Unifying Frequency Combs in Active and Passive Cavities: Temporal Solitons in Externally Driven Ring Lasers.

Frequency combs have become a prominent research area in optics. Of particular interest as integrated comb technology are chip-scale sources, such as semiconductor lasers and microresonators, which consist of resonators embedding a nonlinear medium either with or without population inversion. Such active and passive cavities were so far treated distinctly. Here we propose a formal unification by introducing a general equation that describes both types of cavities. The equation also captures the physics of a hybrid device-a semiconductor ring laser with an external optical drive-in which we show the existence of temporal solitons, previously identified only in microresonators, thanks to symmetry breaking and self-localization phenomena typical of spatially extended dissipative systems.

Efficient parametric generation in a nonlinear photonic crystal pumped by a dual beam.

We investigate parametric down-conversion in a hexagonally poled nonlinear photonic crystal, pumped by a dual pump with a transverse modulation that matches the periodicity of the χ (2) nonlinear grating. A peculiar feature of this resonant configuration is that the two pumps simultaneously generate photon pairs over an entire branch of modes, via quasi-phase matching with both fundamental vectors of the reciprocal lattice of the nonlinearity. The parametric gain of these modes depends thus coherently on the sum of the two pump amplitudes and can be controlled by varying their relative intensities and phases. We find that a significant enhancement of the source conversion efficiency, comparable to that of one-dimensionally poled crystals, can be achieved by a dual symmetric pump. We also show how the four-mode coupling arising among shared modes at resonance can be tailored by changing the dual pump parameters.

Age-Related Changes in Physiological Reactivity to a Stress Task: A Near-Infrared Spectroscopy Study.

Aging is associated with changes in biological functions, such as reduced cardiovascular responses to stressful tasks. However, less is known about the influence of age on the reactivity of the prefrontal cortex (PFC) to acute stressors. Therefore, this study aimed to investigate the effects of a computerized-controlled stress task on the PFC and autonomic system activity in a sample of older and younger adults. We recruited a total of 55 healthy, right-handed persons (26 older adults with mean age 69.5, SD 5.8 years; and 29 younger adults with mean age 23.8, SD 3.3 years); groups were balanced for sex. Tasks included a control and an experimental condition: during both tasks individuals had to solve simple mental arithmetic problems. For the experimental condition, all participants were faced with a time limit that induced significant stress. Physiological indexes were collected continuously during the entire procedure using a 2-channel near infrared spectroscopy (NIRS) and an ECG monitoring system. Repeated measures ANOVA were used to assess changes in hemoglobin concentrations, and changes in both heart rate and performance outcomes. NIRS, ECG and performance data showed a significant interaction between the group and condition. Post-hoc analyses evidenced a significant increase in heart rate and Oxy-Hb concentration in the bilateral PFC between the control and experimental condition only in the younger group. Post-hoc analyses of behavioral data showed lower percentages of correct responses and higher response times in the older group. In summary, these results suggested that cardiovascular and cortical reactivity to stress tasks are a function of age. Older individuals seem to be characterized by blunted physiological reactivity, suggestive of impaired adaptive responses to acute stressors. Therefore, future studies should investigate the underlying physiological mechanisms of prefrontal and cardiovascular changes related to aging.

Micro and nanoparticles as possible pathogenetic co-factors in mixed cryoglobulinemia.

BACKGROUND: Mixed cryoglobulinemia (MC) is a rare multisystem disease whose aetiopathogenesis is not completely understood. Hepatitis C virus (HCV) infection may have a causative role, and genetic and/or environmental factors may also contribute. AIMS: To investigate the presence and possible role of environmental agents in MC. METHODS: We recruited 30 HCV-infected MC patients with different clinical manifestations and a control group of 30 healthy, sex-/age-matched volunteers. We collected serum samples from each patient and incubated at 4°C for 7 days to obtain cryoprecipitate samples. We used environmental scanning electron microscopy (ESEM) and energy dispersive X-ray spectroscopy microanalysis to verify the presence of microparticles (MPs) and nanoparticles (NPs) in serum and cryoprecipitate samples. We evaluated environmental exposure using a medical and occupational history questionnaire for each subject. RESULTS: MC patients had a significantly higher risk of occupational exposure (OR 5.6; 95% CI 1.84-17.50) than controls. ESEM evaluation revealed a significantly higher concentration, expressed as number of positive spots (NS), of serum inorganic particles in MC patients compared with controls (mean NS 18, SD = 16 versus NS 5.4, SD = 5.1; P < 0.05). Cryoprecipitate samples of MC patients showed high concentrations of inorganic particles (mean NS 49, SD = 19). We found a strong correlation between NS and cryocrit (i.e. percentage of cryoprecipitate/total serum after centrifugation at 4°C) levels (P < 0.001). CONCLUSIONS: In addition to HCV infection, MPs and NPs might play an important role in the aetiopathogenesis of MC.

Carcinogenic potential of metal nanoparticles in BALB/3T3 cell transformation assay.

Metal-based nanoparticles (NPs), are currently used in many application fields including consumer products, pharmaceuticals, and biomedical treatments. In spite to their wide applications, an in-depth study of their potential toxic effects is still lacking. The aim of the present research was to investigate the potential initiator or promoter-like activity of different metallic NPs such as gold, iron, cobalt, and cerium using the Balb/3T3 two-stage transformation assay. The results indicated that all the selected metallic NPs, except for cobalt, when used as initiators did not induce any transformation in Balb/3T3 cell line. Moreover, Au and Fe3 O4 NPs, when used in place of the tumor promoter treatment TPA, increased significantly the number of Foci/dish as compared to the MCA treatment alone. The number of Foci/dish was 2.6 for Au NPs and 2.13 for Fe3 O4 ones, similar to those obtained by the positive control treatment (MCA + TPA), whereas 1.27 for MCA treatment alone. On the contrary, CeO2 NPs did not show any difference in the number of Foci/dish, as compared to MCA alone, but it decreased the number of foci by 65% in comparison to the positive control (MCA + TPA). As expected, cobalt NPs showed an increased cytotoxicity and only a few surviving cells were found at the time of analysis showing a number of Foci/dish of 0.13. For the first time, our data clearly showed that Au and Fe3 O4 NPs act as promoters in the two stage transformational assay, suggesting the importance to fully investigate the NPs carcinogenic potential with different models.

Acquired immunodeficiency similar to Gulf War illness in a dead former serviceman.

A 38-year-old non-commissioned officer was certified unfit for military duty several months before his death. The forensic autopsy revealed a severe bone marrow aplasia and a pulmonary angioinvasive aspergillosis. Moreover, the presence of inorganic foreign particles in the pulmonary macrophages and intestinal endothelia was observed. The microanalysis implemented on these last selected specimens revealed the presence of silica particles microimpregnated by lanthanides and steel. The patient's acquired immunodeficiency appears comparable with that of Iraqi civilians suffering from Gulf War illness. This is the first report in the literature of the presence of intestinal endothelia engulfed by foreign war particulates; the silica particles may have entered the intestinal endothelia via the blood stream or by ingestion of impregnated fruit and vegetable foodstuffs. This finding provides new perspectives in the assessment of war-associated diseases and includes electron probe microanalysis among the new techniques of military and forensic medicine.

Features and organization of Pain Centers in the Lazio Region, Italy, in 2011.

BACKGROUND: Evidence on pain management highlights the importance of a multidisciplinary approach in order to achieve optimal therapeutic results. Such programs can be guaranteed by the Centers for Pain Management (CPMs), in which multidisciplinary teams are able to provide advanced and specialized activities for the assessment, diagnosis and treatment of chronic benign pain. To date, information related to healthcare supply and the organizational structure of these centers in Italy is incomplete. The aim of this paper was to provide an overview of the healthcare network of the CPMs in the Lazio region. METHODS: A descriptive survey was conducted in all the 37 CPMs existing in the Lazio region in 2011 of which 28 participated. RESULTS: CPMs were located either in Universities or in public or private hospital facilities. They included a clinic, a Day Hospital service, Day surgery and day-beds. CPMs were managed by anaesthesiologists who, in most instances, did not work in a multidisciplinary team. The number of other health professionals available, such as nurses, psychologists and physiotherapists, was limited. CPMs mainly provided drug therapy, Complementary Alternative Medicine (CAM) and complex interventional treatments. The median waiting time was 30 days. The clinics were not homogeneously distributed in the region with a higher concentration in Rome (56%), followed by other provinces of the Lazio region (26%) and the province of Rome (18%). Clearly, Rome was the city which offered the greatest range of healthcare services and the highest number of consultations with patients, which significantly differed from those of the other areas (χ²=19.6 p<0.01). CONCLUSIONS: In 2011, the availability of CPMs was not equally distributed throughout the territory, and there was an over-utilization of the facilities in Rome and an under-utilization in the provincial areas. Moreover, this study showed a lack of a multi-professional approach to chronic pain management.

Backscattering differential ghost imaging in turbid media.

In this Letter we present experimental results concerning the retrieval of images of absorbing objects immersed in turbid media via differential ghost imaging (DGI) in a backscattering configuration. The method has been applied, for the first time to our knowledge, to the imaging of thin black objects located inside a turbid solution in proximity of its surface. We show that it recovers images with a contrast better than standard noncorrelated direct imaging, but equivalent to noncorrelated diffusive imaging. A simple theoretical model capable of describing the basic optics of DGI in turbid media is proposed.

Metastatic volume: an old oncologic concept and a new prognostic factor for stage IV melanoma patients.

BACKGROUND: The last melanoma staging system of the 2009 American Joint Committee on Cancer takes into account, for stage IV disease, the serum levels of lactate dehydrogenase (LDH) and the site of distant metastases. OBJECTIVE: Our aim was to compare the significance of metastatic volume, as evaluated at the time of stage IV melanoma diagnosis, with other clinical predictors of prognosis. METHODS: We conducted a retrospective multicentric study. To establish which variables were statistically correlated both with death and survival time, contingency tables were evaluated. The overall survival curves were compared using the Kaplan-Meier method. RESULTS: Metastatic volume and number of affected organs were statistically related to death. In detail, patients with a metastatic volume >15 cm(3) had a worse prognosis than those with a volume lower than this value (survival probability at 60 months: 6.8 vs. 40.9%, respectively). The Kaplan-Meier method confirmed that survival time was significantly related to the site(s) of metastases, to elevated LDH serum levels and to melanoma stage according to the latest system. CONCLUSION: Our results suggest that metastatic volume may be considered as a useful prognostic factor for survival among melanoma patients.

Towards an objective theory of subjective liking: A first step in understanding the sense of beauty.

The study of the electroencephalogram signals recorded from subjects during an experience is a way to understand the brain processes that underlie their physical and emotional involvement. Such signals have the form of time series, and their analysis could benefit from applying techniques that are specific to this kind of data. Neuroaesthetics, as defined by Zeki in 1999, is the scientific approach to the study of aesthetic perceptions of art, music, or any other experience that can give rise to aesthetic judgments, such as liking or disliking a painting. Starting from a proprietary dataset of 248 trials from 16 subjects exposed to art paintings, using a real ecological context, this paper analyses the application of a novel symbolic machine learning technique, specifically designed to extract information from unstructured data and to express it in form of logical rules. Our purpose is to extract qualitative and quantitative logical rules, to relate the voltage at specific frequencies and in specific electrodes, and that, within the limits of the experiment, may help to understand the brain process that drives liking or disliking experiences in human subjects.

Experimental observation of a skewed X-type spatiotemporal correlation of ultrabroadband twin beams.

This work presents the experimental observation of the nonfactorable near-field spatiotemporal correlation of ultrabroadband twin beams generated by parametric down-conversion, in an interferometric-type experiment using sum frequency generation, where both the temporal and the spatial degrees of freedom of parametric down-conversion light are controlled with high resolution. The revealed correlation is skewed in space-time in accordance with the X structure predicted by the theory.

Detection of the ultranarrow temporal correlation of twin beams via sum-frequency generation.

We demonstrate the ultranarrow temporal correlation (6 fs full width half maximum) of twin beams generated by parametric down-conversion by using its reverse process, i.e., sum-frequency generation. The result relies on an achromatic imaging of a huge bandwidth of twin beams and on a careful control of their spatial degrees of freedom. The detrimental effects of spatial filtering and imperfect imaging are shown, along with the theoretical model used to describe the results.

[Modalities for access to networks of palliative care and pain management in Lazio: level of information for health personnel aware of the Policlinico Tor Vergata]. / Modalità per l'accesso alle reti di cure palliative e terapia del dolore nel Lazio: grado di informazione del personale sanitario del Policlinico Tor Vergata.

Law no. 38 of 2010 introduces for the first time protection for access to Palliative Care and Pain Management. It was interesting to evaluate the level of knowledge among health care workers at the Policlinico Tor Vergata, procedures relating to such access through the administration of a questionnaire. The questionnaire divided into a general part and the two sections (A and B) The general part concerns the health operator respect to age, gender, profession, and his role within the operating unit of the hospital. The section A and B, is to understand if the operator knows Palliative Care, and Pain Therapy, as he became aware of the two arguments, and if they have been addressed during the university courses he attended. The analysis of the data examined show a general confusion distributed evenly among all professionals. Is greater knowledge of pain therapy compared to Palliative Care.

Long-term controlled-release oxycodone and pregabalin in the treatment of non-cancer pain: an observational study.

AIMS: This study evaluates the efficacy and tolerability of long-term controlled-release (CR) oxycodone + pregabalin in patients with non-cancer pain, in a real-life setting. METHODS: Patients (n = 1,051) with chronic uncontrolled non-cancer pain received CR oxycodone + pregabalin for 1 year. Pain intensity was rated on an 11-point numerical rating scale (NRS) at months 1, 2, 4, 6, 9 and 12. RESULTS: Throughout the study period, the NRS score decreased significantly (baseline: 7.02 ± 1.26; 12 months: 1.45 ± 0.92; p = 0.00001). Following an initial increase in the mean daily doses of CR oxycodone (starting dose: 12.5 ± 8.4 mg) and pregabalin (starting dose: 121.7 ± 97.2 mg), dose reductions were seen for both drugs with the trend particularly evident for CR oxycodone. 23% of patients withdrew from the study, mainly due to adverse events (67.9% of withdrawn subjects). However, 19.7% of withdrawn patients were removed from the study due to complete relief from chronic pain. The combination was generally well tolerated and there were no reports of addiction. CONCLUSION: The combination of CR oxycodone + pregabalin could represent a valuable long-term therapeutic addition to existing pharmacological options for the treatment of non-cancer pain.

Mesotherapy, definition, rationale and clinical role: a consensus report from the Italian Society of Mesotherapy.

OBJECTIVE: Since its introduction in the 1950s, the use of mesotherapy has generated much interest among clinicians and patients. The Italian Society of Mesotherapy (SIM) brought together a panel of experts to review available evidence and to draw up a series of recommendations on the use of intradermal therapy (LIT) in clinical practice. CONSENSUS REPORT: There was overwhelming agreement among Consensus Group members that, when used correctly, LIT is a valuable therapeutic option in the treatment of painful, loco-regional conditions. They also emphasised that the clinical efficacy of LIT has been demonstrated in the management of chronic venous lymphatic insufficiency, oedematous fibrosclerotic panniculopathy and facial skin aging. The experts were unanimous on the use of LIT in vaccination. Mesotherapy is not a substitute for other therapeutic options and should only be used when the patient has been fully informed of its advantages and limitations. Likewise the procedure should only be carried out by an experienced qualified physician. CONCLUSIONS: Although there was widespread agreement among the Consensus Group on the place of LIT in several indications, the Authors reiterated the need for more large-scale clinical trials to determine the specific benefits and limitations in some areas of the application of intradermal therapy.

No evidence of family history as a risk factor for herpes zoster in patients with post-herpetic neuralgia.

Little is known about reactivation of latent varicella zoster virus as herpes zoster in individuals with no underlying immunosuppression. Risk factors include age, sex, ethnicity, exogenous boosting of immunity from varicella contacts, underlying cell-mediated immune disorders, mechanical trauma, psychological stress, and immunotoxin exposure. An association between herpes zoster and family history of zoster has been proposed. A case-control study involving patients affected by post-herpetic neuralgia, which usually follows more severe acute herpes zoster, was performed. The patients with post-herpetic neuralgia were enrolled at the Pain Clinic of the Policlinico Tor Vergata in Rome, Italy, within 1 year from the onset of acute zoster. The controls matched for sex and age were chosen among healthy subjects without a history of herpes zoster presenting at the Internal Medicine Outpatient Clinic for hypertension in the same time period. All the participants in the study gave informed consent and were interviewed by medically trained and blinded investigators using a questionnaire. Similar proportions of the patients and the controls reported a family history of herpes zoster irrespective of the degree of relationship, i.e., 17.4% and 18.2%, respectively, by analyzing only the first-degree relatives [RR 1.03 (CI 95%: 0.78-1.37)], and 28.4% and 29.6%, respectively, by analyzing the total number of relatives [RR 1.03 (CI 95%: 0.81-1.31)]. Further and larger prospective cohort studies are needed to ascertain whether a family history of herpes zoster is really an independent predictor of zoster in different geographical settings.

Differential ghost imaging.

We present a new technique, differential ghost imaging (DGI), which dramatically enhances the signal-to-noise ratio (SNR) of imaging methods based on spatially correlated beams. DGI can measure the transmission function of an object in absolute units, with a SNR that can be orders of magnitude higher than the one achievable with the conventional ghost imaging (GI) analysis. This feature allows for the first time, to our knowledge, the imaging of weakly absorbing objects, which represents a breakthrough for GI applications. Theoretical analysis and experimental and numerical data assessing the performances of the technique are presented.

Influence of acupuncture on type I hypersensitivity itch and the wheal and flare response in adults with atopic eczema - a blinded, randomized, placebo-controlled, crossover trial.

BACKGROUND: Itch is a major symptom of allergic skin disease. Acupuncture has been shown to exhibit a significant effect on histamine-induced itch in healthy volunteers. We investigated the effect of acupuncture on type I hypersensitivity itch and skin reaction in a double-blind, randomized, placebo-controlled, crossover trial. METHODS: An allergen stimulus (house dust mite or grass pollen skin prick) was applied to 30 patients with atopic eczema before (direct effect) and after (preventive effect) two experimental approaches or control observation: acupuncture at points Quchi and Xuehai [verum acupuncture (VA), dominant side], 'placebo-point' acupuncture (PA, dominant side), no acupuncture (NA). Itch intensity was recorded on a visual analogue scale. After 10 min, wheal and flare size and skin perfusion (via LASER-Doppler) were measured at the stimulus site, and the validated Eppendorf Itch Questionnaire (EIQ) was answered. RESULTS: Mean itch intensity was significantly lower in VA (35.7 +/- 6.4) compared to NA (45.9 +/- 7.8) and PA (40.4 +/- 5.8) regarding the direct effect; and significantly lower in VA (34.3 +/- 7.1) and PA (37.8 +/- 5.6) compared to NA (44.6 +/- 6.2) regarding the preventive effect. In the preventive approach, mean wheal and flare size were significantly smaller in VA (0.38 +/- 0.12 cm(2)/8.1 +/- 2.0 cm(2)) compared to PA (0.54 +/- 0.13 cm(2)/13.5 +/- 2.8 cm(2)) and NA (0.73 +/- 0.28 cm(2)/15.1 +/- 4.1 cm(2)), and mean perfusion in VA (72.4 +/- 10.7) compared to NA (84.1 +/- 10.7). Mean EIQ ratings were significantly lower in VA compared to NA and PA in the treatment approach; and significantly lower in VA and PA compared to NA in the preventive approach. CONCLUSIONS: Acupuncture at the correct points showed a significant reduction in type I hypersensitivity itch in patients with atopic eczema. With time the preventive point-specific effect diminished with regard to subjective itch sensation, whereas it increased in suppressing skin-prick reactions.