Enhancement and control of surface plasmon resonance sensitivity using grating in conical mounting configuration.

In this work we propose a method to enhance and control the angular sensitivity of a grating coupled surface plasmon resonance (GCSPR) sensor. We lighted a silver grating, mounted in conical configuration, with a laser source and we measured the transmittance of the grating as a function of the azimuthal angle. To evaluate the sensitivity, grating surface was functionalized with four different alkanethiol self assembled monolayers (SAM) and the correspondent azimuthal transmittance peak shifts were measured. The sensitivity control was performed by simply change the light incident angle. This method offers the possibility to design dynamic GCSPR sensor benches that can be used to amplify the SPR angle shift at any step of a biological detection process.

Development of a complete plasmonic grating-based sensor and its application for self-assembled monolayer detection.

This work presents an integrated plasmonic biosensing device consisting of a one-dimensional metallic lamellar grating designed to exploit extraordinary transmission of light toward an underlying silicon photodetector. By means of finite element simulations, the grating parameters have been optimized to maximize the light transmission variation induced by the functionalization of the gold nanostructures. An optimized grating was fabricated using an electron beam process and an optoelectronic test bench suitable for sample tests was developed. A clear difference in the grating transmitted light due to surface functionalization was observed in presence of TM polarized illumination.

Posthepatectomy liver failure after simultaneous versus staged resection of colorectal cancer and synchronous hepatic metastases.

BACKGROUND: Posthepatectomy liver failure (PHLF) is the third most frequent complication and the major cause of postoperative mortality after resection of colorectal cancer liver metastases (CRLM). In case of synchronous resectable CRLM, it is still unclear if surgical strategy (simultaneous versus staged resection of colorectal cancer and hepatic metastases) influences the incidence and severity of PHLF. The aim of this study was to evaluate the impact of surgical strategy on PHLF and on the early and long-term outcome. PATIENTS AND METHODS: Retrospective study on 106 consecutive patients undergoing hepatectomy for synchronous CRLM between 1997 and 2012. RESULTS: Of 106 patients, 46 underwent simultaneous resection and 60 had staged hepatectomy. The rate of PHLF was similar between groups (16.7% vs 15.2%; p=1) and subgroup analysis restricted to patients undergoing major hepatectomy confirmed this observation (31.8% vs 23.8%; p=0.56). Propensity-score analysis showed that preoperative total bilirubin level and the amount of intra-operative blood transfusion were independently associated with an increased risk of PHLF. Nevertheless, the risk of severe PHLF (grade B - C) was increased in patients who underwent simultaneous resection and major hepatectomy (OR: 4.82; p=0.035). No significant differences were observed in severe (Dindo - Clavien 3 - 4) postoperative morbidity (23.9% vs 20.0%; p=0.64) and survival (3 and 5-year survival: 55% and 34% vs 56% and 33%; p=0.83). CONCLUSIONS: The risk of PHLF is not associated with surgical strategy in the treatment of synchronous CRLM. Nevertheless, the risk of severe PHLF is increased in patients undergoing simultaneous resection and major hepatectomy.

Short-term airing by natural ventilation - implication on IAQ and thermal comfort.

The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. Among the available ventilation strategies that are currently available, buoyancy driven, single-sided natural ventilation has proved to be very effective and can provide high air change rates for temperature and Indoor Air Quality (IAQ) control. However, to promote a wider distribution of these systems an improvement in the knowledge of their working principles is necessary. The present study analyses and presents the results of an experimental evaluation of airing performance in terms of ventilation characteristics, IAQ and thermal comfort. It includes investigations of the consequences of opening time, opening frequency, opening area and expected airflow rate, ventilation efficiency, thermal comfort and dynamic temperature conditions. A suitable laboratory test rig was developed to perform extensive experimental analyses of the phenomenon under controlled and repeatable conditions. The results showed that short-term window airing is very effective and can provide both acceptable IAQ and thermal comfort conditions in buildings. Practical Implications This study gives the necessary background and in-depth knowledge of the performance of window airing by single-sided natural ventilation necessary for the development of control strategies for window airing (length of opening period and opening frequency) for optimum IAQ and thermal comfort in naturally ventilated buildings.

Short-term airing by natural ventilation - modeling and control strategies.

The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. This kind of system frequently integrates traditional mechanical ventilation components with natural ventilation devices, such as motorized windows and louvers. Among the various ventilation strategies that are currently available, buoyancy driven single-sided natural ventilation has proved to be very effective and can provide high air change rates for temperature and IAQ control. However, in order to promote a wider applications of these systems, an improvement in the knowledge of their working principles and the availability of new design and simulation tools is necessary. In this context, the paper analyses and presents the results of a research that was aimed at developing and validating numerical models for the analysis of buoyancy driven single-sided natural ventilation systems. Once validated, these models can be used to optimize control strategies in order to achieve satisfactory indoor comfort conditions and IAQ. Practical Implications Numerical and experimental analyses have proved that short-term airing by intermittent ventilation is an effective measure to satisfactorily control IAQ. Different control strategies have been investigated to optimize the capabilities of the systems. The proposed zonal model has provided good performances and could be adopted as a design tool, while CFD simulations can be profitably used for detailed studies of the pollutant concentration distribution in a room and to address local discomfort problems.

The airborne transmission of infection between flats in high-rise residential buildings: Particle simulation.

Several case clusters occurred in high-rise residential buildings in Hong Kong in the 2003 SARS (the severe acute respiratory syndrome) epidemic, which motivated a series of engineering investigations into the possible airborne transport routes. It is suspected that, driven by buoyancy force, the polluted air that exits the window of the lower floor may re-enter the immediate upper floor through the window on the same side. This cascade effect has been quantified and reported in a previous paper, and it is found that, by tracer gas concentration analysis, the room in the adjacent upstairs may contain up to 7% of the air directly from the downstairs room. In this study, after validation against the experimental data from literatures, Eulerian and Lagrangian approaches are both adopted to numerically investigate the dispersion of expiratory aerosols between two vertically adjacent flats. It is found that the particle concentration in the upper floor is two to three orders of magnitude lower than in the source floor. 1.0 µm particles disperse like gaseous pollutants. For coarse particles larger than 20.0 µm, strong deposition on solid surfaces and gravitational settling effect greatly limit their upward transport.

Ancient Greek text concealed on the back of unrolled papyrus revealed through shortwave-infrared hyperspectral imaging.

Only a few Herculaneum rolls exhibit writing on their reverse side. Since unrolled papyri are permanently glued to paperboard, so far, this fact was known to us only from 18th-century drawings. The application of shortwave-infrared (SWIR; 1000-2500 nm) hyperspectral imaging (HSI) to one of them (PHerc. 1691/1021) has revealed portions of Greek text hidden on the back more than 220 years after their first discovery, making it possible to recover this primary source for the ongoing new edition of this precious book. SWIR HSI has produced better contrast and legibility even on the extensive text preserved on the front compared to former imaging of Herculaneum papyri at 950 nm (improperly called multispectral imaging), with a substantial impact on the text reconstruction. These promising results confirm the importance of advanced techniques applied to ancient carbonized papyri and open the way to a better investigation of hundreds of other such papyri.

The airborne transmission of infection between flats in high-rise residential buildings: Tracer gas simulation.

Airborne transmission of infectious respiratory diseases in indoor environments has drawn our attention for decades, and this issue is revitalized with the outbreak of severe acute respiratory syndrome (SARS). One of the concerns is that there may be multiple transmission routes across households in high-rise residential buildings, one of which is the natural ventilative airflow through open windows between flats, caused by buoyancy effects. Our early on-site measurement using tracer gases confirmed qualitatively and quantitatively that the re-entry of the exhaust-polluted air from the window of the lower floor into the adjacent upper floor is a fact. This study presents the modeling of this cascade effect using computational fluid dynamics (CFD) technique. It is found that the presence of the pollutants generated in the lower floor is generally lower in the immediate upper floor by two orders of magnitude, but the risk of infection calculated by the Wells-Riley equation is only around one order of magnitude lower. It is found that, with single-side open-window conditions, wind blowing perpendicularly to the building may either reinforce or suppress the upward transport, depending on the wind speed. High-speed winds can restrain the convective transfer of heat and mass between flats, functioning like an air curtain. Despite the complexities of the air flow involved, it is clear that this transmission route should be taken into account in infection control.

ExoMars alternative escape trajectories with Soyuz/Fregat.

The objectives of ExoMars are to inject an orbiter around Mars and to land a rover on the surface to look for possible traces of life. During the first stages of the feasibility analysis, the mass margin of the orbiter was very small for a direct transfer in the Soyuz/Fregat scenario. An analysis of the combined use of lunar swing-bys and the Sun gravity gradient is performed with WESBOT in order to obtain alternative trajectories for injecting higher mass into Mars transfer. WESBOT is a GMV tool to find WSB transfers to the Moon and to design escape trajectories by performing several swing-bys with the Moon and the Earth. The weak stability boundary has been successfully used for lunar transfers (Hiten, SMART-1). For escape trajectories from the Earth, the potential mass gains depend on the escape direction and the departure date to make a series of gravity assists with the help of the Sun gravity gradient to save DeltaV. Several strategies are studied depending on the number and order of swing-bys. The departing conditions (date and orbit) are optimized but the arrival date to Mars is maintained because of mission requirements. For each type of strategy, a systematic search of initial guess trajectories is performed. The initial guess trajectory is made up of patched conics arcs and multiple shooting arcs when necessary. The optimal trajectories for the various scenarios are presented and show different morphologies. An analysis in terms of applicability to the ExoMars mission is included.

Exercise-induced myocardial ischemia triggers the early phase of preconditioning but not the late phase.

The aim of the present study was to establish whether exercise-induced ischemia triggers the second window of protection in 15 patients with coronary artery disease undergoing 2 consecutive treadmill exercise tests and a third test 24 hours later. Our findings confirm that a first exercise-induced ischemic challenge induces the early phase of preconditioning but not the late phase, thus suggesting that either a late protective effect of preconditioning does not exist in the setting of demand ischemia or, if it exists, it must be weaker than the early protective effect.

Ovarian stimulation using a new highly purified urinary FSH: a prospective randomized clinical study.

The aim of this study was to determine the effectiveness of a new highly purified urinary FSH. A total of 60 in vitro-fertilization (IVF) patients, undergoing embryo transfer (ET) for the first time, were randomly allocated into two groups: Group A (n = 30). Subcutaneous administration of urinary follicle-stimulating hormone (FSH, Fostimon 75, A.M.S.A., Italy). Group B (n = 30). Subcutaneous administration of urinary follicle-stimulating hormone (FSH, Metrodin 75 HP, Serono, Italy). Statistical analysis was performed using the chi-square test, p < 0.05 was assumed as significant. This prospective randomized clinical study in an IVF-ET program showed that both drugs were equally safe and effective. Except for the number of the high quality embryos (3.16 vs 2.9; p = 0.03) the two groups did not differ in stimulation parameters or clinical pregnancy rates per attempt and per transfer. On the other hand, a mean number of 3.56 vs 2.18 embryos were cryopreserved in group A and in group B, respectively, as a result of the high number of mature oocytes and high quality embryos. When frozen embryos cycles were included, the difference in pregnancy rate became significant.

17-alpha-Hydroxyprogesterone caproate and natural progesterone in assisted reproduction: a comparative study.

The use of luteal phase support has been demonstrated in patients undergoing an IVF/ET procedure. This study was designed to compare the absorption and the efficacy of two different luteal supports: 17-alpha-hydroxyprogesterone caproate (Lentogest, AMSA, Italy) and natural Progesterone (Prontogest, AMSA, Italy). A total of 80 patients received luteal supplementation with 50 mg of natural P/day intramuscularly, until beta-hCG evaluation. Then, in case of positive beta-hCG, patients were randomly divided into two groups (A and B) in order to compare two different protocols: Group A, 17-OHPc (341 mg once a week) and Group B, natural P (50 mg/day) both intramuscularly and extended for 10-12 weeks. Our study showed that the treatment with 17-OHPc results in a higher percentage of pregnancy rate compared to natural P, but the differences are not statistically significant. Thus, we emphasize that 17-OHPc preparation for better acceptance appears to be the most suitable and comfortable method for luteal phase support.

Intramuscular versus vaginal progesterone in assisted reproduction: a comparative study.

The effectiveness and the absorption of two progesterone (P) presentations have been compared for luteal phase support of patients aged < or = 37 years undergoing an in vitro fertilization (IVF) procedure for the first time, who were stimulated after pituitary desensitization with gonadotrophin releasing hormone agonists (GnRHa). All of them had two ovaries, normal ovarian functions and normal endometrial morphology: the indication for the assisted reproductive technique was the tubal factor. Two hundred and fifty patients were randomly allocated to two groups in order to compare two treatment protocols: Group A: natural i.m. P (50 mg/day, Prontogest, AMSA, Italy); Group B: micronized vaginal P (200 mg/day Esolut, Angelini, Italy). We were able to show that the i.m. P resulted in a higher percentage of pregnancies than the vaginal preparation, with statistically significant differences. We recommend the use of injectable P, and suggest reserving intravaginal P as a second choice for patients who cannot tolerate intramuscular administration.

Intramuscular versus vaginal administration of progesterone for luteal phase support after in vitro fertilization and embryo transfer. A comparative randomized study.

A total of 156 patients were randomly treated with exogenous natural progesterone (intramuscularly, 50 mg/day) and vaginal gel (90 mg/day) P or nothing (Controls) from the day before embryo transfer (ET) for two weeks. In case of positive beta-HCG, the treatment was continued for 12 weeks. Plasma P and 17 beta-Estradiol concentrations were estimated and compared with the control not supplemented group. Both treatments were able to increase significantly the luteal plasmatic values of P versus controls. The ongoing pregnancy and the living birth rates per transfer were significantly higher in the patients supplemented with intramuscular P than in those treated with vaginal gel P. The intramuscular natural P appears the most suitable route of administration for luteal phase support in IVF-ET procedures.

[Jeiuno-ileal diverticula complicated by perforation. Clinical case]. / Diverticolosi digiuno-ileale complicata da perforazione. Caso clinico.

The diverticular disease is rarely located in the small intestine (0.1-1.4%). The most important feature is due to the lack of a typical symptomatology which may appear only on the occasion of the complications it may incur (perforation, haemorrhage and so on). It isn't also infrequent that the surgeon may observe intestinal diverticula accidentally, on the occasion of laparotomies carried out in emergency or for other pathologies. The literature on intestinal diverticula is reviewed and personal experience in a clinical case presenting as acute abdomen is described.

[Day Surgery. Five years of experience and activity]. / Day Surgery. Nostra esperienza dopo 5 anni di attività

BACKGROUND: The aim of this paper is to evaluate the management of an integrated unit of Day Surgery in a General Surgery Department. METHODS: An outline of the first 5 years of activity is presented. Setting of investigation: little provincial hospital. Patients have been selected on a basis of Day Surgery specific features: a total of 1,294 patients. Pathologies treated: inguinal hernias, phlebectasias, phimosis, borsitis, arthritic cysts, tendon cysts, carpal tunnel, Dupuytren's disease ("crispatura tendinum"), lymphadenitis, mammary nodules, hemorrhoids, hydroceles, varicoceles, adipomas. Patients' selection parameters, surgical operation type and modalities, postoperative course, protected discharges from hospital, follow-up and complications have all been carefully recorded. RESULTS: The most numerous operations were related to hernial pathology (54.32%) and to adipomas (10.81%). The form of anesthesia was mainly loco-regional. Only 4 cases (0.3%) had to be hospitalized for the night after operation. COMPLICATIONS: 1 serious wound infection, needing removal of the hernial prosthesis; 1 painful "tumefaction" on the inguinal wound for hernioplastic operation; 3 "seromas" in inguinal hernioplastics. CONCLUSIONS: Advantages of Day-Surgery: cut in health costs due to the reduction of admissions to hospital; reduction in hospital infections and in surgical wounds; reduction in drug use; thinning of waiting lists; increase of available beds for other pathologies; reduction of disability days; high appreciation index.

Stressors, stress and stress consequences during long-duration manned space missions: a descriptive model.

Keeping crew members in good health is a major factor in the success or failure of long-duration manned space missions. Among the many possible agents that can affect the crew's general well-being, stress is certainly one of the most critical because of its implications on human health and performance, both physical and mental. Nevertheless, very few studies have been performed on this fundamental issue and none of them has addressed it in its entirety, considering its diverse physical and psychological aspects. In this work, a descriptive model is proposed to expound the mechanism and sequence of events which mediate stress. A critical analysis of the information provided by past manned spaceflights and by dedicated research performed in analogous environments is presented, and an extrapolation of the available data on human stress in such extreme conditions is proposed. Both internal and external stressors have been identified, at physical and psychosocial levels, thus providing the basis for their early detection and preventive reduction. The possible negative consequences of stress that may lead to disease in crewmembers are described. Finally, the most effective instruments which may be of help in reducing space-related human stress and treating its negative consequences are suggested.