Affine diffractive beam dividers

Diffractive optical elements that divide an input beam into a set of replicas are used in many optical applications ranging from image processing to communications. Their design requires time-consuming optimization processes, which, for a given number of generated beams, are to be separately treated for one-dimensional and two-dimensional cases because the corresponding optimal efficiencies may be different. After generalizing their Fourier treatment, we prove that, once a particular divider has been designed, its transmission function can be used to generate numberless other dividers through affine transforms that preserve the efficiency of the original element without requiring any further optimization.

Tracking flowpaths in a complex karst system through tracer test and hydrogeochemical monitoring: Implications for groundwater protection (Gran Sasso, Italy)

Groundwater in karst aquifers is frequently tapped for drinking purposes, due to frequent huge volumes of resources. Unfortunately, vulnerability of these aquifers can be high, due to possible fast transfer of recharge water on springs by the karst network. On Gran Sasso Mountain regional aquifer, several springs are subjected to drinking withdrawal and an updated evaluation of their potential is now a fundamental issue to be considered, facing climate change effects, which reflect on variation of discharge regimen and values. To distinguish between different contribution of spring recharge, a tracer test has been carried out on the Vitella d'Oro spring, fed both by the regional aquifer and by a local system exposed to karst features developed in the Rigopiano Conglomerates formation. Thanks to hydrogeological, hydrogeochemical and isotopic data, a conceptual model of spring recharge has been proposed and subsequently validated by the tracer test results. All information confirms the superimposition on the regional base flow, by a relevant contribution of the karst network, influencing the spring discharge in recharge periods. In detail, a fast flow component is responsible for discharge peaks and frequently of turbidity events, having a mean velocity ranging from 30 to 70 m/h in the aquifer. Besides of this fast flow, an additional aliquot of the recharge is due to the same local aquifer, but slower flow clearly identifiable by hydrochemistry and isotopic data. Thanks to these findings, a renewed management of the spring has been suggested, considering the different degrees of aquifer vulnerability (turbidity occurrence) directly related to the discharge regimen.

The role of mesotherapy in the management of spinal pain. A randomized controlled study

Background

Mesotherapy is a technique through which active ingredients are administered into the thickness of the skin in order to increase the local analgesic effect.

Methods

141 patients with spinal pain not responding to systemic therapy with NSAIDs were randomized to receive one or more intra-cutaneous drugs on a weekly basis.

Results

All patients achieved a pain reduction of at least 50% compared to baseline, and all tolerated the therapy without having to resort to systemic drug dose increases.

Conclusions

The data from our study show that the active ingredients infiltrated into the skin induce a mesodermal modulation between the infiltrated liquid and the cutaneous nervous and cellular structures from which the typical drug-saving effect of mesotherapy arises. Although further studies are needed to establish how to integrate mesotherapy in various clinical settings, it appears to be a useful technique available to the practicing physician. This research is also useful in guiding future clinical research.

Three-dimensional polarization of fields radiated by partially coherent electromagnetic cylindrical sources

Partially coherent electromagnetic sources with cylindrical symmetry and infinite extent radiating outward are introduced. Their 3 × 3 cross-spectral density matrix is given through expansions of the field components in terms of basis functions related to the Hankel functions. The spectral density and the three-dimensional degree of polarization of such sources and the fields they radiate are examined. Several examples are presented and discussed. Among them, a class of cylindrical sources whose coherent vector modes coincide with the above basis functions is defined and studied.

Partially coherent spherical sources with spherical harmonic modes

A class of partially coherent spherical sources is introduced whose cross-spectral density across the surface has a modal expansion made up of spherical harmonics. For such sources, the solution of the propagation problem in all the outer spaces can be written through a series of the propagated modes, which maintains the spherical harmonic structure. The main features of this class of cross-spectral densities are derived illustrating their coherence properties with examples. Attention is paid to the properties of radial coherence. In particular, it is clearly shown that sources with perfect radial coherence exist with angular coherence that is only partial.

Cylindrical partially coherent scalar sources

Partially coherent scalar sources with cylindrical symmetry radiating outwards are introduced. Homogeneous cross-spectral densities are shown to possess angularly modulated Hankel modes, whose amplitudes are subject to a filtering process during propagation. Simple criteria for treating such sources are given. For the case of an incoherent cylinder, the number of effective modes is found and spatial coherence is shown to appear in the radiated light. The radial coherence of the radiated field is then examined. Non-homogeneous cylindrical sources are also introduced.

On-axis polarization of beams radiated by electromagnetic circularly coherent sources

On-axis spectral density and degree of polarization of beams radiated by electromagnetic (EM) sources with circular correlations are shown to be finely controlled by changing the source parameters. We reveal, in particular, that in this beam class, unlike for all previously known stationary beams, it is possible to control independently the dynamics of the on-axis spectral density and the degree of polarization. This was enabled by the obtained analytical expression for the on-axis polarization matrix, derived for general EM sources with circular coherence and Gaussian spectral density across the source plane. A simple experimental scheme for generating a broad class of EM circularly coherent sources is devised involving only a line source, a lens, and a transparency, possibly anisotropic.

Tailoring on-axis spectral density with circularly coherent light beams

The on-axis cross-spectral density (CSD) of a beam radiated by a stationary source with a circular coherence state and a Gaussian spectral density is obtained in the closed form. It is revealed that the on-axis CSD is expressed via the Laplace transform of the source's degree of coherence or the Hilbert transform of the corresponding pseudo-mode weighting function. Such relations enable efficient tailoring of the on-axis spectral density, as we show with a slew of numerical examples.

On z-coherence of beams radiated by Schell-model sources with Gaussian profile

The degree of coherence and the intensity distribution on the axis of the beam radiated by a planar partially coherent source of the Schell-model type are investigated. We present an expression for the on-axis cross-spectral density which is valid for a very general Schell-model source, with the only constraint that the intensity distribution across the source is Gaussian. Furthermore, we show that such an expression takes very simple analytical forms for several commonly used degrees of coherence of the source.

On z-coherence in self-focusing

Both the intensity distribution and the degree of coherence between pairs of points along the propagation axis (z-coherence) are derived in closed form for a phenomenon of self-focusing produced by circularly coherent light. The first confirms results previously obtained numerically, while the second exhibits new complex features. The physical interpretation is obtained by a suitable pseudo-modal expansion that suggests an analogy with a simple two-mode structure.

Intradermal therapy (mesotherapy): the lower the better

BACKGROUND

Intradermal therapy (mesotherapy) is a technique used to inject drugs into the surface layer of the skin. The intradermal micro deposit allows to modulate the kinetics of drugs, slowing down its absorption and prolonging the local mechanism of action. This technique is applied in the treatment of some forms of localized pain when a systemic drug-saving effect is useful, when it is necessary to synergize with other pharmacological or non-pharmacological thera-pies, when other therapies have failed or cannot be used.

AIM

The purpose of our study was to evaluate the effect of a mixture with respect to its lower concentration. We also wanted to evaluate the number of sessions needed to reach the therapeutic goal (50% reduction in pain from baseline) in patients with acute or chronic neck pain.

METHOD

We analyzed retrospectively data from 62 patients with cervicobrachial pain treated with intradermal drugs. Group A received a mixture of drugs; group B received half the dose of drugs.

RESULTS

Patients who received a lower concentration of drugs achieved similar results to those who received a higher dose. The therapeutic goal was achieved on average with 3.5 + 1.7 sessions on a weekly basis (min 1; max 9). Subjects in group A required 4+1.7 treatments (min 1; max 9), while subjects in group B required 3+1.5 treatments (min 1; max 7).

CONCLUSIONS

Our study confirms that even a lower dose of drugs can induce a clinically useful result. This study confirms that the useful effect of mesotherapy is only partly due to the pharmacological action. Further randomized prospective studies are needed to standardize the technique in the various pain syndromes, but it is recommended to follow the guidelines of the Italian Society of Mesotherapy to ensure patients receive appropriate treatment.

A randomised, double-blind, sham-controlled study of left prefrontal cortex 15 Hz repetitive transcranial magnetic stimulation in cocaine consumption and craving

Background

Cocaine use disorder (CUD) is a global health issue with no effective treatment. Repetitive Transcranial Magnetic Stimulation (rTMS) is a recently proposed therapy for CUD.

Methods

We conducted a single-center, randomised, sham-controlled, blinded, parallel-group research with patients randomly allocated to rTMS (15 Hz) or Sham group (1:1) using a computerised block randomisation process. We enrolled 62 of 81 CUD patients in two years. Patients were followed for eight weeks after receiving 15 15 Hz rTMS/sham sessions over the left dorsolateral prefrontal cortex (DLPFC) during the first three weeks of the study. We targeted the DLFPC following the 5 cm method. Cocaine lapses in twice a week urine tests were the primary outcome. The secondary outcomes were craving severity, cocaine use pattern, and psychometric assessments.

Findings

We randomly allocated patients to either an active rTMS group (32 subjects) or a sham treatment group (30 subjects). Thirteen (42%) and twelve (43.3%) of the subjects in rTMS and sham groups, respectively, completed the full trial regimen, displaying a high dropout rate. Ten/30 (33%) of rTMS-treated patients tested negative for cocaine in urine, in contrast to 4/27 of placebo controls (p = 0.18, odd ratio 2.88, CI 0.9–10). The Kaplan-Meier survival curve did not state a significant change between the treated and sham groups in the time of cocaine urine negativisation (p = 0.20). However, the severity of cocaine-related cues mediated craving (VAS peak) was substantially decreased in the rTMS treated group (p<0.03) after treatment at T1, corresponding to the end of rTMS treatment. Furthermore, in the rTMS and sham groups, self-reported days of cocaine use decreased significantly (p<0.03). Finally, psychometric impulsivity parameters improved in rTMS-treated patients, while depression scales improved in both groups.

Conclusions

In CUD, rTMS could be a useful tool for lowering cocaine craving and consumption.

Trial registration

The study number on clinicalTrials.gov is NCT03607591.

Evidence based recommendations on mesotherapy: an update from the Italian society of Mesotherapy

INTRODUCTION

Mesotherapy, also known as local intradermal therapy, widely used all over the world, is a technique used to inject substances into the surface layer of the skin. There are no international guidelines for the correct use of this technique and in many countries, it is still applied empirically without valid patient consent. The Italian society of mesotherapy has planned a study to assess the rationale and clinical applications based on current evidence.

METHODS

An independent steering committee, based on the available scientific literature, has formulated a series of clinical questions. 21 experts responded by writing an evidence-based document. From this document 30 statements were obtained which were presented to 114 experts using the Delphi method.

RESULTS

28 statements reached a broad agreement on definition, technique, pharmacological rationale, indications and some crucial ethical aspect.

CONCLUSIONS

Although further studies are needed to establish the clinical role of this technique in each field of application, our statements recommend the correct application according to the needs of the individual patient in full respect of ethics.

Evidence of Air Trapping During Ex Vivo Lung Perfusion: A Swine Experimental Lung Imaging and Mechanics Study

Ex vivo lung perfusion (EVLP) allows the ventilation and perfusion of lungs to evaluate their viability for transplantation. The aim of this study is to compare the mechanical, morphologic and functional properties of lungs during EVLP with values obtained in vivo to guide a safe mechanical ventilation strategy. Lungs from 5 healthy pigs were studied in vivo and during 4 hours of EVLP. Lung compliance, airway resistance, gas exchange, and hemodynamic parameters were collected at positive end-expiratory pressure (PEEP) of 5 cm H₂O. Computed tomography was performed at PEEP 0, PEEP 5, and total lung capacity (TLC). Lung pressure-volume (PV) curves were performed from PEEP 0 to TLC. Lung compliance decreased during EVLP (53 ± 5 mL/cm H₂O vs 29 ± 7 mL/cm H₂O, P < .05), and the PV curve showed a lower inflection point. Gas content (528 ± 118 mL vs 892 ± 402 mL at PEEP 0) and airway resistance (25 ± 5 vs 44 ± 9 cmH₂O/L∗s^-1, P < .05) were higher during EVLP. Alveolar dead space (5% ± 2% vs 17% ± 6%, P < .05) and intrapulmonary shunt (9% ± 2% vs 28% ± 13%, P < .05) increased ex vivo compared to in vivo, while the partial pressure of oxygen to inspired oxygen fraction ratio (PO₂/FiO₂) did not differ (468 ± 52 mm Hg vs 536 ± 14 mm Hg). In conclusion, during EVLP lungs show signs of air trapping and bronchoconstriction, resulting in low compliance and increased alveolar dead space. Intrapulmonary shunt is high despite oxygenation levels acceptable for transplantation.

Portrait of young Italian university smoker student

Background

Smoking is a widespread problem in all age and social groups. Number of smokers is increasing among students and the years of university are those in which it is most common to start smoking.

The aim of this study is to outline the profile of the smoker university student.

Methods

Between October 2018 and January 2019, a sample of 150 smoking students of Siena University were randomly selected. We administered the structured Fagerstrom test. This test contained six items to evaluate the dependence and the quantity of cigarettes consumption. We conducted a descriptive analysis and a linear regression using software Stata.

Results

The sample was composed of 75 males (50%) and 75 females (50%), with a mean age of 24.6 years (sd 3.1). About 45% of the participants smoked between 11 and 20 cigarettes a day. Fifty per cent of the respondents lighted the first cigarette after 1 hour since they woke up, indeed only about the 25% preferred to smoke just woke up and would hardly give up the first cigarette. About the 80% did not show difficulty to avoid smoking in forbidden places or when they were ill. The mean degree of dependence of cigarettes was 2.7 (sd 2.3), considered as medium-low level of dependence. The degree of dependence (0 -10) was correlated with every items of the test, resulting: time to lighted the first cigarette (r = 0.71, p &lt; 0.005), difficulty to refrain from smoking in places where is forbidden (r = 0.41, p &lt; 0.005), cigarette hate to give up (r = 0.32, p &lt; 0.005), number of cigarettes smoked a day (r = 0.69, p &lt; 0.005), smoking more frequently in the morning (r = 0.26, p &lt; 0.005), smoking even if being sick (r = 0.27, p &lt; 0.005). The gender did not show correlation with any variables.

Conclusions

The our sample showed a medium-low level of dependence from nicotine (11-20 cigarettes a day) with the time to light up the first cigarette after 60 minutes; as resulted from the linear regression analysis. The gender did not have correlation with the dependence from cigarettes.

Key messages

Outline the profile of the joung smoker university student. Smoking is a widespread problem in all age and social groups.

Antibiotic consumption and healthcare associated infection in a third level Italian hospital

Background

The extended length of stay (LoS) is one of the main causes of hospital infections (HAI), followed by an increase in antibiotics consumption. The final step is the development of multiresistant microorganisms, with a consequent increase in costs for the national healthcare system. Aim of this study is to evaluate the prevalence of HAI and to analyze ATB consumption in a teaching hospital

Methods

Between 17-21 June 2019 the infection control team collected the clinical records of 425 patients to perform a point of prevalence analysis (PPA). Eligible patients were hospitalized in surgical and medical wards of the teaching Hospital (615 beds) in Siena, Italy. For each patients according to guidelines of European Centers for Disease Control and Prevention (ECDC 4.2) we searched for evidence of HAI and for all indication of ATB consumption. Data were processed using Stata12

Results

Overall 425 patients have been analyzed (48.24% female), mean age was 60.88 (SD 26.11) years, mean LoS 8.37 (min 1 max 86) days. Patients were admitted mostly in General Medicine wards (48.94%); 34% underwent surgery. 63.8% of patients had Peripheral Venous Catheter, 20% Central Venous Catheter and 31.06% Urinary Catheter. Twenty-nine HAI were discovered (PPA 6.82%); the higher prevalence (19.23%) was in Intensive Care Unit. LoS (OR:1.07;IC95%1.04-1.1) and devices (OR:2.17;IC95%1.39-3.37) were the two variables that significantly influenced the infection risk. Forty-six percent of all patients received ATB, the most used were third generation Cephalosporines (26,18%), followed by Penicillines (24,73%). The main use was to treat community infections (62.12%), followed by medical prophylaxis (30.81%)

Conclusions

PPA of HAI was 6.82%, comparable to 2017 national PPA (6.5%); prolonged LoS is probably the main cause of this result. Our analysis showed that ATB consumption was quite high, in agreement with the Italian prevalence (44.9%), but the percentage of medical prophylaxis was still high.

Key messages

The way to achieve the health care infection control is still long, the length of the hospitalization could be a field to be improved. High consumption of antibiotics for prophylaxis is still the main point to fight in the battle against the multiresistant microorganisms.

Efficacy of tapentadol prolonged release for pre- and post-operative low back pain: a prospective observational study

OBJECTIVE

Low back pain (LBP) is a highly prevalent chronic pain condition with a neuropathic component of pain that limits the benefits of classical opioids. Tapentadol is an innovative drug for the treatment of chronic severe pain, with a dual mechanism of action combining µ-opioid receptors agonism and noradrenaline re-uptake inhibition (NRI). Its efficacy is equal to that of strong opioids, with a better tolerability profile and a consequently lower risk of treatment discontinuation. The aim of this study was to evaluate the analgesic efficacy and tolerability of tapentadol prolonged release (PR) vs. other analgesics in patients with moderate-to-severe neuropathic low back pain, before and after back surgery.

PATIENTS AND METHODS

The primary endpoints of the study were the rate of response to treatment, measured as ≥30% reduction in pain intensity on the Numeric Rating Scale (NRS), and tapentadol PR efficacy for pain relief. The secondary endpoints were the improvements of the neuropathic component of pain and of sleep quality.

RESULTS

A total of 40 patients were enrolled in the study, receiving either tapentadol PR (n=21, 52.5%) or other analgesics (n=19, 47.5%), both before and after surgery. The rate of response to treatment was statistically in favor of tapentadol PR (p<0.01). The reduction in pain intensity was statistically significant in the group treated with tapentadol PR, both before and after surgery (p<0.01), with a complete resolution of pain 90 days after surgery. The quality of sleep after surgery improved more in patients treated with tapentadol PR than in the comparator group (p<0.01), with 100% of the patients reporting a "good" sleep quality 2 months after surgery.

CONCLUSIONS

Tapentadol PR was well tolerated by all patients, and its efficacy for pain relief was also confirmed in our small group of "real-life" patients with chronic, severe low back pain. Overall, the tolerability of this treatment may help to improve patients' quality of life, which is frequently compromised because of pain and its related comorbidities.

The decomposition of life expectancy for age and cause of death in Tuscany, Italy

Introduction

Changing of life expectancy at birth (LE) over time reflects variations of mortality rates of a certain population. Italy is amongst the countries with the highest LE, Tuscany ranks fifth at the national level. The aim of the present work was to evaluate the impact of various causes of death in different age groups on the change in LE in the Tuscany region (Italy) during period 1987-2015.

Material and methods

Mortality data relative to residents that died during the period between 1987/1989 and 2013/2015 were provided by the Tuscan Regional Mortality Registry. The causes of death taken into consideration were cardiovascular (CVS), respiratory (RESP) and infective (INF) diseases and cancer (TUM). The decomposition of LE gain was realized with software Epidat, using the Pollard’s method.

Results

The overall LE gain during the period between two three-years periods was 6.7 years for males, with a major gain between 65-89, and 4.5 years for females, mainly improved between 75-89, &lt;1 year for both sexes. The major gain (2.6 years) was attributable to the reduction of mortality for CVS, followed by TUM (1.76 in males and 0.83 in females) and RESP (0.4 in males; 0.1 in females). The major loss of years of LE was attributable to INF (-0.15 in females; -0.07 in males) and lung cancer in females (-0.13), for which the opposite result was observed for males (gain of 0.62 years of LE).

Conclusions

During the study period (1987-2015) the gain in LE was major for males. To the reduction of mortality for CVS have contributed to the tempestuous treatment of acute CVS events and secondary CVS prevention. For TUM the result is attributable to the adherence of population to oncologic screening programmes. The excess of mortality for INF that lead to the loss of LE can be attributed to the passage from ICD-9 to ICD-10 in 2003 (higher sensibility of ICD-10) and to the diffusion of multi-drug resistant bacteria, which lead to elevated mortality in these years.

Key messages

The gain in LE during the period the 1987-2015 was higher in males. The major contribution to gain in LE was due to a reduction of mortality for CVS diseases.

Mortality trends for multiple sclerosis in Italy

Background

Multiple sclerosis (MS) is the immune-mediated inflammatory disease affecting myelinated axons of the central nervous system with enormous socio-economic impact. The aim of this study was to analyze mortality trends for MS in Italy.

Methods

The mortality data relative to period 1980-2015 were provided by Italian Institute of Statistics, data were aggregated in 5 intervals (1980-1986; 1987-1993; 1994-2000; 2001-2008; 2008-2015). The Age-Standardized mortality Rates (SR) with respective 95% confidence intervals (95%CI) were calculated (using the European standard 2013) in order to evaluate the mortality trends (in confrontation to the initial period) and Standardized Mortality Ratios (SMR), in order to confront mortality in 5 major geographic areas: North-East (NE), North-West (NW), Central Italy (CI), South Italy (SI) and Islands (I).

Results

During the study period 4959 deaths for males and 7433 for females were observed. The SRs were significantly higher for females (0.71;95%CI:0.70-0.73 vs. 0.56; 95%CI:0.54-0.57).

Significantly higher SMR were observed for both sexes in I (M:123.3 vs F:112.7), for females also in NE (106.5) and NW (115.8). Significantly lower SMR for both sexes were observed in SI (M:88.8; F:71.4) and for males in CI (90.9).

The observed SRs during the five intervals for males were: 0.65(95%CI 0.60-0.69); 0.52 (95%CI 0.49-0.56); 0.46 (95%CI 0.43-0.49); 0.53 (95%CI 0.49-0.56); 0.59 (95%CI 0.56-0.62); and for females: 0.69 (0.65-0.73); 0.69 (0.65-0.73); 0.61 (0.58-0.65); 0.68 (0.65-0.72); 0.81(0.77-0.84); respectively. An initial decrease of SRs was observed for males until 2001-2007 in confrontation to the initial period (p &lt; 0.05). For females significant increase of SRs was observed in 2008-2015 (p &lt; 0.05).

Conclusions

An increase of mortality for MS, observed for females, especially after 2000 may reflect the raising prevalence of MS in Italy. Important geographical differences were observed for five main areas.

Key messages

During the study period an increase of mortality for MS was observed for females. Important differences were observed between five main Italian geographic areas.

Hospital acquired infection, evaluation of point of prevalence in a 147 beds italian hospital

Background

Hospital Acquired Infections (HAI) have become a public health priority worldwide, leading to higher medical costs, prolonged hospital stays, and increased mortality. The point of prevalence analysis (PPA) of HAI and antibiotics (ATB) consumption is extremely relevant for its social and economic impact. Aim of this study is to evaluate the prevalence of HAI and to analyze ATB consumption in 147 beds hospital.

Material and Methods

This prevalence study was conduced on March 23, 2018, we analyzed the clinical documentation of 78 patients hospitalized in the Hospital of Val D’Elsa, Siena, Italy and searched for evidence of HAI and for all indication of ATB therapy in all hospital wards. HAI were defined according to guidelines of European Centers for Disease Control and Prevention (ECDC 4.2) using Stata 12.

Results

We analyzed a total of 78 patients (51,3% female), average age was 71,6 (sd ± 23,4) years, mean lenght of stay 7,2 (sd ± 7,9) days. Patients included in the study were recovered mostly in General Medicine ward (62,8%); 23% of patients underwent surgery. Fifty-one point three of patients had Peripheral Venous Catheter, 17,9% Central Venous Catheter and 47,4% Urinary Catheter. Three infections were discovered (PPA 3,8%); 2 HAIs were found in Medicine ward, the third one in the Intensive Care Unit. The chi-square test did not show statistically significant differences with the last year’s results in the same wards (p = 0.3305). Fifty-four percent of all patients received ATB, the most used class were third generation Cephalosporines (50%), followed by Carbapenems (19%) and Fluoroquinolones (7%).

Conclusions

PPA of HAI was 3,8%, comparable to last year’s (3,5%). This is a positive result when compared to regional and national point prevalence study realized by ECDC in 2012 (6,2% in Tuscany Region, 6% in Italy). Our analysis showed that ATB consumption was quite high: and it is in agreement with those provided by the Tuscany Region.

Key messages

in our hospital we report an excellent result about the pint of prevalence of hospital acquired infections 3,8%. The antibiotics consumption in our hospital is quite high, the most frequently used antibiotic class is the third generation Cephalosporines.

Could chips and nuts be vector of food-borne outbreaks during happy hour?

Background

A Greater tendency to eat meals outside the home has led to an increase in the attendance of restaurants, cafes, and fast food. That is one of the reasons why the global interest in handling food has risen over the years. The aim of this study is to understand the level of microbial contamination in the food that is served along happy hour in cafe.

Methods

This cross sectional pilot study was performed from April to May 2018 in the city of Siena, central Italy (&lt;60000 citizens). Ten cafes were randomly selected. Samples of peanuts and potatoes were obtained in three different moments, at the beginning (T0), in the middle (T1), at the end (T2) of happy hours events. Collection of the samples was obtained using sterile kit and laboratory analysis was conducted in the University lab. The samples were located on selective medium and the growth of microbial pathogens were checked at 24 and 48 hours. The tested microorganisms were Enterococci, Staphylococci, Coliforms bacteria, Molds, and Yeasts. The statistical analyses were conducted using the Wilcoxon test using Stata 12.

Results

A significant Yeasts contamination appeared only on chips at T0, while within T0 and T1 we found a significant increase of Enterococci, Staphylococci, and Yeasts (p &lt; 0.05) both in peanuts and chips. Comparing T1 and T2 only Yeasts showed significant growth in potatoes (p = 0.04). Between T0 and T2 we also found the growth of Coliforms bacteria in peanuts (p = 0.03).

Conclusions

We showed an increase in the microbial load associated with food handling, mostly of Enterococci. Long exposure time increased the likelihood of contamination and the possibility to exceed the dose for the occurrence of good outbreak. It is likely that offering small portions of handling food would reduce the manipulation by participants and the risk of food-borne outbreaks.

Key messages

Define the most frequent microrganisms could be associated with backed food and evaluate which one of these can exceed the dose for the occurrence of disease in long time. Reflect on the likelihood that the risk of food-borne outbreak caused by manipulation of happy hour participants, may result in an increase in hospital admissions.

Higher-order twisted/astigmatic Gaussian Schell-model cross-spectral densities and their separability features

Adding a twist phase term to the cross-spectral density (CSD) function of a partially coherent source can be done if and only if the resulting function remains nonnegative definite. Constraints on the twist term that guarantee the validity of the resulting CSD have been derived only for Twisted Gaussian Schell-model (TGSM) sources. Here, an infinite family of higher-order TGSM sources is introduced, whose CSDs are expressed as products of the CSD of a standard TGSM source times Hermite polynomials of arbitrary orders and suitable arguments. All the members present the same twist term and for all of them the twist-coherence constraint keeps obeying the form valid for a standard TGSM source. They can be used as building blocks for constructing an endless number of valid twisted CSDs, with an assigned value of the twist parameter and intensity and/or coherence features that can be very different from those of a standard TGSM source. Through partial transposition, higher-order TGSM CSDs are converted into higher-order Astigmatic Gaussian Schell-model (AGSM) CSDs. The problem of the separability of higher-order TGSM and AGSM CSDs is addressed, and conditions ensuring their separability are derived.

Maximizing Young fringe visibility with a universal SU2 polarization gadget

When a Young interferometer is fed by a general electromagnetic field, the fringe visibility may change upon insertion of an anisotropic optical element over one of the interferometer pinholes. The maximum visibility that the fringes may exhibit in this way is theoretically known, but no direct experimental check seems to be available. Here we discuss the scheme of an experimental test. In particular, maximum fringe visibility is obtained with a three-component universal SU2 polarization gadget for arbitrary coherence features of the illuminating field. Confirming results obtained with a suitable experimental setup are presented.

Partially coherent sources with radial coherence

Partially coherent sources with radial coherence are proposed. They present a circularly symmetric intensity profile and a degree of coherence whose absolute value only depends on the angular difference between the two considered points. In particular, the source is completely coherent at pairs of points belonging to the same radius. The modal structure of such sources is determined in the general case, and conditions are derived under which the field propagated in paraxial approximation remains radially coherent at any transverse plane. In such cases, the angular dependence of the correlation function is preserved upon propagation, although the intensity profile generally changes. An example of this kind of source has been experimentally synthesized by means of a simple setup, and its coherence characteristics have been tested by means of a Young interferometer.

Devising genuine twisted cross-spectral densities

Sticking a twist to a partially coherent source cannot be done at will, since the result can violate the definiteness property of the corresponding cross-spectral density. As a matter of fact, the study of twisted sources has been mainly concentrated on the original case proposed by Simon and Mukunda [J. Opt. Soc. Am. A10, 95 (1993)JOAOD60740-323210.1364/JOSAA.10.000095] of circularly symmetric Gaussian Schell-model sources. Here, we discuss a modeling procedure that can be used to generate numberless genuine twisted sources without symmetry constraints. As geometrically simple examples, two cases of non-Gaussian twisted sources endowed with circular or rectangular symmetry are explicitly worked out.

Synthesis of circularly coherent sources

An experiment is presented in which a partially coherent source endowed with circular coherence is generated. The source is synthesized through a time averaging procedure, so that the mutual intensity is used as the basic correlation function. The correlation between points at different radial distances from the source center is tested by means of a Young interferometer. To confirm the perfect coherence among points along a circle concentric with the source center, the Young mask is replaced by an array of equally spaced pinholes arranged along a circle. The observed pattern is identical to that produced by the same mask, illuminated by perfectly coherent light.

Partially coherent sources with circular coherence

A new class of partially coherent light sources is introduced. At the source plane, they exhibit perfect coherence along any annulus that is concentric to the source center. Between two points at different distances from the center, coherence can be partial or even vanishing. Such sources can be synthesized by using a generalized form of van Cittert-Zernike theorem where axial sources are used. Beams radiated by this type of source are analyzed at the source plane and upon free propagation for some simple cases.

Shape-invariant difference between two Gaussian Schell-model beams

The difference between two Gaussian Schell-model cross-spectral densities can give a new genuine correlation function if suitable conditions are met. Generally speaking, the structure of such cross-spectral density changes in a complicated way upon propagation. We consider here the notable exception of shape-invariant beams, and we investigate their intensity and coherence properties. The modal analysis of this class of cross-spectral densities is exploited to devise a synthesis scheme for this type of beam.

Twisted Gaussian Schell-model beams as series of partially coherent modified Bessel-Gauss beams

We show that twisted Gaussian Schell-model (TGSM) beams can be represented through an incoherent superposition of partially coherent beams carrying optical vortices and whose cross-spectral densities are expressed in terms of modified Bessel functions. Moreover, starting from this result, we show that the modal expansion of the cross-spectral density of a TGSM source can be directly obtained through simple mathematics.

Difference of cross-spectral densities

Generally speaking, the difference between two cross-spectral densities (CSDs) does not represent a correlation function. We will furnish a sufficient condition so that such difference be a valid CSD. Using such a condition, we will show through some examples how new classes of CSDs can be generated.

Propagation of cross-spectral densities from spherical sources

We show that the cross-spectral density in the far zone of a homogeneous spherical source can be described as a low-pass filtered version of that existing across the source surface. We prove that, to an excellent approximation, the corresponding filter with respect to a (normalized) spatial frequency ξ has a functional structure of the form √(1-ξ2), for 0≤ξ≤1. The cases of spatially incoherent and Lambertian sources are treated as significant examples.

A complete characterization of pre-Mueller and Mueller matrices in polarization optics

The Mueller-Stokes formalism that governs conventional polarization optics is formulated for plane waves, and thus the only qualification one could require of a 4 x 4 real matrix M in order that it qualify to be the Mueller matrix of some physical system would be that M map Omega((pol)), the positive solid light cone of Stokes vectors, into itself. In view of growing current interest in the characterization of partially coherent partially polarized electromagnetic beams, there is a need to extend this formalism to such beams wherein the polarization and spatial dependence are generically inseparably intertwined. This inseparability brings in additional constraints that a pre-Mueller matrix M mapping Omega((pol)) into itself needs to meet in order to be an acceptable physical Mueller matrix. These additional constraints are motivated and fully characterized.

Nonquantum entanglement resolves a basic issue in polarization optics

The issue raised in this Letter is classical, not only in the sense of being nonquantum, but also in the sense of being quite ancient: which subset of 4x4 real matrices should be accepted as physical Mueller matrices in polarization optics? Nonquantum entanglement or inseparability between the polarization and spatial degrees of freedom of an electromagnetic beam whose polarization is not homogeneous is shown to provide the physical basis to resolve this issue in a definitive manner.

Prevention of cardiovascular disease through glycemic control in type 2 diabetes: a meta-analysis of randomized clinical trials

BACKGROUND AND AIMS

Randomized clinical trials (RCTs) aimed at the assessment of the efficacy of lowering blood glucose in the prevention of diabetic complications have always failed to detect a significant effect on cardiovascular events. Aim of this meta-analysis is the assessment of the effects of improvement of glycemic control on the incidence of cardiovascular diseases in patients with type 2 diabetes.

METHODS

The RCTs were included in this meta-analysis if: a) the between-group difference in mean HbA1c during the trial was at least 0.5%, b) they had a planned duration of treatment of at least 3 years, c) if they had a cardiovascular endpoint. Data for analysis were extracted independently by two observers and potential contrasts were resolved by a senior investigator.

RESULTS

Five studies (17,267 and 15,362 patients in the intensive and conventional therapy groups, respectively) were included. Intensive treatment, which reduced mean HbA1c by 0.9% on average, was associated with a significant reduction of incident cardiovascular events and myocardial infarction (OR 0.89 [0.83-0.95] and 0.86 [0.78-0.93], respectively), but not of stroke or cardiovascular mortality (OR 0.93 [0.81-1.07] and 0.98 [0.77-1.23], respectively). In meta-regression analysis, a higher BMI duration of diabetes, and incidence of severe hypoglycaemia were associated with greater risk for cardiovascular death in intensive treatment groups.

CONCLUSION

Intensified hypoglycaemic treatment in type 2 diabetic patients leads to a significant reduction of the incidence of myocardial infarction, while it does not affect the incidence of stroke and cardiovascular mortality. Hypoglycemia induced by intensified treatment could be associated with increased cardiovascular mortality.

Genuine cross-spectral densities and pseudo-modal expansions

A necessary and sufficient non-negative definiteness condition for the cross-spectral density (CSD) is provided. It is also shown that any genuine CSD can be expanded in terms of the so-called pseudo-modes of the source, understood as coherent contributions, not orthogonal to one another, that, superposed in an uncorrelated way, give rise to the CSD. Their evaluation is analyzed by means of an illustrative example.

Modal expansion for J0-correlated electromagnetic sources

We introduce a class of sources that turn out to be J0 correlated in a scalar description but exhibit varied correlation properties when examined in electromagnetic terms. We prove that a modal expansion can be built explicitly for any of these sources and give an example to illustrate the richness of their behavior.

Realizability condition for electromagnetic Schell-model sources

The set of functions that appear in the correlation matrix of an electromagnetic source must satisfy the constraint of nonnegative definiteness. Here we derive a necessary and sufficient condition for nonnegativeness for the class of electromagnetic Schell-model sources. This result also suggests a possible synthesis procedure for this type of source. As an illustration, two specific examples of electromagnetic Schell-model sources are discussed.