The role of the surgical volume for clinical outcomes in VATS lobectomy for lung cancer: a national large database multicenter analysis

Improving the quality of lung cancer care at a cost that can be sustained is a hotly debated issue. High-risk, low-volume procedures (such as lung resections) are believed to improve significantly when centralised in high-volume centres. However, limited evidence exists to support volume requirements in lung cancer surgery. On the other hand, there was no evidence that the number of lung resections affected either the short-term perioperative results or the long-term cost. Using data from an extensive nationwide registry, this study investigated the correlations between surgical volumes and selected perioperative outcomes. A retrospective analysis of a prospectively filled national registry that follows stringent quality assurance and security procedures was conducted to ensure data accuracy and security. Patients who underwent VATS lobectomy from 2014 to 2019 at the participating centres were included. Selected perioperative outcomes were reported. Total direct hospital cost is measured at discharge for hospitalisations with a primary diagnosis of lung cancer, hospital stay costs, and postoperative length of hospital stay after lobectomy. After the propensity score matched, centres were divided into three groups according to the surgical volume of the unit where VATS lobectomies were performed (high-volume centre: > 500 lobectomies; medium-volume centre: 200-500 lobectomies; low-volume centre: < 200 lobectomies). 11,347 patients were included and matched (low-volume center = 2890; medium-volume center = 3147; high-volume center = 2907). The mean operative time density plot (Fig. 1A) showed no statistically significant difference (p = 0.67). In contrast, the density plot of the harvested lymph nodes (Fig. 1B) showed significantly higher values in the high-volume centres (p = 0.045), albeit without being clinically significant. The adjusted rates of any and significant complications were higher in the low-volume centre (p = 0.034) without significantly affecting the length of hospital stay (p = 0.57). VATS lobectomies for lung cancer in higher-volume centres seem associated with a statistically significantly higher number of harvested lymph nodes and lower perioperative complications, yet without any significant impact in terms of costs and resource consumption. These findings may advise the investigation of the learning curve effect in a complete economic evaluation of VATS lobectomy in lung cancer. Fig. 1 The mean operative time density plot showed no statistically significant difference (p = 0.67).

Differences in selected postoperative outcomes between simple and complex segmentectomies for lung cancer: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to synthesize the evidence on the preoperative characteristics, operative outcomes, and postoperative complications of simple and complex segmentectomy for lung cancer.

METHODS

A systematic review of EMBASE (through Ovid), MEDLINE (via PubMed), and Cochrane CENTRAL (January 1990 - January 2023) was done. We included studies to compare simple versus complex segmentectomies for lung cancer in terms of characteristics and operative and postoperative outcomes.

RESULTS

There was a statistically significant difference regarding higher operative time in favor of simple segmentectomies (Mean Difference, MD = 15.76, 95% Confidence Interval, CI: 2.46 - 29.07, p = 0.02). The incidence of postoperative complications did not change between the two groups (Risk Ratio, RR = 0.86, 95% CI: 0.66 - 1.13, p = 0.27). There were no significant differences regarding postoperative length of hospital stay between simple or complex segmentectomies (MD = -0.02, 95% CI: 0.56 - 0.51, p = 0.93).

CONCLUSIONS

Simple and complex segmentectomies have comparable postoperative outcomes; in particular, postoperative complication rates and length of hospital stay were similar. Complex segmentectomies were associated with a longer operative time.

Real-world survival outcomes of wedge resection versus lobectomy for cT1a/b cN0 cM0 non-small cell lung cancer: a single center retrospective analysis

Background

JCOG0802/WJOG4607L showed benefits in overall survival (OS) of segmentectomy. CALGB 140503 confirmed that sublobar resection was not inferior to lobectomy concerning recurrence-free survival (RFS) but did not provide specific OS and RFS according to the techniques of sublobar resections. Hence, we retrospectively analyze the survival differences between wedge resection and lobectomies for stage IA lung cancer.

Methods

We reviewed the clinical records of patients with clinical stage IA NSCLC over 20 years. The inclusion criteria were: preoperative staging with CT scan and whole body CT/PET; tumor size <20 mm; wedge resections or lobectomies with or without lymph node dissection; NSCLC as the only primary tumor during the follow-up period. We excluded: multiple invasive lung cancer; positive resection margin; preoperative evidence of nodal disease; distant metastasis at presentation; follow-up time <5 years. The reverse Kaplan - Meier method estimated the median OS and PFS and compared them by the log-rank test. The stratified backward stepwise Cox regression model was employed for multivariable survival analyses.

Results

539 patients were identified: 476 (88.3%) lobectomies and 63 (11.7%) wedge resections. The median OS time for the whole cohort was 189.7 months (range: 173.7 - 213.9 months). The 5-year wedge resection and lobectomy OS were 82.2% and 87.0%. The 5-year RFS of wedge resection and lobectomy were 17.8% and 28.9%. The log-rank test showed no significant differences (p = 0.39) between wedge resections and lobectomies regarding OS and RFS (p = 0.23).

Conclusions

Lobectomy and wedge resection are equivalent oncologic treatments for individuals with cN0/cM0 stage IA NSCLC <20 mm. Validating the current findings requires a prospective, randomized comparison between wedge resection and standard lobectomy to establish the prognostic significance of wedge resection.

Immobilization of biotinylated antibodies through streptavidin binding aptamer

Liquid biopsy approaches are powerful strategies that potentially allow the diagnosis and prognosis of a number of diseases. The field is continuously and rapidly growing, encouraging the discovery of novel predictory biomarkers. Antibodies are usually exploited in sensors to validate biomarker candidates. Unfortunately, the immobilization of antibodies on the surface of sensors represents a challenging task. Immobilization strategies need to be optimized for each antibody, representing a huge obstacle to overcome in the discovery of new biomarkers. Herein we propose a novel strategy for the immobilization of antibodies, based on the use of a streptavidin-binding aptamer. Using this approach it is possible to immobilize antibodies on the surface of sensors with no need for optimization, with the only requirement for antibody to be biotinylated. The proposed strategy potentially paves the way towards a straightforward immobilization of antibodies on biosensors, making their use in biomarker validation more accessible.

A Practical Assessment of the Postoperative Management in Lung Cancer Surgery

Postoperative management after major and minor thoracic surgeries is crucial for patient recovery and can be challenging. Major thoracic surgeries, such as extensive pulmonary resections, especially in patients with poor health status, may require intensive surveillance, particularly during the first 24-72 h after surgery. Moreover, thanks to the demographic development and medical progress in perioperative medicine, more patients with comorbidities undergoing thoracic procedures require proper management in the postoperative period to improve prognosis and decrease hospital stay. Here, we summarize the main thoracic postoperative complications in order to clarify how to prevent them through a series of standardized procedures.

An Unusual Histology for a Lung Nodule: A Case Report of Primary Pulmonary Paraganglioma

Introduction: Primary pulmonary paraganglioma is a rare tumor with few cases reported in literature and unspecific clinical presentation.

Case Presentation: A 49-year-old woman presented to our department with an incidental finding of a pulmonary mass at chest X-ray and no associated clinical symptom. The CT scan and the FDG-PET showed mild uptake of contrast, but a definitive diagnosis was only possible after surgery through histopathological examination.

Conclusion: Paragangliomas originating in the pulmonary tissue are generally non-functioning masses discovered incidentally in otherwise asymptomatic patients. Surgery appears to be the best treatment option, with only radiologic follow-up necessary afterwards.

LABEC, the INFN ion beam laboratory of nuclear techniques for environment and cultural heritage

The LABEC laboratory, the INFN ion beam laboratory of nuclear techniques for environment and cultural heritage, located in the Scientific and Technological Campus of the University of Florence in Sesto Fiorentino, started its operational activities in 2004, after INFN decided in 2001 to provide our applied nuclear physics group with a large laboratory dedicated to applications of accelerator-related analytical techniques, based on a new 3 MV Tandetron accelerator. The new accelerator greatly improved the performance of existing Ion Beam Analysis (IBA) applications (for which we were using since the 1980s an old single-ended Van de Graaff accelerator) and in addition allowed to start a novel activity of Accelerator Mass Spectrometry (AMS), in particular for ¹⁴C dating. Switching between IBA and AMS operation became very easy and fast, which allowed us high flexibility in programming the activities, mainly focused on studies of cultural heritage and atmospheric aerosol composition, but including also applications to biology, geology, material science and forensics, ion implantation, tests of radiation damage to components, detector performance tests and low-energy nuclear physics. This paper describes the facilities presently available in the LABEC laboratory, their technical features and some success stories of recent applications.

#StayHomeStayFit: UNIMI's approach to online healthy lifestyle promotion during the COVID-19 pandemic

The COVID-19 lockdown imposed radical changes in the lifestyles of the population through isolation measures, with considerable health, social, psychological and economic consequences. Lockdown measures may have exacerbated negative population behaviors regarding exercise and nutrition, with risk of weight gain and obesity, collectively predisposing to increased cardiometabolic risk and mortality. At particular risk of deleterious consequences were patients such as those affected by chronic non communicable diseases (CNCD). The benefits of regular exercise are evident at several levels of CNCD prevention, however, from a public health standpoint, it is important to consider they are also related to improved stress management, work/academic performance, and reduced illegal behavior, isolation and depression. Therefore, during enforced isolation, a primary goal for all individuals is to maintain energy balance. During lockdown, several lifestyle interventions were posted online, with the internet playing a major role in exercise and fitness promotion. Among these one must recognize the ambitious “#StayHomeStayFit” project by the University of Milan, providing useful general information and trustworthy advice regarding nutrition, physical activity, and psychological support, for the general population in a time of need. Data showed a total of 21224 views on various social media and webpages during the reference period, with a mean time of 4’ 17’’ spent per page/video. Given the health risks associated with population physical inactivity and unhealthy lifestyle, policymakers should evaluate the benefits of projects such as #StayHomeStayFit and consider how to maximize population perception and reach. After all, additional COVID-19 lockdowns might be implemented in the future. (www.actabiomedica.it)

Development and calibration of a model for the potential establishment and impact of Aedes albopictus in Europe

The Asian tiger mosquito (Aedes albopictus) is one of the most invasive disease vectors worldwide. The species is a competent vector of dengue, chikungunya, Zika viruses and other severe parasites and pathogens threatening human health. The capacity of this mosquito to colonize and establish in new areas (including temperate regions) is enhanced by its ability of producing diapausing eggs that survive relatively cold winters. The main drivers of population dynamics for this mosquito are water and air temperature and photoperiod. In this paper, we present a mechanistic model that predicts the potential distribution, abundance and activity of Asian tiger mosquito in Europe. The model includes a comprehensive description of: i) the individual life-history strategies, including diapause, ii) the influence of weather-driven individual physiological responses on population dynamics and iii) the density-dependent regulation of larval mortality rate. The model is calibrated using field data from several locations along an altitudinal gradient in the Italian Alps, which enabled accurate prediction of cold temperature effects on population abundance, including identification of conditions that prevent overwintering of the species. Model predictions are consistent with the most updated information on species' presence and absence. Predicted population abundance shows a clear south-north decreasing gradient. A similar yet less evident pattern in the activity of the species is also predicted. The model represents a valuable tool for the development of strategies aimed at the management of Ae. albopictus and for the implementation of effective control measures against vector-borne diseases in Europe.

Combined use of daily and hourly data sets for the source apportionment of particulate matter near a waste incinerator plant

A particulate matter (PM) source apportionment study was carried out in one of the most polluted districts of Tuscany (Italy), close to an old waste incinerator plant. Due to the high PM10 levels, an extensive field campaign was supported by the Regional Government to identify the main PM sources and quantify their contributions. PM10 daily samples were collected for one year and analysed by different techniques to obtain a complete chemical characterisation (elements, ions and carbon fractions). Hourly fine (<2.5 μm) and coarse (2.5-10 μm) aerosol samples were collected by a Streaker sampler for a shorter period and hourly elemental concentrations were obtained by PIXE. Positive Matrix Factorization (PMF) analysis of daily and hourly data allowed the identification of 10 main sources: six anthropogenic (Biomass Burning, Traffic, Secondary Nitrates, Secondary Sulphates, Incinerator, Heavy Oil combustion), two natural (Saharan Dust and Fresh Sea Salt) and two mixed sources (Local Dust and Aged Sea Salt). Biomass burning turned out to be the main source of PM, accounting for 30% of the PM10 mass as annual average, followed by Traffic (18%) and Secondary Nitrates (14%). Emissions from the Incinerator turned out to be only 2% of PM10 mass on average. PM10 composition and source apportionment have been assessed in a polluted area near a waste incinerator, by PMF analysis on daily and hourly compositional data sets.

Impact of epilepsy after severe brain injury on safe resumption of driving: two-year follow-up

Safe resumption of driving after a severe acquired brain injury (sABI) is a strongly felt need because driving is related to recovery of independence and social-occupational re-integration. The aim of this prospective observational cohort study was to determine whether epilepsy secondary to sABI is a significant factor for being declared fit to drive by the relevant government authorities in Italy. In the period 2006-2015 we recruited 187 patients with sABI, 30 of whom (16.4%) developed secondary epilepsy. The interval between the acute event and the first seizure varied widely (6-96 months), confirming the need for prolonged follow-up. With regard to the aetiology, traumatic brain injury (TBI) was associated with the highest risk of epilepsy: 66.7% of the 30 patients with epilepsy had TBI, as opposed to cerebrovascular disease or anoxic brain damage (33.3%). The percentage of patients who resumed driving was about the same in the epilepsy (80%) and non-epilepsy (81%) groups.

Spillover Events of Infection of Brown Hares (Lepus europaeus) with Rabbit Haemorrhagic Disease Type 2 Virus (RHDV2) Caused Sporadic Cases of an European Brown Hare Syndrome-Like Disease in Italy and Spain

Rabbit haemorrhagic disease virus (RHDV) is a lagovirus that can cause fatal hepatitis (rabbit haemorrhagic disease, RHD) with mortality of 80–90% in farmed and wild rabbits. Since 1986, RHDV has caused outbreaks in rabbits (Oryctolagus cuniculus) in Europe, but never in European brown hares (Lepus europaeus, EBH). In 2010, a new RHDV‐related virus, called RHDV2, emerged in Europe, causing extended epidemics because it largely overcame the immunity to RHDV present in most rabbit populations. RHDV2 also was identified in Cape hare (Lepus capensis subsp. mediterraneus) and in Italian hare (Lepus corsicanus). Here, we describe two distinct incidents of RHDV2 infection in EBH that occurred in Italy (2012) and Spain (2014). The two RHDV2 strains caused macroscopic and microscopic lesions similar to European brown hare syndrome (EBHS) in hares, and they were genetically related to other RHDV2 strains in Europe. EBHs are common in Europe, often sharing habitat with rabbits. They likely have been exposed to high levels of RHDV2 during outbreaks in rabbits in recent years, yet only two incidents of RHDV2 in EBHs have been found in Italy and Spain, suggesting that EBHs are not a primary host. Instead, they may act as spillover hosts in situations when infection pressure is high and barriers between rabbits and hares are limited, resulting in occasional infections causing EBHS‐like lesions. The serological survey of stocked hare sera taken from Italian and Spanish hare populations provided an understanding of naturally occurring RHDV2 infection in the field confirming its sporadic occurrence in EBH. Our findings increase the knowledge on distribution, host range and epidemiology of RHDV2.

Label-free detection of DNA single-base mismatches using a simple reflectance-based optical technique

Rapid and quantitative detection of the binding of nucleic acids to surface-immobilized probes remains a challenge in many biomedical applications. We investigated the hybridization of a set of fully complementary and defected 12-base long DNA oligomers by using the Reflective Phantom Interface (RPI), a recently developed multiplexed label-free detection technique. Based on the simple measurement of reflected light intensity, this technology enables to quantify the hybridization directly as it occurs on the surface with a sensitivity of 10 pg mm(-2). We found a strong effect of single-base mismatches and of their location on hybridization kinetics and equilibrium binding. In line with previous studies, we found that DNA-DNA binding is weaker on a surface than in the bulk. Our data indicate that this effect is a consequence of weak nonspecific binding of the probes to the surface.

West Nile Virus Surveillance in the Lombardy Region, Northern Italy

In 2013, the circulation of West Nile virus (WNV) was detected in the Lombardy region and the following year a surveillance programme was activated with the aim of early identification of the viral distribution in mosquitoes and wild birds. A total of 50 959 Culex spp. mosquitoes grouped in six hundred and forty-seven pools as well as 1400 birds were screened by RT-PCR for the presence of West Nile virus leading to the identification of the viral genome in 32 mosquito pools and 13 wild birds. The surveillance was able to detect the WNV circulation on an average of 42 days (CI 95% 29.98-53.86; Student's t-distribution) before the occurrence of human West Nile disease (WND) cases in the same area. These results demonstrate the presence of WNV in the Lombardy region and confirm entomological and wild birds surveillance as an effective measure for the early identification of WNV circulation in infected areas, thus providing a useful and cost-effective tool for the public health authorities in the application of measures to prevent human infection.

Biomass burning contributions estimated by synergistic coupling of daily and hourly aerosol composition records

Biomass burning (BB) is a significant source of particulate matter (PM) in many parts of the world. Whereas numerous studies demonstrate the relevance of BB emissions in central and northern Europe, the quantification of this source has been assessed only in few cities in southern European countries. In this work, the application of Positive Matrix Factorisation (PMF) allowed a clear identification and quantification of an unexpected very high biomass burning contribution in Tuscany (central Italy), in the most polluted site of the PATOS project. In this urban background site, BB accounted for 37% of the mass of PM10 (particulate matter with aerodynamic diameter<10 μm) as annual average, and more than 50% during winter, being the main cause of all the PM10 limit exceedances. Due to the chemical complexity of BB emissions, an accurate assessment of this source contribution is not always easily achievable using just a single tracer. The present work takes advantage of the combination of a long-term daily data-set, characterized by an extended chemical speciation, with a short-term high time resolution (1-hour) and size-segregated data-set, obtained by PIXE analyses of streaker samples. The hourly time pattern of the BB source, characterised by a periodic behaviour with peaks starting at about 6 p.m. and lasting all the evening-night, and its strong seasonality, with higher values in the winter period, clearly confirmed the hypothesis of a domestic heating source (also excluding important contributions from wildfires and agricultural wastes burning).

Spatiotemporal and Ecological Patterns of Mycobacterium microti Infection in Wild Boar (Sus scrofa)

Mycobacterium microti has recently been described as the causative agent of tuberculosis-like lesions in wild boar (Sus scrofa), a reservoir specie of Mycobacterium tuberculosis complex (MTBC) in some European Mediterranean ecosystem. Through a five-year survey on tuberculosis in free-living wild boars, the epidemiological trend of M. microti infections and the host and population risk factors linked with its occurrence were described. Retropharyngeal and mandibular lymph nodes of 3041 hunted wild boars from six different districts were macroscopically inspected. The sex and age of each animal were registered, as well as the animal abundance in each district. Lesions compatible with tuberculosis (190) were collected and analysed using a gyrB PCR-RFLP assay. M. microti was identified directly in 99 tissue samples (Prev = 3.26%; 95% CI: 2.67-3.97%), while neither Mycobacterium bovis, nor other members of the MTBC were detected. The probability of being M. microti positive showed spatio-temporal variability, with 26% of increase of risk of being infected for each year. Moreover, a positive effect of wild boar abundance and age on the prevalence was detected. The generalized increase in the European wild boar population, coupled with its sensitivity to M. microti infection, poses a future concern for the identification and management of MTBC members in wild boar.

Rheological and mechanical behavior of polyacrylamide hydrogels chemically crosslinked with allyl agarose for two-dimensional gel electrophoresis

Two-dimensional (2-D) gel electrophoresis currently represents one of the most standard techniques for protein separation. In addition to the most commonly employed polyacrylamide crosslinked hydrogels, acrylamide-agarose copolymers have been proposed as promising systems for separation matrices in 2-D electrophoresis, because of the good resolution of both high and low molecular mass proteins made possible by careful control and optimization of the hydrogel pore structure. As a matter of fact, a thorough understanding of the nature of the hydrogel pore structure as well as of the parameters by which it is influenced is crucial for the design of hydrogel systems with optimal sieving properties. In this work, a series of acrylamide-based hydrogels covalently crosslinked with different concentrations of allyl agarose (0.2-1%) is prepared and characterized by creep-recovery measurements, dynamic rheology and tensile tests, in the attempt to gain a clearer understanding of structure-property relationships in crosslinked polyacrylamide-based hydrogels. The rheological and mechanical properties of crosslinked acrylamide-agarose hydrogels are found to be greatly affected by crosslinker concentration. Dynamic rheological tests show that hydrogels with a percentage of allyl agarose between 0.2% and 0.6% have a low density of elastically effective crosslinks, explaining the good separation of high molecular mass proteins in 2-D gel electrophoresis. Over the same range of crosslinker concentration, creep-recovery measurements reveal the presence of non-permanent crosslinks in the hydrogel network that justifies the good resolution of low molecular mass proteins as well. In tensile tests, the hydrogel crosslinked with 0.4% of allyl agarose exhibits the best results in terms of mechanical strength and toughness. Our results show how the control of the viscoelastic and the mechanical properties of these materials allow the design of mechanically stable hydrogels with improved sieving ability in protein electrophoresis over a wide range of molecular masses.

Hepatitis E virus in wild boar in the central northern part of Italy

Hepatitis E virus (HEV) is responsible for sporadic acute hepatitis in developed countries, where the infection is acquired probably through ingestion of contaminated food, in addition to travel-related cases. In this study, the circulation of HEV in wild boar from nine Italian provinces was evaluated. An overall seroprevalence of 10.2% was found, although there were differences among the provinces, while no samples were positive for HEV RNA detection. This study indicates an active circulation of HEV in the Italian wild boar populations and suggests to consider the zoonotic risk in handling and eating meat from this animal.

Synergetic chemiluminescence and label-free dual detection for developing a hepatitis protein array

A dual detection system for protein arrays is presented that combines label-free detection by optical interference with chemiluminescence. A planar protein array that targets hepatitis B surface antigen is developed. Surface densities for individual antibody spots are quantitated using optical interference prior to use. Target binding (10 ng/ml) is detected label-free. Target binding (1 ng/ml) is detected by both optical interference and chemiluminescence with the inclusion of secondary antibodies. Binding results using both methods are found to be directly proportion to the capture probe density measured initially. The dual detection system provides the analytical utility of optical interference detection with the established clinical utility of chemiluminescence detection.

Multiplexed, rapid point of care platform to quantify allergen-specific IgE

Variation of probe immobilization on microarrays hinders the ability to make high quality, assertive and statistically relevant conclusions needed in the healthcare setting. To address this problem, we have developed a calibrated, compact, inexpensive, multiplexed, dual modality point-of-care detection platform that calibrates and correlates surface probe density measured label-free to captured labeled secondary antibody, is independent of chip-to-chip variability, and improves upon existing diagnostic technology. We have identified four major technological advantages of our proposed platform: the capability to perform single spot analysis based on the fluorophore used for detection, a 10-fold gain in fluorescence signal due to optimized substrate, a calibrated, quantitative method that uses the combined fluorescent and label-free modalities to accurately measure the density of probe and bound target for a variety of systems, and a compact measurement platform offering reliable and rapid results at the doctor's office. Already, we have formulated over a 90% linear correlation between the amount of probe bound to surface and the resulting fluorescence of captured target for IgG, β-lactoglobulin, Ara h 1 peanut allergen, and Phl 5a Timothy grass allergen.

An integrated approach to assess air pollution threats to cultural heritage in a semi-confined environment: the case study of Michelozzo's Courtyard in Florence (Italy)

An example of an integrated approach to assess air pollution threats to cultural heritage in a semi-confined environment is presented in this work, where the monitoring campaign carried out at the Michelozzo's Courtyard (in Palazzo Vecchio, Florence, Italy) is used as a case study. A wide research project was carried out, with the main aim of obtaining the first quantitative data on air quality and microclimate conditions inside the Courtyard, and, if possible, identifying the main causes of degradation and suggesting appropriate conservation strategies. The investigation adopted a holistic approach involving thermographic measurements on the wall paintings, microclimatic analysis, gaseous pollutant monitoring, atmospheric particles characterisation and dry deposition compositional analysis. Attention was focused on the wall painting depicting the city of Hall because of its anomalous and critical conservation conditions, which are visible at a glance, due to the contrast between a wide darker zone around the central subject of the painting and external lighter areas.

Novel blocked functionality copolymers as surface coatings in DNA microarray technology

New copolymers made of 2-(dimethyl amino) ethyl methacrylate (DMAEM) and isocyanate ethyl methacrylate blocked with methyl ethyl ketoxime (IEMB) was synthesized in various composition ratios in order to obtain water reducible copolymers after acidification. They were characterized by infrared spectroscopy, chemical titration for the determination of amine equivalent weight, and by differential scanning calorimetry (DSC). Calorimetric analysis showed the presence of a former broad endothermal peak followed by a latter, stronger exothermal one, which can be respectively attributed to the deblocking of isocyanate groups and to their subsequent reactions. Some copolymer compositions were dip coated onto microscope glass slides and surfaces were characterized by static and dynamic contact angles, revealing a clear effect of the salifying agent and a likely surface rearrangement of polar groups while in contact with water. Finally, oligonucleotides surface immobilization and molecular recognition capability of the coated glass slides were positively assessed by hybridization tests with fluorescently labelled complementary probes.

Giant dipole resonance in the hot and thermalized 132Ce nucleus: damping of collective modes at finite temperature

The gamma decay of the giant dipole resonance (GDR) in the 132Ce compound nucleus with temperature up to approximately 4 MeV has been measured, using the reaction 64Ni + 68Zn at E(beam) = 300, 400, and 500 MeV. The gamma and charged particles measured in coincidence with recoils are consistent with a fully equilibrated compound nucleus emission. The GDR width, obtained with the statistical model analysis, is found to increase almost linearly with temperature. This increase is rather well reproduced within a model including thermal shape fluctuations and the lifetime of the compound nucleus.

Nuclear detecting systems at LNL and LNS: foreseen experiments to provide basic data for heavy-ion risk assessment

The use of existing detecting systems developed for nuclear physics studies allows collecting data on particle and ion production cross-sections in reactions induced by Oxygen and Carbon beams, of interest for hadrontherapy and heavy-ion risk assessment. The MULTICS and GARFIELD apparatus, together with the foreseen experiments, are reviewed.

Capillary electrophoresis investigation on the structure-enantioselectivity relationship in synthetic cyclopeptides as chiral selectors

We recently reported the use of a deconvolution strategy to identify the best chiral selectors for Nalpha-2,4-dinitrophenyl (Dnp) amino acid racemates from a combinatorial library composed of thousands of homodetic cyclohexapeptides. Selection was based on the capillary electrophoresis (CE) enantioresolution for a set of Dnp-amino acids. The groups involved in the chiral discrimination were assessed by nuclear magnetic resonance (NMR) spectroscopy, which revealed a strong involvement of one of the aromatic rings of the cyclopeptide in the binding with the analyte. In order to better understand the recognition mechanism, and thus extend the applicability of the analytical system, modifications on both analyte and selector structure were introduced. The effects on separation were evaluated in terms of resolution values and mobility variation.

Rapid capillary coating by epoxy-poly-(dimethylacrylamide): performance in capillary zone electrophoresis of protein and polystyrene carboxylate

A fast and simple method for the internal coating of capillaries in capillary zone electrophoresis (CZE) is that with epoxy-poly(dimethylacrylamide) (EPDMA). Duration of coating by that method is 30 min, compared with that of 24 h when using uncross-linked polyacrylamide (PA) under otherwise identical conditions. Under the conditions used for the CZE of proteins (pH 9.0, 2% polyethylene glycol), the capillary coating with EPDMA is stable for at least 50 consecutive runs as judged by the constancy of low electroosmotic flow, equalling the stability of coating achieved by PA. Protein mobilities and protein peak asymmetry (suggestive of reversible interaction with the capillary wall) are also found to be the same in EPDMA and PA coated capillaries. Differences between EPDMA and PA coating also exist: The former is unstable upon lowering the ionic strength of the buffer to 0.003, upon the addition of sodium dodecyl sulfate (SDS) to the buffer and in application to the hydrophobic analyte, polystyrene carboxylate.

Performances of new sugar-bearing poly(acrylamide) copolymers as DNA sieving matrices and capillary coatings for electrophoresis

We have synthesized two new sugar monomers, allylamine of gluconic and lactobionic acid, by opening the corresponding lactone ring with allylamine. These monomers were copolymerized with acrylamide leading to formation of copolymers with a relative molecular mass of 288000 and 180000 Da, respectively. Double-stranded DNA fragments were separated in entangled solutions of these linear polymers in capillary electrophoresis. Resolution, peak spacing and peak width were the parameters taken into account to evaluate the quality of the separation achieved with the new polymers. This work indicates that the copolymers of acrylamide and allyl gluconic acid have a high sieving capacity and provide a performance similar to that of hydroxyethylcellulose (HEC) of comparable viscosity. Unlike HEC, this copolymer selfcoats onto the capillary wall, allowing DNA fragments to be efficiently separated in an uncoated capillary.

Stereoselective synthesis of (S)-(+)-Naproxen catalyzed by carboxyl esterase in a multicompartment electrolyzer

The stereoselective hydrolysis of racemic 2-substituted propionates, catalyzed by carboxyl esterase, provides a cost-competitive route to produce the optically pure, anti-inflammatory drug Naproxen. In the present work, we describe the application of the multicompartment electrolyzer reactor (ME) for the stereoselective hydrolysis of a racemic Naproxen ester, (R,S)-ethoxyethyl-[2-(6-methoxy-2-naphtyl)]propionate, catalyzed by a carboxyl esterase. The enzyme was trapped in a reactor chamber, delimited by two isoelectric membranes encompassing the pI value of the enzyme, together with the neutral substrate. After 90 min, a conversion of 45% was obtained with an enantiomeric excess of 84%. The reaction product, (S)-(+)-Naproxen, was electrophoretically removed in continuous from the reaction chamber and collected in a contiguous, more acidic chamber, separated from the enzyme and from the unreacted substrate. Moreover, at the end of the reaction, it was possible to recover the enzyme from the reactor and use it again.

Use of a fluorosurfactant in micellar electrokinetic capillary chromatography

A fluorosurfactant, the anionic N-ethyl-N-[(heptadecafluorooctyl)sulfonyl]glycine potassium salt, trade name FC-129 [CAS 2991-51-7] was investigated for possible application in micellar electrokinetic capillary chromatography (MEKC). The surfactant was characterized with conductometric titration and test sample mixtures were investigated in MEKC systems, and compared with sodium dodecylsulphate. An increased efficiency and interesting selectivity differences were observed.

Chiral capillary electrophoresis and nuclear magnetic resonance investigation on the structure-enantioselectivity relationship in synthetic cyclopeptides as chiral selectors

In the present work, synthetic cyclohexa- and cycloheptapeptides previously singled out by a combinatorial chemistry approach have been evaluated as chiral selectors in capillary electrophoresis. By applying the countercurrent migration technique and employing a new adsorbed coating, a series of dinitrophenyl amino acids as well as some chiral compounds of pharmaceutical interest have been evaluated for enantiorecognition. The results thus obtained led to a deeper investigation of the chiral discrimination process, by carrying out nuclear magnetic resonance (NMR) studies on selected cyclopeptide-analyte complexes. These studies shed light on the chemical groups involved in the analyte-selector interaction and provided useful information for a wider application of these cyclopeptides in the separation of other drug enantiomers.

Allylamine-beta-cyclodextrin copolymer. A novel chiral selector for capillary electrophoresis

A novel, positively charged, copolymer of allylamine and 2-hydroxy-3-methacryloyl-beta-cyclodextrin was synthesized to be used as a chiral selector in capillary electrophoresis. In the copolymer, cyclodextrin molecules are spaced from the backbone though a spacer arm which prevents sterical hindrance of the CD cavity. The self-mobility of the CD polymer in its charged form, opposite to the analytes, is the cause for the enhanced separation factor provided by this selector. Moreover, the positive charged polymer induces a reversal of electroosmotic flow which is beneficial in enantioseparations of acidic compounds as it reduces analysis time and increases peak efficiency. The ability of this copolymer to act as a CE chiral selector in the separation of 2,4-dinitrophenylamino acid enantiomers was investigated in coated and uncoated capillaries and its performance was much better then that of native beta-cyclodextrin.