Comparison of hygiene levels in metal-ceramic and stratified zirconia in prosthetic rehabilitation on teeth and implants: a retrospective clinical study of a three-year follow-up.

The aim of this retrospective clinical study was to evaluate and compare oral hygiene levels in patients subjected to fixed metal-ceramic or stratified zirconia prostheses, either on teeth or on dental implants. Twenty patients, including 10 with metal-ceramic prostheses and 10 with stratified zirconia, were engaged for the study. Considering the prosthesis positioning phase as zero time, all patients were examined twice a year for a follow-up period of 3 years. During each session, to assess oral cavity state of health, both the Plaque Index (IP) and the Bleeding Index (BOP) were recorded. All patients were instructed in home hygiene maintenance and subjected to professional oral hygiene sessions customized according to prothesis type (on natural teeth or dental implants) and materials (metal ceramic or stratified zirconia). Statistically significant evidence was found in IP values, with an increase in the initial stages in zirconia prostheses and in the final stages in metal-ceramic ones. BOP levels showed a reduction during the follow-up period, but no statistically significant differences were found between examined groups. An adequate patient education in hygiene maintenance associated with professional oral hygiene sessions with special tools could positively affect fixed prostheses' maintenance, both on natural teeth and on dental implants.

Spectral µCT with an energy resolving and interpolating pixel detector.

A main challenge in x-ray µCT with laboratory radiation derives from the broad spectral content, which in contrast to monochromatic synchrotron radiation gives rise to reconstruction artifacts and impedes quantitative reconstruction. Due to the low spectral brightness of these sources, monochromatization is unfavorable and parallel recording of a broad bandpath is practically indispensable. While conventional CT sums up all spectral components into a single detector value, spectral CT discriminates the data in several spectral bins. Here we show that a new generation of charge integrating and interpolating pixel detectors is ideally suited to implement spectral CT with a resolution in the range of 10 µm. We find that the information contained in several photon energy bins largely facilitates automated classification of materials, as demonstrated for of a mouse cochlea. Bones, soft tissues, background and metal implant materials are discriminated automatically. Importantly, this includes taking a better account of phase contrast effects, based on tailoring reconstruction parameters to specific energy bins.

The EIGER detector for low-energy electron microscopy and photoemission electron microscopy.

EIGER is a single-photon-counting hybrid pixel detector developed at the Paul Scherrer Institut, Switzerland. It is designed for applications at synchrotron light sources with photon energies above 5 keV. Features of EIGER include a small pixel size (75 µm × 75 µm), a high frame rate (up to 23 kHz), a small dead-time between frames (down to 3 µs) and a dynamic range up to 32-bit. In this article, the use of EIGER as a detector for electrons in low-energy electron microscopy (LEEM) and photoemission electron microscopy (PEEM) is reported. It is demonstrated that, with only a minimal modification to the sensitive part of the detector, EIGER is able to detect electrons emitted or reflected by the sample and accelerated to 8-20 keV. The imaging capabilities are shown to be superior to the standard microchannel plate detector for these types of applications. This is due to the much higher signal-to-noise ratio, better homogeneity and improved dynamic range. In addition, the operation of the EIGER detector is not affected by radiation damage from electrons in the present energy range and guarantees more stable performance over time. To benchmark the detector capabilities, LEEM experiments are performed on selected surfaces and the magnetic and electronic properties of individual iron nanoparticles with sizes ranging from 8 to 22 nm are detected using the PEEM endstation at the Surface/Interface Microscopy (SIM) beamline of the Swiss Light Source.

Towards hybrid pixel detectors for energy-dispersive or soft X-ray photon science.

JUNGFRAU (adJUstiNg Gain detector FoR the Aramis User station) is a two-dimensional hybrid pixel detector for photon science applications at free-electron lasers and synchrotron light sources. The JUNGFRAU 0.4 prototype presented here is specifically geared towards low-noise performance and hence soft X-ray detection. The design, geometry and readout architecture of JUNGFRAU 0.4 correspond to those of other JUNGFRAU pixel detectors, which are charge-integrating detectors with 75 µm × 75 µm pixels. Main characteristics of JUNGFRAU 0.4 are its fixed gain and r.m.s. noise of as low as 27 e(-) electronic noise charge (<100 eV) with no active cooling. The 48 × 48 pixels JUNGFRAU 0.4 prototype can be combined with a charge-sharing suppression mask directly placed on the sensor, which keeps photons from hitting the charge-sharing regions of the pixels. The mask consists of a 150 µm tungsten sheet, in which 28 µm-diameter holes are laser-drilled. The mask is aligned with the pixels. The noise and gain characterization, and single-photon detection as low as 1.2 keV are shown. The performance of JUNGFRAU 0.4 without the mask and also in the charge-sharing suppression configuration (with the mask, with a `software mask' or a `cluster finding' algorithm) is tested, compared and evaluated, in particular with respect to the removal of the charge-sharing contribution in the spectra, the detection efficiency and the photon rate capability. Energy-dispersive and imaging experiments with fluorescence X-ray irradiation from an X-ray tube and a synchrotron light source are successfully demonstrated with an r.m.s. energy resolution of 20% (no mask) and 14% (with the mask) at 1.2 keV and of 5% at 13.3 keV. The performance evaluation of the JUNGFRAU 0.4 prototype suggests that this detection system could be the starting point for a future detector development effort for either applications in the soft X-ray energy regime or for an energy-dispersive detection system.

PTSD prevalence and associated risk factors after a fire disaster that broke out in a paediatric hospital: a cross-sectional study.

BACKGROUND: Several studies have shown a higher risk of psychological problems in health care workers exposed to serious occupational stressors. OBJECTIVES: The aim of the present study was to assess the presence of Post-traumatic Stress Disorder (PTSD) and possible risk factors in a sample of 32 workers who were at the same time rescuers and victims of a fire that broke out in the neonatal intensive care unit of a large paediatric hospital. METHODS: Immediately and six months after the event, the subjects underwent a study protocol aimed at the diagnostic assessment of PTSD, investigated via the Clinician-Administered PTSD Scale (CAPS) and the Impact of Event Scale-Revised (IES-R). RESULTS: Out of the 30 subjects examined (two were missing), six showed the diagnostic criteria for a current PTSD. Risk factors for PTSD onset were a prior psychiatric disorder, the level of involvement in the fire disaster and the presence of phobias in the days immediately after the event. Gender and level of education approached statistical significance. CONCLUSIONS: The high prevalence of PTSD found in this sample was due to the fact that the risk of death or serious injury involved infants.

The Materials Science beamline upgrade at the Swiss Light Source.

The Materials Science beamline at the Swiss Light Source has been operational since 2001. In late 2010, the original wiggler source was replaced with a novel insertion device, which allows unprecedented access to high photon energies from an undulator installed in a medium-energy storage ring. In order to best exploit the increased brilliance of this new source, the entire front-end and optics had to be redesigned. In this work, the upgrade of the beamline is described in detail. The tone is didactic, from which it is hoped the reader can adapt the concepts and ideas to his or her needs.

Capturing dynamics with Eiger, a fast-framing X-ray detector.

Eiger is the next-generation single-photon-counting pixel detector following the widely used Pilatus detector. Its smaller pixel size of 75 µm × 75 µm, higher frame rate of up to 22 kHz, and practically zero dead-time (~4 µs) between exposures will further various measurement methods at synchrotron sources. In this article Eiger's suitability for X-ray photon correlation spectroscopy (XPCS) is demonstrated. By exploiting its high frame rate, complementary small-angle X-ray scattering (SAXS) and XPCS data are collected in parallel to determine both the structure factor and collective diffusion coefficient of a nano-colloid suspension. For the first time, correlation times on the submillisecond time scale are accessible with a large-area pixel detector.

Micrometre resolution of a charge integrating microstrip detector with single photon sensitivity.

A synchrotron beam has been used to test the spatial resolution of a single-photon-resolving integrating readout-chip coupled to a 320 µm-thick silicon strip sensor with a dedicated readout system. Charge interpolation methods have yielded a spatial resolution of σ(x) ≃ 1.8 µm for a 20 µm-pitch strip.

[Cardiovascular prevention in the workplace: scientific evidence for the role of health promotion]. / Prevenzione cardiovascolare in ambito lavorativo: evidenze scientifiche per la promozione della salute.

Cardiovascular disorders represent the leading cause of mortality and morbidity in the western world. A large number of working subjects is potentially involved. On this basis, the work environment may be considered an ideal place for health promotion in this field. The recently involvement of Occupational Medicine in health promotion programs represent an ideal condition for the effective implementation of these programs, Scientific literature convincingly show that well characterized interventions, acting on key factors of the cardiovascular risk, such as smoking, diet, physical activity, hypertension, hyperlipidemia, obesity and work-related stress may prevent the development of overt cardiovascular diseases. A proper administration and presentation of these programs is however an essential requisite for their success. Last but not least, the participation of workers, especially of those of low socioeconomic status should be obtained. In order to reach this goal, adequate incentives need to be proposed to workers, including employer-provided paid time off during the work-day for exercise health screenings, or prevention/wellness programs. Although seemingly costly, this approach seems to be fruitful in terms of financial returns in the mid-long term perspective.

Exposure to thoracic dust, airway symptoms and lung function in cement production workers.

Cement dust exposure has previously been associated with airway symptoms and ventilatory impairment. The aim of the present study was to examine lung function and airway symptoms among employees in different jobs and at different levels of exposure to thoracic dust in the cement production industry. At the start of a 4-yr prospective cohort study in 2007, exposure to cement dust, symptoms and lung function were recorded cross-sectionally in 4,265 employees in 24 European cement plants. Bronchial exposure was assessed by 2,670 full-shift dust samples with cyclones collecting the thoracic aerosol fraction. A job exposure matrix was constructed by grouping dust concentrations according to job type and plant. Elevated odds ratios for symptoms and airflow limitation (range 1.2-2.6 in the highest quartile), but not for chronic bronchitis, were found in the higher quartiles of exposure compared with the lowest quartile. Forced expiratory volume in 1 s (FEV(1)) showed an exposure-response relationship with a 270-mL deficit of FEV(1) (95% CI 190-300 mL) in the highest compared with the lowest exposure level. The results support the hypothesis that exposure to dust in cement production may lead to respiratory symptoms and airway obstruction.

Toxicological effects of titanium dioxide nanoparticles: a review of in vitro mammalian studies.

BACKGROUND AND OBJECTIVE: Recent rapid advances in nanotechnology raise concerns about development, production route, and diffusion in industrial and consumer products of titanium dioxide nanoparticles (TiO2-NPs). In fact, compared to recent increase in applications of this nanomaterial, the health effects of human exposure have not been systematically investigated. The aim of this review was to provide a comprehensive overview on the current knowledge regarding the effects of TiO2-NPs on mammalian cells. EVIDENCE AND INFORMATION SOURCES: This review is based on an analysis of the current literature on this topic. STATE OF THE ART: Fine TiO2 particles have been considered as safe and to pose little risk to humans, suggesting that exposure to this material is relatively harmless. However, available data in the literature showed that TiO2-NPs can cause several adverse effects on mammalian cells such as increase of reactive oxygen species (ROS) production and cytokines levels, reduction of cell viability and proliferation, induction of apoptosis and genotoxicity. PERSPECTIVES AND CONCLUSIONS: Additional research is needed to obtain up-to-date knowledge on health effects of TiO2-NPs and to avoid any potential risk correlated to their exposure. Consequently, future studies need to: (1) use an homogeneous and rigorous exposure classification to clarify how the physicochemical properties of TiO2-NPs correlate with their toxicological effects; (2) assess the potential adverse effects of low level exposures to TiO2-NPs, as most of the information currently available originates from studies in which exposure levels were excessively and unrealistically high; (3) identify the possible roles of TiO2-NPs in genotoxicity and carcinogenicity (4) carry out epidemiologic studies of exposed workers to provide an assessment of possible risks correlated to the occupational exposure to TiO2-NPs.

Environmental discomfort and musculoskeletal disorders.

BACKGROUND: Musculoskeletal disorders (MSDs) are the most common occupational disease in Europe, with high prevalence among hospital workers. Both environmental and psychosocial work factors may impact significantly on the development and exacerbation of MSDs. AIMS: To evaluate whether environmental factors at work are associated with MSDs in hospital workers and to investigate potential interactions between environmental and psychosocial risk factors in the workplace that are associated with MSDs. METHODS: A cross-sectional investigation was performed using the Nordic questionnaire to assess MSDs, the IAQ/MM-040 indoor air questionnaire for environmental factors, the demand-control model for job strain and the Goldberg questionnaire for anxiety and depression. The association between environmental factors and MSDs was studied using logistic regression analysis. In addition, the interactions of environmental factors with strain, anxiety and depression for MSDs were examined. RESULTS: Environmental complaints were associated with MSDs. The strongest associations were found between temperature complaints (OR 2.73), noise and light complaints (OR 2.22), other environmental complaints (OR 3.12) and upper limb disorders. A significant interaction between temperature complaints and strain for upper limb disorders (F = 9.52, P < 0.05) was found. CONCLUSIONS: To prevent MSDs, a multi-level approach is needed, including environmental measures and interventions directed to both psychosocial and organizational factors.

Police job strain during routine activities and a major event.

BACKGROUND: Special police forces are exposed to periods of intense work stress in ensuring public order. AIMS: To explore the relationship between the work context (routine work or special event) of special force policemen and psychological measures of job strain (demand-control) and effort-reward imbalance. METHODS: All policemen assigned to the G8 meeting in L'Aquila, Italy, in July 2009 were invited to complete a questionnaire while engaged in routine work in January 2009 (Time A) and in June 2009 (Time B), while preparing for the special event. RESULTS: Participation rate in the questionnaire study was 292/294 (99%) members of the special police force. Measures of job strain (-0.39, P < 0.001) and effort-reward imbalance (-0.37, P < 0.001) decreased significantly from Time A to Time B. On average, demand decreased from 14.2 ± 1.9 to 12.6 ± 2.7 (P < 0.001), control increased from 11.8 ± 2.5 to 14.4 ± 3.4 (P < 0.001) and social support increased from 17.8 ± 2.9 to 19.0 ± 3.1 (P < 0.001). At the same time, effort decreased from 17.4 ± 3.2 to 11.8 ± 3.8 (P < 0.001), reward grew from 37.6 ± 5.5 to 45.5 ± 7.4 (P < 0.001) and overcommitment dropped from 7.1 ± 2.1 to 6.6 ± 1.7 (P < 0.001). CONCLUSIONS: In special police forces, routine work may be significantly more stressful than a single critical event.

[Influence of environmental discomfort on musculoskeletal disorders]. / Influenza dei fattori ambientali sui disturbi muscoloscheletrici.

Musculoskeletal disorders (MSDs) are common among hospital workers. This cross-sectional study on 1744 hospital workers showed strong interaction between temperature complaints (OR 2.73), other environmental complaints (OR 3.12) and upper limbs disorders. A significant interaction between temperature and strain for upper limbs disorders (F = 9.52, p = 0.023) was also found. Environmental and psychosocial factors can interact increasing significantly the risk of MSDs.

Beam-induced damage on diffractive hard X-ray optics.

The issue of beam-induced damage on diffractive hard X-ray optics is addressed. For this purpose a systematic study on the radiation damage induced by a high-power X-ray beam is carried out in both ambient and inert atmospheres. Diffraction gratings fabricated by three different techniques are considered: electroplated Au gratings both with and without the polymer mold, and Ir-coated Si gratings. The beam-induced damage is monitored by X-ray diffraction and evaluated using scanning electron microscopy.

Benzene metabolites inhibit the release of proinflammatory mediators and cytokines from human basophils.

Benzene and its metabolites have been involved in the pathogenesis of chronic lung inflammation and allergic disorders such as bronchial asthma. However, the effects of these xenobiotics on human basophils, key cells in the development of respiratory allergy, have not been investigated. We examined the effects of hydroquinone (HQ) and benzoquinone (BQ), two important chemicals implicated in benzene toxicity, on the release of preformed (histamine) and de novo synthesized mediators (cysteinyl leukotriene C4, LTC4, and IL-4) from human basophils. Preincubation of basophils purified from normal donors with HQ (3-100 microM) inhibited up to 30% histamine release induced by anti-IgE and up to 55% of that induced by the Ca2+ ionophore A23187. HQ had no effect on histamine release induced by formyl-methionyl-leucyl-phenylalanine (f-Met-Leu-Phe). Preincubation of basophils with BQ (3-100 microM) resulted in the concentration-dependent inhibition of histamine release (up to 70%) induced by anti-IgE, A23187 and f-Met-Leu-Phe. HQ completely suppressed the de novo synthesis of LTC4 from basophils challenged with anti-IgE or f-Met-Leu-Phe and the production of IL-4 in cells stimulated with anti-IgE. These results indicate that two major benzene metabolites, HQ and BQ, inhibit the release of proinflammatory mediators and Th2-promoting cytokines from basophils activated by different stimuli. These results suggest that benzene metabolites interfere with multiple intracellular signals involved in the activation of human basophils.

Incidence of metabolic syndrome among night-shift healthcare workers.

OBJECTIVE: Night-shift work is associated with ischaemic cardiovascular disorders. It is not currently known whether it may be causally linked to metabolic syndrome (MS), a risk condition for ischaemic cardiovascular disorders. The syndrome presents with visceral obesity associated with mild alterations in glucidic and lipidic homeostasis, and in blood pressure. The aim of this study was to assess whether a causal relationship exists between night-shift work and the development of MS. METHODS: Male and female nurses performing night shifts, free from any component of MS at baseline, were evaluated annually for the development of the disorder during a 4-year follow-up. Male and female nurses performing daytime work only, visited during the same time period, represented the control group. RESULTS: The cumulative incidence of MS was 9.0% (36/402) among night-shift workers, and 1.8% (6/336) among daytime workers (relative risk (RR) 5.0, 95% CI -2.1 to 14.6). The annual rate of incidence of MS was 2.9% in night-shift workers and 0.5% in daytime workers. Kaplan-Meier survival curves of the two groups were significantly different (log-rank test; p<0.001). Multiple Cox regression analysis (forward selection method based on likelihood ratio) showed that among selected variables (age, gender, smoking, alcohol intake, familiar history, physical activity, and work schedule) the only predictors of occurrence of MS were sedentariness (hazard ratio (HR) 2.92; 95% CI 1.64 to 5.18; p = 0.017), and night-shift work (HR 5.10; 95% CI 2.15 to 12.11; p<0.001). CONCLUSIONS: The risk of developing MS is strongly associated with night-shift work in nurses. Medical counselling should be promptly instituted in night-shift workers with the syndrome, and in case of persistence or progression, a change in work schedule should be considered.

The impaired radiologist.

The concept of the "impaired physician" is an oxymoron. Physicians are by definition bearers of health, which can lead to overlooking the possibility of them contracting an illness that reduces their diagnostic and therapeutic abilities, with a consequent danger to their patients' health. The clinical reasons for which a radiologist may constitute a danger to patients can be divided into two categories: infectious blood-borne diseases, which can be transmitted to the patient during interventional radiology procedures; and neurodegenerative and psychiatric disorders, including alcohol and drug abuse, which temporarily or permanently impair the faculty of judgement. All radiologists have a duty to periodically verify their own state of health and seek help as soon as possible when they fear it may be a danger. This individual responsibility towards one's own patients is flanked by the health and safety requirements provided by European regulations for radiologists who are employers, directors or department heads. The occupational health physician plays a key role in identifying and managing the impaired radiologist.

[Health effects of engineered nanomaterials]. / Effetti sulla salute dei nanomateriali ingegnerizzati.

Nanotechnology--the manipulation of matter on a near-atomic scale to produce new structures, materials and devices--offers the promise of unprecedented scientific advancement for sectors, such as medicine, consumer products, energy, and materials. Nanotechnology has the power not only to improve existing technologies, but to dramatically enhance the effectiveness of new applications. While nanomaterials present seemingly limitless possibilities, they bring with them new challenges to understanding, predicting, and managing potential safety and health risk to workers. On the basis of available knowledge on ultrafine particles (non-engineered nanoparticles) and on preliminary data on engineered nanoparticles, it may be postulated a potential health risk by these materials. A precautionary approach in occupational setting is therefore needed.

Performance of single-photon-counting PILATUS detector modules.

PILATUS is a silicon hybrid pixel detector system, operating in single-photon-counting mode, that has been developed at the Paul Scherrer Institut for the needs of macromolecular crystallography at the Swiss Light Source (SLS). A calibrated PILATUS module has been characterized with monochromatic synchrotron radiation. The influence of charge sharing on the count rate and the overall energy resolution of the detector were investigated. The dead-time of the system was determined using the attenuated direct synchrotron beam. A single module detector was also tested in surface diffraction experiments at the SLS, whereby its performance regarding fluorescence suppression and saturation tolerance were evaluated, and have shown to greatly improve the sensitivity, reliability and speed of surface diffraction data acquisition.