were pegylated interferon and ribavirin (pegIFN/RBV)-experienced. Thirty-six per cent received ombitasvir + paritaprevir/ritonavir + dasabuvir, 25% sofosbuvir + daclatasvir, 16% sofosbuvir + simeprevir, 17% sofosbuvir + ribavirin and 6% sofosbuvir + ledipasvir; ribavirin was used in 57% of subjects. The SVR12 rate was 91% and 96% in HIV-infected and uninfected patients, respectively (P = 0.44). The 4-week HCV viral decline was similar in the two groups. RAVs were found at baseline in 23 of 49 patients and did not affect SVR12. No predictors of SVR12 were identified in our cohort. CONCLUSIONS: Treatment with all-oral DAA combinations of patients infected with HCV and with HCV/HIV under real-life conditions led to high and similar rates of SVR12. Moreover, the historical factors associated with a sustained virological response to pegIFN/RBV were not predictive of the response to all-oral DAAs.

Laser light triggered smart release of silibinin from a PEGylated-PLGA gold nanocomposite.

In this work a new remotely-triggered drug delivery system based on PEG-PLGA_Au nanocomposite is proposed. Due to the optical properties of gold nanoparticles (Au NPs), the nanovector allows on-demand control of the dose, the timing and the duration of the drug release, upon irradiation with red laser light. The Au NPs are synthesized by laser ablation and subsequently embedded into the PEG-PLGA copolymer via a modified emulsion-diffusion method, devised in such a way that both Au NPs and silibinin (SLB), a flavonolignan with promising anti-neoplastic effects, can be co-loaded into the polymeric system in a single step procedure. A combination of analytical techniques including nuclear magnetic resonance (NMR), static and dynamic light scattering (SLS, DLS), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), infrared (FTIR) spectroscopy and scanning/transmission electron microscopies (SEM/STEM/TEM), have been used to study the structural and morphological properties of the nanocomposite. The loading efficiency and the drug content, evaluated by UV-vis absorption optical spectroscopy, are 89% and 8.8%, respectively. Upon laser irradiation the system releases the encapsulated drug with a higher efficiency (∼10%) than that without irradiation. This behaviour indicates that our nanoplatform is responsive to light and it could be considered a promising new type of light-activated drug delivery carrier applicable to the biomedical field.

Nonclassical radiation from thermal cavities in the ultrastrong coupling regime.

Thermal or chaotic light sources emit radiation characterized by a slightly enhanced probability of emitting photons in bunches, described by a zero-delay second-order correlation function g((2))(0)=2. Here we explore photon-coincidence counting statistics of thermal cavities in the ultrastrong coupling regime, where the atom-cavity coupling rate becomes comparable to the cavity resonance frequency. We find that, depending on the system temperature and coupling rate, thermal photons escaping the cavity can display very different statistical behaviors, characterized by second-order correlation functions approaching zero or greatly exceeding two.

Spontaneous conversion from virtual to real photons in the ultrastrong-coupling regime.

We show that a spontaneous release of virtual photon pairs can occur in a quantum optical system in the ultrastrong coupling regime. In this regime, which is attracting interest both in semiconductor and superconducting systems, the light-matter coupling rate Ω(R) becomes comparable to the bare resonance frequency of photons ω(0). In contrast to the dynamical Casimir effect and other pair creation mechanisms, this phenomenon does not require external forces or time dependent parameters in the Hamiltonian.

Photon blockade in the ultrastrong coupling regime.

We explore photon coincidence counting statistics in the ultrastrong coupling regime, where the atom-cavity coupling rate becomes comparable to the cavity resonance frequency. In this regime, usual normal order correlation functions fail to describe the output photon statistics. By expressing the electric-field operator in the cavity-emitter dressed basis, we are able to propose correlation functions that are valid for arbitrary degrees of light-matter interaction. Our results show that the standard photon blockade scenario is significantly modified for ultrastrong coupling. We observe parametric processes even for two-level emitters and temporal oscillations of intensity correlation functions at a frequency given by the ultrastrong photon emitter coupling. These effects can be traced back to the presence of two-photon cascade decays induced by counterrotating interaction terms.

Clinical presentation and outcome of squamous cell carcinoma of the anus in HIV-infected patients in the HAART-era: a GICAT experience.

INTRODUCTION: Squamous cell carcinoma of the anus (SCCA) is a relatively uncommon cancer. In the HIV-positive patients the introduction of the highly active antiretroviral therapy (HAART) did not change the incidence of SCCA. BACKGROUND AND OBJECTIVES: This paper describes the Italian Cooperative Group on AIDS and Tumours (GICAT) experience on HIV-positive patients with SCCA. The purposes of this retrospective study were: first to describe the clinical presentation and outcome of HIV-positive patients with SCCA, second to compare them with the ones reported in the literature. PATIENTS AND METHODS: Between July 2000 and March 2010 we retrospectively collected epidemiological, clinical and survival data from 65 patients with SCCA in HIV infection enrolled within the GICAT. RESULTS: Fifty-three (81.5%) patients were male. The majority of patients (40%) were homosexual Forty-three patients (66.1%) were diagnosed with HIV before 1996. Thirty-five patients (54%) had CD4-positive cells count > 200 / mm3 and 28 patients (43%) had viral load > 50 cp / ml at the time of SCCA diagnosis. The median time difference between HIV and SCCA diagnosis was 120 months (range 10-282 months). Sixty-one patients (96.8%) received HAART at SCCA diagnosis. Fifty-two patients (80%) had performance status (PS) 0-1 at the time of SCCA diagnosis. Twenty-seven patients (41.5%) underwent surgery with curative intent. Thirty-five patients (53.9%) were given combined modality therapy (CMT) consisting of pelvic radiotherapy with concurrent chemotherapy. No grade 3/4 haematological or extra-haematological effects were observed in our patients. CONCLUSIONS: In summary, despite the retrospective nature of analysis, the absence of patient strict criteria of inclusion/exclusion, our data on HIV-positive patients with SCCA, compared both to general population and to small reports on HIV-positive patients present in the literature, are promising.

Test of the all-optical control of wave-particle duality of cavity photons by ordinary photodetection.

The principle of complementarity refers to the ability of quantum entities to behave as particles or waves under different experimental conditions. We present a proposal for the experimental observation of the ultrafast all-optical control of the wave-particle duality of light. The device is constituted by a three-level quantum emitter strongly coupled to a microcavity (MC) and can be realized by exploiting a great variety of systems, ranging from atomic physics and semiconductor quantum dots to intersubband polaritons and Cooper pair boxes. The wavelike or particlelike behavior of MC photons can be probed by simply measuring the cavity output photon rate after excitation with pairs of phase-locked weak pulses with precise arrival times.

All optical switch of vacuum Rabi oscillations: the ultrafast quantum eraser.

We study the all-optical time control of the strong coupling between a single cascade three-level quantum emitter and a microcavity. We find that only specific arrival times of the control pulses succeed in switching off the Rabi oscillations. Depending on the arrival times of control pulses, a variety of exotic nonadiabatic cavity quantum electrodynamics effects can be observed. We show that control pulses with specific arrival times, performing which-path and quantum-eraser operations, are able to suddenly switch-off and on first-order coherence of cavity photons, without affecting their strong coupling population dynamics.

Quantum plasmonics with quantum dot-metal nanoparticle molecules: influence of the Fano effect on photon statistics.

We study theoretically the quantum optical properties of hybrid molecules composed of an individual quantum dot and a metallic nanoparticle. We calculate the resonance fluorescence of this composite system. Its incoherent part, arising from nonlinear quantum processes, is enhanced by more than 2 orders of magnitude as compared to that of the dot alone. The coupling between the two systems gives rise to a Fano interference effect which strongly influences the quantum statistical properties of the scattered photons: a small frequency shift of the incident light field may cause changes in the intensity correlation function of the scattered field of orders of magnitude. The system opens a good perspective for applications in active metamaterials and ultracompact single-photon devices.

Cryptococcus neoformans infection in a cohort of Italian AIDS patients: natural history, early prognostic parameters, and autopsy findings.

This observational cohort study of 4,160 AIDS patients hospitalised in a single institution in northern Italy between January 1985 and December 1999 was carried out in order to assess the natural history of cryptococcosis, the epidemiological trend of this opportunistic infection, the risk factors predictive of death at 10 weeks, the response to therapy, and autopsy findings. Cryptococcosis was diagnosed in 177 (4.2%) patients and was the AIDS-defining disease in 2.8% of cases. Its prevalence decreased significantly over time (from 6.4% in the period 1985-1989 to 5.7% in 1990-1993, 3.1% in 1994-1996, and 1.9% in 1997-1999, P <0.0001). Although neurologic disease was the most frequent clinical picture, a significant proportion of the patients (24.2%) presented with extraneural cryptococcosis. In a Cox multivariate analysis, high titres of cerebrospinal fluid antigen (>5000) and drug addiction were predictive of death at 10 weeks. A complete clinical and mycological response was achieved in 60.8% of the treated patients, with the highest response rate being observed in those treated with amphotericin plus flucytosine (66.6%). Cryptococcosis relapsed in 12.8% of patients on secondary prophylaxis. Autopsy findings demonstrated that cryptococcosis is a disseminated disease, but long-term antifungal treatment may be able to eradicate it in a subgroup of patients.

Cardiovascular disease risk factors in HIV-infected patients in the HAART era.

HIV infection is accompanied by disturbances in lipid and glucose metabolism, which are further compounded by changes induced by antiretroviral drugs. There is increasing concern that these changes will lead to an epidemic of cardiovascular disease. Cardiovascular disease will no doubt increase, but current data indicate that the average absolute levels are likely to remain low, although patients with additional risks (smoking, hypertension, diabetes, age, family history, etc.) are certainly more susceptible. The complications of therapy need to be taken into account when deciding on the time of treatment, and reducing risk factors should become a routine aspect of the care of an HIV population that now lives longer as a result of highly active antiretroviral therapy.

[Disseminated histoplasmosis in patients with AIDS. 2 case reports]. / Istoplasmosi disseminata in pazienti affetti da AIDS. Descrizione di due casi.

Histoplasmosis is endemic in some areas of United States and in South America, and generally causes an acute self-limiting respiratory infection. In elderly and immunosuppressed patients the infection can spread through the blood, causing a severe systemic illness. Here we describe two cases of disseminated histoplasmosis in AIDS patients. The first was observed in an Italian woman who had never visited endemic countries, and was recognized only at autopsy; the second was observed in a trans-sexual patient, arrived in Italy from Brazil. Clinical suspicion of histoplasmosis is important in immunocompromised patients of non-endemic areas as symptoms are often aspecific and misdiagnosis is frequent.

Post-kala-azar dermal leishmaniasis during highly active antiretroviral therapy in an AIDS patient infected with Leishmania infantum.

We report a case of post-kala-azar dermal leishmaniasis (PKDL) in a woman with AIDS which occurred 13 months after a diagnosis of visceral leishmaniasis concomitantly with immunological recovery induced by highly active retroviral therapy. Cytokine pattern at the time of visceral leishmaniasis and PKDL diagnosis was studied and pathogenic implications were discussed.

Persisting HIV-1 replication triggered by acute hepatitis A virus infection.

We report the case of two patients in whom acute hepatitis A was associated with a marked and prolonged increase in human immunodeficiency virus type 1 (HIV-1) viral load. Although in one patient the rise in HIV-1 RNA might also have been related to the interruption of antiretroviral therapy, we also observed a similar pattern in the other patient who had a stable undetectable plasma viraemia prior to acute hepatitis and never received treatment with anti-retrovirals. Our observation supports the hypothesis that immune activation that is induced by acute hepatitis A virus (HAV) infection may trigger HIV-1 replication. This highlights the importance of maintaining antiretroviral therapy throughout the acute phase of hepatitis A and of preventing HAV infection through active immunization.

Role of brain biopsy in the management of focal brain lesions in HIV-infected patients. Gruppo Italiano Cooperativo AIDS & Tumori.

In this multicenter, retrospective study of 160 brain biopsies in the assessment of HIV-related focal brain lesions, diagnostic sensitivity was acceptable (87%), but the procedure carried considerable morbidity (7.5%) and mortality (3.1%). Moreover, it is not always possible to initiate the changes in therapy indicated by the results, and overall survival remains poor, with a median of 2 months. Criteria for brain biopsy for the diagnosis of focal brain lesions should be redefined to include selected patients for whom a less invasive approach does not yield a definitive diagnosis.

Lung carcinoma in 36 patients with human immunodeficiency virus infection. The Italian Cooperative Group on AIDS and Tumors.

BACKGROUND: The current study describes the clinicopathologic characteristics of 36 patients with lung carcinoma and human immunodeficiency virus (HIV) infection observed within the Italian Cooperative Group on AIDS and Tumors (GICAT). METHODS: Patients with lung carcinoma and HIV infection collected by the GICAT between 1986-1998 were evaluated retrospectively. As a control group, the authors analyzed 102 patients age < 60 years with lung carcinoma but without HIV infection who were seen at the CRO, National Cancer Institute, Aviano, Italy between 1995-1996. RESULTS: Patients with lung carcinoma and HIV infection were younger (38 years vs. 53 years) and previously smoked more cigarettes per day (40 vs. 20) than the control group. The main histologic subtype was adenocarcinoma. TNM Stage III-IV disease was observed in 53% of the patients. The median CD4 cell count was 150/mm(3). The median overall survival was significantly shorter in the patients with HIV compared with the control group (5 months vs. 10 months; P = 0.0001). CONCLUSIONS: The results of the current study demonstrate that lung carcinoma in the HIV setting affects mainly young individuals with a history of heavy tobacco smoking and a moderately advanced immunodeficiency status. Lung carcinoma is associated with a more adverse outcome in HIV patients and represents the cause of death in the majority of these patients.

Body habitus alterations in HIV-infected women treated with combined antiretroviral therapy.

Fat distribution alterations are among the most frequent and unexpected side effects of combined antiretroviral therapy. They may occur in patients receiving protease inhibitor-containing regimens and those treated with combinations of only nucleoside reverse transcriptase inhibitors. The broad spectrum of body fat alterations, which are variably associated with metabolic abnormalities, raises the question as to whether they represent different components of the same syndrome or are manifestations of different pathogenetic mechanisms. Recent clinical evidence is consistent with a higher risk of developing body fat alterations in females. We here report three different aspects of body habitus changes in women treated with various antiretroviral regimens and describe their short-term follow-up. We also discuss the possible pathogenetic implications and the role of different drug classes according to present knowledge.